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The Australian National University is a public university in Canberra, Australian Capital Territory. Located in the suburb of Acton, the main campus encompasses seven teaching and research colleges, in addition to several national institutes.Founded in 1946, it is the only university to have been created by the Parliament of Australia. Originally a postgraduate research university, ANU commenced undergraduate teaching in 1960 when it integrated the Canberra University College, which had been established in 1929 as a campus of the University of Melbourne. ANU enrols 10,359 undergraduate and 9,674 postgraduate students and employs 3,958 staff. The university's endowment stood at A$1.237 billion in 2010.ANU is consistently ranked among the world's top universities. ANU is ranked co-equal 25th in the world with Duke University by the 2014/15 QS World University Rankings, 45th in the world by the 2014/2015 Times Higher Education World University Rankings. In the 2014 Times Higher Education Global Employability University Ranking, an annual ranking of university graduates' employability, ANU was ranked 20th in the world .ANU counts six Nobel laureates among its faculty and alumni. Students entering ANU in 2013 had a median Australian Tertiary Admission Rank of 93, the equal-highest among Australian universities. ANU was named the world's 7th most international university in a 2014 study by Times Higher Education.ANU is a member of the Group of Eight and the International Alliance of Research Universities. As Australia’s only member of this prestigious association, ANU enjoys close relationships and exchange partnerships with the University of Cambridge, University of Oxford, University of California, Berkeley, Yale University, Peking University, National University of Singapore, University of Tokyo, University of Copenhagen and ETH Zurich. Wikipedia.


Simenel C.,Australian National University | Simenel C.,CEA Saclay Nuclear Research Center
Physical Review Letters | Year: 2010

A particle-number projection technique is used to calculate transfer probabilities in the O16+Pb208 reaction below the fusion barrier. The time evolution of the many-body wave function is obtained with the time-dependent Hartree-Fock (TDHF) mean-field theory. The agreement with experimental data for the sum of the proton-transfer channels is good, considering that TDHF has no parameter adjusted on the reaction mechanism. Some perspectives for extensions beyond TDHF to include cluster transfers are discussed. © 2010 The American Physical Society. Source


Shames I.,KTH Royal Institute of Technology | Dasgupta S.,University of Iowa | Fidan B.,University of Waterloo | Anderson B.D.O.,Australian National University
IEEE Transactions on Automatic Control | Year: 2012

Consider an agent A at an unknown location, undergoing sufficiently slow drift, and a mobile agent B that must move to the vicinity of and then circumnavigate A at a prescribed distance from A. In doing so, B can only measure its distance from A, and knows its own position in some reference frame. This paper considers this problem, which has applications to surveillance and orbit maintenance. In many of these applications it is difficult for B to directly sense the location of A, e.g. when all that B can sense is the intensity of a signal emitted by A. This intensity does, however provide a measure of the distance. We propose a nonlinear periodic continuous time control law that achieves the objective using this distance measurement. Fundamentally, a) B must exploit its motion to estimate the location of A, and b) use its best instantaneous estimate of where A resides, to move itself to achieve the circumnavigation objective. For a) we use an open loop algorithm formulated by us in an earlier paper. The key challenge tackled in this paper is to design a control law that closes the loop by marrrying the two goals. As long as the initial estimate of the source location is not coincident with the intial position of B, the algorithm is guaranteed to be exponentially convergent when A is stationary. Under the same condition, we establish that when A drifts with a sufficiently small, unknown velocity, B globally achieves its circumnavigation objective, to within a margin proportional to the drift velocity. © 2011 IEEE. Source


Liu Y.,CAS Institute of Policy and Management | Lu Y.,Australian National University
Applied Energy | Year: 2015

As an important policy instrument for climate mitigation, the carbon tax policy design and its consequent social-economic impact calls for more research. In this paper, a dynamic Computable General Equilibrium (CGE) model - CASIPM-GE model is applied to explore the impact of a carbon tax and different tax revenue recycling schemes on China's economy. Simulation results show that the carbon tax is effective to reduce carbon emissions with mild impact on China's macro economy. In particular, a production tax deduction can be used to recycle the carbon tax revenue if the government wants to reduce the cost of a carbon tax; however, a consumption tax deduction may help the economy to restructure and may benefit the long-run emissions reduction. In terms of industrial output, most industries are negatively affected; sectors with large share of exports are subjected to negative shocks if there is consumption tax deduction financed by the carbon tax revenue. The study suggests that carbon revenue recycling scheme is important in designing the carbon tax policy: a well-designed scheme can help reduce the cost of a carbon tax. © 2014. Source


Wang H.,Henan University of Technology | Qin Q.-H.,Australian National University
European Journal of Mechanics, A/Solids | Year: 2012

A two-dimensional (2D) elastic analysis of functionally graded materials (FGMs) is conducted using the proposed boundary integral based graded element formulation. The graded element model is based on independent internal and frame field approximations. The elemental stiffness contains element boundary integrals only and is calculated using the exact expression of the graded material property. In the construction of the element model, the fundamental solutions of functionally graded plate with quadratic variation of elastic properties are employed to construct the internal approximation and then the graded element is constructed, in which the material definition entails naturally graded variation. Three numerical examples are considered: verification of fundamental solutions, a functionally graded cantilever beam, and a functionally graded link bar, to assess the performance of the hybrid graded model and to show the advantages of FGMs over homogeneous materials. © 2011 Elsevier Masson SAS. All rights reserved. Source


Fell A.,Australian National University
IEEE Transactions on Electron Devices | Year: 2013

Details of Quokka, which is a freely available fast 3-D solar cell simulation tool, are presented. Simplifications to the full set of charge carrier transport equations, i.e., quasi-neutrality and conductive boundaries, result in a model that is computationally inexpensive without a loss of generality. Details on the freely available finite volume implementation in MATLAB are given, which shows computation times on the order of seconds to minutes for a full $I$-$V$ curve sweep on a conventional personal computer. As an application example, the validity of popular analytical models of partial rear contact cells is verified under varying conditions. Consequently, it is observed that significant errors can occur if these analytical models are used to derive local recombination properties from effective lifetime measurements of test structures. © 1963-2012 IEEE. Source


The methylation of histones is a fundamental epigenetic process regulating gene expression programs in mammalian cells. Dysregulated patterns of histone methylation are directly implicated in malignant transformation. Here, we report the unexpected finding that the invasive extracellular matrix degrading endoglycosidase heparanase enters the nucleus of activated human T lymphocytes and regulates the transcription of a cohort of inducible immune response genes by controlling histone H3 methylation patterns. It was found that nuclear heparanase preferentially associates with euchromatin. Genome-wide ChIP-on-chip analyses showed that heparanase is recruited to both the promoter and transcribed regions of a distinct cohort of transcriptionally active genes. Knockdown and overexpression of the heparanase gene also showed that chromatin-bound heparanase is a prerequisite for the transcription of a subset of inducible immune response genes in activated T cells. Furthermore, the actions of heparanase seem to influence gene transcription by associating with the demethylase LSD1, preventing recruitment of the methylase MLL and thereby modifying histone H3 methylation patterns. These data indicate that heparanase belongs to an emerging class of proteins that play an important role in regulating transcription in addition to their well-recognized extra-nuclear functions. Source


Baker-Finch S.C.,Australian National University | McIntosh K.R.,PV Lighthouse
Progress in Photovoltaics: Research and Applications | Year: 2013

A common misconception is that alkaline textured silicon solar cell surfaces are characterised by features that are pyramidal and bounded by {111} planes. In preference to the typical approach of observing scanning electron microscope images, we analyse reflection distributions from various pyramidal textures and find that {111} faceted pyramids are a poor approximation to the features on such surfaces. We conclude that features are hillocks, with an octagonal base. Furthermore, the characteristic base angle of the texture depends on the etchant and is closer to 50-52°than the commonly accepted value of 54.74°. Analyses of antireflection, light trapping, photogeneration and surface recombination properties of textured surfaces should take this feature morphology into account. The base angle has a strong influence on the hemispherical reflectance of the textured surface, with higher angles resulting in reduced reflectance. The influence of this reflection enhancement upon device performance is smallest when an optimised antireflection coating is applied; compared with an array of {111} faceted pyramids, a hillock morphology with 50°base angle results in a 0.2% reduction in photogenerated current in a typical cell. Additionally, as base angle is reduced, an encapsulant of increasingly higher refractive index is required to drive internal reflection at the air-glass interface of light initially reflected from the cell surface. The development of texturing processes resulting in higher base angles is encouraged. Copyright © 2012 John Wiley & Sons, Ltd. A common misconception is that alkaline textured silicon solar cell surfaces are characterised by features that are pyramidal and bounded by {111} planes. We analyse reflection distributions from various pyramidal textures, and find that features are probably hillocks, with an octagonal base and with base angle closer to 50-52°than the commonly accepted 54.74°. Analyses of antireflection, light trapping, photogeneration and recombination properties of textured surfaces should be reconsidered. Development of texturing processes resulting in higher base angles is encouraged. Copyright © 2012 John Wiley & Sons, Ltd. Source


Stern D.I.,Australian National University | Enflo K.,Lund University
Energy Economics | Year: 2013

Though there is a very large literature examining whether energy use Granger causes economic output or vice versa, it is fairly inconclusive. Almost all existing studies use relatively short time series, or panels with a relatively small time dimension. We apply Granger causality and cointegration techniques to a Swedish time series dataset spanning 150. years to test whether increases in energy use and energy quality have driven economic growth or vice versa. We show that these techniques are very sensitive to variable definition, choice of additional variables in the model, sample periods and size, and the introduction of structural breaks. The relationship between energy and growth may also have changed over time - energy causes output in the full sample while output causes energy use in recent smaller samples. Energy prices have a more robust causal impact on both energy use and output. © 2013. Source


Chen W.,University of Windsor | Anderson B.D.O.,Australian National University | Anderson B.D.O.,National ICT Australia Ltd.
IEEE Transactions on Automatic Control | Year: 2012

A combined multiple model adaptive control (CMMAC) scheme, which is a proper combination of the estimator-based MMAC scheme and the unfalsified MMAC scheme, has been proposed with the aim of taking advantage of the strength of each scheme while avoiding their weaknesses. The major novelty of the CMMAC scheme lies in the fact that it monitors not only the adequacy of candidate models in terms of their estimation performances but also the performance of the active candidate controller. As an application of the CMMAC scheme and one example of such new multiple model adaptive controllers, a CMMAC based controller has been designed for a class of nonlinear systems with nonlinear parameterization. Under some sufficient conditions, a strong finite time switching result (which provides a characterization on the maximum number of switching) and the closed-loop stability have been established. A constructive design based on back-stepping is provided for the adaptive control problem of a special class of nonlinearly parameterized systems, which can satisfy all the sufficient conditions to ensure closed-loop stability. © 2011 IEEE. Source


Baker-Finch S.C.,Australian National University | McIntosh K.R.,PV Lighthouse
IEEE Journal of Photovoltaics | Year: 2011

We present a methodology by which one may distinguish three key contributors to enhanced recombination at pyramidally textured silicon surfaces. First, the impact of increased surface area is trivial and equates to a √3-fold increase in S eff,UL•. Second, the presence of {111}-oriented facets drives a fivefold increase in S eff,UL at SiO 2 -passivated surfaces but a small (1.5-fold) increase for SiN x passivation. A third factor, which is often proposed to relate to stress at convex and concave pyramids and edges, is shown to depend on pyramid period (and, hence, vertex/ridge density). This third factor impacts least on S eff,UL when the pyramid period is 10 μm. At this period, it results in a negligible increase in S eff,UL at SiO 2 -passivated textured surfaces but causes at least a sevenfold increase at the Si/SiN x interface. Finally, we found that S eff,UL is 1.5-2.0 times higher at inverted pyramid texture than at surfaces featuring a random arrangement of upright pyramids. The results of this study, particularly for the Si/SiN x system, likely depend on process conditions, but the methodology is universally applicable. We believe this to be the first study to distinguish the impact of {111} facets from those of vertices and edges. Further, we find that {111} surfaces, rather than vertices and edges, are chiefly responsible for the poor-quality passivation achieved by thick oxides on textured surfaces. © 2011 IEEE. Source


Dou C.-X.,Yanshan University | Liu B.,Hunan University of Technology | Liu B.,Australian National University
IEEE Transactions on Smart Grid | Year: 2013

This paper studies the smart control issue for an autonomous microgrid in order to maintain the secure voltages as well as maximize economic and environmental benefits. A control scheme called as multi-agent based hierarchical hybrid control is proposed versus the hierarchical control requirements and hybrid dynamic behaviors of the microgrid. The control scheme is composed of an upper level energy management agent, several middle level coordinated control agents and many lower level unit control agents. The goals of smart control are achieved by designed control strategies. The simulations are given to demonstrate the effectiveness of proposed smart control for an autonomous microgrid. © 2010-2012 IEEE. Source


Da Costa G.S.,Australian National University | Held E.V.,National institute for astrophysics | Saviane I.,European Southern Observatory
Monthly Notices of the Royal Astronomical Society | Year: 2014

We present a detailed study of the strengths of the calcium triplet absorption lines in the spectra of a large sample of red giant members of the luminous outer Galactic halo globular cluster NGC 5824. The spectra were obtained with the FORS2 and GMOS-S multi-object spectrographs at the VLT and the Gemini-S telescope, respectively. By comparing the line strengths of the NGC 5824 stars with those for red giants in clusters with well-established abundances, we conclude that there is an intrinsic abundance dispersion in NGC 5824 characterized by an inter-quartile range in [Fe/H] of 0.10 dex and a total range of ∼0.3 dex. As for ω Cen and M22, the abundance distribution shows a steep rise on the metal-poor side and a shallower decline on the metal-rich side. There is also some indication that the distribution is not unimodal with perhaps three distinct abundance groupings present. NGC 5824 has a further unusual characteristic: the outer surface density profile shows no signs of a tidal cutoff. Instead, the profile has a power-law distribution with cluster stars detected to a radius exceeding 400 pc. We postulate that NGC 5824 may be the remnant nuclear star cluster of a now disrupted dwarf galaxy accreted during the formation of the Galaxy's halo. We further speculate that the presence of an intrinsic [Fe/H] spread is the characteristic that distinguishes former nuclear star clusters from other globular clusters. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Broer S.,Australian National University
Current Opinion in Nephrology and Hypertension | Year: 2013

PURPOSE OF REVIEW: Epithelial neutral amino acid transporters have been identified at the molecular level in recent years. Mouse models have now established the crucial role of these transporters for systemic amino acid homeostasis. This review summarizes recent progress in this field. RECENT FINDINGS: Epithelial neutral amino acid transporters play an important role in the homeostasis of neutral amino acid levels in the body. They are important for the maintenance of body weight and muscle mass and serve as fuels. They also serve a role in providing nutrients to epithelial cells. Changes of plasma amino acid levels are not necessarily correlated to the amino acids appearing in the urine; changes in organ amino acid metabolism need to be taken into account. SUMMARY: Genetic deletion of neutral amino acid transporters provides insight into their role in protein nutrition and homeostasis. Source


Tisserand P.,Australian National University
Astronomy and Astrophysics | Year: 2012

Context. R Coronae Borealis stars (RCBs) are hydrogen-deficient and carbon-rich supergiant stars. They are very rare, with only ∼50 actually known in our Galaxy. Interestingly, RCBs are strongly suspected of being the evolved merger product of two white dwarfs and could therefore be an important tool for understanding supernovae type Ia in the double degenerate scenario. Constraints on the spatial distribution and the formation rate of such stars are needed to picture their origin and test it in the context of actual population synthesis results. Aims. It is crucial to increase the number of known RCBs significantly. With an absolute magnitude M V ∼-5 and a bright/hot circumstellar shell made of amorphous carbon grains, RCBs are so distinctive that we should nowadays be able to find them everywhere in our Galaxy using publicly available catalogues. In the optical, the search is difficult because RCBs are known to undergo unpredictable photometric declines; however, mono-epoch mid-infrared data can help us to discriminate RCBs among other dust-producing stars. The aim is to produce from the mid-infrared WISE and near-infrared 2MASS catalogues a new catalogue of reasonable size, enriched with RCB stars. Methods. Colour-colour cuts used on all stars detected are the main selection criteria. The selection efficiency was monitored using the 52 known RCBs located in the sky area covered by the WISE first preliminary data release. Results. It has been found that selection cuts in mid-infrared colour-colour diagrams are a very efficient method of distinguishing RCBs from other stars. An RCB enriched catalogue made of only 1602 stars was produced, with a high detection efficiency of about 77%. Spectral energy distributions of 49 known RCBs and 5 known HdCs are also presented with estimates of their photosphere and circumstellar shell temperatures. Conclusions. The newly released WISE all sky catalogue has proven to be a valuable resource in finding RCB stars. Actual scenarios predict that between 100 and 500 RCBs exist in our Galaxy. The newly created RCB enriched catalogue is an important step towards significantly increasing the number of known RCB stars and therefore better understanding their origin. © 2012 ESO. Source


Dixon S.,Australian National University
Journal of Pragmatics | Year: 2015

The exchange of objects is a ubiquitous feature of children's play. Yet we know little about how children choose amongst the plethora of strategies at their disposal for getting and maintaining control of objects in the play space. In the present study, the methods of conversation analysis are applied to reveal Aboriginal children in remote Central Australia relying heavily on two 'toy getting' strategies: 'gimme' requests and grabs. Both strategies carry with them an expectation of compliance. The analysis will reveal that in the play session, this expectation of compliance arises from two situational factors: who owns the toy at the time of the request, and the request-maker's 'entitlement' to have the toy. The former can be signalled by various in-turn design features such as assertions of ownership, possessive pronouns and a range of justifications which point to various ownership rights. Entitlement is justified with explicit or tacit reference to 'rules of the game'. © 2015 Elsevier B.V. Source


Fischera J.,University of Toronto | Fischera J.,Australian National University | Martin P.G.,University of Toronto
Astronomy and Astrophysics | Year: 2012

We analyze the physical parameters of interstellar filaments that we describe by an idealized model of isothermal self-gravitating infinite cylinder in pressure equilibrium with the ambient medium. Their gravitational state is characterized by the ratio f cyl of their mass line density to the maximum possible value for a cylinder in a vacuum. Equilibrium solutions exist only for f cyl < 1. This ratio is used in providing analytical expressions for the central density, the radius, the profile of the column density, the column density through the cloud centre, and the FWHM. The dependence of the physical properties on external pressure and temperature is discussed and directly compared to the case of pressure-confined isothermal self-gravitating spheres. Comparison with recent observations of the FWHM and the central column density N H(0) show good agreement and suggest a filament temperature of ~10 K and an external pressure in the range 1.5 × 10 4 K cm -3 to 5 × 10 4 K cm -3. Stability considerations indicate that interstellar filaments become increasingly gravitationally unstable with mass line ratio f cyl approaching unity. For intermediate f cyl > 0.5 the instabilities should promote core formation through compression, with a separation of about five times the FWHM. We discuss the nature of filaments with high mass line densities and their relevance to gravitational fragmentation and star formation. © 2012 ESO. Source


Spencer N.,Warwick Medical School | Strazdins L.,Australian National University
Archives of Disease in Childhood | Year: 2015

Objective: To study the temporal relationship between socioeconomic disadvantage and onset of chronic disabling conditions in childhood. Method: Using parent reported data from the Longitudinal Study of Australian Children, we compared children who developed a chronic disabling condition between the ages of 6/7 and 10/11 years with children without a chronic disabling condition at either age. Logistic regression models assessed association between onset of chronic disabling condition and household income quintiles at 6/7 years, adjusting for confounders. To study the consequences of chronic disabling condition onset for family finances, a linear regression model was fitted on change in household income adjusted for income at 6/7. We compared prevalence of family material hardship in the two groups between 6/7 and 10/11. Results: Of 4010 children present in both waves, complete data were available for 3629 of whom 233 (6.4%) developed a chronic disabling condition between 6/7 and 10/11. After adjustment for confounding, the children from the lowest income quintile were more than twice as likely to develop a chronic disabling condition as those from the highest income quintile. Onset of a chronic disabling condition was associated with a relatively smaller increase in household income over time, but no change in hardship prevalence. Conclusions: Family socioeconomic disadvantage when children are aged 6/7 is associated with their development of a chronic disabling condition over the next 4 years and with adverse effects on household income. © 2015, BMJ Publishing Group. All rights reserved. Source


Dewar R.C.,Australian National University
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2010

Plant ecologists have proposed a variety of optimization theories to explain the adaptive behaviour and evolution of plants from the perspective of natural selection ('survival of the fittest'). Optimization theories identify some objective function such as shoot or canopy photosynthesis, or growth rate which is maximized with respect to one or more plant functional traits. However, the link between these objective functions and individual plant fitness is seldom quantified and there remains some uncertainty about the most appropriate choice of objective function to use. Here, plants are viewed from an alternative thermodynamic perspective, as members of a wider class of non-equilibrium systems for which maximum entropy production (MEP) has been proposed as a common theoretical principle. I show how MEP unifies different plant optimization theories that have been proposed previously on the basis of ad hoc measures of individual fitness the different objective functions of these theories emerge as examples of entropy production on different spatiotemporal scales. The proposed statistical explanation of MEP, that states of MEP are by far the most probable ones, suggests a new and extended paradigm for biological evolution-survival of the likeliest' which applies from biomacromolecules to ecosystems, not just to individuals. copy; 2010 The Royal Society. Source


Singhal S.,Australian National University
Proceedings. Biological sciences / The Royal Society | Year: 2013

Phylogeographic studies frequently reveal multiple morphologically cryptic lineages within species. What is not yet clear is whether such lineages represent nascent species or evolutionary ephemera. To address this question, we compare five contact zones, each of which occurs between ecomorphologically cryptic lineages of skinks from the rainforests of the Australian Wet Tropics. Although the contacts probably formed concurrently in response to Holocene expansion from glacial refugia, we estimate that the divergence times (τ) of the lineage pairs range from 3.1 to 11.5 Ma. Multi-locus analyses of the contact zones yielded estimates of reproductive isolation that are tightly correlated with divergence time and, for lineages with older divergence times (τ > 5 Myr), substantial. These results show that phylogeographic splits of increasing depth represent stages along the speciation continuum, even in the absence of overt change in ecologically relevant morphology. Source


Bray I.,Curtin University Australia | Fursa D.V.,Curtin University Australia | Kadyrov A.S.,Curtin University Australia | Stelbovics A.T.,Curtin University Australia | And 2 more authors.
Physics Reports | Year: 2012

The past decade has seen extraordinary theoretical progress in the field of fully kinematically resolved atomic electron-impact ionisation, and its closely related field of double photoionisation. These processes were challenging to calculate due to formal and computational difficulties associated with break-up problems involving the long-range Coulomb potential. Presently, however, these processes can be calculated accurately for simple targets such as atomic hydrogen and helium, irrespective of the kinematics considered or the geometry of detectors. We report on the computational progress, and how it has resulted in a deeper understanding of the formalism of Coulomb few-body problems. © 2012 Elsevier B.V. Source


Parkin E.R.,Australian National University
Monthly Notices of the Royal Astronomical Society | Year: 2014

The stresses produced by magnetorotational turbulence can provide effective angular momentum transport in accretion discs. However, questions remain about the ability of simulated discs to reproduce observationally inferred stress-to-gas-pressure ratios. In this paper, we present a set of high-resolution global magnetohydrodynamic disc simulations which are initialized with different field configurations: purely toroidal, vertical field lines, and nested poloidal loops. A mass source term is included which allows the total disc mass to equilibrate in simulations with long run times, and also enables the impact of rapid mass injection to be explored. Notably different levels of angular momentum transport are observed during the early-time transient disc evolution. However, given sufficient time to relax, the different models evolve to a statistically similar quasi-steady state with a stress-to-gas-pressure ratio, (αP)~0.032-0.036. Such behaviour is anticipated based on consideration of mean magnetic field evolution subject to our adopted simulation boundary conditions. The indication from our results is that steady, isolated discs may be unable to maintain a large-scale magnetic field or produce values for the stress-to-gas-pressure ratio implied by some observations. Supplementary simulations exploring the influence of trapping magnetic field, injecting vertical field, and rapidly injecting additional mass into the disc show that large stresses can be induced by these mechanisms. In the first instance, a highly magnetized disc is produced with (αP)~0.21, whereas the latter cases lead to a transient burst of accretion with a peak (αP)≃0.1-0.25. As a whole, the simulations highlight the common late-time evolution and characteristics of turbulent discs for which the magnetic field is allowed to evolve freely (i.e. without constraint/replenishment). In contrast, if the boundaries of the disc, the rate of injection of magnetic field, or the rate of mass replenishment are modified to mimic astrophysical discs, markedly different disc evolution occurs. © 2014 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Parkin E.R.,Australian National University
Monthly Notices of the Royal Astronomical Society | Year: 2014

Magnetorotational turbulence draws its energy from gravity and ultimately releases it via dissipation. However, the quantitative details of this energy flow have not been assessed for global disc models. In this work we examine the energetics of a well-resolved, three-dimensional, global magnetohydrodynamic accretion disc simulation by evaluating statistically averaged mean-field equations for magnetic, kinetic and internal energy using simulation data. The results reveal that turbulent magnetic (kinetic) energy is primarily injected by the correlation between Maxwell (Reynolds) stresses and shear in the (almost Keplerian) mean flow, and removed by dissipation. This finding differs from previous work using local (shearing box) models, which indicated that turbulent kinetic energy was primarily sourced from the magnetic energy reservoir. Lorentz forces provide the bridge between the magnetic and kinetic energy reservoirs, converting ̃1/5 of the total turbulent magnetic power input into turbulent kinetic energy. The turbulent energies (both magnetic and kinetic) are mainly driven by terms associated with the turbulent fields, with only a minor influence from mean magnetic fields. The interaction between mean and turbulent fields is most evident in the induction equation, with the mean radial magnetic field being strongly influenced by the turbulent electromotive force. During the quasi-steady turbulent state roughly 2/3 of the Poynting flux travels into the corona, with the remainder transporting magnetic energy in the radial direction. In contrast to previous studies, the stress-related part of the Poynting flux is found to dominate, which may have important implications for 'reflection' models of Seyfert galaxy coronae that typically invoke a picture of buoyant rising of magnetic flux tubes via advection © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Martin N.,Australian National University | Rice J.,Griffith University
Energy Policy | Year: 2013

Solar Photovoltaic (PV) electricity systems are part of Australia's energy supply matrix. In the case of New South Wales (NSW), the state government has had to deal with a complex policy problem. In order to play its role in the federal Small-scale Renewable Energy Scheme, the NSW government initiated the 7 year Solar Bonus Scheme in 2010. However, in attempting to maximise community investment in small-scale solar PV systems, it relied on faulty financial modelling that applied a generous Feed-in Tariff (FiT) and underestimated the level of investor participation and installed capacity. Consequently, the scheme has resulted in very high public costs that will require policy changes that bring investors and energy retailers into conflict, and unpopular electricity retail price adjustments. This paper uses a structured case and stakeholder analysis to critically analyse the FiT policy, while also highlighting important lessons for policymakers engaging in FiT design. © 2013 Elsevier Ltd. Source


Gunningham N.,Australian National University
Energy Policy | Year: 2013

This article argues that a central challenge for energy governance is how to manage a complex 'energy trilemma' involving the sometimes competing demands of energy security, climate change mitigation and (particularly in developing countries) energy poverty. It suggests that tensions between the horns of the trilemma, in large part, explain Indonesia's current, profoundly suboptimal, energy policy. While these tensions are not inherently incapable of resolution, such resolution would require good governance at both state and global levels. The possibilities for and obstacles confronting such governance are explored and provisional solutions canvassed. © 2012 Elsevier Ltd. Source


Karakas A.I.,Australian National University
Monthly Notices of the Royal Astronomical Society | Year: 2014

We present new theoretical stellar evolutionary models of metal-rich asymptotic giant branch (AGB) stars. Stellar models are evolved with initial masses between 1 and 7M at Z = 0.007, and 1 and 8M at Z=0.014 (solar) and at Z=0.03.We evolve models with a canonical helium abundance and with helium-enriched compositions (Y = 0.30, 0.35, and 0.40) at Z = 0.014 and 0.03. The efficiency of third dredge-up and the mass range of carbon stars decreases with an increase in metallicity. We predict carbon stars form from initial masses between 1.75 and 7M at Z = 0.007 and between 2 and 4.5M at solar metallicity. At Z = 0.03, the mass range for C-star production is narrowed to 3.25-4M. The third dredge-up is reduced when the helium content of the model increases owing to the reduced number of thermal pulses on the AGB. A small increase of ΔY = 0.05 is enough to prevent the formation of C stars at Z = 0.03, depending on the mass-loss rate, whereas at Z = 0.014, an increase of ΔY ≳ 0.1 is required to prevent the formation of C stars. We speculate that the probability of finding C stars in a stellar population depends as much on the helium abundance as on the metallicity. To explain the paucity of C stars in the inner region of M31, we conclude that the observed stars have Y ≳ 0.35 or that the stellar metallicity is higher than [Fe/H] ≈ 0.1. © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. Source


Stubbs A.,Australian National University
Australasian Psychiatry | Year: 2015

Objective: The aim of this study was to examine the effectiveness of interventions designed to reduce mental illness stigma among healthcare students and professionals. Method: A literature search was conducted using the Cochrane Library and PubMed. Results: Randomised controlled trial level evidence demonstrated that interventions involving direct contact, indirect filmed contact or an educational email effectively reduced stigma in the short term. Role play was the only intervention with randomised controlled trial level evidence demonstrating no effect. There was not enough evidence to suggest that any intervention can maintain stigma reduction over time. Conclusions: Stigma reduction in healthcare students and professionals needs to be sustained over time if it is to result in positive changes for people living with mental illness. Further research is needed to determine which interventions, if any, can achieve this. Only then will large-scale implementation of a stigma reduction intervention be feasible and beneficial to people living with mental illness. © 2014 The Royal Australian and New Zealand College of Psychiatrists. Source


