164 research outputs found

    Walking school buses as a form of active transportation for children : A review of the evidence

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    ABSTRACT BACKGROUND: Walking School Buses (WSBs) offer a potentially healthier way for children to get to school whilst reducing traffic congestion. A number of pressing societal challenges make it timely to evaluate evidence of their value. METHODS: Studies that focused solely on WSBs were identified through online and manual literature searches. Twelve WSB studies involving a total of 9173 children were reviewed. Study aims, designs, methods, outcomes, and barriers and facilitators were examined. RESULTS: WSBs were found to be associated with increased prevalence of walking to school and general activity levels though not always significantly. Time constraints emerged as barriers to WSBs, impacting on recruitment of volunteers and children to the WSBs. Facilitators of WSBs included children enjoying socializing and interacting with the environment. CONCLUSIONS: Preliminary evidence of the health value of WSBs was demonstrated, along with recommendations for the design of future studies. By tackling barriers of time constraints, volunteer recruitment and parents’ safety concerns whilst at the same time, increasing convenience and time savings for families, future WSBs are likely to be more sustainable and taken up by more schools. Implications for future innovation in school health were identified

    Quadrupole deformation of deuterons and final state interaction in 2H⃗(e,eâ€Čp)^2 \vec H (e,e'p) scattering on tensor polarized deuterons at CEBAF energies

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    The strength of final state interaction (FSI) between struck proton and spectator neutron in 2H⃗(e,eâ€Čp)^2\vec{H}(e,e'p) scattering depends on the alignment of the deuteron. We study the resulting FSI effects in the tensor analyzing power in detail and find substantial FSI effects starting at still low missing momentum p_m \gsim 0.9 fm^{-1}. At larger p_m \gsim 1.5 fm^{-1}, FSI completely dominates both missing momentum distribution and tensor analyzing power. We find that to a large extent FSI masks the sensitivity of the tensor analyzing power to models of the deuteron wave function. For the transversely polarized deuterons the FSI induced forward-backward asymmetry of the missing momentum distribution is shown to have a node at precisely the same value of pmp_m as the PWIA missing momentum distribution. The position of this node is not affected by FSI and can be a tool to distinguish experimentally between different models for the deuteron wave function.Comment: 24 pages, figures available from the authors on reques

    Spin dependence in high pT2p^{2}_{T} elastic pp and np scattering

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    Using the polarized proton capability of the Argonne ZGS the authors recently made 90 degrees /sub cm/ measurements of elastic pp scattering from 6 to 11.75 GeV/c, determining the parallel and anti- parallel pure initial spin state cross sections and the associated spin-spin parameter A/sub nn/ with the spins normal to the scattering plane. They find that the parallel to anti-parallel cross section ratio rises dramatically from 1.2+or-.06 at p/sub t//sup 2/=3.3 (GeV /c)/sup 2/ to 3.2+or-.4 at 4.8 (GeV/c)/sup 2/, similar to the p/sub T //sup 2/ dependence previously observed at the fixed laboratory momentum of 11.75 GeV/c. They have also extended the measurements at 6 GeV/c and find that A/sub nn/ has a small but sharp rise at 90 degrees /sub cm/. In addition a month of 12 GeV/c polarized deuteron acceleration in the ZGS enabled them to measure two A/sub nn/ at two points at 6 GeV/c for np elastic scattering: A/sub nn/=-.17+or-.04 at p/sub T//sup 2/=.8, A/sub nn/=-.19+or-.05 at P/sub T//sup 2/=1.0. These values are opposite in sign from the pp results at the same momentum. (4 refs)

    Femtometer Toroidal Structures in Nuclei

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    The two-nucleon density distributions in states with isospin T=0T=0, spin SS=1 and projection MSM_S=0 and ±\pm1 are studied in 2^2H, 3,4^{3,4}He, 6,7^{6,7}Li and 16^{16}O. The equidensity surfaces for MSM_S=0 distributions are found to be toroidal in shape, while those of MSM_S=±\pm1 have dumbbell shapes at large density. The dumbbell shapes are generated by rotating tori. The toroidal shapes indicate that the tensor correlations have near maximal strength at r<2r<2 fm in all these nuclei. They provide new insights and simple explanations of the structure and electromagnetic form factors of the deuteron, the quasi-deuteron model, and the dpdp, dddd and αd\alpha d LL=2 (DD-wave) components in 3^3He, 4^4He and 6^6Li. The toroidal distribution has a maximum-density diameter of ∌\sim1 fm and a half-maximum density thickness of ∌\sim0.9 fm. Many realistic models of nuclear forces predict these values, which are supported by the observed electromagnetic form factors of the deuteron, and also predicted by classical Skyrme effective Lagrangians, related to QCD in the limit of infinite colors. Due to the rather small size of this structure, it could have a revealing relation to certain aspects of QCD.Comment: 35 pages in REVTeX, 25 PostScript figure

    Measurement of proton proton elastic scattering in pure initial spin states at 11.75 GeV/c

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    The elastic cross section for proton proton scattering at 11.75 GeV/c was measured at the Argonne ZGS using a 50% polarized target. In the range p[perpendicular]2=0.6 --&gt; 2.2 (GeV/c)2 we obtained precise measurements of d[sigma]/dt(ij) for the [two upwards arrow] [two down arrows], and [up and down arrow]; initial spin states perpendicular to the scattering plane. We confirmed that the asymmetry parameter, A, decreases with energy in the diffraction peak, but is approximately energy-independent at large p[perpendicular]2. We found that the spin correlation parameter cnn acquires rather dramatic structure, and at large p[perpendicular]2 seems to grow with energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21719/1/0000111.pd

