نتایج جستجو برای: reproductive behaviors
تعداد نتایج: 220637 فیلتر نتایج به سال:
It is well established that, over the course of development, hormones shape the vertebrate brain such that sex specific physiology and behaviors emerge. Much of this occurs in discrete developmental windows that span gestation through the prenatal period, although it is now becoming clear that at least some of this process continues through puberty. Perturbation of this developmental progressio...
BACKGROUND Reproductive behaviors--such as age of childbearing, parity, and breast-feeding prevalence--have changed over the same historical time period as emissions of polychlorinated biphenyls (PCB) and may produce intergenerational differences in human PCB exposure. OBJECTIVES Our goal in this study was to estimate prenatal, postnatal, and lifetime PCB exposures for women at different ages...
he remarkable benefits of estrogen replacement therapy in preventing cardiovascular illness and osteoporosis in postmenopausal women are well known. However, hormone replacement therapy is not just for the women’s health physician to prescribe. Recent advances in neurobiology have demonstrated that estrogen exerts dramatic effects on the central nervous system (CNS). Psychiatrists are beginning...
The majority of anuran amphibians (frogs and toads) use acoustic communication to mediate sexual behavior and reproduction. Generally, females find and select their mates using acoustic cues provided by males in the form of conspicuous advertisement calls. In these species, vocal signal production and reception are intimately tied to successful reproduction. Research with anurans has demonstrat...
BACKGROUND Medicinal leeches (Hirudo spp.) are simultaneous hermaphrodites. Mating occurs after a stereotyped twisting and oral exploration that result in the alignment of the male and/or female gonopores of one leech with the complementary gonopores of a partner. The neural basis of this behavior is presently unknown and currently impossible to study directly because electrophysiological recor...
to establish the behavioral indicator of reproductive success of female captive alpine musk deer(moschus sifanicus), the focal sampling was used to record the individual behaviors at xinglongshan muskdeer farm (xmdf), gansu province, china. conducted between june 2008 and january 2009, 31 adultfemales were observed, of which 26 had successfully bred in the previous year, and five of which wereb...
Little is known about the reproductive behaviors and the actual outcomes of mating attempts in the gopher tortoise (Gopherus polyphemus). We examined the mating system and reproductive behaviors of a population of gopher tortoises in central Florida. Using microsatellite markers, we assigned fathers to the offspring of seven clutches and determined that multiple fathers were present in two of t...
Despite impressive global investment in reproductive health programs in West Africa, maternal mortality remains unacceptably high and obstetric care is often inadequate. Fertility is among the highest in the world, while contraceptive prevalence remains among the lowest. This paper explores the social and technical dimensions of this situation. We argue that effective reproductive health progra...
Social changes have rapidly removed arranged marriages and it seems the change in marriage pattern has played a role in childbearing. On the other hand, there is a great reduction in population in many countries which requires a comprehensive policy to manage the considerable drop in population. To achieve this goal, initially, the factors affecting fertility must be precisely identified. This ...
In addition to its well documented action in female-typical behaviors, progesterone exerts an influence on the brain and behavior of males. This review will discuss the role of progesterone and its receptor in male-typical reproductive behaviors in adulthood and the role of progesterone and its receptor in neural development, in both sexual differentiation of the brain as well as in the develop...
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