61 research outputs found

    Structure and biological activity of xanthyletin : a new phytoalexin of CITRUS

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    Une coumarine, la xanthylétine, a été identifiée dans les tissus de CITRUS infectés par des PHYTOPHTHORA spp. Cette substance est déterminée par son spectre dans l'infra rouge, par spectrométrie de masse et par résonance magnétique nucléaire. Cette phytoalexine manifeste in vitro une importante toxicité pour le PHYTOPHTHORA CITROPHTHORA et une synergie avec les autres composés phénoliques des CITRUS. (Résumé d'auteur

    Dimensional reduction in numerical relativity: Modified cartoon formalism and regularization

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    We present in detail the Einstein equations in the Baumgarte–Shapiro–Shibata–Nakamura formulation for the case of D-dimensional spacetimes with SO(D−d)isometry based on a method originally introduced in Ref. 1. Regularized expressions are given for a numerical implementation of this method on a vertex centered grid including the origin of the quasi-radial coordinate that covers the extra dimensions with rotational symmetry. Axisymmetry, corresponding to the value d = D − 2, represents a special case with fewer constraints on the vanishing of tensor components and is conveniently implemented in a variation of the general method. The robustness of the scheme is demonstrated for the case of a black-hole head-on collision in D = 7 spacetime dimensions with SO(4) symmetry.U.S. is supported by the H2020 ERC Consolidator Grant “Matter and strong-field gravity: New frontiers in Einstein’s theory” grant agreement No. MaGRaTh–646597, the H2020-MSCA-RISE-2015 Grant No. StronGrHEP-690904, the STFC Consolidator Grant No. ST/L000636/1, the SDSC Comet and TACC Stampede clusters through NSF-XSEDE Award Nos. PHY-090003, the Cambridge High Performance Computing Service Supercomputer Darwin using Strategic Research Infrastructure Funding from the HEFCE and the STFC, and DiRAC’s Cosmos Shared Memory system through BIS Grant No. ST/J005673/1 and STFC Grant Nos. ST/H008586/1, ST/K00333X/1. P.F. and S.T. are supported by the H2020 ERC Starting Grant “New frontiers in numerical general relativity” grant agreement No. NewNGR- 639022. P.F. is also supported by a Royal Society University Research Fellowship. W.G.C. and M.K. are supported by STFC studentships.This is the final version of the article. It first appeared from the World Scientific Publishing Company via http://dx.doi.org/10.1142/S021827181641013

    Phytoalexines et réactions de défense de la tomate aux infections par PHYTOPHTHORA PARASITICA et VERTICILLIUM ALBO-ATRUM

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    Deux cultivars de tomates de phénotype Saint-Pierre, isogéniques pour la résistance à la verticilliose et différents par celle au mildiou (et à PHYTOPHTHORA PARASITICA Dast.), sont inoculés par P. PARASITICA et par VERTICILLIUM ALBO-ATRUM Reinke et Berth. Aux réactions de défense correspond l'accumulation, dans les tissus, de sesquiterpÚnes, de composés phénoliques, de tomatine et de dérivés oxygénés de linoléate de méthyle. Les synthÚses de ces substances chez l'hÎte sont modulées selon les cultivars et les parasites confrontés. Les études d'inhibition in vitro de P. PARASITICA révÚlent une importante synergie entre des diénols d'une part, et des produits phénoliques et la tomatine d'autre part

    Doing the right thing for the right reason: Evaluating artificial moral cognition by probing cost insensitivity

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    Is it possible to evaluate the moral cognition of complex artificial agents? In this work, we take a look at one aspect of morality: `doing the right thing for the right reasons.' We propose a behavior-based analysis of artificial moral cognition which could also be applied to humans to facilitate like-for-like comparison. Morally-motivated behavior should persist despite mounting cost; by measuring an agent's sensitivity to this cost, we gain deeper insight into underlying motivations. We apply this evaluation to a particular set of deep reinforcement learning agents, trained by memory-based meta-reinforcement learning. Our results indicate that agents trained with a reward function that includes other-regarding preferences perform helping behavior in a way that is less sensitive to increasing cost than agents trained with more self-interested preferences.Comment: 11 pages, 3 figure

