Time filter

Source Type

Perth, Australia

The University of Western Australia is a research-intensive university in Perth, Australia that was established by an act of the Western Australian Parliament in February 1911, and began teaching students for the first time in 1913. It is the oldest university in the state of Western Australia and is colloquially known as a "sandstone university". It is also a member of the Group of Eight.UWA was established under and is governed by the University of Western Australia Act 1911. The Act provides for control and management by the university's Senate, and gives it the authority, amongst other things, to make statutes, regulations and by-laws, details of which are contained in the university Calendar.UWA is highly ranked internationally in various publications: the 2013/14 QS World University Rankings placed UWA at 84th internationally, and in August 2014 the The Academic Ranking of World Universities from Shanghai Jiao Tong University placed the university at 88th in the world. To date, the university has produced 100 Rhodes Scholars, 1 Nobel Prize laureate and 1 Australian Prime Minister graduated from UWA.UWA recently joined the Matariki Network of Universities as the youngest member, the only one established during the 20th century. Wikipedia.

Balme J.,University of Western Australia
Quaternary International | Year: 2013

For all of hominin history the Australian continent has been separated by at least 70 km of water from other coastlines. Its colonisation about 50,000 years ago can therefore be considered the first true hominin 'migration' as opposed to the 'dispersals' that happened before it. To the hominins that occupied Sunda before Sahul was colonised by anatomically modern people, the water crossing must have been a barrier. It has been argued that it was the capacity for complex communication associated with modern cognition that allowed this barrier to be transgressed but, why did people use this capacity to build boats and what was the legacy of the associated technology in the subsequent colonisation? The particular maritime physical environment of Wallacea must have been an important factor in this process. Fibre technology, which must have accompanied the mariners who arrived in Sahul, must have played an important role in the continent's colonisation. This aspect of technology is often ignored in discussions about Sahul Pleistocene technology that suggest its simplicity compared to other regions. © 2011.

Giudici M.,University of Western Australia | Parker C.,University of Birmingham
Journal of Combinatorial Theory. Series A | Year: 2013

We construct a family of finite 2-groups which have commuting graph of increasing diameter. © 2013 Elsevier Inc.

Ding J.,National University of Singapore | Kostylev M.,University of Western Australia | Adeyeye A.O.,National University of Singapore
Applied Physics Letters | Year: 2012

We demonstrate functionality of magnetic logic based on a reconfigurable magnonic crystal in the form of a meander-type ferromagnetic nanowire. A ferromagnetic resonance method employing a microscopic coplanar waveguide has been used to detect the logic state of the structure coded in its magnetic ground state. Ferromagnetic resonance responses of anti-ferromagnetic and multi-cluster (mix of anti-ferromagnetic and ferromagnetic) ground states can be switched by applying a DC current in the signal line of the coplanar waveguide. Experimental demonstrations of device functionality as XOR and NOT logic gates are supported by the magnetic force microscopy images and micromagnetic simulations. © 2012 American Institute of Physics.

Khan R.J.,University of Western Australia
Cochrane database of systematic reviews (Online) | Year: 2010

BACKGROUND: There is a lack of consensus on the best management of the acute Achilles tendon rupture. Treatment can be broadly classified into surgical (open or percutaneous) and non-surgical (cast immobilisation or functional bracing). OBJECTIVES: To evaluate the relative effects of surgical versus non-surgical treatment, or different surgical interventions, for acute Achilles tendon ruptures in adults. SEARCH STRATEGY: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (July 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 3), MEDLINE (1966 to 20th July 2009), EMBASE (1966 to 2009 week 29), CINAHL (1983 to July 2007) and reference lists of articles. SELECTION CRITERIA: All randomised and quasi-randomised trials comparing surgical versus non-surgical treatment or different surgical methods for acute Achilles tendon ruptures in adults. DATA COLLECTION AND ANALYSIS: Two review authors independently selected potentially eligible trials; trials were then assessed for quality using a 10-item scale. Where possible, data were pooled. MAIN RESULTS: Twelve trials involving 844 participants were included. One trial tested two comparisons.Quality assessment revealed a poor level of methodological rigour in many studies, particularly with regard to concealment of allocation and the lack of assessor blinding.Open surgical treatment compared with non-surgical treatment (6 trials, 536 participants) was associated with a statistically significant lower risk of rerupture (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.21 to 0.77), but a higher risk of other complications including infection (RR 4.89, 95% CI 1.09 to 21.91), adhesions and disturbed skin sensibility (numbness). Functional status including sporting activity was variably and often incompletely reported, including frequent use of non standardised outcome measures, and the results were inconclusive.Open surgical repair compared with percutaneous repair (4 trials, 174 participants) was associated with a higher risk of infection (RR 9.32, 95% CI 1.77 to 49.16). These figures should be interpreted with caution because of the small numbers involved. Similarly, no definitive conclusions could be made regarding different tendon repair techniques (3 trials, 147 participants). AUTHORS' CONCLUSIONS: Open surgical treatment of acute Achilles tendon ruptures significantly reduces the risk of rerupture compared with non-surgical treatment, but produces significantly higher risks of other complications, including wound infection. The latter may be reduced by performing surgery percutaneously.

Fox A.H.,University of Western Australia
Cold Spring Harbor perspectives in biology | Year: 2010

Paraspeckles are a relatively new class of subnuclear bodies found in the interchromatin space of mammalian cells. They are RNA-protein structures formed by the interaction between a long nonprotein-coding RNA species, NEAT1/Men epsilon/beta, and members of the DBHS (Drosophila Behavior Human Splicing) family of proteins: P54NRB/NONO, PSPC1, and PSF/SFPQ. Paraspeckles are critical to the control of gene expression through the nuclear retention of RNA containing double-stranded RNA regions that have been subject to adenosine-to-inosine editing. Through this mechanism paraspeckles and their components may ultimately have a role in controlling gene expression during many cellular processes including differentiation, viral infection, and stress responses.

Wood F.,University of Western Australia
Clinics in Plastic Surgery | Year: 2012

Each one of us is a self-organizing mass of multiple cell types. From fertilization of the embryo our tissue structures develop until an adult morphology is achieved. At that point our capacity for self-organization is directed to maintaining that morphology in the face of the insults of our daily life and the processes of aging. When a given insult overwhelms our capacity to repair by regeneration the result is scar repair. © 2012 Elsevier Inc.

Stankowski S.,University of Western Australia
Biological Journal of the Linnean Society | Year: 2011

On Rosemary Island, a small continental island (11km2) in the Dampier Archipelago, Western Australia, snails of the genus Rhagada have extremely diverse morphologies. Their shells vary remarkably in size and shape, with the latter ranging from globose to keeled-flat, spanning the range of variation in the entire genus. Based primarily on variation in shell morphology, five distinct species are currently recognized. However, a study of 103 populations has revealed continuity of shell form within a very closely-related group. A phylogenetic analysis of specimens from Rosemary Island, and other islands in the Dampier Archipelago, indicates that much of the morphological variation has evolved on the island, from within a monophyletic group. Within the island, snails with distinct shell morphologies could not be distinguished based on variation in mitochondrial DNA or their reproductive anatomy. The shell variation is geographically structured over a very fine scale, with clines linking the extreme forms over distances less than 200m. Although there is no evidence that the different forms have evolved in isolation or as a consequence of drift, there is a strong association between keeled-flat shells and rocky habitats, suggesting that shell shape may be of adaptive significance. © 2011 The Linnean Society of London.

Benefits arising from facultative mutualisms between ants and plants vary with the identity of the ant partner. Invasive and native ants are both attracted to plants that offer extrafloral nectar, but few studies have compared their abilities to displace herbivores and benefit plants. Yellow crazy ants Anoplolepis gracilipes have invaded eucalypt woodlands of Arnhem Land, northern Australia, where they displace the native dominant weaver ant Oecophylla smaragdina. We compared the plant defense services provided by A. gracilipes and O. smaragdina ants on trees with (Acacia lamprocarpa) and without (Eucalyptus tetrodonta) extrafloral nectar rewards through surrogate herbivore (termite) addition experiments and surveys of herbivore damage. Anoplolepis gracilipes were more likely than O. smaragdina to discover termites on A. lamprocarpa, but the likelihood of termite discovery on E. tetrodonta did not vary with ant species. Anoplolepis gracilipes were also more thorough in their attacks of termites, recruited 3.4-4 times more workers to termites, and were 3.4 times quicker at discovering termites on A. lamprocarpa than were O. smaragdina. Discovery of termites by other predators did not vary significantly between trees in A. gracilipes and O. smaragdina sites. Herbivory scores did not reflect the foliage patrolling pattern by the ants. Old A. lamprocarpa leaves and both new and old leaves and branches on E. tetrodonta in A. gracilipes sites had higher chewing herbivory scores than their counterparts in O. smaragdina sites. Our results reveal that the more aggressive and efficient foliar patrolling by A. gracilipes does not translate to increased plant protection. Ant invasions can disrupt native ant-plant mutualisms despite invasive ants possessing many traits associated with effective plant guarding. © 2011 The Authors.

Prescott S.L.,University of Western Australia | Prescott S.L.,International Inflammation In Network of the World Universities Network
Journal of Allergy and Clinical Immunology | Year: 2013

The unparalleled burden of a diverse range of chronic noncommunicable diseases (NCDs) is a major global challenge in the 21st century. Chronic low-grade inflammation is a common feature of virtually all NCDs, indicating a central role of the immune system. Furthermore, as the most common and earliest-onset NCD, the epidemic of allergic diseases points to specific vulnerability of the developing immune system to modern environmental change. Indeed, many environmental risk factors implicated in the rise of other NCDs have been shown to mediate their effects through immune pathways. The innate immune system provides a clear example of this convergence, with evidence that physical activity, nutrition, pollutants, and the microbiome all influence systemic inflammation through Toll-like receptor pathways (notably Toll-like receptor 4), with downstream effects on the risk of insulin resistance, obesity, cardiovascular risk, immune diseases, and even mood and behavior. Common risk factors will likely mean common solutions, and interdisciplinary strategies to promote immune health should be an integral part of NCD prevention, with a greater focus early in the life course before disease processes are established. In this context allergic disease provides a very important early target to assess the effectiveness of environmental strategies to reduce immune dysregulation. © 2012 American Academy of Allergy, Asthma & Immunology.

Burgess S.S.O.,University of Western Australia
Plant and Soil | Year: 2011

Hydraulic redistribution is the process where soil water is translocated by plant roots from wet to dry areas as it is drawn through xylem pathways by a water potential gradient. Hydraulic redistribution places soil water resources where they would otherwise not be, which results in a range of ecological and hydrological consequences. Although deep-rooted plants can transfer water up from depth into shallow soil layers, any localised 'irrigation' of neighbouring plants tends to be obscured by recovery of the very same water by the donor plants during daytime transpiration. A new intercropping system was recently trialled which eliminates transpiration by the donor plant through complete shoot removal in order to maximise hydraulic redistribution. In the absence of any transpiring shoots, the donor plants are left to wick water up from depth 24 hours a day via their root systems, to the benefit of neighbouring shallow-rooted crops. This system allows deeper-rooted 'nurse plants' to capture water that is out of reach of crops in a 'water safety-net' role, which may be of considerable benefit in water-scarce environments. © 2010 Springer Science+Business Media B.V.

Bekki K.,University of Western Australia
Monthly Notices of the Royal Astronomical Society | Year: 2014

We investigate how ram pressure of intragroup and intracluster medium can influence the spatial and temporal variations of star formation (SF) of disc galaxies with halo masses (Mh) ranging from 1010 to 1012 M⊙ (i.e. from dwarf irregular to Milky Way-type) in groups and clusters with 1013 ≤ Mh/M⊙ ≤ 1015 by using numerical simulations with a new model for time-varying ram pressure. The long-term evolution of SF rates and Hα morphologies corresponding to the distributions of star-forming regions are particularly investigated for different model parameters. The principal results are as follows. Whether ram pressure can enhance or reduce SF depends on Mh of disc galaxies and inclination angles of gas discs with respect to their orbital directions for a given orbit and a given environment. For example, SF can be moderately enhanced in disc galaxies with Mh = 1012 M⊙ at the pericentre passages in a cluster with Mh = 1014 M⊙ whereas it can be completely shut down ('quenching') for low-mass discs with Mh = 1010 M⊙. Ram pressure can reduce the Hα-to-optical-disc-size ratios of discs and the level of the reduction depends on Mh and orbits of disc galaxies for a given environment. Disc galaxies under strong ram pressure show characteristic Hα morphologies such as ring-like, one-sided and crescent-like distributions. © 2013 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society.

Objective: The International Anxiety Disorders Society Conference, held in Melbourne in November 2014, enabled key researchers from Australia and internationally to interact with mental health practitioners with an interest in clinical anxiety disorders. The proceedings of previous conferences in 2006 and 2011 formed the basis of two wellreceived textbooks on anxiety disorders; this time we have taken up the invitation to publish the proceedings as articles in this issue of Australasian Psychiatry. At the end of the first day of the conference a lecture and linked international expert panel explored the topic of guidelines for the management of the anxiety disorders in conjunction with an engaged audience for 90 minutes - key elements of this discussion are presented here. Conclusions: Guidelines for anxiety disorder management should be applied with caution in clinical practice settings.

Kingwell R.,University of Western Australia
Australian Journal of Agricultural and Resource Economics | Year: 2011

Modern farming in Australia is no longer simple. Farms are large, multi-enterprise businesses underpinned by expensive capital investments, changing production technologies, volatile markets and social challenges. The complexity of modern broadacre farming leads to the question: what is the nature of the relationship between farm business complexity and farm profitability? This study uses bioeconomic farm modelling and employs eight measures of complexity to examine the profitability and complexity of a wide range of broadacre farming systems in Australia. Rank order correlations between farm profitability and each measure of complexity show inconsistent relationships, although the most profitable farming systems are found to be reasonably complex on several criteria. Among the set of highly profitable systems are found some characterised by less complexity. A commonly acknowledged feature of farm business complexity is the annual workload of the farmer, yet the trade-off between farm profit and this workload is found not to be large. A case is outlined where the farmer's annual hours worked could be reduced by 9 per cent for a 3 per cent reduction in farm profit. If farmers' workloads are proving problematic now, and in the future, then agricultural R&D, service delivery and policy development will need to focus more on being highly attractive to increasingly time-poor farm managers. © 2011 The Author. AJARE © 2011 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishing Asia Pty Ltd.

Linden M.D.,University of Western Australia
Methods in Molecular Biology | Year: 2013

Flow cytometry is a powerful and versatile tool which can be used to provide substantial phenotypic data on platelets by yielding quantitative information of their physical and antigenic properties. This includes surface expression of functional receptors, bound ligands, expression of granule components, interaction of platelets with other platelets via aggregation, or interaction with other blood components, such as leukocytes or the plasma coagulation system. Quantitative assessment of these parameters may facilitate the diagnosis of inherited or acquired platelet disorders, assist in the diagnosis of diseases associated with platelet activation, or assist in the monitoring of safety and efficacy of antiplatelet therapy. © 2013 Springer Science+Business Media New York.

Hossain M.S.,University of Western Australia
Geotechnique | Year: 2014

Highly layered soils are prevalent in several areas of current offshore activity and in particular in emerging provinces and fields. However, no investigation has been carried out for spudcan penetration in stratified sediments with more than two layers. This paper reports centrifuge modelling of spudcan foundations penetrating through 3~6 clay layers with interbedded stronger clay, silica sand and carbonate sand layers. The aim was to provide insight into the behaviour of spudcan foundations in stratified sediments comprising layers of different drainage conditions and mineralogy. The motivation for this paper emanated directly from the future needs identified by the recent revised version of ISO 19905-1. It was found that the downward soil deformation was extended into 3~4 underlying layers of sand and clay with thickness ratios (t/D) less than 0.6. The limiting squeezing depth was 0.17~0.18D when approaching stiff clay–moderate clay layers and 0.28D when approaching dense sand–stiff clay layers. These depths were enhanced (to 0.3~0.35D) by the soil plug trapped beneath the advancing spudcan. The values obtained using the ISO criteria either overestimated or underestimated these depths. Punch-through failure at a shallow penetration depth occurred with a loadspreading gradient of 1 (horizontal):3 (vertical) in silica sand and with a much smaller gradient of 1:7 in carbonate sand. In both sands, the spreading angle reduced with increasing depth of punch-through failure, and diminished quickly immediately after a failure. In contrast to ISO guidelines, the plug base, where the end bearing was mobilised, was located in one of the lower layers moved down with the advancing spudcan. For all cases, a soil plug developed at the base of the advancing spudcan, with the height of the plug accumulating through trapped clay and sand, regardless of their strength, from layers above and below the advancing spudcan. The height of a soil plug was reduced partly by soil backflow and squeezing out from contact with a strong layer. The observed soil failure mechanisms and corresponding penetration resistance profiles highlight uncertainties in ISO 19905-1. Guidelines are provided to improve the suggested punch-through and squeezing methods in ISO 19905-1. Implications for the bottom-up design approach proposed by ISO, and also a top-down design approach used by some practitioners, are discussed. © 2014, (publisher). All rights reserved.

Anderson W.K.,44 Albany Highway | Anderson W.K.,University of Western Australia
Field Crops Research | Year: 2010

Studies that compare the genotypic improvement of historical cultivars with yield progress in commercial crops provide evidence of the impact of past and current research in crops. The analysis of experiments designed to examine combinations of environment (E), management practices (M) and cultivars (G) also provides evidence of the relative importance of each of these factors for yield improvement. The evidence shows that variation due to E far outweighs the variation of grain yield that can be attributed to M or G, or the interactions between these factors, and between these factors and E. The major 'gap' between yields achieved on farms and the theoretical potential as estimated by seasonal rainfall or water use, is found where seasonal water supply is greater than about 250 mm and when management, not rainfall or cultivar is limiting productivity. This suggests that tactical (in season) management, including the choice of crop and cultivar, fertilizer amount and timing, weed, insect and disease control when combined with management of strategic factors (that have an effect for more than one season) such as soil acidity, compaction, low organic matter, non-wetting and water-logging will provide additive benefits that can address the variability imposed by the environment. In the semi-arid cropping regions of the world where inter-seasonal variability of rainfall is high, it is particularly important for farmers to maximize grain yields in seasons when the rainfall is adequate to produce profitable crops. Current technologies are already relatively efficient in the drier seasons so that the relative impact on farm productivity of research to improve yields in dry years is likely to be small. Field studies in Western Australia that have included a range of environments (sites × seasons) cultivars, and levels of management (sowing times, fertilizer treatments, seed rates) show that the main effect of E has accounted for about 80% of the variability in grain yield, M has accounted for about 6%, and G for about 3%. The G × M and G × E interactions were generally unimportant. This is confirmed by studies in similar rainfed environments elsewhere. Some studies that include M as part of the E term show apparently large G × E interactions, possibly due to either the selection of very different cultivars or environments, or both. The usefulness of such results at the farm level is doubtful due to the variable management inputs in the experiments and a lack of validity for farmers who may not be concerned with variability across widely separated locations. In studies that examine genetic responses to individual management practices differences are often very specific to the environmental conditions experienced in the experiments. The aim of the review is to discuss how management factors can contribute to closing the yield 'gap' between actual and potential grain yields in the variable environment experienced by rainfed crops. The impacts of tactical and strategic management practices appear to be independent and additive rather than co-dependent, allowing for adoption one at a time as resources permit. The use of strategic practices that ameliorate acidity or compaction for example, will lift the grain yield at all levels of tactical inputs such as fertilizer, thus reducing the seasonal variability of yield even though the response to fertilizer does not change. It is concluded that in principle, the best way to maintain productivity under conditions of seasonal variability is to use both tactical and strategic management to close the gap between actual and potential grain yields in the average and better seasons. Crown Copyright © 2009.

Karton A.,University of Western Australia
Chemical Physics Letters | Year: 2014

The vinyl alcohol-acetaldehyde tautomerization reaction has recently received considerable attention as a potential route for the formation of organic acids in the troposphere (Andrews et al., 2012 [7]). We examine the catalytic effect of inorganic acids in the troposphere (e.g. HNO3, H2SO4 and HClO4) on the vinyl alcohol-acetaldehyde tautomerization reaction, by means high-level thermochemical procedures. We show that H2SO4 and HClO4 catalysts lead to near-zero reaction barrier heights for the vinyl alcohol → acetaldehyde reaction, and to low reaction barrier heights in the reverse direction (ΔH298‡=40.6and39.5kJmol-1, respectively). © 2013 Elsevier B.V. All rights reserved.

Shragge J.,University of Western Australia
Geophysics | Year: 2013

Migration of seismic data from topography using methods based on finite-difference (FD) approximation to acoustic wave propagation commonly suffers from a number of imaging drawbacks due to the difficulty of applying FD stencils to irregular computational meshes. Altering the computational geometry from Cartesian to a topographic coordinate system conformal to the data acquisition surface can circumvent many of these issues. The coordinate transformation approach allows for acoustic wave propagation and the crosscorrelation and inversescattering imaging conditions to be posed and computed directly in topographic coordinates. Resulting reverse time migration (RTM) images may then be interpolated back to the Cartesian domain using the known inverse mapping. Orthogonal 2D topographic coordinates can be developed using known conformal mapping transforms and serve as the computational mesh for performing migration from topography. Impulse response tests demonstrate the accuracy of the 2D generalized acoustic wave propagation. RTM imaging examples show the efficacy of performing migration from topography directly from the data acquisition surface on topographic meshes and the ability to image complex near-surface structure even in the presence of strong lateral velocity variation. © 2014 Society of Exploration Geophysicists.

Starkstein S.E.,University of Western Australia
Movement Disorders | Year: 2012

About one-third of patients with Parkinson's disease (PD) are diagnosed with apathy in cross-sectional studies. However, once patients with concomitant depression and dementia are excluded, the frequency of apathy drops to 5% to 10%. Several scales have been recommended to rate apathy in PD, but specific psychiatric interviews have not been developed, and recently proposed standardized diagnostic criteria are still in the validation process. Most studies assessing the association between subthalamic deep brain stimulation (STN-DBS) and apathy have reported a relative increase in the frequency and severity of apathy, although discrepant findings have also been reported. Several mechanisms to explain apathy in PD have been proposed, from dopaminergic imbalances in frontal-basal ganglia circuits to dysfunction of nondopaminergic circuits and the cingulate gyrus. Future studies should provide reliable and valid instruments to diagnose apathy in PD, and should examine the mechanism of apathy accounting for relevant confounders, such as depression and cognitive deficits, and important contextual factors. Finally, treatment for apathy in PD should not be restricted to psychoactive drugs, but should also include nonpharmacological techniques such as psychotherapy and occupational therapy. © 2012 Movement Disorder Society.

Bassett D.,The University of Notre Dame Australia | Bassett D.,University of Western Australia
Australian and New Zealand Journal of Psychiatry | Year: 2012

Objective: Bipolar affective disorder and borderline personality disorder have long been considered to have significant similarities and comorbidity. This review endeavours to clarify the similarities and differences between these disorders, with an effort to determine whether they reflect different forms of the same illness or separate illness clusters.Method: The published literature relating to bipolar affective disorders, borderline personality disorders, and related areas of knowledge was reviewed using searches of several electronic databases (AMED, CINHAL, Embase, Ovid, ProQuest, MEDLINE, Web of Science, ScienceDirect) and published texts. These findings were combined with the personal clinical experience of the author, and information gathered from colleagues, to create a review of this topic.Results: Bipolar affective disorders and borderline personality disorders differ with respect to sense of self, disruption of relationships, family history of bipolar disorders, the benefits of medications, the extent of cognitive deficits, the form of affective dysregulation and mood cycling, the incidence of suicide and suicide attempts, the form of psychotic episodes, the incidence of early sexual abuse but not early trauma in general, the loss of brain substance, alterations in cortical activity, glucocorticoid receptor sensitivity, and mitochondrial dysfunction. They are similar with respect to non-specific features of affective dysregulation, the incidence of atypical depressive features, the incidence of self-mutilation, the incidence of transporter polymorphisms, possible genetic linkages, overall reduction in limbic modulation, reduction in the size of hippocampi and amygdala, and the incidence of sleep disruption.Conclusions: This review concludes that bipolar affective disorders and borderline personality disorder are separate disorders, but have significant elements in common. © 2012 The Royal Australian and New Zealand College of Psychiatrists.

Pistani F.,MCS Kenny | Thiagarajan K.,University of Western Australia
Ocean Engineering | Year: 2012

A sloshing experiment has been setup in order to carry out analysis on the behaviour of LNG (Liquefied Natural Gas) tanks on board of marine vessels. The experiment aimed to measure with accuracy the high pressure generated during the impacts of the fluid in the case of rectilinear sinusoidal motion in the direction of sway. A two-dimensional tank model has been used for this purpose. The pressures due to fluid sloshing are measured at several locations along the tank boundaries together with the position of the tank and acquisition of images of the flow. This paper describes the experimental procedures that have been put in place to acquire the data and ensure its quality. The problems encountered during the activity are illustrated in detail in order to provide useful indications to other researchers. The different types of impact observed during the experiment, the characteristics of the measured pressures and the implementation of an algorithm for their correct identification are discussed in detail. © 2012 Elsevier Ltd.

Davies P.M.,University of Western Australia
Restoration Ecology | Year: 2010

Global biodiversity hotspots contain exceptional concentrations of endemic species in areas of escalating habitat loss. However, most hotspots are geographically constrained and consequently vulnerable to climate change as there is limited ability for the movement of species to less hostile conditions. Predicted changes to rainfall and temperature will undoubtedly further impact on freshwater ecosystems in these hotspots. Southwestern Australia is a biodiversity hotspot and, as one of the first to experience significant climate change, is an example and potentially a global bellwether for issues associated with river restoration. In this hotspot, current and predicted water temperatures may exceed thermal tolerances of aquatic fauna. Gondwanic aquatic fauna, characteristic of southwestern Australia, are typically cold stenotherms and consequently intolerant of elevated temperatures. The hotspot in southwestern Australia is geographically restricted being surrounded by ocean and desert, and many important national parks are located on the extreme south coast, where the landscape is relatively flat. Consequently, fauna cannot change their distribution southwards or with altitude as a response to increasing temperatures. Therefore, any mitigation responses need to be in situ to produce a suitable biophysical envelope to enhance species' resilience. This could be through " over restoration" by increased riparian replanting at a catchment scale. A rule-of-thumb of a 10% increase in riparian cover would be required to reduce water temperatures by 1°C. These restoration techniques are considered applicable to other global biodiversity hotspots where geography constrains species' movement and the present condition is the desired restoration endpoint. © 2010 Society for Ecological Restoration International.

Sahebkar A.,Mashhad University of Medical Sciences | Watts G.F.,University of Western Australia
Clinical Therapeutics | Year: 2013

Background: Reduction in plasma low-density lipoprotein cholesterol (LDL-C) is a fundamental treatment for the prevention of acute coronary syndromes (ACS). Although statin therapy confers significant protection against ACS in both primary and secondary prevention, a considerable residual risk remains after intensive therapy. In addition, a significant proportion of high-risk patients do not achieve the optimal LDL-C goal recommended in the current guidelines (<1.8 mmol/L). Hence, novel LDL-C-lowering agents that act via mechanisms distinct from HMG-CoA reductase inhibition are under investigation. Objective: We reviewed the recent literature on the development of novel LDL-C-lowering agents that could potentially be used as an alternative or adjunct to statin therapy in high-risk coronary patients. Methods: PubMed and Scopus databases were searched to retrieve studies on the efficacy and/or tolerability of novel LDL-C-lowering agents in animals and humans. Results: Agents that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9), apolipoprotein (apo) B, and microsomal triglyceride transfer protein (MTTP) are the most promising therapies. Inhibition of PCSK9, apoB, and MTTP has been achieved mostly via fully humanized monoclonal antibodies (mAbs), antisense oligonucleotides, and synthetic compounds, respectively. PCSK9 inhibitors increase the hepatic uptake of LDL-C, while apoB and MTTP inhibitors decrease the synthesis and secretion of apoB-containing lipoproteins. These 3 mechanisms lead to marked reductions in plasma LDL-C in patients with hypercholesterolemia at risk for ACS, particularly those with familial hypercholesterolemia. Moreover, these agents can exert additional benefits by decreasing plasma levels of apoB, triglycerides, and lipoprotein(a). Mipomersen and lomitapide have been approved by the United States Food and Drug Administration (US FDA) for use in patients with homozygous familial hypercholesterolemia. PCSK9 inhibitors are currently under final evaluation in clinical outcomes studies and are anticipated to find wide application either as monotherapy or as an adjunct to statins. A main safety concern is the risk for hepatic steatosis with apoB and MTTP inhibitors, which needs to be explored in prospective, long-term trials. Conclusions: PCSK9, apoB, and MTTP inhibitors can exert potent reductions in plasma LDL-C and apoB concentrations, either as monotherapy or in combination with statins. These effects are particularly relevant to high-risk individuals with marked hypercholesterolemia, such as those with familial hypercholesterolemia. Although the use of mipomersen and lomitapide is limited to severe familial hypercholesterolemia as a replacement for LDL-apheresis, PCSK9 inhibitors are likely to be more widely prescribed in patients at high risk for CVD, especially those who are resistant to or intolerant of high-intensity statin therapy. PCSK9 mAbs are efficacious and have an excellent safety profile, but their long-term impact on cardiovascular events is currently under investigation. Whether PCSK9 mAbs decrease the rates of recurrent cardiovascular events within 3 months following ACS is questionable; however, these agents, unlike statins, may not have pleiotropic benefits on the unstable plaque. © 2013 Elsevier HS Journals, Inc..

Thomas W.R.,University of Western Australia
Asian Pacific Journal of Allergy and Immunology | Year: 2010

Objective: To consider how the different distribution of house dust mites and their species in different geographical locations affects the allergens in the environment and their use. Data sources: Data were obtained from Medline, Genbank and library and web searches. Study selections: A comprehensive description of the genetic variations of allergens is given. The distribution of house dust mites is illustrated with publications that either make pertinent observations or would be useful for a broad appreciation of their geographical distribution. Results: The review identifies regions where glycyphagid house dust mites have been found and the distribution of the pyroglyphid Dermatophagoides spp. The antigenic differences the allergens of D. pteronyssinus and D. farinae are outlined and how this should affect optimal allergen usage in different regions. The allelic variations within the major allergens of Dermatophagoides sp. are similarly presented. Conclusions: While there is a broad knowledge of the distribution of different species of house dust mites, regions that require further examination have been identified and there are examples of incorrect use of allergens for different regions. The extension of allergy research and practice into new regions will benefit from allergen formulations designed for regional use. Specific knowledge of the allergens in the environments will be required to optimally implement some of the new molecularly-defined medicaments currently being developed for effective allergy vaccination and immunotherapy.

Mozaffarian D.,Brigham and Womens Hospital | Mozaffarian D.,Harvard University | Wu J.H.Y.,Harvard University | Wu J.H.Y.,University of Western Australia
Journal of Nutrition | Year: 2012

Considerable research supports cardiovascular benefits of consuming omega-3 PUFA, also known as (n-3) PUFA, from fish or fish oil. Whether individual long-chain (n-3) PUFA have shared or complementary effects is not well established. We reviewed evidence for dietary and endogenous sources and cardiovascular effects on biologic pathways, physiologic risk factors, and clinical endpoints of EPA [20:5(n-3)], docosapentaenoic acid [DPA, 22:5(n-3)], and DHA [22:6(n-3)]. DHA requires direct dietary consumption, with little synthesis from or retroconversion to DPA or EPA. Whereas EPA is also largely derived from direct consumption, EPA can also be synthesized in small amounts from plant (n-3) precursors, especially stearidonic acid. In contrast, DPA appears principally derived from endogenous elongation from EPA, and DPA can also undergo retroconversion back to EPA. In experimental and animal models, both EPA and DHA modulate several relevant biologic pathways, with evidence for some differential benefits. In humans, both fatty acids lower TG levels and, based on more limited studies, favorably affect cardiac diastolic filling, arterial compliance, and some metrics of inflammation and oxidative stress. All three (n-3) PUFA reduce ex vivo platelet aggregation and DHA also modestly increases LDL and HDL particle size; the clinical relevance of such findings is uncertain. Combined EPA+DHA or DPA+DHA levels are associated with lower risk of fatal cardiac events and DHA with lower risk of atrial fibrillation, suggesting direct or indirect benefits of DHA for cardiac arrhythmias (although not excluding similar benefits of EPA or DPA). Conversely, EPA and DPA, but not DHA, are associated with lower risk of nonfatal cardiovascular endpoints in some studies, and purified EPA reduced risk of nonfatal coronary syndromes in one large clinical trial. Overall, for many cardiovascular pathways and outcomes, identified studies of individual (n-3) PUFA were relatively limited, especially for DPA. Nonetheless, the present evidence suggests that EPA and DHA have both shared and complementary benefits. Based on current evidence, increasing consumption of either would be advantageous compared to little or no consumption. Focusing on their combined consumption remains most prudent given the potential for complementary effects and the existing more robust literature on cardiovascular benefits of their combined consumption as fish or fish oil for cardiovascular benefits. © 2012 American Society for Nutrition.

Ford A.,University of Western Australia | Hart C.J.R.,University of British Columbia
Ore Geology Reviews | Year: 2013

The quality of a mineral potential map is dependent on the quality of the input data used in the analysis. In frontier regions or those with limited or no exploration history, datasets are often of questionable quality, and are generally incomplete with data missing either due to incomplete mapping or data not being made available to the public. This study introduces a method for addressing these challenges in mineral potential mapping to derive exploration targets. Utilizing four established statistical measures, an iterative weights of evidence method is employed to assess the strength of the relationship between known deposits and a set of geological feature layers. This method acts as an indirect validation tool for assessing the quality of the data by allowing an expert user to determine whether the statistics conform to expected relationships. Taking data from Mongolia, this iterative weights of evidence method is used to produce a mineral potential map and to evaluate potential targets for orogenic gold mineralization. The success of the method is determined by the ability of the mineral potential map to predict the location of the known mineralization. © 2012 Elsevier B.V.

