181 research outputs found

    Estimating the incidence of acute infectious intestinal disease in the community in the UK:A retrospective telephone survey

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    Objectives: To estimate the burden of intestinal infectious disease (IID) in the UK and determine whether disease burden estimations using a retrospective study design differ from those using a prospective study design. Design/Setting: A retrospective telephone survey undertaken in each of the four countries comprising the United Kingdom. Participants were randomly asked about illness either in the past 7 or 28 days. Participants: 14,813 individuals for all of whom we had a legible recording of their agreement to participate Outcomes: Self-reported IID, defined as loose stools or clinically significant vomiting lasting less than two weeks, in the absence of a known non-infectious cause. Results: The rate of self-reported IID varied substantially depending on whether asked for illness in the previous 7 or 28 days. After standardising for age and sex, and adjusting for the number of interviews completed each month and the relative size of each UK country, the estimated rate of IID in the 7-day recall group was 1,530 cases per 1,000 person-years (95% CI: 1135 – 2113), while in the 28-day recall group it was 533 cases per 1,000 person-years (95% CI: 377 – 778). There was no significant variation in rates between the four countries. Rates in this study were also higher than in a related prospective study undertaken at the same time. Conclusions: The estimated burden of disease from IID varied dramatically depending on study design. Retrospective studies of IID give higher estimates of disease burden than prospective studies. Of retrospective studies longer recall periods give lower estimated rates than studies with short recall periods. Caution needs to be exercised when comparing studies of self-reported IID as small changes in study design or case definition can markedly affect estimated rates

    ‘Change Today, Choose Fairtrade’ Fairtrade Fortnight and the citizen-consumer

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    The Fairtrade consumer is widely represented as an individual who intentionally and reflexively consumes Fairtrade goods in order to register their support for the plight of producers in the developing world. This figure is imagined to ‘vote’ with her/his pocket every time they visit the supermarket thus demonstrating their commitment to the Fairtrade trading model. However, this image of the Fairtrade citizen-consumer does not emerge automatically as a response to the increasing availability of Fairtrade goods in the market-place but has to be made by various intermediary actors and organizations. This paper examines how the Fairtrade consumer was constructed and called to action by the Fairtrade Fortnight promotional campaign that occurred within the UK in 2008 and was co-ordinated by the Fairtrade Foundation. This annual event offers a unique window into the processes and actors involved in the mobilization of the Fairtrade citizen-consumer. Through a close focus on the promotional material distributed to different audiences and the events that occurred during this Fortnight, this paper reveals the contingent and shifting nature of the citizen-consumer identity. In so doing, it highlights how varying degrees of reflexivity and action are demanded of different audiences and how this shapes the way that Fairtrade goods are qualified and distributed in the market

    The Primarily Undergraduate Nanomaterials Cooperative: A New Model for Supporting Collaborative Research at Small Institutions on a National Scale

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    The Primarily Undergraduate Nanomaterials Cooperative (PUNC) is an organization for research-active faculty studying nanomaterials at Primarily Undergraduate Institutions (PUIs), where undergraduate teaching and research go hand-in-hand. In this perspective, we outline the differences in maintaining an active research group at a PUI compared to an R1 institution. We also discuss the work of PUNC, which focuses on community building, instrument sharing, and facilitating new collaborations. Currently consisting of 37 members from across the United States, PUNC has created an online community consisting of its Web site (nanocooperative.org), a weekly online summer group meeting program for faculty and students, and a Discord server for informal conversations. Additionally, in-person symposia at ACS conferences and PUNC-specific conferences are planned for the future. It is our hope that in the years to come PUNC will be seen as a model organization for community building and research support at primarily undergraduate institutions

    Earliest rock fabric formed in the Solar System preserved in a chondrule rim

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    Rock fabrics – the preferred orientation of grains – provide a window into the history of rock formation, deformation and compaction. Chondritic meteorites are among the oldest materials in the Solar System1 and their fabrics should record a range of processes occurring in the nebula and in asteroids, but due to abundant fine-grained material these samples have largely resisted traditional in situ fabric analysis. Here we use high resolution electron backscatter diffraction to map the orientation of sub-micrometre grains in the Allende CV carbonaceous chondrite: the matrix material that is interstitial to the mm-sized spherical chondrules that give chondrites their name, and fine-grained rims which surround those chondrules. Although Allende matrix exhibits a bulk uniaxial fabric relating to a significant compressive event in the parent asteroid, we find that fine-grained rims preserve a spherically symmetric fabric centred on the chondrule. We define a method that quantitatively relates fabric intensity to net compression, and reconstruct an initial porosity for the rims of 70-80% - a value very close to model estimates for the earliest uncompacted aggregates2,3. We conclude that the chondrule rim textures formed in a nebula setting and may therefore be the first rock fabric to have formed in the Solar System

    Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos

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    Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale

    Deficits in neurite density underlie white matter structure abnormalities in first-episode psychosis

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    Background: Structural abnormalities across multiple white matter tracts are recognised in people with early psychosis, consistent with dysconnectivity as a neuropathological account of symptom expression. We applied advanced neuroimaging techniques to characterise microstructural white matter abnormalities for a deeper understanding of the developmental aetiology of psychosis. Methods: Thirty-five first-episode psychosis patients, and 19 healthy controls, participated in a quantitative neuroimaging study using Neurite Orientation Dispersion and Density Imaging (NODDI), a multi-shell diffusion-weighted MRI technique that distinguishes white matter fibre arrangement and geometry from changes in neurite density. Fractional anisotropy (FA) and mean diffusivity images were also derived. Tract-based spatial statistics compared white matter structure between patients and controls and tested associations with age, symptom severity and medication. Results: Patients with first-episode psychosis had lower regional FA in multiple commissural, corticospinal, and association tracts. These abnormalities predominantly colocalized with regions of reduced neurite density, rather than aberrant fibre bundle arrangement (orientation dispersion index). There was no direct relationship with active symptomatology. FA decreased and orientation dispersion index increased with age in patients, but not controls, suggesting accelerated effects of white matter geometry change. Conclusions: Deficits in neurite density appear fundamental to abnormalities in white matter integrity in early psychosis. In the first application of NODDI in psychosis, we found that processes compromising axonal fibre number, density, and myelination, rather than processes leading to spatial disruption of fibre organisation, are implicated in the aetiology of the disorder. This accords with a neurodevelopmental origin of aberrant brain-wide structural connectivity predisposing individuals to psychosis
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