3,703 research outputs found

    Sea-ice production and air/ice/ocean/biogeochemistry interactions in the Ross Sea during the PIPERS 2017 autumn field campaign

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    The Ross Sea is known for showing the greatest sea-ice increase, as observed globally, particularly from 1979 to 2015. However, corresponding changes in sea-ice thickness and production in the Ross Sea are not known, nor how these changes have impacted water masses, carbon fluxes, biogeochemical processes and availability of micronutrients. The PIPERS project sought to address these questions during an autumn ship campaign in 2017 and two spring airborne campaigns in 2016 and 2017. PIPERS used a multidisciplinary approach of manned and autonomous platforms to study the coupled air/ice/ocean/biogeochemical interactions during autumn and related those to spring conditions. Unexpectedly, the Ross Sea experienced record low sea ice in spring 2016 and autumn 2017. The delayed ice advance in 2017 contributed to (1) increased ice production and export in coastal polynyas, (2) thinner snow and ice cover in the central pack, (3) lower sea-ice Chl-a burdens and differences in sympagic communities, (4) sustained ocean heat flux delaying ice thickening and (5) a melting, anomalously southward ice edge persisting into winter. Despite these impacts, airborne observations in spring 2017 suggest that winter ice production over the continental shelf was likely not anomalous

    Parent-perceived isolation and barriers to psychosocial support: A qualitative study to investigate how peer support might help parents of burn-injured children

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    Introduction: Burn injuries can be traumatic and distressing for the affected child and family, with a prolonged period of recovery. This research explores parents’ experiences of support following their child’s injury and their thoughts on peer support specifically.Methods: Thirteen semi-structured interviews were conducted with parents/caregivers, a mean of three years after their child’s injury, either face-to-face or remotely. Responses were analysed using thematic analysis.Results: Analysis produced four themes and 11 sub-themes. These described parents’ experiences of loss, change, isolation and access to psychosocial support. This paper focuses on themes of isolation and parents’ access to psychosocial support.Discussion: Findings indicate that parents access psychosocial support following their child’s injury and often find it helpful; however, there is a prevailing sense of isolation. Parents often seek information online and find that this is lacking. Many parents reported that peer support would be valuable to them, particularly the sharing of experiential knowledge.Conclusion: An online resource may be beneficial for parents, but further research is needed to confirm the exploratory data gained to date, ensuring that any resource developed would meet the identified needs of parents

    Turkdean Roman Villa, Gloucestershire: archaeological investigations 1997-1998

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    Before the transmission of the first ‘live’ Time Team television programme on 23 August 1997, the existence of a Roman villa near Chalkhill Barn in the parish of Turkdean, 12 miles north-east of Cirencester and 2 miles from the Fosse Way, was hardly known to the archaeological community (FIG. 1). That a Roman building did exist in this location had, however, been suspected for a number of years by the landowner, the late Mr Wilf Mustoe. Distinctive linear parchmarks suggestive of buildings had been clearly visible at ground level in the grass pasture each dry summer, and in 1976 Mr Mustoe made a measured sketch plan of them on the back of an envelope. Subsequently the sketch was drawn up into a scale plan entitled ‘Roman villa’ by Simon Goddard, a relation. There was little knowledge of the site outside of Mr Mustoe's family until it was independently ‘discovered’ by local archaeologist Roger Box in August 1996 whilst fortuitously flying over the site in a helicopter. In the evening light Mr Box instantly recognised the parchmarks of an unmistakable Roman villa and took a series of photographs (FIG. 2). Mr Box showed his photographs to Mr Mustoe, and with his agreement wrote to Time Team suggesting that this would be an excellent site for a television programme. Arrangements were duly set in place and the evidence of the cropmarks was confirmed by a trial geophysical survey in March 199

    Multipole interaction between atoms and their photonic environment

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    Macroscopic field quantization is presented for a nondispersive photonic dielectric environment, both in the absence and presence of guest atoms. Starting with a minimal-coupling Lagrangian, a careful look at functional derivatives shows how to obtain Maxwell's equations before and after choosing a suitable gauge. A Hamiltonian is derived with a multipolar interaction between the guest atoms and the electromagnetic field. Canonical variables and fields are determined and in particular the field canonically conjugate to the vector potential is identified by functional differentiation as minus the full displacement field. An important result is that inside the dielectric a dipole couples to a field that is neither the (transverse) electric nor the macroscopic displacement field. The dielectric function is different from the bulk dielectric function at the position of the dipole, so that local-field effects must be taken into account.Comment: 17 pages, to be published in Physical Review

    Algebraic construction of the Darboux matrix revisited

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    We present algebraic construction of Darboux matrices for 1+1-dimensional integrable systems of nonlinear partial differential equations with a special stress on the nonisospectral case. We discuss different approaches to the Darboux-Backlund transformation, based on different lambda-dependencies of the Darboux matrix: polynomial, sum of partial fractions, or the transfer matrix form. We derive symmetric N-soliton formulas in the general case. The matrix spectral parameter and dressing actions in loop groups are also discussed. We describe reductions to twisted loop groups, unitary reductions, the matrix Lax pair for the KdV equation and reductions of chiral models (harmonic maps) to SU(n) and to Grassmann spaces. We show that in the KdV case the nilpotent Darboux matrix generates the binary Darboux transformation. The paper is intended as a review of known results (usually presented in a novel context) but some new results are included as well, e.g., general compact formulas for N-soliton surfaces and linear and bilinear constraints on the nonisospectral Lax pair matrices which are preserved by Darboux transformations.Comment: Review paper (61 pages). To be published in the Special Issue "Nonlinearity and Geometry: Connections with Integrability" of J. Phys. A: Math. Theor. (2009), devoted to the subject of the Second Workshop on Nonlinearity and Geometry ("Darboux Days"), Bedlewo, Poland (April 2008
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