1,689 research outputs found

    Optimizing Dual Interdependent Products from a Single Crop

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    The objective of the research is to determine the optimal grazing termination date that maximizes expected net returns from dual-purpose winter wheat production. Preliminary results indicate that grazing should be terminated at or before first hollow stem to generate the highest expected net returns in a dual-purpose winter wheat production enterprise.Crop Production/Industries,

    Optimal Grazing Termination Date for Dual-Purpose Winter Wheat Production

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    Dual-purpose winter wheat (fall-winter forage plus grain) production is an important economic enterprise in the southern Great Plains. Grazing termination to enable grain production is a critical decision. The objective is to determine the optimal grazing termination date for dual-purpose wheat. The value of knowing the occurrence of first hollow stem (FHS), a wheat growth threshold for grazing termination, is also determined. Results indicate that for most price situations grazing should be terminated at or before FHS. Marginal wheat returns from extended grazing were negative and the value of FHS information ranges from 1.50to1.50 to 10 per acre.dual-purpose, first hollow stem, plateau function, stocker cattle, value of information, wheat, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Land Economics/Use, Livestock Production/Industries, Production Economics, Q12, Q16,

    Transferring elements of a density matrix

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    We study restrictions imposed by quantum mechanics on the process of matrix elements transfer. This problem is at the core of quantum measurements and state transfer. Given two systems \A and \B with initial density matrices λ\lambda and rr, respectively, we consider interactions that lead to transferring certain matrix elements of unknown λ\lambda into those of the final state r~{\widetilde r} of \B. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of \A. If one diagonal matrix element is transferred, r~aa=λaa{\widetilde r}_{aa}=\lambda_{aa}, the memory on each non-diagonal element λab\lambda_{a\not=b} is completely eliminated from the final density operator of \A. Consider the following three quantities \Re \la_{a\not =b}, \Im \la_{a\not =b} and \la_{aa}-\la_{bb} (the real and imaginary part of a non-diagonal element and the corresponding difference between diagonal elements). Transferring one of them, e.g., \Re\tir_{a\not = b}=\Re\la_{a\not = b}, erases the memory on two others from the final state of \A. Generalization of these set-ups to a finite-accuracy transfer brings in a trade-off between the accuracy and the amount of preserved memory. This trade-off is expressed via system-independent uncertainty relations which account for local aspects of the accuracy-disturbance trade-off in quantum measurements.Comment: 9 pages, 2 table

    Fibronectin and Cyclic Strain Improve Cardiac Progenitor Cell Regenerative Potential In Vitro.

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    Cardiac progenitor cells (CPCs) have rapidly advanced to clinical trials, yet little is known regarding their interaction with the microenvironment. Signaling cues present in the microenvironment change with development and disease. This work aims to assess the influence of two distinct signaling moieties on CPCs: cyclic biaxial strain and extracellular matrix. We evaluate four endpoints for improving CPC therapy: paracrine signaling, proliferation, connexin43 expression, and alignment. Vascular endothelial growth factor A (about 900 pg/mL) was secreted by CPCs cultured on fibronectin and collagen I. The application of mechanical strain increased vascular endothelial growth factor A secretion 2-4-fold for CPCs cultured on poly-L-lysine, laminin, or a naturally derived cardiac extracellular matrix. CPC proliferation was at least 25% higher on fibronectin than that on other matrices, especially for lower strain magnitudes. At 5% strain, connexin43 expression was highest on fibronectin. With increasing strain magnitude, connexin43 expression decreased by as much as 60% in CPCs cultured on collagen I and a naturally derived cardiac extracellular matrix. Cyclic mechanical strain induced the strongest CPC alignment when cultured on fibronectin or collagen I. This study demonstrates that culturing CPCs on fibronectin with 5% strain magnitude is optimal for their vascular endothelial growth factor A secretion, proliferation, connexin43 expression, and alignment

    The National School Lunch Program in Rural Appalachian Tennessee – or Why Implementation of the Healthy, Hunger Free Kids Act of 2010 was Met with Challenges: A Brief Report

