142 research outputs found

    Evaluating the Future for Grey Literature

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    This thesis explores the underlying principles behind the two divergent views relating to a grey literature crisis. It achieves this by presenting a review of the current mechanisms of grey literature production. It acknowledges how methodological and epistemological considerations, supersede any ratification of a coherent disciplinary ontology. Furthermore, by characterising a selected historiography of the archaeological field experience, and exposing the conceptual thinking behind the idea of past as record, it reinforces the prioritisation of record production, over historical enquiry. Through a critical assessment of the optimised field-interventions undertaken in the commercial sector, this prioritisation exposes a series of indicative limitations – first, and foremost pertaining to the viability of the end-product (i.e. the grey literature) of such endeavours. The study utilises the isolatable geopolitical context of England, however, the methodology developed herein, can and should be applied to wider UK contexts as future research. Turning attention to the efforts made to challenge the concept of a grey literature crisis, a subsequent review is undertaken of current perceptions regarding the use-value of grey literature. This is achieved in the context of characterising examples of their selection-for-use within nine synthetic projects. The findings indicate how much faith is placed upon the transformative process of synthesis, to educe data of sufficiently comparable format and standard to facilitate a more up-to-date and better informed narrative. The research then extends the project characterisation by analysing the ways in which the perceived use-value of grey literature is realised. The analysis is able to qualify and quantify how grey literature resources are prioritised within the project narratives, with the findings indicating much variability amongst the projects studied. By establishing a working appreciation of the use of grey literature, as a research-resource, the thesis further considers how an understanding of this use may inform and improve guidance relating to its production, and presents these ideas as a series of working observations and recommendations for further study

    Using extreme value theory to evaluate the leading pedestrian interval road safety intervention

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    Improving road safety is hugely important with the number of deaths on the world's roads remaining unacceptably high; an estimated 1.35 million people die each year as a result of road traffic collisions (WHO, 2020). Current practice for treating collision hotspots is almost always reactive: once a threshold level of collisions has been overtopped during some pre-determined observation period, treatment is applied (e.g. road safety cameras). Traffic collisions are rare, so prolonged observation periods are necessary. However, traffic conflicts are more frequent and are a margin of the social cost; hence, traffic conflict before/after studies can be conducted over shorter time periods. We investigate the effect of implementing the leading pedestrian interval (LPI) treatment (Van Houten et al. 2000) at signalised intersections as a safety intervention in a city in north America. Pedestrian-vehicle traffic conflict data were collected from treatment and control sites during the before and after periods. We implement a before/after study on post-encroachment times (PETs) where small PET values denote a near-miss. Hence, extreme value theory is employed to model extremes of our PET processes, with adjustments to the usual modelling framework to account for temporal dependence and treatment effects.Comment: 16 page

    Using extreme value theory to evaluate the leading pedestrian interval road safety intervention

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    Improving road safety is hugely important with the number of deaths on the world's roads remaining unacceptably high; an estimated 1.3 million people die each year as a result of road traffic collisions. Current practice for treating collision hotspots is almost always reactive: once a threshold level of collisions has been overtopped during some pre‐determined observation period, treatment is applied (e.g., road safety cameras). Traffic collisions are rare, so prolonged observation periods are necessary. However, traffic conflicts are more frequent and are a margin of the social cost; hence, traffic conflict before/after studies can be conducted over shorter time periods. We investigate the effect of implementing the leading pedestrian interval treatment at signalised intersections as a safety intervention in a city in north America. Pedestrian‐vehicle traffic conflict data were collected from treatment and control sites during the before and after periods. We implement a before/after study on post‐encroachment times (PETs) where small PET values denote ‘near‐misses’. Hence, extreme value theory is employed to model extremes of our PET processes, with adjustments to the usual modelling framework to account for temporal dependence and treatment effects