French M.A.H.,University of Western Australia
Medical Journal of Australia | Year: 2012

Restoration of immune responses against opportunistic pathogens after commencing antiretroviral therapy (ART) may cause immune restoration disease (IRD) in about 10%-40% of HIV patients with low CD4+ T-cell counts and usually presents clinically as a type of immune reconstitution inflammatory syndrome (IRIS). IRIS may be associated with many different opportunistic pathogens, but types associated with Mycobacterium tuberculosis, BCG, cryptococci, JC polyomavirus (the cause of progressive multifocal leukoencephalopathy [PML]), hepatitis C virus and hepatitis B virus infection are the most informative about disease pathogenesis and management. A CD4 + T-cell count of < 50/μL and a high pathogen load are the most commonly identified risk factors for IRIS. Recovery of pathogen-specific T-cell responses and perturbations of innate immune responses before and after ART appear to cause immunopathological abnormality in tissues infected by the pathogen. Prevention of IRIS may be influenced by the timing of ART: The risk of tuberculosis (TB)-associated-IRIS can be reduced by commencing ART after 8 weeks of TB treatment, but rates of AIDS or death are lower if ART is commenced during the first 4 weeks of TB treatment. Outcomes for patients with HIV and treated cryptococcal or TB meningitis may be improved by deferring ART until the opportunistic infection is fully suppressed, but data are inadequate. As ART is currently the only effective treatment for PML in patients with HIV, PML-associated IRIS cannot be prevented by manipulating the timing of ART. A greater understanding of the immunopathogenesis of IRIS may lead to targeted therapies.

The population density, activity and bioturbation contribution of the sea cucumber Holothuria whitmaei was investigated on Ningaloo Reef, Western Australia. Two methods, stratified manta tows and blanket manta tows, recorded population densities between 11.4 and > 100 individuals (ind.) ha -1. Further analysis revealed a heterogeneous pattern of distribution, with individuals tending to aggregate (Moran's I; 0.039; p < 0.05) on the outer reef lagoon and particularly in areas of high flow. Densities within aggregations were up to 7.2 times greater than those obtained after blanket manta tows (17.1 ind. ha-1), and 4.5 to 6.3 times greater than those obtained after traditional stratified manta tows (19.3 to 27.1 ind. ha-1). Behavioural studies, including investigations of activity and bioturbation, were conducted over a 2 yr time frame (2002-2003) incorporating 3 monitoring periods within each year: January, April and August. Rates of activity varied diurnally, increasing between morning and afternoon, and seasonally, increasing in April, relative to January and August. Temporal patterns of feeding were more difficult to characterise; although rates of sediment egestion were in many cases higher in the morning, no conclusive diurnal or seasonal patterns could be established. Subsequent regression analysis, however, did find a significant positive correlation between the distance travelled and the volume of sediment egested. The volume of sediment bioturbated by H. whitmaei at a population level was found to represent only a small fraction of the sediments available (ca. 2 to 14% per annum), even though the contribution per individual was greater than that of smaller sea cucumber species. However, at maximum densities and typical rates of activity, H. whitmeai makes physical contact with approximately 2 times the available coral reef sediments per annum per hectare, simply by crawling. This may represent an important ecological contribution, particularly in light of previously documented links between sea cucumber activity, nutrient recycling and the enhancement of benthic microalgal communities. © Inter-Research 2010.

Anderton R.S.,University of Western Australia
Molecular neurobiology | Year: 2013

Spinal muscular atrophy (SMA) is a devastating and often fatal neurodegenerative disease that affects spinal motor neurons and leads to progressive muscle wasting and paralysis. The survival of motor neuron (SMN) gene is mutated or deleted in most forms of SMA, which results in a critical reduction in SMN protein. Motor neurons appear particularly vulnerable to reduced SMN protein levels. Therefore, understanding the functional role of SMN in protecting motor neurons from degeneration is an essential prerequisite for the design of effective therapies for SMA. To this end, there is increasing evidence indicating a key regulatory antiapoptotic role for the SMN protein that is important in motor neuron survival. The aim of this review is to highlight key findings that support an antiapoptotic role for SMN in modulating cell survival and raise possibilities for new therapeutic approaches.

PURPOSE:: To evaluate the success rate of laser chorioretinal anastomosis (L-CRA) creation with a new laser photocoagulator system capable of 5 watts (W) power in patients with central retinal vein occlusion (CRVO). METHODS:: Patients with a treatment-naive CRVO were enrolled as part of an ongoing trial combining L-CRAs with anti–vascular endothelial growth factor treatment. RESULTS:: Thirty-three patients were treated with an L-CRA developing in 29 (88%). Mean power was 2.7 W and mean time for development was 1.8 months. Each patient had two potential sites created. Eighteen patients developed 2 L-CRAs and the remaining 11 patients, one each. Of the 66 potential sites, successful L-CRAs developed at 47 sites (71%). Additional Nd:YAG laser applications were used in 39% of sites. Mean follow-up was 23 months and no significant complications were seen. CONCLUSION:: An L-CRA as a means of permanently bypassing the obstruction to venous outflow in CRVO may become more relevant as not all patients respond well to intravitreal therapy. The limitation to this technique in the past has been lack of availability of a laser system with the power necessary to create the L-CRA. The success rate with the new system has improved to 88% representing a significant improvement over our original success rate of 33%. © 2016 by Ophthalmic Communications Society, Inc.

Doherty J.P.,University of Western Australia | Muir Wood D.,University of Dundee
Geotechnique | Year: 2013

Predicting the settlement of shallow foundations on sand is a routine task for the geotechnical engineering profession. Despite this, there is no well-accepted solution for this very common problem. The aim of the present paper is to address this by presenting a soil model that is simple enough to be applied in routine engineering practice, but sophisticated enough to capture the important mechanical behaviour of sands relevant to the footing settlement problem. Emphasis is placed on the application of the model by presenting details of the process adopted for deriving model parameters prior to back-analysing foundation load tests.

Pfefferle P.I.,University of Marburg | Pfefferle P.I.,Justus Liebig University | Prescott S.L.,Justus Liebig University | Prescott S.L.,University of Western Australia | Kopp M.,University of Lubeck
Journal of Allergy and Clinical Immunology | Year: 2013

Epidemiologic studies indicate that microbes and microbial components are associated with protection against chronic inflammatory disease. Consequently, a plethora of clinical approaches have been used to investigate the benefits of a range of microbial products on inflammatory conditions in human trials. Centered particularly on the use of prebiotics, probiotic bacteria, and bacterial lysates in early life, this review provides an overview on clinical approaches aimed at reducing the global burden of allergic disease through primary prevention. Microbial interventions beginning before birth and in early infancy are discussed in the context of underlying mechanisms of oral tolerance and the establishment of gut colonization as a critical early homeostatic influence. We explore both the findings and challenges faced in existing studies with a view toward improving future clinical studies of the application of microbial compounds for the prevention of allergic disease and other inflammatory diseases. © 2013 American Academy of Allergy, Asthma & Immunology.

Thomas W.R.,University of Western Australia
Clinical and Experimental Allergy | Year: 2013

Activation of receptors of the innate immune system is a critical step in the initiation of immune responses. It has been shown that dominant allergens have properties that could allow them to interact with toll-like and C-type lectin receptors to favour Th2-biased responses and many bind lipids and glycans that could associate with ligands to mimic pathogen-associated microbial patterns. In accord with the proposed allergen-specific innate interactions it has been shown that the immune responses to different allergens and antigens from the same source are not necessarily coordinately regulated. © 2012 Blackwell Publishing Ltd.

Lopresti A.L.,Murdoch University | Hood S.D.,University of Western Australia | Drummond P.D.,Murdoch University
Journal of Affective Disorders | Year: 2013

Research on major depression has confirmed that it is caused by an array of biopsychosocial and lifestyle factors. Diet, exercise and sleep are three such influences that play a significant mediating role in the development, progression and treatment of this condition. This review summarises animal- and human-based studies on the relationship between these three lifestyle factors and major depressive disorder, and their influence on dysregulated pathways associated with depression: namely neurotransmitter processes, immuno-inflammatory pathways, hypothalamic-pituitary-adrenal (HPA) axis disturbances, oxidative stress and antioxidant defence systems, neuroprogression, and mitochondrial disturbances. Increased attention in future clinical studies on the influence of diet, sleep and exercise on major depressive disorder and investigations of their effect on physiological processes will help to expand our understanding and treatment of major depressive disorder. Mental health interventions, taking into account the bidirectional relationship between these lifestyle factors and major depression are also likely to enhance the efficacy of interventions associated with this disorder. © 2013 Elsevier B.V.

Bleby T.M.,University of Western Australia | Mcelrone A.J.,University of California at Davis | Jackson R.B.,Duke University
Plant, Cell and Environment | Year: 2010

Deep water uptake and hydraulic redistribution (HR) are important processes in many forests, savannas and shrublands. We investigated HR in a semi-arid woodland above a unique cave system in central Texas to understand how deep root systems facilitate HR. Sap flow was measured in 9 trunks, 47 shallow roots and 12 deep roots of Quercus, Bumelia and Prosopis trees over 12 months. HR was extensive and continuous, involving every tree and 83% of roots, with the total daily volume of HR over a 1 month period estimated to be approximately 22% of daily transpiration. During drought, deep roots at 20 m depth redistributed water to shallow roots (hydraulic lift), while after rain, shallow roots at 0-0.5 m depth redistributed water among other shallow roots (lateral HR). The main driver of HR appeared to be patchy, dry soil near the surface, although water may also have been redistributed to mid-level depths via deeper lateral roots. Deep roots contributed up to five times more water to transpiration and HR than shallow roots during drought but dramatically reduced their contribution after rain. Our results suggest that deep-rooted plants are important drivers of water cycling in dry ecosystems and that HR can significantly influence landscape hydrology. © 2010 Blackwell Publishing Ltd.

Ma C.,University of Western Australia
Energy Economics | Year: 2010

A common practice in decomposition analyses is to deflate output indicators to purge the impact of inflation by using a general deflator. This practice fails to account for sector heterogeneity and can be hazardous. Although the general identified patterns are largely correct, the calculated magnitudes can be misleading or even wrongly signed. Instead, it is strongly recommended that sector heterogeneity is accounted for by using individual sector price indices for all relevant sectors instead of one general (GDP) deflator. This paper analyzes this advanced decomposition using Chinese data and compares to the usual method of using only one deflator. It is found that while most differences are only of quantitative quality, some show even a qualitative difference. Furthermore, the rising energy intensity in the early 2000s, which has been discussed by previous studies, vanishes completely. © 2009 Elsevier B.V. All rights reserved.

Honeybul S.,Sir Charles Gairdner Hospital | Ho K.M.,University of Western Australia
Plastic and Reconstructive Surgery | Year: 2012

Background: The authors investigated the long-term outcome of frozen autologous bone cranioplasty in patients who had undergone decompressive craniectomy for severe traumatic brain injury. Methods: A retrospective analysis was undertaken of all patients who had undergone decompressive craniectomy at the two major trauma hospitals in Western Australia between 2004 and 2010. A specific note was made regarding "failure" of frozen autologous bone because of either infection or bone flap resorption. Results: A total of 194 patients required either unilateral or bilateral decompressive craniectomy for severe traumatic brain injury during the study period. Of these patients, 156 had had an autologous cranioplasty. Among these patients, the cranioplasty was judged a failure in 45 (29 percent). Thirteen (8.5 percent; 95 percent confidence interval, 5.0 to 14.0 percent) developed an infection requiring removal of the cranioplasty. Thirty-two (21 percent; 95 percent confidence interval, 15 to 28 percent) developed clinical symptoms or signs relating to resorption of the cranioplasty. Fourteen (9 percent) required secondary titanium cranioplasty, two were offered surgical augmentation but declined, and 16 (10 percent) developed significant bone resorption through both the inner and outer tables of the skull. Conclusions: This study has demonstrated that the use of frozen autologous bone is associated with a high long-term failure rate; however, this does not necessarily imply that alternative materials should be routinely used. Although a number are available, their efficacy over and above frozen autologous bone remains to be established and perhaps this will only be demonstrated in the setting of a formal clinical trial. Copyright © 2012 by the American Society of Plastic Surgeons.

Lee J.,University of Western Australia
Environmental and Planning Law Journal | Year: 2014

Adaptive management is an approach to natural resource management that has gained increasing traction in Australia. Despite its appearance in a growing number of natural resource policies and regulatory instruments there remains little consideration of what adaptive management really means, how it is faring in practice and what legal mechanisms are required for its effective implementation. This article examines adaptive management in the context of groundwater impact management at Australian mines. The article first constructs a theoretical model for the practice of adaptive management and uses the United States experience to identify some primary legal obstacles to its effective implementation. The practice of adaptive groundwater management at two Australian mining projects is assessed. Each case study is evaluated against the identified primary legal obstacles with a view to assessing whether similar difficulties are being experienced in Australia. Finally, the article recommends a legal framework for the improved implementation of adaptive groundwater management at Australian mining projects that will address the legal obstacles currently being faced. © 2015, (publisher). All rights reserved.

Reece A.S.,University of Western Australia
Medical Hypotheses | Year: 2011

Whilst the parallels between drug and food craving are receiving increasing attention, the recently elucidated complex physiology of the hypothalamic appetite regulatory centres has been largely overlooked in the efforts to understand drug craving which is one of the most refractory and problematic aspects of drug and behavioural addictions. Important conceptual gains could be made by researchers from both appetite and addiction neuroscience if they were to have an improved understanding of each others' disciplines. It is well known in addiction medicine that the use of many substances is elevated in opiate dependency. There is voluminous evidence of very high rates of drug use in opiate agonist maintained patients, and the real possibility exists that opiate agonist therapy therefore increases drug craving. Conversely, opiate antagonist therapy with naloxone or naltrexone has been shown to reduce most chemical and behavioural addictions, and naltrexone is now being developed together with bupropion as the anti-obesity drug " Contrave" Hypothalamic melanocortins, particularly α-MSH, are known to constitute the main brake to consumptive behaviour of food. There is a well described antagonism between melanocortins and opioids at many loci including the hypothalamus. Administration of exogenous opiates is known to both suppress α-MSH and to stimulate hedonic food consumption. Opiate maintenance programs are associated with weight gain. As monoamines, opioids and cannabinoids are known to be involved in appetite regulation, and as endorphin opioids are known to be perturbed in other addictions, further exploration of the hypothalamic appetite regulatory centre would appear to be an obvious, albeit presently largely overlooked, locus in which to study drug and other craving mechanisms. © 2010 Elsevier Ltd.

Pirajno F.,University of Western Australia | Santosh M.,China University of Geosciences
Precambrian Research | Year: 2015

The formation and disruption of supercontinents exert major influence on mantle dynamics and have important bearing on continental dynamics and mineral systems. Here we evaluate the role of mantle plumes in the rifting and breakup of supercontinents with specific examples involving Columbia, Rodinia and Gondwana. We attempt to trace the formation of associated rift systems and the making of mineral deposits in the processes from failed rifts (aulacogens) to successful rifts. Models on the rifting and breakup of supercontinents through mantle upwellings range from 'thermal blanket' effect and supercontinent self-destruction through plumes rising from the mantle transition zone at the 410-660. km boundary layer to superplumes generated at the core-mantle boundary with subducted slabs acting as the fuel. Intracontinental rifts are potential sites of giant ore systems, such as sedimentary exhalative (SEDEX), stratiform, stratabound and Fe oxide-Cu-Au-U (IOCG) deposits. The age span of these ore systems (~1.6-0.8. Ga) broadly corresponds with the assembly and dispersal of the Palaeoproterozoic supercontinent Columbia, followed by the amalgamation of the Neoproterozoic Rodinia and its subsequent breakup. The Phanerozoic Pangea supercontinent at 260. Ma had two main components, Laurasia in the north and Gondwana in the south, separated by the Palaeotethys Ocean. We focus on the rifting of Gondwana, which led to the formation of present day Atlantic and Indian oceans. Thus, rift systems effectively act as major conduits for both magmas and hydrothermal fluids. Intracontinental rifts host magmatic and hydrothermal mineral deposits including Ni-Cu and Ti-Fe±V and Cu-Ni±PGE deposits in mantle-sourced mafic-ultramafic rocks, U-REE-Nb-Cu sourced from metasomatised subcontinental lithospheric mantle, and hydrothermal Sn-W, among other types. Upwelling plumes and their migration beneath trans-crustal faults or lithospheric discontinuities drive hydrothermal factories channelling heat and fluids and generating economic ore deposits. © 2014 Elsevier B.V.

Zhang K.,Shenzhen University | Wang S.,University of Western Australia
Automatica | Year: 2012

We develop a novel numerical method to price American options on a discount bond under the CoxIngrosllRoss (CIR) model which is governed by a partial differential complementarity problem. We first propose a penalty approach to this complementarity problem, resulting in a nonlinear partial differential equation (PDE). To numerically solve this nonlinear PDE, we develop a novel fitted finite volume method for the spatial discretization, coupled with a fully implicit time-stepping scheme. We show that this full discretization scheme is consistent, stable and monotone, and hence the convergence of the numerical solution to the viscosity solution of the continuous problem is guaranteed. To solve the discretized nonlinear system, we design an iterative method and prove that the method is convergent. Numerical results are presented to demonstrate the accuracy, efficiency and robustness of our methods. © 2012 Elsevier Ltd. All rights reserved.

Waterer G.,University of Western Australia | Rello J.,Autonomous University of Barcelona
Current Opinion in Infectious Diseases | Year: 2011

PURPOSE OF REVIEW: We focus on a number of studies in the past 2 years that herald a dramatic shift in how we treat patients with not just community-acquired pneumonia (CAP), but potentially all sepsis. RECENT FINDINGS: Recent studies report that high bacterial load, and specifically pneumococcal load in CAP, appears to be significantly associated with worse outcomes. These findings change the sepsis paradigm. Bacterial load may identify potential candidates for adjunctive therapy, ICU admission and more aggressive management. SUMMARY: Whereas we all acknowledge the importance of the virulence of the pathogen in the outcome of CAP, microbiological tests currently play little role in management of patients. Whereas molecular tests such as polymerase chain reaction have promised to deliver accurate results in a clinically useful period of time, apart from a few niche situations they have yet to enter routine practice. In particular the ability to calculate the bacterial load in blood, and specifically pneumococcal load in CAP, appears to have significant clinical utility. Not only does bacterial load predict clinical outcome, the data so far available challenge some of our fundamental assumptions about optimal antibiotic therapy and the pathogenesis of severe sepsis. © 2011 International Society of Nephrology.

Reynolds M.,University of Western Australia
Advances in Modal Logic | Year: 2014

We provide a simple, sound, complete and terminating tableau decision procedure for the temporal logic of until and since over the real numbers model of time. This logic is an important basis for reasoning about concurrency, metric constraints and planning. Despite its usefulness and long history, there are no existing implementable reasoning techniques for it. The tableau uses a mosaic-based technique to translate the satisfability problem into a question about the way that intervals of a real-owed model relate to each other. It builds on top of recently developed reasoning tools for general linear time by applying some interesting but computationally simple checks.

Bacchetti T.,Marche Polytechnic University | Sahebkar A.,Mashhad University of Medical Sciences | Sahebkar A.,University of Western Australia
Progress in Lipid Research | Year: 2015

Background Decreased activity of the enzyme paraoxonase-1 (PON1) has been demonstrated in cardiovascular diseases. Statins, the forefront of pharmacotherapy for dyslipidemia, have been shown to enhance PON1 activity but clinical findings have not been conclusive. Objective To systematically review the clinical findings on the impact of statin therapy on PON1 status (protein concentrations and activities of paraoxonase and arylesterase) and calculate an effect size for the mentioned effects through meta-analysis of available data. Methods Scopus and Medline databases were searched to identify clinical trials. A random-effects model and the generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the one-study remove approach. Random-effects meta-regression was performed to assess the impact of potential confounders on the estimated effect sizes. Results Meta-analysis suggested that statin therapy is associated with a significant elevation of PON1 paraoxonase and arylesterase activities, but not PON1 protein concentration. The PON1-enhancing effects of statins were robust in the sensitivity analyses and were independent of statin dose, treatment duration and changes in plasma low-density lipoprotein cholesterol concentration. Conclusion The increase of paraoxonase and arylesterase activities with statins is a pleiotropic lipid-independent clinical benefit that may partly explain the putative effects of statins in preventing cardiovascular outcomes. © 2015 Elsevier B.V.

Kostylev M.,University of Western Australia
Journal of Applied Physics | Year: 2012

In this work, we have studied theoretically the transmission and reflection of electromagnetic waves in the microwave frequency range through the in-plane magnetized exchange-coupled bi-layer ferromagnetic metallic films. It was found that responses of the films in transmission and reflection are very different. In transmission, the response of the fundamental mode dominates, but in reflection, the first exchange mode demonstrates the largest variation in amplitude with respect to the off-resonance regime. The theory also predicts an interesting regime of low-loss transmission associated with the resonance excitation of the first (anti-symmetric) exchange standing spin wave mode. In this regime, the transmission through the sample increases instead of decreasing for this mode. © 2012 American Institute of Physics.

Hart P.H.,University of Western Australia
Discovery medicine | Year: 2012

There is considerable debate about the benefits of vitamin D supplementation for multiple sclerosis, allergic asthma, and type 1 diabetes. This has been driven mainly by observational studies linking vitamin D deficiency and insufficiency with increased prevalence of autoimmune and other diseases driven by immune processes. Randomized controlled trials of vitamin D supplementation to treat these (and other) diseases have been disappointing. This review examines the evidence that circulating vitamin D levels provide a surrogate measure of sun exposure and that it is the other molecules and pathways induced by sun exposure, rather than vitamin D-driven processes, that explain many of the benefits often attributed to vitamin D.

Li N.,Peking University | Chen Y.-J.,Peking University | Santosh M.,China University of Geosciences | Pirajno F.,University of Western Australia
Gondwana Research | Year: 2015

The Qinling Orogen was formed from the closure of the northernmost paleo-Tethys sea and the tectonic suturing of the Yangtze and North China Cratons. The timing of this collision and the tectonic framework are debated. The widely developed Triassic granitoids in the western Qinling Orogen offer a key to understand the tectonic evolution of this region. Here we compile the geological, geochemical and geochronological data of the Triassic granitoids from the Qingling Orogen and conclude that the granitoids north of the Mian-Lue Suture were emplaced in an active continental margin related to the northward subduction of the Mian-Lue oceanic plate during 248-200Ma. The granitoids can be classified into I- and S-types, with the former constituting the major variety. Northward from the Mian-Lue Fault, an S-type granite belt appears, followed by and locally overlapping with an I-type granite belt. The I-type granite belt can be subdivided into four sub-belts from south to north, with increasing contents of K2O, K2O+Na2O, SiO2, Th and U, and the ratios of K2O/Na2O, Rb/Sr and (87Sr/86Sr)i, but decreasing contents of Na2O, Al2O3, Mg#, and εHf(t), except for the northernmost belt which occurs in the Huaxiong Block of the North China Craton. This geochemical polarity of I-type granitoids and the zoned distribution of S- and I-types granitoids cannot be explained through continental collision orogeny (including syn- to post-collision), but can be well interpreted by considering the progressive subduction of the northernmost branch of the paleo-Tethys, as represented by the Mian-Lue Ocean. Thus, the termination of the northernmost paleo-Tethys and the onset of the continental collision between the Yangtze and the North China plates are considered to have occurred at about 200Ma, during the transition from Triassic to Jurassic. Our model is also supported by the available data from other studies and provides a revised framework for the timing and tectonics of assembly of the Yangtze and the North China Cratons. © 2013 International Association for Gondwana Research.

Watson H.J.,Center for Clinical Interventions | Watson H.J.,University of Western Australia | Bulik C.M.,University of North Carolina at Chapel Hill
Psychological Medicine | Year: 2013

Background Anorexia nervosa is a potentially deadly psychiatric illness that develops predominantly in females around puberty but is increasingly being recognized as also affecting boys and men and women across the lifespan. The aim of this environmental scan is to provide an overview of best practices in anorexia nervosa treatment across the age spectrum. Method A triangulation approach was used. First, a detailed review of randomized controlled trials (RCTs) for anorexia nervosa published between 1980 and 2011 was conducted; second, clinical practice guidelines were consulted and reviewed; third, information about RCTs currently underway was sourced. This approach facilitated a comprehensive overview, which addressed the extant evidence base, recent advances in evidence and improvements in treatment, and future directions. Results The evidence base for the treatment of anorexia nervosa is advancing, albeit unevenly. Evidence points to the benefit of family-based treatment for youth. For adults no specific approach has shown superiority and, presently, a combination of renourishment and psychotherapy such as specialist supportive clinical management, cognitive behavioral therapy, or interpersonal psychotherapy is recommended. RCTs have neither sufficiently addressed the more complex treatment approaches seen in routine practice settings, such as multidisciplinary treatment or level of care, nor specifically investigated treatment in ethnically diverse populations. Methodological challenges that hinder progress in controlled research for anorexia nervosa are explained. Conclusions The review highlights evidence-based and promising treatment modalities for anorexia nervosa and presents a triangulated analysis including controlled research, practice guidelines, and emerging treatments to inform and support clinical decision making. Copyright © Cambridge University Press 2012.

Laliberte E.,University of Canterbury | Laliberte E.,University of Western Australia | Tylianakis J.M.,University of Canterbury
Ecology | Year: 2012

There is much concern that the functioning of ecosystems will be affected by human-induced changes in biodiversity, of which land-use change is the most important driver. However, changes in biodiversity may be only one of many pathways through which land use alters ecosystem functioning, and its importance relative to other pathways remains unclear. In particular, although biodiversity-ecosystem function research has focused primarily on grasslands, the increases in agricultural inputs (e.g., fertilization, irrigation) and grazing pressure that drive change in grasslands worldwide have been largely ignored. Here we show that long-term (27-year) manipulations of soil resource availability and sheep grazing intensity caused marked, consistent shifts in grassland plant functional composition and diversity, with cascading (i.e., causal chains of) direct, indirect, and interactive effects on multiple ecosystem functions. Resource availability exerted dominant control over aboveground net primary production (ANPP), both directly and indirectly via shifts in plant functional composition. Importantly, the effects of plant functional diversity and grazing intensity on ANPP shifted from negative to positive as agricultural inputs increased, providing strong evidence that soil resource availability modulates the impacts of plant diversity and herbivory on primary production. These changes in turn altered litter decomposition and, ultimately, soil carbon sequestration, highlighting the relevance of ANPP as a key integrator of ecosystem functioning. Our study reveals how human alterations of bottom-up (resources) and top-down (herbivory) forces together interact to control the functioning of grazing systems, the most extensive land use on Earth. © 2012 by the Ecological Society of America.

A common response of wetland plants to flooding is the formation of aquatic adventitious roots. Observations of aquatic root growth are widespread; however, controlled studies of aquatic roots of terrestrial herbaceous species are scarce. Submergence tolerance and aquatic root growth and physiology were evaluated in two herbaceous, perennial wetland species Cotula coronopifolia and Meionectes brownii. Plants were raised in large pots with 'sediment' roots in nutrient solution and then placed into individual tanks and shoots were left in air or submerged (completely or partially). The effects on growth of aquatic root removal, and of light availability to submerged plant organs, were evaluated. Responses of aquatic root porosity, chlorophyll and underwater photosynthesis, were studied. Both species tolerated 4 weeks of complete or partial submergence. Extensive, photosynthetically active, aquatic adventitious roots grew from submerged stems and contributed up to 90 % of the total root dry mass. When aquatic roots were pruned, completely submerged plants grew less and had lower stem and leaf chlorophyll a, as compared with controls with intact roots. Roots exposed to the lowest PAR (daily mean 4.7 ± 2.4 μmol m(-2) s(-1)) under water contained less chlorophyll, but there was no difference in aquatic root biomass after 4 weeks, regardless of light availability in the water column (high PAR was available to all emergent shoots). Both M. brownii and C. coronopifolia responded to submergence with growth of aquatic adventitious roots, which essentially replaced the existing sediment root system. These aquatic roots contained chlorophyll and were photosynthetically active. Removal of aquatic roots had negative effects on plant growth during partial and complete submergence.

Zhao M.,University of Western Sydney | Cheng L.,University of Western Australia | Cheng L.,Dalian University of Technology
Physics of Fluids | Year: 2014

Vortex-induced vibration (VIV) of a rigid circular cylinder of finite length subject to uniform steady flow is investigated numerically. The study is focused on the effect of the free end on the response of the cylinder. The vibration of the cylinder is confined only in the cross-flow direction. Three-dimensional Navier-Stokes equations are solved by the Petrov-Galerkin finite element method and the equation of the motion is solved for the cylinder displacement. Simulations are conducted for a constant mass ratio of 2, a constant Reynolds number of 300 and cylinder length to diameter ratios of L/D = 1, 2, 5 10, and 20. It is found that the vortex shedding in the wake of a fixed cylinder is suppressed if the cylinder length is less than 2 cylinder diameters. However, if the cylinder is allowed to vibrate, VIV happens at L/D = 1 and 2 and the response amplitudes at these two cylinder lengths are comparable with that of a 2D-cylinder. The vortices that are shed from a short cylinder of L/D = 1 and 2 are found to be generated from the free-end of the cylinder and convected toward the top end of the cylinder by the upwash velocity. They are found to be nearly perpendicular to the cylinder span. The wake flow in a vibrating cylinder with L/D greater than 5 includes the vortex shedding flow at the top part of the cylinder and the end-induced vortex shedding near the free-end of the cylinder. The phase difference between the sectional lift coefficient and the vibration displacement near the free-end of the cylinder changes from 0° to 180° at higher reduced velocity than that near the top end. Strong variation of the flow along the cylinder span occurs at reduced velocities where the lift coefficient near the free-end and that near the top end are in anti-phase with each other. © 2014 AIP Publishing LLC.

Miller K.,University of Western Australia | Lu J.,University of Iowa
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2013

This paper presents main theses of two keynote lectures delivered at Euromech Colloquium "Advanced experimental approaches and inverse problems in tissue biomechanics" held in Saint Etienne in June 2012. We are witnessing an advent of patient-specific biomechanics that will bring in the future personalized treatments to sufferers all over the world. It is the current task of biomechanists to devise methods for clinically-relevant patient-specific modeling. One of the obstacles standing before the biomechanics community is the difficulty in obtaining patient-specific properties of tissues to be used in biomechanical models. We postulate that focusing on reformulating computational mechanics problems in such a way that the results are weakly sensitive to the variation in mechanical properties of simulated continua is more likely to bear fruit in near future. We consider two types of problems: (i) displacement-zero traction problems whose solutions in displacements are weakly sensitive to mechanical properties of the considered continuum; and (ii) problems that are approximately statically determinate and therefore their solutions in stresses are also weakly sensitive to mechanical properties of constituents. We demonstrate that the kinematically loaded biomechanical models of the first type are applicable in the field of image-guided surgery where the current, intraoperative configuration of a soft organ is of critical importance. We show that sac-like membranes, which are prototypes of many thin-walled biological organs, are approximately statically determinate and therefore useful solutions for wall stress can be obtained without the knowledge of the wall's properties. We demonstrate the clinical applicability and effectiveness of the proposed methods using examples from modeling neurosurgery and intracranial aneurysms. © 2013 Elsevier Ltd.

Bekki K.,University of Western Australia
Monthly Notices of the Royal Astronomical Society | Year: 2014

We investigate the physical properties of molecular hydrogen (H2) in isolated and interacting disc galaxies with different masses and Hubble types by using chemodynamical simulations with H2 formation on dust grains and dust growth and destruction in interstellar medium. We particularly focus on the dependences of H2 gas mass fractions (fH2), spatial distributions of H I and H2, and local H2-scaling relations on initial halomasses (Mh), baryonic fractions (fbary), gas mass fractions (fg), and Hubble types. The principal results are as follows. The final fH2 can be larger in disc galaxies with higher Mh, fbary, and fg. Some low-mass discmodels with Mh smaller than 1010M⊙ show extremely low fH2 and thus no/little star formation, even if initial fg is quite large (>0.9). Big galactic bulges can severely suppress the formation of H2 from H I on dust grains whereas strong stellar bars cannot only enhance fH2 but also be responsible for the formation of H2-dominated central rings. The projected radial distributions of H2 are significantly more compact than those of H I and the simulated radial profiles of H2-to-H Iratios (Rmol) follow roughly R-1.5 in Milky Way-type disc models. Galaxy interaction can significantly increase fH2 and total H2 mass in disc galaxies. The local surface mass densities of H2 can be correlated with those of dust in a galaxy. The observed correlation between Rmol and gas pressure (Rmol ∝ P0.92 g) can be well reproduced in the simulated disc galaxies. © 2014 The Authors.

Reid A.,University of Western Australia
Australian and New Zealand Journal of Public Health | Year: 2012

Objective: Since the mid-1990s Australia's immigration program has focused on encouraging skilled migration. This study investigated skill usage in three longitudinal studies of immigrants to Australia and examined if there is an association with mental health status. Methods: Three Longitudinal Surveys of Immigrants to Australia (LSIA), with multiple data collection waves, were conducted between 1994 and 2006. Some 5,192 primary applicants participated in LSIA1, 3,124 in LSIA2 and 9,865 in LSIA3. Data collected included demographics and employment history in all surveys as well as mental health in LSIA1 and 2. Results: Among migrants in LSIA 1, 49% reported working in jobs in which they used their skills sometimes, rarely or never, 31/2 years after immigrating. This was not solely explained by English language proficiency as 47% of migrants who reported speaking English well or very well did not use their qualifications in their job. Migrants who did not use their job qualifications at wave three had a worse GHQ-12 score at wave three after adjusting for age, sex, country of birth and highest educational qualification. There was no difference in wave one or wave two GHQ-12 score between those who did or did not use their job qualifications at wave three. The pattern was similar for those migrants in LSIA 2. Conclusions and Implications: There is a large under-utilisation of employment skills in the migrant population in Australia up to 31/2 years after immigrating. This is associated with poorer mental health. © 2012 Public Health Association of Australia.

