Brisbane, Australia

Queensland University of Technology is a research university in Brisbane, Australia. QUT is located on three campuses in the Brisbane area: Gardens Point, Kelvin Grove, and Caboolture. The university has approximately 35,000 undergraduate students and 5,000 post graduate students, of which 6,000 are international students. It has over 4 000 staff members, and an annual budget of more than AU$750 million.QUT ranks within the top 10 Australian Universities and the upper 3 per cent world-wide. QUT has been ranked as Australia's best university under 50 years of age by the Times Higher Education Top 100, and ranks 26th globally in that category. The university in its current form was founded 1989, when the then Queensland Institute of Technology merged with the Brisbane College of Advanced Education. Wikipedia.

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Lu X.,Huazhong University of Science and Technology | Lu X.,Shanghai JiaoTong University | Naidis G.V.,RAS Joint Institute for High Temperatures | Laroussi M.,Old Dominion University | And 5 more authors.
Physics Reports | Year: 2016

Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmospheric-pressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, time-resolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors' vision for the emerging convergence trends across several disciplines and application domains is presented to stimulate critical discussions and collaborations in the future. © 2016 Elsevier B.V.

Ranasinghe C.D.,University of Colombo | Ranasinghe P.,University of Colombo | Jayawardena R.,Queensland University of Technology
International Journal of Behavioral Nutrition and Physical Activity | Year: 2013

Physical activity (PA) has many beneficial physical and mental health effects. Physical inactivity is considered the fourth leading risk factor for global mortality. At present there are no systematic reviews on PA patterns among South Asian adults residing in the region. The present study aims to systematically evaluate studies on PA patterns in South Asian countries. A five-staged comprehensive search of the literature was conducted in Medline, Web of Science and SciVerse Scopus using keywords 'Exercise', 'Walking', 'Physical activity', 'Inactivity', 'Physical Activity Questionnaire', 'International Physical Activity Questionnaire', 'IPAQ', 'Global Physical Activity Questionnaire' and 'GPAQ', combined with individual country names. The search was restricted to English language articles conducted in humans and published before 31st December 2012. To obtain additional data a manual search of the reference lists of articles was performed. Data were also retrieved from the search of relevant web sites and online resources. The total number of hits obtained from the initial search was 1,771. The total number of research articles included in the present review is eleven (India-8, Sri Lanka-2, Pakistan-1). In addition, eleven country reports (Nepal-3, Bangladesh-2, India-2, Sri Lanka-2, Bhutan-1, Maldives-1) of World Health Organization STEPS survey from the South-Asian countries were retrieved online. In the research articles the overall prevalence of inactivity was as follows; India (18.5%-88.4%), Pakistan (60.1%) and Sri Lanka (11.0%-31.8%). STEPS survey reports were available from all countries except Pakistan. Overall in majority of STEPS surveys females were more inactive compared to males. Furthermore, leisure related inactivity was >75% in studies reporting inactivity in this domain and people were more active in transport domain when compared with the other domains. In conclusion, our results show that there is a wide variation in the prevalence of physical inactivity among South-Asian adults within and between countries. Furthermore, physical inactivity in South Asian adults was associated with several socio-demographic characteristics. Majority of South Asian adults were inactive during their leisure time. These Factors need to be considered when planning future interventions and research aimed at improving PA in the region. © 2013 Ranasinghe et al.; licensee BioMed Central Ltd.

Ho S.T.B.,National University of Singapore | Cool S.M.,Singapore Institute of Medical Biology | Hui J.H.,National University of Singapore | Hutmacher D.W.,Queensland University of Technology
Biomaterials | Year: 2010

Mesenchymal Stem Cells (MSC) are frequently incorporated into osteochondral implants and cell seeding is often facilitated with hydrogels which exert a profound influence on the chondrogenic differentiation of MSC. An attempt was made to elucidate this effect by comparing the chondrogenic differentiation of Bone Marrow Stromal Cells (BMSC) in fibrin and fibrin alginate composites. A biphasic osteochondral model which simulated the native in vivo environment was employed in the study. In the first stage of the experiment, BMSC was encapsulated in fibrin, Fibrin Alginate 0.3% (FA0.3) and 0.6% (FA0.6). Chondrogenic differentiation within these cell-hydrogel pellets was compared against that of standard cell pellets under inductive conditions and the matrices which supported chondrogenesis were used in the cartilage phase of biphasic constructs. Neo-cartilage growth was monitored in these cocultures. It was observed that hydrogel encapsulation influenced mesenchymal condensation which preceded chondrogenic differentiation. Early cell agglomeration was observed in fibrin as compared to fibrin alginate composites. These fibrin encapsulated cells differentiated into chondrocytes which secreted aggrecan and collagen II. When the alginate content rose from 0.3 to 0.6%, chondrogenic differentiation declined with a reduction in the expression of collagen II and aggrecan. Fibrin and FA0.3 were tested in the cartilage phase of the biphasic osteochondral constructs and the former supported superior cartilage growth with higher cellularity, total Glycosaminoglycan (GAG) and collagen II levels. The FA0.3 cartilage phase was found to be fragmented and partially calcified. The use of fibrin for cartilage repair was advocated as it facilitated BMSC chondrogenesis and cartilaginous growth in an osteochondral environment. © 2009 Elsevier Ltd.

James A.,Queensland University of Technology
Environmental Modelling and Software | Year: 2010

Expert elicitation is the process of retrieving and quantifying expert knowledge in a particular domain. Such information is of particular value when the empirical data is expensive, limited or unreliable. This paper describes a new software tool, called Elicitator, which assists in quantifying expert knowledge in a form suitable for use as a prior model in Bayesian regression. Potential environmental domains for applying this elicitation tool include habitat modelling, assessing detectability or eradication, ecological condition assessments, risk analysis and quantifying inputs to complex models of ecological processes. The tool has been developed to be user-friendly, extensible and facilitate consistent and repeatable elicitation of expert knowledge across these various domains. We demonstrate its application to elicitation for logistic regression in a geographically based ecological context. The underlying statistical methodology is also novel, utilizing an indirect elicitation approach to target expert knowledge on a case-by-case basis. For several elicitation sites (or cases), experts are asked simply to quantify their estimated ecological response (e.g. probability of presence), and its range of plausible values, after inspecting (habitat) covariates via GIS. © 2009 Elsevier Ltd. All rights reserved.

Doherty W.O.S.,Queensland University of Technology | Mousavioun P.,Queensland University of Technology | Fellows C.M.,University of New England of Australia
Industrial Crops and Products | Year: 2011

Lignocellulosic waste materials are the most promising feedstock for generation of a renewable, carbon-neutral substitute for existing liquid fuels. The development of value-added products from lignin will greatly improve the economics of producing liquid fuels from biomass. This review gives an outline of lignin chemistry, describes the current processes of lignocellulosic biomass fractionation and the lignin products obtained through these processes, then outlines current and potential value-added applications of these products, in particular as components of polymer composites. © 2010.

Ekaputra A.K.,National University of Singapore | Prestwich G.D.,University of Utah | Cool S.M.,Singapore Institute of Medical Biology | Hutmacher D.W.,Queensland University of Technology
Biomaterials | Year: 2011

A significant stumbling block in the creation of functional three-dimensional (3D) engineered tissues is the proper vascularization of the constructs. Furthermore, in the context of electrospinning, the development of 3D constructs using this technique has been hindered by the limited infiltration of cells into their structure. In an attempt to address these issues, a hybrid mesh of poly (e{open}-caprolactone)-collagen blend (PCL/Col) and hyaluronic acid (HA) hydrogel, Heprasil™ was created via a dual electrodeposition system. Simultaneous deposition of HA and PCL/Col allowed the dual loading and controlled release of two potent angiogenic growth factors VEGF 165 and PDGF-BB over a period of five weeks in vitro. Furthermore, this manner of loading sustained the bioactivity of the two growth factors. Utilizing an in-house developed 3D co-culture assay model of human umbilical vein endothelial cells and lung fibroblasts, the growth factor-loaded hybrid meshes was shown to not only support cellular attachment, but also their infiltration and the recapitulation of primitive capillary network in the scaffold's architecture. Thus, the creation of a PCL/Col-Heprasil hybrid scaffold is a step forward toward the attainment of a 3D bio-functionalized, vascularized tissue engineering construct. © 2011 Elsevier Ltd.

Kumar P.,University of Surrey | Morawska L.,Queensland University of Technology
Atmospheric Environment | Year: 2014

While concrete recycling is practiced worldwide, there are many unanswered questions in relation to ultrafine particle (UFP; Dp<100nm) emissions and exposure around recycling sites. In particular: (i) Does recycling produce UFPs and in what quantities? (ii) How do they disperse around the source? (iii) What impact does recycling have on ambient particle number concentrations (PNCs) and exposure? (iv) How effective are commonly used dust respirators to limit exposure? We measured size-resolved particles in the 5-560nm range at five distances between 0.15 and 15.15m that were generated by an experimentally simulated concrete recycling source and found that: (i) the size distributions were multimodal, with up to ~93% of total PNC in the UFP size range; and (ii) dilution was a key particle transformation mechanism. UFPs showed a much slower decay rate, requiring ~62% more distance to reach 10% of their initial concentration compared with their larger counterparts in the 100-560nm size range. Compared with typical urban exposure during car journeys, exposure decay profiles showed up to ~5 times higher respiratory deposition within 10m of the source. Dust respirators were found to remove half of total PNC; however the removal factor for UFPs was only ~57% of that observed in the 100-560nm size range. These findings highlight a need for developing an understanding of the nature of the particles as well as for better control measures to limit UFP exposure. © 2014 Elsevier Ltd.

Langton C.M.,Queensland University of Technology
Critical Reviews in Oncology/Hematology | Year: 2012

Lumpectomy followed by whole breast radiation therapy (i.e. breast conservation therapy (BCT)) is the standard of care for management of early stage breast cancer. However, its utilization has not been maximized because of a number of reasons including the logistic issues associated with the 5-6. weeks of radiation treatment. Also, pathological and clinical data suggest that most ipsilateral breast cancer recurrences are in the vicinity of the lumpectomy. Accelerated partial breast irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2. cm margin, rather than the whole breast with higher doses of radiation in a shorter period of time. There has been growing interest for APBI and various approaches have been developed and are under phase I-III clinical studies. This paper reviews external beam conformal radiation therapy (EBCRT) as a possible technique to APBI. The various EBCRT approaches such as 3D conformal radiation therapy, IMRT, proton therapy, tomotherapy, and volumetric arc therapy are discussed. Issues with the implementation of these techniques such as target volume delineation and organ motion are also presented. It is evident that EBCRT has potential for APBI of a selected group of early breast cancer patient. However, issues with setup errors and breathing motions need to be adequately addressed. © 2011 Elsevier Ireland Ltd.

Jeung H.,Ecole Polytechnique Federale de Lausanne | Yiu M.L.,Hong Kong Polytechnic University | Zhou X.,Queensland University of Technology | Jensen C.S.,University of Aalborg
VLDB Journal | Year: 2010

In automotive applications, movement-path prediction enables the delivery of predictive and relevant services to drivers, e.g., reporting traffic conditions and gas stations along the route ahead. Path prediction also enables better results of predictive range queries and reduces the location update frequency in vehicle tracking while preserving accuracy. Existing moving-object location prediction techniques in spatial-network settings largely target short-term prediction that does not extend beyond the next road junction. To go beyond short-term prediction, we formulate a network mobility model that offers a concise representation of mobility statistics extracted from massive collections of historical object trajectories. The model aims to capture the turning patterns at junctions and the travel speeds on road segments at the level of individual objects. Based on the mobility model, we present a maximum likelihood and a greedy algorithm for predicting the travel path of an object (for a time duration h into the future). We also present a novel and efficient server-side indexing scheme that supports predictive range queries on the mobility statistics of the objects. Empirical studies with real data suggest that our proposals are effective and efficient. © 2010 Springer-Verlag.

Srinivasan M.V.,Queensland University of Technology
Current Opinion in Neurobiology | Year: 2011

Flying insects display remarkable agility, despite their diminutive eyes and brains. This review describes our growing understanding of how these creatures use visual information to stabilize flight, avoid collisions with objects, regulate flight speed, detect and intercept other flying insects such as mates or prey, navigate to a distant food source, and orchestrate flawless landings. It also outlines the ways in which these insights are now being used to develop novel, biologically inspired strategies for the guidance of autonomous, airborne vehicles. © 2011 Elsevier Ltd.

Zheng K.,Queensland University of Technology | Zheng Y.,Microsoft | Yuan N.J.,Microsoft | Shang S.,University of Aalborg
Proceedings - International Conference on Data Engineering | Year: 2013

The increasing pervasiveness of location-acquisition technologies has enabled collection of huge amount of trajectories for almost any kind of moving objects. Discovering useful patterns from their movement behaviours can convey valuable knowledge to a variety of critical applications. In this light, we propose a novel concept, called gathering, which is a trajectory pattern modelling various group incidents such as celebrations, parades, protests, traffic jams and so on. A key observation is that these incidents typically involve large congregations of individuals, which form durable and stable areas with high density. Since the process of discovering gathering patterns over large-scale trajectory databases can be quite lengthy, we further develop a set of well thought out techniques to improve the performance. These techniques, including effective indexing structures, fast pattern detection algorithms implemented with bit vectors, and incremental algorithms for handling new trajectory arrivals, collectively constitute an efficient solution for this challenging task. Finally, the effectiveness of the proposed concepts and the efficiency of the approaches are validated by extensive experiments based on a real taxicab trajectory dataset. © 2013 IEEE.

Dunne M.P.,Queensland University of Technology
Bulletin of the World Health Organization | Year: 2010

Objective: To examine the prevalence of multiple types of maltreatment (MTM), potentially confounding factors and associations with depression, anxiety and self-esteem among adolescents in Viet Nam. Methods: In 2006 we conducted a cross-sectional survey of 2591 students (aged 12-18 years; 52.1% female) from randomlyselected classes in eight secondary schools in urban (Hanoi) and rural (Hai Duong) areas of northern Viet Nam (response rate, 94.7%). Sequential multiple regression analyses were performed to estimate the relative influence of individual, family and social characteristics and of eight types of maltreatment, including physical, emotional and sexual abuse and physical or emotional neglect, on adolescent mental health. Findings: Females reported more neglect and emotional abuse, whereas males reported more physical abuse, but no statistically significant difference was found between genders in the prevalence of sexual abuse. Adolescents were classified as having nil (32.6%), one (25.9%), two (20.7%), three (14.5%) or all four (6.3%) maltreatment types. Linear bivariate associations between MTM and depression, anxiety and low self-esteem were observed. After controlling for demographic and family factors, MTM showed significant independent effects. The proportions of the variance explained by the models ranged from 21% to 28%. Conclusion: The combined influence of adverse individual and family background factors and of child maltreatment upon mental health in adolescents in Viet Nam is consistent with research in non-Asian countries. Emotional abuse was strongly associated with each health indicator. In Asian communities where child abuse is often construed as severe physical violence, it is important to emphasize the equally pernicious effects of emotional maltreatment.

Zheng K.,Queensland University of Technology | Shang S.,University of Aalborg | Yuan N.J.,Microsoft | Yang Y.,Carnegie Mellon University
Proceedings - International Conference on Data Engineering | Year: 2013

The advances in location positioning and wireless communication technologies have led to a myriad of spatial trajectories representing the mobility of a variety of moving objects. While processing trajectory data with the focus of spatio-temporal features has been widely studied in the last decade, recent proliferation in location-based web applications (e.g., Foursquare, Facebook) has given rise to large amounts of trajectories associated with activity information, called activity trajectory. In this paper, we study the problem of efficient similarity search on activity trajectory database. Given a sequence of query locations, each associated with a set of desired activities, an activity trajectory similarity query (ATSQ) returns k trajectories that cover the query activities and yield the shortest minimum match distance. An order-sensitive activity trajectory similarity query (OATSQ) is also proposed to take into account the order of the query locations. To process the queries efficiently, we firstly develop a novel hybrid grid index, GAT, to organize the trajectory segments and activities hierarchically, which enables us to prune the search space by location proximity and activity containment simultaneously. In addition, we propose algorithms for efficient computation of the minimum match distance and minimum order-sensitive match distance, respectively. The results of our extensive empirical studies based on real online check-in datasets demonstrate that our proposed index and methods are capable of achieving superior performance and good scalability. © 2013 IEEE.

Kitto K.,Queensland University of Technology | Kortschak R.D.,University of Adelaide
Progress in Biophysics and Molecular Biology | Year: 2013

Biological systems exhibit a wide range of contextual effects, and this often makes it difficult to construct valid mathematical models of their behaviour. In particular, mathematical paradigms built upon the successes of Newtonian physics make assumptions about the nature of biological systems that are unlikely to hold true. After discussing two of the key assumptions underlying the Newtonian paradigm, we discuss two key aspects of the formalism that extended it, Quantum Theory (QT). We draw attention to the similarities between biological and quantum systems, motivating the development of a similar formalism that can be applied to the modelling of biological processes. © 2013 Elsevier Ltd.

Nami A.,Queensland University of Technology | Zare F.,Queensland University of Technology | Ghosh A.,Queensland University of Technology | Blaabjerg F.,University of Aalborg
IEEE Transactions on Power Electronics | Year: 2011

A novel H-bridge multilevel pulsewidth modulation converter topology based on a series connection of a high-voltage diode-clamped inverter and a low-voltage conventional inverter is proposed in this paper. A dc link voltage arrangement for the new hybrid and asymmetric solution is presented to have a maximum number of output voltage levels by preserving the adjacent switching vectors between voltage levels. Hence, a 15-level hybrid converter can be attained with a minimum number of power components. A comparative study has been carried out to present high performance of the proposed configuration to approach a very low total harmonic distortion of voltage and current, which leads to the possible elimination of the output filter. Regarding the proposed configuration, a new cascade inverter is verified by cascading an asymmetrical diode-clamped inverter, in which 19 levels can be synthesized in output voltage with the same number of components. To balance the dc link capacitor voltages for the maximum output voltage resolution as well as synthesize asymmetrical dc link combination, a new multi-output boost converter is utilized at the dc link voltage of a seven-level H-bridge diode-clamped inverter. Simulation and hardware results based on different modulations are presented to confirm the validity of the proposed approach to achieve a high-quality output voltage. © 2006 IEEE.

Yigitcanlar T.,Queensland University of Technology | Bulu M.,Istanbul Sehir University
Environment and Planning A | Year: 2015

Knowledge-based urban development (KBUD) has become a popular pursuit for cities, especially from the developing countries, to fast track the catching up process with their counterparts in developed nations. Nevertheless, for these cities the KBUD progress is daunting and full of challenges. The authors aim to shed light on the major KBUD challenges of emerging local economies by undertaking an in-depth empirical investigation in one such city. They scrutinize the prospects and constraints of Istanbul in her KBUD journey through comparative performance and policy context analyses. The findings reveal invaluable insights, not only for Istanbul to reshape the policy context and align development with contemporary KBUD better, but also for other emerging local economies to learn from these experiences. © 2015 Pion Limited. All rights reserved.

Gu M.,National University of Singapore | Chrzanowski H.M.,Australian National University | Assad S.M.,Australian National University | Symul T.,Australian National University | And 6 more authors.
Nature Physics | Year: 2012

Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this information by any other means allows us to use discord to directly quantify this quantum advantage'. We experimentally encode information within the discordant correlations of two separable Gaussian states. The amount of extra information recovered by coherent interaction is quantified and directly linked with the discord consumed during encoding. No entanglement exists at any point of this experiment. Thus we introduce and demonstrate an operational method to use discord as a physical resource. © 2012 Macmillan Publishers Limited. All rights reserved.

Ye X.,Queensland University of Technology | Wolff R.,Queensland University of Technology | Yu W.,Queensland University of Technology | Vaneckova P.,Queensland University of Technology | And 2 more authors.
Environmental Health Perspectives | Year: 2012

Objective: In this paper, we review the epidemiological evidence on the relationship between ambient temperature and morbidity. We assessed the methodological issues in previous studies and proposed future research directions. Data sources and data extraction: We searched the PubMed database for epidemiological studies on ambient temperature and morbidity of noncommunicable diseases published in refereed English journals before 30 June 2010. Forty relevant studies were identified. Of these, 24 examined the relationship between ambient temperature and morbidity, 15 investigated the short-term effects of heat wave on morbidity, and 1 assessed both temperature and heat wave effects. Data synthesis: Descriptive and time-series studies were the two main research designs used to investigate the temperature-morbidity relationship. Measurements of temperature exposure and health outcomes used in these studies differed widely. The majority of studies reported a significant relationship between ambient temperature and total or cause-specific morbidities. However, there were some inconsistencies in the direction and magnitude of nonlinear lag effects. The lag effect of hot temperature on morbidity was shorter (several days) compared with that of cold temperature (up to a few weeks). The temperature-morbidity relationship may be confounded or modified by sociodemographic factors and air pollution. Conclusions: There is a significant short-term effect of ambient temperature on total and cause-specific morbidities. However, further research is needed to determine an appropriate temperature measure, consider a diverse range of morbidities, and to use consistent methodology to make different studies more comparable.

Kuwahara M.,Tohoku University | Miska M.,Queensland University of Technology
IEEE Transactions on Intelligent Transportation Systems | Year: 2011

This paper presents a new methodology for optimizing the signal timing controls of oversaturated networks based on the cell transmission model and a goal programming technique with multiple objectives. The proposed model accounts for intersection spillovers, equity in delays, and system throughputs. This new formulation is solved by genetic algorithms to obtain signal timing plans. A case study with a nine-intersection network and a comparison between the proposed model and the throughput-maximizing strategy are examined. It is found that the new method can efficiently minimize spillovers, balance delay equity, and provide reasonable system throughputs in their respective order for oversaturated networks. The result also indicates that the throughput-maximizing strategy does not always yield minimum spillovers for oversaturated networks and occasionally provides a larger difference in average link delay at a spillover intersection than the proposed model does. © 2011 IEEE.

Bristow H.,Queensland University of Technology | Bristow H.,CSIRO | Eriksson A.,University of Adelaide | Lucey S.,CSIRO
Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition | Year: 2013

Sparse coding has become an increasingly popular method in learning and vision for a variety of classification, reconstruction and coding tasks. The canonical approach intrinsically assumes independence between observations during learning. For many natural signals however, sparse coding is applied to sub-elements ( i.e. patches) of the signal, where such an assumption is invalid. Convolutional sparse coding explicitly models local interactions through the convolution operator, however the resulting optimization problem is considerably more complex than traditional sparse coding. In this paper, we draw upon ideas from signal processing and Augmented Lagrange Methods (ALMs) to produce a fast algorithm with globally optimal sub problems and super-linear convergence. © 2013 IEEE.

Binder B.J.,University of Adelaide | Simpson M.J.,Queensland University of Technology
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We define a pair-correlation function that can be used to characterize spatiotemporal patterning in experimental images and snapshots from discrete simulations. Unlike previous pair-correlation functions, the pair-correlation functions developed here depend on the location and size of objects. The pair-correlation function can be used to indicate complete spatial randomness, aggregation, or segregation over a range of length scales, and quantifies spatial structures such as the shape, size, and distribution of clusters. Comparing pair-correlation data for various experimental and simulation images illustrates their potential use as a summary statistic for calibrating discrete models of various physical processes. © 2013 American Physical Society.

Lei Z.,National University of Singapore | Lu L.,National University of Singapore | Zhao X.S.,Queensland University of Technology
Energy and Environmental Science | Year: 2012

We report a facile and green route to reduce graphite oxide using urea as the reducing agent. UV-Vis, XRD and XPS results revealed that urea was an effective reducing agent in removing oxygen-containing groups from graphite oxide for restoring the conjugated electronic structure of graphene. The obtained reduced graphene oxide was tested as supercapacitor electrode. Gravimetric capacitances of 255 and 100 F g -1 at current densities of 0.5 and 30 A g -1, respectively, were observed. The reduced graphene oxide paper showed a volumetric capacitance of 196 F cm -3. After 1200 continuous cycles of galvanostatic charge-discharge, the electrode retained 93% of its capacitance. The electrocapacitive performance of the urea-reduced graphene oxide outperformed most of the previously reported graphene-based electrode materials, which were reduced by hydrazine or NaBH 4. The present reduction method holds great promise for mass production of soluble graphene-based materials for electrochemical energy storage. This journal is © 2012 The Royal Society of Chemistry.

Zheng Y.,University of Adelaide | Zheng Y.,University of Queensland | Jiao Y.,University of Adelaide | Zhu Y.,King Abdullah University of Science and Technology | And 6 more authors.
Nature Communications | Year: 2014

Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a sustainable energy supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics. © 2014 Macmillan Publishers Limited. All rights reserved.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ENV.2012.6.5-1 | Award Amount: 12.70M | Year: 2012

CITI-SENSE will develop citizens observatories to empower citizens to contribute to and participate in environmental governance, to enable them to support and influence community and societal priorities and associated decision making. CITI-SENSE will develop, test, demonstrate and validate a community-based environmental monitoring and information system using innovative and novel Earth Observation applications. To achieve this, the project will: (i) raise environmental awareness in citizens, (ii) raise user participation in societal environmental decisions and (iii) provide feedback on the impact that citizens had in decisions. It will address the calls request for effective participation by citizens in environmental stewardship, based on broad stakeholder and user involvement in support of both community and policy priorities. The project aims to learn from citizen experience and perception and enable citizenship co-participation in community decision making and co-operative planning. The concept of CITI-SENSE rests on three pillars: technological platforms for distributed monitoring; information and communication technologies; and societal involvement. Three pilot case studies will focus on a range of services related to environmental issues of societal concern: combined environmental exposure and health associated with air quality; noise and development of public spaces, and indoor air at schools. Attention will be given to representativeness of citizen participation. The case studies will be designed in collaboration with citizens groups and decision makers. They will be based on distributed data collection using innovative static, portable and personal devices (low-cost reliable microsensor packs) that communicate with a data repositories through mobile phones or other devices. Development of participatory methods, data management strategies, and applications to facilitate exploitation of the data and information for policy, and society, will be done.

Bivacor Pty Ltd and Queensland University of Technology | Date: 2015-01-13

A cannula including a hollow cannula body having first and second tubular end portions, a collapsible section interconnecting the end portions, the collapsible section including a plurality of circumferentially spaced arms extending between the end portions, wherein in an extended configuration the arms are substantially aligned with the first and second end portions and in a collapsed configuration the arms deform to extend radially outwardly and a flange extending radially outwardly from the first end portion, so that the arms and flange are spaced apart when the cannula body is in the collapsed configuration, thereby allowing tissue to be sandwiched therebetween to thereby effect a seal between the cannula and the tissue so that the cannula provides an opening through the tissue.

In a world of dwindling resources, waste is one thing in no danger of running out. Each Australian generates more than 2,000kg of waste per year, and around half of that ends up in landfill. But at least some of that waste could be turned into a resource that is both in demand and in decline: fuel. The global waste-to-fuel industry is considering options as varied as agave, plastics and disused tyres to solve two environmental problems – reducing waste and increasing fuel production. Landfill and agricultural wastes are already burned to generate heat and electricity, and methane is captured from landfill for the same purpose, but these technologies are both relatively low-hanging fruit. A greater challenge is the production of liquid fuel that can be readily and reliably substituted for conventional petrol or diesel. The Queensland government’s recently appointed biofutures ambassador, Prof Ian O’Hara, says waste-to-fuel is a promising area. “It is a new industry, so there are all the challenges associated with developing supply chains, building networks and developing technologies to convert products to fuels that meet quality standards and are cost-effective,” says O’Hara, also professor of biofuels and biorefining at Queensland University of Technology. “But fuel demand is growing in many industries and there is an opportunity to supply into that growing demand.” There are three main categories of waste that have the potential to be converted to suitable fuels. The first is crop wastes such as the fibrous sugar cane waste known as bagasse. Currently, bagasse is mostly burned to generate power, but it could be used to produce biofuel. “The residues of existing crops offer a lot of opportunity because we’ve got very large-scale resources and the material is often already located at a facility which is operated maybe year-round,” O’Hara says. Bagasse-based biofuel production could take place where the feedstock is found, which O’Hara says could be a significant contributor to regional and rural economies. Recognising this, the Australian Renewable Energy Agency has just announced investment of $2.37m in an advanced biofuels laboratory being built near Gladstone in southern Queensland by Southern Oil Refining. The $16m pilot plant is scheduled to open next year and aims to transform bagasse and prickly acacia waste into one million litres of kerosene and diesel within three years. The second category of waste-to-fuel isn’t so much about using waste as using wasteland to grow crops that can then be converted to biofuels. These tend to be crops that don’t have many other uses, but which are hardy enough to be grown on even the most marginal land. One of these crops is agave – better known as the main ingredient in Mexican tequila. It’s a desert crop that can grow in low-rainfall conditions on land suitable for little else. University of Adelaide researchers have found it’s also energy-rich and could produce bioethanol at a rate that rivals existing bioethanol feedstocks such as sugar cane. And before tequila drinkers panic, this process would use the waste leaves of the plant, not the succulent core used to make the distilled liquor. The third category of waste-to-fuel aims to make use of municipal and industrial waste – the stuff that clogs landfill sites. Waste tyres are one environmental eyesore that the federal government recently targeted with its tyre product stewardship scheme, which promotes “the development of viable markets for end-of-life tyres”. Australian startup Green Distillation Technologies has developed the means to produce around 3,000 litres of oil from a single seven-tonne mining truck tyre. Its recycling process involves heating the tyre rubber in a low-oxygen environment, which produces a vapour that is condensed into oil. Prof Richard Brown, director of the QUT Biofuel Engine Research Facility, says tyres have a significant energy advantage over agricultural waste. “Sugar cane waste or wheat stubble or what’s left over after cropping might have 10-15 megajoules per kilogram,” Brown says. “Tyres are probably double that, they’re quite high and so it’s much easier to make them into something like a diesel or petrol fuel.” Tyre oil does have slightly less embedded energy than conventional diesel, but it also seems to have a better emissions profile, producing less nitrogen oxide and fine particulates. A single tyre processing plant is expected to deal with around 685,000 tyres per year and produce 7,360 tonnes of oil from those tyres, as well as 7,000 tonnes of carbon and 2,000 tonnes of steel. Another global environment issue is waste plastic. Plastic bottles, wrappers, film and containers are an eyesore that blights every inhabited corner of the world, but they’re also a valuable feedstock. “Wherever there’s people, there’s this plastic problem,” says Bevan Dooley, chief executive of Integrated Green Energy. “By converting it to fuel, we stop more oil being taken out of the ground.” Integrated Green Energy has developed a method of processing all forms of waste plastic, excluding Teflon and PVC, to produce petrol and diesel that meets Australian and international fuel standards. The process itself isn’t unique – it involves heating the plastic to 400C in a low-oxygen environment – but Dooley says the innovation is in making a pure product that can be used in any engine. “A lot of your engine manufacturers build their equipment based around certain fuel parameters and those fuel parameters are reflected in the diesel standard,” Dooley says. “The challenge we wanted to overcome was extraction of the minute amounts of impurities that means that we meet the standard all the time.”Having proven its technology in a demonstration facility in Berkley Vale, NSW, the company is now looking to build a full-scale commercial operation in Canberra. It is also partnering with a US company to build up to 10 commercial facilities in the United States. A single plant is capable of processing around 50 tonnes of plastic per day and producing 50,000 litres of petrol and diesel combined. The waste plastic feedstock needs to be shredded and washed, but the plant is at least partly powered by the liquid petroleum gas that is a byproduct of the process. Dooley says with GST and excise added, the fuel would retail for slightly less than regular diesel, but he stresses this is without relying on any kind of government subsidies. Brown says biofuels could be a valuable supplement to the existing petroleum industry and contribute to diversification of energy supply, but would benefit from government incentives and policies to encourage the nascent industry on the road to economic sustainability. “We’ve had a petroleum industry for about 100 years and they’ve got an infrastructure, oil refineries, tankers – the whole thing is all set up so they are doing good on a large scale and their cost per unit of production is very low,” he says. “Biofuel companies are doing small volumes, and they have high overheads so it’s much harder to penetrate into the market.”

The paper resulted from collaborative research led by the U.S. Forest Service with partners including the U.S. Geological Survey, the National Ocean and Atmospheric Administration, University of Georgia and the Queensland University of Technology. The research team drew information from huge stream-temperature and biological databases contributed by over 100 agencies and a USGS-run regional climate model to describe warming trends throughout 222,000 kilometers (138,000 miles) of streams in the northwestern United States. The scientists found that over the last 40 years, stream temperatures warmed at the average rate of 0.10 degrees Celsius (0.18 degrees Fahrenheit) per decade. This translates to thermal habitats shifting upstream at a rate of only 300-500 meters (0.18-0.31 miles) per decade in headwater mountain streams where many sensitive cold-water species currently live. The authors are quick to point out that climate change is still detrimentally affecting the habitats of those species, but at a much slower rate than dozens of previous studies forecast. The results of this study indicate that many populations of cold-water species will continue to persist this century and mountain landscapes will play an increasingly important role in that preservation. "The great irony is that the cold headwater streams that were believed to be most vulnerable to climate change appear to be the least vulnerable. Equally ironic is that we arrived at that insight simply by amassing, organizing and carefully analyzing large existing databases, rather than collecting new data that would have been far more expensive," said Dr. Daniel Isaak, lead author on the study with the U.S. Forest Service. The results also indicate that resource managers will have sufficient time to complete extensive biological surveys of ecological communities in mountain streams so that conservation planning strategies can adequately address all species. "One of the great complexities of restoring trout and salmon under a rapidly changing climate is understanding how this change plays out across the landscape. Dr. Isaak and his colleagues show that many mountain streams may be more resistant to temperature change than our models suggest and that is very good news. This provides us more time to effect the changes we need for long-term persistence of these populations," said Dr. Jack Williams, senior scientist for Trout Unlimited. This study is complementary and builds upon the Cold-Water Climate Shield. This new study is unique as it describes current trends rather than relying on future model projections and addresses a broad scope of aquatic biodiversity in headwater streams (e.g., amphibians, sculpin and trout). In addition, the data density and geographic extent of this study is far greater than most previous studies because over 16,000 stream temperature sites were used with thousands of biological survey locations to provide precise information at scales relevant to land managers and conservationists. Explore further: Rare insect found only in glacier national park imperiled by melting glaciers More information: Daniel J. Isaak et al. Slow climate velocities of mountain streams portend their role as refugia for cold-water biodiversity, Proceedings of the National Academy of Sciences (2016). DOI: 10.1073/pnas.1522429113

The new approach, called Chalkboarding, was developed at Disney Research in collaboration with researchers from STATS, Queensland University of Technology and Caltech as an alternative query language to the keywords typically used to search through massive databases. In user testing with a basketball database, the graphical user interface returned results that were far superior to those identified using keywords. A user can sketch out the desired play or select a play from an actual game and then rapidly search a database to find similar, ranked examples. The researchers presented the method at the Association for Computing Machinery's Intelligent User Interfaces conference in Sonoma, Calif. "Sports analytics is experiencing explosive growth in both the quantity and the granularity of data available for a wide variety of sports leagues," said Jessica Hodgins, vice president at Disney Research. "Chalkboarding promises to be an important tool for accessing information that would otherwise be difficult even to find in these huge databases." In professional basketball, for instance, the sports data company STATS tracks every player and the ball 25 times a second for every game. Simply querying "three-point shot" in a database of 600 games might return 20,000 candidate plays, said Patrick Lucey, director of data science at STATS who began work on Chalkboarding while a scientist at Disney Research. Manually searching to find the most relevant examples would be prohibitively time consuming, he noted. Using more keywords would narrow the search, eliminating the retrieval of unrelated plays, but the results would still be unranked, requiring manual review of all the plays, he said. "Moreover, obtaining fine-gained information such as the location and motion of the players would require an enormous amount of keywords to capture all of the specifics, a prohibitive task," Lucey said. Using a visual representation of plays, similar to the X's and O's coaches have used for years to diagram plays, makes more sense than keywords, given the spatiotemporal nature of games, Lucey said. The Chalkboarding interface allows a user to load in a game of interest and review the plays, visualizing the trajectories of the players and the ball. Once the desired play is identified, the system can then query the database, quickly retrieving similar plays ranked according to similarity. The user can also manipulate the example play to highlight only those trajectories of interest to make the search even more targeted. Or, rather than use an actual play from a game, the user can simply draw the trajectories and player roles of interest. It's also possible for the user to draw atop a broadcast feed of a game, a more intuitive means of interacting than the overhead view of a classic chalkboard. In this mode, the system adds an extra step to calibrate the court from the angle of the camera view. In a user study, 10 people used both keywords and Chalkboarding to perform eight retrieval tasks with a basketball database. For each user, the results with Chalkboarding all had substantially higher precision than those using keywords. In addition to Lucey, the Chalkboarding team included Long Sha of Queensland University of Technology, Peter Carr and Iain Matthews of Disney Research, Yisong Yue of Caltech and Charlie Rohlf of STATS. More information: "Chalkboarding- A New Spatiotemporal Query Paradigm for Sports Play Retrieval-Paper" [PDF, 11.85 MB]

News Article | September 8, 2016

With dementia now the second leading cause of death in Australia, Melbourne scientists have taken inspiration from some of nature’s smallest creatures to help solve an enormous problem. A team led by Swinburne University of Technology researchers has developed surfaces with features measuring billionths of a meter that mimic the extraordinary textured surface of insect wings. Their unique response to light makes these surfaces highly effective sensors, able to detect markers of disease at extremely low concentrations. Swinburne Professor of Nanophotonics, Saulius Juodkazis, has developed nanotextured surface technology that is being used in proof-of-principle studies to look for biomarkers associated with Alzheimer’s disease, the most common form of dementia. It is projected that diagnosed cases of dementia in Australia will reach almost 950,000 by 2050, according to Alzheimer’s Australia. No tests for biomarkers have been validated and Alzheimer’s is currently diagnosed through observations of a patient’s mental decline, by which stage the disease is already well established. Among the goals of scientists in the field is to develop simple and accurate tests that can detect early signs of the disease before symptoms appear. Their hope is that early detection will allow treatments to significantly slow progression of the disease. Juodkazis has long been interested in the relationships between light and materials. Since earning his doctorate in experimental physics and material science from Vilnius University in Lithuania and Lyon-I University in France, in 1997, he has studied the mechanisms and applications of interactions between light and matter in many different settings. After joining Swinburne University of Technology in 2009, he established an Applied Plasmonics research group to find industrial applications in the fields of nanotechnology and nanophotonics. In 2011, his group joined an international collaboration that created a version of aluminum 40 percent denser than metal in its normal form, using an extremely short laser pulse to create a huge concentration of energy in a tiny crystal composed of aluminum oxide. “Using this focused laser technique, we may now be able to create a range of superdense metals that have extraordinary properties,” Juodkazis told Asian Scientist Magazine during the collaboration. “The creation of superdense silver or gold, for example, could lead to many new possibilities for bio-sensing and plasmonics.” In 2012, he and colleagues collaborated with laser physicist Professor Esa Jaatinen from Queensland University of Technology on another application of light, creating a prototype sensor to detect chemicals that are present in many explosives. ‌ The story of the prototype’s development was the focus of media reports that described the sensor as being based on a one-millimeter square corrugated gold surface that picks up traces of explosives floating in the air. Laser light shone on to the surface is altered in a particular way depending on the nature of the explosive chemical. Also in 2012, Juodkazis established the Nano-Lab, Swinburne’s nanofabrication facility in the class-1000 cleanroom of the university’s architecturally striking $100 million Advanced Technologies Centre, an architecturally innovative and environmentally sustainable building that houses $40 million worth of world-class research infrastructure. The inspiration for the Alzheimer’s biomarker work emerged when Swinburne biotechnologist Professor Elena Ivanova reproduced the pattern found on dragonfly wings on a silicon surface. Juodkazis found the surface had an unusual effect on light.

McKilliam R.G.,Queensland University of Technology | Smith W.D.,Center for Range Voting | Clarkson I.V.L.,Queensland University of Technology
IEEE Transactions on Information Theory | Year: 2010

The Coxeter lattices are a family of lattices containing many of the important lattices in low dimensions. This includes An, E7 , E8 and their duals An*, E7*, and E8*. We consider the problem of finding a nearest point in a Coxeter lattice. We describe two new algorithms, one with worst case arithmetic complexity O(n log n) and the other with worst case complexity O(n) where n is the dimension of the lattice. We show that for the particular lattices A n and An* the algorithms are equivalent to nearest point algorithms that already exist in the literature. © 2006 IEEE.

Smith D.M.,Truven Health Analytics | Faddy M.J.,Queensland University of Technology
Journal of Statistical Software | Year: 2016

This article describes the R package CountsEPPM and its use in determining maximum likelihood estimates of the parameters of extended Poisson process models. These provide a Poisson process based family of flexible models that can handle both underdispersion and overdispersion in observed count data, with the negative binomial and Poisson distributions being special cases. Within CountsEPPM models with mean and variance related to covariates are constructed to match a generalized linear model formulation. Use of the package is illustrated by application to several published datasets. © 2016, American Statistical Association. All rights reserved.

Barakat N.,German University of Technology in Oman | Bradley A.P.,Queensland University of Technology
Neurocomputing | Year: 2010

Over the last decade, support vector machine classifiers (SVMs) have demonstrated superior generalization performance to many other classification techniques in a variety of application areas. However, SVMs have an inability to provide an explanation, or comprehensible justification, for the solutions they reach. It has been shown that the '. black-box' nature of techniques like artificial neural networks (ANNs) is one of the main obstacles impeding their practical application. Therefore, techniques for rule extraction from ANNs, and recently from SVMs, were introduced to ameliorate this problem and aid in the explanation of their classification decisions. In this paper, we conduct a formal review of the area of rule extraction from SVMs. The review provides a historical perspective for this area of research and conceptually groups and analyzes the various techniques. In particular, we propose two alternative groupings; the first is based on the SVM (model) components utilized for rule extraction, while the second is based on the rule extraction approach. The aim is to provide a better understanding of the topic in addition to summarizing the main features of individual algorithms. The analysis is then followed by a comparative evaluation of the algorithms' salient features and relative performance as measured by a number of metrics. It is concluded that there is no one algorithm that can be favored in general. However, methods that are kernel independent, produce the most comprehensible rule set and have the highest fidelity to the SVM should be preferred. In addition, a specific method can be preferred if the context of the requirements of a specific application, so that appropriate tradeoffs may be made. The paper concludes by highlighting potential research directions such as the need for rule extraction methods in the case of SVM incremental and active learning and other application domains, where special types of SVMs are utilized. © 2010 Elsevier B.V.

Pangga I.B.,University of the Philippines at Los Baños | Hanan J.,Queensland University of Technology | Chakraborty S.,CSIRO
Plant Pathology | Year: 2011

Canopy-level interactions have been largely ignored in epidemiological models and their applications in defining disease risks under climate change, although these interactions are important for disease management. This paper uses anthracnose of Stylosanthes scabra as a case study and reviews research on dynamics of the pathogen (Colletotrichum gloeosporioides) at the canopy level and pathogen evolution under changing climate. It argues that linking of pathogen dynamics, crop growth and climate models is essential in predicting disease risks under climate change. A plant functional-structural model was used to couple S. scabra growth and architecture with disease under ambient and elevated CO2. A level of induced resistance in plants with enlarged canopy determined anthracnose severity at elevated CO2. Moisture-related microclimatic variables determined infection at ambient but not at elevated CO2. At high CO2 increased disease level from raised pathogen fecundity in enlarged canopy accelerated pathogen evolution after 25 sequential infection cycles. Modelling of pathogen dynamics under climate change currently suffers from a paucity of quantitative data, mismatch of scales in coupling climate and disease models, and model uncertainties. Further experimental research on interactions of biotic and abiotic factors on plant diseases under climate change and validation of models are essential prior to their use in climate-change prediction. Understanding and anticipating trends in host-pathogen evolution under climate change will improve the durability of resistance and lay the foundation for increased crop adaptation through pre-emptive plant breeding. © 2011 CSIRO. Plant Pathology © 2011 BSPP.

