In year 2001 a paper in the ANAS considered links between month of birth and longevity. In the following years we published four papers related to “big killers” (cardiac and oncology) that showed some differences in...In year 2001 a paper in the ANAS considered links between month of birth and longevity. In the following years we published four papers related to “big killers” (cardiac and oncology) that showed some differences in birth months distribution of this group and studied by LA, NS Gavrilov’s centenarians. The aim of this study was to study conception and birth months of another modern “big killer”—cerebral stroke (CVA) that is taking a leading role among cardiovascular causes of death in the last decades. Methods: 130,120 deaths of both gender CVA victims in Lithuania at 1989-2013 were studied. In addition to birth month, the months of conception (9 months before birth) were studied. Our data were compared with results of centenarians (birth of LA, NS Gavrilov’s study and transformed by authors also their conception month). Results: The maximum of births were January, March and May for CVA victims, while the analogical conception maximum were in April, June, May and July. The similar data for centenarians were that maximal births were in November, September, October (LA, NS Gavrilov) and conception in December, January, February. These results are similar to data related to cardiac and oncology deaths published in our previous publications. Conclusion: The conception and birth month of victims of CVA is different of similar data obtained by centenarians study. Different environmental conditions at different parts of the year and solar cycle can play a role affecting the embryo at early stages of development, predisposing to some pathologies in coming years of life.展开更多
Objective To investigate the relation between air pollution exposure and preterm birth in Shanghai, China. Methods We examined the effect of ambient air pollution on preterm birth using time-series approach in Shangha...Objective To investigate the relation between air pollution exposure and preterm birth in Shanghai, China. Methods We examined the effect of ambient air pollution on preterm birth using time-series approach in Shanghai in 2004. This method can eliminate potential confounding by individual risk factors that do not change over a short period of time. Daily numbers of preterm births were obtained from the live birth database maintained by Shanghai Municipal Center of Disease Control and Prevention. We used the generalized additive model （GAM） with penalized splines to analyze the relation between preterm birth, air pollution, and covariates. Results We observed a significant effect of outdoor air pollution only with 8-week exposure before preterm births. An increase of 10 μg/m^3 of 8-week average PM10, SO2, NO2, and O3 corresponded to 4.42% （95%CI 1.60%, 7.25%）, 11.89% （95%CI 6.69%, 17.09%）, 5.43% （95%CI 1.78%, 9.08%）, and 4.63% （95%CI 0.35%, 8.91%） increase of preterm birth. We did not find any significant acute effect of outdoor air pollution on preterm birth in the week before birth. Conclusion Ambient air pollution may contribute to the risk of preterm birth in Shanghai. Our analyses also strengthen the rationale for further limiting air pollution level in the city.展开更多
Objectives:?Investigating the relation between perinatal outcomes and?hospital working shifts.?Methods:?We conducted a cross-sectional study at Philippe Maguilen Senghor health center (PMSHC) in Dakar, Senegal from Ja...Objectives:?Investigating the relation between perinatal outcomes and?hospital working shifts.?Methods:?We conducted a cross-sectional study at Philippe Maguilen Senghor health center (PMSHC) in Dakar, Senegal from January, 1st?2011 to December, 31th 2018. The study population was comprised of all mothers who had delivered at PMSHC and their newborns after completing 22 weeks of gestation. Time of delivery was?divided into three periods of working hours: morning shift (deliveries occurred between 7 am and 4:59 pm);evening shift from 5 pm to 10:59 pm and night shift from 11?pm to 6:59 am.?Maternal outcomes were assessed by mode of delivery, epsisotomy and perineal injuries.?The Apgar scoring system was used to assess newborns at first minute after they were born. Other adverse perinatal outcomes included fresh stillbirth, neonatal referral and early neonatal death. Data were analyzed using Statistical Package for Social Science software (SPSS 24, Mac version).?Results:?A total of 48,270 mothers and their newborns met eligibility criteria. Caesarean section deliveries were less likely to occur during evening (OR 0.84, 95% CI;0.79?