Phenotypical, genotypical and pathological characterization of the moonwalker mouse, a model of ataxia.

We performed a comprehensive study of the morphological, functional, and genetic features of moonwalker (MWK) mice, a mouse model of spinocerebellar ataxia caused by a gain of function of the TRPC3 channel. These mice show numerous behavioral symptoms including tremor, altered gait, circling behavior, impaired motor coordination, impaired motor learning and decreased limb strength. Cerebellar pathology is characterized by early and almost complete loss of unipolar brush cells as well as slowly progressive, moderate loss of Purkinje cell (PCs). Structural damage also includes loss of synaptic contacts from parallel fibers, swollen ER structures, and degenerating axons. Interestingly, no obvious correlation was observed between PC loss and severity of the symptoms, as the phenotype stabilizes around 2 months of age, while the cerebellar pathology is progressive. This is probably due to the fact that PC function is severely impaired much earlier than the appearance of PC loss. Indeed, PC firing is already impaired in 3 weeks old mice. An interesting feature of the MWK pathology that still remains to be explained consists in a strong lobule selectivity of the PC loss, which is puzzling considering that TRPC is expressed in every PC. Intriguingly, genetic analysis of MWK cerebella shows, among other alterations, changes in the expression of both apoptosis inducing and resistance factors possibly suggesting that damaged PCs initiate specific cellular pathways that protect them from overt cell loss.

Explaining attitudes about homosexuality in Confucian and non-Confucian nations: is there a 'cultural' influence?

The majority of research on attitudes about homosexuality has concentrated on the global North and on Christian and Muslim majority nations. Little research attention has been given to the factors that shape tolerance in societies with a Confucian heritage. Residents of Confucian counties are less tolerant than Europeans and Americans. One reason given for this difference is the emphasis on Confucian values in many Asian societies. Using data from the World Values Survey, we examine whether values that could be described as Confucian influence attitudes in Confucian and non-Confucian nations. We find a unique Confucian cultural effect, which can partially be explained with concerns about keeping the family intact. Conversely, in Confucian societies values related to obedience, conformity, and filial piety are unrelated to attitudes. There is also a small Buddhist contextual effect, resulting in more tolerant attitudes, and the Confucian influence cannot be reduced to an Asian regional effect.

Adolescent overweight, social relationships and the transition to first sex: gender and racial variations.

CONTEXT: Being overweight influences adolescents' relationships by increasing their likelihood of experiencing social alienation and discrimination. Its role in sexual development is relatively understudied, as are potential mechanisms through which weight may influence early sexual activity. METHODS: Data from the National Longitudinal Study of Adolescent Health were used in discrete-time event history analyses investigating the association between body weight, social relationships and timing of sexual debut among 8,197 respondents who were in grades 7-12 in 1994-1995 (Wave 1) and were young adults in 2001-2002 (Wave 3). Subgroup analyses explored gender and racial and ethnic variations in the association. RESULTS: Overweight adolescents were less likely than their normal-weight peers to report first intercourse between Waves 1 and 3 (odds ratio, 0.9). Characteristics reflecting social alienation, including having relatively few close friends and no experience with romantic relationships, were negatively associated with first intercourse among overweight youths. Results differed by gender and race and ethnicity. Overweight females had a lower likelihood than normal-weight females of experiencing first intercourse (0.8), but no such association was evident among males. Similarly, overweight white youths--but not those from other racial and ethnic groups--had reduced odds of sexual debut (0.7). CONCLUSIONS: Future studies should seek to understand the broader implications of adolescent weight status for social relationships and subsequent development, and practitioners should apply this knowledge to prevention programs. Postponement of sexual activity may benefit youths, but potential benefits and risks may depend upon the social processes involved.

Adolescent Precursors of Early Union Formation among Asian Americans and Whites.

Using a framework that emphasizes independent vs. interdependent self-construals, this study investigates the relatively low rates of early marriage and cohabitation among Asian Americans compared to Whites. Data from Waves 1 and 3 of Add Health are used to test five hypotheses that focus on family value socialization and other precursors measured in adolescence. Analyses of early marriage indicate that the Asian-White difference is driven primarily by differences in adolescent sexual and romantic relationship experiences, and several measures of family values play a stronger role among Asian Americans than Whites. Asian-White differences in cohabitation persist net of SES and other adolescent precursors, but differences are attenuated when parental value socialization, intimate relationship experiences, and educational investments are controlled. These results are interpreted within a culturally sensitive conceptual framework that emphasizes interdependent construals of the self among Asian Americans.

Longitudinal predictors of change in number of sexual partners across adolescence and early adulthood.

PURPOSE: Although sexual risk behavior has negative consequences in adolescence and early adulthood, little is known about pathways of sexual risk across development and their correlates. Study goals were to examine trajectories of number of sexual partners across adolescence and into early adulthood, and to investigate hypothesized individual and family-level predictors. METHODS: A subset of 8,707 white, black, and Mexican American participants in the National Longitudinal Study of Adolescent Health reported on their motivations to have sex, family warmth, and perceptions of maternal attitudes about sex at Wave 1 and on their sexual relationships at each year of age across the three waves of the study. RESULTS: Multilevel growth curves of number of sexual partners between ages 11 and 27 showed increases in sexual risk across adolescence and deceleration in early adulthood, but differed somewhat as a function of demographic characteristics. As expected, adolescent motivations to have sex and perceptions of permissive maternal attitudes about sex predicted more sexual partners in adolescence, whereas family warmth predicted fewer sexual partners across gender and racial/ethnic groups. Predictors did not differentiate youth as strongly in early adulthood. Interactions between predictors supported a cumulative risk framework, such that perceived permissive maternal attitudes or low family warmth combined with high adolescent motivations to have sex predicted the highest number of sexual partners in adolescence. CONCLUSIONS: This study advances our understanding of change in sexual behavior across development and the individual and contextual correlates of such change. Findings document the cumulative implications of individual cognitions, family experiences, and social contexts for adolescent and young adult sexual experiences.