1,181 research outputs found

    Psychosocial Correlates of Physical Activity and Sedentary Leisure Habits in Young Adolescents: The Teens Eating for Energy and Nutrition at School Study

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    BACKGROUND: Low levels of physical activity (PA) and highly sedentary leisure habits (SLH) in youth may establish behavioral patterns that will predispose youth to increased chronic disease risk in adulthood. The purpose of this paper was to examine associations of demographic and psychosocial factors with self-reported PA and SLH in young adolescents. METHODS: A general linear mixed model predicted self-reported PA and SLH in the spring from demographic and psychosocial variables measured the previous fall in 3798 seventh grade students. RESULTS: PA and SLH differed by race, with Caucasian students reporting among the highest PA and lowest SLH. Perceptions of higher academic rank or expectations predicted higher PA and lower SLH. Depressive symptomatology predicted higher SLH scores but not PA. Higher self-reported value of health, appearance, and achievement predicted higher PA and lower SLH in girls. Girls who reported that their mothers had an authoritative parenting style also reported higher PA and lower SLH. CONCLUSIONS: Determinants of PA and SLH appear to differ from each other, particularly in boys. Development of effective programs to increase PA and/or decrease SLH in young adolescents should be based on a clear understanding of the determinants of these behaviors

    The K(ππ)I=2K\to(\pi\pi)_{I=2} Decay Amplitude from Lattice QCD

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    We report on the first realistic \emph{ab initio} calculation of a hadronic weak decay, that of the amplitude A2A_2 for a kaon to decay into two \pi-mesons with isospin 2. We find ReA2=(1.436±0.063stat±0.258syst)108GeVA_2=(1.436\pm 0.063_{\textrm{stat}}\pm 0.258_{\textrm{syst}})\,10^{-8}\,\textrm{GeV} in good agreement with the experimental result and for the hitherto unknown imaginary part we find {Im}A2=(6.83±0.51stat±1.30syst)1013GeV\,A_2=-(6.83 \pm 0.51_{\textrm{stat}} \pm 1.30_{\textrm{syst}})\,10^{-13}\,{\rm GeV}. Moreover combining our result for Im\,A2A_2 with experimental values of Re\,A2A_2, Re\,A0A_0 and ϵ/ϵ\epsilon^\prime/\epsilon, we obtain the following value for the unknown ratio Im\,A0A_0/Re\,A0A_0 within the Standard Model: ImA0/ReA0=1.63(19)stat(20)syst×104\mathrm{Im}\,A_0/\mathrm{Re}\,A_0=-1.63(19)_{\mathrm{stat}}(20)_{\mathrm{syst}}\times10^{-4}. One consequence of these results is that the contribution from Im\,A2A_2 to the direct CP violation parameter ϵ\epsilon^{\prime} (the so-called Electroweak Penguin, EWP, contribution) is Re(ϵ/ϵ)EWP=(6.52±0.49stat±1.24syst)×104(\epsilon^\prime/\epsilon)_{\mathrm{EWP}} = -(6.52 \pm 0.49_{\textrm{stat}} \pm 1.24_{\textrm{syst}}) \times 10^{-4}. We explain why this calculation of A2A_2 represents a major milestone for lattice QCD and discuss the exciting prospects for a full quantitative understanding of CP-violation in kaon decays.Comment: 5 pages, 1 figur

    Lattice determination of the K(ππ)I=2K \to (\pi\pi)_{I=2} Decay Amplitude A2A_2

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    We describe the computation of the amplitude A_2 for a kaon to decay into two pions with isospin I=2. The results presented in the letter Phys.Rev.Lett. 108 (2012) 141601 from an analysis of 63 gluon configurations are updated to 146 configurations giving ReA2=1.381(46)stat(258)syst108A_2=1.381(46)_{\textrm{stat}}(258)_{\textrm{syst}} 10^{-8} GeV and ImA2=6.54(46)stat(120)syst1013A_2=-6.54(46)_{\textrm{stat}}(120)_{\textrm{syst}}10^{-13} GeV. ReA2A_2 is in good agreement with the experimental result, whereas the value of ImA2A_2 was hitherto unknown. We are also working towards a direct computation of the K(ππ)I=0K\to(\pi\pi)_{I=0} amplitude A0A_0 but, within the standard model, our result for ImA2A_2 can be combined with the experimental results for ReA0A_0, ReA2A_2 and ϵ/ϵ\epsilon^\prime/\epsilon to give ImA0/A_0/ReA0=1.61(28)×104A_0= -1.61(28)\times 10^{-4} . Our result for Im\,A2A_2 implies that the electroweak penguin (EWP) contribution to ϵ/ϵ\epsilon^\prime/\epsilon is Re(ϵ/ϵ)EWP=(6.25±0.44stat±1.19syst)×104(\epsilon^\prime/\epsilon)_{\mathrm{EWP}} = -(6.25 \pm 0.44_{\textrm{stat}} \pm 1.19_{\textrm{syst}}) \times 10^{-4}.Comment: 59 pages, 11 figure