-?0.89, p = 0.001) and night shifts (OR 0.45, CI;0.47?-?0.53, p = 0.001).?Evening shift deliveries had 1.1 the odds of poor perinatal outcome (Apgar score ?- 1.18, p = 0.012). No significant difference was found in the odds of neonate referrals and deaths across the three shifts.?Night shift deliveries had 1.1 the odds of perineal injuries compared to morning shift deliveries (OR 1.11, 95% CI;1.04?- 1.18, p = 0.001, for episiotomy and OR, 1.14;95% CI, 1.04?- 1.26, p = 0.008, for perineal tears). Conclusion:?Off-hours deliveries, particularly during the night shift, were significantly associated with higher proportions of perineal injuries compared to morning shift.?However, no significant difference was found in the odds of neonate referrals and deaths across the three shifts.?Our findings suggest to set up a Neonatology unit at the CSPMS as well as a perinatal network across the country.展开更多
The purpose of this article is to provide an overview of adaptive regression modeling and demonstrate its use in conducting nonlinear analyses of interrupted time series (ITS) data. Adaptive regression modeling is bas...The purpose of this article is to provide an overview of adaptive regression modeling and demonstrate its use in conducting nonlinear analyses of interrupted time series (ITS) data. Adaptive regression modeling is based on heuristic search over alternative models for data controlled by likelihood-cross validation (LCV) scores with larger scores indicating better models. Extended linear mixed models are used for correlated data like ITS data. Power transforms of predictor variables are used to account for nonlinearity. The use of adaptive regression modeling for assessing ITS effects is demonstrated using data on annual proportions of major birth defects in children fathered by male Air Force veterans of the Vietnam War over a 59-year period. The interruption for this ITS is conception after versus before the start of a participant’s first tour in the Vietnam War. Whether the ITS effect is related to dioxin exposure is also addressed. Dioxin is a highly toxic contaminant of the herbicide Agent Orange used in the Vietnam War. The core findings of the reported analyses are that a substantial adverse ITS interruption effect is identified and that this adverse effect can reasonably be attributed to participants having a high dioxin exposure level. Moreover, these results indicate that adaptive regression modeling can identify nonlinear ITS effects in general situations that can lead to consequential insights into nonlinear relationships over time, possibly varying with other available predictors.展开更多
In this paper, a delayed SIR model with exponential demographic structure and the saturated incidence rate is formulated. The stability of the equilibria is analyzed with delay: the endemic equilibrium is locally stab...In this paper, a delayed SIR model with exponential demographic structure and the saturated incidence rate is formulated. The stability of the equilibria is analyzed with delay: the endemic equilibrium is locally stable without delay;and the endemic equilibrium is stable if the delay is under some condition. Moreover the dynamical behaviors from stability to instability will change with an appropriate?critical value. At last, some numerical simulations of the model are given to illustrate the main theoretical results.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
A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by co...A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by constructing two auxiliary equations and squeezing method, the spreading speed for the system with nonmonotone birth function is obtained.展开更多
A new stochastic epidemic model, that is, a general continuous time birth and death chain model, is formulated based on a deterministic model including vaccination. We use continuous time Markov chain to construct the...A new stochastic epidemic model, that is, a general continuous time birth and death chain model, is formulated based on a deterministic model including vaccination. We use continuous time Markov chain to construct the birth and death process. Through the Kolmogorov forward equation and the theory of moment generating function, the corresponding population expectations are studied. The theoretical result of the stochastic model and deterministic version is also given. Finally, numerical simulations are carried out to substantiate the theoretical results of random walk.展开更多
