1,631 research outputs found

    Perceived need of, and interest in, HIV pre-exposure prophylaxis amongst men who have sex with men attending three sexual health clinics in London, UK

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    HIV pre-exposure prophylaxis (PrEP) has proven efficacy in reducing the risk of HIV infection in men who have sex with men (MSM), but has not yet been commissioned in the UK. The aim of this study was to investigate perceived need and benefit (or experience of) PrEP among HIV-negative MSM attending sexual health clinics. HIV-negative MSM attending three sexual health centres in London, UK were opportunistically invited to complete a questionnaire. Data collected comprised demographic data and sexual and drug use behaviours as well as questions regarding perceptions of risk and need for PrEP. Logistic regression analysis was undertaken to identify variables predicting acceptability of, and intention to use, PrEP. In addition, data were gathered in respondents already taking PrEP. Eight hundred and thirty-nine questionnaires were analysed. The median age of respondents was 35 years (IQR 28–41, range 18–78), 650 (77%) were of white ethnicity and 649 (77%) had a university education. Four hundred and fifty-six (54%) reported at least one episode of condomless anal sex in the preceding three months, 437 (52%) reported recreational drug use in the preceding three months and 311 (37%) had been diagnosed with a sexually transmitted infection within the preceding six months. Four hundred and sixty-three (64%) of 726 strongly agreed with the statement ‘I think I would benefit from PrEP’. Multivariate logistic regression analysis demonstrated that having receptive anal intercourse (RAI) without condoms, having an awareness of the risk of unprotected RAI and having belief in the effectiveness of PrEP were independent predictors for someone thinking they would benefit from taking PrEP. Eight percent of respondents (59/724) had already taken or were currently taking PrEP. The results suggest that individuals at risk are likely to perceive themselves as benefiting from PrEP. The majority perceived their risk of acquiring HIV and benefit from PrEP accurately. Overall they appeared to have little concern over the use of PrEP and generally positive attitudes. Further investigation is warranted to understand why those at risk do not perceive benefit from PrEP

    Applications of nutrient profiling : potential role in diet-related chronic disease prevention and the feasibility of a core nutrient-profiling system

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    Background/objectives: A number of different nutrient-profiling models have been proposed and several applications of nutrient profiling have been identified. This paper outlines the potential role of nutrient-profiling applications in the prevention of diet-related chronic disease (DRCD), and considers the feasibility of a core nutrient-profiling system, which could be modified for purpose, to underpin the multiple potential applications in a particular country.Methods: The &lsquo;Four &lsquo;P&rsquo;s of Marketing&rsquo; (Product, Promotion, Place and Price) are used as a framework for identifying and for classifying potential applications of nutrient profiling. A logic pathway is then presented that can be used to gauge the potential impact of nutrient-profiling interventions on changes in behaviour, changes in diet and, ultimately, changes in DRCD outcomes. The feasibility of a core nutrient-profiling system is assessed by examining the implications of different model design decisions and their suitability to different purposes.Results and conclusions: There is substantial scope to use nutrient profiling as part of the policies for the prevention of DRCD. A core nutrient-profiling system underpinning the various applications is likely to reduce discrepancies and minimise the confusion for regulators, manufacturers and consumers. It seems feasible that common elements, such as a standard scoring method, a core set of nutrients and food components, and defined food categories, could be incorporated as part of a core system, with additional application-specific criteria applying. However, in developing and in implementing such a system, several country-specific contextual and technical factors would need to be balanced.<br /

