225 research outputs found

    Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

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    Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. © 2013 Solovyev et al

    Beyond element-wise interactions: identifying complex interactions in biological processes

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    Background: Biological processes typically involve the interactions of a number of elements (genes, cells) acting on each others. Such processes are often modelled as networks whose nodes are the elements in question and edges pairwise relations between them (transcription, inhibition). But more often than not, elements actually work cooperatively or competitively to achieve a task. Or an element can act on the interaction between two others, as in the case of an enzyme controlling a reaction rate. We call “complex” these types of interaction and propose ways to identify them from time-series observations. Methodology: We use Granger Causality, a measure of the interaction between two signals, to characterize the influence of an enzyme on a reaction rate. We extend its traditional formulation to the case of multi-dimensional signals in order to capture group interactions, and not only element interactions. Our method is extensively tested on simulated data and applied to three biological datasets: microarray data of the Saccharomyces cerevisiae yeast, local field potential recordings of two brain areas and a metabolic reaction. Conclusions: Our results demonstrate that complex Granger causality can reveal new types of relation between signals and is particularly suited to biological data. Our approach raises some fundamental issues of the systems biology approach since finding all complex causalities (interactions) is an NP hard problem

    Designing informative warning signals: Effects of indicator type, modality, and task demand on recognition speed and accuracy

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    An experiment investigated the assumption that natural indicators which exploit existing learned associations between a signal and an event make more effective warnings than previously unlearned symbolic indicators. Signal modality (visual, auditory) and task demand (low, high) were also manipulated. Warning effectiveness was indexed by accuracy and reaction time (RT) recorded during training and dual task test phases. Thirty-six participants were trained to recognize 4 natural and 4 symbolic indicators, either visual or auditory, paired with critical incidents from an aviation context. As hypothesized, accuracy was greater and RT was faster in response to natural indicators during the training phase. This pattern of responding was upheld in test phase conditions with respect to accuracy but observed in RT only in test phase conditions involving high demand and the auditory modality. Using the experiment as a specific example, we argue for the importance of considering the cognitive contribution of the user (viz., prior learned associations) in the warning design process. Drawing on semiotics and cognitive psychology, we highlight the indexical nature of so-called auditory icons or natural indicators and argue that the cogniser is an indispensable element in the tripartite nature of signification

    Genetics of the Hippocampal Transcriptome in Mouse: A Systematic Survey and Online Neurogenomics Resource

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    Differences in gene expression in the CNS influence behavior and disease susceptibility. To systematically explore the role of normal variation in expression on hippocampal structure and function, we generated an online microarray database for a diverse panel of strains of mice, including most common inbred strains and numerous recombinant inbred lines (www.genenetwork.org). Using this resource, coexpression networks for families of genes can be generated rapidly to test causal models related to function. The data set is optimized for quantitative trait locus (QTL) mapping and was used to identify over 5500 QTLs that modulate mRNA levels. We describe a wide variety of analyses and novel synthetic approaches that take advantage of this resource, and demonstrate how both the data and associated tools can be applied to the study of gene regulation in the hippocampus and relations to structure and function

    A Cauchy-Dirac delta function

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    The Dirac delta function has solid roots in 19th century work in Fourier analysis and singular integrals by Cauchy and others, anticipating Dirac's discovery by over a century, and illuminating the nature of Cauchy's infinitesimals and his infinitesimal definition of delta.Comment: 24 pages, 2 figures; Foundations of Science, 201