Hutmacher D.W.,Queensland University of Technology | Dalton P.D.,Shanghai JiaoTong University
Chemistry - An Asian Journal | Year: 2011

Melt electrospinning is relatively under-investigated compared to solution electrospinning but provides opportunities in numerous areas, in which solvent accumulation or toxicity are a concern. These applications are diverse, and provide a broad set of challenges to researchers involved in electrospinning. In this context, melt electrospinning provides an alternative approach that bypasses some challenges to solution electronspinning, while bringing new issues to the forefront, such as the thermal stability of polymers. This Focus Review describes the literature on melt electrospinning, as well as highlighting areas where both melt and solution are combined, and potentially merge together in the future. New kid on the block: Melt electrospinning is comparatively under-investigated compared to solution electrospinning but provides opportunities in numerous areas where solvent accumulation or toxicity are a concern. This Focus Review provides an historical perspective and covers all published articles on melt electrospinning. Additionally, we describe two uses for melt-electrospun fibersa-textiles and scaffolds for tissue engineering (TE) applicationsa-and put forth our opinions on the future in these areas. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chang J.,Queensland University of Technology | Chang J.,University of Electro - Communications | Waclawik E.R.,Queensland University of Technology
RSC Advances | Year: 2014

Colloidal semiconductor nanocrystals (CS-NCs) possess compelling benefits of low-cost, large-scale solution processing, and tunable optoelectronic properties through controlled synthesis and surface chemistry engineering. These merits make them promising candidates for a variety of applications. This review focuses on the general strategies and recent developments of the controlled synthesis of CS-NCs in terms of crystalline structure, particle size, dominant exposed facet, and their surface passivation. Highlighted are the organic-media based synthesis of metal chalcogenide (including cadmium, lead, and copper chalcogenide) and metal oxide (including titanium oxide and zinc oxide) nanocrystals. Current challenges and thus future opportunities are also pointed out in this review. © 2014 the Partner Organisations.

Feduccia A.A.,University of California at San Francisco | Simms J.A.,University of California at San Francisco | Mill D.,University of California at San Francisco | Yi H.Y.,University of California at San Francisco | Bartlett S.E.,Queensland University of Technology
British Journal of Pharmacology | Year: 2014

Background and Purpose Varenicline, a neuronal nicotinic acetylcholine receptor (nAChR) modulator, decreases ethanol consumption in rodents and humans. The proposed mechanism of action for varenicline to reduce ethanol consumption has been through modulation of dopamine (DA) release in the nucleus accumbens (NAc) via α4*-containing nAChRs in the ventral tegmental area (VTA). However, presynaptic nAChRs on dopaminergic terminals in the NAc have been shown to directly modulate dopaminergic signalling independently of neuronal activity from the VTA. In this study, we determined whether nAChRs in the NAc play a role in varenicline's effects on ethanol consumption. Experimental Approach Rats were trained to consume ethanol using the intermittent-access two-bottle choice protocol for 10 weeks. Ethanol intake was measured after varenicline or vehicle was microinfused into the NAc (core, shell or core-shell border) or the VTA (anterior or posterior). The effect of varenicline treatment on DA release in the NAc was measured using both in vivo microdialysis and in vitro fast-scan cyclic voltammetry (FSCV). Key Results Microinfusion of varenicline into the NAc core and core-shell border, but not into the NAc shell or VTA, reduced ethanol intake following long-term ethanol consumption. During microdialysis, a significant enhancement in accumbal DA release occurred following systemic administration of varenicline and FSCV showed that varenicline also altered the evoked release of DA in the NAc. Conclusion and Implications Following long-term ethanol consumption, varenicline in the NAc reduces ethanol intake, suggesting that presynaptic nAChRs in the NAc are important for mediating varenicline's effects on ethanol consumption. © 2014 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

Lewis S.E.,James Cook University | Sloss C.R.,Queensland University of Technology | Murray-Wallace C.V.,University of Wollongong | Woodroffe C.D.,University of Wollongong | Smithers S.G.,James Cook University
Quaternary Science Reviews | Year: 2013

It has been known since Rhodes Fairbridge's first attempt to establish a global pattern of Holocene sea-level change by combining evidence from Western Australia and from sites in the northern hemisphere that the details of sea-level history since the Last Glacial Maximum vary considerably across the globe. The Australian region is relatively stable tectonically and is situated in the 'far-field' of former ice sheets. It therefore preserves important records of post-glacial sea levels that are less complicated by neotectonics or glacio-isostatic adjustments. Accordingly, the relative sea-level record of this region is dominantly one of glacio-eustatic (ice equivalent) sea-level changes. The broader Australasian region has provided critical information on the nature of post-glacial sea level, including the termination of the Last Glacial Maximum when sea level was approximately 125. m lower than present around 21,000-19,000 years BP, and insights into meltwater pulse 1A between 14,600 and 14,300. cal.yr. BP. Although most parts of the Australian continent reveals a high degree of tectonic stability, research conducted since the 1970s has shown that the timing and elevation of a Holocene highstand varies systematically around its margin. This is attributed primarily to variations in the timing of the response of the ocean basins and shallow continental shelves to the increased ocean volumes following ice-melt, including a process known as ocean siphoning (i.e. glacio-hydro-isostatic adjustment processes).Several seminal studies in the early 1980s produced important data sets from the Australasian region that have provided a solid foundation for more recent palaeo-sea-level research. This review revisits these key studies emphasising their continuing influence on Quaternary research and incorporates relatively recent investigations to interpret the nature of post-glacial sea-level change around Australia. These include a synthesis of research from the Northern Territory, Queensland, New South Wales, South Australia and Western Australia. A focus of these more recent studies has been the re-examination of: (1) the accuracy and reliability of different proxy sea-level indicators; (2) the rate and nature of post-glacial sea-level rise; (3) the evidence for timing, elevation, and duration of mid-Holocene highstands; and, (4) the notion of mid- to late Holocene sea-level oscillations, and their basis.Based on this synthesis of previous research, it is clear that estimates of past sea-surface elevation are a function of eustatic factors as well as morphodynamics of individual sites, the wide variety of proxy sea-level indicators used, their wide geographical range, and their indicative meaning. Some progress has been made in understanding the variability of the accuracy of proxy indicators in relation to their contemporary sea level, the inter-comparison of the variety of dating techniques used and the nuances of calibration of radiocarbon ages to sidereal years. These issues need to be thoroughly understood before proxy sea-level indicators can be incorporated into credible reconstructions of relative sea-level change at individual locations. Many of the issues, which challenged sea-level researchers in the latter part of the twentieth century, remain contentious today. Divergent opinions remain about: (1) exactly when sea level attained present levels following the most recent post-glacial marine transgression (PMT); (2) the elevation that sea-level reached during the Holocene sea-level highstand; (3) whether sea-level fell smoothly from a metre or more above its present level following the PMT; (4) whether sea level remained at these highstand levels for a considerable period before falling to its present position; or (5) whether it underwent a series of moderate oscillations during the Holocene highstand. © 2012.

Haass-Koffler C.L.,University of California at San Francisco | Bartlett S.E.,University of California at San Francisco | Bartlett S.E.,Queensland University of Technology
Frontiers in Molecular Neuroscience | Year: 2012

Corticotropin releasing factor (CRF) has been shown to induce various behavioral changes related to adaptation to stress. Dysregulation of the CRF system at any point can lead to a variety of psychiatric disorders, including substance use disorders (SUDs). CRF has been associated with stress-induced drug reinforcement. Extensive literature has identified CRF to play an important role in the molecular mechanisms that lead to an increase in susceptibility that precipitates relapse to SUDs. The CRF system has a heterogeneous role in SUDs. It enhances the acute effects of drugs of abuse and is also responsible for the potentiation of drug-induced neuroplasticity evoked during the withdrawal period. We present in this review the brain regions and circuitries where CRF is expressed and may participate in stress-induced drug abuse. Finally, we attempt to evaluate the role of modulating the CRF system as a possible therapeutic strategy for treating the dysregulation of emotional behaviors that result from the acute positive reinforcement of substances of abuse as well as the negative reinforcement produced by withdrawal. © 2012 Haass-koffler and Bartlett.

Sun Q.,University of Queensland | Li Z.,University of Wollongong | Searles D.J.,University of Queensland | Chen Y.,Deakin University | And 2 more authors.
Journal of the American Chemical Society | Year: 2013

Increasing concerns about the atmospheric CO2 concentration and its impact on the environment are motivating researchers to discover new materials and technologies for efficient CO2 capture and conversion. Here, we report a study of the adsorption of CO2, CH4, and H2 on boron nitride (BN) nanosheets and nanotubes (NTs) with different charge states. The results show that the process of CO2 capture/release can be simply controlled by switching on/off the charges carried by BN nanomaterials. CO2 molecules form weak interactions with uncharged BN nanomaterials and are weakly adsorbed. When extra electrons are introduced to these nanomaterials (i.e., when they are negatively charged), CO2 molecules become tightly bound and strongly adsorbed. Once the electrons are removed, CO2 molecules spontaneously desorb from BN absorbents. In addition, these negatively charged BN nanosorbents show high selectivity for separating CO2 from its mixtures with CH4 and/or H2. Our study demonstrates that BN nanomaterials are excellent absorbents for controllable, highly selective, and reversible capture and release of CO2. In addition, the charge density applied in this study is of the order of 1013 cm-2 of BN nanomaterials and can be easily realized experimentally. © 2013 American Chemical Society.

Chen J.,Queensland University of Technology | Chen J.,University of Wollongong | Crawford R.,Queensland University of Technology | Xiao Y.,Queensland University of Technology
Journal of Cellular Biochemistry | Year: 2013

Osteoarthritis is characterized by degenerative alterations of articular cartilage including both the degradation of extracellular matrix and the death of chondrocytes. The PI3K/Akt pathway has been demonstrated to involve in both processes. Inhibition of its downstream target NF-kB reduces the degradation of extracellular matrix via decreased production of matrix metalloproteinases while inhibition of mTOR increased autophagy to reduce chondrocyte death. However, mTOR feedback inhibits the activity of the PI3K/Akt pathway and inhibition of mTOR could result in increased activity of the PI3K/Akt/NF-kB pathway. We proposed that the use of dual inhibitors of PI3K and mTOR could be a promising approach to more efficiently inhibit the PI3K/Akt pathway than rapamycin or PI3K inhibitor alone and produce better treatment outcome. © 2012 Wiley Periodicals, Inc.

Cuesta-Vargas A.I.,University of Malaga | Cuesta-Vargas A.I.,Queensland University of Technology | Gabel P.C.,University of The Sunshine Coast
Health and Quality of Life Outcomes | Year: 2013

Background: The Upper Limb Functional Index (ULFI) is an internationally widely used outcome measure with robust, valid psychometric properties. The purpose of study is to develop and validate a ULFI Spanish-version (ULFI-Sp).Methods: A two stage observational study was conducted. The ULFI was cross-culturally adapted to Spanish through double forward and backward translations, the psychometric properties were then validated. Participants (n = 126) with various upper limb conditions of >12 weeks duration completed the ULFI-Sp, QuickDASH and the Euroqol Health Questionnaire 5 Dimensions (EQ-5D-3 L). The full sample determined internal consistency, concurrent criterion validity, construct validity and factor structure; a subgroup (n = 35) determined reliability at seven days.Results: The ULFI-Sp demonstrated high internal consistency (α = 0.94) and reliability (r = 0.93). Factor structure was one-dimensional and supported construct validity. Criterion validity with the EQ-5D-3 L was fair and inversely correlated (r = -0.59). The QuickDASH data was unavailable for analysis due to excessive missing responses.Conclusions: The ULFI-Sp is a valid upper limb outcome measure with similar psychometric properties to the English language version. © 2013 Cuesta-Vargas and Gabel; licensee BioMed Central Ltd.

Dicks M.,German Sport University Cologne | Button C.,University of Otago | Davids K.,Queensland University of Technology
Attention, Perception, and Psychophysics | Year: 2010

Gaze and movement behaviors of association football goalkeepers were compared under two video simulation conditions (i.e., verbal and joystick movement responses) and three in situ conditions (i.e., verbal, simplified body movement, and interceptive response). The results showed that the goalkeepers spent more time fixating on information from the penalty kick taker's movements than ball location for all perceptual judgment conditions involving limited movement (i.e., verbal responses, joystick movement, and simplified body movement). In contrast, an equivalent amount of time was spent fixating on the penalty taker's relative motions and the ball location for the in situ interception condition, which required the goalkeepers to attempt to make penalty saves. The data suggest that gaze and movement behaviors function differently, depending on the experimental task constraints selected for empirical investigations. These findings highlight the need for research on perceptual-motor behaviors to be conducted in representative experimental conditions to allow appropriate generalization of conclusions to performance environments. © 2010 The Psychonomic Society, Inc.

Grafahrend D.,RWTH Aachen | Heffels K.-H.,RWTH Aachen | Beer M.V.,RWTH Aachen | Gasteier P.,RWTH Aachen | And 6 more authors.
Nature Materials | Year: 2011

Advanced biomaterials and scaffolds for tissue engineering place high demands on materials and exceed the passive biocompatibility requirements previously considered acceptable for biomedical implants. Together with degradability, the activation of specific cell-material interactions and a three-dimensional environment that mimics the extracellular matrix are core challenges and prerequisites for the organization of living cells to functional tissue. Moreover, although bioactive signalling combined with minimization of non-specific protein adsorption is an advanced modification technique for flat surfaces, it is usually not accomplished for three-dimensional fibrous scaffolds used in tissue engineering. Here, we present a one-step preparation of fully synthetic, bioactive and degradable extracellular matrix-mimetic scaffolds by electrospinning, using poly(D,L-lactide-co-glycolide) as the matrix polymer. Addition of a functional, amphiphilic macromolecule based on star-shaped poly(ethylene oxide) transforms current biomedically used degradable polyesters into hydrophilic fibres, which causes the suppression of non-specific protein adsorption on the fibresĝ€™ surface. The subsequent covalent attachment of cell-adhesion-mediating peptides to the hydrophilic fibres promotes specific bioactivation and enables adhesion of cells through exclusive recognition of the immobilized binding motifs. This approach permits synthetic materials to directly control cell behaviour, for example, resembling the binding of cells to fibronectin immobilized on collagen fibres in the extracellular matrix of connective tissue. © 2011 Macmillan Publishers Limited. All rights reserved.

Knicker A.J.,German Sport University Cologne | Renshaw I.,Queensland University of Technology | Oldham A.R.H.,University of Auckland | Cairns S.P.,University of Auckland
Sports Medicine | Year: 2011

Muscle physiologists often describe fatigue simply as a decline of muscle force and infer this causes an athlete to slow down. In contrast, exercise scientists describe fatigue during sport competition more holistically as an exercise-induced impairment of performance. The aim of this review is to reconcile the different views by evaluating the many performance symptomsmeasures and mechanisms of fatigue. We describe how fatigue is assessed with muscle, exercise or competition performance measures. Muscle performance (single muscle test measures) declines due to peripheral fatigue (reduced muscle cell force) andor central fatigue (reduced motor drive from the CNS). Peak muscle force seldom falls by >30 during sport but is often exacerbated during electrical stimulation and laboratory exercise tasks. Exercise performance (whole-body exercise test measures) reveals impaired physicaltechnical abilities and subjective fatigue sensations. Exercise intensity is initially sustained by recruitment of new motor units and help from synergistic muscles before it declines. Techniquemotor skill execution deviates as exercise proceeds to maintain outcomes before they deteriorate, e.g. reduced accuracy or velocity. The sensation of fatigue incorporates an elevated rating of perceived exertion (RPE) during submaximal tasks, due to a combination of peripheral and higher CNS inputs. Competition performance (sport symptoms) is affected more by decision-making and psychological aspects, since there are opponents and a greater importance on the result. Laboratory based decision making is generally faster or unimpaired. Motivation, self-efficacy and anxiety can change during exercise to modify RPE and, hence, alter physical performance.Symptoms of fatigue during racing, team-game or racquet sports are largely anecdotal, but sometimes assessed with time-motion analysis. Fatigue during brief all-out racing is described biomechanically as a decline of peak velocity, along with altered kinematic components. Longer sport events involve pacing strategies, central and peripheral fatigue contributions and elevated RPE. During match play, the work rate can decline late in a match (or tournament) andor transiently after intense exercise bursts. Repeated sprint ability, agility and leg strength become slightly impaired. Technique outcomes, such as velocity and accuracy for throwing, passing, hitting and kicking, can deteriorate. Physical and subjective changes are both less severe in real rather than simulated sport activities. Little objective evidence exists to support exercise-induced mental lapses during sport.A model depicting mind-body interactions during sport competition shows that the RPE centre-motor cortex-working muscle sequence drives overall performance levels and, hence, fatigue symptoms. The sporting outputs from this sequence can be modulated by interactions with muscle afferent and circulatory feedback, psychological and decision-making inputs. Importantly, compensatory processes exist at many levels to protect against performance decrements. Small changes of putative fatigue factors can also be protective. We show that individual fatigue factors including diminished carbohydrate availability, elevated serotonin, hypoxia, acidosis, hyperkalaemia, hyperthermia, dehydration and reactive oxygen species, each contribute to several fatigue symptoms. Thus, multiple symptoms of fatigue can occur simultaneously and the underlying mechanisms overlap and interact. Based on this understanding, we reinforce the proposal that fatigue is best described globally as an exercise-induced decline of performance as this is inclusive of all viewpoints. © 2011 Adis Data Information BV. All rights reserved.

Figl K.,Institute for Information Systems and New Media | Recker J.,Queensland University of Technology | Mendling J.,Vienna University of Economics and Business
Decision Support Systems | Year: 2013

Process modeling grammars are used to create models of business processes. In this paper, we discuss how different routing symbol designs affect an individual's ability to comprehend process models. We conduct an experiment with 154 students to ascertain which visual design principles influence process model comprehension. Our findings suggest that design principles related to perceptual discriminability and pop out improve comprehension accuracy. Furthermore, semantic transparency and aesthetic design of symbols lower the perceived difficulty of comprehension. Our results inform important principles about notational design of process modeling grammars and the effective use of process modeling in practice. © 2012 Elsevier B.V.

Stehbens S.J.,Queensland University of Technology | Wittmann T.,University of California at San Francisco
Methods in Cell Biology | Year: 2014

Recent advances in optical and fluorescent protein technology have rapidly raised expectations in cell biology, allowing quantitative insights into dynamic intracellular processes like never before. However, quantitative live-cell imaging comes with many challenges including how best to translate dynamic microscopy data into numerical outputs that can be used to make meaningful comparisons rather than relying on representative data sets. Here, we use analysis of focal adhesion turnover dynamics as a straightforward specific example on how to image, measure, and analyze intracellular protein dynamics, but we believe this outlines a thought process and can provide guidance on how to understand dynamic microcopy data of other intracellular structures. © 2014 Elsevier Inc.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ICT-2009.1.4 | Award Amount: 4.13M | Year: 2010

Security has always been a stepchild to the developers of embedded\nsystems. In the past they were able to rely on physical\nprotection. Due to the connectivity and ubiquity of todays embedded\nsystems this is no longer possible. The aim of SecFutur is to develop\nand establish a security engineering process for embedded systems. In\norder to achieve this overall goal SecFutur will provide a set of\nimplemented resource-efficient security building blocks for embedded\nsystems, each addressing a specific complex non-functional\nrequirement, and a security engineering framework that supports the\ndeveloper in integrating these building blocks into the overall\nengineering process. SecFutur targets the developer of embedded\nsystems who by using the project results will be able to follow an\napplication driven security engineering approach and increase the\noverall security of the system. Practical scenarios from several\nsecurity-relevant application areas will be used in SecFutur to\nevaluate and demonstrate the advances towards secure\nresource-efficient embedded systems.

Home > Press > Diamond nanothread: Versatile new material could prove priceless for manufacturing: Would you dress in diamond nanothreads? It's not as far-fetched as you might think Abstract: Would you dress in diamond nanothreads? It's not as far-fetched as you might think. And you'll have a Brisbane-based carbon chemist and engineer to thank for it. QUT's Dr Haifei Zhan is leading a global effort to work out how many ways humanity can use a newly-invented material with enormous potential - diamond nanothread (DNT). First created by Pennsylvania State University last year, one-dimensional DNT is similar to carbon nanotubes, hollow cylindrical tubes 10,000 times smaller than human hair, stronger than steel - but brittle. "DNT, by comparison, is even thinner, incorporating kinks of hydrogen in the carbon's hollow structure, called Stone-Wale (SW) transformation defects, which I've discovered reduces brittleness and adds flexibility," said Dr Zhan, from QUT's School of Chemistry, Physics and Mechanical Engineering. "That structure makes DNT a great candidate for a range of uses. It's possible DNT may become as ubiquitous a plastic in the future, used in everything from clothing to cars. "I feel very lucky to have this chance to study a new material in depth - blue-sky applied research opportunities like this are rare." DNT does not look like a rock diamond. Rather, its name refers to the way the carbon atoms are packed together, similar to diamond, giving it its phenomenal strength. Dr Zhan has been modelling the properties of DNT since it was invented, using large-scale molecular dynamics simulations and high-performance computing. He was the first to realise the SW defects were the key to DNT's versatility. "While both carbon nanotubes and DNT have great potential, the more I model DNT properties, the more it looks to be a superior material," Dr Zhan said. "The SW defects give DNT a flexibility that rigid carbon nanotubes can't replicate - think of it as the difference between sewing with uncooked spaghetti and cooked spaghetti. "My simulations have shown that the SW defects act like hinges, connecting straight sections of DNT. And by changing the spacing of those defects, we can a change - or tune - the flexibility of the DNT." That research is published in the peer-reviewed publication Nanoscale. Dr Zhan has also published a number of other results from his DNT-modelling research: The thermal conductivity of DNT can be tuned by changing the spacing between the SW defects (Carbon). SW defects create irregular surfaces on the DNT, allowing it to bond well with polymers. DNT could therefore be used as reinforcement for nanocomposite materials (Advanced Function Materials). The mechanical properties of DNT vary significantly depending on its exact atomic structure, including tensile behaviour. Temperature also affects the mechanical properties. While DNT likely behaves like a flexible elastic rod, the mechanical properties could be tailored for specific purposes (Carbon). "Further modelling is needed to fully investigate all the properties of DNT. However, I am excited about the potential range of applications it could be used for, given we've proven we can control its flexibility, conductivity and strength," Dr Zhang said. "Carbon is the most abundant element on the planet. It's a renewable resource, so the cost of the raw material is extremely low. "Once the manufacturing costs are viable, DNT would likely be used primarily in mechanical applications, combined with other materials to make ultra-strong, light-weight composites and components - such as plane fuselages. "I plan to test how DNT performs as a two-dimensional networked structure - a sheet or layer - for potential use in flexible electronics and screens. "I also want to test is viability as a fibre for textiles or rope, from bullet-proof vests and hard-wearing work gear to a replacement for steel cables in bridge construction. "There's already talk in the global carbon community of DNT being the best candidate yet for building a space elevator. It would be a real honour if my research contributed to the development of DNTs for that purpose." About Queensland University of Technology QUT is part of a national collaborative group of five major Australian universities that form the ATN (Australian Technology Network of Universities). For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

News Article | April 18, 2016

Oil spills at sea, on the land, and in your own kitchen could one day easily be mopped up with a new multipurpose fabric covered with semiconducting nanostructures, developed by a team of researchers from Queensland University of Technology (QUT), CSIRO, and RMIT. “The fabric could also potentially degrade organic matter when exposed to light thanks to these semi-conducting properties,” says Associate Professor Anthony O’Mullane, from QUT’s School of Chemistry, Physics and Chemical Engineering, who collaborated with researchers from CSIRO and RMIT on this project. “This fabric repels water and attracts oil. We have tested it and found it effective at cleaning up crude oil, and separating organic solvents, ordinary olive and peanut oil from water,” he says. “We were able to mop up crude oil from the surface of fresh and salt water.” O’Mullane says the chemistry behind the creation of the new material was not complex. “All steps in its production are easy to carry out and, in principle, production of this fabric could be scaled up to be used on massive oil spills that threaten land and marine ecosystems,” he says. “On a large scale the material could mop up crude oil to saturation point and then be washed with a common organic solvent and reused. “We used nylon, but in principle any fabric could work. We took commercially available nylon that already had a seed layer of silver woven into it which makes it easier to carry out the next part of the process — addition of the copper. “We then dipped this fabric into a vat where a copper layer was electrochemically deposited onto it. “Now with a copper coating, we converted the fabric into a semiconducting material with the addition of another solution that causes nanostructures to grow on the fabric’s surface — the key to its enhanced properties. “The nanostructures are like tiny rods that cover the surface of the fabric. Water just runs straight off it but the rods attract and hold oil. “Also, when the fabric is saturated it allows the oil to permeate where it then acts like a sieve to separate oil and water.” O’Mullane said the fabric could have multiple uses. “What is particularly exciting is that it is multifunctional and can separate water from other liquids like a sieve, it is self-cleaning, antibacterial, and being a semiconductor opens up further applicability,” he says. “Its antibacterial properties arising from the presence of copper could be used to kill bugs while also separating water from industrial waste in waterways or decontaminate water in remote and poor communities where water contamination is an issue. “Because it is also a semi-conductor it can interact with visible light to degrade organic pollutants such as those found in waste water streams.” O’Mullane says the next step was to test the scalability of the approach and if the material was mechanically robust. “Our testing has shown the material is chemically robust but we need to investigate whether the nanostructures can withstand tough wear conditions.” The research was published in the journal ChemPlusChem. The team consisted of Dr. Faegheh Hoshyargar and Associate Professor O’Mullane (QUT), Dr. Louis Kyratzis and Dr. Anand Bhatt (CSIRO) and Manika Mahajan, Anuradha and Dr. Sheshanath Bhosale (RMIT). Source: Queensland University of Technology

News Article | November 30, 2016

One is an eyesore and a health hazard, the other one is plain dirty. So what do you get when you combine processed scrap tires with diesel fuel? In what might be a case of two wrongs making a right, Australian startup Green Distillation Technologies (GDT) has shown that it is possible to get a cleaner blend of fuel by combining oil derived from old tires with diesel. Recent attempts to recycle old tires have included coming up with a more energy-efficient way to break them down, using them as mosquito traps and cutting them up so they can be stored more easily. Despite these and various legislative efforts to minimize the hazards posed by scrap tires, they are incredibly hard to get rid of and there are still more of them than people know what to do with. In Australia alone, nearly 48 million end-of-life tires get discarded every year and most end up in landfills and illegal stockpiles. GDT, which was launched in 2009, has pioneered a recycling technology that it calls destructive distillation to solve this problem. Similar to pyrolysis – the process by which organic materials are broken down by high heat in an oxygen-deprived environment – it reduces whole tires into saleable oil, carbon and steel. It differs from other recycling methods in that it is the only process in Australia at the moment that turns the rubber from these tires into a different form of energy. Others merely change the shape or appearance of the rubber, points out GDT chief executive Craig Dunn. Apart from heat, the process is emission- and waste-free, and since it processes whole tires, no labor or energy is needed to break them down. While this all sounds well and good in theory, how exactly does the oil produced measure up? According to engineers from the Queensland University of Technology (QUT) who subjected it to a series of rigorous tests, the results are highly promising: not only did it produce a fuel with reduced emissions, there was also no loss of engine performance when blended with diesel. "We tested the oil which GDT produces from both recycled natural and synthetic rubber tires in 10 percent and 20 percent diesel blends," says Farhad Hossain, a doctoral candidate at QUT who was part of the study, adding that the tire-oil blends were tested in a turbocharged, common rail, direct injection, six-cylinder engine – typical engine types used in the transport industry. "Our experiments were performed with a constant speed and four different engine loads of 25, 50, 75 and 100 per cent of full load." The researchers found a 30 percent reduction in nitrogen oxide, a greenhouse gas and air pollutant, as well as lower particle mass, which means fewer problems for emission treatment systems. In addition, the oil can also be used as a heating fuel, which is what happens at GDT's facility, and further refined into automotive or aviation jet fuel. "The process recycles end-of-life tires into oil, carbon and steel, leaving nothing wasted," says GDT chief operating officer Trevor Bayley. "The potential of this source of biofuel feedstock is immense, and it is more sustainable than other bio-oils from plants such as corn or algae." While one might question whether a 30 percent reduction in pollutants is enough, the fact that the process helps cities get rid of end-of-life matter in an environmentally sustainable manner is a step forward at least. GDT, which won a bronze award in the resource management or renewable resources category at the Edison Awards last year, has already received offers from at least one company to buy all the eight million liters of oil it will produce at its plant in Warren when it becomes fully operational next year, says Bayley. It is expected to process about 685,000 (19,000 tons) car and truck tires a year – approximately three percent of what ends up being discarded each year. Talks to build a plant in Tasmania, which currently has 900,000 tires waiting to be processed, are still ongoing, and a mining tire processing plant is also planned for either Queensland or Western Australia.

News Article | August 18, 2016

In a scientific first, researchers at the Queensland University of Technology (QUT) in Australia have captured a time-lapse video of how corals typically behave during a bleaching event. With widespread bleaching continuing to threaten reef systems around the world, Luke Nothdurft and his colleagues at QUT examined the impact of climate change on the overall health and well-being of corals. For their work, the researchers exposed a single polyp mushroom coral known as Heliofungia actiniformis to environmental stress brought on by an increase in water temperature. They placed samples of the coral in aquariums and then raised the temperature to about 26 to 32 degrees Celsius (79 to 90 degrees Fahrenheit). The water was kept at the highest temperature for eight days. Nothdurft and his colleagues found that when the corals experienced pressure from their environment, they became less capable of sustaining the colorful algae called zooxanthellae that inhabited their body. The H. actiniformis ended up ejecting the zooxanthellae that they housed when the water became too warm for them to handle. The researchers were able to photograph how one of the corals belched the Symbiodinium algae from its body, causing it to lose much of its colorful veil. While coral bleaching has long been known to scientists, the exact details regarding how coral polyps eject their tiny tenants weren't quite understood until now. "What's really interesting is just how quickly and violently the coral forcefully evicted its resident symbionts," lead author Brett Lewis said. "The H. actiniformis began ejecting the symbionts within the first two hours of us raising the water temperature of the system." According to Lewis, the H. actiniformis has been shown in previous studies to be one of the corals in the Great Barrier Reef relatively resilient to bleaching, even though much of the surrounding species have already succumbed to the event's full effect. The study's findings suggest that the coral polyp's resilience may have something to do with how fast it is able to eject the zooxanthellae algae from its body as it experiences thermal stress. The action may even help increase the organism's likelihood of surviving abnormally high water temperatures. During the experiment, the researchers saw the H. actiniformis employ a process known as pulsed inflation. The size of the coral polyp's body increased by as much as 340 percent just before it forcefully ejected the algae from its body through an oral opening. This action went on for four to eight days. Nothdurft explained that certain species of corals capable of rebuilding reefs have developed a mutually beneficial relationship with the Symbiodinium algae living in their bodies. The Symbiodinium provides the corals with the necessary nutrients to help keep them going, while the corals provide the algae with protection and enough surface area in order to carry out photosynthesis. Nothdurft pointed out that if environmental conditions are able to recover quickly following a bleaching event, then certain species of corals may be able to regain the algae expelled, as well as their color. The findings of the Queensland University of Technology study are featured in the journal Coral Reefs. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.

News Article | December 28, 2016

When the calendar ticks over to 2017 on Sunday, California drivers will no longer be able to hold their phones while driving for any reason. That includes talking, texting, snapping photos or video, or using the phone as a GPS. Drivers will only be able to use their phones in hands-free mode. However, a new study out of the Queensland University of Technology (QUT) in Australia suggests the law doesn't go far enough, because hands-free operation isn't any safer. The dangers of texting while driving are already well established, with texting or making calls on a hand-held phone illegal in many countries around the world. It's been widely accepted that making calls hands-free while driving is a safe option because both of the driver's hands are free to remain in control of the car, but the road safety study conducted at QUT indicates that the mental distraction is just as great during calls on both hands-free and hand-held devices. The study conducted by Dr Shimul (Md Mazharul) Haque used the Centre for Accident Research and Road Safety – Queensland (CARRS-Q) driving simulator to measure the effects of using a mobile phone on reaction time and driving performance. "We took a group of drivers and exposed them to a virtual road network which included a pedestrian entering the driver's peripheral vision from a footpath and walking across a pedestrian crossing," says Dr Haque. "We then monitored the driver's performance and reaction times during hands-free and hand-held phone conversations and without." For drivers conducting a conversation using either a hand-held or hands-free mobile phone, driver reaction time was over 40 percent longer than those not using a phone at all. For a vehicle traveling at 40 km/h (25 mph), Dr Haque says this equates to a delayed response distance of about 11 m (36 ft). "This shows hands-free and hand-held phone conversations while driving have similar detrimental effects in responding to a very common peripheral event of a pedestrian entering a crossing from the footpath," says Dr Haque. "It appears that the increased brain power required to hold a phone conversation can alter a driver's visual scanning pattern." According to Dr Haque, when extra information is sent to the brain during a conversation, it compensates by not sending some visual information to the working memory. This results in distracted drivers looking at, but not "seeing" some objects. He also points out that conversations on a phone and passengers in the car differ, because the passenger can take into account the driving environment and stop talking when approaching a complex driving situation, for example. The study also showed the reaction times for those with provisional driver's licenses was doubled compared to those with full licenses and that drivers engaged in a phone conversation braked more abruptly, which can pose a risk to following vehicles. Dr Haque believes the findings of his study raise questions in relation to mobile phone laws that allow drivers to conduct phone calls with hands-free devices. But given how common it is to see drivers with phones pressed against their heads in places where that is illegal, you have to wonder how much harder it would be to police a law that banned the use of hands-free devices – even if there were governments willing to enact such laws. Autonomous vehicles may be the only viable answer – and that opens another can of worms entirely.

Queensland University of Technology PhD researcher Katherine Cullerton, from QUT's Faculty of Health, found that nutrition professionals, scientists and other public interest bodies tended to stay on the sidelines in national nutrition policy-making while the food industry takes the floor. Her network analysis of policy influencers (published in Obesity Reviews) showed that the food industry had both more and higher level access points to policymakers than nutrition professionals and therefore had the greatest capacity to influence policy. "My analysis shows that nutrition professionals have limited direct links to 'decision makers' and the 'food industry' holds the strategic high ground in advocating their interests to policymakers," Ms Cullerton said. "Manufactured food companies are powerful players and fund the Australian Food and Grocery Council and the Australian Beverage Association which are highly professional in lobbying and maintain the greatest capability to influence policy. "Australia has been languishing without a cohesive national nutrition policy since 1992 that would coordinate nutrition initiatives based on the latest evidence to improve the nutritional status of Australians. "This situation has been allowed to continue when other countries are undertaking policy action to protect their citizens against dangerous levels of salt, sugar, fat in food to combat obesity, diabetes and heart disease. "Instead we have had 'self-regulation' by the food industry lobby whose vested interest has helped ensure no national nutrition policy that could save thousands of lives from poor diets and millions of healthcare dollars." Ms Cullerton said that in order to decrease obesity and chronic disease we needed population-wide approaches, such as a sugar-sweetened beverage tax. "We need such measures as a tax on sugar-sweetened beverages, which is a no-brainer, if we want to reduce obesity and diabetes type-2 and regulation of salt in processed food to lower heart disease and stroke. "Mexico, France, Hungary, several states in the USA have all decreased consumption of sugary drinks and increased water intake through government mandate. "Nutrition professionals must step up and lobby for a tax on sugar-sweetened drinks that could then be used to subsidise healthy food." Ms Cullerton also said front-of-pack-food labelling should be made mandatory. "The current system of stars to indicate healthy food choices is not perfect but it's better than nothing but it is voluntary in that the food industry can pick and choose which products use the star system," she said. "The star system was developed with the food industry which generally gets to call the shots. Ms Cullerton said nutrition professionals could learn from the food industry on how to be better lobbyists and consequently better influence nutrition policy in Australia.

News Article | September 29, 2016

Australia’s biggest mortgage provider has declared a Queensland property with coal seam gas wells “unacceptable” as security for residential lending, raising fresh concerns that people living in the state’s gasfields may be unable to sell their homes. But Queensland Gas Company (QGC), which owns the wells on the Chinchilla acreage, has insisted that no properties that host its infrastructure have had their values negatively affected. A letter from the Commonwealth Bank, obtained by Guardian Australia, shows the presence of four wells on the 240-hectare property, currently on the market, was the sole reason given for refusing the owners’ application for a $500,000 bridging loan to buy a new home. The application “fails to meet the bank’s lending criteria” because the Chinchilla property was “unacceptable” as security, despite being wholly owned by a couple with no outstanding debts or credit blemishes and a primary income reaching well past the top tax bracket. “Long form valuation has revealed coal seam gas wells on the land, making the security unacceptable for residential lending purposes,” the bank said. The owners then asked QGC if it would buy the property, but the company refused. “QGC also does not agree with the assertion that its infrastructure has had a negative impact on the value of your property, or indeed any property currently hosting QGC infrastructure,” a letter from its landholder relationships manager said. “QGC has found no direct negative impacts to the value of rural properties upon which resource activities are conducted within the Surat Basin.” The manager’s letter said that “in QGC’s experience, an application for finance may be declined for a variety of reasons other than the value of the property proposed to be used as security”. In a statement the Commonwealth told Guardian Australia it considered “a number of factors, including individual risk profiles and loan serviceability” when assessing applications. “In some cases, we require an independent valuation to assist with our assessment of the loan application and to make sure we are meeting our responsible lending criteria,” it said. Mark McGovern, a rural economics specialist from the Queensland University of Technology’s school of business, economics and finance, said the case could signal a wider unforeseen economic cost of the gas industry. If the bank regarded property with gas wells as unsuitable security for a bridging loan, it followed it would not lend to people to buy such a property, McGovern said. “Someone buying in as a resident wouldn’t meet the criteria of the Commonwealth bank,” he said. The property owner, who asked to remain anonymous, said he and his wife had become “sort of prisoners in our own home”. “We can’t sell it, we can’t lend against it. It’s useless to us,” he said. His wife said she was “ropeable” on learning of the loan rejection after QGC had given public assurances its activities would not affect property values. QGC offered to pay for an independent valuation of the property, but the couple already had two, as well as one from the bank before it overturned its pre-approval of the loan. The Chinchilla man said their predicament was the latest sign that residents of Queensland’s gasfields, where property owners have no legal right to refuse gas companies access, were “the guinea pigs” for an industry since banned in Victoria and strongly resisted in NSW. “We didn’t have the people power,” he said. Anti-gas industry activists, a local property agency manager and the president of the Real Estate Institute of Queensland (REIQ) all told Guardian Australia it was the first case they had heard of a bank refusing to lend because of gas wells on a property. Guardian Australia asked the Commonwealth Bank, Westpac, ANZ and National Australia Bank if gas wells now represented a black mark under their lending criteria. A spokeswoman for Westpac said the bank dealt with properties “over a certain size” within its business/agricultural division, where “different lending principles [to residential loans] would apply”. The Commonwealth Bank said in a statement that every loan application was assessed on a case-by-case basis and it did “not have a policy of excluding coal seam gas wells as acceptable security in our regional and agribusiness banking.” ANZ and NAB did not respond. The REIQ president, Antonia Mercorella, said it was concerning if the case represented “the start of a new trend where lending institutions were suddenly deciding they were not prepared to loan money to people wanting to buy these properties”. “We know that in regional Queensland there’s a number of properties that this is going to create issues for,” she said. “If they’re applying a blanket rule where they’re not going to give a loan to anyone who has these on their property, then that’s obviously concerning, because it would make it very difficult for those property owners to sell their property. “There’s not too many buyers out there who are cashed up and able to buy without obtaining finance of the purchase.” Lock The Gate organiser Phil Laird said it was the first known case of “something we have been concerned about for a long time … flat out whether a bank will lend money based on your security”. “It feeds into a story of people who are in the gasfields and who are trapped,” he said. “It’s going to make it very difficult for that guy to find another bank and what’s more, it’s going to make it difficult for a lot of people in similar circumstances to find someone and it’s going to cast a pall over their situation. “There’s a lot of reasons why people need to move and change their property holdings and when some other party who’s been imposed on top of you starts to dictate the way in which you can conduct your life, your lifestyle, your succession planning, it becomes a real problem. Laird said the support underpinning the Queensland gas industry represented “a government-sponsored model to transfer risk on to the landholder”. “There’s something fundamentally wrong about this. If you did this to BHP, Lend Lease or other large property holders, there would be hell to pay.”

