Racial differences in urban neighboring

Despite mixed expectations generated by existing theories and evidence, this analysis documents clear racial differences in urban neighboring behavior. Using data from a survey of Nashville, Tennessee, residents, we show that blacks interact with their neighbors more often than whites do, and in a greater variety of ways. The only noteworthy similarity between the two groups is the positive impact of neighboring on feelings of community affect. Overall, our results support the view that neighbor relations — like other kinds of informal participation — have helped blacks cope with constrained social opportunities and provided them with access to resources unavailable through formal institutional channels.Revised version of a paper presented at the annual meeting of the American Sociological Association, San Francisco, August 1989.     

La médiane simpliciale d'Oja: Existence,unicité et stabilité

Oja (1983) examined various ways of measuring location, scatter, skewness, and kurtosis for multivariate distributions. Among other measures of location, he introduced a generalised median known in this paper under the name of the Oja median. In our study of the existence of that median, we show that Oja's definition can only be applied to distributions having a mean. In dimension d θ 2, we establish that the usual method of extension breaks down, which raises the question of the validity of the concept as a notion of median. Two fundamental theoretical properties of that median are also considered: uniqueness and consistency.     

Measuring credibility of compensatory preference statements when trade-offs are interval determined

This paper studies how an overall fuzzy preference relation can be constructed in the compensatory context of the simple additive difference model, when imprecision on the trade-offs has to be taken into account. Three credibility indices of preferences are analysed and illustrated by a numerical example. Arguments are presented supporting the use of the third index, for which an interesting transitivity property (which was an open problem) is proved.     

Households,Families and Prospective Economic Mobility in Mexico

The study analyzed poverty as a function of households’ demographic composition using a longitudinal random sample of 4268 urban and rural households that were followed-up from 2005/6 to 2009/12 in Mexico to estimate short-term changes in living conditions. Well-being was measured as the dwelling unit’s number of rooms, water source, sanitary services, garbage disposal, and fuel. Mobility paths included not poor–not poor, poor–poor, not poor–poor, and poor–not poor. Independent variables included household composition, family characteristics, residential changes, schooling, and occupation. Female headship and older adults negatively impacted poverty, whereas economic dependents may be negatively or positively associated. Fertility incentives for low-income populations are not advisable. Working-age adults contribute only if income-generating opportunities exist locally.     

Job quality,industrial relations and the crisis in Europe

This paper reports results from recent Eurofound research on the impact of the crisis on industrial relations and working conditions in Europe, based on the output of Eurofound's European Working Conditions Observatory and European Industrial Relations Observatory and data from the European Working Conditions Survey. Overall, the crisis – even if it is sometimes difficult to separate the effect of the crisis from megatrends in working conditions and industrial relations – seems to have had an impact on both domains. With reference to industrial relations, the impact of the crisis has influenced actors, processes, and outcomes. Regarding working conditions, the results appear to be in line with the literature on the topic, which relates the crisis to an increase in job insecurity, a decrease in work intensity, in working hours, and in anti-social working time arrangements, and a general improvement in terms of health risks and related outcomes.     

Assessing Participation and Effectiveness of the Peer-Led Approach in Youth Sexual Health Education: Systematic Review and Meta-Analysis in More Developed Countries

Sexual health education for young people is crucial not only for development of norms but also for protection against vulnerabilities during this stage in life. Although several systematic reviews have examined the effectiveness of peer-led sex education, none have focused on the extent of peer participation. The purpose of this review was to evaluate peer-led sexual health education interventions in more developed countries (MDCs). Electronic and manual searches across five social science, education, and medical databases were conducted. Fifteen articles were selected in total. Most (10 of 15) studies gave low or no responsibility to peers. The majority of articles found improvements in sexual health knowledge (13 of 14) and attitudes (11 of 15) at postintervention stages. Two studies showed improved self-efficacy, and three showed behavioral changes. A preliminary synthesis of effectiveness and level of participation was done. Meta-analysis revealed a large effect on knowledge change (Hedges’ g = 0.84, 95% confidence interval [CI]: 0.43 to 1.25) and a medium effect on attitude change (Hedges’ g = 0.49, 95% CI: 0.19 to 0.80). Peer-led interventions could be a powerful tool. This review shows that this approach is effective in changing knowledge and attitudes but not behaviors. Further research and action are needed to understand optimal implementation.     

Intergenerational cooperation within the household: a Public Good game with three generations

We analyze cooperation of individuals in a family context, using a Public Good game. In a lab experiment, 165 individuals from 55 three-generation families (youth, parent, and grandparent) play a repeated Public Good game in three different treatments: one in which three members of the same family play each other (family), a second with the youth and two non-family members, while preserving the previous generational structure (inter-generational), and a third in which three randomly-selected players play each other (random). We find that all the age groups cooperate more when playing with relatives, indicating that family ties may have a positive relationship to contributions to the Public Good. We also find that this trend is more evident for the youths and the parents than for the grandparents. Furthermore, young individuals tend to cooperate less than older generations, especially in non-family treatments. Our results serve as evidence of the relationship between family ties and inter-generational cooperative behaviors.

     

Emerging Genetic and Epigenetic Mechanisms Underlying Pubertal Maturation in Adolescence

The adolescent transition begins with the onset of puberty which, upstream in the brain, is initiated by the gonadotropin‐releasing hormone (GnRH) pulse generator that activates the release of peripheral sex hormones. Substantial research in human and animal models has revealed a myriad of cellular networks and heritable genes that control the GnRH pulse generator allowing the individual to begin the process of reproductive competence and sexual maturation. Here, we review the latest knowledge in neuroendocrine pubertal research with emphasis on genetic and epigenetic mechanisms underlying the pubertal transition.     

Sexual Practices Among a Sample of Young Lesbian and Bisexual Women from Mexico: An Exploratory Study

Objective: To describe sexual practices in Mexican lesbian and bisexual women. Materials and method: An online survey was conducted with a nonprobabilistic sample of self-identified lesbian (n?=?768) and bisexual (n?=?371) women from the 32 states of Mexico. Results: Lesbians less frequently reported having had sex with a man than bisexual women. Preferred sexual practices with other women were external genital stimulation with fingers, internal genital stimulation with fingers, and oral genital stimulation. Most (～80%) participants did not use protection to prevent sexually transmitted infections. Conclusions: Our results can inform the design of promotion and prevention programs in sexual health aimed at sexual minority women.     

Accurate computation of single and product moments of order statistics under progressive censoring

An accurate procedure is proposed to calculate approximate moments of progressive order statistics in the context of statistical inference for lifetime models. The study analyses the performance of power series expansion to approximate the moments for location and scale distributions with high precision and smaller deviations with respect to the exact values. A comparative analysis between exact and approximate methods is shown using some tables and figures. The different approximations are applied in two situations. First, we consider the problem of computing the large sample variance–covariance matrix of maximum likelihood estimators. We also use the approximations to obtain progressively censored sampling plans for log-normal distributed data. These problems illustrate that the presented procedure is highly useful to compute the moments with precision for numerous censoring patterns and, in many cases, is the only valid method because the exact calculation may not be applicable.