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jpme, 1995
Since the introduction of different ovulation induction regimens the incidence of triplet pregnancies increased from a spontaneous rate of about 1:10,000 to the frequency of nearly 1:1000. Sex ratio of trigemini and male/female proportion of the three newborns within the same triplet set is the amazing issue that we attempted to elucidate in the ...
N, Mordel +5 more
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Since the introduction of different ovulation induction regimens the incidence of triplet pregnancies increased from a spontaneous rate of about 1:10,000 to the frequency of nearly 1:1000. Sex ratio of trigemini and male/female proportion of the three newborns within the same triplet set is the amazing issue that we attempted to elucidate in the ...
N, Mordel +5 more
openaire +2 more sources
Genetica, 1970
It is shown that the well known excess of females in anencephalic births is statistically significant when compared with (a) the general population and (b) their normal sibs.
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It is shown that the well known excess of females in anencephalic births is statistically significant when compared with (a) the general population and (b) their normal sibs.
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Sex differences, sex ratios and sex roles
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1994Sexual selection theory predicts that sex roles will be determined by the operational sex ratio (OSR), the sex ratio among individuals searching for mates at any given time. There are two predictions: (i) the sex which is in 'excess' will be the more competitive sex with respect to access to mates; and (ii) the sex of which there is a 'shortage' will ...
I P, Owens, D B, Thompson
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Group sex ratio and sex reversal
Journal of Theoretical Biology, 1980Abstract In hermaphroditic fishes, the initiation of sex reversal by male removal explains the replacement of lost males but does not explain how the number of males in a group may increase. Since numerous species apparently cannot produce primary males, a second means of initiating sex reversal must exist.
Douglas Y. Shapiro, Roger Lubbock
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Sex Ratio And Placenta Praevia
Acta Obstetricia et Gynecologica Scandinavica, 1989In the authors' Department, 144 cases of placenta praevia were treated in the course of 15 years. This number amounted to 0.54% of all births. The sex ratio of fetuses inassociated with this complication was 166.6, which exceeds that of all neonates during the same period of time.
A A, Jakobovits, L, Zubek
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Sex predetermination and the sex ratio at birth
Social Biology, 1973The possible effects of human sex predetermination on the sex ratio at birth are discussed. Methods exist or are being developed to allow separation of X and Y sperm. If acceptable and reliable methods became available to parents for choosing the sex of their children data indicates that they would be used at least by some people.
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