News Article | August 22, 2016

Australian researchers have captured an event that’s happening with alarming frequency worldwide: Coral bleaching. A team from Queensland University of Technology (QUT) in Brisbane, Australia a particular type of mushroom coral as it responded to warming water temperatures. Researchers found the solitary Heliofungia actiniformis coral inflated to more than three times its normal body size before suddenly expelling the tiny algae cells that live in a symbiotic relationship within its tissues. SEE ALSO: A deep-sea camera just discovered a mysterious purple blob The algae, called Symbiodinium, are corals’ main source of food and give coral their vibrant color. But as ocean temperatures rise due to global warming and natural climate variability, corals are becoming increasingly stressed and expelling their algae. Pollution and extreme weather events can also cause coral to shed the algae. Without their food source, coral turn white and grow more susceptible to disease and death, a phenomenon known as coral bleaching. During the past few years, the longest-lasting global coral bleaching event on record has been occurring, a result of global warming and an El Niño event. While scientists have long known that coral bleaching can happen, the new video provides the first recorded evidence of this particular coral species' bloat-then-burp response to heat stress, according to a published Aug. 12 in the journal Coral Reefs. Researchers Brett Lewis and Luke Nothdurft from QUT’s marine facility used a microscope, digital camera and smart tablet to capture the moment. They raised the water temperature in a 2.6-gallon aquarium system from 26 degrees Celsius (78.8 degrees Fahrenheit) to 32 degrees Celsius (89.6 degrees Fahrenheit) over 12 hours. The coral remained in the heated tank for up to eight days. “What’s really interesting is just how quickly and violently the coral forcefully evicted its resident [algae] symbionts,” Lewis said in a . “The H. actiniformis [coral] began ejecting the symbionts within the first two hours of us raising the water temperature of the system.” But the QUT research team suggested the mushroom coral’s fast response to water stress could actually help protect it from dangerous bleaching events over the long-term. This particular type of coral was one of the very few species on the Great Barrier Reef considered relatively resilient to bleaching, even as other nearby species suffered the worst effects. Watching a bowling ball drop from a tower onto an axe is pretty wild

News Article | October 29, 2016

An abundance of fresh fruits, vegetables, meats, and seafood are always on display when we walk into our local supermarket. But how often do any of us really think about the efforts our local farmers go through to make sure this fresh produce is available at our disposal? The pressure on farmers to continue to produce at the same rate — or even higher — is set to worsen as worldwide predictions have concluded that we will face a global food shortage crisis in less than 50 years. Findings in the latest report (PDF) by the Global Harvest Initiative show that the world population will exceed 9 billion people in 2050, and, as a result, the demand for food is likely to outpace the amount that can be produced. This echoes a similar prediction (PDF) made by the Australian government's Department of Agriculture, Fisheries, and Forestry, which highlighted that in order for Australia to maintain a stable food security level, there is a need to increase global agricultural output by 70 percent by 2050. Australia's agricultural sector accounts for 2.4 percent of the country's gross domestic product (GDP). However, in recent times, according to the National Farmers' Federation, agricultural productivity growth has slowed to 1 percent per annum, illustrating the need for the sector to look at new ways to ensure that the industry is able to keep up with growing population demands. Justin Goc and his team at Tasmania's Barilla Bay Oysters have been working closely with Sense-T — a collaboration between the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the University of Tasmania, IBM, and the Tasmanian government — to identify how sensing technology can help Tasmania's agricultural community drive future stability. As part of the project, biological indicators were installed throughout the farm. For the last two years, the indicators have been measuring environmental factors such as the salinity in water, the temperature in and out of water, and wind levels. The data collected from these indicators is now being collated to create a catalogue. Goc, the general manager of Barilla Bay Oysters, said that ideally, he would eventually like to see the data play a role in assisting the farm to figure out the mystery of why oysters fatten up or don't fatten up. "It can be a massive waiting game; sometimes it could just occur, and other times it doesn't. Usually, it's called seasonality. Why that is, the data may be able to shed some light over it," he said. Goc also believes that the technology may potentially be useful in helping the farm to further understand the biology behind oysters. "If we've got elevated temperatures and a lack of wind, then we will know if we're going to get an extended period of warmer weather, then that means we may have to accelerate our growing programs, because the oysters will grow quicker. This is instead of six weeks, where you might have to do it in four weeks to get the same outcome that you did before," he said. "All of these things can then be cross-referenced and help build a catalogue. We hope we can draw parallels between seasons and understand the biology of the animal, how it works, and why it's happy and why it isn't happy." However, Goc said that using technology in oyster farming can never replace a farmer's experience; rather, it would act as an assistant, to help fine tune their existing knowledge. "With oyster farmers, you can never discount the raw experience of dealing with your lease areas and learning the information yourself. These concepts are only there to help and assist our experience." For crop growers, the CSIRO has been trialling the phenonet system, a sensor network that collects information and monitors plants, soil conditions, irrigation levels, and other environmental conditions such as weather patterns to help farmers become better informed about which crops they should plant to get a better harvest. Arkady Zaslavsky, CSIRO digital productivity senior principal research scientist, said during a Gartner presentation in February that farmers are after information that will let them know what they need to do. "Not only from experience, but through the use of science, so they need to know the weather forecast, when to irrigate, how much fertilisation to put in, and so on." He highlighted, though, that only a small percentage of the information collected from the fields is considered valuable. "We collect the data from the field every five minutes, where there is a sensor reading of about 20 bytes. When you multiply that by the amount of sensors in the amount of plots, where there is potentially over 1 million plots, we are dealing with petabytes of agricultural data just coming from digital agricultural fields. "Now, if we look at this data in terms of what is useful for processing, it turns out that 99.95 percent of that data is useless. Only 0.5 percent of the data is called 'golden' data points, which we use for processing and visualising," he said. At the same time, researchers from the Queensland University of Technology (QUT) are now looking at the possibility of using robots to help crop farmers improve their productivity. QUT has designed a prototype AgBot II equipped with cameras, sensors, and software that can navigate, detect, and classify weeds and manage them either chemically or mechanically. It has also been designed to apply fertiliser for site-specific crop management. Trials of the technology are expected to commence in June 2015. QUT robotics professor Tristan Perez said there is enormous potential to give farmers access to data that will assist them in management decisions, particularly given that weed and pest management in crops is a serious problem. He added that the AgBots could potentially replace large, expensive tractors, and work 24 hours a day. "There is enormous potential for AgBots to be combined with sensor networks and drones to provide a farmer with large amounts of data, which ... can be combined with mathematical models and novel statistical techniques (big data analytics) to extract key information for management decisions — not only on when to apply herbicides, pesticides, and fertilisers, but how much to use," he said. Meanwhile, cows are being tagged with collars installed with GPS tracking to enable farmers to locate their herds, identify where they go and where they feed, and examine the health of each individual animal. The CSIRO is currently trialling the technology in its Smart Farm in New England, New South Wales, and Smart Homestead in Townsville, Queensland. Zaslavsky said one of the biggest challenges that the data collected from the cows — roughly 200MB of data per cow each year — helps farmers address is in early detection of when an animal becomes sick. This enables farmers to separate the individual animal from the herd and maintain the health of the others. Raja Jurdak, CSIRO autonomous systems principal research scientist, added that the vision the CSIRO has for the Smart Farm is for all the information collected from the cows to be fed back to farmers on a single dashboard, creating a support system to better manage farms. For example, it could help farmers decide when they should bring their animals in, when to irrigate, and when there are abnormalities in an animal's behaviour. "[Farmers] would often have infrequent access to information, and, if they do, it's often through manual inspection by having the animal on a scale. Typically, it's very labour intensive to get the animals there," he said. "With the new approach, you'd have a structure and an automated scale with data connectivity, and that would facilitate the process a lot more." Jurdak added that the organisation sees the potential of using the collars for sheep farming, too, as farmers are looking to trace where each animal goes, where it grazes, the quality of its milk, and the state of its wool. "We've tested some sensors on some pregnant sheep, because when a sheep is pregnant, there is a certain pattern of movement that characterises that they are pregnant. Our sensors can detect that movement, so we can closely monitor the sheep at that time to make sure that when it gives birth, it's a healthy lamb," he said.

News Article | December 28, 2016

« TriLumina to demo 256-pixel 3D solid-state LiDAR and ADAS systems for autonomous driving at CES 2017 | Main | NRL completes first flight of UAV with custom hydrogen fuel cell with metal bipolar plates; leveraging automotive technology » Talking hands-free on a mobile phone while driving is just as distracting as a conversation using a hand-held phone, according to a recent study by researchers at Queensland University of Technology (QUT) in Australia. Dr. Shimul (Md Mazharul) Haque, from QUT’s School of Civil Engineering and Built Environment and Centre for Accident Research & Road Safety – Queensland ( ), presented the findings at a Driving Distraction Seminar held at QUT. The study is published in Transportation Research Part C: Emerging Technologies. Mobile phone distracted driving (MPDD) is an ongoing challenge for transport network managers. … Different studies report varying effects of MPDD on crash risk. An epidemiological study found that mobile phone conversations increase crash risk by a factor of four. Asbridge et al. reported that the odds of a culpable crash increase by 70% when the driver is using mobile phone. In the United States, an study of police crash reports showed that mobile phone distraction resulted in 18% of fatal crashes and 5% of injury crashes. Epidemiological studies and police reported data, however, often suffer from underreporting problems and do not record the exposure to mobile phone use, and therefore these estimates may be inaccurate. Experimental and/or naturalistic studies, on the other hand, are not suitable for estimating actual crash risk as crashes are rarely observed within the study design. Hence, the use of surrogate measures of safe driving performance has been common, but the variety of these measures and the irregular results obtained has impeded a better understanding of the risk of using mobile phones while driving. Moreover, the nature of the relationship between surrogate measures and actual crash risk is poorly understood and evidence is lacking. The framework specifies the impacts of mobile phone distraction as an inter-related system of outcomes such as speed selection, lane deviations and crashes; human-car controls such as steering control and brake pedal use and human-environment interactions such as visual scanning and navigation. The researchers measured the effects of mobile phone distraction on safety including reaction time and driving performance in the CARRS-Q Advanced Driving Simulator. The researchers exposed a group of drivers to a virtual road network which included a pedestrian entering the driver’s peripheral vision from a footpath and walking across a pedestrian crossing. They monitored driver performance and reaction times during hands-free and hand-held phone conversations and without. The study found that the reaction time of drivers participating in either a hand-held or hands-free conversation was more than 40% longer than those not using a phone. Dr. Haque said it was the cognitive load required to hold a conversation that was the distraction, not whether or not the driver was holding a phone. Dr. Haque said the distraction of mobile phone use also had an impact on driver braking behavior; distracted drivers on average reduced the speed of their vehicle faster and more abruptly than non-distracted drivers, exhibiting excess braking

News Article | January 6, 2016

The latest episode of Star Wars is now upon us and has unleashed a new era of science fantasy robots, or “droids.” as they are known. One of the heroes of the new movie The Force Awakens is BB-8, a cute but capable spherical droid that is at the center of the story (sorry, no spoilers). But droids have been at the heart of the epic science fantasy saga since the original Star Wars movie back in 1977, when C-3PO uttered the immortal words: " I am C-3PO, human-cyborg relations. And this is my counterpart R2-D2." Star Wars has always been a droid story, just as much as a story about the Skywalker family. The old and the new: C-3PO (left), BB-8 (centre) and R2-D2 (right) from the Star Wars universe. Reuters/Carlo Allegri Even though we all know that Star Wars happened a long time ago, in a galaxy far, far away, just how good has it been a predicting the usefulness and development of robots on our own planet today? Is that you R2? For those non-Star Wars experts reading this, R2-D2 is an R-series astromech droid. Such droids work on spaceships and are particularly good at working outside in the vacuum of space. They are the mechanics of space travel and are packed with tools and know-how to fix things. They also seem to be fully waterproof, can fly short distances using deployable thrusters and somehow possess a cheeky character. But did you know that working in orbit around Earth right now is NASA’s Robonaut 2, also known as R2. It is one of the International Space Station’s test bed droids, having a humanoid shape and proportions so that it can undertake maintenance tasks originally designed for human astronauts. Robonaut2 — or R2 for short — from NASA and General Motors, is a robot designed to work side-by-side with people in difficult or dangerous places on Earth and in space. NASA Perhaps in the future, when all spaceship maintenance will be performed by droids, this real R2 unit will replace the humanoid form. The golden humanoid C-3PO is a protocol droid fluent in more than six million forms of communication. A protocol droid’s primary purpose in Star Wars is to help non-droids, creatures of all kinds, communicate with one another and generally avoid potentially dangerous misunderstandings. If there were protocol droids in Mos Eisley’s Cantina then maybe no-one would have shot first! But as the bartender said of R2-D2 and C-3PO: “We don’t serve their kind here.” We have human diplomats in our world to negotiate and attempt to head off conflict, and there seems no need for a mechanical interface, such as a protocol droid. But we are seeing translation apps on our phones, and their accuracy is improving to the point where it is conceivable that live language translation between two people speaking to one another may not be too far away. Until we find non-human sentient equals then there will be few diplomatic jobs for C-3PO-like droids here on earth. A place that we are likely to see humanoid robots like C-3PO is as artificial companions and carers. The advantage of a humanoid robot is that it should be able to cope in our homes or care facilities, as they have all been designed for humans. This is one of the great advantages of the humanoid robot form, although there is the so-called “uncanny valley” to deal with and the feeling by some that we should always ensure people have a human touch. A way of thinking about the dozens of droids of Star Wars is to classify them by how they are used. We have seen them being used in applications as diverse as farming, medicine, war, torture and space exploration. When R2-D2 and C-3PO escape Darth Vader and land in their escape pod on the sand plant of Tatooine, they are picked up by the Jawas scavenging for droids to sell to local moisture farmers. The lack of labor on Tatooine results in droids being critical for the functioning of the farms. Note to non-Star Wars experts: Darth Vader himself, or the least a young Anakin Skywalker, built C-3PO on Tatooine from spare parts. In the past year alone, very capable agricultural robots have been demonstrated by Queensland University of Technology, The University of Sydney and by Swarm Farm Robotics. Robots down on the farm Many other research organizations and companies are developing agricultural robotics as a way of overcoming labor availability issues, reducing the cost of inputs, such as diesel and herbicide, and enabling the use of smaller machines that compact the soil less than the large tractors we see commonly used today. In the Star Wars movies, medical droids appear at critical moments. The medical droids 2-1B and FX-7 twice patched up Luke in The Empire Strikes Back. Once when he survived the Wampa attack on Hoth, and then again at the end when they grafted on a robotic hand to Luke after his father sliced it off. Similar Imperial DD-13 medical droids created the droid-like Darth Vader from his battered body following his light saber duel with Obi Wan on the volcanic plant Mustafar in Revenge of the Sith. An EW-3 midwife droid even helped Padmé give birth to the twins Luke and Leia just prior to her tragic death. Here on Earth, Google has been talking about its plans for new medical robots. It’s teaming up with medical device companies to develop new robotic assistants for minimally invasive surgery. Medical robotic assistants have already become a common sight in well-equipped modern hospitals and are being used to help surgeons during urology procedures and more recently for knee replacements. New research is also showing how novel tentacle-like robot arms may be used to get to difficult to reach places. The hope is that medical robotics will enable shorter training times for surgeons, lengthen a surgeon’s career and improve outcomes for patients. All these benefits could drive the cost of these procedures down, giving access to more people around the world. Unsurprisingly, there are many droids in the Star Wars universe dedicated to killing. In Episodes I-III, the Trade Federation used droid starfighters. These were spaceships that were droids themselves and the droid command ships housed thousands of them. The Trade Federation were also fans of deploying thousands of humanoid shaped B1 Battle Droids. Although they were relatively well-equipped, they seemed stupid and were even worse shots than Stormtroopers. The far more capable Destroyer Droids had deflector shields and rapid fire laser cannons. Killer robots and their development is a hot topic right now on Earth. A campaign has been started with the aim of developing arms controls and some killer robots have already been deployed. In the Middle East, drones are routinely used to deliver missiles. These are human controlled and are not autonomous but they are changing the face of conflict. In the DMZ between the Koreas you will find fully autonomous robots equipped with heavy duty, long-range machine guns. If they spot movement in the DMZ they are capable of firing. There is no need for a human in the command chain. They are real Destroyer Droids. Are these the utility droids you’re looking for? Flickr/donsolo, CC BY-NC-SA Even though we can see many examples of how the droids of Star Wars may have inspired the design of the robots of today, there is one major missing piece of technology that means our robots are nothing like a Star Wars droid. And that is the almost complete lack of reliable and capable artificial intelligence in our robots. Nearly all of the human-created robots that I have mentioned rely entirely on a human expert to either control them remotely or program them to do a small range of very specific tasks. The robots that we have today are not very autonomous. Most of them cannot see, and even if they could, engineers have yet to develop artificial intelligence to the point where a robot by itself could solve a meaningful problem it may encounter in the world. Really smart robots are coming, and many people are working hard to tackle the challenges, but we are not likely to see general-purpose droids in the near future. We have a long time to go, and are far, far away from welcoming cute robot companions such as R2-D2 and BB-8 into our homes and workplaces. Until then, let’s just all enjoy Star Wars. Jonathan Roberts, Professor in Robotics, Queensland University of Technology. This article was originally published on The Conversation. Read the original article.

News Article | December 18, 2015

One of the heroes of the new movie The Force Awakens is BB-8, a cute but capable spherical droid that is at the centre of the story (sorry, no spoilers). But droids have been at the heart of the epic science fantasy saga since the original Star Wars movie back in 1977, when C-3PO uttered the immortal words: I am C-3PO, human-cyborg relations. And this is my counterpart R2-D2. Star Wars has always been a droid story, just as much as a story about the Skywalker family. Even though we all know that Star Wars happened a long time ago, in a galaxy far, far away, just how good has it been a predicting the usefulness and development of robots on our own planet today? Is that you R2? For those non-Star Wars experts reading this, R2-D2 is an R-series astromech droid. Such droids work on spaceships and are particularly good at working outside in the vacuum of space. They are the mechanics of space travel and are packed with tools and know-how to fix things. They also seem to be fully waterproof, can fly short distances using deployable thrusters and somehow possess a cheeky character. But did you know that working in orbit around Earth right now is NASA's Robonaut 2, also known as R2. It is one of the International Space Station's test bed droids, having a humanoid shape and proportions so that it can undertake maintenance tasks originally designed for human astronauts. Perhaps in the future, when all spaceship maintenance will be performed by droids, this real R2 unit will replace the humanoid form. The golden humanoid C-3PO is a protocol droid fluent in more than six million forms of communication. A protocol droid's primary purpose in Star Wars is to help non-droids, creatures of all kinds, communicate with one another and generally avoid potentially dangerous misunderstandings. If there were protocol droids in Mos Eisley's Cantina then maybe no-one would have shot first! But as the bartender said of R2-D2 and C-3PO: "We don't serve their kind here." We have human diplomats in our world to negotiate and attempt to head off conflict, and there seems no need for a mechanical interface such as a protocol droid. But we are seeing translation apps on our phones and their accuracy is improving to the point where it is conceivable that live language translation between two people speaking to one another may not be too far away. Until we find non-human sentient equals then there will be few diplomatic jobs for C-3PO-like droids here on earth. A place that we are likely to see humanoid robots like C-3PO is as artificial companions and carers. The advantage of a humanoid robot is that it should be able to cope in our homes or care facilities as they have all been designed for humans. This is one of the great advantages of the humanoid robot form, although there is the so-called "uncanny valley" to deal with and the feeling by some that we should always ensure people have a human touch. A way of thinking about the dozens of droids of Star Wars is to classify them by how they are used. We have seen them being used in applications as diverse as farming, medicine, war, torture and space exploration. When R2-D2 and C-3PO escape Darth Vader and land in their escape pod on the sand plant of Tatooine, they are picked up by the Jawas scavenging for droids to sell to local moisture farmers. The lack of labour on Tatooine results in droids being critical for the functioning of the farms. Note to non-Star Wars experts: Darth Vader himself, or the least a young Anakin Skywalker, built C-3PO on Tatooine from spare parts. In the past year alone, very capable agricultural robots have been demonstrated by Queensland University of Technology, The University of Sydney and by Swarm Farm Robotics. Many other research organisations and companies are developing agricultural robotics as a way of overcoming labour availability issues, reducing the cost of inputs such as diesel and herbicide, and enabling the use of smaller machines that compact the soil less than the large tractors we see commonly used today. In the Star Wars movies, medical droids appear at critical moments. The medical droids 2-1B and FX-7 twice patched up Luke in The Empire Strikes Back. Once when he survived the Wampa attack on Hoth and then again at the end when they grafted on a robotic hand to Luke after his father sliced it off. Similar Imperial DD-13 medical droids created the droid-like Darth Vader from his battered body following his light sabre duel with Obi Wan on the volcanic plant Mustafar in Revenge of the Sith. An EW-3 midwife droid even helped Padmé give birth to the twins Luke and Leia just prior to her tragic death. Here on Earth, Google has been talking about its plans for new medical robots. It's teaming up with medical device companies to develop new robotic assistants for minimally invasive surgery. Medical robotic assistants have already become a common sight in well-equipped modern hospitals and are being used to help surgeons during urology procedures and more recently for knee replacements. New research is also showing how novel tentacle-like robot arms may be used to get to difficult to reach places. The hope is that medical robotics will enable shorter training times for surgeons, lengthen a surgeon's career and improve outcomes for patients. All these benefits could drive the cost of these procedures down, giving access to more people around the world. Unsurprisingly, there are many droids in the Star Wars universe dedicated to killing. In Episodes I-III, the Trade Federation used droid starfighters. These were spaceships that were droids themselves and the droid command ships housed thousands of them. The Trade Federation were also fans of deploying thousands of humanoid shaped B1 Battle Droids. Although they were relatively well equipped, they seemed stupid and were even worse shots than Stormtroopers. The far more capable Destroyer Droids had deflector shields and rapid fire laser cannons. Killer robots and their development is a hot topic right now on Earth. A campaign has been started with the aim of developing arms controls and some killer robots have already been deployed. In the Middle East, drones are routinely used to deliver missiles. These are human controlled and are not autonomous but they are changing the face of conflict. In the DMZ between the Koreas you will find fully autonomous robots equipped with heavy duty, long-range machine guns. If they spot movement in the DMZ they are capable of firing. There is no need for a human in the command chain. They are real Destroyer Droids. Even though we can see many examples of how the droids of Star Wars may have inspired the design of the robots of today, there is one major missing piece of technology that means our robots are nothing like a Star Wars droid. And that is the almost complete lack of reliable and capable artificial intelligence in our robots. Nearly all of the human created robots that I have mentioned rely entirely on a human expert to either control them remotely or program them to do a small range of very specific tasks. The robots that we have today are not very autonomous. Most of them cannot see, and even if they could, engineers have yet to develop artificial intelligence to the point where a robot by itself could solve a meaningful problem it may encounter in the world. Really smart robots are coming and many people are working hard to tackle the challenges but we are not likely to see general-purpose droids in the near future. We have a long time to go, and are far, far away from welcoming cute robot companions such as R2-D2 and BB-8 into our homes and workplaces. Until then, let's just all enjoy Star Wars.

Davids K.,Queensland University of Technology | Araujo D.,University of Lisbon
Journal of Science and Medicine in Sport | Year: 2010

The concept of organismic asymmetry refers to an inherent bias for seeking explanations of human performance and behaviour based on internal mechanisms and referents. A weakness in this tendency is a failure to consider the performer-environment relationship as the relevant scale of analysis. In this paper we elucidate the philosophical roots of the bias and discuss implications of organismic asymmetry for sport science and performance analysis, highlighting examples in psychology, sports medicine and biomechanics. © 2010.

Araujo D.,University of Lisbon | Davids K.,Queensland University of Technology
Journal of Consciousness Studies | Year: 2011

In this paper we propose that the term skill acquisition, as commonly used in traditional psychology, and the philosophy, education, movement science and performance development literatures, has been biased by an organismic asymmetry. In cognitive and experimental psychology, for example, it refers to the establishment of an internal state or representation of an act which is believed to be acquired as a result of learning and task experience. Here we elucidate an ecological perspective which suggests that the term skill acquisition may not refer to an entity but rather to the emergence of an adaptive, functional relationship between an organism and its environment, thus avoiding an inherent organismic asymmetry in theorizing. In this respect, the terms 'skill adaptation' or 'skill attunement' might be more suitable to describe this process. © Imprint Academic 2011.

Griffith M.,Linköping University | Harkin D.G.,Queensland University of Technology
Current Opinion in Ophthalmology | Year: 2014

PURPOSE OF REVIEW: Artificial corneas are being developed to meet a shortage of donor corneas and to address cases in which allografting is contraindicated. A range of artificial corneas has been developed. Here we review several newer designs and especially those inspired by naturally occurring biomaterials found with the human body and elsewhere. RECENT FINDINGS: Recent trends in the development of artificial corneas indicate a move towards the use of materials derived from native sources including decellularized corneal tissue and tissue substitutes synthesized by corneal cells in vitro when grown either on their own or in conjunction with novel protein-based scaffolds. Biologically inspired materials are also being considered for implantation on their own with the view to promoting endogenous corneal tissue. SUMMARY: More recent attempts at making artificial corneas have taken a more nature-based or nature-inspired approach. Several will in the near future be likely to be available clinically. © 2014 Wolters Kluwer Health.

Rowlings D.W.,Queensland University of Technology | Grace P.R.,Queensland University of Technology | Kiese R.,Karlsruhe Institute of Technology | Weier K.L.,Queensland University of Technology
Global Change Biology | Year: 2012

The temporal variations in CO 2, CH 4 and N 2O fluxes were measured over two consecutive years from February 2007 to March 2009 from a subtropical rainforest in south-eastern Queensland, Australia, using an automated sampling system. A concurrent study using an additional 30 manual chambers examined the spatial variability of emissions distributed across three nearby remnant rainforest sites with similar vegetation and climatic conditions. Interannual variation in fluxes of all gases over the 2 years was minimal, despite large discrepancies in rainfall, whereas a pronounced seasonal variation could only be observed for CO 2 fluxes. High infiltration, drainage and subsequent high soil aeration under the rainforest limited N 2O loss while promoting substantial CH 4 uptake. The average annual N 2O loss of 0.5 ± 0.1 kg N 2O-N ha -1 over the 2-year measurement period was at the lower end of reported fluxes from rainforest soils. The rainforest soil functioned as a sink for atmospheric CH 4 throughout the entire 2-year period, despite periods of substantial rainfall. A clear linear correlation between soil moisture and CH 4 uptake was found. Rates of uptake ranged from greater than 15 g CH 4-C ha -1 day -1 during extended dry periods to less than 2-5 g CH 4-C ha -1 day -1 when soil water content was high. The calculated annual CH 4 uptake at the site was 3.65 kg CH 4-C ha -1 yr -1. This is amongst the highest reported for rainforest systems, reiterating the ability of aerated subtropical rainforests to act as substantial sinks of CH 4. The spatial study showed N 2O fluxes almost eight times higher, and CH 4 uptake reduced by over one-third, as clay content of the rainforest soil increased from 12% to more than 23%. This demonstrates that for some rainforest ecosystems, soil texture and related water infiltration and drainage capacity constraints may play a more important role in controlling fluxes than either vegetation or seasonal variability. © 2011 Blackwell Publishing Ltd.

Mahony R.,Australian National University | Kumar V.,University of Pennsylvania | Corke P.,Queensland University of Technology
IEEE Robotics and Automation Magazine | Year: 2012

This article provides a tutorial introduction to modeling, estimation, and control formultirotor aerial vehicles that includes the common four-rotor or quadrotor case. © 2012 IEEE.

Fawzia S.,Queensland University of Technology | Zhao X.-L.,Monash University | Al-Mahaidi R.,Monash University
Composite Structures | Year: 2010

This paper presents the results of a series of tension tests on CFRP bonded steel plate double strap joints. The main aim of this research is to provide detailed understanding of bond characteristics using experimental and numerical analysis of strengthened double strap joints under tension. A parametric study has been performed by numerical modelling with the variables of CFRP bond lengths, adhesive maximum strain and adhesive layer thicknesses. Finally, bond-slip models are proposed for three different types of adhesives within the range of the parametric study. © 2009 Elsevier Ltd.

Goldberg I.,University of Waterloo | Stebila D.,Queensland University of Technology | Ustaoglu B.,Sabanci University
Designs, Codes, and Cryptography | Year: 2013

Key establishment is a crucial cryptographic primitive for building secure communication channels between two parties in a network. It has been studied extensively in theory and widely deployed in practice. In the research literature a typical protocol in the public-key setting aims for key secrecy and mutual authentication. However, there are many important practical scenarios where mutual authentication is undesirable, such as in anonymity networks like Tor, or is difficult to achieve due to insufficient public-key infrastructure at the user level, as is the case on the Internet today. In this work we are concerned with the scenario where two parties establish a private shared session key, but only one party authenticates to the other; in fact, the unauthenticated party may wish to have strong anonymity guarantees. We present a desirable set of security, authentication, and anonymity goals for this setting and develop a model which captures these properties. Our approach allows for clients to choose among different levels of authentication. We also describe an attack on a previous protocol of Øverlier and Syverson, and present a new, efficient key exchange protocol that provides one-way authentication and anonymity. © 2012 Springer Science+Business Media, LLC.

Lovell A.,Queensland University of Technology | Lovell A.,Royal Brisbane and Womens Hospital | Yates P.,Queensland University of Technology
Palliative Medicine | Year: 2014

Background: Advance Care Planning is an iterative process of discussion, decision-making and documentation about end-of-life care. Advance Care Planning is highly relevant in palliative care due to intersecting clinical needs. To enhance the implementation of Advance Care Planning, the contextual factors influencing its uptake need to be better understood. Aim: To identify the contextual factors influencing the uptake of Advance Care Planning in palliative care as published between January 2008 and December 2012. Methods: Databases were systematically searched for studies about Advance Care Planning in palliative care published between January 2008 and December 2012. This yielded 27 eligible studies, which were appraised using National Institute of Health and Care Excellence Quality Appraisal Checklists. Iterative thematic synthesis was used to group results. Results: Factors associated with greater uptake included older age, a college degree, a diagnosis of cancer, greater functional impairment, being white, greater understanding of poor prognosis and receiving or working in specialist palliative care. Barriers included having non-malignant diagnoses, having dependent children, being African American, and uncertainty about Advance Care Planning and its legal status. Individuals' previous illness experiences, preferences and attitudes also influenced their participation. Conclusion: Factors influencing the uptake of Advance Care Planning in palliative care are complex and multifaceted reflecting the diverse and often competing needs of patients, health professionals, legislature and health systems. Large population-based studies of palliative care patients are required to develop the sound theoretical and empirical foundation needed to improve uptake of Advance Care Planning in this setting. © The Author(s) 2014.

Ahimastos A.A.,Baker IDI Heart and Diabetes Institute | Walker P.J.,University of Queensland | Askew C.,Queensland University of Technology | Leicht A.,James Cook University | And 5 more authors.
JAMA - Journal of the American Medical Association | Year: 2013

Importance: Approximately one-third of patients with peripheral artery disease experience intermittent claudication, with consequent loss of quality of life. Objective: To determine the efficacy of ramipril for improving walking ability, patient-perceived walking performance, and quality of life in patients with claudication. Design, Setting, and Patients: Randomized, double-blind, placebo-controlled trial conducted among 212 patients with peripheral artery disease (mean age, 65.5 [SD, 6.2] years), initiated in May 2008 and completed in August 2011 and conducted at 3 hospitals in Australia. Intervention: Patients were randomized to receive 10 mg/d of ramipril (n=106) or matching placebo (n=106) for 24 weeks. Main Outcome Measures: Maximum and pain-free walking times were recorded during a standard treadmill test. The Walking Impairment Questionnaire (WIQ) and Short-Form 36 Health Survey (SF-36) were used to assess walking ability and quality of life, respectively. Results: At 6 months, relative to placebo, ramipril was associated with a 75-second (95% CI, 60-89 seconds) increase in mean pain-free walking time (P<.001) and a 255-second (95% CI, 215-295 seconds) increase in maximum walking time (P<.001). Relative to placebo, ramipril improved the WIQ median distance score by 13.8 (Hodges-Lehmann 95% CI, 12.2-15.5), speed score by 13.3 (95% CI, 11.9-15.2), and stair climbing score by 25.2 (95% CI, 25.1-29.4) (P<.001 for all). The overall SF-36 median Physical Component Summary score improved by 8.2 (Hodges-Lehmann 95% CI, 3.6-11.4; P=.02) in the ramipril group relative to placebo. Ramipril did not affect the overall SF-36 median Mental Component Summary score. Conclusions and Relevance: Among patients with intermittent claudication, 24-week treatment with ramipril resulted in significant increases in pain-free and maximum treadmill walking times compared with placebo. This was associated with a significant increase in the physical functioning component of the SF-36 score. Trial Registration: Identifier: NCT00681226 ©2013 American Medical Association. All rights reserved.

Vilar L.,University of Lisbon | Araujo D.,University of Lisbon | Davids K.,Queensland University of Technology | Button C.,University of Otago
Sports Medicine | Year: 2012

Performance analysis is a subdiscipline of sports sciences and one-approach, notational analysis, has been used to objectively audit and describe behaviours of performers during different subphases of play, providing additional information for practitioners to improve future sports performance. Recent criticisms of these methods have suggested the need for a sound theoretical rationale to explain performance behaviours, not just describe them. The aim of this article was to show how ecological dynamics provides a valid theoretical explanation of performance in team sports by explaining the formation of successful and unsuccessful patterns of play, based on symmetry-breaking processes emerging from functional interactions between players and the performance environment. We offer the view that ecological dynamics is an upgrade to more operational methods of performance analysis that merely document statistics of competitive performance. In support of our arguments, we refer to exemplar data on competitive performance in team sports that have revealed functional interpersonal interactions between attackers and defenders, based on variations in the spatial positioning of performers relative to each other in critical performance areas, such as the scoring zones. Implications of this perspective are also considered for practice task design and sport development programmes.

Wezeman T.,Karlsruhe Institute of Technology | Brase S.,Karlsruhe Institute of Technology | Masters K.-S.,Queensland University of Technology
Natural Product Reports | Year: 2015

Xanthone dimers are a widespread, structurally-diverse family of natural products frequently found in plants, fungi and lichens. They feature an intriguing variety of linkages between the component xanthones (benzannulated chromanones). These synthetically elusive secondary metabolites are of great interest due to their broad array of bioactivities, which has led to the xanthones being designated as 'privileged structures'. We seek herein to give an overview of all reliably-described xanthone dimers, their structures, occurrence, and the bioactivities established to date. The possible biosynthetic pathways leading to members of this family are also discussed in light of our current knowledge. © 2014 The Royal Society of Chemistry.

Schmitz K.H.,University of Pennsylvania | Speck R.M.,University of Pennsylvania | Rye S.A.,Queensland University of Technology | DiSipio T.,Queensland University of Technology | Hayes S.C.,Queensland University of Technology
Cancer | Year: 2012

BACKGROUND: There is a need to better describe and understand the prevalence of breast cancer treatment-related adverse effects amenable to physical therapy and rehabilitative exercise. Prior studies have been limited to single issues and lacked long-term follow-up. The Pulling Through Study provides data on prevalence of adverse effects in breast cancer survivors followed over 6 years. METHODS: A population-based sample of Australian women (n = 287) diagnosed with invasive, unilateral breast cancer was followed for a median of 6.6 years and prospectively assessed for treatment-related complications at 6, 12, and 18 months and 6 years after diagnosis. Assessments included postsurgical complications, skin or tissue reaction to radiation therapy, upper-body symptoms, lymphedema, 10% weight gain, fatigue, and upper-quadrant function. The proportion of women with positive indication for each complication and 1 or more complication was estimated using all available data at each time point. Women were only considered to have a specific complication if they reported the highest 2 levels of the Likert scale for self-reported issues. RESULTS: At 6 years after diagnosis, more than 60% of women experienced 1 or more side effects amenable to rehabilitative intervention. The proportion of women experiencing 3 or more side effects decreased throughout follow-up, whereas the proportion experiencing no side effects remained stable around 40% from 12 months to 6 years. Weight gain was the only complication to increase in prevalence over time. CONCLUSIONS: These data support the development of a multidisciplinary prospective surveillance approach for the purposes of managing and treating adverse effects in breast cancer survivors. © 2012 American Cancer Society.

Passos P.,University of Lisbon | Araujo D.,University of Lisbon | Davids K.,Queensland University of Technology
Sports Medicine | Year: 2013

In nature, the interactions between agents in a complex system (fish schools; colonies of ants) are governed by information that is locally created. Each agent self-organizes (adjusts) its behaviour, not through a central command centre, but based on variables that emerge from the interactions with other system agents in the neighbourhood. Selforganization has been proposed as a mechanismto explain the tendencies for individual performers to interact with each other in field-invasion sports teams, displaying functional co-adaptive behaviours, without the need for central control. The relevance of self-organization as a mechanism that explains pattern-forming dynamics within attacker-defender interactions in field-invasion sports has been sustained in the literature. Nonetheless, other levels of interpersonal coordination, such as intra-team interactions, still raise important questions, particularly with reference to the role of leadership or match strategies that have been prescribed in advance by a coach. The existence of key properties of complex systems, such as system degeneracy, nonlinearity or contextual dependency, suggests that self-organization is a functional mechanism to explain the emergence of interpersonal coordination tendencies within intra-team interactions. In this opinion article we propose how leadership may act as a key constraint on the emergent, self-organizational tendencies of performers in field-invasion sports. © 2012 Springer International Publishing Switzerland.

Talmor A.,Monash University | Talmor A.,Monash Medical Center | Dunphy B.,Queensland University of Technology | Dunphy B.,University of Newcastle
Best Practice and Research: Clinical Obstetrics and Gynaecology | Year: 2015

Infertility affects one in seven couples, and its rate is on the increase. Ovulatory defects and unexplained causes account for >50% of infertile aetiologies. It is postulated that a significant proportion of these cases are either directly or indirectly related to obesity. The prevalence of overweight and obese men and women has topped 50% in some developed countries. Obesity is on the increase worldwide; in turn, the consequences in terms of the associated morbidity and mortality have also been increasing. Obesity is associated with various reproductive sequelae including anovulation, subfertility and infertility, increased risk of miscarriage and poor neonatal and maternal pregnancy outcomes. Thus, the combination of infertility and obesity poses some very real challenges in terms of both the short- and long-term management of these patients. The mechanism with which obesity impacts female reproductive function is summarised in this review. © 2014 Elsevier Ltd. All rights reserved.

Wezeman T.,Karlsruhe Institute of Technology | Masters K.-S.,Queensland University of Technology | Brase S.,Karlsruhe Institute of Technology
Angewandte Chemie - International Edition | Year: 2014

Double or nothing! Recently the total synthesis of secalonic acids A and D was reported. This work and other natural product syntheses with a dimerization step as a common feature are featured in this Highlight. The significant biological activity of the secalonic acids and the fact that their synthesis has fascinated synthetic chemists for the past forty years make this work a milestone in natural product synthesis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lucey S.,CSIRO | Navarathna R.,Queensland University of Technology | Ashraf A.B.,University of Pennsylvania | Sridharan S.,Queensland University of Technology
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2013

In this paper, we propose a framework for both gradient descent image and object alignment in the Fourier domain. Our method centers upon the classical Lucas & Kanade (LK) algorithm where we represent the source and template/model in the complex 2D Fourier domain rather than in the spatial 2D domain. We refer to our approach as the Fourier LK (FLK) algorithm. The FLK formulation is advantageous when one preprocesses the source image and template/model with a bank of filters (e.g., oriented edges, Gabor, etc.) as 1) it can handle substantial illumination variations, 2) the inefficient preprocessing filter bank step can be subsumed within the FLK algorithm as a sparse diagonal weighting matrix, 3) unlike traditional LK, the computational cost is invariant to the number of filters and as a result is far more efficient, and 4) this approach can be extended to the Inverse Compositional (IC) form of the LK algorithm where nearly all steps (including Fourier transform and filter bank preprocessing) can be precomputed, leading to an extremely efficient and robust approach to gradient descent image matching. Further, these computational savings translate to nonrigid object alignment tasks that are considered extensions of the LK algorithm, such as those found in Active Appearance Models (AAMs). © 2013 IEEE.

Ellem S.J.,Monash University | De-Juan-Pardo E.M.,Queensland University of Technology | Risbridger G.P.,Monash University
Advanced Drug Delivery Reviews | Year: 2014

Prostate cancer is the most commonly diagnosed malignancy in men and advanced disease is incurable. Model systems are a fundamental tool for research and many in vitro models of prostate cancer use cancer cell lines in monoculture. Although these have yielded significant insight they are inherently limited by virtue of their two-dimensional (2D) growth and inability to include the influence of tumour microenvironment. These major limitations can be overcome with the development of newer systems that more faithfully recreate and mimic the complex in vivo multi-cellular, three-dimensional (3D) microenvironment. This article presents the current state of in vitro models for prostate cancer, with particular emphasis on 3D systems and the challenges that remain before their potential to advance our understanding of prostate disease and aid in the development and testing of new therapeutic agents can be realised. © 2014 Elsevier B.V.

Lartillot N.,University Claude Bernard Lyon 1 | Phillips M.J.,Queensland University of Technology | Ronquist F.,Swedish Museum of Natural History
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016

Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. © 2016 The Authors.

Ronquist F.,Swedish Museum of Natural History | Lartillot N.,University Claude Bernard Lyon 1 | Phillips M.J.,Queensland University of Technology
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016

Total-evidence dating (TED) allows evolutionary biologists to incorporate a wide range of dating information into a unified statistical analysis. One might expect this to improve the agreement between rocks and clocks but this is not necessarily the case. We explore the reasons for such discordance using a mammalian dataset with rich molecular, morphological and fossil information. There is strong conflict in this dataset between morphology and molecules under standard stochastic models. This causes TED to push divergence events back in time when using inadequate models or vague priors, a phenomenonwe term‘deep root attraction’ (DRA).We identify several causes of DRA. Failure to account for diversified sampling results in dramatic DRA, but this can be addressed using existing techniques. Inadequate morphological models also appear to be a major contributor to DRA. The major reason seems to be that current models do not account for dependencies among morphological characters, causing distorted topology and branch length estimates. This is particularly problematic for huge morphological datasets, which may contain large numbers of correlated characters. Finally, diversification and fossil sampling priors that do not incorporate all the available background information can contribute to DRA, but these priors can also be used to compensate for DRA. Specifically, we show that DRA in the mammalian dataset can be addressed by introducing a modest extra penalty for ghost lineages that are unobserved in the fossil record, for instance by assuming rapid diversification, rare extinction or high fossil sampling rate; any of these assumptions produces highly congruent divergence time estimates with a minimal gap between rocks and clocks. Under these conditions, fossils have a stabilizing influence on divergence time estimates and significantly increase the precision of those estimates, which are generally close to the dates suggested by palaeontologists. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. © 2016 The Authors.

