نتایج جستجو برای: fertility success
تعداد نتایج: 217483 فیلتر نتایج به سال:
Reduced reproductive success of birds nesting near power lines has been documented but never directly attributed to electromagnetic fields (EMFs). Laboratory studies have identified EMF effects on embryonic development, but reproductive success of wild birds is dependent on additional factors, including fertility, egg size, hatching, and fledging success. We tested whether EMFs affect reproduct...
In species where males express carotenoid-based sexual signals, more intensely coloured males may be signalling their enhanced ability to combat oxidative stress. This may include mitigating deleterious oxidative damage to their sperm, and so be directly related to their functional fertility. Using a split-clutch in vitro fertilization technique and dietary carotenoid manipulation, we demonstra...
Female choice experiments were used to investigate the effect of relative male age on mating success in D. melanogaster. Experiments were conducted with a Canton-S (CS) strain, in which two virgin males of different ages (2, 4, or 8 days old) were offered to virgin females. Older males were found to be more successful under competitive conditions in another group of experiments, vermilion (v) m...
Iran's significant success in implementing Family Planning (FP) during the past 25 years, has made it a role model in the world. The Total Fertility Rate (TFR) in Iran has dropped from 6.5 in 1960 to 1.6 in 2012, which is well below the targeted value of 2.2 for the country. Iran's success story, however, did not merely root in the implementation of FP programs. In other words, families' strong...
The degree to which biocontrol agents impact invasive plants varies widely across landscapes, often for unknown reasons. Understanding this variability can help optimize invasive species management while also informing our understanding of trophic linkages. To address these issues, we tested three hypotheses with contrasting predictions regarding the likelihood of biocontrol success. (1) The bi...
The idea that trade-offs between offspring quantity and quality shape reproductive behaviour has long been central to economic perspectives on fertility. It also has a parallel and richer theoretical foundation in evolutionary ecology. We review the application of the quantity-quality trade-off concept to human reproduction, emphasizing distinctions between clutch size and lifetime fertility, a...
OBJECTIVE To measure the parental attitudes toward fertility preservation in boys with cancer. DESIGN Retrospective cohort study. SETTING Questionnaire survey via regular mail. PATIENT(S) A total of 465 families whose sons were already treated for cancer. INTERVENTION(S) The questionnaire was designed for two groups based on child's age at the time of cancer diagnosis: <12 and ≥12 years...
It is now more than three decades since the first live birth from oocyte cryopreservation. At present, oocyte cryopreservation has become a major component of Assisted Reproductive technologies (ART). Across the world, there is an increasing demand, especially for so-called ‘social egg freezing’ that allows women to preserve their fertility in anticipation of age-related fertility d...
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