THE RACE DOWN FROM EVEREST: Impact Absorption in Extended Downhill Running

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RUNNING SHOE STIFFNESS:THE EFFECT ON WALKING GAIT

Sports shoes can be grouped into various categories based on their stability, protection capabilities, traction, impact characteristics and stiffness. The majority of shoe tests involve measures of traction and impact. Few studies have examined shoe sole stiffness. Therefore, the purpose of this study was to assess shoe sole stiffness by a materials testing procedure, and then examine the effect of shoe stiffness on walking gait. A damped oscillation technique, previously used on muscle-tendon complexes, was utilised to calculate the stiffness and the damping factor of six types of running shoes. The shoes used different rnidsole components which included air sacs, gel sacs, ethylene vinyl acetate (EVA), and kevlar reinforcing. Two shoes at the extremes of the range were then selected from the materials test results for use in the subsequent gait analysis. Nine males ranging in age from 25 to 45 years (mean =36 years) participated in the experiment. Heights ranged from 186cm to 176cm (mean=182cm) and weights ranged from 72.5kg to 89kg (mean=8lkg). No subjects had any musculoskeletal problems affecting the lower limb. Two dimensional video data were collected on the right leg using an Ariel Video Analysis system sampling at 50 Hz, as subjects walked at 5.1 km/hr on a motor driven treadmill. Markers were placed on the greater trochanter, lateral condyle of the femur, lateral malleolus of the fibular, the heel of the shoe and on the shoe at the level of the fifth metatarsal head. Three stride cycles were collected after the subjects had walked on the treadmill for one minute. Data were digitised and downloaded to FMAP software to calculate kinematic variables such as knee and ankle angle and knee and ankle angular velocity. Data were then normalised to 50 points and averaged across stride cycles and subjects. Although a comparison of the stiff and flexible shoes indicated no differences in the kinematic parameters (p>0.05), it may be that the muscles of the lower limb adjust their activity level for the stiffness of the shoe to maintain an invariant kinematic pattern

Validation of the DECAF score to predict hospital mortality in acute exacerbations of COPD

Background Hospitalisation due to acute exacerbations of COPD (AECOPD) is common, and subsequent mortality high. The DECAF score was derived for accurate prediction of mortality and risk strati fi cation to inform patient care. We aimed to validate the DECAF score, internally and externally, and to compare its performance to other predictive tools. Methods The study took place in the two hospitals within the derivation study (internal validation) and in four additional hospitals (external validation) between January 2012 and May 2014. Consecutive admissions were identi fi ed by screening admissions and searching coding records. Admission clinical data, including DECAF indices, and mortality were recorded. The prognostic value of DECAF and other scores were assessed by the area under the receiver operator characteristic (AUROC) curve. Results In the internal and external validation cohorts, 880 and 845 patients were recruited. Mean age was 73.1 (SD 10.3) years, 54.3% were female, and mean (SD) FEV 1 45.5 (18.3) per cent predicted. Overall mortality was 7.7%. The DECAF AUROC curve for inhospital mortality was 0.83 (95% CI 0.78 to 0.87) in the internal cohort and 0.82 (95% CI 0.77 to 0.87) in the external cohort, and was superior to other prognostic scores for inhospital or 30-day mortality. Conclusions DECAF is a robust predictor of mortality, using indices routinely available on admission. Its generalisability is supported by consistent strong performance; it can identify low-risk patients (DECAF 0 – 1) potentially suitable for Hospital at Home or early supported discharge services, and high-risk patients (DECAF 3 – 6) for escalation planning or appropriate early palliation. Trial registration number UKCRN ID 14214

The Muonium Atom as a Probe of Physics beyond the Standard Model

The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium ($M = \mu^+ e^-$) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

New Phase-coherent Measurements of Pulsar Braking Indices

Pulsar braking indices offer insight into the physics that underlies pulsar spin-down. Only five braking indices have been measured via phase-coherent timing; all measured values are less than 3, the value expected from magnetic dipole radiation. Here we present new measurements for three of the five pulsar braking indices, obtained with phase-coherent timing for PSRs J1846-0258 (n=2.65+/-0.01), B1509-58 (n=2.839+/-0.001) and B0540-69 (n=2.140+/-0.009). We discuss the implications of these results and possible physical explanations for them.Comment: 7 pages, 5 figures. To be published in the proceedings of the conference "Isolated Neutron Stars: from the Interior to the Surface" (April 24-28, 2006, London, UK), eds. D. Page, R. Turolla, & S. Zan