4,242 research outputs found
Psychosocial mediators of change in physical activity in the Welsh national exercise referral scheme: secondary analysis of a randomised controlled trial
Objective:
While an increasing number of randomised controlled trials report impacts of exercise referral schemes (ERS) on physical activity, few have investigated the mechanisms through which increases in physical activity are produced. This study examines whether a National Exercise Referral Scheme (NERS) in Wales is associated with improvements in autonomous motivation, self-efficacy and social support, and whether change in physical activity is mediated by change in these psychosocial processes.<p></p>
Methods:
A pragmatic randomised controlled trial of NERS across 12 LHBs in Wales. Questionnaires measured demographic data and physical activity at baseline. Participants (Nâ=â2160) with depression, anxiety or CHD risk factors were referred by health professionals and randomly assigned to control or intervention. At six months psychological process measures were collected by questionnaire. At 12Â months physical activity was assessed by 7 Day PAR telephone interview. Regressions tested intervention effects on psychosocial variables, physical activity before and after adjusting for mediators and socio demographic patterning.<p></p>
Results:
Significant intervention effects were found for autonomous motivation and social support for exercise at 6Â months. No intervention effect was observed for self-efficacy. The data are consistent with a hypothesis of partial mediation of the intervention effect by autonomous motivation. Analysis of moderators showed significant improvements in relative autonomy in all subgroups. The greatest improvements in autonomous motivation were observed among patients who were least active at baseline.<p></p>
Discussion:
The present study offered key insights into psychosocial processes of change in an exercise referral scheme, with effects on physical activity mediated by autonomous motivation. Findings support the use of self-determination theory as a framework for ERS. Further research is required to explain socio-demographic patterning in responses to ERS, with changes in motivation occurring among all sub-groups of participants, though not always leading to higher adherence or behavioural change. This highlights the importance of socio-ecological approaches to developing and evaluating behaviour change interventions, which consider factors beyond the individual, including conditions in which improved motivation does or does not produce behavioural change
Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study.
Background:
Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS) exposure amongst non-smoking children.
Methods:
Approximately 1,750 year 6 (aged 10-11) children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home.
Results:
Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20) pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17), post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml) to lower tertile, though not from the higher end (>0.51 ng/ml) to the middle.
Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly.
The proportion of children reporting that parent figures smoked in the home declined (P = 0.03), with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation.
Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation.
Conclusion:
Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of children's SHS exposure. The legislation was associated with an unexpected reduction in cotinine levels among children with lower SHS exposure pre-legislation. The findings indicate positive rather than harmful effects of legislation on children's SHS exposure, but highlight the need for further action to protect those children most exposed to SHS
Impacts of the Primary School Free Breakfast Initiative on socio-economic inequalities in breakfast consumption among 9â11-year-old schoolchildren in Wales
Objectives - Universal interventions may widen or narrow inequalities if disproportionately effective among higher or lower socio-economic groups. The present paper examines impacts of the Primary School Free Breakfast Initiative in Wales on inequalities in children's dietary behaviours and cognitive functioning.<p></p>
Design Cluster - randomised controlled trial. Responses were linked to free school meal (FSM) entitlement via the Secure Anonymised Information Linkage databank. Impacts on inequalities were evaluated using weighted school-level regression models with interaction terms for intervention Ă whole-school percentage FSM entitlement and intervention Ă aggregated individual FSM entitlement. Individual-level regression models included interaction terms for intervention Ă individual FSM entitlement.<p></p>
Setting - Fifty-five intervention and fifty-six wait-list control primary schools.<p></p>
Subjects - Approximately 4500 children completed measures of dietary behaviours and cognitive tests at baseline and 12-month follow-up.<p></p>
Results School-level models indicated that children in intervention schools ate a greater number of healthy items for breakfast than children in control schools (b = 0·25; 95 % CI 0·07, 0·44), with larger increases observed in more deprived schools (interaction term b = 1·76; 95 % CI 0·36, 3·16). An interaction between intervention and household-level deprivation was not significant. Despite no main effects on breakfast skipping, a significant interaction was observed, indicating declines in breakfast skipping in more deprived schools (interaction term b = â0·07; 95 % CI â0·15, â0·00) and households (OR = 0·67; 95 % CI 0·46, 0·98). No significant influence on inequality was observed for the remaining outcomes.<p></p>
Conclusions - Universal breakfast provision may reduce socio-economic inequalities in consumption of healthy breakfast items and breakfast skipping. There was no evidence of intervention-generated inequalities in any outcomes
Post-caesarean section surgical site infections : A retrospective audit and case note review at an Ethiopian referral hospital
Acknowledgements We thank the administrative and clinical staff of the maternity department at FHRH, Ethiopia, for their contributions to data collection and allowing the audit to take place. Funding sources A. Rose received funding from several sources to complete this audit while an undergraduate medical student (The Hospital Saturday Fund, The British Medical and Dental Studentsâ Trust, The European Wound Management Association, The Highland Council Ross & Cromarty Educational Trust and The Royal College of Physicians and Surgeons of Glasgow).Peer reviewedPublisher PD
Coherent Control of Quantum Chaotic Diffusion
Extensive coherent control over quantum chaotic diffusion using the kicked
rotor model is demonstrated and its origin in deviations from random matrix
theory is identified. Further, the extent of control in the presence of
external decoherence is established. The results are relevant to both areas of
quantum chaos and coherent control.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let
Process evaluation of complex interventions: Medical Research Council guidance.
