Movers and stayers: how residential selection contributes to the association between female body mass index and neighborhood characteristics.

BACKGROUND/OBJECTIVES: To examine how a woman's current body mass index (BMI) is associated with nonrandom residential migration that is based on the average BMI of her origin and destination neighborhoods. SUBJECTS/METHODS: Among women having at least two children, all birth certificates from Salt Lake county from 1989 to 2010 (n=34 010) were used to obtain prepregnancy weights before the first and second births, residential location and sociodemographic information. Census data were used for measures of walkability of neighborhoods. RESULTS: After adjustments for age, education, race/ethnicity and marital status, obese women living in the leanest neighborhoods are found to be three times more likely (odds ratio (OR)=3.03, 95% confidence interval (CI) 2.06-4.47) to move to the heaviest neighborhoods relative to women with healthy weight (BMI between 18 and 25 kg m(-2)). Conversely, obese women in the heaviest neighborhoods are 60% less likely (OR=0.39, 95% CI 0.22-0.69) to move to the leanest neighborhoods relative to healthy weight women. Indicators of relatively greater walkability (older housing, greater proportion of residents who walk to work) and higher median family income characterize leaner neighborhoods. CONCLUSIONS: The findings are consistent with the hypothesis that nonrandom selection into and out of neighborhoods accounts for some of the association between BMI and neighborhood characteristics.

Functional analysis of six androgen receptor mutations identified in patients with partial androgen insensitivity syndrome.

Partial androgen insensitivity syndrome (PAIS) is caused by defects in the androgen receptor gene and presents with a wide range of undervirilization phenotypes. We studied the consequences of six androgen receptor ligand-binding domain mutations on receptor function in transfected cells. The mutations, Met742Ile, Met780Ile, Gln798Glu, Arg840Cys, Arg855His and Ile869Met, were identified in PAIS patients with phenotypes representing the full spectrum seen in this condition. In all cases the androgen receptor was found to be defective, suggesting that the mutation is the cause of the clinical phenotype. The Gln798Glu mutation is exceptional in that it did not cause an androgen-binding defect in our system, although the mutant receptor was defective in transactivation assays. This mutation may affect an aspect of binding not tested, or may be part of a functional subdomain of the ligand-binding domain involved in transactivation. Overall we found milder mutations to be associated with milder clinical phenotypes. There is also clear evidence that phenotype is not solely dependent on androgen receptor function. Some of the mutant receptors were able to respond to high doses of androgen in vitro, suggesting that patients carrying these mutations may be the best candidates for androgen therapy. One such mutation is Ile869Met. A patient carrying this mutation has virilized spontaneously at puberty, so in vivo evidence agrees with the experimental result. Thus a more complete understanding of the functional consequences of androgen receptor mutations may provide a more rational basis for gender assignment in PAIS.

A single-bead decode strategy using electrospray ionization mass spectrometry and a new photolabile linker: 3-amino-3-(2-nitrophenyl)propionic acid.

A new linker that employs a photosensitive 3-amino-3-(2-nitrophenyl)propionyl functionality (ANP-resin) has been developed for the preparation of C-terminal carboxamides. A wide range of carboxamides were prepared and identified using the ANP-resin and electrospray ionization mass spectrometry. A single bead containing tripeptide Fmoc-Asp-Arg(Tos)-Val-NH2 was isolated, photocleaved and the peptide was characterized by tandem mass spectrometry, thereby verifying a library decode strategy that avoids complex tagging procedures.

Parenting practices and peer group affiliation in adolescence.

Social scientists have often assumed that parental influence is sharply curtailed at adolescence because of the rising counterinfluence of peer groups, over which parents have little control. The present study tested a conceptual model that challenged this view by arguing that parents retain a notable but indirect influence over their teenage child's peer associates. Data from a sample of 3,781 high school students (ages 15-19) indicated that specific parenting practices (monitoring, encouragement of achievement, joint decision making) were significantly associated with specific adolescent behaviors (academic achievement, drug use, self-reliance), which in turn were significantly related to membership in common adolescent crowds (jocks, druggies, etc). Findings encourage investigators to assess more carefully parents' role in adolescents' peer group affiliations.

