489 research outputs found
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
Effect of polycrystallinity on the optical properties of highly oriented ZnO grown by pulsed laser deposition
We report the results of photoluminescence and reflectance measurements on highly c-axis oriented polycrystalline ZnO grown by pulsed laser deposition. The samples measured were grown under identical conditions and were annealed in-situ at various temperatures for 10-15 min. The band-edge photoluminescence spectra of the material altered considerably with an increase in grain size, with increased free exciton emission and observable excitonic structure in the reflectance spectra. The green band emission also increased with increasing grain size. A deformation potential analysis of the effect of strain on the exciton energy positions of the A- and B-excitons demonstrated that the experimental exciton energies could not be explained solely in terms of sample strain. We propose that electric fields in the samples due to charge trapping at grain boundaries are responsible for the additional perturbation of the excitons. This interpretation is supported by theoretical estimates of the exciton energy perturbation due to electric fields. The behaviour of the green band in the samples provides additional evidence in favour of our model
Pulsar-wind nebulae and magnetar outflows: observations at radio, X-ray, and gamma-ray wavelengths
We review observations of several classes of neutron-star-powered outflows:
pulsar-wind nebulae (PWNe) inside shell supernova remnants (SNRs), PWNe
interacting directly with interstellar medium (ISM), and magnetar-powered
outflows. We describe radio, X-ray, and gamma-ray observations of PWNe,
focusing first on integrated spectral-energy distributions (SEDs) and global
spectral properties. High-resolution X-ray imaging of PWNe shows a bewildering
array of morphologies, with jets, trails, and other structures. Several of the
23 so far identified magnetars show evidence for continuous or sporadic
emission of material, sometimes associated with giant flares, and a few
possible "magnetar-wind nebulae" have been recently identified.Comment: 61 pages, 44 figures (reduced in quality for size reasons). Published
in Space Science Reviews, "Jets and Winds in Pulsar Wind Nebulae, Gamma-ray
Bursts and Blazars: Physics of Extreme Energy Release
The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour
Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect
Low birthweight, preschool education, and school remediation
Abstract
Studies have documented a strong relationship between low birth weight status and adverse child
outcomes such as poor school performance and need for special education services. Following a cohort of
over 1,300 low-income and predominately African American children in the Chicago Longitudinal Study
we investigated whether birth weight and family socio-economic risk measured at the time of the child’s
birth predicts placement into special education classes or grade retention in elementary school. Contrary
to previous research, we found that low birth weight (< 5 ½ pounds) does not predict special education
placement. Rather, these children (especially boys) were more likely to be retained in grade as an
alternative approach to addressing poor school performance. Family socio-economic risk at birth was a
significant predictor of the need for remedial services. We also assessed whether a high-quality preschool
program offered at ages 3 and 4 can reduce the negative effects of low family SES and birth weight on the
need for special education and grade retention. Preschool participation in the Child-Parent Centers was
found to reduce the likelihood of school remediation. The effects of preschool were greater for children
from families with higher levels of socio-economic disadvantage. The beneficial effects of preschool on
special education placement were also larger for boys than girls
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Grass burning under our feet: Indigenous enterprise development in a political economy of whiteness
In this article we discuss some of our findings from two research projects that explore opportunities for Indigenous enterprise development in remote locations in Northern and Central Australia. Based on a series of focus groups and in-depth interviews with Indigenous community leaders, Traditional Owners, government officials, Land Council officials and other stakeholders, we discuss barriers to economic development faced by Indigenous communities in remote regions. We argue that many of these barriers are the material effects of discursive practices of ‘whiteness’ in the political economy. We discuss the relationships between institutions and Indigenous communities that constitute the Indigenous political economy and argue that these relationships are informed by discursive practices of whiteness and colonial-capitalist relations of power. We conclude by discussing the implications of our findings for management learning and public policy
Stateful Contracts for Affine Types
Abstract. Affine type systems manage resources by preventing some values from being used more than once. This offers expressiveness and performance benefits, but difficulty arises in interacting with components written in a conventional language whose type system provides no way to maintain the affine type system’s aliasing invariants. We propose and implement a technique that uses behavioral contracts to mediate between code written in an affine language and code in a conventional typed language. We formalize our approach via a typed calculus with both affine-typed and conventionally-typed modules. We show how to preserve the guarantees of both type systems despite both languages being able to call into each other and exchange higher-order values.
Topical Issues for Particle Acceleration Mechanisms in Astrophysical Shocks
Particle acceleration at plasma shocks appears to be ubiquitous in the
universe, spanning systems in the heliosphere, supernova remnants, and
relativistic jets in distant active galaxies and gamma-ray bursts. This review
addresses some of the key issues for shock acceleration theory that require
resolution in order to propel our understanding of particle energization in
astrophysical environments. These include magnetic field amplification in shock
ramps, the non-linear hydrodynamic interplay between thermal ions and their
extremely energetic counterparts possessing ultrarelativistic energies, and the
ability to inject and accelerate electrons in both non-relativistic and
relativistic shocks. Recent observational developments that impact these issues
are summarized. While these topics are currently being probed by
astrophysicists using numerical simulations, they are also ripe for
investigation in laboratory experiments, which potentially can provide valuable
insights into the physics of cosmic shocks.Comment: 13 pages, no figures. Invited review, accepted for publication in
Astrophysics and Space Science, as part of the HEDLA 2006 conference
proceeding
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