    GRChombo: An adaptable numerical relativity code for fundamental physics

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    GRChombo is an open-source code for performing Numerical Relativity time evolutions, built on top of the publicly available Chombo software for the solution of PDEs. Whilst GRChombo uses standard techniques in NR, it focusses on applications in theoretical physics where adaptability, both in terms of grid structure, and in terms of code modification, are key drivers

    A parsimonious oscillatory model of handwriting

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    International audienceWe propose an oscillatory model that is theoretically parsimonious, empirically efficient and biologically plausible. Building on Hollerbach’s (Biol Cybern 39:139–156, 1981) model, our Parsimonious Oscillatory Model of Handwriting (POMH) overcomes the latter’s main shortcomings by making it possible to extract its parameters from the trace itself and by reinstating symmetry between the x and y coordinates. The benefit is a capacity to autonomously generate a smooth continuous trace that reproduces the dynamics of the handwriting movements through an extremely sparse model, whose efficiency matches that of other, more computationally expensive optimizing methods. Moreover, the model applies to 2D trajectories, irrespective of their shape, size, orientation and length. It is also independent of the endeffectors mobilized and of the writing direction

    Crop Updates 2005 - Cereals

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    This session covers thirty six papers from different authors: WHEAT AGRONOMY 1. Optimum sowing time of new wheat varieties in Western Australia, Darshan Sharma, Brenda Shackley, Mohammad Amjad, Christine M. Zaicou-Kunesch and Wal Anderson, Department of Agriculture 2. Wheat varieties updated in ‘Flowering Calculator’: A model predicting flowering time, B. Shackley, D. Tennant, D. Sharma and C.M. Zaicou-Kunesch, Department of Agriculture 3. Plant populations for wheat varieties, Christine M. Zaicou-Kunesch, Wal Anderson, Darshan Sharma, Brenda Shackley and Mohammad Amjad, Department of Agriculture 4. New wheat cultivars response to fertiliser nitrogen in four major agricultural regions of Western Australia, Mohammad Amjad, Wal Anderson, Brenda Shackley, Darshan Sharma and Christine Zaicou-Kunesch, Department of Agriculture 5. Agronomic package for EGA Eagle Rock, Steve Penny, Department of Agriculture 6. Field evaluation of eastern and western wheats in large-scale farmer’s trials, Mohammad Amjad, Ben Curtis and Veronika Reck, Department of Agriculture 7. New wheat varieties for a changing environment, Richard Richards, CSIRO Plant Industry; Canberra 8. Farmers can profitably minimise exposure to frost! Garren Knell, Steve Curtin and David Sermon, ConsultAg 9. National Variety Trials, Alan Bedggood, Australian Crops Accreditation System; Horsham 10. Preharvest-sprouting tolerance of wheat in the field, T.B. Biddulph1, T.L. Setter2, J.A. Plummer1 and D.J. Mares3; 1Plant Biology; FNAS, University of Western Australia; 2Department of Agriculture, 3School of Agriculture and Wine, University of Adelaide 11. Waterlogging induces high concentration of Mn and Al in wheat genotypes in acidic soils, H. Khabaz-Saberi, T. Setter, I. Waters and G. McDonald, Department of Agriculture 12. Agronomic responses of new wheat varieties in the Northern Agricultural Region, Christine M. Zaicou-Kunesch and Wal Anderson, Department of Agriculture 13. Agronomic responses of new wheat varieties in the Central Agricultural Region of WA, Darshan Sharma, Steve Penny and Wal Anderson, Department of Agriculture 14. EGA Eagle Rock tolerance to metribuzin and its mixtures, Harmohinder Dhammu, David Nicholson and Chris Roberts, Department of Agriculture 15. Herbicide tolerance of new bread wheats, Harmohinder Dhammu1 and David Nicholson2, Department of Agriculture NUTRITION 16. The impact of fertiliser placement, timing and rates on nitrogen-use efficiency, Stephen Loss, CSBP Ltd 17. Cereals deficient in potassium are most susceptible to some leaf diseases, Ross Brennan and Kith Jayasena, Department of Agriculture 18. Responses of cereal yields to potassium fertiliser type, placement and timing, Eddy