Cardiovascular disease may begin early in adolescence. Platelets release factors contributing to vascular disease. Experiments were designed to test the hypothesis that hormonal transitions associated with sexual maturity differentially affect platelet aggregation and secretion in males and females. Platelets were collected from juvenile (2-3 mo) and sexually mature (adult; 5-6 mo) male and fem...

Dr. RAYMOND PEARL (1912) was the first worker to suggest that sexlinked factors were involved in the inheritance of fecundity. PEARL used as a measure of fecundity the eggs produced during the winter period. He proposed that two major dominant factors were responsible for high egg production, one of which resided in the sex chromosome. GOODALE (1919) and HURST (1921) each failed to confirm the ...

We studied the time of initial sexual maturity and the fecundity of the goldfish Carassius auratus under semi-controlled conditions. During the study the water temperature fluctuated from 21 to 30 degrees C, the pH between 7 and 8, and the dissolved oxygen between 5.5 and 7 ppm. Sixty days old juvenile fish received prophylactic treatments of brackish water (15 per thousand) and methylene blue ...

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species. 2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on...

OBJECTIVES This study examined the roles of identity formation and moral identity in predicting college student mental health (anxiety and depressive symptoms), health-risk behaviors (hazardous alcohol use and sexual risk taking), and psychological well-being (self-esteem and meaning). METHOD The sample comprised 9,500 college students (aged 18-25 years, mean = 19.78, standard deviation = 1.6...

Hon-Tsen Yu and Yao-Sung Lin (1999) Age, reproduction, and demography of the spiny rat (Muridae: Niviventer coxingi) in subtropical central Taiwan. Zoological Studies 38(2): 153-163. Annual reproductive cycles and demographic changes in a wild population of the spiny rat (Niviventer coxingi) in central Taiwan were studied. Reproductive status of the rat was investigated by autopsy and histologi...

Puberty is an important stage of development as a child's sexual and physical characteristics mature because of hormonal changes. To better understand puberty-related effects on brain development, we investigated the magnetic resonance imaging (MRI) data of 306 subjects from 4 to 18 years of age. Subjects were grouped into before and during puberty groups according to their sexual maturity leve...

The interrelationships among five measures of physiologic maturity for 50 French-Canadian girls are evaluated--menarche, peak height velocity (PHV), 75% skeletal maturity, appearance of the ulnar sesamoid, and 90% dental development. The mean ages of occurrence of the events differed significantly (P less than 0.01). Menarche and 90% dental maturity showed the least variability. Ages of PHV, me...

The morphology and histology of the cetacean adrenal gland are poorly understood. Therefore, this study examined 32 pairs of adrenal glands from 18 pan-tropical spotted dolphins (Stenella attenuata) and 14 spinner dolphins (Stenella longirostris). In both species, the cortex was pseudolobulated and contained a typical mammalian zonation. Medullary protrusions (0-3 per section) and a medullary b...

We examined the effects of light intensity (LI) from photostimulation to 45 wk of age on egg production parameters and egg size characteristics and on ovarian and carcass morphology at sexual maturity and 45 wk of age in four layer strains. Floor housed pullets were raised in a light-tight facility from 1 d of age until housing in individually illuminated cages at 17 wk of age. Two white egg st...