Newell B.,Australian National University
Global Environmental Change | Year: 2012

Growing evidence that human societies are on an unsustainable development path has led to widespread calls for a better understanding of the complex dynamics of the human-Earth system. The generation of such an understanding is a considerable challenge. It requires a substantial collaborative effort by a wide range of researchers from the natural and social sciences, engineering, the humanities, and the wider community. The extent to which the participants in this transdisciplinary endeavour manage to create shared understandings will be a critical factor in determining their eventual success. It will set a fundamental limit on their ability to communicate with one another, and hence the degree of integration that they can achieve. It will determine the usefulness of the insights that emerge from their efforts. In this paper it is suggested that the identification of 'powerful ideas', fundamental concepts that are both simple and generic, is an effective way to proceed. Empirical evidence from cognitive science and basic insights from information theory provide a framework for a discussion of the nature of such ideas, and of a practical approach to their formulation. It is argued that the collaborative construction of powerful ideas constitutes an efficient form of 'focused dialogue' that can support the rapid development of the required shared understandings. © 2012 Elsevier Ltd. Source


Maleszka R.,Australian National University
Current Opinion in Insect Science | Year: 2016

Although the nature of the genetic control of adaptive behaviours in insects is a major unresolved problem it is now understood that epigenetic mechanisms, bound by genetic constraints, are prime drivers of brain plasticity arising from both developmental and experience-dependent events. With the recent advancements in methylomics and emerging analyses of histones and non-protein-coding RNAs, insect epigenetics is well positioned to ask more direct questions and importantly, address them experimentally. To achieve rapid progress, insect epigenetics needs to focus on mechanistic explanations of epigenomic dynamics and move beyond low-depth genome-wide analyses to cell-type specific epigenomics. One topic of a high priority is the impact of sequence variants on generating differential methylation patterns and their contribution to behavioural plasticity. © 2016 Elsevier Inc. All rights reserved. Source


Kim R.E.,Australian National University
Review of European Community and International Environmental Law | Year: 2012

No multilateral environmental agreement (MEA) has so far been concluded with a view to addressing the problem of ocean acidification. The United Nations Framework Convention on Climate Change (UNFCCC) is considered by many as being capable of addressing ocean acidification as it regulates carbon dioxide emissions - the root cause of the problem. In this article it is argued that, on the contrary, the UNFCCC does not provide an adequate legal framework for the problem because ocean acidification is not an effect of 'climate change', meaning that it is outside the UNFCCC's jurisdiction. The article provides a critical examination of whether ocean acidification is likely to be addressed through the self-organization of existing MEAs or whether a new MEA is necessary. Specifically, it considers the extent to which the provisions of relevant MEAs are applicable to ocean acidification and how their decision-making bodies have responded to the problem. This article observes inherent weaknesses in the emerging polycentric order and reaches the conclusion that a new MEA on ocean acidification is necessary to fill the regulatory gap. The article concludes by outlining two hypothetical candidates as a way of discussing key considerations informing the choice of an appropriate form and forum for an MEA on ocean acidification. © 2012 Blackwell Publishing Ltd. Source


Kovats R.S.,London School of Hygiene and Tropical Medicine | Butler C.D.,Australian National University
Current Opinion in Environmental Sustainability | Year: 2012

Improving the local and global environment will have immediate benefits for health, welfare and income. The scientific evidence that adverse global environmental change will damage health is accumulating, involving both direct and indirect mechanisms, including the effect of lost livelihoods. Environmental changes will undermine some of the scientific, technological and social progress which has led to the large increase in global life expectancy observed since 1950. Whilst local environmental risks still cause significant impacts on human health and welfare, the biggest threat to global health appears to be from a cascade of future adverse environmental effects. Reducing this risk is vital not just for environmental and ecological integrity, but also to protect future health. Much can be done to promote technologies, policies and lifestyles in order to improve both health and environmental conditions. © 2012. Source


Bahar-Fuchs A.,Australian National University | Clare L.,Bangor University | Woods B.,Bangor University
Alzheimer's Research and Therapy | Year: 2013

Cognitive impairments, and particularly memory deficits, are a defining feature of the early stages of Alzheimer's disease and vascular dementia. Interventions that target these cognitive deficits and the associated difficulties with activities of daily living are the subject of ever-growing interest. Cognitive training and cognitive rehabilitation are specific forms of non-pharmacological intervention to address cognitive and non-cognitive outcomes. The present review is an abridged version of a Cochrane Review and aims to systematically evaluate the evidence for these forms of intervention in people with mild Alzheimer's disease or vascular dementia. Randomized controlled trials (RCTs), published in English, comparing cognitive rehabilitation or cognitive training interventions with control conditions and reporting relevant outcomes for the person with dementia or the family caregiver (or both), were considered for inclusion. Eleven RCTs reporting cognitive training interventions were included in the review. A large number of measures were used in the different studies, and meta-analysis could be conducted for several primary and secondary outcomes of interest. Several outcomes were not measured in any of the studies. Overall estimates of the treatment effect were calculated by using a fixed-effects model, and statistical heterogeneity was measured by using a standard chi-squared statistic. One RCT of cognitive rehabilitation was identified, allowing the examination of effect sizes, but no meta-analysis could be conducted. Cognitive training was not associated with positive or negative effects in relation to any of the reported outcomes. The overall quality of the trials was low to moderate. The single RCT of cognitive rehabilitation found promising results in relation to some patient and caregiver outcomes and was generally of high quality. The available evidence regarding cognitive training remains limited, and the quality of the evidence needs to improve. However, there is still no indication of any significant benefits from cognitive training. Trial reports indicate that some gains resulting from intervention may not be captured adequately by available standardized outcome measures. The results of the single RCT of cognitive rehabilitation show promise but are preliminary in nature. Further well-designed studies of cognitive training and cognitive rehabilitation are required to provide more definitive evidence. Researchers should describe and classify their interventions appropriately by using the available terminology. © 2013 BioMed Central Ltd. Source


Lecaplain C.,R.A.U.M. | Grelu P.,R.A.U.M. | Soto-Crespo J.M.,Institute Aptica | Akhmediev N.,Australian National University
Physical Review Letters | Year: 2012

Rare events of extremely high optical intensity are experimentally recorded at the output of a mode-locked fiber laser that operates in a strongly dissipative regime of chaotic multiple-pulse generation. The probability distribution of these intensity fluctuations, which highly depend on the cavity parameters, features a long-tailed distribution. Recorded intensity fluctuations result from the ceaseless relative motion and nonlinear interaction of pulses within a temporally localized multisoliton phase. © 2012 American Physical Society. Source


Broer S.,Australian National University
Current Molecular Pharmacology | Year: 2013

Amino acid transporters of the SLC6 family mediate the Na+-dependent uptake of neutral amino acids into neurons and epithelial cells of the intestine, kidney and other organs. They are integral parts of amino acid homeostasis in the whole body and the brain. In the intestine they are involved in protein absorption, while in the kidney they regulate plasma amino acid concentrations through reabsorption. The metabolic role of SLC6 amino acid transporters in the brain is less clear and most likely related to anaplerosis of the TCA cycle. Mutations in these transporters cause rare inherited disorders such as Hartnup disorder and iminoglycinuria. They may also play a role in complex traits such as depression, anxiety, obesity, diabetes and cancer. The review does not cover the transport of neurotransmitter amino acids. © 2013 Bentham Science Publishers. Source


Smith J.P.,Australian National University
International Breastfeeding Journal | Year: 2015

This introduction to a special issue on the economics of breastfeeding draws attention to the lack of economic justice for women. Human milk is being bought and sold. Commodifying and marketing human milk and breastfeeding risk reinforcing social and gender economic inequities. Yet there are potential benefits for breastfeeding, and some of the world's poorest women might profit. How can we improve on the present situation where everyone except the woman who donates her milk benefits? Breastfeeding is a global food production system with unsurpassed capacity to promote children's food security and maternal and child health, but it is side-lined by trade negotiators who seek instead to expand world markets for cow's milk-based formula. Regulators focus on potential risks of feeding donated human milk, rather than on health risks of exposing infants and young children to highly processed bovine milk. Similarly, policymakers aspire to provide universal health care access that may be unaffordable when two thirds of the world's children are not optimally nourished in infancy, resulting in a global double burden of infectious and chronic disease. Universal breastfeeding requires greater commitment of resources, but such investment remains lacking despite the cost effectiveness of breastfeeding protection, support and promotion in and beyond health services. Women invest substantially in breastfeeding but current policy - epitomised by the G20 approach to the 'gender gap' - fails to acknowledge the economic value of this unpaid care work. Economic incentives for mothers to optimally breastfeed are dwarfed by health system and commercial incentives promoting formula feeding and by government fiscal policies which ignore the resulting economic costs. 'The market' fails to protect breastfeeding, because market prices give the wrong signals. An economic approach to the problem of premature weaning from optimal breastfeeding may help prioritise global maternity protection as the foundation for sustainable development of human capital and labour productivity. It would remove fiscal subsidies for breast milk substitutes, tax their sale to recoup health system costs, and penalise their free supply, promotion and distribution. By removing widespread incentives for premature weaning, the resources would be available for the world to invest more in breastfeeding. © 2015 Smith; licensee BioMed Central. Source


Suich H.,Australian National University
Land Use Policy | Year: 2013

Incentives are key to attracting and maintaining participation in community based natural resource management (CBNRM) initiatives. However, incentives cannot work if people do not know about them, if they are inappropriate or if they are delivered in insufficient quantities. In southern African CBNRM initiatives, many incentives are offered, particularly jobs and community income from hunting and photographic tourism activities. There is a need to assess - jointly - residents' knowledge and perceptions of these incentives and their actual delivery to determine whether they are likely to be effective in sustaining participation in CBNRM activities over the long run. This paper reports the results of just such an assessment at two CBNRM sites, the Tchuma Tchato project in Mozambique and Kwandu Conservancy in Namibia. While different types of benefits were delivered at both sites, they were largely of low value and low in volume. It appears that the incentives offered are not inappropriate, but are insufficient - too few people benefit directly and the level of benefits is generally too small. Further, a large minority of households feel benefits have been inequitably distributed and that the direct costs of living with wildlife have been ineffectively addressed. These issues should be viewed as potentially serious challenges to maintaining local participation in CBNRM activities in the long run. © 2012 Elsevier Ltd. Source


Biddle N.,Australian National University
Australian Journal of Rural Health | Year: 2012

Objective: To provide the first estimates of a comprehensive measure of social capital for the Indigenous population and to link the indicators to well-being. Design: Observational study-based. Setting: Household survey. Participants: Nationally representative sample of 7823 Indigenous Australians aged 15years and over who were usual residents of private dwellings. Main outcome measure: Whether or not the respondent felt happy in the last 4weeks all or most of the time (happiness), and whether or not they felt so sad that nothing could cheer them up at least a little bit of the time over the same period (sadness). Results: There were no consistent differences in social capital measures between Indigenous men and women, nor were there consistent differences between the remote and non-remote population. High levels of social capital were, however, associated with higher subjective well-being. Conclusion: Social capital is both an indicator and determinant of well-being. It was possible to derive an index of social capital for Indigenous Australians that had a strong positive association with self-reported happiness and a negative association with self-reported sadness. However, the analysis also showed that there are a set of related domains of social capital, rather than there being a single underlying concept. © 2012 The Author. Australian Journal of Rural Health © National Rural Health Alliance Inc. Source


Maron M.,University of Queensland | Rhodes J.R.,University of Queensland | Gibbons P.,Australian National University
Conservation Letters | Year: 2013

The benefit (or additionality) attributable to a conservation action is the difference between the outcomes of two scenarios: (1) the scenario with the conservation action, and (2) the alternative scenario, in which action did not occur. However, many conservation decisions are made using approaches that do not appropriately calculate this benefit. We review recent scientific literature and conservation policies to examine how conservation benefit is calculated in three situations: systematic reserve selection, investment in agri-environment schemes, and biodiversity offset trades. In the examples we considered, the approaches used to calculate conservation benefit often involved assumptions about the alternative scenario that were not explicit, demonstrably wrong or both. We suggest that assumptions about how conservation value changes over time in the alternative scenario can often be substantially refined, and that making these assumptions explicit by calculating directly the expected difference between the two scenarios is likely to improve the quality of conservation decision-making. ©2013 Wiley Periodicals, Inc. Source


Sellbom M.,Australian National University
Journal of Personality Assessment | Year: 2014

A large proportion of prison inmates suffer from mental illnesses or severe personality disorders; therefore, offender classification is a worthwhile endeavor both for efficiently allocating mental health treatment resources and security risk classification. This study sought to elaborate on offender classification by using an advanced statistical technique, factor mixture modeling, which capitalizes on the strengths of both latent trait analysis and latent class analysis. A sample consisting of 616 male and 194 female prison inmates was used for this purpose. The MMPI-2-RF Restructured Clinical (RC) scales were used to elaborate on a variety of latent trait, latent class, and factor mixture models. A 3-factor, 5-class mixture model was deemed optimal in this sample. Remaining MMPI-2-RF scales as well as scores on external criterion measures relevant to externalizing psychopathology were used to further elaborate on the utility of the resulting latent classes. These analyses indicated that 3 of the 5 classes were predominantly different expressions of externalizing personality proclivities, whereas the remaining 2 indicated inmates with substantial internalizing or thought-disordered characteristics. Implications of these findings are discussed. © 2014 Taylor and Francis Group, LLC. Source


Previous work on identifying opportunities for Pacific Island countries to improve the economic returns from their tuna resources in the Western and Central Pacific Ocean (WCPO) has not generally included articulation of aspirations from Islanders themselves. However, generating such an understanding is increasingly important as these countries assert their positions in regional fisheries policy making. This study analyses the self-identified aspirations of industry and government representatives from six Pacific Island countries and finds a wider diversity of attitudes, strategies and success than is generally recognised. Implications for negotiations in the WCPFC are then discussed. © 2009 Elsevier Ltd. All rights reserved. Source


Gordon D.M.,Australian National University
Journal of AOAC International | Year: 2010

Escherichia coil is a commonly encountered commensal of the lower intestinal tract of humans and other mammals. Strains of the species are responsible for a significant amount of human morbidity and mortality each year. Consequently, numerous efforts attempt to track the movement of hospital-acquired infections, determine the source of a foodborne disease outbreak, or investigate the seasonal patterns of pathogen abundance in domestic animals. All of these endeavors require that the isolates acquired be differentiated from each other in some manner. This review briefly describes some of the commonly used molecular typing methods for E. coil. However, the main aim of the review is to describe the many levels, from the species to individual strains, at which E. coil can be considered, and to contend that a hierarchical approach to strain typing may often reveal patterns that are not obvious when a typing scheme is simply designed to differentiate isolates. Source


Lindenmayer D.,Australian National University | Hunter M.,University of Maine, United States
Conservation Biology | Year: 2010

The search for generalities in ecology has often been thwarted by contingency and ecological complexity that limit the development of predictive rules. We present a set of concepts that we believe succinctly expresses some of the fundamental ideas in conservation biology. (1) Successful conservation management requires explicit goals and objectives. (2) The overall goal of biodiversity management will usually be to maintain or restore biodiversity, not to maximize species richness. (3) A holistic approach is needed to solve conservation problems. (4) Diverse approaches to management can provide diverse environmental conditions and mitigate risk. (5) Using nature's template is important for guiding conservation management, but it is not a panacea. (6) Focusing on causes not symptoms enhances efficacy and efficiency of conservation actions. (7) Every species and ecosystem is unique, to some degree. (8) Threshold responses are important but not ubiquitous. (9) Multiple stressors often exert critical effects on species and ecosystems. (10) Human values are variable and dynamic and significantly shape conservation efforts. We believe most conservation biologists will broadly agree these concepts are important. That said, an important part of the maturation of conservation biology as a discipline is constructive debate about additional or alternative concepts to those we have proposed here. Therefore, we have established a web-based, online process for further discussion of the concepts outlined in this paper and developing additional ones. © 2010 Society for Conservation Biology. Source


Paz-Filho G.J.,Australian National University
Neural Plasticity | Year: 2016

Leptin, an adipokine synthesized and secreted mainly by the adipose tissue, has multiple effects on the regulation of food intake, energy expenditure, and metabolism. Its recently-approved analogue, metreleptin, has been evaluated in clinical trials for the treatment of patients with leptin deficiency due to mutations in the leptin gene, lipodystrophy syndromes, and hypothalamic amenorrhea. In such patients, leptin replacement therapy has led to changes in brain structure and function in intra-and extrahypothalamic areas, including the hippocampus. Furthermore, in one of those patients, improvements in neurocognitive development have been observed. In addition to this evidence linking leptin to neural plasticity and function, observational studies evaluating leptin-sufficient humans have also demonstrated direct correlation between blood leptin levels and brain volume and inverse associations between circulating leptin and risk for the development of dementia. This review summarizes the evidence in the literature on the role of leptin in neural plasticity (in leptin-deficient and in leptin-sufficient individuals) and its effects on synaptic activity, glutamate receptor trafficking, neuronal morphology, neuronal development and survival, and microglial function. © 2016 Gilberto J. Paz-Filho. Source


Boswell R.W.,Australian National University | Booth J.P.,Ecole Polytechnique - Palaiseau
Applied Physics Letters | Year: 2012

Through the use of particle-in-cell simulations, we demonstrate that the power deposition in capacitively coupled discharges (in argon) can be increased by replacing sinusoidal waveforms with Gaussian-shaped voltage pulses (with a repetition frequency of 13.56 MHz). By changing the Gaussian pulse width, electron heating can be directly controlled, allowing for an increased plasma density and ion flux for the same gas pressure and geometrical operating conditions. Analysis of the power deposition profiles and electron distribution functions shows that enhanced electron-sheath heating is responsible for the increased power absorption. © 2012 American Institute of Physics. Source


Black L.E.,Australian National University | McIntosh K.R.,PV Lighthouse
Applied Physics Letters | Year: 2012

Atmospheric pressure chemical vapor deposition of Al 2O 3 is shown to provide excellent passivation of crystalline silicon surfaces. Surface passivation, permittivity, and refractive index are investigated before and after annealing for deposition temperatures between 330 and 520 °C. Deposition temperatures >440 °C result in the best passivation, due to both a large negative fixed charge density (∼2 × 10 12cm -2) and a relatively low interface defect density (∼1 × 10 11eV -1cm -2), with or without an anneal. The influence of deposition temperature on film properties is found to persist after subsequent heat treatment. Correlations between surface passivation properties and the permittivity are discussed. © 2012 American Institute of Physics. Source


Shadrivov I.V.,Australian National University
Applied Physics Letters | Year: 2012

We demonstrate a type of meta-atom for creating metamaterials with giant nonlinear optical activity but vanishing linear optical activity in a wide frequency range. Such properties are not found in any natural materials, and we call this regime as pure nonlinear optical activity. We further extend our design concept and show that the metamaterial can be tuned dynamically to exhibit either positive or negative polarization rotation. © 2012 American Institute of Physics. Source


Garcia Munoz A.,University of the Basque Country | Mills F.P.,Australian National University
Astronomy and Astrophysics | Year: 2012

Context. On 5-6 June 2012 ground-based observers have the last opportunity of the century to watch the passage of Venus across the solar disk from Earth. Venus transits have traditionally provided unique insight into the Venus atmosphere through the refraction halo that appears at the planet's outer terminator near ingress/egress. Much more recently, Venus transits have attracted renewed interest because the technique of transits is being successfully applied to the characterization of extrasolar planet atmospheres. Aims. The current work theoretically investigates the interaction of sunlight and the Venus atmosphere through the full range of transit phases, as observed from Earth and from a remote distance. Our model predictions quantify the relevant atmospheric phenomena, thereby assisting the observers of the event in the interpretation of measurements and extrapolation to the exoplanet case. Methods. Our approach relies on numerical integration of the radiative transfer equation, and includes refraction, multiple scattering, atmospheric extinction, and solar limb darkening, as well as an up-to-date description of the Venus atmosphere. Results. We produce synthetic images of the planet's terminator during ingress/egress that demonstrate the evolving shape, brightness, and chromaticity of the halo. Our simulations reveal the impact of micrometer-sized aerosols borne in the upper haze layer of the atmosphere on the halo's appearance. Guidelines are offered for the investigation of the planet's upper haze from vertically-unresolved photometric measurements. In this respect, the comparison with measurements from the 2004 transit appears encouraging. We also show integrated lightcurves of the Venus-Sun system at various phases during transit and calculate the respective Venus-Sun integrated transmission spectra. The comparison of the model predictions to those for a Venus-like planet free of haze and clouds (and therefore a closer terrestrial analog) complements the discussion and sets the conclusions into a broader perspective. © 2012 ESO. Source


Brooks K.,Australian National University
Marine Policy | Year: 2010

The assessment of sustainable development is a relatively recent advent in policy and the evaluation of industry structural adjustments. Although the elements of economic and environmental assessment have been relatively well developed and accepted, the effective inclusion of 'social' aspects in assessments of sustainable development are still being grappled with. This paper, which discusses a project that investigated the sustainable development of the Marine Scalefish Fishery in South Australia, was focused on providing a combined assessment of the interrelationships between the environmental, economic and social aspects of the industry and the effect of its restructure in 2005. The findings highlight the complexities of developing effective policies to address all three aspects of sustainable development, rather than trading off one outcome against another. In the case of the fishery at hand, while the environmental and economic objectives of the adjustment appear to have achieved, the social objectives may well have not. In this circumstance, the findings raise the possibility that the social impacts of the restructure may in fact, alone, compromise the long term future of the industry, despite the economic success of the restructure. This paper addresses the results of the research and presents some salient social issues that policy makers and industry should be aware of, when considering industry structure and futures in a changing economic and climatic environment. © 2009 Elsevier Ltd. All rights reserved. Source


Quentin Grafton R.,Australian National University
Marine Policy | Year: 2010

This paper responds to the challenge of how and when to adapt marine capture fisheries to climate change by (1) providing a set of fisheries policy options to climate change; (2) developing a risk and vulnerability assessment and management decision-making framework for adaptation; and (3) describing the possible strategies and tactics for ex ante and ex post climate adaptation in the marine environment. Its contributions include (1) a discussion of how management objectives and instruments influence resilience and adaptation; (2) a decision-making process to assess vulnerabilities to climate change and to manage adaptation responses; (3) an inter-temporal framework to assist decision-makers on when to adapt; (4) a risk and simulation approach to confront the uncertainties of the possible losses due to climate change and the net benefits of adaptation; (5) an explanation of how adaptive co-management can promote flexible adaptation responses and also strengthen adaptation capacity; and (6) a selection of possible 'win-win' management actions. © 2009 Elsevier Ltd. All rights reserved. Source


Abdel-Latif M.E.,Australian National University
Cochrane database of systematic reviews (Online) | Year: 2012

Nebulised surfactant has the potential to deliver surfactant to the infant lung with the goal of avoiding endotracheal intubation and ventilation, ventilator-induced lung injury and bronchopulmonary dysplasia (BPD). To determine the effect of nebulised surfactant administration either as prophylaxis or treatment compared to placebo, no treatment or intratracheal surfactant administration on morbidity and mortality in preterm infants with, or at risk of, respiratory distress syndrome (RDS). Searches were performed of CENTRAL (The Cochrane Library, January 2012), MEDLINE and PREMEDLINE (1950 to January 2012), EMBASE (1980 to January 2012) and CINAHL (1982 to January 2012), as well as proceedings of scientific meetings, clinical trial registries, Google Scholar and reference lists of identified studies. Expert informants and surfactant manufacturers were contacted. Randomised, cluster-randomised or quasi-randomised controlled trials of nebulised surfactant administration compared to placebo, no treatment, or other routes of administration (laryngeal, pharyngeal instillation of surfactant before the first breath, thin endotracheal catheter surfactant administration or intratracheal surfactant instillation) on morbidity and mortality in preterm infants at risk of RDS. We considered published, unpublished and ongoing trials. Two review authors independently assessed studies for eligibility and quality, and extracted data. No studies of prophylactic or early nebulised surfactant administration were found. A single small study of late rescue nebulised surfactant was included. The study is of moderate risk of bias. The study enrolled 32 preterm infants born < 36 weeks' gestation with RDS on nasal continuous positive airway pressure (nCPAP). The study reported no significant difference between nebulised surfactant administration compared to no treatment groups in chronic lung disease (risk ratio (RR) 5.00; 95% confidence interval (CI) 0.26 to 96.59) or other outcomes (oxygenation 1 to 12 hours after randomisation, need for mechanical ventilation, days of mechanical ventilation or continuous positive airways pressure (CPAP) or days of supplemental oxygen). No side effects of the nebulised surfactant therapy or aerosol inhalation were reported. There are insufficient data to support or refute the use of nebulised surfactant in clinical practice. Adequately powered trials are required to determine the effect of nebulised surfactant administration for prevention or early treatment of RDS in preterm infants. Nebulised surfactant administration should be limited to clinical trials. Source


Bell K.,University of British Columbia | Keane H.,Australian National University
Social Science and Medicine | Year: 2014

The idea that drug use in 'softer' forms leads to 'harder' drug use lies at the heart of the gateway theory, one of the most influential models of drug use of the twentieth century. Although hotly contested, the notion of the 'gateway drug' continues to rear its head in discussions of drug use-most recently in the context of electronic cigarettes. Based on a critical reading of a range of texts, including scholarly literature and media reports, we explore the history and gestation of the gateway theory, highlighting the ways in which intersections between academic, media and popular accounts actively produced the concept. Arguing that the theory has been critical in maintaining the distinction between 'soft' and 'hard' drugs, we turn to its distinctive iteration in the context of debates about e-cigarettes. We show that the notion of the 'gateway' has been transformed from a descriptive to a predictive model, one in which nicotine is constituted as simultaneously 'soft' and 'hard'-as both relatively innocuous and incontrovertibly harmful. © 2014 Elsevier Ltd. Source


Abdel-Latif M.E.,Australian National University
Cochrane database of systematic reviews (Online) | Year: 2011

Intrapartum pharyngeal instillation of surfactant before the first breath may result in surfactant administration to the infant lung, with the potential benefit of avoiding endotracheal intubation and ventilation, ventilator induced lung injury and bronchopulmonary dysplasia. To determine the effect of pharyngeal instillation of surfactant before the first breath compared to placebo, no treatment or intratracheal surfactant administration followed by intermittent positive pressure ventilation (IPPV) on morbidity and mortality in preterm infants at risk of respiratory distress syndrome (RDS). Searches were made of CENTRAL (The Cochrane Library, to September 2010), MEDLINE and PREMEDLINE (1950 to September 2010), EMBASE (1980 to 2010) and CINAHL (1982 to 2010). This strategy was supplemented by searches of proceedings of scientific meetings, Google Scholar and reference lists of identified studies, as well as contact with expert informants and surfactant manufacturers. Published, unpublished and ongoing randomised controlled or quasi-randomised trials (using individual or cluster allocation) of pharyngeal instillation of surfactant before the first breath compared to placebo or no treatment, or intratracheal surfactant instillation followed by IPPV, on morbidity and mortality in preterm infants at risk of RDS. Two authors independently assessed study eligibility and quality. No published, unpublished or ongoing trials that met the inclusion criteria for this review were found. There were no data from randomised controlled or quasi-randomised trials that evaluated the effect of intrapartum instillation of pharyngeal surfactant before the first breath. Evidence from animal and observational human studies suggest that pharyngeal instillation of surfactant before the first breath is potentially safe, feasible and may be effective. Well designed trials are needed. Source


Amiranashvili Sh.,Weierstrass Institute for Applied Analysis And Stochastics | Bandelow U.,Weierstrass Institute for Applied Analysis And Stochastics | Akhmediev N.,Australian National University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We study the propagation of few-cycle optical solitons in nonlinear media with an anomalous, but otherwise arbitrary, dispersion and a cubic nonlinearity. Our approach does not derive from the slowly varying envelope approximation. The optical field is derived directly from Maxwell's equations under the assumption that generation of the third harmonic is a nonresonant process or at least cannot destroy the pulse prior to inevitable linear damping. The solitary wave solutions are obtained numerically up to nearly single-cycle duration using the spectral renormalization method originally developed for the envelope solitons. The theory explicitly distinguishes contributions between the essential physical effects such as higher-order dispersion, self-steepening, and backscattering, as well as quantifies their influence on ultrashort optical solitons. © 2013 American Physical Society. Source


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

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


Price G.D.,Australian National University
Photosynthesis Research | Year: 2011

Cyanobacteria possess an environmental adaptation known as a CO2 concentrating mechanism (CCM) that evolved to improve photosynthetic performance, particularly under CO2-limiting conditions. The CCM functions to actively transport dissolved inorganic carbon species (Ci; HCO 3 - and CO2) resulting in accumulation of a pool of HCO3 - within the cell that is then utilised to provide an elevated CO2 concentration around the primary CO2 fixing enzyme, ribulose bisphosphate carboxylaseoxygenase (Rubisco). Rubisco is encapsulated in unique micro-compartments known as carboxysomes and also provides the location for elevated CO2 levels in the cell. Five distinct transport systems for active Ciuptake are known, including two types of Na+-dependent HCO3 - transporters (BicA and SbtA), one traffic ATPase (BCT1) for HCO3 - uptake and two CO2 uptake systems based on modified NADPH dehydrogenase complexes (NDH-I3 and NDH-I4). The genes for a number of these transporters are genetically induced under Cilimitation via transcriptional regulatory processes. The in-membrane topology structures of the BicA and SbtA HCO3 - transporters are now known and this may aid in determining processes related to transporter activation during dark to light transitions or under severe Cilimitation. © Springer Science+Business Media B.V. 2011. Source


Molina M.I.,University of Chile | Miroshnichenko A.E.,Center for Optics and Photonics | Miroshnichenko A.E.,Australian National University | Kivshar Y.S.,Center for Optics and Photonics
Physical Review Letters | Year: 2012