These are the majority of the participants in the study in Brisbane, Australia, 2012. Credit: CRP cryptic fruit fly pest species. Considered among the agricultural pests with the greatest economic impact, the tephritid fruit flies (Diptera: Tephritidae) are a serious worldwide problem. Destroying fruit and vegetable production and markets across all major continents, some key species have raised international attention, leading to six years of coordinated multidisciplinary research that will contribute to overcome phytosanitary trade barriers and apply more sustainable pest management strategies such as the Sterile Insect Technique (SIT). The collaboration between over fifty researchers from more than twenty countries resulted in twenty-five articles, compiled by editors Drs. Marc De Meyer, Royal Museum for Central Africa, Belgium, Anthony R. Clarke, Queensland University of Technology, Australia, M. Teresa Vera, Facultad de Agronomia y Zootecnia, Universidad Nacional de Tucuman, Argentina, and Jorge Hendrichs, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Austria. They have now been published in a special volume of the open-access journal ZooKeys. Females from numerous native as well as invasive fruit flies species cause tremendous economic losses by laying their eggs directly into ripening fruit and vegetables, where their larvae feed, destroying the crop. Their presence also results in the loss of export markets and expensive quarantine and regulatory controls that further increase the associated costs. The impact of these pests and the requests from the Member States led the Joint Food and Agriculture Organisation / International Atomic Energy Agency (FAO/IAEA) Programme on Nuclear Techniques in Food and Agriculture to assist the governments in developing and applying more environment-friendly pest suppression systems. One example is the SIT package developed and applied against the Mediterranean fruit fly, which resulted in the successful management of this pest species in a number of countries. To further develop such techniques to deal with other major fruit fly species threatening the agriculture in many countries around the world, the scientists needed to resolve first controversies related to species identities, so that they can differentiate taxonomic groups and better understand their biology. Therefore, researchers used multiple, independent lines of evidence to delimit the species boundaries. These included traditional morphology, but also morphometrics, developmental physiology, pre- and postzygotic mating incompatibility, karyology, chemoecology, and a wide range of molecular techniques such as multi-locus markers and microsatellites among others. The present Special Issue presents some of the major findings that are of utmost significance for international horticultural trade and the application of biologically-based pest control methods. The volume is dedicated to two prominent and leading figures in the scientific and research community, Serge Quilici and Peter Teal. Both were part of the initiative from the beginning, but regrettably, passed away recently and were not able to see its conclusion. Explore further: What's in a name? Everything—if you're a fruit fly

News Article | November 19, 2015

The discovery of a stable form of one-dimensional diamond has scientists racing to understand its properties. The first signs are that diamond nanothread will be more versatile than anyone expected. Hardly a week goes by without somebody proclaiming a new application for graphene, the form of carbon that occurs in single sheets with chicken wire-like structure. Roll a graphene sheet into a tube and it forms a carbon nanotube, another wonder material with numerous applications. And wrap it further into a ball and, with a small rearrangement of bonds, it forms buckyballs. Now there is a new kid on the carbon block. Last month, a team at Pennsylvania State University and elsewhere announced they had created another type of carbon that takes the form of a one-dimensional diamond crystal capped with hydrogen. They call this new material diamond nanothread. That caused a flurry of excitement and raised some interesting questions. Materials scientists are fascinated by the potential properties of a diamond nanothread and its applications. But one fear is that such a thread would be so brittle that it would shatter like glass under any kind of load, a property that would severely limit its use. Today, we get some new insight into diamond nanothreads thanks to the work of Haifei Zhan at Queensland University of Technology in Australia and a few pals. These guys have modeled the threads using large-scale molecular dynamics simulations. And they conclude that the material could be more versatile than anyone thought. There are tentative signs that diamond nanothread could be a new a wonder material in its own right. The Penn State team manufactured the nanothread from benzene molecules, simple rings of carbon atoms. It’s not hard to see how a stack of these could bond in a way that forms a thread. And that’s exactly what the Penn State team did. They stacked the molecules into a line, placed it under pressure so that the molecules polymerized and, voila, created a diamond nanothread. That sounds simple in theory but the complexity arises from the way the carbon atoms can bond. Various configurations are possible, and the question that Zhan and co investigate is how the properties of the thread depend on these arrangements. In particular, Zhan and co look at the two most common configurations. The first is straightforward polymerized benzene — a stack of these rings bonded together. This is a rigid molecule that becomes increasingly brittle as it gets longer. Constructing anything complex with long sections of poly-benzene would be like trying to sew with like uncooked spaghetti. But there is another configuration of carbon atoms known as Stone-Wales defects, and these are much more malleable. Indeed, the Stone-Wales defects act like hinges connecting sections of poly-benzene. Zhan and co simulate how the properties of the nanothread vary as the density of these defects increases. And they conclude that when the density crosses a particular threshold, the thread suddenly changes from brittle to entirely flexible — rather like the difference between uncooked and cooked spaghetti. That’s an interesting result. It implies that the property of the nanothread can be tuned simply by controlling the density of Stone-Wales defects along its length. So some parts of the thread can be made rigid, while others are entirely flexible. What of potential applications? “Its highly tunable ductility together with its ultra-light density and high Young’s modulus makes diamond nanothread ideal for the creation of extremely strong three-dimensional nano-architectures,” say Zhan and co. Of course, this work is just a simulation. There are almost certainly going to be differences between its predictions and the behavior of diamond nanothreads in the real world. So the next step will be for materials scientists to create some nanothread construction kits and start measuring this material’s properties for real. Given the huge interest in carbon architecture and the vast sums of money being poured into this area — the European Union alone has a $1.07 billion research project focused purely on graphene — it surely won’t be long before we see diamond nanothreads in the flesh and some of the extraordinary applications that it should make possible. Release Date: November 18, 2015 Source: MIT Technology Review

BRISBANE, Australia, Dec. 20, 2016 (GLOBE NEWSWIRE) -- Factor Therapeutics Limited (ASX:FTT) is pleased to announce that it has enrolled the first patient for its US multi-centre Phase II trial of VF001 in Venous Leg Ulcers ( : NCT02973893). The FPI milestone was achieved at Miami Dade Medical Research Institute under the supervision of Dr. Francisco Oliva. CEO Nigel Johnson commented, “We are delighted to have now formally launched this Phase II trial. It has been clinically and operationally-designed to ensure the very best chance of achieving a successful outcome.” The clinical trial (VF00102) is a 168-patient double blind, placebo controlled Phase II study of VF001-DP (drug product) in moderately-severe Venous Leg Ulcers (VLUs). The trial will randomize patients 1:1:1 into 3 arms: 28µg/ml VF001 (low dose) and 280µg/ml VF001 (high dose), and placebo. All three arms will be combined with compression bandaging and moisture-retentive dressings (standard care). The trial features strict inclusion/exclusion criteria intended to optimise patient response on the basis of the company’s prior clinical experience with the product. After a 2 week screening period to eliminate easy healers, randomised patients will be treated weekly for 12 weeks, with a 12 week follow-up period. Enrolment will take place across up to 26 clinical sites across the US, with up to 32 sites qualified should additional patient recruitment sites be required. The company plans to provide an enrolment update in Q1 2017, and is targeting a top-line read-out of efficacy by Q4 2017. The trial also includes a quality of life survey to support the use of the study as a second confirmatory trial that will support the submission for a CE Mark in Europe, where VF001 is classified as a Class III, Rule 13 medical device. Executive Director Dr Christian Behrenbruch commented, “We have assembled an outstanding clinical team that is able to execute a very sophisticated trial. The Miami investigator meeting was highly successful for the company and we have made a solid launch into the study. We are encouraged by the positive investigator response and engagement with this trial.” About Venous Leg Ulcers Chronic wounds, unlike normal wounds, remain in a prolonged inflammatory state which leads to damage of critical extracellular components.  VLUs cost the US healthcare system in excess of $3Bn/year. Up to one third of all patients experience 4+ recurrent episodes of disease, and VLUs affect up to 1.7% of the US population with a prevalence of ~600,000 patients/year in the 65+ age group. The average per-ulcer cost is $9,600/year. Not only is there a major unmet need for new products to achieve a more robust wound-healing trajectory, but pain management (a secondary end-point in Factor’s trial) is also of major importance in this patient population. There are over 1,000 out-patient wound care centres in the United States, with a trend toward treating patients in the community setting. About VF001 VF001 is a proprietary recombinant fusion protein consisting of an engineered vitronectin motif linked to insulin-like growth factor 1 (IGF-1). The product is designed to accelerate chronic wound repair by providing wound bed cell attachment sites and stimulating cellular proliferation. VF001 is a multi-action product that enables fibroblasts and keratinocytes to attach, migrate, and proliferate within the extracellular matrix, thereby reinstating a more normal wound healing process.  VF001 is part of Factor Therapeutics’ strong intellectual portfolio around vitronectin-targeted growth factors. VF001 and related molecules in the Factor portfolio are also being evaluated for other advanced wound care applications, such as surgical and ocular wound care. About Factor Therapeutics Factor Therapeutics Limited (“Factor”) is a biomedical technology company that is developing treatments for acute and chronic wound healing applications. Factor is a clinical stage company with its lead program (VF001) in Phase II for the treatment of venous leg ulcers (VLUs). The company’s platform technology originates from the Institute of Health and Biomedical Innovation at the Queensland University of Technology, Australia. Factor’s shares are traded on the Australian Securities Exchange (ASX) under the ticker FTT. For more information, please visit Important Information This announcement does not constitute an offer to sell, or a solicitation of an offer to buy, securities in the United States, or in any other jurisdiction in which such an offer would be illegal. The securities referred to herein have not been and will not be registered under the United States Securities Act of 1933 (the “US Securities Act”), or under the securities laws of any state or other jurisdiction of the United States and may not be offered or sold within the United States, unless the securities have been registered under the US Securities Act or an exemption from the registration requirements of the US Securities Act is available.

Dong W.,Nanchang University | Ni Y.,Nanchang University | Kokot S.,Queensland University of Technology
Journal of Agricultural and Food Chemistry | Year: 2013

Near-infrared spectroscopy (NIRS) calibrations were developed for the discrimination of Chinese hawthorn (Crataegus pinnatifida Bge. var. major) fruit from three geographical regions as well as for the estimation of the total sugar, total acid, total phenolic content, and total antioxidant activity. Principal component analysis (PCA) was used for the discrimination of the fruit on the basis of their geographical origin. Three pattern recognition methods, linear discriminant analysis, partial least-squares-discriminant analysis, and back-propagation artificial neural networks, were applied to classify and compare these samples. Furthermore, three multivariate calibration models based on the first derivative NIR spectroscopy, partial least-squares regression, back-propagation artificial neural networks, and least-squares-support vector machines, were constructed for quantitative analysis of the four analytes, total sugar, total acid, total phenolic content, and total antioxidant activity, and validated by prediction data sets. © 2012 American Chemical Society.

Swayne N.,Queensland University of Technology
Environmental and Planning Law Journal | Year: 2012

The current regulatory approach to coal seam gas projects in Queensland is based on the philosophy of adaptive environmental management. This method of "learning by doing" is implemented in Queensland primarily through the imposition of layered monitoring and reporting duties on the coal seam gas operator alongside obligations to compensate and "make good" harm caused. The purpose of this article is to provide a critical review of the Queensland regulatory approach to the approval and minimisation of adverse impacts from coal seam gas activities. Following an overview of the hallmarks of an effective adaptive management approach, this article begins by addressing the mosaic of approval processes and impact assessment regimes that may apply to coal seam gas projects. This includes recent Strategic Cropping Land reforms. This article then turns to consider the preconditions for land access in Queensland and the emerging issues for landholders relating to the negotiation of access and compensation agree- ments. This article then undertakes a critical review of the environmental duties imposed on coal seam gas operators relating to hydraulic fracturing, well head leaks, groundwater management and the disposal and beneficial use of produced water. Finally, conclusions are drawn regarding the overall effectiveness of the Queensland framework and the lessons that may be drawn from Queensland's adaptive environmental management approach.

Sadiq S.,Queensland University of Technology
Lecture Notes in Business Information Processing | Year: 2011

We stipulate that for researchers interested in the computational and organizational aspects of research in compliance and risk management, there are two key aspects to be considered. Firstly, research should aim towards a sustainable methodology for compliance management. Secondly, research in this highly multi-disciplinary area must be aligned with industry demands in order to maximize potential for impact and relevance. We have presented a snapshot recommendation for the two aspects, namely a compliance by design methodology that has a fundamentally preventative focus, and an industry driven research agenda that is derived through expert opinion and practitioner feedback. We hope that this will assist researchers to better position their future research endeavors in the area of risk and compliance management. © 2011 Springer-Verlag.

Feigl B.,Queensland University of Technology | Zele A.J.,Queensland University of Technology
Optometry and Vision Science | Year: 2014

Melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are a class of photoreceptors with established roles in non-image-forming processes. Their contributions to image-forming vision may include the estimation of brightness. Animal models have been central for understanding the physiological mechanisms of ipRGC function and there is evidence of conservation of function across species. Intrinsically photosensitive retinal ganglion cells can be divided into five ganglion cell subtypes that show morphological and functional diversity. Research in humans has established that ipRGCs signal environmental irradiance to entrain the central body clock to the solar day for regulating circadian processes and sleep. In addition, ipRGCs mediate the pupil light reflex (PLR), making the PLR a readily accessible behavioral marker of ipRGC activity. Less is known about ipRGC function in retinal and optic nerve disease, with emerging research providing insight into their function in diabetes, retinitis pigmentosa, glaucoma, and hereditary optic neuropathy. We briefly review the anatomical distributions, projections, and basic physiological mechanisms of ipRGCs and their proposed and known functions in animals and humans with and without eye disease. We introduce a paradigm for differentiating inner and outer retinal inputs to the pupillary control pathway in retinal disease and apply this paradigm to patients with age-related macular degeneration (AMD). In these cases of patients with AMD, we provide the initial evidence that ipRGC function is altered and that the dysfunction is more pronounced in advanced disease. Our perspective is that with refined pupillometry paradigms, the PLR can be extended to AMD assessment as a tool for the measurement of inner and outer retinal dysfunction. Copyright © 2014 American Academy of Optometry.

Nayak R.,Queensland University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Due to the higher expectation more and more online matching companies adopt recommender systems with content-based, collaborative filtering or hybrid techniques. However, these techniques focus on users explicit contact behaviors but ignore the implicit relationship among users in the network. This paper proposes a personalized social matching system for generating potential partners' recommendations that not only exploits users' explicit information but also utilizes implicit relationships among users. The proposed system is evaluated on the dataset collected from an online dating network. Empirical analysis shows the recommendation success rate has increased to 31% as compared to the baseline success rate of 19%. © 2011 Springer-Verlag.

Chen Z.,Queensland University of Technology | Shen H.T.,Queensland University of Technology | Zhou X.,Queensland University of Technology
Proceedings - International Conference on Data Engineering | Year: 2011

The booming industry of location-based services has accumulated a huge collection of users' location trajectories of driving, cycling, hiking, etc. In this work, we investigate the problem of discovering the Most Popular Route (MPR) between two locations by observing the traveling behaviors of many previous users. This new query is beneficial to travelers who are asking directions or planning a trip in an unfamiliar city/area, as historical traveling experiences can reveal how people usually choose routes between locations. To achieve this goal, we firstly develop a Coherence Expanding algorithm to retrieve a transfer network from raw trajectories, for indicating all the possible movements between locations. After that, the Absorbing Markov Chain model is applied to derive a reasonable transfer probability for each transfer node in the network, which is subsequently used as the popularity indicator in the search phase. Finally, we propose a Maximum Probability Product algorithm to discover the MPR from a transfer network based on the popularity indicators in a breadth-first manner, and we illustrate the results and performance of the algorithm by extensive experiments. © 2011 IEEE.

Bilandzic M.,Queensland University of Technology
Interactive Learning Environments | Year: 2016

Learning is most effective when intrinsically motivated through personal interest, and situated in a supportive socio-cultural context. This paper reports on findings from a study that explored implications for design of interactive learning environments through 18 months of ethnographic observations of people's interactions at “Hack The Evening” (HTE). HTE is a meetup group initiated at the State Library of Queensland in Brisbane, Australia, and dedicated to provide visitors with opportunities for connected learning in relation to hacking, making and do-it-yourself technology. The results provide insights into factors that contributed to HTE as a social, interactive and participatory environment for learning – knowledge is created and co-created through uncoordinated interactions among participants that come from a diversity of backgrounds, skills and areas of expertise. The insights also reveal challenges and barriers that the HTE group faced in regards to connected learning. Four dimensions of design opportunities are presented to overcome those challenges and barriers towards improving connected learning in library buildings and other free-choice-learning environments that seek to embody a more interactive and participatory culture among their users. The insights are relevant for librarians as well as designers, managers and decision-makers of other interactive and free-choice-learning environments. © 2013 Taylor & Francis.

Wiles J.,Queensland University of Technology
Behavioral and Brain Sciences | Year: 2011

Mercier & Sperber (M&S) argue for their argumentative theory in terms of communicative abilities. Insights can be gained by extending the discussion beyond human reasoning to rodent and robot navigation. The selection of arguments and conclusions that are mutually reinforcing can be cast as a form of abductive reasoning that I argue underlies the construction of cognitive maps in navigation tasks. © 2011 Cambridge University Press.

Frost R.L.,Queensland University of Technology | Xi Y.,Queensland University of Technology
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

There is a large number of boron containing minerals with water and/or hydroxyl units of which pinnoite MgB2O(OH)6 is one. Some discussion about the molecular structure of pinnoite exists in the literature. Whether water is involved in the structure is ill-determined. The molecular structure of pinnoite has been assessed by the combination of Raman and infrared spectroscopy. The Raman spectrum is characterized by an intense band at 900 cm-1 assigned to the BO stretching vibrational mode. A series of bands in the 1000-1320 cm-1 spectral range are attributed to BO antisymmetric stretching modes and in-plane bending modes. The infrared spectrum shows complexity in this spectral range. Multiple Raman OH stretching vibrations are found at 3179, 3399, 3554 and 3579 cm-1. The infrared spectrum shows a series of overlapping bands with bands identified at 3123, 3202, 3299, 3414, 3513 and 3594 cm-1. By using a Libowitzky type function, hydrogen bond distances were calculated. Two types of hydrogen bonds were identified based upon the hydrogen bond distance. It is important to understand the structure of pinnoite in order to form nanomaterials based upon the pinnoite structure. © 2013 Elsevier Ltd. All rights reserved.

Digby A.,Victoria University of Wellington | Towsey M.,Queensland University of Technology | Bell B.D.,Victoria University of Wellington | Teal P.D.,Victoria University of Wellington
Methods in Ecology and Evolution | Year: 2013

Autonomous acoustic recorders are widely available and can provide a highly efficient method of species monitoring, especially when coupled with software to automate data processing. However, the adoption of these techniques is restricted by a lack of direct comparisons with existing manual field surveys. We assessed the performance of autonomous methods by comparing manual and automated examination of acoustic recordings with a field-listening survey, using commercially available autonomous recorders and custom call detection and classification software. We compared the detection capability, time requirements, areal coverage and weather condition bias of these three methods using an established call monitoring programme for a nocturnal bird, the little spotted kiwi (Apteryx owenii). The autonomous recorder methods had very high precision (>98%) and required <3% of the time needed for the field survey. They were less sensitive, with visual spectrogram inspection recovering 80% of the total calls detected and automated call detection 40%, although this recall increased with signal strength. The areal coverage of the spectrogram inspection and automatic detection methods were 85% and 42% of the field survey. The methods using autonomous recorders were more adversely affected by wind and did not show a positive association between ground moisture and call rates that was apparent from the field counts. However, all methods produced the same results for the most important conservation information from the survey: the annual change in calling activity. Autonomous monitoring techniques incur different biases to manual surveys and so can yield different ecological conclusions if sampling is not adjusted accordingly. Nevertheless, the sensitivity, robustness and high accuracy of automated acoustic methods demonstrate that they offer a suitable and extremely efficient alternative to field observer point counts for species monitoring. © 2013 British Ecological Society.

Matthews B.,Queensland University of Technology | Heinemann T.,University of Southern Denmark
Design Studies | Year: 2012

Since the 'empirical turn' in design studies, many methods drawn from the social and human sciences have been applied to the study of designers' activities. Recently, conversation analysis (CA) has been gaining some attention as one of these approaches that may offer promise for design studies. In this paper, we present an analysis of design work informed by CA. Our analysis is intended both as a means of exemplifying how the approach can be applied to design, and as empirical groundwork for sketching out what a CA program of research in design studies could offer the field. We argue that CA can provide an empirical respecification of central conceptual and theoretical topics in design research. © 2012 Elsevier Ltd. All rights reserved.

Kamruzzaman M.,Queensland University of Technology | Baker D.,Queensland University of Technology
Land Use Policy | Year: 2013

Systematic studies that evaluate the quality of decision-making processes are relatively rare. Using the literature on decision quality, this research develops a framework to assess the quality of decision-making processes for resolving boundary conflicts in the Philippines. The evaluation framework breaks down the decision-making process into three components (the decision procedure, the decision method, and the decision unit) and is applied to two ex-post (one resolved and one unresolved) and one ex-ante cases. The evaluation results from the resolved and the unresolved cases show that the choice of decision method plays a minor role in resolving boundary conflicts whereas the choice of decision procedure is more influential. In the end, a decision unit can choose a simple method to resolve the conflict. The ex-ante case presents a follow-up intended to resolve the unresolved case for a changing decision-making process in which the associated decision unit plans to apply the spatial multi criteria evaluation (SMCE) tool as a decision method. The evaluation results from the ex-ante case confirm that the SMCE has the potential to enhance the decision quality because: a) it provides high quality as a decision method in this changing process, and b) the weaknesses associated with the decision unit and the decision procedure of the unresolved case were found to be eliminated in this process. © 2013 Elsevier Ltd.

Alonso-Caneiro D.,Queensland University of Technology | Read S.A.,Queensland University of Technology | Collins M.J.,Queensland University of Technology
Biomedical Optics Express | Year: 2013

The assessment of choroidal thickness from optical coherence tomography (OCT) images of the human choroid is an important clinical and research task, since it provides valuable information regarding the eye's normal anatomy and physiology, and changes associated with various eye diseases and the development of refractive error. Due to the time consuming and subjective nature of manual image analysis, there is a need for the development of reliable objective automated methods of image segmentation to derive choroidal thickness measures. However, the detection of the two boundaries which delineate the choroid is a complicated and challenging task, in particular the detection of the outer choroidal boundary, due to a number of issues including: (i) the vascular ocular tissue is non-uniform and rich in non-homogeneous features, and (ii) the boundary can have a low contrast. In this paper, an automatic segmentation technique based on graph-search theory is presented to segment the inner choroidal boundary (ICB) and the outer choroidal boundary (OCB) to obtain the choroid thickness profile from OCT images. Before the segmentation, the B-scan is pre-processed to enhance the two boundaries of interest and to minimize the artifacts produced by surrounding features. The algorithm to detect the ICB is based on a simple edge filter and a directional weighted map penalty, while the algorithm to detect the OCB is based on OCT image enhancement and a dual brightness probability gradient. The method was tested on a large data set of images from a pediatric (1083 B-scans) and an adult (90 B-scans) population, which were previously manually segmented by an experienced observer. The results demonstrate the proposed method provides robust detection of the boundaries of interest and is a useful tool to extract clinical data. © 2013 Optical Society of America.

Zhan H.F.,Queensland University of Technology | Gu Y.T.,Queensland University of Technology
Journal of Applied Physics | Year: 2012

Based on the molecular dynamics (MD) simulation and the classical Euler-Bernoulli beam theory, a fundamental study of the vibrational performance of the Ag nanowire (NW) is carried out. A comprehensive analysis of the quality (Q)-factor, natural frequency, beat vibration, as well as high vibration mode is presented. Two excitation approaches, i.e., velocity excitation and displacement excitation, have been successfully implemented to achieve the vibration of NWs. Upon these two kinds of excitations, consistent results are obtained, i.e., the increase of the initial excitation amplitude will lead to a decrease to the Q-factor, and moderate plastic deformation could increase the first natural frequency. Meanwhile, the beat vibration driven by a single relatively large excitation or two uniform excitations in both two lateral directions is observed. It is concluded that the nonlinear changing trend of external energy magnitude does not necessarily mean a non-constant Q-factor. In particular, the first order natural frequency of the Ag NW is observed to decrease with the increase of temperature. Furthermore, comparing with the predictions by Euler-Bernoulli beam theory, the MD simulation provides a larger and smaller first vibration frequencies for the clamped-clamped and clamped-free thin Ag NWs, respectively. Additionally, for thin NWs, the first order natural frequency exhibits a parabolic relationship with the excitation magnitudes. The frequencies of the higher vibration modes tend to be low in comparison to Euler-Bernoulli beam theory predictions. A combined initial excitation is proposed which is capable to drive the NW under a multi-mode vibration and arrows the coexistence of all the following low vibration modes. This work sheds lights on the better understanding of the mechanical properties of NWs and benefits the increasing utilities of NWs in diverse nano-electronic devices. © 2012 American Institute of Physics.

Fisher D.E.,Queensland University of Technology
Environmental and Planning Law Journal | Year: 2014

The statutory arrangements for the management of natural resources in Australia confer powers of decision-making upon government agencies and, at the same time, restrict how these powers are to be exercised by reference either to stated criteria or in some instances to the public interest. These restrictions perform different functions according to their structure, form and language: for example they may be in the form of jurisdictional, deliberative or purposive rules. This article reviews how the offshore resources legislation of the Commonwealth and some examples of the onshore resources legislation of Queensland address the functions performed by the public interest in determining whether there is compliance with the principle of the rule of law. © 2015, (publisher). All rights reserved.

Collins P.F.,University of Southampton | Collins P.F.,Queensland University of Technology | Elia M.,University of Southampton | Stratton R.J.,University of Southampton
Respirology | Year: 2013

Currently, there is confusion about the value of using nutritional support to treat malnutrition and improve functional outcomes in chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis of randomized, controlled trials (RCT) aimed to clarify the effectiveness of nutritional support in improving functional outcomes in COPD. A systematic review identified 12 RCT (n = 448) in stable COPD patients investigating the effects of nutritional support (dietary advice (1 RCT), oral nutritional supplements (10 RCT), enteral tube feeding (1 RCT)) versus control on functional outcomes. Meta-analysis of the changes induced by intervention found that while respiratory function (forced expiratory volume in 1 s, lung capacity, blood gases) was unresponsive to nutritional support, both inspiratory and expiratory muscle strength (maximal inspiratory mouth pressure +3.86 standard error (SE) 1.89 cm H2O, P = 0.041; maximal expiratory mouth pressure +11.85 SE 5.54 cm H2O, P = 0.032) and handgrip strength (+1.35 SE 0.69 kg, P = 0.05) were significantly improved and associated with weight gains of ≥2 kg. Nutritional support produced significant improvements in quality of life in some trials, although meta-analysis was not possible. It also led to improved exercise performance and enhancement of exercise rehabilitation programmes. This systematic review and meta-analysis demonstrates that nutritional support in COPD results in significant improvements in a number of clinically relevant functional outcomes, complementing a previous review showing improvements in nutritional intake and weight. © 2013 Asian Pacific Society of Respirology.

Athukorala P.P.A.W.,Queensland University of Technology | Wilson C.,Queensland University of Technology
Energy Economics | Year: 2010

This study investigates the short-run dynamics and long-run equilibrium relationship between residential electricity demand and factors influencing demand - per capita income, price of electricity, price of kerosene oil and price of liquefied petroleum gas - using annual data for Sri Lanka for the period, 1960-2007. The study uses unit root, cointegration and error-correction models. The long-run demand elasticities of income, own price and price of kerosene oil (substitute) were estimated to be 0.78, - 0.62, and 0.14 respectively. The short-run elasticities for the same variables were estimated to be 0.32, ?. 0.16 and 0.10 respectively. Liquefied petroleum (LP) gas is a substitute for electricity only in the short-run with an elasticity of 0.09. The main findings of the paper support the following (1) increasing the price of electricity is not the most effective tool to reduce electricity consumption (2) existing subsidies on electricity consumption can be removed without reducing government revenue (3) the long-run income elasticity of demand shows that any future increase in household incomes is likely to significantly increase the demand for electricity and (4) any power generation plans which consider only current per capita consumption and population growth should be revised taking into account the potential future income increases in order to avoid power shortages in the country. © 2009 Elsevier B.V.

Wan H.-X.,Wuhan University of Technology | Mahendran M.,Queensland University of Technology
Engineering Structures | Year: 2015

The LiteSteel beam (LSB) is a cold-formed high strength steel channel section made of two torsionally rigid closed flanges and a slender web. Due to its mono-symmetric characteristics, its centroid and shear centre do not coincide. The LSBs can be used in floor systems as joists or bearers and in these applications they are often subjected to transverse loads that are applied away from the shear centre. Hence they are often subjected to combined bending and torsion actions. Previous researches on LSBs have concentrated on their bending or shear behaviour and strengths, and only limited research has been undertaken on their combined bending and torsion behaviour. Therefore in this research a series of nine experiments was first conducted on LSBs subject to combined bending and torsion. Three LSB sections were tested to failure under eccentric loading at mid-span, and appropriate results were obtained from seven tests. A special test rig was used to simulate two different eccentricities and to provide accurate simple boundary conditions at the supports. Finite element models of tested LSBs were developed using ANSYS, and the ultimate strengths, failure modes, and load-displacement curves were obtained and compared with corresponding test results. Finite element analyses agreed well with test results and hence the developed models were used in a parametric study to investigate the effects of load locations, eccentricities, and spans on the combined bending and torsion behaviour of LSBs. The interaction between the ultimate bending and torsional moment capacities was studied and a simple design rule was proposed. This paper presents the details of the tests, finite element analyses, and parametric study of LSBs subject to combined bending and torsion, and the results. © 2014 Elsevier Ltd.

Bilandzic M.,Queensland University of Technology | Foth M.,Queensland University of Technology
International Journal of Human Computer Studies | Year: 2012

Locative media applications have opened up new opportunities for mediated interactions with and within physical spaces. Smart phones with touch-screen displays, QWERTY-keyboards, multimedia recording capabilities, and mobile high-speed Internet connectivity through 3G and WiFi networks enable users to continuously capture, create, upload and share geo-referenced content. The connectivity through mobile devices has transformed urban environments into 'hybrid spaces', where social interaction and communication patterns traverse through physical, digital, and a mix of both spaces. The location-based social networking (LBSN) through mobile applications such as Dodgeball, Loopt, Four-square or Facebook Places enable users to 'check-in', that is digitally confirm their physical presence at a particular place. Users can see where their friends have checked-in and background information of current and previous check-ins of people in their immediate proximity.

Menicucci N.C.,Perimeter Institute for Theoretical Physics | Ma X.,University of Queensland | Ralph T.C.,University of Queensland | Ralph T.C.,Queensland University of Technology
Physical Review Letters | Year: 2010

We present a compact experimental design for producing an arbitrarily large optical continuous-variable cluster state using just one single-mode vacuum squeezer and one quantum nondemolition gate. Generating the cluster state and computing with it happen simultaneously: more entangled modes become available as previous modes are measured, thereby making finite the requirements for coherence and stability even as the computation length increases indefinitely. © 2010 The American Physical Society.

Broome M.A.,Queensland University of Technology | Fedrizzi A.,Queensland University of Technology | Lanyon B.P.,Queensland University of Technology | Kassal I.,Harvard University | And 2 more authors.
Physical Review Letters | Year: 2010

Quantum walks have a host of applications, ranging from quantum computing to the simulation of biological systems. We present an intrinsically stable, deterministic implementation of discrete quantum walks with single photons in space. The number of optical elements required scales linearly with the number of steps. We measure walks with up to 6 steps and explore the quantum-to-classical transition by introducing tunable decoherence. Finally, we also investigate the effect of absorbing boundaries and show that decoherence significantly affects the probability of absorption. © 2010 The American Physical Society.

Buonanno G.,University of Cassino and Southern Lazio | Buonanno G.,Queensland University of Technology | Fuoco F.C.,University of Cassino and Southern Lazio | Morawska L.,Queensland University of Technology | Stabile L.,University of Cassino and Southern Lazio
Atmospheric Environment | Year: 2013

Potential adverse effects on children health may result from school exposure to airborne particles. To address this issue, measurements in terms of particle number concentration, particle size distribution and black carbon (BC) concentrations were performed in three school buildings in Cassino (Italy) and its suburbs, outside and inside of the classrooms during normal occupancy and use. Additional time resolved information was gathered on ventilation condition, classroom activity, and traffic count data around the schools were obtained using a video camera. Across the three investigated school buildings, the outdoor and indoor particle number concentration monitored down to 4 nm and up to 3 μm ranged from 2.8 × 104 part cm-3 to 4.7 × 104 part cm-3 and from 2.0 × 104 part cm-3 to 3.5 × 104 part cm-3, respectively. The total particle concentrations were usually higher outdoors than indoors, because no indoor sources were detected. I/O measured was less than 1 (varying in a relatively narrow range from 0.63 to 0.74), however one school exhibited indoor concentrations higher than outdoor during the morning rush hours. Particle size distribution at the outdoor site showed high particle concentrations in different size ranges, varying during the day; in relation to the starting and finishing of school time two modes were found. BC concentrations were 5 times higher at the urban school compared with the suburban and suburban-to-urban differences were larger than the relative differences of ultrafine particle concentrations. © 2012 Elsevier Ltd.

Recker J.,Queensland University of Technology
European Journal of Information Systems | Year: 2013

Process modeling grammars are used to create scripts of a business domain that a process-aware information system is intended to support. A key grammatical construct of such grammars is known as a Gateway. A Gateway construct is used to describe scenarios in which the workflow of a process diverges or converges according to relevant conditions. Gateway constructs have been subjected to much academic discussion about their meaning, role and usefulness, and have been linked to both process-modeling errors and process-model understandability. This paper examines perceptual discriminability effects of Gateway constructs on an individual's abilities to interpret process models. We compare two ways of expressing two convergence and divergence patterns-Parallel Split and Simple Merge-implemented in a process modeling grammar. On the basis of an experiment with 98 students, we provide empirical evidence that Gateway constructs aid the interpretation of process models due to a perceptual discriminability effect, especially when models are complex. We discuss the emerging implications for research and practice, in terms of revisions to grammar specifications, guideline development and design choices in process modeling. © 2013 Operational Research Society Ltd. All rights reserved.

Chatterjee D.,Indian Institute of Technology Kharagpur | Ghosh A.,Queensland University of Technology
International Journal of Electrical Power and Energy Systems | Year: 2011

This paper discusses the use of trajectory sensitivity analysis (TSA) in determining the transient stability margin of a power system compensated by a shunt FACTS device. The shunt device used is static synchronous compensator (STATCOM). It is shown that TSA can be used for the design of controller for the STATCOM. The preferable locations for the placement of the STATCOM for different fault conditions are also identified. The effects of STATCOM in maintaining different bus voltages in the post-fault condition are studied. The STATCOM is modeled by a voltage source connected to the system through a transformer. The systems used for the study are the WSCC 3-machine 9-bus system and the IEEE 16-machine 68-bus system. © 2010 Elsevier Ltd. All rights reserved.

Gupta R.,Motilal Nehru National Institute of Technology | Ghosh A.,Queensland University of Technology | Joshi A.,Indian Institute of Technology Kanpur
IEEE Transactions on Power Delivery | Year: 2011

In this paper, the performance of voltage-source converter-based shunt and series compensators used for load voltage control in electrical power distribution systems has been analyzed and compared, when a nonlinear load is connected across the load bus. The comparison has been made based on the closed-loop frequency response characteristics of the compensated distribution system. A distribution static compensator (DSTATCOM) as a shunt device and a dynamic voltage restorer (DVR) as a series device are considered in the voltage-control mode for the comparison. The power-quality problems which these compensator address include voltage sags/swells, load voltage harmonic distortions, and unbalancing. The effect of various system parameters on the control performance of the compensator can be studied using the proposed analysis. In particular, the performance of the two compensators are compared with the strong ac supply (stiff source) and weak ac-supply (non-stiff source) distribution system. The experimental verification of the analytical results derived has been obtained using a laboratory model of the single-phase DSTATCOM and DVR. A generalized converter topology using a cascaded multilevel inverter has been proposed for the medium-voltage distribution system. Simulation studies have been performed in the PSCAD/EMTDC software to verify the results in the three-phase system. © 2010 IEEE.

Han P.,Queensland University of Technology | Ivanovski S.,Griffith University | Crawford R.,Queensland University of Technology | Xiao Y.,Queensland University of Technology
Journal of Bone and Mineral Research | Year: 2015

Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. © 2014 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research.

Bruns A.,Queensland University of Technology
First Monday | Year: 2013

The promise of 'big data' has generated a significant deal of interest in the development of new approaches to research in the humanities and social sciences, as well as a range of important critical interventions which warn of an unquestioned rush to 'big data'. Drawing on the experiences made in developing innovative 'big data' approaches to social media research, this paper examines some of the repercussions for the scholarly research and publication practices of those researchers who do pursue the path of 'big data'-centric investigation in their work. As researchers import the tools and methods of highly quantitative, statistical analysis from the 'hard' sciences into computational, digital humanities research, must they also subscribe to the language and assumptions underlying such 'scientificity'? If so, how does this affect the choices made in gathering, processing, analysing, and disseminating the outcomes of digital humanities research? In particular, is there a need to rethink the forms and formats of publishing scholarly work in order to enable the rigorous scrutiny and replicability of research outcomes? © First Monday, 1995-2013.

Smith G.,Queensland University of Technology
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the structure of the title complex, [Cs(C6H2Cl3N2O2)(H2O)] n , the caesium salt of the commercial herbicide picloram, the Cs+ cation lies on a crystallographic mirror plane, which also contains the coordinating water molecule and all non-H atoms of the 4-amino-3,5,6-trichloropicolinate anion except the carboxylate O-atom donors. The irregular CsCl4O5 coordination polyhedron comprises chlorine donors from the ortho-related ring substituents of the picloramate ligand in a bidentate chelate mode, with a third chlorine bridging [Cs - Cl range 3.6052 (11)-3.7151 (11) Å] as well as a bidentate chelate carboxylate group giving sheets extending parallel to (010). A three-dimensional coordination polymer structure is generated through the carboxylate group, which also bridges the sheets down [010]. Within the structure, there are intra-unit water O - H⋯Ocarboxylate and amine N - H⋯Npyridine hydrogen-bonding interactions.

Lin T.R.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Lin T.R.,Queensland University of Technology
Journal of Sound and Vibration | Year: 2012

An analytical solution is presented in this paper for the vibration response of a ribbed plate clamped on all its boundary edges by employing a traveling wave solution. A clamped ribbed plate test rig is also assembled in this study for the experimental investigation of the ribbed plate response and to provide verification results to the analytical solution. The dynamic characteristics and mode shapes of the ribbed plate are measured and compared to those obtained from the analytical solution and from finite element analysis (FEA). General good agreements are found between the results. Discrepancies between the computational and experimental results at low and high frequencies are also discussed. Explanations are offered in the study to disclose the mechanism causing the discrepancies. The dependency of the dynamic response of the ribbed plate on the distance between the excitation force and the rib is also investigated experimentally. It confirms the findings disclosed in a previous analytical study [T.R. Lin, J. Pan, A closed form solution for the dynamic response of finite ribbed plates, Journal of the Acoustical Society of America 119 (2006) 917-925] that the vibration response of a clamped ribbed plate due to a point force excitation is controlled by the plate stiffness when the source is more than a quarter plate bending wavelength away from the rib and from the plate boundary. The response is largely affected by the rib stiffness when the source location is less than a quarter bending wavelength away from the rib. © 2011 Elsevier Ltd. All rights reserved.

Wang Y.,Queensland University of Technology | Bialkowski M.E.,Queensland University of Technology | Abbosh A.M.,Queensland University of Technology
IEEE Microwave and Wireless Components Letters | Year: 2012

The letter describes double microstrip-slot transitions for use in planar ± 90° phase shifters. The described devices exhibit broadband performance and offer compatibility with ordinary microstrip circuits. Full-wave EM simulation results show a phase shift of ± 90° ± 7° over the frequency band of 3.1-12.0 GHz when compared with a suitably chosen section of microstripline. The observed differential phase shift is accompanied by return losses of not less than 14 dB and insertion losses between 0.7 to 1.5 dB in the band 3.1-11.0 GHz. The simulated performance is confirmed by experimental results of ± 90° ± 8° phase shift, return loss not less than 14 dB and insertion loss between 0.5 and 1.8 dB in the frequency band of 3.1-11.0 GHz. © 2006 IEEE.

Bilandzic M.,Queensland University of Technology | Foth M.,Queensland University of Technology
Library Hi Tech | Year: 2013

Purpose: This paper aims to inform design strategies for smart space technology to enhance libraries as environments for coworking and informal social learning. The focus is on understanding user motivations, behaviour, and activities in the library when there is no programmed agenda. Design/methodology/approach: The study analyses gathered data over five months of ethnographic research at The Edge - a "bookless" library space at the State Library of Queensland in Brisbane, Australia, that is explicitly dedicated to coworking, social learning, peer collaboration, and creativity around digital culture and technology. Findings: The results present five personas that embody people's main usage patterns as well as motivations, attitudes, and perceived barriers to social learning. It appears that most users work individually or within pre-organised groups, but usually do not make new connections with co-present, unacquainted users. Based on the personas, four hybrid design dimensions are suggested to improve the library as a social interface for shared learning encounters across physical and digital spaces. Originality/value: The findings in this paper offer actionable knowledge for managers, decision makers, and designers of technology-enhanced library spaces and similar collaboration and coworking spaces. © Emerald Group Publishing Limited.

Abbosh A.M.,Queensland University of Technology
IEEE Transactions on Microwave Theory and Techniques | Year: 2012

A method to design microstrip bandpass filters with ultra-wideband (UWB) performance, wide stopband, and practical dimensions is presented. According to the proposed method, three subsections of different lengths and coupling factors are connected to form a stepped-impedance parallel-coupled microstrip structure. A theoretical model is derived and used to find the optimum length and coupling factor for each of those subsections for an UWB passband and suppressed second and third harmonic responses in the stopband. The required performance is realized by generating and proper positioning of three transmission zeros in the upper stopband and three transmission poles in the passband. The derived model shows that the total length of the three-subsection coupled structure is one-third of the effective wavelength at the center of the passband. The theoretical model is used to find the required design values for the whole structure. The presented method is validated by building a bandpass filter that has a passband from 3.1 to 10.6 GHz with less than 1-dB insertion loss and a wide upper stopband that extends up to 28 GHz. © 2006 IEEE.

La Rosa M.,Queensland University of Technology | Dumas M.,Queensland University of Technology | Uba R.,University of Tartu | Dijkman R.,TU Eindhoven
ACM Transactions on Software Engineering and Methodology | Year: 2013

This article addresses the problem of constructing consolidated business process models out of collections of process models that share common fragments. The article considers the construction of unions of multiple models (called merged models) as well as intersections (called digests). Merged models are intended for analysts who wish to create a model that subsumes a collection of process models - typically representing variants of the same underlying process - with the aim of replacing the variants with the merged model. Digests, on the other hand, are intended for analysts who wish to identify the most recurring fragments across a collection of process models, so that they can focus their efforts on optimizing these fragments. The article presents an algorithm for computing merged models and an algorithm for extracting digests from a merged model. The merging and digest extraction algorithms have been implemented and tested against collections of process models taken from multiple application domains. The tests show that the merging algorithm produces compact models and scales up to process models containing hundreds of nodes. Furthermore, a case study conducted in a large insurance company has demonstrated the usefulness of the merging and digest extraction operators in a practical setting. © 2013 ACM.

Lui H.-S.,Chalmers University of Technology | Shuley N.V.,Queensland University of Technology
IEEE Transactions on Antennas and Propagation | Year: 2012

Automated target recognition based on resonances embedded in the ultrawideband transient signatures has been of significant research interest throughout the years. In most studies, targets are usually illuminated and measured using a linear polarized basis. This could lead to an incorrect result for target recognition as some resonant modes may not be well excited at that particular incident aspect and polarization state. In this communication, the possibility of using a full-polarimetric ultrawideband target signature is investigated. Target recognition of some simple wire targets using the extinction pulse technique demonstrate that it would be easier to fully excite all of the important resonances using a circular polarization basis with due consideration of the co- and cross-polarized target signatures. © 1963-2012 IEEE.

Hou L.,Queensland University of Technology | Bergmann N.W.,Queensland University of Technology
IEEE Transactions on Instrumentation and Measurement | Year: 2012

This paper proposes a novel industrial wireless sensor network (IWSN) for industrial machine condition monitoring and fault diagnosis. In this paper, the induction motor is taken as an example of monitored industrial equipment due to its wide use in industrial processes. Motor stator current and vibration signals are measured for further processing and analysis. On-sensor node feature extraction and on-sensor fault diagnosis using neural networks are then investigated to address the tension between the higher system requirements of IWSNs and the resource-constrained characteristics of sensor nodes. A two-step classifier fusion approach using Dempster-Shafer theory is also explored to increase diagnosis result quality. Four motor operating conditionsnormal without load, normal with load, loose feet, and mass imbalanceare monitored to evaluate the proposed system. Experimental results show that, compared with raw data transmission, on-sensor fault diagnosis could reduce payload transmission data by 99%, decrease node energy consumption by 97%, and prolong node lifetime from 106 to 150 h, an increase of 43%. The final fault diagnosis results using the proposed classifier fusion approach give a result certainty of at least 97.5%. To leverage the advantages of on-sensor fault diagnosis, another system operating mode is explored, which only transmits the fault diagnosis result when a fault happens or at a fixed interval. For this mode, the node lifetime reaches 73 days if sensor nodes transmit diagnosis results once per hour. © 1963-2012 IEEE.

Abbosh A.M.,Queensland University of Technology
IEEE Transactions on Microwave Theory and Techniques | Year: 2012

In the design of reflection-type phase shifters, the coupler that represents the shifter's backbone is usually assumed to be a quarter-wavelength 3-dB coupler. In this paper, a derived theoretical model shows that, for certain values for the odd- and even-mode impedances, a coupled structure with a length that is less than one tenth of a wavelength is sufficient to build a high-performance reflection phase shifter. The presented analysis indicates that reflection phase shifters can be designed with a more compact size and larger phase range compared with the conventional method of using a quarter-wavelength 3-dB coupler. However, the required odd-mode impedance in the proposed design is low (≈10 Ω), whereas the required even-mode impedance is high (≈200 Ω). To realize those impedances when using parallel-coupled lines, slotted ground and shunt chip capacitor are used. The proposed design is supported by full-wave electromagnetic simulations and measurements. The simulated results show that 0.085λ coupled structure achieves 255° phase range across 36% fractional bandwidth with less than 1-dB insertion loss and more than 10-dB return loss. In another design, a full-cycle phase range is obtained with less than 1.5-dB insertion loss across the same band by using two 0.076λ coupled sections. A manufactured prototype for a full-cycle phase range validates the simulation results and, thus, the proposed method. © 1963-2012 IEEE.

Chen W.C.,Queensland University of Technology | Shuley N.V.Z.,Queensland University of Technology
IEEE Transactions on Antennas and Propagation | Year: 2012

In order to correctly identify a remote target, a robust target signatures identification technique is required. Radar target identification based on complex natural resonances (CNRs) has drawn the interest of many researchers following the development of the singularity expansion method (SEM). CNRs are popular due to the fact that they are theoretically independent of the aspect angle between the radar and the target, and they form a minimal set of parameters by which the target can be identified thus assisting the classification problem. As evident from the literature, statistical techniques such as the generalized likelihood ratio test (GLRT) have produced a better identification result, in the presence of noise, compared to some other SEM based identification methods such as the extinction pulse (E-pulse) technique. In this communication, we develop yet another novel statistical method based on canonical correlation analysis (CCA) to perform target classification. Simulation results using various targets show that our method is comparable to the GLRT method in the presence of white Gaussian noise. © 1963-2012 IEEE.

