OBJECTIVES Ascertaining the age when the menarche occurs in school girls living in Angra dos Reis/RJ and the pattern of physical qualities in periods during puberty using the menarche as the benchmark for sexual maturation. METHODS The sample consisted of 232 10-to 16-year-old girls, divided into four groups according to sexual maturation. Following an interview during which the onset of the ...

BACKGROUND Pairing of Schistosoma males and females leads to and maintains female sexual maturation. However, the mechanism by which pairing facilitates sexual maturation of females is not clear. An increasing body of evidence suggests that ribosomal proteins have regulatory rather than constitutive roles in protein translation. METHODOLOGY/PRINCIPAL FINDINGS To investigate the effect of ribo...

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random ef...

Purpose Exposure to various stressors, including psychological, metabolic, and immune, in the perinatal period induces long-lasting effects in physiological function and increase the risk of metabolic disorders in later life. In the present study, sexual maturation and sexual behavior were assessed in prenatally undernourished mature male rats. Methods All the pregnant rats were divided into ...

This study was carried out to determine population structure, growth and reproduction properties of barbel. A total of 198 individuals were sampled. Ages of samples were found between I and VI years, fork lengths between 4.3 and 16.6 cm and total weights between 1.2 and 65.8 g. Length-weight relationship was calculated as W=0.0146×L2.934. Munro’s phi prime index was estimated as 1.9...

Currently, blood levels to define vitamin deficiency or optimal status in adolescents are extrapolated from adults. This may be not adequate as vitamin requirements during adolescence depend on the process of sexual maturation, rapid increasing height and weight, among other factors. In order to establish the state of the art, Medline database (www.ncvi.nlm.nih.gov) was searched for studies pub...

Human offspring are weaned earlier than the offspring of other great apes but take longer to reach nutritional independence. An analysis of human disorders of imprinted genes suggests genes of paternal origin, expressed in infants, have been selected to favor more intense suckling than genes of maternal origin. The same analysis suggests that genes of maternal origin may favor slower childhood ...

Annual migration of pests between different seasonal habitats can lead to serious crop damage. Reproductive immaturity is generally associated with the migratory process (oogenesis-flight syndrome), but the mechanism of reproductive development during migration varies unpredictably. Here, the vitellogenin gene (MsVg) and three key regulatory enzyme genes (MsJhamt, MsJheh and MsJhe) related to j...

Effects of rearing conditions were examined in the development of agonistic behaviors in the male fighting fish. In group-I (highly social), fish were communally reared. In group-II (highly social and isolate), fish were individually housed and exposed to the group-I fish through transparent walls until the sexual maturity (from 6 to 12 weeks post-hatch). In group-III (social and isolate), indi...

In 2002, the Centre for Environment and Health in Flanders, Belgium started a human biomonitoring program. For 1679 adolescents, residing in nine study areas with differing pollution pressure, hormone levels and the degree of sexual maturation were measured. Possible confounding effects of lifestyle and personal characteristics were taken into account. Participants from the nine different study...