Effects of varied extinction conditions with alcoholics and social drinkers.

In a task analogous to excessive drinking behavior, 30 male alcoholics and 30 male social drinkers trained on a 100% rewarded button-pressing response received 1 of 3 extinction conditions: nonreward, simultaneous reward-punishment, and punishment only. Ss could discontinue responding at any time during the extinction phase. Alcoholics showed significantly greater resistance to extinction in the punishment and reward-punishment conditions, but not in the nonreward condition. No differences were found between groups during acquisition. Using an anticipatory punishment response model, an explanation of maladaptive operant responding in the alcoholic is suggested. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of Galaxolide® with the human and trout estrogen receptor-α

Synthetic musks have been detected in sewage effluents, surface waters, and fish tissues where the polycyclic musk compound, HHCB (Galaxolide®) is the dominant compound in those matrices. In the present study, the Galaxolide® formulation was tested in the yeast estrogenicity screening (YES) assay, and also tested in in vitro and in vivo teleost systems to determine whether it interacts with the estrogen receptor as either an agonist or antagonist. In those tests, Galaxolide® did not act as an estrogen agonist, however there was strong evidence of antagonistic activity as Galaxolide® inhibited the estrogenic activity of 17β-estradiol (E2). In the YES assay based on a recombinant strain of yeast containing the human estrogen receptor (i.e. hERα), Galaxolide® inhibited the effects of E2 in a dose-dependent manner (IC50 = 1.63 × 10⁻⁵ M). In a luciferase reporter gene assay based on the rainbow trout estrogen receptor (i.e. rtER) transfected into a rainbow trout gonadal (RTG-2) cell line, the IC50 for the antagonistic effect of Galaxolide® was 2.79 × 10⁻⁹ M. In an in vivo assay based on modulation of vitellogenin in rainbow trout, Galaxolide® i.p. injected into trout at a dose of 3.64 mg/kg caused inhibition of E2-induced vitellogenin production. That dose is within the range of concentrations of Galaxolide® that have been detected in tissues of fish from contaminated locations.     

Individual drinking changes following a brief intervention among college students: Clinical significance in an indicated preventive context.

This study investigated the clinical significance of previously reported statistically significant mean reductions in drinking and related problems among college students in a randomized trial of a brief indicated preventive intervention (G. A. Marlatt et al., 1998). Data were analyzed over a 2-year follow-up for participants from a high-risk intervention group (n?=?153), a high-risk control group (n?=?160), and a functional comparison group (n?=?77). A risk cutpoint for each dependent measure was based on the functional comparison group distribution. Compared with the high-risk controls, more individuals in the high-risk intervention group improved and fewer worsened, especially on alcohol-related problems and, to a lesser extent, on drinking pattern variables. These data from a prevention context clarify the magnitude and direction of individual change obscured by group means. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adolescent tobacco-related associative memory: A cross-sectional and contextual analysis.

Tobacco use is prevalent in adolescents, and understanding factors that contribute to its uptake and early development remains a critical public health priority. Implicit drug-related memory associations (DMAs) are predictive of drug use in older samples, but such models have little application to adolescent tobacco use. Moreover, extant research on memory associations yields little information on contextual factors that may be instrumental in the development of DMAs. The present study examined (a) the degree to which tobacco-related memory associations (TMAs) were associated with concurrent tobacco use and (b) the extent to which TMAs mediated the association of peer and self-use. A sample of 210 Australian high school students was recruited. Participants completed TMA tasks and behavioral checklists designed to obscure the tobacco-related focus of the study. Results showed that TMAs were associated with peer use, and TMAs predicted self-use. We found no evidence that TMAs mediated the association of peer and self-use. Future research might examine the emotive valence of implicit nodes and drinking behavior. The results have implications for testing the efficacy of consciousness-raising interventions for adolescents at risk of tobacco experimentation or regular use.     

The changing influences of self-worth and peer deviance on drinking problems in urban American Indian adolescents.

This study explored the changing relations among self-worth, peer deviance, and alcohol-related problems in a sample of 224 urban-dwelling, American Indian adolescents. Data were collected annually at 7 time points to test a proposed mediational model. As expected, peer deviance mediated the relation between low self-worth and alcohol-related problems in younger adolescents; however, this relation did not hold as participants became older. In older adolescents, low self-worth and peer deviance directly and independently contributed to alcohol problems. Possible explanations for and implications of these findings are discussed in terms of developmental changes during adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abstinence violation effect: Validation of an attributional construct with smoking cessation.

