A Convolution Estimator for the Density of Nonlinear Regression Observations

Abstract. The problem of estimating an unknown density function has been widely studied. In this article, we present a convolution estimator for the density of the responses in a nonlinear heterogenous regression model. The rate of convergence for the mean square error of the convolution estimator is of order n ^?1 under certain regularity conditions. This is faster than the rate for the kernel density method. We derive explicit expressions for the asymptotic variance and the bias of the new estimator, and further a data‐driven bandwidth selector is proposed. We conduct simulation experiments to check the finite sample properties, and the convolution estimator performs substantially better than the kernel density estimator for well‐behaved noise densities.     

“I Want to Feel Like a Full Man”: Conceptualizing Gay,Bisexual, and Heterosexual Men’s Sexual Difficulties

Current understandings of sexual difficulties originate from a model that is based on the study of heterosexual men and women. Most research has focused on sexual difficulties experienced by heterosexual men incapable of engaging in vaginal penetration. To better understand men’s perceptions and experiences of sexual difficulties, seven focus groups and 29 individual interviews were conducted with gay (n = 22), bisexual (n = 5), and heterosexual (n = 25) men. In addition, the extent to which difficulties reported by gay and bisexual men differ from heterosexual men was explored. Data were analyzed using thematic analysis applying an inductive approach. Two intercorrelated conceptualizations were identified: penis function (themes: medicalization, masculine identity, psychological consequences, coping mechanisms) and pain (themes: penile pain, pain during receptive anal sex). For the most part, gay, bisexual, and heterosexual men reported similar sexual difficulties; differences were evident regarding alternative masculinity, penis size competition, and pain during receptive anal sex. The results of this study demonstrate the complexity of men’s sexual difficulties and the important role of sociocultural, interpersonal, and psychological factors. Limitations and suggested directions for future research are outlined.     

The MySocialworker app system – a pilot interview study

An app system was developed in Denmark by caseworkers and clients from three municipalities, a software company, and a University College. The app system enabled young clients to track their wellbeing, positive behaviours, disturbances in their lives, and their experiences of interventions on smartphones. Statutory caseworkers could follow the change in their client’s situation and have an overview of all their clients on a web interface. This article describes the system and the results of a pilot qualitative interview study with six young clients. Clients used the app to reflect on their lives, to set specific personal goals and to remember their goals. The young clients also used the app to monitor changes in how they had been doing overall and as a reminder to keep up specific behaviours that were counterintuitive. The app became an integral part of the young clients’ relationship with their caseworker. The app was a lens that the client and the caseworker used to explore specific aspects of the client’s life. The app itself also became a joint venture, a shared point of interest. The app strengthened the young persons’ relationship with their caseworker, but there was also concern about whether they might become too close.     

Detection of a changepoint,a mean-shift accompanied with a trend change,in short time-series with autocorrelation

In this study, a changepoint model, which can detect either a mean shift or a trend change when accounting for autocorrelation in short time-series, was investigated with simulations and a new method is proposed. The changepoint hypotheses were tested using a likelihood ratio test. The test statistic does not follow a known distribution and depends on the length of the time-series and the autocorrelation. The results imply that it is not possible to detect autocorrelation and that the estimate of the autocorrelation parameter is biased. It is therefore recommended to use critical values from the empirical distribution for a fixed autocorrelation.     

The Danish psychosocial work environment and symptoms of stress: The main,mediating and moderating role of sense of coherence

The aim of this cross-sectional study was to explore the main, mediating and moderating role of sense of coherence (SOC) on stress symptoms and on the association between perceived psychosocial work environment and stress symptoms. The sample includes 2053 Danish employees from 52 workplaces. Hierarchical regression models were applied for each measure of stress. The results strongly supported the presence of a main effect for SOC. People with high levels of SOC experienced fewer stress symptoms. A mediating effect of SOC was also supported. Thus, SOC in part explained the association between work environment and stress symptoms. In addition, some support for a moderating effect of SOC was found, suggesting that people with higher SOC coped more efficiently with work environmental strain that people with lower SOC. Taken together the regression models explained 11–32% of the variance in stress symptoms. The results suggest that measures of individual factors such as SOC should be included in analyses of the effects of work environmental factors on stress and well-being.