Tobacco,Marijuana, and Alcohol Use in University Students: A Cluster Analysis

Abstract

Objective: Segmentation of populations may facilitate development of targeted substance abuse prevention programs. The authors aimed to partition a national sample of university students according to profiles based on substance use. Participants: The authors used 2008–2009 data from the National College Health Assessment from the American College Health Association. The sample consisted of 111,245 individuals from 158 institutions. Methods: The sample was partitioned using cluster analysis according to current substance use behaviors. The association of cluster membership with individual and institutional characteristics was examined. Results: Cluster analysis yielded 6 distinct clusters. Three individual factors—gender, year in school, and fraternity/sorority membership—were the most strongly associated with cluster membership. Conclusions: In a large sample of university students, the authors were able to identify 6 distinct patterns of substance abuse. It may be valuable to target specific populations of college-aged substance users based on individual factors. However, comprehensive intervention will require a multifaceted approach.     

On the Skew-Normal-Cauchy Distribution

A fixed effects one-way layout model of analysis of variance is considered where the variances are taken to be possibly unequal. Conservative single-stage procedures based on Banerjee’s method for the solution of the Behrens-Fisher problem are proposed for the following multiple comparisons problems: 1) all pairwise comparisons with a control population mean, and 2) all pairwise comparisons and all linear contrasts among the means. Since these procedures are likely to be very conservative in practice, approximate procedures based on Welch’s method for the solution of the Behrens-Fisher problem are suggested as alternatives. Monte Carlo studies indicate that the latter are much less conservative and hence may be better in practice. Both these sets of procedures need only the tables of the Student’s t-distribution for their application and are very simple to use. Exact two-stage procedures are proposed for the following multiple comparisons problems: 1) all pairwise comparisons and all linear contrasts among the means, and 2) all linear combinations of the means.     

The Link Between Voter Choice and Religious Identity in Contemporary Society: Bringing Classical Theory Back In*

Objectives. In this article, we analyze voter choice data from six U.S. presidential elections for evidence of religious identity and sociodemographic effects on voter choice. Methods. Voter choice is analyzed over the period 1980 to 2000 with multivariate statistical models. Results. A link is found between voter choice and religious identity, where the effect of religious identity on voter choice is contingent on location within the stratification order defined by race, class, and gender. The article proposes a theory to explain the contingent link between voter choice and religious identity; the theory is derived from classical sociology. Conclusion. In the United States, political behavior related to religious identity is contingent on the individual's location within the stratification order.     

Multimarket pioneers: Does multimarket contact improve their performance?

First-mover advantages (FMA) and multimarket contact (MMC) have evolved independently in the strategic management literature. This is surprising because FMA erode as a result of competition which, in turn, is affected by MMC. This paper links these literatures through the concept of spheres of influence and analyses the effect of MMC on pioneers' profitability. We use the order of market entry to identify spheres of influence and to determine their distribution among multimarket firms. The distribution of spheres of influence allows us to distinguish between reciprocal MMC and non-reciprocal MMC and to study how each of them determines pioneers' profitability. We test our hypotheses in the mobile telecommunications industry. Our findings show that reciprocal MMC has a positive effect on pioneers’ results, but non-reciprocal MMC negatively affects them.     

Statistical quality control at statistics canada

Over the past several years statistical quality control methodologies at Statistics Canada have evolved frotn forrnal Product Control (k Acceptance Sampling By Attributes) to a more complete use of all quality control information obtained to achieve what is now called Acceptance Control. The use of this additional information allows us to continually adapt our quality control methods to the existing conditions of survey operations. In this context this paper reviews the general approach to statistical quality control and its relation to survey processing operations in Statistics Canada.     

Recycling the idea of race: socio-political agenda,transnational business culture,and diversity management in Brazil

ABSTRACT

This article intends to contribute to the line of studies that critically addresses diversity management, bringing the Brazilian experience into the discussion. It aims to demonstrate how large Brazilian companies and transnational corporations operating in the country have been recycling the idea of race in order to cope with the greatest politicisation of debates on the racial issue within the Brazilian public sphere since the late twentieth century. This phenomenon is related to changes in the political actions of the black movement in Brazil, which since the same period has been absorbing the new socio-political agenda existing within the global network of anti-racism advocacy. This is an agenda in which two purposes have a central importance: the battle against racial inequality and the demand for affirmative action policies. The data presented in this paper are part of broader research in which, by means of the biographical method and the ethnographic fieldwork, the social trajectories and career paths of two generations of Brazilian black executives were analysed.     

Bayesian methods for the cross-design synthesis of epidemiological and toxicological evidence

Summary.  Systematic review and synthesis (meta-analysis) methods are now increasingly used in many areas of health care research. We investigate the potential usefulness of these methods for combining human and animal data in human health risk assessment of exposure to environmental chemicals. Currently, risk assessments are often based on narrative review and expert judgment, but systematic review and formal synthesis methods offer a more transparent and rigorous approach. The method is illustrated by using the example of trihalomethane exposure and its possible association with low birth weight. A systematic literature review identified 13 relevant studies (five epidemiological and eight toxicological). Study-specific dose–response slope estimates were obtained for each of the studies and synthesized by using Bayesian meta-analysis models. Sensitivity analyses of the results obtained to the assumptions made suggest that some assumptions are critical. It is concluded that systematic review methods should be used in the synthesis of evidence for environmental standard setting, that meta-analysis will often be a valuable approach in these contexts and that sensitivity analyses are an important component of the approach whether or not formal synthesis methods (such as systematic review and meta-analysis) are used.