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Sydney, Australia

The University of Sydney is a public university located in Sydney, New South Wales. The main campus spreads across the suburbs of Camperdown and Darlington on the southwestern outskirts of the Sydney CBD. Founded in 1850, it is the oldest university in Australia and Oceania. It has 32,393 undergraduate and 16,627 graduate students . The University of Sydney is organised into sixteen faculties and schools, through which it offers bachelor's degrees, master's degrees, and doctoral degrees. Wikipedia.


Dietz H.P.,University of Sydney | Beer-Gabel M.,Tel Aviv University
Ultrasound in Obstetrics and Gynecology | Year: 2012

Recent developments in diagnostic imaging have made gynecologists, colorectal surgeons and gastroenterologists realize as never before that they share a common interest in anorectal and pelvic floor dysfunction. While we often may be using different words to describe the same phenomenon (e.g. anismus/vaginismus) or attributing different meanings to the same words (e.g. rectocele), we look after patients with problems that transcend the borders of our respective specialties. Like no other diagnostic modality, imaging helps us understand each other and provides new insights into conditions we all need to learn to investigate better in order to improve clinical management. In this review we attempt to show what modern ultrasound imaging can contribute to the diagnostic work-up of patients with posterior vaginal wall prolapse, obstructed defecation and rectal intussusception/prolapse. In summary, it is evident that translabial/perineal ultrasound can serve as a first-line diagnostic tool in women with such complaints, replacing defecation proctography and MR proctography in a large proportion of female patients. This is advantageous for the women themselves because ultrasound is much better tolerated, as well as for healthcare systems since sonographic imaging is much less expensive. However, there is a substantial need for education, which currently remains unmet. Copyright © 2012 ISUOG. Source


Humphries R.M.,University of California at Los Angeles | Pollett S.,University of Sydney | Sakoulas G.,University of California at San Diego
Clinical Microbiology Reviews | Year: 2013

Daptomycin is a lipopeptide antimicrobial with in vitro bactericidal activity against Gram-positive bacteria that was first approved for clinical use in 2004 in the United States. Since this time, significant data have emerged regarding the use of daptomycin for the treatment of serious infections, such as bacteremia and endocarditis, caused by Gram-positive pathogens. However, there are also increasing reports of daptomycin nonsusceptibility, in Staphylococcus aureus and, in particular, Enterococcus faecium and Enterococcus faecalis. Such nonsusceptibility is largely in the context of prolonged treatment courses and infections with high bacterial burdens, but it may occur in the absence of prior daptomycin exposure. Nonsusceptibility in both S. aureus and Enterococcus is mediated by adaptations to cell wall homeostasis and membrane phospholipid metabolism. This review summarizes the data on daptomycin, including daptomycin's unique mode of action and spectrum of activity and mechanisms for nonsusceptibility in key pathogens, including S. aureus, E. faecium, and E. faecalis. The challenges faced by the clinical laboratory in obtaining accurate susceptibility results and reporting daptomycin MICs are also discussed. © 2013, American Society for Microbiology. All Rights Reserved. Source


Balleine B.W.,University of Sydney | Balleine B.W.,University of California at Los Angeles | O'Doherty J.P.,Trinity College Dublin | O'Doherty J.P.,California Institute of Technology
Neuropsychopharmacology | Year: 2010

Recent behavioral studies in both humans and rodents have found evidence that performance in decision-making tasks depends on two different learning processes; one encoding the relationship between actions and their consequences and a second involving the formation of stimulus-response associations. These learning processes are thought to govern goal-directed and habitual actions, respectively, and have been found to depend on homologous corticostriatal networks in these species. Thus, recent research using comparable behavioral tasks in both humans and rats has implicated homologous regions of cortex (medial prefrontal cortex/medial orbital cortex in humans and prelimbic cortex in rats) and of dorsal striatum (anterior caudate in humans and dorsomedial striatum in rats) in goal-directed action and in the control of habitual actions (posterior lateral putamen in humans and dorsolateral striatum in rats). These learning processes have been argued to be antagonistic or competing because their control over performance appears to be all or none. Nevertheless, evidence has started to accumulate suggesting that they may at times compete and at others cooperate in the selection and subsequent evaluation of actions necessary for normal choice performance. It appears likely that cooperation or competition between these sources of action control depends not only on local interactions in dorsal striatum but also on the cortico-basal ganglia network within which the striatum is embedded and that mediates the integration of learning with basic motivational and emotional processes. The neural basis of the integration of learning and motivation in choice and decision-making is still controversial and we review some recent hypotheses relating to this issue. © 2010 Nature Publishing Group All rights reserved. Source


Anderson C.S.,University of Sydney | Qureshi A.I.,Zeenat Qureshi Stroke Institute
Stroke | Year: 2015

INTERACT2 provides important new evidence of efficacy and safety of early intensive BP lowering in ICH. These data will be further supplemented with results of the ATACH II study and in a meta-analysis of all such trials being undertaken as part of a new wave of analyses under the auspices of the Blood pressure in Acute Stroke Collaboration.40 We argue that a key next step is to assess the effectiveness of this intervention in routine clinical practice in which the contextspecific systems for delivering care are incorporated into the intervention design and in turn are also tested. To effectively reduce the challenges in implementation of complex interventions that require system changes in clinical practice, data must be acquired on cost-effectiveness and the identification of barriers to such implementation to enhance the application of early targeted BP lowering as a standard of care in ICH. © 2014 American Heart Association, Inc. Source


Bollmer G.D.,University of Sydney
Information Society | Year: 2013

This article examines cultural anxieties surrounding the life and death of online data. Through the examination of a wide range of discourses, including "lifestyle" news articles, online user comments, essays and books by novelists and engineers, and the websites of information management services, I argue that death online-defined as the persistence of informatic remainders after the death of the human user-reveals how networked data are constructed as both an authentic duplicate of identity and as a threat to personal identity that must be managed. Because humans are understood as finite and mortal, while data are immortal and everlasting, the "life" formed out of online data is understood as beyond any possible control of the user. With the death of the user, the perceived connection between the user and data is revealed as a contingency rather than a necessity. Information is produced as autonomous. It is nearly identical to yet separate from the user; it belongs to nobody except, perhaps, the network itself. © 2013 Copyright Taylor and Francis Group, LLC. Source


Dey A.,University of Sydney
Proceedings of the VLDB Endowment | Year: 2013

Many cloud systems provide data stores with limited features, especially they may not provide transactions, or else restrict transactions to a single item. We propose a approach that gives multi-item transactions across heterogeneous data stores, using only a minimal set of features from each store such as single item consistency, conditional update, and the ability to include extra metadata within a value. We offer a client-coordinated transaction protocol that does not need a central coordinating infrastructure. A prototype implemen-tation has been built as a Java library and measured with an extension of YCSB benchmark to exercise multi-item transactions. © 2013 VLDB Endowment. Source


An analysis of early coelom development in the echinoid Holopneustes purpurescens yields a deuterostome body plan that explains the disparity between the pentameral plan of echinoderms and the bilateral plans of chordates and hemichordates, the three major phyla of the monophyletic deuterostomes. The analysis shows an early separation into a medial hydrocoele and lateral coelomic mesoderm with an enteric channel between them before the hydrocoele forms the pentameral plan of five primary podia. The deuterostome body plan thus has a single axial or medial coelom and a pair of lateral coeloms, all surrounding an enteric channel, the gut channel. Applied to the phyla, the medial coelom is the hydrocoele in echinoderms, the notochord in chordates and the proboscis coelom in hemichordates: the lateral coeloms are the coelomic mesoderm in echinoderms, the paraxial mesoderm in chordates and the lateral coeloms in hemichordates. The plan fits frog and chick development and the echinoderm fossil record, and predicts genes involved in coelomogenesis as the source of deuterostome macroevolution. © 2016. Published by The Company of Biologists Ltd. Source


Wilder S.M.,University of Sydney
Advances in Insect Physiology | Year: 2011

Spiders represent a diverse, widespread and abundant group of carnivores. Studying the nutritional ecology of spiders is critical because it can aid in understanding the evolution of prey capture and life history strategies, factors regulating the abundance and diversity of spiders in particular habitats and the role of spiders in arthropod community dynamics including biological control of crop pests. The feeding habits of spiders have long attracted the attention of biologists, in part, because many build webs and are relatively easy to observe. While these studies have provided a wealth of information on the abundance and types of prey captured, they have yielded relatively little information on the types and quantities of nutrients ingested by spiders in nature. Relatively little is also known about the nutritional requirements of spiders, although recent studies using more controlled manipulations of prey nutrient content are beginning to provide a clearer understanding of the types and quantities of nutrients needed by spiders to maximize performance. There is a tremendous opportunity to rapidly advance our understanding of spider nutrition, given a strong foundation in the natural history, behaviour, physiology and ecology of spiders and recent advances in analytical techniques and frameworks for studying nutrition. Studies focusing on the connections between spider nutritional physiology and how this is affected by and affects prey communities may produce particularly exciting results. © 2011 Elsevier Ltd. Source


Farr R.J.,University of Sydney
Pediatric endocrinology reviews : PER | Year: 2013

Death of pancreatic islet beta cells is a common feature of type 1 and 2 diabetes and often follows islet cell transplantation. Measurement of blood glucose is currently the only blunt instrument available to diagnose diabetes mellitus, and we lack tools to quantify islet cell loss or protection thereof. A class of RNA molecules (called microRNAs/miRNAs/miRs) that regulate endogenous gene expression via mRNA cleavage or translational arrest have been identified to be critical for birth, maintenance and regeneration of pancreatic beta cells. Recent demonstration that microRNAs can potentially be utilised as biomarkers due to their serum stability, has triggered increasing interest in understanding their role as regulators or biomarkers of disease. This review aims to delve into the potential of miRNA biomarkers, and whether miRNA profiles are indicators or effector of disease pathology. Furthermore, an outline for identifying and confirming islet-specific miRNA biomarkers is discussed. Source


Vucic S.,University of Sydney | Kiernan M.C.,University of New South Wales
Journal of Neurology, Neurosurgery and Psychiatry | Year: 2010

Background: Upregulation of persistent Na+ conductances has been linked to axonal degeneration in sporadic amyotrophic lateral sclerosis (ALS) and has also been reported in the transgenic superoxide dismutase-1 (SOD-1) mouse model. The mechanisms of ectopic activity (fasciculations and cramp) and axonal degeneration still require clarification in familial ALS (FALS) in humans, and specifically whether there are any differences to the processes identified in sporadic patients. Consequently, novel threshold tracking techniques were used to assess whether upregulation of persistent Na+ conductances was a feature linked to axonal degeneration in FALS. Methods: Axonal excitability studies were undertaken in six FALS patients, 13 asymptomatic SOD-1 mutation carriers and 45 sporadic ALS (SALS) patients. Results: Compound muscle action potential amplitude was significantly reduced in FALS (6.3±1.3 mV) and SALS (6.060.4 mV) compared with controls (10.0±0.4 mV, p<0.05). The mean strength duration time constant (sSD) was significantly increased in FALS (0.55±0.10 ms, p<0.05) and SALS (0.52±0.02 ms, p<0.01) compared with controls (0.41±0.02). There were no differences in sSD between asymptomatic SOD-1 mutation carriers and controls. The increase in τSD correlated with the CMAP amplitude (r=-0.4) and neurophysiological index (r=-0.4). In separate studies that assessed cortical processes, short interval intracortical inhibition (SICI) was significantly reduced (FALS, -2.7±1.3%; controls 13.7±1.3%, p<0.0001) and intracortical facilitation increased (FALS, -5.0±2.2%; controls -0.461.1%, p<0.05) in FALS. The reduction in SICI correlated with τSD (r=-0.8). Conclusions: Taken together, these studies suggest that persistent Na+ conductances are upregulated in FALS and that this upregulation is intrinsically associated with axonal degeneration. Source


Sutherland R.I.,University of Sydney
Foundations of Physics | Year: 2015

A Lagrangian description is presented which can be used in conjunction with particle interpretations of quantum mechanics. A special example of such an interpretation is the well-known Bohm model. The Lagrangian density introduced here also contains a potential for guiding the particle. The advantages of this description are that the field equations and the particle equations of motion can both be deduced from a single Lagrangian density expression and that conservation of energy and momentum are assured. After being developed in a general form, this Lagrangian formulation is then applied to the special case of the Bohm model as an example. It is thereby demonstrated that such a Lagrangian description is compatible with the predictions of quantum mechanics. © 2015, Springer Science+Business Media New York. Source


Yue J.,University of Sydney
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We study the observability of non-standard top Yukawa couplings in the pp→t(→ℓνb)h(→γγ)j channel at 14 TeV high-luminosity LHC (HL-LHC). The small diphoton branching ratio is enhanced when the CP-violating phase, ξ, of the top-Higgs interaction is non-zero. When the modulus of the top-Higgs interaction assumes the SM value, yt=ytSM, we find that the signal significance reaches 2.7σ (7.7σ) when ξ=0.25π (0.5π). Furthermore, the different couplings modify the polarisation of the top quark, and can subsequently be distinguished via asymmetries in spin correlations with the final state leptons. The diphoton decay mode is found to be significantly more promising than the previously considered pp→t(→ℓνℓb)h(→bb-)j channel. © 2015. Source


This paper develops a spatial rural economy model of adaptation to climate change that accounts for a multitude of rural enterprises across a diversity of ecosystems in South America using household surveys. We model adoptions of crops, livestock, and forests. Both specialized and diversified enterprises are modelled. This paper finds that livestock, forests, and a diversification into crops, livestock, and forests are key adaptation strategies. Under the UKMO (United Kingdom Meteorological Office) scenario, a livestock-only enterprise would expand by 4 per cent, a crops-livestock-forests by 3 per cent, and a forests-only by 3 per cent. Adaptation behaviours are closely tied with ecosystem changes under global warming. A livestock-only would increase especially in the grasslands. A crops-livestock-forests enterprise expands into xeromorphic forests. A crops-livestock expands in Andean grasslands and tall grasslands. A forests-only expands in the coasts and woody zones. A crops-only enterprise decreases across South America. © 2012 the author(s). Papers in Regional Science © 2012 RSAI. Source


Kumar S.,CSIRO | Mehdipour H.,CSIRO | Mehdipour H.,University of Sydney | Ostrikov K.,CSIRO
Advanced Materials | Year: 2013

Low-temperature plasmas in direct contact with arbitrary, written linear features on a Si wafer enable catalyst-free integration of carbon nanotubes into a Si-based nanodevice platform and in situ resolution of individual nucleation events. The graded nanotube arrays show reliable, reproducible, and competitive performance in electron field emission and biosensing nanodevices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Emerson E.,Lancaster University | Emerson E.,University of Sydney
Journal of Intellectual Disability Research | Year: 2013

People with intellectual disabilities have poorer health than their non-disabled peers. They are also more likely to be exposed to a wide range of environmental adversities in childhood. Research undertaken in the general population has demonstrated that exposure to environmental adversity in childhood can have an adverse impact on health and well-being across the life course. Recently, research in this area has added new breadth and depth to our understanding of: (1) the extent to which cumulative exposure to environmental adversities across the life course, but especially in early childhood, can reduce health and well-being; (2) the social, psychological and biological mediating pathways through which environmental adversities may impair health; (3) the processes associated with resilience and vulnerability in the face of exposure to adversity; and (4) the social significance of these effects in accounting for the magnitude of the inequalities in health that are apparent both between and within populations. This new knowledge is making a significant contribution to the development of social policies that seek to combine health gain with the reduction in health inequalities. This paper attempts to apply this knowledge to research aimed at understanding and improving the health and well-being of people with intellectual disabilities. © 2012 The Author. Journal of Intellectual Disability Research © 2012 John Wiley & Sons Ltd, MENCAP & IASSID. Source


Summary: The relationship between solar radiation capture and potential plant growth is of theoretical and practical importance. The key processes constraining the transduction of solar radiation into phyto-energy (i.e. free energy in phytomass) were reviewed to estimate potential solar-energy-use efficiency. Specifically, the out-put: input stoichiometries of photosynthesis and photorespiration in C3 and C4 systems, mobilization and translocation of photosynthate, and biosynthesis of major plant biochemical constituents were evaluated. The maintenance requirement, an area of important uncertainty, was also considered. For a hypothetical C3 grain crop with a full canopy at 30°C and 350 ppm atmospheric [CO2], theoretically potential efficiencies (based on extant plant metabolic reactions and pathways) were estimated at c. 0.041 J J-1 incident total solar radiation, and c. 0.092 J J-1 absorbed photosynthetically active radiation (PAR). At 20°C, the calculated potential efficiencies increased to 0.053 and 0.118 J J-1 (incident total radiation and absorbed PAR, respectively). Estimates for a hypothetical C4 cereal were c. 0.051 and c. 0.114 J J-1, respectively. These values, which cannot be considered as precise, are less than some previous estimates, and the reasons for the differences are considered. Field-based data indicate that exceptional crops may attain a significant fraction of potential efficiency. © The Author (2010). Journal compilation © New Phytologist Trust (2010). Source


Finfer S.,University of Sydney
Current Opinion in Critical Care | Year: 2013

Purpose of Review: Fluid resuscitation is a common intervention in acute medical practice. The optimum fluid for resuscitation remains hotly debated and it is likely to vary from one clinical situation to another. Human albumin solutions have been available since the 1940s, but their use varies greatly around the world. This review examines the current evidence for and against the use of albumin as a resuscitation fluid. Recent Findings: Fluid resuscitation with albumin has been compared to resuscitation with saline in large high-quality trials in adult ICU patients and in African children. Within overall equivalent effects, albumin may offer a slight mortality benefit in adult ICU patients with severe sepsis whilst increasing mortality in patients with traumatic brain injury. There are no recent high-quality trials comparing albumin to synthetic colloid solutions. In African children with febrile illness and compensated shock, the effects of bolus resuscitation with albumin and saline are similar, but both increase mortality compared to treatment that avoids fluid boluses. Summary: Fluid resuscitation with albumin is well tolerated and produces similar results to resuscitation with saline. Albumin should be avoided in patients with traumatic brain injury; possible benefits in adults with severe sepsis remain to be confirmed. Copyright © 2013 Lippincott Williams & Wilkins. Source


Gurevitch J.,State University of New York at Stony Brook | Fox G.A.,University of South Florida | Wardle G.M.,University of Sydney | Inderjit,University of Delhi | Taub D.,Southwestern University
Ecology Letters | Year: 2011

A general understanding of biological invasions will provide insights into fundamental ecological and evolutionary problems and contribute to more efficient and effective prediction, prevention and control of invasions. We review recent papers that have proposed conceptual frameworks for invasion biology. These papers offer important advances and signal a maturation of the field, but a broad synthesis is still lacking. Conceptual frameworks for invasion do not require invocation of unique concepts, but rather should reflect the unifying principles of ecology and evolutionary biology. A conceptual framework should incorporate multicausality, include interactions between causal factors and account for lags between various stages. We emphasize the centrality of demography in invasions, and distinguish between explaining three of the most important characteristics by which we recognize invasions: rapid local population increase, monocultures or community dominance, and range expansion. As a contribution towards developing a conceptual synthesis of invasions based on these criteria, we outline a framework that explicitly incorporates consideration of the fundamental ecological and evolutionary processes involved. The development of a more inclusive and mechanistic conceptual framework for invasion should facilitate quantitative and testable evaluation of causal factors, and can potentially lead to a better understanding of the biology of invasions. © 2011 Blackwell Publishing Ltd/CNRS. Source


Hunter D.J.,University of Sydney
Best Practice and Research: Clinical Rheumatology | Year: 2011

The pathogenesis of osteoarthritis (OA) appears to be the result of a complex interplay between mechanical, cellular and biochemical forces. Obesity is the strongest risk factor for disease onset in the knee, and mechanical factors dominate the risk for disease progression. OA is a highly prevalent and disabling disease. The current pre-eminent focus in OA research and clinical practice is on persons with established radiographic symptomatic disease. This is the very end-stage of disease genesis, and modern therapies hence are largely palliative. In an effort to mitigate the rising tide of increasing OA prevalence and disease impact, we need to focus more on preventing the onset of disease and modifying the structural progression of OA. Greater therapeutic attention to the important role of mechanical factors, joint injury and obesity in OA etiopathogenesis, is required if we are to find ways of reducing the public health impact of this condition. © 2011 Elsevier Ltd. All rights reserved. Source


Nankivell B.J.,University of Sydney | Kuypers D.R.,Catholic University of Leuven
The Lancet | Year: 2011

Kidney transplantation is the best possible treatment for many patients with end-stage renal failure, but progressive dysfunction and eventual allograft loss with return to dialysis is associated with increased mortality and morbidity. Immune injury from acute or chronic rejection and non-immune causes, such as nephrotoxicity from calcineurin inhibitors, ischaemia-reperfusion injury, recurrent glomerular disease, and allograft BK viral infection, are potential threats. Serial monitoring of renal function enables early recognition of chronic allograft dysfunction, and investigations such as therapeutic drug concentrations, urinalysis, imaging, and a diagnostic biopsy should be undertaken before irreversible nephron loss has occurred. Specific interventions targeting the pathophysiological cause of dysfunction include strengthening of immunosuppression for chronic rejection, or calcineurin inhibitor minimisation, substitution, or elimination if nephrotoxicity dominates. Recommended proactive preventive measures are control of hypertension, proteinuria, dyslipidaemia, diabetes, smoking, and other comorbidities. Strategies to maintain transplant function and improve long-term graft survival are important goals of translational research. © 2011 Elsevier Ltd. Source


Haire B.G.,University of Sydney
Developing World Bioethics | Year: 2011

This article examines the relationship between bioethics and the therapeutic standards in HIV prevention research in the developing world, focusing on the closure of the pre-exposure prophylaxis (PrEP) trials in the early 2000s. I situate the PrEP trials in the historical context of the vertical transmission debates of the 1990s, where there was protracted debate over the use of placebos despite the existence of a proven intervention. I then discuss the dramatic improvement in the clinical management of HIV and the treatment access movement, and consider how these contexts have influenced research practice. I argue that as HIV prevention trials oblige researchers to observe the rate at which vulnerable people under their care acquire HIV, there is an obligation to provide antiretroviral treatment to seroconverters and other health care benefits that fall within the scope of researchers' entrustment, both to avoid exploitation and to enact reciprocal justice. I argue against propositions that the obligations to provide specific benefits are vague, fall only upon researchers and sponsors, and create injustices by privileging the few over the many. Finally, I contend that the realisation of a broader standard of care in HIV prevention research broadens the role of research from being a simple tool to produce knowledge to a complex intervention that can play a part in the reduction of health disparities. © 2011 Blackwell Publishing Ltd.. Source


Leung S.Y.,University of Sydney
Drug and Alcohol Review | Year: 2011

Issues. Road crashes contribute significantly to the total burden of injury in Australia, with the risk of injury being associated with the presence of drugs and/or alcohol in the driver's blood. Increasingly, some of the most commonly detected drugs include prescription medicines, the most notable of these being benzodiazepines and opioids. However, there is a paucity of experimental research into the effects of prescribed psychoactive drugs on driving behaviours. Approach. This paper provides an overview of experimental studies investigating the effects of prescribed doses of benzodiazepines and opioids on driving ability, and points to future directions for research. Key Findings. There is growing epidemiological evidence linking the therapeutic use of benzodiazepines and opioids to an increased crash risk. However, the current experimental literature remains unclear. Limitations to study methodologies have resulted in inconsistent findings. Implications. Limited experimental evidence exists to inform policy and guidelines regarding fitness-to-drive for patients taking prescribed benzodiazepines and opioids. Conclusion. Further experimental research is required to elucidate the effects of these medications on driving, under varying conditions and in different medical contexts. This will ensure that doctors prescribing benzodiazepines and opioids are well informed, and can appropriately advise patients of the risks associated with driving whilst taking these medications. [Leung SY. Benzodiazepines, opioids and driving: An overview of the experimental research. Drug Alcohol Rev 2011;30:281-286] © 2011 Australasian Professional Society on Alcohol and other Drugs. Source


Verstraete D.,University of Sydney
International Journal of Hydrogen Energy | Year: 2013

Hydrogen is since long seen as an outstanding candidate for an environmentally acceptable, future aviation fuel. Given that most comprehensive studies on its use in aviation were performed over two decades ago, the current article evaluates its potential as a fuel for long range transport aircraft at current and future technology levels. The investigations show that hydrogen has the potential to reduce the energy utilisation of long range transport aircraft by approximately 11%. The use of hydrogen namely allows a much smaller wing area and span since the wing size is not restricted by its fuel storage capacity. At a given price per unit energy content, the smaller wings lead to a reduction of around 30% in take-off gross weight and 3% in direct operating costs for a given fuel price per energy content. The hydrogen-fuelled aircraft are furthermore slightly more sensitive to a possible reduction in operating empty weight in the future and 20% less sensitive to further improvements in engine thrust specific fuel consumption. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source


Baird M.E.,University of Sydney
Journal of Plankton Research | Year: 2010

A size-resolved pelagic ecosystem model has been developed based on a continuous (with size) set of model equations and using allometric relationships to specify size-dependent physiological rates. Numerical experiments with identical model equations but different initial conditions and size-class distributions are used to investigate inherent limits to prediction of instantaneous state from an initial condition. The simulations have relatively constant physical forcings, such as solar radiation, to emphasize the dynamical properties of the size-resolved model. Initial condition experiments show that perturbations of 1, 0.1, 0.01, 0.001 and 0.0001 of the initial biomass of individual size-classes from a flat size spectrum lead to equal spread of model trajectories. The greatest divergence of trajectories occurs when a 2.7 m equivalent spherical radius phytoplankton size-class blooms. This divergence has a finite-time Lyapunov exponent of 0.21 day-1 and a prediction time of 33 days for a precision of 10-3 mol N m-3. Large member ensembles can approximately halve the effect of growth of initial condition perturbations on prediction. Further numerical experiments are undertaken with the mean body weight at which size-classes are solved perturbed randomly with a standard deviation of 0.15, 0.015, 0.0015 and 0.00015 of the unperturbed body weight. The greatest effect, which dominates the = 0.15 and 0.015 ensembles, occurs when the perturbations of the size-class distribution add and/or remove predator-prey links. These results provide a cautionary warning for the prediction of instantaneous states using complex pelagic ecosystems that are displaced from a stable oscillation and for which biological state is not dominated by physical processes. © The Author 2010. Source


Fernando S.L.,University of Sydney
Australasian Journal of Dermatology | Year: 2012

Acute generalised exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction and is caused by drugs in >90% of cases. It is rare, with an incidence of 1-5 patients per million per year. The clinical manifestations are characterised by fever and the rapid appearance of disseminated sterile pustules 3-5 days after the commencement of treatment. It is accompanied by marked neutrophilia. Mucous membranes are not typically involved. The drugs conferring the highest risk of AGEP according to the EuroSCAR study are aminopenicillins, pristinamycin, hydroxychloroquine, antibacterial sulphonamides, terbinafine and diltiazem. The pathogenesis of AGEP involves the initial influx of CD8 cytotoxic T-cells resulting in the apoptosis of keratinocytes and formation of vesicles. Then CXCL-8-producing and granulocyte macrophage-colony stimulating factor-producing CD4 cells enter the epidermis, resulting in neutrophil mediated inflammation and the formation of pustules. As a result, the histology reveals intraepidermal, usually subcorneal, pustules and an accompanying neutrophilic and lymphocytic infiltrate. Epicutaneous patch testing may also support the diagnosis by causing a localised pustular reaction 48-96 h after the offending drug is applied. The condition usually resolves by 15 days after the causative drug is withdrawn but oral corticosteroid therapy may be necessary in some individuals. The mortality rate is up to 5% and mostly occurs in elderly people who have significant comorbidities. © 2011 The Australasian College of Dermatologists. Source


Green M.A.,University of Sydney
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2013

The vast majority of photovoltaic (PV) solar cells produced to date have been based on silicon wafers, with this dominance likely to continue well into the future. The surge in manufacturing volume over the last decade has resulted in greatly decreased costs. Multiple companies are now well below the US1W -1 module manufacturing cost benchmark that was once regarded as the lowest possible with this technology. Despite these huge cost reductions, there is obvious scope for much more, as the polysilicon source material becomes more competitively priced, the new 'quasi-mono' and related controlled crystallization directional solidification processes are brought fully online, the sizes of ingot produced this way increase, wafer slicing switches to much quicker diamond impregnated approaches and cell conversion efficiencies increase towards the 25 per cent level. This makes the US Government's 'SunShot' target of US 1W-1 installed system cost by 2020 very achievable with silicon PVs. Paths to lower cost beyond this point are also explored. Copyright © The Royal Society 2013. Source


Fu D.,University of Sydney
Frontiers in Oncology | Year: 2013

P-glycoprotein (P-gp), an ATP-binding cassette, is able to transport structurally and chemically unrelated substrates. Over-expression of P-gp in cancer cells significantly decreases the intercellular amount of anticancer drugs, and results in multidrug resistance in cancer cells, a major obstacle in cancer chemotherapy. P-gp is mainly localized on the plasma membrane and functions as a drug efflux pump; however, P-gp is also localized in many intracellular compartments, such as endoplasmic reticulum, Golgi, endosomes, and lysosomes. P-gp moves between the intracellular compartments and the plasma membrane in a microtubule-actin dependent manner. This review highlights our current understanding of (1) the intracellular localization of P-gp; (2) the traffic and cycling pathways among the cellular compartments as well as between these compartments and the plasma membrane; and (3) the cellular factors regulating P-gp traffic and cycling. This review also presents a potential implication in overcoming P-gp-mediated multidrug resistance by targeting P-gp traffic and cycling pathways and impairing P-gp localization on the plasma membrane. © 2013 Fu. Source


Graeber M.B.,University of Sfax | Graeber M.B.,University of Sydney | Streit W.J.,University of Florida
Acta Neuropathologica | Year: 2010

The past 20 years have seen a gain in knowledge on microglia biology and microglia functions in disease that exceeds the expectations formulated when the microglia "immune network" was introduced. More than 10,000 articles have been published during this time. Important new research avenues of clinical importance have opened up such as the role of microglia in pain and in brain tumors. New controversies have also emerged such as the question of whether microglia are active or reactive players in neurodegenerative disease conditions, or whether they may be victims themselves. Premature commercial interests may be responsible for some of the confusion that currently surrounds microglia in both the Alzheimer and Parkinson's disease research fields. A critical review of the literature shows that the concept of "(micro)glial inflammation" is still open to interpretation, despite a prevailing slant towards a negative meaning. Perhaps the most exciting foreseeable development concerns research on the role of microglia in synaptic plasticity, which is expected to yield an answer to the question whether microglia are the brain's electricians. This review provides an analysis of the latest developments in the microglia field. © 2009 Springer-Verlag. Source


Mattes T.E.,University of Iowa | Alexander A.K.,University of Iowa | Coleman N.V.,University of Sydney
FEMS Microbiology Reviews | Year: 2010

Extensive use and inadequate disposal of chloroethenes have led to prevalent groundwater contamination worldwide. The occurrence of the lesser chlorinated ethenes [i.e. vinyl chloride (VC) and cis-1,2-dichloroethene (cDCE)] in groundwater is primarily a consequence of incomplete anaerobic reductive dechlorination of the more highly chlorinated ethenes (tetrachloroethene and trichloroethene). VC and cDCE are toxic and VC is a known human carcinogen. Therefore, their presence in groundwater is undesirable. In situ cleanup of VC- and cDCE-contaminated groundwater via oxidation by aerobic microorganisms is an attractive and potentially cost-effective alternative to physical and chemical approaches. Of particular interest are aerobic bacteria that use VC or cDCE as growth substrates (known as the VC- and cDCE-assimilating bacteria). Bacteria that grow on VC are readily isolated from contaminated and uncontaminated environments, suggesting that they are widespread and influential in aerobic natural attenuation of VC. In contrast, only one cDCE-assimilating strain has been isolated, suggesting that their environmental occurrence is rare. In this review, we will summarize the current knowledge of the physiology, biodegradation pathways, genetics, ecology, and evolution of VC- and cDCE-assimilating bacteria. Techniques (e.g. PCR, proteomics, and compound-specific isotope analysis) that aim to determine the presence, numbers, and activity of these bacteria in the environment will also be discussed. © 2010 Federation of European Microbiological Societies Published by Blackwell Publishing Ltd. All rights reserved. Source


