Australian National University

About: Australian National University is a education organization based out in Canberra, Australian Capital Territory, Australia. It is known for research contribution in the topics: Population & Galaxy. The organization has 34419 authors who have published 109261 publications receiving 4315448 citations. The organization is also known as: The Australian National University & ANU.

Simulation of Stationary Gaussian Processes in [0, 1] d

Abstract: A method for simulating a stationary Gaussian process on a fine rectangular grid in [0, 1]d ⊂ℝd is described It is assumed that the process is stationary with respect to translations of ℝd, but the method does not require the process to be isotropic As with some other approaches to this simulation problem, our procedure uses discrete Fourier methods and exploits the efficiency of the fast Fourier transform However, the introduction of a novel feature leads to a procedure that is exact in principle when it can be applied It is established that sufficient conditions for it to be possible to apply the procedure are (1) the covariance function is summable on ℝd, and (2) a certain spectral density on the d-dimensional torus, which is determined by the covariance function on ℝd, is strictly positive The procedure can cope with more than 50,000 grid points in many cases, even on a relatively modest computer An approximate procedure is also proposed to cover cases where it is not feasible to apply

13C discrimination during CO2 assimilation by the terrestrial biosphere

Abstract: Estimates of the extent of the discrimination against13CO2 during photosynthesis (ΔA) on a global basis were made using gridded data sets of temperature, precipitation, elevation, humidity and vegetation type. Stomatal responses to leaf-to-air vapour mole fraction difference (D, leaf-to-air vapour pressure difference divided by atmospheric pressure) were first determined by a literature review and by assuming that stomatal behaviour results in the optimisation of plant water use in relation to carbon gain. Using monthly time steps, modelled stomatal responses toD were used to calculate the ratio of stomatal cavity to ambient CO2 mole fractions and then, in association with leaf internal conductances, to calculate ΔA. Weighted according to gross primary productivity (GPP, annual net CO2 asimilation per unit ground area), estimated ΔA for C3 biomes ranged from 12.9‰ for xerophytic woods and shrub to 19.6‰ for cool/cold deciduous forest, with an average value from C3 plants of 17.8‰. This is slightly less than the commonly used values of 18–20‰. For C4 plants the average modelled discrimination was 3.6‰, again slightly less than would be calculated from C4 plant dry matter carbon isotopic composition (yielding around 5‰). From our model we estimate that, on a global basis, 21% of GPP is by C4 plants and for the terrestrial biosphere as a whole we calculate an average isotope discrimination during photosynthesis of 14.8‰. There are large variations in ΔA across the globe, the largest of which are associated with the precence or absence of C4 plants. Due to longitudinal variations in ΔA, there are problems in using latitudinally averaged terrestrial carbon isotope discriminations to calculate the ratio of net oceanic to net terrestrial carbon fluxes.

The Real Worlds of Welfare Capitalism

Abstract: The Real Worlds of Welfare Capitalism traces how individuals fare over time in each of the three principal types of welfare state. Through a unique analysis of panel data from Germany, the Netherlands and the US, tracking individuals' socio-economic fate over fully ten years, Goodin, Headey, Muffels and Dirven explore issues of economic growth and efficiency, of poverty and inequality, of social integration and social autonomy. It is common to talk of the inevitability of tradeoffs between these goals. However, in this book the authors contend that the social democratic welfare regime, represented here by the Netherlands, equals or exceeds the performance of the corporatist German regime and the liberal US regime across all these social and economic objectives. They thus argue that, whatever one's priorities, the social democratic welfare regime is uniquely well-suited to realizing them.

Climate change and the resurgence of malaria in the East African highlands.

Abstract: The public health and economic consequences of Plasmodium falciparum malaria are once again regarded as priorities for global development. There has been much speculation on whether anthropogenic climate change is exacerbating the malaria problem, especially in areas of high altitude where P. falciparum transmission is limited by low temperature. The International Panel on Climate Change has concluded that there is likely to be a net extension in the distribution of malaria and an increase in incidence within this range. We investigated long-term meteorological trends in four high-altitude sites in East Africa, where increases in malaria have been reported in the past two decades. Here we show that temperature, rainfall, vapour pressure and the number of months suitable for P. falciparum transmission have not changed significantly during the past century or during the period of reported malaria resurgence. A high degree of temporal and spatial variation in the climate of East Africa suggests further that claimed associations between local malaria resurgences and regional changes in climate are overly simplistic.

Specific Ion Effects: Why DLVO Theory Fails for Biology and Colloid Systems

Abstract: The classical Derjaguin-Landau-Verwey-Overbeek theory that underpins colloid and surface science is shown to be flawed, especially at biological salt concentrations. This is in part because the dispersion forces acting on the ions are ignored. When these are included properly very different results are obtained. These results have substantial implications for biological and for ordinary colloid systems at moderate salt concentrations.