A general class of test statistics for Van Valen's Red Queen hypothesis

Van Valen's Red Queen hypothesis states that within a homogeneous taxonomic group the age is statistically independent of the rate of extinction. The case of the Red Queen hypothesis being addressed here is when the homogeneous taxonomic group is a group of similar species. Since Van Valen's work, various statistical approaches have been used to address the relationship between taxon age and the rate of extinction. We propose a general class of test statistics that can be used to test for the effect of age on the rate of extinction. These test statistics allow for a varying background rate of extinction and attempt to remove the effects of other covariates when assessing the effect of age on extinction. No model is assumed for the covariate effects. Instead we control for covariate effects by pairing or grouping together similar species. Simulations are used to compare the power of the statistics. We apply the test statistics to data on Foram extinctions and find that age has a positive effect on the rate of extinction. A derivation of the null distribution of one of the test statistics is provided in the supplementary material.     

Adaptive confidence bands in the nonparametric fixed design regression model

In this note, we consider the problem of the existence of adaptive confidence bands in the fixed design regression model, adapting ideas in Hoffmann and Nickl [(2011), ‘On Adaptive Inference and Confidence Bands’, Annals of Statistics, 39, 2383–2409] to the present case. In the course of the proof, we show that sup-norm adaptive estimators exist as well in the regression setting.     

Social Contagion and General Diffusion Models of Adolescent Religious Transitions: A Tutorial,and EMOSA Applications

Epidemic Models of the Onset of Social Activities (EMOSA) describe behaviors that spread through social networks. Two social influence methods are represented, social contagion (one-to-one spread) and general diffusion (spread through cultural channels). Past models explain problem behaviors—smoking, drinking, sexuality, and delinquency. We provide review, and a tutorial (including examples). Following, we present new EMOSA models explaining changes in adolescent and young adult religious participation. We fit the model to 10 years of data from the 1997 U.S. National Longitudinal Survey of Youth. Innovations include a three-stage bi-directional model, Bayesian Markov Chain Monte Carlo (MCMC) estimation, graphical innovations, and empirical validation. General diffusion dominated rapid reduction in church attendance during adolescence; both diffusion and social contagion explained church attendance stability in early adulthood.     

Left truncation in linked data: A practical guide to understanding left truncation and applying it using SAS and R

Time-to-event data such as time to death are broadly used in medical research and drug development to understand the efficacy of a therapeutic. For time-to-event data, right censoring (data only observed up to a certain point of time) is common and easy to recognize. Methods that use right censored data, such as the Kaplan–Meier estimator and the Cox proportional hazard model, are well established. Time-to-event data can also be left truncated, which arises when patients are excluded from the sample because their events occur before a specific milestone, potentially resulting in an immortal time bias. For example, in a study evaluating the association between biomarker status and overall survival, patients who did not live long enough to receive a genomic test were not observed in the study. Left truncation causes selection bias and often leads to an overestimate of survival time. In this tutorial, we used a nationwide electronic health record-derived de-identified database to demonstrate how to analyze left truncated and right censored data without bias using example code from SAS and R.     

“He invited me and didn't ask anything in return” Migration and Mobility as Vulnerabilities for Sexual Exploitation among Female Adolescents in Mexico

Although human trafficking is recognized as a major human rights violation, there is limited evidence regarding the vulnerabilities that contribute to female adolescents’ risk of being forced or coerced into the sex trade. Vulnerabilities such as gender‐based violence, economic and social inequalities have been shown to shape the risk of sexual exploitation among adolescents. In‐depth interviews (n=18) with current sex workers who reported being deceived or forced into the sex trade as adolescents (<17 years old) were analysed to explore their experiences of migration and mobility in Mexico. Driven by socio‐economic and vulnerabilities in home communities, adolescents often engaged in internal migration and mobility to other Mexican communities and states. Migration and mobility further predisposed them to social isolation, economic hardship and abuse, which were used as tools to trick them into the sex trade. Policies that support safer migration for adolescents in origin, transit, and destination communities are needed.     

Trauma and the effects of violence exposure and abuse on children: A review of the literature

A number of studies examining violence exposure in the passeveral years have been successful in linking physical abuse, sexual abuse, domestic violence, and community violence exposure to a wide variety of physiological, emotional, and behavioral problems manifested in short‐term, mid‐term, and long‐term effects. The literature on the effects of physical and sexual abuse is older than the research on children's exposure to domestic violence, which is a decade older than the research on the effects of community violence exposure on children. Despite the differences between the types of violence to which children are exposed, there are significantly similar findings, which point to a link between violence exposure and traumatization.     

A Social Psychology of National and International Group Relations

This concluding article provides a framework for a social psychological analysis of intergroup conflict and conflict resolution. The framework highlights the individual and intergroup factors that shape the nature of perceptions of intergroup relations and group representations, and describes how these perceptions lead to cognitive, affective, and behavioral responses toward groups. Included in the framework are the metatheoretical, theoretical, and practical contributions of the articles in this issue toward understanding intergroup relations. The potential and responsibility of social psychologists to move beyond the laboratory to applied national and international issues is also discussed.     

Accepting and Negotiating Service Users' Choices in Mental Health Transition Meetings

Across Western welfare regimes, policies emphasize that service users should have more choices regarding their services. This article examines how service choices are presented, responded to and decided in interactions between service users and professionals in mental health transition meetings. Choice is often associated with consumerist user involvement ideas, but in mental health choice also relates to the democratic user involvement approach and to shared decision making between professionals and service users. The results of the study show that professionals construct service users as consumers by offering service options in choice making sequences, expecting users to make appropriate choices. Service users mostly act like consumers by responding to these choice options. However, the study also demonstrates that the professionals do not always accept the user's first choice but respond to them as non‐preferred. Sometimes, they also suggest choices on behalf of the users. In these ‘non‐accepting’ sequences, choices are negotiated in interaction between the parties, rather than users acting as autonomous choice makers. The sequences are based on two kinds of professional reasoning: first, the professional‐led needs assessment and, second, the structure of the service package that the user is being offered. This negotiation has elements of shared decision making and the ‘logic of care’. But it also has elements of paternalist control which challenge both consumerist and democratic service user involvement and suggests consideration of more collectively oriented service user actions.