73 research outputs found
Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre
Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in
red abalone consists of layers of 400-nm thick aragonite crystalline tablets
confined by organic matrix sheets, with the crystal axes of the
aragonite tablets oriented to within 12 degrees from the normal to the
layer planes. Recent experiments demonstrate that this orientational order
develops over a distance of tens of layers from the prismatic boundary at which
nacre formation begins.
Our previous simulations of a model in which the order develops because of
differential tablet growth rates (oriented tablets growing faster than
misoriented ones) yield patterns of tablets that agree qualitatively and
quantitatively with the experimental measurements. This paper presents an
analytical treatment of this model, focusing on how the dynamical development
and eventual degree of order depend on model parameters. Dynamical equations
for the probability distributions governing tablet orientations are introduced
whose form can be determined from symmetry considerations and for which
substantial analytic progress can be made. Numerical simulations are performed
to relate the parameters used in the analytic theory to those in the
microscopic growth model. The analytic theory demonstrates that the dynamical
mechanism is able to achieve a much higher degree of order than naive estimates
would indicate.Comment: 20 pages, 3 figure
Systematic tight-binding analysis of ARPES spectra of transition-metal oxides
We have performed systematic tight-binding (TB) analyses of the
angle-resolved photoemission spectroscopy (ARPES) spectra of transition-metal
(TM) oxides AO ( Ti, V, Mn, and Fe) with the perovskite-type
structure and compared the obtained parameters with those obtained from
configuration-interaction (CI) cluster-model analyses of photoemission spectra.
The values of from ARPES are found to be similar to the
charge-transfer energy from O orbitals to empty TM 3d orbitals
and much larger than (: on-site Coulomb energy) expected for
Mott-Hubbard-type compounds including SrVO. values
from {\it ab initio} band-structure calculations show similar behaviors to
those from ARPES. The values of the transfer integrals to describe the
global electronic structure are found to be similar in all the estimates,
whereas additional narrowing beyond the TB description occurs in the ARPES
spectra of the band.Comment: 5 pages, 3 figure
Concentration Dependent Ion Selectivity in VDAC: A Molecular Dynamics Simulation Study
The voltage-dependent anion channel (VDAC) forms the major pore in the outer mitochondrial membrane. Its high conducting open state features a moderate anion selectivity. There is some evidence indicating that the electrophysiological properties of VDAC vary with the salt concentration. Using a theoretical approach the molecular basis for this concentration dependence was investigated. Molecular dynamics simulations and continuum electrostatic calculations performed on the mouse VDAC1 isoform clearly demonstrate that the distribution of fixed charges in the channel creates an electric field, which determines the anion preference of VDAC at low salt concentration. Increasing the salt concentration in the bulk results in a higher concentration of ions in the VDAC wide pore. This event induces a large electrostatic screening of the charged residues promoting a less anion selective channel. Residues that are responsible for the electrostatic pattern of the channel were identified using the molecular dynamics trajectories. Some of these residues are found to be conserved suggesting that ion permeation between different VDAC species occurs through a common mechanism. This inference is buttressed by electrophysiological experiments performed on bean VDAC32 protein akin to mouse VDAC
Crop Updates 2010 - Farming Systems
This session covers twenty papers from different authors:
Pests and Disease
1. Preserving phosphine for use in Grain Storage Industry, Christopher R Newman, Department of Agriculture and Food
Farming Systems Research
2. Demonstrating the benefits of grazing canola in Western Australia, Jonathan England, Stephen Gherardi and Mohammad Amjad, Department of Agriculture and Food
3. Buloke barley yield when pasture-cropped across subtropical perennial pastures, David Ferris, Department of Agriculture and Food, Phil Ward and Roger Lawes, CSIRO
