Due to socioeconomic factors, more couples are choosing to delay conception than ever. Increasing average maternal and paternal age in developed countries over the past 40 years has raised the question of how aging affects reproductive success of males and females. Since oxidative stress in the male reproductive tract increases with age, we investigated the impact of advanced paternal age on th...

CONTEXT The age of puberty has fallen over the past 130 years in industrialized, western countries, and this fall is widely referred to as the secular trend for earlier puberty. The current study was undertaken to test two evolutionary theories: (a) the reproductive system maximizes the number of offspring in response to positive environmental cues in terms of energy balance, and (b) early pube...

OBJECTIVE The aim of the study was to understand the association between women's reproductive history and their risk of developing type 2 diabetes. We hypothesized that characteristics signifying lower cumulative endogenous estrogen exposure would be associated with increased risk. METHODS Prospective cohort analysis of 124,379 postmenopausal women aged 50 to 79 years from the Women's Health ...

Abstract All animals, including carnivores, adapt their daily activity duration and distribution to satisfy food demands, breed, or avoid mortality risk. We used the kernel density method estimate movement levels patterns of jaguars in Hato Piñero, Venezuelan Western Llanos, based on 3,656 jaguar detection time records from two a half years camera trapping. Jaguars were active for 11.7 h per da...

I present a hierarchy of models that illustrate, within the framework of inclusive fitness theory, how demographic factors can predispose a species to the evolution of eusociality. Delayed reproductive maturation lowers the inclusive fitness of a solitary foundress relative to that of a worker. Variation in age at reproductive maturity makes the worker strategy more profitable to some individua...

In most vertebrates, production of reproductive hormones wanes with age, co-occurring with a decline in reproductive output. Measurement of these hormones can serve as a key marker of the onset of reproductive senescence. Longitudinal studies of physiological parameters in populations of free-living animals are relatively uncommon; however, we have monitored baseline concentrations of hormones ...

We studied reproductive and somatic investments in /700 female Richardson’s ground squirrels (Spermophilus richardsonii ) of known age over a 14-year period to evaluate three hypotheses, restraint, senescence, and residual reproductive value, proposed to explain age-specific life history patterns in iteroparous vertebrates. We found that reproductive investment, measured as litter mass at first...

BACKGROUND Malignancies of the female reproductive tract are estimated to be the third most common group of cancers in women. OBJECTIVES We here aimed to present their epidemiological features in Golestan province located in Northeast of Iran. MATERIALS AND METHODS Data on primary female reproductive cancers diagnosed between 2004-2010 were obtained from Golestan Population-based Cancer Reg...