792 research outputs found

    Sports Participation and Physical Education in American Secondary Schools: Current Levels of Racial/Ethnic and Socioeconomic Disparities

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    Summarizes findings from a study of physical education requirements and school-based physical activity among American schoolchildren. Analyzes data by gender, grade, race/ethnicity and socioeconomic status

    The school food environment and student body mass index and food consumption: 2004 to 2007 national data

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    PURPOSE: This study identifies trends in the availability of various food choices in United States' middle and high schools from 2004 to 2007, and examines the potential associations between such food availability and students' self-reported eating habits and body mass index (BMI)-related outcomes. METHODS: Data are based on nationally representative samples of 78,442 students in 684 secondary schools surveyed from 2004 to 2007 as part of the Youth, Education, and Society (YES) study and the Monitoring the Future (MTF) study. In the YES study, school administrators and food service managers completed self-administered questionnaires on their school's food environment. In the MTF study, students in the same schools completed self-administered questionnaires, providing data used to construct BMI and food consumption measures. RESULTS: Overall, there was a decrease in the availability of regular-sugar/fat food items in both middle and high schools, and some indication of an increase in high school availability of reduced-fat food items through school lunch or a la carte. Some minimal evidence was found for relationships between the school food environment and student BMI-related outcomes and food consumption measures. CONCLUSIONS: United States secondary schools are making progress in the types of foods offered to students, with food items of lower nutritional value becoming less prevalent in recent years. Continued monitoring of food environment trends may help clarify whether and how such factors relate to youth health outcomes.The Youth, Education, and Society (YES) project (part of a larger research initiative, entitled Bridging the Gap: Research Informing Policy and Practice for Healthy Youth Behavior) is funded by the Robert Wood Johnson Foundation. The Monitoring the Future study is funded by the National Institute on Drug Abuse (DA01411). The views expressed in this article are those of the authors and do not necessarily reflect the views of the funders. (Robert Wood Johnson Foundation; DA01411 - National Institute on Drug Abuse

    The role of social relationships in the association between adolescents' depressive symptoms and academic achievement

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    While research has established that depression interferes with academic achievement, less is understood about the processes by which social relationships may buffer the relationship between depression and academic outcomes. In this study we examined the role of positive relationships in the school, family and peer contexts in the association between depressive symptoms and academic achievement among 894 adolescents aged 12-17 years living in Santiago, Chile. Depressive symptoms were associated with lower levels of academic achievement; parental monitoring, school belonging, positive mother relationships, and having academically inclined peers moderated this relationship, though some interactions differed by sex and age. Implications for promoting the academic success of adolescents experiencing depressive symptoms are discussedR01 DA021181 - NIDA NIH HHS; R01 HD033487 - NICHD NIH HH

    Predictors of discordance among Chilean families

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    Parent-youth agreement on parental behaviors can characterize effective parenting. Although discordance in families may be developmentally salient and harmful to youth outcomes, predictors of discordance have been understudied, and existing research in this field has been mostly limited to North American samples. This paper addressed this literature gap by using data from a community-based study of Chilean adolescents. Analysis was based on 1,068 adolescents in Santiago, Chile. The dependent variable was discordance which was measured by the difference between parent and youth’s assessment of parental monitoring. Major independent variables for this study were selected based on previous research findings that underscore youth’s developmental factors, positive parental and familial factors and demographic factors. Descriptive and multivariate analyses were conducted to examine the prevalence and associations between youth, parental and familial measures with parent-youth discordance. There was a sizable level of discordance between parent and youth’s report of parental monitoring. Youth’s gender and externalizing behavior were significant predictors of discordance. Warm parenting and family involvement were met with decreases in discordance. The negative interaction coefficients between parental warmth and youth’s gender indicated that positive parental and familial measures have a greater effect on reducing parent-youth discordance among male youths. Results support the significance of positive family interactions in healthy family dynamics. Findings from this study inform the importance of services and interventions for families that aim to reduce youth’s problem behavior and to create a warm and interactive family environment.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181713/Accepted manuscrip

    SimpactCyan 1.0 : an open-source simulator for individual-based models in HIV epidemiology with R and Python interfaces

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    SimpactCyan is an open-source simulator for individual-based models in HIV epidemiology. Its core algorithm is written in C++ for computational efficiency, while the R and Python interfaces aim to make the tool accessible to the fast-growing community of R and Python users. Transmission, treatment and prevention of HIV infections in dynamic sexual networks are simulated by discrete events. A generic “intervention” event allows model parameters to be changed over time, and can be used to model medical and behavioural HIV prevention programmes. First, we describe a more efficient variant of the modified Next Reaction Method that drives our continuous-time simulator. Next, we outline key built-in features and assumptions of individual-based models formulated in SimpactCyan, and provide code snippets for how to formulate, execute and analyse models in SimpactCyan through its R and Python interfaces. Lastly, we give two examples of applications in HIV epidemiology: the first demonstrates how the software can be used to estimate the impact of progressive changes to the eligibility criteria for HIV treatment on HIV incidence. The second example illustrates the use of SimpactCyan as a data-generating tool for assessing the performance of a phylodynamic inference framework