Egr-1 is implicated in the pathogenesis of myocardial ischemia-reperfusion injury. The aim of this study was to ascertain the effectiveness of intracoronary delivery of DNAzyme targeting the transcription factor Egr-1 at reperfusion following experimental myocardial ischemia. Functional DNAzyme targeting Egr-1 or a size-matched scrambled control were delivered via the intracoronary route immediately on reperfusion after 60 minutes' balloon occlusion of the left anterior descending coronary artery in a pig model of myocardial I/R injury (n=7 per treatment group). Heart function and extent of myocardial infarction were determined following intervention by echocardiography and cardiac magnetic resonance imaging, respectively. Hearts were removed and examined for molecular and histological markers of inflammation and apoptosis. Administration of functional DNAzyme led to an overall decrease in the expression of inflammatory markers including intracellular adhesion molecule-1, tissue factor, and complement 3, with associated decreases in the extent of neutrophil infiltration, oxidative damage, and subsequent apoptosis within the infarct border zone. Functional significance was indicated by an increase in salvaged left ventricular myocardium (P=0.012), ejection fraction (P=0.002), and fractional area change (P=0.039) in the functional DNAzyme-treated group compared with the control. Egr-1 silencing through intracoronary delivery of a targeting DNAzyme at the time of reperfusion following acute myocardial ischemia decreases myocardial inflammation and apoptosis leading to improved cardiac function. Source


Nguyen G.D.,University of Sydney
International Journal of Solids and Structures | Year: 2011

We present a damage model for softening materials with evolving nonlocal interactions. The thermodynamic implications and the material stability issue are addressed. The proposed nonlocal averaging scheme provides the obtained constitutive models with an evolving nonlocal interaction which is activated only when damage occurs. In the analysis of structures made of quasi-brittle materials, this feature helps not only to overcome some issues with the incorrect initiation of damage but also to better control the evolving size of the active fracture process zone. This is an essential feature that is usually not considered in depth in many existing nonlocal approaches to the continuum modelling of quasi-brittle fracture. Numerical examples are given to demonstrate features of the proposed modelling approach. © 2011 Elsevier Ltd. All rights reserved. Source


Lupton D.,University of Sydney
Health, Risk and Society | Year: 2013

While it is generally accepted in writings on the sociocultural aspects of risk that risk and emotion are interrelated, this relationship remains under-theorised. The literature on the affect heuristic model in psychology and research on voluntary risk-taking or edgework in sociology have dominated previous writings on risk and emotion. This essay draws on scholarship from affect theory, cultural studies and cultural geography to argue that both emotion and risk are inevitably and always configured via social and cultural processes and through interaction with others' bodies, material objects, space and place. Furthermore, both emotions and risk judgements and understandings, rather than being located within the individual, are fluid, shared and collective. The concept of the 'emotion-risk assemblage' is introduced to denote a heterogeneous configuration of ideational and material, human and non-human elements that is subject to constant flux and change. I illustrate this analysis with some observations about the emotional elements of risk in the context of public health practice. I argue that although public health discourse represents the field as dispassionately expert and rational, its practices frequently engage affective strategies that covertly, and sometimes overtly, incite or reproduce stigmatisation, marginalisation, blaming, shame, disgust, fear and exclusion of certain social groups. © 2013 Taylor & Francis. Source


Baxter R.C.,University of Sydney
Journal of Cell Communication and Signaling | Year: 2013

In addition to its important role in the regulation of somatic growth by acting as the major circulating transport protein for the insulin-like growth factors (IGFs), IGF binding protein-3 (IGFBP-3) has a variety of intracellular ligands that point to its function within major signaling pathways. The discovery of its interaction with the retinoid X receptor has led to the elucidation of roles in regulating the function of several nuclear hormone receptors including retinoic acid receptor-α, Nur77 and vitamin D receptor. Its interaction with the nuclear hormone receptor peroxisome proliferator-activated receptor-γ is believed to be involved in regulating adipocyte differentiation, which is also modulated by IGFBP-3 through an interaction with TGFβ/Smad signaling. IGFBP-3 can induce apoptosis alone or in conjunction with other agents, and in different systems can activate caspases -8 and -9. At least two unrelated proteins (LRP1 and TMEM219) have been designated as receptors for IGFBP-3, the latter with a demonstrated role in inducing caspase-8-dependent apoptosis. In contrast, IGFBP-3 also has demonstrated roles in survival-related functions, including the repair of DNA double-strand breaks through interaction with the epidermal growth factor receptor and DNA-dependent protein kinase, and the induction of autophagy through interaction with GRP78. The ability of IGFBP-3 to modulate the balance between pro-apoptotic and pro-survival sphingolipids by regulating sphingosine kinase 1 and sphingomyelinases may be integral to its role at the crossroads between cell death and survival in response to a variety of stimuli. The pleiotropic nature of IGFBP-3 activity supports the idea that IGFBP-3 itself, or pathways with which it interacts, should be investigated as targets of therapy for a variety of diseases. © 2013 The International CCN Society. Source


Roberts T.V.,University of Sydney
Clinical & experimental ophthalmology | Year: 2012

One of the key responsibilities of professional bodies, such as the Royal Australian and New Zealand College of Ophthalmologists, is to determine, teach and assess the competencies required for trainees to reach an expert level. Vocational training programs (VTP) need to incorporate advances in educational research and reflect changes in generational thinking and learning styles to provide the most optimal learning environment to meet the desired educational outcomes. This paper seeks to introduce some of the important concepts of adult educational theory and to explain how they connect to four strategic areas in the development and implementation of the VTP: 1 What are the learning needs of trainees? 2 What educational methods best address these needs? 3 What assessment methods best test the acquisition of the desired learning outcomes? 4 What are the needs of supervisors and teachers? © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists. Source


Valenzuela T.,University of Sydney
Journal of the American Medical Directors Association | Year: 2012

Objective: To provide a synthesis of the evidence from clinical trials to determine whether progressive resistance training, as a single exercise intervention, improves strength and functional performance in older institutionalized adults. Methods: A comprehensive systematic database search for randomized controlled trials was performed, including AMED, CINAHL, COCHRANE, and all EMB reviews: Cochrane DSR, ACP Journal Club, DARE, MEDLINE, PREMEDLINE, and PsycINFO, completed in July 2011. Studies were then assessed for potential inclusion. Study quality indicators, cohort characteristics, training intervention, muscle strength, and functional performance outcomes were extracted. Results: Thirteen studies were reviewed; the mean cohort age range was 80 to 89 years. In general, the quality of the reviewed studies was moderately robust; an average of 9 of 11 quality criteria were accounted for in the reviewed literature. Significant improvements were found in muscle strength outcomes and functional performance outcomes, including chair to stand time, stair climbing, gait speed, balance, and functional capacity following progressive resistance training interventions. Conclusions: Significant improvements in muscle strength and functional performance occur in response to progressive resistance training exercise, despite advanced age, presence of chronic diseases, extremely sedentary habits, and functional disabilities in older institutionalized individuals. Therefore, the incorporation of a progressive resistance training exercise program is an effective means to preserve independence levels by maintaining or improving the ability to perform activities of daily living and the implementation of this type of exercise program should be promoted and incorporated into the recreational schedules of long term care institutions. © 2012 American Medical Directors Association, Inc. Source


Broadbent E.,University of Auckland | Donkin L.,University of Sydney | Stroh J.C.,University of Marburg
Diabetes Care | Year: 2011

OBJECTIVE - To investigate diabetic patients' perceptions of illness and treatments, and explore relationships to adherence and blood glucose control. RESEARCH DESIGN ANDMETHODS - Forty-nine type 1 and one hundred and eight type 2 diabetic patients completed questionnaires assessing illness perceptions, treatment beliefs, and adherence to medications, diet, and exercise. Blood glucose control was assessed fromblood tests. RESULTS - Patients rated medication more important than diet and exercise, and reported higher adherence to medications. Insulin was perceived as more helpful for diabetes, while antihypertensives and cholesterol medication were perceived more helpful for preventing heart problems. Perceptions were associated with adherence to insulin, cholesterol and antihypertensive medications, exercise, and diet. Blood glucose control in type 1 diabetic patients was associated with insulin adherence and perceived personal control, and in type 2 diabetic patients to being prescribed insulin or antihypertensives, and perceived personal control. CONCLUSIONS - Patients hold specificmentalmodels about diabetes treatments, which are associated with adherence. © 2011 by the American Diabetes Association. Source


Orr R.,University of Sydney
European Journal of Physical and Rehabilitation Medicine | Year: 2010

Background and aim. The aim of this review was to examine the contribution of muscle weakness to postural stability in healthy older adults and to determine the relationship between muscle weakness and balance impairment. Design. A comprehensive search of electronic databases was performed from earliest record to February 2010. All study designs that contained a measure of muscle strength or muscle power and balance performance in older adults were examined. Population. Participants (z60 years) included healthy, community-dwelling cohorts, nursing home residents, frail, mobility- or functionally-limited adults but not persons with pathophysiological conditions or disease. Methods. Interventions of progressive resistance or power training to increase muscle strength/power were examined but studies that included balance or multimodal training were excluded. Results. A total of 74 papers were eligible for review; 45 with strength measures only; 5 with power measures only and 24 papers containing both strength and power outcomes. Overall, 54% (27/50) of studies reported significantly improved strength and balance measures and 73% (16/22) showed improved power and balance following resistance/power training intervention, whereas 84% and 86% of cross sectional studies observed significant associations between balance and strength/power outcomes respectively. Conclusion. The findings suggest that there is some evidence for the contribution of muscle strength and muscle power to balance performance in older adults. There is, however, weak evidence for the cause and effect relationship between muscle function and balance performance. Clinical Rehabilitation Impact. Inconsistencies in the literature can be attributed to methodological limitations. Source


Lovibond P.F.,University of New South Wales | Colagiuri B.,University of Sydney
Psychological Science | Year: 2013

Reward-associated cues are known to influence motivation to approach both natural and man-made rewards, such as food and drugs. However, the mechanisms underlying these effects are not well understood. To model these processes in the laboratory with humans, we developed an appetitive Pavlovian-instrumental transfer procedure with a chocolate reward. We used a single unconstrained response that led to an actual rather than symbolic reward to assess the strength of reward motivation. Presentation of a chocolate-paired cue, but not an unpaired cue, markedly enhanced instrumental responding over a 30-s period. The same pattern was observed with 10-s and 30-s cues, showing that close cue-reward contiguity is not necessary for facilitation of reward-directed action. The results confirm that reward-related cues can instigate voluntary action to obtain that reward. The effectiveness of long-duration cues suggests that in clinical settings, attention should be directed to both proximal and distal cues for reward. © The Author(s) 2013. Source


Water movement from the xylem to stomata is poorly understood. There is still no consensus about whether apoplastic or symplastic pathways are more important, and recent work suggests vapour diffusion may also play a role. The objective of this study was to estimate the proportions of hydraulic conductance outside the bundle sheath contributed by apoplastic, symplastic and gas phase pathways, using a novel analytical framework based on measurable anatomical and biophysical parameters. The calculations presented here suggest that apoplastic pathways provide the majority of conductance outside the bundle sheath under most conditions, whereas symplastic pathways contribute only a small proportion. The contributions of apoplastic and gas phase pathways vary depending on several critical but poorly known or highly variable parameters namely, the effective Poiseuille radius for apoplastic bulk flow, the thickness of cell walls and vertical temperature gradients within the leaf. The gas phase conductance should increase strongly as the leaf centre becomes warmer than the epidermis - providing up to 44% of vertical water transport for a temperature gradient of 0.2K. These results may help to explain how leaf water transport is influenced by light absorption, temperature and differences in leaf anatomy among species. © 2014 John Wiley & Sons Ltd. Source


Lin C.W.,University of Sydney
Cochrane database of systematic reviews (Online) | Year: 2012

Rehabilitation after ankle fracture can begin soon after the fracture has been treated, either surgically or non-surgically, by the use of different types of immobilisation that allow early commencement of weight-bearing or exercise. Alternatively, rehabilitation, including the use of physical or manual therapies, may start following the period of immobilisation. This is an update of a Cochrane review first published in 2008. To assess the effects of rehabilitation interventions following conservative or surgical treatment of ankle fractures in adults. We searched the Specialised Registers of the Cochrane Bone, Joint and Muscle Trauma Group and the Cochrane Rehabilitation and Related Therapies Field, CENTRAL via The Cochrane Library (2011 Issue 7), MEDLINE via PubMed, EMBASE, CINAHL, PEDro, AMED, SPORTDiscus and clinical trials registers up to July 2011. In addition, we searched reference lists of included studies and relevant systematic reviews. Randomised and quasi-randomised controlled trials with adults undergoing any interventions for rehabilitation after ankle fracture were considered. The primary outcome was activity limitation. Secondary outcomes included quality of life, patient satisfaction, impairments and adverse events. Two review authors independently screened search results, assessed risk of bias and extracted data. Risk ratios and 95% confidence intervals (95% CIs) were calculated for dichotomous variables, and mean differences or standardised mean differences and 95% CIs were calculated for continuous variables. End of treatment and end of follow-up data were presented separately. For end of follow-up data, short term follow-up was defined as up to three months after randomisation, and long-term follow-up as greater than six months after randomisation. Meta-analysis was performed where appropriate. Thirty-eight studies with a total of 1896 participants were included. Only one study was judged at low risk of bias. Eight studies were judged at high risk of selection bias because of lack of allocation concealment and over half the of the studies were at high risk of selective reporting bias.Three small studies investigated rehabilitation interventions during the immobilisation period after conservative orthopaedic management. There was limited evidence from two studies (106 participants in total) of short-term benefit of using an air-stirrup versus an orthosis or a walking cast. One study (12 participants) found 12 weeks of hypnosis did not reduce activity or improve other outcomes.Thirty studies investigated rehabilitation interventions during the immobilisation period after surgical fixation. In 10 studies, the use of a removable type of immobilisation combined with exercise was compared with cast immobilisation alone. Using a removable type of immobilisation to enable controlled exercise significantly reduced activity limitation in five of the eight studies reporting this outcome, reduced pain (number of participants with pain at the long term follow-up: 10/35 versus 25/34; risk ratio (RR) 0.39, 95% confidence interval (CI) 0.22 to 0.68; 2 studies) and improved ankle dorsiflexion range of motion. However, it also led to a higher rate of mainly minor adverse events (49/201 versus 20/197; RR 2.30, 95% CI 1.49 to 3.56; 7 studies).During the immobilisation period after surgical fixation, commencing weight-bearing made a small improvement in ankle dorsiflexion range of motion (mean difference in the difference in range of motion compared with the non-fractured side at the long term follow-up 6.17%, 95% CI 0.14 to 12.20; 2 studies). Evidence from one small but potentially biased study (60 participants) showed that neurostimulation, an electrotherapy modality, may be beneficial in the short-term. There was little and inconclusive evidence on what type of support or immobilisation was the best. One study found no immobilisation improved ankle dorsiflexion and plantarflexion range of motion compared with cast immobilisation, but another showed using a backslab improved ankle dorsiflexion range of motion compared with using a bandage.Five studies investigated different rehabilitation interventions following the immobilisation period after either conservative or surgical orthopaedic management. There was no evidence of effect for stretching or manual therapy in addition to exercise, or exercise compared with usual care. Source


Baxter R.C.,University of Sydney
Gene | Year: 2015

In addition to its actions outside the cell, cellular uptake and nuclear import of insulin-like growth factor binding protein-3 (IGFBP-3) has been recognized for almost two decades, but knowledge of its nuclear actions has been slow to emerge. IGFBP-3 has a functional nuclear localization signal and interacts with the nuclear transport protein importin-β. Within the nucleus IGFBP-3 appears to have a role in transcriptional regulation. It can bind to the nuclear receptor, retinoid X receptor-α and several of its dimerization partners, including retinoic acid receptor, vitamin D receptor (VDR), and peroxisome proliferator-activated receptor-γ (PPARγ). These interactions modulate the functions of these receptors, for example inhibiting VDR-dependent transcription in osteoblasts and PPARγ-dependent transcription in adipocytes. Nuclear IGFBP-3 can be detected by immunohistochemistry in cancer and other tissues, and its presence in the nucleus has been shown in many cell culture studies to be necessary for its pro-apoptotic effect, which may also involve interaction with the nuclear receptor Nur77, and export from the nucleus. IGFBP-3 is p53-inducible and in response to DNA damage, forms a complex with the epidermal growth factor receptor (EGFR), translocating to the nucleus to interact with DNA-dependent protein kinase. Inhibition of EGFR kinase activity or downregulation of IGFBP-3 can inhibit DNA double strand-break repair by nonhomologous end joining. IGFBP-3 thus has the ability to influence many cell functions through its interactions with intranuclear pathways, but the importance of these interactions in vivo, and their potential to be targeted for therapeutic benefit, require further investigation. © 2015 Elsevier B.V. Source


Ralph A.R.,University of Sydney | Lucas R.M.,Australian National University | Norval M.,University of Edinburgh
The Lancet Infectious Diseases | Year: 2013

Improved understanding of the association between tuberculosis and vitamin D is needed to inform clinical practice. Vitamin D has both immunostimulatory and immunosuppressive effects relevant to human antimycobacterial responses. Ultraviolet radiation, the main source of vitamin D, also induces immunomodulation and could affect the relation between vitamin D and tuberculosis. Clinical trials of vitamin D supplementation in patients with tuberculosis have produced largely negative results, prompting the review of dosing regimens-an explanation for low 25-hydroxyvitamin D status in patients with active tuberculosis is also needed. The reporting of vitamin D deficiency needs to address assay inaccuracies, rising thresholds to define sufficiency, and scarce knowledge of the concentrations needed for optimum immune responses. Future research to measure the effect of the inflammatory setting on serum concentrations of 25-hydroxyvitamin D, at tuberculosis diagnosis and during recovery, could help to account for 25-hydroxyvitamin D changes in these concentrations in patients with tuberculosis. Studies into the role of vitamin D supplementation in latent tuberculosis justify clinical trials in this population, but pose methodological challenges. Vitamin D trials in patients with active tuberculosis should be done in well selected populations using adequate vitamin D doses, although such doses remain undefined. © 2013 Elsevier Ltd. Source


Szakonyi D.,John Innes Center | Szakonyi D.,Ghent University | Byrne M.E.,University of Sydney
Plant Journal | Year: 2011

Summary Ribosomal proteins are integral to ribosome biogenesis, and function in protein synthesis. In higher eukaryotes, loss of cytoplasmic ribosomal proteins results in a reduced growth rate as well as developmental defects. To what extent and how ribosomal proteins affect development is currently not known. Here we describe a semi-dominant mutation in the cytoplasmic ribosomal protein gene RPL27aC that affects multiple aspects of plant shoot development, including leaf patterning, inflorescence and floral meristem function, and seed set. In the embryo, RPL27aC is required to maintain the growth rate and for the transition from radial to bilateral symmetry associated with initiation of cotyledons. rpl27ac-1d embryos undergo stereotypical patterning to establish a globular embryo. However, a temporal delay in initiation and outgrowth of cotyledon primordia leads to development of an enlarged globular embryo prior to apical domain patterning. Defects in embryo development are coincident with tissue-specific ectopic expression of the shoot meristem genes SHOOT MERISTEMLESS (STM) and CUP-SHAPED COTYLEDON2 (CUC2), in addition to delayed expression of the abaxial gene FILAMENTOUS FLOWER (FIL) and mis-regulation of the auxin efflux effector PIN-FORMED1 (PIN1). Genetic interactions with other ribosomal protein mutants indicate that RPL27aC is a component of the ribosome. We propose that RPL27aC regulates discrete developmental events by controlling spatial and temporal expression of developmental patterning genes via an as yet undefined process involving the ribosome. © 2010 The Authors. The Plant Journal © 2010 Blackwell Publishing Ltd. Source


O'Malley M.A.,University of Sydney
Studies in History and Philosophy of Science Part C :Studies in History and Philosophy of Biological and Biomedical Sciences | Year: 2013

Much is being written these days about integration, its desirability and even its necessity when complex research problems are to be addressed. Seldom, however, do we hear much about the failure of such efforts. Because integration is an ongoing activity rather than a final achievement, and because today's literature about integration consists mostly of manifesto statements rather than precise descriptions, an examination of unsuccessful integration could be illuminating to understand better how it works. This paper will examine the case of prokaryote phylogeny and its apparent failure to achieve integration within broader tree-of-life accounts of evolutionary history (often called 'universal phylogeny'). Despite the fact that integrated databases exist of molecules pertinent to the phylogenetic reconstruction of all lineages of life, and even though the same methods can be used to construct phylogenies wherever the organisms fall on the tree of life, prokaryote phylogeny remains at best only partly integrated within tree-of-life efforts. I will examine why integration does not occur, compare it with integrative practices in animal and other eukaryote phylogeny, and reflect on whether there might be different expectations of what integration should achieve. Finally, I will draw some general conclusions about integration and its function as a 'meta-heuristic' in the normative commitments guiding scientific practice. © 2012 Elsevier Ltd. Source


Schonrock N.,University of Sydney
Journal of molecular neuroscience : MN | Year: 2012

MicroRNAs (miRNAs) are small non-coding RNA regulators of protein synthesis that are essential for normal brain development and function. Their profiles are significantly altered in neurodegenerative diseases such as Alzheimer's disease (AD) that is characterized by amyloid-β (Aβ) and tau deposition in brain. How deregulated miRNAs contribute to AD is not understood, as their dysfunction could be both a cause and a consequence of disease. To address this question we had previously profiled miRNAs in models of AD. This identified miR-9 and -181c as being down-regulated by Aβ in hippocampal cultures. Interestingly, there was a remarkable overlap with those miRNAs that are deregulated in Aβ-depositing APP23 transgenic mice and in human AD tissue. While the Aβ precursor protein APP itself is a target of miRNA regulation, the challenge resides in identifying further targets. Here, we expand the repertoire of miRNA target genes by identifying the 3' untranslated regions (3' UTRs) of TGFBI, TRIM2, SIRT1 and BTBD3 as being repressed by miR-9 and -181c, either alone or in combination. Taken together, our study identifies putative target genes of miRNAs miR-9 and 181c, which may function in brain homeostasis and disease pathogenesis. Source


Chapman M.G.,University of Sydney
Marine Ecology Progress Series | Year: 2013

Urban shorelines are threatened by 'armouring' from anthropological constructions that are replacing the natural intertidal habitat at an increasing rate. In places, intertidal boulder fields are listed as threatened habitats in urbanized areas. On sheltered shores, these habitats support diverse assemblages, including specialist species, many of which are rare that predominantly or only live under boulders. Activities associated with urbanization threaten these habitats and this specialist biota. Thus, there is a need to learn how to restore these habitats for these assemblages. Most studies of intertidal habitat replacement have focused on habitats dominated by large plants, e.g. mangroves, or by animals that create habitat, e.g. oyster reefs, although previous work has shown that invertebrates will colonize newly created patches of quarried boulders. Here, colonization of newly created patches, either of 50 (50B patches) or 100 (100B patches) quarried boulders replicated in 2 intertidal sites in New South Wales, Australia, is described. Rare specialist and common widespread animals readily colonized these patches, with most of the species randomly distributed between the patch sizes. Of those that did show differences between patch sizes, some species were more abundant on the 100B patches, whereas other related species showed the opposite pattern. After a few weeks, most of the species were as abundant in these patches as on natural boulders. There was no consistent tendency for abundances or diversity to be smaller on the artificial patches than on natural boulders. It is clearly cheap and easy to build an intertidal boulder habitat which is rapidly used by many different common and rare animals. This may assist with the conservation of these fauna living in urbanized environments, where much of their natural habitat has been lost. © Inter-Research 2013. Source


Evans N.,University of Sydney
Journal of Paediatrics and Child Health | Year: 2012

Debate about the importance of the preterm patent ductus arteriosus (PDA) remains unresolved. Ultrasound studies of PDA have suggested that the haemodynamic impact may be much earlier after birth than previously thought, but we still do not know when to treat a PDA. Studies that have tested symptomatic or pre-symptomatic treatment are mainly historical and have not tested the effect of no treatment. Prophylactic treatment is the best studied regimen, but improvements in some short-term outcomes do not translate to any difference in longer term outcomes. Neonatologists have been reluctant to engage in trials that test treatment against not treating at all or very rarely. Targeting treatment on the basis of the early post-natal constrictive response of the duct is currently being tested as a possible strategy. © 2012 Paediatrics and Child Health Division (Royal Australasian College of Physicians). Source


Griffiths P.E.,University of Sydney
Developmental Psychobiology | Year: 2013

The integration of concepts from evolutionary developmental biology, such as the homology concept, into developmental psychobiology has great potential. However, evolutionary developmental biology is an attempt to integrate evolutionary and developmental explanation and developmental psychobiology has traditionally been concerned to avoid conflating these two kinds of explanation. This article examines a recent attempt to explain development in terms of "inherited information." The resulting explanation is an evolutionary explanation of development of a kind typical of evolutionary developmental biology. But its proponent mistakes it for an actual developmental explanation. Any integration of evolutionary developmental biology and developmental psychobiology should pay close attention to longstanding concerns about conflating evolutionary and developmental explanations. © 2012 Wiley Periodicals, Inc. Source


Stening R.J.,University of New South Wales | Winch D.E.,University of Sydney
Journal of Geophysical Research: Space Physics | Year: 2013

An earlier comprehensive analysis of geomagnetic tides by Winch is revisited to display changes in the current systems with season and longitude. The data used come from the quiet Sun years 1964-1965. We choose to present some total equivalent current systems, being the sum of the external and internal parts derived in the spherical harmonic analysis. The latitudes and local times of the current system foci are generally in agreement with other workers. The amplitudes of the current system vortices follow an annual variation with maximum in summer. The longitude variations of the vortex amplitudes vary as the inverse of the magnetic field strength at both equinoxes but have different variations at the solstices. Other longitude maxima which have been reported in the equatorial electrojet intensity were not found. We examine in detail the "invasions" of the summer current systems across the equator, identifying these as signatures of field-aligned currents (FACs). The tilting of current contours with respect to the equator is interpreted as being due to midday FACs. As others have found, the identification of afternoon FACs is more difficult. The seasonal swap-over of FAC directions occurs not in September but in October-November. Key Points Spherical harmonic analysis of global geomagnetic data is revisited for details Cross equator Annual variation of Sq vortex strength is found in both hemispheres ©2013. American Geophysical Union. All Rights Reserved. Source


Rey P.F.,University of Sydney
Australian Journal of Earth Sciences | Year: 2013

This paper exposes the unique set of attributes explaining why precious opal has formed in such abundance in central Australia, and almost nowhere else on Earth. The Early Cretaceous history of the Great Artesian Basin is that of a high-latitude flexural foreland basin associated with a Cordillera Orogen built along the Pacific margin of Gondwana. The basin, flooded by the Eromanga Sea, acted as a sink for volcaniclastic sediments eroded from the Cordillera's volcanic arc. The Eromanga Sea was shallow, cold, poorly connected to the open ocean, muddy and stagnant, which explains the absence of significant carbonates. Iron-rich and organic matter-rich sediments contributed to the development of an anoxic sub-seafloor in which anaerobic, pyrite-producing bacteria thrived. Rich in pyrite, ferrous iron, feldspar, volcanic fragments and volcanic ash, Lower Cretaceous lithologies have an exceptionally large acidification potential and pH neutralisation capacity. This makes Lower Cretaceous lithologies particularly reactive to oxidative weathering. From 97 to 60 Ma, Australia remained at high latitude, and a protracted period of uplift, erosion, denudation and crustal cooling unfolded. It is possibly during this period that the bulk of precious opal was formed via acidic oxidative weathering. When uplift stopped at ca 60 Ma, the opalised redox front was preserved by the widespread deposition of a veneer of Cenozoic sediments. On Earth, regional acidic weathering is rare. Interestingly, acidic oxidative weathering has been documented at the surface of Mars, which shares an intriguing set of attributes with the Great Artesian Basin including: (i) volcaniclastic lithologies; (ii) absence of significant carbonate; (iii) similar secondary assemblages including opaline silica; (iv) similar acidic oxidative weathering driven by very similar surface drying out; and, not surprisingly, (v) the same colour. This suggests that the Australian red centre could well be the best regional terrestrial analogue for the surface of the red planet. © 2013 Copyright Taylor and Francis Group, LLC. Source


Mushrooms are susceptible to a range of diseases and pests that can cause serious crop loss. Effective pest and pathogen control is a very important factor for the maintenance of efficient production of cultivatedmushrooms. Integrated pest management in mushrooms is reliant upon four main principals/elements: sanitation, exclusion,monitoring and pest control. Bradysia ocellaris (Comstock) and Lycoriella ingenua (Dufour) (Diptera: Sciaridae) are major pests of cultivated mushrooms, Agaricus bisporus (Lange) Imbach. These pests cause losses in yield through larval damage of the compost, myceliumand sporophores, and affect the structural features of the compost itself. Adult flies of these species also act as vectors for the introduction of mites and fungal diseases in cultivated mushrooms. © 2010 Society of Chemical Industry. Source


D'Alessandro D.M.,University of Sydney | Smit B.,University of California at Berkeley | Long J.R.,University of California at Berkeley
Angewandte Chemie - International Edition | Year: 2010

Getting CO2under control: This Review highlights the challenges for carbon capture and storage technologies which have been proposed to reduce CO2 emissions from large point sources. The most recent developments in new materials and emerging concepts for CO2 separations by absorption, adsorption, and membranes, amongst other approaches, are discussed, with particular attention on progress in the burgeoning field of metal- organic frameworks (see example). © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Hirsch P.,University of Sydney
Water Alternatives | Year: 2010

This paper explores political dynamics surrounding dam building in the Mekong river basin, prior to, and following, the World Commission on Dams (WCD). Since the 1950s, dam building in the Mekong river basin has been enmeshed in a complex and shifting geopolitical and eco-political landscape. The broad geopolitical sweep of US hegemony, Cold War, regional rapprochement and the rise of China has been superimposed on eco-political shifts between modernist belief in progress as mastery over nature, concerns of global and national environmental movements over dams and their impacts, and a galvanised Mekong environmentalism. During the first decade of the 21st century, mainstream dams on the Lower Mekong have returned to the agenda after having almost disappeared in favour of tributary projects. The growing strength and assertiveness of regional economic players has fundamentally altered the context of energy demand, planning and investment. New sources of finance have relocated the points of political leverage. Environment has been mustered in favour of, as well as in opposition to, dam construction in the contexts of climate-change discourses, protected-area linkage with dam projects, and an industry push for sustainability protocols and certification. Despite the Mekong being one of its focal basins, WCD has not played a prominent role in this transformed arena, yet many of the social and environmental concerns, stakeholder-based processes and safeguard-oriented approaches to hydropower planning that WCD brought to the fore have persisted in the wider ethos of politics around dams in the region. Source


Williams J.G.,Imperial College London | Williams J.G.,University of Sydney
Composites Science and Technology | Year: 2010

An analysis is given for the toughening of particle filled polymers assuming that plastic void growth around debonded, or cavitated particles is the dominant energy absorbing mechanism. The controlling parameter is the debonding (or cavitation) surface energy which triggers the growth of a plastic void around the particle which in turn enhances the toughness. Literature data are examined for particles ranging from 0.01 to 25μm in radius in thermoset resins and it is found that the surface work for very small particles is the surface work of adhesion while for larger sizes it is some fraction of the matrix toughness. This larger debonding energy is found to be proportional to the particle radius. Large toughness increases are predicted, and observed, in the nano-range, i.e. 0.01μm which are shown to require good particle dispersion and high matrix ductility. More modest increases are predicted at the micron scale but these are more robust. © 2010 Elsevier Ltd. Source


