177 research outputs found

    Susceptibility of commercial oat cultivars to \u3ci\u3eCryptolestes pusillus\u3c/i\u3e and \u3ci\u3eOryzaephilus surinamensis\u3c/i\u3e

    Get PDF
    Susceptibility to two storage insect pests [(Cryptolestes pusillus (Schonherr) and Oryzaephilus surinamensis (L.)] of eight commercial oat cultivars from the United States was determined in laboratory studies. Duration of insect development was shorter and number of progeny produced was greater on cracked than on whole oats. Simulations based on data from the study showed that insect populations would reach the threshold level for treatment in 2–3 months of storage at 30°C on cracked oats. Insect population development was slowest on the hulless cultivar Paul when the oat kernels were cracked. Simulations also indicated that all cultivars of whole oats tested could be stored for at least 1 yr at 30°C without reaching the threshold for treatment when infested with these two species of insects, and insect populations would decrease over time on the cultivars Don, Jerry, Milton, NewDak, Otana, and Valley. Analyses of oat grain quality characteristics, including kernel weight, groat hardness, and groat composition, provided little insight into the mechanism of observed differences in insect development among cultivars. Hardness of the kernels (as indicated by % broken groats after dehulling) may be related to near immunity to these two species of insects in whole Otana. Steaming whole oats to inactivate hydrolytic enzymes in the trichomes of the pericarp did not increase susceptibility to these two species of insects, suggesting that enzymes in the trichomes were not responsible for insect population development being slower on whole oats than on cracked oats. Although we were unable to identify the factors that determined relative susceptibility in this study, the results will be useful for selecting commercial oat cultivars for planting that will be less susceptible to insect pests in storage and suggest that the economics of cleaning oats before storage to reduce insect population growth should be investigated

    Susceptibility of commercial oat cultivars to \u3ci\u3eCryptolestes pusillus\u3c/i\u3e and \u3ci\u3eOryzaephilus surinamensis\u3c/i\u3e

    Get PDF
    Susceptibility to two storage insect pests [(Cryptolestes pusillus (Schonherr) and Oryzaephilus surinamensis (L.)] of eight commercial oat cultivars from the United States was determined in laboratory studies. Duration of insect development was shorter and number of progeny produced was greater on cracked than on whole oats. Simulations based on data from the study showed that insect populations would reach the threshold level for treatment in 2–3 months of storage at 30°C on cracked oats. Insect population development was slowest on the hulless cultivar Paul when the oat kernels were cracked. Simulations also indicated that all cultivars of whole oats tested could be stored for at least 1 yr at 30°C without reaching the threshold for treatment when infested with these two species of insects, and insect populations would decrease over time on the cultivars Don, Jerry, Milton, NewDak, Otana, and Valley. Analyses of oat grain quality characteristics, including kernel weight, groat hardness, and groat composition, provided little insight into the mechanism of observed differences in insect development among cultivars. Hardness of the kernels (as indicated by % broken groats after dehulling) may be related to near immunity to these two species of insects in whole Otana. Steaming whole oats to inactivate hydrolytic enzymes in the trichomes of the pericarp did not increase susceptibility to these two species of insects, suggesting that enzymes in the trichomes were not responsible for insect population development being slower on whole oats than on cracked oats. Although we were unable to identify the factors that determined relative susceptibility in this study, the results will be useful for selecting commercial oat cultivars for planting that will be less susceptible to insect pests in storage and suggest that the economics of cleaning oats before storage to reduce insect population growth should be investigated

    Realizability of Polytopes as a Low Rank Matrix Completion Problem

    Full text link
    This article gives necessary and sufficient conditions for a relation to be the containment relation between the facets and vertices of a polytope. Also given here, are a set of matrices parameterizing the linear moduli space and another set parameterizing the projective moduli space of a combinatorial polytope

    Limit-(quasi)periodic point sets as quasicrystals with p-adic internal spaces

    Full text link
    Model sets (or cut and project sets) provide a familiar and commonly used method of constructing and studying nonperiodic point sets. Here we extend this method to situations where the internal spaces are no longer Euclidean, but instead spaces with p-adic topologies or even with mixed Euclidean/p-adic topologies. We show that a number of well known tilings precisely fit this form, including the chair tiling and the Robinson square tilings. Thus the scope of the cut and project formalism is considerably larger than is usually supposed. Applying the powerful consequences of model sets we derive the diffractive nature of these tilings.Comment: 11 pages, 2 figures; dedicated to Peter Kramer on the occasion of his 65th birthda

    A protocol for rapid and parallel isolation of myocytes and non-myocytes from multiple mouse hearts.

