The 1982 and 1990 census data showed the sex ratio of Tibet's population increased from 97.76 to 100.16.But it was still low as compared with the natianal average of 106.6.The sex ratio at birth of Tibet s populat...The 1982 and 1990 census data showed the sex ratio of Tibet's population increased from 97.76 to 100.16.But it was still low as compared with the natianal average of 106.6.The sex ratio at birth of Tibet s population also rose fram 99.42 in 1982 to 100.31 in 1990.However,they are lower than the corre sponding national figures.展开更多
Definition： The final net live birth delivery from the mother＇s womb, with distinct male and female genetic traits, forms a ratioof male live births per 100 female live births, termed as Sex Ratio at Birth （SRB）. ...Definition： The final net live birth delivery from the mother＇s womb, with distinct male and female genetic traits, forms a ratioof male live births per 100 female live births, termed as Sex Ratio at Birth （SRB）. Study areas and source of data： The studyareas are Africa and major worldwide continents and countries. The basic data are compiled from the National Populationand Housing Censuses, Demographic Sample Surveys, Demographic and Health Surveys, and Vital Registration Systems.Analytical approaches： The factors influencing the variations in SRB are identified by reviewing various documents, analysisof variance （ANOVA） techniques, and statistical measures of central tendency and dispersion. Results： The ratios areconsistently higher for advanced countries than the developing countries, with highest for China and India. The ANOVAresults show slight differences among the S0 African countries but show differences among the African regional states,whereas the standard deviation of the SRB among the advanced countries, including some Asian and Latin Americancountries shows non-significant variations. In conclusion, the mean SRB for African populations is 103 as against 106 forother countries.展开更多
Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distr...Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distributed nonhuman primate species and the Taihangshan macaque(Macaca mulatta tcheliensis)occupies the northern limit of all rhesus macaque natural populations worldwide.We observed one macaque troop(Wangwu-1[WW-1])inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013.Our aim was to apply the Trivers–Willard hypothesis to this free-ranging rhesus macaque troop,and to understand the relationship between climatic parameters(precipitation and temperature)and birth sex ratio.We found that the total newborn macaques showed a female-biased sex ratio at birth in the WW-1 troop,but there were no significant biased birth sex ratios in all matriarchs and in high-ranking and middle-ranking matrilineal units.However,the low-ranking macaque matrilineal unit was significantly female-biased.Moreover,we found that the annual precipitation of the previous year was positively associated with the birth sex ratio,and there was an interactive effect of troop size and current winter temperature on the birth sex ratio.The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex,and we discuss several plausible explanations.展开更多
Women’s emancipation is an important part of the people’s liberation movement led by the Communist Party of China.Improving women’s political status is the basic condition for improving their social welfare rights ...Women’s emancipation is an important part of the people’s liberation movement led by the Communist Party of China.Improving women’s political status is the basic condition for improving their social welfare rights and interests.Based on the data from county gazetteers covering more than 1,700 counties,the censuses of 1990 and 2000,and other representative surveys,we conducted an empirical study on the long-term effect of women’s political status on the sex ratio at birth.Our research found that the higher the ratio of female Communist Party members in each county in 1950,the more normal was the sex ratio at birth in the following 50 years.The improved political status of women aged 16-20 significantly raised the proportion of girls among surviving children,especially in the era of family planning.This demographic study provides empirical historical evidence for the first time on one aspect of the long-term social impact of the mission of the Chinese people’s liberation.展开更多
The sex ratio at birth(SRB)in China began to rise rapidly in the 1980s and declined after 2009.The ratio has maintained a downward trend since 2009,but is still higher than the normal level.The government of China has...The sex ratio at birth(SRB)in China began to rise rapidly in the 1980s and declined after 2009.The ratio has maintained a downward trend since 2009,but is still higher than the normal level.The government of China has committed to redress the distortions in SRB and has initiated multiple actions to accomplish that end.Against a background of economic development,accelerating modernization and the empowerment of women,China has strengthened governance and made significant progress in balancing the sex ratio at birth.This paper examines the trend for SRB in China,summarizes the practices that address gender imbalance at birth,and analyzes the challenges ahead.展开更多
文摘The 1982 and 1990 census data showed the sex ratio of Tibet's population increased from 97.76 to 100.16.But it was still low as compared with the natianal average of 106.6.The sex ratio at birth of Tibet s population also rose fram 99.42 in 1982 to 100.31 in 1990.However,they are lower than the corre sponding national figures.
