BACKGROUND We aimed to estimate the median ages at specific stages of sexual maturity stratified by excess weight in boys and girls. MATERIALS AND METHOD This was a cross-sectional study made in 2007 in Florianopolis, Brazil, with 2,339 schoolchildren between 8 to 14 years of age (1,107 boys) selected at random in two steps (by region and type of school). The schoolchildren were divided into:...

Sex differences in early development may play an important role in the expression of sexual size dimorphism at the adult stage. To test whether sexual size dimorphism is present in pre-emergent chinook salmon (Oncorhynchus tshawytscha), alevins were reared at two temperatures (10 °C and 15 °C) and sexed using the OtY1 marker on the Y-chromosome. Linear mixed models were used to test for sex dif...

In order to examine the relation between intra-sexual fightings and sexual maturity, observations of tooth scars on the head of sperm whales (Physeter catodon) were made collected in South Pacific Oceans during 10 to 18 March 1979 on the Nisshin maru No. 3. Tooth scars on the head were observed on 48 males based on the following four relative stages; none, indistinct, distinct and heavy. Distin...

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...

The main types of reproductive system structure, development and functions in cephalopods are described from personal observations and use of the literature. There is one type in males and three in females which are order specific. These have provided a basis for examining possible evolutionary trends in reproductive system development and in reproductive strategies within coleoid cephalopods a...

To reveal the reproductive biology in male bottlenose dolphins (Tursiops truncatus), circulating gonadotropins (follicle stimulating hormone [FSH] and luteinizing hormone [LH]) and testicular hormones (testosterone and inhibin) were monitored for 8-12 years in 2 captive bottlenose dolphins (Mars and Regulus). During the study period, Mars was undergoing sexual maturation, whereas Regulus was al...

hook worm (necator americanus) is one of the major pathogenic parasites in the north of iran. neonatal hamsters 1-3 days old showed a high degree of susceptibility to necator americanus infection and the parasite reached to sexually mature stages in six weeks following skin exposure. this method could be used for production of egg, larvae and adult worms. in this study neonatal hamsters were in...

size at sexual maturity and patterns of somatic growth are important aspects of reproductive history of crab. the main purpose of this study is to provide an estimate for the onset of morphological sexual maturity in mangrove crab, opusia indica from a population located in korangi creek intertidal mud flat (karachi, pakistan) based on relative growth. the crabs were monthly collected through q...

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...

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...