Suicide ideation among a stratified sample of rural and urban adolescents

This study examined factors associated with sucidal ideation among a stratified sample of rural and urban adolescents. Data was collected on 1,728 eighth and tenth grade southern Nevada students from 23 schools. No overall differences were found between rural and urban adolescents, although results did indicate that grade, gender, and school achievement variations exist between rural and urban student populations. Implications for social workers and other youth service providers are discussed.     

Suicide ideation,attempts and abuse among incarcerated gang and nongang delinquents

The present study examines suicide ideation and attempts as well as reported levels of physical and sexual abuse among gang and nongang-involved incarcerated youth. The self-report survey data were collected from 334 males and 61 females who were incarcerated in Nevada youth correctional facilities in the summer of 1994. Over half (58.3 percent) of the males and nearly half (45.2 percent) of the females reported being gang members. Surprisingly high rates of abuse (more than 70 percent for both physical and sexual abuse) were found among the incarcerated females of this study. Females reported significantly more suicide attempts and were more likely to have been physically and sexually abused than males. Nongang males reported significantly more suicide attempts and were more likely to report sexual abuse than gang-involved males. Among the gang-involved delinquents, females reported significantly more suicide attempts than males. In addition, gang members who reported sexual abuse were more likely to have higher levels of suicide ideationand to have attempted suicide. Implications for youth correction specialists and social workers are discussed.The data for this study were collected under Grant #000616 from the Nevada Agricultural Experiment Station.     

Forecasting Multivariate Road Traffic Flows Using Bayesian Dynamic Graphical Models,Splines and Other Traffic Variables

Traffic flow data are routinely collected for many networks worldwide. These invariably large data sets can be used as part of a traffic management system, for which good traffic flow forecasting models are crucial. The linear multiregression dynamic model (LMDM) has been shown to be promising for forecasting flows, accommodating multivariate flow time series, while being a computationally simple model to use. While statistical flow forecasting models usually base their forecasts on flow data alone, data for other traffic variables are also routinely collected. This paper shows how cubic splines can be used to incorporate extra variables into the LMDM in order to enhance flow forecasts. Cubic splines are also introduced into the LMDM to parsimoniously accommodate the daily cycle exhibited by traffic flows. The proposed methodology allows the LMDM to provide more accurate forecasts when forecasting flows in a real high‐dimensional traffic data set. The resulting extended LMDM can deal with some important traffic modelling issues not usually considered in flow forecasting models. Additionally, the model can be implemented in a real‐time environment, a crucial requirement for traffic management systems designed to support decisions and actions to alleviate congestion and keep traffic flowing.     

Exceedance probabilities for parametric control charts

Common control charts assume normality and known parameters. Quite often, these assumptions are not valid and large relative errors result in the usual performance characteristics such as the false alarm rate or the average run length. A fully nonparametric approach can form an attractive alternative but requires more Phase I observations than usually available. Sufficiently general parametric families then provide realistic intermediate models. In this article, the performance of charts based on such families is considered. Exceedance probabilities of the resulting stochastic performance characteristics during in-control are studied. Corrections are derived to ensure that such probabilities stay within prescribed bounds. Attention is also devoted to the impact of the corrections for an out-of-control process. Simulations are presented both to illustrate and to demonstrate that the approximations obtained are sufficiently accurate for practical usage.     

Planning reform beyond planning: the debate on an integrated Environment and Planning Act in the Netherlands

Land-use plans serve a dual function. On the one hand, they are programmes for future development, plans for action. On the other hand, they have a regulative function in relation to construction and land use. This paper investigates how the interplay between these functions is playing a role in the current debate about the new integrated Environment and Planning Act (Omgevingswet) in the Netherlands. Initially, the government proposed abolishing local land-use plans and replacing them with a system of by-laws. However, this proposal did not survive the debate on this bill. This paper will shed light on the relationships between planning and regulation by analysing that debate.     

Contesting Community Online: Virtual Imagery among Dutch Orthodox Protestant Homosexuals

Whereas substantial scholarly attention has been paid to the online presentation of self, symbolic interactionist approaches are largely absent in the literature on virtual communities. Instead, recurrent questions are whether communities can exist online and whether specific online venues qualify as communities. This article aims to move beyond these dichotomous questions by studying how different meanings attached to an online venue can be understood from offline experiences. In a case study of a Dutch forum for orthodox Protestant homosexuals, two types of understanding of online community emerged from an analysis of fifteen in‐depth interviews. Users struggling with stigmatization in offline life seek empathic support and have an encompassing sense of online community—the forum as “refuge.” For users dealing with practical everyday questions, online contacts are part of so‐called personal communities and help ameliorate offline life—the forum as “springboard.” Apart from demonstrating that online forums can serve as Goffmanian backstages in two distinct ways, these results indicate it is fruitful to take a symbolic interactionist approach to uncover relationships between offline and online social life.     

Empirical nonparametric control charts for high-quality processes

For attribute data with (very) small failure rates often control charts are used which decide whether to stop or to continue each time r failures have occurred, for some r?1. Because of the small probabilities involved, such charts are very sensitive to estimation effects. This is true in particular if the underlying failure rate varies and hence the distributions involved are not geometric. Such a situation calls for a nonparametric approach, but this may require far more Phase I observations than are typically available in practice. In the present paper it is shown how this obstacle can be effectively overcome by looking not at the sum but rather at the maximum of each group of size r.