目的比较拮抗剂方案、长方案和高孕激素状态下促排卵(progestin-primed ovarian stimulation,PPOS)方案3种常用促排卵方案在卵巢储备功能正常(normal ovarian reserve,NOR)的高龄患者中的到达活产时间(time to live birth,TTLB)。方法...目的比较拮抗剂方案、长方案和高孕激素状态下促排卵(progestin-primed ovarian stimulation,PPOS)方案3种常用促排卵方案在卵巢储备功能正常(normal ovarian reserve,NOR)的高龄患者中的到达活产时间(time to live birth,TTLB)。方法采用回顾性队列研究方法,选取2020年1月至2023年1月在解放军总医院第七医学中心进行体外受精/卵胞质单精子注射-胚胎移植(in vitrofertilization/intracytoplasmic sperm injection-embryo transfer,IVF/ICSI-ET)的458例高龄(年龄≥35岁)不孕NOR患者。研究共纳入458个取卵周期。按促排卵方案分为拮抗剂方案组(n=230)、长方案组(n=120)和PPOS方案组(n=108)。比较3组患者的一般资料、实验室指标及临床结局。统计学方法采用Kruskal-Wallis秩和检验、单因素方差分析、χ^(2)检验及Cox比例风险回归模型。结果拮抗剂方案组、长方案组和PPOS方案组的促性腺激素(gonadotropin,Gn)使用时间分别为10.00(9.00,11.00)d、11.00(11.00,13.00)d和10.00(9.00,11.00)d,Gn使用总量分别为2175.00(1800.00,2793.75)U、2925.00(2400.00,3487.50)U和1950.00(1743.75,2700.00)U,长方案组的Gn使用时间和总量均显著高于其他2组(Z值分别为38.601和24.432,P值均<0.05)。3组患者在获卵数、成熟卵数、双原核(two pronucleus,2PN)数、可移植胚胎数、优质胚胎数等实验室指标方面差异均无统计学意义(P值均>0.05)。3组患者的累积妊娠率、累积活产率比较,差异均无统计学意义(P值均>0.05)。拮抗剂方案组、长方案组和PPOS方案组的TTLB分别为319.94(305.97,333.91)d、327.20(299.57,354.91)d、370.31(350.58,390.03)d,拮抗方案剂组的TTLB显著短于其他2组,差异均有统计学意义(P值均<0.05)。结论对于高龄NOR患者,拮抗剂方案、长方案和PPOS方案的临床结局相似。与其他2个方案相比,拮抗剂方案的TTLB相对较短。展开更多
文摘In year 2001 a paper in the ANAS considered links between month of birth and longevity. In the following years we published four papers related to “big killers” (cardiac and oncology) that showed some differences in birth months distribution of this group and studied by LA, NS Gavrilov’s centenarians. The aim of this study was to study conception and birth months of another modern “big killer”—cerebral stroke (CVA) that is taking a leading role among cardiovascular causes of death in the last decades. Methods: 130,120 deaths of both gender CVA victims in Lithuania at 1989-2013 were studied. In addition to birth month, the months of conception (9 months before birth) were studied. Our data were compared with results of centenarians (birth of LA, NS Gavrilov’s study and transformed by authors also their conception month). Results: The maximum of births were January, March and May for CVA victims, while the analogical conception maximum were in April, June, May and July. The similar data for centenarians were that maximal births were in November, September, October (LA, NS Gavrilov) and conception in December, January, February. These results are similar to data related to cardiac and oncology deaths published in our previous publications. Conclusion: The conception and birth month of victims of CVA is different of similar data obtained by centenarians study. Different environmental conditions at different parts of the year and solar cycle can play a role affecting the embryo at early stages of development, predisposing to some pathologies in coming years of life.
基金The current work was co-funded by China National Science Foundation through grant 30500397 (PI: Y. Zhang)ShanghaiRising-Star Program for Young Investigators through grant 04QMX1402 (PI: H. Kan).
文摘Objective To investigate the relation between air pollution exposure and preterm birth in Shanghai, China. Methods We examined the effect of ambient air pollution on preterm birth using time-series approach in Shanghai in 2004. This method can eliminate potential confounding by individual risk factors that do not change over a short period of time. Daily numbers of preterm births were obtained from the live birth database maintained by Shanghai Municipal Center of Disease Control and Prevention. We used the generalized additive model （GAM） with penalized splines to analyze the relation between preterm birth, air pollution, and covariates. Results We observed a significant effect of outdoor air pollution only with 8-week exposure before preterm births. An increase of 10 μg/m^3 of 8-week average PM10, SO2, NO2, and O3 corresponded to 4.42% （95%CI 1.60%, 7.25%）, 11.89% （95%CI 6.69%, 17.09%）, 5.43% （95%CI 1.78%, 9.08%）, and 4.63% （95%CI 0.35%, 8.91%） increase of preterm birth. We did not find any significant acute effect of outdoor air pollution on preterm birth in the week before birth. Conclusion Ambient air pollution may contribute to the risk of preterm birth in Shanghai. Our analyses also strengthen the rationale for further limiting air pollution level in the city.