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    Purpose: The purpose of this study was to investigate challenges faced by high schools in rural Appalachia in implementing the Healthy, Hunger Free Kids Act of 2010 (HHFKA). Methodology: We used qualitative, secondary analysis to analyze a collection of thirteen focus groups and 22 interviews conducted in 2013-14 among parents, teachers, and high school students in six counties in rural Appalachian Tennessee (n=98). Results: Five basic themes were identified during the thematic analysis: poor food quality prior to implementation of the HHFKA school nutrition reforms; students’ preference for low-nutrient energy-dense foods; low acceptance of healthier options after implementation of the HHFKA school nutrition reforms; HHFKA school nutrition reforms not tailored to unique needs of under-resourced communities; and students opting out of the National School Lunch Program after implementation of the HHFKA school nutrition reforms. Rural communities face multiple and intersecting challenges in implementing the HHFKA school nutrition reforms. Conclusion: As a result, schools in rural Appalachia may be less likely to derive benefits from these reforms. The ability of rural schools to take advantage of school nutrition reforms to improve student health may depend largely on factors unique to each community or school

    Cross modal perception of body size in domestic dogs (Canis familiaris)

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    While the perception of size-related acoustic variation in animal vocalisations is well documented, little attention has been given to how this information might be integrated with corresponding visual information. Using a cross-modal design, we tested the ability of domestic dogs to match growls resynthesised to be typical of either a large or a small dog to size- matched models. Subjects looked at the size-matched model significantly more often and for a significantly longer duration than at the incorrect model, showing that they have the ability to relate information about body size from the acoustic domain to the appropriate visual category. Our study suggests that the perceptual and cognitive mechanisms at the basis of size assessment in mammals have a multisensory nature, and calls for further investigations of the multimodal processing of size information across animal species

    Sensitivity to Sulfited Foods among Sulfite-Sensitive Subjects with Asthma

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    Eight individuals with asthma who had been diagnosed as sulfite sensitive on the basis of double-blind capsule-beverage challenges were subjected to challenges with various sulfited foods, including lettuce, shrimp, dried apricots, white grape juice, dehydrated potatoes (as mashed potatoes), and mushrooms. Four of these patients failed to respond to challenges with any of the sulfited foods. The other four patients experienced a decrease in pulmonary function on double-blind challenges with sulfited lettuce. Two of three of these patients reacted to challenges with dried apricots and white grape juice; the fourth patient has not yet been challenged with these products. Only one of these four patients reacted to challenges with dehydrated potatoes and mushrooms, and, in this case, the response to double-blind challenges with dehydrated potatoes was not consistent. None of the sulfite-sensitive subjects with asthma responded to challenges with sulfited shrimp. It is concluded that sulfite-sensitive subjects with asthma will not necessarily react after ingestion of sulfited foods. The likelihood of a reaction is dependent on the nature of the food, the level of residual sulfite, the sensitivity of the patient, and perhaps on the form of residual sulfite and the mechanism of the sulfite-induced reaction

    Moving forward in circles: challenges and opportunities in modelling population cycles

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    Population cycling is a widespread phenomenon, observed across a multitude of taxa in both laboratory and natural conditions. Historically, the theory associated with population cycles was tightly linked to pairwise consumer–resource interactions and studied via deterministic models, but current empirical and theoretical research reveals a much richer basis for ecological cycles. Stochasticity and seasonality can modulate or create cyclic behaviour in non-intuitive ways, the high-dimensionality in ecological systems can profoundly influence cycling, and so can demographic structure and eco-evolutionary dynamics. An inclusive theory for population cycles, ranging from ecosystem-level to demographic modelling, grounded in observational or experimental data, is therefore necessary to better understand observed cyclical patterns. In turn, by gaining better insight into the drivers of population cycles, we can begin to understand the causes of cycle gain and loss, how biodiversity interacts with population cycling, and how to effectively manage wildly fluctuating populations, all of which are growing domains of ecological research

    Agribusiness management series: Effect of grazing past first hollow stem on wheat and stocker profits

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
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