Visualization of multidimensional data using modifications of the Grand Tour

Current implementations of Asimov's Grand Tour (for example in XLISP-STAT by Tierney, 1990, or in XGobi by Buja et al., 1996) do not remember the path of projections and show only the current state during the touring process. We propose a modification of the Grand Tour, named Tracking Grand Tour (TGT), that shows the trace of the touring process as small 'comet trails' of the projected points. The usefulness of the TGT is demonstrated with a simulated and a real data set.     

Nonstationary panel data analysis: an overview of some recent developments

This paper overviews some recent developments in panel data asymptotics, concentrating on the nonstationary panel case and gives a new result for models with individual effects. Underlying recent theory are asymptotics for multi-indexed processes in which both indexes may pass to infinity. We review some of the new limit theory that has been developed, show how it can be applied and give a new interpretation of individual effects in nonstationary panel data. Fundamental to the interpretation of much of the asymptotics is the concept of a panel regression coefficient which measures the long run average relation across a section of the panel. This concept is analogous to the statistical interpretation of the coefficient in a classical regression relation. A variety of nonstationary panel data models are discussed and the paper reviews the asymptotic properties of estimators in these various models. Some recent developments in panel unit root tests and stationary dynamic panel regression models are also reviewed.     

Adolescent Depression and Future Smoking Behavior: A Prospective Study

The aim of the study was to examine the associations between depressive symptoms and smoking, concurrently and prospectively, in adolescents in America, the evaluation of depressive symptoms according to different group’s smoking status, and the assessed associations between concurrent depressive level and success in smoking cessation. The participants were 2,735 boys and 2,890 girls from the Add Health data set. The prospective analysis indicated that participants with higher depressive symptoms in Wave I were more likely to start smoking and become regular smokers in Wave II. Moreover, regression analysis found that depressive symptoms in both Waves I and II predicted current smoking status. Findings are discussed within the context of the empirical and theoretical review and implications for social work practice are considered.     

Equicentrality and network centralization: A micro–macro linkage

This paper investigates a linkage between micro- and macrostructures as an intrinsic property of social networks. In particular, it examines the linkage between equicentrality [Kang, S.M., 2007. A note on measures of similarity based on centrality. Social Networks 29, 137–142] as a conceptualization of a microstructural process (i.e., the likelihood of social actors to be connected with similarly central others) and network centralization as a macrostructural construct, and shows that they have a negative linear association. In other words, when actors are connected with similarly central alters (i.e., high equicentrality), the overall network centralization is low. Conversely, when highly central actors are connected with low-centrality actors (i.e., low equicentrality), the overall network centralization is high. The relationship between degree equicentrality and degree centralization is more significant in observed networks, especially those evolving over time, as compared to random networks. An application of this property is given by venture capital co-investment networks.     

An Evaluation of the Effectiveness of an Automated Observation and Feedback System on Safe Sitting Postures

This study evaluated the effectiveness of an automated observation and feedback system in improving safe sitting postures. Participants were four office workers. The dependent variables were the percentages of time participants spent in five safe body positions during experimental sessions. We used a multiple-baseline design counterbalanced across participants to test the system's effectiveness in delivering two types of feedback. For two participants, delayed/low-density feedback was introduced after baseline and immediate/high-density feedback was added in the next phase. For the other two participants, the sequence of implementing the feedback types was reversed. Results indicated that both delayed/low-density feedback and immediate/high-density feedback consistently improved participant postures and that immediate/high-density feedback was more effective than delayed/low-density feedback. The benefits of the automated system of postural data collection are discussed.     

Score Tests for Testing Independence in the Zero-Truncated Bivariate Poisson Models

In this study, score test statistics for testing independence in the zero-truncated bivariate Poisson distributions are proposed. The Monte Carlo study shows that the score tests proposed in this article keep the significance level close to the nominal one, but the LR and Wald tests over-reject the null hypothesis when it is true. The score tests for testing independence in the zero-truncated bivariate Poisson regression models are also derived in this study.     

Ecological Influences on School Achievement in a Diverse Youth Sample: The Mediating Role of Substance Use

This study's purpose was to examine the extent to which closeness to family, peers, and school was associated with substance use and school achievement, based on the integrative model of ecological theory, social attachment theory, and social learning theory. A secondary data analysis was conducted on the first wave of the National Longitudinal Study of Adolescent Health (Add Health). The final sample yielded 3,147 boys and 3,356 girls.

A structural equation model was employed to test a hypothesized model. School closeness was found to be a primary ecological factor that significantly influenced school achievement while substance use emerged as a critical mediator of this relationship. Family closeness was negatively associated with school achievement. Also, substance use did not have a mediating function in the relationship between peer closeness and school achievement. No gender difference was found, except the relationship between family closeness and school achievement, in that family closeness had a significant, direct effect on school achievement among only boys but not girls.

The findings suggest that schools should strengthen adolescents' tie to school to promote their better academic success and to prevent them from substance use.     

An Ecological Approach to Understanding Youth Violence: The Mediating Role of Substance Use

The authors tested an ecological model that posits mediating variables (substance use and mental health) in the association between ecological factors (family closeness, school closeness, and peer closeness) and youth violence in a sample of 4,783 adolescents. Models including substance use present significantly less total effect between ecological factors and youth violence than do models without substance use. Additional probing of significant mediation effect using the Sobel test was performed and suggested that substance use did function as a mediator in the hypothesized path. Considerations of adolescent violence should recognize the possible role of ecological factors and how their influence may vary by substance use.     

A Different Sort of Doctor: The Police Surgeon in England and Wales

Police surgeons occupy a neglected and potentially influential role in the criminal justice system, falling between medical and legal functions. This article considers the implications of this role which operates at the interface of two major areas of social policy concern. Drawing evidence from a unique survey of police surgeons in England and Wales, it considers specifically, the professional background of police surgeons, the administration and management of the police surgeon service, surgeons' attitudes to aspects of their professional practice and the impact of this role on civil liberties. The paper concludes with a brief discussion of the possibilities for the reform of the police surgeon service.     

FAMILY THERAPY WITH INTELLECTUALLY AND CREATIVELY GIFTED CHILDREN

Few family therapists have expertise in the psychology of giftedness, and little research has been conducted to determine the effectiveness of family therapy with talented children and their families. The purposes of this paper are: (1) to provide family therapists with information on the unique psychosocial stressors associated with giftedness and (2) to stimulate further research and development on the efficacy of family therapy in alleviating distress and actualizing potential in gifted and talented children and their families. The paper provides a critical overview of the existing research literature on gifted children and their families. First, current conceptualizations of giftedness are described. Then the research literature on the characteristics of intellectually and creatively gifted children and their families is reviewed with an emphasis on the endogenous (individual) and exogenous (systemic) factors that can create or exacerbate psychosocial problems. Finally, we suggest an eclectic, eco-systemic approach to three common concerns that bring gifted children and their families to therapy.