We introduce a novel concept of surface bound states in the continuum, i.e., surface modes embedded into the linear spectral band of a discrete lattice. We suggest an efficient method for creating such surface modes and the local bounded potential necessary to support the embedded modes. We demonstrate that the surface embedded modes are structurally stable, and the position of their eigenvalues inside the spectral band can be tuned continuously by adding weak nonlinearity. © 2012 American Physical Society. Source


Healy J.M.,Australian National University
International Journal for Quality in Health Care | Year: 2012

Objective: To analyse the strategies used by hospital leaders to improve compliance with the 'ensuring correct patient, correct site and correct procedure protocol'. While following such a protocol saves lives according to an international study of the World Health Organization safe surgery checklist, promoting compliance in hospitals has proved to be a regulatory challenge. Design, Setting and Participants: Using a qualitative research design and 'responsive regulation' theory, this study explored implementation strategies used by hospital leaders in 20 Australian public hospitals. Semi-structured interviews were conducted with 72 informants to analyse how front-line leaders improved compliance with the safe surgery protocol in their hospitals. Interventions: Implementation analysis of the safe surgery protocol. Main Outcome Measures: The use of implementation strategies located on a 'responsive regulation' pyramid. Results: Informants identified many strategies used to improve protocol compliance typically beginning with persuasion. Supportive strategies were located on a regulatory pyramid beginning with softer interventions: persuade, enlist leaders, train, remind, relax protocol requirements, redesign hospital systems and reward compliance. In response to low and slow compliance, many hospital leaders switched to a pyramid of escalating sanctions: direct, delegate, monitor, publicly report, reprimand and penalize. Conclusions: A multiplex problem requires graduated and multiplex regulation. Hospital leaders proved to be responsive regulators in applying both multiple supports and sanctions that improved compliance over 3 years. These experiences with protocol implementation illustrate the multifaceted challenge of health sector regulation and offer lessons for embedding future patient safety solutions. © The Author 2011. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved. Source


Dennis S.,Australian National University
Critical Public Health | Year: 2011

This article is framed by the complexities associated with exploring a morally positioned and emotive practice - the practice of smoking cigarettes. Smoking is bound up with a multiply of issues and positions, including (but not limited to) the role of the state in the regulation of bodies and their practices and in the moral positioning of those practices, and the rights of the individual. It is also bound up with particular understandings of bodies and their relations with other bodies. In antismoking advertisements, smoking practice is firmly situated within frames of corporeal boundedness and individuality, and particular emotions and moral positions are drawn upon to locate the smoking body relative to other (non-smoking) bodies, and to the practice of smoking itself. Based on finegrained ethnographic research, and moving away from moral and dualistic positionings of the practice, I take up a phenomenological perspective to explore the profound experiences of sociality, corporeal connection and rupture, and the wide range of emotional experiences that are central to practices of smoking. I also draw attention to the ways in which public policy and action regarding smoking might be understood, acted upon, resisted and altered, in ways that make it meaningful in the lived experiences of smokers. Many of the responses that smokers make to state policy and action are not those intended by policy makers, and demonstrate both the creativity of the responses, and the dangers of assuming too much about how people will behave. © 2011 Taylor & Francis. Source


Vos M.,Australian National University
Journal of Electron Spectroscopy and Related Phenomena | Year: 2013

We use REELS (reflection electron energy loss spectroscopy) measurements at relatively large energies (up to 40 keV) and good energy resolution (0.3 eV) to extract the bulk and surface loss function for Au, Mo and Ta. For these cases there are small, but significant deviations between the electron-based estimates of the dielectric function as published by Werner et al. (J. Phys. Chem. Ref. Data 38 (2009) 1013), and the corresponding photon absorption/reflection based estimates. The present, higher-resolution electron-based measurements reveal more of the fine structure in the differential inverse inelastic mean free path (DIIMFP) and the differential surface excitation probability (DSEP). The same fine-structure is visible in the photon-derived estimates of the bulk and surface loss function, quantities closely related to the DIIMFP and DSEP. Thus we demonstrate that it is indeed possible to derive these fine details of the surface and bulk loss function with REELS, underlining its potential for extracting information on the dielectric function of materials. © 2013 Elsevier B.V. Source


Chapman C.C.,Australian National University | Chapman C.C.,CSIRO
Journal of Geophysical Research: Oceans | Year: 2014

This study undertakes a detailed comparison of different methods used for detecting and tracking oceanic jets in the Southern Ocean. The methods under consideration are the gradient thresholding method, the probability density function (PDF) method, and the contour method. Some weaknesses of the gradient thresholding method are discussed and an enhancement (the WHOSE method), based on techniques from signal processing, is proposed. The WHOSE method is then compared to the other three methods. Quantitative comparison is undertaken using synthetic sea-surface height fields. The WHOSE method and the contour method are found to perform well even in the presence of a strong eddy field. In contrast, the standard gradient thresholding and PDF methods only perform well in high signal-to-noise ratio situations. The WHOSE, PDF, and the contour methods are then applied to data from the eddy-resolving Ocean General Circulation Model for the Earth Simulator. While the three methods are in broad agreement on the location of the main ACC jets, the nature of the jet fields they produce differ. In particular, the WHOSE method reveals a fine-scale jet field with complex braiding behavior. It is argued that this fine-scale jet field may affect the calculation of eddy diffusivities. Finally, recommendations based on this study are made. The WHOSE and gradient thresholding methods are more suitable for the study of jets as localized strong currents, useful for studies of tracer fluxes. The contour and PDF methods are recommended for studies linking jets to hydrographic fronts. Key Points Different methods for detecting ACC jets reveal differing jet structures Methods from signal processing can improve jet detection techniques Some methods fail in the presence of strong eddy fields © 2014. American Geophysical Union. All Rights Reserved. Source


Objectives. I examined age patterns of mortality differentials associated with body mass because the declining age effect observed in previous comparisons of cross-sectional age groups is susceptible to cohort and period distortions and because previous studies used time since baseline as time at risk, making the evaluation of age-specific mortality impossible. Methods. I conducted a parametric survival analysis of data from the 1988-1994 National Health and Nutrition Examination Survey for 3 cohorts of American men and women born from 1901 through 1957 and observed from 1988 through 2006 under an age-period-cohort framework. Results. Mortality differentials strengthened across cohorts but did not decline with age or change over the study period. Because excess overweight and obesity mortality increased from earlier cohorts to more recent ones, ignoring cohort differences led to a declining age pattern of excess mortality. Conclusions. Cross-sectional age patterns of mortality differentials appear to be distorted by cohort differences. Age should be used as risk time to study age variations in associations between risk factors and time to event. Source


Gunningham N.,Australian National University
Climate Policy | Year: 2014

The question of whether China is on the verge of a 'shale gas revolution' is examined. This has potentially significant consequences for energy policy and climate change mitigation. Contrary to the optimistic reading of some commentators, it argues that various technological, environmental, political, regulatory and institutional factors will constrain the growth of China's shale gas market and that such a revolution might in any event have consequences that are at best mixed, at worst antithetical to climate change mitigation.Policy relevanceChina's reserves of unconventional gas have the potential to transform energy policy, as has occurred in the US, resulting in the substitution of shale gas for coal in the energy mix. Because gas emits only approximately half the GHG per unit as coal, such a move would have important implications for climate policy. However, substantial obstacles stand in the way of the 'energy revolution' that some policy analysts see China as embarking upon. The need to acknowledge these obstacles, particularly those relating to regulation and governance (and whether or to what extent they can be overcome), is an issue of profound importance to the future of climate and energy policy. © 2013 © 2013 Taylor & Francis. Source


Anstey K.J.,Ageing Research Unit | Cherbuin N.,Ageing Research Unit | Budge M.,Australian National University | Young J.,Ageing Research Unit
Obesity Reviews | Year: 2011

The relationship between body mass index (BMI) (in midlife and late-life) and dementia was investigated in meta-analyses of 16 articles reporting on 15 prospective studies. Follow-ups ranged from 3.2 to 36.0 years. Meta-analyses were conducted on samples including 25624 participants evaluated for Alzheimer's disease (AD), 15435 participants evaluated for vascular dementia (VaD) and 30470 followed for any type of dementia (Any Dementia). Low BMI in midlife was associated with 1.96 [95% confidence interval (CI): 1.32, 2.92] times the risk of developing AD. The pooled relative risks for AD, VaD and Any Dementia for overweight BMI in midlife compared with normal BMI were 1.35 (95% CI:1.19, 1.54), 1.33 (95% CI: 1.02, 1.75) and 1.26 (95% CI: 1.10, 1.44), respectively. The pooled relative risks of AD and Any Dementia for obese BMI in midlife compared to normal BMI were 2.04 (95% CI: 1.59, 2.62) and 1.64 (95% CI: 1.34, 2.00), respectively. Continuous BMI in late-life was not associated with dementia. Small numbers of studies included in pooled analyses reduce generalizability of findings, and emphasize the need for publication of additional findings. We conclude that underweight, overweight and obesity in midlife increase dementia risk. Further research evaluating late-life BMI and dementia is required. © 2011 The Authors. obesity reviews © 2011 International Association for the Study of Obesity. Source


Davies D.R.,Australian National University | Rawlinson N.,University of Aberdeen
Geology | Year: 2014

Many intraplate volcanic provinces do not appear to originate from plate-boundary processes or upwelling mantle plumes. Edge-driven convection (EDC), where a small-scale convective instability (induced by local variations in lithospheric thickness) displaces hot mantle material upward, provides an alternative hypothesis for such volcanism. Recently, EDC has been postulated as the trigger for Quaternary intraplate volcanism in Australia, due to the proximity of a craton edge. However, the Precambrian shield region of the Australian continent has a boundary that is at least 10,000 km long, yet the Newer Volcanics Province (NVP) is contained within a 400 × 100 km region. This brings into question EDC as a causal mechanism, unless nucleation at a single location can be explained. Here, we use a combination of seismic tomography and geodynamic modeling to show, for the first time, that (1) the source of the NVP is restricted to the upper mantle, and (2) mantle upwelling triggered by EDC is localized and intensified beneath the NVP as a result of three-dimensional variations in lithospheric thickness and plate motion-induced shear flow. This study helps to solve the global puzzle of why step changes in lithospheric thickness, which occur along craton edges and at passive margins, produce volcanism only at isolated locations. © 2014 Geological Society of America. Source


Binns R.A.,CSIRO | Binns R.A.,Australian National University
Economic Geology | Year: 2014

The 2.7 m Bikpela chimney differs from sulfide-rich chimneys at PACMANUS, eastern Manus basin, by virtue of high silica content, a stromatolite-like layered structure, and the presence of a large internal collapse cavity. Its interior is dominated by 5-to 10-mm-thick primary laminae of opal-A-dominated fronds clouded by submicroscopic sphalerite inclusions, set between thin subhorizontal growth borders. Larger sphalerites with sulfosalt-galena intergrowths at frond ends project into discoid cavities under the growth borders. A steeper, second-order lamination reflects arrested expansion of the 50-cm-high internal collapse cavity. Underlying the cavity floor an axial breccia pipe contains distorted fragments of laminated interior modified by dissolution and then redeposition of opal and further growth of pyrite and sphalerite. Beneath a thin Mn oxide crust, a hard outer sphalerite-barite carapace ∼5 cm thick and devoid of opal is banded parallel to the chimney exterior.At least three stages of chimney growth are evident, beginning with repetitive deposition of opaline frond layers probably developed from microbial mat precursors by overgrowth of hydrothermal opal and fine sphalerite. Next, with rising fluid temperatures, hydrothermal Fe-poor sphalerite with Pb sulfosalts and galena deposited at frond ends and under growth borders and, via lateral diffusion and mixing with seawater, formed abundantly in the outer carapace of the chimney. Passage of hot, more acid fluids into the chimney axial zone then caused dissolution of primary opal and consequent formation of the collapse cavity and underlying breccia pipe, together with deposition of Fe-rich sphalerite and pyrite in second-order fractures and cavities related to the collapse. Finally, conductive cooling during or after this latter stage produced films and spherules of clear opal coating pores and grain margins throughout the structure, apart from in the carapace.Bikpela contains significant gold and silver (avg: 8.7 ppm Au, 250 ppm Ag; n = 9), but it is low overall in Cu (up to 0.5 wt % in the pipe) and Pb (up to 0.7 wt % in the carapace). Its carapace is relatively rich in Zn (up to 54 wt %), Ag, As, and Sb, with one sample containing 0.12 wt % silver. © 2014 by Economic Geology. Source


Iaffaldano G.,Australian National University
Geochemistry, Geophysics, Geosystems | Year: 2014

The ability to map ocean-floor magnetization is key to infer past plate motions. The advent of geodesy in the Earth Sciences offered an independent snapshot of contemporary plate kinematics, averaged over decades. Early studies suggested plate-motions steadiness through geological time, because contemporary rates were similar to past 3-Myr averages. Recent data, however, show that geodetic and paleo-magnetic motions exhibit differences beyond confidence ranges, which might suggest geodesy samples time scales shorter than a few centuries. These differences pose important questions on the character of plate kinematic variability through time. Here I derive inferences on the steadiness of geodetically derived plate motions by combining geodynamical arguments with kinematic data sets. I exploit data sets to build scenarios for the recent evolution of most of the major plates. I compare the minimum rate at which torque needs to vary to generate these scenarios, with the maximum rate at which geological processes can contribute torque. This allows assessing the geodynamical plausibility of each scenario. Results indicate that plate-motion changes recorded since ∼3 Ma must have taken at least 1 Myr to occur. Two exceptions are the Pacific and Australian plates, whose motions changed by less than 5%, and therefore, required torque variations that might be built over periods as short as 0.1 Myr. It remains unresolved for how long geodetically derived plate motions kept steady in the geological past. However, results indicate it is indeed plausible that they did over the past 1-2 Myr. These inferences call for a shift in the way we regard the figure of geodetic plate motions. Key Points Plate motions take at least 1 Myr to change Present-day plate motions could have remained steady since 1-2 Ma ©2013. American Geophysical Union. All Rights Reserved. Source


Tsuboi Z.,Humboldt University of Berlin | Tsuboi Z.,Australian National University
Nuclear Physics B | Year: 2013

In . [1] (Z. Tsuboi, Nucl. Phys. B 826 (2010) 399, . arXiv:0906.2039), we proposed Wronskian-like solutions of the T-system for . [M,N]-hook of the general linear superalgebra . gl(M|N). We have generalized these Wronskian-like solutions to the ones for the general T-hook, which is a union of . [M1,N1]-hook and . [M2,N2]-hook (. M=M1+M2, . N=N1+N2). These solutions are related to Weyl-type supercharacter formulas of infinite dimensional unitarizable modules of . gl(M|N). Our solutions also include a Wronskian-like solution discussed in . [2] (N. Gromov, V. Kazakov, S. Leurent, Z. Tsuboi, JHEP 1101 (2011) 155, . arXiv:1010.2720) in relation to the . AdS5/CFT4 spectral problem. © 2013 Elsevier B.V. Source


Matuszewski M.,Instytut Fizyki PAN | Matuszewski M.,Australian National University
Physical Review Letters | Year: 2010

We show that metastable phases of an antiferromagnetic spin-1 condensate in a simple model with pure contact interactions can exhibit a rotonlike minimum in the excitation spectrum. The introduction of a magnetic field gives rise to the instability of roton modes, which can lead to spontaneous emergence of regular periodic, polygonal, polyhedral, or crystalline patterns, as shown in numerical simulations within the truncated Wigner approximation. An explanation of the occurrence of rotonlike instability is given based on the energy and spin conservation laws. © 2010 The American Physical Society. Source


Oliver R.P.,Murdoch University | Solomon Peter S P.S.,Australian National University
Current Opinion in Plant Biology | Year: 2010

It was generally considered that necrotrophic plant pathogenic fungi possessed simplistic pathogenic mechanisms being typically reliant on 'blasting' their way through host tissue with a battery of lytic and degradative enzymes. However recent studies have suggested that this is not true and that necrotrophic fungal pathogens can subtly manipulate the host during infection in a manner similar to biotrophic pathogens. For example, it has been demonstrated that the wheat pathogens Stagonospora nodorum and Pyrenophora tritici-repentis secrete small unique proteins (effectors) that are internalised by host cells and interact with the host in a gene-for-gene relationship to initiate disease, albeit in an inverse manner compared to biotrophs. This paper reviews recent developments in necrotrophic fungal pathogenicity throughout a critical period that arguably saw this field come of age. © 2010 Elsevier Ltd. Source


Grafton R.Q.,Australian National University | Horne J.,11 Grey St DeakinACT
Agricultural Water Management | Year: 2014

The paper reviews the history of water markets and recent water reforms in the Murray-Darling Basin (MDB), Australia. A detailed examination of water markets in the MDB is given with a focus on: water charge and trading rules, trade restrictions, gains from trade, water market information, inter-temporal market price responses, and the environmental benefits of trade. Twelve lessons from the development of water markets in the MDB are provided to assist decision-makers interested in establishing or improving water markets in Australia, and beyond. © 2013 Elsevier B.V. Source


Sutherland R.S.,Australian National University
Astrophysics and Space Science | Year: 2010

A new hydrodynamics code aimed at astrophysical applications has been developed. The new code and algorithms are presented along with a comprehensive suite of test problems in one, two, and three dimensions. The new code is shown to be robust and accurate, equalling or improving upon a set of comparison codes. Fyris Alpha will be made freely available to the scientific community. © Springer Science+Business Media B.V. 2010. Source


Macintosh A.,Australian National University
Mitigation and Adaptation Strategies for Global Change | Year: 2013

Urban planning has the potential to be a powerful tool for facilitating efficient and equitable adaptation to climate change-related coastal hazards ('coastal climate hazards'). However, if urban planning measures are poorly designed or implemented, it can increase costs and vulnerability, and unfairly affect the interests of particular groups. Through a case study on the coastal climate hazard planning framework in Victoria, Australia, this paper aims to illustrate how urban planning measures can lead to maladaptation and draw lessons for the future design and implementation of planning responses. Five main policy lessons are drawn from the case study. First, planning frameworks should encourage the adoption of robust approaches that are as insensitive to the uncertainties associated with coastal climate hazards as possible. Secondly, policy makers need to be mindful of the opportunity costs and equity implications of planning responses. Thirdly, to be sustainable, planning responses must be robust to social and political factors, something that can be achieved through the use of flexible approaches that allow continued use and development of land but on conditions that protect the interests of governments and communities. Fourthly, policy makers need to be mindful of transaction costs. Finally, when devolving planning responsibilities to lower levels of government, policy makers need to ensure that the objectives of planning frameworks are clear, there is minimal ambiguity in decision guidelines, and that the resourcing and capacity constraints of planning bodies are appropriately considered. © 2012 Springer Science+Business Media B.V. Source


Rendle-Short J.,Australian National University
Journal of Pragmatics | Year: 2010

This paper focuses on the sequential environment of the address term 'mate', contrasting the post-positioned 'mate' (e.g. 'hello mate') with the pre-positioned 'mate' (e.g. 'mate how are ya'). Because 'mate' occurs in a wide variety of situations and carries with it a range of interpretations, it is an extremely popular term that can be used not only when talking to friends, but also between casual acquaintances who may never talk to each other again. However, it can also be negatively interpreted, especially in ironic and antagonistic contexts. This paper will argue that the interpretation of 'mate' is closely tied to its sequential placement. When post-positioned, 'mate' overwhelmingly occurs in openings and closings of conversations or following assessments, agreements, acknowledgements and appreciations, presenting an attitude of open friendliness towards the other person. This is no more evident than when 'mate' plays a mitigating role following requests, advice giving or even disagreements. However when pre-positioned, it changes the sequential organization of the talk (as do pre-positioned address terms in general), giving the turn first status. It will be argued that it is only through understanding its sequential position that we can begin to understand why 'mate' is sometimes interpreted as antagonistic or hostile. © 2009 Elsevier B.V. All rights reserved. Source


Pittock J.,Australian National University
Ecology and Society | Year: 2011

Even in the absence of climate change, freshwater ecosystems and the resources they provide for people are under great pressure because of increasing demand for water and declines in water quality. The imminent onset of climate change will exacerbate these impacts, placing even greater pressure on already stressed resources and regions. A plethora of national climate change policies have been adopted that emphasize structural adjustment in the energy sector and increasing carbon sinks. To date, most public debate on water has focused on the direct impacts of climate change on hydrology. However, there is growing evidence that climate change policies themselves may have substantial additional and negative impacts on freshwater resources and ecosystems and may thus result in maladaptation. To avoid such maladaptation, integrated, coordinated policy making is required. In this paper, national climate change policies from Australia, Brazil, China, the European Union (EU), India, Mexico, South Africa, Tanzania, and the United Kingdom are compared to: (i) identify where negative trade-offs exist between climate change policies and freshwater resources, (ii) analyze where institutions and structures exist to optimize integration among climate, water, and biodiversity policies, and (iii) provide a much needed overview from a broad selection of countries with a view to identifying further opportunities for theoretical exploration and testing. The synergies and conflicts among climate, energy, water, and environmental policies create additional challenges for governments to develop integrated policies to deliver multiple benefits. Success factors for better policy development identified in this assessment and synthesis include engagement of senior political leaders, cyclical policy development, multi-agency and stakeholder processes, and stronger accountability and enforcement measures. © 2011 by the author(s). Source


Hurley J.R.,Swinburne University of Technology | Mackey A.D.,Australian National University
Monthly Notices of the Royal Astronomical Society | Year: 2010

We use direct N-body simulations to investigate the evolution of star clusters with large size-scales with the particular goal of understanding the so-called extended clusters observed in various Local Group galaxies, including M31 and NGC 6822. The N-body models incorporate a stellar mass function, stellar evolution and the tidal field of a host galaxy. We find that extended clusters can arise naturally within a weak tidal field, provided that the tidal radius is filled at the start of the evolution. Differences in the initial tidal filling factor can produce marked differences in the subsequent evolution of clusters and the size-scales that would be observed. These differences are more marked than any produced by internal evolution processes linked to the properties of cluster binary stars or the action of an intermediate-mass black hole, based on models performed in this work and previous work to date. Models evolved in a stronger tidal field show that extended clusters cannot form and evolve within the inner regions of a galaxy, such as M31. Instead, our results support the suggestion that many extended clusters found in large galaxies were accreted as members of dwarf galaxies that were subsequently disrupted. Our results also enhance the recent suggestion that star clusters evolve to a common sequence in terms of their size and mass. © 2010 The Authors. Journal compilation © 2010 RAS. Source


Peakall R.,Australian National University | Smouse P.E.,Rutgers University
Bioinformatics | Year: 2012

GenAlEx: Genetic Analysis in Excel is a cross-platform package for population genetic analyses that runs within Microsoft Excel. GenAlEx offers analysis of diploid codominant, haploid and binary genetic loci and DNA sequences. Both frequency-based (F-statistics, heterozygosity, HWE, population assignment, relatedness) and distance-based (AMOVA, PCoA, Mantel tests, multivariate spatial autocorrelation) analyses are provided. New features include calculation of new estimators of population structure: G' ST, G" ST, Jost's D est and F' ST through AMOVA, Shannon Information analysis, linkage disequilibrium analysis for biallelic data and novel heterogeneity tests for spatial autocorrelation analysis. Export to more than 30 other data formats is provided. Teaching tutorials and expanded step-by-step output options are included. The comprehensive guide has been fully revised. © The Author(s) 2012. Published by Oxford University Press. Source


Wierzbicka A.,Australian National University
Behavioral and Brain Sciences | Year: 2010

Jones recognizes the existence of primitives of conceptual structures, out of which local representations of kinship are constructed. NSM semantics has identified these primitives through a cross-linguistic search for lexical universals ( NSM stands for Natural Semantic Metalanguage and also for the corresponding linguistic theory). These empirical universals provide, I argue, a better bridge between cognitive anthropology and evolutionary psychology than the constructs of OT, with dubious claim to conceptual reality. © 2010 Cambridge University Press. Source


Ross A.,Australian National University
Journal of Hydrology | Year: 2014

Integrated management of surface water and groundwater can provide efficient and flexible use of water by making the best use of the properties of different types of water resources. Integrated cyclical water management can help adaptation to climate variation and uncertainty by varying the proportion of surface water and groundwater allocations over time in response to changing water availability. Water use entitlements and rules specify conditions for the use, storage and exchange of surface water and groundwater. These entitlements and rules provide certainty for water users, investors and managers. Entitlements and rules also need to be flexible to enable users and managers to respond to changing water availability and knowledge. Arrangements to provide certainty and flexibility can conflict. For example guarantees of specific long-term allocations of water, or shares of allocations can conflict with arrangements to bank water underground during wet periods and then to use an increased amount of groundwater in dry periods. Systems of water entitlements and rules need to achieve a balance between certainty and flexibility. This article explores the effect of water entitlements and rules, and arrangements to provide certainty and flexibility for the integration of surface water and groundwater management over time. The analysis draws on case studies from the Namoi River basin in New South Wales and the South Platte River basin in Colorado. Integrated cyclical water management requires a comprehensive, flexible and balanced system of water entitlements and rules that allow extended water carryover, water banking, aquifer storage and recovery over the wet and dry climate cycle. Opportunities for extended carryover and aquifer storage and recovery over the wet and dry climate cycle merit further consideration in New South Wales, Colorado and other jurisdictions. © 2014 Elsevier B.V. Source


Burges S.,Australian National University
Development Policy Review | Year: 2014

Brazil has entered the world of development assistance, but with its own twist. This article argues that Brazil is taking a cross-government policy approach to the provision of development assistance, and which includes recruitment of business interests. There is a genuine concern with global poverty alleviation in Brazil, but this does not preclude policy-makers from using aid and development-related activities to advance national interests. The added quirk that sets Brazil apart from Northern counterparts is that the provision of development assistance offers significant benefits in terms of building up international bureaucratic experience inside the country and helping national firms internationalise their market activities. © 2014 Overseas Development Institute. Source


Roberts A.P.,Australian National University
Earth-Science Reviews | Year: 2015

Reduction-oxidation (redox) reactions occur during burial because sediments contain reactive mixtures of oxidised and reduced components. Diagenetic chemical reactions represent the approach of all sedimentary components toward equilibrium, and control the long-term stability of sedimentary iron-bearing minerals. Magnetic minerals are sensitive indicators of sedimentary redox conditions and of changes in these conditions through time, with diagenetic effects ranging from subtle to pervasive. Despite the importance of magnetic mineral diagenesis in paleomagnetism, rock magnetism, and environmental magnetism, and the usefulness of these subjects in the Earth and environmental sciences, there is no systematic single published treatment of magnetic mineral diagenesis. This paper is an attempt to provide such a treatment for the full range of diagenetic environments. Magnetic mineral diagenesis during early burial is driven largely by chemical changes associated with organic matter degradation in a succession of environments that range from oxic to nitrogenous to manganiferous to ferruginous to sulphidic to methanic, where the free energy yielded by different oxidants decreases progressively in each environment. In oxic environments, the most important diagenetic processes involve surface oxidation of detrital minerals, and precipitation of Fe3+-bearing minerals from solution. In ferruginous environments, the most reactive detrital and authigenic iron oxides undergo dissolution, often mediated by dissimilatory iron-reducing bacteria, which releases Fe2+ that becomes available for other reactions. The Fe2+ in solution can diffuse upward where it is oxidised to form new authigenic iron (oxyhydr-)oxide minerals or it can become bioavailable to enable magnetotactic bacteria to biomineralise magnetite, generally at the base of the overlying nitrogenous zone. Alternatively, dissimilatory iron-reducing bacteria can produce extracellular magnetite within ferruginous environments. In sulphidic environments, iron-bearing detrital mineral assemblages undergo more radical alteration. Hydrogen sulphide, which is a byproduct of bacterial sulphate reduction or of anaerobic oxidation of methane, reacts with the Fe2+ released from iron mineral dissolution or directly with solid iron (oxyhydr-)oxide minerals to form iron sulphide minerals (mackinawite, greigite, and pyrite). Authigenic growth of ferrimagnetic greigite has important implications for paleomagnetic recording. Secondary iron sulphide formation can also occur as a result of anaerobic oxidation of methane. Methane migration through sediments in association with biogenic or thermogenic methane production or in association with gas hydrate dissociation can disrupt the diagenetic steady state and give rise to greigite and monoclinic pyrrhotite formation that remagnetises sediments. Most of the above-described diagenetic processes occur below 50°C. With continuing burial above 50°C, but at sub-metamorphic temperatures, magnetic minerals can undergo further thermally-induced chemical changes that give rise to a wide range of mineralogical transformations that affect the magnetic record of the host sediment. These changes include remagnetisations. Magnetic analysis can provide much valuable information concerning diagenesis in environmental processes. The range of processes discussed in this paper should assist researchers in analysing sediment magnetic properties for which the assessment of diagenetic effects has become a necessary component. © 2015 Elsevier B.V. Source


van Kerkhoff L.,Australian National University
Sustainability Science | Year: 2014

The importance of taking an integrative approach to research has long been integral to sustainability science, and has recently been highlighted as fundamental to the co-design of research and co-production of knowledge. Just what this means, however, and how to implement such a broad notion has escaped effective methodological development. In order to become more than a generic descriptor, integrative research needs to be conceptualized and presented in ways that offer guidance to researchers designing and conducting integrative research projects, whilst remaining broad enough to be relevant to the breadth and depth of sustainability-related problems. Drawing on complexity theory and fundamental aspects of integrative research, I present a methodological framing that seeks to achieve this balance. Using a definition of integrative research as "research in the context of complexity, with an action imperative", I draw from complexity theory that proposes minimal specifications, generative relationships, focusing on enablers and seeking diversity as core features of a complexity-based approach. On that basis I propose four principles that can be used by researchers to guide the design and implementation of their projects: embrace uncertainty; engage stakeholders; be transdisciplinary; and have a learning orientation. Each of these principles is explained, and their relationships to research design, methodological framing, choice of methods and project development are presented. Two integrative research project frameworks are presented as examples of how this principles-based approach can be implemented in research design. Using this approach offers a simple but powerful structure to guide integrative research for sustainability science at the project scale. © 2013 Springer Japan. Source


