A-B status of behavior therapy technicians as related to success of Mowrer's conditioning treatment for enuresis.

Evaluated the relationship of therapy technician A-B status and the outcomes of a specific behavior treatment: O. H. Mowrer's conditioning paradigm for the treatment of enuresis. 36 5-16 yr old enuretic children were treated by their mothers who served as behavior technicians following a 1-hr consultation-training session. Results support the hypothesis that B-status technicians would be associated with higher successful outcomes than A-status technicians. Implications for clarifying existing behavior therapy and A-B literature are discussed, together with suggestions for future research. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Learned safety" as a mechanism in long-delay taste-aversion learning in rats.

Notes that rats learn taste aversions with unusually long CS-UCS delays. The hypothesis was tested that the CS-UCS delay gradient is a learning curve: During the delay, a rat gradually learns that a taste is "safe." In 2 experiments with female white rats, a solution which an S drank only once became safe and resistant to learned aversions for at least 3 wks, suggesting a learned safety mechanism. If an S drank a solution twice (within the effective CS-UCS interval) before a single poisoning, it learned less aversion than if it received only the 2nd presentation. The learned-safety theory explains this result; a trace-decay or interference model cannot. (34 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning and generalization of a two-dimensional sameness-difference concept by chimpanzees and orangutans.

Taught 4 adult chimpanzees and 4 orangutans a 2-dimensional sameness-difference concept in which the positive pair of stimuli were the same color (or form) and different forms (or colors), while the negative pair were the same form (or color) and different colors (or forms). Testing with nondifferentially reinforced equivalence trials showed that the training generalized to a set of novel stimuli. Further equivalence trials demonstrated that color was more salient than form. Equivalence trials demonstrated that color was more salient than form. Equivalence trials with 3- instead of 2-object arrays as stimuli revealed significant generalization gradients along the heterogeneity-homogeneity dimension for both color and form cues. There were no important differences in the performances of the chimpanzees and the orangutans. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Similarity between shock and safe areas during acquisition, transfer, and extinction of escape behavior in rats.

Demonstrated, in 3 experiments with a total of 128 female hooded rats, that performance in escape training was impaired when shock- and safe-box stimuli were similar rather than dissimilar to each other. Prior training with similar shock and safe boxes impaired responding during subsequent training or extinction under the dissimilar shock and safe condition. Prior training under the dissimilar condition did not reliably influence subsequent training or extinction under the similar shock-safe condition. Resistance to extinction under the dissimilar condition was reliably better following training with random presentations to both similar and dissimilar conditions than following training with the dissimilar condition alone. Exp III showed that impairment of escape behavior during training was attributable to response-contingent similarity between shock and safe boxes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ECS in one-trial appetitive learning of rats: Retention and amnesia.

Conducted 4 experiments with 214 male hooded rats to assess the kind and degree of amnesia induced by ECS following a 1-trial appetitive learning experience. Exp I (n = 30) and II (n = 60) show that although there is a definite amnesia that cannot be explained as an artifact of ECS-induced aversiveness, some memory of the experience does survive the ECS. Exp III (n = 96) suggests that this memory is for the novelty aspects of the learning experience, while there is at least a partial amnesia for the positive reinforcement received. Results of a 4th experiment (n = 28) suggest that the ECS has the effect of interrupting or preventing the classification of a novel object as reinforcing or nonreinforcing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alcohol on acquisition and retention of passive-avoidance conditioning in different mouse strains.

270 male Ss of the C57BL/6 and DBA/2 inbred mouse strains and of the F1 hybrid of these 2 were trained and tested in a passive-avoidance task under 0-3 gm/kg doses of ethanol. The C57 Ss performed better in acquisition at higher alcohol doses than either the DBA or hybrid Ss. The hybrids showed retention the following day at higher doses than either of the parental strains. The DBA and C57 Ss showed evidence of state-dependent learning at some alcohol doses while the hybrid mice did not. Low doses markedly disinhibited DBA mice in initial exploratory behavior, so that they became identical in this parameter to the other strains which were not so affected. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-produced reflex inhibition in the rat during induction of and recovery from barbiturate anesthesia.