Bradley A.P.,Queensland University of Technology
Pattern Recognition Letters | Year: 2013

This paper describes a simple, non-parametric and generic test of the equivalence of receiver operating characteristic (ROC) curves based on a modified Kolmogorov-Smirnov (KS) test. The test is described in relation to the commonly used techniques such as the area under the ROC curve (AUC) and the Neyman-Pearson method. We first review how the KS test is used to test the null hypotheses that the class labels predicted by a classifier are no better than random. We then propose an interval mapping technique that allows us to use two KS tests to test the null hypothesis that two classifiers have ROC curves that are equivalent. We demonstrate that this test discriminates different ROC curves both when one curve dominates another and when the curves cross and so are not discriminated by AUC. The interval mapping technique is then used to demonstrate that, although AUC has its limitations, it can be a model-independent and coherent measure of classifier performance. © 2013 Elsevier B.V. All rights reserved.

Tong S.,Queensland University of Technology
Environmental health : a global access science source | Year: 2014

Few data on the relationship between temperature variability and childhood pneumonia are available. This study attempted to fill this knowledge gap. A quasi-Poisson generalized linear regression model combined with a distributed lag non-linear model was used to quantify the impacts of diurnal temperature range (DTR) and temperature change between two neighbouring days (TCN) on emergency department visits (EDVs) for childhood pneumonia in Brisbane, from 2001 to 2010, after controlling for possible confounders. An adverse impact of TCN on EDVs for childhood pneumonia was observed, and the magnitude of this impact increased from the first five years (2001-2005) to the second five years (2006-2010). Children aged 5-14 years, female children and Indigenous children were particularly vulnerable to TCN impact. However, there was no significant association between DTR and EDVs for childhood pneumonia. As climate change progresses, the days with unstable weather pattern are likely to increase. Parents and caregivers of children should be aware of the high risk of pneumonia posed by big TCN and take precautionary measures to protect children, especially those with a history of respiratory diseases, from climate impacts.

Smith G.,Queensland University of Technology
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the structure of the title complex, [Cs(C7H 4NO2)(H2O)2]n, the caesium salt of 4-nitrobenzoic acid, the irregular CsO9coordination sphere comprises three bridging nitro O-atom donors, a bidentate carboxylate O,O′-chelate interaction, a triple-bridging water molecule and a monodentate water molecule. A three-dimensional framework polymer is generated, within which there are water-carboxylate O-H⋯O and water-water O-H⋯O hydrogen-bonding interactions.

Smith G.,Queensland University of Technology
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the structure of the title complex, [Cs(C8H 4Cl3O2)(H2O)] n, the caesium salt of the commercial herbicide fenac [(2,3,6-trichlorophenyl)acetic acid], the irregular eight-coordination about Cs+ comprises a bidentate O:Cl-chelate interaction involving a carboxylate-O atom and an ortho-related ring-substituted Cl atom, which is also bridging, a triple-bridging carboxylate-O atom and a bridging water molecule. A two-dimensional polymer is generated, lying parallel to (100), within which there are water-carboxylate O-H⋯O hydrogen-bonding interactions.

Zhan H.F.,Queensland University of Technology | Gu Y.T.,Queensland University of Technology
Computational Materials Science | Year: 2012

Based on the AFM-bending experiments, a molecular dynamics (MD) bending simulation model is established which could accurately account for the full spectrum of the mechanical properties of NWs in a double clamped beam configuration, ranging from elasticity to plasticity and failure. It is found that, loading rate exerts significant influence to the mechanical behaviours of nanowires (NWs). Specifically, a loading rate lower than 10 m/s is found reasonable for a homogonous bending deformation. Both loading rate and potential between the tip and the NW are found to play an important role in the adhesive phenomenon. The force versus displacement (F-d) curve from MD simulation is highly consistent in shapes with that from experiments. Symmetrical F-d curves during loading and unloading processes are observed, which reveal the linear-elastic and non-elastic bending deformation of NWs. The typical bending induced tensile-compressive features are observed. Meanwhile, the simulation results are excellently fitted by the classical Euler-Bernoulli beam theory with axial effect. It is concluded that, axial tensile force becomes crucial in bending deformation when the beam size is down to nanoscale for double clamped NWs. In addition, we find shorter NWs will have an earlier yielding and a larger yielding force. Mechanical properties (Young's modulus and yield strength) obtained from both bending and tensile deformations are found comparable with each other. Specifically, the modulus is essentially similar under these two loading methods, while the yield strength during bending is observed larger than that during tension. © 2011 Elsevier B.V. All rights reserved.

Steindl R.J.,Queensland University of Technology
International Sugar Journal | Year: 2011

Fermentation feedstocks in the sugar industry are based on cane juice, B molasses or final molasses. Brazil has been producing ethanol by directing sugarcane juice to fermentation directly or using lower quality juice as a diluent with B molasses to prepare the fermentation broth. One issue that has received only limited interest particularly from outside Brazil is the most appropriate conditions for clarification of the juice going to fermentation. Irrespective of whether the juice supply is the total flow from the milling tandem or a diffuser station or a part of the total flow, removal of the insoluble solids is essential. However, the standard defecation process used by sugar factories around the world to clarify juice can introduce unwanted calcium ions and remove other nutrients such as phosphorus and nitrogen that are considered essential for the fermentation process. An investigation was undertaken by SRI to assess the effects on the constituents of cane juice when subjected to the typical clarification process in an Australian factory and what conditions would be needed to provide a clarified juice suitable for fermentation. Typical juices from one factory were clarified in laboratory trials under a range of pH conditions and the resulting clarified juices analysed. The results indicated that pH had a major effect on the residual concentrations of key constituents in the clarified juice and that the selected clarification conditions are determined by the nominated quality criteria of clarified juice feedstock for fermentation. Further trials were conducted in overseas factories to confirm the results obtained in Australia. It became apparent that the preferred specifications for clarified juice going to fermentation varied from country to country. Each supplier of fermentation technology had criteria applying to clarified juice feedstock that would have a major impact on the standard of clarification required to achieve compliance with the criteria.

Ni Y.,Nanchang University | Li S.,Nanchang University | Kokot S.,Queensland University of Technology
Food Chemistry | Year: 2011

The new simple, cost effective and well performing differential pulse stripping voltammetry method for the simultaneous determination of antibiotics - oxytetracycline, tetracycline and chlorotetracycline was researched and developed. It depends on the reduction of these compounds at a hanging mercury drop electrode. The samples were extracted from (i) spiked animal feed, and (ii) fresh fish muscle dosed with the drugs. The voltammograms from the drug mixture produced complex, overlapping profiles, and chemometrics methods were applied for calibration modelling. The analytical linear ranges were within 0.02-0.18μgmL-1 and the corresponding LODs were 3-5μgL-1 for the three analytes. These values compare well with those from the HPLC and fluorescence methods in the literature. The % relative prediction errors from the verification trials were between 4% and 9% with % Recoveries being 103-107. Also, the % Recoveries of the antibiotics from animal feeds as measured by the new method were comparable with those from the HPLC analysis (85%), i.e. the method is highly competitive, especially as a screening approach. © 2010 Elsevier Ltd.

Shukla A.,ABB | Ghosh A.,Queensland University of Technology | Joshi A.,Indian Institute of Technology Kanpur
IEEE Transactions on Industrial Electronics | Year: 2010

This paper proposes a flying-capacitor-based chopper circuit for dc capacitor voltage equalization in diode-clamped multilevel inverters. Its important features are reduced voltage stress across the chopper switches, possible reduction in the chopper switching frequency, improved reliability, and ride-through capability enhancement. This topology is analyzed using three- and four-level flying-capacitor-based chopper circuit configurations. These configurations are different in capacitor and semiconductor device count and correspondingly reduce the device voltage stresses by half and one-third, respectively. The detailed working principles and control schemes for these circuits are presented. It is shown that, by preferentially selecting the available chopper switch states, the dc-link capacitor voltages can be efficiently equalized in addition to having tightly regulated flying-capacitor voltages around their references. The various operating modes of the chopper are described along with their preferential selection logic to achieve the desired performances. The performance of the proposed chopper and corresponding control schemes are confirmed through both simulation and experimental investigations. © 2010 IEEE.

Light B.,Queensland University of Technology
First Monday | Year: 2016

I attend to two areas of increasing significance in relation to Web 2.0 since its announcement in 2005. The first is a focus on the non-human in digital media research, and the second is the normalisation of dating apps in society. Building upon ideas from speculative design and speculative method, I introduce the idea of speculative devices, those things that are set in place based on a conjecture of an outcome. Drawing upon a case study of Ashley Madison, generated using a walkthrough method and analysis of media coverage, I demonstrate how the speculative devices of bots and profiles can operate, and why. I argue we need to give careful thought to how our research and practice is understood, and conducted where speculative devices are concerned.

Martins C.,Norwegian University of Science and Technology | Kulseng B.,Norwegian University of Science and Technology | King N.A.,Queensland University of Technology | Holst J.J.,Copenhagen University | Blundell J.E.,University of Leeds
Journal of Clinical Endocrinology and Metabolism | Year: 2010

Context: The magnitude of exercise-induced weight loss depends on the extent of compensatory responses. An increase in energy intake is likely to result from changes in the appetite control system toward an orexigenic environment; however, few studies have measured how exercise impacts on both orexigenic and anorexigenic peptides. Objective: The aim of the study was to investigate the effects of medium-term exercise on fasting/postprandial levels of appetite-related hormones and subjective appetite sensations in overweight/ obese individuals. Design and Setting: We conducted a longitudinal study in a university research center. Participants and Intervention: Twenty-two sedentary overweight/obese individuals (age, 36.9 ± 8.3 yr; body mass index, 31.3 ± 3.3 kg/m2) took part in a 12-wk supervised exercise programme (five times per week, 75% maximal heart rate) and were requested not to change their food intake during the study. Main Outcome Measures: We measured changes in body weight and fasting/postprandial plasma levels of glucose, insulin, total ghrelin, acylated ghrelin (AG), peptide YY, and glucagon-like peptide-1 and feelings of appetite. Results: Exercise resulted in a significant reduction in body weight and fasting insulin and an increase in AG plasma levels and fasting hunger sensations. A significant reduction in postprandial insulin plasma levels and a tendency toward an increase in the delayed release of glucagon-like peptide-1 (90-180 min) were also observed after exercise, as well as a significant increase (127%) in the suppression of AG postprandially. Conclusions: Exercise-induced weight loss is associated with physiological and biopsychological changes toward an increased drive to eat in the fasting state. However, this seems to be balanced by an improved satiety response to a meal and improved sensitivity of the appetite control system. Copyright © 2010 by The Endocrine Society.

Krosch M.N.,Queensland University of Technology
Australian Journal of Entomology | Year: 2011

The eastern Australian rainforests have experienced several cycles of range contraction and expansion since the late Miocene that are closely correlated with global glaciation events. Together with ongoing aridification of the continent, this has resulted in current distributions of native closed forest that are highly fragmented along the east coast. Several closed forest endemic taxa exhibit patterns of population genetic structure that are congruent with historical isolation of populations in discrete refugia and reflect evolutionary histories dramatically affected by vicariance. Currently, limited data are available regarding the impact of these past climatic fluctuations on freshwater invertebrate taxa. The non-biting midge species Echinocladius martini Cranston is distributed along the east coast and inhabits predominantly montane streams in closed forest habitat. Phylogeographic structure in E. martini was resolved here at a continental scale by incorporating data from a previous pilot study and expanding the sampling design to encompass populations in the Wet Tropics of north-eastern Queensland, south-east Queensland, New South Wales and Victoria. Patterns of phylogeographic structure revealed several deeply divergent mitochondrial lineages from central and south-eastern Australia that were previously unrecognised and were geographically endemic to closed forest refugia. Estimated divergence times were congruent with late Miocene onset of rainforest contractions across the east coast of Australia. This suggested that dispersal and gene flow among E. martini populations isolated in refugia has been highly restricted historically. Moreover, these data imply, in contrast to existing preconceptions about freshwater invertebrates, that this taxon may be acutely susceptible to habitat fragmentation. © 2011 The Author; Journal compilation © 2011 Australian Entomological Society.

Chakraborty R.,Queensland University of Technology | Read S.A.,Queensland University of Technology | Collins M.J.,Queensland University of Technology
Investigative Ophthalmology and Visual Science | Year: 2011

Purpose. To investigate the pattern of diurnal variations in axial length (AL), choroidal thickness, intraocular pressure (IOP), and ocular biometrics over 2 consecutive days. Methods. Measurements of ocular biometrics and IOP were collected for 30 young adult subjects (15 myopes, 15 emmetropes) at 10 different times over 2 consecutive days. Five sets of measurements were collected each day at approximately 3-hour intervals, with the first measurement taken at ~9 AM and final measurement at ~9 PM. Results. AL underwent significant diurnal variation (P < 0.0001) that was consistently observed across the 2 measurement days. The longest AL was typically observed at the second measurement session (mean time, 12:26) and the shortest AL at the final session of each day (mean time, 21:06). The mean diurnal change in AL was 0.032 ± 0.018 mm. Choroidal thickness underwent significant diurnal variation (mean change, 0.029 ± 0.016 mm; P < 0.001) and varied approximately in antiphase to the AL changes. Significant diurnal variations were also found in vitreous chamber depth (VCD; mean change, 0.06 ± 0.029 mm; P < 0.0001) and IOP (mean change, 3.54 ± 0.84 mm Hg; P < 0.0001). A positive association was found between the variations of AL and IOP (r 2 = 0.17, P < 0.0001) and AL and VCD (r 2 = 0.31, P < 0.0001) and a negative association between AL and choroidal thickness (r 2 = 0.13, P < 0.0001). There were no significant differences in the magnitude and timing of diurnal variations associated with refractive error. Conclusions. Significant diurnal variations in AL, choroidal thickness, and IOP were consistently observed over 2 consecutive days of testing. © 2011 The Association for Research in Vision and Ophthalmology, Inc.

Phillips M.J.,Queensland University of Technology
Systematic Biology | Year: 2016

In modern evolutionary divergence analysis the role of geological information extends beyond providing a timescale, to informing molecular rate variation across the tree. Here I consider the implications of this development. I use fossil calibrations to test the accuracy of models of molecular rate evolution for placental mammals, and reveal substantial misspecification associated with life history rate correlates. Adding further calibrations to reduce dating errors at specific nodes unfortunately tends to transfer underlying rate errors to adjacent branches. Thus, tight calibration across the tree is vital to buffer against rate model errors. I argue that this must include allowing maximum bounds to be tight when good fossil records permit, otherwise divergences deep in the tree will tend to be inflated by the interaction of rate errors and asymmetric confidence in minimum and maximum bounds. In the case of placental mammals I sought to reduce the potential for transferring calibration and rate model errors across the tree by focusing on well-supported calibrations with appropriately conservative maximum bounds. The resulting divergence estimates are younger than others published recently, and provide the long-Anticipated molecular signature for the placental mammal radiation observed in the fossil record near the 66 Ma Cretaceous-Paleogene extinction event. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved.

While some existing carrying capacity methodologies offer significant insights into the assessment of population carrying capacities, a comprehensive model is yet to be developed. This research identifies, examines and compares a range of methodological approaches to carrying capacity assessment and considers their relevance to future spatial planning. A range of key criteria are employed to compare various existing carrying capacity assessment models. These criteria include integrated systems analysis, dynamic responses, levels of risk, systemic constraints, applicability to future planning and the consideration of regional boundary delineation. It is suggested that by combining successful components from various authors, and collecting a range of interconnected data, a practical and workable system-based model may be achievable in the future. © 2010 Elsevier Ltd.

Doggrell S.A.,Queensland University of Technology
Patient Preference and Adherence | Year: 2013

Type 2 diabetes remains an escalating problem worldwide, despite a range of treatments being available. The revelation that insulin secretion is under the control of a gut hormone, glucagon-like peptide 1, has led to a new paradigm in the management of type 2 diabetes, ie, use of medicines that directly stimulate or prolong the actions of endogenous glucagon-like peptide 1 at its receptors. Exenatide is an agonist at the glucagon-like peptide 1 receptor, and was initially developed as a subcutaneous medication twice daily (ExBID). Clinical trials with ExBID established a role for exenatide in the treatment of type 2 diabetes. Subsequently, exenatide once weekly (ExQW) was shown to have advantages over ExBID, and there is now more emphasis on the development of ExQW. ExQW alone reduces glycosylated hemoglobin (HbA1c) and body weight, and is well tolerated. ExQW has been compared with sitagliptin, pioglitazone, and metformin, and been shown to have a greater ability to reduce HbA1c than these other medicines. The only preparation of insulin with which ExQW has been compared is insulin glargine, and ExQW had some favorable properties in this comparison, notably causing weight loss compared with the weight gain on insulin glargine. ExQW has been compared with another glucagon-like peptide 1 receptor agonist, liraglutide, and was noninferior to liraglutide in reducing HbA1c. The small amount of evidence available shows that subjects with type 2 diabetes prefer ExQW to ExBID, and that adherence is high in the clinical trial setting. Health care and economic modeling suggests that ExQW will reduce diabetic complications and be cost-effective, compared with other medications, in long-term use. Little is known about whether subjects with type 2 diabetes prefer ExQW to other medicines, and whether adherence is good with ExQW in practice. These important topics require further study. © 2013 Doggrell, publisher and licensee Dove Medical Press Ltd.

Park Y.,Queensland University of Technology | Ayoko G.A.,Queensland University of Technology | Frost R.L.,Queensland University of Technology
Journal of Colloid and Interface Science | Year: 2011

Organoclays were synthesised through ion exchange of a single surfactant for sodium ions, and characterised by a range of method including X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The change in surface properties of montmorillonite and organoclays intercalated with the surfactant, tetradecyltrimethylammonium bromide (TDTMA) were determined using XRD through the change in basal spacing and the expansion occurred by the adsorbed p-nitrophenol. The changes of interlayer spacing were observed in TEM. In addition, the surface measurement such as specific surface area and pore volume was measured and calculated using BET method, this suggested the loaded surfactant is highly important to determine the sorption mechanism onto organoclays. The collected results of XPS provided the chemical composition of montmorillonite and organoclays, and the high-resolution XPS spectra offered the chemical states of prepared organoclays with binding energy. Using TGA and FT-IR, the confirmation of intercalated surfactant was investigated. The collected data from various techniques enable an understanding of the changes in structure and surface properties. This study is of importance to provide mechanisms for the adsorption of organic molecules, especially in contaminated environmental sites and polluted waters. © 2011 Elsevier Inc.

Park Y.,Queensland University of Technology | Ayoko G.A.,Queensland University of Technology | Frost R.L.,Queensland University of Technology
Journal of Colloid and Interface Science | Year: 2011

Water purification is imperative for the welfare of a healthy population. Water is widely contaminated by recalcitrant organic chemicals such a pesticides, herbicides and hormones. One inexpensive method for purifying water from these types of molecules is through adsorption. One suite of materials for this adsorption is based upon organoclays. This paper reviews the adsorption of organics on organoclays. © 2010 Elsevier Inc.

Milford M.J.,Queensland University of Technology | Wiles J.,Queensland University of Technology | Wyeth G.F.,Queensland University of Technology
PLoS Computational Biology | Year: 2010

To successfully navigate their habitats, many mammals use a combination of two mechanisms, path integration and calibration using landmarks, which together enable them to estimate their location and orientation, or pose. In large natural environments, both these mechanisms are characterized by uncertainty: the path integration process is subject to the accumulation of error, while landmark calibration is limited by perceptual ambiguity. It remains unclear how animals form coherent spatial representations in the presence of such uncertainty. Navigation research using robots has determined that uncertainty can be effectively addressed by maintaining multiple probabilistic estimates of a robot's pose. Here we show how conjunctive grid cells in dorsocaudal medial entorhinal cortex (dMEC) may maintain multiple estimates of pose using a brain-based robot navigation system known as RatSLAM. Based both on rodent spatially-responsive cells and functional engineering principles, the cells at the core of the RatSLAM computational model have similar characteristics to rodent grid cells, which we demonstrate by replicating the seminal Moser experiments. We apply the RatSLAM model to a new experimental paradigm designed to examine the responses of a robot or animal in the presence of perceptual ambiguity. Our computational approach enables us to observe short-term population coding of multiple location hypotheses, a phenomenon which would not be easily observable in rodent recordings. We present behavioral and neural evidence demonstrating that the conjunctive grid cells maintain and propagate multiple estimates of pose, enabling the correct pose estimate to be resolved over time even without uniquely identifying cues. While recent research has focused on the grid-like firing characteristics, accuracy and representational capacity of grid cells, our results identify a possible critical and unique role for conjunctive grid cells in filtering sensory uncertainty. We anticipate our study to be a starting point for animal experiments that test navigation in perceptually ambiguous environments. © 2010 Milford et al.

Cheung A.,Queensland University of Technology | Vickerstaff R.,Agresearch Ltd.
PLoS Computational Biology | Year: 2010

Successful navigation is fundamental to the survival of nearly every animal on earth, and achieved by nervous systems of vastly different sizes and characteristics. Yet surprisingly little is known of the detailed neural circuitry from any species which can accurately represent space for navigation. Path integration is one of the oldest and most ubiquitous navigation strategies in the animal kingdom. Despite a plethora of computational models, from equational to neural network form, there is currently no consensus, even in principle, of how this important phenomenon occurs neurally. Recently, all path integration models were examined according to a novel, unifying classification system. Here we combine this theoretical framework with recent insights from directed walk theory, and develop an intuitive yet mathematically rigorous proof that only one class of neural representation of space can tolerate noise during path integration. This result suggests many existing models of path integration are not biologically plausible due to their intolerance to noise. This surprising result imposes significant computational limitations on the neurobiological spatial representation of all successfully navigating animals, irrespective of species. Indeed, noise-tolerance may be an important functional constraint on the evolution of neuroarchitectural plans in the animal kingdom. © 2010 Cheung, Vickerstaff.

Efron N.,Queensland University of Technology
Contact Lens and Anterior Eye | Year: 2010

Scleral and corneal rigid lenses represented 100 per cent of the contact lens market immediately prior to the invention of soft lenses in the mid-1960s. In the United Kingdom today, rigid lenses comprise 2 per cent of all new lens fits. Low rates of rigid lens fitting are also apparent in 27 other countries which have recently been surveyed. Thus, the 1998 prediction of the author that rigid lenses - also referred to as 'rigid gas permeable' (RGP) lenses or 'gas permeable' (GP) lenses - would be obsolete by the year 2010 has essentially turned out to be correct. In this obituary, the author offers 10 reasons for the demise of rigid lens fitting: initial rigid lens discomfort; intractable rigid lens-induced corneal and lid pathology; extensive soft lens advertising; superior soft lens fitting logistics; lack of rigid lens training opportunities; redundancy of the rigid lens 'problem solver' function; improved soft toric and bifocal/varifocal lenses; limited uptake of orthokeratology; lack of investment in rigid lenses; and the emergence of aberration control soft lenses. Rigid lenses are now being fitted by a minority of practitioners with specialist skills/training. Certainly, rigid lenses can no longer be considered as a mainstream form of contact lens correction. May their dear souls (bulk properties) rest in peace. © 2010 British Contact Lens Association.

Guo Y.,Queensland University of Technology | Punnasiri K.,Queensland University of Technology | Tong S.,Queensland University of Technology
Environmental Health: A Global Access Science Source | Year: 2012

Background: The association between temperature and mortality has been examined mainly in North America and Europe. However, less evidence is available in developing countries, especially in Thailand. In this study, we examined the relationship between temperature and mortality in Chiang Mai city, Thailand, during 1999-2008. Method. A time series model was used to examine the effects of temperature on cause-specific mortality (non-external, cardiopulmonary, cardiovascular, and respiratory) and age-specific non-external mortality (<=64, 65-74, 75-84, and>=85years), while controlling for relative humidity, air pollution, day of the week, season and long-term trend. We used a distributed lag non-linear model to examine the delayed effects of temperature on mortality up to 21days. Results: We found non-linear effects of temperature on all mortality types and age groups. Both hot and cold temperatures resulted in immediate increase in all mortality types and age groups. Generally, the hot effects on all mortality types and age groups were short-term, while the cold effects lasted longer. The relative risk of non-external mortality associated with cold temperature (19.35°C, 1st percentile of temperature) relative to 24.7°C (25th percentile of temperature) was 1.29 (95% confidence interval (CI): 1.16, 1.44) for lags 0-21. The relative risk of non-external mortality associated with high temperature (31.7°C, 99 th percentile of temperature) relative to 28°C (75th percentile of temperature) was 1.11 (95% CI: 1.00, 1.24) for lags 0-21. Conclusion: This study indicates that exposure to both hot and cold temperatures were related to increased mortality. Both cold and hot effects occurred immediately but cold effects lasted longer than hot effects. This study provides useful data for policy makers to better prepare local responses to manage the impact of hot and cold temperatures on population health. © 2012 Guo et al.; licensee BioMed Central Ltd.

Grigg N.L.,Queensland University of Technology | Wearing S.C.,Bond University | Wearing S.C.,Queensland Academy of Sport | Smeathers J.E.,Queensland University of Technology
Medicine and Science in Sports and Exercise | Year: 2012

PURPOSE: Eccentric exercise has become the treatment of choice for Achilles tendinopathy. However, little is known about the acute response of tendons to eccentric exercise or the mechanisms underlying its clinical benefit. This research evaluated the sonographic characteristics and acute anteroposterior (AP) strain response of control (healthy), asymptomatic, and symptomatic Achilles tendons to eccentric exercise. METHODS: Eleven male adults with unilateral midportion Achilles tendinopathy and nine control male adults without tendinopathy participated in the research. Sagittal sonograms of the Achilles tendon were acquired immediately before and after completion of a common eccentric rehabilitation exercise protocol and again 24 h later. Tendon thickness, echogenicity, and AP strain were determined 40 mm proximal to the calcaneal insertion. RESULTS: Compared with the control tendon, both the asymptomatic and symptomatic tendons were thicker (P < 0.05) and hypoechoic (P < 0.05) at baseline. All tendons decreased in thickness immediately after eccentric exercise (P < 0.05). The symptomatic tendon was characterized by a significantly lower AP strain response to eccentric exercise compared with both the asymptomatic and control tendons (P < 0.05). AP strains did not differ in the control and asymptomatic tendons. For all tendons, preexercise thickness was restored 24 h after exercise completion. CONCLUSIONS: These observations support the concept that Achilles tendinopathy is a bilateral or systemic process and structural changes associated with symptomatic tendinopathy alter fluid movement within the tendon matrix. Altered fluid movement may disrupt remodeling and homeostatic processes and represents a plausible mechanism underlying the progression of tendinopathy.

Baade P.D.,Viertel Center for Research in Cancer Control | Youlden D.R.,Queensland University of Technology | Chambers S.K.,Griffith University
Medical Journal of Australia | Year: 2011

Objective: To report the latest conditional survival estimates for patients with cancer in Queensland, Australia. Design, setting and participants: Descriptive study of state-wide population-based data from the Queensland Cancer Registry on patients aged 15-89 years who were diagnosed with invasive cancer between 1982 and 2007. Main outcome measure: Conditional 5-year relative survival for the 13 most common types of invasive cancer, and all cancers combined. Results: The prognosis for patients with cancer generally improves with each additional year that they survive. A significant excess in mortality compared with the general population ceases to occur within 10 years after diagnosis for survivors of stomach, colorectal, cervical and thyroid cancer and melanoma, with these groups having a conditional 5-year relative survival of at least 95% after 10 years. For the remaining cancers we studied (pancreatic, lung, breast, prostate, kidney, and bladder cancer, non-Hodgkin lymphoma, and leukaemia), conditional 5-year relative survival estimates (at 10 years after diagnosis) ranged from 82% to 94%, suggesting that patients in these cohorts continue to have poorer survival compared with the age-matched general population. Conclusions: Estimates of conditional survival have the potential to provide useful information for cancer clinicians, patients and their carers as they are confronted by personal and surveillance-related decisions. This knowledge may be effective in building realistic hope and helping people manage uncertainty about the future. We suggest that measures of conditional survival be incorporated into routine statistical reporting in Australia.

Zuccon G.,Queensland University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Although relevance is known to be a multidimensional concept, information retrieval measures mainly consider one dimension of relevance: topicality. In this paper we propose a method to integrate multiple dimensions of relevance in the evaluation of information retrieval systems. This is done within the gain-discount evaluation framework, which underlies measures like rank-biased precision (RBP), cumulative gain, and expected reciprocal rank. Albeit the proposal is general and applicable to any dimension of relevance, we study specific instantiations of the approach in the context of evaluating retrieval systems with respect to both the topicality and the understandability of retrieved documents. This leads to the formulation of understandability biased evaluation measures based on RBP. We study these measures using both simulated experiments and real human assessments. The findings show that considering both understandability and topicality in the evaluation of retrieval systems leads to claims about system effectiveness that differ from those obtained when considering topicality alone. © Springer International Publishing Switzerland 2016.

Prasadam I.,Queensland University of Technology
Journal of molecular medicine (Berlin, Germany) | Year: 2013

We hypothesised that a potentially disease-modifying osteoarthritis (OA) drug such as hyaluronic acid (HA) given in combination with anti-inflammatory signalling agents such as mitogen-activated protein kinase kinase-extracellular signal-regulated kinase (MEK-ERK) signalling inhibitor (U0126) could result in additive or synergistic effects on preventing the degeneration of articular cartilage. Chondrocyte differentiation and hypertrophy were evaluated using human OA primary cells treated with either HA or U0126, or the combination of HA + U0126. Cartilage degeneration in menisectomy (MSX) induced rat OA model was investigated by intra-articular delivery of either HA or U0126, or the combination of HA + U0126. Histology, immunostaining, RT-qPCR, Western blotting and zymography were performed to assess the expression of cartilage matrix proteins and hypertrophic markers. Phosphorylated ERK (pERK)1/2-positive chondrocytes were significantly higher in OA samples compared with those in healthy control suggesting the pathological role of that pathway in OA. It was noted that HA + U0126 significantly reduced the levels of pERK, chondrocyte hypertrophic markers (COL10 and RUNX2) and degenerative markers (ADAMTs5 and MMP-13), however, increased the levels of chondrogenic markers (COL2) compared to untreated or the application of HA or U0126 alone. In agreement with the results in vitro, intra-articular delivery of HA + U0126 showed significant therapeutic improvement of cartilage in rat MSX OA model compared with untreated or the application of HA or U0126 alone. Our study suggests that the combination of HA and MEK-ERK inhibition has a synergistic effect on preventing cartilage degeneration.

Doggrell S.A.,Queensland University of Technology
Expert Opinion on Drug Safety | Year: 2015

Several new medicines are in development for the treatment of type 2 diabetes, and cardiovascular outcome trials are the gold standard for these medicines. This editorial demonstrates that despite being available for over 10 years, there are no cardiovascular outcome studies for any of the glucagon-like peptide-1 receptor agonists, which demonstrate cardiovascular safety or benefit in subjects with high cardiovascular risk. The author argues that the FDA should be ensuring that clinical outcome studies for subjects with type 2 diabetes and high cardiovascular risk be undertaken in a timelier manner. © 2015 Informa UK, Ltd.

Hopkins M.,University of Leeds | Blundell J.E.,University of Leeds | King N.A.,Queensland University of Technology
British Journal of Sports Medicine | Year: 2014

Background While compensatory eating following acute aerobic exercise is highly variable, little is known about the underlying mechanisms that contribute to the alterations in exercise-induced eating behaviour. Methods Overweight and obese women (body mass index=29.6±4.0 kg/m2) performed a bout of cycling individually tailored to expend 400 kcal (EX) or a timematched no exercise control condition in a randomised, counter-balanced order. 60 min after the cessation of exercise, an ad libitum test meal was provided. Substrate oxidation and subjective appetite ratings were measured during exercise/time-matched rest, and during the period between the cessation of exercise and food consumption. Results While ad libitum energy intake (EI) did not differ between EX and the control condition (666.0 ±203.9 vs 664.6±174.4 kcal, respectively; ns), there was a marked individual variability in compensatory EI. The difference in EI between EX and the control condition ranged from -234.3 to 278.5 kcal. Carbohydrate oxidation during exercise was positively associated with postexercise EI, accounting for 37% of the variance in EI (r=0.57; p=0.02). Conclusions These data indicate that the capacity of acute exercise to create a short-term energy deficit in overweight and obese women is highly variable. Furthermore, exercise-induced CHO oxidation can explain a part of the variability in acute exercise-induced compensatory eating. Postexercise compensatory eating could serve as an adaptive response to facilitate the restoration of carbohydrate balance.

Hayes I.J.,Queensland University of Technology
Formal Aspects of Computing | Year: 2016

The rely-guarantee technique allows one to reason compositionally about concurrent programs. To handle interference the technique makes use of rely and guarantee conditions, both of which are binary relations on states. A rely condition is an assumption that the environment performs only atomic steps satisfying the rely relation and a guarantee is a commitment that every atomic step the program makes satisfies the guarantee relation. In order to investigate rely-guarantee reasoning more generally, in this paper we allow interference to be represented by a process rather than a relation and hence derive more general rely-guarantee laws. The paper makes use of a weak conjunction operator between processes, which generalises a guarantee relation to a guarantee process, and introduces a rely quotient operator, which generalises a rely relation to a process. The paper focuses on the algebraic properties of the general rely-guarantee theory. The Jones-style rely-guarantee theory can be interpreted as a model of the general algebraic theory and hence the general laws presented here hold for that theory. © 2016 British Computer Society

Jimmieson N.L.,Queensland University of Technology
Journal of Occupational and Environmental Medicine | Year: 2016

OBJECTIVE:: This research undertook a time-ordered investigation of Australian employees in regards to their experiences of change in psychosocial work factors across time (decreases, increases, or no change) in the prediction of psychological, physical, attitudinal, and behavioral employee strain. METHODS:: Six hundred and ten employees from 17 organizations participated in Time 1 and Time 2 psychosocial risk assessments (average time lag of 16.7 months). Multi-level regressions examined the extent to which change in exposure to six demands and four resources predicted employee strain at follow-up, after controlling for baseline employee strain. RESULTS:: Increases in demands and decreases in resources exacerbated employee strain, but even constant moderate demands and resources resulted in poor employee outcomes, not just constant high or low exposure, respectively. CONCLUSIONS:: These findings can help employers prioritize hazards, and guide tailored psychosocial organizational interventions. Copyright © 2016 by the American College of Occupational and Environmental Medicine

Fawzia S.,Queensland University of Technology
Composite Structures | Year: 2013

Advanced composite materials offer remarkable potential in the strengthening of Civil Engineering structures. This research is targeted to provide in depth knowledge and understanding of bond characteristics of advanced and corrosion resistant material carbon fibre reinforced polymer (CFRP) that has a unique design tailor-ability and cost effective nature. The objective of this research is to investigate and compare the bonding mechanism between CFRP strengthened single and double strap steel joints. Investigations have been made in regards to failure mode, ultimate load and effective bond length for CFRP strengthened double and single strap joints. A series of tensile tests were conducted with different bond lengths for both type of joints. The bond behaviour of these specimens was further investigated by using nonlinear finite element analysis. Finally a bilinear relationship of shear stress-slip has been proposed by using the Finite element model for single and double strap joints. © 2013 Elsevier Ltd.

Gunalan S.,Queensland University of Technology | Mahendran M.,Queensland University of Technology
Journal of Constructional Steel Research | Year: 2013

Traditionally the fire resistance rating of LSF wall systems is based on approximate prescriptive methods developed using limited fire tests. Therefore a detailed research study into the performance of load bearing LSF wall systems under standard fire conditions was undertaken to develop improved fire design rules. It used the extensive fire performance results of eight different LSF wall systems from a series of full scale fire tests and numerical studies for this purpose. The use of previous fire design rules developed for LSF walls subjected to non-uniform elevated temperature distributions based on AISI design manual and Eurocode3 Parts 1.2 and 1.3 was investigated first. New simplified fire design rules based on AS/NZS 4600, North American Specification and Eurocode 3 Part 1.3 were then proposed in this study with suitable allowances for the interaction effects of compression and bending actions. The importance of considering thermal bowing, magnified thermal bowing and neutral axis shift in the fire design was also investigated. A spread sheet based design tool was developed based on the new design rules to predict the failure load ratio versus time and temperature curves for varying LSF wall configurations. The accuracy of the proposed design rules was verified using the test and FEA results for different wall configurations, steel grades, thicknesses and load ratios. This paper presents the details and results of this study including the improved fire design rules for predicting the load capacity of LSF wall studs and the failure times of LSF walls under standard fire conditions. © 2013 Elsevier Ltd.

Veldman S.L.,Queensland University of Technology
Composite Structures | Year: 2013

The wing and tail of an aircraft typically consist of a stiffened skin, combined with ribs and spars. This arrangement divides the skin into rectangular pocket. These pockets may be designed for over a thousand different load cases so it is important to understand the interaction between load combinations in order to asses which load cases are critical. Buckling interaction curves are well known for isotropic materials but not for anisotropic materials. This paper presents approximate buckling interaction curves for anisotropic plates. A comparison between eigenvalues derived using the approximate method and finite element method is made and it is shown that both methods correlate well. © 2013 Elsevier Ltd.

Keerthan P.,Queensland University of Technology | Mahendran M.,Queensland University of Technology
Fire Technology | Year: 2013

In recent times, light gauge steel frame (LSF) wall systems are increasingly used in the building industry. They are usually made of cold-formed and thin-walled steel studs that are fire-protected by two layers of plasterboard on both sides. A composite LSF wall panel system was developed recently, where an insulation layer was used externally between the two plasterboards to improve the fire performance of LSF wall panels. In this research, finite element thermal models of the new composite panels were developed using a finite element program, SAFIR, to simulate their thermal performance under both standard and Eurocode design fire curves. Suitable apparent thermal properties of both the gypsum plasterboard and insulation materials were proposed and used in the numerical models. The developed models were then validated by comparing their results with available standard fire test results of composite panels. This paper presents the details of the finite element models of composite panels, the thermal analysis results in the form of time-temperature profiles under standard and Eurocode design fire curves and their comparisons with fire test results. Effects of using rockwool, glass fibre and cellulose fibre insulations with varying thickness and density were also investigated, and the results are presented in this paper. The results show that the use of composite panels in LSF wall systems will improve their fire rating, and that Eurocode design fires are likely to cause severe damage to LSF walls than standard fires. © 2012 Springer Science+Business Media, LLC.

Keerthan P.,Queensland University of Technology | Mahendran M.,Queensland University of Technology
Journal of Constructional Steel Research | Year: 2013

LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a simultaneous cold-forming and dual electric resistance welding process. It is commonly used as floor joists and bearers with web openings in residential, industrial and commercial buildings. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. A cost effective method of eliminating the detrimental effects of a large web opening is to attach suitable stiffeners around the web openings of LSBs. Experimental and numerical studies were undertaken to investigate the shear behavior and strength of LSBs with circular web openings reinforced using plate, stud, transverse and sleeve stiffeners with varying sizes and thicknesses. Both welding and varying screw-fastening arrangements were used to attach these stiffeners to the web of LSBs. Finite element models of LSBs with stiffened web openings in shear were developed to simulate their shear behavior and strength of LSBs. They were then validated by comparing the results with experimental test results and used in a detailed parametric study. These studies have shown that plate stiffeners were the most suitable, however, their use based on the current American standards was found to be inadequate. Suitable screw-fastened plate stiffener arrangements with optimum thicknesses have been proposed for LSBs with web openings to restore their original shear capacity. This paper presents the details of the numerical study and the results. © 2012 Elsevier Ltd. All rights reserved.

Bandula Heva Y.,Queensland University of Technology | Mahendran M.,Queensland University of Technology
Steel and Composite Structures | Year: 2013

Current design standards do not provide adequate guidelines for the fire design of cold-formed steel compression members subject to flexural-torsional buckling. Eurocode 3 Part 1.2 (2005) recommends the same fire design guidelines for both hot-rolled and cold-formed steel compression members subject to flexural-torsional buckling although considerable behavioural differences exist between cold-formed and hot-rolled steel members. Past research has recommended the use of ambient temperature cold-formed steel design rules for the fire design of cold-formed steel compression members provided appropriately reduced mechanical properties are used at elevated temperatures. To assess the accuracy of flexural-torsional buckling design rules in both ambient temperature cold-formed steel design and fire design standards, an experimental study of slender cold-formed steel compression members was undertaken at both ambient and elevated temperatures. This paper presents the details of this experimental study, its results, and their comparison with the predictions from the current design rules. It was found that the current ambient temperature design rules are conservative while the fire design rules are overly conservative. Suitable recommendations have been made in relation to the currently available design rules for flexural-torsional buckling including methods of improvement. Most importantly, this paper has addressed the lack of experimental results for slender cold-formed steel columns at elevated temperatures. Copyright © 2013 Techno Press.

Ni Y.,Nanchang University | Xia Z.,Nanchang University | Kokot S.,Queensland University of Technology
Journal of Hazardous Materials | Year: 2011

A novel kinetic spectrophotometric method was developed for determination of pyrocatechol, resorcin, hydroquinone and phenol based on their inhibitory effect on the oxidation of Rhodamine B (RhB) in acid medium at pH=3.0. A linear relationship was observed between the inhibitory effect and the concentrations of the compounds. The absorbance associated with the kinetic reactions was monitored at the maximum wavelength of 557nm. The effects of different parameters such as pH, concentration of RhB and KBrO3, and temperature of the reaction were investigated and optimum conditions were established. The linear ranges were 0.22-3.30, 0.108-0.828, 0.36-3.96 and 1.52-19.76μgmL-1 for pyrocatechol, resorcin, hydroquinone and phenol, respectively, and their corresponding detection limits were 0.15, 0.044, 0.16 and 0.60μgmL-1. The measured data were processed by several chemometrics methods, such as principal component regression (PCR), partial least squares (PLS) and artificial neural network (ANN), and a set of synthetic mixtures of these compounds was used to verify the established models. It was found that the prediction ability of PLS, PCR and RBF-ANN was similar, however, the RBF-ANN model did perform somewhat better than the other methods. The proposed method was also applied satisfactorily for the simultaneous determination of pyrocatechol, resorcin, hydroquinone and phenol in real water samples. © 2011 Elsevier B.V.

Loessner D.,Queensland University of Technology | Paige Little J.,Queensland University of Technology | Pettet G.J.,Queensland University of Technology | Hutmacher D.W.,Queensland University of Technology
Journal of Cell Science | Year: 2013

Computational models represent a highly suitable framework, not only for testing biological hypotheses and generating new ones but also for optimising experimental strategies. As one surveys the literature devoted to cancer modelling, it is obvious that immense progress has been made in applying simulation techniques to the study of cancer biology, although the full impact has yet to be realised. For example, there are excellent models to describe cancer incidence rates or factors for early disease detection, but these predictions are unable to explain the functional and molecular changes that are associated with tumour progression. In addition, it is crucial that interactions between mechanical effects, and intracellular and intercellular signalling are incorporated in order to understand cancer growth, its interaction with the extracellular microenvironment and invasion of secondary sites. There is a compelling need to tailor new, physiologically relevant in silico models that are specialised for particular types of cancer, such as ovarian cancer owing to its unique route of metastasis, which are capable of investigating anti-cancer therapies, and generating both qualitative and quantitative predictions. This Commentary will focus on how computational simulation approaches can advance our understanding of ovarian cancer progression and treatment, in particular, with the help of multicellular cancer spheroids, and thus, can inform biological hypothesis and experimental design. © 2013 Published by The Company of Biologists Ltd.

Banu S.,Queensland University of Technology | Hu W.,University of Queensland | Hurst C.,Queensland University of Technology | Tong S.,Queensland University of Technology
Tropical Medicine and International Health | Year: 2011

Objective To review the scientific evidence about the impact of climate change and socio-environmental factors on dengue transmission, particularly in the Asia-Pacific region. Methods Search of the published literature on PubMed, ISI web of Knowledge and Google Scholar. Articles were included if an association between climate or socio-environmental factors and dengue transmission was assessed in any country of the Asia-Pacific region. Results Twenty-two studies met the inclusion criteria. The weight of the evidence indicates that global climate change is likely to affect the seasonal and geographical distribution of dengue fever (DF) in the Asia-Pacific region. However, empirical evidence linking DF to climate change is inconsistent across geographical locations and absent in some countries where dengue is endemic. Conclusion Even though climate change may play an increasing role in the transmission of DF, no clear evidence shows that such impact has already occurred. More research is needed across countries to better understand the relationship between climate change and dengue transmission. Future research should also consider and adjust for the influence of important socio-environmental factors in the assessment of the climate change-related effects on dengue transmission. © 2011 Blackwell Publishing Ltd.