Dann S.,Australian National University
First Monday | Year: 2010

This paper delivers a new Twitter content classification framework based 16 existing Twitter studies and a grounded theory analysis of a personal Twitter history. It expands the existing understanding of Twitter as a multifunction tool for personal, profession, commercial and phatic communications with a split level classification scheme that offers broad categorization and specific sub categories for deeper insight into the real world application of the service. Source


Holman L.,Australian National University
Behavioral Ecology | Year: 2014

The nonreproductive helpers of many arthropod, bird and mammal species are a perennial puzzle for evolutionary biologists. Theory and evidence suggests that helping is favored by high relatedness between social partners and by certain ecological factors. I suggest that the availability of information on reproductive value may be another important factor predicting whether helping evolves. Using simple models, I show that conditional helping strategies, in which individuals assess the reproductive value of themselves and their relatives and then help conditionally, evolve more easily than unconditional helping strategies. The models also identify conditions that cause parent-offspring conflict over helping strategy and produce predictions regarding the evolution of honest signaling and parental effects. Crucially, the evolution of facultative helping can select for specialization in helping, which in turn selects for more frequent helping, creating positive feedback. Facultative helping might thereby act as stepping-stone to advanced forms of obligate helping. © 2014 © The Author 2014. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. Source


Tierney M.L.,Australian National University
Biochimica et Biophysica Acta - Biomembranes | Year: 2011

The fundamental properties of ion channels assure their selectivity for a particular ion, its rapid permeation through a central pore and that such electrical activity is modulated by factors that control the opening and closing (gating) of the channel. All cell types possess ion channels and their regulated flux of ions across the membrane play critical roles in all steps of life. An ion channel does not act alone to control cell excitability but rather forms part of larger protein complexes. The identification of protein interaction partners of ion channels and their influence on both the fundamental biophysical properties of the channel and its expression in the membrane are revealing the many ways in which electrical activity may be regulated. Highlighted here is the novel use of the patch clamp method to dissect out the influence of protein interactions on the activity of individual GABAA receptors. The studies demonstrate that ion conduction is a dynamic property of a channel and that protein interactions in a cytoplasmic domain underlie the channel's ability to alter ion permeation. A structural model describing a reorganisation of the conserved cytoplasmic gondola domain and the influence of drugs on this process are presented. © 2010 Elsevier B.V. All rights reserved. Source


Craig V.S.J.,Australian National University
Soft Matter | Year: 2011

Atomic Force Microscope images and other experiments show us that very small stable bubbles, known as nanobubbles, can be present on surfaces despite well founded theoretical considerations that predict otherwise. Nanobubbles are thought to play a role in the rupture of thin films during froth flotation, hydrodynamic slip over surfaces, interaction forces between hydrophobic surfaces and influence the electroplating and electrolysis processes. Here we describe what is known of nanobubbles and discuss the challenges in understanding nanobubble morphology and stability. © 2011 The Royal Society of Chemistry. Source


Bell A.,Australian National University
PLoS ONE | Year: 2012

Background: How does the cochlea analyse sound into its component frequencies? In the 1850s Helmholtz thought it occurred by resonance, whereas a century later Békésy's work indicated a travelling wave. The latter answer seemed to settle the question, but with the discovery in 1978 that the cochlea emits sound, the mechanics of the cochlea was back on the drawing board. Recent studies have raised questions about whether the travelling wave, as currently understood, is adequate to explain observations. Approach: Applying basic resonance principles, this paper revisits the question. A graded bank of harmonic oscillators with cochlear-like frequencies and quality factors is simultaneously excited, and it is found that resonance gives rise to similar frequency responses, group delays, and travelling wave velocities as observed by experiment. The overall effect of the group delay gradient is to produce a decelerating wave of peak displacement moving from base to apex at characteristic travelling wave speeds. The extensive literature on chains of coupled oscillators is considered, and the occurrence of travelling waves, pseudowaves, phase plateaus, and forced resonance in such systems is noted. Conclusion and significance: This alternative approach to cochlear mechanics shows that a travelling wave can simply arise as an apparently moving amplitude peak which passes along a bank of resonators without carrying energy. This highlights the possible role of the fast pressure wave and indicates how phase delays and group delays of a set of driven harmonic oscillators can generate an apparent travelling wave. It is possible to view the cochlea as a chain of globally forced coupled oscillators, and this model incorporates fundamental aspects of both the resonance and travelling wave theories. © 2012 Bell. Source


Mcmurtrie R.E.,University of New South Wales | Dewar R.C.,Australian National University
New Phytologist | Year: 2013

Allocation of carbon (C) between tree components (leaves, fine roots and woody structures) is an important determinant of terrestrial C sequestration. Yet, because the mechanisms underlying C allocation are poorly understood, it is a weak link in current earth-system models. We obtain new theoretical insights into C allocation from the hypothesis (MaxW) that annual wood production is maximized. MaxW is implemented using a model of tree C and nitrogen (N) balance with a vertically resolved canopy and root system for stands of Norway spruce (Picea abies). MaxW predicts optimal vertical profiles of leaf N and root biomass, optimal canopy leaf area index and rooting depth, and the associated optimal pattern of C allocation. Key insights include a predicted optimal C-N functional balance between leaves at the base of the canopy and the deepest roots, according to which the net C export from basal leaves is just sufficient to grow the basal roots required to meet their N requirement. MaxW links the traits of basal leaves and roots to whole-tree C and N uptake, and unifies two previous optimization hypotheses (maximum gross primary production, maximum N uptake) that have been applied independently to canopies and root systems. © 2013 The Authors © 2013 New Phytologist Trust. Source


Davis A.,Australian National University | Tinker A.V.,Vancouver Center | Friedlander M.,University of New South Wales
Gynecologic Oncology | Year: 2014

"Platinum resistant" ovarian cancer was historically defined as disease recurrence within 6 months of completion of first-line platinum-based chemotherapy, although this is now more broadly applied to also include patients progressing within 6 months after multiple lines of chemotherapy. However, this definition ignores the heterogeneity and complexity of the spectrum of diseases that comprise "platinum resistant ovarian cancer" (PROC) and is innately flawed as it was initially derived using methods of detection of recurrence that would now be regarded as outdated. The outcome of patients with PROC is generally poor, with low response rates to further chemotherapy and a median survival of less than 12 months, but this is unpredictable and can be quite variable from study to study. This review outlines the complexity of PROC, examines how this impacts on the interpretation of the results of clinical trials, and explores how the definition may be improved. We also briefly describe the mechanisms of platinum resistance, the results of clinical trials to date as well as treatment options for patients with PROC and highlight the need for better methods of assessing clinical benefit in this poor prognostic sub group of patients. Crown Copyright © 2014 Published by Elsevier Inc. All rights reserved. Source


Corry B.,Australian National University
PeerJ | Year: 2013

The recent publication of a number of high resolution bacterial voltage-gated sodium channel structures has opened the door for the mechanisms employed by these channels to distinguish between ions to be elucidated. The way these channels select between Na+ and K+ has been investigated in computational studies, but the selectivity for Na+ over Ca2+ has not yet been studied in this way. Here we use molecular dynamics simulations to calculate the energetics of Na+ and Ca2+ transport through the channel. Single ion profiles show that Ca2+ experiences a large barrier midway through the selectivity filter that is not seen by Na+. This barrier is caused by the need for Ca2+ to partly dehydrate to pass through this region and the lack of compensating interactions with the protein.Multi-ion profiles show that ions can pass each other in the channel, which is why the presence of Ca2+ does not block Na+ conduction despite binding more strongly in the pore. © 2013 Corry. Source


Anderson J.M.,Australian National University
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2012

The concept that the two photosystems of photosynthesis cooperate in series, immortalized in Hill and Bendall's Z scheme, was still a black box that defined neither the structural nor the molecular organization of the thylakoid membrane network into grana and stroma thylakoids. The differentiation of the continuous thylakoid membrane into stacked grana thylakoids interconnected by single stroma thylakoids is a morphological reflection of the non-random distribution of photosystem II/light-harvesting complex of photosystem II, photosystem I and ATP synthase, which became known as lateral heterogeneity. © 2012 The Royal Society. Source


Frankcombe T.J.,Australian National University
Journal of Physical Chemistry C | Year: 2013

Density functional theory calculations have been performed on slabs of NaH doped with transition metals. These calculations suggest barrierless dissociative chemisorption of H2 onto Sc, Ti, and V dopant sites, while indicating that Rh and Pt do not support dissociative chemisorption. Furthermore, sufficient energy is liberated in the H2 adsorption to allow at least one of the adsorbed hydrogen atoms to diffuse away from the adsorption site without additional energy input. Detaching the second adsorbed hydrogen atom requires a small energy input. These results support an active hydrogen pump mechanism being involved in the rehydrogenation of NaAlH 4 decomposition products. © 2013 American Chemical Society. Source


Lamb T.D.,Australian National University
Progress in Retinal and Eye Research | Year: 2013

Evidence is reviewed from a wide range of studies relevant to the evolution of vertebrate photoreceptors and phototransduction, in order to permit the synthesis of a scenario for the major steps that occurred during the evolution of cones, rods and the vertebrate retina. The ancestral opsin originated more than 700Mya (million years ago) and duplicated to form three branches before cnidarians diverged from our own lineage. During chordate evolution, ciliary opsins (C-opsins) underwent multiple stages of improvement, giving rise to the 'bleaching' opsins that characterise cones and rods. Prior to the '2. R' rounds of whole genome duplication near the base of the vertebrate lineage, 'cone' photoreceptors already existed; they possessed a transduction cascade essentially the same as in modern cones, along with two classes of opsin: SWS and LWS (short- and long-wave-sensitive). These cones appear to have made synaptic contact directly onto ganglion cells, in a two-layered retina that resembled the pineal organ of extant non-mammalian vertebrates. Interestingly, those ganglion cells appear to be descendants of microvillar photoreceptor cells. No lens was associated with this two-layered retina, and it is likely to have mediated circadian timing rather than spatial vision. Subsequently, retinal bipolar cells evolved, as variants of ciliary photoreceptors, and greatly increased the computational power of the retina. With the advent of a lens and extraocular muscles, spatial imaging information became available for central processing, and gave rise to vision in vertebrates more than 500Mya. The '2. R' genome duplications permitted the refinement of cascade components suitable for both rods and cones, and also led to the emergence of five visual opsins. The exact timing of the emergence of 'true rods' is not yet clear, but it may not have occurred until after the divergence of jawed and jawless vertebrates. © 2013 The Author. Source


McKay B.D.,Australian National University
Combinatorics Probability and Computing | Year: 2011

Let d = (d1, d2,dn) be a vector of non-negative integers with even sum. We prove some basic facts about the structure of a random graph with degree sequence d, including the probability of a given subgraph or induced subgraph. Although there are many results of this kind, they are restricted to the sparse case with only a few exceptions. Our focus is instead on the case where the average degree is approximately a constant fraction of n. Our approach is the multidimensional saddle-point method. This extends the enumerative work of McKay and Wormald (1990) and is analogous to the theory developed for bipartite graphs by Greenhill and McKay (2009). © 2011 Cambridge University Press. Source


Ivanov I.A.,Australian National University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We consider the process of atomic ionization driven by a laser pulse with varying ellipticity. We study the distribution of the momenta of the photoelectrons, ionized by a strong laser field, emitted in the direction perpendicular to the polarization plane (transverse distribution). We show that with changing laser pulse ellipticity, the transverse distribution evolves from the singular cusplike distribution for the close to linear polarization to the smooth Gaussian-like structure for the close to circular polarization. In the latter case, when the ellipticity parameter ε→1, the strong-field approximation formula for the transverse momentum distribution becomes quantitatively correct. © 2014 American Physical Society. Source


Loos P.-F.,Australian National University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We explicitly build a generalized local-density approximation (GLDA) correlation functional based on one-dimensional uniform electron gases (UEGs). The fundamental parameters of the GLDA - a generalization of the widely known local-density approximation used in density-functional theory - are the electronic density ρ and a two-electron local parameter called the hole curvature η. The UEGs considered in this study are finite versions of the conventional infinite homogeneous electron gas and consist of n electrons on an infinitely thin wire with periodic boundary conditions. We perform a comprehensive study of these finite UEGs at high, intermediate, and low densities using perturbation theory and quantum Monte Carlo calculations. We show that the present GLDA functional yields accurate estimates of the correlation energy for both weakly and strongly correlated one-dimensional systems and can be easily generalized to higher-dimensional systems. © 2014 American Physical Society. Source


Sterelny K.,Australian National University
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016

This paper suggests (i) that while work on animal innovation has made good progress in understanding some of the proximate mechanisms and selective regimes through which innovation emerges, it has somewhat neglected the role of the social environment of innovation; a neglect manifest in the fact that innovation counts are almost always counts of resource-acquisition innovations; the invention of social tools is rarely considered. The same is true of many experimental projects, as these typically impose food acquisition tasks on their experimental subjects. (ii) That neglect is important, because innovations often pose collective action problems; the hominin species were technically innovative because they were also socially adaptable. (iii) In part for this reason, there remains a disconnect between research on hominin innovation and research on animal innovation. (iv) Finally, the paper suggests that there is something of a disconnect between the theoretical work on innovation in hominin evolution (based on theories of cultural evolution) and the experimental tradition on human innovation. That disconnect is largely due to the theoretical work retreating from strong claims about the proximate mechanisms of human cultural accumulation. © 2016 The Author(s) Published by the Royal Society. All rights reserved. Source


Christen P.,Australian National University
IEEE Transactions on Knowledge and Data Engineering | Year: 2012

Record linkage is the process of matching records from several databases that refer to the same entities. When applied on a single database, this process is known as deduplication. Increasingly, matched data are becoming important in many application areas, because they can contain information that is not available otherwise, or that is too costly to acquire. Removing duplicate records in a single database is a crucial step in the data cleaning process, because duplicates can severely influence the outcomes of any subsequent data processing or data mining. With the increasing size of today's databases, the complexity of the matching process becomes one of the major challenges for record linkage and deduplication. In recent years, various indexing techniques have been developed for record linkage and deduplication. They are aimed at reducing the number of record pairs to be compared in the matching process by removing obvious nonmatching pairs, while at the same time maintaining high matching quality. This paper presents a survey of 12 variations of 6 indexing techniques. Their complexity is analyzed, and their performance and scalability is evaluated within an experimental framework using both synthetic and real data sets. No such detailed survey has so far been published. © 2012 IEEE. Source


Gunningham N.,Australian National University
Journal of Environmental Law | Year: 2011

For environmental legislation to 'work' it must not only be well designed but also efficiently and effectively enforced. Strategies must be developed as to how inspectors should go about the task of intervening in the affairs of regulated organisations to ensure compliance and enforcement-a question regarding which there is little consensus. This article examines this question from a number of angles: descriptive; analytical; and normative. It explores the practices of a representative sample of environmental regulators, identifying a number of distinctive intervention strategies (which are only limitedly shaped by existing theoretical models). It goes on to examine the strengths and weaknesses of each strategy and to consider how best to balance the sometimes competing criteria of effectiveness, efficiency and legitimacy. Finally, it considers how resource allocation and intervention strategies can best be integrated, whether there is a single 'best practice' strategy, and if not, what sorts of hybrids might be developed. © The Author 2011. Published by Oxford University Press. All rights reserved. Source


Minority world consumers are being asked to rethink about their I-ness fixations and the individualism apparent in community food practice. Meanwhile, poor and economically marginalised in the majority world are prioritising civic we-ness and taking collective responsibility for meeting local food needs. In Mindanao in the Philippines, a municipality-wide communal gardening project is feeding malnourished children in schools, supporting poor families in self-provisioning and generating income and employment opportunities for volunteer gardeners. As such, it is benefiting the individual households and the community simultaneously. Of interest is how different actors within this project "successfully" negotiate I-ness and civic we-ness in ways that achieve desired outcomes such as reduced malnutrition. In this paper, I examine the ethical economic decision making of various actors within the Opol Food Project in Mindanao. I reveal how economic decisions are generating social surplus, creating and sustaining commons and building a community-based food economy. I also demonstrate the valuable role that local government can play in enabling and cultivating civic we-ness and in building a different food future. © 2011 Taylor & Francis. Source


Thomas E.R.,British Antarctic Survey | Abram N.J.,Australian National University
Geophysical Research Letters | Year: 2016

Antarctic sea ice has been increasing in recent decades, but with strong regional differences in the expression of sea ice change. Declining sea ice in the Bellingshausen Sea since 1979 (the satellite era) has been linked to the observed warming on the Antarctic Peninsula, while the Ross Sea sector has seen a marked increase in sea ice during this period. Here we present a 308 year record of methansulphonic acid from coastal West Antarctica, representing sea ice conditions in the Amundsen-Ross Sea. We demonstrate that the recent increase in sea ice in this region is part of a longer trend, with an estimated ~1° northward expansion in winter sea ice extent (SIE) during the twentieth century and a total expansion of ~1.3° since 1702. The greatest reconstructed SIE occurred during the mid-1990s, with five of the past 30 years considered exceptional in the context of the past three centuries. ©2016. The Authors. Source


Ball R.,Australian National University
Process Safety and Environmental Protection | Year: 2011

Abstract: A stability analysis is presented of the hydrolysis of methyl isocyanate (MIC) using a homogeneous flow reactor paradigm. The results simulate initiation of the thermal runaway that occurred inside the storage tank of MIC at the Bhopal Union Carbide plant in December 1984. The stability properties of the model indicate that the thermal runaway may have been initiated at a large amplitude, hard thermal oscillation at a subcritical Hopf bifurcation. This type of thermal misbehavior cannot be predicted using conventional thermal diagrams and classical ignition theory, and may be typical of liquid thermoreactive systems. © 2011 The Institution of Chemical Engineers. Source


Welberry T.R.,Australian National University
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2014

It is not generally appreciated that X-ray diffuse scattering has been known for almost as long as the Bragg scattering that is used in crystal structure determination. While we are celebrating the centenary of the birth of crystallography, marked by the first diffraction of X-rays by a crystal (Laue) and the formulation of Bragg's Law that laid the foundation for crystal structure determination, it is salutary to remember that diffuse scattering was observed in the very earliest experiments. Within a few years, in a paper on mixed crystals, Laue showed that occupational disorder produces a continuous background scattering between the Bragg peaks - the so-called Laue monotonic scattering. In this brief review, we trace the development of diffuse scattering methods over the course of a century. © 2013 The Minerals, Metals & Materials Society and ASM International. Source


Pellegrino C.,Australian National University | Lodhia S.,University of South Australia
Journal of Cleaner Production | Year: 2012

This paper explores how disclosure is used by key bodies in the Australian mining industry as a means to respond to climate change and ensure their social licence to operate. The study utilises a legitimacy theory framework and a multi-case analysis to examine the environmental disclosure practices via a variety of media of two companies and two industry bodies within Australia's mining industry. It is revealed that a combination of legitimising strategies is undertaken by key bodies in the Australian mining industry, however to differing degrees depending on the organisation. There is also support for the notion that different media plays a critical role in facilitating the legitimacy seeking behaviours of the companies and industry bodies. This study extends existing literature on legitimacy theory by highlighting the value of utilising this perspective to explore contemporary phenomena such as corporate responses to climate change. The findings of this study have practical significance as they are expected to have important policy ramifications. One of the differentiating features of this paper, compared to prior studies utilising a legitimacy theory framework, is the examination of legitimising disclosure strategies at an industry level, which complements a company level analysis. Moreover, variations in legitimising disclosure strategies and communication media employed may be due to their focus on differing conferring publics and stakeholder groups. © 2012 Elsevier Ltd. All rights reserved. Source


Andrews J.G.,University of Texas at Austin | Claussen H.,Alcatel - Lucent | Dohler M.,Catalonia Technology Center of Telecomunications | Rangan S.,New York University | Reed M.C.,Australian National University
IEEE Journal on Selected Areas in Communications | Year: 2012

Femtocells, despite their name, pose a potentially large disruption to the carefully planned cellular networks that now connect a majority of the planet's citizens to the Internet and with each other. Femtocells - which by the end of 2010 already outnumbered traditional base stations and at the time of publication are being deployed at a rate of about five million a year - both enhance and interfere with this network in ways that are not yet well understood. Will femtocells be crucial for offloading data and video from the creaking traditional network? Or will femtocells prove more trouble than they are worth, undermining decades of careful base station deployment with unpredictable interference while delivering only limited gains? Or possibly neither: are femtocells just a "flash in the pan"; an exciting but short-lived stage of network evolution that will be rendered obsolete by improved WiFi offloading, new backhaul regulations and/or pricing, or other unforeseen technological developments? This tutorial article overviews the history of femtocells, demystifies their key aspects, and provides a preview of the next few years, which the authors believe will see a rapid acceleration towards small cell technology. In the course of the article, we also position and introduce the articles that headline this special issue. © 2006 IEEE. Source


Austermann J.,Harvard University | Iaffaldano G.,Australian National University
Tectonics | Year: 2013

Large topographic belts along convergent margins have been recognized with the ability to slowdown the kinematics of subduction over geologically short time periods (i.e., few Myr), because their associated gravitational spreading provides significant resistive force within the framework of plate tectonics. The record of past and present-day plate kinematics provides important constraints on the dynamics of the lithosphere, because plate-motion changes must reflect temporal changes in the balance of driving and resisting forces. Here we focus on the convergence between the Arabian and Eurasian plates, across the Zagros mountain belt. Relative motion across this plate boundary is reconstructed since 13 Ma from published paleomagnetic and geodetic data, and features a slowdown of ∼30% from ∼5 Ma to the present day. We employ global dynamic models of the mantle/lithosphere system to test whether the most recent uplift across the Arabia-Eurasia collision zone, including the Zagros orogeny, may induce the observed slowdown since 5 Ma. Specifically, we use constraints from the geologic record to infer past topography and quantify its influence on the convergence rate between Arabia and Eurasia. We test the sensitivity of our models to assumptions made in estimating the paleoelevation by perturbing the orogeny parameterization within reasonable ranges. Finally, we speculate on the potential effects of Tethys slab break-off, changes of the deformation style within the collision zone, and the Afar plume on the dynamics of convergence. Our results indicate that orogenic uplift across the Arabia-Eurasia collision zone played a key role in slowing down convergence since ∼5 Ma. Key Points We reconstruct the Ar/Eu convergence slowdown since 5 MaWe test the influence of Zagros mountain uplift on the convergence rateThe orogenic uplift is the key control for the convergence decrease since 5 Ma ©2013. American Geophysical Union. All Rights Reserved. Source


Pawlowska M.M.,University of Cambridge | Butterfield N.J.,University of Cambridge | Brocks J.J.,Australian National University
Geology | Year: 2013

The pre-Ediacaran biomarker record has several characteristic features that distinguish it from its Phanerozoic counterpart, including high concentrations of unresolved complex mixture (UCM), low concentrations or absence of eukaryotic steranes, and a conspicuous carbon isotopic enrichment of n-alkyl lipids relative to bulk sedimentary carbon. We propose that these derive from a common, non-actualistic taphonomy based on the pervasive presence of microbial mats prior to the "Cambrian substrate revolution." Such mats would have formed a significant mechanical and biochemical barrier to in-falling plankton, leaving a biomarker record dominated by benthic microbial lipids, most of which would have originated from the lower, heterotrophically reworked layers of the mat. Most Proterozoic biomarker assemblages studied in this work derive from shallow-water sediments, where cyanobacteria-dominated upper mats represent a focused source of corrosive molecular oxygen. This "mat-seal effect" was broken with the onset of bioturbation in the Ediacaran and early Cambrian, at which point the primary source of fossil biomarkers switched from the benthos to the plankton. © 2012 Geological Society of America. Source


Li B.,Australian National University
Environment and Urbanization | Year: 2013

There is a growing, although still far from comprehensive, literature within China on the impacts of climate change in urban areas; also an evolving policy framework at national level to address these concerns and an increased interest in climate change adaptation from many local governments. This paper summarizes the urban risks and vulnerabilities highlighted by the literature, and reviews central and local government responses. It then assesses policy response, including how this considers vulnerability and future risks, formulates an adaptation strategy, engages stakeholders and assesses adaptive capacity. This shows how the Chinese system limits the influence on climate change adaptation of residents and small businesses, and of social scientists. The reasons for this include the tendency to use climate change as an economic growth engine (and GDP growth remains the most important factor for assessing local government officials' performance), little provision for participation in policy-making, and weak post-implementation evaluation once a policy has been scaled up at national level. These have affected the quality of evidence-based policy-making and make it difficult to draw lessons from unsuccessful practice. © 2013 International Institute for Environment and Development (IIED). Source


Roberts S.,Australian National University
Environmental Pollution | Year: 2013

The author investigates whether the mortality effect of particulate matter air pollution (PM10) has changed in Australia over the period 1993-2007. This period corresponds to an era of increasing Government intervention aimed at improving air quality and, as a result, a potential decrease in the toxicity of PM10. Evidence is found that the mortality effect of PM10 has declined in both Brisbane and Sydney. For Sydney we estimate that the effects of PM10 on total and cardiovascular mortality are, respectively, decreasing at the rate of 10% and 13% annually. We speculate that one possible reason for this decline could be a reduction in the toxicity of PM10. A difference between this study and a similar United States study is that PM10 concentrations have not been declining in Australia. This means that the observed decline in the mortality effect of PM10 is not an artefact of a declining PM 10 concentration. © 2013 Elsevier Ltd. All rights reserved. Source


L1 is an insertional mutagen that is capable of mediating permanent gene disruption in mammalian genomes. However, currently available L1 retrotransposition vectors exhibit low or unstable transgene expression when expressed in somatic cells and tissues. This restriction limits their potential utility in long-term screening procedures or somatic mutagenesis applications. In this study, we addressed this problem by developing a minicircle, nonviral L1 retrotransposition vector using a scaffold/matrix attachment region (S/MAR) in the vector backbone and evaluated its utility in human cell lines. The S/MAR-based L1 retrotransposition vector provides stable, elevated levels of L1 expression compared to the currently used EBNA1-based L1 vector. In addition, the S/MAR elements effectively mediate sustained levels of L1 retrotransposition in prolonged cell culturing without suffering from epigenetic silencing by DNA methylation or from vector integration problems even in the absence of selection pressure. These findings indicate that the simple inclusion of S/MAR in the vector backbone increased levels of L1 expression and retrotransposition that can be used as an effective tool to generate insertional mutagenesis in large-scale somatic mutagenesis applications in mammalian cells. © 2010 Landes Bioscience. Source


Creutzig T.,TU Darmstadt | Ridout D.,Australian National University
Nuclear Physics B | Year: 2012

The modular properties of fractional level . ŝl(2)-theories and, in particular, the application of the Verlinde formula, have a long and checkered history in conformal field theory. Recent advances in logarithmic conformal field theory have led to the realisation that problems with fractional level models stem from trying to build the theory with an insufficiently rich category of representations. In particular, the appearance of negative fusion coefficients for admissible highest weight representations is now completely understood. Here, the modular story for certain fractional level theories is completed. Modular transformations are derived for the complete set of admissible irreducible representations when the level is . k=?12 or . k=?43. The S-matrix data and Verlinde formula are then checked against the known fusion rules with complete agreement. Finally, an infinite set of modular invariant partition functions is constructed in each case. © 2012 Elsevier B.V. Source


Hynes M.,Australian National University
British Journal of Sociology | Year: 2013

This paper re-examines the sociological study of resistance in light of growing interest in the concept of affect. Recent claims that we are witness to an 'affective turn' and calls for a 'new sociological empiricism' sensitive to affect indicate an emerging paradigm shift in sociology. Yet, mainstream sociological study of resistance tends to have been largely unaffected by this shift. To this end, this paper presents a case for the significance of affect as a lens by which to approach the study of resistance. My claim is not simply that the forms of actions we would normally recognize as resistance have an affective dimension. Rather, it is that the theory of affect broadens 'resistance' beyond the purview of the two dominant modes of analysis in sociology; namely, the study of macropolitical forms, on the one hand, and the micropolitics of everyday resistance on the other. This broadened perspective challenges the persistent assumption that ideological forms of power and resistance are the most pertinent to the contemporary world, suggesting that much power and resistance today is of a more affective nature. In making this argument, it is a Deleuzian reading of affect that is pursued, which opens up to a level of analysis beyond the common understanding of affect as emotion. I argue that an affective approach to resistance would pay attention to those barely perceptible transitions in power and mobilizations of bodily potential that operate below the conscious perceptions and subjective emotions of social actors. These affective transitions constitute a new site at which both power and resistance operate. © London School of Economics and Political Science 2013. Source


Friel S.,University College London | Friel S.,Australian National University | Marmot M.G.,University College London
Annual Review of Public Health | Year: 2011

Marked health inequities exist between regions, between countries, and within countries. Reducing these inequities in health requires attention to the unfair distribution of power, money, and resources and the conditions of everyday life. These are the social determinants of health. The World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) brought together a global evidence base of what could be done to reduce these health inequities, demonstrating that economic and social policy, if done well, can improve health and health equity. A global movement for health equity was reignited by the WHO Commission on Social Determinants of Health when it made a call to action upon delivering its final report. © 2011 by Annual Reviews. rights reserved. Source


Bulbeck D.,Australian National University
Human Biology | Year: 2013

Genetic research into Southeast Asia's "negritos" has revealed their deep-rooted ancestry, with time depth comparable to that of Southwest Pacific populations. This finding is often interpreted as evidence that negritos, in contrast to other Southeast Asians, can trace much of their ancestry directly back to the early dispersal of Homo sapiens in the order of 70 kya from Africa to Pleistocene New Guinea and Australia. One view on negritos is to lump them and Southwest Pacific peoples into an "Australoid" race whose geographic distribution had included Southeast Asia prior to the Neolithic incursion of "Mongoloid" farmers. Studies into Semang osteology have revealed some hints of Southwest Pacific affinities in cranial shape, dental morphology, and dental metrical "shape." On the other hand, the Andamanese have been shown to resemble Africans in their craniometrics and South Asians in their dental morphology, while Philippine negritos resemble Mongoloid Southeast Asians in these respects and also in their dental metrics. This study expands the scope of negrito cranial comparisons by including Melayu Malays and additional coverage of South Asians. It highlights the distinction between the Mongoloid-like Philippine negritos and the Andamanese and Semang (and Senoi of Malaya) with their non-Mongoloid associations. It proposes that the early/mid-Holocene dispersal of the B4a1a mitochondrial DNA clade across Borneo, the Philippines, and Taiwan may be important for understanding the distinction between Philippine and other negritos. © 2013 Wayne State University Press. Source