Ethnic differences in adolescent achievement. An ecological perspective.

Using data collected from a large sample of high school students, the authors challenge three widely held explanations for the superior school performance of Asian-American adolescents, and the inferior performance of African- and Hispanic-American adolescents: group differences in (a) parenting practices, (b) familial values about education, and (c) youngsters' beliefs about the occupational rewards of academic success. They found that White youngsters benefit from the combination of authoritative parenting and peer support for achievement, whereas Hispanic youngsters suffer from a combination of parental authoritarianism and low peer support. Among Asian-American students, peer support for academic excellence offsets the negative consequences of authoritarian parenting. Among African-American youngsters, the absence of peer support for achievement undermines the positive influence of authoritative parenting.

The relationship between phoneme discrimination, speech production, and language comprehension in cerebral-palsied individuals.

Twenty-four individuals with impaired speech (anarthria or dysarthria) were compared on tests of receptive language to a control group with normal speech. All subjects were cerebral-palsied and groups were matched on age and nonverbal ability. The speech-impaired subjects performed less well than controls on a phoneme discrimination task in which they were required to judge whether pairs of nonwords were the same or different. They were also impaired relative to controls on a receptive vocabulary test, but not in understanding of grammatical structure. One year later, phoneme discrimination skills were reassessed in this sample, using another same-different task, plus a new task in which subjects were required to judge if the name of a picture was spoken correctly or altered by one sound. Speech-impaired subjects performed as well as controls on the word judgment task, indicating that they can discriminate phoneme contrasts adequately. However, the same-different task again resulted in highly significant differences between speech-impaired and control groups. It is concluded that poor performance on the same-different task reflects weak memory for novel phonological strings, rather than impaired phoneme perception. It is proposed that retention of unfamiliar words is facilitated by overt or covert repetition, so individuals who cannot speak fluently have difficulty remembering nonwords. This explanation can account both for the poor performance of speech-impaired subjects on the same-different task, and for their selective deficit in vocabulary acquisition.

Peer-group affiliation and adolescent self-esteem: an integration of ego-identity and symbolic-interaction theories.

To evaluate expectations derived from ego-identity theory and symbolic-interaction theories about the association between self-concept and peer-group affiliations in adolescence, we examined the self-esteem of 221 7th through 12th graders associated by peers with one of five major school crowds and 106 students relatively unknown by classmates and not associated with any school crowd. Among crowd members, self-esteem was directly related to the position of one's crowd in the peer-group status hierarchy (based on both peer-rated and self-perceived crowd affiliation). Outsiders' self-esteem differed in relation to the accuracy of their reflected appraisal of and the salience they attached to crowd affiliation. Crowd members as a whole exhibited higher self-esteem than outsiders as a whole. Differences, however, were mediated by crowd status, salience of crowd affiliation, and the accuracy of reflected appraisals. An adequate interpretation of the findings required an integration of Festinger's (1954, 1957) social comparisons and cognitive-dissonance theories, Cooley's (1902) notions of reflected appraisal, and Newman and Newman's (1976) extrapolations from ego-identity theory.

The importance of peer group ("crowd") affiliation in adolescence.

Many researchers have speculated about the role peer groups play in adolescent development, but few have examined teenagers' own perspective on the importance of group affiliations. The two studies reported here, involving 1,300 7th to 12th graders in three Midwestern U.S. communities, assessed teenagers' valuation of belonging to a "crowd" as well as the reasons they cited to support or oppose crowd affiliation. The importance of crowd affiliation declined across age. Younger adolescents generally favored membership, emphasizing the crowd's ability to provide emotional or instrumental support, foster friendships and facilitate social interaction. Older respondents expressed dissatisfaction with the conformity demands of crowds and felt their established friendship networks obviated the need for peer group ties. The importance of crowd affiliation was not related to the strength of respondents' sense of identity but did vary significantly with their willingness to conform to peers and the centrality of their position in peer groups or the type of crowd to which they belonged. Findings emphasized that adolescent peer groups can serve multiple functions, whose salience shifts with age.

The multidimensionality of peer pressure in adolescence.

