BACKGROUND Why do males and females behave differently? Sexually dimorphic behaviors could arise from sex-specific neurons or by the modification of circuits present in both sexes. C. elegans males exhibit different behaviors than hermaphrodites. Although there is a single class of sex-specific sensory neurons in the head of males, most of their neurons are part of a core nervous system also pr...

Hepatic sterol carrier protein-2 (SCP2) and sterol carrier protein-X (SCPx) levels in normal and in mutant Niemann-Pick Type C mice were determined by immunoblotting with antiserum against rat SCP2. A 14-kDa protein (SCP2) was detected in the cytosol fraction and a 58-kDa protein (SCPx) was found in both cytosolic and organellar fractions. Expression of hepatic SCPx protein was developmentally ...

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...

Background: In this study, we report the first case of a male reef manta ray, Mobula alfredi, becoming sexually mature in captivity and present its reproductive characteristics. Methods: We investigated changes in external morphology, behavior, and levels of steroid hormones in a male M. alfredi during its sexual maturation process. Results: At 2 years and 6 months of age, the male exceeded 300...

This article presents an overview of the maturation process in children and discusses data from some Brazilian samples. Data related to secondary sexual characteristics in both sexes are compared to other populations. The national median menarcheal age in Brazilian girls obtained by INAN (1990) was 13.2 years. The menarcheal age of Brazilian athletes is higher than the non-athletic population. ...

OBJECTIVES Describe the characteristics of body composition, somatotype, basic physical qualities, dermatoglyphics and bone age regarding sexual maturation stages of boys. METHODS A transversal study was carried out in 136 boys, between 10 and 14 years of age. Clinical assessment, physical examination and radiography of wrists and hands to calculate bone age were performed. RESULTS A tenden...