The creation of a marine reserve network is an active area of policy in Australia. Here, a discrete choice experiment is used to estimate how the community values the ecology of the Ningaloo Marine Park, with a view to understanding the drivers of social welfare in relation to marine conservation. A novel aspect of this research is that it not only considers the values people hold for conservation outcomes, but also their preferences for how those outcomes are achieved. The results indicate that management process does have an impact on individuals' preferences for conservation. By considering management process within the choice model, we gain a richer understanding of the relationship between social welfare and marine conservation. © 2013 Canadian Agricultural Economics Society.

The Wakatobi National Park in eastern Indonesia offers valuable insights into the effectiveness of governance incentives in a national context characterised by uncoordinated policies and evolving conflicts over power and authority within government. Economic incentives resulting from strategic alliances between the public and private sector have been targeted towards enhanced regulation of fisheries and supporting tourism interests. However, the absence of coherent policies relating to tourism, which partly reflects contests over jurisdiction between national and local levels of government, opens up considerable potential for inappropriate forms of development. Furthermore, any incentives designed to facilitate governance should explicitly recognise the status of the Bajau, who constitute a key stakeholder group yet have been consistently marginalised through both state and NGO initiatives. The possible outcomes of ongoing decentralisation, which include enhanced government accountability, flexibility in developing regulations relating to marine resource use and greater participation of minority groups in decision-making, offer some prospect for improved governance of the Wakatobi and other marine protected areas in Indonesia. © 2012 Elsevier Ltd.

Jablensky A.,University of Western Australia
World Psychiatry | Year: 2016

Despite historical assumptions to the contrary, there is little evidence that the majority of recognized mental disorders are separated by natural boundaries. Diagnostic categories defined by their clinical syndromes should be regarded as 'valid' only if they have been shown to be truly discrete entities. Most diagnostic concepts in psychiatry have not been demonstrated to be valid in this sense, though many possess 'utility' by virtue of the information they convey about presenting symptoms, outcome, treatment response and, in some instances, aetiology. While researchers in genetics, neurobiology and population epidemiology are increasingly more likely to adopt a continuum/dimensional view of the variation in symptomatology, clinicians prefer to hold on to the categorical approach embodied in current classifications such as ICD-10 and DSM-5. Both points of view have plausible justification in their respective contexts, but the way forward may be in their conceptual reconciliation.

Wang C.,Huazhong Agricultural University | Chen S.,University of Western Australia | Yu S.,Huazhong Agricultural University
Theoretical and Applied Genetics | Year: 2011

The gene GS3 has major effect on grain size and plays an important role in rice breeding. The C to A mutation in the second exon of GS3 was reported to be functionally associated with enhanced grain length in rice. In the present study, besides the C-A mutation at locus SF28, three novel polymorphic loci, SR17, RGS1, and RGS2, were discovered in the second intron, the last intron and the final exon of GS3, respectively. A number of alleles at these four polymorphic loci were observed in a total of 287 accessions including Chinese rice varieties (Oryza sativa), African cultivated rice (O. glaberrima) and AA-genome wild relatives. The haplotype analysis revealed that the simple sequence repeats (AT)n at RGS1 and (TCC)n at RGS2 had differentiated in the wild rice whilst the C-A mutation occurred in the cultivated rice recently during domestication. It also indicated that A allele at SF28 was highly associated with long rice grain whilst various motifs of (AT)n at RGS1 and (TCC)n at RGS2 were mainly associated with medium to short grain in Chinese rice. The C-A mutation at SF28 explained 33.4% of the grain length variation in the whole rice population tested in this study, whereas (AT)n at RGS1 and (TCC)n at RGS2 explained 26.4 and 26.2% of the variation, respectively. These results would be helpful for better understanding domestication of GS3 and its manipulation for grain size in rice. The genic marker RGS1 based on the motifs (AT)n was further validated as a functional marker using two sets of backcross recombinant inbred lines. These results suggested that the functional markers developed from four different loci within GS3 could be used for fine marker-assisted selection of grain length in rice breeding. © 2010 Springer-Verlag.

Schuepp K.,University of Western Australia | Sly P.D.,University of Queensland
Paediatric Respiratory Reviews | Year: 2012

Nanoparticles have unique physico-chemical properties compared to larger particles that have the potential to provide promising new possibilities for biomedical applications. Considerable research is currently exploring these potentials of nanotechnology. In contrast, airborne particles as components of indoor air, ambient air pollution associated with traffic-related pollution, industry, power plants, and other combustion sources have the potential to harm children's health. However, a similar research effort into the potential health effects of exposure to nanoparticles is lacking. Children differ markedly from adults in their developmental biology rendering young children the most vulnerable group with regard to potentially harmful effects induced by particulate exposure. This review discusses the differences between children and adults in regard to nanoparticle exposure highlighting the uniqueness and vulnerability of children. © 2011 Elsevier Ltd.

Hammer K.A.,University of Western Australia
International Journal of Antimicrobial Agents | Year: 2015

Over-the-counter acne treatments containing tea tree oil from the plant Melaleuca alternifolia are widely available, and evidence indicates that they are a common choice amongst those self-treating their acne. The aims of this review were to collate and evaluate the clinical evidence on the use of tea tree oil products for treating acne, to review safety and tolerability and to discuss the underlying modes of therapeutic action. © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

van den Biggelaar A.H.J.,University of Western Australia | Pomat W.S.,Papua New Guinea Institute of Medical Research
Vaccine | Year: 2013

Bacterial conjugate vaccines are based on the principle of coupling immunogenic bacterial capsular polysaccharides to a carrier protein to facilitate the induction of memory T-cell responses. Following the success of Haemophilus influenzae type b conjugate vaccines in the 1980s, conjugate vaccines for Streptococcus pneumoniae and Neisseria meningitidis infections were developed and proven to be effective in protecting children against invasive disease. In this review, the use of conjugate vaccines in human newborns is discussed. Neonatal Haemophilus influenzae type b and pneumococcal conjugate vaccination schedules have been trialed and proven to be safe, with the majority of studies demonstrating no evidence for the induction of immune tolerance. Whether their neonatal administration also results in an earlier induction of clinical protection in the first 2-3 critical months of life is still to be demonstrated. © 2012 Elsevier Ltd.

Majumder M.,Monash University | Corry B.,University of Western Australia
Chemical Communications | Year: 2011

Carbon nanotube membranes have been shown to rapidly transport liquids; but progressive hydrophilic modification - contrary to expectations - induces a drastic reduction of water flow. Enhanced electrostatic interaction and the disruption of the mechanically smooth graphitic walls is the determinant of this behavior. These results have critical implications in the design of nanofluidic devices. © 2011 The Royal Society of Chemistry.

Marschner P.,University of Adelaide | Crowley D.,University of California at Riverside | Rengel Z.,University of Western Australia
Soil Biology and Biochemistry | Year: 2011

Iron and phosphorus availability is low in many soils; hence, microorganisms and plants have evolved mechanisms to acquire these nutrients by altering the chemical conditions that affect their solubility. In plants, this includes exudation of organic acid anions and acidification of the rhizosphere by release of protons in response to iron and phosphorus deficiency. Grasses (family Poaceae) and microorganisms further respond to Fe deficiency by production and release of specific chelators (phytosiderophores and siderophores, respectively) that complex Fe to enhance its diffusion to the cell surface. In the rhizosphere, the mutual demand for Fe and P results in competition between plants and microorganisms with the latter being more competitive due to their ability to decompose plant-derived chelators and their proximity to the root surface; however microbial competitiveness is strongly affected by carbon availability. On the other hand, plants are able to avoid direct competition with microorganisms due to the spatial and temporal variability in the amount and composition of exudates they release into the rhizosphere. In this review, we present a model of the interactions that occur between microorganisms and roots along the root axis, and discuss advantages and limitations of methods that can be used to study these interactions at nanometre to centimetre scales. Our analysis suggests mechanisms such as increasing turnover of microbial biomass or enhanced nutrient uptake capacity of mature root zones that may enhance plant competitiveness could be used to develop plant genotypes with enhanced efficiency in nutrient acquisition. Our model of interactions between plants and microorganisms in the rhizosphere will be useful for understanding the biogeochemistry of P and Fe and for enhancing the effectiveness of fertilization. © 2011 Elsevier Ltd.

Robert K.A.,University of Western Australia | Bronikowski A.M.,Iowa State University
American Naturalist | Year: 2010

Evolutionary theories of aging are linked to life-history theory in that age-specific schedules of reproduction and survival determine the trajectory of age-specific mutation/selection balances across the life span and thus the rate of senescence. This is predicted to manifest at the organismal level in the evolution of energy allocation strategies of investing in somatic maintenance and robust stress responses in less hazardous envirnments in exchange for energy spent on growth and reproduction. Here we report experiments from long-studied populations of western terrestrial garter snakes (Thamnophis elegans) that reside in low and high extrinsic mortality environments, with evolved long and short life spans, respectively. Laboratory common-environment colonies of these two ecotypes were tested for a suite of physiological traits after control and stressed gestations. In offspring derived from control and corticosteronetreated dams, we measured resting metabolism; mitochondrial oxygen consumption, ATP and free radical production rates; and erythrocyte DNA damage and repair ability. We evaluated whether these aging biomarkers mirrored the evolution of life span and whether they were sensitive to stress. Neonates from the long-lived ecotype (1) were smaller, (2) consumed equal amounts of oxygen when corrected for body mass, (3) had DNA that damaged more readily but repaired more efficiently, and (4) had more efficient mitochondria and more efficient cellular antioxidant defenses than short-lived snakes. Many ecotype differences were enhanced in offspring derived from stress-treated dams, which supports the conclusion that nongenetic maternal effects may further impact the cellular stress defenses of offspring. Our findings reveal that physiological evolution underpins reptilian life histories and sheds light on the connectedness between stress response and aging pathways in wild-dwelling organisms. © 2010 by The University of Chicago.

Hool L.C.,University of Western Australia
Antioxidants and Redox Signaling | Year: 2015

Significance: Oxygen plays a key role in cellular metabolism and function. Oxygen delivery to cells is crucial, and a lack of oxygen such as that which occurs during myocardial infarction can be lethal. Cells should, therefore, be able to respond to changes in oxygen tension. Recent Advances: Since the first studies examining the acute cellular effect of hypoxia on activation of transmitter release from glomus or type I chemoreceptor cells, it is now known that virtually all cells are able to respond to changes in oxygen tension. Critical Issues: Despite advances made in characterizing hypoxic responses, the identity of the "oxygen sensor" remains debated. Recently, more evidence has evolved as to how cardiac myocytes sense acute changes in oxygen. This review will examine the available evidence in support of acute oxygen-sensing mechanisms providing a brief historical perspective and then more detailed insights into the heart and the role of cardiac ion channels in hypoxic responses. Future Directions: A further understanding of these cellular processes should result in interventions that assist in preventing the deleterious effects of acute changes in oxygen tension such as alterations in contractile function and cardiac arrhythmia. Antioxid. Redox Signal. 22, 522-536. © Copyright 2015, Mary Ann Liebert, Inc. 2015.

Kuzenko S.M.,University of Western Australia
European Physical Journal C | Year: 2011

Consistent supercurrent multiplets are naturally associated with linearized off-shell supergravity models. In S.M. Kuzenko, J. High Energy Phys. 1004, 022 (2010) we presented the hierarchy of such supercurrents which correspond to all the models for linearized 4D N = 1 supergravity classified a few years ago. Here we analyze the correspondence between the most general supercurrent given in S.M. Kuzenko, J. High Energy Phys. 1004, 022 (2010) and the one obtained eight years ago in M. Magro et al., Ann. Phys. 298, 123 (2002) using the superfield Noether procedure. We apply the Noether procedure to the general N =1 supersymmetric nonlinear sigma-model and show that it naturally leads to the so-called S-multiplet, revitalized in Z. Komargodski, N. Seiberg, J. High Energy Phys. 1007, 017 (2010). © The Author(s) 2011.

Lawrance I.C.,Center for Inflammatory Bowel Diseases | Lawrance I.C.,University of Western Australia
World Journal of Gastroenterology | Year: 2014

The inflammatory bowel diseases (IBDs) are chronic incurable conditions that primarily present in young patients. Being incurable, the IBDs may be part of the patient's life for many years and these conditions require therapies that will be effective over the long-term. Surgery in Crohn's disease does not cure the disease with endoscopic recurrent in up to 70% of patients 1 year post resection. This means that, the patient will require many years of medications and the goal of the treating physician is to induce and maintain long-term remission without side effects. The development of the antitumour necrosis factor alpha (TNFα) agents has been a magnificent clinical advance in IBD, but they are not always effective, with loss of response overtime and, at times, discontinuation is required secondary to side effects. So what options are available if of the anti-TNFα agents can no longer be used? This review aims to provide other options for the physician, to remind them of the older established medications like azathioprine/6-mercaptopurine and methotrexate, the less established medications like mycophenolate mofetil and tacrolimus as well as newer therapeutic options like the anti-integins which block the trafficking of leukocytes into the intestinal mucosa. The location of the intestinal inflammation must also be considered, as topical therapeutic agents may also be worthwhile to consider in the longterm management of the more challenging IBD patient. The more options that are available the more likely the patient will be able to have tailored therapy to treat their disease and a better long-term outcome. © 2014 Baishideng Publishing Group Co., Limited. All rights reserved.

Shane M.W.,University of Western Australia | Fedosejevs E.T.,Queens University | Plaxton W.C.,Queens University
Plant Physiology | Year: 2013

Accumulating evidence indicates important functions for phosphoenolpyruvate (PEP) carboxylase (PEPC) in inorganic phosphate (Pi)-starved plants. This includes controlling the production of organic acid anions (malate, citrate) that are excreted in copious amounts by proteoid roots of nonmycorrhizal species such as harsh hakea (Hakea prostrata). This, in turn, enhances the bioavailability of mineral-bound Pi by solubilizing Al3+, Fe3+, and Ca2+ phosphates in the rhizosphere. Harsh hakea thrives in the nutrient-impoverished, ancient soils of southwestern Australia. Proteoid roots from Pi-starved harsh hakea were analyzed over 20 d of development to correlate changes in malate and citrate exudation with PEPC activity, posttranslational modifications (inhibitory monoubiquitination versus activatory phosphorylation), and kinetic/allosteric properties. Immature proteoid roots contained an equivalent ratio of monoubiquitinated 110-kD and phosphorylated 107-kD PEPC polypeptides (p110 and p107, respectively). PEPC purification, immunoblotting, and mass spectrometry indicated that p110 and p107 are subunits of a 430-kD heterotetramer and that they both originate from the same plant-type PEPC gene. Incubation with a deubiquitinating enzyme converted the p110:p107 PEPC heterotetramer of immature proteoid roots into a p107 homotetramer while significantly increasing the enzyme's activity under suboptimal but physiologically relevant assay conditions. Proteoid root maturation was paralleled by PEPC activation (e.g. reduced Km [PEP] coupled with elevated I50 [malate and Asp] values) via in vivo deubiquitination of p110 to p107, and subsequent phosphorylation of the deubiquitinated subunits. This novel mechanism of posttranslational control is hypothesized to contribute to the massive synthesis and excretion of organic acid anions that dominates the carbon metabolism of the mature proteoid roots. © 2013 American Society of Plant Biologists. All Rights Reserved.

Jablensky A.,University of Western Australia
Epidemiology and Psychiatric Sciences | Year: 2012

Background. The current debate concerning the forthcoming revisions of the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual of Mental Disorders (DSM) lacks sufficient historical perspective on groundwork concepts in psychiatry, such as the nature of the disease entity, categorical typologies, dimensional models and their validity and utility. Objective. To offer an overview of the evolution and metamorphoses of the conceptual basis of classification in psychiatry, with particular focus on psychotic disorders. Method. Discursive, proceeding from history of ideas to a critique of present dilemmas. Results. Much of the present-day discussion of basic issues concerning the classification of mental disorders is a replay of debates that took place in the earlier periods of scientific psychiatry. Conclusion. The mainstream nosological paradigm adopted in psychiatry since early 20th century is in need to be critically examined and transcended with the help of concepts and methodological tools available today. © 2012 Cambridge University Press.

Bekki K.,University of Western Australia
Monthly Notices of the Royal Astronomical Society | Year: 2013

We consider that the stellar initial mass function (IMF) depends on physical properties of star-forming molecular clouds in galaxies and thereby investigate how such a non-universal IMF (NUIMF) influences galaxy evolution. We incorporate an NUIMF model into galaxyscale chemodynamical simulations in order to investigate the differences in chemical and dynamical evolution of disc galaxies between the NUIMF and universal IMF (UIMF) models. In the adopted NUIMF model, the three slopes of the Kroupa IMF depend independently on densities and metallicities ([Fe/H]) of molecular gas clouds, and production rates of metals and dust from massive and asymptotic giant branch stars, formation efficiencies of molecular hydrogen (H2) and feedback effects of supernovae (SNe) can vary according to the time evolution of the three IMF slopes. The preliminary results of the simulations are as follows. Star formation rates (SFRs) in actively star-forming disc galaxies can be significantly lower in the NUIMF model than in the UIMF model, and the differences between the two models can be larger in galaxies with higher SFRs. Chemical enrichment can proceed faster in the NUIMF model, and [Mg/Fe] for a given metallicity is higher in the NUIMF model. The evolution of H2 fraction (fH2 ) and dust-to-gas ratio (D) is faster in the NUIMF model so that the final fH2 and D can be higher in the NUIMF model. Formation of massive stellar clumps in gas-rich discs is more strongly suppressed owing to the stronger SN feedback effect in the NUIMF model. The radial density profiles of new stars within the central 1 kpc are shallower in the NUIMF model. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Bekki K.,University of Western Australia
Monthly Notices of the Royal Astronomical Society | Year: 2013

We investigate the time evolution of dust properties, molecular hydrogen (H2) contents and star formation histories in galaxies by using our original chemodynamical simulations. The simulations include the formation of dust in the stellar winds of supernovae and asymptotic giant branch (AGB) stars, the growth and destruction processes of dust in the interstellar medium (ISM), the formation of polycyclic aromatic hydrocarbon (PAH) dust in carbon-rich AGB stars, the H2 formation on dust grains and the H2 photodissociation due to far-ultraviolet light in a self-consistent manner.We focus mainly on disc galaxies with the total masses ranging from 1010 to 1012M⊙ in this preliminary study. The principal results are as follows. The star formation histories of disc galaxies can be regulated by the time evolution of interstellar dust, mainly because the formation rates of H2 can be controlled by dust properties. The observed correlation between dust-to-gas-ratios (D) and gas-phase oxygen abundances [AO ≡ 12 + log (O/H)] can be reproduced reasonably well in the present models. The discs show negative radial gradients (i.e. larger in inner regions) of H2 fraction (fH2 ), PAH-to-dustmass ratio (fPAH), D and AO, and these gradients evolve with time. The surface mass densities of dust (Σdust) are correlated more strongly with the total surface gas densities (Σgas) than with those of H2 (ΣH2 ). Local gaseous regions with higher D are more likely to have higher fH2 in individual discs and total H2 masses (MH2 ) correlate well with total dust masses (Mdust). More massive disc galaxies are more likely to have higher D, fPAH and fH2 , and smaller dust-to-stellar mass ratios (Rdust = Mdust/Mstar). Early-type E/S0 galaxies formed by major galaxy merging can have lower Rdust than isolated late-type disc galaxies. We also compare between galactic star formation histories in the metallicity-dependent and dust-dependent star formation models and find no major differences. Based on these results, we discuss the roles of dust in chemical and dynamical evolution of galaxies. © 2013 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society.

Speciation is the process by which reproductive isolation evolves between populations. Two general models of speciation have been proposed: ecological speciation, where reproductive barriers evolve due to ecologically based divergent selection, and mutation-order speciation, where populations fix different mutations as they adapt to similar selection pressures. I evaluate these alternative models and determine the progress of speciation in a diverse group of land snails, genus Rhagada, inhabiting Rosemary Island. A recently derived keeled-flat morphotype occupies two isolated rocky hills, while globose-shelled snails inhabit the surrounding plains. The study of one hill reveals that they are separated by a narrow hybrid zone. As predicted by ecological speciation theory, there are local and landscape level associations between shell shape and habitat, and the morphological transition coincides with a narrow ecotone between the two distinct environments. Microsatellite DNA revealed a cline of hybrid index scores much wider than the morphological cline, further supporting the ecological maintenance of the morphotypes. The hybrid zone does not run through an area of low population density, as is expected for mutation-order hybrid zones, and there is a unimodal distribution of phenotypes at the centre, suggesting that there is little or no prezygotic isolation. Instead, these data suggest that the ecotypes are maintained by ecologically dependent postzygotic isolation (i.e. ecological selection against hybrids). Mitochondrial and Microsatellite DNA indicate that the keeled-flat form evolved recently, and without major historical disruptions to gene flow. The data also suggest that the two keeled-flat populations, inhabiting similar rocky hills, have evolved in parallel. These snails provide a complex example of ecological speciation in its early stages. © 2013 Blackwell Publishing Ltd.

Laing N.G.,University of Western Australia
Critical Reviews in Clinical Laboratory Sciences | Year: 2012

Neuromuscular disorders affect the peripheral nervous system and muscle. The principle effect of neuromuscular disorders is therefore on the ability to perform voluntary movements. Neuromuscular disorders cause significant incapacity, including, at the most extreme, almost complete paralysis. Neuromuscular diseases include some of the most devastating disorders that afflict mankind, for example motor neuron disease. Neuromuscular diseases have onset any time from in utero until old age. They are most often genetic. The last 25 years has been the golden age of genetics, with the disease genes responsible for many genetic neuromuscular disorders now identified. Neuromuscular disorders may be inherited as autosomal dominant, autosomal recessive, or X-linked traits. They may also result from mutations in mitochondrial DNA or from de novo mutations not present in the peripheral blood DNA of either parent. The high incidence of de novo mutation has been one of the surprises of the recent increase in information about the genetics of neuromuscular disorders. The disease burden imposed on families is enormous including decision making in relation to presymptomatic diagnosis for late onset neurodegenerative disorders and reproductive choices. Diagnostic molecular neurogenetics laboratories have been faced with an ever-increasing range of disease genes that could be tested for and usually a finite budget with which to perform the possible testing. Neurogenetics has moved from one known disease gene, the Duchenne muscular dystrophy gene in July 1987, to hundreds of disease genes in 2011. It can be anticipated that with the advent of next generation sequencing (NGS), most, if not all, causative genes will be identified in the next few years. Any type of mutation possible in human DNA has been shown to cause genetic neuromuscular disorders, including point mutations, small insertions and deletions, large deletions and duplications, repeat expansions or contraction and somatic mosaicism. The diagnostic laboratory therefore has to be capable of a large number of techniques in order to identify the different mutation types and requires highly skilled staff. Mutations causing neuromuscular disorders affect the largest human proteins for example titin and nebulin. Successful molecular diagnosis can make invasive and expensive diagnostic procedures such as muscle biopsy unnecessary. Molecular diagnosis is currently largely based on Sanger sequencing, which at most can sequence a small number of exons in one gene at a time. NGS techniques will facilitate molecular diagnostics, but not for all types of mutations. For example, NGS is not good at identifying repeat expansions or copy number variations. Currently, diagnostic molecular neurogenetics is focused on identifying the causative mutation(s) in a patient. In the future, the focus might move to prevention, by identifying carriers of recessive diseases before they have affected children. The pathobiology of many of the diseases remains obscure, as do factors affecting disease severity. The aim of this review is to describe molecular diagnosis of genetic neuromuscular disorders in the past, the present and speculate on the future. © 2012 Informa Healthcare USA, Inc.

Barkan A.,University of Oregon | Small I.,University of Western Australia
Annual Review of Plant Biology | Year: 2014

Pentatricopeptide repeat (PPR) proteins constitute one of the largest protein families in land plants, with more than 400 members in most species. Over the past decade, much has been learned about the molecular functions of these proteins, where they act in the cell, and what physiological roles they play during plant growth and development. A typical PPR protein is targeted to mitochondria or chloroplasts, binds one or several organellar transcripts, and influences their expression by altering RNA sequence, turnover, processing, or translation. Their combined action has profound effects on organelle biogenesis and function and, consequently, on photosynthesis, respiration, plant development, and environmental responses. Recent breakthroughs in understanding how PPR proteins recognize RNA sequences through modular base-specific contacts will help match proteins to potential binding sites and provide a pathway toward designing synthetic RNA-binding proteins aimed at desired targets. Copyright © 2014 by Annual Reviews.

Reese P.P.,University of Pennsylvania | Boudville N.,University of Western Australia | Garg A.X.,University of Western Ontario
The Lancet | Year: 2015

Since the first living-donor kidney transplantation in 1954, more than half a million living kidney donations have occurred and research has advanced knowledge about long-term donor outcomes. Donors in developed countries have a similar life expectancy and quality of life as healthy non-donors. Living kidney donation is associated with an increased risk of end-stage renal disease, although this outcome is uncommon (<0·5% increase in incidence at 15 years). Kidney donation seems to elevate the risks of gestational hypertension and pre-eclampsia. Many donors incur financial expenses due to factors such as lost wages, need for sick days, and travel expenses. Yet, most donors have no regrets about donation. Living kidney donation is practised ethically when informed consent incorporates information about risks, uncertainty about outcomes is acknowledged when it exists, and a donor's risks are proportional to benefits for the donor and recipient. Future research should determine whether outcomes are similar for donors from developing countries and donors with pre-existing conditions such as obesity. © 2015 Elsevier Ltd.

Besant P.G.,University of Western Australia
Methods in enzymology | Year: 2010

The investigation of protein histidine phosphorylation has required the development of a number of methods that differ from traditional methods of phosphoprotein analysis that were developed to study phosphorylation of serine, threonine, and tyrosine, which are, unlike phosphohistidine, acid-stable. The investigation of histidine phosphorylation is further complicated by the fact that in mammalian proteins, phosphorylation appears to occur at either 1-N or 3-N positions of the imidazole ring, depending on the source of the kinase. In this review, we describe methods developed for phosphoamino acid analysis to detect phosphohistidine, including the determination of the isoform present, using chromatographic and mass spectrometric analysis of phosphoprotein hydrolysates and 1H- and 31P NMR analysis of intact phosphoproteins and phosphopeptides. We also describe methods for the assay of protein histidine kinase activity, including a quantitative assay of alkali-stable, acid-labile protein phosphorylation, and an in-gel kinase assay applied to histidine kinases. Most of the detailed descriptions of methods are as they are applied in our laboratory to the investigation of histone H4 phosphorylation and histone H4 histidine kinases, but which can be applied to the phosphorylation of any proteins and to any such histidine kinases. Copyright © 2010 Elsevier Inc. All rights reserved.

Wood F.M.,University of Western Australia
International Journal of Biochemistry and Cell Biology | Year: 2014

The integration of engineering into biological science has resulted in the capacity to provide tissue engineered solutions for tissue damage. Skin regeneration remains the goal of skin repair to reduce the long term consequences of scarring to the individual. A scar is abnormal in its architecture, chemistry and cell phenotype, tissue engineering of scaffolds and cells opens up the potential of tissue regeneration into the future. Tissue engineering solutions have been applied to skin many decades despite technical success the clinical application has been modest. To realise the potential of the developing technologies needs alignment of not only the science and engineering but also the commercial upscaling of production in a safe and regulated framework for clinical use. In addition the education and training for the introduction of new technology within the health system is essential, bringing together the technology and systems for utilisation to optimise the patient outcome. This article is part of a Directed Issue entitled: Regenerative Medicine: The challenge of translation. © 2014 Published by Elsevier Ltd. All rights reserved.

Wu C.,University of Western Australia
Science of Computer Programming | Year: 2012

The IR-style Web services discovery represents an important approach that applies proven techniques developed in the field of Information Retrieval (IR). Many studies exploited the Web Services Description Language (WSDL) syntax to extract useful service metadata for building indexes. However, a fundamental issue associated with this approach is the WSDL term tokenization. This paper proposes the application of three statistical methods for WSDL term tokenizationMDL, TP, and PPM. With the increasing need for effective IR-style Web services discovery facilities, term tokenization is of fundamental importance for properly indexing WSDL documents. We compare our applied methods with two baseline methods. The experiment suggests the superiority of MDL and PPM methods based on IR evaluation metrics. To the best of our knowledge, our work is the first to systematically investigate the issue of WSDL term tokenization for Web services discovery. Our solution can benefit source coding mining, in which a key step is to tokenize names (i.e. terms) of variables, functions, classes, modules, etc. for semantic analysis. Our methods could also be used for solving Web-related string tokenization problems such as URL analysis and Web scripts comprehension. © 2011 Elsevier B.V. All rights reserved.

Dam H.H.,Curtin University Australia | Cantoni A.,University of Western Australia
Signal Processing | Year: 2015

This paper proposes a new computational procedure for solving the optimal zero-forcing beamforming problem in multiple antenna channels that maximizes user achievable rate with restriction on the per-antenna element power constraints. An interior point method with optimal step size procedure is developed in which the step size for the line search in the Newton search direction is calculated exactly for each iteration. This significantly enhances the efficiency associated with the line search. Design examples show that the proposed algorithm converges rapidly to the optimal solution with low computational complexity. © 2014 Published by Elsevier B.V. All rights reserved.

Marano R.J.,Ear science Institute Australia | Marano R.J.,University of Western Australia | Ben-Jonathan N.,University of Cincinnati
Molecular Endocrinology | Year: 2014

Prolactin (PRL) is an important hormone with many diverse functions. Although it is predominantly produced by lactrotrophs of the pituitary there are a number of other organs, cells, and tissues in which PRL is expressed and secreted. The impact of this extrapituitary PRL (ePRL) on localized metabolism and cellular functions is gaining widespread attention. In 1996, a comprehensive review on ePRL was published. However, since this time, there have been a number of advancements in ePRL research. This includes a greater understanding of the components of the control elements located within the superdistal promoter of the ePRL gene. Furthermore, several new sites of ePRL have been discovered, each under unique control by a range of transcription factors and elements. The functional role of ePRL at each of the expression sites also varies widely leading to gender and site bias. This review aims to provide an update to the research conducted on ePRL since the 1996 review. The focus is on new data concerning the sites of ePRL expression, its regulation, and its function within the organs in which it is expressed. © 2014 by the Endocrine Society.

Kemp V.,University of Western Australia
Current Opinion in Psychiatry | Year: 2014

PURPOSE OF REVIEW: The issue of workplace bullying has become an area of research interest in the last 3 decades. Much of the extant literature is published in the business management journals. This is problematic as the targets of workplace bullying may need psychiatric treatment; as a discipline, therefore psychiatrists may benefit from a deeper understanding of the nature of workplace bullying and its sequelae. RECENT FINDINGS: There is still no agreed upon definition, although most definitions include similar criteria. Managers and human resources personnel frequently have difficulty identifying and effectively managing workplace bullying. The consequences for the targets of bullying can be severe; they may need psychiatric treatment and it can have a lifelong impact. There is a paucity of research into effective prevention and intervention programs. Preventive measures that focus on the whole workplace culture or on targets alone have mixed results. Workplace policies and procedures may lessen the prevalence and incidence of bullying, but often competing interests of senior management, human resources personnel, supervisors and workers may mitigate any antibullying interventions. SUMMARY: Although psychiatrists are likely to treat the targets of bullying, bullying has yet to attract much attention as a research topic in psychiatry. Although the consequences of bullying can be severe for both targets and workplaces, prevention strategies are hampered by competing interests. © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Duarte C.M.,University of Western Australia | Duarte C.M.,CSIC - Mediterranean Institute for Advanced Studies
Trends in Ecology and Evolution | Year: 2014

The 200-kiloannus (ka) use of red ochre and shells by humans is interpreted as a simple clue of symbolic thinking. Integration of multiple lines of evidence supports the opinion that the use of red ochre and shells might have had direct significance for human evolution. Use of seafood and red ochre supplies docosahexaenoic acid (DHA), possibly iron, and other essential nutrients for brain development and reproductive health, improving human fitness and triggering brain growth. The fitness advantages to humans of using shells, and possibly red ochre, might have selected for artistic and symbolic expression, and, thereby, lead to social cohesion. Current global health syndromes show that an adequate supply of seafood and iron continues to play a fundamental role in human health. © 2014 Elsevier Ltd.

Wallace M.C.,Mount Sinai School of Medicine | Wallace M.C.,University of Western Australia | Friedman S.L.,Mount Sinai School of Medicine
Gene Expression | Year: 2014

Hepatocellular carcinoma is an emerging worldwide health threat that has few curative treatment options and poor overall survival. Progressive hepatic fibrosis is a common pathway for all forms of chronic liver disease and is closely linked epidemiologically to hepatocellular carcinoma risk. However, the molecular events that predispose a fibrotic liver to cancer development remain elusive. Nonetheless, a permissive hepatic microenvironment provides fertile soil for transition of damaged hepatocytes into hepatocellular carcinoma. Key predisposing features include alterations in the extracellular matrix, bidirectional signaling pathways between parenchymal and nonparenchymal cells, and immune dysfunction. Emerging research into the contributions of autophagy, tumor-associated fibroblasts, and hepatocellular carcinoma progenitor cells to this dangerous milieu also provides new mechanistic underpinnings to explain the contribution of fibrosis to cancer. As effective antifibrotic therapies are developed, these approaches could attenuate the rising surge of hepatocellular carcinoma associated with chronic liver disease. Copyright © 2014 Cognizant Comm. Corp. All rights reserved.

