BACKGROUND Dioxins, furans, and polychlorinated biphenyls (PCBs), dioxin-like and non-dioxin-like, have been linked to alterations in puberty. OBJECTIVES We examined the association of peripubertal serum levels of these compounds [and their toxic equivalents (TEQs)] with pubertal onset and maturity among Russian boys enrolled at ages 8-9 years and followed prospectively through ages 17-18 yea...

Cigarette smoking has been hypothesized to have a carcinogenic effect on breast tissue, particularly when exposure occurs before sexual maturity and breast tissue differentiation (1). Epidemiologic studies of cigarette smoking on breast cancer risk during this developmental period have produced inconsistent results (2-14). However, recent cohort studies (7-10), including two with mainly young w...

Blacktip reef sharks Carcharhinus melanopterus were the most abundant predator in the lagoons at Palmyra Atoll. They were evenly distributed throughout the lagoons, although there was some evidence of sexual segregation. Males reach sexual maturity between 940-1,020 mm L(T). Bird remains were found in some C. melanopterus stomachs. C. melanopterus at Palmyra appear to be smaller than those at o...

Keeping Japanese quail is an economic way for producing egg, because of their early sexual maturity (laying egg after 35 days), high egg production (250–270 eggs per year), resistance to most of poultry disease and great egg production persistency on a high level (approximately 14–18 months) (MURAKAMI and ARIKI, 1998). Japanese quail maturation happens in about 6 weeks of age and mature females...

A large body of work on monkey cranial metrics (involving conclusions about interspecific variation, sexual dimorphism, and ontogeny) depends on the assumptions that growth effectively ceases with dental maturity and that intraspecific variation is negligible. We test these assumptions by examining variation in 39 measurements of 166 dentally mature Alouatta palliata skulls from animals found d...

An appropriate dietary CP level and feeding regimen during rearing is considered important for controlling BW and improving semen production in broiler breeder males. A total of 640 day-old broiler breeder male chicks of two commercial strains (A and B) received treatments of a factorial arrangement of two CP levels (12 and 16%) of corn-soybean grower diets and two feeding regimens [changing fe...

Reproductive biology is important in formulating management interventions for fish stocks. Limits on catch size are established based the identified at first sexual maturity of target species, which can be accurately determined through histological analysis gonads. The study investigated reproductive characteristics endangered Sardinella tawilis and analysis. Between 2017 2018, 312 samples with...

The effects of various social contexts on sexual maturation in captive male prairie voles were investigated. Sexual maturity was assessed as the ability of a young male to produce urine capable of activating a diestrous adult female into estrus, as females remain anestrus until they ingest a male urinary chemosignal. In five experiments the postweaning social environments of developing males we...