    Crop Updates 2000 - Weeds

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    This session covers thirty six papers from different authors: INTRODUCTION, Vanessa Stewart Agriculture Western Australia INTEGRATED WEED MANAGEMENT Effect of seeding density, row spacing and Trifluralin on the competitive ability of Annual Ryegrass in a minimum tillage system, David Minkey, Abul Hashem, Glen Riethmuller and Martin Harries, Agriculture Western Australia High wheat seeding rates coupled with narrow row spacing increases yield and suppresses grass, Peter Newman1 and Cameron Weeks2,1Agronomist, Elders Limited 2Mingenew/Irwin Group Resistant ryegrass management in a wheat – lupin rotation, Abul Hashem, Harmohinder S. Dhammu, Aik Cheam, David Bowran and Terry Piper, Agriculture Western Australia Integrated weed management – Will it work with my rotation? Alexandra Wallace, Agriculture Western Australia Long term herbicide resistance trial – Mingenew, Peter Newman Elders, Cameron Weeks Mingenew-Irwin Group Is two years enough? Bill Roy, Agricultural Consulting and Research Services The fate of ryegrass seed when sheep graze chaff cart heaps, Keith L. Devenish1 and Lisa J. Leaver2 1 Agriculture Western Australia, 2Curtin University of Technology, Muresk Institute of Agriculture Can blanket wiping and crop topping prevent seed set of resistant wild radish and mustard? StAbul Hashem, Harmohinder Dhammu, Vanessa Stewart, Brad Rayner and Mike Collins, Agriculture Western Australia The value of green manuring in the integrated management of ryegrass, Marta Monjardino1,2, David Pannell2, Stephen Powles1 ,1Western Australia Herbicide Resistance Initiative, 2Agricultural and Resource Economics, University of Western Australia Some ways of increasing wheat competitiveness against ryegrass,, Mike Collins Centre for Cropping Systems, Agriculture Western Australia WEED BIOLOGY Understanding and driving weed seed banks to very low levels, Sally Peltzer, Agriculture Western Australi HERBICIDE RESISTANCE Cross resistance of chlorsulfuron-resistant wild radish to imidazolinones, Abul Hashem, Harmohinder Dhammu and David Bowran, Agriculture Western Australia Investigation of suspected triazine resistant ryegrass populations for cross-resistance and multiple resistance to herbicides, Michael Walsh, Charles Boyle and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Genetics and fitness of glyphosate resistant ryegrass, S. Powles1, P. Neve1, D. Lorraine-Colwill2, C. Preston2 ,1WAHRI, University of Western Australia 2 CRC Weed Management Systems, University of Adelaide Managing herbicide resistance – the effect of local extinction of resistance genes, Art Diggle1, Paul B. Neve2, Stephen B. Powles2 ,1Agriculture Western Australia, 2WAHRI, Faculty of Agriculture, University of Western Australia The double knock - the best strategy for conserving glyphosate susceptibility? Paul B. Neve1, Art Diggle2, Stephen B. Powles1,1WAHRI, Faculty of Agriculture, University of Western Australia, 2Agriculture Western Australia Wild radish had evolved resistance to triazines, Abul Hashem, Harmohinder S. Dhammu, David Bowran and Aik Cheam, Agriculture Western Australia Ryegrass resistance in Western Australia – where and how much? Rick Llewellyn and Stephen Powles, Western Australian Herbicide Resistance Initiative, Faculty of Agriculture, University of Western Australia Wild radish herbicide resistance survey, Michael Walsh, Ryan Duane and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Knockdown resistance in the Western Australian wheatbelt – a proposed survey, Paul B. Neve1, Abul Hashem2, Stephen B. Powles1,1Western Australian Herbicide Resistance Initiative, University of Western Australia, 2Agriculture Western Australia Diflufenican resistant wild radish, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australi Multiple resistance to triazines and diflufenican further complicates wild radish control, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australia HERBICIDE TOLERANCE 25. Herbicide tolerance of lupins, Terry Piper, Weed Science Group, Agriculture Western Australia 26. Tanjil lupins will tolerate metribuzin under the right conditions, Peter Newman, Agronomist Elders Limited and Cameron Weeks, Mingenew/Irwin Group 27. Herbicide damage does not mean lower yield in Lupins, Peter Carlton, Trials Coordinator, Elders Limited 28. Herbicide tolerance of new pea varieties, Dr Terry Piper, Agriculture Western Australia 29. Herbicide tolerance of (waterlogged) wheat, Dr Terry Piper, Agriculture Western Australia 30. Wheat tolerance trials – Mingenew 1999, Peter Newman1, Cameron Weeks2 and Stewart Smith3,1Elders, Mingenew, 2Mingenew-Irwin Group,3Agriculture Western Australia ISSUES OF TRIFLURALIN USE 31. Trifluralin works better on ryegrass when no-tilling into thick wheat stubbles as granules, or mixed with limesand, Bill Crabtree, WANTFA Scientific Officer 32. Increasing trifluralin rate did not compensate for delaying incorporation, Bill Crabtree, WANTFA Scientific Officer 33. Poor emergence survey, 1999, Terry Piper, Weed Science Group, Agriculture Western Australia HERBICIDES – ISSUES AND OPTIONS 34. AFFINITY 400DF – A new herbicide with a new mode of action (Group G) for Broadleaf Weed Control in Cereals, Gordon Cumming, Technical Officer, Crop Care Australasia 35 Herbicide screening for Marshmallow, David Minkey1 and David Cameron2,1Agriculture Western Australia, 2Elders Ltd, Merredin 36. The control of Capeweed in Clearfield Production System for Canola, Mike Jackson and Scott Paton, Cyanamid Agriculture Pty Ltd 37.Effect of herbicides Tordonä 75D and Lontrelä,used for eradication of Skeleton Weed, on production of Lupins I the following seasons, John R. Peirce and Brad J. Rayner, Agriculture Western Australia INDUSTRY PROTECTION 38. Graingaurd – Opportunities for agribusiness to help protect the West Australian grains industry, Greg Shea, Executive Officer, GrainGuard Agriculture Western Australi

