1,758 research outputs found

    On Schwarzschild's Topology in Brane-Worlds

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    The topological structure of Schwarzschild's space-time and its maximal analytic extension are investigated in context of brane-worlds. Using the embedding coordinates, these geometries are seen as different states of the evolution of a single brane-world. Comparing the topologies and the embeddings it is shown that this evolution must be followed by a signature change in the bulk.Comment: 6 page

    Size and Shape Control of Gold Nanodeposits in an Array of Silica Nanowells on a Gold Electrode

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    Ordered arrays of hemispherical nanowells were formed in a sol-gel-derived silica film on a gold electrode using 500 nm diameter polystyrene latex spheres as templates. The conductive domain located at the bottom of each nanowell upon template removal was enlarged via electroless deposition from a gold plating solution. The structured electrodes thus formed were characterized using scanning electron microscopy and atomic force microscopy. Depending on the method used to make the films, the extent of the long-range packing and the size of the conductive domain changed. Electroless deposition in the nanowells produced (near) sphere-like nanostructures of gold, the size of which depended on the incubation time in the plating solution and the size of the conductive domain. Longer exposure times yielded nanostructures that filled the nanowell, whereas smaller exposure time yielded much smaller structures. Significantly larger, rougher deposits were formed in nanowells with large conductive domains. The electrochemical response observed at these electrodes was strongly dependent on the extent of long-range packing, the presence of defect sites in the film and their relative spacing, and the redox species in solution

    Pressure ulcer related pain in community populations: a prevalence survey.

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    BACKGROUND: Pressure ulcers are costly to the healthcare provider and can have a major impact on patient's quality of life. One of the most distressing symptoms reported is pain. There is very little published data on the prevalence and details of pain experienced by patients with pressure ulcers, particularly in community populations. The study was conducted in two community NHS sites in the North of England. METHODS: The aim was to estimate the prevalence of pressure area related pain within a community population. We also explored the type and severity of the pain and its association with pressure ulcer classification. A cross-sectional survey was performed of community nurses caseloads to identify adult patients with pressure ulcers and associated pain. Consenting patients then had a full pain assessment and verification of pressure ulcer grade. RESULTS: A total of 287 patients were identified with pressure ulcers (0.51 per 1000 adult population). Of the 176 patients who were asked, 133 (75.6%) reported pain. 37 patients consented to a detailed pain assessment. Painful pressure ulcers of all grades and on nearly all body sites were identified. Pain intensity was not related to number or severity of pressure ulcer. Both inflammatory and neuropathic pain were reported at all body sites however the proportion of neuropathic pain was greater in pressure ulcers on lower limbs. CONCLUSIONS: This study has identified the extent and type of pain suffered by community patients with pressure ulcers and indicates the need for systematic and regular pain assessment and treatment

    The Embedding of Schwarzschild in Braneworld

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    The braneworlds models were inspired partly by Kaluza-Klein's theory, where both the gravitational and the gauge fields are obtained from the geometry of a higher dimensional space. The positive aspects of these models consist in perspectives of modifications it could bring in to particle physics, such as: unification in a TeV scale, quantum gravity in this scale and deviation of Newton's law for small distances. One of the principles of these models is to suppose that all space-times can be embedded in a bulk of higher dimension. The main result in these notes is a theorem showing a mathematical inconsistency of the Randall-Sundrum braneworld model, namely that the Schwarzschild space-time cannot be embedded locally and isometrically in a five dimensional bulk with constant curvature,(for example AdS-5). From the point of view of semi-Riemannian geometry this last result represents a serious restriction to the Randall-Sundrum's braneworld model.Comment: Published in the Int. J. Theor. Phys, 200

    A Core outcome set for childhood epilepsy treated with ketogenic diet therapy (CORE-KDT study): international parent and health professional consensus.

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    OBJECTIVE: Ketogenic diet therapy (KDT) can result in benefits (seizure and non-seizure related) for children with drug resistant epilepsy. However, clinical trials report a wide range of outcomes making synthesis of evidence difficult, and do not adequately reflect parent views on important outcomes for their child. To address this, we established the first international parent, health professional and researcher consensus to develop a core outcome set, guided by the Core Outcome Measures in Effectiveness Trials (COMET) Initiative (COMET registration #1116). METHODS: Ethical approval was granted (London-Surrey REC19/LO/1680). A scoping review and interviews with parents identified a comprehensive list of potentially important outcomes, followed by a two-round online Delphi survey of parents and health professionals to prioritise outcomes of importance for inclusion in a core outcome set. This informed a stakeholder consensus meeting and consultation process to finalise the core outcome set. RESULTS: In total, 97 outcomes were identified; 90 from the scoping review and seven from parent interviews. These were rationalised to 77 by the study advisory group, then rated in the first Delphi round by 49 parents and 96 health professionals who suggested 12 new outcomes for rating in round two. 66% of participants (30 parents and 66 professionals) completed round two, where 22 outcomes met criteria for inclusion. In the consensus meeting (9 parents and 13 professionals), 27 undecided outcomes were discussed and scored; one further outcome reached consensus for inclusion. After consultation and ratification, 14 outcomes across five domains were included in the core outcome set. SIGNIFICANCE: A core outcome set for childhood epilepsy treated with KDT has been developed, incorporating the views of international parents and professionals. Implementation in research and clinical settings will standardise outcome selection and reporting, facilitate data synthesis and ultimately enhance the relevance of outcomes to parents, researchers and health professionals

