Testosterone and men's depression: the role of social behavior.

Medical research suggests that testosterone has positive effects on mood (thereby reducing the chances of depression), and social science research finds testosterone to be related to antisocial behavior, risk behavior, unemployment and low paying jobs, and being unmarried--factors known to be positively related to depression. Analysis of a sample of 4,393 men finds a parabolic model best fits the data. The relationship between testosterone and depression is inverse for men with below average testosterone and direct for those with above average testosterone. The relationship disappears for those with above average testosterone when controls for antisocial and risk behaviors and the absence of protective factors such as marriage and steady employment are in the equation. The relationship is unchanged for those with below average testosterone. The results help explain the difference between medical and social research findings. Mechanisms accounting for the findings are explored.     

Structured measurement error in nutritional epidemiology: applications in the Pregnancy, Infection, and Nutrition (PIN) Study

Preterm birth, defined as delivery before 37 completed weeks' gestation, is a leading cause of infant morbidity and mortality. Identifying factors related to preterm delivery is an important goal of public health professionals who wish to identify etiologic pathways to target for prevention. Validation studies are often conducted in nutritional epidemiology in order to study measurement error in instruments that are generally less invasive or less expensive than "gold standard" instruments. Data from such studies are then used in adjusting estimates based on the full study sample. However, measurement error in nutritional epidemiology has recently been shown to be complicated by correlated error structures in the study-wide and validation instruments. Investigators of a study of preterm birth and dietary intake designed a validation study to assess measurement error in a food frequency questionnaire (FFQ) administered during pregnancy and with the secondary goal of assessing whether a single administration of the FFQ could be used to describe intake over the relatively short pregnancy period, in which energy intake typically increases. Here, we describe a likelihood-based method via Markov Chain Monte Carlo to estimate the regression coefficients in a generalized linear model relating preterm birth to covariates, where one of the covariates is measured with error and the multivariate measurement error model has correlated errors among contemporaneous instruments (i.e. FFQs, 24-hour recalls, and/or biomarkers). Because of constraints on the covariance parameters in our likelihood, identifiability for all the variance and covariance parameters is not guaranteed and, therefore, we derive the necessary and suficient conditions to identify the variance and covariance parameters under our measurement error model and assumptions. We investigate the sensitivity of our likelihood-based model to distributional assumptions placed on the true folate intake by employing semi-parametric Bayesian methods through the mixture of Dirichlet process priors framework. We exemplify our methods in a recent prospective cohort study of risk factors for preterm birth. We use long-term folate as our error-prone predictor of interest, the food-frequency questionnaire (FFQ) and 24-hour recall as two biased instruments, and serum folate biomarker as the unbiased instrument. We found that folate intake, as measured by the FFQ, led to a conservative estimate of the estimated odds ratio of preterm birth (0.76) when compared to the odds ratio estimate from our likelihood-based approach, which adjusts for the measurement error (0.63). We found that our parametric model led to similar conclusions to the semi-parametric Bayesian model.     

Sample size calculation for the Power Model for dose proportionality studies

There are several approaches to assess or demonstrate pharmacokinetic dose proportionality. One statistical method is the traditional ANOVA model, where dose proportionality is evaluated using the bioequivalence limits. A more informative method is the mixed effects Power Model, where dose proportionality is assessed using a decision rule for the estimated slope. Here we propose analytical derivations of sample sizes for various designs (including crossover, incomplete block and parallel group designs) to be analysed according to the Power Model.     

Statewide Implementation of “Reducing Disability in Alzheimer’s Disease”: Impact on Family Caregiver Outcomes

There have been few replications of efficacious evidence-based programs for dementia caregivers offered in community settings. This study highlights the replication of the evidence-based Reducing Disability in Alzheimer’s Disease program and explores the changes in outcomes for participating caregivers and whether those changes are related to level of program utilization. With data from 219 caregivers, regression results indicate that more exercise sessions are associated with a decrease in caregiver strain and more behavior management sessions are associated with a decrease in unmet needs after 3 months. Findings demonstrate how a multicomponent program can have positive benefits for family caregivers.     

The Timing of Cohabitation and Engagement: Impact on First and Second Marriages

Using a multistate sample of marriages that took place in the 1990s, this study examined associations between premarital cohabitation history and marital quality in first (N = 437) and second marriages (N = 200) and marital instability in first marriages (intact N = 521, divorced N = 124). For first marriages, cohabiting with the spouse without first being engaged or married was associated with more negative interaction, higher self‐reported divorce proneness, and a greater probability of divorce compared to cohabiting after engagement or marriage (with patterns in the same direction for marital positivity). In contrast, there was a general risk associated with premarital cohabitation for second marriages on self‐reported indices of marital quality, with or without engagement when cohabitation began.     