Etherton-Beer C.D.,University of Western Australia
Maturitas | Year: 2014

Vascular risk factors and cerebrovascular disease are common causes of dementia. Shared risk factors for vascular dementia and Alzheimer's disease, as well as frequent coexistence of these pathologies in cognitively impaired older people, suggests convergence of the aetiology, prevention and management of the commonest dementias affecting older people. In light of this understanding, the cognitive impairment associated with cerebrovascular disease is an increasingly important and recognised area of the medicine of older people. Although the incidence of cerebrovascular events is declining in many populations, the overall burden associated with brain vascular disease will continue to increase associated with population ageing. A spectrum of cognitive disorders related to cerebrovascular disease is now recognised. Cerebrovascular disease in older people is associated with specific clinical and imaging findings. Although prevention remains the cornerstone of management, the diagnosis of brain vascular disease is important because of the potential to improve clinical outcomes through clear diagnosis, enhanced control of risk factors, lifestyle interventions and secondary prevention. Specific pharmacological intervention may also be indicated for some patients with cognitive impairment and cerebrovascular disease. However the evidence base to guide intervention remains relatively sparse. © 2014 Elsevier Ireland Ltd. All rights reserved.

Davis T.M.E.,University of Western Australia
Diabetes, Obesity and Metabolism | Year: 2014

The dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of blood glucose-lowering therapy with proven efficacy, tolerability and safety. Four of the five commercially available DPP-4 inhibitors are subject to significant renal clearance, and pharmacokinetic studies in people with renal impairment have led to lower recommended doses based on creatinine clearance in order to prevent drug accumulation. Data from these pharmacokinetic studies and from supratherapeutic doses in healthy individuals and people with uncomplicated diabetes during development suggest, however, that there is a wide therapeutic margin. This should protect against toxicity if people with renal impairment are inadvertently prescribed higher doses than recommended. Doses appropriate to renal function are associated with reductions in HbA1c that are equivalent to those observed in people with type 2 diabetes who do not have renal impairment. Recent large-scale cardiovascular safety trials of saxagliptin and alogliptin have identified heart failure as a potential concern and renal impairment may increase the risk of this complication. Although the incidence of pancreatitis does not appear to be significantly increased by DPP-4 inhibitor therapy, renal impairment is also an independent risk factor. Additional data from other ongoing DPP-4 inhibitor cardiovascular safety trials should provide a more precise assessment of the risks of these uncommon complications, including in people with renal impairment. © 2014 John Wiley & Sons Ltd.

Davies W.I.,University of Western Australia
Personalized Medicine | Year: 2014

Visual impairment, and in particular the inherited retinopathies, is a significant problem worldwide. Many disorders are progressive so their early and accurate detection is crucial to the development and application of appropriate disease management and treatment strategies, some of which are currently being tested in clinical trials. Over the past few decades, the identification of genetic causes that mediate many inherited diseases has largely been based on traditional 'Sanger sequencing' and microchip approaches that are expensive and time consuming. However, with the advent of next-generation sequencing it is now possible to apply high-throughput technologies to the clinical arena and sequence the entire exome or genome of an affected individual. Despite the potential for a paradigm shift in the clinical diagnosis of retinal disease, it may prove difficult to interpret and confirm the pathogenicity of any variants discovered by next-generation sequencing pipelines. In this review, I examine the application of next-generation sequencing to inherited retinal disorders and discuss current limitations and future perspectives. © 2014 Future Medicine Ltd.

Yeap B.B.,University of Western Australia
Asian Journal of Andrology | Year: 2014

As men grow older, testosterone (T) levels decline and the significance of this change is debated. The evidence supporting a causal role for lower circulating T, or its metabolites dihydrotestosterone (DHT) and estradiol, in the genesis of atherosclerosis and cardiovascular disease (CVD) in men is limited. Observational studies associate low baseline T levels with carotid atherosclerosis, aortic and peripheral vascular disease, and with the incidence of cardiovascular events and mortality. Studies using mass spectrometry suggest that when total T is assayed optimally, calculation of free T might not necessarily improve risk stratification. There is limited evidence to support an association of estradiol with CVD. Interventional studies of T therapy in men with coronary artery disease have shown beneficial effects on exercise-induced myocardial ischemia. However, placebo-controlled, randomized clinical trials (RCTs) of T therapy in men with the prespecified outcomes of cardiovascular events or deaths are lacking. Meta-analyses of randomized controlled trials of T published up to 2010 found no increase in cardiovascular events, mortality, or prostate cancer with therapy. Recently, in a trial of older men with mobility limitations, men randomized to receive a substantial dose of T reported cardiovascular adverse effects. This phenomenon was not reported from a comparable trial where men received a more conservative dose of T, suggesting a prudent approach should be adopted when considering therapy in frail older men with existing CVD. Adequately powered RCTs of T in middle-aged and older men are needed to clarify whether or not hormonal intervention would reduce the incidence of CVD. © 2014 AJA, SIMM & SJTU. All rights reserved.

Yeap B.B.,University of Western Australia
Maturitas | Year: 2014

Demographic changes resulting in ageing of the world's population have major implications for health. As men grow older, circulating levels of the principal androgen or male sex hormone testosterone (T) decline, while the prevalence of ill-health increases. Observational studies in middle-aged and older men have shown associations between lower levels of T and poorer mental health in older men, including worse cognitive performance, dementia and presence of depressive symptoms. The role of T metabolites, the more potent androgen dihydrotestosterone (DHT) and the oestrogen receptor ligand estradiol (E2) in the pathophysiology of cognitive decline are unclear. Studies of men undergoing androgen deprivation therapy in the setting of prostate cancer have shown subtle detrimental effects of reduced T levels on cognitive performance. Randomised trials of T supplementation in older men have been limited in size and produced variable results, with some studies showing improvement in specific tests of cognitive function. Interventional data from trials of T therapy in men with dementia are limited. Lower levels of T have also been associated with depressive symptoms in older men. Some studies have reported an effect of T therapy to improve mood and depressive symptoms in men with low or low-normal T levels. T supplementation should be considered in men with a diagnosis of androgen deficiency. Beyond this clinical indication, further research is needed to establish the benefits of T supplementation in older men at risk of deteriorating cognition and mental health. © 2014 Elsevier Ireland Ltd. All rights reserved.

Ford A.H.,University of Western Australia
Maturitas | Year: 2014

Dementia affects approximately 6.5% of people over the age of 65. Whilst cognitive impairment is central to the dementia concept, neuropsychiatric symptoms are invariably present at some stage of the illness. Neuropsychiatric symptoms result in a number of negative outcomes for the individual and their caregivers and are associated with higher rates of institutionalization and mortality. A number of factors have been associated with neuropsychiatric symptoms including neurobiological changes, dementia type, and illness severity and duration. Specific patient, caregiver and environmental factors are also important. Neuropsychiatric symptoms can be broadly divided into four clusters: psychotic symptoms, mood/affective symptoms, apathy, and agitation/aggression. Neuropsychiatric symptoms tend to persist over time although differing symptom profiles exist at various stages of the illness. Assessment should take into account the presenting symptoms together with an appreciation of the myriad of likely underlying causes for the symptoms. A structured assessment/rating tool can be helpful. Management should focus on non-pharmacological measures initially with pharmacological approaches reserved for more troubling symptoms. Pharmacological approaches should target specific symptoms although the evidence-base for pharmacological management is quite modest. Any medication trial should include an adequate appreciation of the risk-benefit profile in individual patients and discussion of these with both the individual and their caregiver. © 2014 Elsevier Ireland Ltd. All rights reserved.

Norman P.E.,University of Western Australia | Powell J.T.,Imperial College London
Circulation Research | Year: 2014

Vitamin D plays a classical hormonal role in skeletal health by regulating calcium and phosphorus metabolism. Vitamin D metabolites also have physiological functions in nonskeletal tissues, where local synthesis influences regulatory pathways via paracrine and autocrine mechanisms. The active metabolite of vitamin D, 1α,25-dihydroxyvitamin D, binds to the vitamin D receptor that regulates numerous genes involved in fundamental processes of potential relevance to cardiovascular disease, including cell proliferation and differentiation, apoptosis, oxidative stress, membrane transport, matrix homeostasis, and cell adhesion. Vitamin D receptors have been found in all the major cardiovascular cell types including cardiomyocytes, arterial wall cells, and immune cells. Experimental studies have established a role for vitamin D metabolites in pathways that are integral to cardiovascular function and disease, including inflammation, thrombosis, and the renin-angiotensin system. Clinical studies have generally demonstrated an independent association between vitamin D deficiency and various manifestations of degenerative cardiovascular disease including vascular calcification. However, the role of vitamin D supplementation in the management of cardiovascular disease remains to be established. This review summarizes the clinical studies showing associations between vitamin D status and cardiovascular disease and the experimental studies that explore the mechanistic basis for these associations. © 2014 American Heart Association, Inc.

Munro P.R.T.,University of Western Australia | Olivo A.,University College London
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

Grating-based quantitative polychromatic x-ray phase imaging is currently a very active area of research. It has already been shown that, in such systems, the retrieved differential phase depends upon the spectral properties of the source, the gratings, the detector, and the sample. In this paper, we show that the retrieved sample absorption also depends upon the spectral properties of the gratings. Further, we compare the spectral dependence of both retrieved phase and absorption for the grating interferometer and coded aperture techniques. These results enable us to conclude that in both cases quantitative phase imaging systems cannot be described by an effective energy which is independent of the sample. This has important implications for applications where an absolute measure of phase is important and in tomography. © 2013 American Physical Society.

Turner J.H.,University of Western Australia
Annals of Nuclear Medicine | Year: 2012

In the beginning, nuclear medicine was radionuclide therapy, which has evolved into molecular tumourtargeted control of metastatic cancer. Safe, efficacious, clinical practice of therapeutic nuclear oncology may now be based upon accurate personalised dosimetry by quantitative gamma SPECT/CT imaging to prescribe tumoricidal activities without critical organ toxicity. Preferred therapy radionuclides possess gamma emission of modest energy and abundance to enable quantitative SPECT/CT imaging for calculation of the beta therapy dosimetry, without radiation exposure risk to hospital personnel, carers, family or members of the public. The safety of outpatient radiopharmaceutical therapy of cancer with Iodine-131, Samarium-153, Holmium-166, Rhenium-186, Rhenium-188, Lutetium-177 and Indium-111 is reviewed. Measured activity release rates and radiation exposure to carers and the public are all within recommendations and guidelines of international regulatory agencies and, when permitted by local regulatory authorities allow cost-effective, safe, outpatient radionuclide therapy of cancer without isolation in hospital. © The Japanese Society of Nuclear Medicine 2012.

Saxeyn D.W.,University of Oxford | Saxeyn D.W.,University of Western Australia
Ultramicroscopy | Year: 2011

Several techniques are presented for extracting information from atom probe mass spectra by investigating correlations within multiple-ion detector events. Analyses of this kind can provide insights into the origins of noise, the shape of mass peaks, or unexpected anomalies within the spectrum. Data can often be recovered from within the spectrum noise by considering the time-of-flight differences between ions within a multiple event. Correlated ion detection, particularly when associated with shifts in ion energies, may be used to probe the phenomenon of molecular ion dissociation, including the questions of data loss due to ion pile-up or the generation of neutrals in the dissociation process. © 2010 Elsevier B.V.

Andrich D.,University of Western Australia
Expert Review of Pharmacoeconomics and Outcomes Research | Year: 2011

Assessments with ratings in ordered categories have become ubiquitous in health, biological and social sciences. Ratings are used when a measuring instrument of the kind found in the natural sciences is not available to assess some property in terms of degree - for example, greater or smaller, better or worse, or stronger or weaker. The handling of ratings has ranged from the very elementary to the highly sophisticated. In an elementary form, and assumed in classical test theory, the ratings are scored with successive integers and treated as measurements; in a sophisticated form, and used in modern test theory, the ratings are characterized by probabilistic response models with parameters for persons and the rating categories. Within modern test theory, two paradigms, similar in many details but incompatible on crucial points, have emerged. For the purposes of this article, these are termed the statistical modeling and experimental measurement paradigms. Rather than reviewing a compendium of available methods and models for analyzing ratings in detail, the article focuses on the incompatible differences between these two paradigms, with implications for choice of model and inferences. It shows that the differences have implications for different roles for substantive researchers and psychometricians in designing instruments with rating scales. To illustrate these differences, an example is provided. © 2011 Expert Reviews Ltd.

Techera E.J.,University of Western Australia | Klein N.,Macquarie University
Marine Policy | Year: 2013

Marine-based tourism offers opportunities for economic, educational and environmental benefits but is not without risks to people, animals and the environment. If the benefits of this sector are to be harnessed it will require an increasing focus upon law and policy governing the industry. This is particularly the case for shark eco-tourism, which can be an important conservation tool for these species. Australia has a longstanding history of tourism involving whale sharks and great white sharks and an examination of Australian law and policy in shark eco-tourism provides a powerful case study. This article identifies lessons that may be learnt from Australian shark eco-tourism as a first step towards identification of best practice legal strategies that both support the industry and ensure environmental integrity. © 2012 Elsevier Ltd.

Raven J.A.,Scottish Crop Research Institute | Raven J.A.,University of Western Australia
Physiologia Plantarum | Year: 2011

Photoinhibition is an inevitable consequence of oxygenic photosynthesis. However, the concept of a 'photoinhibition-proof' plant in which photosystem II (PSII) is immune to photodamage is useful as a benchmark for considering the performances of plants with varying mixes of mechanisms which limit the extent of photodamage and which repair photodamage. Some photodamage is bound to occur, and the energy costs of repair are the direct costs of repair plus the photosynthesis foregone during repair. One mechanism permitting partial avoidance of photodamage is restriction of the number of photons incident on the photosynthetic apparatus per unit time, achieved by phototactic movement of motile algae to places with lower incident photosynthetically active radiation (PAR), by phototactic movement of plastids within cells to positions that minimize the incident PAR and by photonastic relative movements of parts of photolithotrophs attached to a substrate. The other means of avoiding photodamage is dissipating excitation of photosynthetic pigments including state transitions, non-photochemical quenching by one of the xanthophyll cycles or some other process and photochemical quenching by increased electron flow through PSII involving CO2 and other acceptors, including the engagement of additional electron transport pathways. These mechanisms inevitably have the potential to decrease the rate of growth. As well as the decreased photosynthetic rates as a result of photodamage and the restrictions on photosynthesis imposed by the repair, avoidance, quenching and scavenging mechanisms, there are also additional energy, nitrogen and phosphorus costs of producing and operating repair, avoidance, quenching and scavenging mechanisms. A comparison is also made between the costs of photoinhibition and those of other plant functions impeded by the occurrence of oxygenic photosynthesis, i.e. the competitive inhibition of the carboxylase activity of ribulose bisphosphate carboxylase-oxygenase by oxygen via the oxygenase activity, and oxygen damage to nitrogenase in diazotrophic organisms. © Physiologia Plantarum 2011.

Holmer M.,University of Southern Denmark | Kendrick G.A.,University of Western Australia
Estuaries and Coasts | Year: 2013

Five temperate seagrasses (Amphibolis antartica, Halophila ovalis, Posidonia australis, Posidonia sinuosa and Zostera nigricaulis) were surveyed along the south-west coast of Western Australia. These morphological different seagrasses grow in contrasting sediments with large variations in sedimentary organic matter, carbonate and iron contents. We tested if sulfur composition in the plants responded to sulfur dynamics in the sediments and if plant morphology affected the sulfur composition of the plants. The sediments were characterized by low sulfate reduction rates (<9 mmol m-2day-1), low concentrations of dissolved sulfides in the pore waters (<74 μM) and low burial of sulfides (total reducible sulfur <0. 8 mol m-2) in the sediments. However, all seagrasses showed high intrusion in the below-ground parts with up to 84 % of the sulfur derived from sedimentary sulfides. There were no direct links between sulfur in the plants and sulfur dynamics in the sediments, probably due to low iron contents in the sediments limiting the buffering capacity of the sediments and exposing the plants to sulfides despite low rates of production and low pools of sulfides. The intrusion was linked between plant compartments (roots, rhizomes and leaves) for the two small species (H. ovalis and Z. nigricaulis), whereas the intrusion into the leaves was limited for the larger species (P. australis and P. sinuosa) and for A. antarctica, where extensive rhizomes and roots and the long stem for A. antarctica separate the leaves from the sediment compartment. Elevated intrusion was observed at two study locations, where natural deposition of organic matter or nutrient enrichment may be contributing factors to enhanced sulfide pressure. © 2012 Coastal and Estuarine Research Federation.

Ghasemi A.,Dalhousie University | Hodkiewicz M.R.,University of Western Australia
IEEE Transactions on Reliability | Year: 2012

This paper develops a prognostics model to estimate the Mean Residual Life of Rail Wagon Bearings within certain confidence intervals. The prognostics model is constructed using a Proportional Hazards approach, informed by imperfect data from a bearing acoustic monitoring system, and a failure database. The model supports prediction within a defined maintenance planning window from the time of receipt of the latest acoustic condition monitoring information. We use the model to decide whether to replace a bearing, or leave it until collection of the next condition monitoring indicators. The model is tested on a limited number of cases, and demonstrates good predictive capability. Opportunities to improve the performance of the model are identified, and the processes necessary and time required to build the model are described. Lessons learned from dealing with real field data will assist those interested in using prognostics to support maintenance planning activities. © 1963-2012 IEEE.

Rosser N.L.,University of Western Australia
Molecular Ecology | Year: 2015

Genetic subdivision within a species is a vital component of the evolution of biodiversity. In some species of Acropora corals in Western Australia, conspecific individuals spawn in two seasons 6 months apart, which has the potential to impede gene flow and result in genetic divergence. Genetic comparison of sympatric spring and autumn spawners of Acropora samoensis was conducted to assess the level of reproductive isolation and genetic divergence between the spawning groups based on multiple loci (13 microsatellite loci, the mitochondrial control region and two nuclear introns). Bayesian clustering and principal coordinate analysis of the microsatellite loci showed a high level of genetic differentiation between the spawning groups (F'ST = 0.30; P < 0.001), as did the sequence data from PaxC and Calmodulin (ΦST = 0.97 and 0.31, respectively). At the PaxC locus, the autumn and spring spawners were associated with two divergent lineages that were separated by an evolutionary distance of 1.7% and statistical tests indicate divergent selection in PaxC, suggesting this gene may play a role in coral spawning. This study indicates that the autumn and spring spawners represent two cryptic species, and highlights the importance of asynchronous spawning as a mechanism influencing speciation in corals. © 2015 John Wiley & Sons Ltd.

Burtscher H.,University of Applied Sciences and Arts Northwestern Switzerland | Schuepp K.,University of Western Australia
Paediatric Respiratory Reviews | Year: 2012

Interest in ultrafine particles (UFP) has been increasing due to their specific physico-chemical characteristics. Ultrafine particles are those with an aerodynamic diameter of. <. 0.1. μm and are also commonly know as nanoparticles (0.1. μm. =. 100. nm). Due to their small size UFP contribute mostly to particle number concentrations and are therefore underestimated in actual pollution measurements, which commonly measure mass concentration. Children represent the most vulnerable group in regard to particulate exposure due to their developing status and different exposures compared to adults. This review discusses the sources of ultrafine particles as well as the specific exposures of children highlighting the importance and uniqueness of this age group. © 2011 Elsevier Ltd.

Thomas M.L.,University of Western Australia
Biological Reviews | Year: 2011

Males of many species choose their mate according to the female's reproductive status, and there is now increasing evidence that male fitness can depend on this discrimination. However, females will also aim to regulate their mating activity so as to maximize their own fitness. As such, both sexes may attempt to dictate the frequency and timing of female mating, reflecting the potentially different costs of female signaling to both sexes. Here, I review evidence that chemical cues and signals are used widely by males to discriminate between mated and unmated females, and explore the mechanisms by which female odour changes post-mating. There is substantial empirical evidence that mated and unmated females differ in their chemical profile, and that this variation provides males with information on a female's mating status. Although there appears to be large variation among species regarding the mechanisms by which female odour is altered post-mating, the transfer of male substances to females during or subsequent to copulation appear to play a major role. This transfer of substances by males may be part of their strategy to suppress reproduction by competing males, particularly in species where females mate more than once. © 2010 The Author. Biological Reviews © 2010 Cambridge Philosophical Society.

Hobbs R.J.,University of Western Australia
Restoration Ecology | Year: 2013

I consider the possibility that people engaged in conservation and management of species and ecosystems are experiencing grief related to ongoing loss of species, assemblages, ecosystem integrity, and so on. In human psychology, five stages of the grieving process have been identified, namely denial, anger, bargaining, depression, and acceptance. Although presented as a series of stages, it is recognized that the progression through them is not linear and people can move quickly among them or experience more than one at any one time. I then consider whether current polarized debates in conservation and restoration, for instance in relation to non-native species and novel ecosystems, result in part from people operating from different places in the grief spectrum. Throughout the grieving process, hope remains a constant feature, and it is important to recognize the place of hope in motivating and sustaining people engaged in conservation and restoration. Although restoration provides great hope that losses can be minimized and, in some cases, reversed, this hope needs to be grounded in a realistic assessment of what is possible in a rapidly changing world. © 2013 Society for Ecological Restoration.

Gagne M.,University of Western Australia
Psychological Assessment | Year: 2014

Self-determination theory (SDT) proposes a multidimensional conceptualization of motivation in which the different regulations are said to fall along a continuum of self-determination. The continuum has been used as a basis for using a relative autonomy index as a means to create motivational scores. Rasch analysis was used to verify the continuum structure of the Multidimensional Work Motivation Scale and of the Academic Motivation Scale. We discuss the concept of continuum against SDT's conceptualization of motivation and argue against the use of the relative autonomy index on the grounds that evidence for a continuum structure underlying the regulations is weak and because the index is statistically problematic. We suggest exploiting the full richness of SDT's multidimensional conceptualization of motivation through the use of alternative scoring methods when investigating motivational dynamics across life domains. © 2014 American Psychological Association.

Hocking G.,University of Western Australia | Mitchell C.H.,Sir Charles Gairdner Hospital
Current Opinion in Anaesthesiology | Year: 2012

PURPOSE OF REVIEW: Significant improvements have been made in the quality of ultrasound imaging, and it is now much easier to see nerves. However, the key to safe ultrasound-guided regional anesthesia is to be able to direct the needle to the target. This relies on good needle visibility. We review the recent advances that have been made in this crucial area. RECENT FINDINGS: Echogenic needles can improve shaft and tip visibility independent of experience level, compensate for suboptimal scanning technique, allow steeper insertion angles, reduce technical difficulty, and increase both confidence and satisfaction by anesthesiologists. An echogenic needle encourages holding the probe in one place on the patient, only advancing the needle when it can be seen, hence reducing the likelihood of quality-compromising behaviors. The poor visibility of nonechogenic needles when inserted at steeper angles commonly causes the observer to underestimate the insertion depth of the needle. Significant differences in echogenicity are found when comparing the currently available needles. SUMMARY: Good echogenic needles should increase safety, efficacy, and simplicity, and hopefully further drive the adoption of ultrasound-guided techniques, to the benefit of our patients. © 2012 Wolters Kluwer Health | Lippincott Williams &Wilkins.

Ellis I.K.,University of Western Australia
Rural and remote health | Year: 2010

People living in rural and remote areas have been found to suffer higher rates of mental illness and psychological distress than their urban counterparts. However, rural and remote Australians also suffer from a lack of specialist mental health services. Mental health consumers are concerned about the lack of access to specialist mental health care and report poor service quality and stigmatizing staff attitudes when presenting with mental health emergencies at acute care facilities. Standards for the Mental Health Workforce released in 2002 promote respect for the individual, their family and carers; best practice in the assessment, early detection and management of acute illness; promotion of mental health and safety; and the prevention of relapse. These standards are for generalists providing care to mentally ill patients; their family and carers in the acute care setting; as well as specialist mental health professionals. Up-skilling generalists in rural and remote areas to respectfully and effectively manage mental health emergency care is a priority. A short course, 'Managing Mental Health Emergencies' was developed by the Australian Rural Nurses and Midwives in 2002. Almost 750 participants had completed the course at the time of the evaluation. The objectives of the course were to: develop an increased knowledge of mental health presentations and gain confidence in managing and assessing mental health clients; gain an understanding of the referral processes in the local environment; gain an insight into the impact of mental health emergencies on individuals, their family and carers; and identify strategies to minimise the impact of managing mental health emergencies on the healthcare team. The model of training matched what is known to be best practice in rural and remote health practitioner development in emergency care, being local, interdisciplinary, and engaging local expert service providers while being overseen by a national steering committee. The evaluation consisted of a pre- (n=456) and post-course (n=163) survey, and follow-up interviews with participants between 3 and 6 months post-course (n=44). The pre- and post-survey identified that, as a result of the course, participants had improved confidence in seeking information about suicide ideation, were significantly more able to differentiate between substance intoxication and psychosis (χ(2)[df=1, n=619] =140.9, p<.000); and between dementia and delirium (χ(2)[df=3, n=619] =126.5, p<.000). The follow-up interview notes were analysed using thematic analysis. Three themes were used: changing attitudes; changing clinical practice; and communication. Participants had reflected on their attitudes following the course and recognized how these had been stigmatizing. Many participants reported putting their new skills into practice and reported better recognition of non-verbal cues and better information seeking from family members, past history and police. The Managing Mental Health Emergencies course is a valuable addition to the emergency courses available to rural and remote healthcare providers.

Chubb S.A.P.,University of Western Australia
Clinical Biochemistry | Year: 2012

Serum CTX assays measure a fragment of the C-terminal telopeptide of type 1 collagen released during resorption of mature bone. Assay reagents are available in manual and automated formats and give good analytical performance. However their standardisation is not transparent and significant differences in results between methods have been demonstrated. CTX is most stable in EDTA plasma, although serum samples processed promptly would be satisfactory. sCTX shows a profound circadian rhythm, especially in non-fasting subjects; specimens should be collected from fasting patients at a well-defined time of day to minimise biological variation. Reference intervals in pre-menopausal women have been well studied but in other adult groups there is less information. Healthy children show the expected age-related variation corresponding to growth rate. Serum CTX fulfils or partially fulfils all the criteria of a reference bone turnover marker. Further studies aimed at reducing inter-method differences in results and establishing the relationships of sCTX with fracture risk and with fracture risk improvement with treatment are required. © 2012 The Canadian Society of Clinical Chemists.

Berners-Price S.J.,Griffith University | Filipovska A.,University of Western Australia
Metallomics | Year: 2011

The application of gold in medicine is traceable for several thousand years and Au(i) compounds have been used clinically to treat rheumatoid arthritis since the last century. Recently research into gold-based drugs for a range of human diseases has seen a renaissance. Old as well as new Au(i) and Au(iii) compounds have been used and designed with an aim of targeting cellular components that are implicated in the onset or progression of cancers, rheumatoid arthiritis, viral and parasitic diseases. In addition, new disease targets have been found for gold compounds that have given insight into the mechanism of action of these compounds, as well as in the molecular pathophysiology of human diseases. Here we discuss the rationale for the design and use of gold compounds that have specific and selective targets in cells to alleviate the symptoms of a range of human diseases. We summarise the most recent findings in this research and our own discoveries to show that gold compounds can be developed to become versatile and powerful drugs for diseases caused by dysfunction of selenol and thiol containing proteins. © 2011 The Royal Society of Chemistry.

Genetic subdivision within populations can ultimately lead to the evolution of new species, and in populations of broadcast-spawners a potential facilitator of genetic subdivision is asynchronous reproduction. However, the factors that shape genetic variation in marine systems are complex and ambiguous, and ecological genetic structure may be influenced by the overriding signature of past demographic events. Here, the relative roles of the timing of reproduction and historical geography on the partitioning of genetic variation were examined in seven populations of the broadcast-spawning coral Acropora tenuis over 12° of latitude. The analysis of multiple loci (mitochondrial control region, two nuclear introns and six microsatellites) revealed significant genetic division between the most northern reef and all other reefs, suggesting that WA reefs were re-colonized from two different sources after the Pleistocene glaciation. Accompanying this pattern was significant genetic differentiation associated with different breeding seasons (spring and autumn), which was greatest in PaxC, in which there were two divergent lineages (ΦST = 0.98). This is the second study to find divergent clades of PaxC associated with spring and autumn spawners, strengthening the suggestion of some selective connection to timing of reproduction in corals. This study reiterates the need to incorporate reproductive timing into population genetic studies of corals because it facilitates genetic differentiation; however, careful analysis of population genetic data is required to separate ecological and evolutionary processes. © 2016 Elsevier Inc.

Milne N.,University of Western Australia | O'Higgins P.,University of York
Proceedings of the Royal Society B: Biological Sciences | Year: 2012

How animals cope with increases in body size is a key issue in biology. Here, we consider scaling of xenarthrans, particularly how femoral form and function varies to accommodate the size range between the 3 kg armadillo and its giant relative the 300 kg glyptodont. It has already been noted that femoral morphology differs between these animals and suggested that this reflects a novel adaptation to size increase in glyptodont. We test this idea by applying a finite element analysis of coronal plane forces to femoral models of these animals, simulating the stance phase in the hind limb; where the femur is subject to bending owing to longitudinal compressive as well as abduction loads on the greater trochanter. We use these models to examine the hypothesis that muscles attaching on the third trochanter (T3) can reduce this bending in the loaded femur and that the T3 forces are more effective at reducing bending in glyptodont where the T3 is situated at the level of the knee. The analysis uses traditional finite element methods to produce strain maps and examine strains at 200 points on the femur. The coordinates of these points before and after loading are also used to carry out geometric morphometric (GM) analyses of the gross deformation of the model in different loading scenarios. The results show that longitudinal compressive and abductor muscle loading increases bending in the coronal plane, and that loads applied to the T3 reduce that bending. In the glyptodont model, the T3 loads are more effective and can more readily compensate for the bending owing to longitudinal and abductor loads. This study also demonstrates the usefulness of GM methods in interpreting the results of finite element analyses. © 2012 The Royal Society.

Adams L.A.,University of Western Australia
Journal of Gastroenterology and Hepatology (Australia) | Year: 2011

Fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. Blood-based biomarkers offer a number of advantages over the traditional standard of fibrosis assessment of liver biopsy, including safety, cost-savings and wide spread accessibility. Current biomarker algorithms include indirect surrogate measures of fibrosis, including aminotransaminases and platelet count, or direct measures of fibrinogenesis or fibrinolysis such as hyaluronic acid and tissue inhibitor of metalloproteinase-1. A number of algorithms have now been validated across a range of chronic liver disease including chronic viral hepatitis, alcoholic and non-alcoholic fatty liver disease. Furthermore, several models have been demonstrated to be dynamic to changes in fibrosis over time and are predictive of liver-related survival and overall survival to a greater degree than liver biopsy. Current limitations of biomarker models include a significant indeterminate range, and a predictive ability that is limited to only a few stages of fibrosis. Utilization of these biomarker models requires knowledge of patient co-morbidities which may produce false positive or negative results in a small proportion of individuals. Furthermore, knowledge of the underlying prevalence of fibrosis in the patient population is required for interpretation of the positive or negative predictive values of a test result. Novel proteins identified by proteomic technology and genetic polymorphisms from genome association studies offer the possibility for further refinement and individualization of biomarker fibrosis models in the future. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

Ferrari P.,University of Western Australia
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2010

Cortisol and aldosterone have the same in vitro affinity for the mineralocorticoid receptor (MR), although in vivo only aldosterone acts as a physiologic agonist of the MR, despite circulating levels of cortisol in humans and corticosterone in rodents being three orders of magnitude higher than aldosterone levels. In mineralocorticoid target organs the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) inactivates 11-hydroxy steroids, to their inactive keto-forms, thus protecting the nonselective MR from activation by glucocorticoids. The gene is highly expressed in all sodium-transporting epithelia, particularly in the kidney and colon, but also in human placenta and vascular wall. Mutations in the HSD11B2 gene cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, compromised 11βHSD2 enzyme activity results in activation of the MR by cortisol, causing sodium retention, hypokalaemia, and salt-dependent hypertension. Whereas mutations or inhibition of 11βHSD2 by licorice have been clearly shown to produce a congenital or acquired syndrome of mineralocorticoid excess, the questions remaining are the extent to which subtle abnormalities in MR/11βHSD2 mechanisms may contribute to essential hypertension. Studies in patients with essential hypertension showed a prolonged half-life of cortisol and an increased ratio of urinary cortisol to cortisone metabolites, suggesting a deficient 11βHSD2 activity. These abnormalities may be genetically determined, as suggested by the association of a microsatellite flanking the HSD11B2 gene with hypertension in black patients with end-stage kidney disease and with salt sensitivity of blood pressure in healthy subjects. These findings indicate that variants of the HSD11B2 gene may contribute to the enhanced blood pressure response to salt and possibly to hypertension in humans. © 2009 Elsevier B.V.

Ho K.M.,University of Western Australia | Chavan S.,Center for Outcome and Resource Evaluation | Pilcher D.,Alfred Hospital
Chest | Year: 2011

Background: VTE is a preventable cause of death within hospitals. This study aimed to assess the association between omission of early thromboprophylaxis for > 24 h after ICU admission and mortality in critically ill patients. Methods: This study involved 175,665 critically ill adult patients admitted to 134 ICUs in Australia and New Zealand between 2006 and 2010. Results: The crude ICU and hospital mortality in patients who did not receive thromboprophylaxis within 24 h of ICU admission was higher than those who were treated with early thromboprophylaxis (7.6% vs 6.3%, P =.001; 11.2% vs 10.6%, P =.003, respectively), despite the former patients being associated with a slightly lower acuity of illness (mean APACHE [Acute Physiology and Chronic Health Evaluation] III model predicted mortality, 13% vs 14%; P =.001). The association between omission of early thromboprophylaxis and hospital mortality remained significant after adjusting for other covariates (OR, 1.22; 95% CI, 1.15-1.30; P =.001), particularly for patients with multiple trauma, sepsis, cardiac arrest, and preexisting metastatic cancer. The estimated attributable mortality effect of omitting early thromboprophylaxis for patients with multiple trauma, sepsis, cardiac arrest, and preexisting metastatic cancer was 3.9% (95% CI, 2.2-5.6), 8.0% (95% CI, 5.6-10.4), 15.4% (95% CI, 11.1-19.8), and 9.4% (95% CI, 6.4-12.4), respectively. Conclusions: Omission of thromboprophylaxis within the first 24 h of ICU admission without obvious reasons was associated with an increased risk of mortality in critically ill adult patients. © 2011 American College of Chest Physicians.