Carberry A.E.,University of Sydney
Cochrane database of systematic reviews (Online) | Year: 2011

Fetal growth restriction is defined as failure to reach growth potential and considered one of the major complications of pregnancy. These infants are often, although not universally, small for gestational age (SGA). SGA is defined as a weight less than a specified percentile (usually the 10th percentile). Identification of SGA infants is important because these infants are at increased risk of perinatal morbidity and mortality. Screening for SGA is a challenge for all maternity care providers and current methods of clinical assessment fail to detect many infants that are SGA. Large observational studies suggest that customised growth charts may be better able to differentiate between constitutional and pathologic smallness. Customised charts adjust for physiological variables such as maternal weight and height, ethnicity and parity. To assess the benefits and harms of using population-based growth charts compared with customised growth charts as a screening tool for detection of fetal growth in pregnant women. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011), reviewed published guidelines and searched the reference lists of review articles. Randomised, quasi-randomised or cluster randomised clinical trials comparing customised versus population-based growth charts used as a screening tool for detection of fetal growth in pregnant women. Two review authors independently assessed trials for inclusion. No randomised trials met the inclusion criteria. There is no randomised trial evidence currently available. Further randomised trials are required to accurately assess whether the improvement in detection shown is secondary to customised charts alone or an effect of the policy change. Future research in large trials is needed to investigate the benefits and harms (including perinatal mortality) of using customised growth charts in different settings and for both fundal height and ultrasound measurements. Source


Hunter L.,University of Sydney
Beilstein Journal of Organic Chemistry | Year: 2010

Organofluorine compounds are widely used in many different applications, ranging from pharmaceuticals and agrochemicals to advanced materials and polymers. It has been recognised for many years that fluorine substitution can confer useful molecular properties such as enhanced stability and hydrophobicity. Another impact of fluorine substitution is to influence the conformations of organic molecules. The stereoselective introduction of fluorine atoms can therefore be exploited as a conformational tool for the synthesis of shape-controlled functional molecules. This review will begin by describing some general aspects of the C-F bond and the various conformational effects associated with C-F bonds (i.e. dipole-dipole interactions, charge-dipole interactions and hyperconjugation). Examples of functional molecules that exploit these conformational effects will then be presented, drawing from a diverse range of molecules including pharmaceuticals, organocatalysts, liquid crystals and peptides. © 2010 Hunter. Source


Wyman D.A.,University of Sydney
Precambrian Research | Year: 2013

Criticisms of Archean plate tectonic models rarely offer detailed descriptions of alternative paradigms. The catalytic delamination-driven model for the coupled genesis of Archean crust and sub-continental lithospheric mantle described by Bédard (2006) is an exception in that a relatively comprehensive, but essentially 2-D, model is described. Although this novel model is frequently cited as an example of the diversity in geodynamic thought for the Archean, it is rarely assessed with reference to events in a specific craton, such as the Superior Province or a particular greenstone belt, such as the Abitibi. When this type of assessment is undertaken it becomes clear that the apparent simplicity of the model, one of its supposed virtues, constitutes a critical weakness. Although Bédard (2006) developed the catalytic model to overcome the perceived "melt productivity deficit" of Archean plate tectonic models, the catalytic process at the heart of the model is likely to be inefficient and provides insignificant improvements to crustal generation rates associated with subduction and "non-catalytic" plume tectonics. The model implies a near global craton in the Mesoarchean to Neoarchean but fails to address that fate of this craton during and after "crustal rigidification". Seismic reflectors observed beneath Archean cratons are characterized as failed delamination features but their global abundance suggests that syn- to posttectonic TTG suites could not have been generated as a result of crustal restite delamination. The brief descriptions of suggested mechanisms for the generation of minor rock types, such as sanukitoids, mask the complexity inherent in the overall model. When considered in terms of the evolution of the Superior Province as a whole, it is evident that many of these suggestions are not only implausible, they are inconsistent with the timing and distribution of geological criteria used to mark the onset of "crustal rigidification". © 2012 Elsevier B.V. Source


Introduction In April 2010, the Australian government became the first to announce legislation mandating that tobacco products be sold in plain packaging. The announcement generated significant media coverage and public feedback. The increased readership of and community commentary on online news present an opportunity to assess the range of arguments most likely to be used by opponents to this policy. Methods A content analysis was conducted of reader commentary posted on Australian online news items about the plain packaging announcement. Reader opinion polls on the plain packaging were also recorded. All arguments opposed to plain packaging contained within reader comments were categorised into 11 debating frames. Results Of 117 relevant news items, 41 included 1818 reader comments. 1187 (65.3%) comments contained no reference to plain packaging, and mainly addressed a tobacco tax rise announced at the same time. The comments about plain packaging were more than 2.5 times more likely to oppose than support the policy. The dominant argumentative frame, comprising 27% of oppositional comments, was that plain packaging would be ineffective in reducing smoking. Online reader poll results showed equal support for and opposition to plain packaging. Conclusions The results of this study can be used by tobacco control advocates to anticipate opposition and assist in reframing and counteracting arguments opposed to plain packaging. Source


Postnova S.,University of Sydney
Pharmacopsychiatry | Year: 2013

The hypothalamic-pituitary-adrenal axis (also called the HPA or stress axis) exhibits distinct circadian and ultradian rhythms in cortisol release that cannot be explained solely by the feedback loops from cortisol to the control systems in the paraventricular nucleus (PVN) and pituitary gland. The HPA axis is intimately connected with other brain functions. In particular, it is strongly affected by the sleep-wake cycles via direct and indirect effects of the circadian and homeostatic mechanisms. For example, the HPA axis has direct inputs from the master circadian clock in the suprachiasmatic nuclei (SCN), and from the various sleep-wake related neuronal populations, which themselves are under the effects of the circadian and homeostatic processes. In this paper a first step towards a physiologically based mathematical model of the HPA-axis under effects of the sleep-wake cycles is presented. This model accounts for 3 major characteristics of daily cortisol profile in the blood: i) abrupt increase of cortisol concentration in response to awakening, the so-called cortisol-awakening response (CAR); ii) reduced cortisol levels during daytime with underlying ultradian oscillations; and iii) suppression of cortisol release during sleep. © Georg Thieme Verlag KG Stuttgart · New York. Source


Wilson N.J.,University of Sydney | Cordier R.,James Cook University
Health and Social Care in the Community | Year: 2013

Men's Sheds are community-based organisations that typically provide a space for older men to participate in meaningful occupation such as woodwork. Men's Sheds are considered an exemplar for the promotion of men's health and well-being by health and social policy-makers. The objective of this literature review was to determine the state of the science about the potential for Men's Sheds to promote male health and well-being. Between October 2011 and February 2012, we conducted searches of databases, the grey literature and manual searches of websites and reference lists. In total, we found 5 reports and 19 articles about Men's Sheds. The majority of the literature has emanated from Australian academics and is about older men's learning in community contexts. There is a limited body of research literature about Men's Sheds; the literature consists of either descriptive surveys or small qualitative studies. The range of variables that might contribute towards best practice in Men's Sheds has not yet been adequately conceptualised, measured, tested or understood. Future research should be focussed on the health and well-being benefits of Men's Sheds; it needs to incorporate social determinants of health and well-being within the study designs to enable comparison against other health promotion research. Without this research focus, there is a danger that the potential health and well-being benefits of Men's Sheds as supportive and socially inclusive environments for health will not be incorporated into future male health policy and practice. © 2013 Blackwell Publishing Ltd. Source


Hall R.M.,University of Sydney
Future Microbiology | Year: 2010

Antibiotic resistance in several Salmonella enterica serovars that cause gastrointestinal disease in humans is due to a set of related genomic islands carrying a class 1 integron, which carries the resistance genes. Salmonella genomic island 1 (SGI1), the first island of this type, was found in S. enterica serovar Typhimurium DT104 isolates, which are resistant to ampicillin, chloramphenicol, florfenicol, streptomycin, spectinomycin, sulfonamides and tetracycline. Several Salmonella serovars and Proteus mirablis have since been shown to harbor SGI1 or related islands carrying various sets of resistance genes and some distinct groups have emerged. SGI1 is an integrative mobilizable element and can be transferred experimentally into Escherichia coli. However, within serovars, isolates recovered from different parts of the world appear to be clonal, indicating that SGI1 movement may be rare. Potential reservoirs in food-producing animals or in ornamental fish have been identified for some serovars. © 2010 Future Medicine Ltd. Source


Seo S.N.,University of Sydney
Australian Journal of Agricultural and Resource Economics | Year: 2011

This paper examines the newly constructed geographically scaled economic output measure, Gross Cell Product (GCP), of Australia and New Zealand to quantify the impacts of climate change in the region. The paper discusses advantages of using the GCP instead of the Gross Domestic Product. The paper reveals that the GCP falls sharply as temperature increases in the region. A 1°C increase in temperature would decrease the productivity with an elasticity of -2.4. A 1 per cent decrease in precipitation would decrease productivity with an elasticity of -2.3. However, forest vegetation on the coasts will benefit from initial warming. We find that the changes in climate means are potentially more harmful than changes in climate variability. In the long term, a 3.4° warming coupled with 6.6mm decrease in rainfall would decrease the GCP by 34 per cent by 2060. The damage is largely accounted for by population effects. The paper confirms that Australia is highly constrained by climate and geographic factors. © 2011 The Author. AJARE © 2011 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishing Asia Pty Ltd. Source


Chan E.H.W.,University of Sydney
Applied Optics | Year: 2014

A microwave photonic mixer basedon a single electro-optic Mach-Zehnder intensity modulator operating in both directions is presented. In this mixer structure, the light from the optical source travels in opposite directions inside the modulator and is modulated by both the RF signal and the local oscillator (LO). The output optical spectrum comprises the RF signal and LO sidebands without the optical carrier. This enables a high conversion efficiency mixing operation to be obtained. The mixer has a simple structure, and its performance is insensitive to the modulator bias voltage; hence no DC bias voltage and no modulator bias controller are required to obtain robust high conversion efficiency mixing operation. Experimental results are presented showing large conversion efficiency improvement of 25.7 dB compared to the conventional dual Mach-Zehnder modulator-based microwave photonic mixer and a modulator bias insensitive mixing performance. © 2014 Optical Society of America. Source


Obeng-Odoom F.,University of Sydney
Housing Studies | Year: 2010

A combination of rapid population growth and low incomes results in housing shortages in Ghana. Migration to Europe, America and Scandinavia has provided a way for some Ghanaians to escape this housing problem, as they take advantage of salaries there in order to save and build houses much quicker back home. This study of Ghanaian migrants in Sydney shows that by keeping at two or more jobs and saving about 33 per cent of their incomes, they are able to build houses worth US$100 000 in Ghana within 3-6 years. How these Ghanaians acquire land, how they build and their experiences after completing their houses provide clues on how to improve housing policy in Ghana. © 2010 Taylor & Francis. Source


Chong B.H.,University of New South Wales | Chong J.J.-H.,University of Sydney
Blood | Year: 2013

In this issue of Blood, Jaax and colleagues show that heparin-PF4 antibodies cross-reacted with nucleic acid (NA)-PF4 complexes and induced platelet activation, suggesting that NA-PF4 can potentially cause a heparin-induced thrombocytopenia (HIT)-like prothrombotic disorder. © 2013 by The American Society of Hematology. Source


Hunter D.J.,University of Sydney
British Journal of Sports Medicine | Year: 2011

The current pre-eminent focus in osteoarthritis research and clinical practice is on persons with established radiographic disease. This is the very end-stage of disease genesis and modern therapies are thus largely palliative. A major shift in the focus of osteoarthritis research and clinical practice is critically needed if an impact is to be made for the millions living with the chronic pain and disability of osteoarthritis. The disease management paradigm needs to be revolutionised to focus on persons at high risk of developing or with early disease in which structural changes may be preventable or reversible. Similarly, current palliation should shift towards coordinated conservative management with reorganisation of the delivery of health services. Source


Carney T.,University of Sydney
International Journal of Law and Psychiatry | Year: 2012

This paper draws on a multi-year Australian collaborative study of mental health review tribunals ('MHTs') in three jurisdictions (Victoria, New South Wales and the Australian Capital Territory) undertaken in conjunction with the NSW Law and Justice Foundation, using qualitative and quantitative methods to examine the role of MHTs in advancing goals such as fairness, legality and access to treatment. Study findings regarding stakeholder and client concerns - about access to quality treatment and associated support services, review of treatment adequacy and drug regimes, and their 'participation' or dignity of engagement in review processes - are presented as variants of the need for adequate hearing 'space': temporal, jurisdictional, cognate/relational, physical and symbolic, and 'connective'. Building on earlier arguments for MHTs to engage not only legal, but also clinical and social domains, and for adopting some processes more characteristic of case-conferencing, this paper examines the implications of tribunal 'flexibility' and a wider overall 'governance' jurisdiction in mental health. © 2011 Elsevier Ltd. Source


Lewis G.F.,University of Sydney
Monthly Notices of the Royal Astronomical Society | Year: 2013

It is generally agreed that there is matter in the universe, and in this paper, we show that the existence of matter is extremely problematic for the proposed Rh = ct universe. Considering a dark energy component with an equation of state of w = -1/3, it is shown that the presence of matter destroys the strict expansion properties that define the evolution of Rh = ct cosmologies, distorting the observational properties that are touted as its success. We further examine whether an evolving dark energy component can save this form of cosmological expansion in the presence of matter by resulting in an expansion consistent with a mean value of 〈w〉=-1/3, finding that the presence of mass requires unphysical forms of the dark energy component in the early universe. We conclude that matter in the universe significantly limits the fundamental properties of the Rh = ct cosmology and that novel, and unphysical, evolution of the matter component would be required to save it. Given this, Rh = ct cosmology is not a simpler or more accurate description of the universe than prevailing cosmological models, and its presentation to date possesses significant flaws. © 2013 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Glasziou P.,Bond University | Houssami N.,University of Sydney
Preventive Medicine | Year: 2011

The history of breast cancer screening is littered with controversy. With 10 trials spanning 4 decades, we have a substantial body of evidence, but with different aims and flaws. Combined analysis of the intention-to-treat results gives an overall relative reduction in breast cancer mortality of 19% (95% CI 12%-26%), which, if adjusted for non-attendance gives an approximate 25% relative reduction for those who attend screening. However, given that 4% of all-cause mortality is due to breast cancer deaths, this translates into a less than 1% reduction in all-cause mortality. An emerging issue in interpretation is the improvements in treatment since these trials recruited women. Modern systemic therapy would have improved survival (models suggest between 12% and 21%) in both screened and non-screened groups, which would result in a lesser difference in. absolute risk reduction from screening but probably a similar, or slightly smaller, relative risk reduction. However benefits and harms, particularly over-diagnosis, need to balanced and differ by age-groups. The informed views of recipients of screening are needed to guide current and future policy on screening. © 2011. Source


Vladimirov S.V.,University of Sydney
Plasma Physics and Controlled Fusion | Year: 2011

A fundamental question that is important for the understanding of plasma processes concerns charged particles and plasma interactions. For moving particles (test objects in a plasma flow), these include the formation of plasma wakes. The plasma flow provides not only a direct dragging influence, but is also responsible for the generation of associated collective plasma processes, and the plasma wake can strongly affect interactions between charged objects themselves and the plasma. An example is the interaction between dust particles in the plasma sheath, where ions flowing to the electrode form the ion wake behind negatively charged grains. Here, a number of phenomena starting from the well-known case of a negatively charged body moving in a plasma (or immersed in a plasma ion flow) are briefly discussed. Most emphasis is given to recent results including, in particular, an absorbing moving object and a classical object in a quantum plasma. © 2011 IOP Publishing Ltd. Source


Matthews L.R.,University of Sydney
International Journal of Health Services | Year: 2012

Research and policy on occupational health and safety have understandably focused on workers as the direct victims of workplace hazards. However, serious illness, injury, or death at work also has cascading psychological, social, and economic effects on victims' families and close friends. These effects have been neglected by researchers and policymakers. The number of persons immediately affected by workplace death is significant, even in rich countries with relatively low rates of workplace fatality. Every year, more than 5,000 family members and close friends of Australian workers become survivors of traumatic work-related death (TWD). This study investigated the health, social, and financial consequences of TWD on surviving families. In-depth exploratory interviews were conducted with seven family members who had experienced TWD from one to 20 years before the interviews, with an average of three years. All reported serious health, social, and financial consequences, including prolonged grief and unresolved loss, physical health problems, family disruption and behavioral effects on children, immediate financial difficulties, and disturbance of longer term commitments such as retirement planning. Recommendations for policy development and improved practice are proposed to minimize the trauma and suffering experienced by families, mitigate consequences, and improve outcomes following a TWD. © 2012, Baywood Publishing Co., Inc. Source


Moss D.J.,University of Sydney | Morandotti R.,INRS EMT | Gaeta A.L.,Cornell University | Lipson M.,Cornell University
Nature Photonics | Year: 2013

Nonlinear photonic chips can generate and process signals all-optically with far superior performance to that possible electronically-particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics, its high two-photon absorption at telecommunication wavelengths poses a fundamental limitation. We review recent progress in non-silicon CMOS-compatible platforms for nonlinear optics, with a focus on Si3N4 and Hydex®. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement. We highlight their potential future impact as well as the challenges to achieving practical solutions for many key applications. © 2013 Macmillan Publishers Limited. Source


Stewart C.L.,University of Sydney
Medical Journal of Australia | Year: 2012

Futility assessments, which are unavoidable in end-of-life settings, need to be procedurally fair. This necessitates communication between health professionals and substitute decisionmakers regarding the decision to define treatments as futile. • The common law test for whether treatment should be withheld or withdrawn is the best interests test. A futile treatment is not in any patient's best interests. • While it is rare for the law to disagree with a futility determination made by health professionals, if a determination has been made without consultation and fails to reflect the patient's best interests, the courts will overturn it. • The best regulatory regimes provide for a balance between the powers of health professionals and substitute decisionmakers to make decisions for incompetent patients, and for clear and efficient dispute resolution. • The Queensland law and its requirement for consent to withhold or withdraw futile treatment represents a good model of futility determination, with clear powers given to substitute decisionmakers and health professionals. Disputes concerning the treatment of incompetent patients automatically trigger the appointment of the adult guardian as the decisionmaker, and there are avenues for appeal. Source


Eslick G.D.,University of Sydney
Obesity Reviews | Year: 2012

Weight loss is a recognized alarm symptom for organic gastrointestinal (GI) disease, yet the association between obesity and specific GI symptoms remains poorly described. A meta-analysis was conducted to determine which GI symptoms predominate among obese individuals. A search of the literature using the databases MEDLINE, EMBASE PubMed and Current Contents (1950-November 2011) was conducted. All studies assessing GI symptoms and increasing body mass index (BMI)/obesity were included. English and non-English articles were searched. A random effect model of the studies was undertaken. Overall, significant associations between GI symptoms and increasing BMI were found for upper abdominal pain (odds ratio [OR] = 2.65, 95% confidence interval [CI]: 1.23-5.72), gastroesophageal reflux (OR = 1.89, 95% CI: 1.70-2.09), diarrhoea (OR = 1.45, 95% CI: 1.26-1.64), chest pain/heartburn (OR = 1.74, 95% CI: 1.49-2.04), vomiting (OR = 1.76, 95% CI: 1.28-2.41), retching (OR = 1.33, 95% CI: 1.01-1.74) and incomplete evacuation (OR = 1.32, 95% CI: 1.03-1.71). However, no significant associations were found for all abdominal pain, lower abdominal pain, bloating, constipation/hard stools, fecal incontinence, nausea and anal blockage. Several key GI symptoms are associated with increasing BMI and obesity. In addition, there were a number of other GI symptoms that had no relationship with obesity. A greater knowledge of the GI symptoms associated with obesity along with the physiology will be important in the clinical management of these patients. © 2011 The Author. © 2011 International Association for the Study of Obesity. Source


Robbins D.W.,University of Sydney
Journal of Strength and Conditioning Research | Year: 2012

The purpose of this study was to investigate the relationships between the athletic skills measured at the National Football League (NFL) combine. The combine comprises the following tests: 36.6-m sprint with split times at 9.1 and 18.3 m, vertical and horizontal jumps, 18.3-m shuttle run, 3-cone drill, and 102.1-kg bench press. Draftees to the NFL who participated in the annual combine from 2005 to 2009 were included in the study (n = 1,136). Pearson's (r) correlations were calculated to determine the relationships between the tests, and coefficients of determination (r 2) were used to determine common variance. The 9.1-, 18.3-, and 36.6-m sprint times are nearly perfectly correlated (r ranges from 0.900 to 0.967) as are the change-of-direction ability tests, 18.3-m shuttle run, and 3-cone drill (r = 0.948), suggesting similar skills are being measured. Performance in both jumping tasks is more strongly associated with longer sprint distances, suggesting mechanisms such as the stretch-shortening cycle may be more important at maximal, or near-maximal, speeds. The correlations between change-of-direction ability and sprinting and jumping are generally much weaker (r ranges from 0.250 to 20.653), suggesting less association and independent motor skills. Although not particularly large correlation coefficients, bench press performance is positively correlated with outcomes in all running drills and inversely correlated with jump abilities, suggesting that in the observed cohort, upper body strength may be of little benefit to these tasks. Incorporation of a nonacceleration influenced (i.e., moving start) measure of maximal speed may be preferred if the intention of a test battery is to measure independent motor skills. Further, when constructing test batteries, either the 18.3-m shuttle or 3-cone drill is likely sufficient as a measure of change-of-direction ability. Test batteries should be constructed to measure independent motor skills. © 2012 National Strength and Conditioning Association. Source


Shine R.,University of Sydney
Evolutionary Applications | Year: 2012

The arrival of an invasive species can have wide-ranging ecological impacts on native taxa, inducing rapid evolutionary responses in ways that either reduce the invader's impact or exploit the novel opportunity that it provides. The invasion process itself can cause substantial evolutionary shifts in traits that influence the invader's dispersal rate (via both adaptive and non-adaptive mechanisms) and its ability to establish new populations. I briefly review the nature of evolutionary changes likely to be set in train by a biological invasion, with special emphasis on recent results from my own research group on the invasion of cane toads (Rhinella marina) through tropical Australia. The toads' invasion has caused evolutionary changes both in the toads and in native taxa. Many of those changes are adaptive, but others may result from non-adaptive evolutionary processes: for example, the evolved acceleration in toad dispersal rates may be due to spatial sorting of dispersal-enhancing genes, rather than fitness advantages to faster-dispersing individuals. Managers need to incorporate evolutionary dynamics into their conservation planning, because biological invasions can affect both the rates and the trajectories of evolutionary change. © 2011 Blackwell Publishing Ltd. Source


Clarke N.F.,University of Sydney
Seminars in Pediatric Neurology | Year: 2011

Congenital fiber-type disproportion is a form of congenital myopathy that may be best viewed as a syndrome rather than as a formal diagnosis. The central histologic abnormality is that type 1 fibers are consistently smaller than type 2 fibers by at least 35%-40%. Care is needed in diagnosing patients, as this histologic abnormality can occur in other congenital myopathies and in other neuromuscular disorders. Many of the genetic causes have been identified. Careful surveillance of respiratory function is required in all patients until the specific genetic cause is known and advice can be individualized. © 2011 Elsevier Inc. Source


Wade C.M.,University of Sydney
Veterinary Journal | Year: 2011

This review assesses evidence from DNA analysis to determine whether there is sufficient genetic diversity within breeds to ensure that populations are sustainable in the absence of cross breeding and to determine whether genetic diversity is declining. On average, dog breeds currently retain approximately 87% of the available domestic canine genetic diversity. Requirements that breeding stock must be 'clear' for all genetic disorders may firstly place undue genetic pressure on animals tested as being 'clear' of known genetic disorders, secondly may contribute to loss of diversity and thirdly may result in the dissemination of new recessive disorders for which no genetic tests are available.Global exchange of genetic material may hasten the loss of alleles and this practice should be discussed in relation to the current effective population size of a breed and its expected future popularity. Genomic data do not always support the results from pedigree analysis and possible reasons for this are discussed. © 2011 Elsevier Ltd. Source


Robbins D.W.,University of Sydney
Journal of Strength and Conditioning Research | Year: 2011

To investigate the positional physical requirements necessary to be drafted into the National Football League (NFL), data from the annual NFL combine over the years 2005-2009 were examined. Only those players invited to the combine and subsequently drafted in the same year (n = 1,136) were included in the study. Data from 8 combine physical performance tests were examined for 15 positions. Combine measures evaluated for the center, cornerback, defensive end, defensive tackle, free safety, fullback, inside linebacker, offensive guard, offensive tackle, outside linebacker, quarterback, running back, strong safety, tight end, and wide receiver positions were the 9.1-, 18.3-, and 36.6-m sprints, the vertical and broad jumps, the 18.3-m shuttle run, the 3-cone drill, and the 102.1-kg bench press for maximum repetitions and, from this, a predicted measure of 1 repetition maximum. A 1-way analysis of variance detected differences in all 9 performance measures (p < 0.01). Post hoc independent t-tests indicated that over most tests many positions exhibited outcomes significantly different from most other positions. Generally, lineman positions performed inferiorly in sprint, jump and change-of-direction ability measures and superiorly in the upper body strength measures. Conversely, defensive back positions were the worst performers in the upper body strength test, and wide receivers and defensive backs were the best performers in all other measures. In general, offensive and defensive positions that commonly compete directly against one another display similar physical characteristics. Any advantages (statistically significant and not) between positions in direct competition were consistently in favor of defensive positions. The results of the present research present position-specific profiles for each of 15 positions. Coaches and practitioners will be able to use the findings of this research to better prepare athletes for entry into the NFL. © 2011 National Strength and Conditioning Association. Source


Bilger R.W.,University of Sydney
Combustion and Flame | Year: 2011

A mixture fraction is carefully defined for evaporation and combustion of droplets and sprays. The definition is valid at points in either the liquid or gas phases and care is taken to distinguish between definitions based on conserved scalars appropriate for heat transfer and those for mass transfer. Results are presented for Spalding B numbers and values of the mixture fraction at the droplet surface for the fast chemistry case and for the case where the droplet cannot sustain an envelope flame. The classical theory for an isolated droplet with spherical symmetry yields simple formulae when expressed in mixture fraction terms. New results are then readily obtained for several quantities of interest in spray modeling. The formulation provides a seamless unification of droplet evaporation processes with gas-phase mixing and reaction. Mixing in a turbulent spray jet is identified as a model problem that clarifies the role of large scale structures in the overall mixing process. Important constraints on the parameter space for sprays are shown to be greatly clarified when expressed in the mixture fraction framework. It is shown how the classical approach for segregated flow with Eulerian/Lagrangian modeling of dispersion and transfer processes in turbulent sprays can be upgraded to include fluctuations in the temperature and composition surrounding the droplets on top of those coming from the turbulent velocity fluctuations. Such preliminary calculations that assume a simple chemically reacting system can readily be upgraded using flamelet functions derived from counterflow experiments or computations: these can then form the starting point for full chemistry calculations using such approaches as conditional moment closure. © 2010. Source


Shin E.H.,University of Sydney
Molecular medicine (Cambridge, Mass.) | Year: 2012

Fibrosis affects an extensive range of organs and is increasingly acknowledged as a major component of many chronic disorders. It is now well accepted that the elevated expression of certain inflammatory cell-derived cytokines, especially transforming growth factor β (TGFβ), is involved in the epithelial-to-mesenchymal transition (EMT) leading to the pathogenesis of a diverse range of fibrotic diseases. In lens, aberrant TGFβ signaling has been shown to induce EMT leading to cataract formation. Sproutys (Sprys) are negative feedback regulators of receptor tyrosine kinase (RTK)-signaling pathways in many vertebrate systems, and in this study we showed that they are important in the murine lens for promoting the lens epithelial cell phenotype. Conditional deletion of Spry1 and Spry2 specifically from the lens leads to an aberrant increase in RTK-mediated extracellular signal-regulated kinase 1/2 phosphorylation and, surprisingly, elevated TGFβ-related signaling in lens epithelial cells, leading to an EMT and subsequent cataract formation. Conversely, increased Spry overexpression in lens cells can suppress not only TGFβ-induced signaling, but also the accompanying EMT and cataract formation. On the basis of these findings, we propose that a better understanding of the relationship between Spry and TGFβ signaling will not only elucidate the etiology of lens pathology, but will also lead to the development of treatments for other fibrotic-related diseases associated with TGFβ-induced EMT. Source


Evans N.,University of Sydney
Seminars in Perinatology | Year: 2012

The current uncertainty in relation to treatment of the preterm patent ductus arteriosus reflects limitations to our understanding of the pathophysiology of ductal shunting, most particularly which ducts matter to which babies and when they matter. Doppler ultrasound offers a pragmatic tool with which to assess ductal patency and shunt significance and to allow prediction of spontaneous and therapeutic closure. Biomarkers, such as B-type natriuretic peptide, and clinical signs may have a diagnostic role where ultrasound is not available and also possibly as an adjunct to echocardiography in determining the pathophysiological impact of a ductal shunt in an individual baby. © 2012 Elsevier Inc. Source


Truscott R.J.W.,University of Sydney
Rejuvenation Research | Year: 2010

There are a number of sites in the body where proteins are present for decades and sometimes for all of our lives. Over a period of many years, such proteins are subject to two types of modifications. The first results from the intrinsic instability of certain amino acid residues and leads to deamidation, racemization, and truncation. The second type can be traced to relentless covalent modification of such ancient proteins by reactive biochemicals produced during cellular metabolism.The accumulation of both types of posttranslational modifications over time may have important consequences for the properties of tissues that contain such proteins. It is proposed that the age-related decline in function of organs such as the eye, heart, brain, and lung, as well as skeletal components, comes about, in part, from the posttranslational modification of these long-lived proteins. Examples are provided in which this may be an important factor in the etiology of age-related conditions. As the properties of these proteins alter inexorably over time, the molecular changes contribute to a gradual decline in the function of individual organs and also tissues such as joints. This cumulative degeneration of old proteins at multiple sites in the bodymay also constrain the ultimate life span of the individual. The human lens may be particularly useful for discovering which reactive metabolites in the body are of most importance for posttranslational modification of long-lived proteins. © Mary Ann Liebert, Inc. Source


Curthoys I.S.,University of Sydney
Laryngoscope | Year: 2012

Recently, new clinical tests of canal and otolith function have been introduced. They rest on sound anatomical and physiological evidence; however, the interpretation of the results of these tests has only recently been clarified. This review summarizes the anatomical and physiological evidence underpinning the tests of both canal and otolith function to provide a full picture of the interpretation of the tests, which allow the clinician to assess the status of the peripheral vestibular function of a patient-all six canals and four otoliths. The present review does not document all the minute details associated with each test, but provides an overview of the interpretation of properly presented tests and shows typical response profiles of patients with various types of vestibular loss, based on published anatomical, physiological, and clinical evidence. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc. Source


Khalid M.,University of Sydney
Biophysical journal | Year: 2010

Investigations of the E2 --> E1 conformational change of Na(+),K(+)-ATPase from shark rectal gland and pig kidney via the stopped-flow technique have revealed major differences in the kinetics and mechanisms of the two enzymes. Mammalian kidney Na(+),K(+)-ATPase appears to exist in a diprotomeric (alphabeta)(2) state in the absence of ATP, with protein-protein interactions between the alpha-subunits causing an inhibition of the transition, which occurs as a two-step process: E2:E2 --> E2:E1 --> E1:E1. This is evidenced by a biphasicity in the observed kinetics. Binding of ATP to the E1 or E2 states causes the kinetics to become monophasic and accelerate, which can be explained by an ATP-induced dissociation of the diprotomer into separate alphabeta protomers and relief of the preexisting inhibition. In the case of enzyme from shark rectal gland, the observed kinetics are monophasic at all ATP concentrations, indicating a monoprotomeric enzyme; however, an acceleration of the E2 --> E1 transition by ATP still occurs, to a maximum rate constant of 182 (+/- 6) s(-1). This indicates that ATP has two separate mechanisms whereby it accelerates the E2 --> E1 transition of Na(+),K(+)-ATPase alphabeta protomers and (alphabeta)(2) diprotomers. Copyright 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved. Source


