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Jeremy Vanhelst Laurent Béghin Julia Salleron Jonathan R. Ruiz Francesco B Ortega Charlene Ottevaere 《Journal of sports sciences》2013,31(2):110-115
AbstractThe aim of this study was to assess the impact of the choice of threshold on physical activity patterns measured in adolescents under free living conditions (FLC) using a uniaxial accelerometer. The study comprised 2043 adolescents (12.5–17.5 years) participating in the HELENA Study. Participants wore a uniaxial accelerometer for 7 days. The PA patterns were assessed using thresholds determined from six different studies. For each of the thresholds used, the number of adolescents fulfilling the recommendation of 60 min of moderate to vigorous PA (MVPA) per day was also calculated. A significant difference was found between thresholds regardless of the activity level: differences of 38%, 207%, 136%, and 2780% for sedentary, light, moderate, and vigorous intensity PA, respectively (P < 0.001). Time of MVPA varied between methods from 25.3 to 55.2 min · day–1. The number of adolescents fulfilling the recommendation varied from 5.9% to 37% according to the thresholds used. The kappa coefficient for concordance in the assessment of the number of adolescents achieving the PA recommendations was generally low. The definition of the threshold for PA intensity may considerably affect the PA patterns in FLC when assessed using a uniaxial accelerometer and the number of participants fulfilling the recommendations. 相似文献
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David C. Wiley Marina Plesons Venkataram Chandra-Mouli Margarita Ortega 《American journal of sexuality education》2020,15(1):53-81
AbstractComprehensive sexuality education (CSE), one of the key evidence-based strategies in our programmatic toolbox to address adolescent pregnancy and birth rates, remains a politically-charged issue countrywide. Though there is some funding available at the federal level, there are no national policies mandating the provision of sex education; as such, most decision-making occurs at the state or even the local level. Consequently, the provision of sex education and the quality and comprehensiveness of curricula used to do so are highly variable across the country, and are heavily influenced by the level of support or resistance in communities. This paper analyzes the experience of institutionalizing an evidence-based sex education in a large suburban school district in San Antonio, Texas, a socially conservative context. Understanding the politics of sex education is key to developing effective policies and strategies to ensure quality sex education programs are provided in public schools. However, there are no published papers documenting specific experiences with resistance to sex education in local communities in the USA. Given this, the strategies employed by opponents and the response by district officials can be informative for other school settings in the USA and around the world. Abbreviations: AFLA: Adolescent Family Life Act; CHAMPSS: Choosing And Maintaining effective Programs for Sex education in Schools Model; CSE: Comprehensive sexuality education; DTL/RTL: Draw the Line/Respect the Line; HSAE: Human Sexuality and Abstinence Education, the middle school sex education curriculum in NEISD prior to 2008; NEISD: North East Independent School District; SAFA: San Antonio Family Association; SHAC: School health advisory council; STI: Sexually transmitted infection; TEC: Texas Education Code; TPIA: Texas Public Information Act; USA: United States of America; UTHSC: University of Texas Health Science Center 相似文献
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Lorena Ortega Lars-Erik Malmberg Pam Sammons 《School Effectiveness & School Improvement》2018,29(2):308-337
This study investigates school effects on primary school students’ language and mathematics achievement trajectories in Chile, a context of particular interest given its large between-school variability in educational outcomes. The sample features an accelerated longitudinal design (3 time points, 4 cohorts) together spanning Grades 3 to 8 (n = 19,704 students in 156 schools). The magnitudes of school effects on students’ growth trajectories were found to be sizeable (generally larger than school effects in Western industrialised countries) and moderately consistent across school subjects. School composition effects on student achievement status were found for both school subjects. However, there was no evidence of composition effects on student achievement growth. The study provides new evidence on the size and nature of school effects in a developing country context based on state-of-the-art methods (i.e., accelerated longitudinal and growth curve models). 相似文献