Zhang G.,University of Electronic Science and Technology of China | James M.R.,Australian National University
IEEE Transactions on Automatic Control | Year: 2011

The purpose of this paper is to study and design direct and indirect couplings for use in coherent feedback control of a class of linear quantum stochastic systems. A general physical model for a nominal linear quantum system coupled directly and indirectly to external systems is presented. Fundamental properties of stability, dissipation, passivity, and gain for this class of linear quantum models are presented and characterized using complex Lyapunov equations and linear matrix inequalities (LMIs). Coherent H∞ and LQG synthesis methods are extended to accommodate direct couplings using multistep optimization. Examples are given to illustrate the results. © 2011 IEEE. Source


Liu B.,Australian National University | Hill D.J.,University of Sydney
IEEE Transactions on Automatic Control | Year: 2011

This note investigates dissipativity and related stability for discrete-time switched systems. The new concept of decomposable dissipativity is proposed for this kind of systems. By decomposing the supply rate into the main supply rate and the subsidiary supply rate, the energy changes of subsystems and energy dissipation in the whole switched system are explained. The uniform stability conditions are derived for decomposable dissipative discrete-time switched systems. By the decomposition of supply rate, the non-positive condition of the supply rate, which is often required in the literature to derive stability, is relaxed. Finally, one example is given to illustrate the results. © 2011 IEEE. Source


Buckman G.,Australian National University | Diesendorf M.,University of New South Wales
Energy Policy | Year: 2010

Renewable electricity is pivotal to the medium and long-term reduction of Australia's greenhouse gas (GHG) emissions, if deep cuts in them are eventually implemented. This paper examines the effectiveness of the principal existing policies that could potentially promote the expansion of renewable electricity (RElec) in Australia: the expanded Renewable Energy Target (RET); the proposed emissions trading scheme (ETS); and the state and territory-based feed-in tariffs. We find the effectiveness of RET is severely eroded by the inclusion of solar and heat pump hot water systems; by the inclusion of 'phantom' tradable certificates; and by high electricity consumption growth. We also find that the ETS will not produce a high enough carbon price to assist most RElec technologies before 2020; and that most of the feed-in tariffs exclude large-scale RElec and will give little assistance to small-scale RElec because they are mostly net tariffs. Unless there is a major revision of its RElec policy mechanisms, Australia will fail to reach its renewable electricity target and in particular will fail to build up its solar generation capacity which could be a major source of future deep cuts in the country's electricity generation emissions. © 2010 Elsevier Ltd. Source


Punzmann H.,Australian National University
Nature Physics | Year: 2014

The ability to send a wave to fetch an object from a distance would find a broad range of applications. Quasi-standing Faraday waves on water create horizontal vortices, yet it is not known whether propagating waves can generate large-scale flows-small-amplitude irrotational waves only push particles in the direction of propagation. Here we show that when waves become three-dimensional as a result of the modulation instability, a floater can be forced to move towards the wave source. The mechanism for this is the generation of surface vortices by waves propagating away from vertically oscillating plungers. We introduce a new conceptual framework for understanding wave-driven flows, which enables us to engineer inward and outward surface jets, stationary vortices, and other complex flows. The results form a new basis for the remote manipulation of objects on fluid surfaces and for a better understanding of the motion of floaters in the ocean, the generation of wave-driven jets, and the formation of Lagrangian coherent structures. Source


Tabataba F.S.,Sharif University of Technology | Sadeghi P.,Australian National University | Pakravan M.R.,Sharif University of Technology
IEEE Transactions on Wireless Communications | Year: 2011

This paper studies the statistical properties of the signal-to-noise ratio (SNR) of the dual-hop relaying link in a cooperative wireless communication system in the presence of channel estimation errors for fixed-gain (FG) and variable-gain (VG) relays. The SNR expression is derived and three different analytical approaches with different simplifying assumptions are proposed to obtain the probability distribution function of the SNR and the outage probability in each mode. All but one approach result in closed-form expressions for the outage probability. The simplest approach in each mode has been used to find an optimum power allocation scheme for pilot and data symbols transmission at the source and the relay that results in minimizing the outage probability. Numerical analysis is used to confirm the accuracy of the derived theory and to show that the analytical approaches have a good outage performance, especially as the relay-destination distance increases. It is shown that significant power savings (e.g. 6 dB in VG mode) can be obtained by using the proposed power optimization method. © 2011 IEEE. Source


Mallmann G.,University of Sao Paulo | O'Neill H.S.C.,Australian National University
Journal of Petrology | Year: 2013

The evolution of basaltic magmas depends on their redox state, hence oxygen fugacity, but there is increasing evidence that this intensive thermodynamic variable may be less well understood in basalts than commonly supposed. The redox state of terrestrial basalts has to a large extent been inferred from the Fe3+/Fe2+ ratios of their quenched glasses. However, this quantity appears to be significantly affected during late and post-eruptive processes in magmatic systems (e.g. by degassing, charge-transfer reactions of redox-variable species, and alteration), so that the degree to which the Fe3+/Fe2+ ratios preserved in basaltic glasses reflect the oxidation state of the magma at high temperature is unclear. Because olivine is the first silicate mineral to crystallize from primitive basaltic liquids on cooling following decompression, the equilibrium partitioning relations preserved in olivine phenocrysts in basalts are, in principle, less disturbed by these late and post-eruptive processes and, therefore, may better reflect the high-temperature (pre-eruptive) conditions of the magma. Here we calibrate an oxybarometer based on the strong sensitivity of the partitioning of vanadium between olivine and silicate melt to oxygen fugacity. Our empirical parameterization, calibrated over a range of redox conditions between four log10 units above and below the quartz-fayalite-magnetite (QFM) oxygen buffer, takes into account the effects of temperature, olivine composition (i.e. Mg/Fe ratios) and melt composition (namely the activities of CaO, SiO2, AlO1.5, NaO0.5 and KO0.5), and allows oxygen fugacity determinations to within ̃0.25 log10 units. We also explore the sensitivity of the exchange partitioning of Sc and Y between olivine and melt to temperature as a geothermometer. Our calibration indicates that this geothermometer allows temperature to be estimated to within 15°C, but precision is strongly dependent on the Sc and Y measurements in olivine and melt. © The Author 2013. Published by Oxford University Press. Source


Endicott P.,University of Paris Descartes | Ho S.Y.W.,Australian National University | Stringer C.,Natural History Museum in London
Journal of Human Evolution | Year: 2010

A better understanding of the evolutionary relationship between modern humans and Neanderthals is essential for improving the resolution of hominin phylogenetic hypotheses. Currently, four distinct chronologies for the timing of population divergence are available, ranging from the late Middle Pleistocene to the late Early Pleistocene, each based on different interpretations of hominin taxonomy. Genetic data can present an independent estimate of the evolutionary timescale involved, making it possible to distinguish between these competing models of hominin evolution. We analysed five dated Neanderthal mitochondrial genomes, together with those of 54 modern humans, and inferred a genetic chronology using multiple age calibrations. Our mean date estimates are consistent with a process of genetic divergence within an ancestral population, commencing approximately 410-440 ka. These results suggest that a reappraisal of key elements in the Pleistocene hominin fossil record may now be required. © 2010. Source


Nataf D.M.,Australian National University
Publications of the Astronomical Society of Australia | Year: 2016

The stellar population of the Milky Way bulge is thoroughly studied, with a plethora of measurements from virtually the full suite of instruments available to astronomers. It is thus perhaps surprising that alongside well-established results lies some substantial uncertainty in its star-formation history. Cosmological models predict the bulge to host the Galaxy's oldest stars for [Fe/H] ≲ −1, and this is demonstrated by RR Lyrae stars and globular cluster observations. There is consensus that bulge stars with [Fe/H] ≲ 0 are older than t ≈ 10 Gyr. However, at super-solar metallicity, there is a substantial unresolved discrepancy. Data from spectroscopic measurements of the main-sequence turnoff and subgiant branch, the abundances of asymptotic giant branch stars, the period distribution of Mira variables, the chemistry and central-star masses of planetary nebulae, all suggest a substantial intermediate-age population (t ≈ 3 Gyr). This is in conflict with predictions from cosmologically motivated chemical evolution models and photometric studies of the main-sequence turnoff region, which both suggest virtually no stars younger than t ≈ 8 Gyr. A possible resolution to this conflict is enhanced helium-enrichment, as this would shift nearly all of the age estimates in the direction of decreasing discrepancy. Copyright © Astronomical Society of Australia 2016 Source


Nataf D.M.,Australian National University
Publications of the Astronomical Society of Australia | Year: 2016

I review the literature covering the issue of interstellar extinction towards the Milky Way bulge, with emphasis placed on findings from planetary nebulae, RR Lyrae, and red clump stars. I also report on observations from HI gas and globular clusters. I show that there has been substantial progress in this field in recent decades, most particularly from red clump stars. The spatial coverage of extinction maps has increased by a factor ~ 100 × in the past 20 yr, and the total-to-selective extinction ratios reported have shifted by ~ 20–25%, indicative of the improved accuracy and separately, of a steeper-than-standard extinction curve. Problems remain in modelling differential extinction, explaining anomalies involving the planetary nebulae, and understanding the difference between bulge extinction coefficients and ‘standard’ literature values. Copyright © Astronomical Society of Australia 2016 Source


Dracoulis G.D.,Australian National University
Physica Scripta | Year: 2013

Isomers and their roles in discovery and as probes of nuclear structure are discussed, with a focus on neutron-rich nuclei in the mass 180-190 region. Long-lived, high-K isomers are predicted in the heavy hafnium nuclei for example, some of which should be accessible by projectile fragmentation and deep-inelastic reactions. Progress with these reactions in reaching a broad range of isotopes to the right of the stability line is summarized. Recent results for isomers in the iridium and osmium isotopes produced in deep-inelastic reactions and studied with time-correlated γ-ray spectroscopy are presented as examples. These studies venture into the border region where well-deformed prolate shapes give way to soft, transitional nuclei. Prolate, oblate and triaxial structures are predicted, but with shapes that depend sensitively on the multi-particle configurations. Dynamical effects such as rotation alignment also play a significant role and produce isomeric states. In some cases, very low-lying multi-quasiparticle intrinsic states are predicted but these are possibly missed with current approaches. The prospects for the identification and characterization of such exotic isomers using new storage ring techniques, that might also provide a window into exotic states populated in their subsequent decay are outlined, as is the potential for studies with beams of isomers themselves. © 2013 The Royal Swedish Academy of Sciences. Source


Vasilyev V.,Australian National University
Theoretical Chemistry Accounts | Year: 2010

In this paper, we describe how it is possible to extend the visualization and publishing capabilities of the ubiquitous Adobe portable document format (PDF) from the static 2-dimensional (2D) pictures to interactive 3-dimensional (3D) models, 3D-PDF. Embedding 3D scenes of molecules and molecular properties into the electronic Computational Chemistry publications could be very important for visualization of complex molecular properties. No additional 3D-rendering software is required, because the 3D information has been already integrated within the PDF document, which can be displayed by any computer with up-to-date Adobe Acrobat software installed. We briefly describe a computer program, Jamberoo, which can be used for creating 3D-PDF documents and demonstrate several simple examples of integrated 3D models within the PDF. Finally, we show some possibilities of Acrobat JavaScript programming for creating dynamic 3D-PDF content with the elements of the Graphical User Interface (GUI). © Springer-Verlag 2009. Source


Dai C.-Q.,Zhejiang Agriculture And forestry University | Dai C.-Q.,Australian National University | Zhu H.-P.,Lishui University
Journal of the Optical Society of America B: Optical Physics | Year: 2013

The 2 1-dimensional coupled nonlinear Schrödinger equation with distributed coefficients in a graded-index grating waveguide is investigated, and an exact two-breather solution for certain functional relations is obtained. From this solution, the superposed Kuznetsov-Ma (KM) solitons can be constructed. The explicit functions that describe the evolution of the peak, width, center, and phase are found exactly, from which one knows that diffraction and chirp factors play important roles in the evolutional characteristics, such as phase, center and widths, while the gain/loss parameter only affects the evolution of their peaks. Moreover, we can change the propagation type of the superposed KM solitons by adjusting the relation between the maximumeffective propagation distance Zm and the periodic locations Zij based on the maximum amplitude of the superposed KM solitons. The controllability for the type of excitation, such as partial excitation, maintenance, and postponement of the superposed KM solitons, is exhibited. © 2013 Optical Society of America. Source


Das M.P.,Australian National University
Journal of Superconductivity and Novel Magnetism | Year: 2011

The magnetic vortices in superconductors usually repel each other. Several cases are discussed when the vortex interaction has an attractive tail, and thus a minimum, leading to vortex clusters and chains. Decoration pictures then typically look like in the intermediate state of type-I superconductors, showing lamellae or islands of Meissner state or surrounded by Meissner state, but with the normal regions filled with Abrikosov vortices that are typical for type-II superconductors in the mixed state. Such intermediate-mixed state was observed and investigated in detail in pure Nb, TaN and other materials 40 years ago; last year it was possibly also observed in MgB 2, where it was called "a totally new state" and ascribed to the existence of two superconducting electron bands, one of type-I and one of type-II. The complicated electronic structure of MgB 2 and its consequences for superconductivity and vortices are discussed. It is shown that for the real superconductor MgB 2 which possesses a single transition temperature, the assumption of two independent order parameters with separate penetration depths and separate coherence lengths is unphysical. © Springer Science+Business Media, LLC 2010. Source


Frankcombe T.J.,Australian National University
Journal of Physical Chemistry C | Year: 2010

Plane wave density functional theory calculations have been performed to study the potential hydrogen storage material Ca(BH4)2 and the proposed CaB2Hx dehydrogenation intermediate. It is shown that three different published structures of β-Ca(BH 4)2 are essentially identical. Likewise, four proposed structures of β-Ca(BH4)2 are the same. The previously proposed CaB2H2 structure of space group Pnma is both structurally unstable and too high in energy to be a Ca(BH4) 2 dehydrogenation intermediate. A direct computational search failed to find a viable CaB2Hx candidate structure. © 2010 American Chemical Society. Source


Morgan I.G.,Australian National University | Morgan I.G.,Sun Yat Sen University | Ohno-Matsui K.,Tokyo Medical and Dental University | Saw S.-M.,National University of Singapore | Saw S.-M.,Singapore Eye Research Institute
The Lancet | Year: 2012

Myopia has emerged as a major health issue in east Asia, because of its increasingly high prevalence in the past few decades (now 80-90% in school-leavers), and because of the sight-threatening pathologies associated with high myopia, which now affects 10-20% of those completing secondary schooling in this part of the world. Similar, but less marked, changes are occurring in other parts of the world. The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside. There are no reported major genes for school myopia, although there are several genes associated with high myopia. Any genetic contribution to ethnic differences may be small. However, to what extent many genes of small effect and gene-environment interactions contribute to variations in school myopia within populations remains to be established. There are promising optical and pharmacological interventions for preventing the development of myopia or slowing its progression, which require further validation, and promising vision-sparing treatments for pathological myopia. Source


Wood P.J.,Australian National University
Annals of the New York Academy of Sciences | Year: 2011

This paper examines the problem of achieving global cooperation to reduce greenhouse gas emissions. Contributions to this problem are reviewed from noncooperative game theory, cooperative game theory, and implementation theory. We examine the solutions to games where players have a continuous choice about how much to pollute, as well as games where players make decisions about treaty participation. The implications of linking cooperation on climate change with cooperation on other issues, such as trade, are also examined. Cooperative and noncooperative approaches to coalition formation are investigated in order to examine the behavior of coalitions cooperating on climate change. One way to achieve cooperation is to design a game, known as a mechanism, whose equilibrium corresponds to an optimal outcome. This paper examines some mechanisms that are based on conditional commitments, and their policy implications. These mechanisms could make cooperation on climate change mitigation more likely. © 2011 New York Academy of Sciences. Source


Stern D.I.,Australian National University
Annals of the New York Academy of Sciences | Year: 2011

This paper reviews the mainstream, resource economics, and ecological economics models of growth. A possible synthesis of energy-based and mainstream models is presented. This shows that when energy is scarce it imposes a strong constraint on the growth of the economy; however, when energy is abundant, its effect on economic growth is much reduced. The industrial revolution released the constraints on economic growth by the development of new methods of using coal and the discovery of new fossil fuel resources. Time-series analysis shows that energy and GDP cointegrate, and energy use Granger causes GDP when capital and other production inputs are included in the vector autoregression model. However, various mechanisms can weaken the links between energy and growth. Energy used per unit of economic output has declined in developed and some developing countries, owing to both technological change and a shift from poorer quality fuels, such as coal, to the use of higher quality fuels, especially electricity. Substitution of other inputs for energy and sectoral shifts in economic activity play smaller roles. © 2011 New York Academy of Sciences. Source


Simenel C.,Australian National University | Simenel C.,CEA Saclay Nuclear Research Center
Physical Review Letters | Year: 2011

The Balian-Vénéroni (BV) variational principle, which optimizes the evolution of the state according to the relevant observable, is used at the mean-field level to determine the particle-number fluctuations in fragments of many-body systems. For fermions, the numerical evaluation of such fluctuations requires the use of a time-dependent Hartree-Fock (TDHF) code. Proton, neutron, and total nucleon number fluctuations in fragments produced in collisions of two Ca40 are computed well above the fusion barrier. For deep-inelastic collisions, the fluctuations calculated from the BV variational principle are much larger than standard TDHF results, and closer to experimental fluctuations. Correlations between proton and neutron numbers are determined. These correlations are shown to be larger with exotic systems where charge equilibration occurs. © 2011 American Physical Society. Source


Da Costa G.S.,Australian National University
Astrophysical Journal | Year: 2012

The multi-object fiber-fed spectrograph AAOmega at the Anglo-Australian Telescope has been used to establish and measure accurate (≤1kms -1) radial velocities for a new sample of members in the outer parts of the stellar system ω Centauri. The new sample more than doubles the number of known members with precise velocities that lie between 25′ and 45′ from the cluster center. Combining this sample with earlier work confirms that the line-of-sight velocity dispersion of ω Cen remains approximately constant at 6.5kms-1 in the outer parts of the cluster, which contain only a small fraction of the total cluster stellar mass. It is argued that the approximately constant velocity dispersion in the outer regions is most likely a consequence of external influences, such as the tidal shock heating that occurs each time ω Cen crosses the Galactic plane. There is therefore no requirement to invoke dark matter or non-standard gravitational theories. © 2012. The American Astronomical Society. All rights reserved.. Source


Alibert C.,Australian National University
Geochimica et Cosmochimica Acta | Year: 2016

Minerals from the Hamersley banded iron formation, Western Australia, were analyzed for Y and rare earth elements (YREEs) by laser ablation ICP-MS to investigate diagenetic pathways, from precursor phases to BIF minerals. One group of apatites carries the seawater REE signature, giving evidence that P and REEs, thoroughly scavenged from the water column by Si-ferrihydrite particles, were released upon microbial Fe3+ reductive dissolution of Si-ferrihydrite in pore-water and finally sequestered mainly in authigenic apatite. The absence of fractionation between apatite and seawater suggests that REE were first incorporated into an amorphous calcium phosphate as fully hydrated cations, i.e. as outer-sphere complexes. The iron oxides and carbonates carry only a small fraction of the whole-rock REE budget. Their REE patterns are distinctly enriched in Yb and show some M-type tetrad effect consistent with experimental K d(REE) between solid and saline solution with low carbonate ion concentrations. It is deduced that hematite formed at an incipient stage of Fe2+-catalyzed dissolution of Si-ferrihydrite, via a dissolution-reprecipitation pathway. The REE pattern of greenalite, found as sub-micron particles in quartz in a chert-siderite sample, is consistent with its authigenic origin by precipitation in pore-water after dissolution of a small amount of Si-ferrihydrite. Magnetite carries very low YREEs (ppb-level), has an homogeneous pattern distinctly enriched in the mid-REEs compared to hematite, and includes a late population depleted in light-REEs, Ba and As. Magnetite forming aggregates and massive laminae is tentatively interpreted as reflecting some fluid-aided hematite-magnetite re-equilibration or transformation at low-grade metamorphic temperatures. © 2016 Elsevier Ltd. Source


Pearce J.G.,Australian National University
Optometry and Vision Science | Year: 2016

PURPOSE: To investigate the level of test-retest variability in the Medmont M700 automated perimeter. We compare the retest variability of the outer 20° test points of one test method to test points in the inner 10° of two test methods to determine whether test points from different tests and regions exhibit different retest variability. We also generate some clinically applicable coefficient of repeatability (CoR) values for M700 Overall Defect (OD) and Pattern Defect (PD) indices. METHODS: Twenty-four glaucoma patients with varying degrees of field loss were enrolled, and 21 patients (40 eyes) had usable results. The Central (30°) test and the Macula (10°) test were performed on each eye on the same day. To determine retest variability, the tests were repeated 1 week later at the same time of day. RESULTS: Test points from 5 to 20 dB in the outer 20° of the 30° test showed lower retest variance than points of equal decibel value in the central 10° of the same test. For the 30° test, the OD CoR was 2.4 dB. The PD retest CoR varied with glaucoma severity, ranging from 1.24 dB for PD less than or equal to 2.8 to 3.1 dB for PD more than 5.7. The 10° test CoR for OD was 2.1 dB, and PD retest CoR ranged from 1.58 for PD less than or equal to 2.8 to 2.4 for PD more than 5.7. CONCLUSIONS: In glaucoma patients, retest variance for some decibel values does not seem to increase with increasing eccentricity in the M700. The OD values as graded by the M700 do not appear to correspond well with the amount of visual field loss and are not directly comparable to mean deviation results reported by other perimeters. Pattern defect values in the M700 seem to correlate well with the degree of field loss. © 2016 American Academy of Optometry Source


Baxter R.J.,Australian National University
Journal of Physics A: Mathematical and Theoretical | Year: 2010

For the Ising model, the calculation of the spontaneous magnetization leads to the problem of evaluating a determinant. Yang did this by calculating the eigenvalues in the large-lattice limit. Montroll, Potts and Ward expressed it as a Toeplitz determinant and used Szeg's theorem: this is almost certainly the route originally travelled by Onsager. For the corresponding problem in the superintegrable chiral Potts model, neither approach appears to work: here we show that the determinant DPQ can be expressed as that of a product of two Cauchy-like matrices. One can then use the elementary exact formula for the Cauchy determinant. One of course regains the known result, originally conjectured in 1989. © 2010 IOP Publishing Ltd. Source


Von Caemmerer S.,Australian National University
Plant, Cell and Environment | Year: 2013

In the challenge to increase photosynthetic rate per leaf area mathematical models of photosynthesis can be used to help interpret gas exchange measurements made under different environmental conditions and predict underlying photosynthetic biochemistry. To do this successfully it is important to improve the modelling of temperature dependencies of CO2 assimilation and gain better understanding of internal CO2 diffusion limitations. Despite these shortcomings steady-state models of photosynthesis provide simple easy to use tools for thought experiments to explore photosynthetic pathway changes such as redirecting photorespiratory CO2, inserting bicarbonate pumps into C3 chloroplasts or inserting C4 photosynthesis into rice. Here a number of models derived from the C3 model by Farquhar, von Caemmerer and Berry are discussed and compared. In the challenge to increase photosynthetic rate per leaf area steady state models of photosynthesis provide not only tools for gas exchange analysis but also for thought experiments that can explore photosynthetic pathway changes. These include redirecting photorespiratory CO2, inserting bicarbonate pumps into C3 chloroplasts or inserting C4 photosynthesis into rice. Here a number of models derived from the C3 model by Farquhar, von Caemmerer and Berry are discussed and compared. © 2013 John Wiley & Sons Ltd. Source


Hardham A.R.,Australian National University
Plant Journal | Year: 2013

Plant microtubules undergo extensive reorganization in response to symbiotic and pathogenic organisms. During the development of successful symbioses with rhizobia and mycorrhizal fungi, novel microtubule arrays facilitate the progression of infection threads and hyphae, respectively, from the plant surface through epidermal and cortical cells. During viral and nematode infections, plant microtubules appear to be commandeered by the pathogen. Viruses use plant microtubules for intra and intercellular movement, as well as for interhost transmission. Nematodes manipulate spindle and phragmoplast microtubules to enhance mitosis and partial cytokinesis during the development of syncytia and giant cells. Pathogenic bacteria, fungi and oomycetes induce a range of alterations to microtubule arrays and dynamics. In many situations, the pathogen, or the elicitor or effector proteins derived from them, induce depolymerization of plant cortical microtubule arrays. In some cases, microtubule disruption is associated with the plant defence response and resistance. In other cases, microtubule depolymerization increases plant susceptibility to the invading pathogen. The reasons for this apparent inconsistency may depend on a number of factors, in particular on the identity of the organism orchestrating the microtubule changes. Overall, the weight of evidence indicates that microtubules play an important role in both the establishment of functional symbioses and in defence against invading pathogens. Research is beginning to unravel details about the nature of both the chemical and the mechanical signals to which the plant microtubule arrays respond during biotic interactions. © 2013 The Author The Plant Journal © 2013 John Wiley & Sons Ltd. Source


Cernusak L.A.,Australian National University | Kahmen A.,ETH Zurich
Plant, Cell and Environment | Year: 2013

This article comments on: Transpiration rate relates to within- and across-species variations in effective path length in a leaf water model of oxygen isotope enrichment © 2013 John Wiley & Sons Ltd. Source


Delghingaro-Augusto V.,Australian National University
Nature Genetics | Year: 2016

Type 1 (T1D) and type 2 (T2D) diabetes share pathophysiological characteristics, yet mechanistic links have remained elusive. T1D results from autoimmune destruction of pancreatic beta cells, whereas beta cell failure in T2D is delayed and progressive. Here we find a new genetic component of diabetes susceptibility in T1D non-obese diabetic (NOD) mice, identifying immune-independent beta cell fragility. Genetic variation in Xrcc4 and Glis3 alters the response of NOD beta cells to unfolded protein stress, enhancing the apoptotic and senescent fates. The same transcriptional relationships were observed in human islets, demonstrating the role of beta cell fragility in genetic predisposition to diabetes. © 2016 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. Source


Parsons D.F.,Australian National University
Journal of Colloid and Interface Science | Year: 2014

A new theoretical framework is now available to help explain ion specific (Hofmeister) effects. All measurements in physical chemistry show ion specificity, inexplicable by classical electrostatic theories. These ignore ionic dispersion forces that change ionic adsorption.We explored ion specificity in supercapacitors using a modified Poisson-Boltzmann approach that includes ionic dispersion energies. We have applied ab initio quantum chemical methods to determine required ion sizes and ion polarisabilities. Our model represents graphite electrodes through their optical dielectric spectra. The electrolyte was 1.2. M Li salt in propylene carbonate, using the common battery anions, PF6-,BF4- and ClO4- We also investigated the perhalate series with BrO4- and IO4. The capacitance C = dσ / dψ was calculated from the predicted electrode surface charge σ of each electrode with potential ψ between electrodes. Compared to the purely electrostatic calculation, the capacitance of a positively charged graphite electrode was enhanced by more than 15%, with PF6- showing > 50 % increase in capacitance. IO4- provided minimal enhancement. The enhancement is due to adsorption of both anions and cations, driven by ionic dispersion forces. The Hofmeister series in the single-electrode capacitance was PF6->BF4->ClO4->BrO4->IO4- When the graphite electrode was negatively charged, the perhalates provided almost no enhancement of capacitance, while PF6- and BF4- decreased capacitance by about 15%.Due to the asymmetric impact of nonelectrostatic ion interactions, the capacitances of positive and negative electrodes are not equal. The capacitance of a supercapacitor should therefore be reported as two values rather than one, similar to the matrix of mutual capacitances used in multielectrode devices. © 2014 Elsevier Inc. Source


Braithwaite J.,Australian National University
Australian and New Zealand Journal of Criminology | Year: 2012

This research is about the insight that some of the same dynamics may cause war and crime. Because this is not well understood, national peace agreements sometimes fail to resolve root causes; violent death is sometimes higher after the peace than during the war. The second ambition is a macrosociological imagination that opens a new way of seeing global patterns of crime-war. A third explores what to do about it. Five starting hypotheses toward a theory of crime-war are advanced:Violence cascades whenThose displaced by violence displace others from spaces to which refugees flee.Refugee camps become recruiting centres for those who cause violence to cascade.Hot spots destabilized by successive waves of violence become anomic Hobbesian vacuums that attract violent tyrannies.Violent crime is highly concentrated at hot spots; twenty-first century warfare is concentrated at local hot spots.Peace is accomplished hot spot by hot spot more than nation by nation. Political settlements and a politics of reconciliation are needed to resolve contemporary violence that are less national, more oriented to a local politics of place.One control policy is a responsive enforcement pyramid that gives violent groups in control of hot spots an opportunity to negotiate a truce at the base of the pyramid. When they do, reintegration of perpetrators and shaming of their crimes can occur. When the opportunity to renounce violence is spurned, firm resolve to escalate to arrest backed by military capability in the case of armed resistance to arrest is necessary. Where this resolve is absent, violent hot spots proliferate.Negotiations that persuade violent groups to relinquish control of local hot spots of criminal opportunity under threat of prosecution will prevent violence more permanently when accompanied by reconciliation that is followed by reintegration into legitimate opportunity structures. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source


