نتایج جستجو برای: reproductive behavior
تعداد نتایج: 708940 فیلتر نتایج به سال:
Sexual reproduction requires coordinated contributions from both sexes to proceed efficiently. However, the reproductive strategies that the sexes adopt often have the potential to give rise to sexual conflict because they can result in divergent, sex-specific costs and benefits. These conflicts can occur at many levels, from molecular to behavioral. Here, we consider sexual conflict mediated t...
Understanding speciation hinges on understanding how reproductive barriers arise between incompletely isolated populations. Despite their crucial role in speciation, prezygotic barriers are relatively poorly understood and hard to predict. We use two closely related cricket species, Gryllus bimaculatus and G. campestris, to experimentally investigate premating barriers during three sequential m...
Relatives play an important role in human reproduction according to evolutionary theories of reproductive behavior, but previous empirical studies show large differences in the effects of kin on fertility outcomes. In our paper we examine the effect of co-resident kin and non-kin on the length of birth intervals over the reproductive life course of Dutch women born between 1842 and 1920. We est...
The sex of surviving children is an important determinant of reproductive behaviour in South Asia in general and Pakistan in particular. This cohort study evaluates the role of the sex of children on reproductive intentions and subsequent behaviour of women in urban slums of Karachi, Pakistan. The analysis is based on two rounds of surveys conducted in 1990-91 and 1995 of a cohort of married wo...
Sound duration can play a pivotal role in the reproductive behavior of anuran amphibians. Here, we report the first whole-cell recordings from duration-selective neurons in the anuran torus semicircularis, in vivo. We show that most short-pass duration-selective cells exhibited short-latency inhibition and delayed excitation. The duration of the inhibition increased with tone burst duration. He...
Reproductive wastage was investigated over two seasons in ten Merino flocks grazing pastures based on oestrogenic subterranean clover. Only 65 percent of ewes were served during the first 16 days of joining. Ovulation rates were low, averaging 1.13. Fertilization rates (73%) were low when compared with flocks unaffected by oestrogenic pastures. Embryonic mortality varied considerably between pr...
Given the recent increase in the prevalence of cohabiting unions in Botswana, this paper speculates on the role this type of union plays in contemporary Botswana family system. The analysis is based on the combination of qualitative and quantitative data from the 2001 Cohabitation Survey and the 1996 Botswana Family Health Survey respectively. The overall results reveal that cohabitation differ...
introduction: diabetes mellitus is an growing national and international public health concern. the number of people affected by diabetes in world by 2030 will be 69% in developing countries. regular physical activity plays a key role in the management of type 2 diabetes melitus, particularly glycemic control. it has been recommended that peoples with type 2 diabetes participate in moderate-int...
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