    Bayesian inference for a spatio-temporal model of road traffic collision data

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    Improving road safety is hugely important with the number of deaths on the world’s roads remaining unacceptably high; an estimated 1.35 million people die each year (WHO, 2020). Current practice for treating collision hotspots is almost always reactive: once a threshold level of collisions has been exceeded during some predetermined observation period, treatment is applied (e.g. road safety cameras). However, more recently, methodology has been developed to predict collision counts at potential hotspots in future time periods, with a view to a more proactive treatment of road safety hotspots. Dynamic linear models provide a flexible framework for predicting collisions and thus enabling such a proactive treatment. In this paper, we demonstrate how such models can be used to capture both seasonal variability and spatial dependence in time dependent collision rates at several locations. The model allows for within- and out-of-sample forecasting for locations which are fully observed and for locations where some data are missing. We illustrate our approach using collision rate data from 8 Traffic Administration Zones in the US, and find that the model provides a good description of the underlying process and reasonable forecast accuracy

    Reliability of the submaximal iSTEP performance test in children with haemophilia

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    Performance on the iSTEP and 10 m-ISWT in boys with haemophilia

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    INTRODUCTION: Boys with haemophilia (BwH) have improved health outcomes. Measures of physical function in haemophilia are not challenging or sensitive enough to reflect physical limitations or guide rehabilitation. To identify meaningful tests, we aimed to: evaluate the performance of BwH on two physical performance measures: iSTEP and 10 m-ISWT; identify factors which predict performance and compare BwH to their unaffected peers. METHODS: BwH completed both iSTEP and 10 m-ISWT. Disease severity, age, BMI, HJHS, lower limb muscle torque, time spent in moderate to vigorous physical activity, sedentary time, were included as factors to predict performance. Results were compared to unaffected peers. RESULTS: 43 boys median age 10 (10 mild/moderate, 26 severe, 7 inhibitors) were recruited. BwH were less likely to complete the iSTEP and performed less well on the 10 m-ISWT than age matched peers. Ceiling effects were apparent for iSTEP, but not the 10 m-ISWT test. Age was the only significant predictor for performance in the iSTEP, with older boys being more likely to achieve a higher level or complete the test. Greater age, lower BMI, milder disease severity and more time spent in MVPA all predicted better performance on the 10 m-ISWT, with BMI and habitual physical activity a potential rehabilitation focus for underperforming individuals. HJHS and muscle strength did not predict performance on either test. CONCLUSION: Despite the space need to conduct the 10 m-ISWT, it appears to be a superior performance measure than the iSTEP in BwH and provides clinically meaningful information, which can be interpreted using age-specific normative reference equations

    School leaders, community cohesion and the Big Society

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    This report summarises research conducted on community cohesion in English schools in 2010. The research uses an opportunity sample of 27 primary and secondary schools in three local authorities to generate insights on how the duty to promote community cohesion has been interpreted, enacted and accounted for since its beginning in 2007. The significance of this report is not in the sample size or spectrum but in the themes that emerged from semi-structured interviews. A related document, Teaching, Learning and Community Cohesion: a study of primary and secondary schools’ responses to a new statutory duty, which provides guidance for teachers and school leaders, is also published by CfBT (Rowe et al, 2011). The background to the duty to promote community cohesion, including its inception as a policy and its roots in other measures, is discussed in an opening section. The findings from group and individual interviews with teachers and school senior leaders are analysed under themed headings. Finally, some pointers for future policy development, including links with the ‘Big Society’ agenda, are discussed. The main messages of this report are that: • nearly all teachers and schools welcome community cohesion and agree personally and professionally with its underpinning values, although they interpret the duty very differently, according to their school context and present practice • schools have had varied success in implementing the duty, paying more attention to action than to underlying social policy coherence, but in most cases the duty and the fact that it was to be inspected has resulted in schools developing and improving their provision • some teachers are not clear about current guidance and inspection criteria, while a small number of teachers have objections to the legal and/or inspectable status of the duty • strong resonances and opportunities exist for the development of schools’ achievements in the light of the recent Education White Paper (Department for Education, 2010), a growing focus on localism (CLG, 2010) and the emergent policy focus on the Big Societ

    Autism spectrum disorders in boys at a major UK hemophilia center: prevalence and risk factors

