55,989 research outputs found

    Survey of psychosocial support provided by UK paediatric oncology centres

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    Aim: To obtain a comprehensive overview of current patterns of psychosocial support provided by National Health Service ( NHS) paediatric oncology treatment centres across the UK. Methods: A postal questionnaire was sent to co-ordinators in the UK Children's Cancer Study Group ( a professional body that is responsible for the organisation of treatment and management of childhood cancer in the UK) in 21 treatment centres and three separate Teenage Cancer Trus units. A range of psychosocial topics were explored, including ratio of staff providing support to patients; facilities provided for children and families; psychosocial support services such as support groups; information provision; and transition support. Results: There were many good areas of support provided by centres, but there was also a lack of standard practices and procedures. All centres employed social workers, play specialists, and paediatric oncology outreach nurses, but patient to staff ratios varied across centres. The poorest staff provision was among psychologists, where patient to staff ratios ranged from 132:1 to 1100:1. Written information was standard practice, while provision of other types of information (audiovisual, online) varied; none of the centres provided audio information specifically for children/young people. Conclusion: This variability in practices among centres frequently occurred, as centres rarely had procedures formally agreed or recorded in writing. British government policy currently seeks to develop standards and guidelines of care throughout the National Health Service. This study further demonstrates the importance of standards and the need to agree guidelines for the provision of psychosocial support for children/young people and their families throughout the course of the illness

    MHD simulations of the formation and propagation of protostellar jets to observational length scales

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    We present 2.5-D global, ideal MHD simulations of magnetically and rotationally driven protostellar jets from Keplerian accretion discs, wherein only the initial magnetic field strength at the inner radius of the disc, BiB_{\rm i}, is varied. Using the AMR-MHD code AZEUS, we self-consistently follow the jet evolution into the observational regime (>103 AU>10^3\,\mathrm{AU}) with a spatial dynamic range of ∼6.5×105\sim6.5\times10^5. The simulations reveal a three-component outflow: 1) A hot, dense, super-fast and highly magnetised 'jet core'; 2) a cold, rarefied, trans-fast and highly magnetised 'sheath' surrounding the jet core and extending to a tangential discontinuity; and 3) a warm, dense, trans-slow and weakly magnetised shocked ambient medium entrained by the advancing bow shock. The simulations reveal power-law relationships between BiB_{\rm i} and the jet advance speed, vjetv_{\rm jet}, the average jet rotation speed, ⟨vφ⟩\langle v_\varphi\rangle, as well as fluxes of mass, momentum, and kinetic energy. Quantities that do not depend on BiB_{\rm i} include the plasma-β\beta of the transported material which, in all cases, seems to asymptote to order unity. Jets are launched by a combination of the 'magnetic tower' and 'bead-on-a-wire' mechanisms, with the former accounting for most of the jet acceleration---even for strong fields---and continuing well beyond the fast magnetosonic point. At no time does the leading bow shock leave the domain and, as such, these simulations generate large-scale jets that reproduce many of the observed properties of protostellar jets including their characteristic speeds and transported fluxes.Comment: 26 pages, 16 figures. Accepted for publication in MNRA

    AZEuS: An Adaptive Zone Eulerian Scheme for Computational MHD

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    A new adaptive mesh refinement (AMR) version of the ZEUS-3D astrophysical magnetohydrodynamical (MHD) fluid code, AZEuS, is described. The AMR module in AZEuS has been completely adapted to the staggered mesh that characterises the ZEUS family of codes, on which scalar quantities are zone-centred and vector components are face-centred. In addition, for applications using static grids, it is necessary to use higher-order interpolations for prolongation to minimise the errors caused by waves crossing from a grid of one resolution to another. Finally, solutions to test problems in 1-, 2-, and 3-dimensions in both Cartesian and spherical coordinates are presented.Comment: 52 pages, 17 figures; Accepted for publication in ApJ
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