OBJECTIVE To determine the contributions of genetic and environmental influences to variation in self-report of obsessive-compulsive (OC) symptoms in a population-based twin sample of adolescent boys and girls. METHOD Self-report ratings on the eight-item Youth Self-Report Obsessive-Compulsive Scale were collected in Dutch mono- and dizygotic twin pairs who participated at age 12 (N = 746 twi...

We investigated trends in participation, performance and sex difference in performance in 3000 m freestyle in age groups swimmers (25-29 to 85-89 years) competing in the Fédération Internationale de Natation World Masters Championships between 1992 and 2014. During this period, participation increased in women and men. Women and men improved race times across years in all age groups. Women were...

PURPOSE We measured offspring sex ratios in a resident insectivorous passerine bird, the Great tit Parus major, to find out whether metal pollution around a Finnish copper smelter would bias sex ratios in this territorial forest bird species. Besides a direct effect of pollutants, we were interested in possible indirect effects of pollution-related resource limitation, i.e., changes in food qua...

Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. Studies investigating sex ratio variation in mammals, including humans, have obtained notoriously inconsistent results, except when maternal condition is measured around conception. Several mechanisms for sex ratio adjustment have ...

A growing number of sex differences in infancy have been reported. One task on which they have been observed reliably is the event-mapping task. In event mapping, infants view an occlusion event involving 1 or 2 objects, the occluder is removed, and then infants see 1 object. Typically, boys are more likely than girls to detect an inconsistency between a 2-object occlusion event and a 1-object ...

There was a significant male excess in the newborns of pregnant women with severe chronic constipation during pregnancy compared to pregnant women without constipation and pregnant women with new onset severe constipation, during pregnancy.

Five newly identified sex-biased transcripts in Drosophila are full of surprises: although they are found in fly heads, and manipulating two of them affects mating behaviors, their genes are expressed sex-specifically in non-neural tissues. The way these genes are regulated suggests new complexities in the sex determination pathway.

A hitherto unremarked peculiarity of homicide in the United States is that women kill their husbands almost as often as the reverse. For every 100 US. men who kill their wives, about 75 women kill their husbands; this spousal “sex ratio of killing” (SROK) is more than twice that in other Western nations. Our analyses of spousal homicide samples from the United States, Canada, Australia, and Gre...

Primary headache associated with sexual activity is a rare headache disorder that has only been reported twice previously in adolescents. Although it can mimic life-threatening causes of thunderclap-onset headache, primary sex headache is benign, self-limited, and highly responsive to indomethacin. Given the sensitive nature of sexual development in adolescents, it is important that pediatric p...

There is strong evidence that the sex ratio at birth is partially determined by environmental and social factors. The modern change in those factors serves as an explanation for the secular decline in sex ratio at birth in most of the industrialized countries. This article is the reexamination of the results from my previous communication in which no trend in sex ratio at birth was established ...