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    Background: Autism spectrum disorders (ASDs) are diagnosed by social communication difficulties strong, narrow interests, and repetitive stereotyped behavior. An apparently-elevated prevalence of ASD at a major UK hemophilia center warranted investigation. Objectives: To screen boys with hemophilia for difficulties in social communication and executive function and identify the prevalence and risk factors for ASD. Methods: Parents of boys with hemophilia aged 5 to 16 years completed the Social Communication Questionnaire, Children’s Communication Checklist, and the Behavior Rating Inventory of executive function. Prevalence and potential risk factors for ASD were evaluated. Boys with an existing diagnosis of ASD did not complete questionnaires, but were included in the prevalence analysis. Results: Negative scores on all 3 questionnaires were observed for 60 of 79 boys. Positive scores on 1, 2, and 3 questionnaires were seen in 12 of 79, 3 of 79, and 4 of 79 boys, respectively. In addition to the 11 of 214 boys with a prior ASD diagnosis, 3 further boys were diagnosed with ASD, yielding a prevalence of 14 (6.5%) of 214, greater than that of boys in the UK general population. Premature birth was linked to having ASD, but did not fully explain the increased prevalence with more boys born <37 weeks scoring positively on the Social Communications Questionnaire and Children’s Communication Checklist compared with those born at term. Conclusion: This study identified an increased prevalence of ASD at 1 UK hemophilia center. Prematurity was identified as a risk factor but did not fully explain the higher prevalence of ASD. Further investigation in the wider national/global hemophilia communities is warranted to determine whether this is an isolated finding

    Comparison of Short-Term Estrogenicity Tests for Identification of Hormone-Disrupting Chemicals

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    The aim of this study was to compare results obtained by eight different short-term assays of estrogenlike actions of chemicals conducted in 10 different laboratories in five countries. Twenty chemicals were selected to represent direct-acting estrogens, compounds with estrogenic metabolites, estrogenic antagonists, and a known cytotoxic agent. Also included in the test panel were 17β-estradiol as a positive control and ethanol as solvent control. The test compounds were coded before distribution. Test methods included direct binding to the estrogen receptor (ER), proliferation of MCF-7 cells, transient reporter gene expression in MCF-7 cells, reporter gene expression in yeast strains stably transfected with the human ER and an estrogen-responsive reporter gene, and vitellogenin production in juvenile rainbow trout. 17β-Estradiol, 17α-ethynyl estradiol, and diethylstilbestrol induced a strong estrogenic response in all test systems. Colchicine caused cytotoxicity only. Bisphenol A induced an estrogenic response in all assays. The results obtained for the remaining test compounds—tamoxifen, ICI 182.780, testosterone, bisphenol A dimethacrylate, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol dodecylethoxylate, butylbenzylphthalate, dibutylphthalate, methoxychlor, o,p′-DDT, p,p′-DDE, endosulfan, chlomequat chloride, and ethanol—varied among the assays. The results demonstrate that careful standardization is necessary to obtain a reasonable degree of reproducibility. Also, similar methods vary in their sensitivity to estrogenic compounds. Thus, short-term tests are useful for screening purposes, but the methods must be further validated by additional interlaboratory and interassay comparisons to document the reliability of the methods

    Radio observations of the first three-month Fermi-AGN at 4.8 GHz

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    Using the Urumqi 25m radio telescope, sources from the first three-month Fermi-LAT detected AGN catalog with declination >0 were observed in 2009 at 4.8 GHz. The radio flux density appears to correlate with the gamma-ray intensity. Intra-day variability (IDV) observations were performed in March, April and May in 2009 for selected 42 gamma-ray bright blazars, and 60% of them show evident flux variability at 4.8 GHz during the IDV observations, the IDV detection rate is higher than that in previous flat-spectrum AGN samples. The IDV appears more often in the VLBI-core dominant blazars, and the non-IDV blazars show relatively `steeper' spectral indices than the IDV blazars. Pronounced inter-month variability has been found in two BL Lac objects: J0112+2244 and J0238+1636.Comment: 10 pages, 3 figures, accepted for publication in RA
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