246 research outputs found

    Polychlorinated Biphenyl (PCB) Exposure and Diabetes: Results from the Anniston Community Health Survey

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    Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world

    "Ordinary, the same as anywhere else": notes on the management of spoiled identity in 'marginal' middle class neighbourhoods

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    Urban sociologists are becoming increasingly interested in neighbourhood as a source of middle-class identity. Particular emphasis is currently being given to two types of middle-class neighbourhood; gentrified urban neighbourhoods of ‘distinction’ and inconspicuous ‘suburban landscapes of privilege’. However, there has been a dearth of work on ‘marginal’ middle-class neighbourhoods that are similarly ‘inconspicuous’ rather than distinctive, but less exclusive, thus containing sources of ‘spoiled identity’. This article draws on data gathered from two ‘marginal’ middleclass neighbourhoods that contained a particular source of ‘spoiled identity’: social renters. Urban sociological analyses of neighbour responses to these situations highlight a process of dis-identification with the maligned object, which exacerbates neighbour differences. Our analysis of data from the ‘marginal’ middle-class neighbourhoods suggests something entirely different and Goffmanesque. This entailed the management of spoiled identity, which emphasized similarities rather than differences between neighbours.</p

    The low level of debris disk activity at the time of the Late Heavy Bombardment: a Spitzer study of Praesepe

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    We present 24 micron photometry of the intermediate-age open cluster Praesepe. We assemble a catalog of 193 probable cluster members that are detected in optical databases, the Two Micron All Sky Survey (2MASS), and at 24 micron, within an area of ~ 2.47 square degrees. Mid-IR excesses indicating debris disks are found for one early-type and for three solar-type stars. Corrections for sampling statistics yield a 24 micron excess fraction (debris disk fraction) of 6.5 +- 4.1% for luminous and 1.9 +- 1.2% for solar-type stars. The incidence of excesses is in agreement with the decay trend of debris disks as a function of age observed for other cluster and field stars. The values also agree with those for older stars, indicating that debris generation in the zones that emit at 24 micron falls to the older 1-10 Gyr field star sample value by roughly 750 Myr. We discuss our results in the context of previous observations of excess fractions for early- and solar-type stars. We show that solar-type stars lose their debris disk 24 micron excesses on a shorter timescale than early-type stars. Simplistic Monte Carlo models suggest that, during the first Gyr of their evolution, up to 15-30% of solar-type stars might undergo an orbital realignment of giant planets such as the one thought to have led to the Late Heavy Bombardment, if the length of the bombardment episode is similar to the one thought to have happened in our Solar System. In the Appendix, we determine the cluster's parameters via boostrap Monte Carlo isochrone fitting, yielding an age of 757 Myr (+- 36 Myr at 1 sigma confidence) and a distance of 179 pc (+- 2 pc at 1 sigma confidence), not allowing for systematic errors.Comment: 22 pages, 14 figures, 9 tables, emulateapj format; Accepted for publication in The Astrophysical Journa

    Testing foundations of quantum mechanics with photons

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    The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

    Workplace learning from a socio-cultural perspective: creating developmental space during the general practice clerkship

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    Workplace learning in undergraduate medical education has predominantly been studied from a cognitive perspective, despite its complex contextual characteristics, which influence medical students’ learning experiences in such a way that explanation in terms of knowledge, skills, attitudes and single determinants of instructiveness is unlikely to suffice. There is also a paucity of research which, from a perspective other than the cognitive or descriptive one, investigates student learning in general practice settings, which are often characterised as powerful learning environments. In this study we took a socio-cultural perspective to clarify how students learn during a general practice clerkship and to construct a conceptual framework that captures this type of learning. Our analysis of group interviews with 44 fifth-year undergraduate medical students about their learning experiences in general practice showed that students needed developmental space to be able to learn and develop their professional identity. This space results from the intertwinement of workplace context, personal and professional interactions and emotions such as feeling respected and self-confident. These forces framed students’ participation in patient consultations, conversations with supervisors about consultations and students’ observation of supervisors, thereby determining the opportunities afforded to students to mind their learning. These findings resonate with other conceptual frameworks and learning theories. In order to refine our interpretation, we recommend that further research from a socio-cultural perspective should also explore other aspects of workplace learning in medical education

    Effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine on appetite, food intake and emotional processing in healthy volunteers

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    RATIONALE: The treatment of obesity is an increasing global health priority, yet few effective drug treatments are currently available. The discovery of novel anti-obesity therapies could be assisted by the validation of experimental (translational) medicine models in healthy volunteers that assess efficacy and safety at an early stage of drug development. OBJECTIVES: The aim of this study was to examine the effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) in an experimental medicine model assessing both appetite and mood. METHODS: Using a between-subjects, double-blind, placebo-controlled design, 24 male and 24 female participants were randomly assigned to either placebo, 15- or 30-mg mCPP treatment groups. Lunch was eaten from a Universal Eating Monitor (UEM) that measured eating rate, and the participants completed the P1vital® Oxford Emotional Test Battery (ETB) and a series of appetite and mood ratings. RESULTS: mCPP reduced appetite and, in women, enhanced measures of satiation. The drug also enhanced memory for emotional material in the word recall and recognition memory tasks of the ETB. CONCLUSIONS: The results provide new insight into the effects of mCPP on appetite, satiety and memory in humans. In addition, our data provide an illustration of the value of measuring changes in appetite and mood in healthy volunteers to determine the potential efficacy and safety of novel anti-obesity drugs

    On-chip quantum interference between silicon photon-pair sources

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    Large-scale integrated quantum photonic technologies will require the on-chip integration of identical photon sources with reconfigurable waveguide circuits. Relatively complex quantum circuits have already been demonstrated, but few studies acknowledge the pressing need to integrate photon sources and waveguide circuits together on-chip. A key step towards such large-scale quantum technologies is the integration of just two individual photon sources within a waveguide circuit, and the demonstration of high-visibility quantum interference between them. Here, we report a silicon-on-insulator device combining two four-wave mixing sources, in an interferometer with a reconfigurable phase shifter. We configure the device to create and manipulate two-colour (non-degenerate) or same-colour (degenerate), path-entangled or path-unentangled photon pairs. We observe up to 100.0+/-0.4% visibility quantum interference on-chip, and up to 95+/-4% off-chip. Our device removes the need for external photon sources, provides a path to increasing the complexity of quantum photonic circuits, and is a first step towards fully-integrated quantum technologies

    Piloting online self-audit of methadone treatment in Irish general practice: results, reflections and educational outcomes

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    Background: Work based learning underpins the training and CPD of medical practitioners. Medical audit operates on two levels; individual self-assessment and professional/practice development. In Ireland, annual practice improvement audit is an essential requirement for the successful completion of continuous professional development (CPD) as determined by the regulatory body, the Irish Medical Council. All general practice (GP) doctors providing methadone maintenance treatment (MMT) in Ireland have a contractual obligation to partake in a yearly methadone practice audit. The Irish College of General Practitioners (ICGP) as national training provider is tasked to facilitate this annual audit process. The purpose of this audit is to assess the quality of care provided to patients against an agreed set of national standards, enhance learning, and promote practice improvement and reflective practice. The aim was to present an online MTP self-audit and evaluate results from a 12-month pilot among GPs providing MMT in Ireland. Method A mixed method study describing three phases (design and development, pilot/implementation and evaluation) of a new online self –audit tool was conducted. Descriptive and thematic analysis of audit and evaluation data was conducted. Results: Survey Monkey is a suitable software package for the development and hosting of an easy to use online audit for MMT providing doctors. Analysis of the audit results found that the majority of GPs scored 80% or over for the 25 identified essential criteria for MMT provision. The evaluation of the GP audit experience underscores the positive outcomes of the online self-audit in terms of improving practice systems, encouraging reflective practice, enhanced patient care and doctor commitment to continued provision of MMT in addiction clinics and in primary care. Conclusions: Results from this audit demonstrate a high level of compliance with best practise MMT guidelines by Irish GPs providing MMT. The online self-audit process was well received and encouraged reflective practice. The audit process hinged on the individual GP’s ability to review and critically analyse their professional practice, and manage change. This model of audit could be adapted and used to monitor the management of other chronic illnesses in general practice
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