Pol, CSBP Limited 19. Sulphate of Potash, the potash of choice at seeding, Simon Teakle, United Farmers Co-operative 20. Essential disease management for successful barley production, K. Jayasena, R. Loughman, C. Beard, B. Paynter, K. Tanaka, G. Poulish and A. Smith, Department of Agriculture 21. Genotypic differences in potassium efficiency of wheat, Paul Damon and Zed Rengel, Faculty of Natural and Agricultural Sciences, University of Western Australia 22. Genotypic differences in potassium efficiency of barley, Paul Damon and Zed Rengel, Faculty of Natural and Agricultural Sciences, University of Western Australia 23. Investigating timing of nitrogen application in wheat, Darshan Sharma and Lionel Martin, Department of Agriculture, and Muresk Institute of Agriculture, Curtin University of Technology 24. Nutrient timing requirements for increased crop yields in the high rainfall cropping zone, Narelle Hill, Ron McTaggart, Dr Wal Anderson and Ray Tugwell, Department of Agriculture DISEASES 25. Integrate strategies to manage stripe rust risk, Geoff Thomas, Robert Loughman, Ciara Beard, Kith Jayasena and Manisha Shankar, Department of Agriculture 26. Effect of primary inoculum level of stripe rust on variety response in wheat, Manisha Shankar, John Majewski and Robert Loughman, Department of Agriculture 27. Disease resistance update for wheat varieties in WA, M. Shankar, J.M. Majewski, D. Foster, H. Golzar, J. Piotrowski and R. Loughman, Department of Agriculture 28. Big droplets for wheat fungicides, Rob Grima, Agronomist, Elders 29. On farm research to investigate fungicide applications to minimise leaf disease impacts in wheat, Jeff Russell and Angie Roe, Department of Agriculture, and Farm Focus Consultants PESTS 30. Rotations for nematode management, Vivien A. Vanstone, Sean J. Kelly, Helen F. Hunter and Mena C. Gilchrist, Department of Agriculture 31. Investigation into the adaqyacy of sealed farm silos in Western Australia to control phosphine-resistant Rhyzopertha dominica, C.R. Newman, Department of Agriculture 32.Insect contamination of cereal grain at harvest, Svetlana Micic and Phil Michael, Department of Agriculture 33. Phosure – Extending the life of phosphine, Gabrielle Coupland and Ern Kostas, Co-operative Bulk Handling SOIL 34. Optimum combinations of ripping depth and tine spacing for increasing wheat yield, Mohammed Hamza and Wal Anderson, Department of Agriculture 35. Hardpan penetration ability of wheat roots, Tina Botwright Acuña and Len Wade, School of Plant Biology, University of Western Australia MARKETS 36. Latin America: An emerging agricultural powerhouse, Ingrid Richardson, Food and Agribusiness Research, Rabobank; Sydne

    Somatosensory processing in neurodevelopmental disorders

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    The purpose of this article is to review the role of somatosensory perception in typical development, its aberration in a range of neurodevelopmental disorders, and the potential relations between tactile processing abnormalities and central features of each disorder such as motor, communication, and social development. Neurodevelopmental disorders that represent a range of symptoms and etiologies, and for which multiple peer-reviewed articles on somatosensory differences have been published, were chosen to include in the review. Relevant studies in animal models, as well as conditions of early sensory deprivation, are also included. Somatosensory processing plays an important, yet often overlooked, role in typical development and is aberrant in various neurodevelopmental disorders. This is demonstrated in studies of behavior, sensory thresholds, neuroanatomy, and neurophysiology in samples of children with Fragile X syndrome, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), and cerebral palsy (CP). Impaired somatosensory processing is found in a range of neurodevelopmental disorders and is associated with deficits in communication, motor ability, and social skills in these disorders. Given the central role of touch in early development, both experimental and clinical approaches should take into consideration the role of somatosensory processing in the etiology and treatment of neurodevelopmental disorders
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