    Analysis of Collective Neutrino Flavor Transformation in Supernovae

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    We study the flavor evolution of a dense gas initially consisting of pure mono-energetic νe\nu_e and νˉe\bar\nu_e. Using adiabatic invariants and the special symmetry in such a system we are able to calculate the flavor evolution of the neutrino gas for the cases with slowly decreasing neutrino number densities. These calculations give new insights into the results of recent large-scale numerical simulations of neutrino flavor transformation in supernovae. For example, our calculations reveal the existence of what we term the ``collective precession mode''. Our analyses suggest that neutrinos which travel on intersecting trajectories subject to destructive quantum interference nevertheless can be in this mode. This mode can result in sharp transitions in the final energy-dependent neutrino survival probabilities across all trajectories, a feature seen in the numerical simulations. Moreover, this transition is qualitatively different for the normal and inverted neutrino mass hierarchies. Exploiting this difference, the neutrino signals from a future galactic supernova can potentially be used to determine the actual neutrino mass hierarchy.Comment: 18 pages, 6 figures, retex4 forma

    Regge behaviour of distribution functions and t and x-evolutions of gluon distribution function at low-x

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    In this paper t and x-evolutions of gluon distribution function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi(DGLAP) evolution equation in leading order(LO) at low-x, assuming the Regge behaviour of quark and gluon at this limit, are presented. We compare our results of gluon distribution function with MRST 2001, MRST 2004 and GRV '98 parameterizations and show the compatibility of Regge behaviour of quark and gluon distribution functions with perturbative quantum chromodynamics(PQCD) at low-x. We also discuss the limitations of Taylor series expansion method used earlier to solve DGLAP evolution equations, in the Regge behaviour of distribution functions.Comment: 19 pages, 7 figure

    Athenaeus the Navigator

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    Copyright © The Society for the Promotion of Hellenic Studies 2008. Published version reproduced with the permission of the publisher.This study concerns navigation in a geographical sense and in the sense of the reader finding a way through a complex text with the help of points of reference. Recent studies in Athenaeus have suggested that he was a more sophisticated writer than the second-hand compiler of Hellenistic comment on classical Greek authors, which has been a dominant view. Building on these studies, this article argues that Athenaeus' approach to his history of ancient dining draws on traditional poetic links between the symposium and the sea, and expands such metaphors with a major interest in place and provenance, which also belongs to the literature of the symposium. Provenance at the same time evokes a theme of imperial thought, that Rome can attract to herself all the good things of the earth that are now under her sway. Good things include foods and the literary heritage of Greece now housed in imperial libraries. Athenaeus deploys themes of navigation ambiguously, to celebrate diversity and to warn against the dangers of luxury. Notorious examples of luxury are presented – the Sybarites and Capuans, for example – but there seem to be oblique warnings to Rome as well. Much clearer censure is reserved for the gastronomic poem of Archestratus of Gela, which surveys the best cities in which to eat certain fish. The Deipnosophists deplore the immorality of the poet and his radical rewriting of their key authors Homer and Plato, while at the same time quoting him extensively for the range of his reference to geography and fish. This commentary on Archestratus is a good example of the Deipnosophists' guidance to the reader, Roman or otherwise, who wishes to ‘navigate’ the complicated history of the Greek deipnon and symposium

    The development and validation of an urbanicity scale in a multi-country study

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    Background : Although urban residence is consistently identified as one of the primary correlates of non-communicable disease in low- and middle-income countries, it is not clear why or how urban settings predispose individuals and populations to non-communicable disease (NCD), or how this relationship could be modified to slow the spread of NCD. The urban&ndash;rural dichotomy used in most population health research lacks the nuance and specificity necessary to understand the complex relationship between urbanicity and NCD risk. Previous studies have developed and validated quantitative tools to measure urbanicity continuously along several dimensions but all have been isolated to a single country. The purposes of this study were 1) To assess the feasibility and validity of a multi-country urbanicity scale; 2) To report some of the considerations that arise in applying such a scale in different countries; and, 3) To assess how this scale compares with previously validated scales of urbanicity. Methods : Household and community-level data from the Young Lives longitudinal study of childhood poverty in 59 communities in Ethiopia, India and Peru collected in 2006/2007 were used. Household-level data include parents&rsquo; occupations and education level, household possessions and access to resources. Community-level data include population size, availability of health facilities and types of roads. Variables were selected for inclusion in the urbanicity scale based on inspection of the data and a review of literature on urbanicity and health. Seven domains were constructed within the scale: Population Size, Economic Activity, Built Environment, Communication, Education, Diversity and Health Services. Results : The scale ranged from 11 to 61 (mean 35) with significant between country differences in mean urbanicity; Ethiopia (30.7), India (33.2), Peru (39.4). Construct validity was supported by factor analysis and high corrected item-scale correlations suggest good internal consistency. High agreement was observed between this scale and a dichotomized version of the urbanicity scale (Kappa 0.76; Spearman&rsquo;s rank-correlation coefficient 0.84 (p&thinsp;&lt;&thinsp;0.0001). Linear regression of socioeconomic indicators on the urbanicity scale supported construct validity in all three countries (p&thinsp;&lt;&thinsp;0.05). Conclusions : This study demonstrates and validates a robust multidimensional, multi-country urbanicity scale. It is an important step on the path to creating a tool to assess complex processes like urbanization. This scale provides the means to understand which elements of urbanization have the greatest impact on health