文摘Objectives:?Investigating the relation between perinatal outcomes and?hospital working shifts.?Methods:?We conducted a cross-sectional study at Philippe Maguilen Senghor health center (PMSHC) in Dakar, Senegal from January, 1st?2011 to December, 31th 2018. The study population was comprised of all mothers who had delivered at PMSHC and their newborns after completing 22 weeks of gestation. Time of delivery was?divided into three periods of working hours: morning shift (deliveries occurred between 7 am and 4:59 pm);evening shift from 5 pm to 10:59 pm and night shift from 11?pm to 6:59 am.?Maternal outcomes were assessed by mode of delivery, epsisotomy and perineal injuries.?The Apgar scoring system was used to assess newborns at first minute after they were born. Other adverse perinatal outcomes included fresh stillbirth, neonatal referral and early neonatal death. Data were analyzed using Statistical Package for Social Science software (SPSS 24, Mac version).?Results:?A total of 48,270 mothers and their newborns met eligibility criteria. Caesarean section deliveries were less likely to occur during evening (OR 0.84, 95% CI;0.79?-?0.89, p = 0.001) and night shifts (OR 0.45, CI;0.47?-?0.53, p = 0.001).?Evening shift deliveries had 1.1 the odds of poor perinatal outcome (Apgar score ?- 1.18, p = 0.012). No significant difference was found in the odds of neonate referrals and deaths across the three shifts.?Night shift deliveries had 1.1 the odds of perineal injuries compared to morning shift deliveries (OR 1.11, 95% CI;1.04?- 1.18, p = 0.001, for episiotomy and OR, 1.14;95% CI, 1.04?- 1.26, p = 0.008, for perineal tears). Conclusion:?Off-hours deliveries, particularly during the night shift, were significantly associated with higher proportions of perineal injuries compared to morning shift.?However, no significant difference was found in the odds of neonate referrals and deaths across the three shifts.?Our findings suggest to set up a Neonatology unit at the CSPMS as well as a perinatal network across the country.
文摘The purpose of this article is to provide an overview of adaptive regression modeling and demonstrate its use in conducting nonlinear analyses of interrupted time series (ITS) data. Adaptive regression modeling is based on heuristic search over alternative models for data controlled by likelihood-cross validation (LCV) scores with larger scores indicating better models. Extended linear mixed models are used for correlated data like ITS data. Power transforms of predictor variables are used to account for nonlinearity. The use of adaptive regression modeling for assessing ITS effects is demonstrated using data on annual proportions of major birth defects in children fathered by male Air Force veterans of the Vietnam War over a 59-year period. The interruption for this ITS is conception after versus before the start of a participant’s first tour in the Vietnam War. Whether the ITS effect is related to dioxin exposure is also addressed. Dioxin is a highly toxic contaminant of the herbicide Agent Orange used in the Vietnam War. The core findings of the reported analyses are that a substantial adverse ITS interruption effect is identified and that this adverse effect can reasonably be attributed to participants having a high dioxin exposure level. Moreover, these results indicate that adaptive regression modeling can identify nonlinear ITS effects in general situations that can lead to consequential insights into nonlinear relationships over time, possibly varying with other available predictors.
文摘In this paper, a delayed SIR model with exponential demographic structure and the saturated incidence rate is formulated. The stability of the equilibria is analyzed with delay: the endemic equilibrium is locally stable without delay;and the endemic equilibrium is stable if the delay is under some condition. Moreover the dynamical behaviors from stability to instability will change with an appropriate?critical value. At last, some numerical simulations of the model are given to illustrate the main theoretical results.
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.
基金Supported by the NSF of China(11171120)Supported by the Doctoral Program of Higher Education of China(20094407110001)Supported by the NSF of Guangdong Province(10151063101000003)
文摘A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by constructing two auxiliary equations and squeezing method, the spreading speed for the system with nonmonotone birth function is obtained.
文摘A new stochastic epidemic model, that is, a general continuous time birth and death chain model, is formulated based on a deterministic model including vaccination. We use continuous time Markov chain to construct the birth and death process. Through the Kolmogorov forward equation and the theory of moment generating function, the corresponding population expectations are studied. The theoretical result of the stochastic model and deterministic version is also given. Finally, numerical simulations are carried out to substantiate the theoretical results of random walk.