Rhodes P.,University of Sydney
Clinical Child Psychology and Psychiatry | Year: 2012

This paper advocates for process research as a valid source of evidence in clinical psychology, research that focuses on why and how therapy works, both across the course of treatment and in the minutiae of interactions between therapist and client. Process research is consistent with the aims of the scientist-practitioner model, supporting the provision of practical and realistic guidance to clinicians. Specific examples of methods are provided, including the analysis of mechanisms of change, patient-focused research, conversational analysis and interpersonal process recall. © The Author(s) 2011. Source


Gao S.,University of Sydney
Entropy | Year: 2011

The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde's example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic force in a thermodynamics system. Furthermore, we show that the entropy increase of the screen is not caused by its statistical tendency to increase entropy as required by the existence of entropic force, but in fact caused by gravity. Therefore, Verlinde's argument for the entropic origin of gravity is problematic. In addition, we argue that the existence of a minimum size of spacetime, together with the Heisenberg uncertainty principle in quantum theory, may imply the fundamental existence of gravity as a geometric property of spacetime. This may provide a further support for the conclusion that gravity is not an entropic force. © 2011 by the authors; licensee MDPI, Basel, Switzerland. Source


Arulsamy A.D.,Jozef Stefan Institute | Arulsamy A.D.,University of Sydney
Annals of Physics | Year: 2011

Proofs are developed to explicitly show that the ionization energy theory is a renormalized theory, which mathematically exactly satisfies the renormalization group formalisms developed by Gell-Mann-Low, Shankar and Zinn-Justin. However, the cutoff parameter for the ionization energy theory relies on the energy-level spacing, instead of lattice point spacing in k-space. Subsequently, we apply the earlier proofs to prove that the mathematical structure of the ionization-energy dressed electron-electron screened Coulomb potential is exactly the same as the ionization-energy dressed electron-phonon interaction potential. The latter proof is proven by means of the second-order time-independent perturbation theory with the heavier effective mass condition, as required by the electron-electron screened Coulomb potential. The outcome of this proof is that we can derive the heat capacity and the Debye frequency as a function of ionization energy, which can be applied in strongly correlated matter and nanostructures. © 2010 Elsevier Inc. Source


Rickles D.,University of Sydney
Studies in History and Philosophy of Science Part B - Studies in History and Philosophy of Modern Physics | Year: 2011

Many of the advances in string theory have been generated by the discovery of new duality symmetries connecting what were once thought to be distinct theories. Indeed, duality has played an enormously important role in the creation and development of numerous theories in physics and numerous fields of mathematics. Dualities often lie at those fruitful intersections at which mathematics and physics are especially strongly intertwined. In this paper I describe several of these dualities and unpack some of their philosophical implications, focusing primarily on string theoretic dualities. © 2011 Elsevier Ltd. Source


Baber R.,University of Sydney
Maturitas | Year: 2010

The use of phytoestrogens for various perceived health benefits is widespread. Despite 20 years of research the evidence for any significant health benefits remains inconclusive. Pre clinical trials have demonstrated both non-genomic and genomic actions of constituents of phytoestrogens including selective, but weak, binding to estrogen receptors, with a preference for ER B over ER A. Evidence of clinically relevant biological effects from observational studies and randomized trials has, in general, been lacking. Despite many trials there remains little evidence that phytoestrogens, whether dietary or supplemented, significantly relieve menopausal vasomotor symptoms or cognition. Several potential mechanisms for a positive effect on bone and cardiovascular health have been demonstrated however no fracture prevention data or cardiovascular end point benefit has yet been demonstrated. In vitro effects of phytoestrogens on breast cells have been both stimulatory and inhibitory however net effects appear neutral with observational studies finding no change in breast cancer risk. No effect has been seen on endometrial or other cancers and side effect profiles have, in general, been mild. © 2010 Elsevier Ireland Ltd. Source


Early coelomic development in the abbreviated development of the sea urchin Holopneustes purpurescens is described and then used in a comparison with coelomic development in chordate embryos to support homology between a single arm of the five-armed radial body plan of an echinoderm and the single bilateral axis of a chordate. The homology depends on a positional similarity between the origin of the hydrocoele in echinoderm development and the origin of the notochord in chordate development, and a positional similarity between the respective origins of the coelomic mesoderm and chordate mesoderm in echinoderm and chordate development. The hydrocoele is homologous with the notochord and the secondary podia are homologous with the somites. The homology between a single echinoderm arm and the chordate axis becomes clear when the aboral to oral growth from the archenteron in the echinoderm larva is turned anteriorly, more in line with the anterior- posterior axis of the early zygote. A dorsoventral axis inversion in chordates is not required in the proposed homology. © Springer-Verlag 2012. Source


Warren C.R.,University of Sydney
New Phytologist | Year: 2012

• The quantitative significance of amino acids to plant nutrition remains controversial. This experiment determined whether post-uptake metabolism and root to shoot export differ between glycine and glutamine, and examined implications for estimation of amino acid uptake. • Field soil containing a Eucalyptus pauciflora seedling was injected with uniformly 13C- and 15N-labelled glycine or glutamine. I quantified 15N and 13C excess in leaves and roots and intact labelled amino acids in leaves, roots and stem xylem sap. A tunable diode laser quantified fluxes of 12CO 2 and 13CO 2 from leaves and soil. • 60-360min after addition of amino acid, intact molecules of U- 13C, 15N glutamine were < 5% of 15N excess in roots, whereas U- 13C, 15N glycine was 30-100% of 15N excess in roots. Intact molecules of glutamine, but not glycine, were exported from roots to shoots. • Post-uptake metabolism and transport complicate interpretation of isotope labelling such that root and shoot contents of intact amino acid, 13C and 15N may not reflect rates of uptake. Future experiments should focus on reconciling discrepancies between intact amino acid, 13C and 15N by determining the turnover of amino acids within roots. Alternatively, post-uptake metabolism and transport could be minimized by harvesting plants within minutes of isotope addition. © 2011 The Author. New Phytologist © 2011 New Phytologist Trust. Source


Magnusson R.S.,University of Sydney
BMC Public Health | Year: 2010

Background. In Australia, the food industry and public health groups are locked in serious struggle for regulatory influence over the terms of front-of-pack food labelling. Clear, unambiguous labelling of the nutritional content of pre-packaged foods and of standardized food items sold in chain restaurants is consistent with the prevailing philosophy of 'personal responsibility'. An interpretive, front-of-pack labelling scheme has the capacity to encourage healthier patterns of eating, and to be a catalyst for improvements in the nutritional quality of food products through re-formulation. On the other hand, the strength of opposition of the Australian Food and Grocery Council to 'Traffic Light Labelling', and its efforts to promote a non-interpretive, voluntary scheme, invite the interpretation that the food industry is resistant to any reforms that could destabilise current (unhealthy) purchasing patterns and the revenues they represent. Discussion. This article argues that although policies that aim to educate consumers about the nutritional content of food are welcome, they are only one part of a broader basket of policies that are needed to make progress on obesity prevention and public health nutrition. However, to the extent that food labelling has the capacity to inform and empower consumers to make healthier choices - and to be a catalyst for improving the nutritional quality of commercial recipes - it has an important role to play. Furthermore, given the dietary impact of meals eaten in fast food and franchise restaurants, interpretive labelling requirements should not be restricted to pre-packaged foods. Summary. Food industry resistance to an interpretive food labelling scheme is an important test for government, and a case study of how self-interest prompts industry to promote weaker, voluntary schemes that pre-empt and undermine progressive public health regulation. © 2010 Magnusson; licensee BioMed Central Ltd. Source


OBJECTIVE To evaluate experience with high power LBO laser for large prostates PATIENTS AND METHODS Prospective database of 288 men treated with PVP from November 2006-2009 33 men identified to have transrectal ultrasound measured prostate size >120cc All but 9 men not in urinary retention or on anticoagulant medications Average ASA Score 2.25 (range 1-4) with 11 having an ASA Score of 3 or more RESULTS Mean operating time and laser time 109 and 86 minutes respectively IPSS, QoL and Qmax changes from baseline to 3 months for those not in retention were 24 to 8.6, 5.0 to 1.8 and 7.5mL/s to 19.6mL/s respectively Post void residual in these men fell from a mean of 235mL to 88mL Average fall in PSA was 38% for 22 men with paired PSA data Post operative urinary retention in 4 men resolved. 2 late onset clot urinary retention CONCLUSION Early results demonstrate PVP to be safe and efficacious on early follow up in a high risk group of patients with significantly enlarged prostates, anticoagulation and urinary retention. © 2010 BJU INTERNATIONAL. Source


Dorsch N.,University of Sydney
Acta Neurochirurgica, Supplementum | Year: 2011

The continuation of a review of delayed vasospasm after aneurysmal subarachnoid haemorrhage, originally published in 1994 and partially updated at the ninth vasospasm conference in Turkey, is presented. Further online and physical searches have been made of the relevant literature. The incidence of delayed ischaemic deficit (DID) or symptomatic vasospasm reported in 1994 was 32.5% in over 30,000 reported cases. In recent years, 1994-2009, it was 6,775/23,806, or 28.5%. Many of the recent reports did not specify whether a calcium antagonist was used routinely, and when this was stated (usually nimodipine or nicardipine), DID was noted in 22.0% of 10,739 reported patients. The outcome of delayed ischaemia in the earlier survey was a death rate of 31.6%, with favourable outcomes in 36.2%. In recent reports, though with fewer than 1,000 patients, the outcome is possibly better, with death in 25.6% and good outcome in 54.1%. It thus appears likely that delayed vasospasm is still common but less so, and that the overall outcome has improved. This may be due to the more widespread use of calcium antagonists and more effective fluid management. A number of other mechanical and drug treatments are also mentioned. © 2011 Springer-Verlag/Wien. Source


Henderson-Smart D.J.,University of Sydney
Cochrane database of systematic reviews (Online) | Year: 2010

Weaning and extubating preterm infants on intermittent positive pressure ventilation (IPPV) for respiratory failure may be difficult. A significant contributing factor is thought to be the relatively poor respiratory drive and tendency to develop hypercarbia and apnoea, particularly in very preterm infants. Methylxanthine treatment started before extubation might stimulate breathing and increase the chances of successful weaning from IPPV. To determine the effects of prophylactic methylxanthine treatment on the use of intubation and IPPV and other clinically important side effects in preterm infants being weaned from IPPV and in whom endotracheal extubation is planned. The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2010), the Oxford Database of Perinatal Trials, MEDLINE (1966 to July 2010), CINAHL (1982 to July 2010) and EMBASE (1988 to July 2010). All published trials utilising random or quasi-random patient allocation in which treatment with methylxanthines (theophylline or caffeine) was compared with placebo or no treatment to improve the chances of successful extubation of preterm or low birth weight infants were included. The standard methods of the Cochrane Collaboration and its Neonatal Review Group were used. Seven studies were identified for inclusion. Methylxanthine treatment results in a reduction in failure of extubation within one week (summary RR 0.48, 95%CI 0.32 to 0.71; summary RD -0.27, 95%CI -0.39 to -0.15; NNT 4, 95%CI 3 to 7; six trials, 172 infants). There is significant heterogeneity in the RD meta-analysis perhaps related to the large variation in baseline rate in the control groups (range 20 to 100%).The CAP trial enrolled the largest number of infants, but did not report extubation rates. In the caffeine group, there were lower rates of bronchopulmonary dysplasia, PDA ligation, cerebral palsy and death or major disability at 18 to 21 months. Infants receiving caffeine had reduced postmenstrual ages at time of discontinuing oxygen therapy, positive pressure ventilation and endotracheal intubation. Methylxanthines increase the chances of successful extubation of preterm infants within one week of age. Important neurodevelopmental outcomes are improved by methylxanthine therapy. In any future trials, there is a need to stratify infants by gestational age (a better indicator of immaturity than birth weight). Caffeine, with its wider therapeutic margin, would be the better treatment to evaluate against placebo. Source


Mohan I.V.,University of Sydney | Stephen M.S.,Northern Endovascular Specialists
Progress in Cardiovascular Diseases | Year: 2013

Peripheral arterial aneurysms are uncommon; for some aneurysm types, data are limited to case reports and small case series. There is no Level A evidence in most cases to determine the choice between open or endovascular intervention. The evolution of endovascular technology has vastly improved the armamentarium available to the vascular surgeon and interventionalists in the management of these rare and unusual aneurysms.The choice of operative approach will ultimately be determined on an individual basis, dependent on the patient risk factors, and aneurysm anatomy. After consideration, some aneurysms (femoral, subclavian, carotid and ECAA) fare better with an open first approach; renal, splenic and some visceral artery aneurysms do better with an endovascular first approach. In our practice PAAs are treated with an endovascular first approach. For these rare conditions, both open and endovascular therapy will continue to work in harmony to enhance and extend the capabilities of modern surgical management. © 2013 Elsevier Inc. Source


Philip Morris has recently brought claims against Australia (2011) and Uruguay (2010) under international investment agreements (IIAs). The claims allege that Philip Morris is entitled to compensation following the introduction of innovative tobacco packaging regulations to reduce smoking and prevent noncommunicable diseases (NCDs). Since tobacco control measures are often viewed as a model for public health nutrition measures, the claims raise the question of how investment law governs the latter. This paper begins to answer this question and to explain how governments can proactively protect policy space for public health nutrition in an era of expanding IIAs. The authors first consider the main interventions proposed to reduce diet-related NCDs and their intersection with investment in the food supply chain. They then review the nature of investment regimes and relevant case law and examine ways to maximize policy space for public health nutrition intervention within this legal context. As foreign investment increases across the food-chain and more global recommendations discouraging the consumption of unhealthful products are issued, investment law will increase in importance as part of the legal architecture governing the food supply. The implications of investment law for public health nutrition measures depend on various factors: the measures themselves, the terms of the applicable agreements, the conditions surrounding the foreign investment and the policies governing agricultural support. This analysis suggests that governments should adopt proactive measures - e.g. the clarification of terms and reliance on exceptions - to manage investment and protect their regulatory autonomy with respect to public health nutrition. Source


Liu K.,University of Sydney | Kaffes A.J.,Morrow Gastroenterology and Liver Center
European Journal of Gastroenterology and Hepatology | Year: 2012

Iron deficiency anaemia (IDA) is the most common form of anaemia worldwide. In men and postmenopausal women the commonest cause of IDA is blood loss from lesions in the gastrointestinal tract, making it a common cause of referral to gastroenterologists. Causes of IDA relate either to blood loss or iron malabsorption. After confirmation with laboratory tests, gastrointestinal evaluation is almost always indicated to exclude gastrointestinal malignancy. Specific patient groups such as premenopausal women, patients with low-normal ferritin and iron-deficient patients without anaemia may need an individualized approach. A small proportion of patients have recurrent or persistent IDA despite negative standard endoscopies. These patients with obscure gastrointestinal bleeding usually require evaluation of the small bowel with capsule endoscopy or double balloon enteroscopy. Treatment should involve prompt iron replacement plus diagnostic steps directed towards correcting the underlying cause of IDA. Oral iron replacement is cheap and effective, but parenteral (intravenous) therapy may be required due to intolerance, noncompliance or treatment failure with oral therapy. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source


Ostrikov K.,University of Sydney | Mehdipour H.,Sahand University of Technology
Applied Physics Letters | Year: 2011

It is shown that plasmas can minimize the adverse Gibbs-Thompson effect in thin quantum wire growth. The model of Si nanowire nucleation includes the unprecedented combination of the plasma sheath, ion- and radical-induced species creation and heating effects on the surface and within an Au catalyst nanoparticle. Compared to neutral gas thermal processes, much thinner, size-selective wires can nucleate at the same temperature and pressure while much lower energy and matter budget is needed to grow same-size wires. This explains the experimental observations and may lead to energy- and matter-efficient synthesis of a broader range of one-dimensional quantum structures. © 2011 American Institute of Physics. Source


Chan B.,University of Sydney | Yim W.-L.,Institute of High Performance Computing of Singapore
Journal of Chemical Theory and Computation | Year: 2013

High-level CCSD(T)-F12-type procedures have been used to assess the performance of a variety of computationally less demanding methods for the calculation of cohesive energies for small to medium-sized gold clusters. For geometry optimization for small gold clusters, the PBE-PBE/cc-pVDZ-PP procedure gives structures that are in close agreement with the benchmark geometries. We have devised a CCSD(T)-F12b-based composite protocol for the accurate calculation of cohesive energies for medium-sized gold clusters. Using these benchmark (nonspin-orbit vibrationless) cohesive energies, we find that fairly good agreement is achieved by the PBE-PBE-D3/cc-pVTZ-PP method. In conjunction with PBE-PBE/cc-pVDZ-PP zero-point vibrational energies and spin-obit corrections obtained with the PBE-PBE-2c/dhf-TZVP-2c method, we have calculated 0 K cohesive energies for Au2-Au20. Extrapolation of these cohesive energies to bulk yields an estimated value of 383.2 kJ mol -1, which compares reasonably well with the experimental value of 368 kJ mol-1. © 2013 American Chemical Society. Source


Adams M.A.,University of Sydney | Adams M.A.,Bushfire Cooperative Research Center
Forest Ecology and Management | Year: 2013

Global evidence posits that we are on the cusp of fire-driven 'tipping points' in some of the world's most important woody biomes including savannah woodlands, temperate forests, and boreal forests, with consequences of major changes in species dominance and vegetation type. The evidence also suggests that mega-fires are positive feedbacks to changing climates via carbon emissions, and will be responsible for large swings in water yield and quality from temperate forests at the regional scale.Two factors widely considered to have contributed to our current proximity to tipping points are changing climates and human management - the latter most obviously taking the form of allowing fuels to build up, either through policies of fire suppression or failure to implement sufficient fuel reduction fires - to the point where wildfire intensity increases dramatically. Much of the evidence comes from Australia and the USA, but domains such as Africa and the boreal north provide additional insights.Forests adapted to regimes of low-moderate intensity fires may not face the same challenges as the iconic ash forests of Australia and the coniferous forests of Yellowstone or the west coast of the USA that are adapted to high intensity fire. However the often modest physical barriers (including distance, topography and climate) between forests adapted to more frequent, low-moderate intensity fires on the one hand, and less frequent, high intensity fires on the other, are easily overcome by confluences of continually increasing fuel loads and changing climates that serve to increase both fire frequency and intensity.For temperate forests, we can mitigate the extent of large-scale, high intensity fires and their consequences if we carefully use fuel reduction fires and other standard forest management practises such as thinning. Mitigation will require assessing impacts on biodiversity of smaller, low-intensity fires at intervals of 5-10. years (to reduce fuels and mitigate fire size and intensity), against those of large-scale, high intensity wildfires at increasing (but unknown) frequency. Mitigation will require that forests be managed contiguously, not via different agencies with different objectives according to land tenure. Managing requires that governments and the communities they serve acknowledge the limitations of fire-suppression. Mitigating the incidence and effects of large-scale, high intensity fires through embracing the use of managed fire in conjunction with judicious use of fire suppression offers opportunity to avoid potentially large changes in vegetation and biomass (e.g. abundance of dominant species, biodiversity, fuel structure and loads), as well as in water yield and quality and carbon carrying capacity. © 2012 Elsevier B.V. Source


Webster M.M.,University of St. Andrews | Ward A.J.W.,University of Sydney
Biological Reviews | Year: 2011

There has been considerable interest among biologists in the phenomenon of non-human animal personality in recent years. Consistent variations among individuals in their behavioural responses to ecologically relevant stimuli, often relating to a trade-off between level of risk and reward, have been recorded in a wide variety of species, representing many animal taxa. Research into behavioural variation among individuals has major implications for our understanding of ecological patterns and processes at scales from the level of the individual to the level of the population. Until recently, however, many studies that have considered the broader ecological implications of animal personality have failed to take into account the crucial moderating effect of social context. It is well documented that social processes, such as conformity and facilitation, exert considerable influence on the behaviour of grouping animals and hence that isolated individuals may often behave in a qualitatively as well as quantitatively different manner to those in groups. Recently, a number of studies have begun to address aspects of this gap in our knowledge and have provided vital insights. In this review we examine the state of our knowledge on the relationship between individual personality and sociality. In doing so we consider the influence of the social context on individual personality responses, the interaction between the collective personalities of group members and the expression of those personalities in the individual, and the influence of the personalities of group members on group structure and function. We propose key areas of focus for future studies in order to develop our understanding of this fundamentally important area. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society. Source


Van Doorn N.,University of Sydney
Disability and Rehabilitation | Year: 2010

Purpose. The aim of this article was to review the evidence for using exercise programs to improve pulmonary function and fitness in children with cystic fibrosis (CF). Method. Electronic databases - Medline, SPORTDiscus, CINAHL, AMED, EMBASE, and Cochrane Central Register of Controlled Trials were searched with terms CF and keywords related to exercise. These papers were analysed for study quality, participant details, exercise intervention details, and outcomes on pulmonary function and fitness components. Results. Only four randomized controlled trials (RCTs) met the eligibility criteria for review. These detailed exercise interventions cover short- and long-term duration. Modalities consisted of aerobic, strength, and anaerobic interventions. Severity of CF ranged from mild to severe. Significant improvement in pulmonary function was seen from short-term inhospital aerobic or strength interventions. Significant strength gains were seen from strength training interventions. Aerobic fitness was shown to improve with short-term aerobic training. Conclusions. There is some evidence to support that both aerobic and strength training can impact positively on pulmonary function, aerobic fitness, and strength. More RCTs in this area would be welcomed. There is potential for future research into designing exercise programs for children with CF using a combination of modalities. © 2010 Informa UK Ltd. Source


Objective The study aims to provide information about variance components of psychosocial outcomes: within and between-participant variance, within-participant correlation and for cluster randomised trials, the intra-cluster correlation (ICC) and, also, to demonstrate how estimates of these variance components and ICCs can be used to design randomised trials and cluster randomised trials. Method Data from 15 longitudinal multi-centre psycho-oncology studies were analysed, and variance components including ICCs were estimated. Studies with psychosocial outcomes that had at least one measurement post-baseline including individual randomised controlled trials, cluster randomised trials and observational studies were included. Results Variance components and ICCs from 87 outcome measures were estimated. The unadjusted, single timepoint (first post-baseline) ICCs ranged from 0 to 0.16, with a median value of 0.022 and inter-quartile range 0 to 0.0605. The longitudinal ICCs ranged from 0 to 0.09 with a median value of 0.0007 and inter-quartile range 0 to 0.018. Conclusions Although the magnitude of variance components and ICCs used for sample-size calculation cannot be known in advance of the study, published estimates can help reduce the uncertainty in sample-size calculations. Psycho-oncology researchers should be conservative in their sample-size calculations and use approaches that improve efficiency in their design and analysis. Copyright © 2012 John Wiley & Sons, Ltd. Source


Hunter D.J.,University of Sydney
New England Journal of Medicine | Year: 2015

A 67-year-old woman with right-knee osteoarthritis is referred by her primary care physician for treatment of her knee pain. The patient weighs 83 kg and is 161 cm tall, and her body-mass index (the weight in kilograms divided by the square of the height in meters) is 32. She has had pain intermittently for 9 years, which has been relieved with infrequent use of naproxen. She has recently become more sedentary and is finding it increasingly difficult to play golf. A recent radiograph of her right knee reveals moderate joint-space narrowing and osteophytes, affecting primarily the medial tibiofemoral compartment and lateral patellofemoral compartment. A friend at her golf club received a hyaluronate injection and had sustained relief of her knee pain for 6 months. The patient inquires about whether this form of therapy may be appropriate for her. The specialist recommends weight loss and exercise and counsels the patient about the appropriate use of viscosupplements. Copyright © 2015 Massachusetts Medical Society. Source


Croom S.M.,University of Sydney
Astrophysical Journal | Year: 2011

We examine how much information measured broad-line widths add to virial black hole (BH) mass estimates for flux-limited samples of quasars. We do this by comparing the BH mass estimates to those derived by randomly reassigning the quasar broad-line widths to different objects and re-calculating the BH mass. For 9000 BH masses derived from the Hβ line we find that the distributions of original and randomized BH masses in the MBH-redshift plane and the MBH-luminosity plane are formally identical. A two-dimensional Kolmogorov-Smirnov test does not find a difference at >90% confidence. For the Mg II line (32,000 quasars) we do find very significant differences between the randomized and original BH masses, but the amplitude of the difference is still small. The difference for the C IV line (14,000 quasars) is 2σ-3σ and again the amplitude of the difference is small. Subdividing the data into redshift and luminosity bins we find that the median absolute difference in BH mass between the original and randomized data is 0.025, 0.01, and 0.04dex for Hβ, Mg II, and C IV, respectively. The maximum absolute difference is always ≤0.1dex. We investigate whether our results are sensitive to corrections to Mg II virial masses, such as those suggested by Onken & Kollmeier. These corrections do not influence our results, other than to reduce the significance of the difference between original and randomized BH masses to only 1σ-2σ for Mg II. Moreover, we demonstrate that the correlation between mass residuals and Eddington ratio discussed by Onken & Kollmeier is more directly attributable to the slope of the relation between Hβ and Mg II line width. The implication is that the measured quasar broad-line velocity widths provide little extra information, after allowing for the mean velocity width. In this case virial estimates are equivalent to MBHL ∝ α, with L/LEddL ∝ 1-α (with α ≃ 0.5). This leaves an unanswered question of why the accretion efficiency changes with luminosity in just the right way to keep the mean broad-line widths fixed as a function of luminosity. © 2011. The American Astronomical Society. All rights reserved. Source


Semsarian C.,Centenary Institute | Semsarian C.,University of Sydney | Hamilton R.M.,University of Toronto
Heart Rhythm | Year: 2012

Sudden Cardiac Death (SCD) is a major and tragic complication of a number of cardiovascular diseases. While in the older populations, SCD is most frequently caused by underlying coronary artery disease and heart failure, in those aged under 40 years, the causes of SCD commonly include genetic disorders, such as inherited cardiomyopathies and primary arrhythmogenic diseases. As part of the evaluation of families in which SCD has occurred, the role of genetic testing has evolved as an important feature in both establishing an underlying diagnosis and in screening at-risk family relatives. Specifically, in cases where no definitive cause is identified at postmortem, i.e. Sudden Unexpected Death (SUD), the "molecular autopsy" has emerged as a key process in the investigation of the cause of death. The combination of clinical and genetic evaluation of families in which SUD has occurred provides a platform for early initiation of therapeutic and prevention strategies, with the ultimate goal to reduce sudden death among the young in our communities. Source


Neal B.,University of Sydney
Canadian Journal of Cardiology | Year: 2014

High blood pressure is the leading cause of premature mortality worldwide. Reducing salt intake lowers blood pressure and blood pressure-lowering reduces vascular disease. There is a very high likelihood that reducing dietary salt intake will prevent vascular disease and no evidence to suggest it will cause harm. With average population salt consumption levels typically 5-10 times greater than physiological requirements, even moderately effective community-wide salt reduction programs offer the potential for very large health gains. This opportunity has been recognized and adopted by the World Health Organization as a priority action to combat chronic diseases. © 2014 Canadian Cardiovascular Society. Source


Bathgate R.,University of Sydney
Reproduction in Domestic Animals | Year: 2011

Contents: While being an important component of normal cellular function, excess levels of reactive oxygen species (ROS) cause cell damage and death. The ability to protect sperm against oxidative damage is of particular importance in the artificial reproduction industry because of the increased production of ROS by the sperm cell during processing. This review discusses the formation of ROS and the use of antioxidants in protecting boar sperm against oxidative damage. © 2011 Blackwell Verlag GmbH. Source


Sakr S.,University of New South Wales | Liu A.,University of New South Wales | Batista D.M.,University of Campinas | Alomari M.,University of Sydney
IEEE Communications Surveys and Tutorials | Year: 2011

In the last two decades, the continuous increase of computational power has produced an overwhelming flow of data. Moreover, the recent advances in Web technology has made it easy for any user to provide and consume content of any form. This has called for a paradigm shift in the computing architecture and large scale data processing mechanisms. Cloud computing is associated with a new paradigm for the provision of computing infrastructure. This paradigm shifts the location of this infrastructure to the network to reduce the costs associated with the management of hardware and software resources. This paper gives a comprehensive survey of numerous approaches and mechanisms of deploying data-intensive applications in the cloud which are gaining a lot of momentum in both research and industrial communities. We analyze the various design decisions of each approach and its suitability to support certain classes of applications and end-users. A discussion of some open issues and future challenges pertaining to scalability, consistency, economical processing of large scale data on the cloud is provided. We highlight the characteristics of the best candidate classes of applications that can be deployed in the cloud. © 2005 IEEE. Source


Goumas C.,University of Sydney
European Journal of Sport Science | Year: 2014

Home advantage is well documented in a wide range of team sports including association football (soccer). Home team crowd support has been shown to be a likely causal factor and its influence on referee decision-making appears to play a significant role. Match data from the 2009/2010 and 2010/2011 seasons of the Union of European Football Associations (UEFA) Champions League and Europa League were used to investigate referee bias in terms of the association between match location (home vs. away) and disciplinary sanctions used by football referees. The adjusted mean number of yellow cards received by home and away teams and the ratios of these means were estimated from Poisson regression models. After controlling for within-match measures of attacking dominance referees in the Champions League and Europa League issued 25% (p<0.001) and 10% (p=0.002) more yellow cards, respectively, to away teams than to home teams. The higher level of home team bias in the Champions League appeared to be mainly due to higher crowd densities. In a combined analysis of both UEFA leagues the magnitude of referee bias increased with increasing crowd density (p<0.001). Crowd size and crowd proximity were not associated with referee bias after controlling for crowd density. These results provide further evidence that crowd support influences referee decisions. Failure to control for within-match team performance may over-estimate the extent of referee bias in terms of the number of disciplinary sanctions used. © 2014 Copyright European College of Sport Science. Source


Wellings C.R.,University of Sydney
Euphytica | Year: 2011

Stripe rust, caused by Puccinia striiformis, has been an important disease of wheat, barley, rye, triticale and certain graminaceous hosts for centuries. The significance of the disease on cultivated cereals has waxed and waned according to the vagaries of climate, inoculum levels and susceptible varieties. A progressive understanding of pathogen biology has revealed levels of specialisation between and within host groups, and these had varying impacts on the hosts concerned. The most economically important form is P. striiformis f. sp. tritici (Pst), the causal pathogen of stripe (yellow) rust of wheat, which is the major focus of this paper. The recent discovery of the perfect stage of Pst on Berberis spp. will encourage further work to uncover the potential importance of the sexual stage in pathogen biology in regions where Berberis spp. occur. A review of the evolution of pathotypes within Pst over the past 50 years reveals recurrent pandemics emanating from a combination of specific virulence in the pathogen population, wide scale cultivation of genetically similar varieties, and agronomic practices that led to high yield potential. When these factors operate in concert, regional stripe rust epidemics have proven to be dramatic, extensive and serious in terms of the magnitude of losses and the economic hardships endured. A review of these epidemics suggests that little progress has been made in containing the worst effects of epidemics. The current status of stripe rust was gauged from a survey of 25 pathologists and breeders directly associated with the disease. It was evident that Pst remains a significant threat in the majority of wheat growing regions of the world with potential to inflict regular regional crop losses ranging from 0.1 to 5%, with rare events giving losses of 5-25%. Regions with current vulnerability include the USA (particularly Pacific North West), East Asia (China north-west and south-west), South Asia (India, Pakistan, Nepal), Oceania (Australia, New Zealand), East Africa (Ethiopia, Kenya), the Arabian Peninsula (Yemen) and Western Europe (east England). The resources deployed to contain the worst effects of Pst will need to find a balance between training a new generation of breeders and pathologists in host-pathogen genetics, and an investment in infrastructure in IARCs and NARs. © 2011 Springer Science+Business Media B.V. Source


