Results 211 to 220 of about 305,098 (258)
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Human fertility: sociodemographic aspects
Contraception, 2005This study analyzes the sociodemographic factors at the root of the reduction in fertility in developed countries and the way in which these are correlated to the increase in levels of infertility. The postponement of marriage and of bearing the first child, the transition still underway toward nontraditional family forms and unfavorable economic and ...
Antonella, Pinnelli +1 more
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Fertilization abnormalities in human in-vitro fertilization
Human Reproduction, 1992Fertilization abnormalities (premature chromosome condensation of spermatozoa (PCC), triploidy, haploidy) were analysed in order to determine their origin. PCC occurs in 9% of unfertilized oocytes and seems to be the consequence of a failure of oocyte activation, leading to the continuing presence of cytoplasmic chromosome-condensing factors, causing ...
Plachot, M., Crozet, N.
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American Journal of Sociology, 1946
India's population problem might be solved if her traditionally high fertility could be reduced. The present analysis assesses the possibility of such a reduction in the next two or three decades. The birth rate in the past shows no definite downward trend. The rural-urban differential shows no increase in the gap between city and country.
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India's population problem might be solved if her traditionally high fertility could be reduced. The present analysis assesses the possibility of such a reduction in the next two or three decades. The birth rate in the past shows no definite downward trend. The rural-urban differential shows no increase in the gap between city and country.
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JAMA: The Journal of the American Medical Association, 1982
To the Editor.— Regarding the article entitled "Human In Vitro Fertilization: A Conservative View" (1982; 247:3235), I would like to challenge Dr Tiefel on several of the following points. "There is some justification for deeming in vitro fertilization to be harmful to the offspring thus conceived." Actually, there is good reason to believe that ...
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To the Editor.— Regarding the article entitled "Human In Vitro Fertilization: A Conservative View" (1982; 247:3235), I would like to challenge Dr Tiefel on several of the following points. "There is some justification for deeming in vitro fertilization to be harmful to the offspring thus conceived." Actually, there is good reason to believe that ...
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HUMAN FERTILITY IN PUERTO RICO
Obstetrical & Gynecological Survey, 1947The gross reproduction ratio of Puerto Rico has remained unchanged at a level of 2.5 from 1899 to 1940. This has resulted from a decline of marital fertility of about 25 per cent, balanced by an increased frequency of the married state. The decline of marital fertility has been greater in urban than in rural areas.
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Dispermic fertilization of human oocytes
Journal of Electron Microscopy Technique, 1991AbstractRegardless of whether fertilization occurs in vivo or in vitro, polyspermic penetration of the human oocyte is a not infrequent cause of reproductive failure. This report describes the occurrence of human eggs fertilized by two spermatozoa and the variable developmental potentials expressed by the resultant embryos. The cellular and subcellular
J, Van Blerkom, G, Henry
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Sociology, 1968
Recent attempts at a sociological explanation of various aspects of fertility in industrial societies have, with two partial exceptions, failed, and for three reasons: they have placed too great a reliance on survey methods, they have ignored the causal importance of people's intentions, and they have eschewed theory. Recent developments in population
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Recent attempts at a sociological explanation of various aspects of fertility in industrial societies have, with two partial exceptions, failed, and for three reasons: they have placed too great a reliance on survey methods, they have ignored the causal importance of people's intentions, and they have eschewed theory. Recent developments in population
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An Update on Human Fertilization
Seminars in Reproductive Medicine, 1998The process of fertilization and the role that each gamete plays in that process have been the subject of investigation in a large number of species and for many years. However, while much is now known for some species relatively little is known for others.
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Human Fertility and Population Equilibrium
Annals of the New York Academy of Sciences, 1994In preindustrial settings, biological, economic, and social mechanisms caused fertility to respond to feedback signals from population size variation in such a way as to steer populations toward equilibrium levels. It is unlikely that the relevant signal was population density; more plausibly the signal was economic well being, which in turn responded ...
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