Bruza P.D.,Queensland University of Technology | Wang Z.,Ohio State University | Busemeyer J.R.,Indiana University
Trends in Cognitive Sciences | Year: 2015

What type of probability theory best describes the way humans make judgments under uncertainty and decisions under conflict? Although rational models of cognition have become prominent and have achieved much success, they adhere to the laws of classical probability theory despite the fact that human reasoning does not always conform to these laws. For this reason we have seen the recent emergence of models based on an alternative probabilistic framework drawn from quantum theory. These quantum models show promise in addressing cognitive phenomena that have proven recalcitrant to modeling by means of classical probability theory. This review compares and contrasts probabilistic models based on Bayesian or classical versus quantum principles, and highlights the advantages and disadvantages of each approach. © 2015 Elsevier Ltd.

Visser T.A.W.,University of Queensland | Ohan J.L.,Queensland University of Technology
PLoS ONE | Year: 2012

Background: When observers are asked to identify two targets in rapid sequence, they often suffer profound performance deficits for the second target, even when the spatial location of the targets is known. This attentional blink (AB) is usually attributed to the time required to process a previous target, implying that a link should exist between individual differences in information processing speed and the AB. Methodology/Principal Findings: The present work investigated this question by examining the relationship between a rapid automatized naming task typically used to assess information-processing speed and the magnitude of the AB. The results indicated that faster processing actually resulted in a greater AB, but only when targets were presented amongst high similarity distractors. When target-distractor similarity was minimal, processing speed was unrelated to the AB. Conclusions/Significance: Our findings indicate that information-processing speed is unrelated to target processing efficiency per se, but rather to individual differences in observers' ability to suppress distractors. This is consistent with evidence that individuals who are able to avoid distraction are more efficient at deploying temporal attention, but argues against a direct link between general processing speed and efficient information selection. © 2012 Visser, Ohan.

Swedberg J.E.,Queensland University of Technology | Harris J.M.,Queensland University of Technology
Biochemistry | Year: 2011

Perioperative bleeding is a cause of major blood loss and is associated with increased rates of postoperative morbidity and mortality. To combat this, antifibrinolytic inhibitors of the serine protease plasmin are commonly used to reduce bleeding during surgery. The most effective and previously widely used of these is the broad range serine protease inhibitor aprotinin. However, adverse clinical outcomes have led to use of alternative serine lysine analogues to inhibit plasmin. These compounds suffer from low selectivity and binding affinity. Consequently, a concerted effort to discover potent and selective plasmin inhibitors has developed. This study used a noncombinatorial peptide library to define plasmins extended substrate specificity and guide the design of potent transition state analogue inhibitors. The various substrate binding sites of plasmin were found to exhibit a higher degree of cooperativity than had previously been appreciated. Peptide sequences capitalizing on these features produced high-affinity inhibitors of plasmin. The most potent of these, Lys-Met(sulfone)-Tyr-Arg-H [KM(O 2)YR-H], inhibited plasmin with a K i of 3.1 nM while maintaining 25-fold selectivity over plasma kallikrein. Furthermore, 125 nM (0.16 μg/mL) KM(O 2)YR-H attenuated fibrinolysis in vitro with an efficacy similar to that of 15 nM (0.20 μg/mL) aprotinin. To date, this is the most potent peptide inhibitor of plasmin that exhibits selectivity against plasma kallikrein, making this compound an attractive candidate for further therapeutic development. © 2011 American Chemical Society.

Soole D.W.,Queensland University of Technology | Watson B.C.,Queensland University of Technology | Fleiter J.J.,Queensland University of Technology
Accident Analysis and Prevention | Year: 2013

Average speed enforcement is a relatively new approach gaining popularity throughout Europe and Australia. This paper reviews the evidence regarding the impact of this approach on vehicle speeds, crash rates and a number of additional road safety and public health outcomes. The economic and practical viability of the approach as a road safety countermeasure is also explored. A literature review, with an international scope, of both published and grey literature was conducted. There is a growing body of evidence to suggest a number of road safety benefits associated with average speed enforcement, including high rates of compliance with speed limits, reductions in average and 85th percentile speeds and reduced speed variability between vehicles. Moreover, the approach has been demonstrated to be particularly effective in reducing excessive speeding behaviour. Reductions in crash rates have also been reported in association with average speed enforcement, particularly in relation to fatal and serious injury crashes. In addition, the approach has been shown to improve traffic flow, reduce vehicle emissions and has also been associated with high levels of public acceptance. Average speed enforcement offers a greater network-wide approach to managing speeds that reduces the impact of time and distance halo effects associated with other automated speed enforcement approaches. Although comparatively expensive it represents a highly reliable approach to speed enforcement that produces considerable returns on investment through reduced social and economic costs associated with crashes. © 2013 Elsevier Ltd. All rights reserved.

Blackman R.A.,Queensland University of Technology | Haworth N.L.,Queensland University of Technology
Accident Analysis and Prevention | Year: 2013

The increased popularity of mopeds and motor scooters in Australia and elsewhere in the last decade has contributed substantially to the greater use of powered two-wheelers (PTWs) as a whole. As the exposure of mopeds and scooters has increased, so too has the number of reported crashes involving those PTW types, but there is currently little research comparing the safety of mopeds and, particularly, larger scooters with motorcycles. This study compared the crash risk and crash severity of motorcycles, mopeds and larger scooters in Queensland, Australia. Comprehensive data cleansing was undertaken to separate motorcycles, mopeds and larger scooters in police-reported crash data covering the five years to 30 June 2008. The crash rates of motorcycles (including larger scooters) and mopeds in terms of registered vehicles were similar over this period, although the moped crash rate showed a stronger downward trend. However, the crash rates in terms of distance travelled were nearly four times higher for mopeds than for motorcycles (including larger scooters). More comprehensive distance travelled data is needed to confirm these findings. The overall severity of moped and scooter crashes was significantly lower than motorcycle crashes but an ordered probit regression model showed that crash severity outcomes related to differences in crash characteristics and circumstances, rather than differences between PTW types per se. Greater motorcycle crash severity was associated with higher (>80 km/h) speed zones, horizontal curves, weekend, single vehicle and nighttime crashes. Moped crashes were more severe at night and in speed zones of 90 km/h or more. Larger scooter crashes were more severe in 70 km/h zones (than 60 km/h zones) but not in higher speed zones, and less severe on weekends than on weekdays. The findings can be used to inform potential crash and injury countermeasures tailored to users of different PTW types. © 2013 Elsevier Ltd. All rights reserved.

Gildersleeve M.J.,Queensland University of Technology
IEEE Pulse | Year: 2013

Current research investigating human performance in surgical robotics is dominated by the use of third-person methods, i.e., the research relies primarily on experimental methods over first-person or experiential methods. Although one cannot deny the many results obtained using this line of inquiry, recent research has unfortunately overlooked the phenomenological element of human?robot interaction. By disregarding subjectivity and first-person point of view, current research analyzing surgical performance ignores one fundamental characteristic: the mental activity leading to the observed behavior captured by thirdperson methods, including attempts to explain what is happening inside the minds of surgeons when using robotics. Yet, the integration of first-and third-person data within the context of surgical performance offers the potential for a more rigorous and refined understanding of this area of study. © 2010-2012 IEEE.

Kim Y.R.,University of Queensland | Harden F.A.,Queensland University of Technology | Toms L.M.L.,Queensland University of Technology | Norman R.E.,University of Queensland
Chemosphere | Year: 2014

Background: Brominated flame retardants (BFRs), are chemicals widely used in consumer products including electronics, vehicles, plastics and textiles to reduce flammability. Experimental animal studies have confirmed that these compounds may interfere with thyroid hormone homeostasis and neurodevelopment but to date health effects in humans have not been systematically examined. Objectives: To conduct a systematic review of studies on the health impacts of exposure to BFRs in humans, with a particular focus on children. Methods: A systematic review was conducted using the MEDLINE and EMBASE electronic databases up to 1 February 2012. Published cohort, cross-sectional, and case-control studies exploring the relationship between BFR exposure and various health outcomes were included. Results: In total, 36 epidemiological studies meeting the pre-determined inclusion criteria were included. Plausible outcomes associated with BFR exposure include diabetes, neurobehavioral and developmental disorders, cancer, reproductive health effects and alteration in thyroid function. Evidence for a causal relationship between exposure to BFRs and health outcomes was evaluated within the Bradford Hill framework. Conclusion: Although there is suggestive evidence that exposure to BFRs is harmful to health, further epidemiological investigations particularly among children, and long-term monitoring and surveillance of chemical impacts on humans are required to confirm these relationships. © 2014 Elsevier Ltd.

Rouzikhah H.,Queensland University of Technology | King M.,Queensland University of Technology | Rakotonirainy A.,Queensland University of Technology
Accident Analysis and Prevention | Year: 2013

This paper examines the effects of an eco-driving message on driver distraction. Two in-vehicle distracter tasks were compared with an eco-driving task and a baseline task in an advanced driving simulator. N = 22 subjects were asked to perform an eco-driving, CD changing, and a navigation task while engaged in critical manoeuvres during which they were expected to respond to a peripheral detection task (PDT) with total duration of 3.5 h. The study involved two sessions over two consecutive days. The results show that drivers' mental workloads are significantly higher during navigation and CD changing tasks in comparison to the two other scenarios. However, eco-driving mental workload is still marginally significant (p ∼.05) across different manoeuvres. Similarly, event detection tasks show that drivers miss significantly more events in the navigation and CD changing scenarios in comparison to both the baseline and eco-driving scenario. Analysis of the practice effect shows that drivers' baseline scenario and navigation scenario exhibit significantly less demand on the second day. Drivers also can detect significantly more events on the second day for all scenarios. The authors conclude that even reading a simple message while driving could potentially lead to missing an important event, especially when executing critical manoeuvres. However, there is some evidence of a practice effect which suggests that future research should focus on performance with habitual rather than novel tasks. It is recommended that sending text as an eco-driving message analogous to the study circumstances should not be delivered to drivers on-line when vehicle is in motion. © 2012 Elsevier Ltd.

Hopkins M.,University of Leeds | King N.A.,Queensland University of Technology | Blundell J.E.,University of Leeds
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2010

Purpose of review: To examine the relationship between energy intake, appetite control and exercise, with particular reference to longer term exercise studies. This approach is necessary when exploring the benefits of exercise for weight control, as changes in body weight and energy intake are variable and reflect diversity in weight loss. Recent findings: Recent evidence indicates that longer term exercise is characterized by a highly variable response in eating behaviour. Individuals display susceptibility or resistance to exercise-induced weight loss, with changes in energy intake playing a key role in determining the degree of weight loss achieved. Marked differences in hunger and energy intake exist between those who are capable of tolerating periods of exercise-induced energy deficit, and those who are not. Exercise-induced weight loss can increase the orexigenic drive in the fasted state, but for some this is offset by improved postprandial satiety signalling. Summary: The biological and behavioural responses to acute and long-term exercise are highly variable, and these responses interact to determine the propensity for weight change. For some people, long-term exercise stimulates compensatory increases in energy intake that attenuate weight loss. However, favourable changes in body composition and health markers still exist in the absence of weight loss. The physiological mechanisms that confer susceptibility to compensatory overconsumption still need to be determined. © 2010 Wolters Kluwer Health. Lippincott Williams & Wilkins.

Srinivasan M.V.,Queensland University of Technology
Annual Review of Entomology | Year: 2010

Among the so-called simpler organisms, the honey bee is one of the few examples of an animal with a highly evolved social structure, a rich behavioral repertoire, an exquisite navigational system, an elaborate communication system, and an extraordinary ability to learn colors, shapes, fragrances, and navigational routes quickly and accurately. This review examines vision and complex visually mediated behavior in the honey bee, outlining the structure and function of the compound eyes, the perception and discrimination of colors and shapes, the learning of complex tasks, the ability to establish and exploit complex associations, and the capacity to abstract general principles from a task and apply them to tackle novel situations. All this is accomplished by a brain that weighs less than a milligram and carries fewer than a million neurons, thus making the bee a promising subject in which to study a variety of fundamental questions about behavior and brain function. © 2010 by Annual Reviews All rights reserved.

Miao X.,Queensland University of Technology | Sun D.,University of Ulster
Materials | Year: 2010

Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young's moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering. © 2010 by the authors.

Wang J.,Queensland University of Technology | Feng Y.,Queensland University of Technology
Journal of Geodesy | Year: 2013

Reliable ambiguity resolution (AR) is essential to real-time kinematic (RTK) positioning and its applications, since incorrect ambiguity fixing can lead to largely biased positioning solutions. A partial ambiguity fixing technique is developed to improve the reliability of AR, involving partial ambiguity decorrelation (PAD) and partial ambiguity resolution (PAR). Decorrelation transformation could substantially amplify the biases in the phase measurements. The purpose of PAD is to find the optimum trade-off between decorrelation and worst-case bias amplification. The concept of PAR refers to the case where only a subset of the ambiguities can be fixed correctly to their integers in the integer least squares (ILS) estimation system at high success rates. As a result, RTK solutions can be derived from these integer-fixed phase measurements. This is meaningful provided that the number of reliably resolved phase measurements is sufficiently large for least-square estimation of RTK solutions as well. Considering the GPS constellation alone, partially fixed measurements are often insufficient for positioning. The AR reliability is usually characterised by the AR success rate. In this contribution, an AR validation decision matrix is firstly introduced to understand the impact of success rate. Moreover the AR risk probability is included into a more complete evaluation of the AR reliability. We use 16 ambiguity variance-covariance matrices with different levels of success rate to analyse the relation between success rate and AR risk probability. Next, the paper examines during the PAD process, how a bias in one measurement is propagated and amplified onto many others, leading to more than one wrong integer and to affect the success probability. Furthermore, the paper proposes a partial ambiguity fixing procedure with a predefined success rate criterion and ratio test in the ambiguity validation process. In this paper, the Galileo constellation data is tested with simulated observations. Numerical results from our experiment clearly demonstrate that only when the computed success rate is very high, the AR validation can provide decisions about the correctness of AR which are close to real world, with both low AR risk and false alarm probabilities. The results also indicate that the PAR procedure can automatically chose adequate number of ambiguities to fix at given high-success rate from the multiple constellations instead of fixing all the ambiguities. This is a benefit that multiple GNSS constellations can offer. © 2012 Springer-Verlag.

Bahfenne S.,Queensland University of Technology | Frost R.L.,Queensland University of Technology
Applied Spectroscopy Reviews | Year: 2010

This review focuses on the vibrational spectroscopy of the compounds and minerals containing the arsenite, antimonite, and antimonate anions. The review collects and correlates the published data. Copyright © Taylor & Francis Group, LLC.

Fisher D.E.,Queensland University of Technology
Environmental and Planning Law Journal | Year: 2010

The status of rights and interests in relation to water has never been unambiguous. Are they rights of access, of use or of property? Is the status of individual rights the same as the status of the statutory rights of the State to the use and control of water? Much depends upon which stage of the hydrological cycle is relevant: water in its natural state, water stored in a reservoir, water piped to a distant destination, or water contained in a receptacle. The High Court has recently addressed some of these issues in the context of s 51(xxxi) of the Commonwealth Constitution restricting acquisition of property to acquisition on just terms. In undertaking this analysis the High Court has revealed an interesting range of approaches to legal reasoning. This article seeks to review some of these issues.

Wang J.,Queensland University of Technology | Feng Y.,Queensland University of Technology
GPS Solutions | Year: 2013

In the context of ambiguity resolution (AR) of global navigation satellite systems (GNSS), decorrelation among entries of an ambiguity vector, integer ambiguity search, and ambiguity validations are three standard procedures for solving integer least-squares problems. This paper contributes to AR issues from three aspects. Firstly, the orthogonality defect is introduced as a new measure of the performance of ambiguity decorrelation methods and compared with the decorrelation number and with the condition number, which are currently used as the judging criterion to measure the correlation of ambiguity variance-covariance matrix. Numerically, the orthogonality defect demonstrates slightly better performance as a measure of the correlation between decorrelation impact and computational efficiency than the condition number measure. Secondly, the paper examines the relationship of the decorrelation number, the condition number, the orthogonality defect, and the size of the ambiguity search space with the ambiguity search candidates and search nodes. The size of the ambiguity search space can be properly estimated if the ambiguity matrix is decorrelated well, which is shown to be a significant parameter in the ambiguity search progress. Thirdly, a new ambiguity resolution scheme is proposed to improve ambiguity search efficiency through the control of the size of the ambiguity search space. The new AR scheme combines the LAMBDA search and validation procedures together, which results in a much smaller size of the search space and higher computational efficiency while retaining the same AR validation outcomes. In fact, the new scheme can deal with the case there are only one candidate, while the existing search methods require at least two candidates. If there are more than one candidate, the new scheme turns to the usual ratio-test procedure. Experimental results indicate that this combined method can indeed improve ambiguity search efficiency for both the single constellation and dual constellations, respectively, showing the potential for processing high-dimension integer parameters in multi-GNSS environment. © 2012 Springer-Verlag.

Hoang V.-N.,Queensland University of Technology
Journal of Environmental Management | Year: 2014

This article integrates the material/energy flow analysis into a production frontier framework to quantify resource efficiency (RE). The emergy content of natural resources instead of their mass content is used to construct aggregate inputs. Using the production frontier approach, aggregate inputs will be optimised relative to given output quantities to derive RE measures. This framework is superior to existing RE indicators currently used in the literature. Using the exergy/emergy content in constructing aggregate material or energy flows overcomes a criticism that mass content cannot be used to capture different quality of differing types of resources. Derived RE measures are both 'qualitative' and 'quantitative', whereas existing RE indicators are only qualitative. An empirical examination into the RE of 116 economies was undertaken to illustrate the practical applicability of the new framework. The results showed that economies, on average, could reduce the consumption of resources by more than 30% without any reduction in per capita gross domestic product (GDP). This calculation occurred after adjustments for differences in the purchasing power of national currencies. The existence of high variations in RE across economies was found to be positively correlated with participation of people in labour force, population density, urbanisation, and GDP growth over the past five years. The results also showed that economies of a higher income group achieved higher RE, and those economies that are more dependent on imports and primary industries would have lower RE performance. © 2014 Elsevier Ltd.

Mathews B.,Queensland University of Technology
Medical Journal of Australia | Year: 2011

• The issue of whether medical practitioners should perform "ritual nicks" as a method of meeting demand for female genital mutilation (FGM) has recently been debated in the United States and Australia. • Due to increasing numbers of people arriving and settling in Australia from African nations in which FGM is customary, demand for FGM in Australia is present and may be increasing. • Australian law clearly prohibits performance of any type of FGM. • FGM is also prohibited by the most recent policy of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). • For legal, medical and social reasons, the RANZCOG policy is sound, and medical practitioners should not administer FGM in any form. • Development of an evidence base regarding incidence of and attitudes towards FGM, and the need for post-FGM treatment, would help inform sound policy and practical responses. • Strategies adopted in African nations to abolish FGM may assist in refining educational and supportive efforts.

Ma Z.,Carnegie Mellon University | Yang Y.,Queensland University of Technology | Sebe N.,University of Trento | Hauptmann A.G.,Carnegie Mellon University
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2014

Multimedia event detection (MED) is an emerging area of research. Previous work mainly focuses on simple event detection in sports and news videos, or abnormality detection in surveillance videos. In contrast, we focus on detecting more complicated and generic events that gain more users' interest, and we explore an effective solution for MED. Moreover, our solution only uses few positive examples since precisely labeled multimedia content is scarce in the real world. As the information from these few positive examples is limited, we propose using knowledge adaptation to facilitate event detection. Different from the state of the art, our algorithm is able to adapt knowledge from another source for MED even if the features of the source and the target are partially different, but overlapping. Avoiding the requirement that the two domains are consistent in feature types is desirable as data collection platforms change or augment their capabilities and we should be able to respond to this with little or no effort. We perform extensive experiments on real-world multimedia archives consisting of several challenging events. The results show that our approach outperforms several other state-of-the-art detection algorithms. © 1979-2012 IEEE.

Baker R.E.,University of Oxford | Simpson M.J.,Queensland University of Technology
Physica A: Statistical Mechanics and its Applications | Year: 2012

Continuum, partial differential equation models are often used to describe the collective motion of cell populations, with various types of motility represented by the choice of diffusion coefficient, and cell proliferation captured by the source terms. Previously, the choice of diffusion coefficient has been largely arbitrary, with the decision to choose a particular linear or nonlinear form generally based on calibration arguments rather than making any physical connection with the underlying individual-level properties of the cell motility mechanism. In this work we provide a new link between individual-level models, which account for important cell properties such as varying cell shape and volume exclusion, and population-level partial differential equation models. We work in an exclusion process framework, considering aligned, elongated cells that may occupy more than one lattice site, in order to represent populations of agents with different sizes. Three different idealisations of the individual-level mechanism are proposed, and these are connected to three different partial differential equations, each with a different diffusion coefficient; one linear, one nonlinear and degenerate and one nonlinear and nondegenerate. We test the ability of these three models to predict the population-level response of a cell spreading problem for both proliferative and nonproliferative cases. We also explore the potential of our models to predict long time travelling wave invasion rates and extend our results to two-dimensional spreading and invasion. Our results show that each model can accurately predict density data for nonproliferative systems, but that only one does so for proliferative systems. Hence great care must be taken to predict density data with varying cell shape. © 2012 Elsevier B.V. All rights reserved.

Zhang Q.,Nanchang University | Ni Y.,Nanchang University | Kokot S.,Queensland University of Technology
Journal of Agricultural and Food Chemistry | Year: 2013

The effect of ionic surfactants, sodium dodecyl sulfate (SDS) and N-cetyl-N,N,N-trimethylammonium bromide (CTAB), on the interaction between β-agonist salbutamol (SAL) and bovine serum albumin (BSA) was investigated with the use of fluorescence spectroscopy (FLS) and chemometrics methods [multivariate curve resolution-alternating least-squares (MCR-ALS) and parallel factor analysis algorithm (PARAFAC)]. It was found that the binding constant of SAL to BSA in the presence of CTAB was much larger than that without this ligand. The ligand/BSA stoichiometry was 4:1, that is, (CTAB)4-BSA, and was 2:1 with the ligand, that is, (SAL)2-BSA. These results were obtained from the concentration profiles extracted by MCR-ALS for all three reactants. Quantitative information on the complex CTAB-BSA-SAL species was obtained with the resolution of the excitation-emission fluorescence three-way data matrices by PARAFAC. This research has implications for the analysis of SAL in food and might be performed in laboratories associated with organizations such as the U.S. Food and Drug Administration (FDA) and the International Olympic Committee (IOC). © 2013 American Chemical Society.

Frost R.L.,Queensland University of Technology | Xi Y.,Queensland University of Technology
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Vibrational spectroscopy has been used to assess the structure of kotoite a borate mineral of magnesium which is isostructural with jimboite. The mineral is orthorhombic with point group: 2/m 2/m 2/m. The mineral has the potential as a new memory insulator material. The mineral has been characterised by a combination of Raman and infrared spectroscopy. The Raman spectrum is dominated by a very intense band at 835 cm-1, assigned to the symmetric stretching mode of tetrahedral boron. Raman bands at 919, 985 and 1015 cm -1 are attributed to the antisymmetric stretching modes of tetrahedral boron. Kotoite is strictly an hydrous borate mineral. An intense Raman band observed at 3559 cm-1 is attributed to the stretching vibration of hydroxyl units, more likely to be associated with the borate mineral hydroxyborate. The lack of observation of water bending modes proves the absence of water in the kotoite structure. © 2012 Elsevier B.V. All rights reserved.

Ling M.T.,Queensland University of Technology | Luk S.U.,University of Hong Kong | Al-Ejeh F.,Queensland Institute of Medical Research | Khanna K.K.,Queensland Institute of Medical Research
Carcinogenesis | Year: 2012

Vitamin E is composed of two structurally similar compounds: tocopherols (TPs) and tocotrienols (T3). Despite being overshadowed by TP over the past few decades, T3 is now considered to be a promising anticancer agent due to its potent effects against a wide range of cancers. A growing body of evidence suggests that in addition to its antioxidative and pro-apoptotic functions, T3 possesses a number of anticancer properties that make it superior to TP. These include the inhibition of epithelial-to-mesenchymal transitions, the suppression of vascular endothelial growth factor tumor angiogenic pathway and the induction of antitumor immunity. More recently, T3, but not TP, has been shown to have chemosensitization and anti-cancer stem cell effects, further demonstrating the potential of T3 as an effective anticancer therapeutic agent. With most of the previous clinical studies on TP producing disappointing results, research has now focused on testing T3 as the next generation vitamin E for chemoprevention and cancer treatment. This review will summarize recent developments in the understanding of the anticancer effects of T3. We will also discuss current progress in clinical trials involving T3 as an adjuvant to conventional cancer therapy. © The Author 2011. Published by Oxford University Press. All rights reserved.

Himawan I.,Queensland University of Technology | McCowan I.,Queensland University of Technology | Sridharan S.,Queensland University of Technology
IEEE Transactions on Audio, Speech and Language Processing | Year: 2011

Microphone arrays have been used in various applications to capture conversations, such as in meetings and teleconferences. In many cases, the microphone and likely source locations are known a priori, and calculating beamforming filters is therefore straightforward. In ad-hoc situations, however, when the microphones have not been systematically positioned, this information is not available and beamforming must be achieved blindly. In achieving this, a commonly neglected issue is whether it is optimal to use all of the available microphones, or only an advantageous subset of these. This paper commences by reviewing different approaches to blind beamforming, characterizing them by the way they estimate the signal propagation vector and the spatial coherence of noise in the absence of prior knowledge of microphone and speaker locations. Following this, a novel clustered approach to blind beamforming is motivated and developed. Without using any prior geometrical information, microphones are first grouped into localized clusters, which are then ranked according to their relative distance from a speaker. Beamforming is then performed using either the closest microphone cluster, or a weighted combination of clusters. The clustered algorithms are compared to the full set of microphones in experiments on a database recorded on different ad-hoc array geometries. These experiments evaluate the methods in terms of signal enhancement as well as performance on a large vocabulary speech recognition task. © 2006 IEEE.

Smith G.,Queensland University of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Linearizability is the standard notion of correctness for concurrent objects. A number of approaches have been developed for proving linearizability along with associated tool support. In this paper, we extend the tool support for an existing simulation-based method. We complement the current theorem-prover support with model checking to allow a means of quickly finding problems with an implementation before attempting a full verification. Our model checking approach is novel in that it is used to verify the simulation rules, rather than directly trying to check an object being accessed by a number of threads. As a consequence, verification can be done for an arbitrary number of accessing threads; something that is not possible with existing approaches based on model checking. © Springer International Publishing Switzerland 2016.

Dolamune Kankanamge N.,Queensland University of Technology | Mahendran M.,Queensland University of Technology
Thin-Walled Structures | Year: 2012

Cold-formed steel beams are increasingly used as floor joists and bearers in buildings and often their behaviour and moment capacities are influenced by lateral-torsional buckling. With increasing usage of cold-formed steel beams their fire safety design has become an important issue. Fire design rules are commonly based on past research on hot-rolled steel beams. Hence a detailed parametric study was undertaken using validated finite element models to investigate the lateral-torsional buckling behaviour of simply supported cold-formed steel lipped channel beams subjected to uniform bending at uniform elevated temperatures. The moment capacity results were compared with the predictions from the available ambient temperature and fire design rules and suitable recommendations were made. European fire design rules were found to be over-conservative while the ambient temperature design rules could not be used based on single buckling curve. Hence a new design method was proposed that includes the important non-linear stress-strain characteristics observed for cold-formed steels at elevated temperatures. Comparison with numerical moment capacities demonstrated the accuracy of the new design method. This paper presents the details of the parametric study, comparisons with current design rules and the new design rules proposed in this research for lateral-torsional buckling of cold-formed steel lipped channel beams at elevated temperatures. © 2012 Elsevier Ltd. All rights reserved.

Millichamp A.,Queensland University of Technology | Gallegos D.,Queensland University of Technology
Public Health Nutrition | Year: 2013

Objective To explore whether area-level socio-economic position or the form of retail stream (conventional v. farmers' market) is associated with differences in the price, availability, variety and quality of a range of fresh fruit and vegetables. Design A multi-site cross-sectional pilot study of farmers' markets, supermarkets and independent fruit and vegetable retailers. Each was surveyed to assess the price, availability, variety and quality of fifteen fruit and eighteen vegetable items. Setting Retail outlets were located in south-east Queensland. Subjects Fifteen retail outlets were surveyed (five of each retail stream). Results Average basket prices were not significantly different across the socio-economic spectrum, but prices in low socio-economic areas were cheapest. Availability, variety and quality did not differ significantly across levels of socio-economic position; however, the areas with the most socio-economic disadvantage scored poorest for quality and variety. Supermarkets had significantly better fruit and vegetable availability than farmers' markets, although price, variety and quality scores were not different across retail streams. Results demonstrate a trend to fruit and vegetable prices being more expensive at farmers' markets, with the price of the fruit basket being significantly greater at the organic farmers' market compared with the non-organic farmers' markets. Conclusions Neither area-level socio-economic position nor the form of retail stream was significantly associated with differences in the availability, price, variety and quality of fruit and vegetables, except for availability which was higher in supermarkets than farmers' markets. Further research is needed to determine what role farmers' markets can play in affecting fruit and vegetable intake. © 2012 The Authors.

Majumder R.,Queensland University of Technology | Ghosh A.,Queensland University of Technology | Ledwich G.,Queensland University of Technology | Zare F.,Queensland University of Technology
IEEE Transactions on Power Systems | Year: 2010

This paper proposes a method for power flow control between utility and microgrid through back-to-back converters, which facilitates desired real and reactive power flow between utility and microgrid. In the proposed control strategy, the system can run in two different modes depending on the power requirement in the microgrid. In mode-1, specified amount of real and reactive power are shared between the utility and the microgrid through the back-to-back converters. Mode-2 is invoked when the power that can be supplied by the distributed generators (DGs) in the microgrid reaches its maximum limit. In such a case, the rest of the power demand of the microgrid has to be supplied by the utility. An arrangement between DGs in the microgrid is proposed to achieve load sharing in both grid connected and islanded modes. The back-to-back converters also provide total frequency isolation between the utility and the microgrid. It is shown that the voltage or frequency fluctuation in the utility side has no impact on voltage or power in microgrid side. Proper relay-breaker operation coordination is proposed during fault along with the blocking of the back-to-back converters for seamless resynchronization. Both impedance and motor type loads are considered to verify the system stability. The impact of dc side voltage fluctuation of the DGs and DG tripping on power sharing is also investigated. The efficacy of the proposed control arrangement has been validated through simulation for various operating conditions. The model of the microgrid power system is simulated in PSCAD. © 2010 IEEE.

Gable G.,Queensland University of Technology
Journal of Strategic Information Systems | Year: 2010

The Journal of Strategic Information Systems (JSIS) has been an international outlet for Information Systems research that focuses on strategic issues since 1991. This paper reports on an analysis of the research published in JSIS to date. The paper presents a preliminary classification system for research topics related to Strategic Information Systems into which all 316 JSIS research papers as at end 2009 are classified. Discussion on changing emphases in topics over time is provided, in the context of the editorial philosophy of the journal. The paper seeks to stimulate discussion on future directions for research in Strategic Information Systems. © 2010 Elsevier B.V. All rights reserved.

Saha S.C.,Queensland University of Technology | Khan M.M.K.,Central Queensland University
International Journal of Heat and Mass Transfer | Year: 2012

A scaling analysis for the natural convection boundary layer adjacent to an inclined semi-infinite plate subject to a non-instantaneous heating in the form of an imposed wall temperature which increases linearly up to a prescribed steady value over a prescribed time is reported. The development of the boundary layer flow from start-up to a steady-state has been described based on scaling analyses and verified by numerical simulations. The analysis reveals that, if the period of temperature growth on the wall is sufficiently long, the boundary layer reaches a quasi-steady mode before the growth of the temperature is completed. In this mode the thermal boundary layer at first grows in thickness and then contracts with increasing time. However, if the imposed wall temperature growth period is sufficiently short, the boundary layer develops differently, but after the wall temperature growth is completed, the boundary layer develops as though the startup had been instantaneous. The steady state values of the boundary layer for both cases are ultimately the same. © 2012 Elsevier Ltd. All rights reserved.

Wang H.,Queensland University of Technology | Liu K.,CAS Institute of Software
Proceedings of the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining | Year: 2012

Trajectory similarity search studies the problem of finding a trajectory from the database such the found trajectory most similar to the query trajectory. Past research mainly focused on two aspects: shape similarity search and semantic similarity search, leaving personalized similarity search untouched. In this paper, we propose a new query which takes user's preference into consideration to provide personalized searching. We define a new data model for this query and identify the efficiency issue as the key challenge: given a user specified trajectory, how to efficiently retrieve the most similar trajectory from the database. By taking advantage of the spatial localities, we develop a two-phase algorithm to tame this challenge. Two optimized strategies are also developed to speed up the query process. Both the theoretical analysis and the experiments demonstrate the high efficiency of the proposed method. © 2012 ACM.

Durrant N.,Queensland University of Technology
Climate Law | Year: 2011

This paper critically analyses the proposed Australian regulatory approach to the crediting of biological sequestration activities (biosequestration) under the Australian Carbon Farming Initiative and its interaction with state-based carbon rights, the national carbon-pricing mechanism, and the international Kyoto Protocol and carbon-trading markets. Norms and principles have been established by the Kyoto Protocol to guide the creation of additional, verifiable, and permanent credits from biosequestration activities. This paper examines the proposed arrangements under the Australian Carbon Farming Initiative and Carbon Pricing Mechanism to determine whether they are consistent with those international norms and standards. This paper identifies a number of anomalies associated with the legal treatment of additionality and permanence and issuance of carbon credits within the Australian schemes. In light of this, the paper considers the possible legal implications for the national and international transfer, surrender and use of these offset credits. © 2012-IOS Press and the authors. All rights reserved.

Karim M.A.,Queensland University of Technology
Applied Thermal Engineering | Year: 2011

Air-conditioning forms a large proportion of annual peak electrical demand, requiring expansion of power plants to meet the peak demand, which goes unused most of the time. Use of well-designed cool thermal storage can offset the peak demand to a large extent. In this study, an air-conditioning system with naturally stratified storage tank was designed, constructed and tested. A new type of diffuser was designed and used in this study. Factors that influenced the performance of chilled-water storage tanks were investigated. The results indicated that stratified storage tank consistently stratified well without any physical barrier. Investigation also showed that storage efficiency decreased with increasing flow rate due to increased mixing of warm and chilled water. Diffuser design and layout primarily affected the mixing near the inlet diffuser and the extent of this mixing had primary influence on the shape of the thermocline. The heat conduction through tank walls and through the thermocline caused widening of mixed volume. Thermal efficiency of stratified storage tanks was as high as 90%, which indicates that stratified tanks can effectively be used as a load management technique. © 2011 Elsevier Ltd. All rights reserved.

Chakraborty R.,Queensland University of Technology | Read S.A.,Queensland University of Technology | Collins M.J.,Queensland University of Technology
Experimental Eye Research | Year: 2012

Recent research indicates that brief periods (60 min) of monocular defocus lead to small but significant changes in human axial length. However, the effects of longer periods of defocus on the axial length of human eyes are unknown. We examined the influence of a 12 h period of monocular myopic defocus on the natural daily variations occurring in axial length and choroidal thickness of young adult emmetropes. A series of axial length and choroidal thickness measurements (collected at ∼3 hourly intervals, with the first measurement at ∼9 am and the final measurement at ∼9 pm) were obtained for 13 emmetropic young adults over three consecutive days. The natural daily rhythms (Day 1, baseline day, no defocus), the daily rhythms with monocular myopic defocus (Day 2, defocus day, +1.50 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, recovery day, no defocus) were all examined. Significant variations over the course of the day were observed in both axial length and choroidal thickness on each of the three measurement days (p < 0.0001). The magnitude and timing of the daily variations in axial length and choroidal thickness were significantly altered with the monocular myopic defocus on day 2 (p < 0.0001). Following the introduction of monocular myopic defocus, the daily peak in axial length occurred approximately 6 h later, and the peak in choroidal thickness approximately 8.5 h earlier in the day compared to days 1 and 3 (with no defocus). The mean amplitude (peak to trough) of change in axial length (0.030 ± 0.012 on day 1, 0.020 ± 0.010 on day 2 and 0.033 ± 0.012 mm on day 3) and choroidal thickness (0.030 ± 0.007 on day 1, 0.022 ± 0.006 on day 2 and 0.027 ± 0.009 mm on day 3) were also significantly different between the three days (both p < 0.05). The introduction of monocular myopic defocus disrupts the daily variations in axial length and choroidal thickness of human eyes (in terms of both amplitude and timing) that return to normal the following day after removal of the defocus. © 2012 Elsevier Ltd.

Zeitler E.,Queensland University of Technology | Buys L.,Queensland University of Technology
Ageing and Society | Year: 2015

Governments are challenged by the need to ensure that ageing populations stay active and engaged as they age. Therefore, it is critical to investigate the role of mobility in older people's engagement in out-of-home activities, and to identify the experiences they have within their communities. This research investigates the use of transportation by older people and its implications for their out-of-home activities within suburban environments. The qualitative, mixed-method approach employs data collection methods which include a daily travel diary (including a questionnaire), Global Positioning System (GPS) tracking and semi-structured interviews with older people living in suburban environments in Brisbane, Australia. Results show that older people are mobile throughout the city, and their car provides them with that opportunity to access desired destinations. This ability to drive allows older people to live independently and to assist others who do not drive, particularly where transport alternatives are not as accessible. The ability to transport goods and other people is a significant advantage of the private car over other transport options. People with no access to private transportation who live in low-density environments are disadvantaged when it comes to participation within the community. Further research is needed to better understand the relationship between transportation and participation within the community environment, to assist policy makers and city and transportation planners to develop strategies for age-friendly environments within the community. Copyright © Cambridge University Press 2014.

Osuagwu U.L.,Queensland University of Technology
Optometry and Vision Science | Year: 2016

PURPOSE: To investigate the operation of the Shin-Nippon/Grand Seiko autorefractor and whether higher-order aberrations affect its peripheral refraction measurements. METHODS: Information on instrument design, together with parameters and equations used to obtain refraction, was obtained from a patent. A model eye simulating the operating principles was tested with an optical design program. Effects of induced defocus and astigmatism on the retinal image were used to calibrate the model eye to match the patent equations. Coma and trefoil were added to assess their effects on the image. Peripheral refraction of a physical model eye was measured along four visual field meridians with the Shin-Nippon/Grand Seiko autorefractor SRW-5000 and a Hartmann-Shack aberrometer, and simulated autorefractor peripheral refraction was derived using the Zernike coefficients from the aberrometer. RESULTS: In simulation, the autorefractor’s square image was changed in size by defocus, into rectangles or parallelograms by astigmatism, and into irregular shapes by coma and trefoil. In the presence of 1.0 D oblique astigmatism, errors in refraction were proportional to the higher-order aberrations, with up to 0.8 D sphere and 1.5 D cylinder for ±0.6 μm of coma or trefoil coefficients with a 5-mm-diameter pupil. For the physical model eye, refraction with the aberrometer was similar in all visual field meridians, but refraction with the autorefractor changed more quickly along one oblique meridian and less quickly along the other oblique meridian than along the horizontal and vertical meridians. Simulations predicted that higher-order aberrations would affect refraction in oblique meridians, and this was supported by the experimental measurements with the physical model eye. CONCLUSIONS: The autorefractor’s peripheral refraction measurements are valid for horizontal and vertical field meridians, but not for oblique field meridians. Similar instruments must be validated before being adopted outside their design scope. © 2016 American Academy of Optometry

Hewitt B.,University of Queensland | Turrell G.,Queensland University of Technology | Giskes K.,Queensland University of Technology
Journal of Epidemiology and Community Health | Year: 2012

Objectives: To investigate the impact of transitions out of marriage (separation, widowhood) on the self reported mental health of men and women, and examine whether perceptions of social support play an intervening role. Methods: The analysis used six waves (2001-06) of an Australian population based panel study, with an analytical sample of 3017 men and 3225 women. Mental health was measured using the MHI-5 scale scored 0-100 (α=0.97), with a higher score indicating better mental health. Perceptions of social support were measured using a 10-item scale ranging from 10 to 70 (α0.79), with a higher score indicating higher perceived social support. A linear mixed model for longitudinal data was used, with lags for marital status, mental health and social support. Results: After adjustment for social characteristics there was a decline in mental health for men who separated (-5.79 points) or widowed (-7.63 points), compared to men who remained married. Similar declines in mental health were found for women who separated (-6.65 points) or became widowed (-9.28 points). The inclusion of perceived social support in the models suggested a small mediation effect of social support for mental health with marital loss. Interactions between perceived social support and marital transitions showed a strong moderating effect for men who became widowed. No significant interactions were found for women. Conclusion: Marital loss significantly decreased mental health. Increasing, or maintaining, high levels of social support has the potential to improve widowed men's mental health immediately after the death of their spouse.

Dixon J.,Australian National University | Richards C.,Queensland University of Technology
Agriculture and Human Values | Year: 2016

This paper offers one explanation for the institutional basis of food insecurity in Australia, and argues that while alternative food networks and the food sovereignty movement perform a valuable function in building forms of social solidarity between urban consumers and rural producers, they currently make only a minor contribution to Australia’s food and nutrition security. The paper begins by identifying two key drivers of food security: household incomes (on the demand side) and nutrition-sensitive, ‘fair food’ agriculture (on the supply side). We focus on this second driver and argue that healthy populations require an agricultural sector that delivers dietary diversity via a fair and sustainable food system. In order to understand why nutrition-sensitive, fair food agriculture is not flourishing in Australia we introduce the development economics theory of urban bias. According to this theory, governments support capital intensive rather than labour intensive agriculture in order to deliver cheap food alongside the transfer of public revenues gained from rural agriculture to urban infrastructure, where the majority of the voting public resides. We chart the unfolding of the Urban Bias across the twentieth century and its consolidation through neo-liberal orthodoxy, and argue that agricultural policies do little to sustain, let alone revitalize, rural and regional Australia. We conclude that by observing food system dynamics through a re-spatialized lens, Urban Bias Theory is valuable in highlighting rural–urban socio-economic and political economy tensions, particularly regarding food system sustainability. It also sheds light on the cultural economy tensions for alternative food networks as they move beyond niche markets to simultaneously support urban food security and sustainable rural livelihoods. © 2015, Springer Science+Business Media Dordrecht.

Hughes S.,Queensland University of Technology
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2011

This paper presents evidence of an apparent connection between ball lightning and a green fireball. On the evening of the 16 May 2006 at least three fireballs were seen by many people in the skies of Queensland, Australia. One of the fireballs was seen passing over the Great Divide about 120km west of Brisbane, and soon after, a luminous green ball about 30 cm in diameter was seen rolling down the slope of the Great Divide. A detailed description given by a witness indicates that the phenomenon was probably a highly luminous form of ball lightning. A hypothesis presented in this paper is that the passage of the Queensland fireball meteor created an electrically conductive path between the ionosphere and ground, providing energy for the ball lightning phenomenon. A strong similarity is noted between the Queensland fireball and the Pasamonte fireball seen in New Mexico in 1933. Both meteors exhibit a twist in the tail that could be explained by hydrodynamic forces. The possibility that multiple sightings of fireballs across southeast Queensland were produced owing to fragments from comet 73P Schwassmann-Wachmann 3 is discussed. © 2010 The Royal Society.