    Crop Updates - 2003 Weeds

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    This session covers Thirty four papers from different authors INTRODUCTION INTEGRATED WEED MANAGEMENT IWM system studies/demonstration sites Six years of IWM investigation – what does it tell us? Bill Roy, Agricultural Consulting and Research Services Pty Ltd Long term herbicide resistance site, the final chapter, Peter Newman and Glen Adam, Department of Agriculture Management of skeleton weed (chondrilla juncea) in a cropping rotation in Western Australia, J. R. Peirce and B. J. Rayner, Department of Agriculture WEED BIOLOGY AND COMPETITION Annual ryegrass seedbanks: The good, the bad and the ugly, Kathryn J. Steadman1, Amanda J. Ellery2 and Sally C. Peltzer3 , 1WA Herbicide Resistance Initiative, UWA, 2CSIRO Plant Industry, 3 Department of Agriculture Annual ryegrass seeds after-ripen faster during a hot summer, Kathryn J. Steadman1, Gavin P. Bignell1 and Amanda J. Ellery2, 1WA Herbicide Resistance Initiative, UWA, 2CSIRO Plant Industry Predicting annual ryegrass dormancy from climatic variables, Amanda Ellery, Andrew Moore, Sandy Nedelkos, Ross Chapman, CSIRO Plant Industry Removing dormancy in annual ryegrass seeds for early herbicide resistance testing, Kathryn J. Steadman and Mechelle J. Owen, WA Herbicide Resistance Initiative, UWA Annual ryegrass germination responds to nitrogen, Amanda Ellery1, Simone Dudley1 and Robert Gallagher2, 1CSIRO Plant Industry, 2Washington State University The agro-ecology of Malva parviflora (small flowered mallow), Pippa J. Michael, Kathryn J. Steadman and Julie A. Plummer, Western Australia Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia The looming threat of wild radish, Peter Newman, Department of Agriculture IWM TOOLS Double knock, how close can we go? Peter Newman and Glen Adam, Department of Agriculture Double knock herbicide effect on annual ryegrass, Catherine Borger, Abul Hashem and Nerys Wilkins, Department of Agriculture Tactical techniques for managing Annual Ryegrass, Sally Peltzer1, Alex Douglas1, Fran Hoyle1, Paul Matson1 and Michael Walsh2 Department of Agriculture and 2Western Australian Herbicide Resistance Initiative. Weed control through soil inversion, Sally Peltzer, Alex Douglas and Paul Matson, Department of Agriculture The burning issues of annual ryegrass seed control, Darren Chitty and Michael Walsh, Western Australian Herbicide Resistance Initiative, UWA No sign of chaff-cart resistant ryegrass! David Ferris, WA Herbicide Resistance Initiative UWA PACKAGES AND MODELLING Conserving glyphosate susceptibility – modelling past, present and future us. Paul Neve1, Art Diggle2, Patrick Smith3 and Stephen Powles1 ,1Western Australian Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia, 2Department of Agriculture, 3CSIRO Sustainable Ecosystems WEEDEM: A program for predicting weed emergence in Western Australia, Michael Walsh,1 David Archer2, James Eklund2 and Frank Forcella2, 1Western Australia Herbicide Resistance Initiative, UWA, 2USDA-Agricultural Research Service, 803 Iowa Avenue, Morris, MN 56267, USA Weed and herbicide management for long term profit: A workshop, Alister Draper1 and Rick Llewellyn12, 1WA Herbicide Resistance Initiative, 2School of Agricultural and Resource Economics, University of Western Australia HERBICIDE RESISTANCE Alternative herbicides for control of triazine and diflufenican multiple resistant wild radish, Aik Cheam1, Siew Lee1, David Nicholson1 and Mike Clarke2 1Department of Agriculture, Western Australia, 2Bayer CropScience Resistance of wild mustard biotype to ALS-inhibiting herbicides in WA Wheatbelt, Abul Hashem, Department of Agriculture Glyphosate-resistant ryegrass biotypes in the WA wheatbelt, Abul Hashem, Catherine Borger and Nerys Wilkins, Department of Agriculture Implications of herbicide rates for resistance management, Paul Neve, Western Australian Herbicide Resistance Initiative, University of Western Australia Putting a price on herbicide resistance, Rick Llewellyn, School of Agricultural and Resource Economics/WA Herbicide Resistance Initiative, University of Western Australia Herbicide resistance from over the fence: Mobility and management, Debbie Allena, Rick Llewellynb, aUniversity of Western Australia, 4th year student, 2002. Mingenew-Irwin Group, bSchool of Agricultural and Resource Economics/Western Australia Herbicide Resistance Initiative, University of Western Australia HERBICIDE TOLERANCE Herbicide tolerance of new barley varieties, Harmohinder S. Dhammu and Terry Piper, Department of Agriculture Herbicide tolerance of new lupins, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Department of Agriculture Herbicide tolerance of new field pea varieties, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Department of Agriculture Herbicide tolerance of new lentil varieties, H.S. Dhammu, T.J. Piper and L.E. Young, Department of Agriculture HERBICIDES – NEW PRODUCTS/PRODUCT USES; USE Kill half leaf ryegrass with Spray.Seed® at night, Peter Newman and Glenn Adam, Department of Agriculture CLEARFIELD™ wheat to control hard-to-kill weeds, Abul Hashem, Catherine Borger and Nerys Wilkins, Department of Agriculture Diuron, a possible alternative to simazine pre-emergent in lupins, Peter Newman and Glenn Adam, Department of Agriculture Dual Gold® soft on barley, soft on weeds in dry conditions, Peter Newman and Glenn Adam, Department of Agriculture Dual Gold® soft on lupins, soft on ryegrass in dry conditions, Peter Newman and Glenn Adam, Department of Agricultur