Morahan G.,Western Research Institute | Morahan G.,University of Western Australia
Current Opinion in Endocrinology, Diabetes and Obesity | Year: 2012

Purpose of review Recent identification of over 60 loci contributing to the susceptibility of developing type 1 diabetes (T1D) provides a timely opportunity to assess what is currently known of the genetics of T1D, and what these discoveries may tell us about the disease itself. Recent findings The major findings will be discussed under five main themes: T1D risk gene identification, molecular mechanisms of susceptibility, shared genetic cause with other diseases, development of novel analytical methods, and understanding disease heterogeneity. Summary The plethora of T1D risk genes that have been identified risk overwhelming clinicians with lists of gene names and symbols that have little bearing on management, and provide a challenge for researchers to place the genetics of T1D in a more amenable clinical context. Copyright © Lippincott Williams & Wilkins.

Corry B.,University of Western Australia
Energy and Environmental Science | Year: 2011

The use of semipermeable membranes containing carbon nanotubes (CNTs) that form continuous pores has been suggested as a way to reduce the cost of desalination via reverse osmosis. Example membranes containing aligned CNTs have been fabricated, but obtaining only the very narrow pores that are able to block the passage of ions while allowing a rapid flow of water remains a challenge and previous computational studies have focused on idealised tubes. Here molecular dynamics simulations are used to examine water and ion transport through functionalised CNTs with the aim of investigating whether such chemical modification allows the performance of CNT based membranes to be improved, or for larger diameter pores to be used. A range of different charged and polar functional groups were added to a 1.1 nm diameter (8,8) CNT that was previously found to be only moderately effective at rejecting ions. These CNTs were incorporated into membranes and simulations were conducted with a hydrostatic pressure difference to determine the ion rejection and flux of water passing through each as well as the energy barriers presented to ions and water molecules. The results show that the addition of charges at the entrance of the pore can help to prevent the passage of ions, however, any functionalisation also reduces the flow of water through the membrane due to increased electrostatic interactions between the water molecules and the CNT. Assuming pore densities that have previously been achieved, the performance of these membranes in the simulations is still many times better than existing technology and thus the inclusion of functionalised CNTs in desalination membranes may prove to be useful in achieving salt rejection and rapid water flow. © 2011 The Royal Society of Chemistry.

Hollams E.M.,University of Western Australia
Current Opinion in Allergy and Clinical Immunology | Year: 2012

Purpose of Review: To give an overview of the recent research into whether a lack of vitamin D contributes to the development of atopy and asthma in childhood. Recent Findings: I describe here the recent epidemiological studies relating vitamin D status to atopy and asthma in children, focusing on determinants of major asthma phenotypes in childhood. Recent findings include the observations that vitamin D levels are inversely associated with degree of corticosteroid use, worsening airflow limitation and increased exacerbations among asthmatics. Low vitamin D has been associated with atopy and asthma in children and adolescents in a community cohort, predominantly in boys, with vitamin D at age 6 predicting these outcomes at 14. I also detail the mechanistic studies examining relevant vitamin D-regulated processes; recent findings include the demonstration that offspring of mice with vitamin D deficiency in pregnancy show reduced lung volume and function. Summary: The current literature suggests that intervention to ensure adequate vitamin D levels during both pregnancy and childhood may reduce the development of atopy and asthma in children. However, important questions need to be answered regarding the levels of vitamin D required, which may vary between the sexes and between individuals, and the optimal timing and duration of such intervention. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Raven J.A.,University of Western Australia | Raven J.A.,James Hutton Institute
Journal of Experimental Botany | Year: 2014

Recent work has made progress in relating the size of stomata to stomatal functioning and, in particular, the speed of opening and closing and its implications. Calculations of the influence of stomatal size on the potential rate of osmolarity increase, assuming size-independent ion influx rate per unit area of guard cell plasmalemma set at the value found in large (60 μm long) stomata, show that 10 μm long stomata could have at least a 6-fold higher rate of osmolarity increase. There could be a corresponding decrease in the time taken in going from the closed to the fully open state from about 1h to about 10min; this is approximately the range found for stomata.. However, there are no data on the rate of stomatal movement over a sufficient size range to test this suggestion. Faster opening requires, assuming optimal allocation, a higher activity of the required enzymes per unit volume of guard cells. This is explored for cytosolic carbonic anhydrase which is needed in guard cells, at least in the light, for malic acid synthesis which is involved in stomatal opening in most stomata. Faster opening and closing of smaller than of larger stomata could allow closer tracking of environmental (mainly light) variations, although the available data are not adequate to determine if such a greater tracking occurs. The range of speeds of stomatal movement is similar to that for photoinhibition-related phenomena, despite the very different mechanisms involved. © The Author 2014.

Coall D.A.,University of Western Australia | Hertwig R.,University of Basel
Behavioral and Brain Sciences | Year: 2010

What motivates grandparents to their altruism? We review answers from evolutionary theory, sociology, and economics. Sometimes in direct conflict with each other, these accounts of grandparental investment exist side-by-side, with little or no theoretical integration. They all account for some of the data, and none account for all of it. We call for a more comprehensive theoretical framework of grandparental investment that addresses its proximate and ultimate causes, and its variability due to lineage, values, norms, institutions (e.g., inheritance laws), and social welfare regimes. This framework needs to take into account that the demographic shift to low fecundity and mortality in economically developed countries has profoundly altered basic parameters of grandparental investment. We then turn to the possible impact of grandparental acts of altruism, and examine whether benefits of grandparental care in industrialized societies may manifest in terms of less tangible dimensions, such as the grandchildren's cognitive and verbal ability, mental health, and well-being. Although grandparents in industrialized societies continue to invest substantial amounts of time and money in their grandchildren, we find a paucity of studies investigating the influence that this investment has on grandchildren in low-risk family contexts. Under circumstances of duress-for example, teenage pregnancy or maternal depression-there is converging evidence that grandparents can provide support that helps to safeguard their children and grandchildren against adverse risks. We conclude by discussing the role that grandparents could play in what has been referred to as Europe's demographic suicide. © 2010 Cambridge University Press.

Holt P.G.,University of Western Australia | Sly P.D.,University of Queensland
Nature Medicine | Year: 2012

Prospective birth cohort studies tracking asthma initiation and consolidation in community cohorts have identified viral infections occurring against a background of allergic sensitization to aeroallergens as a uniquely potent risk factor for the expression of acute severe asthma-like symptoms and for the ensuing development of asthma that can persist through childhood and into adulthood. A combination of recent experimental and human studies have suggested that underlying this bipartite process are a series of interactions between antiviral and atopic inflammatory pathways that are mediated by local activation of myeloid cell populations in the airway mucosa and the parallel programming and recruitment of their replacements from bone marrow. Targeting key components of these pathways at the appropriate stages of asthma provides new opportunities for the treatment of established asthma but, more crucially, for primary and secondary prevention of asthma during childhood. © 2012 Nature America, Inc. All rights reserved.

Ingley E.,University of Western Australia
IUBMB Life | Year: 2012

Many extrinsic and intrinsic factors control the development of red blood cells from committed progenitors, with the Erythropoietin- receptor (Epo-R) signaling network being the primary controlling molecular hub. Although much is understood about erythroid signaling pathways, new and intriguing factors that influence different aspects of erythroid cell development are still being uncovered. New extrinsic effectors include hypoxia and polymeric IgA1 (pIgA1), and new Epo-R signaling pathway components include Lyn/Cbp and Lyn/Liar. Hypoxia directly activates committed erythroid progenitors to expand, whereas pIgA1 activates the Akt and MAP-Kinase (MAPK) pathways through transferrin receptors on more mature erythroid cells. The Lyn/ Cbp pathway controls the activity and protein levels of Lyn through recruitment of Csk and SOCS1, as well as feeding into the control of other pathways mediated by recruitment of ras- GAP, PI3-kinase, PLCc, Fes, and EBP50. Nuclear/cytoplasmic shuttling of Lyn and other signaling molecules is influenced by Liar and results in regulation of their intersecting signaling pathways. The challenge of future research is to flesh out the details of these new signaling regulators/networks and integrate their influences during the different stages of erythropoiesis. © 2012 IUBMB.

Giles K.M.,University of Western Australia
Methods in molecular biology (Clifton, N.J.) | Year: 2011

Aberrant expression of the epidermal growth factor receptor (EGFR) and/or human epidermal growth factor receptor 2 (HER2) is a feature of many human tumors and is associated with disease progression, treatment resistance, and poor prognosis. Protein kinase B/Akt, an important downstream effector of these receptor tyrosine kinases, induces signaling pathways that control cancer cell proliferation, invasion, angiogenesis, and apoptosis resistance. MicroRNAs (miRNAs), small noncoding RNAs that bind to the 3'-untranslated region of target mRNAs, are now recognized to play key roles in the regulation of gene expression, particularly in tumor development and metastasis. We have shown that miRNA-7 (miR-7) and miRNA-331-3p (miR-331-3p) directly regulate expression of EGFR and HER2, respectively, in glioblastoma and prostate cancer cell lines. As a consequence, miR-7 and miR-331-3p reduce Akt activity and thus have the capacity to regulate a signaling pathway critical to the development and progression of glioblastoma and prostate cancer. This chapter provides a detailed approach outlining how to confirm that a putative target of a miRNA is a direct target, and subsequent assessment of downstream signaling mediators.

Urmee T.,Murdoch University | Harries D.,University of Western Australia
Renewable Energy | Year: 2011

Large numbers of households in rural areas in Bangladesh have no access to electricity. Providing these households with electricity by extending the country's already overloaded grids is neither an economically nor a technically feasible option. Rural electrification strategies therefore, by necessity, need to rely on stand-alone generation systems. One of these is solar home systems (SHS) and the SHS program developed and implemented in Bangladesh has been highly successful, with very large numbers of rural households now participating in the program. What makes the program's success most remarkable is the fact that it targets households with very low incomes using a purely market-based approach. Those participating in the program pay the full, unsubsidised cost of their SHS using a micro-credit loan facility and are charged high interest rates. Understanding the reasons behind the success of the Bangladeshi program therefore holds potentially valuable lessons for SHS programs being implemented in other developing countries. A comprehensive qualitative and quantitative survey was used to find those factors perceived by program stakeholders as being most critical to the program's success to date and the factors considered most likely to impact on its future success. The two primary reasons for the program's success were perceived to be its strong focus on meeting householders' needs and on its ability to make the solar home systems as affordable as possible. The continued success of the program was considered likely to be determined by a variety of factors, including the ability of program implementers to control increases in the cost of SHS, to maintain the quality of SHS and components and to increase program loan recovery rates, the degree to which the program is integrated into national, energy policy, and the degree to which local banks become involved in the program. © 2011 Elsevier Ltd.

Tonts M.,University of Western Australia
Geographical Research | Year: 2010

Labour shortages have become an increasingly significant barrier to economic development in regional Australia. Many firms and government agencies are operating below capacity as a result of their inability to fill jobs. In the mineral resources sector, this has been compounded by rapidly rising demand for commodities and the very remote locations of many mine sites. This paper explores the dynamics of labour shortages in the minerals sector of the Western Australian Goldfields. It demonstrates close linkages between commodity price, labour supply and demand, and resource output. Against the background of a state-wide 'resources boom', the paper also points to an increase in intra- and inter- regional competition for labour. © 2009 The Author. Journal compilation © 2009 Institute of Australian Geographers.

Pirajno F.,Geological Survey of Western Australia | Pirajno F.,University of Western Australia
Journal of Geodynamics | Year: 2010

In the orogenic belts of the Central Asian Orogenic Belt (CAOB), many mafic and felsic plutons are temporally and spatially associated with orogen-scale strike-slip faults. The CAOB is a huge and complex orogenic collage of accreted terranes that was formed in the Early to Mid-Palaeozoic. In the CAOB, orogen-scale strike-slip faults extend for 100-1000. s of kilometres marking the boundaries of tectonic units and terranes. I use examples from southern Siberia and NW China to illustrate the important role that strike-slip faults have in localising intraplate magmatism and associated metallogeny. Cases from the Altay-Sayan in southern Siberia, the Altay and Tianshan orogens in NW China, are compelling for providing good evidence of the control that strike-slip structures exert for the emplacement of magmas and related mineral systems. These strike-slip faults controlled the emplacement of mafic-ultramafic intrusions, alkaline mafic and felsic magmatism in the period 280-240. Ma, which coincides with mantle plume(s) activity that led to the emplacement of the Tarim and Siberian large igneous provinces (LIPs). Mineral systems that are associated with these LIPs include magmatic Ni-Cu in sill-like intrusions, concentrically zoned mafic-ultramafic intrusions (e.g. Kalatongke, the second largest Ni-Cu sulphide deposit in China, after Jinchuan), epithermal systems, breccia pipes, polymetallic hydrothermal veins, granitoid-related greisen and rare earth pegmatites, as well as kimberlite fields. In the Altay-Sayan and NW China regions, orogen-scale translithospheric strike-slip faults provided the channels for the emplacement of magmas, resulting from lateral flow of mantle melts along the base of the lithosphere. This lateral flow is interpreted to have resulted from the impingement of mantle plumes to the base of the lithosphere of what was, to all intents and purposes, a stationary plate. Lateral flow from mantle plumes head was sustained or facilitated, during stages of extension and movements along orogen-scale strike-slip faults. In the Altay-Sayan and NW China, decompression melting of the mantle material produced mafic-ultramafic magmas that were emplaced along the comparatively narrow conduits of the strike-slip zones, forming concentrically zoned complexes that locally, where favourable conditions allowed it (e.g. crustal contamination), host magmatic Ni-Cu sulphides. Flow of mantle melts into translithospheric strike-slip structures also caused partial melting of a thinned and metasomatised lithosphere, resulting in alkaline magmatic products and a wide range of related mineral systems, from polymetallic veins to greisens. Partial melting of the lower crust also produced A-type granitic magmas that locally vented to the surface, forming calderas hosting epithermal and porphyry systems, as observed in NW China. © 2010 Elsevier Ltd.

Rate A.W.,University of Western Australia
Chemistry and Ecology | Year: 2010

Sorption by humic acids is known to modify the bioavailability and toxicity of metals in soils and aquatic systems. The sorption of cadmium(II) and copper(II) to two soil humic acids was measured at pH 6.0 using ion-selective electrode potentiometric titration at different temperatures. Sorption reactions were studied with all components in aqueous solution, or with the humates in suspension. Adsorption reactions were described using a multiple site-binding model, and a model assuming a continuous log-normal distribution of adsorption constants. Adsorption of Cu2+ was more favourable than adsorption of Cd2+. The log-normal distribution model provided the closest fit to observations and allowed parameterisation of adsorption data using a mean adsorption constant (log Kμ). Sorption of Cd2+ to dissolved humic acids increased slightly in extent and sorption affinity with increasing temperature, but the effect was small (log Kμ 2.96-3.15). A slightly greater temperature effect occurred for sorption of Cd2+ to solid-phase humic acids (log Kμ 1.30-2.08). Sorption of copper(II) to both aqueous- and colloidal-phase humates showed more pronounced temperature dependence, with extent of sorption, and sorption affinity, increasing with increasing temperature (log Kμ 3.4-4.9 in solution and 1.4-4.5 in suspension). The weaker adsorption of Cd2+ than Cu2+, and smaller temperature effects for dissolved humates than suspended humates, suggested that the observed temperature effects had a kinetic, rather than thermodynamic, origin. For any metal-to-ligand ratio, free metal ion concentration, and by inference metal bioavailability, decreased with increasing temperature. The consistency of the data with kinetic rather than thermodynamic control of metal bioavailability suggests that equilibrium modelling approaches to estimating bioavailability may be insufficient. © 2010 Taylor & Francis.

Said N.,University of Western Australia | Kerrich R.,University of Saskatchewan
Precambrian Research | Year: 2010

Three premetamorphic magnesian dyke suites are prominent in the Woolyeneer basalt Formation of the ∼2.7 Ga Kambalda Sequence, Kalgoorlie Terrane, Yilgarn craton, Western Australia: the Butterfly (Mg# 76-70; Ni 640-370 ppm), the Norseman (Mg# 72-66, Ni 1105-1030 ppm), and the Crown (Mg# 73-72, Ni 1240-1170 ppm) Dyke suites. Butterfly Dykes have flat HREE at 6-8 times chondrite, mildly depleted LREE, and Nb/Th > 8; compositionally they resemble high-Mg basalts associated with komatiites and tholeiitic basalts in many Archean greenstone terranes erupted from mantle plumes. Crustally contaminated counterparts have the conjunction of greater (La/Sm)N with Nb/Th < 8. Norseman and Crown suites have composite compositional characteristics: (1) high MgO contents, low Al2O3 and Al2O3/TiO2 ratios, enriched LREE, but fractionated HREE; and (2) positive Nb anomalies, fractionated REE, deep negative P anomalies, and downturn from Pr to Th on primitive mantle normalised diagrams. The former characteristics are of norites, abundant in Neoarchean to Proterozoic intrusions, and interpreted to be melts of low-Al metasomatised continental lithospheric mantle (CLM), whereas the latter characteristics are typical of high-μ ocean island basalts (HIMU-OIB) where the concensus is of ocean crust processed through a subduction zone and recycled into the mantle plume source of HIMU-OIB. Epsilon Nd values of +2.4 to +3.6 are in keeping with a depleted mantle source(s). Accordingly these dyke suites are consistent with melting of depleted continental lithospheric mantle metasomatised by low degree melts from HIMU-OIB. On the Th/Yb versus Nb/Yb discrimination diagram, Butterfly Dykes plot near depleted mantle, and Noresmam and Crown suites within the MORB-OIB array towards the HIMU endmember; consequently, the MORB-OIB array was established in the Archean mantle. Taken with published trace element and Sm-Nd isotope data, the most straightforward geodynamic-magmatic scenario is that the Butterfly Dykes are intrusive equivalents of high-Mg flows in the Kambalda Sequence, erupted from a mantle plume melting at the base of the lithosphere, whereas Norseman and Crown Dyke suites represent melts of metasomatised mantle lithosphere induced by some combination of rifting and thermal input from the plume. © 2010 Elsevier B.V. All rights reserved.

Baker J.A.,Poole Hospital NHS Foundation Trust | Pereira G.,University of Western Australia
Clinical Rehabilitation | Year: 2013

Objectives: A systematic review and meta-analysis using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach to evaluate Botulinum Toxin Type A efficacy on spasticity and pain in the upper/lower limb in adults. Data Sources: Pubmed, Cinahl, Amed, Embase and Cochrane Databases. English language. 1989 to April 2013. Review methods: All randomized controlled trials on adults with spasticity of any origin in the upper or lower limb, treated with a single dose of Botulinum Toxin A, with outcome measures for pain or spasticity. Quality was assessed by GRADE, which uses a transparent, structured process for developing and presenting summaries of evidence, including its quality, for systematic reviews. Results:A total of 37 studies were reviewed. A meta-analysis was carried out on 10 for pain and 21 for spasticity. Evidence quality was low/very low for pain. No significant effect was found in the upper limb (standardised mean difference (SMD) = 0.44, confidence interval (CI) 0.02 to 0.90, Z = 1.88, P=0.06), and no effect was found in the lower limb (risk ratio (RR) = 1.01 CI 0.19 to 5.36, Z = 0.02, P=0.99). Evidence quality for spasticity was moderate. Significant effects were found for Botulinum Toxin in the upper limb (weighted mean difference (WMD) = 0.88, CI 0.63 to 1.14, Z = 6.86, P<0.00001), and the lower limb (RR=2.42, CI 1.60 to 3.65, Z=4.18, P<0.0001). Conclusion:The use of Botulinum Toxin A is supported for upper and lower limb spasticity. Further evidence is needed for spasticity-related pain. Evidence quality is reduced by inadequate study design. © 2013 The Author(s).

The Gram-negative bacterial cell envelope consists of an inner membrane (IM) that surrounds the cytoplasm and an asymmetrical outer-membrane (OM) that forms a protective barrier to the external environment. The OM consists of lipopolysaccahride (LPS), phospholipids, outer membrane proteins (OMPs), and lipoproteins. Oxidative protein folding mediated by periplasmic oxidoreductases is required for the biogenesis of the protein components, mainly constituents of virulence determinants such as pili, flagella, and toxins, of the Gram-negative OM. Recently, periplasmic oxidoreductases have been implicated in LPS biogenesis of Escherichia coli and Neisseria meningitidis. Differences in OM biogenesis, in particular the transport pathways for endotoxin to the OM, the composition and role of the protein oxidation, and isomerization pathways and the regulatory networks that control them have been found in these two Gram-negative species suggesting that although form and function of the OM is conserved, the pathways required for the biosynthesis of the OM and the regulatory circuits that control them have evolved to suit the lifestyle of each organism.

Rogers A.A.,University of Western Australia
Land Economics | Year: 2013

This study investigates whether public and expert preferences diverge in a valuation of two marine reserves inWestern Australia. Identical choice experiments are applied to a sample of marine scientists and the Western Australian community. Evidence of both divergence and convergence between public and expert values is found, with public awareness factors helping to explain differences of opinion. This result implies that, in instances of divergence, it may be preferable to support potential environmental policies through community awareness campaigns, rather than using uninformed public preferences in policy design. © 2013 by the Board of Regents of the University of Wisconsin System.

Nidorf S.M.,Heart Care Western Australia | Eikelboom J.W.,McMaster University | Budgeon C.A.,University of Western Australia | Thompson P.L.,Western Research Institute
Journal of the American College of Cardiology | Year: 2013

Objectives: The objective of this study was to determine whether colchicine 0.5 mg/day can reduce the risk of cardiovascular events in patients with clinically stable coronary disease. Background: The presence of activated neutrophils in culprit atherosclerotic plaques of patients with unstable coronary disease raises the possibility that inhibition of neutrophil function with colchicine may reduce the risk of plaque instability and thereby improve clinical outcomes in patients with stable coronary disease. Methods: In a clinical trial with a prospective, randomized, observer-blinded endpoint design, 532 patients with stable coronary disease receiving aspirin and/or clopidogrel (93%) and statins (95%) were randomly assigned colchicine 0.5 mg/day or no colchicine and followed for a median of 3 years. The primary outcome was the composite incidence of acute coronary syndrome, out-of-hospital cardiac arrest, or noncardioembolic ischemic stroke. The primary analysis was by intention-to-treat. Results: The primary outcome occurred in 15 of 282 patients (5.3%) who received colchicine and 40 of 250 patients (16.0%) assigned no colchicine (hazard ratio: 0.33; 95% confidence interval [CI] 0.18 to 0.59; p < 0.001; number needed to treat: 11). In a pre-specified secondary on-treatment analysis that excluded 32 patients (11%) assigned to colchicine who withdrew within 30 days due to intestinal intolerance and a further 7 patients (2%) who did not start treatment, the primary outcome occurred in 4.5% versus 16.0% (hazard ratio: 0.29; 95% CI: 0.15 to 0.56; p < 0.001). Conclusions: Colchicine 0.5 mg/day administered in addition to statins and other standard secondary prevention therapies appeared effective for the prevention of cardiovascular events in patients with stable coronary disease. © 2013 American College of Cardiology Foundation.

Cardell-Oliver R.,University of Western Australia
Water Resources Research | Year: 2013

Providers of potable water to households and businesses are charged with conserving water. Addressing this challenge requires accurate information about how water is actually being used. So smart meters are being deployed on a large scale by water providers to collect medium resolution water use data. This paper presents water use signature patterns, the first technique designed for medium resolution meters for discovering patterns that explain how households use water. Signature patterns are clusters (subsets) of water meter readings specified by patterns on volumes and calendar dates. Four types of signature pattern are introduced in this paper: continuous flow days; exceptional peak use days; programmed patterns with recurrent hours; and normal use partitioned by season and period of the day. Signature patterns for each household are calculated using efficient selection rules that scale for city populations and years of data collection. Data from a real-world, large-scale, smart metering trial are analyzed using water use signature patterns. The results demonstrate that water use behaviors are distinctive, for both individuals and populations. Signatures can identify behaviors that are promising targets for water conservation. Pattern discovery can be automated with an efficient and scalable computer program. By identifying relevant consumption patterns in medium resolution meter data, water use signature patterns can help to achieve the water conservation potential of large-scale smart metering. © 2013. American Geophysical Union. All Rights Reserved.

The 3426-3350 Ma Strelley Pool Formation (SPF) is a silicified, dominantly sedimentary unit within the Pilbara Supergroup, Western Australia. It is found widely across the East Pilbara Terrane, and it forms a prominent marker horizon and separates the largely volcanic 3520-3427 Ma Warrawoona and 3350-3315 Ma Kelly groups. It has become one of the key formations for study by astrobiologists, following reports of some of the world's oldest stromatolites. Abundant contextural and morphological evidence has been presented over the last decade in support of a biological role in SPF stromatolite formation. This evidence is reviewed here, and additional data are presented from recent fieldwork carried out across the ∼25 km of SPF outcrops in the East Strelley greenstone belt of the East Pilbara Terrane. In addition to contextural and morphological evidence, a compelling claim for early life requires geochemical evidence for biological cycling. A potential avenue of approach to obtain such evidence for the SPF stromatolites (and other ancient examples) is discussed in the context of a pilot study in which nano-scale secondary ion mass spectrometry (NanoSIMS) was used. © Mary Ann Liebert, Inc.

McArthur I.N.,University of Western Australia
Journal of High Energy Physics | Year: 2010

The embedding of a p-brane into higher dimensional spacetime breaks not only translational symmetries transverse to the worldvolume, but also Lorentz symmetries. There exist formulations for p-brane actions which associate Goldstone bosons with the generators of the broken Lorentz symmetries. These Goldstone bosons are unphysical, in that they can be eliminated in favour of other Goldstone bosons either via their equations of motion or via the imposition of an inverse Higgs constraint. In this paper, we examine the inter-relationship between the coset parameterization necessary to implement the inverse Higgs constraint, the equivalence of the inverse Higgs constraint to equations of motion, and the ability to find versions of the action with no explicit dependence on the unphysical Goldstone bosons. This is evidence that the unphysical Goldstone bosons are gauge degrees of freedom associated with an enlarged isotropy group. In addition to p-brane actions, a number of other cases, including conformally invariant dilaton actions, are shown to exhibit the same structure. © 2010 SISSA.

Wu C.,University of Western Australia
Expert Systems with Applications | Year: 2011

The Social Web holds significant value for consumer intelligence. Today, tremendous valuable information behind the social Web has not yet been fully utilized by firms to achieve competitive advantages. In this paper, we propose a machine learning approach to model latent, heterogeneous consumer tastes from social Web reviews. Our approach employs the Mixture of Experts (ME) method to derive a set of distinct consumer clusters, each of which has a cluster-conditional taste template regression model. Furthermore, our approach is able to predict the cluster membership as well as the overall response solely from a consumer's review ratings. We provide system architecture, model specification, and result analysis. We also compare the ME model with the Latent Regression Model. In practice, our ME learning approach will enable businesses to identify distinct consumer clusters directly from the social Web in order to satisfy consumers through customization and differentiation based on cluster-specific taste templates and cluster membership. © 2010 Elsevier Ltd. All rights reserved.

Stubbs K.A.,University of Western Australia
Carbohydrate Research | Year: 2014

Carbohydrate-processing enzymes are gaining more attention due to their roles in health and disease as these enzymes are involved in the construction and deconstruction of vast arrays of glycan structures. As a result, the development of methods to identify these enzymes in complex biological systems is of increasing interest. Activity-based proteomics probes (ABPPs) are increasingly being used in glycobiology to detect and identify functionally related proteins (and homologues) within a biological system. This review will describe the design of activity-based proteomics probes, provide examples of compounds that have been used to profile activity in the area of carbohydrate-processing enzymes, and give some future perspectives. © 2014 Elsevier Ltd. All rights reserved.

Sampson D.D.,University of Western Australia
IEEE Photonics Journal | Year: 2011

The year 2010 has seen many major developments in optical bioimaging - too many to fully survey here. We concentrate on breakthroughs that impact on future bioimaging of live animals and humans, including advances in resolution, imaging depth, speed, and function. © 2011 IEEE.

Mori T.A.,University of Western Australia
Food and Function | Year: 2014

Clinical and epidemiological studies provide support that the polyunsaturated omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid from fish and fish oils are cardioprotective, particularly in the setting of secondary prevention. Omega-3 fatty acids benefit multiple cardiometabolic risk factors including lipids, blood pressure, vascular reactivity and cardiac function, as well as having antithrombotic, anti-inflammatory and anti-oxidative actions. Omega-3 fatty acids do not associate with any adverse effects and do not adversely interact with prescriptive drugs such as lipid-lowering, antihypertensive or hypoglycaemic medications. Clinical studies suggest that doses up to 4 g daily when prescribed with anticoagulant or antiplatelet drugs do not associate with increased risk of major bleeding episodes. Omega-3 fatty acids have gained widespread usage by general practitioners and clinicians in clinical settings such as pregnancy and infant development, secondary prevention in coronary heart disease patients and treatment of dyslipidaemias. Health authorities currently recommend an intake of at least two oily fish meals per week for the general population which equates to approximately 500 mg per day of eicosapentaenoic acid and docosahexaenoic acid. In patients with coronary heart disease the guidelines recommend 1 g daily supplements and in hypertriglyceridaemic patients up to 4 g per day. These doses are now achievable with readily available purified encapsulated preparations of omega-3 fatty acids. However, a more practical recommendation for increasing omega-3 fatty acid intake in the general population is to incorporate fish as part of a healthy diet that includes increased consumption of fruits and vegetables, and moderation of salt intake. © the Partner Organisations 2014.

Smith S.M.,University of Western Australia | Li J.,CAS Institute of Genetics and Developmental Biology
Current Opinion in Plant Biology | Year: 2014

Strigolactone (SL) and karrikin (KAR) signalling control many aspects of plant growth and development through similar mechanisms employing related α/β-fold hydrolase-receptors and a common F-box protein named MORE AXILARY BRANCHES2 (MAX2) in Arabidopsis or DWARF3 (D3) in rice. D3 mediates SL-dependent ubiquitination and proteolysis of DWARF53 (D53) protein, thought to be involved in the control of gene expression, while a related protein SUPPRESSOR OF MAX2-1 (SMAX1) is implicated in the response to KAR in Arabidopsis. Different members of the D53/SMAX1 multigene family likely mediate different responses in plant growth and development. Analysis of responses to SL or KAR has identified many genes regulated by these compounds. Crosstalk with other signalling systems including light, hormones and abiotic stress has also been identified. Here we critically analyse how to progress towards a clearer understanding of the targets and functions of the SL and KAR signalling systems. © 2014 Elsevier Ltd.

Mian A.,University of Western Australia | Hartley R.,Australian National University
Optics Express | Year: 2012

Hyperspectral video acquisition is a trade-off between spectral and temporal resolution. We present an algorithm for recovering dense hyperspectral video of dynamic scenes from a few measured multispectral bands per frame using optical flow and sparse coding. Different set of bands are measured in each video frame and optical flow is used to register them. Optical flow errors are corrected by exploiting sparsity in the spectra and the spatial correlation between images of a scene at different wavelengths. A redundant dictionary of atoms is learned that can sparsely approximate training spectra. The restoration of correct spectra is formulated as an ℓ1 convex optimization problem that minimizes a Mahalanobis-like weighted distance between the restored and corrupt signals as well as the restored signal and the median of the eight connected neighbours of the corrupt signal such that the restored signal is a sparse linear combination of the dictionary atoms. Spectral restoration is followed by spatial restoration using a guided dictionary approach where one dictionary is learned for measured bands and another for a band that is to be spatially restored. By constraining the sparse coding coefficients of both dictionaries to be the same, the restoration of corrupt band is guided by the more reliable measured bands. Experiments on real data and comparison with an existing volumetric image denoising technique shows the superiority of our algorithm. © 2012 Optical Society of America.

Beeson M.,University of Western Australia
Environmental Politics | Year: 2010

The East Asian region generally and Southeast Asia in particular have long been associated with authoritarian rule. It is argued that the intensification of a range of environmental problems means that authoritarian rule is likely to become even more commonplace there in the future. Countries with limited state capacity will struggle to deal with the consequences of population expansion, economic development and the environmental degradation with which they are associated. A resurgence of authoritarian rule is made even more likely by China's 'successful' developmental example and the extent of the region's existing environmental problems. The dispiriting reality may be that authoritarian regimes - unattractive as they may be - may even prove more capable of responding to the complex political and environmental pressures in the region than some of its democracies. © 2010 Taylor & Francis.

Thompson P.L.,Heart Research Institute | Thompson P.L.,University of Western Australia
Medical Journal of Australia | Year: 2013

While the Australian National Health and Medical Research Council guideline document of 2009 on reducing health risks from drinking alcohol provided sensible advice for public policy on alcohol, it appeared to dismiss the cardiovascular benefits of low to moderate consumption. Undue prominence was given to a hypothesis from a single research group that the well documented J-curve relationship of lower risk of ischaemic heart disease events with low to moderate intake alcohol consumption may have been due to a misclassification of drinking patterns. The misclassification hypothesis suggested that the higher risks among abstainers may have been due to the inclusion of high-risk subjects who had become abstainers later in life. Recent studies have separated recent abstainers from lifetime abstainers and the misclassification hypothesis has not been confirmed as an explanation for the J-shaped curve. The J-shaped relationship between alcohol consumption and cardiovascular risk has been studied and confirmed in multiple studies; while it complicates the formulation of public policy on alcohol consumption, it cannot be dismissed.

