Adolescent AIDS Prevention in Context: The Impact of Peer Educator Qualities and Classroom Environments on Intervention Efficacy

Peer-led, school-based interventions show promise for preventing AIDS among adolescents, but little is known about the processes underlying effective peer education or the conditions that promote its efficacy. This study examined the implementation in one school of an effective, peer-led AIDS prevention program for inner-city 7th-grade participants (n = 123) and identified the qualities of peer educators (n = 15) and classroom environments (n = 5) that contributed to improvement in participants' postintervention AIDS-related attitudes. The Peer Educator Rating Scale was developed to assess two dimensions of participants' perceptions of peer educators: positive regard and perceived similarity. Participants reported greater positive regard for more highly individuated and less shy peer educators, and participants' positive regard for peer educators in turn was associated with lowered AIDS risk as measured by perceptions of peer norms regarding sexual activity and self-efficacy for peer communication regarding sexual topics and condoms. Participants' perceived similarity was not associated with any postintervention improvements in AIDS-related knowledge and attitudes. Participants' classroom membership was associated with improvements in all 5 knowledge and attitude scales, and exploratory classroom-level findings indicated that classroom intervention environments perceived as more organized by participants showed slightly greater overall improvements across AIDS-related knowledge and attitudes scales. Consistent with individual-level findings regarding participants' positive regard for peer educators, the two classrooms with the greatest positive regard for their peer educator teams showed the most student improvement. Implications for further research and the design of future prevention and promotion programs for adolescents are discussed.     

Correlation between Changes in Stress-Induced Corticosterone Secretion and GR mRNA Levels

The current study was conducted to determine the potential relationship between stress-induced corticosterone secretion and corticosteroid receptor mRNA levels after 5 days of intermittent stress. In particular, we were interested in the rate at which animals terminate a stress response, and how this termination may be altered by repeated stress. Adult male Sprague-Dawley rats were subjected to either 5 days of restraint stress or 5 days of an unpredictable stress paradigm. Restraint-stress induced corticosterone secretion was measured on Days 1 and 5 in both groups, and animals were killed on Day 6. Glucocorticoid receptor (GR), and mineralocorticoid (MR) mRNA levels were determined using in-situ hybridization techniques. Five days of restraint stress caused an habituation of the plasma corticosterone response to stress measured 60 and 90 min post-stress initiation; this pattern of corticosterone secretion was not observed in the animals subjected to unpredictable stress. Five days of either stress paradigm did not alter MR mRNA levels measured within the hippocampus or GR mRNA levels within the hippocampus or the medial parvocellular division of the paraventricular nucleus of the hypothalamus (mpPVN). However, an individual's GR mRNA levels measured within the CA1/2 region of the hippocampus and the mpPVN were significantly correlated with the degree of habituation of the corticosterone response to stress measured on Day 5. This suggests that an increase in the rate of termination of the stress response and levels of GR within the hippocampus and mpPVN may be functionally related.     

Adolescents' concepts of depression among their peers

The purpose of this study was to quantify the behavioral cues adolescents use to identify their peers as depressed in order to gain a more accurate understanding of the factors associated with adolescent depressive symptomatology. Because of limited information about depression in adolescents, a questionnaire was constructed to explore the concept in this age group. Ninety-nine middle and high school students, 12 to 18 years old, completed the questionnaire which included open-ended and forced choice questions. The results indicated that social isolation was an important component of adolescents' concepts of depression among their peers. Subjects felt that there was a higher frequency of alcohol and marijuana use among depressed as compared to non-depressed peers. Eighty-six percent of the subjects believed that most depressed adolescents had suicidal thoughts, but only 35% believed that most depressed adolescents had attempted suicide. Factor analyses of the subjects' responses to the open-ended questions delineated several underlying dimensions of depressive symptomatology which adolescents appear to use in identifying their peers as depressed.     

Evidence from rats that morphine tolerance is a learned response.

It is proposed that the direct analgesic effect of morphine becomes attenuated over the course of successive administrations of the narcotic by a conditioned, compensatory, hyperalgesic response elicited by the administration procedure, the net result being analgesic tolerance. Using the "hot plate" analgesia assessment situation with rats, this conditioning view of tolerance is supported by several findings: (a) It is necessary to have reliable environmental cues predicting the systemic effects of morphine if tolerance is to be observed, (b) a hyperalgesic conditioned response may be observed in morphine-tolerant subjects when drug administration cues are followed by a placebo, and (c) merely by repeatedly presenting environmental cues previously associated with morphine (but now presented with a placebo), morphine tolerance can be extinguished.     

Hue discrimination as a function of stimulus luminance

The relation between hue discrimination and stimulus luminance was investigated. It was found that discrimination was best at the highest luminance and deteriorated at the lowest, except in the yellow region.     

Color name as a function of surround luminance and stimulus duration

A color-naming experiment was performed in which both surround luminance and exposure duration were varied. The data showed substantial effects from these changes; however, none could be interpreted to indicate the presence of a Bezold-Brucke shift or tritanopia.     

Suppression of normal speech disfluencies through response cost

The speech disfluencies of five normal-speaking college students were modified in a series of 10 to 17 sessions by means of response cost. During Point-loss, each disfluency (repetition or interjection of a sound, syllable, word, etc.) resulted in the loss of a penny, as indicated on a screen in front of the subject. Disfluencies were suppressed and kept at very low levels for four of the subjects during the punishment procedures, and there was general resistance to extinction. Even though points were subtracted only during speech, there was a tendency for disfluencies to decrease, though not as markedly, during reading probes as well.     

A note on psychophysical measures

The nature of liminal measurement is discussed, and the standard deviation is proposed asa suitable alternative measure to the limen.