Modeling Longitudinal Obesity Data with Intermittent Missingness Using a New Latent Variable Model

We propose a latent variable model for informative missingness in longitudinal studies which is an extension of latent dropout class model. In our model, the value of the latent variable is affected by the missingness pattern and it is also used as a covariate in modeling the longitudinal response. So the latent variable links the longitudinal response and the missingness process. In our model, the latent variable is continuous instead of categorical and we assume that it is from a normal distribution. The EM algorithm is used to obtain the estimates of the parameter we are interested in and Gauss–Hermite quadrature is used to approximate the integration of the latent variable. The standard errors of the parameter estimates can be obtained from the bootstrap method or from the inverse of the Fisher information matrix of the final marginal likelihood. Comparisons are made to the mixed model and complete-case analysis in terms of a clinical trial dataset, which is Weight Gain Prevention among Women (WGPW) study. We use the generalized Pearson residuals to assess the fit of the proposed latent variable model.     

Consequences of Eye Color,Positioning, and Head Movement for Eye‐Tracking Data Quality in Infant Research

Eye tracking has become a valuable tool for investigating infant looking behavior over the last decades. However, where eye‐tracking methodology and achieving high data quality have received a much attention for adult participants, it is unclear how these results generalize to infant research. This is particularly important as infants behave different from adults in front of the eye tracker. In this study, we investigated whether eye physiology, positioning, and infant behavior affect measures of eye‐tracking data quality: accuracy, precision, and data loss. We report that accuracy and precision are lower, and more data loss occurs for infants with bluish eye color compared to infants with brownish eye color. Moreover, accuracy was lower for infants positioned in a high chair or in the parents' lap compared to infants positioned in a baby seat. Finally, precision decreased and data loss increased as a function of time. We highlight the importance of data quality when comparing multiple groups, as differences in data quality can affect eye‐tracking measures. In addition, we investigate how two different measures to quantify infant movement influence eye‐tracker data quality. These findings might help researchers with data collection and help manufacturers develop better eye‐tracking systems for infants.     

The Differential Earnings and Income Effects of Involuntary Job Loss on Workers with Disabilities — Evidence from Sweden

People with disabilities are consistently found to face considerable difficulties in the labour market. In this study we investigated whether their earnings and income trajectories are more adversely affected in case of involuntary job loss. Earnings of those with and without disabilities began to diverge already several years prior to job loss because of larger incidence of sickness. Following job loss much more job losers with disabilities became disability retirees resulting in a considerable and seemingly permanent earnings differential. However, larger uptake of public social insurances among job losers with disabilities resulted in a much smaller income differential.     

中国城乡迁移对代际经济支持的影响——基于社会性别视角的研究

中国城乡迁移带来的家庭结构的改变有可能影响中国农村传统的家庭观念和养老方式。文章利用深圳市外来农村流动人口调查数据,分析深圳市外来已婚农村打工者的性别因素对流动后其对仍生活在农村的父母及配偶父母的经济支持的影响。结果显示,男女打工者在流动后都增加了对父母的经济支持,但女性打工者在流动后更可能增加给配偶父母的经济支持。这一结果说明,依靠儿子养老的传统养老模式仍然占主导地位,但外出打工女性正在缩小这种社会性别差异。     

Ein Ansatz zur Verbesserung der Steuerung des Zahlungsausfallrisikos im E-Commerce (B-to-C)

In recent years, the situation of e-commerce in Germany especially in the retail sector has not only been characterized by a sustained growth in sales but also by an increase in deficits in payment. Companies considering a general exclusion of risky payment methods to be suboptimal are challenged by an adequate assessment of their prospective customers’ risk of payment default. Thereby, inability and unwillingness to pay has to be considered as possible reasons on a transactional basis and in real-time. This paper presents a new approach combining common methods for risk identification and assessment. Case studies show that a more sophisticated risk control can be achieved by applying the approach presented.     

A dynamic macro social indicator model of changes in marriage, family, and population in the United States: 1947–1974

This paper presents an integrated 21-equation model of how marriage, family, and population conditions, as indexed by macro social indicators, affect each other and are affected by other social, demographic, and economic forces. An opportunity structures theoretical paradigm is applied to the specification of dynamic structural equations for determining changes (both trends and cyclical fluctuations) in marriage formation and dissolution, family and household composition, fertility, mortality, population growth, and population distribution. The equations are estimated on annual national data for the United States during the post-World War II years 1947 to 1972, and then they are used to make conditional forecasts of the values of some of the endogenous variables for 1973 and 1974. It is found that the equations fit the observed data well, lack demonstrable autocorrelation of disturbances, and forecast the 1973 and 1974 values usually with less than 2% error. Strategies are sketched for further refining some of the equations, and it is suggested that this model should be integrated into a larger societal model in order to estimate some of the effects of changes in demographic phenomena on other social conditions.     

Manifestations of the therapeutic alliance in children and adolescents

Building the therapeutic alliance is a creative process and is a central issue for all age groups. In the absence of an alliance, there can be no therapy. The alliance contains many primitive sources for collaboration with the therapist. It is a combination of both rational and irrational elements. The therapist's awareness of developmental issues and defense mechanisms are utilized to guide one along the pathway of productive therapy. In addition, the unique psychodynamic factors are considered when working with children and adolescents. The clinical examples distinguish pitfalls which are destructive and could be avoided, in contrast with understanding and responding appropriately to the verbal and nonverbal communications of the young patient.This paper was presented to the International Conference for the Advancement of Private Practice of Clinical Social Work, Rio de Janeiro, Brazil, August 1987. Ms. Marcus is in private practice in New Orleans.     

追求卓越：一流大学的创新路径

结合斯坦福大学的实际和费尔德曼教授的研究经历和切身感受,介绍了一流大学的使命、创新路径,论述了一流的大学、一流的教授、一流的科研项目应具备的条件,以及研究生与博士后在科研中的角色和作用,同时介绍了斯坦福大学的一些新动向。     

Friends’ religiosity and first sex

Researchers have established that individual religiosity influences sexual behavior and that religious support can increase consistency between personal religiosity and behavior. Researchers are less certain, however, of the effect that religious friendship networks have on sexual behavior. In addition, the effects of network characteristics such as density and one’s position in a social network have not been established. This paper uses a network subsample of the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of friends’ religiosity on the probability of first sex. We find that friends’ religiosity has an independent influence on adolescent sexual behavior that is similar in magnitude to personal religiosity. We also find evidence that friends’ religiosity has the strongest influence on the sexual behavior of adolescents who are embedded in dense social networks, in which teens’ friends are also friends with one another. These results support the hypothesis that group influences depend on the degree of embeddedness within the network and highlight the importance of studying religion as a property of groups as well as individuals.