Minasny B.,University of Sydney | Hartemink A.E.,ISRIC
Earth-Science Reviews | Year: 2011

It is practically impossible to measure soil properties continuously at each location across the globe. Therefore, it is necessary to have robust systems that can predict soil properties at a given location. That is needed in many tropical countries where the dearth of soil property measurements is large. This paper reviews the use of pedotransfer functions (PTF) for predicting properties of soils in the tropics. First, the guiding principles of prediction and the type of predictors are discussed, including laboratory data, field description and soil morphology, electromagnetic spectrum, proximal and remote sensed data. In the subsequent section, PTFs are discussed for soil physical and chemical properties followed by infrared spectroscopy, proximal sensing and remote sensing. An analysis of ISRIC (mainly tropical) and USDA (mainly temperate) soil databases showed that soils in the tropics have higher clay content, lower cation exchange capacity, higher bulk density, lower water content at - 10 kPa and - 1500 kPa than soils in the temperate regions. Various methods developed in temperate regions can be applied for the soils in the tropical regions although calibration and careful selection of predictors remains necessary. It is concluded that PTFs are an important tool to overcome the dearth of soil data in many tropical countries. © 2011 Elsevier B.V. Source


Elliot S.,University of Sydney
MIS Quarterly: Management Information Systems | Year: 2011

The quality and future of human existence are directly related to the condition of our natural environment, but we are damaging the environment. Scientific evidence has mounted a compelling case that human behavior is responsible for deterioration in the Earth's natural environment, with the rate of deterioration predicted to increase in the future. Acknowledging this evidence, the governments of 192 countries have formally agreed to take action to resolve problems with the climate system, one of the most highly stressed parts of the natural environment. While the intention is clear, the question of how best to proceed is not. The research reported here undertook a three-phase approach of selecting, analyzing, and synthesizing relevant literature to develop a holistic, transdisciplinary, integrative framework for IT-enabled business transformation. The focus on business transformation is because business is recognized as being a critical contributor in realizing the challenges of environmental sustainability due to its potential capacity for innovation and change-locally, nationally, and globally. This article also serves as a resource base for researchers to begin to undertake significant information systems and multidisciplinary work toward the goal of environmental sustainability. Through selection and analysis of illustrative examples of current work from 12 academic disciplines across 6 core categories, the framework addresses the key issues of uncertainty: (1) What is meant by environmental sustainability? (2) What are its major challenges? (3) What is being done about these challenges? (4) What needs to be done?. Source


Eggleton B.J.,University of Sydney | Luther-Davies B.,Australian National University | Richardson K.,Clemson University
Nature Photonics | Year: 2011

The unique and striking material properties of chalcogenide glasses have been studied for decades, providing applications in the electronics industry, imaging and more recently in photonics. This Review summarizes progress in photonic devices that exploit the unique optical properties of chalcogenide glasses for a range of important applications, focusing on recent examples in mid-infrared sensing, integrated optics and ultrahigh-bandwidth signal processing. © 2011 Macmillan Publishers Limited. All rights reserved. Source


Celi P.,University of Sydney
Immunopharmacology and Immunotoxicology | Year: 2011

The study of oxidative stress is a relatively young field of research in ruminant medicine. Oxidative stress results from increased exposure to or production of oxidants, or from decreased dietary intake, de novo synthesis or increased turnover of antioxidants. The understanding of the role of oxidants and antioxidants in physiological and pathological conditions is rapidly increasing. Oxidative stress is an active field of research in veterinary medicine and has been implicated in numerous disease processes including sepsis, mastitis, acidosis, ketosis, enteritis, pneumonia, respiratory, and joint diseases. Compared to human medicine, only a limited number of conditions have been investigated in regard to the effects of oxidative stress in ruminants. Studies in cattle have been sporadic and mainly with mastitis, pneumonia, and retained placenta. More recently, studies have been focused on metabolic diseases that affect dairy cows during the peripartum period. Numerous and rapidly evolving methodologies for evaluating oxidative stress are available to researchers and clinicians, each with their own distinct advantages and disadvantages. Differences in models and methodologies make it difficult to make meaningful comparisons, even for studies that seem quite similar superficially. With this in mind, it is the goal of this review to discuss the advantages and shortfalls of different methodologies commonly used to measure oxidative stress and damage in ruminants. Clarity of understanding of the pathophysiology of oxidative stress in ruminants will allow the design of specific antioxidant therapies. Future research should focus on the establishment of a reference panel of biomarker of oxidative stress to be used in ruminant medicine. To help accelerate practical applications, we propose the development of an oxidative stress index as an approach in ruminant and veterinary medicine. © 2011 Informa Healthcare USA, Inc. Source


Garrett G.,University of Sydney
Global Policy | Year: 2010

The post-global financial crisis world will be increasingly dominated by China and the United States. What the de facto G2 do, together, independently or in conflict, will increasingly define the global bounds of the possible. Both countries want to embed their bilateral diplomacy in the multilateralism of the G20. The problem for the emergent G2 in G20 global architecture is that economic relations between China and the US will be increasingly difficult to manage. The large economic imbalances between the two countries, in which China buys American debt and Americans buy Chinese goods, will endure. Before the crisis, the codependence these imbalances created was a source of stability in Sino-American relations. After the crisis, they will be a source of frustration and conflict, as the second half of 2009 showed. To manage economic relations between China and the US effectively, the G20 agenda will have to move from crisis management to strategic planning for the global economy. The G20 will also have to become more institutionalized, but in a way that resembles more a nonexecutive board of directors of a multinational firm than a management committee of C-level executives. © 2010 London School of Economics and Political Science and John Wiley & Sons Ltd. Source


Figueira W.F.,University of Technology, Sydney | Figueira W.F.,University of Sydney | Booth D.J.,University of Technology, Sydney
Global Change Biology | Year: 2010

The southeast coast of Australia is a global hotspot for increasing ocean temperatures due to climate change. The temperate incursion of the East Australian Current (EAC) is increasing, affording increased connectivity with the Great Barrier Reef. The survival of tropically sourced juveniles over the winter is a significant stumbling block to poleward range shifts of marine organisms in this region. Here we examine the dependence of overwintering on winter severity and prewinter recruitment for eight species of juvenile coral reef fishes which are carried into temperate SE Australia (30-371S) by the EAC during the austral summer. The probability of persistence was most strongly influenced by average winter temperature and there was no effect of recruitment strength. Long-term (138 years) data indicate that winter water temperatures throughout this region are increasing at a rate above the global average and predictions indicate a further warming of >2 °C by the end of the century. Rising ocean temperatures are resulting in a higher frequency of winter temperatures above survival thresholds. Current warming trajec-tories predict 100% of winters will be survivable by at least five of the study species as far south as Sydney (34°S) by 2080. The implications for range expansions of these and other species of coral reef fish are discussed. © 2009 Blackwell Publishing Ltd. Source


Short A.D.,University of Sydney
Coastal Engineering | Year: 2010

The Australian coast contains 10,685 beaches which occupy 49% of the 30,000 km coast and average 1.37 km in length. Their relatively short length is largely due to the presence of bedrock, calcarenite and laterite, which form boundaries to many of the beaches, as well as occurring as rocks, reefs and islands along and off the beaches. This geological inheritance plays a major role in Australian beach systems - determining their length and through wave refraction and attenuation influencing beach location, shape, type, morphodynamics and circulation, which in turn influence sediment transport and the backing dune and barrier systems. This paper uses a database covering every Australian beach to review the role of headlands, rocks and reefs on Australian beaches. Major effects are the short average beach length; reduction in breaker height resulting in lower energy beach types; wave refraction resulting in increased beach curvature; the presence of topographic rips on moderate and higher energy beaches and megarips during high wave conditions; and the interruption of and/or trapping of longshore sand transport leading to beach rotation. © 2009 Elsevier B.V. All rights reserved. Source


Chan E.H.W.,University of Sydney
Journal of Lightwave Technology | Year: 2011

A technique that enables two or more infinite impulse response optical delay lines to be connected in series without the coherent interference problem is presented. It is based on inserting an optical frequency shifter into the infinite impulse response optical delay line structure. Signal processors based on the cascaded optical delay line structure have a higher frequency response performance than the single optical delay line structure. Experimental results are presented, which demonstrate a dual series frequency shifting amplified recirculating delay line can realise a high-resolution, high skirt selectivity, high stopband rejection level bandpass filter response, and a narrow-passband, flat-top bandpass filter response using a non-commensurate delay line approach. © 2011 IEEE. Source


Dietz H.P.,University of Sydney
Acta Obstetricia et Gynecologica Scandinavica | Year: 2015

Cesarean section rates have become a political issue, attracting the attention of governments, health bureaucrats and professional organizations. In some instances this has led to a renewed interest in forceps delivery, even Kielland's rotational forceps. It is suggested that calls for a greater use of forceps, especially rotational forceps, are ill-advised and commonly based on ignorance of recent urogynecological and imaging literature. Forceps use is associated with a much higher likelihood of major maternal trauma, especially to the anal sphincter and levator ani muscles, which may result in substantial future morbidity. Hence, its use should be avoided whenever possible. This is particularly obvious for rotational forceps. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology. Source


Johnston G.A.R.,University of Sydney
Neurochemical Research | Year: 2014

Muscimol, a psychoactive isoxazole from Amanita muscaria and related mushrooms, has proved to be a remarkably selective agonist at ionotropic receptors for the inhibitory neurotransmitter GABA. This historic overview highlights the discovery and development of muscimol and related compounds as a GABA agonist by Danish and Australian neurochemists. Muscimol is widely used as a ligand to probe GABA receptors and was the lead compound in the development of a range of GABAergic agents including nipecotic acid, tiagabine, 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol, (Gaboxadol®) and 4-PIOL. © 2014, Springer Science+Business Media New York. Source


Baxter R.C.,University of Sydney
Nature Reviews Cancer | Year: 2014

The six members of the family of insulin-like growth factor (IGF) binding proteins (IGFBPs) were originally characterized as passive reservoirs of circulating IGFs, but they are now understood to have many actions beyond their endocrine role in IGF transport. IGFBPs also function in the pericellular and intracellular compartments to regulate cell growth and survival-they interact with many proteins, in addition to their canonical ligands IGF-I and IGF-II. Intranuclear roles of IGFBPs in transcriptional regulation, induction of apoptosis and DNA damage repair point to their intimate involvement in tumour development, progression and resistance to treatment. Tissue or circulating IGFBPs might also be useful as prognostic biomarkers. © 2014 Macmillan Publishers Limited. Source


Howell V.M.,University of Sydney
Seminars in Cell and Developmental Biology | Year: 2014

The development of preclinical spontaneous genetically engineered mouse models (GEMMs) requires an understanding of the genetic basis of the human disease. Such robust models have proven invaluable for increasing understanding of human malignancies as well as identifying new biomarkers and testing new therapies for these diseases. While GEMMs have been reported for ovarian cancer, the majority have proven disappointing overall in their recapitulation of paired genetic and histological features especially for serous ovarian epithelial cancer. This review describes GEMMs for ovarian cancer, in particular, high grade serous ovarian cancer and assesses these in light of recent changes in our understanding of the human malignancy. © 2014 Elsevier Ltd. Source


The impact of climate change on US agriculture has been debated for more than two decades, but the estimates ranged from no damage at the lower end to 80 % losses of grain yields at the higher end. This essay aims to help understand such divergent predictions by clarifying the concepts of weather and climate. First, the widely-read panel fixed effects models capture only the impacts of weather fluctuations but not of climate normals. Random weather fluctuations and climatic shifts are two different meteorological events and they have distinct implications on farming decisions. The former is perceived as random while the latter is perceived as non-random by the farmers. Using the historical corn yield data in the US, I explain the differences between the impact of random weather and that of climate change. Second, adaptation strategies to climatic changes and increased climate risks cannot be accounted for by the panel fixed effects models. Using the farm household data collected in sub-Saharan Africa and Latin America, I discuss quantitative significance of modeling adaptation strategies in the estimates of climate damage. Distinction between random weather fluctuations and climatic shifts is critical in modeling farming decisions, as they are fundamental to climate science, but is poorly understood by the impact researchers. © 2013 Springer Science+Business Media Dordrecht. Source


Ghafournia N.,University of Sydney
Aggression and Violent Behavior | Year: 2011

This paper explores the status of battered migrant women in Australian migration policy. It will start with a general review of domestic violence among migrant families as well as the historical changes in policies in response to this issue. It will be argued that the policies have been mostly shaped in order to protect non-resident women from being abused by their partners or husbands due to their uncertain residence status. However, there are still some significant concerns that are overlooked. These concerns, as will be discussed, are mostly related to underlying social, economic, and cultural factors. The current policies do not take these factors into account. When it comes to filling in the gaps by considering cultural and social factors, one needs to be aware of ideological and theoretical perspectives. By examining two perspectives a 'universalist' and a relativist, the paper will argue for the necessity of looking for a middle approach in addressing domestic violence against migrant women. In conclusion, by taking the moderate approach, further policy reforms will be proposed in order to fill the identified gaps in the policy. © 2011 Elsevier Ltd. Source


Darke S.,University of Sydney
Drug and Alcohol Review | Year: 2010

Issues. The toxicology of homicide offenders and victims, and homicide as a cause of death among psychoactive substance users. Approach. Review of the toxicology of homicide, and homicide as a cause of death among psychoactive substance users. Key Findings. A half or more of offenders are intoxicated by a psychoactive substance at the time of the homicide, with alcohol the most commonly reported substance. Levels of substances among victims are comparable with those seen among perpetrators. Among both offenders and victims, levels of substances far exceed population use. Among substance users, homicide specific mortality rates of substance users far exceed population rates. Reducing rates of alcohol and other drug consumption, at national and individual levels, can be expected to substantially reduce rates of, and risk for, homicide. Conclusions and Implications. Psychoactive substances are strongly associated with homicide. One of the major societal benefits that can be derived from active attempts to reduce alcohol and other drug use are reductions in homicide rates. [Darke S. The toxicology of homicide offenders and victims: A review. Drug Alcohol Rev 2009]. © 2009 Australasian Professional Society on Alcohol and other Drugs. Source


Cross R.,University of Sydney
American Journal of Physics | Year: 2011

The physics of swinging a tennis racquet is examined by modeling the forearm and the racquet as a double pendulum. We consider differences between a forehand and a serve, and show how they differ from the swing of a bat and a golf club. It is also shown that the swing speed of a racquet, like that of a bat or a club, depends primarily on its moment of inertia rather than on its mass. © 2011 American Association of Physics Teachers. Source


Myburgh J.,University of New South Wales | Finfer S.,University of Sydney
BMC Medicine | Year: 2013

The Fluid Expansion as Supportive Therapy (FEAST study) was an extremely well conducted study that gave unexpected results. The investigators had reported that febrile children with impaired perfusion treated in low-income countries without access to intensive care are more likely to die if they receive bolus resuscitation with albumin or saline compared with no bolus resuscitation at all. In a secondary analysis of the trial, published in BMC Medicine, the authors found that increased mortality was evident in patients who presented with clinical features of severe shock in isolation or in conjunction with features of respiratory or neurological failure. The cause of excess deaths was primarily refractory shock and not fluid overload. These features are consistent with a potential cardiotoxic or ischemia-reperfusion injury following resuscitation with boluses of intravenous fluid. Although these effects may have been amplified by the absence of invasive monitoring, mechanical ventilation or vasopressors, the results provide compelling insights into the effects of intravenous fluid resuscitation and potential adverse effects that extend beyond the initial resuscitation period. These data add to the increasing body of literature about the safety and efficacy of intravenous resuscitation fluids, which may be applicable to management of other populations of critically ill patients. © 2013 Myburgh and Finfer; licensee BioMed Central Ltd. Source


Chen M.,University of Sydney
Annual Review of Biochemistry | Year: 2014

Chlorophylls are magnesium-tetrapyrrole molecules that play essential roles in photosynthesis. All chlorophylls have similar five-membered ring structures, with variations in the side chains and/or reduction states. Formyl group substitutions on the side chains of chlorophyll a result in the different absorption properties of chlorophyll b, chlorophyll d, and chlorophyll f. These formyl substitution derivatives exhibit different spectral shifts according to the formyl substitution position. Not only does the presence of various types of chlorophylls allow the photosynthetic organism to harvest sunlight at different wavelengths to enhance light energy input, but the pigment composition of oxygenic photosynthetic organisms also reflects the spectral properties on the surface of the Earth. Two major environmental luencing factors are light and oxygen levels, which may play central roles in the regulatory pathways leading to the different chlorophylls. I review the biochemical processes of chlorophyll biosynthesis and their regulatory mechanisms. Copyright © 2014 by Annual Reviews. All rights reserved. Source


Han Z.J.,CSIRO | Ostrikov K.,CSIRO | Ostrikov K.,University of Sydney
Journal of the American Chemical Society | Year: 2012

Precisely controlled reactive chemical vapor synthesis of highly uniform, dense arrays of vertically aligned single-walled carbon nanotubes (SWCNTs) using tailored trilayered Fe/Al 2O 3/SiO 2 catalyst is demonstrated. More than 90% population of thick nanotubes (>3 nm in diameter) can be produced by tailoring the thickness and microstructure of the secondary catalyst supporting SiO 2 layer, which is commonly overlooked. The proposed model based on the atomic force microanalysis suggests that this tailoring leads to uniform and dense arrays of relatively large Fe catalyst nanoparticles on which the thick SWCNTs nucleate, while small nanotubes and amorphous carbon are effectively etched away. Our results resolve a persistent issue of selective (while avoiding multiwalled nanotubes and other carbon nanostructures) synthesis of thick vertically aligned SWCNTs whose easily switchable thickness-dependent electronic properties enable advanced applications in nanoelectronic, energy, drug delivery, and membrane technologies. © 2012 American Chemical Society. Source


Background: Proper noun anomia has received significant attention as a source of evidence for the organisation of the lexicon, and the neuroanatomical bases of language. There is also some evidence that people with aphasia and related disorders may have particular difficulty producing proper nouns. However, very few studies have examined how proper noun anomia manifests in everyday conversation.Aims: This study uses conversation analysis (CA) to describe how a man with chronic anomia constructed turns that referred to people, places, and other entities that can be named with proper nouns.Methods & Procedures: A man with chronic anomia following a closed head injury (Paul) was recorded during everyday conversations involving two friends and the researcher. Approximately 21/2 hours of recordings were collected and transcribed. A collection of referencing turns was assembled from this dataset and analysed.Outcomes & Results: Two design features of Paul's referencing turns are identified and described. First, Paul recurrently delayed the production of reference forms in referencing turns. It is speculated that these practices generated extra time for Paul to produce proper nouns. Second, Paul recurrently utilised common noun phrases (e.g., that young bloke) as reference forms in place of proper nouns. These references were easier to produce than proper nouns, and solicited proper nouns from his conversation partners. Securing the involvement of conversation partners allowed Paul to partially distribute the productive and moral responsibility for proper noun generation.Conclusions: It is argued that these turn construction practices represent adaptations to proper noun anomia in conversation. These findings may contribute to the development of interaction-focused interventions targeting referencing by people with anomia. Future investigation should focus on how the referencing turns of people with anomia change over time. © 2013 Copyright Taylor and Francis Group, LLC. Source


Colagiuri S.,University of Sydney
Diabetes, Obesity and Metabolism | Year: 2010

A pathogenic relationship exists between type 2 diabetes and obesity. Over the last decade, the escalation in diabetes cases has paralleled the rapid increase in obesity rates, constituting a global health crisis. Environmental risk factors attributed to the global increase in obesity include the consumption of high-calorie, high-fat foods and inadequate physical activity. Obese individuals may also have a genetic predisposition for obesity. Both diabetes and obesity confer an elevated risk of developing a range of complications and comorbidities, including cardiovascular disease, hypertension and stroke, which can complicate disease management. This review examines the aetiology of the linkages between diabetes and obesity and the range of available therapies. Recent clinical evidence substantiating the efficacy and safety of incretin-based antidiabetic therapies is analysed, in addition to data on antiobesity therapeutic strategies, such as antiobesity agents, behaviour modification and bariatric surgery. Glucose control is often accompanied by weight-neutral or modest weight reduction effects with DPP-4 inhibitor treatment (sitagliptin, vildagliptin, saxagliptin) and weight loss with GLP-1 receptor agonist therapy (exenatide, liraglutide). Studies of antiobesity agents including orlistat, sibutramine and rimonabant have shown attrition rates of 30-40%, and the long-term effects of these agents remain unknown. Bariatric surgical procedures commonly performed are laparoscopic adjustable banding of the stomach and the Roux-en-Y gastric bypass, and have produced type 2 diabetes remission rates of up to 73%. Therapeutic strategies that integrate glycaemic control and weight loss will assume greater importance as the prevalence of diabetes and obesity increase. © 2010 Blackwell Publishing Ltd. Source


Llewellyn G.,University of Sydney
Acta Obstetricia et Gynecologica Scandinavica | Year: 2012

Biological factors and/or the mothers' social-environmental situation may be responsible for the much higher relative risk for pregnant intellectually disabled women and their newborns reported in articles by Höglund et al. in this issue. This population has increased exposure to key social determinants of health such as poverty and social exclusion. This is compounded by institutional discriminatory beliefs and practices. People with intellectual disability may also struggle to communicate their needs effectively and to be heard and understood by health professionals. Further research is warranted to understand the reasons for two stand-out findings: why rates of stillbirth and perinatal death are significantly higher in this group and whether varying obstetric practices are responsible for the significantly lower use of pain relief during childbirth. Quality health care requires that due attention is given to meeting the specific needs of this vulnerable group of mothers and their newborns. © 2012 Nordic Federation of Societies of Obstetrics and Gynecology. Source


Heathers J.A.J.,University of Sydney
Frontiers in Physiology | Year: 2014

Frequency analysis of the electrocardiographic RR interval is a common method of quantifying autonomic outflow by measuring the beat-to-beat modulation of the heart (heart rate variability; HRV). This review identifies a series of problems with the methods of doing so-the interpretation of low-frequency spectral power, the multiple use of equivalent normalized low frequency (LFnu), high frequency (HFnu) and ratio (LF/HF) terms, and the lack of control over extraneous variables, and reviews research in the calendar year 2012 to determine their prevalence and severity. Results support the mathematical equivalency of ratio units across studies, a reliance on those variables to explain autonomic outflow, and insufficient control of critical experimental variables. Research measurement of HRV has a substantial need for general methodological improvement. © 2014 Heathers. Source


Fransen M.,University of Sydney
The Cochrane database of systematic reviews | Year: 2013

Heterotopic bone formation (HBF) in the soft tissues surrounding the hip joint is a frequent complication of hip surgery. Non-steroidal anti-inflammatory drugs (NSAIDs) administered in the immediate perioperative period reduce the risk of HBF. However, the magnitude of the effect on HBF, and the effects on other associated outcomes, such as pain and physical function, are uncertain. To determine the effects of perioperative NSAID therapy versus control on the risk of HBF and other outcomes in patients undergoing hip arthroplasty. We searched the Cochrane Bone, Joint and Muscle Trauma Group specialised register (October 2002), the Cochrane Central Register of Controlled Trials (The Cochrane Library issue 3, 2002), MEDLINE (1966 to October 2002), EMBASE (1988 to 2002 Week 43), CURRENT CONTENTS (1993 Week 27 to 2002 Week 44) and reference lists of articles. We also contacted trialists and drug manufacturers. All trials which enrolled patients scheduled to undergo hip arthroplasty with random or quasi-random allocation to perioperative NSAID or control and that recorded post-operative radiographically determined HBF. The primary outcome was post-operative radiographic HBF. Secondary outcomes were pain, function (including range of motion), gastro-intestinal and other bleeding complications, and other causes of major morbidity or mortality. Two reviewers independently assessed methodological quality and extracted data. All analyses were conducted on dichotomised outcomes. Sixteen randomised and two quasi-randomised trials involving a total of 4,763 patients were included. Overall, in 17 trials that examined the effects of medium to high doses of NSAIDs, there was a reduced risk of developing HBF after hip surgery (59% reduction, 95% confidence interval 54% to 64% reduction). In contrast, one large trial examining low-dose aspirin, demonstrated no effect on the risk of HBF (2% reduction, 95% confidence interval 15% reduction to 12% increase). There was strong evidence of differences in the size of the treatment effects observed between the trials examining medium to high doses of NSAIDs, but reasons were not clearly identified.There was a non-significant one third increased risk of gastro-intestinal side effects among patients assigned NSAIDs (29% increase, 95% confidence interval 0% to 76% increase). Most of this increase was due to an increased risk of minor gastro-intestinal complications. Data on the late post-operative outcomes of pain, impaired physical function and range of joint movement were few and no formal overviews of the effects of NSAIDs on these outcomes were possible. Perioperative NSAIDs, apart from low dose aspirin, appear to produce between a one half and two thirds reduction in the risk of HBF. With routine use, such agents may be able to prevent 15-20 cases of HBF among every 100 total hip replacements performed. However, while medium to high doses of perioperative NSAIDs clearly produce a substantial reduction in the incidence of radiographic HBF, there remains some uncertainty about short-term side effects of treatment and substantial uncertainty about effects on long-term clinical outcomes such as chronic pain and impaired physical function. The net effect of routine HBF prophylaxis with NSAIDs requires formal assessment in a randomised trial designed to determine the balance of benefits and risks for all outcomes. Source


Barnes L.A.,University of Sydney | Haehnelt M.G.,Institute of Astronomy and Kavli Institute for Cosmology
Monthly Notices of the Royal Astronomical Society | Year: 2014

We discuss the recent Baryon Oscillation Spectroscopic Survey measurement of a rather high bias factor for the host galaxies/haloes of damped Lyman alpha absorbers (DLAs), in the context of our previous modelling of the physical properties of DLAs within the Λ cold dark matter paradigm. Joint modelling of the column density distribution, the velocity width distribution of associated low-ionization metal absorption, and the bias parameter suggests that DLAs are hosted by galaxies with dark matter halo masses in the range 10.5 < log Mv<13, with a rather sharp cutoff at the lower mass end, corresponding to virial velocities of ~90 km s-1. The observed properties of DLAs appear to suggest very efficient (stellar) feedback in haloes with masses/virial velocities below the cutoff and a large retained baryon fraction (≳35 per cent) in haloes above the cutoff. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Interventions for autism are limited. The synthetic hormone oxytocin may provide a potential treatment to improve core social and behavioral difficulties in autism, but its efficacy has yet to be evaluated in young children who potentially may benefit to a greater extent. We investigated the efficacy, tolerability and safety of oxytocin treatment in young children with autism using a double-blind, randomized, placebo-controlled, crossover, clinical trial. Thirty-one children with autism received 12 International Units (IU) of oxytocin and placebo nasal spray morning and night (24 IU per day) for 5 weeks, with a 4-week washout period between each treatment. Compared with placebo, oxytocin led to significant improvements on the primary outcome of caregiver-rated social responsiveness. Overall, nasal spray was well tolerated, and the most common reported adverse events were thirst, urination and constipation. This study is the first clinical trial to support the potential of oxytocin as an early intervention for young children with autism to help improve social interaction deficits.Molecular Psychiatry advance online publication, 27 October 2015; doi:10.1038/mp.2015.162. © 2015 Macmillan Publishers Limited Source


Snowdon J.,University of Sydney
International Psychogeriatrics | Year: 2010

Background: The prevalence of mental disorders in long-term care (LTC) homes is high, but quality and availability of mental health services to assess and help in management of cases have been criticized. Method: Literature concerning mental health problems in LTC homes was reviewed, especially regarding models of mental health service delivery and factors that affect development, persistence and reduction of symptoms and distress. Results: The advantages of consultation-liaison arrangements and of telepsychiatry were noted.Discussions led to development of recommendations aimed at improving mental health expertise and provision of assessment and intervention services in LTC homes in diverse countries. Prompt recognition of mental health problems among residents is required, with availability of a team working within the facility to deal with these problems. Commonly such multidisciplinary teams are formed by facility staff linking with visiting mental health professionals or services. Quality of care is also affected by the organization, attitudes and education within LTC facilities. Conclusion: Provision of optimal mental health care in LTC settings is dependent on adequate funding, availability of expertise and education, positive and caring attitudes, recognition of needs, and supportive teamwork. The latter should include cooperative links between well-resourced and under-resourced regions. © 2010 International Psychogeriatric Association. Source


Reddel H.K.,University of Sydney
Journal of Allergy and Clinical Immunology | Year: 2015

In their most typical forms, asthma and chronic obstructive pulmonary disease (COPD) are clearly distinguishable, but many patients with chronic airflow limitation demonstrate features of both conditions and have worse health outcomes than those with either disease alone. This has been called the asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS), but as yet, it lacks a precise definition. However, given the different pathways by which a patient can come to demonstrate features of both asthma and COPD, ACOS is not thought to represent a single disease but to include several heterogeneous phenotypes with different underlying mechanisms. These issues have important implications for guidelines because some existing treatment recommendations for asthma and COPD are in conflict, and patients with both asthma and COPD have specifically been excluded from major pharmacologic trials. As a result, there is little evidence at present to support specific treatment recommendations for ACOS on the basis of efficacy or effectiveness, yet these patients continue to present for diagnosis and management, mainly in primary care. This article highlights the need for clinical guidance about ACOS, summarizes recommendations about its diagnosis and treatment from a sample of national asthma and COPD guidelines, and proposes a way forward, as suggested in a collaborative Global Initiative for Asthma/Global Initiative for Chronic Obstructive Lung Disease report, to provide health professionals with interim recommendations about syndromic recognition and initial treatment based on both potential effectiveness and potential risk. Additional research in broad populations is urgently needed to develop a precise definition for ACOS, characterize its phenotypes, and identify opportunities for targeted treatment. © 2015 American Academy of Allergy, Asthma & Immunology. Source


Gomes L.J.,University of Sydney
Current Allergy and Asthma Reports | Year: 2010

Cerebral vasculitis is diagnosed with difficulty. Its presentation with heterogeneous symptoms and signs often delays diagnosis. In this context, imaging plays an important role in advancing the diagnosis. Digital subtraction cerebral angiography, MRI, and MRA, the most useful examinations for vasculitis, provide supportive, but not pathognomonic, evidence of cerebral vasculitis. On MRI, multiple infarcts in different vascular territories and of different ages are suggestive of vasculitis. On digital subtraction cerebral angiography, areas of stenosis, dilatation, and occlusion are suggestive of vasculitis. Small vessel vasculitis is currently best demonstrated by changes seen in brain parenchyma on MRI, but high field strength (7 T) magnetic resonance angiography offers the possibility of directly evaluating small vessel vasculitis. Ultrasound and high-resolution contrast MRI are excellent modalities for evaluating the superficial extracranial circulation. © 2010 Springer Science+Business Media, LLC. Source


Chan E.H.W.,University of Sydney
Journal of Lightwave Technology | Year: 2011

Two new high-order infinite impulse response microwave photonic filters, which have multiple poles and zeros in the transfer characteristic, are presented. They are based on either the wavelength division multiplexing technique with a single infinite impulse response delay line structure or a single laser with multiple infinite impulse response delay line structures. A wavelength converter is used to increase the filter order without the coherent interference problem. A high-resolution and high-performance bandpass filter response can be realized. Experimental results are presented that demonstrate high-resolution bandpass filter responses with robust operation, and high stopband rejection level and high skirt selectivity. © 2011 IEEE. Source


McDonald T.M.,University of California at Berkeley | D'Alessandro D.M.,University of Sydney | Krishna R.,University of Amsterdam | Long J.R.,University of California at Berkeley
Chemical Science | Year: 2011

