2,235 research outputs found

    Complete topology of cells, grains, and bubbles in three-dimensional microstructures

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    We introduce a general, efficient method to completely describe the topology of individual grains, bubbles, and cells in three-dimensional polycrystals, foams, and other multicellular microstructures. This approach is applied to a pair of three-dimensional microstructures that are often regarded as close analogues in the literature: one resulting from normal grain growth (mean curvature flow) and another resulting from a random Poisson-Voronoi tessellation of space. Grain growth strongly favors particular grain topologies, compared with the Poisson-Voronoi model. Moreover, the frequencies of highly symmetric grains are orders of magnitude higher in the the grain growth microstructure than they are in the Poisson-Voronoi one. Grain topology statistics provide a strong, robust differentiator of different cellular microstructures and provide hints to the processes that drive different classes of microstructure evolution.Comment: 5 pages, 6 figures, 5 supplementary page

    Distribution of Topological Types in Grain-Growth Microstructures

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    An open question in studying normal grain growth concerns the asymptotic state to which microstructures converge. In particular, the distribution of grain topologies is unknown. We introduce a thermodynamic-like theory to explain these distributions in two- and three-dimensional systems. In particular, a bending-like energy EiE_i is associated to each grain topology tit_i, and the probability of observing that particular topology is proportional to 1s(ti)eβEi\frac{1}{s(t_i)}e^{-\beta E_i}, where s(ti)s(t_i) is the order of an associated symmetry group and β\beta is a thermodynamic-like constant. We explain the physical origins of this approach, and provide numerical evidence in support.Comment: 6 pages, 5 figure

    Missouri 2011 Soft Red Winter Wheat Performance Tests

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    This report is published by the MU Variety Testing Program, Division of Plant Sciences, University of Missouri. The work was supported by fees from companies and organizations submitting varieties for evaluation. The large number of varieties available makes selection of a superior variety difficult. To select intelligently, producers need a reliable, unbiased, up-to-date source of information that will permit valid comparisons among available varieties. The objective of the MU Variety Testing Program is to provide this information. Tests are conducted under as close to uniform conditions as possible. Small plots are used to reduce the chance of soil and other variations occurring among variety plots. Results obtained should aid individual growers in judging the relative merits of many of the commercial wheat varieties available in Missouri

    Missouri 2011 Corn Performance Tests

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    This report is published by the MU Variety Testing Program, Division of Plant Sciences, University of Missouri. The work was supported by fees provided by companies submitting hybrids for evaluation. The University of Missouri's hybrid performance testing program began in the mid-1930s, with results first published in 1937. The number of entries in the program has grown from fewer than 50 in the early years to more than 250 today. The large number of commercial hybrids available makes selection of a superior hybrid difficult. To select intelligently, producers need a reliable, unbiased, up-to-date source of information that will permit valid comparisons among available hybrids. The objective of the MU Variety Testing Program is to provide this information

    Systematic review of economic evaluations and cost analyses of guideline implementation strategies

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    Objectives To appraise the quality of economic studies undertaken as part of evaluations of guideline implementation strategies; determine their resources use; and recommend methods to improve future studies. Methods Systematic review of economic studies undertaken alongside robust study designs of clinical guideline implementation strategies published (1966-1998). Studies assessed against the BMJ economic evaluations guidelines for each stage of the guideline process (guideline development, implementation and treatment). Results 235 studies were identified, 63 reported some information on cost. Only 3 studies provided evidence that their guideline was effective and efficient. 38 reported the treatment costs only, 12 implementation and treatment costs, 11 implementation costs alone, and two guideline development, implementation and treatment costs. No study gave reasonably complete information on costs. Conclusions Very few satisfactory economic evaluations of guideline implementation strategies have been performed. Current evaluations have numerous methodological defects and rarely consider all relevant costs and benefits. Future evaluations should focus on evaluating the implementation of evidence based guidelines. Keywords: Cost-effectiveness analysis, physician (or health care professional) behaviour, practice guidelines, quality improvement, systematic review.Peer reviewedAuthor versio

    PDX Finder: A portal for patient-derived tumor xenograft model discovery.

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    Patient-derived tumor xenograft (PDX) mouse models are a versatile oncology research platform for studying tumor biology and for testing chemotherapeutic approaches tailored to genomic characteristics of individual patients\u27 tumors. PDX models are generated and distributed by a diverse group of academic labs, multi-institution consortia and contract research organizations. The distributed nature of PDX repositories and the use of different metadata standards for describing model characteristics presents a significant challenge to identifying PDX models relevant to specific cancer research questions. The Jackson Laboratory and EMBL-EBI are addressing these challenges by co-developing PDX Finder, a comprehensive open global catalog of PDX models and their associated datasets. Within PDX Finder, model attributes are harmonized and integrated using a previously developed community minimal information standard to support consistent searching across the originating resources. Links to repositories are provided from the PDX Finder search results to facilitate model acquisition and/or collaboration. The PDX Finder resource currently contains information for 1985 PDX models of diverse cancers including those from large resources such as the Patient-Derived Models Repository, PDXNet and EurOPDX. Individuals or organizations that generate and distribute PDXs are invited to increase the \u27findability\u27 of their models by participating in the PDX Finder initiative at www.pdxfinder.org

    PDCM Finder: an open global research platform for patient-derived cancer models.

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    PDCM Finder (www.cancermodels.org) is a cancer research platform that aggregates clinical, genomic and functional data from patient-derived xenografts, organoids and cell lines. It was launched in April 2022 as a successor of the PDX Finder portal, which focused solely on patient-derived xenograft models. Currently the portal has over 6200 models across 13 cancer types, including rare paediatric models (17%) and models from minority ethnic backgrounds (33%), making it the largest free to consumer and open access resource of this kind. The PDCM Finder standardises, harmonises and integrates the complex and diverse data associated with PDCMs for the cancer community and displays over 90 million data points across a variety of data types (clinical metadata, molecular and treatment-based). PDCM data is FAIR and underpins the generation and testing of new hypotheses in cancer mechanisms and personalised medicine development
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