Ambrose M.C.,University of Western Australia | Stamps R.L.,University of Glasgow
New Journal of Physics | Year: 2013

Skyrmions are spiral structures observed in thin films of certain magnetic materials (Uchida et al 2006 Science 311 359-61). Of the phases allowed by the crystalline symmetries of these materials (Yi et al 2009 Phys. Rev. B 80 054416), only the hexagonally packed phases (SCh) have been observed. Here the melting of the SCh phase is investigated using Monte Carlo simulations. In addition to the usual measure of skyrmion density, chiral charge, a morphological measure is considered. In doing so it is shown that the low-temperature reduction in chiral charge is associated with a change in skyrmion profiles rather than skyrmion destruction. At higher temperatures, the loss of six-fold symmetry is associated with the appearance of elongated skyrmions that disrupt the hexagonal packing. © IOP Publishing and Deutsche Physikalische Gesellschaft.

Lach L.,University of Western Australia
Arthropod-Plant Interactions | Year: 2013

Ants are often considered antagonists when they visit flowers because they typically steal nectar without providing pollination services. Previous research on ant-flower interactions on two species of South African Proteaceae in the Cape Floral Kingdom revealed that the invasive Argentine ant (Linepithema humile), but not native ants, displace other floral arthropod visitors. To determine how common Argentine ant use of inflorescences is, how Argentine and native ant visits differ in the numbers they recruit to inflorescences, and what factors may affect Argentine and native ant foraging in inflorescences, I surveyed 723 inflorescences in 10 species in the genera Protea and Leucospermum across 16 sites and compared ant presence and abundance in inflorescences with abundance at nearby cat food and jam baits. Argentine ants were the most commonly encountered ant of the 22 observed. Argentine ants, as well as six species of native ants were present in all inflorescences for which they were present at nearby baits. Mean Argentine ant abundance per inflorescence was 4. 4 ± 0. 84 (SE) ants and similar to that of Anoplolepis custodiens and Crematogaster peringueyi, but higher than observed for the other most commonly encountered native ants, Camponotus niveosetosus and Lepisiota capensis. Both Argentine ants and A. custodiens were more likely to be found foraging in spring and under humid conditions, and in inflorescences closer to the ground, with lower sucrose concentrations, and with a greater proportion of open flowers. Argentine ants were more likely to be found in Protea inflorescences, whereas A. custodiens and L. capensis more often visited Leucospermum inflorescences. Considering its displacement of floral arthropods and widespread use of Proteaceae inflorescences, the Argentine ant could be posing a serious threat to plant and pollinator conservation in this biodiversity hotspot. © 2012 Springer Science+Business Media Dordrecht.

Chen M.-H.,University of Western Australia
Resources Policy | Year: 2010

In recent times, the prices of internationally traded metals have reached record highs and there is considerable uncertainty regarding their future. This phenomenon is partially driven by strong demand from a small number of emerging economies, such as China and India. This paper uses a long time-series (1900-2007) on 21 metals prices to investigate their properties, and presents unique features of their volatility, including a decomposition into within- and between-group components. If most volatility is commodity-specific rather than "global", then metals-exporting dependent economies can smooth income via diversification. © 2010 Elsevier Ltd.

Thickbroom G.W.,University of Western Australia
Brain Stimulation | Year: 2011

Background: In paired-pulse (conditioned-test) transcranial magnetic stimulation (TMS) protocols, the effect of the conditioning pulse on the test response can be substantial. Epidural recordings indicate that this is mediated through modulation of late indirect (I-) wave volleys. It is not well understood how strong effect sizes could arise from the later, and usually weaker, I-wave volleys. Objective: To formulate a model of I-wave summation at the spinal level to explore the contribution of late I-waves to the activation of the α-motoneuronal pool and to paired-pulse TMS measures of intracortical inhibition and facilitation. Methods: I-wave recruitment curves were modeled for the first three I-waves. A series of steps converted I-wave inputs to α-motoneuronal activation. The role of I3 in activating the α-motoneuronal pool was investigated by manipulating the amplitude of the I3 volley. Results: For all TMS intensities, I3 made a contribution to the firing of the α-motoneuronal pool that was disproportional to its contribution to the descending volley. At its most influential, I3 increased the descending volley by 23.5% but increased the proportion of motoneurons that fired by 567%. There was a U-like relationship to stimulus intensity with inhibition of I3, and an inverted-U relationship for facilitation of I3, in keeping with empirical observation. Changes in spinal excitability disproportionally influenced α-motoneuronal recruitment. Conclusions: Late I-waves have a pivotal role in determining the response to paired-pulse TMS. The spinal transfer function that converts I-wave input to α-motoneuron activation can amplify the role of late I-waves and potentially influence paired-pulse TMS measures of intracortical inhibition and facilitation. © 2011 Elsevier Inc.

Mian A.,University of Western Australia
Optics Express | Year: 2011

We propose illumination invariant face recognition and 3D face reconstruction using desktop optics. The computer screen is used as a programmable extended light source to illuminate the face from different directions and acquire images. Features are extracted from these images and projected to multiple linear subspaces in an effort to preserve unique features rather than the most varying ones. Experiments were performed using our database of 4347 images (106 subjects), the extended Yale B and CMU-PIE databases and better results were achieved compared to the existing state-of-the-art. We also propose an efficient algorithm for reconstructing the 3D face models from three images under arbitrary illumination. The subspace coefficients of training faces are used as input patterns to train multiple Support Vector Machines (SVM) where the output labels are the subspace parameters of ground truth 3D face models. Support Vector Regression is used to learn multiple functions that map the input coefficients to the parameters of the 3D face. During testing, three images of an unknown/novel face under arbitrary illumination are used to estimate its 3D model. Quantitative results are presented using our database of 106 subjects and qualitative results are presented on the Yale B database. © 2011 Optical Society of America.

Nadew G.T.,University of Western Australia
Rural and Remote Health | Year: 2012

Introduction: Generations of Aboriginal people have been exposed to strings of traumatic events with devastating psychosocial health consequences, including psychiatric morbidities and mortalities, and medical complications. Posttraumatic Stress Disorder (PTSD) is a psychiatric morbidity directly linked to traumatic events. Despite research findings indicating traumatic exposure and resultant PTSD in Indigenous communities, little attention has been given to this condition in mental healthcare delivery. Consequently, clinical and psychosocial interventions are misguided and failed to deliver positive outcomes. The objective of this study is to explore the relationship between exposure to traumatic events, prevalence of PTSD and alcohol abuse in remote Aboriginal communities in Western Australia. Methods: A combination of structured clinical interview and multiple survey questionnaires - Composite International Diagnostic Interview (CIDI), and Impact of Events Scale (IES), Alcohol Use Disorder Identification Test (AUDIT) and Indigenous Trauma Profile (ITP) - were administered to 221 Indigenous participants aged 18 to 65 years. Results: The overwhelming majority, 97.3% (n=215) of participants were exposed to traumatic events. Analysis of CIDI results using DSM-IV diagnostic criteria shows a life time prevalence of 55.2% (n=122) for PTSD, 20% (n=44) for major depression (recurrent) and 2.3% (n=5) for a single episode. A total of 96% (n=212) participants reported consuming a drink containing alcohol and 73.8% (n=163) met diagnostic criteria for alcohol use related disorders, abuse and dependence. Of participants who met the PTSD diagnostic criteria, 91% (n=111) met diagnostic criteria for alcohol use related disorders. Other impacts of trauma such as other anxiety disorders, dysthymic disorder and substances abuses were also identified. Conclusion: The rate of exposure to traumatic events and prevalence of PTSD are disproportionately higher in the communities studied than the national average and one of the highest recorded in survivors of specific traumatic events in the world. A very high rate of alcohol abuse and dependence in participants who met diagnostic criteria for PTSD demonstrates correlation between alcohol abuse and PTSD. It also suggests that alcohol is used as self-medication © GT Nadew 2012.

Slominski A.T.,University of Tennessee Health Science Center | Manna P.R.,Texas Tech University Health Sciences Center | Tuckey R.C.,University of Western Australia
Experimental Dermatology | Year: 2014

Human skin has the ability to synthesize glucocorticoids de novo from cholesterol or from steroid intermediates of systemic origin. By interacting with glucocorticoid receptors, they regulate skin immune functions as well as functions and phenotype of the epidermal, dermal and adnexal compartments. Most of the biochemical (enzyme and transporter activities) and regulatory (neuropeptides mediated activation of cAMP and protein kinase A dependent pathways) principles of steroidogenesis in the skin are similar to those operating in classical steroidogenic organs. However, there are also significant differences determined by the close proximity of synthesis and action (even within the same cells) allowing para-, auto- or intracrine modes of regulation. We also propose that ultraviolet light B (UVB) can regulate the availability of 7-dehydrocholesterol for transformation to cholesterol with its further metabolism to steroids, oxysterols or {increment}7 steroids, because of its transformation to vitamin D3. In addition, UVB can rearrange locally produced {increment}7 steroids to the corresponding secosteroids with a short- or no-side chain. Thus, different mechanisms of regulation occur in the skin that can be either stochastic or structuralized. We propose that local glucocorticosteroidogenic systems and their regulators, in concert with cognate receptors operate to stabilize skin homeostasis and prevent or attenuate skin pathology. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Raven J.A.,University of Western Australia
Philosophical transactions of the Royal Society of London. Series B, Biological sciences | Year: 2013

Photolithotrophs are divided between those that use water as their electron donor (Cyanobacteria and the photosynthetic eukaryotes) and those that use a different electron donor (the anoxygenic photolithotrophs, all of them Bacteria). Photolithotrophs with the most reduced genomes have more genes than do the corresponding chemoorganotrophs, and the fastest-growing photolithotrophs have significantly lower specific growth rates than the fastest-growing chemoorganotrophs. Slower growth results from diversion of resources into the photosynthetic apparatus, which accounts for about half of the cell protein. There are inherent dangers in (especially oxygenic) photosynthesis, including the formation of reactive oxygen species (ROS) and blue light sensitivity of the water spitting apparatus. The extent to which photolithotrophs incur greater DNA damage and repair, and faster protein turnover with increased rRNA requirement, needs further investigation. A related source of environmental damage is ultraviolet B (UVB) radiation (280-320 nm), whose flux at the Earth's surface decreased as oxygen (and ozone) increased in the atmosphere. This oxygenation led to the requirements of defence against ROS, and decreasing availability to organisms of combined (non-dinitrogen) nitrogen and ferrous iron, and (indirectly) phosphorus, in the oxygenated biosphere. Differential codon usage in the genome and, especially, the proteome can lead to economies in the use of potentially growth-limiting elements.

Forrester J.V.,University of Aberdeen | Xu H.,University of Aberdeen | Kuffova L.,University of Aberdeen | Dick A.D.,University of Bristol | McMenamin P.G.,University of Western Australia
Immunological Reviews | Year: 2010

The eye and the brain are immunologically privileged sites, a property previously attributed to the lack of a lymphatic circulation. However, recent tracking studies confirm that these organs have good communication through classical site-specific lymph nodes, as well as direct connection through the blood circulation with the spleen. In addition, like all tissues, they contain resident myeloid cell populations that play important roles in tissue homeostasis and the response to foreign antigens. Most of the macrophage and dendritic cell (DC) populations in the eye are restricted to the supporting connective tissues, including the cornea, while the neural tissue (the retina) contains almost no DCs, occasional macrophages (perivascularly distributed), and a specialized myeloid cell type, the microglial cell. Resident microglial cells are normally programmed for immunological tolerance. The privileged status of the eye, however, is relative, as it is susceptible to immune-mediated inflammatory disease, both infectious and autoimmune. Intraocular inflammation (uveitis and uveoretinitis) and corneal graft rejection constitute two of the more common inflammatory conditions affecting the eye leading to considerable morbidity (blindness). As corneal graft rejection occurs almost exclusively by indirect allorecognition, host DCs play a major role in this process and are likely to be modified in their behavior by the ocular microenvironment. Ocular surface disease, including allergy and atopy, also comprise a significant group of immune-mediated eye disorders in which DCs participate, while infectious disease such as herpes simplex keratitis is thought to be initiated via corneal DCs. Intriguingly, some more common conditions previously thought to be degenerative (e.g. age-related macular degeneration) may have an autoimmune component in which ocular DCs and macrophages are critically involved. Recently, the possibility of harnessing the tolerizing potential of DCs has been applied to experimental models of autoimmune uveoretinitis with good effect. This approach has considerable potential for use in translational clinical therapy to prevent sight-threatening disease caused by ocular inflammation. © 2010 John Wiley & Sons A/S.

Invasion and metastasis are controlled by the invadopodia, which delivers matrix-degrading enzymes to the invasion interface permitting cancer cell penetration and spread into healthy tissue. We have identified a novel pathway that directs Lyn/Src family tyrosine kinase signals to the invadopodia to regulate sarcoma cell invasion via the molecule AFAP-1-like-1 (AFAP1L1), a new member of the AFAP (actin filament-associated protein) family. We show that AFAP1L1 can transform cells, promote migration and co-expression with active Lyn profoundly influences cell morphology and movement. AFAP1L1 intersects several invadopodia pathway components through its multiple domains and motifs, including the following (i) pleckstrin homology domains that bind phospholipids generated at the plasma membrane by phosphoinositide 3-kinase, (ii) a direct filamentous-actin binding domain and (iii) phospho-tyrosine motifs (pY136 and pY566) that specifically bind Vav2 and Nck2 SH2 domains, respectively. These phosphotyrosine motifs are essential for AFAP1L1-mediated cytoskeleton regulation. Through its interaction with Vav2, AFAP1L1 regulates Rac activity and downstream control of PAK1/2/3 (p21-activated kinases) phosphorylation of myosin light chain (MLC) kinase and MLC2. AFAP1L1 interaction with Nck2 recruits actin-nucleating complexes. Significantly, in osteosarcoma cell lines, knockdown of AFAP1L1 inhibits phosphorylated MLC2 recruitment to filamentous-actin structures, disrupts invadopodia formation, cell attachment, migration and invasion. These data define a novel pathway that directs Lyn/Src family tyrosine kinase signals to sarcoma cell invadopodia through specific recruitment of Vav2 and Nck2 to phosphorylated AFAP1L1, to control cell migration and invasion.Oncogene advance online publication, 27 July 2015; doi:10.1038/onc.2015.272. © 2015 Macmillan Publishers Limited

Gucciardi D.F.,Curtin University Australia | Jackson B.,University of Western Australia
Journal of Science and Medicine in Sport | Year: 2015

Objectives: Fostering individuals' long-term participation in activities that promote positive development such as organised sport is an important agenda for research and practice. We integrated the theories of planned behaviour (TPB) and basic psychological needs (BPN) to identify factors associated with young adults' continuation in organised sport over a 12-month period. Design: Prospective study, including an online psycho-social assessment at Time 1 and an assessment of continuation in sport approximately 12 months later. Methods: Participants (N=. 292) aged between 17 and 21 years (M=. 18.03; SD. =. 1.29) completed an online survey assessing the theories of planned behaviour and basic psychological needs constructs. Bayesian structural equation modelling (BSEM) was employed to test the hypothesised theoretical sequence, using informative priors for structural relations based on empirical and theoretical expectations. Results: The analyses revealed support for the robustness of the hypothesised theoretical model in terms of the pattern of relations as well as the direction and strength of associations among the constructs derived from quantitative summaries of existing research and theoretical expectations. The satisfaction of basic psychological needs was associated with more positive attitudes, higher levels of perceived behavioural control, and more favourable subjective norms; positive attitudes and perceived behavioural control were associated with higher behavioural intentions; and both intentions and perceived behavioural control predicted sport continuation. Conclusions: This study demonstrated the utility of Bayesian structural equation modelling for testing the robustness of an integrated theoretical model, which is informed by empirical evidence from meta-analyses and theoretical expectations, for understanding sport continuation. © 2013.

Index Decomposition Analysis (IDA) has been extensively applied in studies of energy consumption and energy-related emissions. Most have focused on the impacts of industrial structural change and technology progress and a few have also looked at inter-fuel substitution. There has been no study examining spatial aspects within an IDA setting. This paper first describes an analytical framework analyzing driving forces behind a country's changing energy consumption with special highlights on the spatial dimension and then develops an IDA model to operationalize the analytical framework. The model is applied to a panel of 29 Chinese provinces over the period of 1995-2010. It is shown that the model not only captures the impact of changes of economic and human geography but also provides valuable insights and richer information on spatial variations of other contributing factors than conventional country-level analysis. © 2013 Elsevier B.V.

This paper is based on dynamic optimization methodology to investigate the economic energy efficiency issues in developing countries. The paper introduces some definitions about energy efficiency both in economics and physics, and establishes a quantitative way for measuring the economic energy efficiency. The linkage between economic energy efficiency, energy consumption and other macroeconomic variables is demonstrated primarily. Using the methodology of dynamic optimization, a maximum problem of economic energy efficiency over time, which is subjected to the extended Solow growth model and instantaneous investment rate, is modelled. In this model, the energy consumption is set as a control variable and the capital is regarded as a state variable. The analytic solutions can be derived and the diagrammatic analysis provides saddle-point equilibrium. A numerical simulation based on China is also presented; meanwhile, the optimal paths of investment and energy consumption can be drawn. The dynamic optimization encourages governments in developing countries to pursue higher economic energy efficiency by controlling the energy consumption and regulating the investment state as it can conserve energy without influencing the achievement of steady state in terms of Solow model. If that, a sustainable development will be achieved. © 2014 Elsevier Ltd.

Hankey G.J.,University of Western Australia
The Lancet Neurology | Year: 2014

Survivors of stroke and transient ischaemic attacks are at risk of a recurrent stroke, which is often more severe and disabling than the index event. Optimum secondary prevention of recurrent stroke needs rapid diagnosis and treatment and prompt identification of the underlying cardiovascular cause. Effective treatments include organised acute assessment and intervention with antithrombotic therapy, carotid revascularisation, and control of causal risk factors, as appropriate. However, effective treatments are not implemented optimally in clinical practice. Recurrent strokes continue to account for 25-30% of all strokes and represent unsuccessful secondary prevention. Immediate and sustained implementation of effective and appropriate secondary prevention strategies in patients with first-ever stroke or transient ischaemic attack has the potential to reduce the burden of stroke by up to a quarter. © 2014 Elsevier Ltd.

Lambert R.,University of Western Australia
Globalizations | Year: 2014

Free trade is entrenched and sustained by the political and economic power of global corporations. Adaption and accommodation to this reality is a widespread response of the trade union movement, both nationally and internationally. This article analyses a counter trend where democratic unions in the Global South are united in their opposition to the neoliberal model. In this they are mobilizing new forms of power in their struggle against corporations and states which represent the market model as the sole option. © 2014 © 2014 Taylor & Francis.

Ritz M.-E.A.,University of Western Australia
Journal of Pragmatics | Year: 2010

This paper examines extensions in present perfect (PP) usage in a corpus of police media reports published on the web in Australia, following previous work on extensions in the uses of the PP in oral narratives (Engel and Ritz, 2000; Ritz, 2007; Ritz and Engel, 2008). The following were examined: proportion of tenses in the corpus, lexical aspect of VPs, co-occurrences of the PP with temporal adverbials, and discourse characteristics. The latter were the main focus of the paper, and patterns in PP usage in relation to rhetorical and information structures were examined in detail. The results show that PP clauses are almost as frequent as simple past clauses; that the PP appears frequently in sequences expressing temporal progression, and that it is often combined with a range of adverbials, including past dates and times. It is also argued that police usage of the PP can be seen to give rise to mirative effects, with consequences at the level of discourse usage. In particular, the PP is favoured for introduction of new/unexpected discourse information, while the SP is used in-between clauses in the PP to continue a sub-segment. I use and extend Caudal and Roussarie's (2006) viewpoint analysis of perfects that have acquired perfective past meanings as well as Vikner's (1985) three two-place relations system for the representation of tenses, and propose that the non-standard PP in Australian English can be represented as having a result stage filling a temporal interval between a past reference time and a present one, the extended-now. I suggest that such an interval is exploited to give rise to various meanings and discourse effects. © 2010 Elsevier B.V.

Eliot M.,University of Western Australia
Journal of Geophysical Research: Oceans | Year: 2010

Diurnal and semidiurnal tides are modulated over a range of time scales, including systematic annual and interannual variations. Although identified for other parts of the world, the effects of interannual tidal modulations have had limited attention on the Western Australian coast. Research described here identified that tidal modulations are a significant and regular factor in the frequency with which high water level thresholds are exceeded. Hence, tidal modulations provide a predictable contribution to the coastal management effort required on a year-to-year basis and allow prediction of periods where there is enhanced risk of flooding to coastal infrastructure. As has been demonstrated elsewhere, these cycles are obscured within conventional harmonic and extreme analysis, and their identification requires dedicated techniques. In this study, annual standard deviations and exceedance frequency have been used to examine both hourly and high-pass-filtered water levels to establish the influence of tidal modulations. The relative contribution of the two principal cycles and their subharmonics varies along the Western Australian coast from north to south and hence is strongly linked to the tidal form. High-tide levels for Western Australian locations with diurnal tidal dominance are dominated by the lunar nodal cycle, with a clear 18.6 year signal in the Fremantle-Bunbury region. The cycle most recently peaked in 2007 with declining tidal peaks expected until 2017. High-tide levels for locations with semidiurnal tidal dominance are mainly affected by the lunar perigean subharmonic, causing a 4.4 year cycle along the Northwest Shelf. The last peak occurred in 2006 with the next peak due in 2011. © 2010 by the American Geophysical Union.

Weinberg R.F.,Monash University | Regenauer-Lieb K.,University of Western Australia | Regenauer-Lieb K.,CSIRO
Geology | Year: 2010

Mechanisms proposed to explain efficient melt transport away from hot, ductile source regions are problematic. Brittle-elastic fracturing is a well-known mechanism that allows fast magma migration as dikes through cold crust. Ductile fractures have been propo sed as an alternative for ductile environments, where brittle-elastic diking is inhibited. Ductile fracturing results from rock creep and growth of microscale voids that become interconnected, leading to rock failure. In this paper, we present observations and numerical models supporting the hypothesis that ductile fracture controls early steps in magma migration. We postulate that once developed, ductile fracture dikes may reach a critical length where magma stresses at dike tips overcome fracture toughness and lead to brittle-elastic diking, which subsequently controls magma migration. © 2010 Geological Society of America.

Asgari A.,University of Tabriz | Asgari A.,University of Western Australia | Razi S.,University of Tabriz
Optics Express | Year: 2010

In this paper we present a novel long wave length infrared quantum dot photodetector. A cubic shaped 6nm GaN quantum dot (QD) within a large 18 nm Al0.2Ga0.8N QD (capping layer) embedded in Al 0.8Ga0.2N has been considered as the unit cell of the active layer of the device. Single band effective mass approximation has been applied in order to calculate the QD electronic structure. The temperature dependent behavior of the responsivity and dark current were presented and discussed for different applied electric fields. The capping layer has been proposed to improve upon the dark current of the detector. The proposed device has demonstrated exceptionally low dark current, therefore low noise, and high detectivity. Excellent specific detectivity (D*) up to ~3 × 10 8 CmHz 1/2IW is achieved at room temperature. © 2010 Optical Society of America.

Conservation practitioners are increasingly faced with the need to compensate resource users because of restrictions imposed on access and use of natural resources. The idea that direct payments may facilitate compensation more effectively than a programme based upon income substitution is questioned through examining two direct payments initiatives in an Indonesian marine national park. Elite capture of the direct payments process was facilitated in a context characterized by malleable state institutions and powerful private business interests, thereby disadvantaging key resource-dependent groups. The ecological benefits of direct payments initiatives and of protected areas were compromised through the emphasis on business priorities rather than environmental criteria. These difficulties were mitigated through taking account of existing practices regarding resource access, ensuring equal distribution of benefits and introducing new systems gradually over a period of time through trusted individuals, thereby facilitating the acceptance of direct payments initiatives amongst key user groups. © Foundation for Environmental Conservation 2013.

Lumley D.,University of Western Australia
Leading Edge (Tulsa, OK) | Year: 2010

The 4D seismic monitoring of CO2 sequestration has been reported. 4D seismic involves repeating 3D seismic surveys in time lapse mode to image changes in the subsurface over time, whether due to injection or depletion in a hydrocarbon reservoir, injection and storage of CO2 for sequestration projects, or other subsurface processes such as groundwater flow or environmental contaminant remediation. 4D seismic can be extremely useful for monitoring CO2 injection and storage in subsurface geologic reservoirs. 4D seismic is sensitive to the compressibility of the dry rock frame, in addition to the pore fluid properties. A good 4D seismic signal requires rocks with high values of porosity and dry-frame compressibility. The strength of the 4D signal is related to the compressibility of the reservoir rocks, and the compressibility contrast between fluid types. Gravity data are approximately linearly dependent on CO2 saturation since the density of CO2 is less than that of water.

Filipovska A.,University of Western Australia
RNA biology | Year: 2011

Post-transcriptional regulation of gene expression is ubiquitous and fundamental for the control of cell growth, differentiation and the complex developmental programs of multicellular eukaryotes. Despite this realization, the current tools that are available to study RNAs are limited in many respects. Recently we expanded the RNA recognition code of Pumilio and FBF homology (PUF) proteins, enabling RNA-binding proteins with programmable specificities to be designed. The design of proteins that can bind any RNA sequence of interest and modulate its function will be important to elucidate the mechanisms by which gene expression is controlled at the level of RNA and may provide potential therapeutics in the future.

Kuzenko S.M.,University of Western Australia
Journal of High Energy Physics | Year: 2010

In N = 1 rigid supersymmetric theories, there exist three standard realizations of the supercurrent multiplet corresponding to the (i) old minimal, (ii) new minimal and (iii) non-minimal off-shell formulations for N = 1 supergravity. Recently, Komargodski and Seiberg in arXiv:1002.2228 put forward a new supercurrent and proved its consistency, although in the past it was believed not to exist. In this paper, three new variant supercurrent multiplets are proposed. Implications for supergravity-matter systems are discussed. © SISSA 2010.

Raven J.A.,University of Western Australia | Hurd C.L.,University of Otago
Photosynthesis Research | Year: 2012

Macroalgae occur in the marine benthos from the upper intertidal to depths of more than 200 m, contributing up to 1 Pg C per year to global primary productivity. Freshwater macroalgae are mainly green (Chlorophyta) with some red (Rhodophyta) and a small contribution of brown (Phaeophyceae) algae, while in the ocean all three higher taxa are important. Attempts to relate the depth distribution of three higher taxa of marine macroalgae to their photosynthetic light use through their pigmentation in relation to variations in spectral quality of photosynthetically active radiation (PAR) with depth (complementary chromatic adaptation) and optical thickness (package effect) have been relatively unsuccessful. The presence (Chlorophyta, Phaeophyceae) or absence (Rhodophyta) of a xanthophyll cycle is also not well correlated with depth distribution of marine algae. The relative absence of freshwater brown algae does not seem to be related to their photosynthetic light use. Photosynthetic inorganic carbon acquisition in some red and a few green macroalgae involves entry of CO2 by diffusion. Other red and green macroalgae, and brown macroalgae, have CO2 concentrating mechanisms; these frequently involve acid and alkaline zones on the surface of the alga with CO2 (produced from HCO3 -) entering in the acid zones, while some macroalgae have CCMs based on active influx of HCO3 -. These various mechanisms of carbon acquisition have different responses to the thickness of the diffusion boundary layer, which is determined by macroalgal morphology and water velocity. Energetic predictions that macroalgae growing at or near the lower limit of PAR for growth should rely on diffusive CO2 entry without acid and alkaline zones, and on NH 4 + rather than NO3 - as nitrogen source, are only partially borne out by observation. The impact of global environmental change on marine macroalgae mainly relates to ocean acidification and warming with shoaling of the thermocline and decreased nutrient flux to the upper mixed layer. Predictions of the impact on macroalgae requires further experiments on interactions among increased inorganic carbon, increased temperature and decreased nitrogen and phosphorus supply, and, when possible, studies of genetic adaptation to environmental change. © 2012 Springer Science+Business Media B.V.

Fogarty J.J.,University of Western Australia
Applied Economics | Year: 2012

As food is an experience good, the market for restaurant meals is a market where the cost of acquiring information regarding quality is relatively high. In such markets consumers often turn to reputation measures to guide purchase decisions. As Australia does not have a longstanding cuisine style of its own, and given Australia has been open to substantial immigration inflows since federation, it represents an especially appropriate market to study regarding the impact of individual restaurant reputation and collective cuisine reputation on meal prices. The following study uses the hedonic price approach to investigate the implicit price of individual reputation indicators, cuisine type reputation indicators and other objective indicators in the market for restaurant meals. The empirical findings presented suggest that both individual restaurant reputation and cuisine type reputation are important. Other important factors are shown to include the quality of the restaurant wine list, the availability of private dining rooms, and whether or not there is an outdoor dining option. © 2012 Taylor & Francis.

Zhao X.,North China Electrical Power University | Ma C.,University of Western Australia
Energy Economics | Year: 2013

In 2003, China's integrated electricity utility - the State Power Corporation (SPC) - was unbundled and dismantled into five generation groups and two grid companies in an effort to increase competition and improve efficiency. In this paper, we study the impact of this deregulation reform on the operational efficiency for a balanced panel of 34 large power plants for the period 1997-2010. We find that on average these power plants have converged to the technological frontier over the sample period. Controlling for substantial heterogeneity in the technical profile, we also find that the unbundling reform has boosted productivity of China's large thermal power plants; however, the presumably differential impacts of the reform on the previously SPC-managed power plants and the independent power producers in our sample are insignificant. © 2013 Elsevier B.V.

Kragt M.E.,University of Western Australia
Environmental and Resource Economics | Year: 2013

Choice Experiments (CE) are widely used to estimate the values of changes in non-market goods and services. A cost attribute is typically included in a CE questionnaire to enable the estimation of monetary values for changes in the non-market attributes presented. Notwithstanding the central importance of the cost attribute, relatively little research has been undertaken on the impacts of varying cost attribute levels on value estimates, or on individual heterogeneity. In this paper, I present results from mixed logit and generalised mixed logit models that account for unobserved idiosyncratic preference and scale heterogeneity. Respondents are found to anchor their choices on the relative cost levels presented in the survey with results suggesting that people are more sensitive to relative rather than absolute cost vectors. However, the higher cost levels do not lead to significantly higher value estimates, partly because of observed preference heterogeneity towards the environmental attributes. An important observation is that scale heterogeneity is important: accounting for scale- as well as preference-heterogeneity in the generalised mixed logit model leads to significantly improved model fit. The results indicate significant unobserved error variance across respondents, unrelated to whether a high or low cost vector is used. © 2012 Springer Science+Business Media B.V.

Van Aken O.,University of Western Australia | Van Breusegem F.,Ghent University
Trends in Plant Science | Year: 2015

Programmed cell death (PCD) is crucial in plant organogenesis and survival. In this review the involvement of mitochondria and chloroplasts in PCD execution is critically assessed. Recent findings support a central role for mitochondria in PCD, with newly identified components of the mitochondrial electron transport chain (mETC), FOF1 ATP synthase, cardiolipins, and ATPase AtOM66. While chloroplasts received less attention, their contribution to PCD is well supported, suggesting that they possibly contribute by producing reactive oxygen species (ROS) in the presence of light or even contribute through cytochrome f release. Finally we discuss two working models where mitochondria and chloroplasts could cooperatively execute PCD: mitochondria initiate the commitment steps and recruit chloroplasts for swift execution or, alternatively, mitochondria and chloroplasts could operate in parallel. © 2015 Elsevier Ltd.

Ejaculates comprise multiple and potentially interacting traits that determine male fertility and sperm competitiveness. Consequently, selection on these traits is likely to be intense, but the efficacy of selection will depend critically on patterns of genetic variation and covariation underlying their expression. In this study, I provide a prospective quantitative genetic analysis of ejaculate traits in the guppy Poecilia reticulata, a highly promiscuous livebearing fish. I used a standard paternal half-sibling breeding design to characterize patterns of genetic (co)variation in components of sperm length and in vitro sperm performance. All traits exhibited high levels of phenotypic and additive genetic variation, and in several cases, patterns of genetic variation was consistent with Y-linkage. There were also highly significant negative genetic correlations between the various measures of sperm length and sperm performance. In particular, the length of the sperm's midpiece was strongly, negatively and genetically correlated with sperm's swimming velocityan important determinant of sperm competitiveness in this and other species. Other components of sperm length, including the flagellum and head, were independently and negatively genetically correlated with the proportion of live sperm in the ejaculate (sperm viability). Whether these relationships represent evolutionary trade-offs depends on the precise relationships between these traits and competitive fertilization rates, which have yet to be fully resolved in this (and indeed most) species. Nevertheless, these prospective analyses point to potential constraints on ejaculate evolution and may explain the high level of phenotypic variability in ejaculate traits in this species. © 2011 Macmillan Publishers Limited All rights reserved 0018-067X/11.

Johnson M.S.,University of Western Australia
Heredity | Year: 2011

Few continuous, long-term studies have measured the intensity and variability of natural selection within a framework of clear adaptive hypotheses. In the snail Theba pisana, the proportion of effectively unbanded shells is higher in exposed habitats than in adjacent acacia thickets, which has been explained by microclimatic selection. Comparisons across an ecotone for 34 consecutive years determined the combined effects on morph frequencies of habitat and changes in weather conditions during summer. The long-term average (s.e.) frequency of effectively unbanded shells was 0.5770.011 in the open habitat when compared with 0.3530.005 in the acacia. The persistent association of shell banding with habitat accounted for 34% of the variation in morph frequencies. Differences among years were also large, representing 23% of the variation. Higher proportions of effectively unbanded snails were associated with hotter, sunnier summers. Thus, temporal variation supports the hypothesis of microclimatic selection, consistent with the spatial association with habitat. Based on observed rates of change, the mean annual selection on this polymorphism was about 0.13, but with a large variance: s was as high as 0.5, but 0.05 in about 40% of the years. The large variance and frequent reversals in direction of selection indicate a potential for rapid genetic change, but with little net change in morph frequencies over three decades, highlighting the value of long-term continuous studies of populations facing natural environmental variation. © 2011 Macmillan Publishers Limited All rights reserved 0018-067X/11.