The abstinence violation effect (AVE) proposed in Marlatt and Gordon's (1980, 1985) model of smoking relapse was operationalized as a combination of internal, stable, and global causal attributions for smoking a cigarette following the attainment of abstinence from smoking. Causal attributions both for maintaining abstinence and for smoking in hypothetical high-risk situations were obtained prior to quitting from participants in a smoking cessation program. After treatment, subjects who relapsed also provided retrospective causal attributions for initial smoking episodes. Results showed that participants who relapsed following a slip reported significantly higher AVEs (more internal, stable, and global causal attributions) than those who regained abstinence following a slip. Furthermore, the AVE emerged as the strongest predictor of subsequent smoking when included in a discriminant analysis along with other factors associated with the initial smoking episode. Prospective pretreatment attributions for smoking and not smoking in hypothetical high-risk situations were not significantly related to attributions for actual smoking episodes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological and pharmacological influences in cigarette smoking withdrawal: Effects of nicotine gum and expectancy on smoking withdrawal symptoms and relapse.

To determine the relative effects of expectancy and nicotine depletion on aversive withdrawal symptoms, we gave 109 smokers attempting to quit either nicotine gum or placebo within a balanced placebo design and monitored their withdrawal symptoms and smoking for 2 weeks. Subjects who believed they were getting nicotine gum reported less physical symptoms of withdrawal, showed less arousal, and smoked fewer cigarettes during the first week of quitting when compared with those who thought they were receiving placebo gum. The actual nicotine content of gum had no effect on withdrawal or relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Construction and maintenance of randomized retroviral expression libraries for transmembrane protein engineering

Genetic selection from libraries expressing proteins with randomized amino acid segments is a powerful approach to identify proteins with novel biological activities. Here, we assessed the utility of deep DNA sequencing to characterize the composition, diversity, size and stability of such randomized libraries. We used 454 pyrosequencing to sequence a retroviral library expressing small proteins with randomized transmembrane domains. Despite the potential for unintended random mutagenesis during its construction, the overall hydrophobic composition and diversity of the proteins encoded by the sequenced library conformed well to its design. In addition, our sequencing results allowed us to calculate a more accurate estimate of the number of different proteins encoded by the library and suggested that the traditional methods for estimating the size of randomized libraries may overestimate their true size. Our results further demonstrated that no significant genetic bottlenecks exist in the methods used to express complex retrovirus libraries in mammalian cells and recover library sequences from these cells. These findings suggest that deep sequencing can be used to determine the quality and content of other libraries with randomized segments and to follow individual sequences during selection.     

Social determinants of alcohol consumption: The effects of social interaction and model status on the self-administration of alcohol.

Conducted 2 studies with 106 male undergraduates to assess variables related to the social determinants of alcohol consumption. In Study 1, 51 moderate- and heavy-drinking Ss were paired with confederates who behaved in a sociable or unsociable manner while modeling either light or heavy consumption during a 30-min drinking period in a simulated cocktail lounge. It was found that modeling occurred in the sociable conditions but not in the unsociable conditions, where Ss tended to drink heavily. In Study 2, 54 Ss were exposed to 1 of 3 social status conditions crossed with light vs heavy consumption in a 40-min drinking period in the same setting. Results indicate a modeling effect in all social status conditions. Findings support the existence of a modeling effect that can be disrupted by a lack of rapport between drinking partners. Implications for this etiology of problem drinking are considered that are based on the notion that increased alcohol consumption may serve as a strategy for coping with aversive social interactions. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task structure and the experimental modification of verbal behavior.

Numerous studies have investigated techniques assumed to modify verbal behavior. The present article focuses on 3 of the most important procedures: instructions, verbal models, and verbal conditioning. These procedures are reviewed and interpreted as sources of information available to the S in the experimental task. The effects of task structure and S uncertainty are discussed in terms of these sources of information and their effects upon the S's awareness and intention related to task performance. Studies that have compared the use of the 3 modification techniques with verbal behavior are evaluated within the context of this theoretical approach. Similarities and differences between experimental studies of verbal behavior and the psychotherapeutic setting are discussed in terms of applying modification procedures to problems outside of the laboratory. (78 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)