751 research outputs found

    Improvement of propeller static thrust estimation Final report, Jul. 1, 1964 - Aug. 31, 1965

    Get PDF
    Research facility development for propeller thrust and torque measurements under static thrust condition

    Tests on propellers under static thrust conditions

    Get PDF
    Dynamometer tests of propellers under static thrust condition

    The Decline of the St Helena Gumwood Commidendrum robustum

    Get PDF

    A Cladistic Analysis of \u3cem\u3endh\u3c/em\u3eF Sequences from Representative Species of \u3cem\u3eSaintpaulia\u3c/em\u3e and \u3cem\u3eStreptocarpus\u3c/em\u3e Subgenera and \u3cem\u3eStreptocarpella\u3c/em\u3e (Gesneriaceae)

    Get PDF
    Two African genera of the Gesneriaceae, Saintpaulia and Streptocarpus, are similar in many respects. Both genera have blue to purple flowers, pollen of similar shape and exine sculpting, embryos with one-celled uninucleate chalazal haustoria, shared vegetative structures among some species, and are among the few genera in the Gesneriaceae which include species with chromosome count of n=15. Similarity of these features has indicated that the two genera are likely to be closely related. This study examines the sequences of the chloroplast gene ndhF among several representative Saintpaulia and representatives of Streptocarpus subgenera Streptocarpella and Streptocarpus. The results of this analysis are congruent with those of previous analysis based on the nuclear ribosomal region, ITS. Saintpaulia was found to be nested within Streptocarpus and Streptocarpella. The results raise the possibility of the taxonomic revision of these genera, and this is discussed. Comparisons between the data sets are made regarding utility of the two regions, sample size and outgroup

    Health Risk Perceptions Are Associated with Domestic Use of Basic Water and Sanitation Services—Evidence from Rural Ethiopia

    Get PDF
    We examine factors associated with the use of basic water supply and sanitation services as part of an integrated community-based nutrition programme which included a drinking water, sanitation and hygiene (WaSH) intervention and emphasise findings related to health risk perceptions. Data were collected from 2658 households in four regions in Ethiopia with a cross-sectional survey in WaSH intervention areas, as well as in control areas, where the intervention was not implemented. The data were analysed using bivariate and multivariable regression analysis. Awareness of health risk factors related to inadequate WaSH was high in the programme area. The use of basic water and sanitation services was associated with several health risk perceptions: Perceiving water quality as good increased the odds of using basic water services as opposed to believing the water quality was poor (OR 3.94; CI 3.06–5.08; p ≤ 0.001). Believing that drinking unsafe water was the main cause for diarrhoea increased the odds of using basic water services (OR 1.48; CI 1.20–1.81; p ≤ 0.001). In the WaSH intervention group, the use of basic sanitation was more likely than in the control group. The use of basic sanitation was associated with households who had previously received sanitation training, as opposed to such who had not (OR 1.55; CI 1.22–1.97; p ≤ 0.001). Perceiving dirty space as the main cause of diarrhoea (OR 1.81; CI 1.50–2.19; p ≤ 0.001), and privacy when using a latrine (OR 2.00; CI 1.67–2.40; p ≤ 0.001), were associated with higher odds of using basic sanitation. Households that indicated a disadvantage of owning a latrine was maintenance costs were less likely to use basic sanitation (OR 0.49; CI 0.38–0.63; p ≤ 0.001). Risk perceptions were important determinants of use of basic services. The findings point to risk perceptions motivating the application of positive WaSH-related and health-protective behaviours. This suggests that well-designed health risk communication strategies may be effective for engaging households in healthy WaSH behaviour

    Geologic structure map of the northwestern Illinois zinc-lead district

    Get PDF
    Cover title.Bibliography: p. 7

    Age and structure of the Shyok Suture in the Ladakh region of Northwestern India: Implications for slip on the Karakoram Fault System