A sample of 689 adolescents (grades 7-12) from two Midwestern communities who had been identified by peers as members of one of three major peer groups responded to a self-report survey measuring perceptions of peer pressure in five areas of behavior: involvement with peers, school involvement, family involvement, conformity to peer norms, and misconduct. Perceived pressures toward peer involvement were particularly strong, whereas peer pressures concerning misconduct were relatively ambivalent. Perceived pressures toward misconduct increased across grade levels and pressures to conform to peer norms diminished; grade differences in perceived peer pressures concerning family involvement were community specific. Compared to druggie-toughs, jock-populars perceived stronger peer pressures toward school and family involvement, and less pressure toward (stronger pressure against) misconduct; patterns of perceived pressure among loners were more variable across communities. Results elaborated the process of peer influence in adolescent socialization and identity development.

Drug and alcohol abuse among the elderly: is being alone the key?

Despite the rising incidence of drug and alcohol abuse among the elderly, information concerning the social and psychological factors fostering such abuse is scanty and potentially biased toward the limited number of older abusers who obtain professional help. Using a brief interview with carefully selected samples, the present study compares characteristics of social background and social support among 21 older clients (age 55 and over) of drug treatment facilities, 30 older abusers not in treatment, and 155 elderly nonabusers. Analyses suggest that age and gender affect the likelihood of receiving treatment for substance abuse more than the likelihood of being an abuser. Controlling for age and gender effects, substance abuse appeared more prevalent among single and divorced elderly and among respondents who lived alone; presence or absence of living companions was more influential than relationships with nearby social supports. Implications for health and social service programs as well as for further research are discussed.

The analysis of malignancy by cell fusion. IX. Re-examination and clarification of the cytogenetic problem.

Previous experiments with crosses between malignant and diploid mouse cells had shown that the reappearance of malignancy in hybrids in which it was initially suppressed was associated in some cases with the elimination of the chromosomes 4 derived from the diploid parent cell. In others, however, this did not appear to be so. In the present study, we have re-examined the role of the diploid chromosomes 4 in the suppression of malignancy using natural polymorphisms of the centromeric heterochromatin to identify the parental origin of the chromosomes 4 in the hybrid cells. We now find that the diploid chromosomes 4 are indeed involved in the suppression of malignancy in all the tumours that we have examined, which include a carcinoma, a melanoma, a sarcoma and a lymphoma. In all crosses between these malignant tumour cells and diploid fibroblasts, there is selective pressure in vivo against the chromosomes 4 derived from the diploid cell and in favour of the chromosomes 4 derived from the malignant cell. This indicates that the chromosomes 4 in all these tumours are in some way functionally different from the chromosomes 4 of the diploid fibroblast. Reappearance of malignancy in hybrids in which it was initially suppressed may result from a reduction in the number of diploid chromosomes 4, an increase in the number of malignant chromosomes 4, or both. The gene on the diploid chromosome 4 responsible for the suppression of malignancy acts in a dose-dependent manner.

The extent and effects of peer pressure among high school students: A retrospective analysis.

Although people assume that peer pressure is an influential component of adolescent development, few empirical studies have investigated the nature and extent of its influence. Using retrospective accounts from 297 college undergraduates, the present study assessed how much pressure peers exerted in numerous areas of high school life and how this pressure influenced teenagers' attitudes and behaviors. One-third of both genders identified peer pressure as one of the hardest things they had to face as a teenager. Generally, however, peer pressure appeared stronger for females than males, and the genders disagreed about the areas in which pressure was strongest. Perceptions of peer pressure were significantly associated with dating attitudes, sexual activity, and use of drugs and alcohol, but not with relationships with parents. The findings suggested that adolescents may be their own worst enemy in any attempt to break away from gender-stereotypic attitudes and behavior.

Meiosis in Sxr male mice: II. Further absence of cytological evidence for a Y-autosome rearrangement in sex-reversed (Sxr) mice.

If the sex-reversal factor (Sxr) in mice is represented by a segment of the Y chromosome translocated on to an autosome, this segment might be expected to show some evidence of attempted pairing with the normal Y chromosome at the first meiotic division. Our failure to find such evidence in a light microscope study of the silver-stained pachytene spermatocytes from Sxr/4, XY males further supports existing cytological information that the factor is more likely to be represented by an autosomal dominant gene mutation.