Reported 3 experiments which show that the inhibitory effect of a preliminary stimulus on the acoustic startle reflex was disrupted during the induction of sodium pentobarbital (40 mg/kg) in a total of 50 male Holtzman rats. In Exp I (n = 35) and II (n = 8), Ss were injected with the barbiturate, and a startle stimulus was presented either alone or preceded by a white noise burst. Results show that (a) stimulus inhibition was present immediately after injection, (b) was lost during a phase of hyperreactivity which accompanied induction of the anesthesia, and (c) recovered as reactivity diminished in the anesthetic state. Exp III showed that inhibition recovered during an intervening stage prior to complete areflexia and that this recovery revealed that the earlier and later inhibitory failure cannot be ascribed to a drug-dependent degradation in a hypothetical inhibitory system. It was suggested that the expression of reflex inhibition depends on the balanced interplay of excitatory and inhibitory processes which are differentially sensitive to drug intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in rumen bacterial and archaeal communities over the transition period in primiparous Holstein dairy cows

In the present study, we hypothesized that the rumen bacterial and archaeal communities would change significantly over the transition period of dairy cows, mainly as an adaptation to the classical use of low-grain prepartum and high-grain postpartum diets. Bacterial 16S rRNA gene amplicon sequencing of rumen samples from 10 primiparous Holstein dairy cows revealed no changes over the transition period in relative abundance of genera such as Ruminococcus, Butyrivibrio, Clostridium, Coprococcus, and Pseudobutyrivibrio. However, other dominant genus-level taxa, such as Prevotella, unclassified Ruminococcaceae, and unclassified Succinivibrionaceae, showed distinct changes in relative abundance from the prepartum to the postpartum period. Overall, we observed individual fluctuation patterns over the transition period for a range of bacterial taxa that, in some cases, were correlated with observed changes in the rumen short-chain fatty acids profile. Combined results from clone library and terminal-restriction fragment length polymorphism (T-RFLP) analyses, targeting the methyl-coenzyme M reductase α-subunit (mcrA) gene, revealed a methanogenic archaeal community dominated by the Methanobacteriales and Methanomassiliicoccales orders, particularly the genera Methanobrevibacter, Methanosphaera, and Methanomassiliicoccus. As observed for the bacterial community, the T-RFLP patterns showed significant shifts in methanogenic community composition over the transition period. Together, the composition of the rumen bacterial and archaeal communities exhibited changes in response to particularly the dietary changes of dairy cows over the transition period.     

Gender differences relative to smoking behavior and emissions of toxins from mainstream cigarette smoke.

This study examined whether gender differences exist in the exposure to select mainstream cigarette smoke toxins as a result of differences in smoking behavior or type of cigarettes smoked among 129 female and 128 male smokers. Smoking topography data indicated that, compared with men, women took smaller puffs (37.6 ml/puff vs. 45.8 ml/puff; p = .0001) of shorter duration (1.33 s/puff vs. 1.48 s/puff; p = .002) but drew more puffs per cigarette (13.5 vs. 12.0; p = .001) and left longer butts (36.3 mm or 40.2% of cigarette length vs. 34.3 mm or 39.2% of cigarette length; p = .01). These trends were similar in both African Americans and European Americans. The emissions of select toxins per cigarette, as determined by mimicking human smoking behaviors were greater among the male smokers than the female smokers and correlated significantly with delivered smoke volume per cigarette. The geometric means of emissions of nicotine from cigarettes were 1.92 mg/cigarette (95% CI = 1.80-2.05) for women versus 2.20 (95% CI = 2.04-2.37) for men (p = .005). Cigarettes smoked by women yielded 139.5 ng/cigarette of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; 95% CI = 128.8-151.0), compared with 170.3 ng/cigarette (95% CI = 156.3-185.6) for men (p = .0007); benzo(a)pyrene (BaP) emissions were 18.0 ng/cigarette (95% CI = 17.0-19.0) for women and 20.5 ng/cigarette (95% CI = 18.8-22.3) for men (p = .01). The gender differences with regard to cigarette smoke yields of toxins were more profound in European Americans than in African Americans. On average, African American men's smoking habits produced the highest emissions of select toxins from cigarettes, and European American female smokers had the lowest exposure to carcinogens and toxins. Several studies have suggested that women may be more susceptible than men to the ill effects of carcinogens in tobacco and tobacco smoke, whereas other studies have not found differences in lung cancer risk between men and women. The present study suggests that gender differences in exposure to tobacco smoke cannot account for a higher rate of lung cancer in female smokers compared with male smokers.