The relationship between lifetime health trajectories and socioeconomic attainment in middle age

A large literature demonstrates the direct and indirect influence of health on socioeconomic attainment, and reveals the ways in which health and socioeconomic background simultaneously and dynamically affect opportunities for attainment and mobility. Despite an increasing understanding of the effects of health on social processes, research to date remains limited in its conceptualization and measurement of the temporal dimensions of health, especially in the presence of socioeconomic circumstances that covary with health over time. Guided by life course theory, we use data from the British National Child Development Study, an ongoing panel study of a cohort born in 1958, to examine the association between lifetime health trajectories and socioeconomic attainment in middle age. We apply finite mixture modeling to identify distinct trajectories of health that simultaneously account for timing, duration and stability. Moreover, we employ propensity score weighting models to account for the presence of time-varying socioeconomic factors in estimating the impact of health trajectories. We find that, when poor health is limited to the childhood years, the disadvantage in socioeconomic attainment relative to being continuously healthy is either insignificant or largely explained by time-varying socioeconomic confounders. The socioeconomic impact of continuously deteriorating health over the life course is more persistent, however. Our results suggest that accounting for the timing, duration and stability of poor health throughout both childhood and adulthood is important for understanding how health works to produce social stratification. In addition, the findings highlight the importance of distinguishing between confounding and mediating effects of time-varying socioeconomic circumstances.     

Random effects regression mixtures for analyzing infant habituation

Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.     

Fuzzy K-means clustering models for triangular fuzzy time trajectories

We focus our attention on the classification of fuzzy time trajectories with triangular membership function, described by a given set of individuals. To this purpose, we adopt a fullyinformational approach, explicitly recognizing the informational nature shared by the ingredients of the classification procedure: the observed data (Empirical Information) and the classification model (Theoretical Information). In particular, by supposing that the informational paradigm has a fuzzy nature, we suggest three fuzzy clustering models allowing the classification of the triangular fuzzy time trajectories, based on the analysis of the cross sectional and/or longitudinal characteristics of their components (centers and spreads). Two applicative examples are illustrated.     

Navigating the migration industry: migrants moving through an African-European web of facilitation/control

ABSTRACT

This paper approaches the African-European migration industry as a complex web of relations in which different actors liaise, objectives oppose each other, and roles overlap. Starting from this notion, the question emerges: How do migrants navigate this fuzzy web of migration facilitation/control? To answer this question, this paper uses a ‘trajectory ethnography’ that follows the im/mobility processes of migrants from West – and Central Africa to, and inside, Europe. In so doing, it particularly focuses on two practices that are related to the concept of social navigation. First, it concerns débrouillardise, a term that points to the power of improvisation, creativity and hustling. Second, it regards social negotiation, a term referring to the process of how migrants ‘massage’ their relations with important actors in the field. The findings stress the relational dimension of the migration industry in the sense that the functioning of one actor depends so much on the intentions and efforts of others. I conclude that we could enhance our knowledge on migration industries with studies that constantly shift between the perspective of the migrant, the social network, the facilitator and controller. Such a dynamic approach unpacks further the multiple efforts that produce migrant im/mobility.     

新型职业农民:成长轨迹、影响因素及培育策略——基于19个省市39位新型职业农民生命历程的分析

通过对全国19个省市39位优秀新型职业农民的生命历程进行分析,发现其成长轨迹呈现出折勾型、倒梯型、V字型、阶梯型以及N字型五种类型,并且不同来源、不同世代的新型职业农民成长轨迹具有一定的差异性。究其原因,新型职业农民终身发展的动力支撑显得不足;新型职业农民的个体主观能动性得到了充分的发挥;政府扶持与引领作用有待继续加强;新型职业农民培育时机并未得到恰当的把握;影响新型职业农民成长的相关利益主体分布比较广泛。针对以上情况,提出新型职业农民的培育策略:强化政府主导力量,增强新型职业农民职业吸引力;吸收年轻优秀群体,壮大新型职业农民的新生力量;重视人地实际需求,把握新型职业农民培育的时机。     

城市规划专业人才培养方案探讨

根据我校建筑工程管理系及国内城市规划专业教育的现状,对城市规划专业课程体系进行了适当调整,提出应确立具有自己特色的、服务地方的应用型人才的培养模式。     

制定管理信息系统(MIS)总体规划的方法

本文论述了制定管理信息系统总体规划的方法。自顶向下逐层分解与自底向上逐层综合是制定总体规划的有效方法。文章详细讨论了使用这一方法的过程和有关的辅助方法,包括确定規划范围的总体法(Portfolio),定义职能领域、职能、管理活动和有关实体的自顶向下分析,确定系统结构的实体分析与组合、实体活动分析和U-C数据库计划。     

关于中国人口控制问题的商榷

中国人口占世界人口1/5,是世界人口最多的发展中国家。中国政府把计划生育政策定为基本国策,并取得了举世瞩目的成就。中国人口基数过大,人均耕地远小于国土面积与中国相当的美国,加上其他不利因素,经有关专家组研究,中国最大环境人口容量为16亿。又经预测,按现行中国人口政策,到2030年前后中国人口将达到16亿。中国人口控制喜忧参半,仍十分严峻,且任重而道远。因此,讨论了中国人口控制的成就和问题,并提出了若干建议供参考。     

Trajectory of problem behaviours of Korean adopted children: using piecewise hierarchical linear growth modelling

This study examined the trajectory of problem behaviours in domestically adopted children in South Korea as they aged. This study used the Panel Study on Korean Adopted Children's longitudinal, three‐wave data (2006, 2008 and 2010). Although data were collected at three time points, our data consisted of six time points, which covered the 5–10 years age range of the adopted children at the time of survey. One hundred sixty‐four children were included in the analysis, 75 of whom contributed to one time point, 74 to two time points and 15 to three time points. The trajectory of the problem behaviours of adopted children was examined using a piecewise hierarchical linear growth model. Because the initial exploration of the data suggested non‐linear changes in behaviour problems over time, we split the growth trajectory into two time periods: Time 1 (5–7 years) and Time 2 (7–10 years). A two‐rate model was used to estimate separate slopes for the two time periods. Results showed that the externalizing and internalizing problems of adopted children have different trajectories. Internalizing problems did not show significant changes after 5 years of age, while externalizing problems increased until 7 years of age and decreased significantly thereafter.     

The reproductive health indices and sex hormone levels in middle-aged and elderly Chinese men

Objective: The aim of this study was to analyze the age-related recession trajectory of reproductive health indices in middle-aged and elderly Chinese men.

Methods: A population-based cross-sectional study was conducted in Jiashan County, Zhejiang in 2012. Healthy men between 40 and 80 years of age were considered eligible for the study. Physical examination and the sex hormones were measured. The subjects were assessed based on the 5-item version of the International Index of Erectile Function (IIEF-5) for Erectile Dysfunction (ED), and Aging Males’ Symptoms (AMS) scale for Symptomatic Late-Onset Hypogonadism (SLOH).

Results: TG showed a decrease at age 60 years. Testis volume and TT did not show significant difference among the four age groups; cFT began to decrease at age 50 years and Bio-T decreased faster at age 50 years. SHBG and LH increased faster at age 50 and 70 years, respectively. IIEF5 score decrease faster at age 60 years. AMS scores increased faster at age 70 years. With the increase in age, the symptoms of ED and SLOH became severer.

Conclusion: Different indices on reproductive health of men showed turning points at different ages. At first, androgenic sex hormones decreased faster, and then erectile dysfunction got severer, and the last overall male syndromes declined.