    Feminist phenomenology and the woman in the running body

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    Modern phenomenology, with its roots in Husserlian philosophy, has been taken up and utilised in a myriad of ways within different disciplines, but until recently has remained relatively under-used within sports studies. A corpus of sociological-phenomenological work is now beginning to develop in this domain, alongside a longer standing literature in feminist phenomenology. These specific social-phenomenological forms explore the situatedness of lived-body experience within a particular social structure. After providing a brief overview of key strands of phenomenology, this article considers some of the ways in which sociological, and particularly feminist phenomenology, might be used to analyse female sporting embodiment. For illustrative purposes, data from an autophenomenographic project on female distance running are also included, in order briefly to demonstrate the application of phenomenology within sociology, as both theoretical framework and methodological approach

    Using an ethnographic approach to explore the influences on uptake and adherence in cardiac rehabilitation

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    Qualitative inquiry provides a powerful means to investigate which contextual mechanisms contribute to intervention uptake and adherence. Ethnography is efficacious in researching social interactions, behaviours and perceptions within groups, teams, organisations and communities, and can provide rich insights into individual/group views and actions. This ethnographic study will draw on longitudinal observations and two in-depth interviews conducted over a 6-month period with 10-20 participants. Working with two NHS Trusts, the researcher will collaborate with cardiology and cardiac rehabilitation staff to opportunistically recruit those who have opted to and opted not to attend core cardiac rehabilitation. Eligibility screening will take place as part of usual clinical care, with study criteria mirroring that of cardiac rehabilitation eligibility criteria. Snowball sampling will be used to recruit a maximum of two significant others (family and/or friends) as identified by patients. Thematic analysis sensitive to a Bourdieusian theoretical framework will be employed

    Birth season and environmental influences on blood leucocyte and lymphocyte subpopulations in rural Gambian infants

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    BACKGROUND: In rural Gambia, birth season predicts infection-related adult mortality, providing evidence that seasonal factors in early life may programme immune development. This study tested whether lymphocyte subpopulations assessed by automated full blood count and flow cytometry in cord blood and at 8, 16 and 52 weeks in rural Gambian infants (N = 138) are affected by birth season (DRY = Jan-Jun, harvest season, few infections; WET = Jul-Dec, hungry season, many infections), birth size or micronutrient status. RESULTS: Geometric mean cord and postnatal counts were higher in births occurring in the WET season with both season of birth and season of sampling effects. Absolute CD3+, CD8+, and CD56+ counts, were higher in WET season births, but absolute CD4+ counts were unaffected and percentage CD4+ counts were therefore lower. CD19+ counts showed no association with birth season but were associated with concurrent plasma zinc status. There were no other associations between subpopulation counts and micronutrient or anthropometric status. CONCLUSION: These results demonstrate a seasonal influence on cell counts with a disproportionate effect on CD8+ and CD56+ relative to CD4+ cells. This seasonal difference was seen in cord blood (indicating an effect in utero) and subsequent samples, and is not explained by nutritional status. These findings are consistent with the hypothesis than an early environmental exposure can programme human immune development

    'Working out’ identity: distance runners and the management of disrupted identity

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    This article contributes fresh perspectives to the empirical literature on the sociology of the body, and of leisure and identity, by analysing the impact of long-term injury on the identities of two amateur but serious middle/long-distance runners. Employing a symbolic interactionist framework,and utilising data derived from a collaborative autoethnographic project, it explores the role of ‘identity work’ in providing continuity of identity during the liminality of long-term injury and rehabilitation, which poses a fundamental challenge to athletic identity. Specifically, the analysis applies Snow and Anderson’s (1995) and Perinbanayagam’s (2000) theoretical conceptualisations in order to examine the various forms of identity work undertaken by the injured participants, along the dimensions of materialistic, associative and vocabularic identifications. Such identity work was found to be crucial in sustaining a credible sporting identity in the face of disruption to the running self, and in generating momentum towards the goal of restitution to full running fitness and reengagement with a cherished form of leisure. KEYWORDS: identity work, symbolic interactionism, distance running, disrupted identit
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