This study was designed to observe and compare the circadian fluctuations in tactile sense, joint reposition sense and two-point discrimination in healthy subjects. Twenty-one healthy adult subjects received perceptua...This study was designed to observe and compare the circadian fluctuations in tactile sense, joint reposition sense and two-point discrimination in healthy subjects. Twenty-one healthy adult subjects received perceptual ability tests through these three different sensory modules at approximately 9：00, 13：00 and 18：00 in a day. The distribution of ranking for perceptual ability was significantly different among the three different time points in each individual, with highest perceptual ability in the evening compared with noon and morning, in terms of tactile sense and two-point discrimination. These findings suggest that the perceptual ability of healthy subjects fluctuates according to the time points in a day.展开更多
While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons...While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology,No.2012R1A1B4003477
文摘This study was designed to observe and compare the circadian fluctuations in tactile sense, joint reposition sense and two-point discrimination in healthy subjects. Twenty-one healthy adult subjects received perceptual ability tests through these three different sensory modules at approximately 9：00, 13：00 and 18：00 in a day. The distribution of ranking for perceptual ability was significantly different among the three different time points in each individual, with highest perceptual ability in the evening compared with noon and morning, in terms of tactile sense and two-point discrimination. These findings suggest that the perceptual ability of healthy subjects fluctuates according to the time points in a day.
基金the U.S.National Science Foundation(SBE 9523623,BCS 9808273,DGE 0333415,BCS 0554747,DGE 0966166,BCS 1028471),Ford,Leakey,Wenner-Gren and H.F.Guggenheim Foundations,American Association for the Advancement of Science-Women's International Scientific Cooperation Project,and Columbia University,all to M.C.
文摘While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.