    Get PDF
    A precise age for the collision of the Kohistan-Ladakh block with Eurasia along the Shyok suture zone (SSZ) is one key to understanding the accretionary history of Tibet and the tectonics of Eurasia during the India-Eurasia collision. Knowing the age of the SSZ also allows the suture to be used as a piercing line for calculating total offset along the Karakoram Fault, which effectively represents the SE border of the Tibetan Plateau and has played a major role in plateau evolution. We present a combined structural, geochemical, and geochronologic study of the SSZ as it is exposed in the Nubra region of India to test two competing hypotheses: that the SSZ is of Late Cretaceous or, alternatively, of Eocene age. Coarse-continental strata of the Saltoro Molasse, mapped in this area, contain detrital zircon populations suggestive of derivation from Eurasia despite the fact that the molasse itself is deposited unconformably onto Kohistan-Ladakh rocks, indicating that the molasse is postcollisional. The youngest population of detrital zircons in these rocks (approximately 92 Ma) and a U/Pb zircon date for a dike that cuts basal molasse outcrops (approximately 85 Ma) imply that deposition of the succession began in the Late Cretaceous. This establishes a minimum age for the SSZ and rules out the possibility of an Eocene collision between Kohistan-Ladakh and Eurasia. Our results support correlation of the SSZ with the Bangong suture zone in Tibet, which implies a total offset across the Karakoram Fault of approximately 130–190 km

    Genome resequencing reveals multiscale geographic structure and extensive linkage disequilibrium in the forest tree Populus trichocarpa

    Get PDF
    This is the publisher’s final pdf. The article is copyrighted by the New Phytologist Trust and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291469-8137. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.•Plant population genomics informs evolutionary biology, breeding, conservation and bioenergy feedstock development. For example, the detection of reliable phenotype–genotype associations and molecular signatures of selection requires a detailed knowledge about genome-wide patterns of allele frequency variation, linkage disequilibrium and recombination.\ud •We resequenced 16 genomes of the model tree Populus trichocarpa and genotyped 120 trees from 10 subpopulations using 29 213 single-nucleotide polymorphisms.\ud •Significant geographic differentiation was present at multiple spatial scales, and range-wide latitudinal allele frequency gradients were strikingly common across the genome. The decay of linkage disequilibrium with physical distance was slower than expected from previous studies in Populus, with r² dropping below 0.2 within 3–6 kb. Consistent with this, estimates of recent effective population size from linkage disequilibrium (N[subscript e] ≈ 4000–6000) were remarkably low relative to the large census sizes of P. trichocarpa stands. Fine-scale rates of recombination varied widely across the genome, but were largely predictable on the basis of DNA sequence and methylation features.\ud •Our results suggest that genetic drift has played a significant role in the recent evolutionary history of P. trichocarpa. Most importantly, the extensive linkage disequilibrium detected suggests that genome-wide association studies and genomic selection in undomesticated populations may be more feasible in Populus than previously assumed

    The immune cell infiltrate populating meningiomas is composed of mature, antigen-experienced T and B cells

    Get PDF
    BACKGROUND: Meningiomas often harbor an immune cell infiltrate that can include substantial numbers of T and B cells. However, their phenotype and characteristics remain undefined. To gain a deeper understanding of the T and B cell repertoire in this tumor, we characterized the immune infiltrate of 28 resected meningiomas representing all grades. METHODS: Immunohistochemistry was used to grossly characterize and enumerate infiltrating lymphocytes. A molecular analysis of the immunoglobulin variable region of tumor-infiltrating B cells was used to characterize their antigen experience. Flow cytometry of fresh tissue homogenate and paired peripheral blood lymphocytes was used to identify T cell phenotypes and characterize the T cell repertoire. RESULTS: A conspicuous B and T cell infiltrate, primarily clustered in perivascular spaces, was present in the microenvironment of most tumors examined. Characterization of 294 tumor-infiltrating B cells revealed clear evidence of antigen experience, in that the cardinal features of an antigen-driven B cell response were present. Meningiomas harbored populations of antigen-experienced CD4+ and CD8+ memory/effector T cells, regulatory T cells, and T cells expressing the immune checkpoint molecules PD-1 and Tim-3, indicative of exhaustion. All of these phenotypes were considerably enriched relative to their frequency in the circulation. The T cell repertoire in the tumor microenvironment included populations that were not reflected in paired peripheral blood. CONCLUSION: The tumor microenvironment of meningiomas often includes postgerminal center B cell populations. These tumors invariably include a selected, antigen-experienced, effector T cell population enriched by those that express markers of an exhausted phenotype
    corecore