The Virtuality of Virtual Worlds,or What We Can Learn from Playacting Horse Girls and Marginalized Developers

This article discusses the emergence of Habbo Hotel as a large‐scale virtual world and its changing versions through time. We consider how social events taking place within the hotel are conditioned by designed‐in symbolic resources and how, in turn, with creative processes of symbolization, novel social objects emerge out of particular interactions. We then discuss how the membership trajectories of hotel members are essential in understanding how these interactions are shaped and evolve. We also look at how the digital infrastructure and its evolution lends itself to being material for actualizing particular social worlds within the hotel and how the trajectory of the infrastructure reflects the relationship between the user and the developer communities of Habbo. Finally, we discuss why, to understand more fully what virtual worlds consist of at large, analysts should look into the mutually constitutive interactions among users, developers, and surrounding business models over longer periods of time in the constantly varying actualization of any given virtual world.     

Reproductive health and domestic violence: Are the poorest women uniquely disadvantaged?

We use Demographic and Health Survey data from Cambodia, the Dominican Republic, and Haiti to compare women in different poverty and violence categories in terms of their experience of selected reproductive health outcomes. "Poor" women are those who belong to the bottom quintile of households arrayed according to a widely accepted asset-based wealth index. The results suggest that women who are both poor and have experienced violence are not unique in their reproductive health disadvantage. In particular, for all three reproductive health outcomes we consider the negative association with having experienced violence cuts across all women, poor and wealthy.     

Newborn Infants' Preference for Attractive Faces: The Role of Internal and External Facial Features

Several previous experiments have found that newborn and young infants will spend more time looking at attractive faces when these are shown paired with faces judged by adults to be unattractive. Two experimental conditions are described with the aim of finding whether the “attractiveness effect” results from attention to internal or external facial features, or both. Pairs of attractive and less attractive faces (as judged by adults) were shown to newborn infants (mean age 2 days, 9 hours), where each pair had either identical internal features (and different external features) or identical external features (and different internal features). In the latter, but not the former, condition the infants looked longer at the attractive faces. These findings are clear evidence that newborn infants use information about internal facial features in making preferences based on attractiveness. It is suggested that when newborn (and older) infants are presented with facial stimuli, whether dynamic or static, they are able to attend both to internal and external facial features.     

Perspectives on American Kinship in the Later 1990s

This paper reviews the current status of kinship research in the United States and identifies factors that might account for the declining interest in the subject among family researchers. The analysis uses both structural and cultural factors to illustrate how they can determine the diversity in kinship functioning that ranges from those family systems where kinship relationships flourish and those where they play a small part in family life. The structural and demographic variables determine the numbers and availability of kin, whereas the cultural variables determine the norms that establish the motivation to sustain kinship bonds. To illustrate how these factors operate among subgroups in the United States, I analyze three types of kinship systems: the lineal emphasis in White families of the very old; the collateral emphasis in the families of their Black counterparts; and the egocentric emphasis of White suburban families that are undergoing marital change.     

Maternal Interactive Style Across Contexts: Relations to Emotional, Behavioral and Physiological Regulation During Toddlerhood

Sixty-five mothers and their 24-month-old toddlers were observed in a series of laboratory procedures designed to assess relations between maternal interactive style and emotional, behavioral and physiological regulation. Emotional regulation was assessed by examining the child's behaviors (aggression, distraction, object focus) when confronted by three emotion-eliciting tasks. Behavioral regulation was measured by examining children's ability to comply to maternal requests and to inhibit behavior during a delay task. Physiological regulation was derived from children's cardiac vagal tone responses to emotionally-arousing situations. Maternal interactive style was assessed by examining mothers' strategies for child behavior management (negative controlling, positive guidance) during three mother-child tasks. Maternal behavior was related to regulation in each of the three domains. Negative maternal behavior was related to poor physiological regulation, less adaptive emotion regulation, and noncompliant behavior. Positive maternal behavior was correlated with compliance, but not with any of the physiological or emotional measures. These findings are discussed in terms of the adaptive value of self-regulation in early development, and the importance of identifying the causal relations between maternal behavior and child regulation.