    Efficacy of Infection Control Interventions in Reducing the Spread of Multidrug-Resistant Organisms in the Hospital Setting

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    Multidrug-resistant organisms (MDRO) continue to spread in hospitals globally, but the population-level impact of recommended preventive strategies and the relative benefit of individual strategies targeting all MDRO in the hospital setting are unclear. To explore the dynamics of MDRO transmission in the hospital, we develop a model extending data from clinical individual-level studies to quantify the impact of hand hygiene, contact precautions, reducing antimicrobial exposure and screening surveillance cultures in decreasing the prevalence of MDRO colonization and infection. The effect of an ongoing increase in the influx of patients colonized with MDRO into the hospital setting is also quantified. We find that most recommended strategies have substantial effect in decreasing the prevalence of MDRO over time. However, screening for asymptomatic MDRO colonization among patients who are not receiving antimicrobials is of minimal value in reducing the spread of MDRO

    Assessing the outcomes of participatory research: protocol for identifying, selecting, appraising and synthesizing the literature for realist review

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    <p>Abstract</p> <p>Background</p> <p>Participatory Research (PR) entails the co-governance of research by academic researchers and end-users. End-users are those who are affected by issues under study (<it>e.g.</it>, community groups or populations affected by illness), or those positioned to act on the knowledge generated by research (<it>e.g.</it>, clinicians, community leaders, health managers, patients, and policy makers). Systematic reviews assessing the generalizable benefits of PR must address: the diversity of research topics, methods, and intervention designs that involve a PR approach; varying degrees of end-user involvement in research co-governance, both within and between projects; and the complexity of outcomes arising from long-term partnerships.</p> <p>Methods</p> <p>We addressed the above mentioned challenges by adapting realist review methodology to PR assessment, specifically by developing inductively-driven identification, selection, appraisal, and synthesis procedures. This approach allowed us to address the non-uniformity and complexity of the PR literature. Each stage of the review involved two independent reviewers and followed a reproducible, systematic coding and retention procedure. Retained studies were completed participatory health interventions, demonstrated high levels of participation by non-academic stakeholders (<it>i.e.</it>, excluding studies in which end-users were not involved in co-governing throughout the stages of research) and contained detailed descriptions of the participatory process and context. Retained sets are being mapped and analyzed using realist review methods.</p> <p>Results</p> <p>The librarian-guided search string yielded 7,167 citations. A total of 594 citations were retained after the identification process. Eighty-three papers remained after selection. Principle Investigators (PIs) were contacted to solicit all companion papers. Twenty-three sets of papers (23 PR studies), comprising 276 publications, passed appraisal and are being synthesized using realist review methods.</p> <p>Discussion</p> <p>The systematic and stage-based procedure addressed challenges to PR assessment and generated our robust understanding of complex and heterogeneous PR practices. To date, realist reviews have focussed on evaluations of relatively uniform interventions. In contrast our PR search yielded a wide diversity of partnerships and research topics. We therefore developed tools to achieve conceptual clarity on the PR field, as a beneficial precursor to our theoretically-driven synthesis using realist methods. Findings from the ongoing review will be provided in forthcoming publications.</p

    Simultaneous measurement of 2 and 3 spins in proton proton elastic scattering at 6 GeV/c

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    The elastic cross section for proton proton scattering at 6 GeV/c was measured using a 70% polarized beam and a 75% polarized target at the Argonne ZGS. In the range P[perpendicular]2 = 0.5 --> 2.0(GeV/c)2 we obtained small error measurements for the [short up arrow][short up arrow], [downwards arrow][downwards arrow] and [short up arrow][downwards arrow] initial spin states perpendicular to the scattering plane. At P[perpendicular]2 = 0.5 we also measured the recoil spin and found that the 5 different cross sections were very unequal.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22271/1/0000710.pd

    Assessment of human resources for health using cross-national comparison of facility surveys in six countries

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    Abstract Background Health facility assessments are being increasingly used to measure and monitor indicators of health workforce performance, but the global evidence base remains weak. Partly this is due to the wide variability in assessment methods and tools, hampering comparability across and within countries and over time. The World Health Organization coordinated a series of facility-based surveys using a common approach in six countries: Chad, CĂŽte d'Ivoire, Jamaica, Mozambique, Sri Lanka and Zimbabwe. The objectives were twofold: to inform the development and monitoring of human resources for health (HRH) policy within the countries; and to test and validate the use of standardized facility-based human resources assessment tools across different contexts. Methods The survey methodology drew on harmonized questionnaires and guidelines for data collection and processing. In accordance with the survey's dual objectives, this paper presents both descriptive statistics on a number of policy-relevant indicators for monitoring and evaluation of HRH as well as a qualitative assessment of the usefulness of the data collection tool for comparative analyses. Results The findings revealed a large diversity in both the organization of health services delivery and, in particular, the distribution and activities of facility-based health workers across the sampled countries. At the same time, some commonalities were observed, including the importance of nursing and midwifery personnel in the skill mix and the greater tendency of physicians to engage in dual practice. While the use of standardized questionnaires offered the advantage of enhancing cross-national comparability of the results, some limitations were noted, especially in relation to the categories used for occupations and qualifications that did not necessarily conform to the country situation. Conclusion With increasing experience in health facility assessments for HRH monitoring comes greater need to establish and promote best practices regarding methods and tools for their implementation, as well as dissemination and use of the results for evidence-informed decision-making. The overall findings of multi-country facility-based survey should help countries and partners develop greater capacity to identify and measure indicators of HRH performance via this approach, and eventually contribute to better understanding of health workforce dynamics at the national and international levels.</p
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