OBJECTIVE:To evaluate the 6-month impact of a physical activity (PA) multilevel intervention on activity patterns and psychological predictors of PA among adolescents. The intervention was directed at changing knowledge and attitudes and at providing social support and environmental conditions that encourage PA of adolescents inside and outside school. SUBJECTS AND DESIGN: Randomised, controlled ongoing field trial (ICAPS) in middle-school's first-level adolescents from eight schools selected in the department of the Bas-Rhin (Eastern France) with a cohort of 954 adolescents (92% of the eligible students) initially aged 11.770.6 y. The 6-month changes in participation in leisure organised PA (LOPA), high sedentary (SED) behaviour (43h/day), self-efficacy (SELF) and intention (INTENT) towards PA were analysed after controlling for baseline measures and different covariables (age, overweight, socioprofessional occupation), taking into account the cluster randomisation design. RESULTS: The proportion of intervention adolescents not engaged in organised PA was reduced by 50% whereas it was unchanged among control students. After adjustment for baseline covariables, LOPA participation significantly increased among the intervention adolescents (odds ratio (95% confidence interval) (OR) ¼ 3.38 (1.42-8.05) in girls; 1.73 (1.12-2.66) in boys), while high SED was reduced (OR ¼ 0.54 (0.38-0.77) in girls; 0.52 (0.35-0.76) in boys). The intervention improved SELF in girls, whatever their baseline LOPA (Po10 À4 ) and INTENT in girls with no baseline LOPA (P ¼ 0.04). SELF tended to improve in boys with no baseline LOPA, without reaching statistical significance. When included in the regression, follow-up LOPA was associated with improvement of SELF in girls (P ¼ 0.02) and of INTENT in girls with no baseline PA (Po0.02). The intervention effect was then attenuated. CONCLUSION: After 6 months of intervention, ICAPS was associated with a significant improvement of activity patterns and psychological predictors, indicating a promising approach for modifying the long-term PA level of adolescents.

Classically derived estimates of heritability from twin models have been plagued by the possibility of genetic-environmental covariance. Survey questions that attempt to measure directly the extent to which more genetically similar kin (such as monozygotic twins) also share more similar environmental conditions represent poor attempts to gauge a complex underlying phenomenon of GE-covariance. The present study exploits a natural experiment to address this issue: Self-misperception of twin zygosity in the National Longitudinal Survey of Adolescent Health (Add Health). Such twins were reared under one "environmental regime of similarity" while genetically belonging to another group, reversing the typical GE-covariance and allowing bounded estimates of heritability for a range of outcomes. In addition, we examine twins who were initially misclassified by survey assignment-a stricter standard-in three datasets: Add Health, the Minnesota Twin Family Study and the Child and Adolescent Twin Study in Sweden.Results are similar across approaches and datasets and largely support the validity of the equal environments assumption.

Existing evidence of educational effects on intergenerational mobility is associational. This study employs early compulsory schooling laws to approach a causal estimate of the relationship between education and mobility in the context of a large-scale policy change. Using IPUMS Linked Representative Samples ðlinked census dataÞ, regression discontinuity models exploit state differences in the timing of compulsory schooling laws to estimate an intent-to-treat effect on intergenerational occupational mobility among white males. Despite increasing equality of attendance, results reveal that compulsory laws initially reduced relative mobility for the first few cohorts affected by the laws. Among later cohorts, who were required to attend the maximum years of school, mobility was similar to prelaw levels. School funding and other data suggest that structural lag could explain this nonlinear relationship. It seems, therefore, that educational expansion inadvertently reduced mobility through institutional inertia rather than elite efforts to maintain advantage.

Much of the research on human trafficking focuses on the prosecution of traffickers and protection of survivors after the crime has occurred. Less is known about the social disparities that make someone vulnerable to trafficking. This project examines human trafficking from a preventive focus, using data from a case study of service providers working with at-risk populations in the Kansas City, MO-KS area. The research team conducted 42 in-depth interviews with service providers working in the medical, educational, legal, and social services sectors from 2013 to 2016. Participants identified risk factors that could make someone vulnerable to labor or sexual exploitation. These factors clustered into four key areas: economic insecurity, housing insecurity, education, and migration. The research findings also suggest that human trafficking may be driven by an accumulation of risk factors that move vulnerable persons closer to labor exploitation and sex trafficking, fitting with a chain-of-risk model. We propose a model that reconceives of trafficking as a continuum that includes a range of vulnerabilities, violence, and traumas. In order to address human trafficking, policy makers and advocates need to focus on upstream prevention factors to address vulnerabilities that can lead to sex and labor exploitation.