High capacity, high selectivity, and low-cost regeneration conditions are the most important criteria by which new adsorbents for post-combustion carbon dioxide capture will be judged. The incorporation of N,N′- dimethylethylenediamine (mmen) into H3[(Cu4Cl) 3(BTTri)8 (CuBTTri; H3BTTri = 1,3,5-tri(1H-1,2,3-triazol-4-yl)benzene), a water-stable, triazolate-bridged framework, is shown to drastically enhance CO2 adsorption, resulting in one of the best performing metal-organic frameworks for CO2 separation reported to date. High porosity was maintained despite stoichiometric attachment of mmen to the open metal sites of the framework, resulting in a BET surface area of 870 m2 g-1. At 25 °C under a 0.15 bar CO2/0.75 bar N2 mixture, mmen-CuBTTri adsorbs 2.38 mmol CO2 g-1 (9.5 wt%) with a selectivity of 327, as determined using Ideal Adsorbed Solution Theory (IAST). The high capacity and selectivity are consequences of the exceptionally large isosteric heat of CO2 adsorption, calculated to be -96 kJ mol-1 at zero coverage. Infrared spectra support chemisorption between amines and CO2 as one of the primary mechanisms of uptake. Despite the large initial heat of adsorption, the CO2 uptake was fully reversible and the framework could be easily regenerated at 60 °C, enabling a cycling time of just 27 min with no loss of capacity over the course of 72 adsorption/desorption cycles. © The Royal Society of Chemistry 2011. Source


Connell J.,University of Sydney
Singapore Journal of Tropical Geography | Year: 2010

Predictions for the future of small islands and island states are invariably pessimistic. Poverty has increased, free trade offers limited possibilities, governance is weak and urban biased, and aid dependence has not declined despite aid fatigue. Populations are contracting from outer islands. One outcome has been increasing migration and remittances, as safety valve and diversification strategy. Selective migration and limited return migration have contributed to skill drain. Yet migration has enabled peripheries to survive through improved welfare and investment, and sustained social structures. Formal development strategies, whether international or national, emphasize 'modernity', with culture to be abhorred and ignored; yet hybridity offers possibilities for more equitable sustainable development. A combination of migration, economic diversification and cultural hybridity provides alternative development trajectories. © 2010 The Author. Journal compilation © 2010 Department of Geography, National University of Singapore and Blackwell Publishing Asia Pty Ltd. Source


Bird G.A.,University of Sydney
Physics of Fluids | Year: 2011

The quantum-kinetic, or Q-K, model is based on the quantum vibration model that is employed in the computation of gas flows at the molecular level by the direct simulation Monte Carlo (DSMC) method. The Q-K procedure for dissociation is physically realistic within the context of the vibration model in that the reaction occurs upon the selection of the vibrational level that corresponds to dissociation. An analogous, but entirely phenomenological, procedure has been presented for endothermic exchange and chain reactions. These procedures for the endothermic reactions have been well validated, but the existing procedures for the corresponding exothermic reactions have proved to be problematic. This paper presents new procedures for the exothermic reactions that are computationally efficient and provide a near exact match with the equilibrium constant of statistical mechanics. The Q-K model does not depend on the availability of continuum rate coefficients. Instead, the simplicity of the new DSMC procedures allows analytical expressions to be written down for the corresponding rate coefficients in an equilibrium gas. These are used to validate the Q-K model for reactions in high temperature air and in hydrogen-oxygen combustion. The development of the Q-K model has been driven by the need for efficient reaction procedures in DSMC applications that often involve the computation of billions of simulated collisions. It is not intended to compete with the modern theories for gas-phase chemical reactions that employ more accurate physical representations of real reactions. At the same time, the degree of validation of the model is such that the analytical expressions for the rate coefficients that correspond to the model should be useful in their own right. © 2011 American Institute of Physics. Source


Osborn D.A.,University of Sydney
The Cochrane database of systematic reviews | Year: 2013

Prebiotics (commonly oligosaccharides) added to infant feeds have the potential to prevent sensitisation of infants to dietary allergens. To determine the effect of prebiotic given to infants for the prevention of allergy. We performed an updated search in August 2012 of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8), MEDLINE, EMBASE, conference proceedings, citations, expert informants and clinical trials registries. Randomised and quasi-randomised controlled trials that compared the use of a prebiotic to no prebiotic, or a specific prebiotic compared to a different prebiotic in infants for prevention of allergy. Assessment of trial quality, data extraction and synthesis of data were performed using the standard methods of The Cochrane Collaboration. The 2012 update identified 13 studies classified as ongoing or awaiting classification (yet to report allergy outcomes). Forty-three studies were excluded, primarily as no allergy data were reported, although none of these enrolled infants were at high risk of allergy. Four studies enrolling 1428 infants were eligible for inclusion. All studies were at high risk of attrition bias. Allergy outcomes were reported from four months to two years of age.Meta-analysis of two studies (226 infants) found no significant difference in infant asthma although significant heterogeneity was found between studies. Meta-analysis of four studies found a significant reduction in eczema (1218 infants, typical risk ratio 0.68, 95% CI 0.48 to 0.97; typical risk difference -0.04, 95% CI -0.07 to -0.00; number needed to treat to benefit (NNTB) 25, 95% CI 14 to > 100; P = 0.03). No statistically significant heterogeneity was found between studies. One study reported no significant difference in urticaria.No statistically significant subgroup differences were found according to infant risk of allergy or type of infant feed. However, individual studies reported a significant reduction in asthma and eczema from supplementation with a mixture of galacto- and fructo-oligosaccharide (GOS/FOS 9:1 ratio) (8 g/L) in infants at high risk of allergy; and in eczema from supplementation with GOS/FOS (9:1) (6.8 g/L) and acidic oligosacccharide (1.2 g/L) in infants not selected for allergy risk. Further research is needed before routine use of prebiotics can be recommended for prevention of allergy in formula fed infants. There is some evidence that a prebiotic supplement added to infant feeds may prevent eczema. It is unclear whether the use of prebiotic should be restricted to infants at high risk of allergy or may have an effect in low risk populations; or whether it may have an effect on other allergic diseases including asthma. Source


Conventional antineoplastic, novel immunosuppressive agents and antibiotics used in cancer treatment can directly affect the growth, development and virulence of Candida and Aspergillus species. Cytotoxic and cisplatin compounds have anti-Candida activity and may be synergistic with antifungal drugs; they also inhibit Candida and Aspergillus filamentation/conidation and effect increased virulence in vitro. Glucocorticoids enhance Candida adherence to epithelial cells, germination in serum and in vitro secretion of phospholipases and proteases, as well as growth of A. fumigatus. Calcineurin and target of rapamycin inhibitors perturb Candida and Aspergillus morphogenesis, stress responses and survival in serum, reduce azole tolerance in Candida, but yield conflicting in vivo data. Inhibition of candidal heat shock protein 90 and candidal-specific histone deacetylase represent feasible therapeutic approaches for candidiasis. Tyrosine kinase inhibitors inhibit fungal cell entry into epithelial cells and phagocytosis. Quinolone and other antibiotics may augment activity of azole and polyene agents. The correlation of in vitro effects with clinically meaningful in vivo systems is warranted.  Source


Clarke R.J.,University of Sydney
Biophysical Journal | Year: 2015

The kinetics of conformational changes of P-type ATPases necessary for the occlusion or deocclusion of transported ions are known to be sensitive to the composition of the surrounding membrane, e.g., phospholipid content, mole percentage of cholesterol, and the presence of lipid-bound anions. Research has shown that many membrane components modify the dipole potential of the lipid head-group region. Based on the observation that occlusion/deocclusion reactions of ion pumps perturb the membrane surrounding the protein, a mechanism is suggested whereby dipole potential modifiers induce preferential stabilization or destabilization of occluded or nonoccluded states of the protein, leading to changes in the forward and backward rate constants for the transition. The mechanism relies on the assumption that conformational changes of the protein are associated with changes in its hydrophobic thickness that requires a change in local lipid packing density to allow hydrophobic matching with the membrane. The changes in lipid packing density cause changes in local lipid dipole potential that are responsible for the dependence of conformational kinetics on dipole potential modifiers. The proposed mechanism has the potential to explain effects of lipid composition on the kinetics of any membrane protein undergoing significant changes in its membrane cross-sectional area during its activity. © 2015 Biophysical Society. Source


Bendall L.J.,University of Sydney | Bradstock K.F.,Westmead Hospital
Cytokine and Growth Factor Reviews | Year: 2014

G-CSF was among the first cytokines to be identified and rapidly transitioned into clinical medicine. Initially used to promote the production of neutrophils in patients with chemotherapy-induced neutropenia it helped to revolutionize the delivery of cancer therapy. Its ability to mobilize hematopoietic stem cells from the bone marrow into the blood was subsequently exploited, changing the face of hematopoietic stem cell transplantation. Today the knowledge gained in unraveling the mechanisms of stem cell mobilization by G-CSF is being explored as a means to increase chemosensitivity in hematological malignancies. This review provides a brief history of G-CSF and then focuses on recent advances in our understanding of G-CSF-induced stem cell mobilization and the potential clinical application of this knowledge in chemo-sensitization. © 2014 The Authors. Source


Maron B.J.,Minneapolis Heart Institute Foundation | Ommen S.R.,Mayo Medical School | Semsarian C.,University of Sydney | Spirito P.,Ente Ospedaliero Ospedali Galliera | Olivotto I.,University of Florence
Journal of the American College of Cardiology | Year: 2014

Hypertrophic cardiomyopathy (HCM) is a common inherited heart disease with diverse phenotypic and genetic expression, clinical presentation, and natural history. HCM has been recognized for 55 years, but recently substantial advances in diagnosis and treatment options have evolved, as well as increased recognition of the disease in clinical practice. Nevertheless, most genetically and clinically affected individuals probably remain undiagnosed, largely free from disease-related complications, although HCM may progress along 1 or more of its major disease pathways (i.e., arrhythmic sudden death risk; progressive heart failure [HF] due to dynamic left ventricular [LV] outflow obstruction or due to systolic dysfunction in the absence of obstruction; or atrial fibrillation with risk of stroke). Effective treatments are available for each adverse HCM complication, including implantable cardioverter-defibrillators (ICDs) for sudden death prevention, heart transplantation for end-stage failure, surgical myectomy (or selectively, alcohol septal ablation) to alleviate HF symptoms by abolishing outflow obstruction, and catheter-based procedures to control atrial fibrillation. These and other strategies have now resulted in a low disease-related mortality rate of <1%/year. Therefore, HCM has emerged from an era of misunderstanding, stigma, and pessimism, experiencing vast changes in its clinical profile, and acquiring an effective and diverse management armamentarium. These advances have changed its natural history, with prevention of sudden death and reversal of HF, thereby restoring quality of life with extended (if not normal) longevity for most patients, and transforming HCM into a contemporary treatable cardiovascular disease. © 2014 by the American College of Cardiology Foundation. Source


Race K.,University of Sydney
Journal of Bioethical Inquiry | Year: 2012

How can we register the participation of a range of elements, extending beyond the human subject, in the production of HIV events? In the context of proposals around biomedical prevention, there is a growing awareness of the need to find ways of responding to complexity, as everywhere new combinations of treatment, behavior, drugs, norms, meanings and devices are coming into encounter with one another, or are set to come into encounter with one another, with a range of unpredictable effects. In this paper I consider the operation of various framing devices that attribute responsibility and causation with regard to HIV events. I propose that we need to sharpen our analytic focus on what these devices do, their performativity-that is, their full range of worldly implications and effects. My primary examples are the criminal law and the randomized control trial. I argue that these institutions operate as framing devices: They attribute responsibility for HIV events and externalize other elements and effects in the process. Drawing on recent work in science and technology studies as well as queer theory, I set out an analytic frame that marks out a new role for HIV social research. Attentiveness to the performative effects of these devices is crucial, I suggest, if we want better to address the global HIV epidemic. © 2012 Springer Science+Business Media B.V. Source


Hardy T.A.,University of Sydney | Hardy T.A.,Brain and Mind Research Institute | Miller D.H.,University College London
The Lancet Neurology | Year: 2014

Baló's concentric sclerosis is often regarded as a rare variant of multiple sclerosis. Patients with this disorder present with acute or subacute neurological deterioration, with MRI showing one or more concentrically multilayered ring-like lesions usually in the cerebral white matter. Historically, Baló's concentric sclerosis was thought fatal in all cases. However, the availability of MRI has led to a better appreciation of the variable natural history of patients presenting with radiologically evident Baló lesions and the clinical association with multiple sclerosis and, less often, with other neurological disorders. Important advances have increased understanding of the immunopathogenic mechanisms associated with the formation of Baló lesions. However, how to treat an acute lesion and when or whether to start treatment are less well understood, although for patients with Baló lesions who also fulfil standard diagnostic criteria for multiple sclerosis, our opinion is that treatment with multiple sclerosis disease-modifying therapy would seem reasonable. © 2014 Elsevier Ltd. Source


Maleknia S.D.,University of New South Wales | Downard K.M.,University of Sydney
Chemical Society Reviews | Year: 2014

Radical Probe Mass Spectrometry (RP-MS), first introduced in 1999, utilizes hydroxyl radicals generated directly within aqueous solutions using synchrotron radiolysis, electrical discharge, and photochemical laser sources to probe protein structures and their interactions. It achieves this on millisecond and submillisecond timescales that can be used to capture protein dynamics and folding events. Hydroxyl radicals are ideal probes of solvent accessibility as their size approximates a water molecule. Their high reactivity results in oxidation at a multitude of amino acid side chains providing greater structural information than a chemical cross-linker that reacts with only one or few residues. The oxidation of amino acid side chains occurs at rates in accord with the solvent accessibility of the residue so that the extent of oxidation can be quantified to reveal a three-dimensional map or footprint of the protein's surface. Mass spectrometry is central to this analysis of chemical oxidative labelling. This tutorial review, some 15 years on from the first reports, highlights the development and significant growth of the application of RP-MS including its validation and utility with ion-mobility mass spectrometry (IM-MS), the use of RP-MS data to help model protein complexes, studies of the onset of oxidative damage, and more recent advances that enable high throughput applications through simultaneous protein oxidation and on-plate deposition. The accessibility of the RP-MS technology, by means of a modified electrospray ionization source, enables the approach to be implemented in many laboratories to address a wide range of applications in chemical biology. © 2014 the Partner Organisations. Source


Hackett M.L.,University of Sydney | Hackett M.L.,University of Central Lancashire | Kohler S.,Maastricht University | O'Brien J.T.,University of Cambridge | Mead G.E.,Royal Infirmary
The Lancet Neurology | Year: 2014

The most common neuropsychiatric outcomes of stroke are depression, anxiety, fatigue, and apathy, which each occur in at least 30% of patients and have substantial overlap of prevalence and symptoms. Emotional lability, personality changes, psychosis, and mania are less common but equally distressing symptoms that are also challenging to manage. The cause of these syndromes is not known, and there is no clear relation to location of brain lesion. There are important gaps in knowledge about how to manage these disorders, even for depression, which is the most studied syndrome. Further research is needed to identify causes and interventions to prevent and treat these disorders. © 2014 Elsevier Ltd. Source


Hartemink A.E.,University of Wisconsin - Madison | Minasny B.,University of Sydney
Geoderma | Year: 2014

Digital soil morphometrics is defined as the application of tools and techniques for measuring and quantifying soil profile attributes and deriving continuous depth functions. This paper reviews how proximal soil sensing and other tools can be used in soil profile descriptions where techniques and toolkits have not changed in the past decades. The application of such tools is compared to standard soil profile descriptions for 11 common attributes: horizons, texture, color, structure, moisture, mottles, consistence, carbonates, rock fragments, pores and roots. These attributes are extensively used in soil classification and are indicative of many soil functions. There has been progress in distinguishing soil horizons, texture and soil color, mainly using vis-NIR, GPR and electrical resistivity. There is potential for in situ digital morphometrics for all attributes of a soil profile. Smaller depth increments can be sampled and analyzed, and that gives continuous depth functions of soil properties. The combined use of in situ digital morphometrics and continuous depth functions of soil properties may enhance our pedological understanding. It will take time before the toolbox of the field pedologists will be digitally enriched, but we think that digital soil morphometrics has the potential to complement existing description and analytical methods. It may yield new insights in soil horizonation, how soils form and how they could be classified. © 2014. Source


Maron B.J.,Minneapolis Heart Institute Foundation | Maron M.S.,Hypertrophic Cardiomyopathy Center | Semsarian C.,University of Sydney
Heart Rhythm | Year: 2012

Risk stratification strategies employing sarcomere gene mutational analysis have proved imprecise in identifying high-risk patients with hypertrophic cardiomyopathy (HCM). Therefore, additional genetic risk markers that reliably determine which patients are predisposed to sudden death are needed. The objective of this study was to determine whether multiple disease-causing sarcomere mutations can be regarded as markers for sudden death in the absence of other conventional risk factors. Databases of 3 HCM centers were accessed, and 18 probands with 2 disease-causing mutations in genes encoding proteins of the cardiac sarcomere were identified. Severe disease progression or adverse cardiovascular events occurred in 7 of these 18 patients (39%), including 3 patients (ages 31, 37, and 57 years) who experienced sudden cardiac arrest but also were without evidence of conventional HCM risk factors; 2 survived with timely defibrillation and therapeutic hypothermia and 1 died. These 3 probands carried distinct and heterozygous disease-causing sarcomere mutations (including a man who inherited 1 mutation independently from each of his parents with HCM)that is, double MYBPC3 and TNNI3 mutations and compound MYBPC3 mutationsas the only predisposing clinical markers evident to potentially explain their unexpected cardiac event. These observations support the emerging hypothesis that double (or compound) mutations detected by genetic testing may confer a gene dosage effect in HCM, thereby predisposing patients to adverse disease progression. In 3 families, multiple sarcomere mutations were associated with a risk of sudden death, even in the absence of conventional risk factors. Source


Jones I.S.F.,University of Sydney
Marine Ecology Progress Series | Year: 2011

There have been suggestions that an increase in the productivity of the ocean would store more carbon in the ocean organic carbon cycle, as well as enhancing the higher trophic levels of the marine food web. Proposals have included fertilisation of regions low in one or more of nitrogen, phosphorus or iron, the latter being termed a micronutrient. Iron is available from mining, phosphorus from mining or artificially induced upwelling, and the provision of nitrogen involves using either cyanobacteria, the Haber-Bosch process or artificially induced upwelling. All these fertilisation methods can be effective in locally increasing new primary production, but the global impact varies because of iron scavenging, nutrient stealing or the role of regenerative primary production. Examination of these concepts leads to the conclusion that macronutrient nourishment supplied by the Haber-Bosch process is an attractive approach for slowing climate change and increasing marine productivity. The carbon storage capacity of nitrogen fertilisation appears to be limited by the supply of phosphorus to support additional new primary production. © Inter-Research 2011. Source


Bonner C.,University of Sydney
The Medical journal of Australia | Year: 2013

To identify factors that influence the extent to which general practitioners use absolute risk (AR) assessment in cardiovascular disease (CVD) risk assessment. Semi-structured interviews with 25 currently practising GPs from eight Divisions of General Practice in New South Wales, Australia, between October 2011 and May 2012. Data were analysed using framework analysis. The study identified five strategies that GPs use with patients in different situations, defined in terms of the extent to which AR was used and the reasons given for this: the AR-focused strategy, used when AR assessment was considered useful for the patient; the AR-adjusted strategy, used to account for additional risk factors such as family history; the clinical judgement strategy, used when GPs considered that their judgement took multiple risk factors into account as effectively as AR; the passive disregard strategy, used when GPs lacked sufficient time, access or experience to use AR; and the active disregard strategy, used when AR was considered to be inappropriate for the patient. The strategies were linked with different opportunity, capability and motivation barriers to the use of AR. This study provides an in-depth insight into the factors that influence GPs' use of AR in CVD risk assessment. The results suggest that GPs use a range of strategies in different situations, so different approaches may be required to improve the use of AR guidelines in practice. Source


Dissection of the internal carotid or vertebral artery has been recognized as a cause of stroke in young patients. It is disproportionate in its representation as a cause of stroke in this age group. Intimal tears, intramural hematomas, and dissection aneurysms may be the result of trauma or may occur spontaneously. Spontaneous dissection may be the result of inherent arterial weakness or in association with other predisposing factors. Clinical diagnosis is often difficult, but increased awareness and a range of modern investigations such as computerized tomography or magnetic resonance imaging may aid in diagnosis. Management options include antiplatelet therapy, anticoagulation, thrombolysis, and surgical or endovascular procedures. Prognosis is variable, and dissection may be asymptomatic but may lead to profound neurological deficit and death. © The Author(s) 2013. Source


Byrne S.N.,University of Sydney
Photochemical and Photobiological Sciences | Year: 2014

Living on a sun-drenched planet has necessitated adaption to and protection from the harmful effects of solar ultraviolet (UV) radiation, particularly skin cancer. However, convincing epidemiological and recent empirical evidence also supports a protective effect of UV against a range of diseases including multiple sclerosis, asthma and cardiovascular disease. Despite years of research attention into the biological effects of sunlight exposure, we are still far from being able to fully answer the question: How much sunlight is enough? This is probably because the answer is dependent on many complex and interacting variables. Many talented researchers are focused on exploring whether UV-induced vitamin D explains some of these effects. This perspectives article proposes an alternative hypothesis, namely that targeting UV-induced immune suppression by affecting the activation of regulatory cells and molecules will be of therapeutic benefit. This journal is © the Partner Organisations 2014. Source


Brand-Miller J.,University of Sydney | Buyken A.E.,University of Bonn
Current Opinion in Lipidology | Year: 2012

Purpose of review: In recent years, many of the concerns surrounding the glycemic index have been addressed by methodological studies and clinical trials comparing diets carefully matched for other nutrients. These findings are reviewed together with new observational evidence for the role of the dietary glycemic index in the etiology of cardiovascular disease. Recent findings: The determination and classification of the glycemic index of a food product is now standardized by the International Standards Organization. Systematic studies using isoenergetic single and mixed meals have shown that glycemic index and/or glycemic load are stronger predictors of postprandial glycemia and insulinemia than carbohydrate content alone. In overweight individuals, a diet that combined modestly higher protein and lower glycemic index carbohydrates was the most effective diet for prevention of weight regain. New observational studies have reported increased risks of coronary heart disease associated with higher intakes of carbohydrates from high glycemic index foods. Epidemiological evidence has emerged linking dietary glycemic index to visceral fat and inflammatory disease mortality. Summary: There is growing recognition that replacing saturated fat with refined, high glycemic index carbohydrates increases postprandial glycemia and may be detrimental for weight control and predisposition to cardiovascular and inflammatory disease. In contrast, low glycemic index carbohydrates reduce risk. © 2012 Lippincott Williams & Wilkins. Source


Ullrich S.E.,University of Houston | Byrne S.N.,University of Sydney
Journal of Investigative Dermatology | Year: 2012

UV radiation targets the skin and is a primary cause of skin cancer (both melanoma and nonmelanoma skin cancer). Exposure to UV radiation also suppresses the immune response, and UV-induced immune suppression is a major risk factor for skin cancer induction. The efforts of dermatologists and cancer biologists to understand how UV radiation exposure suppresses the immune response and contributes to skin cancer induction led to the development of the subdiscipline we call photoimmunology. Advances in photoimmunology have generally paralleled advances in immunology. However, there are a number of examples in which investigations into the mechanisms underlying UV-induced immune suppression reshaped our understanding of basic immunological concepts. Unconventional immune regulatory roles for Langerhans cells, mast cells, and natural killer T (NKT) cells, as well as the immune-suppressive function of lipid mediators of inflammation and alarmins, are just some examples of how advances in immunodermatology have altered our understanding of basic immunology. In this anniversary issue celebrating 75 years of cutaneous science, we provide examples of how concepts that grew out of efforts by immunologists and dermatologists to understand immune regulation by UV radiation affected immunology in general. © 2012 The Society for Investigative Dermatology. Source


Little M.,University of Sydney
Journal of Evaluation in Clinical Practice | Year: 2013

Rationale There seem to be some misunderstandings abroad in the literature about medical epistemology and person-centered medicine concerning the nature of 'modest' or aetiological foundationalism, and some vagueness about 'emergence'. Aims and objectives This paper urges a greater tolerance for a modest, Humean variety of foundationalism, not least because it seems to offer significant support for person-centred medicine. It also suggests a closer examination of emergence as an explanation or justification for medicine, since emergence is a complex concept that does nothing to rule out foundationalism. Methods Reading of relevant literatures relating to foundationalism, emergence and person-centered medicine, and reflection on the arguments they contain. Results Foundationalism has been condemned tout court without recognizing that it comes in various styles and degrees. Emergence has been used as a property of medicine to dismiss any need to seek its foundations. But emergence too comes in different forms, not all of them at odds with modest foundationalism. Modest or aetiological foundationalism is far more flexible than Cartesian foundationalism, and is compatible with modern understandings of emergence. Conclusions Modest foundationalism and a particular understanding of emergence support the ontological and epistemological underpinning of person-centered medicine. © 2013 John Wiley & Sons Ltd. Source


Mitchell P.,University of Sydney | Wong T.Y.,Singapore Eye Research Institute
American Journal of Ophthalmology | Year: 2014

Purpose To provide evidence-based recommendations for diabetic macular edema (DME) management based on updated information from publications on DME treatment modalities. Design Perspective. Methods A literature search for "diabetic macular edema" or "diabetic maculopathy" was performed using the PubMed, Cochrane Library, and ClinicalTrials.gov databases to identify studies from January 1, 1985 to July 31, 2013. Meta-analyses, systematic reviews, and randomized controlled trials with at least 1 year of follow-up published in the past 5 years were preferred sources. Results Although laser photocoagulation has been the standard treatment for DME for nearly 3 decades, there is increasing evidence that superior outcomes can be achieved with anti-vascular endothelial growth factor (anti-VEGF) therapy. Data providing the most robust evidence from large phase II and phase III clinical trials for ranibizumab demonstrated visual improvement and favorable safety profile for up to 3 years. Average best-corrected visual acuity change from baseline ranged from 6.1-10.6 Early Treatment Diabetic Retinopathy Study (ETDRS) letters for ranibizumab, compared to 1.4-5.9 ETDRS letters with laser. The proportion of patients gaining ≥10 or ≥15 letters with ranibizumab was at least 2 times higher than that of patients treated with laser. Patients were also more likely to experience visual loss with laser than with ranibizumab treatment. Ranibizumab was generally well tolerated in all studies. Studies for bevacizumab, aflibercept, and pegaptanib in DME were limited but also in favor of anti-VEGF therapy over laser. Conclusions Anti-VEGF therapy is superior to laser photocoagulation for treatment of moderate to severe visual impairment caused by DME. Source


Shine R.,University of Sydney
Current Biology | Year: 2013

Most small children can tell you that 'reptiles' are the snakes, lizards, crocodiles, and turtles (perhaps with the dinosaurs thrown in) - suggesting that it's easy to tell the difference between reptiles and other animals. Unfortunately, evolutionary biologists struggle with the same task, because phylogenetic analysis tells us loud and clear that these different types of what we loosely call 'reptiles' are not particularly closely related to each other (Figure 1). On the evolutionary tree, some of them (dinosaurs, crocodiles) are much more closely related to birds than to the other animals that we call reptiles. Other reptiles are the descendants of very ancient lineages; for example, turtles separated from the other reptiles, including the now-dominant Squamata (lizards and snakes), at least 200 million years ago. And another 200-million-year-old lineage has left just a single survivor, a lizard-like creature (the tuatara), on a few islands in New Zealand. © 2013 Elsevier Ltd. Source


Tonkin M.A.,University of Sydney
Journal of Hand Surgery: European Volume | Year: 2014

In 1937, Müller introduced the concept of a teratological sequence of thumb hypoplasia with increasing severity from mild deficiency, through severe deficiency, to thumb absence. Blauth subsequently detailed five specific grades. In 1992, Manske and McCarroll altered Blauth's classification such that Grade 3 was sub-divided into Grades 3A and 3B, according to a presence or absence of the proximal metacarpal. Buck-Gramcko added a Grade 3C in which there was only a remnant metacarpal head. This article investigates their publications and those of others to identify 'who said what' and clarify the definitions of grades of thumb hypoplasia. A modification of Blauth's classification is proposed, which retains the integrity of the concept of Müller and the skeletal and soft tissue grading of Blauth, but which also incorporates the disparate anomalies that may present in Grades 2 and 3 hypoplastic thumbs. © The Author(s) 2013. Source


Surjana D.,University of Sydney
Skinmed | Year: 2011

Nicotinamide (the amide form of vitamin B3) has been used in dermatology for more than 40 years for a diverse range of conditions including acne, rosacea, autoimmune bullous dermatoses, and now the treatment and prevention of photoaging and photoimmunosuppression. The broad clinical effects of nicotinamide may be explained by its role as a cellular energy precursor, a modulator of inflammatory cytokines, and an inhibitor of the nuclear enzyme poly(adenosine diphosphate-ribose) polymerase-1, which plays a significant role in DNA repair, maintenance ofgenomic stability, and cellular response to injury including inflammation and apoptosis. This review outlines the use of nicotinamide for inflammatory dermatoses and photoaging and focuses on its emerging role in photoprotection. Source


There is generally good evidence that pain management interventions that include self-management strategies can substantially reduce disability and improve psychological well-being in patients with chronic pain. Reductions in unhelpful responses, especially catastrophising and fear-avoidance beliefs, have been established as key contributors to these gains. In contrast, there is surprisingly little evidence that adherence to self-management strategies contributes to achieving these outcomes. Difficulties in defining and measuring the use of pain self-management strategies have been obstacles for this research. Using a pragmatic way of assessing the practice of specific strategies this study investigated their ability to account for changes in pain, disability and depressive symptoms after a 3-week cognitive-behavioural pain management program. The post-treatment outcomes on these dimensions were found to be statistically and, for many, clinically significant. Consistent with previous research, reductions in catastrophising and fear-avoidance beliefs, and increased pain self-efficacy beliefs, were also associated with these gains. But the key new finding was that there was a clear gradient between adherence to specific self-management strategies and reductions in pain, disability and depressive symptoms. Furthermore, adherence to the self-management strategies was predictive of better outcomes even after controlling for the moderating effects of initial catastrophising, fear-avoidance and pain self-efficacy beliefs. © 2011 European Federation of International Association for the Study of Pain Chapters. Source


Older people are often prescribed multiple medicines and have a high prevalence of polypharmacy. Polypharmacy is associated with an increased risk of inappropriate use of medicines and drug-related problems. As experts in pharmacotherapy, pharmacists are well placed to review complex medication regimens and identify causes of drug-related problems and recommend solutions to prevent or resolve them. Involvement in medication review services represents a major philosophical shift and paradigm change in the way pharmacists practice, in that the focus is shifted away from the dispensing of prescription medicines to the provision of a professional service for a patient, in collaboration with their general practitioner (GP). In Australia, there are two established medication review programs: Home Medicines Review (HMR) and Residential Medication Management Review (RMMR). The objectives of this article were to describe the process of government-funded medication review services in Australia and to evaluate the contribution of pharmacists to HMR and RMMR, using evidence-based measures, such as the Drug Burden Index (DBI) and the Medication Appropriateness Index (MAI). This review found that there is good evidence to support the role of pharmacists in delivering medication review services across different settings. Although the positive impact of such services has been demonstrated using a variety of validated measures (DBI, MAI), there remains a need to also evaluate actual clinical outcomes and/or patient-reported outcomes. © 2016, Springer International Publishing Switzerland. Source


