An evaluation of the efficacy of the exercise on referral scheme in Northumberland, UK: association with physical activity and predictors of engagement. A naturalistic observation study

Objectives Exercise on referral schemes (ERS) are widely commissioned in the UK but there is little evidence of their association with physical activity levels. We sought to assess the Northumberland exercise on referral scheme in terms of increased levels of physical activity and identify predictors of engagement. Design A naturalistic observational study. Setting 9 local authority leisure sites in Northumberland. Participants 2233 patients referred from primary and secondary care between July 2009 and September 2010. Intervention A 24-week programme including motivational consultations and supervised exercise sessions for participants. Outcome measures Uptake, 12-week adherence, 24-week completion, changes in Godin Leisure-Time Exercise Questionnaire scores after 24-weeks and attendance levels at supervised exercise sessions during the scheme. Three binary logistic regressions were used to examine demographic and referral factors associated with initial uptake, 12-week adherence and 24-week completion. Results Uptake was 81% (n=1811), 12-week adherence was 53.5% (n=968) and 24-week completion was 42.9% (n=777). Participants who completed significantly increased their self-reported physical activity levels at 24-weeks t (638)=−11.55, p<0.001. Completers attended a mean of 22.87 (12.47 SD) of a target 48 supervised sessions. Increasing age, being female and leisure site were associated with uptake, increasing age, Index of Multiple Deprivation and leisure site were associated with 12-week adherence and Body Mass Index and leisure site were associated with 24-week completion. Each regression significantly increased the prediction accuracy of stage of exit (non-starters vs starters 81.5%, dropouts before 12 weeks vs 12-week adherers 66.9%, and dropouts between 13 and 24 weeks 82.2%). Conclusions Completers of the Northumberland ERS increased physical activity at 24 weeks, although the levels achieved were below the current UK guidelines of 150 min of moderate exercise per week. Leisure site was associated with uptake, adherence and completion

Using zebrafish to probe the genetics of osteoarthritis

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Radio Source Heating in the ICM: The Example of Cygnus A

One of the most promising solutions for the cooling flow problem involves energy injection from the central AGN. However it is still not clear how collimated jets can heat the ICM at large scale, and very little is known concerning the effect of radio lobe expansion as they enter into pressure equilibrium with the surrounding cluster gas. Cygnus A is one of the best examples of a nearby powerful radio galaxy for which the synchrotron emitting plasma and thermal emitting intra-cluster medium can be mapped in fine detail, and previous observations have inferred possible shock structure at the location of the cocoon. We use new XMM-Newton observations of Cygnus A, in combination with deep Chandra observations, to measure the temperature of the intra-cluster medium around the expanding radio cavities. We investigate how inflation of the cavities may relate to shock heating of the intra-cluster gas, and whether such a mechanism is sufficient to provide enough energy to offset cooling to the extent observed.Comment: To appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany), Eds. H. Boehringer, G.W. Pratt, A. Finoguenov, P. Schuecker, Springer-Verlag series "ESO Astrophysics Symposia", p.101, in press. 8 pages, 3 multiple figure

Impact of supplemental home enteral feeding postesophagectomy on nutrition, body composition, quality of life, and patient satisfaction

