16,881 research outputs found

    Extension of and improvements to the ERDC low frequency magnetic direction finding system

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    In 1985, a three station direction finding lightning location system was established in the United Kingdom. A description of its evolution from an experimental system to a five station commercial system providing both on-line and historical location information is presented. A method of error reduction which enables simultaneous optimization of strike location and calculation of aerial twist error is described, together with results of the analysis of four station data from 1989. It is demonstrated that one station with a twist error can produce an apparent bearing dependent error in a station without errors. Application of the bearing corrections has significantly improved the accuracy of the system. Average location errors of better that 1 km can be achieved at a distance of 200 km from the stations

    The past is the future: innovative designs in acute stroke therapy trials

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    When it comes to behaviour, isn’t it time for young people to be seen and heard

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    At the start of this research in September 2010, reported crime in general and specifically in the borough of Fairfield in London, continued to fall, and this included youth crime (Metropolitan Police 2010). Fairfield has replaced the name of the actual Borough. Despite this there was a perceived problem by many of those in authority and the community of Fairfield, of greatly increased anti-social behaviour and criminality involving young people. This resulted in anti-social behaviour orders being imposed and the increased use of exclusion zones as a tactic to reduce this behaviour. It would be unwise to go as far as to deny that the behaviour of the young is problematic; but the criminalisation of this behaviour ensures that its causes, and indeed, its objectives, recede into the background (Smith 2003: p188). To deal with this perceived level of crime there was a heavy emphasis in terms of police time and budget on catching and punishing offenders as a way of dealing with crime and anti-social behaviour as opposed to preventing the offending. There was also in the opinion of the author, but with academic support, a lack of understanding of what worked to positively influence the behaviour of young people. From talking to young people through his work this included in the home, school, and within the criminal justice system. This was combined with a belief that young people were neither consulted, nor listened to on the rare occasions they were spoken to. This work will look to answer the following questions: • Why ‘society’ has the perception it does about young people concerning criminal and poor behaviour. • What governments have sought to do to achieve a level of control of such behaviour through legislation and policy, the theoretical support for this, and whether these are the most effective policies considering all the factors in the young people’s lives. • Finally it will look to examine what young people feel are the things that effect their behaviour in a positive or negative way in the home, in school, and in the community. The opinions of the young people were obtained through surveys conducted over three years which were analysed using SPSS, together with one to one interviews and group discussions. Taken together, this provided sufficient information on which to base analysis and conclusions concerning behaviour and the most effective interventions in Fairfield and beyond

    Association between disability measures and healthcare costs after initial treatment for acute stroke

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    <p><b>Background and Purpose:</b> The distribution of 3-month modified Rankin scale (mRS) scores has been used as an outcome measure in acute stroke trials. We hypothesized that hospitalization and institutional care home stays within the first 90 days after stroke should be closely related to 90-day mRS, that each higher mRS category will reflect incremental cost, and that resource use may be less clearly linked to the National Institutes of Health Stroke Scale (NIHSS) or Barthel index.</p> <p><b>Methods:</b> We examined resource use data from the GAIN International trial comparing 90-day mRS with total length of stay in hospital or other institutions during the first 90 days. We repeated analyses using NIHSS and Barthel index scores. Relationships were examined by analysis of variance (ANOVA) with Bonferroni contrasts of adjacent score categories. Estimated costs were based on published Scottish figures.</p> <p><b>Results:</b> We had full data from 1717 patients. Length of stay was strongly associated with final mRS (P<0.0001). Each mRS increment from 0 to 1–2 to 3–4 was significant (mean length of stay: 17, 25, 44, 58, 79 days; P<0.0005). Ninety-five percent confidence limits for estimated costs (£) rose incrementally: 2493 to 3412, 3369 to 4479, 5784 to 7008, 7300 to 8512, 10 095 to 11 141, 11 772 to 13 560, and 2623 to 3321 for mRS 0 to 5 and dead, respectively. Weaker relationships existed with Barthel and NIHSS.</p> <p><b>Conclusions:</b> Each mRS category reflects different average length of hospital and institutional stay. Associated costs are meaningfully different across the full range of mRS outcomes. Analysis of the full distribution of mRS scores is appropriate for interpretation of treatment effects after acute stroke and more informative than Barthel or NIHSS end points.</p&gt

    The use of prevalence as a measure of lice burden: a case study of Lepeophtheirus salmonis on Scottish Atlantic salmon, Salmo salar L., farms

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    This study investigates the benefits of using prevalence as a summary measure of sea lice infestation on farmed Atlantic salmon, Salmo salar L. Aspects such as sampling effort, the relationship between abundance and prevalence arising from the negative binomial distribution, and how this relationship can be used to indicate the degree of aggregation of lice on a site at a given time point are discussed. As a case study, data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. Descriptive statistics and formal analysis using a linear modelling technique identified significant variations in sea lice prevalence across year class, region and season. Supporting evidence of a functional relationship between prevalence and abundance of sea lice is provided, which is explained through the negative binomial distribution

    Variability in modified rankin scoring across a large cohort of observers

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    <br>Background and Purpose— The modified Rankin scale (mRS) is the most commonly used outcome measure in stroke trials. However, substantial interobserver variability in mRS scoring has been reported. These studies likely underestimate the variability present in multicenter clinical trials, because exploratory work has only been undertaken in single centers by a few observers, all of similar training. We examined mRS variability across a large cohort of international observers using data from a video training resource.</br> <br>Methods— The mRS training package includes a series of “real-life” patient interviews for grading. Training data were collected centrally and analyzed for variability using kappa statistics. We examined variability against a standard of “correct” mRS grades; examined variability by country; and for UK assessors, examined variability by center and by professional background of the observer.</br> <br>Results— To date, 2942 assessments from 30 countries have been submitted. Overall reliability for mRS grading has been moderate to good with substantial heterogeneity across countries. Native English language has had little effect on reliability. Within the United Kingdom, there was no significant variation by profession.</br> <br>Conclusion— Our results confirm interobserver variability in mRS assessment. The heterogeneity across countries is intriguing because it appears not to be related solely to language. These data highlight the need for novel strategies to improve reliability.</br&gt

    Reliability of the modified Rankin Scale: a systematic review

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    <p><b>Background and Purpose:</b> A perceived weakness of the modified Rankin Scale is potential for interobserver variability. We undertook a systematic review of modified Rankin Scale reliability studies.</p> <p><b>Methods:</b> Two researchers independently reviewed the literature. Crossdisciplinary electronic databases were interrogated using the following key words: Stroke*; Cerebrovasc*; Modified Rankin*; Rankin Scale*; Oxford Handicap*; Observer variation*. Data were extracted according to prespecified criteria with decisions on inclusion by consensus.</p> <p><b>Results:</b> From 3461 titles, 10 studies (587 patients) were included. Reliability of modified Rankin Scale varied from weighted κ=0.95 to κ=0.25. Overall reliability of mRS was κ=0.46; weighted κ=0.90 (traditional modified Rankin Scale) and κ=0.62; weighted κ=0.87 (structured interview).</p> <p><b>Conclusion:</b> There remains uncertainty regarding modified Rankin Scale reliability. Interobserver studies closest in design to large-scale clinical trials demonstrate potentially significant interobserver variability.</p&gt
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