1,950 research outputs found

    'Treatment of the Sportsman's groin': British Hernia Society's 2014 position statement based on the Manchester Consensus Conference

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    <b>Introduction</b> The aim was to produce a multidisciplinary consensus to determine the current position on the nomenclature, definition, diagnosis, imaging modalities and management of Sportsman's groin (SG).<p></p> <b>Methods</b> Experts in the diagnosis and management of SG were invited to participate in a consensus conference held by the British Hernia Society in Manchester, UK on 11–12 October 2012. Experts included a physiotherapist, a musculoskeletal radiologist and surgeons with a proven track record of expertise in this field. Presentations detailing scientific as well as outcome data from their own experiences were given. Records were made of the presentations with specific areas debated openly.<p></p> <b>Results</b> The term ‘inguinal disruption’ (ID) was agreed as the preferred nomenclature with the term ‘Sportsman's hernia’ or ‘groin’ rejected, as no true hernia exists. There was an overwhelming agreement of opinion that there was abnormal tension in the groin, particularly around the inguinal ligament attachment. Other common findings included the possibility of external oblique disruption with consequent small tears noted as well as some oedema of the tissues. A multidisciplinary approach with tailored physiotherapy as the initial treatment was recommended with any surgery involving releasing the tension in the inguinal canal by various techniques and reinforcing it with a mesh or suture repair. A national registry should be developed for all athletes undergoing surgery.<p></p> <b>Conclusions</b> ID is a common condition where no true hernia exists. It should be managed through a multidisciplinary approach to ensure consistent standards and outcomes are achieved

    Calculation of AGARD Wing 445.6 Flutter Using Navier-Stokes Aerodynamics

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    An unsteady, 3D, implicit upwind Euler/Navier-Stokes algorithm is here used to compute the flutter characteristics of Wing 445.6, the AGARD standard aeroelastic configuration for dynamic response, with a view to the discrepancy between Euler characteristics and experimental data. Attention is given to effects of fluid viscosity, structural damping, and number of structural model nodes. The flutter characteristics of the wing are determined using these unsteady generalized aerodynamic forces in a traditional V-g analysis. The V-g analysis indicates that fluid viscosity has a significant effect on the supersonic flutter boundary for this wing

    On the origin of the large scale structures of the universe

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    We revise the statistical properties of the primordial cosmological density anisotropies that, at the time of matter radiation equality, seeded the gravitational development of large scale structures in the, otherwise, homogeneous and isotropic Friedmann-Robertson-Walker flat universe. Our analysis shows that random fluctuations of the density field at the same instant of equality and with comoving wavelength shorter than the causal horizon at that time can naturally account, when globally constrained to conserve the total mass (energy) of the system, for the observed scale invariance of the anisotropies over cosmologically large comoving volumes. Statistical systems with similar features are generically known as glass-like or lattice-like. Obviously, these conclusions conflict with the widely accepted understanding of the primordial structures reported in the literature, which requires an epoch of inflationary cosmology to precede the standard expansion of the universe. The origin of the conflict must be found in the widespread, but unjustified, claim that scale invariant mass (energy) anisotropies at the instant of equality over comoving volumes of cosmological size, larger than the causal horizon at the time, must be generated by fluctuations in the density field with comparably large comoving wavelength.Comment: New section added; final version to appear in Physical Review D; discussion extended and detailed with new calculations to support the claims of the paper; statistical properties of vacuum fluctuations now discussed in the context of FRW flat universe; new important conclussions adde

    The evolution of a network of cosmic string loops

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    We set up and analyse a model for the non-equilibrium evolution of a network of cosmic strings initially containing only loops and no infinite strings. Due to this particular initial condition, our analytical approach differs significantly from existing ones. We describe the average properties of the network in terms of the distribution function n(l,t) dl, the average number of loops per unit volume with physical length between l and l + dl at time t. The dynamical processes which change the length of loops are then estimated and an equation, which we call the `rate equation', is derived for (dn/dt). In a non-expanding universe, the loops should reach the equilibrium distribution predicted by string statistical mechanics. Analysis of the rate equation gives results consistent with this. We then study the rate equation in an expanding universe and suggest that three different final states are possible for the evolving loop network, each of which may well be realised for some initial conditions. If the initial energy density in loops in the radiation era is low, then the loops rapidly disappear. For large initial energy densities, we expect that either infinite strings are formed or that the loops tend towards a scaling solution in the radiation era and then rapidly disappear in the matter era. Such a scenario may be relevant given recent work highlighting the problems with structure formation from the standard cosmic string scenario.Comment: LaTeX, 27 pages, 10 figures included as .eps file