Huang J.,Australian National University
Artificial Intelligence | Year: 2010

The past decade has seen clause learning as the most successful algorithm for SAT instances arising from real-world applications. This practical success is accompanied by theoretical results showing clause learning as equivalent in power to resolution. There exist, however, problems that are intractable for resolution, for which clause-learning solvers are hence doomed. In this paper, we present extended clause learning, a practical SAT algorithm that surpasses resolution in power. Indeed, we prove that it is equivalent in power to extended resolution, a proof system strictly more powerful than resolution. Empirical results based on an initial implementation suggest that the additional theoretical power can indeed translate into substantial practical gains. © 2010 Elsevier B.V. All rights reserved. Source


Dornan M.,Australian National University
Renewable and Sustainable Energy Reviews | Year: 2014

Energy poverty is widespread in Small Island Developing States (SIDS) of the Pacific. It is estimated that 70 percent of Pacific Islander households do not have access to electricity, which is equivalent to access rates in sub-Saharan Africa and slightly below the average for low income countries. Pacific SIDS face unique challenges in expanding access to electricity, given that their populations are spread across tens of thousands of islands. Governments and development partners in Pacific SIDS continue to prioritise development of electricity grids, as is evident in ongoing subsidisation of grid-based power consumption and the establishment of ambitious (grid-based) renewable energy targets. This paper argues that traditional approaches to rural electrification which prioritise grid extension are not suited to the Pacific islands region. Increased funding should be directed by both governments and development partners towards rural electrification, especially in off-grid areas where isolated systems are more appropriate. Institutional reform is also important. Regulatory reform is needed for power utilities to extend electricity grids into rural areas. Institutional arrangements that facilitate the sustainable operation and maintenance of off-grid systems also need to be established. Past donor and government-funded off-grid rural electrification projects have rarely been sustainable. Alternative approaches involving payment of output-based subsidies to energy service companies are worth exploring, although will only succeed where sound regulatory arrangements are in place. © 2014 Elsevier Ltd. Source


Connell D.,Australian National University
Water Resources Management | Year: 2011

Australia's Murray-Darling Basin (MDB) is now well advanced on a major program of water reform to reduce threats to resource security, halt the ongoing decline in environmental conditions and improve the capacity to deal with climate change. Management of the MDB has been a focus for conflict between the Australian governments since federation in 1901. Within the region water is still managed with a high degree of autonomy by state governments but through implementation of the Water Act 2007 the Commonwealth (national) government is now asserting a basin-wide coordinating role for the first time. This paper places water management in the MDB within the larger context of the history of the evolution of the federal system in Australia and highlights a number of factors inherent in such systems that make it difficult to strengthen integration. It also suggests that the Commonwealth Environmental Water Holder, created by the Water Act, is emerging as a powerful new institutional force in the MDB even though this was not an intended consequence when the Act was designed. © 2011 Springer Science+Business Media B.V. Source


Fishwick S.,University of Leicester | Rawlinson N.,Australian National University
Australian Journal of Earth Sciences | Year: 2012

During the last 20 years, seismic tomography has frequently been used to provide information on the structure of the lithosphere beneath the Australian continent. New tomographic models are presented using two complementary seismological techniques in order to illustrate the current state-of-knowledge. Surface wave tomography is the ideal method to obtain information of velocity variations across the whole continent. The latest models use data from over 13 000 source-receiver paths, allowing a higher resolution than in previous studies using the same technique. In Western Australia the results at 100 km depth clearly reveal the contrast in structure between the Pilbara and Yilgarn Cratons and the Capricorn Orogen. At greater depths, the Kimberley Block has a distinct fast velocity anomaly in comparison with the surrounding mobile belts. In the east of the continent, strong horizontal gradients in velocity indicate transitions in lithospheric structure, although the new high resolution models reveal a complexity in the transitions through central Victoria and New South Wales. Complementing the surface wave tomography, we also present the results from the inversion of over 25 000 relative arrival times from body wave phases recorded in southeast Australia and Tasmania. The body wave tomography uses the surface wave model to provide information on long-wavelength structure and absolute velocities that would otherwise be lost. The new results indicate a distinct boundary between the Delamerian and Lachlan orogens within the upper mantle, the location of which is consistent with an east-dipping Moyston Fault, as observed by deep seismic reflection profiling. The new models also confirm a distinct region of fast velocities beneath the central sub province of the Lachlan Orogen. A significant new observation is that the inferred eastern edge of this central sub-province has a strong correlation with the location of copper/gold deposits; a similar relationship is observed at a larger scale in Western Australia where mineral deposits appear to flank the regions of fastest velocity within the West Australian Craton. © 2012 Copyright Taylor and Francis Group, LLC. Source


Iaffaldano G.,Australian National University
Earth and Planetary Science Letters | Year: 2012

Friction controls most of the strength of tectonic plate boundaries, and thus the force mutually exchanged between plates. Estimates of the plate-boundary friction-coefficient are therefore of paramount importance to our understanding of the lithosphere torque balance. However, several lines of evidence indicate that the friction-coefficient of plate margins is significantly lower than is measured in laboratory experiments on fractured rocks. This poses a significant limit to extrapolation from the laboratory scale to the large-scale of Earth's lithosphere. The record of past and present-day plate motions represents an efficient probe into the torque balance of plate tectonics, because plate-motions readjust virtually instantaneously to temporal changes in driving and resisting forces. Here I derive inferences on the strength of large-scale plate boundaries by focusing on the convergence of the fast-moving Philippine Sea plate towards Eurasia, since subduction initiation ~5. Myr ago. Because at the present-day the Philippine slab reaches depths shallower than the 410-km transition zone in the upper mantle, its weight is unlikely to provide sufficient driving force to shear the trailing plate over the viscous mantle at the observed rates. Using global models of the coupled mantle/lithosphere system, I argue that frictional coupling with the Pacific and Eurasia plates is the main driver for the dynamics of the Philippine Sea plate. This allows me to infer that the friction-coefficient of large-scale plate boundaries is in range 0.01-0.07, and that the amount of sediments entering plate margins efficiently modulates the friction-coefficient, contributing significantly to its lateral variations. Importantly, I corroborate my conclusions by looking at the present-day vertical deformation of the Philippine Sea/Eurasia margin, evident from observed trench-parallel gravity anomalies. © 2012 Elsevier B.V. Source


Bissell D.,Australian National University
Environment and Planning A | Year: 2011

Stillness occupies an ambivalent position in a world of flows. Opening up space required for reflective, contemplative thought, stillness is often posited as a vital supplement to movement. Yet, in spite of its reverence as a cornerstone of moral responsibility and a key technic of modernity, reflective thought is now taken to be just one modality of thinking amongst many others that compose the body. This paper explores what happens to the capacities of reflective thought when gathered into a vitalist diagram of the body. It does this by tracing how different forms of stillness participate in the constitution of differently susceptible bodies. It considers how habit works to both hold still and move the body in different ways which helps to disrupt an understanding of a body that has a particular capacity for wilful, reflective sovereign thought. As such, and parallel to suggestions that we currently inhabit an era of thought maximisation, this paper argues that reflective thought itself might be better understood as enrolled into a particular diagram of habit that allows us to consider how reflection and contemplation might function not as a redemptive force of liberation from habit, but as the turbulent reverberations of the shock of the outside that can become debilitating. © 2011 Pion Ltd and its Licensors. Source


Burden C.J.,Australian National University
Statistical applications in genetics and molecular biology | Year: 2012

The D(2) statistic, defined as the number of matches of words of some pre-specified length k, is a computationally fast alignment-free measure of biological sequence similarity. However there is some debate about its suitability for this purpose as the variability in D(2) may be dominated by the terms that reflect the noise in each of the single sequences only. We examine the extent of the problem and the effectiveness of overcoming it by using two mean-centred variants of this statistic, D(2)* and D(2c). We conclude that all three statistics are potentially useful measures of sequence similarity, for which reasonably accurate p-values can be estimated under a null hypothesis of sequences composed of identically and independently distributed letters. We show that D(2) and D(2)c, and to a somewhat lesser extent D(2)*, perform well in tests to classify moderate length query sequences as putative cis-regulatory modules. Source


Tacconi L.,Australian National University
Environmental Conservation | Year: 2011

Environmental problems are often complex and it is widely recognized that they cannot be satisfactorily addressed by single disciplines. The review of forest cover change studies points to the need to carry out research integrating economic, political, social and environmental aspects. Existing interdisciplinary study areas, namely ecological economics, political ecology, sustainability science and Earth system governance do not yet fully integrate all the required aspects. This paper points out that the establishment of greater synergies between those study areas would be beneficial in developing the broader study area of environmental governance. A definition of environmental governance as a subject of study is developed. Lack of an all encompassing theory of environmental governance is highlighted, while the improbability of such a theory is acknowledged. In relation to normative work, the refinement of principles of good environmental governance could support the design and prioritization of policies. Empirical research needs to include the testing of hypotheses arising from theoretical developments, assessment of policy uptake and new exploratory research. Methodologically, environmental governance might start from an interdisciplinary approach followed by further integration leading to a transdisciplinary study area that uses a mixed methods research approach. © Copyright Foundation for Environmental Conservation 2011. Source


Filer C.,Australian National University
Environmental Conservation | Year: 2011

Papua New Guinea (PNG) has been the site of a great deal of scientific work, and a fair amount of interdisciplinary debate, within the broad field of historical ecology, which encompasses the study of indigenous society-environment relationships over different time periods. However, this in itself provides no guarantee that scientists engaged in such debate will have a greater influence on the formulation of environmental conservation policies in a state where indigenous decision makers now hold the levers of political power. Five environmental policy paradigms which have emerged in the course of public debate about environmental conservation in PNG over the past half century; the wildlife management, environmental planning, biodiversity conservation, ecosystem assessment, and carbon sequestration paradigms. Each paradigm has framed a distinctive form of interdisciplinary debate about indigenous society-environment relationships within a contemporary political framework. However, a further connection can be drawn between the role of interdisciplinary debate in an evolving national policy framework and the history of scientific debate about the nature of indigenous society-environment relationships in the pre-colonial era. This connection places a distinctive emphasis on the relationship between indigenous agricultural practices and management of the national forest estate for reasons which are themselves a contingent effect of the nature of European colonial intervention over the course of the last century and a half. This particular bias in the relationship between historical ecology and environmental policy has lasted down to the present day. PNG's environmental policy problems are unlikely to have any rational or sensible solution in the absence of a better scientific understanding of the complexity of indigenous society-environment relationships. Scientists need to understand the complexity of the environmental policy process as a historical process in its own right in order to work out which policy problems offer both the scope and the incentive to sustain specific forms of interdisciplinary debate that are likely to produce better policy outcomes. © Copyright Foundation for Environmental Conservation 2011. Source


Kheifets A.S.,Australian National University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We use the nonrelativistic random-phase approximation with exchange to perform calculations of valence-shell photoionization of Ne, Ar, Kr, and Xe from their respective thresholds to photon energy of 200 eV. The energy derivative of the complex phase of the photoionization matrix elements is converted to the photoelectron group delay that can be measured in attosecond streaking or two-photon sideband interference experiments. Comparison with reported time-delay measurements in Ne and Ar at a few selected photon energies is made. Systematic mapping of time delay across a wide range of photon energies in several atomic targets allows to highlight important aspects of fundamental atomic physics that can be probed by attosecond-time-delay measurements. © 2013 American Physical Society. Source


Bauer A.,Australian National University | Leucker M.,TU Munich | Schallhart C.,TU Darmstadt
ACM Transactions on Software Engineering and Methodology | Year: 2011

This article studies runtime verification of properties expressed either in lineartime temporal logic (LTL) or timed lineartime temporal logic (TLTL). It classifies runtime verification in identifying its distinguishing features to model checking and testing, respectively. It introduces a three-valued semantics (with truth values true, false, inconclusive) as an adequate interpretation as to whether a partial observation of a running system meets an LTL or TLTL property. For LTL, a conceptually simple monitor generation procedure is given, which is optimal in two respects: First, the size of the generated deterministic monitor is minimal, and, second, the monitor identifies a continuously monitored trace as either satisfying or falsifying a property as early as possible. The feasibility of the developed methodology is demontrated using a collection of real-world temporal logic specifications. Moreover, the presented approach is related to the properties monitorable in general and is compared to existing concepts in the literature. It is shown that the set of monitorable properties does not only encompass the safety and cosafety properties but is strictly larger. For TLTL, the same road map is followed by first defining a three-valued semantics. The corresponding construction of a timed monitor is more involved, yet, as shown, possible. © 2011 ACM. Source


Brinker J.K.,Australian National University
European Journal of Ageing | Year: 2013

Reminiscence is proposed as an important activity for well-being in late life but recent reviews highlight the differential outcomes of this behavior. If older adults engage in reminiscing as a natural process, but do so with a ruminative style of thinking, it may actually be detrimental to successful development and well-being. This project explored the relationship between rumination, reminiscence, mood, and psychosocial development. One hundred and fifty community dwelling older adults completed measures assessing these variables. As expected, increased rumination was related to increased depressed mood. Fifty-four of the participants completed a follow-up measure of depressed mood. Rumination also accounted for follow-up depressed mood beyond that explained by time-1 mood. The interaction between rumination and reminiscing significantly predicted future depressed mood after controlling for main effects and baseline mood. Further, this interaction significantly predicted overall psychosocial development. Implications for clinical practice are discussed. © 2013 Springer-Verlag Berlin Heidelberg. Source


Endex thermoreactive processes, in which an exothermic reaction is coupled thermokinetically to an endothermic reaction, in principle are more efficient than conventional processes. The purpose of this research is to quantify rigorously and in detail the thermodynamic efficiency advantage of an Endex calcium looping process for CO2 capture from flue gas streams, relative to a comparable conventional process, by entropy generation analysis. The theoretical background of second law analysis is reviewed, control volumes are defined and modelled, and the entropy generation rates are computed of all identified subprocesses. The Endex process is found to have superior relative second law efficiency by a factor of approximately 1.8, achieved mainly by a large reduction in the entropy penalty of regeneration at the expense of a modest increase in the entropy penalty of separation. The subprocesses most worthy (and unworthy) of optimization are identified. Results indicate that the Endex process is a promising candidate for thermal engineering optimization, because entropy generation is distributed relatively evenly across many subprocesses rather than concentrated in one or two. © 2014 Elsevier Ltd. All rights reserved. Source


Cuevas A.,Australian National University
Progress in Photovoltaics: Research and Applications | Year: 2014

When the metal contact of a silicon solar cell is restricted to a fraction of the rear surface, the flow of electrons and holes towards that contact is constricted, which is beneficial for minority charge carriers but detrimental for majority carriers. It is possible to describe their 2D/3D transport and determine their concentration in the vertical and transversal dimensions of the solar cell by separately studying the central region near the contact and the peripheral region surrounding it. A virtue of such geometric approach is that it establishes a link between analytical models and computer simulations, providing both physical insight and sufficient accuracy to optimise partial rear contact devices. In this paper, we extend a previous version of the geometric model to solar cells having a full-area, locally contacted dopant diffusion on the rear surface. The case for n-type versus p-type wafers is considered, point contacts are compared with line contacts, including the impact of the metal/semiconductor resistance and bulk recombination is evaluated. Copyright © 2013 John Wiley & Sons, Ltd. Source


Cazzonelli C.I.,Australian National University
Functional Plant Biology | Year: 2011

Carotenoids are natural isoprenoid pigments that provide leaves, fruits, vegetables and flowers with distinctive yellow, orange and some reddish colours as well as several aromas in plants. Their bright colours serve as attractants for pollination and seed dispersal. Carotenoids comprise a large family of C40 polyenes and are synthesised by all photosynthetic organisms, aphids, some bacteria and fungi alike. In animals carotenoid derivatives promote health, improve sexual behaviour and are essential for reproduction. As such, carotenoids are commercially important in agriculture, food, health and the cosmetic industries. In plants, carotenoids are essential components required for photosynthesis, photoprotection and the production of carotenoid-derived phytohormones, including ABA and strigolactone. The carotenoid biosynthetic pathway has been extensively studied in a range of organisms providing an almost complete pathway for carotenogenesis. A new wave in carotenoid biology has revealed implications for epigenetic and metabolic feedback control of carotenogenesis. Developmental and environmental signals can regulate carotenoid gene expression thereby affecting carotenoid accumulation. This review highlights mechanisms controlling (1) the first committed step in phytoene biosynthesis, (2) flux through the branch to synthesis of α- and β-carotenes and (3) metabolic feedback signalling within and between the carotenoid, MEP and ABA pathways. © 2011 CSIRO. Source


Nisbet D.R.,Australian National University
Biointerphases | Year: 2012

The fabrication of tissue engineering scaffolds is a well-established field that has gained recent prominence for the in vivo repair of a variety of tissue types. Recently, increasing levels of sophistication have been engineered into adjuvant scaffolds facilitating the concomitant presentation of a variety of stimuli (both physical and biochemical) to create a range of favourable cellular microenvironments. It is here that self-assembling peptide scaffolds have shown considerable promise as functional biomaterials, as they are not only formed from peptides that are physiologically relevant, but through molecular recognition can offer synergy between the presentation of biochemical and physio-chemical cues. This is achieved through the utilisation of a unique, highly ordered, nano- to microscale 3-D morphology to deliver mechanical and topographical properties to improve, augment or replace physiological function. Here, we will review the structures and forces underpinning the formation of self-assembling scaffolds, and their application in vivo for a variety of tissue types. Source


Vos M.,Australian National University
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2010

The measurement of the energy loss spectra of energetic electrons scattered from Xe over large angles is reported. The incoming energy was chosen between 600 eV and 1550 eV. The calculated Xe elastic scattering cross section has a sharp minimum for 750 eV electrons near 135°. This minimum is confirmed by studying a Xe-H2 mixture and separating their elastic peak based on the recoil effect. The energy loss part of the Xe spectra is rich in structure. Surprisingly the shape and intensity (relative to the elastic peak) changes dramatically if one approaches the scattering conditions for which the elastic cross section has a minimum. These observations are rationalized by describing the inelastic intensity semi-classically, as a consequence of a two-step process occurring at the same atom involving scattering from the nucleus and an electronic excitation. The change in shape of the loss spectra is attributed to a large increase in relative intensity of the dipole-forbidden transitions near sharp minima in the elastic cross section. © 2010 IOP Publishing Ltd. Source


Howard J.,Australian National University
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2010

This paper presents an overview of developments in imaging spectro-polarimetry for magnetic fusion diagnostics. Using various multiplexing strategies, it is possible to construct optical polarization interferometers that deliver images of underlying physical parameters such as flow speed, temperature (Doppler effect) or magnetic pitch angle (motional Stark and Zeeman effects). This paper also describes and presents first results for a new spatial heterodyne interferometric system used for both Doppler and polarization spectroscopy. © 2010 IOP Publishing Ltd. Source


Ajani J.,Australian National University
Environmental Conservation | Year: 2011

Global wood consumption trends are reviewed in the context of framing a coherent forest policy in the era of climate change. Over the period 1980 to 2007, global wood consumption has been essentially stagnant, increasing by only 0.4% per year. In contrast over the same period, global consumption of wood products increased steadily, paper by an average 3.2% per annum and solid wood products (sawn timber and wood panels) by 0.8% per annum. Wood saving explains these significantly different growth trajectories in unprocessed wood and processed wood products. Wood saving strategies include recycling paper (in particular), investing in higher yielding pulp technologies, substituting reconstituted wood panels for sawn timber and plywood and growing high pulp-yielding trees in a plantation regime. China's rapidly growing wood products industry has lifted wood saving to a new high. Consistent with the theory of induced innovation, China has so far avoided triggering a global wood shortage and associated wood price increases through a progression of strategies: successful pre-emptive price negotiations, increased use of recycled paper, adoption of high-yielding pulp technologies, substitution of reconstituted wood panels for sawn timber and tree planting substituting for natural forest supply. If China's current wood saving strategies were emulated worldwide, through increased use of recycled paper in particular, and to a lesser extent, substitution of reconstituted wood panels for sawn timber and plywood, the already low growth in global wood consumption would flatten further and perhaps start to decline. These economic realities in the wood products industry align positively with the interlinked imperatives of biodiversity conservation and carbon storage in natural forests, if wood-saving is converted to forest-saving. Copyright © 2011 Foundation for Environmental Conservation. Source


Chung E.,University of Toronto | Sen J.,Australian National University
Reviews in Medical Virology | Year: 2012

HSV is among the most common human pathogens in the world. It is known to cause painful, persistent skin lesions, while also being the most common cause of fatal non-epidemic encephalitis as well as the leading cause of corneal blindness. The development of prophylactic vaccines could substantially reduce global health problems associated with HSV. So far, HSV vaccine strategies have shown noticeable efficacy in early development during preclinical phases but remained unsuccessful or unproven in human trials. New understanding of how the immune system mounts a defence against HSV offers practical strategies for vaccine development. A number of promising vaccine candidates are currently awaiting clinical development or already undergoing clinical testing. Therefore, this is a suitable time to assess the progress of HSV vaccine development and consider existing challenges and future improvements needed to achieve an effective prophylactic HSV vaccine. Copyright © 2012 John Wiley & Sons, Ltd. © 2012 John Wiley & Sons, Ltd. Source


Dick K.A.,Lund University | Caroff P.,Australian National University
Nanoscale | Year: 2014

Semiconductor nanowires composed of III-V materials have enormous potential to add new functionality to electronics and optical applications. However, integration of these promising structures into applications is severely limited by the current near-universal reliance on gold nanoparticles as seeds for nanowire fabrication. Although highly controlled fabrication is achieved, this metal is entirely incompatible with the Si-based electronics industry. In this Feature we review the progress towards developing gold-free bottom-up synthesis techniques for III-V semiconductor nanowires. Three main categories of nanowire synthesis are discussed: selective-area epitaxy, self-seeding and foreign metal seeding, with main focus on the metal-seeded techniques. For comparison, we also review the development of foreign metal seeded synthesis of silicon and germanium nanowires. Finally, directions for future development and anticipated important trends are discussed. We anticipate significant development in the use of foreign metal seeding in particular. In addition, we speculate that multiple different techniques must be developed in order to replace gold and to provide a variety of nanowire structures and properties suited to a diverse range of applications. This journal is © The Royal Society of Chemistry. Source


Linterman M.A.,Cambridge Institute for Medical Research | Vinuesa C.G.,Australian National University
Seminars in Immunopathology | Year: 2010

Follicular helper T cells have recently emerged as a separate CD4 + T helper lineage specialised in provision of help to B cells. They develop independently from Th1, Th2 and Th17 cells and are critical for humoral immunity, including the generation of long-lived and high affinity plasma cells and memory cells crucial for long-term protection against infections. A stepwise differentiation programme has emerged in which T cell receptor (TCR) signalling strength, CD28-mediated costimulation, B cell-derived inducible costimulator ligand signals, induction of c-maf and actions of cytokines, including interleukin (IL)-6 and IL-21, lead to upregulation of the transcriptional repressor B cell lymphoma 6 (Bcl-6) that drives T follicular helper (Tfh) cell differentiation. Bcl-6 turns on a repression programme that targets Blimp-1, transcriptional regulators of other helper lineages and microRNAs. Their concerted actions modulate expression of chemokine receptors, surface molecules and cytokines critical for follicular homing and B cell helper functions. Here, we review the nature of Tfh cells providing help to B cells during the two phases of B cell activation that occur in the outer T zone and, for some B cells, in germinal centres (GC). Recent insights into the signalling events that drive terminal differentiation of Tfh cells critical for selecting somatically mutated GC B cells and the consequences of Tfh dysregulation for immunodeficiency and autoimmune pathology are discussed. © 2010 Springer-Verlag. Source


Orlov A.A.,Saint Petersburg State University of Information Technologies, Mechanics and Optics | Voroshilov P.M.,Saint Petersburg State University of Information Technologies, Mechanics and Optics | Belov P.A.,Queen Mary, University of London | Kivshar Y.S.,Australian National University
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

We analyze dispersion properties of layered metal-dielectric structures, which can be considered as a simple example of nanostructured metamaterials. We demonstrate that, in sharp contrast to the results of the theory of effective media, the layered structure demonstrates strong optical nonlocality due to excitation of surface plasmon polaritons. Such nonlocality can be engineered by changing a ratio between the thicknesses of metal and dielectric layers. Importantly, the nonlocality leads to the existence of an additional extraordinary wave that manifests itself in the splitting of the transverse-magnetic polarized beam refracted at an air-metamaterial interface. © 2011 American Physical Society. Source


Holman L.,Australian National University
American Naturalist | Year: 2014

Reproductive skew theory seeks to explain how reproduction is divided among group members in animal societies. Existing theory is framed almost entirely in terms of selection, though nonadaptive processes must also play some role in the evolution of reproductive skew. Here I propose that a genetic correlation between helper fecundity and breeder fecundity may frequently constrain the evolution of reproductive skew. This constraint is part of a wider phenomenon that I term "caste load," which is defined as the decline in mean fitness caused by caste-specific selection pressures, that is, differential selection on breeding and nonbreeding individuals. I elaborate the caste load hypothesis using quantitative and population genetic arguments and individual-based simulations. Although selection can sometimes erode genetic correlations and resolve caste load, this may be constrained when mutations have similar pleiotropic effects on breeder and helper traits. I document evidence for caste load, identify putative genomic adaptations to it, and suggest future research directions. The models highlight the value of considering adaptation within the boundaries imposed by genetic architecture and incidentally reaffirm that monogamy promotes the evolutionary transition to eusociality. © 2013 by The University of Chicago. Source


Osmond B.,University of Wollongong | Osmond B.,Australian National University
Annual Review of Plant Biology | Year: 2014

This is a tale of a career in plant physiological ecology that enjoyed the freedom to address photosynthetic physiology and biochemistry in leaves of plants from diverse environments. It was supported by block funding (now sadly a thing of the past) for research at the Australian National University, by grants during appointments in the United States and in Germany, and by Columbia University. It became a "career experiment" in which long-term, high-trust support for curiosity-driven plant biology in Australia, and at times in the United States, led to surprisingly innovative results. Although the rich diversity of short-term competitive grant opportunities in the United States sustained ongoing research, it proved difficult to mobilize support for more risky long-term projects. A decade after the closure of the Biosphere 2 Laboratory, this article highlights the achievements of colleagues in experimental climate change research from 1998 to 2003. Copyright © 2014 by Annual Reviews. Source


Ferguson B.J.,University of Queensland | Mathesius U.,Australian National University
Journal of Chemical Ecology | Year: 2014

The symbiosis between legumes and nitrogen fixing bacteria called rhizobia leads to the formation of root nodules. Nodules are highly organized root organs that form in response to Nod factors produced by rhizobia, and they provide rhizobia with a specialized niche to optimize nutrient exchange and nitrogen fixation. Nodule development and invasion by rhizobia is locally controlled by feedback between rhizobia and the plant host. In addition, the total number of nodules on a root system is controlled by a systemic mechanism termed 'autoregulation of nodulation'. Both the local and the systemic control of nodulation are regulated by phytohormones. There are two mechanisms by which phytohormone signalling is altered during nodulation: through direct synthesis by rhizobia and through indirect manipulation of the phytohormone balance in the plant, triggered by bacterial Nod factors. Recent genetic and physiological evidence points to a crucial role of Nod factor-induced changes in the host phytohormone balance as a prerequisite for successful nodule formation. Phytohormones synthesized by rhizobia enhance symbiosis effectiveness but do not appear to be necessary for nodule formation. This review provides an overview of recent advances in our understanding of the roles and interactions of phytohormones and signalling peptides in the regulation of nodule infection, initiation, positioning, development, and autoregulation. Future challenges remain to unify hormone-related findings across different legumes and to test whether hormone perception, response, or transport differences among different legumes could explain the variety of nodules types and the predisposition for nodule formation in this plant family. In addition, the molecular studies carried out under controlled conditions will need to be extended into the field to test whether and how phytohormone contributions by host and rhizobial partners affect the long term fitness of the host and the survival and competition of rhizobia in the soil. It also will be interesting to explore the interaction of hormonal signalling pathways between rhizobia and plant pathogens. © 2014 Springer Science+Business Media New York. Source


Guard cells regulate CO2 uptake and water loss of a leaf by controlling stomatal movement in response to environmental factors such as CO2, humidity, and light. The mechanisms by which stomata respond to red light are actively debated in the literature, and even after decades of research it is still controversial whether stomatal movement is related to photosynthesis or not. This review summarizes the current knowledge of the red-light response of stomata. A comparison of published evidence suggests that stomatal movement is controlled by the redox state of photosynthetic electron transport chain components, in particular the redox state of plastoquinone. Potential consequences for the modeling of stomatal conductance are discussed. © 2013 Springer Science+Business Media Dordrecht. Source


Wang H.,Australian National University
Applied Physics Letters | Year: 2013

An undoped single GaAs nanowire (NW) photodetector based on a metal-semiconductor-metal Schottky diode structure is fabricated by a focused ion beam method. The photoconductive gain of the device reaches 20 000 at low laser excitation. Bias-dependence of gain proves that the surface contributes more to the gain at higher bias because of an increased surface charge region. The spectral response demonstrates not only the band-edge absorption profile of the single GaAs NW, but also the existence of leaky-mode resonance. © 2013 AIP Publishing LLC. Source


BACKGROUND AND AIMS: Both environmental and genetic effects contribute to phenotypic variation within and among populations. Genetic differentiation of quantitative traits among populations has been shown in many species, yet it can also be accompanied by other genetic changes, such as divergence in phenotypic plasticity and in genetic variance. Sideroxylonal (a formylated phloroglucinol compound or FPC) is an important chemical defence in eucalypts. The effect of environmental variation on its production is a critical gap in our understanding of its genetics and evolution. METHODS: The stability of genetic variation in sideroxylonal was assessed within and among populations of Eucalyptus tricarpa in three replicated provenance/progeny trials. The covariance structure of the data was also modelled to test whether genetic variances were consistent among populations and Fain's test was applied for major gene effects. KEY RESULTS: A significant genotype x environment interaction occurred at the level of population, and was related to temperature range and seasonality in source populations. Within-population genetic variation was not affected by genotype x environment effects or different sampling years. However, within-population genetic variance for sideroxylonal concentration differed significantly among source populations. Regression of family variance on family mean suggested that this trait is subject to major gene effects, which could explain the observed differences in genetic variances among populations. CONCLUSIONS: These results highlight the importance of replicated common-garden experiments for understanding the genetic basis of population differences. Genotype x environment interactions are unlikely to impede evolution or responses to artificial selection on sideroxylonal, but the lack of genetic variation in some populations may be a constraint. The results are broadly consistent with localized selection on foliar defence and illustrate that differentiation in population means, whether due to selection or to drift, can be accompanied by changes in other characteristics, such as plasticity and genetic variance. Source