Coetzee J.C.,Queensland University of Technology
International Journal of Microwave Science and Technology | Year: 2011

Decoupling networks can alleviate the effects of mutual coupling in antenna arrays. Conventional decoupling networks can provide decoupled and matched ports at a single frequency. This paper describes dual-frequency decoupling which is achieved by using a network of series or parallel resonant circuits instead of single reactive elements. Copyright © 2011 Jacob Carl Coetzee.

Borradale D.C.,Queensland University of Technology | Kimlin M.G.,Queensland University of Technology
Nutrition Reviews | Year: 2012

Folate is essential for human health in the prevention of megaloblastic anemia and neural tube birth defects and plays important roles in cardiovascular disease and cancer. Therefore, research into environmental factors that may impact folate status, such as solar ultraviolet (UV) radiation, is of great health significance. In vitro studies have shown that UV radiation can degrade folate and folic acid in human blood and this has been confirmed in several human studies. Despite these findings, there is a dearth of epidemiological research into investigating the relationship between folate status and the links to solar UV exposure. © 2012 International Life Sciences Institute.

O'Shea P.,Queensland University of Technology
IEEE Transactions on Aerospace and Electronic Systems | Year: 2010

Newton algorithms are commonly used in the final "refinement" stage of parameter estimation for sinusoids and higher order phase polynomial signals. Such parameter estimation scenarios arise commonly in radar applications where the radial target velocity (which is possibly time-varying) must be estimated. The author and coworkers have previously proposed an elegant and efficient alternative to a Newton gradient search type algorithm based on filtering and phase unwrapping. A statistical and computational analysis of this filtering/phase unwrapping method is presented here. The analysis shows the algorithm to be computationally efficient and much less sensitive to the accuracy of the initial guesses for the parameters than a Newton algorithm. A first-order statistical analysis of the filtering/phase unwrapping algorithm is performed, and guidelines are derived for the required accuracy of the initial estimates. Simulations are presented to confirm the analysis. © 2010 IEEE.

Chopin L.K.,Queensland University of Technology | Seim I.,Queensland University of Technology | Walpole C.M.,Queensland University of Technology | Herington A.C.,Queensland University of Technology
Endocrine Reviews | Year: 2012

Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk;however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation,andangiogenesis;however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression. © 2012 by The Endocrine Society.

Costello M.-E.,Queensland Medical Laboratory | Huygens F.,Queensland University of Technology
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2011

Emergence and dissemination of community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) strains are being reported with increasing frequency in Australia and worldwide. These strains of CA-MRSA are genetically diverse and distinct in Australia. Genotyping of CA-MRSA using eight highly-discriminatory single nucleotide polymorphisms (SNPs) is a rapid and robust method for monitoring the dissemination of these strains in the community. In this study, a SNP genotyping method was used to investigate the molecular epidemiology of 249 community acquired non-multiresistant MRSA (nm-MRSA) isolates over a 12-month period from routine diagnostic specimens. A real-time PCR for the presence of Panton-Valentine leukocidin (PVL) was also performed on these isolates. The CA-MRSA isolates were sourced from a large private laboratory in Brisbane, Australia that serves a wide geographic region encompassing Queensland and Northern New South Wales. This study identified 16 different STs and 98% of the CA-MRSA isolates were positive for the PVL gene. The most common ST was ST93 with 41% of isolates testing positive for this clone. © 2011 Springer-Verlag.

Drovandi C.C.,Queensland University of Technology | Pettitt A.N.,Queensland University of Technology | Pettitt A.N.,Lancaster University
Biometrics | Year: 2011

We estimate the parameters of a stochastic process model for a macroparasite population within a host using approximate Bayesian computation (ABC). The immunity of the host is an unobserved model variable and only mature macroparasites at sacrifice of the host are counted. With very limited data, process rates are inferred reasonably precisely. Modeling involves a three variable Markov process for which the observed data likelihood is computationally intractable. ABC methods are particularly useful when the likelihood is analytically or computationally intractable. The ABC algorithm we present is based on sequential Monte Carlo, is adaptive in nature, and overcomes some drawbacks of previous approaches to ABC. The algorithm is validated on a test example involving simulated data from an autologistic model before being used to infer parameters of the Markov process model for experimental data. The fitted model explains the observed extra-binomial variation in terms of a zero-one immunity variable, which has a short-lived presence in the host. © 2010, The International Biometric Society.

Bailey I.L.,University of California at Berkeley | Lovie-Kitchin J.E.,Queensland University of Technology
Vision Research | Year: 2013

The need for precision in visual acuity assessment for low vision research led to the design of the Bailey-Lovie letter chart. This paper describes the decisions behind the design principles used and how the logarithmic progression of sizes led to the development of the logMAR designation of visual acuity and the improved sensitivity gained from letter-by-letter scoring. While the principles have since been adopted by most major clinical research studies and for use in most low vision clinics, use of charts of this design and application of letter-by-letter scoring are also important for the accurate assessment of visual acuity in any clinical setting. We discuss the test protocols that should be applied to visual acuity testing and the use of other tests for assessing profound low vision when the limits of visual acuity measurement by letter charts are reached. © 2013 Elsevier Ltd.

Vlacic-Zischke J.,Griffith University | Hamlet S.M.,Griffith University | Friis T.,Queensland University of Technology | Tonetti M.S.,European Research Group on Periodontology | Ivanovski S.,Griffith University
Biomaterials | Year: 2011

The topography of titanium implants has been identified as an important factor affecting the osseointegration of surgically placed dental implants. Further modification to produce a hydrophilic microrough titanium implant surface has been shown to increase osseointegration compared with microrough topology alone. This study aimed to determine possible molecular mechanisms to explain this clinical observation by examining differences in the whole genome mRNA expression profile of primary human osteoblasts in response to sand-blasted acid-etched (SLA) and hydrophilic SLA (modSLA) titanium surfaces. A decrease in osteoblast proliferation associated with the titanium surfaces (modSLA > SLA > control) correlated with an increase in expression of the osteogenic differentiation markers BSPII and osteocalcin. Pathway analysis demonstrated that a number of genes associated with the TGFβBMP signalling cascade (BMP2, BMP6, SP1, CREBBP, RBL2, TBS3, ACVR1 and ZFYVE16) were significantly differentially up-regulated with culture on the modSLA surface. BMP2 was shown to have the largest fold change increase in expression which was subsequently confirmed at the protein level by ELISA. Several other genes associated with the functionally important mechanisms relevant to bone healing, such as Wnt signalling (CTNNA1, FBX4, FZD6), angiogenesis (KDR), osteoclastogenesis (HSF2, MCL1) and proteolysis (HEXB, TPP1), were also differentially regulated. These results suggest that chemical (hydrophilic) modification of the SLA surface may result in more successful osseointegration through BMP signalling. © 2010 Elsevier Ltd.

Doherty W.O.S.,Queensland University of Technology
Journal of Agricultural and Food Chemistry | Year: 2011

It is accepted that the efficiency of sugar cane clarification is closely linked with sugar juice composition (including suspended or insoluble impurities), the inorganic phosphate content, the liming condition and type, and the interactions between the juice components. These interactions are not well understood, particularly those between calcium, phosphate, and sucrose in sugar cane juice. Studies have been conducted on calcium oxide (CaO)/phosphate/sucrose systems in both synthetic and factory juices to provide further information on the defecation process (i.e., simple liming to effect impurity removal) and to identify an effective clarification process that would result in reduced scaling of sugar factory evaporators, pans, and centrifugals. Results have shown that a two-stage process involving the addition of lime saccharate to a set juice pH followed by the addition of sodium hydroxide to a final juice pH or a similar two-stage process where the order of addition of the alkalis is reversed prior to clarification reduces the impurity loading of the clarified juice compared to that of the clarified juice obtained by the conventional defecation process. The treatment process showed reductions in CaO (27% to 50%) and MgO (up to 20%) in clarified juices with no apparent loss in juice clarity or increase in residence time of the mud particles compared to those in the conventional process. There was also a reduction in the SiO2 content. However, the disadvantage of this process is the significant increase in the Na2O content. © 2011 American Chemical Society.

Fan W.,Queensland University of Technology | Crawford R.,Queensland University of Technology | Xiao Y.,Queensland University of Technology
Differentiation | Year: 2011

Angiogenesis, or neovascularization, is a finely balanced process controlled by pro- and anti-angiogenic factors. Vascular endothelial growth factor (VEGF) is a major pro-angiogenic factor, whereas pigment epithelial-derived factor (PEDF) is the most potent natural angiogenesis inhibitor. In this study, the regulatory role of bone marrow stromal cells (BMSCs) during angiogenesis was assessed by the endothelial differentiation potential, VEGF/PEDF production and responses to pro-angiogenic and hypoxic conditions. The in vivo regulation of blood vessel formation by BMSCs was also explored in a SCID mouse model. Results showed that PEDF was expressed more prominently in BMSCs compared to VEGF. This contrasted with human umbilical vein endothelial cells (HUVECs) where the expression of VEGF was higher than that of PEDF. The ratio of VEGF/PEDF gene expression in BMSCs increased when VEGF concentration reached 40ng/ml in the culture medium, but decreased at 80ng/ml. Under CoCl2-induced hypoxic conditions, the VEGF/PEDF ratio of BMSCs increased significantly in both normal and angiogenic culture media. There was no expression of endothelial cell markers in BMSCs cultured in either pro-angiogenic or hypoxia culture conditions when compared with HUVECs. The in vivo study showed that VEGF/PEDF expression closely correlated with the degree of neovascularization, and that hypoxia significantly induced pro-angiogenic activity in BMSCs. These results indicate that, rather than being progenitors of endothelial cells, BMSCs play an important role in regulating the neovascularization process, and that the ratio of VEGF and PEDF may, in effect, be an indicator of the pro- or anti-angiogenic activities of BMSCs. © 2010.

Headrick J.,Queensland University of Technology
Journal of sports sciences | Year: 2012

The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.

Wilson G.J.,Queensland University of Technology | Will G.D.,Queensland University of Technology
Inorganica Chimica Acta | Year: 2010

Excited state transitions and energies of a series of [Ru(bpy)3]2+ type complexes incorporating the ligand, 4,4′-bis-phosphonato(methyl)-2,2′-bipyridine (dmpbpy) was investigated, and the influence of this organometallic ligand on the electronic structure of the complexes was examined using Time-Dependent Density Functional Theory (TD-DFT). Experimental data and the theoretical TD-DFT calculations were presented to support the effect of non-equivalent ligand substitution on spectral and molecular orbital (MO) energy properties on this class of tris-chelate surface sensitisers. For the series of complexes studied, it was identified that the lowest lying LUMO states were consistently found to reside on the ligand 2,2′-bipyridine (bpy) for gas phase calculations. As an implication of this, it was suggested that this could impact the effectiveness of these complexes as surface sensitisers in PEC cell applications such as the dye-sensitised solar cell (DSC) due to the lower probability of the excited state electron residing on a ligand anchored to the semiconductor substrate. However, further calculations in a solvation medium showed that the electron withdrawing nature of PO3H2 on dmpbpy saw the lowest lying LUMO states are populated on dmpbpy. This inhomogeneous distribution of electron density across non-equivalent ligands may have implications for further 'spectral tuning' of surface sensitisers. Despite the TD-DFT gas phase calculations not being corrected for solvent/media effects, the three longest wavelength bands associated with known charge transfer phenomena were identified. The symmetry allowed over(ν, ̄)MLCT in the visible region was assigned as a πψ * ← dπ transition, the mid-UV spectrum over(ν, ̄)LC was assigned πψ * ← π in origin. Whilst the near-UV shoulder on the blue side of over(ν, ̄)MLCT showed dσ ← dπ and π* ← dπ transitional character and was tentatively described as over(ν, ̄)MC/MLCT. UV-Vis absorption spectra calculated for solvated analogues containing dmpbpy indicated that the low energy transitions associated with the MLCT are subject to bathochromic shift due to solvent polarity by 0.062 eV (500 cm-1) compared with the gas phase calculations, which is more highly correlated to the observed experimental transitions. © 2010 Elsevier B.V. All rights reserved.

McGee A.,Queensland University of Technology
Journal of Medicine and Philosophy (United Kingdom) | Year: 2016

In this paper, I examine Jeff McMahan's arguments for his claim that we are not human organisms, and the arguments of Derek Parfit to the same effect in a recent paper. McMahan uses these arguments to derive conclusions concerning the moral status of embryos and permanent vegetative state (PVS) patients. My claim will be that neither thinker has successfully shown that we are not human beings, and therefore these arguments do not establish the ethical conclusions that McMahan has sought to draw from the arguments in respect of the moral status of embryos and PVS patients. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc.

Zhu H.,Queensland University of Technology | Ke X.,Queensland University of Technology | Yang X.,Queensland University of Technology | Yang X.,Inner Mongolia University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2010

Shedding light: Nitroaromatic compounds on gold nanoparticles (3 wt %) supported on ZrO2 can be reduced directly to the corresponding azo compounds when illuminated with visible light or ultraviolet light at 40 °C (see picture). The process occurs with high selectivity and at ambient temperature and pressure, and enables the selection of intermediates that are unstable in thermal reactions. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shakespeare-Finch J.,Queensland University of Technology | Barrington A.J.,Queensland University of Technology
Journal of Traumatic Stress | Year: 2012

This study aimed to identify positive behavioural changes that people may make as a result of negotiating the aftermath of a traumatic experience, thereby extending the current cognitive model of posttraumatic growth (PTG). It was hypothesised that significant others would corroborate survivors' cognitive and behavioural reports of PTG. The sample comprised 176 participants: 88 trauma survivors and 88 significant others. University students accounted for 64%; 36% were from the broader community. Approximately one third were men. All participants completed the Posttraumatic Growth Inventory (PTGI) and open-ended questions regarding behavioural changes. The PTGI scores of the survivors were corroborated by their significant others with only the Appreciation of Life factor of the PTGI differing between the 2 groups (e.g., total PTGI scores between groups explained 33% of variance). Nearly all of the survivors also reported positive changes in their behaviour; these changes were also corroborated by the significant others. Results provide validation of the PTG construct and the PTGI as an instrument of measurement. Findings may also influence therapeutic practice by pointing to the potential usefulness of corroborating others in the recovery and growth process. © 2012 International Society for Traumatic Stress Studies.

Morgan P.B.,University of Manchester | Efron N.,Queensland University of Technology
Contact Lens and Anterior Eye | Year: 2015

We sought to determine the impact of optometric practice setting on contact lens prescribing by analysing annual survey data of lens fits collected between 2009 and 2013 from independent and national group practices throughout the United Kingdom. Compared to national group practices, independent practices fit contact lenses to older patients and more females. Independent practices also undertake a lower proportion of soft lens fits overall (and thus a higher proportion of rigid lens fits), soft toric lens fits and daily disposable lens fits. There is a higher proportion of soft extended wear and multifocal lens fits in independent practices. We conclude that contact lens fitting behaviour is influenced by optometric practice setting. © 2014 British Contact Lens Association.

Liu Z.,South China University of Technology | Wen F.,Queensland University of Technology | Ledwich G.,Queensland University of Technology
IEEE Transactions on Power Delivery | Year: 2011

Some uncertainties, such as the uncertain output power of a plug-in electric vehicle (PEV) due to its stochastic charging and discharging schedule, that of a wind generation unit due to the stochastic wind speed, and that of a solar generating source due to the stochastic illumination intensity, volatile fuel prices, and future uncertain load growth could lead to some risks in determining the optimal siting and sizing of distributed generators (DGs) in distribution system planning. Given this background, under the chance constrained programming (CCP) framework, a new method is presented to handle these uncertainties in the optimal siting and sizing of DGs. First, a mathematical model of CCP is developed with the minimization of the DGs' investment cost, operating cost, maintenance cost, network loss cost, as well as the capacity adequacy cost as the objective, security limitations as constraints, and the siting and sizing of DGs as optimization variables. Then, a Monte Carlo simulation-embedded genetic-algorithm-based approach is employed to solve the developed CCP model. Finally, the IEEE 37-node test feeder is used to verify the feasibility and effectiveness of the developed model and method, and the test results have demonstrated that the voltage profile and power-supply reliability for customers can be significantly improved and the network loss substantially reduced. © 2011 IEEE.

Crilley L.R.,Queensland University of Technology | Ayoko G.A.,Queensland University of Technology | Morawska L.,Queensland University of Technology
Environmental Pollution | Year: 2014

An Aerodyne Aerosol Mass Spectrometer was deployed at five urban schools to examine spatial and temporal variability of organic aerosols (OA) and positive matrix factorization (PMF) used for the first time in the Southern Hemisphere to apportion the sources of the OA across an urban area. The sources identified included hydrocarbon-like OA (HOA), biomass burning OA (BBOA) and oxygenated OA (OOA). At all sites, the main source was OOA, which accounted for 62-73% of the total OA mass and was generally more oxidized compared to those reported in the Northern Hemisphere. This suggests that there are differences in aging processes or regional sources in the two hemispheres. Unlike HOA and BBOA, OOA demonstrated instructive temporal variations but not spatial variation across the urban area. Application of cluster analysis to the PMF-derived sources offered a simple and effective method for qualitative comparison of PMF sources that can be used in other studies. © 2013 Published by Elsevier Ltd.

Carr E.J.,Queensland University of Technology | Turner I.W.,Queensland University of Technology | Perre P.,École Centrale Paris
Journal of Computational Physics | Year: 2013

large, stiff systems of differential equations encountered when simulating transport in heterogeneous porous media. Our method utilises the exponential Rosenbrock-Euler method, which is explicit in nature and requires a matrix-vector product involving the exponential of the Jacobian matrix at each step of the integration process. These products can be approximated using Krylov subspace methods, which permit a large integration stepsize to be utilised without having to precondition the iterations. This means that our method is truly "Jacobian-free" - the Jacobian need never be formed or factored during the simulation. We assess the performance of the new algorithm for simulating the drying of softwood. Numerical experiments conducted for both low and high temperature drying demonstrates that the new approach outperforms (in terms of accuracy and efficiency) existing simulation codes that utilise the backward Euler method via a preconditioned Newton-Krylov strategy. © 2012 Elsevier Inc.

Taimre T.,University of Queensland | Rakic A.D.,Queensland University of Technology
Applied Optics | Year: 2014

Quasi-static interferometric signals in lasers under feedback arise from slowly varying perturbations of the intracavity electric field resulting from the reinjection of a portion of the emitted field into the cavity. Such interferometric signals are well described by the steady-state solution to the Lang-Kobayashi rate equation model. We give an exact series expansion for this steady-state solution that shows precisely how Acket's characteristic parameter C and Henry's linewidth enhancement factor α influence such signals. We show how the series coefficients canbe extracted easily and explain how to determine C and α directly from them. Moreover, we draw a precise analogy between self-mixing and FM signals, showing that C plays exactly the same role in self-mixing as the modulation index doesin FM. © 2014 Optical Society of America.

Della Gatta P.A.,Deakin University | Garnham A.P.,Deakin University | Peake J.M.,Queensland University of Technology | Cameron-Smith D.,University of Auckland
Brain, Behavior, and Immunity | Year: 2014

Aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. Exercise training, in addition to improving muscle function, reduces these circulating pro-inflammatory cytokines. Yet, few studies have evaluated changes in the expression of cytokines within skeletal muscle after exercise training. The aim of the current study was to examine the expression of cytokines both at rest and following a bout of isokinetic exercise performed before and after 12. weeks of resistance exercise training in young (n=8, 20.3. ±. 0.8. yr) and elderly men (n=8, 66.9. ±. 1.6. yr). Protein expression of various cytokines was determined in muscle homogenates. The expression of MCP-1, IL-8 and IL-6 (which are traditionally classified as 'pro-inflammatory') increased substantially after acute exercise. By contrast, the expression of the anti-inflammatory cytokines IL-4, IL-10 and IL-13 increased only slightly (or not at all) after acute exercise. These responses were not significantly different between young and elderly men, either before or after 12. weeks of exercise training. However, compared with the young men, the expression of pro-inflammatory cytokines 2. h post exercise tended to be greater in the elderly men prior to training. Training attenuated this difference. These data suggest that the inflammatory response to unaccustomed exercise increases with age. Furthermore, regular exercise training may help to normalize this inflammatory response, which could have important implications for muscle regeneration and adaptation in the elderly. © 2014 Elsevier Inc.

Gunawardana C.,Queensland University of Technology | Egodawatta P.,Queensland University of Technology | Goonetilleke A.,Queensland University of Technology
Environmental Pollution | Year: 2014

Despite common knowledge that the metal content adsorbed by fine particles is relatively higher compared to coarser particles, the reasons for this phenomenon have gained little research attention. The research study discussed in the paper investigated the variations in metal content for different particle sizes of solids associated with pollutant build-up on urban road surfaces. Data analysis confirmed that parameters favourable for metal adsorption to solids such as specific surface area, organic carbon content, effective cation exchange capacity and clay forming minerals content decrease with the increase in particle size. Furthermore, the mineralogical composition of solids was found to be the governing factor influencing the specific surface area and effective cation exchange capacity. There is high quartz content in particles >150 μm compared to particles <150 μm. As particle size reduces below 150 μm, the clay forming minerals content increases, providing favourable physical and chemical properties that influence adsorption. © 2013 Elsevier Ltd. All rights reserved.

Moroney T.,Queensland University of Technology | Yang Q.,Queensland University of Technology
Journal of Computational Physics | Year: 2013

We develop a fast Poisson preconditioner for the efficient numerical solution of a class of two-sided nonlinear space-fractional diffusion equations in one and two dimensions using the method of lines. Using the shifted Grünwald finite difference formulas to approximate the two-sided (i.e. the left and right Riemann-Liouville) fractional derivatives, the resulting semi-discrete nonlinear systems have dense Jacobian matrices owing to the non-local property of fractional derivatives. We employ a modern initial value problem solver utilising backward differentiation formulas and Jacobian-free Newton-Krylov methods to solve these systems. For efficient performance of the Jacobian-free Newton-Krylov method it is essential to apply an effective preconditioner to accelerate the convergence of the linear iterative solver. The key contribution of our work is to generalise the fast Poisson preconditioner, widely used for integer-order diffusion equations, so that it applies to the two-sided space-fractional diffusion equation. A number of numerical experiments are presented to demonstrate the effectiveness of the preconditioner and the overall solution strategy. © 2013 Elsevier Inc.

Hine J.,University of Ulster | Kamruzzaman M.,Queensland University of Technology
Health and Place | Year: 2012

This paper examines changing patterns in the utilisation and geographic access to health services in Great Britain using National Travel Survey data (1985-2006). The utilisation rate was derived using the proportion of journeys made to access health services. Geographic access was analysed by separating the concept into its accessibility and mobility dimensions. Regression analyses were conducted to investigate the differences between different socio-spatial groups in these indicators over the period 1985-2006. This study found that journey distances to health facilities were significantly shorter and also gradually reduced over the period in question for Londoners, females, those without a car or on low incomes, and older people. However, most of their rates of utilisation of health services were found to be significantly lower because their journey times were significantly longer and also gradually increased over the periods. These findings indicate that the rate of utilisation of health services largely depends on mobility level although previous research studies have traditionally overlooked the mobility dimension. © 2011.

Doggrell S.A.,Queensland University of Technology | McIntyre K.,Queensland University of Technology
Expert Opinion on Pharmacotherapy | Year: 2014

Introduction: Inhibition of the sodium-glucose cotransporter 2 (SGLT2), to promote the excretion of glucose, is a new paradigm in the treatment of type 2 diabetes. Areas covered: Canagliflozin is an SGLT2 inhibitor, which has been the subject of two recent clinical trials, which are evaluated. Expert opinion: Studies with canagliflozin, in subjects with type 2 diabetes, have shown that its use is associated with reductions in HbA1c and body weight and small reductions in blood pressure and triglycerides, while increasing high-density lipoprotein cholesterol and low-density lipoprotein cholesterol. As monotherapy in Japanese subjects, or in comparison with glimepiride in CANTATA-SU (CANagliflozin Treatment and Trial Analysis versus SUlphonylurea), canagliflozin causes a low incidence of hypoglycemia, and this is an advantage over glimepiride. However, one of the disadvantages with canagliflozin, which was also highlighted in CANTATA-SU, is that canagliflozin can cause urogenital infections, which are not observed with other antidiabetic drugs. The Federal Drug Administration has recently approved canagliflozin for use in type 2 diabetes, while directing that a clinical outcome safety trial be undertaken. We are concerned that canagliflozin has been approved for use in type 2 diabetes prior to a clinical outcome study of efficacy being undertaken and without the outcome of further safety testing. © 2014 Informa UK, Ltd.

Mathur A.,Queensland University of Technology | Atchison D.A.,Queensland University of Technology
Optometry and Vision Science | Year: 2013

PURPOSE: To investigate hyperopic shifts and the oblique (or 45-degree/135-degree) component of astigmatism at large angles in the horizontal visual field using the Hartmann-Shack technique. METHODS: The adult participants consisted of 6 hypermetropes, 13 emmetropes and 11 myopes. Measurements were made with a modified COAS-HD Hartmann-Shack aberrometer across ±60 degrees along the horizontal visual field in 5-degree steps. Eyes were dilated with 1% cyclopentolate. Peripheral refraction was estimated as mean spherical (or spherical equivalent) refraction, with/against the rule of astigmatism and oblique astigmatism components, and as horizontal and vertical refraction components based on 3-mm major diameter elliptical pupils. RESULTS: Thirty percent of eyes showed a pattern that was a combination of type IV and type I patterns of Rempt et al. (Rempt F, Hoogerheide J, Hoogenboom WP. Peripheral retinoscopy and the skiagram. Ophthalmologica 1971;162:1-10), which shows the characteristics of type IV (relative hypermetropia along the vertical meridian and relative myopia along the horizontal meridian) out to an angle of between 40 and 50 degrees before behaving like type I (both meridians show relative hypermetropia). We classified this pattern as type IV/I. Seven of 13 emmetropes had this pattern. As a group, there was no significant variation of the oblique component of astigmatism with angle, but about one-half of the eyes showed significant positive slopes (more positive or less negative values in the nasal field than in the temporal field) and one-fourth showed significant negative slopes. CONCLUSIONS: It is often considered that a pattern of relative peripheral hypermetropia predisposes to the development of myopia. In this context, the finding of a considerable portion of emmetropes with the IV/I pattern suggests that it is unlikely that refraction at visual field angles beyond 40 degrees from fixation contributes to myopia development. Copyright © 2013 American Academy of Optometry.

Dargaville T.R.,Queensland University of Technology | Farrugia B.L.,Queensland University of Technology | Broadbent J.A.,Queensland University of Technology | Pace S.,University of South Australia | And 2 more authors.
Biosensors and Bioelectronics | Year: 2013

Wound healing involves a complex series of biochemical events and has traditionally been managed with 'low tech' dressings and bandages. The concept that diagnostic and theranostic sensors can complement wound management is rapidly growing in popularity as there is tremendous potential to apply this technology to both acute and chronic wounds. Benefits in sensing the wound environment include reduction of hospitalization time, prevention of amputations and better understanding of the processes which impair healing. This review discusses the state-of-the-art in detection of markers associated with wound healing and infection, utilizing devices imbedded within dressings or as point-of-care techniques to allow for continual or rapid wound assessment and monitoring. Approaches include using biological or chemical sensors of wound exudates and volatiles to directly or indirectly detect bacteria, monitor pH, temperature, oxygen and enzymes. Spectroscopic and imaging techniques are also reviewed as advanced wound monitoring techniques. The review concludes with a discussion of the limitations of and future directions for this field. © 2012 Elsevier B.V.

Freestone R.,University of New South Wales | Baker D.,Queensland University of Technology
Journal of Air Transport Management | Year: 2010

The privatization of major Australian airports in the late 1990s unleashed an unprecedented development wave as corporate lessees implemented ambitious business plans. While planning and environmental regulations governing on-airport development were significantly enhanced, there has been national disquiet about a governance regime that remains under the auspices of the federal government and is not effectively integrated into state and local decision-making machinery. Tensions in major airport regions have been exacerbated by the building of highly conspicuous non-aeronautical developments approved with no determining input by local decision-makers as well as the growing pressures on off-airport locations for aviation-related development. This paper canvasses this context and overviews the evolving structure of planning controls for Australia's privatized federal airports. A range of issues surfacing through the National Aviation Policy Review process in 2008-2009 is described. © 2010 Elsevier Ltd.

Parker R.,Queensland University of Technology
European Urban and Regional Studies | Year: 2010

The aim of this paper is to advance understandings of the processes of cluster-building and evolution, or transformative and adaptive change, through the conscious design and reflective activities of private and public actors. A model of transformation is developed which illustrates the importance of actors becoming exposed to new ideas and visions for industrial change by political entrepreneurs and external networks. Further, actors must be guided in their decision-making and action by the new vision, and this requires that they are persuaded of its viability through the provision of test cases and supportive resources and institutions. In order for new ideas to become guiding models, actors must be convinced of their desirability through the portrayal of models as a means of confronting competitive challenges and serving the economic interests of the city/region. Subsequent adaptive change is iterative and reflexive, involving a process of strategic learning amongst key industrial and political actors. © The Author(s) 2010.

Recker J.,Queensland University of Technology
Information and Management | Year: 2010

Our objective was to determine the factors that lead users to continue working with process modeling grammars after their initial adoption. We examined the explanatory power of three theoretical models of IT usage by applying them to two popular process modeling grammars. We found that a hybrid model of technology acceptance and expectation-confirmation best explained user intentions to continue using the grammars. We examined differences in the model results, and used them to provide three contributions. First, the study confirmed the applicability of IT usage models to the domain of process modeling. Second, we discovered that differences in continued usage intentions depended on the grammar type instead of the user characteristics. Third, we suggest implications and practice. © 2010 Elsevier B.V. All rights reserved.

Sedera D.,Queensland University of Technology | Gable G.G.,Queensland University of Technology
Journal of Strategic Information Systems | Year: 2010

This study conceptualizes, operationalises and validates the concept of Knowledge Management Competence as a four-phase multidimensional formative index. Employing survey data from 310 respondents representing 27 organizations using the SAP Enterprise System Financial module, the study results demonstrate a large, significant, positive relationship between Knowledge Management Competence and Enterprise Systems Success (ES-success, as conceived by Gable et al., 2008); suggesting important implications for practice. Strong evidence of the validity of Knowledge Management Competence as conceived and operationalised, too suggests potential from future research evaluating its relationships with possible antecedents and consequences. © 2010 Published by Elsevier B.V. All rights reserved.

Saha S.C.,Queensland University of Technology | Saha S.C.,Central Queensland University | Khan M.M.K.,Central Queensland University
Energy and Buildings | Year: 2011

This paper presents a review of studies on natural convection heat transfer in the triangular enclosure namely, in attic-shaped space. Much research activity has been devoted to this topic over the last three decades with a view to providing thermal comfort to the occupants in attic-shaped buildings and to minimising the energy costs associated with heating and air-conditioning. Two basic thermal boundary conditions of attic are considered to represent hot and cold climates or day and night time. This paper also reports on a significant number of studies which have been performed recently on other topics related to the attic space, for example, attics subject to localized heating and attics filled with porous media. © 2011 Elsevier B.V. All rights reserved.

Vivekananthan C.,Queensland University of Technology | Mishra Y.,Queensland University of Technology | Ledwich G.,Queensland University of Technology | Li F.,University of Tennessee at Knoxville
IEEE Transactions on Smart Grid | Year: 2014

This paper proposes a reward based demand response algorithm for residential customers to shave network peaks. Customer survey information is used to calculate various criteria indices reflecting their priority and flexibility. Criteria indices and sensitivity based house ranking is used for appropriate load selection in the feeder for demand response. Customer Rewards (CR) are paid based on load shift and voltage improvement due to load adjustment. The proposed algorithm can be deployed in residential distribution networks using a two-level hierarchical control scheme. Realistic residential load model consisting of non-controllable and controllable appliances is considered in this study. The effectiveness of the proposed demand response scheme on the annual load growth of the feeder is also investigated. Simulation results show that reduced peak demand, improved network voltage performance, and customer satisfaction can be achieved. © 2014 IEEE.

Wang H.,Queensland University of Technology
International Journal of Photoenergy | Year: 2011

The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,Ga)Se2 (CIGS) in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS) semiconductor material has emerged as one of the most promising candidates for this aim and has attracted considerable interest recently. Significant progress in this relatively new research area has been achieved in the last three years. Over 130 papers on CZTS have been published since 2007, and the majority of them are on the preparation of CZTS thin films by different methods. This paper, will review the wide range of techniques that have been used to deposit CZTS semiconductor thin films. The performance of the thin film solar cells using the CZTS material will also be discussed. Copyright © 2011 Hongxia Wang.

Bishop C.,University of South Australia | Paul G.,Queensland University of Technology | Thewlis D.,University of South Australia
Gait and Posture | Year: 2013

Kinematic models are commonly used to quantify foot and ankle kinematics, yet no marker sets or models have been proven reliable or accurate when wearing shoes. Further, the minimal detectable difference of a developed model is often not reported. We present a kinematic model that is reliable, accurate and sensitive to describe the kinematics of the foot-shoe complex and lower leg during walking gait. In order to achieve this, a new marker set was established, consisting of 25 markers applied on the shoe and skin surface, which informed a four segment kinematic model of the foot-shoe complex and lower leg. Three independent experiments were conducted to determine the reliability, accuracy and minimal detectable difference of the marker set and model. Inter-rater reliability of marker placement on the shoe was proven to be good to excellent (ICC=0.75-0.98) indicating that markers could be applied reliably between raters. Intra-rater reliability was better for the experienced rater (ICC=0.68-0.99) than the inexperienced rater (ICC=0.38-0.97). The accuracy of marker placement along each axis was <6.7mm for all markers studied. Minimal detectable difference (MDD90) thresholds were defined for each joint; tibiocalcaneal joint - MDD90=2.17-9.36°, tarsometatarsal joint - MDD90=1.03-9.29° and the metatarsophalangeal joint - MDD90=1.75-9.12°. These thresholds proposed are specific for the description of shod motion, and can be used in future research designed at comparing between different footwear. © 2012 Elsevier B.V.

Doggrell S.A.,Queensland University of Technology
Expert Opinion on Pharmacotherapy | Year: 2013

There is a debate as to whether percutaneous coronary intervention (PCI) with drug-eluting stents or coronary artery bypass surgery (CABG) is the best procedure for subjects with type 2 diabetes and coronary artery disease requiring revascularization. There is some evidence that by following these procedures, there is less further revascularization with CABG than PCI in subjects with diabetes. Two recent studies, namely, the FREEDOM (Future Revascularization Evaluation in patients with Diabetes mellitus: Optimal Management of Multivessel Disease) trial and a trial using a real-world diabetic population from a Registry have shown that the benefits of CABG over PCI in subjects with type 2 diabetes extend to lower rates of death and myocardial infarction, in addition to lower rates of revascularization. However, the rates of stroke may be higher with CABG than PCI with drug-eluting stents in this population. Thus, if CABG is going to be preferred to PCI in subjects with type 2 diabetes and multivessel coronary disease, consideration should be given as to how to reduce the rates of stroke with CABG. © 2013 Informa UK, Ltd.

Miller E.,Queensland University of Technology
Journal of Leisure Research | Year: 2016

How do older adults living in residential aged care experience leisure activities? What restricts and facilitates participation? These two research questions guided this semi-longitudinal qualitative research, tracking the lived experience of aged care from the perspective of 20 new-aged care residents over 18 months (average age, 80 years) through repeated in-depth semi-structured interviews. Interview data were analyzed using phenomenography, an under-utilized qualitative analysis technique that identifies the variations in how people experience, understand, or conceive of a phenomenon. Phenomenography revealed three qualitatively different ways to understand residents' leisure experience: (1) as a structure for living, (2) creating social connections and (3) maintaining ability. By illustrating the variation and similarities in how these older Australian residents conceptualise and experience leisure in aged care, the findings may help facilitate a more thoughtful understanding that informs theory, policy, and practice.

Ishaq M.,CSIRO | Evans M.D.M.,CSIRO | Ostrikov K.K.,CSIRO | Ostrikov K.K.,Queensland University of Technology
Biochimica et Biophysica Acta - Molecular Cell Research | Year: 2014

Atmospheric pressure gas plasma (AGP) generates reactive oxygen species (ROS) that induce apoptosis in cultured cancer cells. The majority of cancer cells develop a ROS-scavenging anti-oxidant system regulated by Nrf2, which confers resistance to ROS-mediated cancer cell death. Generation of ROS is involved in the AGP-induced cancer cell death of several colorectal cancer cells (Caco2, HCT116 and SW480) by activation of ASK1-mediated apoptosis signaling pathway without affecting control cells (human colonic sub-epithelial myofibroblasts; CO18, human fetal lung fibroblast; MRC5 and fetal human colon; FHC). However, the identity of an oxidase participating in AGP-induced cancer cell death is unknown. Here, we report that AGP up-regulates the expression of Nox2 (NADPH oxidase) to produce ROS. RNA interference designed to target Nox2 effectively inhibits the AGP-induced ROS production and cancer cell death. In some cases both colorectal cancer HT29 and control cells showed resistance to AGP treatment. Compared to AGP-sensitive Caco2 cells, HT29 cells show a higher basal level of the anti-oxidant system transcriptional regulator Nrf2 and its target protein sulfiredoxin (Srx) which are involved in cellular redox homeostasis. Silencing of both Nrf2 and Srx sensitized HT29 cells, leads to ROS overproduction and decreased cell viability. This indicates that in HT29 cells, Nrf2/Srx axis is a protective factor against AGP-induced oxidative stress. The inhibition of Nrf2/Srx signaling should be considered as a central target in drug-resistant colorectal cancer treatments. © 2014 Elsevier B.V.

Brodribb W.,University of Queensland | Miller Y.,Queensland University of Technology
Journal of Human Lactation | Year: 2013

Background: Recommendations for the introduction of solids and fluids to an infants diet have changed over the past decade. Since these changes, there has been minimal research to determine patterns in the introduction of foods and fluids to infants. Methods: This retrospective cohort study surveyed mothers who birthed in Queensland, Australia, from February 1 to May 31, 2010, around 4 months postpartum. Frequencies of foods and fluids given to infants at 4, 8, 13, and 17 weeks were described. Logistic regression determined associations between infant feeding practices, the introduction of other foods and fluids at 17 weeks, and sociodemographic characteristics. Results: Response rate was 35.8%. At 17 weeks, 68% of infants were breastfed and 33% exclusively breastfed. Solids and water had been introduced in 8.6% and 35.0% of infants, respectively. The introduction of solids by 17 weeks was associated with younger maternal age and the infant being given water and infant formula at 4 weeks. The infant being given water at 17 weeks was associated with younger maternal age, the infant being given infant formula at 4 weeks, level of education, relative socioeconomic disadvantage, parity, and birth facility. Conclusion: Over the past decade, there has been a significant reduction in the proportion of infants in Australia who have been given solids by 17 weeks. Sociodemographic characteristics and formula feeding practices at 4 weeks were associated with the introduction of solids and water by 17 weeks. Further research should examine these barriers to improve compliance with current infant feeding recommendations. © 2013 The Author(s).

Algergawy A.,Tanta University | Mesiti M.,University of Milan | Nayak R.,Queensland University of Technology | Saake G.,Otto Von Guericke University of Magdeburg
ACM Computing Surveys | Year: 2011

In the last few years we have observed a proliferation of approaches for clustering XML documents and schemas based on their structure and content. The presence of such a huge amount of approaches is due to the different applications requiring the clustering of XML data. These applications need data in the form of similar contents, tags, paths, structures, and semantics. In this article, we first outline the application contexts in which clustering is useful, then we survey approaches so far proposed relying on the abstract representation of data (instances or schema), on the identified similarity measure, and on the clustering algorithm. In this presentation, we aim to draw a taxonomy in which the current approaches can be classified and compared. We aim at introducing an integrated view that is useful when comparing XML data clustering approaches, when developing a new clustering algorithm, and when implementing an XML clustering component. Finally, the article moves into the description of future trends and research issues that still need to be faced. © 2011 ACM.

Little J.P.,Queensland University of Technology | Adam C.J.,Queensland University of Technology
Clinical Biomechanics | Year: 2011

Background: In vitro investigations have demonstrated the importance of the ribcage in stabilizing the thoracic spine. Surgical alterations of the ribcage may change load-sharing patterns in the thoracic spine. Computer models are used in this study to explore the effect of surgical disruption of the rib-vertebrae connections on ligament load-sharing in the thoracic spine. Methods: A finite element model of a T7-8 motion segment, including the T8 rib, was developed using CT-derived spinal anatomy for the Visible Woman. Both the intact motion segment and the motion segment with four successive stages of destabilization (discectomy and removal of right costovertebral joint, right costotransverse joint and left costovertebral joint) were analyzed for a 2000 Nmm moment in flexion/extension, lateral bending and axial rotation. Joint rotational moments were compared with existing in vitro data and a detailed investigation of the load sharing between the posterior ligaments carried out. Findings: The simulated motion segment demonstrated acceptable agreement with in vitro data at all stages of destabilization. Under lateral bending and axial rotation, the costovertebral joints were of critical importance in resisting applied moments. In comparison to the intact joint, anterior destabilization increases the total moment contributed by the posterior ligaments. Interpretation: Surgical removal of the costovertebral joints may lead to excessive rotational motion in a spinal joint, increasing the risk of overload and damage to the remaining ligaments. The findings of this study are particularly relevant for surgical procedures involving rib head resection, such as some techniques for scoliosis deformity correction. © 2011 Elsevier Ltd.

Opar D.A.,Queensland University of Technology | Williams M.D.,University of South Wales | Timmins R.G.,Queensland University of Technology | Dear N.M.,Queensland University of Technology | Shield A.J.,Queensland University of Technology
American Journal of Sports Medicine | Year: 2013

Background: The effect of prior strain injury on myoelectrical activity of the hamstrings during tasks requiring high rates of torque development has received little attention. Purpose: To determine if recreational athletes with a history of unilateral hamstring strain injury will exhibit lower levels of myoelectrical activity during eccentric contraction, rate of torque development (RTD), and impulse (IMP) at 30, 50, and 100 milliseconds after the onset of myoelectrical activity or torque development in the previously injured limb compared with the uninjured limb. Study Design: Case control study; Level of evidence, 3. Methods: Twenty-six recreational athletes were recruited. Of these, 13 athletes had a history of unilateral hamstring strain injury (all confined to biceps femoris long head), and 13 had no history of hamstring strain injury. Following familiarization, all athletes undertook isokinetic dynamometry testing and surface electromyography (integrated EMG; iEMG) assessment of the biceps femoris long head and medial hamstrings during eccentric contractions at -60 and -180 deg-s-1. Results: In the injured limb of the injured group, compared with the contralateral uninjured limb, RTD and IMP was lower during -60 deg-s-1 eccentric contractions at 50 milliseconds (RTD: injured limb, 312.27 ± 191.78 N-m-s-1 vs uninjured limb, 518.54 ± 172.81 N-m-s-1, P =.008; IMP: injured limb, 0.73 ± 0.30 N-m-s vs uninjured limb, 0.97 ± 0.23 N-m-s, P =.005) and 100 milliseconds (RTD: injured limb, 280.03 ± 131.42 N-m-s-1 vs uninjured limb, 460.54 ± 152.94 N-m-s-1, P =.001; IMP: injured limb, 2.15 ± 0.89 N-m-s vs uninjured limb, 3.07 ± 0.63 N-m-s, P <.001) after the onset of contraction. Biceps femoris long head muscle activation was lower at 100 milliseconds at both contraction speeds (-60 deg-s-1, normalized iEMG activity [X1000]: injured limb, 26.25 ± 10.11 vs uninjured limb, 33.57 ± 8.29, P =.009; -180 deg-s -1, normalized iEMG activity [X1000]: injured limb, 31.16 ± 10.01 vs uninjured limb, 39.64 ± 8.36, P =.009). Medial hamstring activation did not differ between limbs in the injured group. Comparisons in the uninjured group showed no significant between limbs difference for any variables. Conclusion: Previously injured hamstrings displayed lower RTD and IMP during slow maximal eccentric contraction compared with the contralateral uninjured limb. Lower myoelectrical activity was confined to the biceps femoris long head. Regardless of whether these deficits are the cause of or the result of injury, these findings could have important implications for hamstring strain injury and reinjury. Particularly, given the importance of high levels of muscle activity to bring about specific muscular adaptations, lower levels of myoelectrical activity may limit the adaptive response to rehabilitation interventions and suggest that greater attention be given to neural function of the knee flexors after hamstring strain injury. © 2013 The Author(s).

