14,467 research outputs found

    Trends in Pulse and Oilseed Crops in Winter Cereal Rotations in NSW

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    The key aims in this study are to assess the current level of importance of pulse and oilseed (broadleaf) crops in winter cereal rotations in NSW, and to identify recent trends. The production of broadleaf crops has increased in each region of NSW, but different crops have been favoured. Canola has played a key role in southern regions, and chickpea in the northern regions. In many areas, pulse crops have been grown more because of rotational benefits than their direct gross margins. If recent trends continue, the role of broadleaf crops will increase to 25% of the area sown to field crops in NSW by 2020. However, that will only be achieved with a focussed effort in both research and extension activities.broadleaf crop, oilseed, pulse, production, rotation, NSW, Agribusiness, Crop Production/Industries, Production Economics, Research and Development/Tech Change/Emerging Technologies, Q160,

    Physicochemical properties of concentrated Martian surface waters

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    Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions

    Reparameterizing the Birkhoff Polytope for Variational Permutation Inference

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    Many matching, tracking, sorting, and ranking problems require probabilistic reasoning about possible permutations, a set that grows factorially with dimension. Combinatorial optimization algorithms may enable efficient point estimation, but fully Bayesian inference poses a severe challenge in this high-dimensional, discrete space. To surmount this challenge, we start with the usual step of relaxing a discrete set (here, of permutation matrices) to its convex hull, which here is the Birkhoff polytope: the set of all doubly-stochastic matrices. We then introduce two novel transformations: first, an invertible and differentiable stick-breaking procedure that maps unconstrained space to the Birkhoff polytope; second, a map that rounds points toward the vertices of the polytope. Both transformations include a temperature parameter that, in the limit, concentrates the densities on permutation matrices. We then exploit these transformations and reparameterization gradients to introduce variational inference over permutation matrices, and we demonstrate its utility in a series of experiments

    Suspected Case of Loxoscelism (Spider-bite) in a Dog

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    Loxoscelism is a disease caused by envenomation by spiders belonging to the genus Loxosceles. Loxoscelism (also known as necrotic arachnidism or gangrenous spot ) has been mentioned as a disease in humans since the 1870\u27S,1 but the etiological agent was not discovered until 1934.2 Since the 1930\u27s there has been an abundance of material published on loxoscelism in humans in South America. However, this literature remained mostly unknown in North America until 1957, when a report implicated Loxosceles reclusa as the possible etiological agent of spider-bite in Missouri and other midwestern states. 2 Subsequently a significant amount of research has been reported in the United States on the condition in humans, but no reports have been found in veterinary journals. The lack of reports in the veterinary literature may be responsible for loxoscelism being overlooked or misdiagnosed in animals

    Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah

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    Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, and sandstones of the Frontier Formation along the western edge of the Green River basin in southwestern Wyoming), show that although each fracture domain may contain consistently oriented fractures, the orientations and patterns of the fractures vary considerably from domain to domain. Most of the fracture patterns in the brittle sandstones are related to local stresses created by subtle, irregular flexures resulting from mobility of the associated, interbedded ductile strata (halite or shale). Sequential episodes of evaporite dissolution and/or mobility in different directions can result in multiple, superimposed fracture sets in the associated sandstones. Multiple sets of superimposed fractures create reservoir-quality fracture interconnectivity within restricted localities of a formation. However, it is difficult to predict the orientations and characteristics of this type of fracturing in the subsurface. This is primarily because the orientations and characteristics of these fractures typically have little relationship to the regional tectonic stresses that might be used to predict fracture characteristics prior to drilling. Nevertheless, the high probability of numerous, intersecting fractures in such settings attests to the importance of determining fracture orientations in these types of fractured reservoirs

    Economics, Innovations, Technology, and Engineering Education: The Connections

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    Throughout history the success of economies around the world has in large part been influenced by technological growth and innovations. Along with such growth and innovations came higher living standards and an improved quality of life for citizens residing and participating in those economies. However, not all countries were able to grow and develop at the same rate, resulting in considerable differences in economic welfare across populations. As nations around the world address the 21st century, economic growth and prosperity for some nations will depend upon how well their citizens are equipped and motivated to seek new technological discoveries and innovations or participate in the supply chain for the production of such new innovations. Such decision making by individuals will be influenced by both economic and political factors existing within each respective country. After providing a description of economic development, the researchers analyze the current economic conditions in several advanced and developing countries and regions around the world, identifying factors that impact the development in those areas. In the remainder of the article, the focus is placed on the skills needed for 21st century workers and the role technology and engineering education might play in eroding the gaps in skill sets required for developing a workforce, thus moving a country forward in development and affluence
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