Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primate...Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a ＂V＂ style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.展开更多
目的评估妊娠期膳食模式对早产发生风险的影响,为降低早产发生率提供膳食指导依据。方法系统检索PubMed、Web of Science、知网等数据库关于妊娠期膳食模式和早产关联的相关研究,将膳食模式按照食物成分相似性,分为“健康”“不健康”...目的评估妊娠期膳食模式对早产发生风险的影响,为降低早产发生率提供膳食指导依据。方法系统检索PubMed、Web of Science、知网等数据库关于妊娠期膳食模式和早产关联的相关研究,将膳食模式按照食物成分相似性,分为“健康”“不健康”和“混合”3种膳食模式,运用RevMan5.4软件对纳入研究中妊娠期膳食最高和最低依从性的结局效应进行meta分析,并进行亚组分析和敏感性分析。结果最终纳入23篇文献,总样本量312892例。对其中18篇文献进行meta分析结果显示,健康膳食模式依从性高可降低早产发生风险[OR=0.82,95%CI(0.76,0.89)],进行亚组分析和敏感性分析后结局稳定。纳入文献中的健康膳食模式漏斗图不对称,存在发表偏倚。不健康膳食模式和混合膳食模式与早产发生风险之间未发现显著相关性。结论不同的膳食模式对早产的发生风险具有较大影响,妊娠期高摄入水果、蔬菜、全谷物、低脂乳制品、豆类、植物油和鱼类等健康膳食模式可降低早产发生风险。展开更多
基金Foundation items： This study was supported by the National Natural Science Foundation of China （31160422, 30960084）, China Postdoctoral Science Foundation （2013M542379）, Program for New Century Excellent Talents in University （NCET-12-1079）, and Key Subject of Wildlife Conservation and Utilization in Yunnan Province We thank the directors and staff from the Administrative Bureau of Yunling National Reserve, Lanping County, Nujiang Prefecture, Yunan Province, the residents of Dashanqing village and assistants Qing-Sheng Su and Jin-Fu Zhang.
文摘Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a ＂V＂ style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.
文摘目的评估妊娠期膳食模式对早产发生风险的影响,为降低早产发生率提供膳食指导依据。方法系统检索PubMed、Web of Science、知网等数据库关于妊娠期膳食模式和早产关联的相关研究,将膳食模式按照食物成分相似性,分为“健康”“不健康”和“混合”3种膳食模式,运用RevMan5.4软件对纳入研究中妊娠期膳食最高和最低依从性的结局效应进行meta分析,并进行亚组分析和敏感性分析。结果最终纳入23篇文献,总样本量312892例。对其中18篇文献进行meta分析结果显示,健康膳食模式依从性高可降低早产发生风险[OR=0.82,95%CI(0.76,0.89)],进行亚组分析和敏感性分析后结局稳定。纳入文献中的健康膳食模式漏斗图不对称,存在发表偏倚。不健康膳食模式和混合膳食模式与早产发生风险之间未发现显著相关性。结论不同的膳食模式对早产的发生风险具有较大影响,妊娠期高摄入水果、蔬菜、全谷物、低脂乳制品、豆类、植物油和鱼类等健康膳食模式可降低早产发生风险。
