Discerning the epidemiology of drug use among a sample of college students

Although estimates concerning the prevalence of various forms of substance abuse vary considerably, it is critical to note that even the more conservative estimates indicate a major public health problem. Furthermore, increased drug experimentation has been frequently associated with the college experience. Utilizing a slightly modified version of the National Institute on Drug Abuse (NIDA) Monitoring the Future Survey, the present study examined the epidemiology of self-reported drug taking behaviors (e.g., alcohol, marijuana, tranquilizers, stimulants, psychedelics, etc.) among a sample (n = 683) of students attending a major public university. Data analyses focused on the specific settings and social groupings in which drug use occurred as well as on the frequency and type(s) of drug taking behaviors. Based on the results yielded from a disjoint cluster analysis, four distinct groups of drug users were identified. These four groups then served as categories of the dependent variable in a discriminant function analysis. A general linear models procedure was employed to identify the more efficacious discriminating (i.e., independent) variables.     

Clinical observations on interferences of early father absence in the achievement of femininity

In clinical work, we have observed that the loss of the father through divorce has a significant effect on the young girl's developing sense of feminity. This paper briefly reviews the research findings from sex-role development theory and psychoanalytic theory, and presents clinical discussions of latency aged girls whose parents divorced during their daughter's early and oedipal years. The most common defensive or coping patterns seen in these child patients during latency are identified, with clinical material presented to illustrate both the existence of these patterns and implications for treatment.     

Arrow's theorem for economic environments and effective social preferences

Arrow's impossibility theorem has been proved for the realm of private goods and economic preferences by Border and by Bordes and Le Breton. However, their proofs require the exclusion of the zero vector from the commodity space. This paper proves the impossibility theorem for the entire allocation space and the classical domain of economic preferences by adding effectiveness to Arrow's hypothesis. Social preference is effective if every nonempty compact set contains at least one socially optimal allocation.Financial support from the Social Sciences and Humanities Research Council (Canada) is gratefully acknowledged. The comments of an anonymous referee were much appreciated. The author assumes responsibility for any errors.     

Nonverbal expectancy violations and conversational involvement

A central feature of nonverbal expectancy violations theory is that unexpected behaviors trigger a cognitive-affective appraisal of such behavior, leading to a valencing of the behavior(s) as positive or negative. It has been proposed that communicator reward mediates the interpretation and evaluation of such violations but may be more important when the violative act is ambiguous in meaning than when it is not. Unclear is whether nonverbal behavioral composites introduce greater or less equivocality of interpretation. Two experiments employing multi-cue conversational involvement violations addressed this issue. In the first, dyads (N=51) engaged in a 10-minute baseline interview, after which participants rated each other on several measures of reward valence. One randomly selected member then served as a confederate interviewee during a second interview and either significantly increased or decreased involvement. In the second experiment, reward was manipulated as physical attractiveness, status, and task expertise. Dyads (N = 60) engaged in prolonged problem-solving discussions during which the confederates either committed an involvement violation or not. In both experiments, the involvement changes were sufficiently unexpected, arousing, and distracting to qualify as violations of expectations. Analysis of message interpretations indicated that (1) relative to normal involvement levels, increased nonverbal involvement was interpreted as most immediate/affectionate, receptive, similar, dominant, and composed, and decreased involvement as least so, and (2) reward mediated only the interpretation of formality. High involvement violations in turn produced greater attraction, credibility, and persuasiveness than low involvement violations for high as well as low-reward communicators, as predicted.where Joe Walther and Jim Baesler are doctoral students. An earlier version of this paper was presented to the annual meeting of the International Communication Association, New Orleans, May 1988.     

Chlamydia trachomatis infection in a male college student population

Male university students were studied to evaluate the merit of routine screening for chlamydia urethritis. Two hundred fourteen sexually active male students answered a questionnaire about symptoms of urethritis and exposure to and treatment for sexually transmitted diseases (STDs). All subjects were screened for chlamydia by enzyme immunoassay (Chlamydiazyme, Abbott Laboratories). Overall, Chlamydiazyme was positive in 42 of 214 subjects (19.6%). Eighty-six subjects had no symptoms and no history of untreated exposure to STD; 6 of these had positive Chlamydiazyme assays. Based on our results, we conclude that the proportion of male urethral chlamydia infections that are asymptomatic may be much higher than has previously been believed. We further conclude that asymptomatic sexually active male students on this campus are a high-risk population for whom routine chlamydia screening is appropriate.     

New approach in biased regression

SUMMARY An optimization problem which provides a new characterization for ridge regression is discussed. A variant of this optimization problem leads to a new family of biased estimators that includes the Stein estimation method and principal components regression as particular cases. The whole approach is illustrated on the basis of real data sets.