The aim of this prospective cohort study is to analyze the impact of supplemental home enteral nutrition (HEN) post-esophageal cancer surgery on nutritional parameters, quality of life (QL), and patient satisfaction. A systematic review reported that over 60% of patients lose \u3e10% of both body weight and BMI by 6 months after esophagectomy. Enteral feeding (EF) is increasingly a modern standard postoperatively; however, the impact of extended HEN postdischarge has not been systematically studied. One hundred forty-nine consecutive patients [mean age 62 ± 9, 80% male,76% adenocarcinoma, 66% on multimodal protocols, and 69% with BMI ≥ 25 kg/m2] were studied. Jejunal EF commenced day 1 postoperatively, and supplemental overnight HEN (764 kcal; 32g protein) continued on discharge for a planned further 4 weeks. Weight, BMI, and body composition analysis (bioimpedance analysis) were measured at baseline, preoperatively and at 1, 3, and 6 months, along with the EORTC QLQ-C30/OES18 QL measures. A patient satisfaction questionnaire addressed eight key items in relation to HEN (max score 100/item). Median (range) total duration of EF was 49 days (28-96). Overall compliance was 96%. At 6 months, compared with preoperatively, 58 (39%) patients lost \u3e10% weight, with median (IQR) loss of 6.8 (4-9) kg, and 62 (41%) patients lost \u3e10% BMI. Lean body mass and body fat were significantly (p \u3c 0.001) decreased. Mean global QL decreased (p \u3c 0.01) from 82 to 72. A high mean satisfaction score (\u3e70 ± 11/100) was reported, \u3e80 for practical training, activities of daily living, pain, anxiety, recovery and impact on caregivers, with lower scores for appetite (33 ± 24) and sleep (63 ± 30). Supplemental HEN for a minimum of one month postdischarge is associated with high compliance and patient satisfaction. Weight and BMI loss may still be substantial, however this may be less than published literature, in addition the impact on HR-QL may be attenuated. HEN has both subjective and objective rationale and merits further validation toward optimizing nutritional recovery and overall wellbeing

Theory and computation of covariant Lyapunov vectors

Lyapunov exponents are well-known characteristic numbers that describe growth rates of perturbations applied to a trajectory of a dynamical system in different state space directions. Covariant (or characteristic) Lyapunov vectors indicate these directions. Though the concept of these vectors has been known for a long time, they became practically computable only recently due to algorithms suggested by Ginelli et al. [Phys. Rev. Lett. 99, 2007, 130601] and by Wolfe and Samelson [Tellus 59A, 2007, 355]. In view of the great interest in covariant Lyapunov vectors and their wide range of potential applications, in this article we summarize the available information related to Lyapunov vectors and provide a detailed explanation of both the theoretical basics and numerical algorithms. We introduce the notion of adjoint covariant Lyapunov vectors. The angles between these vectors and the original covariant vectors are norm-independent and can be considered as characteristic numbers. Moreover, we present and study in detail an improved approach for computing covariant Lyapunov vectors. Also we describe, how one can test for hyperbolicity of chaotic dynamics without explicitly computing covariant vectors.Comment: 21 pages, 5 figure

Dynamic Evolution Model of Isothermal Voids and Shocks

We explore self-similar hydrodynamic evolution of central voids embedded in an isothermal gas of spherical symmetry under the self-gravity. More specifically, we study voids expanding at constant radial speeds in an isothermal gas and construct all types of possible void solutions without or with shocks in surrounding envelopes. We examine properties of void boundaries and outer envelopes. Voids without shocks are all bounded by overdense shells and either inflows or outflows in the outer envelope may occur. These solutions, referred to as type $\mathcal{X}$ void solutions, are further divided into subtypes $\mathcal{X}_{\rm I}$ and $\mathcal{X}_{\rm II}$ according to their characteristic behaviours across the sonic critical line (SCL). Void solutions with shocks in envelopes are referred to as type $\mathcal{Z}$ voids and can have both dense and quasi-smooth edges. Asymptotically, outflows, breezes, inflows, accretions and static outer envelopes may all surround such type $\mathcal{Z}$ voids. Both cases of constant and varying temperatures across isothermal shock fronts are analyzed; they are referred to as types $\mathcal{Z}_{\rm I}$ and $\mathcal{Z}_{\rm II}$ void shock solutions. We apply the `phase net matching procedure' to construct various self-similar void solutions. We also present analysis on void generation mechanisms and describe several astrophysical applications. By including self-gravity, gas pressure and shocks, our isothermal self-similar void (ISSV) model is adaptable to various astrophysical systems such as planetary nebulae, hot bubbles and superbubbles in the interstellar medium as well as supernova remnants.Comment: 24 pages, 13 figuers, accepted by ApS

Magnetic Field Amplification in Galaxy Clusters and its Simulation

We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure