743 research outputs found

    Emitter-site selective photoelectron circular dichroism of trifluoromethyloxirane

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    The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane, C3H3F3O, is studied experimentally and theoretically. Thereby, we investigate the photoelectron circular dichroism (PECD) for nearly-symmetric O 1s and F 1s electronic orbitals, which are localized on different molecular sites. The respective dichroic β1\beta_{1} and angular distribution β2\beta_{2} parameters are measured at the photoelectron kinetic energies from 1 to 16 eV by using variably polarized synchrotron radiation and velocity map imaging spectroscopy. The present experimental results are in good agreement with the outcome of ab initio electronic structure calculations. We report a sizable chiral asymmetry β1\beta_{1} of up to about 9% for the K-shell photoionization of oxygen atom. For the individual fluorine atoms, the present calculations predict asymmetries of similar size. However, being averaged over all fluorine atoms, it drops down to about 2%, as also observed in the present experiment. Our study demonstrates a strong emitter- and site-sensitivity of PECD in the one-photon inner-shell ionization of this chiral molecule

    Area-level socioeconomic characteristics, prevalence and trajectories of cardiometabolic risk

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    This study examines the relationships between area-level socioeconomic position (SEP) and the prevalence and trajectories of metabolic syndrome (MetS) and the count of its constituents (i.e., disturbed glucose and insulin metabolism, abdominal obesity, dyslipidemia, and hypertension). A cohort of 4,056 men and women aged 18+ living in Adelaide, Australia was established in 2000-2003. MetS was ascertained at baseline, four and eight years via clinical examinations. Baseline area-level median household income, percentage of residents with a high school education, and unemployment rate were derived from the 2001 population Census. Three-level random-intercepts logistic and Poisson regression models were performed to estimate the standardized odds ratio (SOR), prevalence risk ratio (SRR), ratio of SORs/SRRs, and (95% confidence interval (CI)). Interaction between area- and individual-level SEP variables was also tested. The odds of having MetS and the count of its constituents increased over time. This increase did not vary according to baseline area-level SEP (ratios of SORs/SRRs ≈ 1; p ≥ 0.42). However, at baseline, after adjustment for individual SEP and health behaviours, median household income (inversely) and unemployment rate (positively) were significantly associated with MetS prevalence (SOR (95%CI) = 0.76 (0.63-0.90), and 1.48 (1.26-1.74), respectively), and the count of its constituents (SRR (95%CI) = 0.96 (0.93-0.99), and 1.06 (1.04-1.09), respectively). The inverse association with area-level education was statistically significant only in participants with less than post high school education (SOR (95%CI) = 0.58 (0.45-0.73), and SRR (95%CI) = 0.91 (0.88-0.94)). Area-level SEP does not predict an elevated trajectory to developing MetS or an elevated count of its constituents. However, at baseline, area-level SEP was inversely associated with prevalence of MetS and the count of its constituents, with the association of area-level education being modified by individual-level education. Population-level interventions for communities defined by area-level socioeconomic disadvantage are needed to reduce cardiometabolic risks.Anh D. Ngo, Catherine Paquet, Natasha J. Howard, Neil T. Coffee, Anne W. Taylor, Robert J. Adams, and Mark Danie

    Leading ‘us’ to be active: A two-wave test of relationships between identity leadership, group identification, and attendance

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    Although physical activity participation has numerous physiological and psychological benefits, inactivity rates remain high, and a greater understanding of the factors that drive participation is needed. Growing evidence indicates that (1) the strength of individuals’ social identification as a member of a particular physical activity group (e.g., an exercise group or sports team) is positively associated with their group-relevant participation, and (2) physical activity leaders (e.g., exercise group leaders, coaches, and captains) can foster members’ identification, and thus their greater group-relevant participation. Extending previous cross-sectional research, we examined relationships over time between sports group members’ perceptions of their leaders’ engagement in identity leadership, their group identification, and attendance. Participants (N = 186) from amateur sports teams completed measures of identity leadership, group identification, and attendance on two occasions, eight weeks apart. Lagged regressions indicated that perceptions of leaders’ engagement in identity leadership at Time 1 predicted members’ group identification at Time 2, controlling for their group identification at Time 1; and members’ group identification at Time 2 was associated with their attendance at Time 2, controlling for their attendance at Time 1. Mediation analysis demonstrated a significant indirect effect of perceptions of leaders’ engagement in identity leadership on group members’ attendance through greater group identification. Findings provide evidence of the participation-related benefits of forming, and maintaining, strong social identities in physical activity settings, and point to the role leaders can play in fostering members' sustained identification and participation

    Associations between resident perceptions of the local residential environment and metabolic syndrome

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    Extent: 11p.A substantial body of research has arisen concerning the relationships between objective residential area features, particularly area-level socioeconomic status and cardiometabolic outcomes. Little research has explored residents’ perceptions of such features and how these might relate to cardiometabolic outcomes. Perceptions of environments are influenced by individual and societal factors, and may not correspond to objective reality. Understanding relations between environmental perceptions and health is important for the development of environment interventions. This study evaluated associations between perceptions of local built and social environmental attributes and metabolic syndrome, and tested whether walking behaviour mediated these associations. Individual-level data were drawn from a population-based biomedical cohort study of adults in Adelaide, South Australia (North West Adelaide Health Study). Participants’ local-area perceptions were analysed in cross-sectional associations with metabolic syndrome using multilevel regression models (n = 1,324). A nonparametric bootstrapping procedure evaluated whether walking mediated these associations. Metabolic syndrome was negatively associated with greater local land-use mix, positive aesthetics, and greater infrastructure for walking, and was positively associated with greater perceived crime and barriers to walking. Walking partially mediated associations between metabolic syndrome and perceived environmental features. Initiatives targeting residents’ perceptions of local areas may enhance the utility of environmental interventions to improve population health.Katherine Baldock, Catherine Paquet, Natasha Howard, Neil Coffee, Graeme Hugo, Anne Taylor, Robert Adams, and Mark Danie

    Leaders’ creation of shared identity impacts group members’ effort and performance: Evidence from an exercise task

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    There is growing evidence that leaders’ effectiveness derives in part from their creation of a sense of identity that is shared by members of a group they are attempting to lead (i.e., their identity entrepreneurship). Little is known, however, about the impact of identity entrepreneurship in sport and exercise settings, particularly in relation to its effect on group members’ effort and performance. Using a pre-post between subjects experimental design, we examined the effect of leaders’ identity entrepreneurship on group members’ effort and performance during 5km cycling time trials. Following a baseline session (in which time trials were completed individually), participants (N=72) were randomly allocated to either a high or low identity entrepreneurship condition, and further randomly divided into groups of five (including a leader who was a confederate). In the subsequent test sessions (which participants attended with their fellow group members), leaders displayed either high or low identity entrepreneurship behaviors. Results indicated that, compared to participants in the low identity entrepreneurship condition, those in the high identity entrepreneurship condition maintained greater effort (maximum heart rate), and demonstrated improved (rather than poorer) performance (average power output in the first 60 seconds of time trials). Examination of pacing showed that the largest increases in participants’ average power output occurred in theearly stages of their second time trials for those in the high identity entrepreneurship condition only. Results provide causal evidence that leaders who create a shared sense of identity among team members are able to inspire greater participant effort and performance
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