Predictors and outcomes of social network compositions: A compositional structural equation modeling approach

Proportions of a total, including social network compositions (proportions of partner, family, friends, etc.) lie in a restricted space, which challenges statistical analysis. Network compositions can be both dependent and explanatory variables and are usually measured with error by survey instruments. Structural equation models make it possible to correct measurement error bias. Coenders et al. (2011) fitted a factor analysis model to transformed network compositions. In this article, we use another transformation called an isometric log-ratio and we extend the model to include predictors and outcomes. The findings and hypotheses in the literature can be reformulated with isometric log-ratios in a more interpretable manner. For instance, we find relationships of gender with partner support, of education and extraversion with friend support, and of family support with tie multiplexity and closeness.     

Estimation of Risk Assessment of Some Heavy Metals Intake Through Black Scabbardfish (Aphanopus carbo) Consumption in Portugal

The intake of Cd, methyl‐Hg, and Pb through consumption of black scabbardfish (BSF) (Aphanopus carbo) in Portugal as well as the associated probability of exceeding the respective provisional tolerable weekly intakes (PTWIs) was estimated. For this purpose, the contamination levels of heavy metals in this fish species were combined with constructed consumption scenarios or with a hypothesized consumption distribution. Whereas Cd and Pb posed no serious risk, the consumption of at least one portion of BSF per month as well as the hypothetical study in the Portuguese population produced nonnegligible probabilities of surpassing the PTWI for Me‐Hg. Risk assessment for Portuguese consumers revealed a higher risk regarding Me‐Hg, 1.19% and 1.81% with the plug‐in (PI) and the tail estimation (TE) estimators, respectively. On the other hand, the risk for Cd and Pb was less than 1 in 100,000. TE was more realistic and accurate for Cd and Pb. Concerning Me‐Hg, TE and PI estimators produced similar results. Furthermore, the limitations of a deterministic approach were shown.     

The impact of an integrated family planning program in Russia

In 1995, the U.S. Agency for International Development implemented an integrated program of family planning education and services in six Russian cities to increase physicians' and women's contraceptive knowledge and change current contraceptive use. Large population-based surveys of women ages 15-44 were carried out at the beginning of project implementation (in 1996) and 3 years later in two project sites and a comparison site. Results from these surveys indicate that project activities affected women's knowledge of family planning methods, and caused women to have more favorable attitudes toward modern contraception. In addition, abortion rates decreased in project sites while remaining virtually unchanged in the comparison site. Because of uneven implementation of project interventions in the demonstration sites, however, the intervention's actual impact on abortion rates remains unclear.     

Overcoming interruptions in educational trajectories: Youth in Ghana with international migrant parents

Literature on the effects of parental migration on the education of children who stay at origin, what we call ‘stayer’ youth, mainly focuses on educational outcomes without looking at the process leading to such outcomes. This article addresses this gap by showing how the educational trajectories of stayer youth unfold. Stayer youth may encounter a range of obstacles and interruptions to their education when their parents move overseas, and we explore the agency these youth exert and the support networks they activate to try to overcome them. We employ a youth-centric methodology, based on 15 months of ethnographic fieldwork in three cities in Ghana, with young people whose parents migrated internationally. We find that frequent changes in residence, limited financial means, and lack of academic support cause interruptions in educational trajectories. In response, the young people mobilize support from local social networks to compensate for what they lack from their transnational connections.