Links Between Sex-Typed Time Use in Middle Childhood and Gender Development in Early Adolescence.

The authors studied sex-typing in the kinds (e.g., sports, handicrafts) and social contexts (same- vs. other-sex companions) of children's free time activities, and the links between sex-typed activities and gender development over 2 years. Participants were 200 White, working- and middle-class children (103 girls, 97 boys; mean age = 10.86 years). In annual home interviews, children rated their self-esteem, gender role attitudes and sex-typed personality qualities, academic interests, and school grades. During 7 nightly phone interviews each year, children reported on their activities. Boys were more sex-typed than girls in their peer activities, and children were least sex-typed in their activities with siblings. Sex-typed activities in middle childhood predicted individual differences in gender development in early adolescence (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parental reports of coparenting and observed coparenting behavior during the toddler period.

Fifty-two married partners played with their 30-mo-olds in both dyadic (parent–child) and whole family contexts and reported on their own coparenting activities (family integrity-promoting behavior, conflict, disparagement, and reprimand). Coparenting behavior observed in the whole family context was evaluated for antagonism, warmth and cooperation, child–adult centeredness, balance of positive involvement, and management of toddler behavior. Parallel balance and management scores were also formed using dyadic session data. Men's reported family integrity-promoting activities and women's reported conflict and reprimand activities were reliable correlates of family group process in both bivariate and discriminant analyses, with links enduring even after controlling for marital quality. Whole family- and dyad-based estimates of coparenting were altogether unrelated, and reported coparenting was tied only to behavior in family context, not to family measures created from dyad-based data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of a strong magnetic field on the damping of second sound in dilute3He-4He mixtures below 100 mK

We have measured the increase in damping of second sound in 0.1% and 0.05%³He-⁴He solutions upon application of a magnetic field of 10 T. The increase is caused by changes in the thermal conductivity and viscosity of the mixture as the system becomes spin polarized. We show how to fit the data for the viscosity in zero-field to obtain an estimate of the interaction between the³He quasiparticles. It is then possible to predict the viscosity in a field of 10 T using the calculation of Hampson et al. The data agree with the theory to within 2%.     

A gene for autosomal recessive symmetrical spastic cerebral palsy maps to chromosome 2q24-25

Cerebral palsy has an incidence of approximately 1/500 births, although this varies between different ethnic groups. Genetic forms of the disease account for approximately 1%-2% of cases in most countries but contribute a larger proportion in populations with extensive inbreeding. We have clinically characterized consanguineous families with multiple children affected by symmetrical spastic cerebral palsy, to locate recessive genes responsible for this condition. The eight families studied were identified from databases of patients in different regions of the United Kingdom. After ascertainment and clinical assessment, we performed a genomewide search for linkage, using 290 polymorphic DNA markers. In three families, a region of homozygosity at chromosome 2q24-q25 was identified between the markers D2S124 and D2S148. The largest family gave a maximum LOD score of 3.0, by multipoint analysis (HOMOZ). The maximum combined multipoint LOD score for the three families was 5.75. The minimum region of homozygosity is approximately 5 cM between the markers D2S124 and D2S2284. We have shown that a proportion of autosomal recessive symmetrical spastic cerebral palsy maps to chromosome 2q24-25. The identification of genes involved in the etiology of cerebral palsy may lead to improved management of this clinically intractable condition.     

Thermal conductivity measurement of liquids in a microfluidic device

A new microfluidic-based approach to measuring liquid thermal conductivity is developed to address the requirement in many practical applications for measurements using small (microlitre) sample size and integration into a compact device. The approach also gives the possibility of high-throughput testing. A resistance heater and temperature sensor are incorporated into a glass microfluidic chip to allow transmission and detection of a planar thermal wave crossing a thin layer of the sample. The device is designed so that heat transfer is locally one-dimensional during a short initial time period. This allows the detected temperature transient to be separated into two distinct components: a short-time, purely one-dimensional part from which sample thermal conductivity can be determined and a remaining long-time part containing the effects of three-dimensionality and of the finite size of surrounding thermal reservoirs. Identification of the one-dimensional component yields a steady temperature difference from which sample thermal conductivity can be determined. Calibration is required to give correct representation of changing heater resistance, system layer thicknesses and solid material thermal conductivities with temperature. In this preliminary study, methanol/water mixtures are measured at atmospheric pressure over the temperature range 30–50°C. The results show that the device has produced a measurement accuracy of within 2.5% over the range of thermal conductivity and temperature of the tests. A relation between measurement uncertainty and the geometric and thermal properties of the system is derived and this is used to identify ways that error could be further reduced.     

Covert antisocial behavior in boys with attention-deficit hyperactivity disorder: External validation and effects of methylphenidate.

Covert antisocial behaviors such as stealing, destroying property, and cheating carry high risk for delinquency. An individual laboratory setting was devised in which youngsters could take desired objects and use answer keys to assist with worksheets. 22 boys with attention-deficit hyperactivity disorder (ADHD) and 22 comparison boys were observed on 2 occasions, with the ADHD Ss receiving a methylphenidate–placebo crossover. Lab stealing and property destruction were positively correlated with maternal and staff ratings of parallel behaviors. Methylphenidate resulted in significant reductions of these acts, but it also effected an increase in cheating, presumably because of its enhancement of task involvement. The generalizability of the lab findings, actions of stimulants in this domain, and the ethics of experimental investigations of covert antisocial behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testosterone and child and adolescent adjustment: The moderating role of parent-child relationships.

In a sample of established middle- and working-class families with normally developing children and adolescents ranging in age from 6 to 18 years, sons' and daughters' testosterone levels showed little direct connection to risk behavior or symptoms of depression. In contrast, testosterone's positive relation with risk behavior and negative relation with depression were conditional on the quality of parent-child relations. As parent-child relationship quality increased, testosterone-related adjustment problems were less evident. When relationship quality decreased, testosterone-linked risk-taking behavior and symptoms of depression were more in evidence. Few relations were found between parents' testosterone and child behavior. Boys' and girls' ages and stages of pubertal development were important for understanding the expression of hormone-related problem behavior in some cases but not in others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)