Process evaluation is an essential part of designing and testing complex interventions. New MRC guidance provides a framework for conducting and reporting process evaluation studiesThe work was funded by the MRC Population Health Science Research Network (PHSRN45).This is the final published version. It first appeared at http://www.bmj.com/content/350/bmj.h1258
Associations of socioeconomic status, parental smoking and parental e-cigarette use with 10â11-year-old childrenâs perceptions of tobacco cigarettes and e-cigarettes: cross sectional analysis of the CHETS Wales 3 survey
Background: This study examines primary schoolchildrenâs perceptions of e-cigarettes and tobacco cigarettes, and associations with parental smoking, vaping and socioeconomic status. Methods: Survey of 2218 10â11-year-old children in 73 schools in Wales. Results: Overall, 36% reported that a parent figure smoked compared to 21% for vaping, with parental smoking lower in affluent families (OR = 0.72; 95% CI = 0.68 to 0.76). Overall, 1% had tried a cigarette, while 5% had tried an e-cigarette. Most said they would not smoke or vape in 2 yearsâ time; susceptibility to vaping (20%) was higher than smoking (12%). Exposure to and perceptions of tobacco cigarettes were more positive for children of smokers. Having a parent who vaped was associated with exposure to and positive perceptions of e-cigarettes, but not smoking. Most children perceived e-cigarettes as used by adults to stop smoking (64%). Susceptibility to smoking (OR = 0.57; 95% CI = 0.41 to 0.79) and vaping (OR = 0.78; 95% CI = 0.62 to 0.99) were lower among children who perceived e-cigarettes as cessation aids. Conclusions: Parental smoking continues to be concentrated in poorer families. This study provides no evidence that parental vaping in the absence of smoking is associated with more positive perceptions of tobacco cigarettes. Communicating to children the role of e-cigarettes as cessation devices for smokers may help to limit their appeal to young people
Quantum signatures of chaos in the dynamics of a trapped ion
We show how a nonlinear chaotic system, the parametrically kicked nonlinear
oscillator, may be realised in the dynamics of a trapped, laser-cooled ion,
interacting with a sequence of standing wave pulses. Unlike the original
optical scheme [G.J.Milburn and C.A.Holmes, Phys. Rev A, 44, p4704, (1991)],
the trapped ion enables strongly quantum dynamics with minimal dissipation.
This should permit an experimental test of one of the quantum signatures of
chaos; irregular collapse and revival dynamics of the average vibrational
energy.Comment: 9 pages, 9 Postscript figures, Revtex, submitted to Phys. Rev.
A comparison of Qatari and Chinese cadet table tennis players: analysis of Asian championship team competition
Video analysis was performed during the Asian Cadet Table Tennis Championships to determine playing style and patterns of top and lower ranked nations. China and Qatar were chosen for analysis based on their performance during the tournament (1st/2nd playoff and 7th/8th playoff respectively). Notational analysis techniques were implemented
to analyze 3 matches for each nation. Significant (p<0.05) differences were identified in serve and return placement and shot choice. Chinese players used a higher proportion of long return placement and a higher percentage of topspin shots compared to Qatari players. This preliminary study suggests that at cadet level, Chinese players exhibit a
more attacking style of play than Qatari players
Empirical Models for Dark Matter Halos. III. The Kormendy relation and the log(rho_e)-log(R_e) relation
We have recently shown that the 3-parameter density-profile model from
Prugniel & Simien provides a better fit to simulated, galaxy- and
cluster-sized, dark matter halos than an NFW-like model with arbitrary inner
profile slope gamma (Paper I). By construction, the parameters of the
Prugniel-Simien model equate to those of the Sersic R^{1/n} function fitted to
the projected distribution. Using the Prugniel-Simien model, we are therefore
able to show that the location of simulated (10^{12} M_sun) galaxy-sized dark
matter halos in the _e-log(R_e) diagram coincides with that of brightest
cluster galaxies, i.e., the dark matter halos appear consistent with the
Kormendy relation defined by luminous elliptical galaxies. These objects are
also seen to define the new, and equally strong, relation log(rho_e) = 0.5 -
2.5log(R_e), in which rho_e is the internal density at r=R_e. Simulated
(10^{14.5} M_sun) cluster-sized dark matter halos and the gas component of real
galaxy clusters follow the relation log(rho_e) = 2.5[1 - log(R_e)]. Given the
shapes of the various density profiles, we are able to conclude that while
dwarf elliptical galaxies and galaxy clusters can have dark matter halos with
effective radii of comparable size to the effective radii of their baryonic
component, luminous elliptical galaxies can not. For increasingly large
elliptical galaxies, with increasingly large profile shapes `n', to be dark
matter dominated at large radii requires dark matter halos with increasingly
large effective radii compared to the effective radii of their stellar
component.Comment: AJ, in press. (Paper I can be found at astro-ph/0509417
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