Seasonal distribution of the birth dates of 405 pre-menopausal and 285 post-menopausal breast cancer patients was investigated in order to determine whether or not the season of their birth was related to various reproductive risk factors of breast cancer, including nulliparity, late age at first birth, early age at menarche, late age at menopause, and a history of benign breast diseases. The s...

Sensory plasticity related to reproductive state, hormonal profiles, and experience is widespread among vertebrates, including humans. Improvements in audio-vocal coupling that heighten the detection of conspecifics are part of the reproductive strategy of many nonmammalian vertebrates. Although seasonal changes in hearing are known, molecular mechanisms determining this form of adult sensory p...

The pampas deer (Ozotoceros bezoarticus) is a South American grazing deer which is in extreme danger of extinction. Very little is known about the biology of the pampas deer. Moreover, most information has not been published in peer-reviewed scientific journals, and is only available in local publications, theses, etc. Therefore, our aim was to update and summarize the available information reg...

Michelle L. Sauther Department of Anthropology Washington University St. Louis, MO 63130 U.S.A. Stresses imposed on female lemurs by adapting their reproductive events to seasonal resource availability may be exacerbated by high preand post-natal maternal investment and by group living. Within such a context female dominance can be seen as a critical behavior, enabling females to coexist with m...

Although artificial control of the light cycle can be used to regulate the seasonal reproductive cycle of many animals under laboratory conditions, such regulation is often not possible in a standard agricultural environment. An alternative strategy for regulating the seasonal reproductive cycle of photoperiodic animals is to use drugs that either mimic the effects of light on reproductive func...

The seasonal dynamics of biological traits in a population of European bitterling Rhodeus amarus from a small river in central Europe (River Kyjovka, Czech Republic) were investigated from April 2007 to March 2008. The reproductive season lasted from early April to mid-June, with a peak in late April when > 50% of females possessed ripe eggs in their ovaries. The sex ratio was female-biased, wi...

In seasonal breeding vertebrates, hormone regulation of catecholamines, which include dopamine and noradrenaline, may function, in part, to modulate behavioral responses to conspecific vocalizations. However, natural seasonal changes in catecholamine innervation of auditory nuclei is largely unexplored, especially in the peripheral auditory system, where encoding of social acoustic stimuli is i...