148 research outputs found

    Pressures measured in flight on the aft fuselage and external nozzle of a twin-jet fighter

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    Fuselage, boundary layer, and nozzle pressures were measured in flight for a twin jet fighter over a Mach number range from 0.60 to 2.00 at test altitudes of 6100, 10,700, and 13,700 meters for angles of attack ranging from 0 deg to 7 deg. Test data were analyzed to find the effects of the propulsion system geometry. The flight variables, and flow interference. The aft fuselage flow field was complex and showed the influence of the vertical tail, nacelle contour, and the wing. Changes in the boattail angle of either engine affected upper fuselage and lower fuselage pressure coefficients upstream of the nozzle. Boundary layer profiles at the forward and aft locations on the upper nacelles were relatively insensitive to Mach number and altitude. Boundary layer thickness decreased at both stations as angle of attack increased above 4 deg. Nozzle pressure coefficient was influenced by the vertical tail, horizontal tail boom, and nozzle interfairing; the last two tended to separate flow over the top of the nozzle from flow over the bottom of the nozzle. The left nozzle axial force coefficient was most affected by Mach number and left nozzle boattail angle. At Mach 0.90, the nozzle axial force coefficient was 0.0013

    AutoSNPdb: an annotated single nucleotide polymorphism database for crop plants

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    Single nucleotide polymorphisms (SNPs) may be considered the ultimate genetic marker as they represent the finest resolution of a DNA sequence (a single nucleotide), are generally abundant in populations and have a low mutation rate. Analysis of assembled EST sequence data provides a cost-effective means to identify large numbers of SNPs associated with functional genes. We have developed an integrated SNP discovery pipeline, which identifies SNPs from assembled EST sequences. The results are maintained in a custom relational database along with EST source and annotation information. The current database hosts data for the important crops rice, barley and Brassica. Users may rapidly identify polymorphic sequences of interest through BLAST sequence comparison, keyword searches of annotations derived from UniRef90 and GenBank comparisons, GO annotations or in genes corresponding to syntenic regions of reference genomes. In addition, SNPs between specific varieties may be identified for targeted mapping and association studies. SNPs are viewed using a user-friendly graphical interface. The database is freely accessible at http://autosnpdb.qfab.org.au/

    Identification of recruitment and retention strategies for rehabilitation professionals in Ontario, Canada: results from expert panels

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    <p>Abstract</p> <p>Background</p> <p>Demand for rehabilitation services is expected to increase due to factors such as an aging population, workforce pressures, rise in chronic and complex multi-system disorders, advances in technology, and changes in interprofessional health service delivery models. However, health human resource (HHR) strategies for Canadian rehabilitation professionals are lagging behind other professional groups such as physicians and nurses. The objectives of this study were: 1) to identify recruitment and retention strategies of rehabilitation professionals including occupational therapists, physical therapists and speech language pathologists from the literature; and 2) to investigate both the importance and feasibility of the identified strategies using expert panels amongst HHR and education experts.</p> <p>Methods</p> <p>A review of the literature was conducted to identify recruitment and retention strategies for rehabilitation professionals. Two expert panels, one on <it>Recruitment and Retention </it>and the other on <it>Education </it>were convened to determine the importance and feasibility of the identified strategies. A modified-delphi process was used to gain consensus and to rate the identified strategies along these two dimensions.</p> <p>Results</p> <p>A total of 34 strategies were identified by the <it>Recruitment and Retention </it>and <it>Education </it>expert panels as being important and feasible for the development of a HHR plan for recruitment and retention of rehabilitation professionals. Seven were categorized under the <it>Quality of Worklife and Work Environment </it>theme, another seven in <it>Financial Incentives and Marketing</it>, two in <it>Workload and Skill Mix</it>, thirteen in <it>Professional Development </it>and five in <it>Education and Training</it>.</p> <p>Conclusion</p> <p>Based on the results from the expert panels, the three major areas of focus for HHR planning in the rehabilitation sector should include strategies addressing <it>Quality of Worklife and Work Environment</it>, <it>Financial Incentives and Marketing </it>and <it>Professional Development</it>.</p

    The precarious supply of physical therapists across Canada: exploring national trends in health human resources (1991 to 2005)

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    <p>Abstract</p> <p>Background</p> <p>Health Human Resource (HHR) ratios are one measure of workforce supply, and are often expressed as a ratio in the number of health professionals to a sub-set of the population. In this study, we explore national trends in HHR among physical therapists (PTs) across Canada.</p> <p>Methods</p> <p>National population data were combined with provincial databases of registered physical therapists in order to estimate the HHR ratio in 2005, and to establish trends between 1991 and 2005.</p> <p>Results</p> <p>The national HHR ratio was 4.3 PTs per 10,000 population in 1991, which increased to 5.0 by 2000. In 2005, the HHR ratios varied widely across jurisdictions; however, we estimate that the national average dropped to 4.8 PTs per 10,000. Although the trend in HHR between 1991 and 2005 suggests positive growth of 11.6%, we have found negative growth of 4.0% in the latter 5-years of this study period.</p> <p>Conclusion</p> <p>Demand for rehabilitation services is projected to escalate in the next decade. Identifying benchmarks or targets regarding the optimal number of PTs, along with other health professionals working within inter professional teams, is necessary to establish a stable supply of health providers to meet the emerging rehabilitation and mobility needs of an aging and increasingly complex Canadian population.</p

    The Evolutionary Analysis of Emerging Low Frequency HIV-1 CXCR4 Using Variants through Time—An Ultra-Deep Approach

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    Large-scale parallel pyrosequencing produces unprecedented quantities of sequence data. However, when generated from viral populations current mapping software is inadequate for dealing with the high levels of variation present, resulting in the potential for biased data loss. In order to apply the 454 Life Sciences' pyrosequencing system to the study of viral populations, we have developed software for the processing of highly variable sequence data. Here we demonstrate our software by analyzing two temporally sampled HIV-1 intra-patient datasets from a clinical study of maraviroc. This drug binds the CCR5 coreceptor, thus preventing HIV-1 infection of the cell. The objective is to determine viral tropism (CCR5 versus CXCR4 usage) and track the evolution of minority CXCR4-using variants that may limit the response to a maraviroc-containing treatment regimen. Five time points (two prior to treatment) were available from each patient. We first quantify the effects of divergence on initial read k-mer mapping and demonstrate the importance of utilizing population-specific template sequences in relation to the analysis of next-generation sequence data. Then, in conjunction with coreceptor prediction algorithms that infer HIV tropism, our software was used to quantify the viral population structure pre- and post-treatment. In both cases, low frequency CXCR4-using variants (2.5–15%) were detected prior to treatment. Following phylogenetic inference, these variants were observed to exist as distinct lineages that were maintained through time. Our analysis, thus confirms the role of pre-existing CXCR4-using virus in the emergence of maraviroc-insensitive HIV. The software will have utility for the study of intra-host viral diversity and evolution of other fast evolving viruses, and is available from http://www.bioinf.manchester.ac.uk/segminator/
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