    Crop Updates 2007 - Farming Systems

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    This session covers forty papers from different authors: 1. Quality Assurance and industry stewardship, David Jeffries, Better Farm IQ Manager, Cooperative Bulk Handling 2. Sothis: Trifolium dasyurum (Eastern Star clover), A. Loi, B.J. Nutt and C.K. Revell, Department of Agriculture and Food 3. Poor performing patches of the paddock – to ameliorate or live with low yield? Yvette Oliver1, Michael Robertson1, Bill Bowden2, Kit Leake3and Ashley Bonser3, CSIRO Sustainable Ecosystems1, Department of Food and Agriculture2, Kellerberrin Farmer3 4. What evidence is there that PA can pay? Michael Robertson, CSIRO Floreat, Ian Maling, SilverFox Solutions and Bindi Isbister, Department of Agriculture and Food 5.The journey is great, but does PA pay? Garren Knell, ConsultAg; Alison Slade, Department of Agriculture and Food, CFIG 6. 2007 Seasonal outlook, David Stephens and Michael Meuleners, Department of Agriculture and Food 7. Towards building farmer capacity to better manage climate risk, David Beard and Nicolyn Short, Department of Agriculture and Food 8. A NAR farmers view of his farming system in 2015, Rob Grima, Department of Agriculture and Food 9. Biofuels opportunities in Australia, Ingrid Richardson, Food and Agribusiness Research, Rabobank 10. The groundwater depth on the hydrological benefits of lucerne and the subsequent recharge values, Ruhi Ferdowsian1and Geoff Bee2; 1Department of Agriculture and Food, 2Landholder, Laurinya, Jerramungup 11. Subsoil constraints to crop production in the high rainfall zone of Western Australia, Daniel Evans1, Bob Gilkes1, Senthold Asseng2and Jim Dixon3; 1University of Western Australia, 2CSIRO Plant Industry, 3Department of Agriculture and Food 12. Prospects for lucerne in the WA wheatbelt, Michael Robertson, CSIRO Floreat, Felicity Byrne and Mike Ewing, CRC for Plant-Based Management of Dryland Salinity, Dennis van Gool, Department of Agriculture and Food 13. Nitrous oxide emissions from a cropped soil in the Western Australian grainbelt, Louise Barton1, Ralf Kiese2, David Gatter3, Klaus Butterbach-Bahl2, Renee Buck1, Christoph Hinz1and Daniel Murphy1,1School of Earth and Geographical Sciences, The University of Western Australia, 2Institute for Meteorology and Climate Research, Atmospheric Environmental Research, Garmisch-Partenkirchen, Germany, 3The Department of Agriculture and Food 14. Managing seasonal risk is an important part of farm management but is highly complex and therefore needs a ‘horses for courses’ approach, Cameron Weeks, Planfarm / Mingenew-Irwin Group, Dr Michael Robertson, Dr Yvette Oliver, CSIRO Sustainable Ecosystems and Dr Meredith Fairbanks, Department of Agriculture and Food 15. Novel use application of clopyralid in lupins, John Peirce, and Brad Rayner Department of Agriculture and Food 16. Long season wheat on the South Coast – Feed and grain in a dry year – a 2006 case study, Sandy White, Department of Agriculture and Food 17. Wheat yield response to potassium and the residual value of PKS fertiliser drilled at different depths, Paul Damon1, Bill Bowden2, Qifu Ma1 and Zed Rengel1; Faculty of Natural and Agricultural Sciences, The University of Western Australia1, Department of Agriculture and Food2 18. Saltbush as a sponge for summer rain, Ed Barrett-Lennard and Meir Altman, Department of Agriculture and Food and CRC for Plant-based Management of Dryland Salinity 19. Building