Short A.D.,University of Sydney
Journal of Coastal Research | Year: 2010

The Australian coast can be subdivided into three broad sedimentary provinces occupying the east, south, west, and northwest coasts. The 11,978-km long eastern province extends from the western Gulf of Carpentaria along the entire east coast to eastern Tasmania. It is characterized by tropical to temperate humid climates, quartz sediments, and overall northerly sediment transport, with significant onshore transport where shoreline orientation and wave and wind energy combine to produce massive coastal dune systems, including the world's largest sand islands. The 9587-km long south and west coast province has an arid to semiarid climate with little terrigenous sediment. Much of the coast faces into the prevailing southerly winds and the high year-round Southern Ocean swell, resulting in massive transfer of shelf and nearshore carbonate-rich sediments to the shore and into extensive coastal barrier-dunes systems, the largest dunes extending 110 km inland. The 9106-km long northwest province has a tropical arid to monsoonal climate with coral reefs fringing parts of the coast and has predominately offshore winds. While several large rivers deliver substantial terrigenous sediment to the coast, little is deposited above sea level. © 2010 Coastal Education and Research Foundation. Source


Craven L.K.,University of Sydney
Asia Pacific Viewpoint | Year: 2015

Migration is increasingly being promoted as a possible adaptive response to risks associated with climate change and other stresses. While migration may present an adaptation pathway in certain contexts, existing research fails to consider the ways in which migration could contribute to vulnerability in sending communities. This paper examines the impact of migration-affected change on local vulnerability in Lamen Bay, Vanuatu. Qualitative methods, including interviews and focus groups with 58 individuals, were used to determine how migration interacts with the multiple stressors faced by the community. The results show that migration is likely to contribute to vulnerability in already vulnerable communities. In Lamen Bay, migration affects a number of contextual factors that influence exposure and the capacity to respond to change, including labour supply, food security, migrant attitudes, underdevelopment and institutional viability. These results suggest that development policy in Vanuatu needs to address existing vulnerabilities while offering the opportunity to migrate. © 2015 Victoria University of Wellington and Wiley Publishing Asia Pty Ltd. Source


This paper provides an analysis of public adaptation to climate change using agricultural water schemes in South American farms. Unlike other studies of adaptation, this paper examines the differences between private irrigation and public irrigation schemes based on around 1400 farm surveys collected across seven countries in South America which recorded detailed water schemes. We analyze the choice of water schemes in the first stage and the land values for each scheme in the second stage. We find that public irrigations do not increase in response to a warmer climate, but private irrigations do. On the other hand, we find that public irrigation schemes are provided primarily as a response to water scarcity. Moreover, we find that private irrigations are taken gradually while public irrigations are provided as a lump sum, resulting in either too much or too little provision. Therefore, public adaptations to climate change will likely involve two inefficiencies. No provision of irrigation in a hotter climate may result from a lack of knowledge. Overprovision of irrigation in dry zones may result from a lump-sum provision of a public good. © 2010 Elsevier B.V. Source


Anderson E.,University of Sydney
Operations Research | Year: 2012

It is common for rewards to be given on the basis of a rank ordering, so that relative performance amongst a cohort is the criterion. In this paper we formulate an equilibrium model in which an agent makes successive decisions on whether or not to gamble and is rewarded on the basis of a rank ordering of the final position amongst competing players. One application of this model is to the behavior of mutual fund managers who are paid depending on funds under management, which in turn are greatly influenced by annual or quarterly rank orderings. Our model deals with a situation in which fund managers can elect either to pick stocks or to use a market-tracking strategy. In equilibrium the distribution of the final position will have a negative skew. We explore how this distribution depends on the number of players, the probability of success when gambling, the structure of the rewards, and on information regarding the performance of other players. © 2012 INFORMS. Source


Windsor P.A.,University of Sydney
Veterinary Microbiology | Year: 2015

Paratuberculosis is a chronic insidious, often serious, disease of the global small ruminant industries, mainly causing losses from mortalities and reduced productivity on-farm, interference in trading and, in Australia, profound socio-economic impacts that have periodically compromised harmony of rural communities. The pathogenesis, diagnosis, impacts and disease management options for ovine and caprine paratuberculosis are reviewed, comparing current controls in the extensive management system for sheep in wool flocks in Australia with the semi-intensive system of dairy flocks/herds in Greece. Improved understanding of the immune and cellular profiles of sheep with varying paratuberculosis outcomes and the recognition of the need for prolonged vaccination and biosecurity is considered of relevance to future control strategies. Paratuberculosis in goats is also of global distribution although the prevalence, economic impact and strategic control options are less well recognized, possibly due to the relatively meagre resources available for goat industry research. Although there have been some recent advances, more work is required on developing control strategies for goats, particularly in dairy situations where there is an important need for validation of improved diagnostic assays and the recognition of the potential impacts for vaccination. For all species, a research priority remains the identification of tests that can detect latent and subclinical infections to enhance removal of future sources of infectious material from flocks/herds and the food chain, plus predict the likely outcomes of animals exposed to the organism at an early age. Improving national paratuberculosis control programs should also be a priority to manage disease risk from trade. The importance of strong leadership and communication, building trust within rural communities confused by the difficulties in managing this insidious disease, reflects the importance of change management considerations for animal health authorities. Although concerns of vaccine efficacy, safety and issues with diagnosis and administration persist, vaccination is increasingly recognized as providing a robust strategy for managing paratuberculosis, having made important contributions to the health of Australian sheep and the lives of producers with affected properties, and offering a mechanism to reduce risk of infection entering the food chain in ovine and caprine products. © 2015 Elsevier B.V.. Source


McLean A.S.,Nepean Hospital | McLean A.S.,University of Sydney
Critical Care Medicine | Year: 2015

The development of Intensive Care Medicine as a recognizable branch of medicine has been underway for more than half a century, with delivery by a number of different service models. This delivery may be entirely by related medical specialties, such as anesthesiology or pulmonology; alternatively, it may be as a standalone-recognized specialty and frequently by a hybrid of these two extremes. A country may have a completely different delivery model from neighboring countries, and different models may exist within a single country. Debate about the most appropriate method of providing critical care services frequently centers around the training. However, an alternative perspective is that training regimes only follow on from another objective, namely to have Intensive Care Medicine represented in important forums by dedicated critical care physicians. A historical perspective of the development of critical care in two countries over a 40-year period is discussed, whereby a transition from a multiple specialty provision of critical care medicine to that of a single binational pathway occurred. The perceived advantages and disadvantages are outlined, offering insights into how possible future challenges in a highly complex medical specialty can be anticipated and strategies formulated. © 2015 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. Source


Ward M.P.,University of Sydney
Preventive Veterinary Medicine | Year: 2014

Rabies continues to spread through the Indonesian archipelago. During the past 20 years, several islands - including Flores, Ambon and Bali - that had historically been free of rabies have become infected. However, the Dutch East Indies (a Dutch colony that became modern Indonesia following World War II) had been infected since the 1880s. The spread of rabies is a lesson in the emergence of an infectious disease.Reports of human cases treated for rabies and livestock rabies cases from the 1880s to 1917 were compiled. The spatial and temporal distribution of these cases was analyzed using maps, spatial statistics and time-series techniques. The first confirmed case of rabies was reported in 1889 from the Batavia [Jakarta] district (although disease suspicion was reported as early as 1884). During the 1890s rabies was already commonly reported from Java and the east coast of Sumatra, and by the late 1890s, from Celebes [Sulawesi]. Between 1900 and 1916, cases were reported from other parts of Java, Sumatra and Sulawesi, and from Borneo, the Moluccas and other outlying islands. Between 1897 and 1916, a total of 8826 human cases treated for rabies were reported and between 1908 and 1917, 1033 livestock cases were reported. Most (97.5%) human cases treated were attributed to rabid dogs. Increasing numbers of reports were observed during the period. Between 1908 and 1916 the correlation between human and livestock case reports was 64.2%, and at the district level it was 75.9%. Moderate correlations (>40%) were found between human cases and livestock cases reported up to six months previously. Based on year of first report from each district, human cases were strongly clustered (Moran's autocorrelation 0.47, P=. 0.005). The most likely spatio-temporal cluster of reported cases of humans treated for rabies originated from the west coast of Sumatra between 1899 and 1905, and other clusters were identified in west Java (1898-1899), the district of Batavia and in east Java (1910-1911), Nusa Tengarra Barat (1912), Borneo (1914) and the east coast of Sumatra (1903-1906).Rabies was probably first introduced to the colonial capital of the Dutch Indies, Batavia [Jakarta] in the 1880s. It then spread rapidly throughout most of the archipelago during the next two to three decades because of the movement of dogs via the military forces, for trade and as pets, despite government regulations designed to control the epidemic. Such a history suggests that further emergence and reemergence of rabies in rabies-free islands will occur based on an island's location and position within the complex social, trade and transport network that represents the Indonesian archipelago. Targeted surveillance and enforcement of quarantine regulations remain critical, to prevent history repeating itself. © 2014 Elsevier B.V. Source


Salvador-Carulla L.,University of Sydney
The journal of mental health policy and economics | Year: 2013

Intellectual developmental disorder or Intellectual disability (ID) is a prevalent condition with a high impact along the life-span particularly when associated to other mental disorders (MD). To estimate the unmet needs and to design a knowledge to action plan to reduce the care gap in ID-MD in Spain. We followed a 5-step `maxi' impact assessment and a mixed qualitative/quantitative design including expert panels, secondary analysis of databases and a prospective survey in the 17 regions in Spain. Schizophrenia was used as comparator due to similar prevalence rates and burden. Persons with ID-MD had ten times less outpatient contacts and hospital admissions than patients with schizophrenia. The outpatient case load was 2.31% in ID and 14.6% in schizophrenia. ID had the lowest hospitalization rate amongst all mental disorders but the highest length of stay. The expert panel estimated that half of persons with ID-MD are not adequately assessed and 95% do not receive the required care in Spain. Basic care needs include 6.5 beds and an ID-MD outpatient service per 1 million population. At least 134 specialized psychiatrists and psychologists and 277 beds are needed to reach the minimum standards in Spain. This study quantifies the ID-MD care gap in Spain and the basic specialized services needed. In spite of the societal and health implications of ID-MD the knowledge-to-action plan had a modest impact limited at the regions where ID-MD programmes were already implemented. Specific priority setting on ID-MH should be incorporated to mental health strategy at the Ministry of Health within a broader health and ID plan. National and regional policies should incorporate an integrative care approach through the life cycle. The development of excellence centers on ID-MD and a national observatory on this topic should be encouraged. Source


New public transport investment can improve accessibility for existing and new users of the urban transport network and this can lead to land value uplift with uplift benefits being distributed in relation to the proximity of the location of the property to the infrastructure. This paper quantifies land value uplift and its spatial distribution for accessibility to different destinations for residential properties around a new-build Liverpool Parramatta transitway for buses in a suburban area of south-west Sydney, Australia. Geographically weighted regression (GWR) is used to take account of spatial dependency in the estimation process with the results being presented in map form. Results indicate that property prices are mainly determined by the property's internal features and the neighbourhood effects, but accessibility by car and accessibility to employment along the transitway also contribute non-marginally. The GWR local model shows that accessibility varies significantly over geographical space demonstrating the advantages of this approach. © 2013 Urban Studies Journal Limited. Source


Keith D.A.,University of Sydney
Applied Vegetation Science | Year: 2014

Berg and colleagues, in this issue, describe a framework for assessing risks to biodiversity and setting conservation priorities in northeast Germany. Their method explicitly separates community endangerment from conservation value, and derives its plant communities from a sound regional classification. It could be improved by incorporating ecological processes into risk assessment, and socio-political constraints, economic costs and the likelihood of success into priority setting. © 2014 International Association for Vegetation Science. Source


Rutledge P.J.,University of Sydney | Challis G.L.,University of Warwick
Nature Reviews Microbiology | Year: 2015

Microorganisms produce a wealth of structurally diverse specialized metabolites with a remarkable range of biological activities and a wide variety of applications in medicine and agriculture, such as the treatment of infectious diseases and cancer, and the prevention of crop damage. Genomics has revealed that many microorganisms have far greater potential to produce specialized metabolites than was thought from classic bioactivity screens; however, realizing this potential has been hampered by the fact that many specialized metabolite biosynthetic gene clusters (BGCs) are not expressed in laboratory cultures. In this Review, we discuss the strategies that have been developed in bacteria and fungi to identify and induce the expression of such silent BGCs, and we briefly summarize methods for the isolation and structural characterization of their metabolic products. © 2015 Macmillan Publishers Limited. All rights reserved. Source


Drake P.L.,Bentley Delivery Center | Froend R.H.,Edith Cowan University | Franks P.J.,University of Sydney
Journal of Experimental Botany | Year: 2013

Maximum and minimum stomatal conductance, as well as stomatal size and rate of response, are known to vary widely across plant species, but the functional relationship between these static and dynamic stomatal properties is unknown. The objective of this study was to test three hypotheses: (i) operating stomatal conductance under standard conditions (gop) correlates with minimum stomatal conductance prior to morning light [gmin(dawn)]; (ii) stomatal size (S) is negatively correlated with gop and the maximum rate of stomatal opening in response to light, (dg/dt)max; and (iii) gop correlates negatively with instantaneous water-use efficiency (WUE) despite positive correlations with maximum rate of carboxylation (Vc max) and light-saturated rate of electron transport (J max). Using five closely related species of the genus Banksia, the above variables were measured, and it was found that all three hypotheses were supported by the results. Overall, this indicates that leaves built for higher rates of gas exchange have smaller stomata and faster dynamic characteristics. With the aid of a stomatal control model, it is demonstrated that higher g op can potentially expose plants to larger tissue water potential gradients, and that faster stomatal response times can help offset this risk. © 2013 The Author(s). Source


Hudson T.S.,University of Sydney
Journal of Physical Chemistry C | Year: 2010

The packing density of binary (A13B) and ternary (A 12BC) hard-sphere systems with the NaZn13 structure type is investigated in detail using a combination of Monte Carlo simulated annealing and gradient optimizations. This paper shows that if distortions from the perfect icosahedral arrangement of Zn spheres are considered the binary packing density can exceed that of segregated spheres in close packed lattices and that the optimal packing fraction of 0.748431 occurs at a radius ratio of 0.578458. This accurately coincides with the size ratio observed in precious opal structures with this structure type. Atomic alloys with this structure type are also distorted but not in the same way as would be required for ideal binary sphere packing. Instead, they are broadly consistent with the distortions required for ideal packing of ternary sphere systems when the central sphere in the icosahedron of small spheres is permitted to take on a different size. This paper also presents an improved optimal ternary structure with a packing fraction of 0.77124, which also has relevance to lower pressure binary phase diagrams, and systems with a degree of polydispersity. © 2010 American Chemical Society. Source


Studies of organic nitrogen (N) cycling and uptake by plants have focused on protein amino acids, but the soil solution includes organic N compounds from many other compound classes. The two aims of this study were to characterize the 30-50 most abundant molecules of small (< 250 Da), nonpeptide organic N in the soil solution from six soils, and to determine if two ecologically disparate species (nonmycorrhizal Banksia oblongifolia and mycorrhizal Triticum aestivum) have the ability to take up intact molecules of three quaternary ammonium compounds (betaine, carnitine and acetyl-carnitine). Protein amino acids were dominant components of the pool of small nonpeptide organic N in all soils. The most abundant other compound classes were quaternary ammonium compounds (1-28% of nonpeptide small organic N) and nonprotein amino acids (3-19% of nonpeptide small organic N). B. oblongifolia and T. aestivum took up intact quaternary ammonium compounds from dilute hydroponic solution, while T. aestivum growing in field soil took up intact quaternary ammonium compounds injected into soil. Results of this study show that the pool of organic N in soil is more diverse and plants have an even broader palate than is suggested by most of the literature on organic N. © 2013 New Phytologist Trust. Source


Beatty J.,University of Sydney
Veterinary Journal | Year: 2014

The most widely recognised cause of feline lymphoma is the gammaretrovirus feline leukaemia virus (FeLV). Research into the mechanisms of cellular transformation employed by FeLV and other oncogenic retroviruses has provided as much information on the regulation of eukaryotic cell growth and differentiation as it has about cancer. The recognition that a cancer has a viral cause opens up the possibility of novel treatments that spare the host from cytotoxic side-effects by specifically targeting the virus, or the host's immune response to it. The ultimate prize for viral-associated cancers is their prevention. Vaccination and changes in management practices have seen the global prevalence of FeLV infection fall and, with it, the incidence of FeLV-related cancers. Remarkably, in the face of this success, the prevalence of feline lymphoma remains high. At least one other virus, the lentivirus feline immunodeficiency virus (FIV), accounts for some of these cases. Transformation by FIV involves incompletely understood mechanisms that are distinct from those employed by FeLV. This review will focus on the current understanding of FeLV-associated and FIV-associated lymphoma and consider whether yet more viral aetiologies could be waiting to be discovered. © 2014 Elsevier Ltd. Source


Arimura T.H.,Sophia University | Darnall N.,George Mason University | Katayama H.,University of Sydney
Journal of Environmental Economics and Management | Year: 2011

Using Japanese facility-level data, we estimate the effects of ISO 14001 certification on the promotion of more advanced practices, namely green supply chain management (GSCM). Our results show that ISO 14001 promotes GSCM practices. Facilities with environmental management systems (EMS) certified to ISO 14001 are 40% more likely to assess their suppliers' environmental performance and 50% more likely to require that their suppliers undertake specific environmental practices. Further, government programs that encourage voluntary EMS adoption indirectly promote GSCM practices. These programs increase the probabilities that facilities will assess their suppliers' environmental performance and require suppliers to undertake specific environmental practices by 7% and 8%, respectively. Combined, these findings suggest that there may be significant but previously unnoticed spillover effects of ISO 14001 and government promotion of voluntary action. © 2010 Elsevier Inc. Source


Aitchison J.C.,University of Sydney | Buckman S.,University of Wollongong
Gondwana Research | Year: 2012

The Early Paleozoic Lachlan Fold Belt of eastern Australia is widely regarded as an ancient convergent plate margin beneath which paleo-Pacific (Panthalassic) oceanic lithosphere was continuously subducted. It is cited as the type example of a retreating accretionary orogeny. However, sandstone compositions, the sedimentological nature and timing of chert accumulation and overall stratigraphic architecture are not necessarily consistent with this model. We suggest an alternative explanation for growth of Gondwanan continental margin. Oceanic lithosphere outboard of the passive Gondwana continental margin was subducted beneath an extensive intra-oceanic island arc that now crops out as an allochthonous element (Macquarie arc) within the fold belt. Once intervening oceanic lithosphere was eliminated this arc collided with, and was emplaced upon the Gondwana margin. Recognition of four such events along this margin through the Phanerozoic suggests it is a significant mechanism for continental growth. © 2012 . Source


Hull B.,University of Sydney
Communicable diseases intelligence | Year: 2011

This, the third annual immunisation coverage report, documents trends during 2009 for a range of standard measures derived from Australian Childhood Immunisation Register data, including overall coverage at standard age milestones and for individual vaccines included on the National Immunisation Program (NIP). Coverage by Indigenous status and mapping by smaller geographic areas as well as trends in timeliness is also summarised according to standard templates. With respect to overall coverage, the Immunise Australia Program targets have been reached for children at 12 and 24 months of age but not for children at 5 years of age. Coverage at 24 months of age exceeds that at 12 months of age, but as receipt of varicella vaccine at 18 months is excluded from calculations of 'fully immunised' this probably represents delayed immunisation, with some contribution from immunisation incentives. Similarly, the decrease in coverage estimates for immunisations due at 4 years of age from March 2008 is primarily due to changing the assessment age from 6 years to 5 years of age from December 2007. With respect to individual vaccines, a number of those available on the NIP are not currently assessed for 'fully immunised' status or for eligibility for incentive payments. These include pneumococcal conjugate and meningococcal C conjugate vaccines, for which coverage is comparable with vaccines that are assessed for 'fully immunised' status, and rotavirus and varicella vaccines for which coverage is lower. Coverage is also suboptimal for vaccines recommended for Indigenous children only (i.e. hepatitis A and pneumococcal polysaccharide vaccine) as previously reported for other vaccines for both children and adults. Delayed receipt of vaccines is an important issue for vaccines recommended for Indigenous children and has not improved among non-Indigenous children despite improvements in coverage at the 24-month milestone. Although Indigenous children in Australia have coverage levels that are similar to non-Indigenous children at 24 months of age, the disparity in delayed vaccination between Indigenous and non-Indigenous children remains a challenge. Source


You Y.,University of Sydney
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2010

The formation of North Pacific Intermediate Water (NPIW) requires a densification of ∼0.2-0.3 σθ through interior transformation processes. Evidence of this density anomaly is discovered on neutral density surfaces in the subarctic-tropical frontal zone (SATFZ) showing an eastward tongue of positive density anomaly coincident with a cabbeling maximum tongue. The northward displacement of the SATFZ with depth east of dateline enables the transformed dense water from overlying thermocline to sink into the northeast subtropical NPIW domain. The further southward and southwestward spreading across the subtropical gyre yields the observed distribution of NPIW. Crown Copyright © 2010. Source


Objective: To define the cardiovascular effects of lowering blood pressure in people with chronic kidney disease. Design: Collaborative prospective meta-analysis of randomised trials. Data sources and eligibility: Participating randomised trials of drugs to lower blood pressure compared with placebo or each other or that compare different blood pressure targets, with at least 1000 patient years of follow-up per arm. Main outcome measures: Major cardiovascular events (stroke, myocardial infarction, heart failure, or cardiovascular death) in composite and individually and all cause death. Participants: 26 trials (152 290 participants), including 30 295 individuals with reduced estimated glomerular filtration rate (eGFR), which was defined as eGFR <60 mL/min/1.73m2. Data extraction: Individual participant data were available for 23 trials, with summary data from another three. Meta-analysis according to baseline kidney function was performed. Pooled hazard ratios per 5 mm Hg lower blood pressure were estimated with a random effects model. Results: Compared with placebo, blood pressure lowering regimens reduced the risk of major cardiovascular events by about a sixth per 5 mm Hg reduction in systolic blood pressure in individuals with (hazard ratio 0.83, 95% confidence interval 0.76 to 0.90) and without reduced eGFR (0.83, 0.79 to 0.88), with no evidence for any difference in effect (P=1.00 for homogeneity). The results were similar irrespective of whether blood pressure was reduced by regimens based on angiotensin converting enzyme inhibitors, calcium antagonists, or diuretics/ß blockers. There was no evidence that the effects of different drug classes on major cardiovascular events varied between patients with different eGFR (all P>0.60 for homogeneity). Conclusions: Blood pressure lowering is an effective strategy for preventing cardiovascular events among people with moderately reduced eGFR. There is little evidence from these overviews to support the preferential choice of particular drug classes for the prevention of cardiovascular events in chronic kidney disease. Source


Zetterlund P.B.,University of New South Wales | Perrier S.,University of Sydney
Macromolecules | Year: 2011

The mechanism for the rate enhancement in reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene under microwave irradiation has been investigated by means of modeling and simulations. Quantitative analysis of previously published data [Chem. Commun. 2007, 2145 -2147] has revealed that the high propagating radical concentration that can be inferred from the polymerization rate would (based on classical kinetics of radical polymerization) lead to a bimolecular termination rate inconsistent with the radical generation rate and the control/livingness observed experimentally. The data were modeled based on (i) an increase in temperature caused by microwave irradiation, (ii) microwave-enhanced propagation (kp) and addition to RAFT moiety (kadd), and (iii) microwave-induced radical generation from monomer. It was found that only model ii can be invoked to explain the experimental data, which are consistent with the microwave irradiation resulting in an increase in kp and kadd by ∼1 order of magnitude in this particular case. © 2011 American Chemical Society. Source


Race K.,University of Sydney
Culture, Health and Sexuality | Year: 2015

This paper considers how certain functions of online hook-up devices are participating in the emergence of new forms of sexual relation, new distributions of intimacy and new sexual arrangements. Though not without precedent, it argues that online hook-up devices generally act in gay culture as ‘framing devices’, framing sex as a ‘no-strings’ encounter via their default application. These frames are variously rejected, reconfigured, re-embedded or confounded by participants; they become subject to various forms of overflowing. Understanding this dynamic, its typical forms of connection and estrangement, is pivotal for grasping the emergence of new forms of sexual community and new sexual publics among gay men – and/or ‘un-community’, as some have put it. My analysis prompts a series of methodological reflections wrought from the encounter it stages between queer theory and Science and Technology Studies. At a time when marriage and monogamy are increasingly monopolising the public discourse of gay life, digital devices are affording novel ways of arranging sex, intimacy and sexual community, with their own qualities and limitations. © 2014, © 2014 Taylor & Francis. Source


Menicucci N.C.,University of Sydney
Physical Review Letters | Year: 2014

A long-standing open question about Gaussian continuous-variable cluster states is whether they enable fault-tolerant measurement-based quantum computation. The answer is yes. Initial squeezing in the cluster above a threshold value of 20.5 dB ensures that errors from finite squeezing acting on encoded qubits are below the fault-tolerance threshold of known qubit-based error-correcting codes. By concatenating with one of these codes and using ancilla-based error correction, fault-tolerant measurement-based quantum computation of theoretically indefinite length is possible with finitely squeezed cluster states. © 2014 American Physical Society. Source


Shepherd B.,University of Sydney
Security Dialogue | Year: 2012

This article examines the tension between food security as strategic practice and as the human insecurity of hunger. It makes the case that hunger is a security matter that warrants greater attention from security scholars, but identifies some limitations with state-centric and human security approaches. The article explores Ken Booth's 'emancipatory realism' security project as one avenue for overcoming these limitations and uses Booth's work to assist in developing a reframing of food security. It proposes redefining food security in terms of securing vulnerable populations from the structural violence of hunger, and argues that such a framing offers both conceptual and practical value for efforts to confront the problem of increasing and widespread hunger. © The Author(s) 2012. Source


Li L.,University of Sydney
The Cochrane database of systematic reviews | Year: 2013

Jellyfish envenomations are common amongst temperate coastal regions and vary in severity depending on the species. Stings result in a variety of symptoms and signs, including pain, dermatological reactions and, in some species, Irukandji syndrome (including abdominal/back/chest pain, tachycardia, hypertension, sweating, piloerection, agitation and sometimes cardiac complications). Many treatments have been suggested for the symptoms and signs of jellyfish stings. However, it is unclear which interventions are most effective. To determine the benefits and harms associated with the use of any intervention, in both adults and children, for the treatment of jellyfish stings, as assessed from randomised trials. We searched the following electronic databases in October 2012 and again in October 2013: the Cochrane Central Register of Controlled Trials (CENTRAL;The Cochrane Library, Issue 9, 2013); MEDLINE via Ovid SP (1948 to 22 October 2013); EMBASE via Ovid SP (1980 to 21 October 2013); and Web of Science (all databases; 1899 to 21 October 2013). We also searched reference lists from eligible studies and guidelines, conference proceedings and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and contacted content experts to identify trials. We included randomised controlled trials that compared any intervention(s) to active and/or non-active controls for the treatment of symptoms and signs of jellyfish sting envenomation. No language, publication date or publication status restrictions were applied. Two review authors independently conducted study selection and data extraction and assessed risk of bias using a standardised form. Disagreements were resolved by consensus with a third review author when necessary. We included seven trials with a total of 435 participants. Three trials focused on Physalia (Bluebottle) jellyfish, one trial on Carukia jellyfish and three on Carybdea alata (Hawaiian box) jellyfish. Two ongoing trials were identified.Six of the seven trials were judged as having high risk of bias. Blinding was not feasible in four of the included trials because of the nature of the interventions. A wide range of interventions were assessed across trials, and a wide range of outcomes were measured. We reported results from the two trials for which data were available and reported the effects of interventions according to our definition of primary or secondary outcomes.Hot water immersion was superior to ice packs in achieving clinically significant (at least 50%) pain relief at 10 minutes (one trial, 96 participants, risk ratio (RR) 1.66, 95% confidence interval (CI) 1.01 to 2.72; low-quality evidence) and 20 minutes (one trial, 88 participants, RR 2.66, 95% CI 1.71 to 4.15; low-quality evidence). No statistically significant differences between hot water immersion and ice packs were demonstrated for dermatological outcomes.Treatment with vinegar or Adolph's meat tenderizer compared with hot water made skin appear worse (one trial, 25 participants, RR 0.31, 95% CI 0.14 to 0.72; low-quality evidence).Adverse events due to treatment were not reported in any trial. This review located a small number of trials that assessed a variety of different interventions applied in different ways and in different settings. Although heat appears to be an effective treatment for Physalia (Bluebottle) stings, this evidence is based on a single trial of low-quality evidence. It is still unclear what type of application, temperature, duration of treatment and type of water (salt or fresh) constitute the most effective treatment. In addition, these results may not apply to other species of jellyfish with different envenomation characteristics. Future research should further assess the most effective interventions using standardised research methodology. Source


Chen M.,University of Virginia | Menicucci N.C.,University of Sydney | Pfister O.,University of Virginia
Physical Review Letters | Year: 2014

We report the experimental realization and characterization of one 60-mode copy and of two 30-mode copies of a dual-rail quantum-wire cluster state in the quantum optical frequency comb of a bimodally pumped optical parametric oscillator. This is the largest entangled system ever created whose subsystems are all available simultaneously. The entanglement proceeds from the coherent concatenation of a multitude of Einstein, Podolsky, and Rosen pairs by a single beam splitter, a procedure which is also a building block for the realization of hypercubic-lattice cluster states for universal quantum computing. © 2014 American Physical Society. Source


Zoellner H.,University of Sydney
Seminars in Thrombosis and Hemostasis | Year: 2011

Periodontitis is a chronic inflammatory response to bacterial plaque in which the anchoring bone and soft tissues supporting teeth are destroyed, resulting in tooth mobility and loss. Dental caries involves the spread of infection from the dentine to the vascular dental pulp and periapical bony tissues, before involvement of adjacent soft tissues and spreading sepsis. Several case-controlled, cross-sectional, and cohort studies report correlation between periodontitis and increased cardiovascular, cerebrovascular, and peripheral artery disease, as determined by clinical disease, angiography, ultrasonography, and reduced flow-mediated dilation. Some studies report a similar relationship of atherosclerosis with periapical infection and potentially also with coronal caries, and this review identifies the need to investigate these associations further. Smoking and cadmium exposure are epidemiologically confounding environmental risk factors shared by atherosclerosis and periodontitis. Further complicating epidemiological studies are the risk factors for both atherosclerosis and periodontitis, with which periodontitis appears to have separate positive feedback relationships. These include diabetes, increased plasma lipid levels, hypertension, and white blood cell count. Animal and human intervention studies provide some direct support of a causal role for periodontitis in atherosclerosis, and possible mechanisms include bacterial invasion of arteries, specific atherogenic properties of oral bacteria, the acute phase response, and cytokine polymorphisms. Copyright © 2011 by Thieme Medical Publishers, Inc. Source


We developed a novel individualised training program regarding end-of-life communication, designed to be time effective for busy junior-doctors working in hospital settings. We aimed to pilot this brief individualised training program with junior-doctors to explore its acceptability, feasibility and effect on the doctors' confidence, communication skills, attitudes towards psychosocial care and burnout. The content of the training intervention was informed by a systematic literature review and evidence-based clinical practice guidelines regarding end-of-life communication. The intervention was based on sound educational principles and involved three one-hour teaching sessions over a three-week period, including two individual sessions with an expert facilitator and simulated patient/caregiver. In addition, participants received written and audiovisual take-home learning materials. Participants were videotaped consulting with a simulated patient/caregiver pre/post training to assess the impact of the course on their communication behaviours. Participants completed de-identified questionnaires pre/post training, including self-assessed confidence, attitudes to psychosocial care, and the Maslach Burnout inventory. Participants: Participants included 22 junior-doctors from a large teaching hospital in Sydney, Australia. All participants reported that the training was useful, had been helpful for their communication with patients and that they would recommend the training to others. Significant improvements were found in participants' communication skills (in seven out of 21 specific and all three global communication behaviours assessed, range P=0.02 to <0.001), confidence in communicating about relevant topics (P<0.001), attitudes towards psychosocial care (P=0.03) and sense of personal accomplishment (P=0.043). There were no overall differences in participants' burnout levels. This intervention shows promise and warrants further formal evaluation. Source


