Contrasts between related diploid and polyploid taxa can serve as windows into the evolution of sexual systems. A recent study of a moving diploid-polyploid contact zone explores this topic in novel ways.

Contact patterns in populations fundamentally influence the spread of infectious diseases. Current mathematical methods for epidemiological forecasting on networks largely assume that contacts between individuals are fixed, at least for the duration of an outbreak. In reality, contact patterns may be quite fluid, with individuals frequently making and breaking social or sexual relationships. He...

background hepatitis c virus (hcv) is a major cause of chronic liver disease worldwide. the role of intra familial hcv transmission is still controversial. the aim of the present study is to determine intra familial transmission (sexual and non sexual contacts) of hcv in a group of iranian population. patients and methods in this historical cohort study, 270 first degree relatives of hepatitis ...

BACKGROUND Sexual violence is a worldwide problem affecting children and adults. Knowledge of trends in prevalence is essential to inform the design and evaluation of preventive and intervention programmes. We aimed to assess the prevalence of lifetime sexual violence for both sexes and to document the prevalence of adult and child abuse by birth year in the general population. METHODS Nation...

Although much is currently known about hypersexuality (in the form of excessive sexual behavior) among sexual offenders, the degree to which hypersexual behavior is linked to paraphilic and especially pedophilic interests in non-forensic populations has not been established.The purpose of the present study was to elucidate the associations between total sexual outlets(TSO) and other sex drive i...

BACKGROUND Peru has a concentrated HIV epidemic in which men who have sex with men are particularly vulnerable. We describe the lifetime prevalence of same-sex sexual contact and associated risk behaviors of men in Peru's general population, regardless of their sexual identity. METHODS AND RESULTS A probability sample of males from low-income households in three Peruvian cities completed an e...

Animal models have shown that the neural bases of social attachment, sexual preference and pair bonds, depend on dopamine D2-type receptor and oxytocin activity. In addition, studies have demonstrated that cohabitation can shape partner preference via conditioning. Herein, we used rats to explore the development of learned same-sex partner preferences in adulthood as a result of cohabitation du...