Gender diagnosticity refers to the Bayesian probability that an individual is predicted to be male or female on the basis of some set of gender-related diagnostic indicators. We computed gender diagnostic probabilities from occupational preference ratings made by 117 male and 110 female subjects. Subjects also completed the Personal Attributes Questionnaire and the Bern Sex-Role Inventory and were assessed on a number of gender-related criterion variables. Gender diagnostic probabilities proved to be factorially distinct from PAQ and BSRI masculinity and femininity and generally displayed greater predictive utility than did masculinity and femininity. Unlike existing scales, gender diagnosticity measures are not based on gender stereotypes, and they do not reify gender-related individual differences or freeze them into specific constructs such as instrumental or expressive traits. Furthermore, they are well suited to developmental and cross-cultural research.

A component analysis of the reciprocal peer tutoring (RPT) strategy was performed, which previous research had demonstrated to be effective in producing cognitive gains, lowering subjective distress, and enhancing course satisfaction. One hundred students were randomly assigned to one of four groups designed to systematically compare the RPT strategy with its hypothesized components: dyadic, mutual exchange, and structured-learning format. Pretest analyses revealed no significant group differences in demographic variables or pretest scores on course examinations and self-report inventories of subjective distress. Further analyses supported past findings on the superiority of the RPT strategy. This superiority was attributed to the RPT group's unique combination of elements: preparing to teach a peer, teaching a peer, and accountability for this process. We discuss implications for future research.

Activation of the epidermal growth factor receptor (EGFR) provides a measure of protection to immortalized epidermal keratinocytes (HaCaT cells) against apoptosis induced by diverse cellular stressors. This effect is due, in part, to sustained MAPK-dependent Bcl-x L expression. Here, we report a second EGFR/MAPK-dependent signaling event that protects HaCaT cells against apoptosis incurred during forced suspension culture (anoikis). This pathway targets Bim, a pro-apoptotic BH3-only Bcl-2 family member. Bim expression was functionally relevant to HaCaT cell survival as demonstrated by partial protection against anoikis provided by siRNA-induced Bim downregulation. Growth factor starvation of attached and suspended cells was associated with enhanced Bim expression whereas EGFR activation reduced Bim expression by inducing Bim phosphorylation and proteasomal degradation. EGFR-dependent Bim phosphorylation required MAPK activation. Furthermore, PKC-δ activity contributed to both MEK/MAPK phosphorylation and Bim phosphorylation as demonstrated using both pharmacological inhibitors of PKC-δ and siRNA-mediated PKC-δ knockdown. In addition to HaCaT cells, EGFR activation supported survival and induced Bim phosphorylation in several squamous carcinoma cell lines in a strictly MAPK-dependent fashion. These results establish that EGFR activation attenuates susceptibility of immortalized and malignant keratinocytes to apoptosis by post-translational control of Bim-EL expression through a pathway requiring PKC-δ and MEK/MAPK activation.

This study applied a social-genetic perspective to examine hypotheses concerning displays of cooperation. The sample included children from 14 monozygotic and 16 dizygotic twin pairs, organized into 30 unfamiliar partnerships. Two puzzle completion sessions were videotaped and evaluated on five dimensions of cooperation. Repeated measures of analysis of variance indicated significantly higher ratings among female than male pairs on Overall Cooperation, Mutuality of Goal and Accommodation. Contrary to expectation, social-interactional differences between unfamiliar MZ and DZ dyads were not detected. Findings are discussed with reference to new research perspectives on cooperative behavior.

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