The 2.7Ga Kambalda Sequence comprises a mafic and ultramafic volcanic rock-dominated sequence of the Kalgoorlie Terrane, Yilgarn Craton, Western Australia. The Sequence is divided into the Lower Basalt and Upper Basalt Units, separated by the Kambalda komatiite lava units. Upper Basalts have a total range of Ε+3.0 to +1.5, defining a trend in Ε versus Nb/Th from the uncontaminated Victorious Basalt (Ε+3, Nb/Th 8.8-9.7), through the Big Dick, Devon Consols, and Coolgardie komatiite basalts, to the most contaminated Bent Tree Basalt (Ε+1.5, Nb/Th 2.9-3.5). Recent geological and geochronological results show that the Black Flag Group (BFG) tonalite-trondhjemite-dacite has an early eruptive phase coeval with the Upper Basalts, as well as a later phase overlying the Kambalda Sequence. Modeling of assimilation-fractional crystallisation (AFC) of the Kambalda Komatiite by 10-15% addition of average BFG, followed by 30-40% crystallisation, generates the best fit to the compositional spectrum of the LREE-enriched Devon Consols Basalts. Modeling of Archean average lower-, middle-, or upper continental crust generates a poor fit. Collectively, the results are consistent with decompressional melting at ≤ ~100km, of an asthenosphere plume impinging on the base of thinned, rifted, cratonic lithosphere where the most primitive, hottest liquids were contaminated by the Black Flag Group, or its melts, whereas the more evolved, cooler liquids were not. Contamination was dominantly by crust rather than cratonic mantle lithosphere. © 2010 Elsevier B.V.

Peeling P.,University of Western Australia
European Journal of Applied Physiology | Year: 2010

Iron is a trace mineral used by the body in many physiological processes that are essential for athletic performance. However, it is common that an athlete's iron stores are compromised via several well-established exercise-related mechanisms such as hemolysis, hematuria, sweating and gastrointestinal bleeding. Recently, however, a new mechanism for athletics-induced iron deficiency has been proposed, involving the influence of physical activity on the post-exercise hepcidin response. Hepcidin is a liver-produced hormone that regulates iron metabolism in the gut and macrophages. This hormone has become the focus of recent investigations into altered iron metabolism in athletes, and may be a mitigating factor implicated in athletics-induced iron deficiency. This review attempts to summarize and disseminate the collective knowledge currently held regarding exercise and hepcidin expression, in addition to suggesting the direction for future research in this area. © 2010 Springer-Verlag.

Kuzenko S.M.,University of Western Australia
Journal of High Energy Physics | Year: 2010

For two families of four-dimensional off-shell N = 2 supersymmetric nonlinear σ-models constructed originally in projective superspace, we develop their formulation in terms of N = 1 chiral superfields. Specifically, these theories are: (i) σ-models on cotangent bundles T * M of arbitrary real analytic Kähler manifolds M; (ii) general superconformal σ-models described by weight-one polar supermultiplets. Using superspace techniques, we obtain a universal expression for the holomorphic symplectic two-form ω (2,0) which determines the second supersymmetry transformation and is associated with the two complex structures of the hyperkähler space T *M that are complimentary to the one induced from M. This two-form is shown to coincide with the canonical holomorphic symplectic structure. In the case (ii), we demonstrate that ω (2,0) and the homothetic conformal Killing vector determine the explicit form of the superconformal transformations. At the heart of our construction is the duality (generalized Legendre transform) between off-shell N = 2 supersymmetric nonlinear σ-models and their on-shell N = 1 chiral realizations. We finally present the most general N = 2 superconformal nonlinear σ-model formulated in terms of N = 1 chiral superfields. The approach developed can naturally be generalized in order to describe 5D and 6D superconformal nonlinear σ-models in 4D N = 1 superspace. © SISSA 2010.

Blakeney M.,University of Western Australia
Journal of Experimental Botany | Year: 2012

This article considers the relationship between patenting and plant variety rights protection, through a detailed analysis of the recent determination by the Extended Board of Appeal of the European Patent Office that methods for breeding broccoli and tomatoes were not patentable. It concludes that the right to patent agricultural innovations is increasingly located within a political context. © 2012 The Author.

Du X.,Beijing University of Technology | Jin L.,Beijing University of Technology | Ma G.,University of Western Australia
International Journal of Impact Engineering | Year: 2014

Tensile failure behavior of concrete invariably dominates the behavior of concrete specimens as well as structural elements and it is strongly affected by loading rate. The present study focuses on the effects of loading rate and heterogeneity of meso-/micro-structure on the failure pattern and the macroscopic mechanical properties of concrete. For simplicity, concrete is regarded as a two-phase composite composed of aggregate and mortar matrix at meso-scale. The damaged plasticity theory combined with strain-rate effect is employed to describe the dynamic mechanical behavior of mortar matrix, and the aggregate phase is assumed to be elastic. The dynamic tensile failure modes of a single-edge notched concrete specimen and the L specimen under different loading rates are numerically investigated. The simulation results indicate that dynamic failure pattern and the direction of crack propagation of concrete have pronounced loading rate sensitivity. With the increase of loading rate, the failure mode of concrete changes from mode-I to mixed mode. The more complex the meso-structure is, the higher the interaction intensity between the meso components has and the more complicated the crack paths are, resulting in a more obvious crack branching behavior. Furthermore, as loading rate increases much more branching cracks generate within concrete and the width of the damaged region increases, implying that the fracture process at relatively high strain rates requires more energy demand to reach failure. And this should be the main reason for the improvement of the dynamic tensile strength of concrete. © 2013 Elsevier Ltd. All rights reserved.

Pellicano E.,Institute of Education | Pellicano E.,University of Western Australia | Stears M.,University of Oxford
Autism Research | Year: 2011

Recent developments in the science of autism have provoked widespread unease among autism activists. Drawing on the findings of a major international gathering of researchers, ethicists, and activists, this paper presents the first major analysis of the ethical questions arising from this unease. We outline the scientific developments that have provoked the most discomfort, analyze the response to these developments from within and without the autism community, and trace the current state of the ethical debate. Having done so, we contend that these ethical questions are unlikely to be resolved as they depend on fundamentally conflicting assumptions about the nature and desirability of neurocognitive difference. We conclude by arguing for a new range of democratic mechanisms that could enable the scientific community, autistics, and other concerned parties to respond collectively to such entrenched ethical disputes. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.

Ma C.,University of Western Australia
Ecological Economics | Year: 2010

A remaining challenge for environmental inequality researchers is to translate the principles developed in the U.S. to China which is experiencing the staggering environmental impacts of its astounding economic growth and social changes. This study builds on U.S. contemporary environmental justice literature and examines the issue of environmental inequality in China through an analysis of the geographical distribution of industrial pollution sources in Henan province. This study attempts to answer two central questions: 1) whether environmental inequality exists in China and if it does, 2) what socioeconomic lenses can be used to identify environmental inequality. The study found that: 1) race and income-the two common lenses used in many U.S. studies play different roles in the Chinese context; 2) rural residents and especially rural migrants are disproportionately exposed to industrial pollution. © 2010 Elsevier B.V.

Pandit R.,University of Western Australia | Laband D.N.,Auburn University
Ecological Economics | Year: 2010

Trees cast shade on homes and buildings, lowering the inside temperatures and thus reducing demand for power to cool these buildings during hot times of the year. Drawing from a large sample of residences in Auburn, Alabama, we develop a statistical model that produces specific estimates of the electricity savings generated by shade-producing trees in a suburban environment. This empirical model links residential energy consumption during peak summer (winter) months to average energy consumption during non-summer/non-winter months, behaviors of the occupants, and the extent, density, and timing of shade cast on the structures. Our estimates reveal that tree shade generally is associated with reduced (increased) electricity consumption in the summertime (wintertime). In summertime, energy savings are maximized by having dense shade. In wintertime, energy consumption increases as shade percentage in the morning, when outdoor temperatures are at their lowest, increases. © 2010 Elsevier B.V. All rights reserved.

Karton A.,University of Western Australia
Wiley Interdisciplinary Reviews: Computational Molecular Science | Year: 2016

Composite ab initio methods are multistep theoretical procedures specifically designed to obtain highly accurate thermochemical and kinetic data with confident sub-kcal mol-1 or sub-kJ mol-1 accuracy. These procedures include all energetic terms that contribute to the molecular binding energies at these levels of accuracy (e.g., CCSD(T), post-CCSD(T), core-valence, relativistic, spin-orbit, Born-Oppenheimer, and zero-point vibrational energy corrections). Basis-set extrapolations (and other basis-set acceleration techniques) are used for obtaining these terms at sufficiently high levels of accuracy. Major advances in computer hardware and theoretical methodologies over the past two decades have enabled the application of these procedures to medium-sized organic systems (e.g., ranging from benzene and hexane to amino acids and DNA bases). With these advances, there has been a proliferation in the number of developed composite ab initio methods. We give an overview of the accuracy and applicability of the various types of composite ab initio methods that were developed in recent years. General recommendations to guide selection of the most suitable method for a given problem are presented, with a special emphasis on organic molecules. WIREs Comput Mol Sci 2016, 6:292-310. doi: 10.1002/wcms.1249 For further resources related to this article, please visit the WIREs website. © 2016 John Wiley & Sons, Ltd.

Reynolds M.A.,University of Western Australia
Journal of Logic and Computation | Year: 2013

We use mosaics to provide a simple, sound, complete and terminating tableau reasoning procedure for the temporal logic of until and since over general linear time. © The Author, 2012. Published by Oxford University Press. All rights reserved.

Today, frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength for confined conditions corresponding to the seismogenic layer. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism, the rock failure associated with consecutive creation of small slabs (known as 'domino-blocks') from the intact rock in the rupture tip is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance, self-sustaining stress intensification, and self-unbalancing conditions. Due to this the failure process caused by the mechanism is very dynamic and violent. This makes it impossible to directly observe and study the mechanism and can explain why the mechanism has not been detected before. This paper provides physical motivation for the mechanism, based upon side effects accompanying the failure process. Physical and mathematical models of the mechanism presented in the paper explain unique and paradoxical features of the mechanism. The new shear rupture mechanism allows a novel point of view for understanding the nature of spontaneous failure processes in hard rocks including earthquakes. © 2014 Elsevier B.V.

Oddy W.H.,University of Western Australia | Rosales F.,Mead Johnson Nutritionals and Company
Pediatric Allergy and Immunology | Year: 2010

Cytokines in milk like transforming growth factor-beta (TGF-β) have been shown to induce oral tolerance in experimental animal studies. However, human studies are less consistent with these findings. The primary objective of this review was to conduct a systematic review of published studies on the association between TGF-β identified in human milk and immunological outcomes in infancy and early childhood. Human prospective clinical studies were identified through MEDLINE, CAB Abstracts, Biological Abstracts and Scopus. Selection criteria included: well described populations of mothers and infants, time of milk sampling, immunological outcome measures and analytical methods of TGF-β determination. We considered a wide range of immunological outcomes in infancy and early childhood, such as wheeze, atopy, eczema and the immunoglobulin switch. Twelve human studies were included in the review and 67% showed a positive association with TGF-β1 or TGF-β2 demonstrating protection against allergy-related outcomes in infancy and early childhood. High variability in concentrations of TGF-β was noted between and within studies, some of it explained by maternal history of atopy or by consumption of probiotics. Human milk TGF-β appears to be essential in developing and maintaining appropriate immune responses in infants and may provide protection against adverse immunological outcomes, corroborating findings from experimental animal studies. Further large clinical studies in diverse human populations are indicated to confirm these results. © 2009 John Wiley & Sons A/S.

Flicker L.,Western Research Institute | Flicker L.,University of Western Australia
Journal of Alzheimer's Disease | Year: 2010

There is increasing evidence that some lifestyle factors are linked to the development of Alzheimer's disease. Many of these are potentially modifiable and include smoking, physical activity, education, social engagement, cognitive stimulation, and diet. Modification of most of these factors has other health advantages, increasing the potential benefits of modifying the individual's lifestyle. Unfortunately, most of the current evidence is based on observational data, and where human trials have been performed they have used surrogate outcomes rather than the development of Alzheimer's disease. For many of these modifiable lifestyle factors, such trials may never be performed, and an individual's choice may need to be based on the available evidence. © 2010 - IOS Press and the authors.

Honeybul S.,Sir Charles Gairdner Hospital | Ho K.M.,University of Western Australia
Injury | Year: 2014

Object To assess the impact that injury severity has on complications in patients who have had a decompressive craniectomy for severe traumatic brain injury (TBI). Methods This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia from 2004 to 2012. All complications were recorded during this period. The clinical and radiological data of the patients on initial presentation were entered into a web-based model prognostic model, the CRASH (Corticosteroid Randomization After Significant Head injury) collaborators prediction model, to obtain the predicted risk of an unfavourable outcome which was used as a measure of injury severity. Results Complications after decompressive craniectomy for severe TBI were common. The predicted risk of unfavourable outcome was strongly associated with the development of neurological complications such as herniation of the brain outside the skull bone defects (median predicted risk of unfavourable outcome for herniation 72% vs. 57% without herniation, p = 0.001), subdural effusion (median predicted risk of unfavourable outcome 67% with an effusion vs. 57% for those without an effusion, p = 0.03), hydrocephalus requiring ventriculo-peritoneal shunt (median predicted risk of unfavourable outcome 86% for those with hydrocephalus vs. 59% for those without hydrocephalus, p = 0.001), but not infection (p = 0.251) or resorption of bone flap (p = 0.697) and seizures (0.987). We did not observe any associations between timing of cranioplasty and risk of infection or resorption of bone flap after cranioplasty. Conclusions Mechanical complications after decompressive craniectomy including herniation of the brain outside the skull bone defects, subdural effusion, and hydrocephalus requiring ventriculo-peritoneal shunt were more common in patients with a more severe form of TBI when quantified by the CRASH predicted risk of unfavourable outcome. The CRASH predicted risk of unfavourable outcome represents a useful baseline characteristic of patients in observational and interventional trials involving patients with severe TBI requiring decompressive craniectomy. © 2014 Elsevier Ltd.

Stanga J.P.,University of Georgia | Smith S.M.,University of Western Australia | Briggs W.R.,Carnegie Institution for Science | Nelson D.C.,University of Georgia
Plant Physiology | Year: 2013

Abiotic chemical signals discovered in smoke that are known as karrikins (KARs) and the endogenous hormone strigolactone (SL) control plant growth through a shared MORE AXILLARY GROWTH2 (MAX2)-dependent pathway. A SL biosynthetic pathway and candidate KAR/SL receptors have been characterized, but signaling downstream of MAX2 is poorly defined. A screen for genetic suppressors of the enhanced seed dormancy phenotype of max2 in Arabidopsis (Arabidopsis thaliana) led to identification of a suppressor of max2 1 (smax1) mutant. smax1 restores the seed germination and seedling photomorphogenesis phenotypes of max2 but does not affect the lateral root formation, axillary shoot growth, or senescence phenotypes of max2. Expression of three transcriptional markers of KAR/SL signaling, D14-LIKE2, KAR-UP F-BOX1, and INDOLE-3-ACETIC ACID INDUCIBLE1, is rescued in smax1 max2 seedlings. SMAX1 is a member of an eight-gene family in Arabidopsis that has weak similarity to HEAT SHOCK PROTEIN 101, which encodes a caseinolytic peptidase B chaperonin required for thermotolerance. SMAX1 and the SMAX1-like (SMXL) homologs are differentially expressed in Arabidopsis tissues. SMAX1 transcripts are most abundant in dry seed, consistent with its function in seed germination control. Several SMXL genes are up-regulated in seedlings treated with the synthetic SL GR24. SMAX1 and SMXL2 transcripts are reduced in max2 seedlings, which could indicate negative feedback regulation by KAR/SL signaling. smax1 seed and seedling growth mimics the wild type treated with KAR/SL, but smax1 seedlings are still responsive to 2H-furo[2,3-c]pyran-2-one (KAR2) or GR24. We conclude that SMAX1 is an important component of KAR/SL signaling during seed germination and seedling growth but is not necessary for all MAX2-dependent responses. We hypothesize that one or more SMXL proteins may also act downstream of MAX2 to control the diverse developmental responses to KARs and SLs. © 2013 American Society of Plant Biologists. All Rights Reserved.

Luo M.,University of Western Australia | Chen Z.-Q.,Wuhan University
Geological Journal | Year: 2014

Abundant scratching traces are described from the Early Triassic Kockatea Shale Formation in the Northampton area of the northern Perth Basin, Western Australia. Except for the Radichnus trace that represents grazing of a possible decapod mecochirids, Scalpoichnus minchinensis igen. and isp. nov. is established to accommodate other scratching sculptures, which might have been produced by arthropods that share similar feeding behaviours to those of decapods. These arthropod traces occurred on a mat-bound substratum defined by wrinkle structures. Microbial mats may have served as food resources for trace-makers feeding on the substratum. Furthermore, microbial envelopes functioning as a sole veneer in early diagenesis acted as a crucial role for the preservation of those shallow-tiered engraving traces. Abundant arthropod traces indicate frequent grazing activities probably by decapods or organisms having similar feeding habits upon microbial mat-bound substratum, implying that the deposit-feeders or omnivores survived on the matgrounds in the aftermath of the end-Permian mass extinction in Gondwanaland. © 2013 John Wiley & Sons, Ltd.

Zhelezinskaia I.,The Interdisciplinary Center | Kaufman A.J.,The Interdisciplinary Center | Farquhar J.,The Interdisciplinary Center | Cliff J.,University of Western Australia
Science | Year: 2014

The minor extent of sulfur isotope fractionation preserved in many Neoarchean sedimentary successions suggests that sulfate-reducing microorganisms played an insignificant role in ancient marine environments, despite evidence that these organisms evolved much earlier. We present bulk, microdrilled, and ion probe sulfur isotope data from carbonate-associated pyrite in the ∼2.5-billion-year-old Batatal Formation of Brazil, revealing large mass-dependent fractionations (approaching 50 per mil) associated with microbial sulfate reduction, as well as consistently negative Δ 33S values (∼ -2 per mil) indicative of atmospheric photochemical reactions. Persistent 33S depletion through ∼60 meters of shallow marine carbonate implies long-term stability of seawater sulfate abundance and isotope composition. In contrast, a negative Δ 33S excursion in lower Batatal strata indicates a response time of ∼40,000 to 150,000 years, suggesting Neoarchean sulfate concentrations between ∼1 and 10 μM. © 2014, American Association for the Advancement of Science. All rights reserved.

We discuss a possible physical connection between helium-rich (Y ≥ 0.35) stellar populations of massive globular clusters (GCs) and the ultraviolet (UV) upturn of galactic spheroids by using analytical and numerical models. In our model, all stars are initially formed as bound or unbound star clusters (SCs) formed from giant molecular clouds (GMCs) and the SCs can finally become GCs, open clusters, and field stars depending on the physical properties of their host GMCs. An essential ingredient of the model is that helium-rich stars are formed almost purely from gas ejected from massive asymptotic giant branch stars. The helium-rich star formation is assumed to occur within massive SCs if the masses of the progenitor GMCs are larger than a threshold mass (M thres). These massive SCs can finally become either massive GCs or helium-rich field stars depending on whether they are disintegrated or not. Using this model, we show that if the initial mass functions (IMFs) in galactic spheroids are mildly top-heavy, then the mass fractions of helium-rich main-sequence stars (F He) can be as large as 0.1 for M thres = 107 M ⊙. F He is found to depend on IMFs and M thres such that it can be larger for shallower IMFs and smaller M thres. The inner regions of galactic spheroids show larger F He in almost all models. Based on these results, we suggest that if the UV upturn of elliptical galaxies is due to the larger fractions of helium-rich stars, then its origin can be closely associated with top-heavy IMFs in the galaxies. © 2012. The American Astronomical Society. All rights reserved.

Buchbinder E.I.,University of Western Australia | Constantin A.,University of Oxford | Lukas A.,University of Oxford
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We study two phases of a heterotic standard model, obtained from a Calabi-Yau compactification of the E8×E8 heterotic string, in the context of the associated four-dimensional effective theories. In the first phase we have a standard model gauge group, an MSSM spectrum, four additional U(1) symmetries and singlet fields. In the second phase, obtained from the first by continuing along the singlet directions, three of the additional U(1) symmetries are spontaneously broken and the remaining one is a B-L symmetry. In this second phase, dimension five operators inducing proton decay are consistent with all symmetries and as such, they are expected to be present. We show that, contrary to this expectation, these operators are forbidden due to the additional U(1) symmetries present in the first phase of the model. We emphasise that such "unexpected" absences of operators, due to symmetry enhancement at specific loci in the moduli space, can be phenomenologically relevant and, in the present case, protect the model from fast proton decay. © 2015 The Authors.

Smith J.T.,University of Western Australia
Advances in experimental medicine and biology | Year: 2013

Kisspeptin cells appear to be the "missing link," bridging the divide between levels of gonadal steroids and feedback control of gonadotropin-releasing hormone (GnRH) secretion. Kisspeptin neurons are important in the generation of both sex steroid negative and estrogen positive feedback signals to GnRH neurons, the former being involved in the tonic regulation of GnRH secretion in males and females and the latter governing the preovulatory GnRH/luteinizing hormone (LH) surge in females. In rodents, kisspeptin-producing cells populate the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (ARC), and estrogen regulation of kisspeptin has been extensively studied in these regions. Kisspeptin cells in the ARC appear to receive and forward signals applicable to negative feedback regulation of GnRH. In the female rodent AVPV, kisspeptin cells are important for positive feedback regulation of GnRH and the preovulatory LH surge. In sheep and primates, a rostral population of kisspeptin cells is located in the dorsolateral preoptic area (POA) as well as the ARC. Initial studies showed kisspeptin cells in the latter were involved in both the positive and negative feedback regulation of GnRH. Interestingly, further studies now suggest that kisspeptin cells in the ovine POA may also play an important role in generating estrogen positive feedback. This chapter discusses the current consensus knowledge regarding the interaction between sex steroids and kisspeptin neurons in mammals.

Kilburn M.R.,University of Western Australia
ISME Journal | Year: 2015

Diazotrophic bacteria are instrumental in generating biologically usable forms of nitrogen by converting abundant dinitrogen gas (N2) into available forms, such as ammonium. Although nitrogen is crucial for coral growth, direct observation of associations between diazotrophs and corals has previously been elusive. We applied fluorescence in situ hybridization (FISH) and nanoscale secondary ion mass spectrometry to observe the uptake of 15N-enriched diazotrophic Vibrio sp. isolated from Acropora millepora into conspecific coral larvae. Incorporation of Vibrio sp. cells was observed in coral larvae after 4-h incubation with enriched bacteria. Uptake was restricted to the aboral epidermis of larvae, where Vibrio cells clustered in elongated aggregations. Other bacterial associates were also observed in epidermal areas in FISH analyses. Although the fate and role of these bacteria requires additional investigation, this study describes a powerful approach to further explore cell associations and nutritional pathways in the early life stages of the coral holobiont.The ISME Journal advance online publication, 22 December 2015; doi:10.1038/ismej.2015.229. © 2015 International Society for Microbial Ecology

Ristic B.,Defence Science and Technology Organisation, Australia | Vo B.-N.,University of Western Australia
Automatica | Year: 2010

The problem addressed in this paper is information theoretic sensor control for recursive Bayesian multi-object state-space estimation using random finite sets. The proposed algorithm is formulated in the framework of partially observed Markov decision processes where the reward function associated with different sensor actions is computed via the Rnyi or alpha divergence between the multi-object prior and the multi-object posterior densities. The proposed algorithm in implemented via the sequential Monte Carlo method. The paper then presents a case study where the problem is to localise an unknown number of sources using a controllable moving sensor which provides range-only detections. Four sensor control reward functions are compared in the study and the proposed scheme is found to perform the best. © 2010 Elsevier Ltd. All rights reserved.

Loft S.,University of Western Australia | Remington R.W.,University of Queensland
Quarterly Journal of Experimental Psychology | Year: 2013

Remembering to perform deferred actions when an event is encountered in the future is referred to as event-based prospective memory (PM). We examined whether the failure of individuals to allocate sufficient attentional resources to nonfocal PM tasks can be linked to the response demands inherent in PM paradigms that require the PM task to race for response selection with the speeded ongoing task. In three experiments, participants performed a lexical decision task while being required to make a separate PM response to a specific word (focal), an exemplar of a category (nonfocal), or a syllable (nonfocal). We manipulated the earliest time participants could make task responses by presenting a tone at varying onsets (0-1,600 ms) following stimulus presentation. Improvements in focal PM and nonfocal PM were observed at response delays as brief as 200 ms and 400 ms, respectively. Nonfocal PM accuracy was comparable to focal PM accuracy at delays of 600 ms and 1,600 ms for categorical targets and syllable targets, respectively. Delaying task responses freed the resource-demanding processing operations used on the ongoing task for use on the nonfocal PM task, increasing the probability that the nonfocal PM features of ongoing task stimuli were adequately assessed prior to the ongoing task response. © 2013 Copyright The Experimental Psychology Society.

Trevelyan J.,University of Western Australia
Engineering Studies | Year: 2010

Using data from interviews and field observations, this article argues that engineering needs to be understood as a much broader human social performance than traditional narratives that focus just on design and technical problem-solving. The article proposes a model of practice based on observations from all the main engineering disciplines and diverse settings in Australia and South Asia. Observations presented in the article reveal that engineers not only relegate social aspects of their work to a peripheral status but also many critical technical aspects like design checking that are omitted from prevailing narratives. The article argues that the foundation of engineering practice is distributed expertise enacted through social interactions between people: engineering relies on harnessing the knowledge, expertise and skills carried by many people, much of it implicit and unwritten knowledge. Therefore social interactions lie at the core of engineering practice. The article argues for relocating engineering studies from the curricular margins to the core of engineering teaching and research and opens new ways to resolve contested issues in engineering education. © 2010 Taylor & Francis.

Tearne J.E.,University of Western Australia
Fertility and Sterility | Year: 2015

The trend toward delayed childbearing is widespread in industrialized nations. Although the physical consequences for offspring in utero and in the prenatal period are well known, the psychologic consequences of older motherhood for offspring have received less attention in the literature. In contrast to the heightened physical risks for offspring, the existing research suggests that children of older mothers are often at lower risk for problem behavioral and academic outcomes compared with offspring of mothers in their teens and twenties. Maternal age is inextricably linked with a complex web of psychosocial variables, and the challenge for future research is to better understand the relative influence of these variables on the relationship between maternal age and offspring outcomes. © 2015 American Society for Reproductive Medicine.

Mozaffarian D.,Harvard University | Wu J.H.Y.,Harvard University | Wu J.H.Y.,University of Western Australia
Journal of the American College of Cardiology | Year: 2011

We reviewed available evidence for cardiovascular effects of N-3 polyunsaturated fatty acid (PUFA) consumption, focusing on long chain (seafood) N-3 PUFA, including their principal dietary sources, effects on physiological risk factors, potential molecular pathways and bioactive metabolites, effects on specific clinical endpoints, and existing dietary guidelines. Major dietary sources include fatty fish and other seafood. N-3 PUFA consumption lowers plasma triglycerides, resting heart rate, and blood pressure and might also improve myocardial filling and efficiency, lower inflammation, and improve vascular function. Experimental studies demonstrate direct anti-arrhythmic effects, which have been challenging to document in humans. N-3 PUFA affect a myriad of molecular pathways, including alteration of physical and chemical properties of cellular membranes, direct interaction with and modulation of membrane channels and proteins, regulation of gene expression via nuclear receptors and transcription factors, changes in eicosanoid profiles, and conversion of N-3 PUFA to bioactive metabolites. In prospective observational studies and adequately powered randomized clinical trials, benefits of N-3 PUFA seem most consistent for coronary heart disease mortality and sudden cardiac death. Potential effects on other cardiovascular outcomes are less-well-established, including conflicting evidence from observational studies and/or randomized trials for effects on nonfatal myocardial infarction, ischemic stroke, atrial fibrillation, recurrent ventricular arrhythmias, and heart failure. Research gaps include the relative importance of different physiological and molecular mechanisms, precise dose-responses of physiological and clinical effects, whether fish oil provides all the benefits of fish consumption, and clinical effects of plant-derived N-3 PUFA. Overall, current data provide strong concordant evidence that N-3 PUFA are bioactive compounds that reduce risk of cardiac death. National and international guidelines have converged on consistent recommendations for the general population to consume at least 250 mg/day of long-chain N-3 PUFA or at least 2 servings/week of oily fish. © 2011 American College of Cardiology Foundation.

Prescott S.,University of Western Australia | Saffery R.,Murdoch Childrens Research Institute
Clinical Epigenetics | Year: 2011

The epidemic of allergic disease in early life is one of the clearest indicators that the developing immune system is vulnerable to modern environmental changes. A range of environmental exposures epidemiologically associated with allergic disease have been shown to have effects on the foetal immune function in pregnancy, including microbial burden, dietary changes and environmental pollutants. Preliminary studies now suggest that these early effects on immune development may be mediated epigenetically through a variety of processes that collectively modify gene expression and allergic susceptibility and that these effects are potentially heritable across generations. It is also possible that rising rates of maternal allergy, a recognized direct risk factor for infant allergic disease, may be further amplifying the effects of environmental changes. Whilst effective prevention strategies are the ultimate goal in reversing the allergy epidemic, the specific environmental drivers, target genes, and intracellular pathways and mechanisms of early life immune programming are still unclear. It is hoped that identifying genes that are differentially regulated in association with subsequent allergic disease will assist in identifying causal pathways and upstream contributing environmental factors. In this way, epigenetic paradigms are likely to provide valuable insights into how the early environment can be modified to more favourably drive immune development and reverse the allergic epidemic. © Springer-Verlag 2011.

Lawrance I.C.,University of Western Australia
Expert Opinion on Investigational Drugs | Year: 2012

Introduction: The Inflammatory Bowel Diseases (IBDs) are life-long chronic relapsing incurable inflammatory conditions that usually appear in the first few decades of life. There have been marked advances in the management of these conditions, but none of the currently available therapies are a panacea as they are neither universally efficacious nor will their efficacy necessarily last. There is a desperate need for new therapies that target the immunological deficits within the immune system with low side effects and long-term efficacy. Areas covered: Leukocyte trafficking into the intestinal mucosa is central to the inflammatory pathogenesis in both Crohn's disease (CD) and ulcerative colitis (UC) and modification of this trafficking has the ability to reduce the level of inflammation. The α4β7 integrin heterodimer is highly expressed on the CD4 CD45RA-memory T-cell subpopulation located within the intestine, and these play a critical part in the pathogenesis of IBD. Expert opinion: By modifying the integrin and chemokine interactions with their specific receptors, inhibition of α4 and α4β7 T-cell trafficking to the sites of intestinal inflammation is possible with promising outcomes in the management of IBD. © 2012 Informa UK, Ltd.

Yeap B.B.,University of Western Australia
Current Opinion in Endocrinology, Diabetes and Obesity | Year: 2010

Purpose of Review: There is increasing interest in age-related changes in sex hormone levels as a potentially treatable cause of ill-health in men. Relationships between androgens and cardiovascular disease will be discussed, with particular attention to more recently published research. Recent Findings: In middle-aged and older men, lower testosterone levels are associated with insulin resistance, metabolic syndrome and diabetes, interrelated conditions that predispose to cardiovascular disease. The relationship between androgens and preclinical atherosclerosis requires confirmation. Nevertheless, lower testosterone levels predict cardiovascular events, such as stroke and transient ischaemic attack, in older men and are associated with higher cardiovascular and overall mortality. Testosterone is aromatized to oestradiol, and both higher and lower oestradiol levels have been associated with cardiovascular risk. Randomized trials have shown that testosterone supplementation in men with existing coronary artery disease can be protective against myocardial ischaemia. However, additional interventional studies are needed with endpoints of cardiovascular events. Summary: Observational studies continue to relate reduced circulating testosterone to cardiovascular risk, atherosclerosis and mortality in men. The role of oestradiol as a marker for cardiovascular disease requires clarification. Larger randomized trials are needed to establish whether hormonal therapy would reduce the burden of cardiovascular disease in ageing men. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Flower T.P.,University of Cape Town | Flower T.P.,University of Cambridge | Gribble M.,University of Cambridge | Ridley A.R.,University of Cape Town | Ridley A.R.,University of Western Australia
Science | Year: 2014

Deception is common in nature, but victims of deception discriminate against and ultimately ignore deceptive signals when they are produced too frequently. Flexible variation of signals could allow evasion of such constraints. Fork-tailed drongos (Dicrurus adsimilis) use false alarm calls to scare other species away from food that they then steal. We show that drongos mimic the alarms of targeted species. Further, target species reduce their response to false alarm calls when they are repeated. However, the fear response is maintained when the call is varied. Drongos exploit this propensity by changing their alarm-call type when making repeated theft attempts on a particular species. Our results show that drongos can evade the frequency-dependent constraints that typically limit deception payoffs through flexible variation of their alarm calls.

Rasiah P.,University of Western Australia
Journal of Pragmatics | Year: 2010

Evasion (equivocation) has been identified as a matter of concern in political interviews, but no systematic study has been undertaken in the context of parliamentary discourse, notably Question Time, anywhere in the world. This study applies and adapts various approaches on how politicians 'resist' answering questions, all of which are based on political news interviews, to the study of evasion in parliamentary discourse. A comprehensive, unified framework for the analysis of evasion is described, a decision flow-chart for the framework is provided, and an illustrative example of the applied framework is given based on Australia's Question Time. It involved the classification of responses as 'answers', 'intermediate responses', and 'evasions' based on specific criteria. Responses which were considered evasions were further analysed to determine the levels of evasion, whether they were covert or overt in nature and the types of 'agenda shifts' that occurred, if any. The corpus investigated consists of Australia's House of Representatives' Question Time transcripts, for the months of February and March 2003, on the specific issue of Iraq. The study provides empirical evidence that evasion does occur during parliamentary Question Time. © 2009 Elsevier B.V. All rights reserved.