4. Is pasture cropping viable in WA? Grower perceptions and EverCrop initiatives to evaluate, David Ferris, Tim Wiley, Perry Dolling, Department of Agriculture and Food, Philip Barrett-Lennard, Evergreen farming
5. Best-bet management for dual-purpose canola, John Kirkegaard, Susan Sprague, Hugh Dove and Walter Kelman, CSIRO, Canberra, Peter Hamblin, Agritech Research, Young, NSW
6. Pasture in cropping systems – with and without sheep, Brad Nutt and Angelo Loi, Department of Agriculture and Food
7. Can technology substitute for a lupin break? Wayne Parker, Department of Agriculture and Food
8. Canola row spacing with and without long term stubble retention on a sandy clay loam at Merredin, Glen Riethmuller, Department of Agriculture and Food
9. Impact of stubble retention on water balance and crop yield, Phil Ward1, Ken Flower2,3, Neil Cordingley2 and Shayne Micin1, 1CSIRO, Wembley, Western Australia, 2Western Australian No-Till Farmers Association, 3University of Western Australia
Analysis and Modelling
10. Using POAMA rainfall forecasts for crop management in South-West WA, Senthold Asseng1, Peter McIntosh2,3, Mike Pook2,3, James Risbey2,3, Guomin
Wang3, Oscar Alves3, Ian Foster4, Imma Farre4 and Nirav Khimashia1, 1CSIRO Plant Industry, Perth, 2CSIRO Marine and Atmospheric Research, Hobart, 3Centre for Australian Weather and Climate Research (CAWCR), A partnership between the Australian Bureau of Meteorology and CSIRO, Melbourne, 4Department of Agriculture and Food
11. Adaption to changing climates and variability – results of the Agribusiness Changing Climates regional workshop, Anderson W3, Beard D3, Blake J3, Grieve R1, Lang M3, Lemon J3, McTaggart R3, Gray D3, Price M2 and Stephens D3, 1Roderick Grieve Farm Management Consultants, 2Coffey International P/L, 3Department of Agriculture and Food
12. Farmers’ management of seasonal variability and climate change in WA, DA Beard, DM Gray, P Carmody, Department of Agriculture and Food
13. Is there a value in having a frost forecast for wheat in South-West WA? Imma Farre1, Senthold Asseng2, Ian Foster1 and Doug Abrecht3, 1Department of Agriculture and Food, CSIRO, Floreat, 2CSIRO Plant Industry, Perth
3Department of Agriculture and Food, Centre for Cropping Systems
14. Does buying rainfall pay? Greg Kirk, Planfarm Agricultural Consultants
15. Which region in the WA wheatbelt makes best use of rainfall? Peter Rowe, Bankwest Agribusiness
16. POAMA – the Predictive Ocean-Atmosphere Model for Australia, Guomin Wang and Oscar Alves, Centre for Australian Weather and Climate Research (CAWCR), A partnership between the Australian Bureau of Meteorology and CSIRO, Melbourne
17. Exploring the link between water use efficiency and farm profitability, Cameron Weeks, Planfarm and Peter Tozer, PRT Consulting
Precision Agriculture
18. A plethora of paddock information is available – how does it stack up? Derk Bakker, Department of Agriculture and Food
18. Variable rate prescription mapping for lime inputs based on electromagnetic surveying and deep soil testing, Frank D’Emden, Quenten Knight and Luke Marquis, Precision Agronomics, Australia
19. Trial design and analysis using precision agriculture and farmer’s equipment, Roger Lawes, CSIRO Sustainable Ecosystems, Centre for Environment and Life
Sciences, Floreat
20. Farmer perspectives of precision agriculture in Western Australia: Issues and the way forward, Dr Roger Mandel, Curtin Universit
Evaluation of morphological characteristics in Venezuelan maize (Zea mays L.) genotypes under drought stress
First measurement of ice-bedrock interface of alpine glaciers by cosmic muon radiography
Applying data mining tools to improve grain quality for growers
Most of the crop variety information from breeding organisations promotes the positive aspects of varieties included, rather than a grower specific view.
The grower needs to take into account across all the new varieties improved germplasm traits when making cropping decisions.
Data mining techniques offer opportunities for summarising diverse data into a coherent format which is understandable by growers.
Data mining offers opportunities to improve the process of identifying and recommending new varieties as it can facilitate the analysis of multiple information sources.
Data mining can provide both the crop breeder and grower with a more translucent view of the general trends in the performance and other plant traits of new varieties
Large-scale redox plume in glaciofluvial deposits due to sugar-factory wastes and wastewater at Aarberg, Switzerland
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