Univariate and multivariate models of positive and negative networks: Liking,disliking, and bully–victim relationships

Three relations between elementary school children were investigated: networks of general dislike and bullying were related to networks of general like. These were modeled using multivariate cross-sectional (statistical) network models. Exponential random graph models for a sample of 18 classrooms, numbering 393 students, were summarized using meta-analyses. Results showed (balanced) network structures with positive ties between those who were structurally equivalent in the negative network. Moreover, essential structural parameters for the univariate network structure of positive (general like) and negative (general dislike and bullying) tie networks were identified. Different structures emerged in positive and negative networks. The results provide a starting point for further theoretical and (multiplex) empirical research about negative ties and their interplay with positive ties.     

Pension policy in China, Singapore, and South Korea: An assessment of the potential value of the notional defined contribution model

The rate of population aging is increasing in the developing world and the trend is particularly dramatic in East Asia. One consequence is sharp increases in old-age dependency ratios which have major implications for the sustainability of current public pension schemes. These trends are pushing pension policy experts in many of these countries to search for new pension models that are more suited to the increased demographic pressures they will be facing in the decades ahead. In this article we discuss five alternative public pension models with a focus on the newest of these models, the notional defined contribution (NDC) approach. We consider three countries with very different pension systems in place, two from East Asia (China and South Korea) and one from South East Asia (Singapore). The central question we address is which (if any) of the limitations in these existing models might more adequately be addressed using a variant of the NDC model. We conclude that the NDC model has the most to offer China and the least to offer Singapore.     

Mistreatment and self-reported emotional symptoms: results from the National Elder Mistreatment Study

Many community-residing older adults in the United States report past year mistreatment; however, little is known about mental health correlates of abuse. This study investigated whether a recent history of emotional, physical, or sexual abuse is associated with self-reported emotional symptoms (e.g., anxiety, depression) among a representative sample of older adults. Results demonstrated that each abuse type increased likelihood of reporting emotional symptoms; when other known correlates were controlled, only emotional abuse remained a significant predictor. Additional study of mistreatment-related correlates of depression and anxiety is needed, with a focus on the often overlooked category of emotional mistreatment.     

Work and breastfeeding decisions are jointly determined for higher socioeconomic status US mothers

We study postpartum decisions about paid work and breastfeeding using a simultaneous equations model. For our sample of higher socioeconomic status mothers, we find a joint decision process for three sets of decisions modeled: work leave duration and duration of any, as well as of exclusive, breastfeeding, and daily work hours and daily breastfeedings at infant age 3 months. We find that returning to paid work 1 week earlier reduces any breastfeeding duration by about two-thirds of a week while extending breastfeeding by a week delays work participation by about one-third of a week. We find larger elasticities for decisions involving daily work hours and number of breastfeedings at 3 months than for work leave duration and any breastfeeding duration and the smallest elasticities for duration of exclusive breastfeeding and work leave. This marks the first study to find a joint decision-making process for postpartum work and breastfeeding decisions and suggests that, in addition to increased leave impacting breastfeeding behaviors, successful breastfeeding promotion policies can have nontrivial impacts on the US labor market.     

Does generosity beget generosity? The relationships between transfer receipt and formal and informal volunteering

This paper examines whether receipt of public or private assistance is associated with recipients’ own generosity in the form of formal and informal volunteering. Using matched data from the 2007–2011 American Time Use Survey and the Annual Social and Economic Supplement to the Current Population Survey, this paper finds that receipt of private assistance from friends and relatives is negatively associated with the time women spend caring for non-household adults and the time men spend caring for non-household children. Receipt of public assistance is found to be negatively associated with men’s care of non-household adults. No associations are found between either type of assistance and time spent volunteering for a formal organization.     

Body postures versus production requirements - the case of a fiberglass parts factory

This study aimed to perform an ergonomic analysis in a fiberglass parts factory. For this purpose, was used the methodology of Ergonomic Work Analysis (EWA). At the end of the study it was possible to identify some ways to the development of improvements in order to contribute to the transformation of working conditions in the sector analyzed.     

The effect of visualization method on the performance of simulated microsurgery tasks

The operating microscopes may be a significant cause of fatigue and discomfort in surgeons. The need for the microscope to be placed over the operating field forces surgeons to remain at the microscope's eyepieces at an uncomfortable posture for the entirety of the surgery. This study compared the effects on microsurgical task performance for four visualization methods: a monocular microscope, a binocular microscope, a three-dimensional (3D) flat-panel television display and a two-dimensional (2D) flat-panel television display. Eleven subjects each performed two microsurgical tasks and their performance was documented by video camera. The statistical analysis performed indicated utilization of the microscope as a visualization method increased subject performance. No significant difference in performance between the 2D and stereoscopic visualization methods.     

The profile of cyclists in the city of Juiz de Fora

The problems related to the means of transport in urban Brazilians have been getting worse over the years. The increase of the fleet, to the detriment of the adequacy and extent of the road network of cities contributes to this fact. This paper presents a profile of users of cycling in the city of Juiz de Fora, and thus contributes to the study of sustainable urban mobility, providing researchers with information that can guide the search for the encouragement of the use of means of transport to meet environmental needs urban centers that contributes to social equity.