strong working relationships between grower groups and their industry partners, Tracey M. Gianatti, Grower Group Alliance 20. To graze or not to graze – the question of tactical grazing of cereal crops, Lindsay Bell and Michael Robertson, CSIRO Sustainable Ecosystems 21. Can legume pastures and sheep replace lupins? Ben Webb and Caroline Peek, Department of Agriculture and Food 22. EverGraze – livestock and perennial pasture performance during a drought year, Paul Sanford, Department of Agriculture and Food, and CRC for Plant-based Management of Dryland Salinity 23. Crop survival in challenging times, Paul Blackwell1, Glen Riethmuller1, Darshan Sharma1and Mike Collins21Department of Agriculture and Food, 2Okura Plantations, Kirikiri New Zealand 24. Soil health constraints to production potential – a precision guided project, Frank D’Emden, and David Hall, Department of Agriculture and Food 25. A review of pest and disease occurrence in 2006, Mangano, G.P. and Severtson, D.L., Department of Agriculture and Food 26. e-weed – an information resource on seasonal weed management issues, Vanessa Stewart and Julie Roche, Department of Agriculture and Food 27. Review of Pesticide Legislation and Policies in Western Australia, Peter Rutherford, BSc (Agric.), Pesticide Legislation Review, Office of the Chief Medical Adviser, WA Department of Health 28. Future wheat yields in the West Australian wheatbelt, Imma Farré and Ian Foster, Department of Agriculture and Food, Stephen Charles, CSIRO Land and Water 29. Organic matter in WA arable soils: What’s active and what’s not, Frances Hoyle, Department of Agriculture and Food, Australia and Daniel Murphy, UWA 30. Soil quality indicators in Western Australian farming systems, D.V. Murphy1, N. Milton1, M. Osman1, F.C. Hoyle2, L.K Abbott1, W.R. Cookson1and S. Darmawanto1; 1UWA, 2Department of Agriculture and Food 31. Impact of stubble on input efficiencies, Geoff Anderson, formerly employed by Department of Agriculture and Food 32. Mixed farming vs All crop – true profit, not just gross margins, Rob Sands and David McCarthy, FARMANCO Management Consultants, Western Australia 33. Evaluation of Local Farmer Group Network – group leaders’ surveys 2005 and 2006, Paul Carmody, Local Farmer Group Network, Network Coordinator, UWA 34. Seeding rate and nitrogen application and timing effects in wheat, J. Russell, Department of Agriculture and Food, J. Eyres, G. Fosbery and A. Roe, ConsultAg, Northam 35. Foliar fungicide application and disease control in barley, J. Russell, Department of Agriculture and Food, J. Eyres, G. Fosbery and A. Roe, ConsultAg, Northam 36. Brown manuring effects on a following wheat crop in the central wheatbelt, , J. Russell, Department of Agriculture and Food, J. Eyres, G. Fosbery and A. Roe, ConsultAg, Northam 37. Management of annual pastures in mixed farming systems – transition from a dry season, Dr Clinton Revell and Dr Phil Nichols; Department of Agriculture and Food 38. The value of new annual pastures in mixed farm businesses of the wheatbelt, Dr Clinton Revell1, Mr Andrew Bathgate2and Dr Phil Nichols1; 1Department of Agriculture and Food, 2Farming Systems Analysis Service, Albany 39. The influence of winter SOI and Indian Ocean SST on WA winter rainfall, Meredith Fairbanks and Ian Foster, Department of Agriculture and Food 40. Market outlook – Grains, Anne Wilkins, Market Analyst, Grains, Department of Agriculture and Foo
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