Stages of the Demographic Transition from a Child's Perspective: Family Size,Cohort Size,and Children's Resources

This article provides a new characterization of stages of the demographic transition from the perspective of children competing for resources within families and cohorts. In Stage 1 falling mortality increases the size of both families and birth cohorts. In Stage 2 falling fertility overtakes falling mortality to reduce family size, but population momentum causes continued growth in cohort size. In Stage 3 falling fertility overtakes population momentum to produce declining cohort size. We apply our framework to census microdata for eight countries and to United Nations population projections for a larger set of countries. The results suggest that most countries spend two to three decades in Stage 2, with declining family size offset by increasing cohort size. From the perspective of children aged 9–11, many countries enter Stage 3 between 2000 and 2010. Other countries, especially in Africa, will continue to experience increasing cohort size for several more decades.     

Family Ties and Young Fathers' Engagement in Cape Town,South Africa

Young South African fathers are often engaged in their children's lives even if they do not live together. Using longitudinal data on children (n = 1,209) from the Cape Town area, the authors show that although only 26% of young fathers live with their children, 66% of nonresidential fathers maintain regular contact, and 61% provide financial support. The father–child relationship, however, is embedded in broader family ties. The type of father–mother relationship is strongly associated with whether fathers coreside with their children but not with fathers' contact with nonresidential children. Close mother and maternal grandmother bonds reduce the likelihood that fathers live with their children, whereas close ties between fathers and paternal grandmothers increase the chance that fathers visit nonresidential children. Family ties do not affect fathers' financial contributions, which are driven by men's current economic situation. These findings illustrate that father–child relationships are best understood in the context of interacting family systems.     

Physical and psychosocial indicators among office workers from public sector with and without musculoskeletal symptoms

Work-related musculoskeletal disorders (WRMD) are the result of the combination of different risk factors. They are very common among computer workers, mainly when neck and upper limbs are considered. Forty-two office workers from a public university participated in this study. They were divided into two groups: Symptomatic Subjects (SS, n=20) and Asymptomatic Subjects (AS, n=22), according to the Nordic Musculoskeletal Questionnaire (NMQ). Psychosocial indicators were assessed using the Job Content Questionnaire (JCQ) and Utrecht Work Engagement Scale (UWES). Workplaces were evaluated according to the Ergonomic Workplace Analysis (EWA), proposed by the Finnish Institute of Occupational Health. The NMQ showed higher weekly prevalence of complaints on neck, shoulders and wrist/hands (p=0.00) among SS. The annual prevalence of symptoms on wrist/hands was also higher among SS (p=0.02). The JCQ did not show any difference between groups (p>0.05). Higher proportion of servers with 'high level' of engagement, dedication and absorption, according to UWES, was identified among SS (p<0.01). EWA showed worse scores for 'Work Site', 'Job Content' and 'Repetitiveness of the Work' among SS (p<0.05). Servers are exposed to physical and psychosocial risk factors that can contribute to the development of WRMD. Work conditions need to be change in order to improve musculoskeletal health.     

Teaching ergonomics to undergraduate physical therapy students: new methodologies and impressions of a Brazilian experience

Being ergonomics a scientific discipline based on knowledge of several areas, it is important to use education methodologies that promote critical thinking and reflective during the educational process. The article discusses the importance of interdisciplinarity in undergraduate courses in health care in particular in disciplines that address the ergonomics issue. The aspects of the introduction of new education methodologies, as well as case studies in undergraduate courses in Brazil, are discussed in this study. Based on the literature review conducted, some proposals for action in the interdisciplinary teaching of ergonomics in Physiotherapy courses are presented.     

Step-Down diagnostic analysis for monitoring the covariance matrix of bivariate normal processes

ABSTRACT

A comparison among VMIX, VMAX and the adapted step-down Sullivan et al. (SE) tests for covariance matrix under bivariate normal assumption is presented. The type I error and power estimates were obtained by using Monte Carlo simulation under different scenarios with respect to covariance and correlation structures. In general, VMIX was more powerful than VMAX being SE more powerful than both, with few exceptions. SE test is more general since it can be used for normal and non-normal data, with no restriction with respect to the pattern of the covariance matrix shifts, and for larger dimension than the bivariate case.     

The Changing Impact of Family Size on Adolescents’ Schooling: Assessing the Exogenous Variation in Fertility Using Twins in Brazil

Researchers have long been interested in the influence of family size on children??s educational outcomes. Simply put, theories have suggested that resources are diluted within families that have more children. Although the empirical literature on developed countries has generally confirmed the theoretical prediction that family size is negatively related to children??s education, studies focusing on developing societies have reported heterogeneity in this association. Recent studies addressing the endogeneity between family size and children??s education have also cast doubt on the homogeneity of the negative role of family size on children??s education. The goal of this study is to examine the causal effect of family size on children??s education in Brazil over a 30-year period marked by important social and demographic change, and across extremely different regions within the country. We implement a twin birth instrumental variable approach to the nationally representative 1977?C2009 PNAD data. Our results suggest an effect of family size on education that is not uniform throughout a period of significant social, economic, and demographic change. Rather, the causal effect of family size on adolescents?? schooling resembles a gradient that ranges from positive to no effect, trending to negative.     

株洲市"一县一特"主导特色产业高质量发展对策

从2018年起,湖南省开始实施"一县一特"主导特色产业发展战略,作为实现农业产业兴旺、乡村振兴、农民增收的重要抓手.借助数据分析与同类对比方法,对株洲市"一县一特"主导特色产业发展的成效与不足作了分析;基于产业生命周期理论,对其所处发展阶段作了判断;并认为推进株洲市"一县一特"主导特色产业实现高质量发展,重点在于把握好"特"与"质"两方面:做到因业施策,找准着力点,坚决将"特"做到底;实现整体谋划,凝聚精气神,切实把"质"提上来.     

Educational Inequalities among Latin American Adolescents: Continuities and Changes over the 1980s, 1990s and 2000s

The goal of this paper is to examine recent trends in educational stratification for Latin American adolescents growing up in three distinct periods: the 1980s, during severe recession; the 1990s, a period of structural adjustments imposed by international organizations; and the late 2000s, when most countries in the region experienced positive and stable growth. In addition to school enrollment and educational transitions, we examine the quality of education through enrollment in private schools, an important aspect of inequality in education that most studies have neglected. We use nationally representative household survey data for the 1980s, 1990s and 2000s in Brazil, Chile, Mexico and Uruguay. Our overall findings confirm the importance of macroeconomic conditions for inequalities in educational opportunity, suggesting important benefits brought up by the favorable conditions of the 2000s. However, our findings also call attention to increasing disadvantages associated with the quality of the education adolescents receive, suggesting the significance of the EMI framework-Effectively Maintained Inequality-and highlighting the value of examining the quality in addition to the quantity of education in order to fully understand educational stratification in the Latin American context.     

Confidence intervals for the symmetry point: an optimal cutpoint in continuous diagnostic tests

Continuous diagnostic tests are often used for discriminating between healthy and diseased populations. For this reason, it is useful to select an appropriate discrimination threshold. There are several optimality criteria: the North‐West corner, the Youden index, the concordance probability and the symmetry point, among others. In this paper, we focus on the symmetry point that maximizes simultaneously the two types of correct classifications. We construct confidence intervals for this optimal cutpoint and its associated specificity and sensitivity indexes using two approaches: one based on the generalized pivotal quantity and the other on empirical likelihood. We perform a simulation study to check the practical behaviour of both methods and illustrate their use by means of three real biomedical datasets on melanoma, prostate cancer and coronary artery disease. Copyright © 2016 John Wiley & Sons, Ltd.