    Black Stork Down: Military Discourses in Bird Conservation in Malta

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    Tensions between Maltese hunters and bird conservation NGOs have intensified over the past decade. Conservation NGOs have become frustrated with the Maltese State for conceding to the hunter lobby and negotiating derogations from the European Union’s Bird Directive. Some NGOs have recently started to organize complex field-operations where volunteers are trained to patrol the landscape, operate drones and other surveillance technologies, detect illegalities, and lead police teams to arrest poachers. We describe the sophisticated military metaphors which conservation NGOs have developed to describe, guide and legitimize their efforts to the Maltese public and their fee-paying members. We also discuss why such groups might be inclined to adopt these metaphors. Finally, we suggest that anthropological studies of discourse could help understand delicate contexts such as this where conservation NGOs, hunting associations and the State have ended in political deadlock

    Searching for Long Strings in CMB Maps

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    Using analytical methods and Monte Carlo simulations, we analyze new statistics designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent temperature discontinuities are predicted by the Kaiser-Stebbins effect to form due to long cosmic strings present in our present horizon. The background of the coherent step-like seed is assumed to be a scale invariant Gaussian random field which could have been produced by a superposition of seeds on smaller scales and/or by inflationary quantum fluctuations. We find that the proposed statistics can detect the presense of a coherent discontinuity at a sensitivity level almost an order of magnitude better compared to more conventional statistics like the skewness or the kurtosis.Comment: 10 pages, 3 Figures, Use RevTe

    The 1999 international emergency humanitarian evacuation of the Kosovars to Canada: A qualitative study of service providers' perspectives at the international, national and local levels

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    BACKGROUND: In response to the Kosovo crisis, Canada received 5,500 Albanian Kosovar refugees in 1999 as part of the emergency humanitarian evacuation and settlement effort. This study attempts to describe the experiences of service providers at the international, national, and local levels, involved in the organization and delivery of health and settlement services in Canada for the Kosovar refugees. METHODS: A qualitative case study design using key informant interviews was used. Nominated sampling was used to identify 17 individuals involved in the organization and delivery of health and settlement. Key themes were identified and recommendations made to provide a framework for the development of policy to guide response to future humanitarian emergencies. RESULTS: Six themes emerged: (1) A sense of being overwhelmed, (2) A multitude of health issues, (3) critical challenges in providing health care, (4) access to health and settlement services, (5) overall successes and (6) need for a coordinated approach to migration health. CONCLUSIONS: For those involved, the experience was overwhelming but rewarding. Interviewees' major concerns were the need for a more comprehensive and coordinated approach to the flow of medical information and handling of specific health problems

    An Attempt to Determine the Largest Scale of Primordial Density Perturbations in the Universe

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    Inflationary cosmology predicts that the particle horizon should be generically much bigger than the present-day Hubble radius, 1/H01/H_0. This implies a special regime of super-Hubble scale energy density fluctuations imprinted on the cosmic microwave background radiation (CMBR), which from present theory could only be explained by inflation Causality constraints are used to determine models for the power spectrum that accommodate a suppression scale. A three parameter likelihood analysis is performed of the COBE-DMR 4-year data with respect to the amplitude, spectral index, and suppression scale. It is found that all suppression length scales larger than 1/H01/H_0 are consistent with the data, but that scales of order 1/H01/H_0 are slightly preferred, at roughly the one-sigma level. Many non-inflation models would be consistent with a small suppression length scale, whereas for standard inflation models, the duration of the inflation epoch would have to be bounded by a fairly small upper limit. Suppression scales smaller than 1/H01/H_0 are strongly excluded by the anisotrophy data.Comment: 9 pages, Latex, 1 figure, additional tests reporte
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