    Get PDF
    This protocol features parallel isolation of myocytes and non-myocytes from murine hearts. It was designed with considerations for (1) time required to extract cardiac cells, (2) cell viability, and (3) protocol scalability. Here, a peristaltic pump and 3D-printed elements are combined to perfuse the heart with enzymes to dissociate cells. Myocytes and non-myocytes extracted using this protocol are separated by centrifugation and/or fluorescence-activated cell sorting for use in downstream applications including single-cell omics or other bio-molecular analyses. For complete details on the use and execution of this protocol, please refer to McLellan et al. (2020)

    The chemerin knockout rat reveals chemerin dependence in female, but not male, experimental hypertension

    Full text link
    Measures of the adipokine chemerin are elevated in multiple cardiovascular diseases, including hypertension, but little mechanistic work has been done to implicate chemerin as being causative in such diseases. The chemerin knockout (KO) rat was created to test the hypothesis that removal of chemerin would reduce pressure in the normal and hypertensive state. Western analyses confirmed loss of chemerin in the plasma and tissues of the KO vs. wild‐type (WT) rats. Chemerin concentration in plasma and tissues was lower in WT females than in WT males, as determined by Western analysis. Conscious male and female KO rats had modest differences in baseline measures vs. the WT that included systolic, diastolic, mean arterial and pulse pressures, and heart rate, all measured telemetrically. The mineralocorticoid deoxycorticosterone acetate (DOCA) and salt water, combined with uninephrectomy as a hypertensive stimulus, elevated mean and systolic blood pressures of the male KO higher than the male WT. By contrast, all pressures in the female KO were lower than their WT throughout DOCA‐salt treatment. These results revealed an unexpected sex difference in chemerin expression and the ability of chemerin to modify blood pressure in response to a hypertensive challenge.—Watts, S. W., Darios, E. S., Mullick, A. E., Garver, H., Saunders, T. L., Hughes, E. D., Filipiak, W. E., Zeidler, M. G., McMullen, N., Sinal, C. J., Kumar, R. K., Ferland, D. J., Fink, G. D. The chemerin knockout rat reveals chemerin dependence in female, but not male, experimental hypertension. FASEB J. 32, 6596–6614 (2018). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154357/1/fsb2fj201800479.pd

    A Qualitative Modeling Approach for Whole Genome Prediction Using High-Throughput Toxicogenomics Data and Pathway-Based Validation

    Get PDF
    Efficient high-throughput transcriptomics (HTT) tools promise inexpensive, rapid assessment of possible biological consequences of human and environmental exposures to tens of thousands of chemicals in commerce. HTT systems have used relatively small sets of gene expression measurements coupled with mathematical prediction methods to estimate genome-wide gene expression and are often trained and validated using pharmaceutical compounds. It is unclear whether these training sets are suitable for general toxicity testing applications and the more diverse chemical space represented by commercial chemicals and environmental contaminants. In this work, we built predictive computational models that inferred whole genome transcriptional profiles from a smaller sample of surrogate genes. The model was trained and validated using a large scale toxicogenomics database with gene expression data from exposure to heterogeneous chemicals from a wide range of classes (the Open TG-GATEs data base). The method of predictor selection was designed to allow high fidelity gene prediction from any pre-existing gene expression data set, regardless of animal species or data measurement platform. Predictive qualitative models were developed with this TG-GATES data that contained gene expression data of human primary hepatocytes with over 941 samples covering 158 compounds. A sequential forward search-based greedy algorithm, combining different fitting approaches and machine learning techniques, was used to find an optimal set of surrogate genes that predicted differential expression changes of the remaining genome. We then used pathway enrichment of up-regulated and down-regulated genes to assess the ability of a limited gene set to determine relevant patterns of tissue response. In addition, we compared prediction performance using the surrogate genes found from our greedy algorithm (referred to as the SV2000) with the landmark genes provided by existing technologies such as L1000 (Genometry) and S1500 (Tox21), finding better predictive performance for the SV2000. The ability of these predictive algorithms to predict pathway level responses is a positive step toward incorporating mode of action (MOA) analysis into the high throughput prioritization and testing of the large number of chemicals in need of safety evaluation
    • 

    corecore