Firman R.C.,University of Western Australia
Behavioral Ecology and Sociobiology | Year: 2014

Multiple mating is a common reproductive strategy among mammals, and rodents living in communal, mixed sex social groups are predisposed to a polygamous existence. The sandy inland mouse is a naturally polyandrous species that occurs across most of Australia's arid region. Females typically have greater reproductive restrictions compared with males and are therefore expected to acquire substantial fitness benefits from copulating with more than one male. Here, I show that the reproductive output of female sandy inland mice did not differ between females mated monandrously (single male) or polyandrously (two males). Paternity data obtained from the polyandrous litters revealed that in most cases, there was a first male-to-mate advantage. I discuss this result in relation to the chastity enforcement hypothesis for the evolution of the copulatory plug. Finally, I compared ejaculate traits of competing males and found that the paternity loss of males that mated first was attributable to their own sperm density and sperm quality, and not to that of their rivals. The sperm data also revealed that second males gained greater paternity representation when sperm velocities and motilities were higher in first-mated males. This investigation indicates that mating position is a critical determinant of male fitness in mammalian sperm competition. © 2013, Springer-Verlag Berlin Heidelberg.

Kuzenko S.M.,University of Western Australia
Journal of Physics A: Mathematical and Theoretical | Year: 2010

N = 2 supersymmetry in four spacetime dimensions is intimately related to hyperkähler and quaternionic Kähler geometries. On one hand, the target spaces for rigid supersymmetric sigma-models are necessarily hyperkähler manifolds. On the other hand, when coupled to N = 2 supergravity, the sigma-model target spaces must be quaternionic Kähler. It is known that such manifolds of restricted holonomy are difficult to generate explicitly. Projective superspace is a field-theoretic approach to construct general N = 2 supersymmetric nonlinear sigma-models, and hence to generate new hyperkähler and quaternionic Kähler metrics. Intended for a mixed audience consisting of both physicists and mathematicians, these lectures provide a pedagogical introduction to the projective-superspace approach. © 2010 IOP Publishing Ltd.

Ludwig M.,University of Western Australia
Plant, Cell and Environment | Year: 2012

C4 photosynthesis, a biochemical CO2-concentrating mechanism (CCM), evolved more than 60 times within the angiosperms from C3 ancestors. The genus Flaveria, which contains species demonstrating C3, C3-C4, C4-like or C4 photosynthesis, is a model for examining the molecular evolution of the C4 pathway. Work with carbonic anhydrase (CA), and C3 and C4Flaveria congeners has added significantly to the understanding of this process. The C4 form of CA3, a β-CA, which catalyses the first reaction in the C4 pathway by hydrating atmospheric CO2 to bicarbonate in the cytosol of mesophyll cells (mcs), evolved from a chloroplastic C3 ancestor. The molecular modifications to the ancestral CA3 gene included the loss of the sequence encoding the chloroplast transit peptide, and mutations in regulatory regions that resulted in high levels of expression in the C4 mesophyll. Analyses of the CA3 proteins and regulatory elements from Flaveria photosynthetic intermediates indicated C4 biochemistry very likely evolved in a specific, stepwise manner in this genus. The details of the mechanisms involved in the molecular evolution of other C4 plant β-CAs are unknown; however, comparative genetics indicate gene duplication and neofunctionalization played significant roles as they did in Flaveria. The current knowledge of carbonic anhydrase multigene families in plants using C4 photosynthesis is reviewed, and the novel insights this enzyme has given into the molecular evolution of this photosynthetic pathway are highlighted. Work with members of the genus Flaveria is described as a case study, and consideration is also given to carbonic anhydrases from C4 plants for which there is whole genome sequence information. With the current interest in C4 plants as sustainable sources of fuel, the transfer of the C4 pathway into C3 crops, and the evolution of angiosperms, the information presented is of interest to plant physiologists and molecular and evolutionary biologists. © 2011 Blackwell Publishing Ltd.

Arendts G.,University of Western Australia | Howard K.,University of New South Wales
Age and Ageing | Year: 2010

Background: Emergency care for older people living in residential aged care facilities (RACF) is a complex area of health policy. The epidemiology of patient transfer between RACF and hospital emergency departments (ED), clinical outcomes and costs associated with transfer and efficacy of programs aiming to reduce transfer are not well known. Design: systematic review based on a comprehensive literature search in three electronic databases and published article reference lists. Results: the incidence of transfer from RACF to ED is >30 transfers/100 RACF beds/year in most studies. The casemix from RACF is varied and reflects that of the broad elderly population, with some risk difference. At least 40% of transfers are not admitted to hospital. There is insufficient data to fully address our other questions; however, hospitalisations from RACF can be reduced through advanced care planning, use of management guidelines for acute illnesses and improved primary care. Conclusions: residents of RACF have a high annual risk of transfer to ED. The clinical benefit and cost effectiveness of ED care, and alternate programs to reduce ED transfer, cannot be confidently compared from published work. Further research is required to accurately describe these and to determine their comparative worth. © The Author 2010. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

Hart R.,University of Western Australia | Norman R.J.,University of Adelaide
Human Reproduction Update | Year: 2013

Background: Several million children have been born from in vitro fertilization (IVF) treatment, but limited data exist regarding their health and development beyond the first year of life. It has been alleged that IVF may lead to long-term adverse consequences, in addition to the documented worse perinatal outcome and increased risk of congenital abnormalities in children born resulting from IVF treatment. methods: A search strategy restricted to studies relating to the medical condition of children of at least 1 year of age born as a result of IVF treatment was performed to include case series, data linkage and prospective studies published 1 January 2000-1 April 2012. results: Limited long-term follow-up data suggest that there is potentially an increase in the incidence of raised blood pressure, elevated fasting glucose, increase in total body fat composition, advancement of bone age and potentially subclinical thyroid disorder in the IVF offspring. Whether these potential associations are related to the IVF treatment per se, the adverse obstetric outcomes associated with IVF treatment or are related to the genetic origin of the children is yet to be determined. conclusions: This review provides evidence to suggest that the short-term health outcome for children born from IVF treatment is positive. However, it is expected that the cardiovascular and metabolic risk factors found in childhood and tracking into adulthood could be worse in later life, and may be responsible for chronic cardiometabolic disease. These observations need to be addressed by further studies. © The Author 2013. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.

Kelley L.A.,University of Cambridge | Kelley J.L.,University of Western Australia
Behavioral Ecology | Year: 2014

In 1909, Abbott Thayer suggested that the study of animal coloration lies in the domain of artists because it deals with optical illusions. He proposed, for example, that prey color patterns may obliterate the animal's outline to make the wearer appear invisible to its predators. Despite a long history of research on the neuropsychology of visual illusions in humans, the question of whether they can occur in other animals has remained largely neglected. In this review, we first examine whether the visual effects generated by an animal's shape, coloration, movement, social environment, or direct manipulation of the environment might distort the receiver's perspective to form an illusion. We also consider how illusions fit into the wider conceptual framework of sensory perception and receiver psychology, in order to understand the potential significance of these (and other) visual effects in animal communication. Secondly, we consider traits that manipulate visual processing tasks to intimidate or mislead the viewer. In the third part of the review, we consider the more extreme cases of sensory manipulation, in which individuals or their traits disrupt, overstimulate, or inactivate receivers' sensory systems. Although illusions present just one form of sensory manipulation, we suggest that they are likely to be more common than previously suspected. Furthermore, we expect that research in this area of sensory processing will provide significant insights into the cognitive psychology of animal communication. © The Author 2013.

When females mate with multiple males both pre- and post-copulatory sexual selections occur. It has been suggested that females benefit from polyandry when better-quality males are successful in sperm competition and sire high-quality offspring. Indeed, studies of experimental evolution have confirmed that sperm competition selects for both increased ejaculate quality and elevated offspring viability. Fewer investigations have explored whether these fitness benefits are evident beyond early life-history stages. Here, I used house mice (Mus domesticus) from selection lines that had been evolving for 25 generations under either polygamy or monogamy to test whether females preferred males from lines that had evolved with sperm competition. Males from the polygamous lines had previously been shown to achieve a fitness advantage under semi-natural conditions, deeming them to be of high genetic quality and leading to the a priori expectation that females would prefer males that had evolved with sperm competition compared with males that had not. Contrary to expectation, the data showed that sexually receptive females spent more time associating with males from the monogamous lines. This unexpected but interesting result is discussed in relation to sperm competition theory that predicts a trade-off between male investment in pre- and post-copulatory sexually selected traits. © 2014 The Author(s).

Raven J.A.,University of Western Australia
Plant Science | Year: 2012

Phosphorus (P) is the proximate (immediate) limiting element for primary productivity in some habitats, and is generally the ultimate limiting element for primary productivity. Although RNA can account for over half of the non-storage P in photosynthetic organisms, some primary producers have more ribosomes than the minimum needed for the observed rate of net protein synthesis; some of this RNA may be needed for protein turnover. Two cases of protein turnover which can occur at a much faster rate than the bulk protein turnover are those of photodamaged photosystem II and O 2-damaged nitrogenase. While RNA involved in photosystem II repair accounts for less than 1% of the non-storage P in photosynthetic organisms, a maximum, of 12% of non-storage P could occur in RNA associated with replacement of damaged nitrogenase and/or O 2 damage avoidance mechanism in diazotrophic (N 2 fixing) organisms. There is a general trend in published data towards lower P use efficiency (g dry matter gain per day per mol P in the organism) for photosynthetic diazotrophic organisms growing under P limitation with N 2 as their nitrogen source, rather than with NH 4 +, urea or NO 3 -. Additional work is needed to examine the generality of a statistically verified decrease in P use efficiency for diazotrophic growth relative to growth on other nitrogen sources and, if this is confirmed, further investigation of the mechanism is needed. The outcome of such work would be important for relating the global distribution of diazotrophy to P availability. There are no known P acquisition mechanisms specific to diazotrophs. Phosphorus (P) is the proximate (immediate) limiting element for primary productivity in some habitats, and is generally the ultimate limiting element for primary productivity. Although RNA can account for over half of the non-storage P in photosynthetic organisms, some primary producers have more ribosomes than the minimum needed for the observed rate of net protein synthesis; some of this RNA may be needed for protein turnover. Two cases of protein turnover which can occur at a much faster rate than the bulk protein turnover are those of photodamaged photosystem II and O 2-damaged nitrogenase. While RNA involved in photosystem II repair accounts for less than 1% of the non-storage P in photosynthetic organisms, a maximum, of 12% of non-storage P could occur in RNA associated with replacement of damaged nitrogenase and/or O 2 damage avoidance mechanism in diazotrophic (N 2 fixing) organisms. There is a general trend in published data towards lower P use efficiency (g dry matter gain per day per mol P in the organism) for photosynthetic diazotrophic organisms growing under P limitation with N 2 as their nitrogen source, rather than with NH 4 +, urea or NO 3 -. Additional work is needed to examine the generality of a statistically verified decrease in P use efficiency for diazotrophic growth relative to growth on other nitrogen sources and, if this is confirmed, further investigation of the mechanism is needed. The outcome of such work would be important for relating the global distribution of diazotrophy to P availability. There are no known P acquisition mechanisms specific to diazotrophs. © 2012 Elsevier Ireland Ltd.

Carboxylate-releasing cluster roots of Proteaceae play a key role in acquiring phosphorus (P) from ancient nutrient-impoverished soils in Australia. However, cluster roots are also found in Proteaceae on young, P-rich soils in Chile where they allow P acquisition from soils that strongly sorb P. Unlike Proteaceae in Australia that tend to proficiently remobilize P from senescent leaves, Chilean Proteaceae produce leaf litter rich in P. Consequently, they may act as ecosystem engineers, providing P for plants without specialized roots to access sorbed P. We propose a similar ecosystem-engineering role for species that release large amounts of carboxylates in other relatively young, strongly P-sorbing substrates, e.g. young acidic volcanic deposits and calcareous dunes. Many of these species also fix atmospheric nitrogen and release nutrient-rich litter, but their role as ecosystem engineers is commonly ascribed only to their diazotrophic nature. We propose that the P-mobilizing capacity of Proteaceae on young soils, which contain an abundance of P, but where P is poorly available, in combination with inefficient nutrient remobilization from senescing leaves allows these species to function as ecosystem engineers. We suggest that diazotrophic species that colonize young soils with strong P-sorption potential should be considered for their positive effect on P availability, as well as their widely accepted role in nitrogen fixation. Their P-mobilizing activity possibly also enhances their nitrogen-fixing capacity. These diazotrophic species may therefore facilitate the establishment and growth of species with less-efficient P-uptake strategies on more-developed soils with low P availability through similar mechanisms. We argue that the significance of cluster roots and high carboxylate exudation in the development of young ecosystems is probably far more important than has been envisaged thus far.

Taylor M.F.,University of Western Australia
International Journal of Mental Health and Addiction | Year: 2012

This paper, details from an educational perspective the reasons graffitists give for their involvement in graffiti. Data gathered from interviews, web-blogs and newspaper reports were analysed within the grounded theory tradition allowing the core category of, addicted to the risk, recognition and respect that the graffiti lifestyle provides to emerge. In this regard, adolescent graffiti-writers contend that sustained involvement in graffiti-writing provides a rush experience, which over time becomes addictive as it rewards them with a non-conforming social identity, recognitional status, and the highly-prized graffiti-writer reputation. However, as they move out of adolescence into early adulthood, the addictive rushes previously gained from engagement in illegal high-risk acts of graffiti tagging, they claim, morphs into an obsessive desire for obtaining community respect. Thus, the outcome of the study suggests that the issue of graffiti-proliferation goes beyond the confines of educational/criminological research and enters the sphere of mental health, opening up different treatment options for recidivist graffiti-writers. © 2010 Springer Science+Business Media, LLC.

Dowling D.K.,Monash University | Simmons L.W.,University of Western Australia
PLoS ONE | Year: 2012

Trade-offs between investment into male sexual traits and immune function provide the foundation for some of the most prominent models of sexual selection. Post-copulatory sexual selection on the male ejaculate is intense, and therefore trade-offs should occur between investment into the ejaculate and the immune system. Examples of such trade-offs exist, including that between sperm quality and immunity in the Australian cricket, Teleogryllus oceanicus. Here, we explore the dynamics of this trade-off, examining the effects that increased levels of sexual interaction have on the viability of a male's sperm across time, and the concomitant effects on immune function. Males were assigned to a treatment, whereby they cohabited with females that were sexually immature, sexually mature but incapable of copulation, or sexually mature and capable of copulation. Sperm viability of each male was then assessed at two time points: six and 13 days into the treatment, and immune function at day 13. Sperm viability decreased across the time points, but only for males exposed to treatment classes involving sexually mature females. This decrease was similar in magnitude across both sexually mature classes, indicating that costs to the expression of high sperm viability are incurred largely through levels of pre-copulatory investment. Males exposed to immature females produced sperm of low viability at both time points. Although we confirmed a weak negative association between sperm viability and lytic activity (a measure of immune response to bacterial infection) at day 13, this relationship was not altered across the mating treatment. Our results highlight that sperm viability is a labile trait, costly to produce, and subject to strategic allocation in these crickets. © 2012 Dowling, Simmons.

Waithman J.,University of Western Australia
Virulence | Year: 2012

Influenza A virus (IAV) is a dangerous virus equipped with the potential to evoke widespread pandemic disease. The 2009 H1N1 pandemic highlights the urgency for developing effective therapeutics against IAV infection. Vaccination is a major weapon to combat IAV and efforts to improve current regimes are critically important. Here, we will review the role of dendritic cells (DCs), a pivotal cell type in the initiation of robust IAV immunity. The complexity of DC subset heterogeneity in the respiratory tract and lymph node that drains the IAV infected lung will be discussed, together with the varied and in some cases, conflicting contributions of individual DC populations to presenting IAV associated antigen to T cells.

Barrow N.J.,University of Western Australia | Debnath A.,Bidhan Chandra Krishi Viswavidyalaya
Plant and Soil | Year: 2014

Aims: Enormous quantities of phosphate have been applied to world soils, yet we know little about effects of phosphate status on sorption properties. Methods: We measured sorption and desorption of phosphate on soils from fertilized tea plantations from northern India and compared them with unfertilized soils. We also incubated phosphate at high temperature with a previously unfertilized soil and measured the effects. Results: Sorption of phosphate was less marked on soils of high phosphate status whether derived from inherent fertility or fertilizer application. This occurred because high phosphate status made the surface charge on the reacting surfaces more negative. Phosphate status also affected desorption. The higher the phosphate status, the smaller the difference between sorption and desorption curves. This occurred because on soils of high phosphate status the pathways by which adsorbed anions diffuse were saturated and the slow reaction that follows adsorption was stopped. Conclusions: When low-phosphate soils are first fertilized, it is necessary to supply more phosphate than is removed in produce. However, after long-term phosphate fertilization, it is sufficient to only replace phosphate lost in produce. We need to find how much phosphorus it takes to reach this state and how many of the world's soils have already reached it. © 2014 Springer International Publishing Switzerland.

In this contribution I presents definitions of mineral systems, followed by a proposed classification of mineral deposits. The concept of mineral systems has been tackled by various authors within the framework of genetic models with the aim of improving the targeting of new deposits in green field areas. A mineral system has to be considered taking into account, by and large, space-time patterns or trends of mineralisation at the regional scale, their tectonic controls and related metallogenic belts. This leads to a suggested classification of mineral systems, together with a summary of previous ideas on what is, without doubt, a kind of "mine field", because if a classification is based on genetic processes, these can be extremely complex due to the fact that ore genesis usually involves a number of interactive processes. The classification presented is based on magmatic, magmatic-hydrothermal, sedimentary-hydrothermal, non-magmatic, and mechanical-residual processes.An overview of plate tectonics (convergent and divergent margins) is discussed next. Convergent plate margins are characterised by a tectonic plate subducting beneath a lower density plate. Convergent plate margins have landward of a deep trench, a subduction-accretion complex, a magmatic arc and a foreland thrust belt. An important feature is the subduction angle: a steep angle of descent, is exemplified by the Mariana, or Tonga-Kermadec subduction systems, conducive to porphyry-high-sulphidation epithermal systems, whereas in an intra-arc rift systems with spreading centres is conducive to the generation of massive sulphide deposits of kuroko affinity. A shallower subduction zone is the domain of large porphyry Cu-Mo and epithermal deposits. The implications of this difference in terms of metallogenesis are extremely important. Continent-continent, arc-continent, arc-arc, amalgamation of drifting microcontinents, and oceanic collision events are considered to be a major factor in uplift, the inception of fold-and-thrust belts and high P metamorphism. Examples are the Alpine-Himalayan orogenic belt formed by the closure of the Tethys oceanic basins and the great Central Asian Orogenic Belt (CAOB), a giant accretionary collage of island arcs and continental fragments. The closing of oceanic basins, and the accretion of allochthonous terranes, result in the emplacement of ophiolites by the obduction process. Divergent plates include mid-ocean ridges, passive margins and various forms of continental rifting. At mid-ocean spreading centres, magma chambers are just below the spreading centre. Once the oceanic crust moves away from the ridge it is either consumed in a subduction zone, or it may be accreted to continental margins, or island arcs. Spreading centres also form in back arc marginal basins. Transform settings include transtensional with a component of tension due to oblique divergence, transform or strike-slip sensu stricto and transpressive with a component of compression due to oblique convergence. Strike-slip faults that form during extensional processes lead to the formation of pull-apart basins.Mineral systems that form at convergent margins, the topic of this special issue, are succinctly introduced in Tables 1 to 7, as follows: principal geological features of selected mineral systems at convergent plate margins and back-arcs (Table 1); their recognition criteria (Table 2); principal geological features of selected ore deposits of back-arc basins and post-subduction rifting (Table 3) and of subduction-related magmatic arcs (Table 4), their respective recognition criteria (Table 5); accretionary and collisional tectonics and associated mineral systems (Table 6); principal geological features and associated mineral systems of transform faults (Table 7). © 2015 International Association for Gondwana Research.

Ding J.,National University of Singapore | Kostylev M.,University of Western Australia | Adeyeye A.O.,National University of Singapore
Physical Review Letters | Year: 2011

We show that periodic magnetic nanostructures represent a perfect system for studying excitations on disordered periodical lattices because of the possibility of controlled variation of the degree of disorder by varying the applied magnetic field. Magnetic force microscopy images and ferromagnetic resonance (FMR) data collected inside minor hysteresis loops for a periodic array of Permalloy nanowires were used to demonstrate correlation between the type of FMR response and the degree of disorder of the magnetic ground state. © 2011 American Physical Society.

Oddy W.H.,University of Western Australia
Breastfeeding Review | Year: 2012

Early nutrition in infancy may influence later child health outcomes including overweight through 'programming'. Systematic reviews suggest that breastfeeding is associated with a modest reduction in the risk of later overweight and obesity. This commentary explores some of these mechanisms behind this association. Generally breastfed infants are leaner than artificially (formula)-fed infants and behavioural and hormonal mechanisms may explain this difference. The theory is that a high nutrient diet in infancy adversely programs the principal components of the metabolic syndrome in the child [body mass index, blood pressure and blood lipids) by promoting growth acceleration, whereas slower growth benefits later cardiovascular disease and its risk factors. Artificial-feeding stimulates a higher postnatal growth velocity with the adiposity rebound occurring earlier in those children who have greater fatness later, whereas breastfeeding has been shown to promote slower growth. The adverse long-term effects of early growth acceleration emerge as fundamental in later overweight and obesity. The higher protein content of artificial baby milk compared to the lower protein content in breastmilk is responsible for the increased growth rate and adiposity during the influential period of infancy of formula-fed infants. Breastfeeding, on the other hand, has a protective effect on child overweight and obesity by inducing lower plasma insulin levels, thereby decreasing fat storage and preventing excessive early adipocyte development. Plausible biological mechanisms underlying the protective effect of breastfeeding against obesity are based on the unique composition of human milk and the metabolic and physiological responses to human milk.

Pivonka P.,University of Western Australia | Komarova S.V.,McGill University
Bone | Year: 2010

Although conceptual and experimental models are historically well incorporated in bone biology studies, mathematical modeling has been much less-frequently utilized. This review aims to introduce mathematical modeling to readers who are not familiar with the concept underlying this methodology, to outline how mathematical models can help to improve current understanding of bone biology and to discuss examples where mathematical modeling was used to provide new insights into important questions of bone biology. © 2010 Elsevier Inc.

Brennan D.,University of Western Australia
Water Resources Research | Year: 2010

Significant reforms made to Australian irrigation property rights in recent years have enabled the development of an active seasonal water market. In contrast, decisions regarding the allocation of water across time are typically based on central decisions, with little or no opportunity offered to irrigators to manage risk by physically transferring their water access right between years by leaving it in the public dam. An empirical examination of the economics of water storage is presented using a case study of the Goulburn Valley, a major irrigation region in the state of Victoria. It is shown that, compared to the historically used, centrally determined storage policy, a market-based storage policy would store more water, on average, and would also allocate more water in periods of low rainfall. The analysis indicates that the costs associated with a recent prolonged drought were $100 million more than they would have been if water storage decisions had been guided by the market and prices were 3 times higher. Copyright © 2010 by the American Geophysical Union.

Barnes S.J.,CSIRO | Fiorentini M.L.,University of Western Australia
Economic Geology | Year: 2012

Komatiites are found in most Archean granite-greenstone terranes, but sulfide Ni mineralization associated with these rocks has a very biased distribution. The global endowment of sulfides Ni in Archean komatiites is overwhelmingly dominated by the Kalgoorlie terrane of the Eastern Goldfields Superterrane in the Yilgarn Craton. The question of whether the Kalgoorlie terrane komatiites possess any exceptional attributes which could explain this bias is addressed through an exhaustive compilation of geochemical data from this terrane and a number of others: the southeastern Youanmi terrane of the Yilgarn Craton; the eastern terranes of the Eastern Goldfields superterrane (Kurnalpi, Burtville and others); and the Abitibi greenstone belt of the Superior province. High MgO komatiite magmas, with MgO in the 25 to 30% range, are found in all the terranes sampled, but the proportion of these compositions appears to be higher in the Kalgoorlie terrane, and the abundance of strongly adcumulate olivine cumulates is much higher. Crustal contamination is apparently more extensive and advanced in the Kalgoorlie terrane than in all the others, but there is no systematic difference in the lithophile trace element (LILE) characteristics and degree of source depletion evident in the most primitive magmas from all the terranes. Consideration of variable-valency transition metals V and Cr indicates there are no systematic variations in oxidation state between the terranes and komatiites uniformly evolved close to the quartz-fayalite-magnetite buffer. Platinum-group element (PGE) variations imply that komatiites in all the terranes were emplaced sulfide undersaturated and were derived from sources with remarkably similar PGE contents. There is no evidence that the Kalgoorlie terrane magmas were in any way exceptional. The Forrestania and Lake Johnston Belts of the Youanmi terrane include the only known examples of Al-depleted komatiites hosting significant Ni sulfide resources, and they are also the only komatiites of this type that form adcumulate dunite bodies. The presence of adcumulate dunites, formed by high magma fluxes in central conduits, is the common feature between these belts and the Kalgoorlie terrane. Coupled with evidence for higher degrees of contamination in the Kalgoorlie terrane, and the availability of accessible crustal S sources, it appears that magma flux, rather than primitive magma composition, is the critical factor, and that craton-scale deep lithospheric structure is the ultimate control on the rate of magma supply between mantle source and crustal emplacement site. The Kalgoorlie terrane komatiites were emplaced at exceptionally high rates, giving rise to well-developed long-lived magma conduits, either lava tubes or subvolcanic channelized sills, which are interpreted to be the essential condition for forming large deposits. © 2012 Society of Economic Geologists, Inc.

Asseng S.,University of Florida | Asseng S.,CSIRO | Pannell D.J.,University of Western Australia
Climatic Change | Year: 2013

The Western Australian wheat-belt has experienced more rainfall decline than any other wheat-cropping region in Australia. Future climate change scenarios suggest that the Western Australian wheat-belt is likely to see greater future reductions in rainfall than other regions, together with a further increase in temperatures. While these changes appear adverse for water-limited rain-fed agriculture, a close analysis of the changes and their impacts reveals a more complex story. Twentieth century changes in rainfall, temperature and atmospheric CO2 concentration have had little or no overall impact on wheat yields. Changes in agricultural technology and farming systems have had much larger impacts. Contrary to some claims, there is no scientific or economic justification for any immediate actions by farmers to adapt to long-term climate change in the Western Australian wheat-belt, beyond normal responses to short-term variations in weather. Rather than promoting current change, the most important policy response is research and development to enable farmers to facilitate future adaptation to climate change. Research priorities are proposed. © 2012 Springer Science+Business Media Dordrecht.

Spackman M.A.,University of Western Australia
Physica Scripta | Year: 2013

Hirshfeld surface analysis has developed from the serendipitous discovery of a novel partitioning of the crystal electron density into discrete molecular fragments, to a suite of computational tools used widely for the identification, analysis and discussion of intermolecular interactions in molecular crystals. The relationship between the Hirshfeld surface and very early ideas on the internal structure of crystals is outlined, and applications of Hirshfeld surface analysis are presented for three molecules of historical importance in the development of modern x-ray crystallography: hexamethylbenzene, hexamethylenetetramine and diketopiperazine. © 2013 The Royal Swedish Academy of Sciences.

Blakeney W.G.,Sir Charles Gairdner Hospital | Khan R.J.K.,University of Western Australia | Wall S.J.,Sir Charles Gairdner Hospital
Journal of Bone and Joint Surgery - Series A | Year: 2011

Background: Optimal alignment of the prosthesis in total knee arthroplasty results in improved patient outcomes. The goal of this study was to determine the most accurate technique for component alignment in total knee arthroplasty by comparing computer-assisted surgery with two conventional techniques involving use of an intramedullary guide for the femur and either an intramedullary or an extramedullary guide for the tibia. Methods: One hundred and seven patients were randomized prior to surgery to one of three arms: computer-assisted surgery for both the femur and the tibia (the computer-assisted surgery group), intramedullary guides for both the femur and the tibia (the intramedullary guide group), and an intramedullary guide for the femur and an extramedullary guide for the tibia (the extra-medullary guide group). Measurements of alignment on hip-to-ankle radiographs and computed tomography (CT) scans made three months after surgery were evaluated. The operative times and complications were compared among the three groups. Results: The coronal tibiofemoral angle demonstrated, on average, less malalignment in the computer-assisted surgery group (1.91°) than in the extramedullary (3.22°) and intramedullary (2.59°) groups (p = 0.007). The coronal tibiofemoral angle was >3° of varus or valgus deviation in 19% (seven) of the thirty-six patients treated with computer-assisted surgery compared with 38% (thirteen) of the thirty-four in the extramedullary guide group and 36% (thirteen) of the thirty-six in the intramedullary guide group (p = 0.022). The increase in accuracy with computer-assisted surgery came at a cost of increased operative time. The operative time for the computer-assisted surgery group averaged 107 minutes compared with eightythree and eighty minutes, respectively, for the surgery with the extramedullary and intramedullary guides (p < 0.0001). There was no significant difference in any of the outcomes between the intramedullary and extramedullary guide groups. Conclusions: This study provides evidence that the implant alignment with computer-assisted total knee arthroplasty, as measured with radiography and computed tomography, is significantly improved compared with that associated with conventional surgery with intramedullary or extramedullary guides. This finding adds to the body of evidence showing an improved radiographic outcome with computer-assisted surgery compared with that following conventional total knee arthroplasty. Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence. Copyright © 2011 by The Journal of Bone and Joint Surgery, Incorporated.

Eroglu E.,University of Western Australia | Melis A.,University of California at Berkeley
Bioresource Technology | Year: 2011

Photobiological hydrogen production has advanced significantly in recent years, and on the way to becoming a mature technology. A variety of photosynthetic and non-photosynthetic microorganisms, including unicellular green algae, cyanobacteria, anoxygenic photosynthetic bacteria, obligate anaerobic, and nitrogen-fixing bacteria are endowed with genes and proteins for H 2-production. Enzymes, mechanisms, and the underlying biochemistry may vary among these systems; however, they are all promising catalysts in hydrogen production. Integration of hydrogen production among these organisms and enzymatic systems is a recent concept and a rather interesting development in the field, as it may minimize feedstock utilization and lower the associated costs, while improving yields of hydrogen production. Photobioreactor development and genetic manipulation of the hydrogen-producing microorganisms is also outlined in this review, as these contribute to improvement in the yield of the respective processes. © 2011 Elsevier Ltd.

Hoang H.G.,University of Western Australia
2012 International Conference on Control, Automation and Information Sciences, ICCAIS 2012 | Year: 2012

In multi-object stochastic systems, the issue of sensor control is a theoretically and computationally challenging problem. In this paper, we present a novel random finite set (RFS) approach to the multi-target sensor management problem. Our approach is based on a partially observed Markov decision process (POMDP) where the reward function is a measure of information gain. The multi-target state is modelled as Multi-Bernoulli RFS, and the Multi-Bernoulli filter is used in conjunction with two different reward functions: maximizing the expected Rényi divergence between the predicted and updated densities, and minimizing the expected cardinality variance. Numerical studies and discussions are presented with range only measurements. © 2012 IEEE.

Martin C.M.,University of Oxford | White D.J.,University of Western Australia
Geotechnique | Year: 2012

The ultimate bearing capacity of a rigid, plane-strain pipe segment embedded in undrained clay is studied using numerical limit analysis. The pipe is considered to be 'wished in place' at invert penetrations ranging from zero to five pipe diameters, thus providing coverage of both on-bottom (partially embedded) and trenched (fully embedded) offshore pipelines. The soil is modelled as a rigid-plastic Tresca material with either uniform strength or strength proportional to depth. The effects of soil weight, interface roughness and interface tensile capacity are investigated in a systematic manner. All calculations are performed using the finite-element limit analysis code OxLim, which uses adaptive mesh refinement to compute tightly bracketed lower- and upper-bound plasticity solutions. The velocity fields from the upper-bound analyses provide the corresponding failure mechanisms. The paper initially focuses on purely vertical loading (penetration and uplift), and then addresses combined vertical and horizontal loading. A comprehensive set of design curves and failure envelopes is presented, with the results explained in terms of the changing failure mechanisms. These results are immediately applicable in practice. In particular, current industry-standard procedures for design against pipeline upheaval are critically reviewed, and are shown to have potentially unconservative shortcomings.

Heller N.E.,Duke University | Hobbs R.J.,University of Western Australia
Conservation Biology | Year: 2014

Conservation goals at the start of the 21st century reflect a combination of contrasting ideas. Ideal nature is something that is historically intact but also futuristically flexible. Ideal nature is independent from humans, but also, because of the pervasiveness of human impacts, only able to reach expression through human management. These tensions emerge in current management rationales because scientists and managers are struggling to accommodate old and new scientific and cultural thinking, while also maintaining legal mandates from the past and commitments to preservation of individual species in particular places under the stresses of global change. Common management goals (such as integrity, wilderness, resilience), whether they are forward looking and focused on sustainability and change, or backward looking and focused on the persistence and restoration of historic states, tend to create essentialisms about how ecosystems should be. These essentialisms limit the options of managers to accommodate the dynamic, and often novel, response of ecosystems to global change. Essentialisms emerge because there is a tight conceptual coupling of place and historical species composition as an indicator of naturalness (e.g., normal, healthy, independent from humans). Given that change is increasingly the norm and ecosystems evolve in response, the focus on idealized ecosystem states is increasingly unwise and unattainable. To provide more open-ended goals, we propose greater attention be paid to the characteristics of management intervention. We suggest that the way we interact with other species in management and the extent to which those interactions reflect the interactions among other biotic organisms, and also reflect our conservation virtues (e.g., humility, respect), influences our ability to cultivate naturalness on the landscape. We call this goal a natural practice (NP) and propose it as a framework for prioritizing and formulating how, when, and where to intervene in this period of rapid change. © 2014 Society for Conservation Biology.