    A set-based approach for coordination of multi-level collaborative design studies

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    Presented in this paper is a framework for design coordination of hierarchical (multi-level) design studies. The proposed framework utilizes margin management and set-based design principles for handling the challenges associated with vertical and horizontal design coordination. The former is based on flexible constraints/margins, while the latter is handled by intersecting feasible design spaces across different teams. The framework is demonstrated with an industrial test-case from the UK ATI APPROCONE (Advanced PROduct CONcept analysis Environment) project

    Adverse events during reoperative cardiac surgery: Frequency, characterization, and rescue

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    ObjectivesTo (1) determine frequency of occurrence and risk factors for intraoperative adverse events (IAE) during reoperative cardiac surgery, (2) characterize them with respect to structure injured, timing, and use of preventive strategies, and (3) identify the impact on outcome in terms of successful and unsuccessful rescue and cost.MethodsOperative notes of 1847 patients undergoing reoperative cardiac surgery were reviewed to identify and characterize documented intraoperative adverse events. Logistic regression modeling was used to identify risk factors for intraoperative adverse events and outcomes. Expected versus observed poor outcomes (stroke, myocardial infarction, death) was used to measure rescue.ResultsAmong 127 patients, 145 (7%) intraoperative adverse events occurred. These included injuries to bypass grafts (n = 47), heart (n = 38), and great vessels (n = 28) and ischemia without graft injury (n = 22). Most occurred on opening (n = 34, 23%) and during prebypass dissection (n = 57, 39%). Risk incremented as reoperations increased. Seventy-seven patients experienced 1 or more lapses in preventive strategies. Patients with intraoperative adverse events had a greater number of poor outcomes (n = 24 [19%] vs n = 107 [6.2%]; P < .0001) and incurred higher direct technical intraoperative and postoperative costs (ratio 1.3). Twelve patients with intraoperative adverse events were predicted to have poor outcomes versus 24 who did (P < .0001), indicating 12 “failures to rescue.”ConclusionsAdverse events still occur regularly during cardiac reoperation, are related to complexity of the procedure, and occur particularly during dissection and often when preventive strategies have not been used. Compensatory rescue measures are not always successful. Adverse events lead to poor patient outcome and higher cost

    The response of perennial and temporary headwater stream invertebrate communities to hydrological extremes

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    The headwaters of karst rivers experience considerable hydrological variability, including spates and streambed drying. Extreme summer flooding on the River Lathkill (Derbyshire, UK) provided the opportunity to examine the invertebrate community response to unseasonal spate flows, flow recession and, at temporary sites, streambed drying. Invertebrates were sampled at sites with differing flow permanence regimes during and after the spates. Following streambed drying at temporary sites, dewatered surface sediments were investigated as a refugium for aquatic invertebrates. Experimental rehydration of these dewatered sediments was conducted to promote development of desiccation-tolerant life stages. At perennial sites, spate flows reduced invertebrate abundance and diversity, whilst at temporary sites, flow reactivation facilitated rapid colonisation of the surface channel by a limited number of invertebrate taxa. Following streambed drying, 38 taxa were recorded from the dewatered and rehydrated sediments, with Oligochaeta being the most abundant taxon and Chironomidae (Diptera) the most diverse. Experimental rehydration of dewatered sediments revealed the presence of additional taxa, including Stenophylax sp. (Trichoptera: Limnephilidae) and Nemoura sp. (Plecoptera: Nemouridae). The influence of flow permanence on invertebrate community composition was apparent despite the aseasonal high-magnitude flood events

    Deconstructing interventions: approaches to studying behavior change techniques across obesity interventions

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    Deconstructing interventions into the specific techniques that are used to change behavior represents a new frontier in behavioral intervention research. This paper considers opportunities and challenges in employing the Behavior Change Techniques Taxonomy (BCTTv1) developed by Michie and colleagues, to code the behavior change techniques (BCTs) across multiple interventions addressing obesity and capture dose received at the technique level. Numerous advantages were recognized for using a shared framework for intervention description. Coding interventions at levels of the social ecological framework beyond the individual level, separate coding for behavior change initiation vs. maintenance, fidelity of BCT delivery, accounting for BCTs mode of delivery, and tailoring BCTs, present both challenges and opportunities. Deconstructing interventions and identifying the dose required to positively impact health-related outcomes could enable important gains in intervention science

    Action spectrum of the retinal mechanism mediating nocturnal light-induced suppression of rat pineal gland N-acetyltransferase

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    The spectral properties of the retinal mechanism mediating the inhibitory effects of nocturnal light on pineal gland N-acetyltransferase (NAT) activity were determined. Pineal gland NAT activity declined linearly in albino rats exposed to different irradiances of a 460 or 580 nm monochromatic light during the middle of the dark phase of the cycle. The difference in sensitivity to the test lights is that predicted for a photopigment having peak absorbance at 495 nm, suggesting the inhibition of pineal gland N-acetyltransferase activity is mediated by the photopigment found in rat rods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26770/1/0000322.pd
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