2,068 research outputs found

    Optimization of the Ballistic Guide Design for the SNS FNPB 8.9 A Neutron Line

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    The optimization of the ballistic guide design for the SNS Fundamental Neutron Physics Beamline 8.9 A line is described. With a careful tuning of the shape of the curve for the tapered section and the width of the straight section, this optimization resulted in more than 75% increase in the neutron flux exiting the 33 m long guide over a straight m=3.5 guide with the same length.Comment: 21 pages, 13 figures; added a paragraph on existing ballistic guides to respond to referee comments; accepted for publication in Nuclear Inst. and Methods in Physics Research,

    Parametric resonance enhancement in neutron interferometry and application for the search for non-Newtonian gravity

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    The parametric resonance enhancement of the phase of neutrons due to non-Newtonian anomalous gravitationis considered. The existence of such resonances is confirmed by numerical calculations. A possible experimentalscheme for observing this effect is discussed based on an existing neutron interferometer design

    Fundamental Neutron Physics at Spallation Sources

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    Low-energy neutrons have been a useful probe in fundamental physics studies for more than 70 years. With advances in accelerator technology, many new sources are spallation based. These new, high-flux facilities are becoming the sites for many next-generation fundamental neutron physics experiments. In this review, we present an overview of the sources and the current and upcoming fundamental neutron physics programs

    The Green Eating Project: web-based intervention to promote environmentally conscious eating behaviours in US university students

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    Objective: To investigate the effectiveness of an online, interactive intervention, referred to as the Green Eating (GE) Project, to motivate university students to adopt GE behaviours. Design: The study was quasi-experimental and integrated into courses for credit/extra credit. Courses were randomly stratified into experimental or non-treatment control. The 5-week intervention consisted of four modules based on different GE topics. Participants completed the GE survey at baseline (experimental, n 241; control, n 367) and post (experimental, n 187; control, n 304). The GE survey has been previously validated and consists of Transtheoretical Model constructs including stage of change (SOC), decisional balance (DB: Pros and Cons) and self-efficacy (SE: School and Home) as well as behaviours for GE. Modules contained basic information regarding each topic and knowledge items to assess content learning. Setting: The GE Project took place at a public university in the north-eastern USA. Subjects: Participants were full-time students between the ages of 18 and 24 years. Results: The GE Project was effective in significantly increasing GE behaviours, DB Pros, SE School and knowledge in experimental compared with control, but did not reduce DB Cons or increase SE Home. Experimental participants were also more likely to be in later SOC for GE at post testing. Conclusions: The GE Project was effective in increasing GE behaviours in university students. Motivating consumers towards adopting GE could assist in potentially mitigating negative consequences of the food system on the environment. Future research could tailor the intervention to participant SOC to further increase the effects or design the modules for other participants

    Racial/Ethnic Disparities in US Adolescents’ Dietary Quality and Its Modification by Weight-Related Factors and Physical Activity

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    There are well-known disparities in the prevalence of obesity across racial-ethnic groups, although the behavioral and psychological factors driving these disparities are less well understood. Therefore, the objectives of this study were: (1) to examine differences in dietary quality by race/ethnicity and weight-related variables [body mass index (BMI), weight loss attempt, and weight dissatisfaction] and physical activity (PA) using the Health Eating Index-2015 (HEI-2015); and (2) to investigate the interactions and independent associations of race/ethnicity, weight-related variables and PA on dietary quality. Data for adolescents aged 12–19 years (n = 3373) were abstracted from the 2007–2014 National Health and Nutrition and Examination Survey and analyzed using multiple PROC SURVEYREG, adjusting for demographics and accounting for complex sampling. Analyses determined that Hispanic males had better overall HEI-2015 scores than non-Hispanic whites (48.4 ± 0.5 vs. 45.7 ± 0.6, p = 0.003) or blacks (48.4 ± 0.5 vs. 45.5 ± 0.5, p \u3c 0.001). Hispanic females also had better dietary quality than non-Hispanic whites (50.2 ± 0.4 vs. 47.5 ± 0.5, p \u3c 0.001) and blacks (50.2 ± 0.4 vs. 47.1 ± 0.5, p \u3c 0.001). Meeting the PA recommendation modified racial/ethnic differences in dietary quality for females (p = 0.011) and this was primarily driven by the associations among non-Hispanic white females (ΔR2 = 2.6%, p = 0.0004). The study identified racial/ethnic and gender differences among adolescents in factors that may promote obesity. Results may be useful for obesity prevention efforts designed to reduce health disparities in adolescents