文摘Definition： The final net live birth delivery from the mother＇s womb, with distinct male and female genetic traits, forms a ratioof male live births per 100 female live births, termed as Sex Ratio at Birth （SRB）. Study areas and source of data： The studyareas are Africa and major worldwide continents and countries. The basic data are compiled from the National Populationand Housing Censuses, Demographic Sample Surveys, Demographic and Health Surveys, and Vital Registration Systems.Analytical approaches： The factors influencing the variations in SRB are identified by reviewing various documents, analysisof variance （ANOVA） techniques, and statistical measures of central tendency and dispersion. Results： The ratios areconsistently higher for advanced countries than the developing countries, with highest for China and India. The ANOVAresults show slight differences among the S0 African countries but show differences among the African regional states,whereas the standard deviation of the SRB among the advanced countries, including some Asian and Latin Americancountries shows non-significant variations. In conclusion, the mean SRB for African populations is 103 as against 106 forother countries.
基金We acknowledge the editors for their effort in communication between us and reviewers.Thanks to the three anonymous reviewers for their constructive criticisms which help to improve the early version of our manuscript greatly.We are grateful to Wang Haofeng,Wang Yonghong,Hou Jiafu,Kong Maocai,and Hou Xiquan for assistance in the field.We appreciate Professor Paul A.Garber(University of Illinois,USA)for his editing and suggestion on our manuscript.We especially thank the Jiyuan Administration of Taihangshan Macaque National Nature Reserve for permission and logistic support to this research.This research was financially supported by the National Natural Science Foundation of China(No.30970378 and 31170503).The authors declare no conflict of interest.
文摘Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distributed nonhuman primate species and the Taihangshan macaque(Macaca mulatta tcheliensis)occupies the northern limit of all rhesus macaque natural populations worldwide.We observed one macaque troop(Wangwu-1[WW-1])inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013.Our aim was to apply the Trivers–Willard hypothesis to this free-ranging rhesus macaque troop,and to understand the relationship between climatic parameters(precipitation and temperature)and birth sex ratio.We found that the total newborn macaques showed a female-biased sex ratio at birth in the WW-1 troop,but there were no significant biased birth sex ratios in all matriarchs and in high-ranking and middle-ranking matrilineal units.However,the low-ranking macaque matrilineal unit was significantly female-biased.Moreover,we found that the annual precipitation of the previous year was positively associated with the birth sex ratio,and there was an interactive effect of troop size and current winter temperature on the birth sex ratio.The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex,and we discuss several plausible explanations.
文摘Women’s emancipation is an important part of the people’s liberation movement led by the Communist Party of China.Improving women’s political status is the basic condition for improving their social welfare rights and interests.Based on the data from county gazetteers covering more than 1,700 counties,the censuses of 1990 and 2000,and other representative surveys,we conducted an empirical study on the long-term effect of women’s political status on the sex ratio at birth.Our research found that the higher the ratio of female Communist Party members in each county in 1950,the more normal was the sex ratio at birth in the following 50 years.The improved political status of women aged 16-20 significantly raised the proportion of girls among surviving children,especially in the era of family planning.This demographic study provides empirical historical evidence for the first time on one aspect of the long-term social impact of the mission of the Chinese people’s liberation.
文摘The sex ratio at birth(SRB)in China began to rise rapidly in the 1980s and declined after 2009.The ratio has maintained a downward trend since 2009,but is still higher than the normal level.The government of China has committed to redress the distortions in SRB and has initiated multiple actions to accomplish that end.Against a background of economic development,accelerating modernization and the empowerment of women,China has strengthened governance and made significant progress in balancing the sex ratio at birth.This paper examines the trend for SRB in China,summarizes the practices that address gender imbalance at birth,and analyzes the challenges ahead.
