37,134 research outputs found

    Review of N N Interaction from Lattice QCD

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    Historically, lattice studies of QCD have concentrated on understanding the properties and structure of an isolated hadron. Recently, there have efforts at understanding the interactions between hadrons. In this talk I will review two approaches to this problem.Comment: 2 pages, 1 postscript figure. To appear in proceedings of Chiral Dynamics 2000, Jefferson Laboratory, July 17-22, 200

    Threshold Resonances - a Lattice Perspective

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    The calculation of the masses of the lightest nucleon resonances using lattice QCD is surveyed. Recent results for the mass of the first radial excitation of the nucleon, the Roper resonance, are reviewed and the interpretation in terms of models of hadronic resonances, such as the quark model and hadronic molecules, discussed. The talk concludes with an outline of prospects for future calculations.Comment: 5 Pages, 2 figures, invited contribution to Focus Session on Nature of Threshold N*, to be published in Proceedings of NSTAR 2002, Pittsburgh, October 9-12, 2002 (World Scientific

    Target shape dependence in a simple model of receptor-mediated endocytosis and phagocytosis

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    Phagocytosis and receptor-mediated endocytosis are vitally important particle uptake mechanisms in many cell types, ranging from single-cell organisms to immune cells. In both processes, engulfment by the cell depends critically on both particle shape and orientation. However, most previous theoretical work has focused only on spherical particles and hence disregards the wide-ranging particle shapes occurring in nature, such as those of bacteria. Here, by implementing a simple model in one and two dimensions, we compare and contrast receptor-mediated endocytosis and phagocytosis for a range of biologically relevant shapes, including spheres, ellipsoids, capped cylinders, and hourglasses. We find a whole range of different engulfment behaviors with some ellipsoids engulfing faster than spheres, and that phagocytosis is able to engulf a greater range of target shapes than other types of endocytosis. Further, the 2D model can explain why some nonspherical particles engulf fastest (not at all) when presented to the membrane tip-first (lying flat). Our work reveals how some bacteria may avoid being internalized simply because of their shape, and suggests shapes for optimal drug delivery.Comment: 18 pages, 5 figure

    A survey of occupational therapy practitioners in mental health

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    As part of the College of Occupational Therapists’ Mental Health Project, a survey of occupational therapists practising in mental health in the UK was conducted. A questionnaire was sent to 200 members of the Association of Occupational Therapists in Mental Health and achieved a 68.5% response rate. The majority of the 137 respondents were female, with Senior I staff between 20 and 30 years of age who were unlikely to have worked in another area forming the largest group. Although most had received additional training, they identified the need for more training, especially in aspects of occupational therapy. Most were managed by an occupational therapist and 96% received supervision. Community mental health was the most frequently reported area of work with leisure, counselling, anxiety management and creative activities the most frequently used interventions. Respondents were committed to the core principles of occupational therapy and the need to develop outcome measures and evidence based practice, and were concerned about moves to generic working. This study has provided data, not only for the position paper on the way ahead for occupational therapy in mental health but also for individual occupational therapists and managers

    Summer of Code: Assisting Distance-Learning Students with Open-Ended Programming Tasks

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    A significant difficulty in teaching programming lies in the transition from novice to intermediate programmer, characterised by the assimilation and use of schemas of standard programming approaches. A significant factor assisting this transition is practice with tasks which develop this schema use. We describe the Summer of Code, a two-week activity for part-time, distance-learning students which gave them some additional programming practice. We analysed their submissions, forum postings, and results of a terminal survey. We found learners were keen to share and discuss their solutions and persevered with individual problems and the challenge overall. 93% respondents rated the activity 3 or better on a 5-point Likert scale (n=58). However, a quarter of participants, mainly those who described themselves as average or poor programmers, felt less confident in their abilities after the activity, though half of these students liked the activity overall. 54% of all participants said the greatest challenge was developing a general approach to the problems, such as selecting appropriate data structures. This is corroborated by forum comments, where students greatly appreciated “think aloud” presentations by faculty tackling the problems. These results strongly suggest that students would benefit from more open-ended practice, where they have to select and design their own solutions to a range of problems
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