179 research outputs found

    The effects of soil moisture, soil texture, and host orientation on the ability of Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) to infect Galleria mellonella (Lepidoptera: Pyralidae)

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    Abstract Entomopathogenic nematodes (EPN) demonstrate potential as a biological control for soil dwelling insects. However, edaphic factors, such as soil moisture and texture impact the efficacy of EPN on a host. The objectives were to examine the effects of soil texture and moisture on 1) the infection rate of Galleria mellonella L. by EPN and; 2) the ability of H. bacteriophora (Poinar) to move through the soil to find a host at different orientations. Soil textures consisted of sand, a sand/silt/peat mixture, and a silt/peat mixture at 50% and 100% moisture. A general linear model was used to evaluate infection rates and EPN movement. Both soil moisture (p \u3c 0.05) and texture (p \u3c 0.05) had significant effects on nematodes infection rates of G. mellonella. Texture, moisture, and host orientation did not significantly affect (p \u3e 0.05) the ability of EPN to find a host. While EPN were able to find a host within a variety of soil types, soils that held more water had higher infection rates than soils that held less water, suggesting that moisture may be a key component in facilitating infection by EPN. By understanding the factors that influence the ability of EPN to find and infect a host, improved bio-control programs using EPN can be developed

    Snowfall Trends in the Central and Southern Appalachians 1963-1964 to 1992-1993

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    A report submitted by Suzanne Hartley to the Research and Creative Productions Committee in 1999 on variations in seasonal snowfall over the central and southern Appalachians from West Virginia to Alabama

    The effects of soil moisture, soil texture, and host orientation on the ability of Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) to infect Galleria mellonella (Lepidoptera: Pyralidae)

    Get PDF
    Abstract Entomopathogenic nematodes (EPN) demonstrate potential as a biological control for soil dwelling insects. However, edaphic factors, such as soil moisture and texture impact the efficacy of EPN on a host. The objectives were to examine the effects of soil texture and moisture on 1) the infection rate of Galleria mellonella L. by EPN and; 2) the ability of H. bacteriophora (Poinar) to move through the soil to find a host at different orientations. Soil textures consisted of sand, a sand/silt/peat mixture, and a silt/peat mixture at 50% and 100% moisture. A general linear model was used to evaluate infection rates and EPN movement. Both soil moisture (p \u3c 0.05) and texture (p \u3c 0.05) had significant effects on nematodes infection rates of G. mellonella. Texture, moisture, and host orientation did not significantly affect (p \u3e 0.05) the ability of EPN to find a host. While EPN were able to find a host within a variety of soil types, soils that held more water had higher infection rates than soils that held less water, suggesting that moisture may be a key component in facilitating infection by EPN. By understanding the factors that influence the ability of EPN to find and infect a host, improved bio-control programs using EPN can be developed

    Failure to Censor Forbidden Clones of CD4 T Cells in Autoimmune Diabetes

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    Type 1 diabetes and other organ-specific autoimmune diseases often cluster together in human families and in congenic strains of NOD (nonobese diabetic) mice, but the inherited immunoregulatory defects responsible for these diseases are unknown. Here we track the fate of high avidity CD4 T cells recognizing a self-antigen expressed in pancreatic islet β cells using a transgenic mouse model. T cells of identical specificity, recognizing a dominant peptide from the same islet antigen and major histocompatibility complex (MHC)-presenting molecule, were followed on autoimmune susceptible and resistant genetic backgrounds. We show that non-MHC genes from the NOD strain cause a failure to delete these high avidity autoreactive T cells during their development in the thymus, with subsequent spontaneous breakdown of CD4 cell tolerance to the islet antigen, formation of intra-islet germinal centers, and high titre immunoglobulin G1 autoantibody production. In mixed bone marrow chimeric animals, defective thymic deletion was intrinsic to T cells carrying diabetes susceptibility genes. These results demonstrate a primary failure to censor forbidden clones of self-reactive T cells in inherited susceptibility to organ-specific autoimmune disease, and highlight the importance of thymic mechanisms of tolerance in organ-specific tolerance

    Use of NHS Digital datasets as trial data in the UK: a position paper

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    Background: Clinical trial teams increasingly want to make use of data from healthcare systems (“healthcare data”), particularly to enhance recruitment and follow-up of participants, to reduce time and cost, and to stop the duplication of effort. However, there is continued uncertainty of how regulators regard healthcare data used for trial purposes, in terms of provenance, quality and reliability. Objectives: There were two key objectives: First, to demonstrate the data integrity of two datasets held by NHS Digital (NHSD) that are most requested by trial teams; and second, to set out an approach by which any other healthcare systems datasets can be similarly evaluated. Method: The data lifecycles of the datasets were carefully documented, mapping the flow of data from the originating healthcare provider’s databases to NHSD warehouses and onwards to clinical trials teams. These were assessed for evidence of whether the datasets are accurate, reliable, complete, contemporaneous, and well-governed. Result: The assessment method was applied to (a) the Hospital Episode Statistics Admitted Patient Care (HES APC) dataset and (b) the Civil Registration of Deaths (CRD) dataset. This paper clearly demonstrates that their collection and management through NHSD systems ensure their integrity and reliability. The datasets are accurate representations of the data held by the originating providers (acute NHS trusts and local registrars). Conclusion: Based on these findings, the HES APC and CRD datasets satisfy the assessment criteria that demonstrate they are reliable transcribed copies of the original source data. Implications: First, these datasets can be used directly for clinical trial data, with trial teams focusing on the accuracy of algorithms and processes to identify particular outcomes rather than on the integrity of the data flow. Second, this assessment approach should be used to assess whether other healthcare systems datasets are ready to be used as transcribed copies of source data, and for data providers to take appropriate steps to redress this matter if they are not

    Defined covalent assembly of protein molecules on graphene using a genetically encoded photochemical reaction handle

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    We have created modified protein variants by introducing a non-canonical amino acid p-azido-Lphenylalanine (azF) into defined positions for photochemically-induced covalent attachment to graphene. Attachment of GFP, TEM and cyt b562 proteins was verified through a combination of atomic force and scanning tunnelling microscopy, resistance measurements, Raman data and fluorescence measurements. This method can in principle be extended to any protein which can be engineered in this way without adversely affecting its structural stabilit

    Leishmaniavirus-dependent metastatic leishmaniasis is prevented by blocking IL-17A

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    Cutaneous leishmaniasis has various outcomes, ranging from self-healing reddened papules to extensive open ulcerations that metastasise to secondary sites and are often resistant to standard therapies. In the case of L. guyanensis (L.g), about 5-10% of all infections result in metastatic complications. We recently showed that a cytoplasmic virus within L.g parasites (LRV1) is able to act as a potent innate immunogen, worsening disease outcome in a murine model. In this study, we investigated the immunophenotype of human patients infected by L.g and found a significant association between the inflammatory cytokine IL-17A, the presence of LRV1 and disease chronicity. Further, IL-17A was inversely correlated to the protective cytokine IFN-γ. These findings were experimentally corroborated in our murine model, where IL-17A produced in LRV1+ L.g infection contributed to parasite virulence and dissemination in the absence of IFN-γ. Additionally, IL-17A inhibition in mice using digoxin or SR1001, showed therapeutic promise in limiting parasite virulence. Thus, this murine model of LRV1-dependent infectious metastasis validated markers of disease chronicity in humans and elucidated the immunologic mechanism for the dissemination of Leishmania parasites to secondary sites. Moreover, it confirms the prognostic value of LRV1 and IL-17A detection to prevent metastatic leishmaniasis in human patients
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