Observations of the external morphology of wild-caught and captive male brown long-eared bats (Plecotus auritus) revealed a marked seasonal pattern of spermatogenesis, similar to that established by histological examination of other temperate-zone vespertilionids, with a peak in testes size in August and a lag between testicular growth and epididymal distension. This was followed by complete ce...

OBJECTIVE This research tests the influences of age, biological, and psychosocial factors on sexual expression in later life. METHOD The American Association of Retired Persons Modern Maturity Sexuality Survey collected data on diagnosed illnesses, treated illnesses, sexual desire, sexual attitudes, partner circumstances, and sexual behavior from 1,384 persons ages 45 and older. Ordered logis...

In the United States, considerable attention has been directed to sexual behaviors of black and white adolescents, particularly age at first sexual experience and the prevalence of teenage pregnancies. More limited attention has been paid to comparing established sexual relationships in these two racial groups. In this study, we used a national probability sample to compare black (n = 251) and ...

In 64% of Rembrandt's female portraits the poser's left-cheek faces the viewer. However, this occurs in only 33% of his male portraits. This asymmetry is consistent with viewers rating Rembrandt's left-cheeked male portraits as likely to be avoided, which may reflect that aggressive displays of dominance are governed by the contralateral right-hemisphere, while rating left-cheeked female faces ...

M A T U R A T I O N and maintenance of ovarian function are under the control of the pituitary gonadotrophins. The capacity of the ovary to respond to FSH stimulation develops gradually with age, and is most pronounced when the animal approaches sexual maturity. In very young animals reactivity to gonadotrophins is found to be lacking, and up to a certain age, which is characteristic for each s...

Size at 50% maturity (l50%) is commonly evaluated for wild populations as a point of biological reference (see Table 1). To estimate l50%, a sample of organisms known to have just reached sexual maturity could be available and their arithmetic mean size can be used as an estimator. However, the sample needed to obtain such a designbased estimator (Smith, 1990) for wild populations might be too ...

BACKGROUND The purpose of this study was to investigate the lifetime prevalence of teenage pregnancy in the histories of detained adolescent females and to examine the relationship between teenage pregnancy on the one hand and mental health and sexuality related characteristics on the other. METHODS Of 256 admitted detained adolescent females aged 12-18 years, a representative sample (N = 212...