    Perception of neighborhood crime and drugs Increases cardiometabolic risk in Chilean adolescents

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    PURPOSE: Studies report an association between neighborhood risk and both obesity and cardiometabolic risk factors (CMR) among adolescents. Here we describe the effect of perceived neighborhood risk on adiposity and CMR among Chilean adolescents. METHODS: Participants were 523 low- to middle-income Chilean adolescents. We assessed neighborhood risk in early adolescence, adiposity in childhood and in early and later adolescence, and blood pressure and fasting glucose in later adolescence. Neighborhood risk profiles were estimated using latent profile analysis (LPA) and based on reported perceptions of crime and drug sales/use. Using linear and logistic regression, we examined the effect of neighborhood risk on adiposity and CMR. RESULTS: Mean age in early and later adolescence was 14 and 17 years, respectively. Participants were 52% male, with a mean BMI z-score of .67, and 8% met criteria for metabolic syndrome. LPA identified two neighborhood profiles: 61% low risk and 39% high risk. In later adolescence, being in the high risk profile predicted a higher BMI z-score, waist-to-height ratio, and fat mass index (p < .05). Adolescents in the high risk profile had three times greater odds of meeting criteria for metabolic syndrome (OR = 3.1, 95% CI: 1.5, 5.8) compared with those in the low risk profile. CONCLUSIONS: Our findings suggest that there are physiological responses to living in a neighborhood perceived as "risky," which may contribute to obesity and CMR even in adolescence. For Chilean neighborhoods with high crime and drugs, targeted public health interventions and policies for youth could be beneficial.This research was funded by R01HL088530 (NIH-NHLBI, PI: Gahagan); R01HD33487 (NIH-NICHD, PIs: Lozoff and Gahagan); R01DA021181 (NIH-NIDA, PI: Delva). The first author acknowledges D. Eastern Kang Sim for his support. All authors would like to thank the study participants for their on-going commitment to the project. (R01HL088530 - NIH-NHLBI; R01HD33487 - NIH-NICHD; R01DA021181 - NIH-NIDA

    A comparison between matter wave and light wave interferometers for the detection of gravitational waves

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    We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves

    The role of religiousness on substance-use disorder treatment outcomes: a comparison of black and white adolescents

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    This study compares 41 Black and 124 White adolescents at intake and discharge from a residential treatment program for substance-use disorders. Study data were obtained as part of a larger study (N = 195) that sought to assess the relationship of helping behavior and addiction recovery. This post-hoc analysis aims to identify cultural strengths that may be associated with recovery from substance-use disorders among Black adolescents. Using regression analyses and controlling for the severity of substance use and background variables that distinguish racial groups, religious practices and behaviors at intake were examined. Specifically, Black youth and White youth were compared on treatment outcomes, including alcohol or drug use during treatment, drug craving, 12-Step work, and 12-Step helping. The burden of health and socioeconomic disparities at intake did not disproportionately disfavor Black adolescents. Outcomes related to 12-Step measures were similar between Black and White youth. White adolescents reported higher craving scores at discharge, and Black adolescents were more likely to use drugs during treatment. High levels of religiousness at treatment intake were linked to greater 12-Step work and greater 12-Step helping at discharge. High levels of religiousness at intake were not related to drug use during treatment or to craving scores at discharge. The relationship between intake levels of religiousness and treatment-related outcomes did not differ by race.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437261/Accepted manuscrip

    Proton cyclotron wave generation mechanisms upstream of Venus

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    [1] Long-term observations of proton cyclotron waves in the upstream region of Venus raise the question of under which general solar wind conditions these waves are generated and maintained. The waves are characterized by their occurrence at the local proton cyclotron frequency and left-hand polarization, both in the spacecraft frame. Magnetometer data of the Venus Express spacecraft for two Venus years of observations are analyzed before, during, and after the occurrence of these waves. The configuration of the upstream magnetic field and the solar wind velocity is investigated, to study if the waves are generated from a ring distribution of pickup ions in velocity space or from a parallel pickup ion beam, i.e., for quasi-parallel conditions of solar wind velocity and magnetic field when the solar wind motional electric field is weak. It is found that stable and mainly quasi-parallel magnetic field conditions for up to ∼20 min prior to wave observation are present, enabling sufficient ion pickup and wave growth to obtain observable waves in the magnetometer data. Persistent waves occur mainly under quasi-parallel conditions. This is in agreement with linear theory, which predicts efficient wave growth for instabilities driven by field-aligned planetary ion beams, already for low pickup ion density. The occurrence of highly coherent waves at 4 RV upstream toward the Sun implies that planetary neutral hydrogen is initially picked up at least 5 RV toward the Sun from a sufficiently dense Venus hydrogen exosphere.Fil: Delva, M.. Austrian Academy of Sciences; AustriaFil: Mazelle, C.. Universitá Paul Sabatier; FranciaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Volwerk, M.. Austrian Academy of Sciences; AustriaFil: Vörös, Z.. University of Innsbruck; AustriaFil: Zhang, T. L.. Austrian Academy of Sciences; Austri
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