Chen X.,Star Intellect Pty Ltd. | Jones H.M.,Australian National University | Jayalath D.,Queensland University of Technology
IEEE Transactions on Mobile Computing | Year: 2011

In wireless mobile ad hoc networks (MANETs), packet transmission is impaired by radio link fluctuations. This paper proposes a novel channel adaptive routing protocol which extends the Ad hoc On-Demand Multipath Distance Vector (AOMDV) routing protocol to accommodate channel fading. Specifically, the proposed Channel-Aware AOMDV (CA-AOMDV) uses the channel average nonfading duration as a routing metric to select stable links for path discovery, and applies a preemptive handoff strategy to maintain reliable connections by exploiting channel state information. Using the same information, paths can be reused when they become available again, rather than being discarded. We provide new theoretical results for the downtime and lifetime of a live-die-live multiple path system, as well as detailed theoretical expressions for common network performance measures, providing useful insights into the differences in performance between CA-AOMDV and AOMDV. Simulation and theoretical results show that CA-AOMDV has greatly improved network performance over AOMDV. © 2011 IEEE.

Rackemann D.W.,Queensland University of Technology | Doherty W.O.,Queensland University of Technology
Biofuels, Bioproducts and Biorefining | Year: 2011

Biomass represents an abundant and relatively low cost carbon resource that can be utilized to produce platform chemicals such as levulinic acid. Current processing technology limits the cost-effective production of levulinic acid in commercial quantities from biomass. The key to improving the yield and efficiency of levulinic acid production from biomass lies in the ability to optimize and isolate the intermediate products at each step of the reaction pathway and reduce re-polymerization and side reactions. New technologies (including the use of microwave irradiation and ionic liquids) and the development of highly selective catalysts would provide the necessary step change for the optimization of key reactions. A processing environment that allows the use of biphasic systems and/or continuous extraction of products would increase reaction rates, yields and product quality. This review outlines the chemistry of levulinic acid synthesis and discusses current and potential technologies for producing levulinic acid from lignocellulosics. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd.

Conant R.T.,Colorado State University | Conant R.T.,Queensland University of Technology
Wiley Interdisciplinary Reviews: Climate Change | Year: 2011

Current climate mitigation policies have not fully resolved contentious issues regarding the inclusion of carbon sequestration through changes in forestry and agricultural management practices. Terrestrial carbon sinks could be a low-cost mitigation option that fosters conservation and development, yet issues related to accurately documenting the amount of carbon sequestered undermine confidence that emission offsets through sequestration are equivalent to emission reductions. From an atmospheric perspective, net of CO 2 removals through sequestration are equivalent to emission reductions over a given period of time. But carbon will not remain sequestered in biomass or soils indefinitely and investments in sequestration could stifle investments in reducing emissions from other sources. Many international climate agreements cap emissions from some countries or sectors but enable participation of uncapped countries or sectors for forestry and agricultural sequestration. This structure can prompt emission increases in parts of the uncapped entities that weaken the value of emission reductions earned through sequestration. This has been a minor issue under the Clean Development Mechanism of the Kyoto Protocol. Reduced emissions through deforestation and degradation is susceptible to the same problems. The purpose of this article is to review the science, politics, and policy that form the basis of arguments for and against the inclusion forestry and agricultural sequestration as a component of current and future international climate mitigation policies. © 2011 John Wiley & Sons, Ltd.

Demark-Wahnefried W.,University of Alabama at Birmingham | Campbell K.L.,University of British Columbia | Hayes S.C.,Queensland University of Technology
Cancer | Year: 2012

Overweight and obesity are risk factors for postmenopausal breast cancer, and many women diagnosed with breast cancer, irrespective of menopausal status, gain weight after diagnosis. Weight management plays an important role in rehabilitation and recovery because obesity and/or weight gain may lead to poorer breast cancer prognosis, as well as prevalent comorbid conditions (eg, cardiovascular disease and diabetes), poorer surgical outcomes (eg, increased operating and recovery times, higher infection rates, and poorer healing), lymphedema, fatigue, functional decline, and poorer health and overall quality of life. Health care professionals should encourage weight management at all phases of the cancer care continuum as a means to potentially avoid adverse sequelae and late effects, as well as to improve overall health and possibly survival. Comprehensive approaches that involve dietary and behavior modification, and increased aerobic and strength training exercise have shown promise in either preventing weight gain or promoting weight loss, reducing biomarkers associated with inflammation and comorbidity, and improving lifestyle behaviors, functional status, and quality of life in this high-risk patient population. © 2012 American Cancer Society.

Doggrell S.A.,Queensland University of Technology
Breast Cancer Research and Treatment | Year: 2011

There is a perception that women on oral endocrine treatments for oestrogen receptor-positive breast cancer will be adherent to these medicines, as they are facing a serious life-threatening disease, and the oral endocrine treatments are effective, easy to use and generally well tolerated. This is not in fact the case, and this is the basis of the first half of this review. The second half is of whether the changes/interventions to 'improve' adherence do actually increase adherence to the oral endocrine medicines. The review shows that better outcomes are achieved with good adherence to endocrine treatments in breast cancer. The rates of adherence to endocrine treatments range between 15 and 50%, and are influenced by a large number of factors (e.g. adverse effects, lack of belief in treatment, psychological problems and poor patient-health care provider relationship). Interventions to minimise the adverse effects have been used in an attempt to improve the adherence to the endocrine treatment therapies, but it is not known whether these do actually improve adherence. Similar, it has been assumed that interventions by health professionals (doctors, nurses and pharmacists) will improve the adherence, but this has not been tested. In conclusion, in women with breast cancer, we know there is a problem with adherence. There are also many approaches and suggestions about how to improve adherence to the oral endocrine treatments, but none of these approaches/suggestions have been scientifically tested, and they need to be. © 2011 Springer Science+Business Media, LLC.

Greulich H.,Dana-Farber Cancer Institute | Greulich H.,Harvard University | Greulich H.,Cambridge Broad Institute | Pollock P.M.,Queensland University of Technology
Trends in Molecular Medicine | Year: 2011

Fibroblast growth factor receptors (FGFRs) play diverse roles in the control of cell proliferation, cell differentiation, angiogenesis and development. Activating the mutations of FGFRs in the germline has long been known to cause a variety of skeletal developmental disorders, but it is only recently that a similar spectrum of somatic FGFR mutations has been associated with human cancers. Many of these somatic mutations are gain-of-function and oncogenic and create dependencies in tumor cell lines harboring such mutations. A combination of knockdown studies and pharmaceutical inhibition in preclinical models has further substantiated genomically altered FGFR as a therapeutic target in cancer, and the oncology community is responding with clinical trials evaluating multikinase inhibitors with anti-FGFR activity and a new generation of specific pan-FGFR inhibitors. © 2011 Elsevier Ltd.

Doggrell S.A.,Queensland University of Technology
Expert Opinion on Therapeutic Targets | Year: 2011

Despite the present treatments for asthma (β2-adrenoceptor agonists, glucocorticoids, leukotriene receptor antagonists), many subjects with asthma have difficulty controlling it. Bitter taste receptors have recently been identified on human lung. The paper evaluated considers these receptors as a target for bronchodilation, by characterizing the effects of agonists in cultured human airway smooth muscle cells, isolated human bronchial smooth muscle and a mouse model of allergic asthma. The study confirmed that a bitter taste receptor (TAS2R) is a viable target for bronchodilation. Many diverse chemicals are known to stimulate the bitter taste receptors to produce the bitter taste, and many of these have more than one mechanism of action. Thus, it is not known whether any of these have clinical potential in asthma. It may be necessary to design and develop selective agonists for TAS2R, before the clinical potential of this target can be thoroughly investigated. © 2011 Informa UK, Ltd.

Gallagher M.,Queensland University of Technology
Soft Computing | Year: 2016

The field of Metaheuristics has produced a large number of algorithms for continuous, black-box optimization. In contrast, there are few standard benchmark problem sets, limiting our ability to gain insight into the empirical performance of these algorithms. Clustering problems have been used many times in the literature to evaluate optimization algorithms. However, much of this work has occurred independently on different problem instances and the various experimental methodologies used have produced results which are frequently incomparable and provide little knowledge regarding the difficulty of the problems used, or any platform for comparing and evaluating the performance of algorithms. This paper discusses sum of squares clustering problems from the optimization viewpoint. Properties of the fitness landscape are analysed and it is proposed that these problems are highly suitable for algorithm benchmarking. A set of 27 problem instances (from 4-D to 40-D), based on three well-known datasets, is specified. Baseline experimental results are presented for the Covariance Matrix Adaptation-Evolution Strategy and several other standard algorithms. A web-repository has also been created for this problem set to facilitate future use for algorithm evaluation and comparison. © 2016 Springer-Verlag Berlin Heidelberg

Woodruff M.A.,Queensland University of Technology | Hutmacher D.W.,Queensland University of Technology
Progress in Polymer Science (Oxford) | Year: 2010

During the resorbable-polymer-boom of the 1970s and 1980s, polycaprolactone (PCL) was used extensively in the biomaterials field and a number of drug-delivery devices. Its popularity was soon superseded by faster resorbable polymers which had fewer perceived disadvantages associated with long-term degradation (up to 3-4 years) and intracellular resorption pathways; consequently, PCL was almost forgotten for most of two decades. Recently, a resurgence of interest has propelled PCL back into the biomaterials-arena. The superior rheological and viscoelastic properties over many of its aliphatic polyester counterparts renders PCL easy to manufacture and manipulate into a large range of implants and devices. Coupled with relatively inexpensive production routes and FDA approval, this provides a promising platform for the design and fabrication of longer term degradable implants which may be manipulated physically, chemically and biologically to possess tailorable degradation kinetics to suit a specific anatomical site. This review will discuss the application of PCL as a biomaterial over the last two decades focusing on the advantages which have propagated its return into the spotlight with a particular focus on medical devices, drug delivery and tissue engineering. © 2010 Elsevier Ltd. All rights reserved.

Wood J.M.,Queensland University of Technology
Investigative ophthalmology & visual science | Year: 2013

To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.

Shakespeare-Finch J.,Queensland University of Technology | Lurie-Beck J.,Queensland University of Technology
Journal of Anxiety Disorders | Year: 2014

Traumatic experiences can have a powerful impact on individuals and communities but the relationship between perceptions of beneficial and pathological outcomes are not known. Therefore, this meta-analysis examined both the strength and the linearity of the relationship between symptoms of posttraumatic stress disorder (PTSD) and perceptions of posttraumatic growth (PTG) as well as identifying the potential moderating roles of trauma type and age. Literature searches of all languages were conducted using the ProQuest, Wiley Interscience, ScienceDirect, Informaworld and Web of Science databases. Linear and quadratic (curvilinear) rs as well as βs were analysed. Forty-two studies (N=11,469) that examined both PTG and symptoms of PTSD were included in meta-analytic calculations. The combined studies yielded a significant linear relationship between PTG and PTSD symptoms (r=0.315, CI=0.299, 0.331), but also a significantly stronger (as tested by Fisher's transformation) curvilinear relationship (r=0.372, CI. =. 0.353, 0.391). The strength and linearity of these relationships differed according to trauma type and age. The results remind those working with traumatised people that positive and negative post-trauma outcomes can co-occur. A focus only on PTSD symptoms may limit or slow recovery and mask the potential for growth. © 2013.

Zhou X.,Queensland University of Technology
Proceedings of the IEEE | Year: 2012

The centenary of the Proceedings of the IEEE is celebrated with achievements in data storage and data retrieval research, development, and application. Masaru Kitsuregawa and his colleagues at The University of Tokyo, Tokyo, Japan, are studying data storage and data management for more than three decades, working in parallel database management systems, web-scale applications, and intelligent massive data storage systems. They present a brief history of data storage technology from the precomputer era to the latest trends in this area. They also report their firsthand experiences in archiving the World Wide Web for more than ten years. Mark Sanderson and Bruce Croft give an expert view on the chronicled development in information retrieval.

Wood J.M.,Queensland University of Technology | Owsley C.,University of Alabama at Birmingham
Gerontology | Year: 2014

The useful field of view test was developed to reflect the visual difficulties that older adults experience with everyday tasks. Importantly, the useful field of view test (UFOV) is one of the most extensively researched and promising predictor tests for a range of driving outcomes measures, including driving ability and crash risk as well as other everyday tasks. Currently available commercial versions of the test can be administered using personal computers; these measure the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter. The test is believed to assess higher-order cognitive abilities, but performance also relies on visual sensory function because in order for targets to be attended to, they must be visible. The format of the UFOV has been modified over the years; the original version estimated the spatial extent of useful field of view, while the latest version measures visual processing speed. While deficits in the useful field of view are associated with functional impairments in everyday activities in older adults, there is also emerging evidence from several research groups that improvements in visual processing speed can be achieved through training. These improvements have been shown to reduce crash risk, and can have a positive impact on health and functional well-being, with the potential to increase the mobility and hence the independence of older adults. © 2014 S. Karger AG, Basel.

Tang K.D.,Queensland University of Technology | Ling M.-T.,Queensland University of Technology
Current Medicinal Chemistry | Year: 2014

The phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR pathway is one of the most frequently activated signaling pathways in prostate cancer cells, and loss of the tumor suppressor PTEN and amplification of PIK3CA are the two most commonly detected mechanisms for the activation of these pathways. Aberrant activation of PI3K/Akt/mTOR has been implicated not only in the survival and metastasis of prostate cancer cells but also in the development of drug resistance. As such, selective inactivation of this pathway may provide opportunities to attack prostate cancer from all fronts. However, while preclinical studies examining specific inhibitors of PI3K or mTOR have yielded promising results, the evidence from clinical trials is less convincing. Emerging evidence from the analyses of some solid tumors suggests that a class of dual PI3K/mTOR inhibitors, which bind to and inactivate both PI3K and mTOR, may achieve better anti-cancer outcomes. In this review, we will summarize the mechanisms of action of these inhibitors, their effectiveness when used alone or in combination with other chemotherapeutic compounds, and their potential to serve as the next generation therapies for prostate cancer patients, particularly those who are resistant to the frontline chemotherapeutic drugs.

Hines S.,Queensland University of Technology
International journal of evidence-based healthcare | Year: 2010

This systematic review aimed to establish best practice in relation to thickened fluids for people with dementia living in residential aged care facilities. This review considered all types of studies that examined the prescription and administration of thickened fluids to people with dementia in residential aged care facilities. English-language articles published from 1995 to 2008 were sought in a comprehensive search of an extensive range of databases, online sources and unpublished literature. Two independent reviewers critically appraised each article using the relevant Joanna Briggs Institute System for the Unified Management, Assessment and Review of Information (JBI-SUMARI) instruments, then data were extracted from those articles that met the inclusion criteria. No meta-analysis was possible because of significant clinical and methodological heterogeneity, therefore results are reported narratively. From 112 papers originally identified, 14 met the inclusion criteria and formed the basis of the findings. Nine studies recommend the use of thickened fluids as a strategy to maintain adequate fluid intake for persons with dementia with dysphagia in residential aged care and four papers recommend their use for people with dementia in general. One paper reported that the use of thickened fluids was found to be acceptable to older people in the event of dementia and dysphagia. From the retrieved data, evidence-based best practices cannot be concluded. It can, however, be cautiously inferred that thickened fluids may be effective for residents with dementia if set guidelines are instituted. © 2010 The Authors. International Journal of Evidence-Based Healthcare © 2010 The Joanna Briggs Institute.

Berglund E.,Queensland University of Technology
Applied Intelligence | Year: 2010

The original Parameter-Less Self-Organising Map (PLSOM) algorithm was introduced as a solution to the problems the Self-Organising Map (SOM) encounters when dealing with certain types of mapping tasks. Unfortunately the PLSOM suffers from over-sensitivity to outliers and over-reliance on the initial weight distribution. The PLSOM2 algorithm is introduced to address these problems with the PLSOM. PLSOM2 is able to cope well with outliers without exhibiting the problems associated with the standard PLSOM algorithm. The PLSOM2 requires very little computational overhead compared to the standard PLSOM, thanks to an efficient method of approximating the diameter of the inputs, and does not rely on a priori knowledge of the training input space. This paper provides a discussion of the reasoning behind the PLSOM2 and experimental results showing its effectiveness for mapping tasks. © 2008 Springer Science+Business Media, LLC.

Adam C.,Queensland University of Technology
Cell and Tissue Research | Year: 2012

Two major difficulties facing widespread clinical implementation of existing Tissue Engineering (TE) strategies for the treatment of musculoskeletal disorders are (1) the cost, space and time required for ex vivo culture of a patient's autologous cells prior to re-implantation as part of a TE construct, and (2) the potential risks and availability constraints associated with transplanting exogenous (foreign) cells. These hurdles have led to recent interest in endogenous TE strategies, in which the regenerative potential of a patient's own cells is harnessed to promote tissue regrowth without ex vivo cell culture. This article provides a focused perspective on key issues in the development of endogenous TE strategies, progress to date, and suggested future research directions toward endogenous repair and regeneration of musculoskeletal tissues and organs. © Springer-Verlag 2011.

Antoniades M.A.,University of Toronto | Antoniades M.A.,Queensland University of Technology | Eleftheriades G.V.,University of Toronto
IEEE Transactions on Antennas and Propagation | Year: 2012

A compact, fully-printed negative-refractive-index transmission-line (NRI-TL) metamaterial-loaded dipole antenna is proposed, which exhibits multiband resonant characteristics that are not harmonically related. The multiband behavior is achieved by loading a host dipole antenna with series capacitive gaps and shunt inductive strips, to form a two unit-cell NRI-TL loaded antenna. By modeling the right-handed dipole sections as biconical transmission lines, the rich dispersion properties of the NRI-TL structure can be exploited, while still creating an effective radiator. An equivalent circuit model of the NRI-TL antenna is developed, and it is shown that its performance agrees well with the results obtained using full-wave simulations. It is also shown that the resonant behavior of the antenna can be adjusted by changing its geometrical parameters, which in turn tune the loading parameters of each NRI-TL unit cell. As such, both dual-band and triband versions of the antenna are designed and fabricated. The dual-band version exhibits three distinct resonances at 1.15, 2.88, and 3.72 GHz, with measured-10 dB bandwidths of 37 and 1150 MHz. The lowest resonance at 1.15 GHz corresponds to a 47% reduction in the resonant frequency compared to that of a reference unloaded dipole antenna, which translates into a size miniaturization factor of approximately two. The antenna exhibits stable dipolar radiation patterns with a linear electric field polarization, and has a total size of 50× 10× 0.79mm3 or 0.19λ0× 0.04λ0× 0.003λ0 at 1.15 GHz. Throughout the operating bands the measured gain and radiation efficiency vary from 0.11 to 3.26 dBi and 49.5% to 95.6%, respectively. © 2012 IEEE.

Turner L.R.,Queensland University of Technology
Prehospital and disaster medicine | Year: 2013

Introduction Heat waves have significant impacts on mortality and morbidity. However, little is known regarding effects on pre-admission health outcomes such as ambulance attendances, particularly in subtropical regions. Problem This study investigated both main temperature effects and the added effects of heat waves on ambulance attendances in Brisbane, a subtropical city in Australia. Daily data relating to 783,935 ambulance attendances, along with data on meteorological variables and air pollutants, were collected for the period 2000-2007. Ambient temperature (main) effects were assessed using a distributed lag nonlinear approach that accounted for delayed effects of temperature, while added heat wave effects were incorporated separately using a local heat wave definition. Effect estimates were obtained for total, cardiovascular and respiratory attendances, and different age groups. Main effects of temperature were found for total attendances, which increased by 50.6% (95% CI, 32.3%-71.4%) for a 9.5°C increase above a reference temperature of 29°C. An added heat wave effect on total attendances was observed (18.8%; 95% CI, 6.5%-32.5%). Significant effects were found for both respiratory and cardiovascular attendances, particularly for those aged 65 and above. Ambulance attendances can be significantly impacted by sustained periods of high temperatures, and are a valid source of early detection of the effects of extreme temperatures on the population. The planning of ambulance services may need to be adapted as a consequence of increasing numbers of heat waves in the future. Ambulance attendance data also should be utilized in the development of heat warning systems and climate change adaptation strategies.

Croker B.,Queensland University of Technology
The Journal of the Acoustical Society of America | Year: 2012

A method for detecting vocalization of giant barred frogs (Mixophyes iteratus) in noisy audio is proposed. Audio recordings from remote wireless sensor nodes were segmented into individual sounds and from each sound a small set of features was extracted. Feature vectors were compared to those of example calls using a Euclidean distance formula as a detection system. The system achieved a sensitivity of 0.85 with specificity of 0.92 when distinguishing M. iteratus calls from other species' calls and sensitivity of 0.88 with specificity 0.82 against background noise.

Gunawardena J.,Queensland University of Technology | Egodawatta P.,Queensland University of Technology | Ayoko G.A.,Queensland University of Technology | Goonetilleke A.,Queensland University of Technology
Atmospheric Environment | Year: 2013

Atmospheric deposition is one of the most important pathways of urban stormwater pollution. Atmospheric deposition, which can be in the form of either wet or dry deposition have distinct characteristics in terms of associated particulate sizes, pollutant types and influential parameters. This paper discusses the outcomes of a comprehensive research study undertaken to identify important traffic characteristics and climate factors such as antecedent dry period and rainfall characteristics which influences the characteristics of wet and dry deposition of solids and heavy metals. The outcomes confirmed that Zinc (Zn) is correlated with traffic volume whereas Lead (Pb), Cadmium (Cd), Nickel (Ni), and Copper (Cu) are correlated with traffic congestion. Consequently, reducing traffic congestion will be more effective than reducing traffic volume for improving air quality particularly in relation to Pb, Cd, Ni, and Cu. Zn was found to have the highest atmospheric deposition rate compared to other heavy metals. Zn in dry deposition is associated with relatively larger particle size fractions (>10 μm), whereas Pb, Cd, Ni and Cu are associated with relatively smaller particle size fractions (<10 μm). The analysis further revealed that bulk (wet plus dry) deposition which is correlated with rainfall depth and contains a relatively higher percentage of smaller particles compared to dry deposition which is correlated with the antecedent dry period. As particles subjected to wet deposition are smaller, they disperse over a larger area from the source of origin compared to particles subjected to dry deposition as buoyancy forces become dominant for smaller particles compared to the influence of gravity. Furthermore, exhaust emission particles were found to be primarily associated with bulk deposition compared to dry deposition particles which mainly originate from vehicle component wear. © 2012 Elsevier Ltd.

White K.M.,Queensland University of Technology | Hyde M.K.,Queensland University of Technology
Accident Analysis and Prevention | Year: 2010

Swimming at patrolled beaches reduces the likelihood of drownings and near-drownings. The present study tested the Theory of Planned Behaviour (TPB), with the addition of risk perceptions, in predicting people's intentions to swim between the flags at patrolled beaches. We examined also the predictors of people's willingness to swim [1] up to 10 m and [2] more than 10 m outside of the patrol flags. Participants (N=526) completed measures of attitudes, subjective norm, perceived behavioural control (PBC), intentions/willingness, and both objective and subjective risk perceptions. Two weeks later, a sub-sample of participants reported on their beach swimming behaviour for the previous fortnight. Attitude and subjective norm predicted intentions to swim between and willingness to swim outside of the flags. Age and PBC influenced willingness to swim beyond the flags. Objective risk predicted willingness to swim beyond the flags (both distances) while subjective risk predicted willingness to swim up to 10 m outside the flags. People's intentions to swim between the flags were correlated with their behaviour at followup. This study provides a preliminary investigation into an important safety behaviour and identifies factors to target when promoting safe swimming behaviours to prevent drowning deaths on Australian beaches. © 2010 Elsevier Ltd. All rights reserved.

Mendling J.,Humboldt University of Berlin | Recker J.,Queensland University of Technology | Reijers H.A.,TU Eindhoven
International Journal of Information System Modeling and Design | Year: 2010

The value of business process models is dependent on the choice of graphical elements in the model and their annotation with additional textual and graphical information. This research discusses the use of text and icons for labeling the graphical constructs in a process model. The authors use two established verb classification schemes to examine the choice of activity labels in process modeling practice. Based on the author's findings, this paper synthesizes a set of twenty-five activity label categories. Proposed is a systematic approach for graphically representing these label categories through the use of graphical icons, such that the resulting process models are easier and more readily understandable by end users. The author's findings contribute to an ongoing stream of research investigating the practice of process modeling and thereby contribute to the body of knowledge about conceptual modeling quality overall. Copyright © 2010 IGI Global.

Tickner J.A.,Queensland University of Technology | Urquhart A.J.,Queensland University of Technology | Stephenson S.-A.,Queensland University of Technology | Richard D.J.,Queensland University of Technology | O'Byrne K.J.,Queensland University of Technology
Frontiers in Oncology | Year: 2014

The role of exosomes in cancer development has become the focus of much research, due to the many emerging roles possessed by exosomes. These micro-vesicles that are ubiquitously released in to the extracellular milieu, have been found to regulate immune system function, particularly in tumorigenesis, as well as conditioning future metastatic sites for the attachment and growth of tumor tissue. Through an interaction with a range of host tissue, exosomes are able to generate a pro-tumor environment that is essential for carcinogenesis. Herein, we discuss the contents of exosomes and their contribution to tumorigenesis, as well as their role in chemotherapeutic resistance and the development of novel cancer treatments and the identification of cancer biomarkers. © 2014 Tickner, Urquhart, Stephenson, Richard and O'Byrne.

Minett G.M.,Queensland University of Technology | Duffield R.,University of Technology, Sydney
Frontiers in Physiology | Year: 2014

Prolonged intermittent-sprint exercise (i.e., team sports) induce disturbances in skeletal muscle structure and function that are associated with reduced contractile function, a cascade of inflammatory responses, perceptual soreness, and a delayed return to optimal physical performance. In this context, recovery from exercise-induced fatigue is traditionally treated from a peripheral viewpoint, with the regeneration of muscle physiology and other peripheral factors the target of recovery strategies. The direction of this research narrative on post-exercise recovery differs to the increasing emphasis on the complex interaction between both central and peripheral factors regulating exercise intensity during exercise performance. Given the role of the central nervous system (CNS) in motor-unit recruitment during exercise, it too may have an integral role in post-exercise recovery. Indeed, this hypothesis is indirectly supported by an apparent disconnect in time-course changes in physiological and biochemical markers resultant from exercise and the ensuing recovery of exercise performance. Equally, improvements in perceptual recovery, even withstanding the physiological state of recovery, may interact with both feed-forward/feed-back mechanisms to influence subsequent efforts. Considering the research interest afforded to recovery methodologies designed to hasten the return of homeostasis within the muscle, the limited focus on contributors to post-exercise recovery from CNS origins is somewhat surprising. Based on this context, the current review aims to outline the potential contributions of the brain to performance recovery after strenuous exercise. © 2014 Minett and Duffield.

Vromans L.P.,Queensland University of Technology | Schweitzer R.D.,Queensland University of Technology
Psychotherapy Research | Year: 2011

This study investigated depressive symptom and interpersonal relatedness outcomes from eight sessions of manualized narrative therapy for 47 adults with major depressive disorder. Post-therapy, depressive symptom improvement (d = 1.36) and proportions of clients achieving reliable improvement (74%), movement to the functional population (61%), and clinically significant improvement (53%) were comparable to benchmark research outcomes. Post-therapy interpersonal relatedness improvement (d =.62) was less substantial than for symptoms. Three-month follow-up found maintenance of symptom, but not interpersonal gains. Benchmarking and clinical significance analyses mitigated repeated measure design limitations, providing empirical evidence to support narrative therapy for adults with major depressive disorder. © 2011 Society for Psychotherapy Research.

Coffey B.,Deakin University | Marston G.,Queensland University of Technology
Journal of Environmental Policy and Planning | Year: 2013

'Sustainability' provides the dominant frame within which environmental policy debate occurs, notwithstanding its divergent meanings. However, how different discourses combine to shape understanding of the environment, the causes of environmental issues, and the responses required, is less clear cut. Drawing primarily on the approach to critical discourse analysis (CDA) developed by Fairclough, this paper explores the way in which neoliberal and ecologically modern discourses combine to shape environmental policy. Environmental scholars have made relatively little use of this approach to CDA to date, despite the significant interest in the discursive aspects of environmental issues, and its wide use in other areas of policy interest. Using the case of environmental policy-making in Victoria, Australia, this paper illustrates how neoliberalism and weak ecological modernization represented sustainability in ways that seriously limited the importance of environmental issues. © 2013 Copyright Taylor and Francis Group, LLC.

Lin X.,Nanchang University | Ni Y.,Nanchang University | Kokot S.,Queensland University of Technology
Journal of Hazardous Materials | Year: 2013

A novel modified electrode was constructed by the electro-polymerization of 4,5-dihydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]-2,7-naphthalenedisulfonic acid trisodium salt (acid chrome blue K (ACBK)) at a graphene oxide (GO)-nafion modified glassy carbon electrode (GCE). The characterization of an electrochemically synthesized poly-ACBK/GO-nafion film was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques, and the results were interpreted and compared at each stage of the electrode construction. Electrochemical oxidation of eight β-agonists - clenbuterol, salbutamol, terbutaline, ractopamine, dopamine, dobutamine, adrenaline, and isoprenaline, was investigated by CV at the different electrodes. At the poly-ACBK/GO-nafion/GCE, the linear sweep voltammetry peak currents of the eight β-agonists increased linearly with their concentrations in the range of 1.0-36.0ngmL-1, respectively, and their corresponding limits of detection (LODs) were within the 0.58-1.46ngmL-1 range. This electrode showed satisfactory reproducibility and stability, and was used successfully for the quantitative analysis of clenbuterol in pork samples. © 2013 Elsevier B.V.

Iu C.K.,Queensland University of Technology
Engineering Structures | Year: 2015

The finite element method in principle adaptively divides the continuous domain with complex geometry into discrete simple subdomain by using an approximate element function, and the continuous element loads are also converted into the nodal load by means of the traditional lumping and consistent load methods, which can standardise a plethora of element loads into a typical numerical procedure, but element load effect is restricted to the nodal solution. It in turn means the accurate continuous element solutions with the element load effects are merely restricted to element nodes discretely, and further limited to either displacement or force field depending on which type of approximate function is derived. On the other hand, the analytical stability functions can give the accurate continuous element solutions due to element loads. Unfortunately, the expressions of stability functions are very diverse and distinct when subjected to different element loads that deter the practical applications. To this end, this paper presents a displacement-based finite element function (generalised element load method) with a plethora of element load effects in the similar fashion that never be achieved by the stability function, as well as it can generate the continuous first- and second-order elastic displacement and force solutions along an element without loss of accuracy considerably as the analytical approach that never be achieved by neither the lumping nor consistent load methods. Hence, the salient and unique features of this paper (generalised element load method) embody its robustness, versatility and accuracy in continuous element solutions when subjected to the great diversity of transverse element loads. © 2015 Elsevier Ltd.

Taulis M.,Queensland University of Technology | Milke M.,University of Canterbury
Water Research | Year: 2013

A pilot study has produced 31 groundwater samples from a coal seam gas (CSG) exploration well located in Maramarua, New Zealand. This paper describes sources of CSG water chemistry variations, and makes sampling and analytical recommendations to minimize these variations. The hydrochemical character of these samples is studied using factor analysis, geochemical modelling, and a sparging experiment. Factor analysis unveils carbon dioxide (CO2) degassing as the principal cause of sample variation (about 33%). Geochemical modelling corroborates these results and identifies minor precipitation of carbonate minerals with degassing. The sparging experiment confirms the effect of CO2 degassing by showing a steady rise in pH while maintaining constant alkalinity. Factor analysis correlates variations in the major ion composition (about 17%) to changes in the pumping regime and to aquifer chemistry variations due to cation exchange reactions with argillaceous minerals. An effective CSG water sampling program can be put into practice by measuring pH at the wellhead and alkalinity at the laboratory; these data can later be used to calculate the carbonate speciation at the time the sample was collected. In addition, TDS variations can be reduced considerably if a correct drying temperature of 180 °C is consistently implemented. © 2012 Elsevier Ltd.

Davoodi A.,Ferdowsi University of Mashhad | Esfahani Z.,Hakim Sabzevari University | Sarvghad M.,Queensland University of Technology
Corrosion Science | Year: 2016

Microstructure and the corrosion behaviour of friction stir weld region in an aluminium AA5083/AA7023 dissimilar joint was studied using SEM/EDS, potentiodynamic polarization, EIS and AFM/SKPFM techniques. In the presence of an inhomogeneous borderline consisting of Al-Mg-Zn precipitates, a galvanic cell was formed at the interfacial region. Corrosion tests showed that the corrosion resistance of FSW region is in between that of AA5083 and AA7023. AA5083 possesses lower Volta potential compared to AA7023, however, corrosion initiates from both the FSW borderline and areas around intermetallic particles, particularly in AA7023 side. © 2016 Elsevier Ltd.

Brown R.,Queensland University of Technology | Chanson H.,University of Queensland
Journal of Hydraulic Engineering | Year: 2013

In urbanized areas, flood flows constitute a hazard to populations and infrastructure, as illustrated during major floods in 2011. During the 2011 Brisbane River flood, some turbulent velocity data were collected using acoustic Doppler velocimetry in an inundated street. The field deployment showed some unusual features of flood flow in the urban environment. That is, the water elevations and velocities fluctuated with distinctive periods between 50 and 100 s linked with some local topographic effects. The instantaneous velocity data were analyzed using a triple decomposition. The velocity fluctuations included a large energy component in the slow fluctuation range, whereas the turbulent motion components were much smaller. The suspended sediment data showed some significant longitudinal flux. Altogether, the results highlighted that the triple decomposition approach originally developed for periodic flows is well-suited to complicated flows in an inundated urban environment. © 2013 American Society of Civil Engineers.

Simpson M.J.,Queensland University of Technology | Jazaei F.,Auburn University | Clement T.P.,Auburn University
Journal of Hydrology | Year: 2013

Groundwater flow models are usually characterized as being either transient flow models or steady state flow models. Given that steady state groundwater flow conditions arise as a long time asymptotic limit of a particular transient response, it is natural for us to seek a finite estimate of the amount of time required for a particular transient flow problem to effectively reach steady state. Here, we introduce the concept of mean action time (MAT) to address a fundamental question: how long does it take for a groundwater recharge process or discharge processes to effectively reach steady state? This concept relies on identifying a cumulative distribution function, F(t;x), which varies from F(0;x)=0 to F(t;x)→1- as t→∞, thereby providing us with a measurement of the progress of the system towards steady state. The MAT corresponds to the mean of the associated probability density function f(t;x)=dF/dt, and we demonstrate that this framework provides useful analytical insight by explicitly showing how the MAT depends on the parameters in the model and the geometry of the problem. Additional theoretical results relating to the variance of f(t;x), known as the variance of action time (VAT), are also presented. To test our theoretical predictions we include measurements from a laboratory-scale experiment describing flow through a homogeneous porous medium. The laboratory data confirms that the theoretical MAT predictions are in good agreement with measurements from the physical model. © 2013 The Authors.

Yigitbasioglu O.,Queensland University of Technology
Australasian Journal of Information Systems | Year: 2014

This paper uses transaction cost theory to study cloud computing adoption. A model is developed and tested with data from an Australian survey. According to the results, perceived vendor opportunism and perceived legislative uncertainty around cloud computing were significantly associated with perceived cloud computing security risk. There was also a significant negative relationship between perceived cloud computing security risk and the intention to adopt cloud services. This study also reports on adoption rates of cloud computing in terms of applications, as well as the types of services used.

Nguyen K.,Queensland University of Technology | Sridharan S.,Queensland University of Technology | Denman S.,Queensland University of Technology | Fookes C.,Queensland University of Technology
Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition | Year: 2012

The low resolution of images has been one of the major limitations in recognising humans from a distance using their biometric traits, such as face and iris. Superresolution has been employed to improve the resolution and the recognition performance simultaneously, however the majority of techniques employed operate in the pixel domain, such that the biometric feature vectors are extracted from a super-resolved input image. Feature-domain superresolution has been proposed for face and iris, and is shown to further improve recognition performance by capitalising on direct super-resolving the features which are used for recognition. However, current feature-domain superresolution approaches are limited to simple linear features such as Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), which are not the most discriminant features for biometrics. Gabor-based features have been shown to be one of the most discriminant features for biometrics including face and iris. This paper proposes a framework to conduct super-resolution in the non-linear Gabor feature domain to further improve the recognition performance of biometric systems. Experiments have confirmed the validity of the proposed approach, demonstrating superior performance to existing linear approaches for both face and iris biometrics. © 2012 IEEE.

Schroeter R.,Queensland University of Technology
Proceedings of the ACM Conference on Computer Supported Cooperative Work, CSCW | Year: 2012

Local governments struggle to engage time poor and seemingly apathetic citizens, as well as the city's young digital natives, the digital locals. This project aims at providing a lightweight, technological contribution towards removing the hierarchy between those who build the city and those who use it. We aim to narrow this gap by enhancing people's experience of physical spaces with digital, civic technologies that are directly accessible within that space. This paper presents the findings of a design trial allowing users to interact with a public screen via their mobile phones. The screen facilitated a feedback platform about a concrete urban planning project by promoting specific questions and encouraging direct, in-situ, real-time responses via SMS and twitter. This new mechanism offers additional benefits for civic participation as it gives voice to residents who otherwise would not be heard. It also promotes a positive attitude towards local governments and gathers information different from more traditional public engagement tools. © 2012 ACM.

Seeburger J.,Queensland University of Technology
2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012 | Year: 2012

This paper introduces our research on influencing the experience of people in urban public places through mobile mediated interactions. Information and communication technology (ICT) devices are sometimes used to create personal space while in public. ICT devices could also be utilised to digitally augment the urban space with non-privacy sensitive data enabling mobile mediated interactions in an anonymous way between collocated strangers. We present what motivates the research on digital augmentations and mobile mediated interactions between unknown urban dwellers, define the research problem that drives this study and why it is significant research in the field of pervasive social networking. The paper illustrates three design interventions enabling social pervasive content sharing and employing pervasive presence, awareness and anonymous social user interaction in urban public places. The paper concludes with an outlook and summarises the research effort. © 2012 IEEE.

Seeburger J.,Queensland University of Technology | Foth M.,Queensland University of Technology
Proceedings of the 24th Australian Computer-Human Interaction Conference, OzCHI 2012 | Year: 2012

This paper describes the design and study of public urban screen applications aiming to facilitate urban dwellers to control content shown on public urban screens. Two types of content sharing are presented: aggregating existing social media content about particular locations for sharing, and sharing online videos with collocated people at a public urban screen. The paper describes an exploratory study, an observational study, as well as an interpretational study in regards to application usage and user experience. Sharing content on public urban screens can pique the curiosity of users towards collocated people and the application itself resulting in raised awareness of collocated people. © 2012 ACM.

Santo Y.,Queensland University of Technology
Proceedings of the 24th Australian Computer-Human Interaction Conference, OzCHI 2012 | Year: 2012

This paper reports outcomes of a pilot study to develop a conceptual framework to allow people to retrofit a building-layer to gain better control of their own built-environments. The study was initiated by the realisation that discussions surrounding the improvement of building performances tend to be about top-down technological solutions rather than to help and encourage bottom-up involvement of building-users. While users are the ultimate beneficiaries and their feedback is always appreciated, their direct involvements in managing buildings would often be regarded as obstruction or distraction. This is largely because casual interventions by uninformed building-users tend to disrupt the system. Some earlier researches showed however that direct and active participation of users could improve the building performance if appropriate training and/or systems were introduced. We also speculate this in long run would also make the built environment more sustainable. With this in mind, we looked for opportunities to retrofit our own office with an interactive layer to study how we could introduce ad-hoc systems for building-users. The aim of this paper is to describe our vision and initial attempts followed by discussion. © 2012 ACM.

Atchison D.A.,Queensland University of Technology | Rosen R.,Abbott Laboratories
Optometry and Vision Science | Year: 2016

Recent longitudinal studies do not support the current theory of relative peripheral hyperopia causing myopia. The theory is based on misunderstanding of the Hoogerheide et al. article of 1971, which actually found relative peripheral hyperopia to be present after, rather than before, myopia development. The authors present two alternative theories of the role of peripheral refraction in the development and progression of myopia. The one for which most detail is given is based on cessation of ocular growth when the periphery is at an emmetropic stage as determined by equivalent blur of the two line foci caused by oblique astigmatism. This paper is based on an invited commentary on the role of lens treatments in myopia from the 15th International Myopia Conference in Wenzhou, China in September 2015. © 2016 American Academy of Optometry.

Read S.A.,Queensland University of Technology
Optometry and Vision Science | Year: 2016

Recent advances in measurement technology have improved our ability to quantify a range of ocular components and some environmental exposures that are relevant to myopia. In particular, environmental sensors now allow the dense sampling of personal ambient light exposure data, and advances in ocular imaging, such as developments in optical coherence tomography (OCT), enables high resolution measures of the choroid to be captured in human subjects. The detailed, objective information produced by these noninvasive measurement technologies has the potential to provide important new insights into the complex array of factors underlying eye growth, and myopia development and progression in childhood. Wearable light sensors and enhanced depth imaging OCT were both employed in a recently completed prospective, observational longitudinal study examining factors associated with eye growth in myopic and non-myopic children. Personal light exposure, choroidal thickness, and axial eye growth were quantified in 101 children over an 18-month period. A significant association was found between objectively measured personal daily ambient light exposure and eye growth (independent of refractive status), consistent with greater light exposure protecting against rapid growth of the eye in childhood. Variations in the thickness of the choroid also appeared to be closely linked to the growth of the eye, with choroidal thinning typically being associated with more rapid eye growth, and choroidal thickening with a slowing of eye growth in childhood. The implications of these findings for our understanding of human eye growth regulation, along with their potential importance for our understanding of myopia control interventions, are discussed. © 2016 American Academy of Optometry.

Okolicsanyi R.K.,Queensland University of Technology | Griffiths L.R.,Queensland University of Technology | Haupt L.M.,Queensland University of Technology
Developmental Biology | Year: 2014

Along with the tri-lineage of bone, cartilage and fat, human mesenchymal stem cells (hMSCs) retain neural lineage potential. Multiple factors have been described that influence lineage fate of hMSCs including the extracellular microenvironment or niche. The niche includes the extracellular matrix (ECM) providing structural composition, as well as other associated proteins and growth factors, which collectively influence hMSC stemness and lineage specification. As such, lineage specific differentiation of MSCs is mediated through interactions including cell-cell and cell-matrix, as well as through specific signalling pathways triggering downstream events. Proteoglycans (PGs) are ubiquitous within this microenvironment and can be localised to the cell surface or embedded within the ECM. In addition, the heparan sulfate (HS) and chondroitin sulfate (CS) families of PGs interact directly with a number of growth factors, signalling pathways and ECM components including FGFs, Wnts and fibronectin. With evidence supporting a role for HSPGs and CSPGs in the specification of hMSCs down the osteogenic, chondrogenic and adipogenic lineages, along with the localisation of PGs in development and regeneration, it is conceivable that these important proteins may also play a role in the differentiation of hMSCs toward the neuronal lineage. Here we summarise the current literature and highlight the potential for HSPG directed neural lineage fate specification in hMSCs, which may provide a new model for brain damage repair. © 2014 Elsevier Inc.