    Content Validation of a Home Parenteral Nutrition–Patient‐Reported Outcome Questionnaire

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    Background: Patient‐reported outcome (PRO) instruments collect information from patients about health conditions and disease management, including quality of life (QOL). Clinicians acknowledge patient concerns about QOL but need guidance to assess the nature and severity of individually experienced problems. The Home Parenteral Nutrition (HPN)–Patient‐Reported Outcome Questionnaire (PROQ) was developed for use during medical appointments or homecare visits to address this gap. The purpose of this research was to provide evidence that the HPN‐PROQ items and scale possess content validity. Methods: A mixed‐method study design was used. In phase 1, cognitive interviews (CIs) were conducted with 32 HPN patients. Thematic analysis was used to assess participant understanding of the instructions, items, and response scales and overall utility of the HPN‐PROQ. In phase 2, 13 expert clinicians evaluated the relevance of items to the HPN population using the Content Validity Index (CVI) to produce item‐level (I‐CVI) and scale‐level (S‐CVI) scores. Items with an I‐CVI score ≄0.783 were retained. Results: Fifty‐four percent of items were deemed as being comprehensible, acceptable, and clear; 25% were revised; and 11% were deleted. In phase 2, 79% of items were rated highly relevant. The S‐CVI score was 0.96. The final HPN‐PROQ contains 34 items. Conclusion: This study established acceptable content validity of the HPN‐PROQ. This PROQ may help foster patient‐clinician communication about lifestyle adaptation and QOL

    The Association between Physical Activity and Metabolic Syndrome in Older Adults with Obesity

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    Background: Physical activity reduces the likelihood of developing metabolic syndrome (MetS). However, the association between different physical activity levels and MetS remains unclear in older adults with obesity. Methods: This cross-sectional study used four waves of data (2007-2008, 2009-2010, 2011-2012, 2013-2014) from two datasets: The National Health and Nutrition Examination Survey and United Sates Department of Agriculture’s Food Patterns Equivalents Database. The sample included adults 60+ years of age (n= 613) with obesity who had physical activity and MetS data. Physical activity was assessed using the Global Physical Activity Questionnaire and categorized into three physical activity levels (low, medium, and high); and medium or high physical activity levels are aligned with or exceed current physical activity recommendations. Participants were classified as having MetS using a commonly agreed upon definition. Multiple logistic regression models examined the association between the three physical activity levels and MetS risk factors and MetS. All analyses adjusted for potential confounding variables and accounted for complex sampling. Results: Of 613 respondents, 72.1% (n=431) were classified as having MetS, and 44.3% (n = 263) had not met physical activity recommendations. Participants with high levels of physical activity had a lower risk of MetS (OR = 0.31, 95%CI: 0.13, 0.72) and more healthful levels of high-density lipoprotein cholesterol (OR = 0.39, 95%CI: 0.18, 0.84), blood pressure (OR = 0.39, 95%CI: 0.20, 0.77), fasting glucose (OR = 0.34, 95%CI: 0.15, 0.78) than participants categorized as having low physical activity. Conclusions: Physical activity is associated with lower risk of MetS only for participants with the highest level of physical activity, which suggests that physical activity dosage is important to reduce MetS risk in older adults with obesity

    Relationship between diet quality, physical activity and health-related quality of life in older adults: findings from 2007-2014 National Health and Nutrition Examination Survey.

