216 research outputs found

    On the equivalence of the Einstein-Hilbert and the Einstein-Palatini formulations of general relativity for an arbitrary connection

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    In the framework of the Einstein-Palatini formalism, even though the projective transformation connecting the arbitrary connection with the Levi Civita connection has been floating in the literature for a long time and perhaps the result was implicitly known in the affine gravity community, yet as far as we know Julia and Silva were the first to realise its gauge character. We rederive this result by using the Rosenfeld-Dirac-Bergmann approach to constrained Hamiltonian systems and do a comprehensive self contained analysis establishing the equivalence of the Einstein-Palatini and the metric formulations without having to impose the gauge choice that the connection is symmetric. We also make contact with the the Einstein-Cartan theory when the matter Lagrangian has fermions.Comment: 18 pages. Slight change in the title and wording of some sections to emphasize the main results. References added. Matches published versio

    Design and methods of Shape Up Under 5: Integration of systems science and community-engaged research to prevent early childhood obesity

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    Shape Up Under 5 (SUU5) was a two-year early childhood obesity prevention pilot study in Somerville, Massachusetts (2015–2017) designed to test a novel conceptual framework called Stakeholder-driven Community Diffusion. For whole-of-community interventions, this framework posits that diffusion of stakeholders’ knowledge about and engagement with childhood obesity prevention efforts through their social networks will improve the implementation of health-promoting policy and practice changes intended to reduce obesity risk. SUU5 used systems science methods (agent-based modeling, group model building, social network analysis) to design, facilitate, and evaluate the work of 16 multisector stakeholders (‘the Committee’). In this paper, we describe the design and methods of SUU5 using the conceptual framework: the approach to data collection, and methods and rationale for study inputs, activities and evaluation, which together may further our understanding of the hypothesized processes within Stakeholder-driven Community Diffusion. We also present a generalizable conceptual framework for addressing childhood obesity and similar complex public health issues through whole-of-community interventions

    Qualitative Examination of Voting Empowerment and Participation Among People Living With Traumatic Brain Injury

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    Objective To examine political participation after traumatic brain injury (TBI). Design Qualitative, participatory research via interviews and observations. Each participant was interviewed to discuss their experience of voting in 2007 or 2008. Data were coded using Grounded Theory to develop themes, metacodes, and theories. Setting Community. Participants A total of 57 individuals with history of TBI and 28 family members (N=85). Main Outcome Measures Not applicable. Results Four themes emerged from the data: (1) people with TBI have barriers to voting; (2) the voting process can be improved for people with TBI; (3) voting is the responsibility of members of society; and (4) voting is one way we have a voice in society. Conclusions The data support the importance of voting as an American right regardless of the presence of disability. While persons with TBI report voting represents their freedom and voice, there may be barriers that can threaten or limit their voice

    Critical materials for infrastructure: local vs global properties

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    Introducing new technologies into infrastructure (wind turbines, electric vehicles, low-carbon materials and so on) often demands materials that are ‘critical’; their supply is likely to be disrupted owing to limited reserves, geopolitical instability, environmental issues and/or increasing demand. Non-critical materials may become critical if introduced into infrastructure, owing to its gigatonne scale. This potentially poses significant risk to the development of low-carbon infrastructure. Analysis of this risk has previously overlooked the relationship between the ‘local properties’ that determine the selection of a technology and the overall vulnerability of the system, a global property. Treating materials or components as elements having fixed properties overlooks optima within the local–global variable space that could be exploited to minimise vulnerability while maximising performance. In this study, a framework for such analysis is presented along with a preliminary measure of relative materials criticality by way of a case study (a wind turbine generator). Although introduction of critical materials (in this case, rare earth metals) enhances technical performance by up to an order of magnitude, the associated increase in criticality may be two or three orders of magnitude. Analysis at the materials and component levels produces different results; design decisions should be based on analysis at several levels

    Associations with intraocular pressure across Europe: The European Eye Epidemiology (E3) Consortium.

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    Raised intraocular pressure (IOP) is the most important risk factor for developing glaucoma, the second commonest cause of blindness globally. Understanding associations with IOP and variations in IOP between countries may teach us about mechanisms underlying glaucoma. We examined cross-sectional associations with IOP in 43,500 European adults from 12 cohort studies belonging to the European Eye Epidemiology (E3) consortium. Each study conducted multivariable linear regression with IOP as the outcome variable and results were pooled using random effects meta-analysis. The association of standardized study IOP with latitude was tested using meta-regression. Higher IOP was observed in men (0.18 mmHg; 95 % CI 0.06, 0.31; P = 0.004) and with higher body mass index (0.21 mmHg per 5 kg/m2; 95 % CI 0.14, 0.28; P < 0.001), shorter height (-0.17 mmHg per 10 cm; 95 % CI -0.25, -0.08; P < 0.001), higher systolic blood pressure (0.17 mmHg per 10 mmHg; 95 % CI 0.12, 0.22; P < 0.001) and more myopic refraction (0.06 mmHg per Dioptre; 95 % CI 0.03, 0.09; P < 0.001). An inverted U-shaped trend was observed between age and IOP, with IOP increasing up to the age of 60 and decreasing in participants older than 70 years. We found no significant association between standardized IOP and study location latitude (P = 0.76). Novel findings of our study include the association of lower IOP in taller people and an inverted-U shaped association of IOP with age. We found no evidence of significant variation in IOP across Europe. Despite the limited range of latitude amongst included studies, this finding is in favour of collaborative pooling of data from studies examining environmental and genetic determinants of IOP in Europeans.Medical Research Council (G1000143), Cancer Research UK (C864/A14136), Research into Ageing (262), Wellcome Trust, Richard Desmond Charitable Trust (via Fight for Sight), National Institute for Health Research, Stichting Lijf en Leven, Krimpen aan de Lek, MD Fonds, Utrecht, Rotterdamse Vereniging Blindenbelangen, Rotterdam, Stichting Oogfonds Nederland, Utrecht, Blindenpenning, Amsterdam, Blindenhulp, The Hague, Algemene Nederlandse Vereniging ter Voorkoming van Blindheid (ANVVB), Doorn, Landelijke Stichting voor Blinden en Slechtzienden, Utrecht, Swart van Essen, Rotterdam, Stichting Winckel-Sweep, Utrecht, Henkes Stichting, Rotterdam, Lameris Ootech BV, Nieuwegein, Medical Workshop, de Meern, NWO (Graduate Programme 2010 BOO (022.002.023)), Laboratoires Thea (Clermont-Ferrand, France), inter regional grant (PHRC) and the regional Council of Burgundy, European Community’s Seventh Framework Programme (FP7/2007-2013), Rheinland-Pfalz AZ 961-386261/733), Johannes Gutenberg-University of Mainz, Boehringer Ingelheim, PHILIPS Medical Systems, Novartis Pharma, Novartis European Union (European Social Fund—ESF), Greek National Strategic Reference Framework (NSRF) (Research Funding Program: THALES), European Social FundThis is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10654-016-0191-
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