BACKGROUND Previous studies have shown that age at menopause is an important indicator of duration of endogenous estrogen exposure. The present study investigates whether combining more information on reproductive factors is useful in estimating individual total duration of exposure to endogenous estrogens. METHODS Bone mineral density (BMD) was used as operational outcome. The study populati...

chainsaw is an important machine for tree felling limbing and bucking in hyrcanian forest and the major problems related to using forest machines was sound intensity. the aim of this study was to measure the sound level in occupational exposure of workers, determine the exposure time of workers and comparison of the variables among the workers. this study was carried out in namkhaneh district i...

A woman's reproductive history influences her risk of breast cancer. The authors hypothesized that reproductive history also influences stage of disease at the time of diagnosis. The authors analyzed a population-based cohort of 1.5 million Danish women born between 1935 and 1978 for whom individual information on births was available. Between 1978 and 1994, 10,790 incident cases of breast canc...

The role of complement in host resistance to infection with Trypanosoma musculi was studied in normal, C5-deficient, and C3-depleted mice. Infections in normocomplementemic strains (CBA and B10.D2/n) were generally similar to those in strains genetically deficient in C5 (A and B10.D2/o). There were no differences in inhibition of reproduction, duration of infection, persistence of parasites in ...

in order to study of the effect of priming and salinity on physiological and chemical characteristics of wheat(triticum aestivum l.), an experiment was carried out at the experimental farm of shiraz university. results showedthat primed plants significantly reduced its gas exchanges by accelerating senescence under a series of salt stress,which became more serious along with the increasing of s...

in order to study of the effect of priming and salinity on physiological and chemical characteristics of wheat(triticum aestivum l.), an experiment was carried out at the experimental farm of shiraz university. results showedthat primed plants significantly reduced its gas exchanges by accelerating senescence under a series of salt stress,which became more serious along with the increasing of s...

Temperate ectotherms, especially those at higher latitudes, are expected to benefit from climate warming, but few data yet exist to verify this prediction. Furthermore, most previous studies on the effects of climate change utilized a model of uniform annual change, which assumes that temperature increases are symmetric on diurnal or seasonal time scales. In this study, we simulated observed tr...

The reproductive ecology of the freshwater fish Cichla monoculus Spix, 1831 (Osteichthyes: Cichlidae) was investigated in the Campo Grande Reservoir, Northeast Brazil. Rainfall, temperature, pH, dissolved oxygen and electrical conductivity of the water were recorded monthly. Fish collected on a monthly basis were measured, weighted, dissected, sexed and the stage of maturation of the gonads wer...