Van Dooren G.G.,Australian National University | Kennedy A.T.,University of Melbourne | McFadden G.I.,University of Melbourne
Antioxidants and Redox Signaling | Year: 2012

Significance: Heme is an essential prosthetic group for most life on Earth. It functions in numerous cellular redox reactions, including in antioxidant defenses and at several stages of the electron transport chain in prokaryotes and eukaryotic mitochondria. Heme also functions as a sensor and transport molecule for gases such as oxygen. Heme is a complex organic molecule and can only be synthesized through a multienzyme pathway from simpler precursors. Most free-living organisms synthesize their own heme by a broadly conserved metabolic pathway. Parasites are adept at scavenging molecules from their hosts, and heme is no exception. Recent Advances: In this review we examine recent advances in understanding heme usage and acquisition in Apicomplexa, a group of parasites that include the causative agents of malaria, toxoplasmosis, and several major parasites of livestock. Critical Issues: Heme is critical to the survival of Apicomplexa, although the functions of heme in these organisms remain poorly understood. Some Apicomplexa likely scavenge heme from their host organisms, while others retain the ability to synthesize heme. Surprisingly, some Apicomplexa may be able to both synthesize and scavenge heme. Several Apicomplexa live in intracellular environments that contain high levels of heme. Since heme is toxic at high concentrations, parasites must carefully regulate intracellular heme levels and develop mechanisms to detoxify excess heme. Indeed, drugs interfering with heme detoxification serve as major antimalarials. Future Directions: Understanding heme requirements and regulation in apicomplexan parasites promises to reveal multiple targets for much-needed therapeutic intervention against these parasites. © Copyright 2012, Mary Ann Liebert, Inc. Source


Featherstone R.,Australian National University
IEEE Robotics and Automation Magazine | Year: 2010

Spatial vectors are six-dimensional (6-D) vectors that describe the motions of rigid bodies and the forces acting upon them. In Part 1, we saw how spatial vectors can simplify the process of expressing and analyzing the dynamics of a simple rigid-body system. In this tutorial, we shall examine the application of spatial vectors to various problems in robot kinematics and dynamics. To demonstrate that spatial vectors are both a tool for analysis and a tool for computation, we shall consider both the mathematical solution of a problem and the computer code to calculate the answer. © 2006 IEEE. Source


Studies of domesticated animals have led to the suggestion that domestication could have significant effects on patterns of molecular evolution. In particular, analyses of mitochondrial genome sequences from domestic dogs and yaks have yielded higher ratios of non-synonymous to synonymous substitutions in the domesticated lineages than in their wild relatives. These results are important because they imply that changes to selection or population size operating over a short timescale can cause significant changes to the patterns of mitochondrial molecular evolution. In this study, our aim is to test whether the impact on mitochondrial genome evolution is a general feature of domestication or whether it is specific to particular examples. We test whether domesticated mammals and birds have consistently different patterns of molecular evolution than their wild relatives for 16 phylogenetically independent comparisons of mitochondrial genome sequences. We find no consistent difference in branch lengths or dN/dS between domesticated and wild lineages. We also find no evidence that our failure to detect a consistent pattern is due to the short timescales involved or low genetic distance between domesticated lineages and their wild relatives. However, removing comparisons where the wild relative may also have undergone a bottleneck does reveal a pattern consistent with reduced effective population size in domesticated lineages. Our results suggest that, although some domesticated lineages may have undergone changes to selective regime or effective population size that could have affected mitochondrial evolution, it is not possible to generalize these patterns over all domesticated mammals and birds. Source


Nolan C.J.,Australian National University
Cell Metabolism | Year: 2014

Gestational diabetes (GDM) is caused by failure of islet β cells to meet the increased insulin requirements of pregnancy. Recently, Prentice et al. (2014) discovered a 7-fold elevation of the furan fatty acid metabolite 3-carboxy-4-methyl-5-propyl-2-furanopropanoic acid (CMPF) in plasma of women with GDM and showed that CMPF directly induces β cell dysfunction. © 2014 Elsevier Inc. Source


Berry H.L.,Australian National University
International journal of public health | Year: 2010

OBJECTIVES: Climate change will bring more frequent, long lasting and severe adverse weather events and these changes will affect mental health. We propose an explanatory framework to enhance consideration of how these effects may operate and to encourage debate about this important aspect of the health impacts of climate change. METHODS: Literature review. RESULTS: Climate change may affect mental health directly by exposing people to trauma. It may also affect mental health indirectly, by affecting (1) physical health (for example, extreme heat exposure causes heat exhaustion in vulnerable people, and associated mental health consequences) and (2) community wellbeing. Within community, wellbeing is a sub-process in which climate change erodes physical environments which, in turn, damage social environments. Vulnerable people and places, especially in low-income countries, will be particularly badly affected. CONCLUSIONS: Different aspects of climate change may affect mental health through direct and indirect pathways, leading to serious mental health problems, possibly including increased suicide mortality. We propose that it is helpful to integrate these pathways in an explanatory framework, which may assist in developing public health policy, practice and research. Source


Ho S.Y.W.,Australian National University | Gilbert M.T.P.,Copenhagen University
Mitochondrion | Year: 2010

The mitochondrial genome has been the traditional focus of most research into ancient DNA, owing to its high copy number and population-level variability. Despite this long-standing interest in mitochondrial DNA, it was only in 2001 that the first complete ancient mitogenomic sequences were obtained. As a result of various methodological developments, including the introduction of high-throughput sequencing techniques, the total number of ancient mitogenome sequences has increased rapidly over the past few years. In this review, we present a brief history of ancient mitogenomics and describe the technical challenges that face researchers in the field. We catalogue the diverse sequencing methods and source materials used to obtain ancient mitogenomic sequences, summarise the associated genetic and phylogenetic studies that have been conducted, and evaluate the future prospects of the field. © 2009 Mitochondria Research Society. Source


Zhou X.,Australian National University | McKay M.R.,Hong Kong University of Science and Technology
IEEE Transactions on Vehicular Technology | Year: 2010

We consider the problem of secure communication with multiantenna transmission in fading channels. The transmitter simultaneously transmits an information-bearing signal to the intended receiver and artificial noise to the eavesdroppers. We obtain an analytical closed-form expression of an achievable secrecy rate and use it as the objective function to optimize the transmit power allocation between the information signal and the artificial noise. Our analytical and numerical results show that equal power allocation is a simple yet near-optimal strategy for the case of noncolluding eavesdroppers. When the number of colluding eavesdroppers increases, more power should be used to generate the artificial noise. We also provide an upper bound on the SNR, above which, the achievable secrecy rate is positive and shows that the bound is tight at low SNR. Furthermore, we consider the impact of imperfect channel state information (CSI) at both the transmitter and the receiver and find that it is wise to create more artificial noise to confuse the eavesdroppers than to increase the signal strength for the intended receiver if the CSI is not accurately obtained. © 2006 IEEE. Source


Renewable Portfolio Standards (RPSs) are renewable electricity (RES-E) subsidy mechanisms in which governments mandate how much RES-E should be generated and markets determine the cost of the subsidy needed to generate the RES-E. Two modifications of the RPS that can help support high-cost types of RES-E are banding, where governments mandate higher multiples of RPS tradable certificates for high-cost types of RES-E, and carve-outs, where governments prescribe parts of a RPS target that can be met only by a particular type, or types, of RES-E. This paper analyses the design and generation performance of banding, as used in the UK, with some reference to Italy; and carve-outs, as used in the USA. To date, there is insufficient experience of either device to reach firm conclusions about their generation effectiveness. However, there is early, tentative evidence that banding is successful at supporting high-cost types of RES-E in the UK. Carve-outs are not being fully exploited in US states that use a RPS mechanism, and Italy is using banding in a fairly insignificant way. Though both devices have different design strengths and weaknesses, and either could be adapted to specific RPS markets, banding is probably the better device for supporting high-cost RES-E. © 2011 Elsevier Ltd. Source


Boulton E.,Australian National University
Wiley Interdisciplinary Reviews: Climate Change | Year: 2016

Climate policy, climate communication and cognitive science researches have identified that better ways of conveying the climate change story are needed; specifically, a new frame or narrative is required. There are also increasing calls for the arts and humanities to play a greater role in the 'meaning-making' task around climate change. Philosopher and literary theorist Timothy Morton has created a new approach, one which frames global warming as a 'hyperobject'. Morton's work demonstrates the value of artistic and philosophical approaches in helping people perceive climate change, as well as understand how it may feel. It opens up a potentially crucial discussion about ontology (the study of 'Being' and existence) illuminating the difficult emotional and conceptual territory humans must cross. His work is intended to awaken people abruptly but debate exists as to whether Morton's approach is too harsh and disempowering, or whether it is the spur required for humans to adjust cognitively and emotionally to a new climate reality. Morton's frame vividly captures human vulnerability, but his association of vulnerability with shame and humiliation is concerning. Morton's narrative style, brilliantly evocative at times, is at others contentiously obscure. While this engenders what may be a necessary experience of dislocation, it also risks rendering his more valuable ideas impenetrable to many readers. © 2016 Wiley Periodicals, Inc. Source


Cox D.,University of Wollongong | Carver J.A.,Australian National University | Ecroyd H.,University of Wollongong
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2014

Protein homeostasis, or proteostasis, is the process of maintaining the conformational and functional integrity of the proteome. The failure of proteostasis can result in the accumulation of non-native proteins leading to their aggregation and deposition in cells and in tissues. The amyloid fibrillar aggregation of the protein α-synuclein into Lewy bodies and Lewy neuritis is associated with neurodegenerative diseases classified as α-synucleinopathies, which include Parkinson's disease and dementia with Lewy bodies. The small heat-shock proteins (sHsps) are molecular chaperones that are one of the cell's first lines of defence against protein aggregation. They act to stabilise partially folded protein intermediates, in an ATP-independent manner, to maintain cellular proteostasis under stress conditions. Thus, the sHsps appear ideally suited to protect against α-synuclein aggregation, yet these fail to do so in the context of the α-synucleinopathies. This review discusses how sHsps interact with α-synuclein to prevent its aggregation and, in doing so, highlights the multi-faceted nature of the mechanisms used by sHsps to prevent the fibrillar aggregation of proteins. It also examines what factors may contribute to α-synuclein escaping the sHsp chaperones in the context of the α-synucleinopathies. © 2014. Source


Dunn R.I.,Australian National University | Hearps P.J.,University of Melbourne | Wright M.N.,Beyond Zero Emissions
Proceedings of the IEEE | Year: 2012

Molten-salt storage is already commercially available for concentrating solar power (CSP) plants, allowing solar power to be produced on demand and to backup variable renewable sources such as wind and photovoltaics. The first CSP plants to operate commercially with molten-salt storage utilized parabolic trough concentrators, for example, the Andasol-1 plant. A new type of storage plant has now reached commercial status, with the 19.9-MW$ \rm e Torresol Gemasolar power tower, featuring 15 h of molten-salt storage, having come online in Spain in May 2011. Advantages of the power tower storage system include the elimination of heat transfer oil and associated heat exchangers, a lower salt requirement, higher steam cycle efficiency, better compatibility with air cooling, improved winter performance, and simplified piping schemes. Near-term advances in molten-salt power tower technology include planned up-scaling, with SolarReserve due to begin constructing a 110-MW$ \rm e plant in Nevada by August 2011. Other advances include improvements to the thermal properties of molten salts and the development of storage solutions in a single tank. With these developments at hand, CSP will continue to provide dispatchable solar power, with the capacity to provide energy storage for 100% renewable electricity grids in sun-belt countries. © 2006 IEEE. Source


Dornan M.,Australian National University
Renewable Energy | Year: 2011

Solar photovoltaic technologies have for some time been promoted as a cost effective means of rural electrification in developing countries. However, institutional structures resulting in poor maintenance have adversely affected the sustainability of past solar projects. In Fiji, the Renewable Energy Service Company (RESCO) program is the latest attempt to promote solar-based rural electrification in a fee-for-service model, aiming to remove the high upfront capital costs associated with solar technologies and using a public-private sector partnership for maintenance. This paper assesses the program using survey and interview data. Major flaws are identified, relating to incorrect treatment of principal-agent problems, information asymmetries, motivational problems, and resourcing of government agencies. General lessons for fee-for-service solar home system models emerge, including that incentives for stakeholders must take centre stage in designing and administering such programs, and that active government support and ownership are required to make programs sustainable. © 2010 Elsevier Ltd. Source


Mills S.J.,Khan Research Laboratories | Christy A.G.,Australian National University
Acta Crystallographica Section B: Structural Science | Year: 2013

Bond-valence parameters r 0 and b have been re-determined for Te IV-O: r 0 = 1.9605Å, b = 0.41; TeVI-O: r 0 = 1.921Å, b = 0.56; and TeIV-Cl: r 0 = 2.3115Å, b = 0.555. Bond distance data from 208 independent TeIV-O polyhedra, 118 Te VI-O polyhedra and 26 TeIV-Cl polyhedra were used, and all neighbours out to 3.5Å were included. Root-mean square deviations of bond-valence sums on Te from ideal values were 0.1934, 0.1939 and 0.0865v.u. The good fit for TeIV-O over a range of Te coordination numbers from 3 to 12 demonstrates that there is no essential difference in character between short 'primary' Te-O bonds, oriented away from the Te lone pair, and longer 'secondary' Te-O bonds on the same side of the Te atom as the lone pair. Comparison of bond-valence sums for Te-O polyhedra obtained using the new parameters with those calculated using earlier literature values shows that the new parameters give a narrower spread of calculated bond-valence sums, which means much closer to the formal valence for both oxidation states of tellurium. © 2013 International Union of Crystallography Printed in Singapore-all rights reserved. Source


Maksymov I.S.,Australian National University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

We propose a hybrid resonance architecture in which a plasmonic element is coupled to a silicon-on-insulator photonic crystal nanobeam cavity operating at telecom wavelengths. It benefits from the combined characteristics of the photonic cavity and the plasmonic element, and exploits the unique properties of Fano resonances resulting from interactions between the continuum and the localized cavity states. As confirmed through 3D time-domain simulations, a strong cavity mode damping by the plasmonic element offers mechanisms of controlling a probe signal propagating in the nanobeam. It makes possible to create optical switching devices and logic gates relying on any optical nonlinear effect. © 2010 Elsevier B.V. All rights reserved. Source


Davoyan A.R.,Australian National University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

Usually nonlinear response of metals is neglected in the study of plasmonic waveguiding structures. Recent prediction of strong third-order optical response of metals due to ponderomotive forces opens up novel possibilities for utilizing this effect in the design of active plasmonic devices. We discuss the possibility of implementation of nonlinear response of metals in the design of plasmonic coupler. We analyze the structure and dispersions of linear and nonlinear guided plasmonic modes of two coupled thin metallic films and predict bifurcations of symmetry breaking. © 2011 Elsevier B.V. All rights reserved. Source


Robson B.A.,Australian National University
International Journal of Modern Physics E | Year: 2011

A quantum theory of gravity, based upon a composite model of leptons and quarks, is presented. The model treats leptons and quarks as composites of three kinds of spin-1/2 particles (rishons) and/or their antiparticles. A strong color force, mediated by massless hypergluons, binds rishons and/or antirishons together to form colorless leptons or colored quarks, the fundamental particles of the Standard Model. The new model provides a qualitative understanding of the mass hierarchy of the three generations of leptons and quarks. An earlier conjecture that the residual interaction of the strong color force acting between any two colorless particles be identified with the corresponding gravitational interaction, is shown to lead approximately to Newton's law of gravitation. © 2011 World Scientific Publishing Company. Source


Ho S.Y.,Australian National University
Decision Support Systems | Year: 2012

The rising pervasiveness of mobile commerce has prompted firms to rapidly leverage mobile technologies to foster business-to-consumer connections. Firms send individuals mobile messages to promote their products and personalize the message content to make it more relevant to individual consumers. An important factor in mobile personalization is location. This research examines the effects of location personalization on individuals' intention to use mobile services. We draw on motivational theories to identify two groups of variables. One group includes features of location personalization that intrinsically motivate an individual to use a service, whereas the other group includes features that extrinsically motivate an individual to use a service. We examine how individuals' initial perceptions of mobile services influence the development of intrinsic and extrinsic motivations. Perceived novelty and perceived community-based involvement belong to the former group of variables, while perceived location accuracy and perceived location precision belong to the latter. We also examine how intrinsic and extrinsic motivations formed at an early stage of use influence individuals' intention to use mobile services in the long run. We developed eight hypotheses to explore these dimensions. Through a four-week study, we found that when individuals first interacted with location-based personalized services, they were driven by both intrinsic and extrinsic motivations. After a few weeks of interaction, the extrinsic motivation formed at the early stage of use proved to be less important in retaining users' interest. This research provides empirical evidence of the effectiveness of location personalization and helps firms understand and quantify new mobile commerce opportunities. It also sheds light on personalization studies by examining the role of location in personalization and explores factors that not only attract individuals to mobile services but also keep them engaged in the services in the long term. © 2012 Elsevier B.V. All rights reserved. Source


Gould S.,Australian National University
Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition | Year: 2012

A popular approach to pixel labeling problems, such as multiclass image segmentation, is to construct a pairwise conditional Markov random field (CRF) over image pixels where the pairwise term encodes a preference for smoothness within local 4-connected or 8-connected pixel neighborhoods. Recently, researchers have considered higherorder models that encode soft non-local constraints (e.g., label consistency, connectedness, or co-occurrence statistics). These new models and the associated energy minimization algorithms have significantly pushed the state-of-the-art for pixel labeling problems. In this paper, we consider a new non-local constraint that penalizes inconsistent pixel labels between disjoint image regions having similar appearance. We encode this constraint as a truncated higher-order matching potential function between pairs of image regions in a conditional Markov random field model and show how to perform efficient approximate MAP inference in the model. We experimentally demonstrate quantitative and qualitative improvements over a strong baseline pairwise conditional Markov random field model on two challenging multiclass pixel labeling datasets. © 2012 IEEE. Source


Hogg A.M.,Australian National University
Geophysical Research Letters | Year: 2010

Simulations of an idealised, but eddy-resolving, channel model of the Antarctic Circumpolar Current (ACC) are used to investigate the sensitivity of ACC transport to wind and surface buoyancy forcing. The results are consistent with theoretical predictions of the eddy-saturated limit, where transport is independent of wind stress. In this parameter regime, buoyancy forcing provides the primary control over ACC transport. © 2010 by the American Geophysical Union. Source


Donohue M.,Australian National University | Denham T.,Monash University
Current Anthropology | Year: 2010

Current portrayals of Island Southeast Asia (ISEA) over the past 5,000 years are dominated by discussion of the Austronesian "farming/language dispersal," with associated linguistic replacement, genetic clines, Neolithic "packages," and social transformations. The alternative framework that we present improves our understanding of the nature of the Austronesian language dispersal from Taiwan and better accords with the population genetics, archaeological evidence, and crop domestication histories for ISEA. Genetic studies do not demonstrate that the dispersal of Austronesian languages through ISEA was associated with large-scale displacement, replacement, or absorption of preexisting populations. Linguistic phylogenies for Austronesian languages do not support staged movement from Taiwan through the Philippines into Indo-Malaysia; in addition, the lexical and grammatical structure of many Austronesian languages suggests significant interaction with pre-Austronesian languages and cultures of the region. Archaeological evidence, including domestication histories for major food plants, indicates that ISEA was a zone of considerable maritime interaction before the appearance of Austronesian languages. Material culture dispersed through ISEA from multiple sources along a mosaic of regional networks. The archaeological evidence helps us to shape a new interpretative framework of the social and historical processes that more parsimoniously accounts for apparent discrepancies between genetic phylogenies and linguistic distributions and allows for more nuanced models of the dispersal of technologies and societies without reference to the farming/language dispersal hypothesis.© 2010 by The Wenner-Gren Foundation for Anthropological Research. Source


Environmental and public health-focused sciences are increasingly characterised as constituting an emerging discipline-planetary medicine. From a governance perspective, the ethical components of that discipline may usefully be viewed as bestowing upon our ailing natural environment the symbolic moral status of a patient. Such components emphasise, for example, the origins and content of professional and social virtues and related ethical principles needed to promote global governance systems and policies that reduce ecological stresses and pathologies derived from human overpopulation, selfishness and greed-such as pollution, loss of biodiversity, deforestation and greenhouse gas emissions, as well as provide necessary energy, water and food security. Less well explored in this context, however, is the ethics that should underpin global use of emerging technologies such as nanotechnology as forms of planetary therapeutics. Nanotechnology may be particularly important, for instance, as a mechanism for improving upon photosynthesis and engineering it into human structures for localised production of carbon-neutral hydrogen based-fuel and carbohydrate-based food and fertilizer. Artificial photosynthesis, because of its unique and widespread public and environmental benefits in this period of human history, may even be termed the moral culmination of nanotechnology, assisting this planet to move beyond the Anthropocene epoch to that of the Sustainocene. This paper explores practical steps towards planetary nanomedicine involving governance of artificial photosynthesis, including a UNESCO Universal Declaration on the Bioethics and Human Rights of Natural and Artificial Photosynthesis (Global Solar Fuels and Foods). © 2012 Springer Science+Business Media B.V. Source


McCarthy J.F.,Australian National University | Vel J.A.C.,Leiden University | Afiff S.,University of Indonesia
Journal of Peasant Studies | Year: 2012

While the size and speculative nature of land transactions in the wake of energy, food and climate crises have surprised observers, the reasons for partial implementation of many land developments remain largely unexamined. This contribution investigates trajectories of land acquisition and enclosure by analyzing four acquisition processes in Indonesia - those associated with rice, oil palm, Jatropha and carbon sequestration - considering their implications for comparative studies elsewhere. The paper finds that current patterns of land use change represent a continuation of ongoing land transformation processes. It describes the logic leading to partial realization of large-scale schemes. Highlighting the importance of interactions between formal and vernacular rural land development processes, the essay concludes that many large-scale schemes are better understood as virtual land acquisitions. © 2012 Copyright Taylor and Francis Group, LLC. Source


Kemp J.,Australian National University
Geomorphology | Year: 2010

Downstream trends in flow, channel morphology, and sediments were investigated over 220. km of the middle and upper alluvial Lachlan River in southeastern Australia. The Lachlan is a perennial river that rises from temperate, humid highlands and flows inland into a semiarid low-gradient plain lacking perennial tributaries. Long daily stage records were used to calculate flow parameters and flood frequencies in single and anabranching channel reaches of the river. Morphological trends were based on cross section and height data compiled from new and water authority data, and from particle size trends constructed from bed and bank sediment samples. Mean and peak flows, channel size, and bed particle size all diminish in a downstream direction. In the partially confined piedmont zone, channel and floodplain morphology feature large flood effects and large channel dimensions that reflect extreme flow variability. On the alluvial plains, the unconfined, single-channel contracts with distance downvalley; and anabranches develop at high flow stages. The development of a full anabranching pattern is associated with large flood volume losses. Diminishing flood volumes, mean flows, and channel dimensions is attributed to storage of flood waters in lakes, floodways, and lagoons and through transmission losses during overbank flows. The frequency of bankfull discharge consistently decreases downstream, and may reflect the long duration and lower frequency of floods in the lower reaches of the river. Particle size of bed sediment fines downstream at rates consistent with those reported from sand-bed rivers elsewhere. This is attributed to a combination of hydraulic sorting and low rates of sediment supply from the catchment. © 2010 Elsevier B.V. Source


McDougall I.,Australian National University
Geological Magazine | Year: 2010

Potassium-argon (K-Ar) ages on whole rock samples have been measured on lavas from the subaerial Samoa Islands, which form a broadly linear volcanic chain that extends from the ESE to the WNW for about 360 km. The Manu'a Islands near the southeast limit of the chain exhibit youthful ages, with most <0.4 Ma, in keeping with the geological observations. Tutuila consists of several volcanoes, and previous work yielded a mean K-Ar age of 1.26 ± 0.15 Ma for the shield-building volcanism. Upolu, to the WNW of Tutuila, gives a mean age of 2.15 ± 0.35 Ma for the shield-building phase, represented by the Fagaloa Volcanics, with much of the island covered by significantly younger volcanic rocks. Savai'i, further to the WNW, is dominated by youthful volcanism, extending into historic times. In a restricted area, adjacent to the NE coast of Savai'i, previously thought to have volcanic rocks correlating with the Fagaloa Volcanics of Upolu, the ages are much younger than those on Upolu, lying between 0.32 and 0.42 Ma. Considering only the subaerial volcanism from Ta'u to Upolu, but also including Vailulu'u, the volcanism has migrated in a systematic ESE direction at 130 ± 8 mm a-1 over 300 km in the last 2.2 Ma. This rate is nearly twice that obtained from GPS measurements of Pacific Plate motion of 72 mm a-1 at N64°W in this area. However, if the much older age of shield-building volcanism from the submarine foundations of Savai'i is included, the regression yields a volcanic migration rate of 72 ± 14 mm a-1, in keeping with the measured GPS rate and consistent with a hotspot origin for the island chain. This suggests that the volcanic migration rates determined from the age of subaerial volcanism can be considerably overestimated, and this is now evident in other Pacific Ocean island chains. Clearly, the ages of the main shield-building volcanism from subaerial volcanism are minima, and if the older submarine lavas can be measured, these may yield a migration rate more in keeping with current plate motions. Copyright © Cambridge University Press 2010. Source


Fichtner A.,University Utrecht | Tkalcic H.,Australian National University
Earth and Planetary Science Letters | Year: 2010

The accurate modelling and prediction of volcanic eruptions depends critically on information concerning the interaction between the caldera and the underlying magma chamber. Knowledge concerning the kinematics of a caldera in the course of an eruption is therefore essential. Here we provide detailed seismological constraints on the kinematics of a volcanic caldera drop and the geometry of a caldera ring fault. For this we performed a finite-source inversion of the September 29, 1996 Bárdarbunga, Iceland, earthquake that was caused by caldera subsidence. Our methodology is based on spectral element simulations of seismic wave propagation through a realistic model of the Icelandic crust and upper mantle. A particularly robust feature is the initiation of the rupture in the north-western part of the ring fault that is about 10. km in diameter. From there it spread to the other fault segments within about 3. s. Without invoking super-shear propagation sensu stricto, we can explain this unusually fast rupture propagation by the triggering of fault segments through P waves that propagated across the caldera. Our results favour outward-dipping fault segments in the western half of the ring fault, while the eastern half is preferentially inward-dipping. This variability may reflect structural heterogeneities or an irregular magma chamber geometry. The individual segments of the caldera ring fault radiated approximately equal amounts of energy. This indicates that the caldera dropped coherently as one single block.The work presented here is intended to aid in the design of realistic models of magma chamber and caldera dynamics. © 2010 Elsevier B.V. Source


Boyd P.W.,University of Otago | Ellwood M.J.,Australian National University
Nature Geoscience | Year: 2010

Advances in iron biogeochemistry have transformed our understanding of the oceanic iron cycle over the past three decades: multiple sources of iron to the ocean were discovered, including dust, coastal and shallow sediments, sea ice and hydrothermal fluids. This new iron is rapidly recycled in the upper ocean by a range of organisms; up to 50% of the total soluble iron pool is turned over weekly in this way in some ocean regions. For example, bacteria dissolve particulate iron and at the same time release compounds - iron-binding ligands - that complex with iron and therefore help to keep it in solution. Sinking particles, on the other hand, also scavenge iron from solution. The balance between these supply and removal processes determines the concentration of dissolved iron in the ocean. Whether this balance, and many other facets of the biogeochemical cycle, will change as the climate warms remains to be seen. © 2010 Macmillan Publishers Limited. All rights reserved. Source


Allen M.S.,University of Auckland | Ussher E.,Australian National University
Journal of Archaeological Science | Year: 2013

Starch analysis is proving particularly useful in tropical regions like the central Pacific where crop inventories are often dominated by starchy fruits and tubers and recovery of macrobotanical remains is rare. Analysis of 23 shell tools from the Marquesas Islands provides direct evidence for translocation of five traditional crop plants. Four taxa derive from the western Pacific, including Artocarpus altilis (breadfruit), Piper methysticum (kava), Colocasia esculenta (taro), and one or more species of Dioscorea (yam). The fifth taxon, the South American Ipomoea batatas (sweet potato), dates from the 14th century AD onward and constitutes the earliest record of this cultigen in the archipelago. The occurrence of sweet potato starch suggests that this crop plant may have been more important than usually is assumed, while the limited recovery of breadfruit starch, the main Marquesan food plant at western contact, requires further investigation. The starch residues also inform on tool use, demonstrating that shell tools ethnographically associated with specific crops (e.g., " breadfruit peelers" ) had more generalised functions. This study is a further demonstration of the potential of starch analysis to provide important information on the history of crop introductions, on-site activities, and artefact use. © 2013 Elsevier Ltd. Source


Anderson K.,Australian National University | Rausser G.,University of California at Berkeley | Swinnen J.,Stanford University
Journal of Economic Literature | Year: 2013

The agricultural and food sector is an ideal case for investigating the political economy of public policies. Many of the policy developments in this sector since the 1950s have been sudden and transformational, while others have been gradual but persistent. This article reviews and synthesizes the literature on trends and fuctuations in market distortions and the political-economy explanations that have been advanced. Based on a rich global data set covering a half-century of evidence on commodities, countries, and policy instruments, we identify hypotheses that have been explored in the literature on the extent of market distortions and the conditions under which reform may be feasible. Source


