The effect of nest aggregation in courtship behaviour was tested experimentally in an ecologically constrained, sex-role reversed population of the peacock blenny Salaria pavo. Mixed sex groups of eight males and eight females were tested in experimental tanks, containing eight potential nests either aggregated or dispersed. In the aggregated treatment, males spent more time inside their nests ...

Fertility declines across Europe and the Anglo-world have been explained as the result of reversals of intergenerational flows of wealth. According to this theory, the child was transformed from an economically-useful household asset to an emotionally-valued parental burden. This article is based on a comparative study of changing understandings of parenthood in three provincial English localit...

objective: to evaluate reproductive health education which is essential to the prevention of sexual risk behavior and its associated adverse outcomes of unwanted pregnancy, aids and other sexually transmitted disease in adolescents. little is known about youth educational needs about reproductive health in iran. the aim of this study is evaluation of female youth educational needs about reprodu...