Commonwealth Scientific and Industrial Research Organisation

About: Commonwealth Scientific and Industrial Research Organisation is a government organization based out in Canberra, Australian Capital Territory, Australia. It is known for research contribution in the topics: Population & Soil water. The organization has 33765 authors who have published 79910 publications receiving 3356114 citations.

Radiation Profiles in Extended Water Clouds. II: Parameterization Schemes

Abstract: The shortwave absorption, albedo and longwave emissivity of water clouds are parameterized for use in operational and climatic models of the atmosphere. The parameterization also provides the shortwave heating and longwave cooling rates within the cloud. The scheme presented in this paper assumes a prior knowledge of the broadband spectral fluxes incident on the cloud and further assumes that the atmospheric models will provide the surface albedo, solar zenith angle, cloud temperature and total vertical liquid water path. The last parameter was chosen because it likely to be available in atmospheric circulation models and both observational and theoretical evidence suggest that it is strongly related to the radiative properties of clouds (Paltridge, 1974; Platt, 1976). The parameterization of shortwave radiation resembles a two-stream approximation which has been “tuned” to match the results from a detailed theoretical model. The longwave scheme simply involves the parameterization of effective e...

Proteins at interfaces.

Abstract: Publisher Summary The chapter discusses the proteins at interfaces and aims to present protein adsorption and its ramifications, such as the effects of adsorption on conformation and reactivity from a fundamental physicochemical approach Although many proteins are very soluble in water, adsorption leads to stable monolayers that are extremely difficult to desorb Adsorption may be followed at fluid/fluid interfaces by measuring changes in interfacial pressure, potential, or viscosity, using spread monolayers for calibration purposes Before a protein molecule can adsorb and exert its influence at a phase boundary or take part in an interfacial reaction, it must arrive at the interface by a diffusion process At fluid/fluid interfaces, it is established that proteins lose their tertiary structure One of the advantages of the fluid/fluid type interface is that the distribution between adsorbed (trains) and displaced segments (loops) may be quantitatively studied by carrying out measurements with a film balance This approach has been used for spread monolayers of protein The high free energy of adsorption of proteins results in all segments being at the interface at low interfacial pressures The conformational changes that accompany desorption from an interface have direct bearing on the important subject of protein biosynthesis The chapter also discusses the equilibrium aspects of adsorption, reactions at interfaces, and proteins at interfaces in biological systems

Selectable traits to increase crop photosynthesis and yield of grain crops

Abstract: The grain yield of cereals has almost doubled this century as a result of genetic manipulation by plant breeding. Surprisingly, there has been no change in the rate of photosynthesis per unit leaf area to accompany these increases. However, total photosynthesis has increased as a result of an increase in leaf area, daily duration of photosynthesis or leaf area duration. There remain substantial opportunities to continue to improve total photosynthesis and crop yield genetically using conventional breeding practices. Selectable traits are discussed here in the context of increasing total above-ground biomass under favourable conditions. Opportunities exist to alter crop duration and the timing of crop development to match it better to radiation, temperature and vapour pressure during crop growth, and to increase the rate of development of early leaf area to achieve rapid canopy closure. The importance of these traits will depend on the environment in which the crop is grown. Increases in crop photosynthesis through breeding are also likely to come via indirect means. Selection for a high and sustained stomatal conductance during the period of stem elongation is one way. Increasing assimilate allocation to the reproductive primordia so as to establish a large potential sink should also indirectly increase total crop photosynthesis. Evidence in the major grain crops suggests that by anthesis the capacity for photosynthesis is high and that photosynthesis is not limiting during grain filling. To use this surplus capacity it is suggested that carbon and nitrogen partitioning to the reproductive meristem be increased so as to establish a high potential grain number and the potential for a large grain size. It is then expected that additional photosynthesis will follow, either by a longer daily duration of photosynthesis or by an extended leaf area duration.

Choosing functions for semi‐variograms of soil properties and fitting them to sampling estimates

Abstract: SUMMARY The semi-variogram is central to geostatistics and the single most important tool in geo-statistical applications to soil. Mathematical functions for semi-variograms must be conditional negative semi-definite, and there are only a few families of simple function that meet this demand. These include the transitive models with finite a priori variance deriving from moving average processes. The spherical and exponential schemes are the most often encountered members. The other major group is that of unbounded models in which the variance appears to increase without limit. The linear model is the most common in this group. If more complex models are needed they can be formed by combining two or more simple models. The usual estimator of the semi-variance is often considered inefficient and to be sensitive to departures from normality in the data. It is compared with a robust estimator and shown to be generally preferable in being unbiased and having confidence intervals that are no wider. For routine analysis, fitting models to sample semi-variograms by weighted least squares approximation, with weights proportional to the expected semi-variance, is preferred to the more elaborate and computationally demanding statistical procedures of generalized least squares and maximum likelihood. The Akaike information criterion is recommended for selecting the best model from several plausible ones to describe the observed variation in soil, though for kriging it may be desirable to validate the chosen model. Examples of models fitted to soil semi-variograms are shown and compared.