This paper studies the properties of a new class of demographic parameters for age-structured populations and analyzes the effect of natural selection on these parameters. Two new demographic variables are introduced: the entropy of a population and the reproductive potential. The entropy of a population measures the variability of the contribution of the different age classes to the stationary...

Potential reproductive effects from occupational exposures to ethylene glycol ethers (EGE) are of concern since these organic solvents have been used widely in industry, and their reproductive toxicity has been well documented in animal studies. For determination of whether occupational exposure to EGE was associated with increased risks of spontaneous abortion and subfertility (i.e., taking mo...

A short-term Tisbe battagliai toxicity test design was used to assess the potential ecological effects of pollutants in coastal marine communities. By exposing nauplii and reproductive females over 4 and 6 d, respectively, to 3 toxic substances (fluoranthene, cypermethin and deltamethrin), the bioassay was seen to successfully measure survival effects on egg, nauplii and adults and sublethal ef...

Traditionally, drug toxicity in the reproductive system has been a concern only as it affects fertility and fecundity in young individuals. The purpose of this report is to address the potential problem of synergy between drug actions and abnormal secretion of reproductive hormones that together produce disease in older individuals. Thus, reproductive toxicity has different, but no less serious...

objective(s):the present study was undertaken to determine the effects of acute exposure to malathion on oxidative stress and cytotoxic potential of anticholinesterase insecticide, malathion in reproductive toxicology of adolescent male mice. materials and methods: thirty two adolescent male mice at pubertal age were treated with 500 mg/kg body weight (bw) of malathion for three days. after exp...

Background Polycystic ovary syndrome is a frequent condition in women of reproductive age with prevalence rate of 5-10%. This study purposed to determine the relationship between polycystic ovary syndrome and the outcome of assisted reproductive treatment (ART) cycle in Tehran, Iran. MaterialsAndMethods In this historical cohort study, 996 infertile women who were referred to Royan Institute (T...

In recent years, studies have shown that reproductive effort decelerates in response to pathogenic infection. If infection substantially reduces a host's residual reproductive value (RRV), however, then an acceleration of effort may instead occur (e.g. terminal investment). Reproductive acceleration would theoretically allow hosts to maintain or exaggerate their sexual signal upon infection. Th...

Xanthine oxidase plays crucial roles in the production of reactive oxygen species (ROS), and uric acid in blood which may lead to gout, one of the oldest known forms of arthritis amongst humans. Summer savory (Satureja hortensis L.) a medicinal/spice exhibits antioxidant activity, but unknown effects on xanthine oxidase activity. Here, for the first time, we examined the effects of S. hortensis...

Variation in habitat quality is common across terrestrial, freshwater, and marine habitats. We investigated how habitat quality influenced the reproductive potential of mud crabs across 30 oyster reefs that were degraded to different extents. We further coupled this field survey with a laboratory experiment designed to mechanistically determine the relationship between resource consumption and ...

Habitat isolation occurs when habitat preferences lower the probability of mating between individuals associated with differing habitats. While a potential barrier to gene flow during ecological speciation, the effect of habitat isolation on reproductive isolation has rarely been directly tested. Herein, we first estimated habitat preference for each of six populations of the gall wasp Belonocn...