Wierzbicka A.,Australian National University
Language Sciences | Year: 2015

The invention of the spoon may not be quite as ground-breaking in human history as the invention of the wheel or the needle, but arguably it is also a significant conceptual (as well as technological) event. It has been claimed that "all people in the world use spoons", that "spoons have been used as eating utensils since Paleolithic times", that chimpanzees in Gombe use "sort-of-spoons".. Can we draw a line, in a principled and precise way, between 'spoons' and 'sort-of' spoons'? For example, is the so-called "Chinese spoon" (tāngchí) a 'spoon'? Can we explain why a 'tāngchí' is different in many respects from a ('European') 'spoon' and similar in others? Most importantly, perhaps, can we reconstruct with any plausibility the conceptual model in the minds of the first prehistoric inventors of 'spoons'? Can we tell in what part of the world they lived, when they lived, what they wanted to eat with those first 'spoons', and why they found 'spoons' more suited to their needs than something like 'tāngchí' ('Chinese spoons')? These are some of the questions that this paper will address, using as a tool NSM techniques of semantic and conceptual analysis. © 2014. Source


Fogden A.,Australian National University
Energy and Fuels | Year: 2011

While the wettability of oil reservoirs has been the focus of many studies, little is known as to whether, and to what extent, the wettability evolves during oil recovery by waterflooding. To this end, a model silicate substrate, namely glass, was treated by oil drainage of the surrounding salt solution and aging (representing the initial state), followed by oil displacement by a second salt solution (flooded state). The two states were analyzed by scanning electron microscopy of the oil components attached to the substrate and measurement of their influence on macroscopic contact angles. Initial-state wettability took the form of an incomplete asphaltenic film interrupted by nanoscale channels and pockets of trapped salt solution. The film was observed to remain fluidic and, on flooding, could retract and detach to leave a more incomplete coverage, usually of oil nanodroplets. The influence of pH of the initial and flooding solutions on these two states was generally opposite; high pH, at which oil-substrate repulsion is prevalent, tended to reduce film coverage in the initial state but aid its retention by the substrate on flooding. Contact angles on flooded substrates depended on this residual adhering nanoscale oil and on the ability of bulk oil to adhere by reconnecting to it. Again, the pH dependence of these two factors was opposite. The results suggested a possible supplementary mechanism for enhanced recovery by low salinity flooding. © 2011 American Chemical Society. Source


Pittock J.,Australian National University
Wiley Interdisciplinary Reviews: Climate Change | Year: 2013

Governance of Australia's Murray-Darling Basin (the Basin) is frequently lauded as an example to other river managers globally. Freshwater environments in the Basin are particularly vulnerable to water scarcity and change. In this paper, governmental responses are assessed to draw global lessons on climate change adaptation for rivers. A range of climate change adaptation measures for freshwater ecosystem conservation in the Basin are outlined namely: higher, long-term allocations of water to the environment; reviewing water allocation on a cyclical basis; allocating an equal or greater share of available water to the environment in dry years; and environmental works and measures to use less water to conserve wetlands. Examples of poor translation of science into policy that do not adequately consider the risks, costs, and benefits of adaptation interventions are explored. Adaptation policy in the Basin illustrates the risks of heavy reliance on infrastructure, of the high costs of trade-offs between environmental measures versus socio-economic and political concerns, and of dependence on too few measures. Lessons include the need for rigorous evaluation of risks, costs, and benefits to minimize perverse outcomes, and for adequate incentives and penalties for implementation of adaptation policies across governance scales. It is concluded that rather than a focus on only a few interventions, such as environmental flows, better adaptation practice requires deployment of a suite of different but complementary measures that spreads risk and maximizes resilience to climate variability and change. © 2013 John Wiley & Sons, Ltd. Source


Looi J.C.L.,Australian National University | Walterfang M.,University of Melbourne
Molecular Psychiatry | Year: 2013

The striatum, comprising the caudate nucleus, putamen and nucleus accumbens, occupies a strategic location within cortico-striato-pallido- thalamic-cortical (corticostriatal) re-entrant neural circuits. Striatal neurodevelopment is precisely determined by phylogenetically conserved homeobox genes. Consisting primarily of medium spiny neurons, the striatum is strictly topographically organized based on cortical afferents and efferents. Particular corticostriatal neural circuits are considered to subserve certain domains of cognition, emotion and behaviour. Thus, the striatum may serve as a map of structural change in the cortical afferent pathways owing to deafferentation or neuroplasticity, and conversely, structural change in the striatum per se may structurally disrupt corticostriatal pathways. The morphology of the striatum may be quantified in vivo using advanced magnetic resonance imaging, as may cognitive functioning pertaining to corticostriatal circuits. It is proposed that striatal morphology may be a biomarker in neurodegenerative disease and potentially the basis of an endophenotype. © 2013 Macmillan Publishers Limited. Source


Hill H.,Australian National University
Asian Economic Policy Review | Year: 2013

This paper examines Cambodia's socioeconomic development since the early 1990s peace settlement. The country's economic growth has arguably been the fastest among post-conflict societies, driven by the credible restoration of peace and security, large public and private capital inflows, economic openness, reasonably prudent macroeconomic management, and a dynamic, integrating neighborhood. A legacy of history and small size is that the government has limited policy space, although this has not necessarily retarded economic development. We also highlight some key challenges, including rising inequality, uneven spatial development, weak institutions, and high levels of corruption. Looking forward, we highlight the importance of strengthening supply side capabilities, broadening the benefits of growth, and developing stronger institutions and property rights. © 2013 The Authors. Asian Economic Policy Review © 2013 Japan Center for Economic Research. Source


Hall I.,Australian National University
British Journal of Politics and International Relations | Year: 2013

From 1997 onwards the FCO was reshaped by New Labour. The removal of responsibility for overseas aid to a new Department of International Development (DFID) was perhaps the most dramatic change. Successive cuts to the FCO budget and the progressive centralization of foreign-policy decision-making in Number 10 also had their effects, as did a series of government-directed reforms to recruitment practices. In an effort to make it more accountable to the public, the FCO was also bound by Public Service Agreements specifying targets for service delivery, publish Strategy Reports and mission statements, and Annual Departmental Reports setting benchmarks for performance. Together these reforms were designed to transform the FCO's culture, replacing inherited traditions of thought and practice with new ones believed better suited to contemporary world politics. This paper examines these inherited and new traditions, as well as the dilemmas they addressed. © 2012 Political Studies Association. Source


Sumartojo S.,Australian National University
Cultural Geographies | Year: 2013

Since 1999 the Fourth Plinth in Trafalgar Square has seen the installation of a range of contemporary artworks that have prompted a national discussion about national identity, tolerance, diversity and history in the context of Trafalgar Square. This article explores aspects of the narrative around the Fourth Plinth scheme since 2005 to discuss the relationship between different versions of national identity and public place, and how the use of historical narratives can shore up contemporary versions of national identity. © The Author(s) 2012. Source


Thomson J.S.,Australian National University
The Medical journal of Australia | Year: 2011

This article explores various models and ideas for future sustainable general practice vocational training supervision in Australia. The general practitioner supervisor in the clinical practice setting is currently central to training the future general practice workforce. Finding ways to recruit, retain and motivate both new and experienced GP teachers is discussed, as is the creation of career paths for such teachers. Some of the newer methods of practice-based teaching are considered for further development, including vertically integrated teaching, e-learning, wave consulting and teaching on the run, teaching teams and remote teaching. Approaches to supporting and resourcing teaching and the required infrastructure are also considered. Further research into sustaining the practice-based general practice supervision model will be required. Source


Wildenschild D.,Oregon State University | Sheppard A.P.,Australian National University
Advances in Water Resources | Year: 2013

We report here on recent developments and advances in pore-scale X-ray tomographic imaging of subsurface porous media. Our particular focus is on immiscible multi-phase fluid flow, i.e., the displacement of one immiscible fluid by another inside a porous material, which is of central importance to many natural and engineered processes. Multiphase flow and displacement can pose a rather difficult problem, both because the underlying physics is complex, and also because standard laboratory investigation reveals little about the mechanisms that control micro-scale processes. X-ray microtomographic imaging is a non-destructive technique for quantifying these processes in three dimensions within individual pores, and as we report here, with rapidly increasing spatial and temporal resolution. © 2012 Elsevier Ltd. Source


Beltrando M.,University of Turin | Rubatto D.,Australian National University | Manatschal G.,French National Center for Scientific Research
Geology | Year: 2010

A lithostratigraphic association consisting of serpentinized mantle rocks, continent-derived allochthons, mid-oceanic ridge gabbros of Jurassic age and post-rift sediments, typical of an ocean-continent transition, is found in the eclogitic Piemonte units, in the Western Alps. In situ U-Pb geochronology was performed on zircons from an orthogneiss sampled at the bottom of a sliver of continental basement, in contact with serpentinites. Primary magmatic zircons of Permian age were overgrown by a second generation of zircon at ca. 166-150 Ma, likely related to melt infiltration associated with the intrusion of the underlying gabbroic body. This indicates that continental basement slices and oceanic basement rocks were already juxtaposed in the Jurassic and they were probably part of hyper-extended crust related to the opening of the Tethys. Therefore, the complex lithological association described here, which is also characteristic of several (ultra) high-pressure mélange zones worldwide, was acquired prior to the orogenic event, during which it was only partly reworked. Ocean-continent transitions are in positions favorable to reach (ultra)high-pressure conditions, following negatively buoyant oceanic lithosphere into subduction, and then being accreted to the orogen, in response to the arrival of more buoyant continental lithosphere, resisting subduction. The ocean-continent transition is now found in the immediate footwall of a 500-m-thick shear zone, which accommodated multiple episodes of deformation during Eocene-Oligocene time, suggesting an important link between Alpine deformation and rift-related structures. © 2010 Geological Society of America. Source


Butterworth P.,Australian National University
Psychological medicine | Year: 2013

Employment is associated with health benefits over unemployment, but the psychosocial characteristics of work also influence health. There has, however, been little research contrasting the prevalence of psychiatric disorders among people who are unemployed with those in jobs of differing psychosocial quality. Analysis of data from the English Adult Psychiatric Morbidity Survey (APMS) considered the prevalence of common mental disorders (CMDs) among 2603 respondents aged between 21 and 54 years who were either (i) employed or (ii) unemployed and looking for work at the time of interview in 2007. Quality of work was assessed by the number of adverse psychosocial job conditions reported (low control, high demands, insecurity and low job esteem). The prevalence of CMDs was similar for those respondents who were unemployed and those in the poorest quality jobs. This pattern remained after controlling for relevant demographic and socio-economic covariates. Although employment is thought to promote mental health and well-being, work of poor psychosocial quality is not associated with any better mental health than unemployment. Policy efforts to improve community mental health should consider psychosocial job quality in conjunction with efforts to increase employment rates. Source


Nolan C.J.,Australian National University | Ruderman N.B.,Boston University | Kahn S.E.,University of Washington | Pedersen O.,Novo Nordisk AS | Prentki M.,University of Montreal
Diabetes | Year: 2015

Stratifying the management of type 2 diabetes (T2D) has to take into account marked variability in patient phenotype due to heterogeneity in its pathophysiology, different stages of the disease process, and multiple other patient factors including comorbidities. The focus here is on the very challenging subgroup of patients with T2D who are overweight or obese with insulin resistance (IR) and the most refractory hyperglycemia due to an inability to change lifestyle to reverse positive energy balance. For this subgroup of patients with T2D, we question the dogma that IR is primarily harmful to the body and should be counteracted at any cost. Instead we propose that IR, particularly in this high-risk subgroup, is a defense mechanism that protects critical tissues of the cardiovascular system from nutrient-induced injury. Overriding IR in an effort to lower plasma glucose levels, particularly with intensive insulin therapy, could therefore be harmful. Treatments that nutrient off-load to lower glucose are more likely to be beneficial. The concepts of "IR as an adaptive defense mechanism" and "insulin-induced metabolic stress" may provide explanation for some of the unexpected outcomes of recent major clinical trials in T2D. Potential molecular mechanisms underlying these concepts; their clinical implications for stratification of T2D management, particularly in overweight and obese patients with difficult glycemic control; and future research requirements are discussed. © 2015 by the American Diabetes Association. Source


Bahar-Fuchs A.,Australian National University
The Cochrane database of systematic reviews | Year: 2013

Cognitive impairments, particularly memory problems, are a defining feature of the early stages of Alzheimer's disease (AD) and vascular dementia. Cognitive training and cognitive rehabilitation are specific interventional approaches designed to address difficulties with memory and other aspects of cognitive functioning. The present review is an update of previous versions of this review. The main aim of the current review was to evaluate the effectiveness and impact of cognitive training and cognitive rehabilitation for people with mild Alzheimer's disease or vascular dementia in relation to important cognitive and non-cognitive outcomes for the person with dementia and the primary caregiver in the short, medium and long term. The CDCIG Specialized Register, ALOIS, which contains records from MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS and many other clinical trial databases and grey literature sources, was most recently searched on 2 November 2012. Randomised controlled trials (RCTs), published in English, comparing cognitive rehabilitation or cognitive training interventions with control conditions, and reporting relevant outcomes for the person with dementia and/or the family caregiver, were considered for inclusion. Eleven RCTs reporting cognitive training interventions were included in the review. A large number of measures were used in the different studies, and meta-analysis could be conducted for 11 of the primary and secondary outcomes of interest. Several outcomes were not measured in any of the studies. The unit of analysis in the meta-analysis was the change from baseline score. Overall estimates of treatment effect were calculated using a fixed-effect model, and statistical heterogeneity was measured using a standard Chi(2) statistic. One RCT of cognitive rehabilitation was identified, allowing examination of effect sizes, but no meta-analysis could be conducted. Cognitive training was not associated with positive or negative effects in relation to any reported outcomes. The overall quality of the trials was low to moderate. The single RCT of cognitive rehabilitation found promising results in relation to a number of participant and caregiver outcomes, and was generally of high quality. Available evidence regarding cognitive training remains limited, and the quality of the evidence needs to improve. However, there is still no indication of any significant benefit derived from cognitive training. Trial reports indicate that some gains resulting from intervention may not be captured adequately by available standardised outcome measures. The results of the single RCT of cognitive rehabilitation show promise but are preliminary in nature. Further, well-designed studies of cognitive training and cognitive rehabilitation are required to obtain more definitive evidence. Researchers should describe and classify their interventions appropriately using available terminology. Source


Martinez-Boti M.A.,UK National Oceanography Center | Foster G.L.,UK National Oceanography Center | Chalk T.B.,UK National Oceanography Center | Rohling E.J.,UK National Oceanography Center | And 6 more authors.
Nature | Year: 2015

Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2. © 2015 Macmillan Publishers Limited. All rights reserved. Source


Charles C.,Australian National University
Applied Physics Letters | Year: 2010

A two-dimensional mapping of ion density and plasma potential in a diverging magnetized low pressure (0.4 mTorr) carbon dioxide helicon plasma containing a double layer reveals the presence of high density conics (∼7× 109 cm-3) along the most diverging magnetic field lines exiting the helicon source and connecting with the grounded expansion chamber. The density in the conic is about 30% greater than the density at the double layer and this results from local ionization associated with the presence of a high energy tail in the electron energy probability function. The plasma potential along the conic is constant at about 30 V. © 2010 American Institute of Physics. Source


Cylindrical anisotropy in Earth's inner core has been invoked to account for travel times of PKP core-sensitive seismic waves, such as from the South Sandwich Islands (SSI) earthquakes observed in Alaska, which depart from predictions. Newly collected travel-time residuals from seismic waves from the SSI region that sample only Earth's mantle (PcP and P waves) have a comparable range to the PKP differential travel-time residuals, yet they are insensitive to core structure. This observation suggests that mantle structure affects PKP travel time residuals more than previously acknowledged and challenges the existing conceptual framework of a uniform inner core anisotropy. The inner core could be a conglomerate of anisotropic domains, and the PKP travel times are most likely influenced by the geometry of inner core sampling and inhomogeneous mantle structure. This concept reconciles observed complexities in travel times while preserving a net inner core anisotropy that is required by observations of Earth's free oscillations. © 2010 by the American Geophysical Union. Source


Davies G.F.,Australian National University
Geochemistry, Geophysics, Geosystems | Year: 2010

It is proposed that noble gases in the mantle reside mainly in a "hybrid pyroxenite" component that is formed as melt from old subducted oceanic crust reacts with surrounding refractory peridotite under midocean ridges. The gases are presumed to have been acquired early in Earth history, and mixing under midocean ridges of melts from pyroxenites and old crust would pass the noble gases to successive generations of pyroxenites. Much of the complement of noble gases would not be erupted at mid-ocean ridges and would recirculate in the mantle, so the hybrid pyroxenite would degas rather slowly over Earth history. The hybrid pyroxenite would also be denser than average mantle and would tend to settle into the D. zone at the base of the mantle, in the same way as subducted oceanic crust. Because residence times in D. are longer than in the rest of the mantle, the D. pyroxenite would be less degassed and its noble gases would be less radiogenic than that in the mid-ocean ridge basalt (MORB) source. Plumes could therefore tap a mixture of old, degassed oceanic crust and less degassed hybrid pyroxenite. This could resolve the long-standing question of the source of unradiogenic helium in many ocean island basalts (OIBs). Abundances of noble gases are not very well constrained and are plausibly larger than conventional estimates, which would remove the need for a large, deep, "undegassed" reservoir. The 40Ar mass balance may be satisfied if account is taken of uncertainties in the potassium content of the continental crust and the bulk silicate Earth and in the Earth's total budget of 40Ar. A relatively simple quantitative theory for the evolution of the noble gases is presented that accounts for the present concentrations and isotopic compositions of helium, neon, and argon in the MORB and OIB source regions. In particular, it confirms that longer residence times in D. can account for the less radiogenic noble gases in OIBs. Copyright 2010 by the American Geophysical Union. Source


Kim R.E.,Australian National University | Kim R.E.,United Nations University
Global Environmental Change | Year: 2013

The conventional piecemeal approach to environmental treaty-making has resulted in a 'maze' of international agreements. However, little is known empirically about its overall structure and evolutionary dynamics. This study reveals and characterizes the evolving structure of the web of international environmental treaty law. The structure was approximated using 1001 cross-references among 747 multilateral environmental agreements concluded from 1857 to 2012. Known network analysis measures were used to answer the following questions: has a complex system of international environmental treaty law emerged? If so when, and what does it look like? What are its topological properties? To what extent is the institutional complex fragmented? The network analysis suggested that multilateral environmental agreements have self-organized into an interlocking system with a complex network structure. Furthermore, the system has defragmented as it coevolved with the increasing complexity and interconnectivity of global environmental challenges. This study demonstrates the need to approach multilateral environmental agreements in the context of a complex networked system, and recommends against assuming the overall institutional structure is fragmented. Proposals for global environmental governance reform should pay attention to this network's emergent polycentric order and complexity and to the implications of these features for the functioning of the multilateral environmental agreement system. © 2013 Elsevier Ltd. Source


Joseph J.F.,University of Texas at San Antonio | Guillaume J.H.A.,Australian National University
Environmental Modelling and Software | Year: 2013

Markov Chain Monte Carlo (MCMC) algorithms allow the analysis of parameter uncertainty. This analysis can inform the choice of appropriate likelihood functions, thereby advancing hydrologic modeling with improved parameter and quantity estimates and more reliable assessment of uncertainty. For long-running models, the Differential Evolution Adaptive Metropolis (DREAM) algorithm offers spectacular reductions in time required for MCMC analysis. This is partly due to multiple parameter sets being evaluated simultaneously. The ability to use this feature is hindered in models that have a large number of input files, such as SWAT. A conceptually simple, robust method for applying DREAM to SWAT in R is provided. The general approach is transferrable to any executable that reads input files. We provide this approach to reduce barriers to the use of MCMC algorithms and to promote the development of appropriate likelihood functions. © 2013 Elsevier Ltd. Source


Turner J.S.,Australian National University
Journal of Physical Oceanography | Year: 2010

This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the halocline over the past few decades.Aseries of laboratory model experiments has previously been carried out to explore the possibility that the extra heating at depth could be responsible for the enhanced melting rate. These experiments have demonstrated that a one-dimensional heat flux from below through a series of double-diffusive layers can in principle lead to faster melting of floating ice. However, it is now essential to test these ideas quantitatively under ocean conditions and to compare the results with other possible mechanisms of melting. Asimple calculation shows that there is enough heat in the intruding Atlantic water to melt all the ice in the Arctic in a few years if all the heat could be brought to the surface in this time. The vertical double-diffusive transport of heat is slower than this, but it is large enough to make a substantial contribution to the increased rate of melting over the last three or four decades. Another proposed mechanism for melting is the solar input to the surface mixed layer from the atmosphere. In particular years when detailed measurements and calculations have been made, this atmospheric input can explain both the seasonal cyclic behavior of ice and the increased melting rate. Given the large heat content in the intruding Atlantic layer, however, it seems worth exploring further other advective two-dimensional mechanisms that could transport this heat upward more rapidly than the purely vertical double-diffusive convection. For example, dense salty water produced by freezing on the shelves around the Arctic Basin could flow down the slope and penetrate through the halocline, thus mixing with the warm water and bringing it to the surface. © 2010 American Meteorological Society. Source


Young G.C.,Australian National University
Palaeoworld | Year: 2010

The complex data set resulting from early vertebrate diversification during the middle Palaeozoic has played a key role in developing analytical methods in palaeobiogeography. Rather than using fossils to test hypotheses based on Recent taxa, or geological/geophysical interpretations of palaeogeography, it is argued that the primary criterion for applying cladistic methods is whether data sets have hierarchical structure. Any evidence (biological or non-biological) concerned with connections or barriers between areas is hierarchical, and can be analysed cladistically, but data supporting nodes of cladograms diverging through time have different properties to those converging through time, because more general attributes historically precede the less general in the former, and less general precede more general in the latter. Standard parsimony algorithms can be used for non-biological data in diverging area cladograms, but for converging area cladograms different algorithms are needed, even though the principle of parsimony analysis still holds; i.e., the preferred hypothesis is that which minimises independent explanations of empirical geological, geophysical or biological data. The historical development of these ideas using early vertebrate examples is reviewed. © 2009 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS. Source


Spandler C.,James Cook University | O'Neill H.S.C.,Australian National University
Contributions to Mineralogy and Petrology | Year: 2010

Lattice diffusion coefficients have been determined for 19 elements (Li, Be, Na, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Eu, Gd, Lu and Hf) in a single crystal of San Carlos olivine as a function of crystallographic orientation, at 1,300°C, 1 bar and fO2 = 10-8.3 bars, by equilibration with a synthetic silicate melt. Results for Li, Na, V, Cr, Fe and Zn are from diffusion of these elements out of the olivine, starting from their indigenous concentrations; those for all other elements are from diffusion into the olivine, from the silicate melt reservoir. Our 25-day experiment produced diffusion profiles 50 to > 700 μm in length, which are sufficiently long that precise analyses could be achieved by scanning laser ablation inductively coupled plasma mass spectrometry, even at concentration levels well below 1 μg g-1. For the divalent cations Ca, Mn, Fe and Ni, profiles were also obtained by electron microprobe analysis. The results of the two methods agree well with each other, and are consistent with divalent cation diffusion coefficients previously determined using different experimental methodologies. Olivine/melt partition coefficients retrieved from the data are also consistent with other published partitioning data, indicating that element incorporation and transport in olivine in our experiment occurred via mechanisms appropriate to natural conditions. Most of the examined trace elements diffuse through olivine at similar rates to the major octahedral cations Fe and Mg, showing that cation charge and radius have little direct influence on diffusion rates. Aluminium and P remain low and constant in the olivine, implying negligible transport at our analytical scale, hence Al and P diffusion rates that are at least two orders of magnitude slower than the other cations studied here. All determined element diffusivities are anisotropic, with diffusion fastest along the [001] axis, except Y and the REEs, which diffuse isotropically. The results suggest that element diffusivity in olivine is largely controlled by cation site preference, charge balance mechanisms and point-defect concentrations. Elements that are present on multiple cation sites in olivine (e.g. Be and Ti) and trivalent elements that are charge-balanced by octahedral site vacancies tend to diffuse at relatively fast rates. © Springer-Verlag 2009. Source


Sukhorukov A.A.,Australian National University
Optics Letters | Year: 2010

We present an approach for the realization of reflectionless potentials in linear coupled-resonator optical waveguides or optical waveguide arrays with modulated coupling. We show that soliton solutions of nonlinear Ablowitz-Ladik equations can be used to define analytically refiectionless modulations for linear photonic structures. Such structures fully transmit incident waves and simultaneously support a pair of localized modes. These results suggest new possibilities for pulse and beam shaping, including a realization of cavities that do not reflect incident light. © 2010 Optical Society of America. Source


Stern D.I.,Australian National University
PLoS ONE | Year: 2014

Do citations accumulate too slowly in the social sciences to be used to assess the quality of recent articles? I investigate whether this is the case using citation data for all articles in economics and political science published in 2006 and indexed in the Web of Science. I find that citations in the first two years after publication explain more than half of the variation in cumulative citations received over a longer period. Journal impact factors improve the correlation between the predicted and actual future ranks of journal articles when using citation data from 2006 alone but the effect declines sharply thereafter. Finally, more than half of the papers in the top 20% in 2012 were already in the top 20% in the year of publication (2006). ©2014 David Ian Stern. This. Source


Arkell R.M.,Australian National University | Tam P.P.L.,University of Sydney
Open Biology | Year: 2012

The generation of an embryonic body plan is the outcome of inductive interactions between the progenitor tissues that underpin their specification, regionalization and morphogenesis. The intercellular signalling activity driving these processes is deployed in a time- and site-specific manner, and the signal strength must be precisely controlled. Receptor and ligand functions are modulated by secreted antagonists to impose a dynamic pattern of globally controlled and locally graded signals onto the tissues of early post-implantation mouse embryo. In response to the WNT, Nodal and Bone Morphogenetic Protein (BMP) signalling cascades, the embryo acquires its body plan, which manifests as differences in the developmental fate of cells located at different positions in the anterior-posterior body axis. The initial formation of the anterior (head) structures in the mouse embryo is critically dependent on the morphogenetic activity emanating from two signalling centres that are juxtaposed with the progenitor tissues of the head. A common property of these centres is that they are the source of antagonistic factors and the hub of transcriptional activities that negatively modulate the function of WNT, Nodal and BMP signalling cascades. These events generate the scaffold of the embryonic head by the early-somite stage of development. Beyond this, additional tissue interactions continue to support the growth, regionalization, differentiation and morphogenesis required for the elaboration of the structure recognizable as the embryonic head. © 2012 The Authors. Source


Abdel-Latif M.E.,Australian National University
Archives of disease in childhood. Fetal and neonatal edition | Year: 2013

To characterise the actuarial day-by-day survival of premature infants in a geographically defined population. 10 Neonatal Intensive Care Units (NICUs) in New South Wales (NSW) and Australian Capital Territory (ACT), Australia. Retrospective analysis of prospectively collected data as part of NICUs' data collection in NSW and ACT. Premature infants born at 22(+0) to 31(+6) weeks' gestation between January 1997 and December 2006 and admitted to one of the 10 NICUs in NSW and ACT. Actuarial day-by-day survival to discharge from NICU. Survival to discharge after initiation of neonatal intensive care ranges from 30.0% at 23 weeks' gestation to 98.8% at 31 weeks. Actuarial day-by-day survival increased across all gestations. This improvement was most notable among the babies who were born <26 weeks gestation. Preterm infants who survive the first few postnatal days have considerable chances of long-term survival. It is important to revise the information stored regarding chances of survival so it covers chances at regular intervals, especially after the first few days of life. Source


McClelland D.E.,Australian National University | Mavalvala N.,Massachusetts Institute of Technology | Chen Y.,California Institute of Technology | Schnabel R.,Leibniz University of Hanover
Laser and Photonics Reviews | Year: 2011

Currently operating laser interferometric gravitational wave detectors are limited by quantum noise above a few hundred Hertz. Detectors that will come on line in the next decade are predicted to be limited by quantum noise over their entire useful frequency band (from 10 Hz to 10 kHz). Further sensitivity improvements will, therefore, rely on using quantum optical techniques such as squeezed state injection and quantum non-demolition, which will, in turn, drive these massive mechanical systems into quantum states. This article reviews the principles behind these optical and quantum optical techniques and progress toward there realization. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Hill C.E.,Australian National University
Microcirculation | Year: 2012

The mechanism enabling coordination of the resistance of feed arteries with microcirculatory arterioles to rapidly regulate tissue blood flow in line with changes in metabolic demand has preoccupied scientists for a quarter of a century. As experiments uncovered the underlying electrical events, it was frequently questioned how vasodilation could conduct over long distances without appreciable attenuation. This perspective reviews the data pertinent to this phenomenon and provides evidence that this remarkable response could be made possible by a simple mechanism based on the steep relationship between membrane potential and calcium entry demonstrated by the voltage-dependent calcium channels which mediate the control of vascular tone in vivo. © 2012 John Wiley & Sons Ltd. Source


Luger K.,Colorado State University | Luger K.,Howard Hughes Medical Institute | Dechassa M.L.,Colorado State University | Tremethick D.J.,Australian National University
Nature Reviews Molecular Cell Biology | Year: 2012

The compaction of genomic DNA into chromatin has profound implications for the regulation of key processes such as transcription, replication and DNA repair. Nucleosomes, the repeating building blocks of chromatin, vary in the composition of their histone protein components. This is the result of the incorporation of variant histones and post-translational modifications of histone amino acid side chains. The resulting changes in nucleosome structure, stability and dynamics affect the compaction of nucleosomal arrays into higher-order structures. It is becoming clear that chromatin structures are not nearly as uniform and regular as previously assumed. This implies that chromatin structure must also be viewed in the context of specific biological functions. © 2012 Macmillan Publishers Limited. All rights reserved. Source