468 research outputs found

    The Impact of State Physical Education Requirements on Youth Physical Activity and Overweight

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    To combat childhood overweight, which has risen dramatically in the past three decades, many medical and public health organizations have called for students to spend more time in physical education (PE) classes. This paper is the first to exploit state PE requirements as quasi-natural experiments in order to estimate the causal impact of PE on student activity and weight. We study nationwide data from the YRBSS for 1999, 2001, and 2003 merged with data on state minimum PE requirements from the 1994 and 2000 School Health Policies and Programs Study and the 2001 Shape of the Nation Report. We find that certain state regulations are effective in raising the number of minutes during which students are active in PE. Our results also indicate that additional PE time raises the number of days per week that students report having exercised or engaged in strength-building activities, but lowers the number of days in which students report light physical activity. PE time has no detectable impact on youth BMI or the probability that a student is overweight. We conclude that while raising PE requirements may make students more active by some (but not all) measures, there is not yet the scientific base to declare raising PE requirements an anti-obesity initiative.

    War and Peace in the Nuclear Age

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    Combinatorial synthesis of oxysulfides in the lanthanum-bismuth-copper system

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    Establishing synthesis methods for a target material constitutes a grand challenge in materials research, which is compounded with use-inspired specifications on the format of the material. Solar photochemistry using thin film materials is a promising technology for which many complex materials are being proposed, and the present work describes application of combinatorial methods to explore the synthesis of predicted Laā€“Biā€“Cu oxysulfide photocathodes, in particular alloys of LaCuOS and BiCuOS. The variation in concentration of three cations and two anions in thin film materials, and crystallization thereof, is achieved by a combination of reactive sputtering and thermal processes including reactive annealing and rapid thermal processing. Composition and structural characterization establish composition-processing-structure relationships that highlight the breadth of processing conditions required for synthesis of LaCuOS and BiCuOS. The relative irreducibility of La oxides and limited diffusion indicate the need for high temperature processing, which conflicts with the temperature limits for mitigating evaporation of Bi and S. Collectively the results indicate that alloys of these phases will require reactive annealing protocols that are uniquely tailored to each composition, motivating advancement of dynamic processing capabilities to further automate discovery of synthesis routes

    A novel experience-based internet intervention for smoking cessation : feasibility randomised controlled trial

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    The iPEx programme presents independent research funded by the UK National Institute for Health Research (NIHR) under its Programme Grants for Applied Research funding scheme (RP-PG-0608-10147). The views expressed in this paper are those of the authors, representing iPEx, and not necessarily those of the NHS, the NIHR or the Department of Health.Peer reviewedPublisher PD

    High Throughput Light Absorber Discovery, Part 1: An Algorithm for Automated Tauc Analysis

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    High-throughput experimentation provides efficient mapping of compositionā€“property relationships, and its implementation for the discovery of optical materials enables advancements in solar energy and other technologies. In a high throughput pipeline, automated data processing algorithms are often required to match experimental throughput, and we present an automated Tauc analysis algorithm for estimating band gap energies from optical spectroscopy data. The algorithm mimics the judgment of an expert scientist, which is demonstrated through its application to a variety of high throughput spectroscopy data, including the identification of indirect or direct band gaps in Fe_2O_3, Cu_2V_2O_7, and BiVO_4. The applicability of the algorithm to estimate a range of band gap energies for various materials is demonstrated by a comparison of direct-allowed band gaps estimated by expert scientists and by automated algorithm for 60 optical spectra

    Combinatorial screening yields discovery of 29 metal oxide photoanodes for solar fuel generation

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    Combinatorial synthesis combined with high throughput electrochemistry enabled discovery of 29 ternary oxide photoanodes, 15 with visible light response for oxygen evolution. Yā‚ƒFeā‚…Oā‚ā‚‚ and trigonal Vā‚‚CoOā‚† emerge as particularly promising candidates due to their photorepsonse at sub-2.4 eV illumination

    Results from the NASA Spacecraft Fault Management Workshop: Cost Drivers for Deep Space Missions

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    Fault Management, the detection of and response to in-flight anomalies, is a critical aspect of deep-space missions. Fault management capabilities are commonly distributed across flight and ground subsystems, impacting hardware, software, and mission operations designs. The National Aeronautics and Space Administration (NASA) Discovery & New Frontiers (D&NF) Program Office at Marshall Space Flight Center (MSFC) recently studied cost overruns and schedule delays for five missions. The goal was to identify the underlying causes for the overruns and delays, and to develop practical mitigations to assist the D&NF projects in identifying potential risks and controlling the associated impacts to proposed mission costs and schedules. The study found that four out of the five missions studied had significant overruns due to underestimating the complexity and support requirements for fault management. As a result of this and other recent experiences, the NASA Science Mission Directorate (SMD) Planetary Science Division (PSD) commissioned a workshop to bring together invited participants across government, industry, and academia to assess the state of the art in fault management practice and research, identify current and potential issues, and make recommendations for addressing these issues. The workshop was held in New Orleans in April of 2008. The workshop concluded that fault management is not being limited by technology, but rather by a lack of emphasis and discipline in both the engineering and programmatic dimensions. Some of the areas cited in the findings include different, conflicting, and changing institutional goals and risk postures; unclear ownership of end-to-end fault management engineering; inadequate understanding of the impact of mission-level requirements on fault management complexity; and practices, processes, and tools that have not kept pace with the increasing complexity of mission requirements and spacecraft systems. This paper summarizes the findings and recommendations from that workshop, particularly as fault management development issues affect operations and the development of operations capabilities

    Perspectives from deductible plan enrollees: plan knowledge and anticipated care-seeking changes

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    <p>Abstract</p> <p>Background</p> <p>Consumer directed health care proposes that patients will engage as informed consumers of health care services by sharing in more of their medical costs, often through deductibles. We examined knowledge of deductible plan details among new enrollees, as well as anticipated care-seeking changes in response to the deductible.</p> <p>Methods</p> <p>In a large integrated delivery system with a range of deductible-based health plans which varied in services included or exempted from deductible, we conducted a mixed-method, cross-sectional telephone interview study.</p> <p>Results</p> <p>Among 458 adults newly enrolled in a deductible plan (71% response rate), 51% knew they had a deductible, 26% knew the deductible amount, and 6% knew which medical services were included or exempted from their deductible. After adjusting for respondent characteristics, those with more deductible-applicable services and those with lower self-reported health status were significantly more likely to know they had a deductible. Among those who knew of their deductible, half anticipated that it would cause them to delay or avoid medical care, including avoiding doctor's office visits and medical tests, even services that they believed were medically necessary. Many expressed concern about their costs, anticipating the inability to afford care and expressing the desire to change plans.</p> <p>Conclusion</p> <p>Early in their experience with a deductible, patients had limited awareness of the deductible and little knowledge of the details. Many who knew of the deductible reported that it would cause them to delay or avoid seeking care and were concerned about their healthcare costs.</p
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