Maron B.J.,Minneapolis Heart Institute Foundation | Maron M.S.,Hypertrophic Cardiomyopathy Center | Semsarian C.,University of Sydney
Journal of the American College of Cardiology | Year: 2012

Hypertrophic cardiomyopathy (HCM) is the most common familial heart disease with vast genetic heterogeneity, demonstrated over the past 20 years. Mutations in 11 or more genes encoding proteins of the cardiac sarcomere (>1,400 variants) are responsible for (or associated with) HCM. Explosive progress achieved in understanding the rapidly evolving science underlying HCM genomics has resulted in fee-for-service testing, making genetic information widely available. The power of HCM mutational analysis, albeit a more limited role than initially envisioned, lies most prominently in screening family members at risk for developing disease and excluding unaffected relatives, which is information not achievable otherwise. Genetic testing also allows expansion of the broad HCM disease spectrum and diagnosis of HCM phenocopies with different natural history and treatment options, but is not a reliable strategy for predicting prognosis. Interfacing a heterogeneous disease such as HCM with the vast genetic variability of the human genome, and high frequency of novel mutations, has created unforeseen difficulties in translating complex science (and language) into the clinical arena. Indeed, proband diagnostic testing is often expressed on a probabilistic scale, which is frequently incompatible with clinical decision making. Major challenges rest with making reliable distinctions between pathogenic mutations and benign variants, and those judged to be of uncertain significance. Genotyping in HCM can be a powerful tool for family screening and diagnosis. However, wider adoption and future success of genetic testing in the practicing cardiovascular community depends on a standardized approach to mutation interpretation, and bridging the communication gap between basic scientists and clinicians. © 2012 American College of Cardiology Foundation. Source


Caldwell P.H.,University of Sydney
The Cochrane database of systematic reviews | Year: 2013

Nocturnal enuresis (bedwetting) is a socially disruptive and stressful condition which affects around 15% to 20% of five year olds and up to 2% of adults. Although there is a high rate of spontaneous remission, the social, emotional and psychological costs can be great. Behavioural interventions for treating bedwetting are defined as interventions that require a behaviour or action by the child which promotes night dryness and includes strategies which reward that behaviour. Behavioural interventions are further divided into:(a) simple behavioural interventions - behaviours or actions that can be achieved by the child without great effort; and(b) complex behavioural interventions - multiple behavioural interventions which require greater effort by the child and parents to achieve, including enuresis alarm therapy.This review focuses on simple behavioural interventions.Simple behavioural interventions are often used as a first attempt to improve nocturnal enuresis and include reward systems such as star charts given for dry nights, lifting or waking the children at night to urinate, retention control training to enlarge bladder capacity (bladder training) and fluid restriction. Other treatments such as medications, complementary and miscellaneous interventions such as acupuncture, complex behavioural interventions and enuresis alarm therapy are considered elsewhere. To determine the effects of simple behavioural interventions in children with nocturnal enuresis.The following comparisons were made:1. simple behavioural interventions versus no active treatment;2. any single type of simple behavioural intervention versus another behavioural method (another simple behavioural intervention, enuresis alarm therapy or complex behavioural interventions);3. simple behavioural interventions versus drug treatment alone (including placebo drugs) or drug treatment in combination with other interventions. We searched the Cochrane Incontinence Group Specialised Trials Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE in process, and handsearching of journals and conference proceedings (searched 15 December 2011). The reference lists of relevant articles were also searched. All randomised or quasi-randomised trials of simple behavioural interventions for treating nocturnal enuresis in children up to the age of 16. Studies which included children with daytime urinary incontinence or children with organic conditions were also included in this review if the focus of the study was on nocturnal enuresis. Trials focused solely on daytime wetting and trials of adults with nocturnal enuresis were excluded. Two reviewers independently assessed the quality of the eligible trials and extracted data. Differences between reviewers were settled by discussion with a third reviewer. Sixteen trials met the inclusion criteria, involving 1643 children of whom 865 received a simple behavioural intervention. Within each comparison, outcomes were mostly addressed by single trials, precluding meta-analysis. The only exception was bladder training versus enuresis alarm therapy which included two studies and demonstrated that alarm therapy was superior to bladder training.In single small trials, rewards, lifting and waking and bladder training were each associated with significantly fewer wet nights, higher full response rates and lower relapse rates compared to controls. Simple behavioural interventions appeared to be less effective when compared with other known effective interventions (such as enuresis alarm therapy and drug therapies with imipramine and amitriptyline). However, the effect was not sustained at follow-up after completion of treatment for the drug therapies. Based on one small trial, cognitive therapy also appeared to be more effective than rewards. When one simple behavioural therapy was compared with another, there did not appear to be one therapy that was more effective than another. Simple behavioural methods may be superior to no active treatment but appear to be inferior to enuresis alarm therapy and some drug therapy (such as imipramine and amitriptyline). Simple behavioural therapies could be tried as first line treatment before considering enuresis alarm therapy or drug therapy, which may be more demanding and have adverse effects, although evidence supporting their efficacy is lacking. Source


Dear R.F.,University of Sydney
The Cochrane database of systematic reviews | Year: 2013

Combination chemotherapy can cause greater tumour cell kill if the drug dose is not compromised, while sequential single agent chemotherapy may allow for greater dose intensity and treatment time, potentially meaning greater benefit from each single agent. In addition, sequentially using single agents might cause less toxicity and impairment of quality of life, but it is not known whether this might compromise survival time. To assess the effect of combination chemotherapy compared to the same drugs given sequentially in women with metastatic breast cancer. We searched the Cochrane Breast Cancer Group Specialised Register, using the search terms "advanced breast cancer" and "chemotherapy", MEDLINE and EMBASE on 31 October 2013. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were also searched (22 March 2012). Randomised controlled trials of combination chemotherapy compared to the same drugs used sequentially in women with metastatic breast cancer in the first-, second- or third-line setting. Two authors independently extracted data from published trials. Hazard ratios (HR) were derived from time-to-event outcomes where possible, and a fixed-effect model was used for meta-analysis. Response rates were analysed as dichotomous variables (risk ratios (RR)), and toxicity and quality of life data were extracted where available. Twelve trials reporting on nine treatment comparisons (2317 patients randomised) were identified. The majority of trials (10 trials) had an unclear or high risk of bias. Time-to-event data were collected for nine trials for overall survival and eight trials for progression-free survival. All 12 trials reported results for tumour response. In the 12 trials there were 1023 deaths in 2317 women randomised. There was no difference in overall survival, with an overall HR of 1.04 (95% confidence interval (CI) 0.93 to 1.16; P = 0.45), and no significant heterogeneity. This result was consistent in the four subgroups analysed (risk of bias, line of chemotherapy, type of schema of chemotherapy, and relative dose intensity). In particular, there was no difference in survival according to the type of schema of chemotherapy, that is whether chemotherapy was given on disease progression or after a set number of cycles. In the eight trials that reported progression-free survival, 678 women progressed out of the 886 women randomised. The combination arm had a higher risk of progression than the sequential arm (HR 1.16; 95% CI 1.03 to 1.31; P = 0.01) with no significant heterogeneity. This result was consistent in all subgroups. Overall tumour response rates were higher in the combination arm (RR 1.13; 95% CI 1.03 to 1.24; P = 0.008) but there was significant heterogeneity for this outcome across the trials. In the seven trials that reported treatment-related deaths, there was no significant difference between the two arms, although the CIs were very wide due to the small number of events (RR 1.53; 95% CI 0.71 to 3.29; P = 0.28). The risk of febrile neutropenia was higher in the combination arm (RR 1.32; 95% CI 1.06 to 1.65; P = 0.01). There was no statistically significant difference in the risk of neutropenia, nausea and vomiting, or treatment-related deaths. Overall quality of life showed no difference between the two groups, but only three trials reported this outcome. Sequential single agent chemotherapy has a positive effect on progression-free survival, whereas combination chemotherapy has a higher response rate and a higher risk of febrile neutropenia in metastatic breast cancer. There is no difference in overall survival time between these treatment strategies, both overall and in the subgroups analysed. In particular, there was no difference in survival according to the schema of chemotherapy (giving chemotherapy on disease progression or after a set number of cycles) or according to the line of chemotherapy (first-line versus second- or third-line). Generally this review supports the recommendations by international guidelines to use sequential monotherapy unless there is rapid disease progression. Source


Using data from the Legacy Media Tracking Survey II, this study investigated relations among youth's evaluations of the truth antismoking campaign, campaign-related interpersonal discussion, and campaign-relevant outcomes (n=8,000). Regression analyses showed that smokers were less likely to have discussed the campaign than nonsmokers, and this effect was mediated by negative campaign evaluation. However, smokers with a negative evaluation of the campaign were more likely to talk about it than were nonsmokers reporting negative evaluation. Nonsmokers who talked about the campaign had beliefs, attitudes, and intentions in greater agreement with campaign messages than those who did not talk about the campaign. For smokers, talking about the campaign was associated with beliefs, attitudes, and intentions in greater agreement with campaign messages, but only if associated with positive campaign evaluation. For smokers with a negative campaign evaluation, talking about the campaign was associated with beliefs and attitudes counter to the campaign messages. Copyright © Taylor & Francis Group, LLC. Source


Burton O.J.,University of Aberdeen | Phillips B.L.,University of Sydney | Travis J.M.J.,University of Aberdeen
Ecology Letters | Year: 2010

Ecology Letters (2010)During range-advance, individuals on the expanding edge of the population face a unique selective environment. In this study, we use a three-trait trade-off model to explore the evolution of dispersal, reproduction and competitive ability during range expansion. We show that range expansion greatly affects the evolution of life-history traits due to differing selection pressures at the front of the range compared with those found in stationary and core populations. During range expansion, dispersal and reproduction are selected for on the expanding population front, whereas traits associated with fitness at equilibrium density (competitive ability) show dramatic declines. Additionally, we demonstrate that the presence of a competing species can considerably reduce the extent to which dispersal is selected upwards at an expanding front. These findings have important implications for understanding both the rate of spread of invasive species and the range-shifting dynamics of native species in response to climate change. © 2010 Blackwell Publishing Ltd/CNRS. Source


Ramesh N.,Indian Institute of Science | Ramesh N.,University of Sydney | Murtugudde R.,The Interdisciplinary Center
Nature Climate Change | Year: 2013

The El Niño/Southern Oscillation phenomenon, characterized by anomalous sea surface temperatures and winds in the tropical Pacific, affects climate across the globe. El Niños occur every 2-7 years, whereas the El Niño/Southern Oscillation itself varies on decadal timescales in frequency and amplitude, with a different spatial pattern of surface anomalies each time the tropical Pacific undergoes a regime shift. Recent work has shown that Bjerknes feedback (coupling of the atmosphere and the ocean through changes in equatorial winds driven by changes in sea surface temperature owing to suppression of equatorial upwelling in the east Pacific) is not necessary for the development of an El Niño. Thus it is unclear what remains constant through regimes and is crucial for producing the anomalies recognized as El Niño. Here we show that the subsurface process of discharging warm waters always begins in the boreal summer/autumn of the year before the event (up to 18 months before the peak) independent of regimes, identifying the discharge process as fundamental to the El Niño onset. It is therefore imperative that models capture this process accurately to further our theoretical understanding, improve forecasts and predict how the El Niño/Southern Oscillation may respond to climate change. © 2013 Macmillan Publishers Limited. All rights reserved. Source


Aubret F.,French National Center for Scientific Research | Aubret F.,University of Sydney
American Naturalist | Year: 2012

Mean adult size has been used as the traditional measure of body size to explain trends of insular gigantism and dwarfism in a wide array of taxa. However, patterns of variation in body size at birth have received surprisingly little attention, leaving open the possibility that adult body-size differences are nonadaptive consequences of selection acting on neonate body size. Here I used an empirical and correlative approach to test this hypothesis in a mosaic of 12 island and mainland snake populations in Australia. Data collected on 597 adult and 1,084 neonate tiger snakes showed that (1) both adult and neonate mean body sizes varied strongly across populations; (2) prey diversity and size convincingly explained birth-size variations: birth size-notably, gape size-correlated with prey size; (3) neonate snout-vent length was significantly correlated with neonate gape size; and (4) neonate snout-vent length was significantly correlated with adult snout-vent length. Postnatal growth rates recorded under common-garden conditions differed across populations and were correlated with mean prey size. These data collectively suggest that (1) prey size is the main driver for the evolution of body size at birth in gape-limited predators, (2) adult size variations may reflect selective forces acting on earlier life stages, and (3) adult size variations may also reflect resource availability during ontogeny (notably, prey diversity). © 2012 by The University of Chicago. Source


Athab H.S.,Multimedia University | Lu D.D.-C.,University of Sydney
IEEE Transactions on Power Electronics | Year: 2010

This letter presents a novel ac/dc converter based on a quasi-active power factor correction (PFC) scheme. In the proposed circuit, the power factor is improved by using an auxiliary winding coupled to the transformer of a cascade dc/dc flyback converter. The auxiliary winding is placed between the input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an input inductor. Since the dc/dc converter is operated at high-switching frequency, the auxiliary windings produce a high frequency pulsating source such that the input current conduction angle is significantly lengthened and the input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC, which results in lower cost and higher efficiency. In order to achieve low harmonic content, the input inductor is designed to operate in discontinuous current mode. Operating principles, analysis, and experimental results of the proposed method are presented. © 2006 IEEE. Source


Wilcken B.,University of Sydney
Journal of Inherited Metabolic Disease | Year: 2010

Assessing the outcome of fatty acid oxidation disorders is difficult, as most are rare. For diagnosis by newborn screening, the situation is compounded: far more cases are diagnosed by screening than by clinical presentation, representing a somewhat different cohort. The literature on outcome was reviewed. For disorders other than medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) deficiency there was insufficient evidence to make many firm statements. In MCAD deficiency, risk of death in the first 72 h is around 4%, with a further approximately 5-7% fatality rate in the first 6 years but very low subsequent risk in previously undiagnosed patients. The risk of death after diagnosis is very low at any age, with good management. The long-term outcome is good nowadays. Very-long-chain acyl-CoA dehydrogenase deficiency poses a risk of death in early infancy, but the condition is generally treatable, with a good outcome after diagnosis. Approximately 10-20% of patients diagnosed by newborn screening and treated nevertheless suffer episodic rhabdomyolysis. Some patients never become symptomatic. Isolated long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency is treatable, but most patients suffer episodic hypoketotic hypoglycaemia and rhabdomyolysis. Generalised mitochondrial tri-functional protein deficiency has high early mortality rate. A more insidious presentation also occurs, with symptoms sometimes confined to progressive axonal neuropathy. Among carnitine cycle disorders, carnitine transporter deficiency, potentially lethal, is uniformly successfully treated orally with carnitine. Carnitine-acylcarnitine translocase and early-onset carnitine palmitoyl transferase type II (CPT II) deficiencies have an extremely high neonatal mortality rate. Late-onset CPT II is characterised only by episodic rhabdomyolysis on severe exercise. CPT type IA deficiency may often be benign, although early presentation with hypoketotic hypoglycaemia certainly occurs. © 2009 SSIEM and Springer. Source


Law S.S.C.,National Cheng Kung University | McDonald K.L.,University of Sydney
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The seesaw mechanism can be generalized to a type-III variant and a quintuplet variant. We present two models that provide analogous generalizations of the inverse seesaw mechanism. The first model employs a real fermion triplet F∼(1,3,0) and requires no additional multiplets or parameters relative to the standard inverse seesaw. We argue that, from a bottom-up perspective, there appears to be no particular reason to preference the usual scenario over this variant. The second model employs a fermion quintuplet F∼(1,5,0) and requires an additional scalar S∼(1,4,1). We also show that minimal inverse seesaws with even larger fermionic representations are not expected to realize naturally small neutrino masses. © 2013 American Physical Society. Source


Hayes R.,University of Newcastle | Imberti S.,Rutherford Appleton Laboratory | Warr G.G.,University of Sydney | Atkin R.,University of Newcastle
Angewandte Chemie - International Edition | Year: 2012

Water in ionic liquids: When equal masses of water and the protic ionic liquid ethylammonium nitrate are mixed a bicontinuous nanostructure results. This nanostructure resembles aqueous surfactant mesophases but has length scales at least an order of magnitude smaller. The local structure of both the water and the ionic liquid are strikingly similar to that found in the pure liquids (see picture). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Eggleton B.J.,University of Sydney
Optics Express | Year: 2010

Introduction to a focus issue of invited articles that review recent progress in chalcogenide photonics. © 2010 Optical Society of America. Source


Rungsiyakull C.,University of Sydney
The International journal of oral & maxillofacial implants | Year: 2011

To provide a preliminary understanding of the biomechanics with respect to the effect of cusp inclination and occlusal loading on the mandibular bone remodeling. Three different cusp inclinations (0, 10, and 30 degrees) of a ceramic crown and different occlusal loading locations (central fossa and 1- and 2-mm offsets horizontally) were taken into account to explore the stresses and strains transferred from the crown to the surrounding dental bone through the implant. A strain energy density obtained from two-dimensional plane-strain finite element analysis was used as the mechanical stimulus to drive cancellous and cortical bone remodeling in a buccolingual mandibular section. Different ceramic cusp inclinations had a significant effect on bone remodeling responses in terms of the change in the average peri-implant bone density and overall stability. The remodeling rate was relatively high in the first few months of loading and gradually decreased until reaching its equilibrium. A larger cusp inclination and horizontal offset (eg, 30 degrees and 2-mm offset) led to a higher bone remodeling rate and greater interfacial stress. The dental implant superstructure design (in terms of cusp inclination and loading location) determines the load transmission pattern and thus largely affects bone remodeling activities. Although the design with a lower cusp inclination recommended in previous studies may reduce damage and fracture failure, it could, to a certain extent, compromise bone engagement and long-term stability. Source


Qiao L.,University of Sydney
Current gene therapy | Year: 2015

Notch signaling is an evolutionarily conserved pathway crucial for the development and homeostasis of many organs including liver. Aberrant Notch signaling has been mechanistically linked to cancer development including liver cancer. The two principal types of liver cancer are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHCC). HCCs comprise over 80% of all liver cancers and are the 6(th) most common malignancy worldwide. Hepatocellular carcinoma is also a cancer with an extremely poor prognosis, being the 3(rd) commonest cause of cancer-related mortality. Accumulating evidence indicates that the role of Notch signaling in liver cancer is more complex than once thought and is dependent on the expression of specific Notch signaling components and the complex crosstalk with other signaling pathways. Currently there are a variety of gene therapy based approaches used to target Notch signaling in preclinical studies to successfully treat liver cancer including neutralizing antibodies, siRNA, shRNA and miRNA. The use of targeted anti-Notch therapy in the clinic to treat liver cancer will require considerable refinement of our current knowledge on the regulation of Notch signaling components and their effects in both normal and malignant liver cells in order to target specific Notch subunits which are critical to liver cancer tumorigenesis but not to the homeostasis of normal cells. Using this approach will reduce the major side effects, which are frequently seen in patients treated with GSIs to inhibit the entire Notch signaling pathway. Here our understanding of Notch signaling is reviewed, highlighting its function in liver cancer initiation, progress and opportunities for liver cancer therapies. Source


Bell K.J.,University of Sydney
European Journal of Clinical Nutrition | Year: 2014

Background/objective:The Food Insulin Index (FII) is a novel algorithm for ranking foods on the basis of insulin responses in healthy subjects relative to an isoenergetic reference food. Our aim was to compare postprandial glycemic responses in adults with type 1 diabetes who used both carbohydrate counting and the FII algorithm to estimate the insulin dosage for a variety of protein-containing foods.Subjects/methods:A total of 11 adults on insulin pump therapy consumed six individual foods (steak, battered fish, poached eggs, low-fat yoghurt, baked beans and peanuts) on two occasions in random order, with the insulin dose determined once by the FII algorithm and once with carbohydrate counting. Postprandial glycemia was measured in capillary blood glucose samples at 15-30 min intervals over 3 h. Researchers and participants were blinded to treatment.Results:Compared with carbohydrate counting, the FII algorithm significantly reduced the mean blood glucose level (5.7±0.2 vs 6.5±0.2 mmol/l, P=0.003) and the mean change in blood glucose level (-0.7±0.2 vs 0.1±0.2 mmol/l, P=0.001). Peak blood glucose was reached earlier using the FII algorithm than using carbohydrate counting (34±5 vs 56±7 min, P=0.007). The risk of hypoglycemia was similar in both treatments (48% vs 33% for FII vs carbohydrate counting, respectively, P=0.155).Conclusions:In adults with type 1 diabetes, compared with carbohydrate counting, the novel FII algorithm improved postprandial hyperglycemia after consumption of protein-containing foods.European Journal of Clinical Nutrition advance online publication, 9 July 2014; doi:10.1038/ejcn.2014.126. Source


Anderson E.J.,University of Sydney
Mathematical Programming | Year: 2013

Supply function equilibria are used in the analysis of divisible good auctions with a large number of identical objects to be sold or bought. An important example occurs in wholesale electricity markets. Despite the substantial literature on supply function equilibria the existence of a pure strategy Nash equilibria for a uniform price auction in asymmetric cases has not been established in a general setting. In this paper we prove the existence of a supply function equilibrium for a duopoly with asymmetric firms having convex non-decreasing marginal costs, with decreasing concave demand subject to an additive demand shock, provided that the second derivative of the demand function is small enough and not increasing. The proof is constructive and also gives insight into the structure of the equilibrium solutions. © 2013 Springer-Verlag Berlin Heidelberg and Mathematical Optimization Society. Source


Soyer O.S.,University of Warwick | O'Malley M.A.,University of Sydney
BioEssays | Year: 2013

Evolutionary systems biology (ESB) is a rapidly growing integrative approach that has the core aim of generating mechanistic and evolutionary understanding of genotype-phenotype relationships at multiple levels. ESB's more specific objectives include extending knowledge gained from model organisms to non-model organisms, predicting the effects of mutations, and defining the core network structures and dynamics that have evolved to cause particular intracellular and intercellular responses. By combining mathematical, molecular, and cellular approaches to evolution, ESB adds new insights and methods to the modern evolutionary synthesis, and offers ways in which to enhance its explanatory and predictive capacities. This combination of prediction and explanation marks ESB out as a research manifesto that goes further than its two contributing fields. Here, we summarize ESB via an analysis of characteristic research examples and exploratory questions, while also making a case for why these integrative efforts are worth pursuing. © 2013 WILEY Periodicals, Inc. Source


Clopidogrel and ticagrelor, antagonists to P2Y12 receptor molecules on platelet membranes, significantly ameliorate acute myocardial infarction due to coronary artery thrombosis, the most common cause of death in the developed world. A personal account is given here of the foundational research that lead to the identification of P2Y receptors, carried out 50 years ago in the Melbourne University Zoology Department headed by Geoffrey Burnstock. In Christmas 1962, I made the serendipitous observation of large hyperpolarizing changes across the membranes of smooth muscle cells in the taenia coli of the intestine on stimulating its nerve supply. I then showed that these potentials relaxed the muscle and were not due to noradrenaline or acetylcholine, which were then the only substances known to be released from nerves. I called these non-adrenergic, non-cholinergic (NANC) terminals in the laboratory and showed that this NANC transmitter acted at receptor molecules on the muscle cells, promoting efflux of potassium ions, and so the observed potential changes. In 1968, Graeme Campbell showed that ATP relaxed the taenia coli muscle, and in 1969, David Satchell, using purine chromatography, showed that ATP was likely to be released from NANC terminals. The receptor molecules involved were shown to be exceptionally sensitive to 2-methylthio-ATP (Satchell and Macguire, 1975, J Pharmacol Exp Ther, 195, 540), and so belonged to the class P2Y receptors as designated by Abbracchio and Burnstock, with subclasses P2Y1-P2Y12. The discovery of the role of P2Y12 receptors in increasing thrombosis lead to the focused research that resulted in clopidogrel and ticagrelor. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society. Source


Lupton D.,University of Sydney
IEEE Technology and Society Magazine | Year: 2013

The concepts of ¿self-tracking¿ and ¿the quantified self¿ have recently begun to emerge in discussions of how best to optimize one¿s life. These concepts refer to the practice of gathering data about oneself on a regular basis and then recording and analyzing the data to produce statistics and other data (such as images) relating to one¿s bodily functions and everyday habits. Some self-trackers collect data on only one or two dimensions of their lives, and only for a short time. Others may do so for hundreds of phenomena and for long periods. © 2013 IEEE. Source


Morris B.J.,University of Sydney
Free Radical Biology and Medicine | Year: 2013

Sirtuins are a class of NAD+-dependent deacetylases having beneficial health effects. This extensive review describes the numerous intracellular actions of the seven mammalian sirtuins, their protein targets, intracellular localization, the pathways they modulate, and their role in common diseases of aging. Selective pharmacological targeting of sirtuins is of current interest in helping to alleviate global disease burden. Since all sirtuins are activated by NAD+, strategies that boost NAD+ in cells are of interest. While most is known about SIRT1, the functions of the six other sirtuins are now emerging. Best known is the involvement of sirtuins in helping cells adapt energy output to match energy requirements. SIRT1 and some of the other sirtuins enhance fat metabolism and modulate mitochondrial respiration to optimize energy harvesting. The AMP kinase/SIRT1-PGC-1α- PPAR axis and mitochondrial sirtuins appear pivotal to maintaining mitochondrial function. Downregulation with aging explains much of the pathophysiology that accumulates with aging. Posttranslational modifications of sirtuins and their substrates affect specificity. Although SIRT1 activation seems not to affect life span, activation of some of the other sirtuins might. Since sirtuins are crucial to pathways that counter the decline in health that accompanies aging, pharmacological agents that boost sirtuin activity have clinical potential in treatment of diabetes, cardiovascular disease, dementia, osteoporosis, arthritis, and other conditions. In cancer, however, SIRT1 inhibitors could have therapeutic value. Nutraceuticals such as resveratrol have a multiplicity of actions besides sirtuin activation. Their net health benefit and relative safety may have originated from the ability of animals to survive environmental changes by utilizing these stress resistance chemicals in the diet during evolution. Each sirtuin forms a key hub to the intracellular pathways affected. © 2012 Elsevier Inc. Source


Ahmadian M.,Salk Institute for Biological Studies | Suh J.M.,Salk Institute for Biological Studies | Hah N.,Salk Institute for Biological Studies | Liddle C.,University of Sydney | And 3 more authors.
Nature Medicine | Year: 2013

Thiazolidinediones (TZDs) are potent insulin sensitizers that act through the nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) and are highly effective oral medications for type 2 diabetes. However, their unique benefits are shadowed by the risk for fluid retention, weight gain, bone loss and congestive heart failure. This raises the question as to whether it is possible to build a safer generation of PPARγ-specific drugs that evoke fewer side effects while preserving insulin-sensitizing potential. Recent studies that have supported the continuing physiologic and therapeutic relevance of the PPARγ pathway also provide opportunities to develop newer classes of molecules that reduce or eliminate adverse effects. This review highlights key advances in understanding PPARγ signaling in energy homeostasis and metabolic disease and also provides new explanations for adverse events linked to TZD-based therapy. © 2013 Nature America, Inc. All rights reserved. Source


Lawen A.,Monash University | Lane D.J.R.,University of Sydney
Antioxidants and Redox Signaling | Year: 2013

Iron is a crucial factor for life. However, it also has the potential to cause the formation of noxious free radicals. These double-edged sword characteristics demand a tight regulation of cellular iron metabolism. In this review, we discuss the various pathways of cellular iron uptake, cellular iron storage, and transport. Recent advances in understanding the reduction and uptake of non-transferrin-bound iron are discussed. We also discuss the recent progress in the understanding of transcriptional and translational regulation by iron. Furthermore, we discuss recent advances in the understanding of the regulation of cellular and systemic iron homeostasis and several key diseases resulting from iron deficiency and overload. We also discuss the knockout mice available for studying iron metabolism and the related human conditions. © Copyright 2013, Mary Ann Liebert, Inc. Source


Melrose D.B.,University of Sydney
Astrophysical Journal | Year: 2012

Inclusion of the inductive electric field, E ind, due to the temporally changing B, in magnetic explosions is discussed, with emphasis on solar flares. Several roles played by E ind are identified: on a global scale, E ind produces the electromotive force that drives the explosion; the associated E ind × B drift is identified with the inflow of magnetic field lines into a reconnection region; the polarization current, associated with ∂E ind/∂t, implies a J × B force that accelerates this inflow; and the component of E ind parallel to B accelerates the energetic electrons that cause hard X-ray emission and type III radio bursts. Some simple models that describe these effects are presented. A resolution of the long-standing "number problem" in solar flares is suggested. © 2012 The American Astronomical Society. All rights reserved. Source


Melrose D.B.,University of Sydney
Astrophysical Journal | Year: 2012

An accepted model for magnetospheric substorms is proposed as the basis for a generic model for magnetic explosions and is applied to solar flares. The model involves widely separated energy-release and particle-acceleration regions, with energy transported Alfvénically between them. On a global scale, these regions are coupled by a large-scale current that is set up during the explosion by redirection of pre-existing current associated with the stored magnetic energy. The explosion-related current is driven by an electromotive force (EMF) due to the changing magnetic flux enclosed by this current. The current path and the EMF are identified for an idealized quadrupolar model for a flare. © 2012. The American Astronomical Society. All rights reserved.. Source


Connor L.H.,University of Sydney | Higginbotham N.,University of Newcastle
Global Environmental Change | Year: 2013

This article analyses lay understandings of climate change elicited through a longitudinal population-based survey of climate change, place and community among 1162 residents in the Hunter Valley, Southeast Australia. We explore how older residents in contrasting rural and coastal geographic areas perceive climate change information in terms of culturally relevant meanings and values, lived experiences and emotional responses to seasonal cycles, temperature fluctuations and altered landscapes. Thematic analysis of comments given by 467 interviewees to an open-ended question identified a significant subset for whom the concepts of "nature" and "science" express competing views about changing climatic conditions. For them, the idea of "natural cycles" is a significant cultural construct that links nature and humans through time in a way that structures stable and resilient understandings of environmental change, drawing on established cosmological frameworks for contemplating the future in relation to the past. In contrast to other studies that postulate scepticism and denial as individuals' fear management strategies in the face of climate change threat, we found that the natural cycles view is founded on a reassuring deeper conviction about how nature works, and is linked to other pro-environmental values not commonly found in sceptical groups. It is a paradox of natural cycles thinking that it rejects the anthropocentrism that is at the heart of science-based environmentalism. By contrast, it places humans as deeply integrated with nature, rather than operating outside it and attempting with uncertain science to control something that is ultimately uncontrollable. © 2013 Elsevier Ltd. Source


Matthews J.M.,University of Sydney | Potts J.R.,University of York
FEBS Letters | Year: 2013

The tandem β-zipper protein-protein binding interface involves an intrinsically disordered protein (IDP) binding two or more globular domains through β-sheet-augmentation in a modular fashion, and represents a paradigm in IDP-mediated protein-protein interactions. While characterised tandem β-zippers are rare, known examples are associated with diverse biological processes. A combination of their advantages (binding specificity and the ability to generate high affinity binding sites by linking multiple lower affinity motifs) and the prevalence of both tandem domains and IDPs points to the existence of many more β-zippers in nature. The characterisation of these interactions has greatly enhanced the understanding of the biological systems involved but given their apparent tolerance to mutation, detecting other tandem β-zipper interactions using bioinformatics may be challenging. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Source


Guhur A.,Ecole Polytechnique - Palaiseau | Jackson S.D.,University of Sydney
Optics Express | Year: 2010

We demonstrate a highly efficient and high power Ho3+-doped fluoride glass fiber laser that is resonantly pumped with a Tm 3+-doped silicate glass fiber laser operating at 2.051 μm. The laser operates at 2080 nm and generated 6.66 W at a slope efficiency of 72%. We observe strong visible upconversion fluorescence centered at a variety of wavelengths including 491 nm which results from three sequential energy transfer upconversion processes; the fluorescence to pump energy ratio for this emission is one the largest reported to date. © 2010 Optical Society of America. Source