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    Background: A growing body of research shows that diet quality and physical activity (PA) are associated with health-related quality of life (HRQOL). However, no study to date has assessed this association using the Healthy Eating Index-2015 as a measure of diet quality. Furthermore, few studies have examined the association between PA dose and HRQOL among a nationally representative sample of older adults. Objectives: To investigate the relationship between diet quality, physical activity, and HRQOL. Objectives: To investigate the relationship between diet quality, physical activity, and HRQOL. Design: A cross-sectional analysis was conducted using data obtained from 5,311 adults aged 60+ years who took part in the National Health and Nutrition Examination Survey between 2007 and 2014. Measurements: HRQOL was assessed by general health status, and number of physically unhealthy days, mentally unhealthy days, and inactive days in past 30 days. Diet quality was assessed by the Healthy Eating Index-2015 using data generated by two 24-hour dietary recalls. PA was measured by the Global Physical Activity Questionnaire. Multivariate logistic/or linear regression models were used to examine the association between diet quality, PA and HRQOL controlling for confounders and accounting for complex sampling. Results: Approximately half of the participants (55.2%) were women, 45.1% met current PA recommendations, 65% had less healthful diets according to the Healthy Eating Index-2015. Diet quality was associated with HROQL. For every 1-point diet quality score increase, the likelihood of respondents rating their general health as being excellent/good increased by 3% (OR=1.03, 95%CI: 1.02, 1.04), and number of inactive days (ÎČ =-0.03, 95%CI: -0.05, 0.00) and mental unhealthy days (ÎČ =-0.03, 95%CI: -0.05, -0.01) declined by 0.03 days. PA was associated with all HROQL measures and respondents with high PA levels reported better general health (OR=3.53, 95%CI: 2.69, 4.63), fewer inactive days (ÎČ =-1.53, 95%CI: -2.11, -0.95), fewer physical unhealthy days (ÎČ =-1.88, 95%CI: -2.74, -1.02) than individuals with low PA levels but not fewer mentally unhealthy days. Conclusion: Among older adults in this study, eating a healthier diet and being physically active were associated with better general health and reporting fewer physical unhealthy days and inactive days. Study results provide valuable information that could inform policies, programs and interventions designed to improve HRQOL in older adults and reduce potentially preventable health disparities

    A Neutron Interferometric Method to Provide Improved Constraints on Non-Newtonian Gravity at the Nanometer Scale

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    In recent years, an energetic experimental program has set quite stringent limits on a possible "non - 1/r^2" dependence on gravity at short length scales. This effort has been largely driven by the predictions of theories based on compactification of extra spatial dimensions. It is characteristic of many such theories that the strength and length scales of such anomalous gravity are not clearly determined from first principles. As a result, it is productive to extend the current limits the range and strength of such hypothetical interactions. As a heavy, neutral, and (almost) stable particle, the neutron provides an ideal probe for the study of such hypothetical interactions at very short range. In this work, we describe methods based on neutron interferometry which have the capability to provide improved sensitivity non-Newtonian forces down to length scales at and below an nanometer.Comment: PDF-fil

    The Impact of a Community-Based Childhood Obesity Prevention Program on Children’s Physical Activity and Fitness

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    The purpose of this study is to determine the effects of South County Food, Fitness and Fun (SCFFF), a 16-week community-based obesity prevention program, on children’s moderate to vigorous physical activity (MVPA), physical fitness, body mass index (BMI), and BMI z-score. A non-randomized pre-test and post-test study design was used to assess changes in MVPA, physical fitness, BMI and BMI z-score from baseline to program end. MVPA was measured by accelerometer, physical fitness measured by Fitnessgram, and height and weight were measured by stadiometer and scale and used to calculate BMI. The analytic sample for this study included 53 children from nine SCFFF programs conducted between 2011-2016. There was a significant increase in the percentage of time children spent participating in MVPA (1.12%; p=0.022), curl-ups (p\u3c0.001) and trunk lifts (p=0.004). BMI z-score decreased (p\u3c0.001). Results reinforce the importance of offering community-based interventions that include caregivers to prevent excess weight gain in children
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