    Cost-effectiveness of oral versus intravenous antibiotics (OVIVA) in patients with bone and joint infection : evidence from a non-inferiority trial

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    Background: Bone and joint infections are becoming increasingly common and are usually treated with surgery and a course of intravenous antibiotics. However, there is no evidence to support the superiority of intravenous therapy and there is a growing body of literature showing that oral therapy is effective in treating these infections. Given this lack of evidence the clinical trial ‘Oral Versus Intravenous Antibiotics’ (OVIVA) was designed to assess the clinical and cost-effectiveness of intravenous versus oral antibiotics for the treatment of bone and joint infections, using a non-inferiority design. Clinical results from the trial indicate that oral antibiotics are non-inferior to intravenous antibiotics. The aim of this paper is to evaluate the cost-effectiveness of intravenous compared to oral antibiotics for treating bone and joint infections, using data from OVIVA. Methods: A cost-utility analysis was carried out, the main economic outcome measure was the quality adjusted life-year, measured using the EQ-5D-3L questionnaire, combined with costs to estimate cost-effectiveness over 12-months follow-up. Results: Results show that costs were significantly lower in the oral arm compared to the intravenous arm, a difference of £2,740 (95% confidence interval £1,488 to £3,992). Results of four sensitivity analyses were consistent with the base-case results. QALYs were marginally higher in the oral arm, however this difference was not statistically significant; -0.007 (95% confidence interval -0.045 to 0.031). Conclusions: Treating patients with bone and joint infections for the first six weeks of therapy with oral antibiotics is both less costly and does not result in detectable differences in quality of life compared to treatment with intravenous antibiotics. Adopting a practice of treating bone and joint infections with oral antibiotics early in the course of therapy could potentially save the UK National Health Service over £17 million annually

    The Simple View of Reading Made Complex by Morphological Decoding Fluency in Bilingual Fourth-Grade Readers of English

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordThis study examined the complexity of the Simple View of Reading focusing on morphological decoding fluency in fourth-grade readers of English in Singapore. The participants were three groups of students who all learned to become bilingual and biliterate in the English language (EL) and their respective ethnic language in school but differed in the home language they used. The first group was ethnic Chinese students who used English as the dominant home language (Chinese EL1); the other two groups were ethnic Chinese and Malay students whose dominant home language was not English but Chinese (Chinese EL2) and Malay (Malay EL2), respectively. The measures included pseudo word decoding (phonemic decoding), timed decoding of derivational words (morphological decoding fluency), oral vocabulary, and passage comprehension. Path analysis showed that oral vocabulary significantly predicted reading comprehension across all three groups; yet a significant effect of morphological decoding fluency surfaced in the Chinese EL1 and Malay EL2 groups but not the Chinese EL2 group. Multi-group path analysis and commonality analysis further confirmed that morphological decoding played a larger role in the in the Chinese EL1 and Malay EL2 groups. These findings are discussed in light of the joint influence of target language experience and cross-linguistic influence on second language or bilingual reading development.Office of Education Research, National Institute of Education, Nanyang Technological Universit
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