Evaluating Dependence Among Mule Deer Siblings in Fetal and Neonatal Survival Analyses

Abstract: The assumption of independent sample units is potentially violated in survival analyses where siblings comprise a high proportion of the sample. Violation of the independence assumption causes sample data to be overdispersed relative to a binomial model, which leads to underestimates of sampling variances. A variance inflation factor, c, is therefore required to obtain appropriate estimates of variances. We evaluated overdispersion in fetal and neonatal mule deer (Odocoileus hemionus) datasets where more than half of the sample units were comprised of siblings. We developed a likelihood function for estimating fetal survival when the fates of some fetuses are unknown, and we used several variations of the binomial model to estimate neonatal survival. We compared theoretical variance estimates obtained from these analyses with empirical variance estimates obtained from data-bootstrap analyses to estimate the overdispersion parameter, c. Our estimates of c for fetal survival ranged from 0.678 to 1.118, which indicate little to no evidence of overdispersion. For neonatal survival, 3 different models indicated that ĉ ranged from 1.1 to 1.4 and averaged 1.24–1.26, providing evidence of limited overdispersion (i.e., limited sibling dependence). Our results indicate that fates of sibling mule deer fetuses and neonates may often be independent even though they have the same dam. Predation tends to act independently on sibling neonates because of dam-neonate behavioral adaptations. The effect of maternal characteristics on sibling fate dependence is less straightforward and may vary by circumstance. We recommend that future neonatal survival studies incorporate additional sampling intensity to accommodate modest overdispersion (i.e., ĉ = 1.25), which would facilitate a corresponding ĉ adjustment in a model selection analysis using quasi-likelihood without a reduction in power. Our computational approach could be used to evaluate sample unit dependence in other studies where fates of individually marked siblings are monitored.     

Severe Neutropenia in Infectious Mononucleosis

Mild neutropenia is a well-known concomitant of infectious mononucleosis caused by the Epstein-Barr virus (EBV) occurring in the first weeks of illness. However, severe neutropenia (less than 200 polymorphonuclear leukocytes per μl) is not generally regarded as a complication of infectious mononucleosis. Three patients were seen with severe neutropenia and EBV infection, and an additional eight cases were found in the literature. In two of the latter cases the neutropenia was fatal.In the 11 cases the severe neutropenia began 14 to 40 days after illness and usually lasted for three to seven days. At the time of severe neutropenia, studies of marrow specimens showed increased proportions of promyelocytes and myelocytes. Our data suggest that EBV infection is the proximate cause of the severe neutropenia in some patients with infectious mononucleosis and that in such cases close observation and early treatment of suspected superinfections is necessary.     

Spouses and Siblings in Sa Stories1

Earlier functionalist and structuralist approaches treat myths as texts rather than as stories told by people speaking in specific and variable contexts. An analysis of variations in the telling of two Sa stories from South Pentecost, Vanuatu, suggests that myths are not so much collective charters or manifestations of a deep unconscious structure of the mind but are stories which might be more biographically and historically situated.     

小圆形病毒样因子引起新生儿急性胃肠炎的研究

33例新生儿急性胃肠炎的粪便标本经EM检测,12份(36.4％)粪便标本中检出了病毒样颗粒,其中11份(33,3％)为SRV样因子(SRV),1份为其他病毒样颗粒。经粪便包埋超薄切片和IEM证实SRV是引起新生儿急性胃肠炎的病原。SRV的直径为26nm,表面结构清晰。在氯化铯(CsCl)中的浮密度为1.36—1.40g/cm~3。应用微量CF试验,5例双份血清中的1例抗体有三倍升高,3例恢复期皿清抗补体,1例为阴性,该病人为其他病毒样颗粒感染。核酸电泳未显带。培养未见细胞病变。5例正常对照新生儿粪便未检出任何病毒样颗粒。     

影响儿童重症病房新生儿发生急性肾损伤及预后相关因素分析

目的:评估在儿童重症病房(PICU)中治疗的新生儿发生急性肾损伤(AKI)及影响预后的相关因素。方法:对在我院PICU治疗的215例新生儿进行回顾性研究,采用KDIGO标准对患儿进行诊断与分级,根据新生儿是否发生AKI将新生儿分为AKI组(n=75)与非AKI组(n=140),收集并比较二组患者的临床资料,采用多元逻辑回归分析PCIU新生儿发生AKI的危险因素与AKI预后相关因素。结果:单因素逻辑回归分析表明,菌血症(OR=5.34,95%CI:1.37-20.33,P=0.013)、较低基线e GFR(OR=0.93,95%CI:0.89-0.97,P=0.002)与最大钠浓度(OR=1.11,95%CI:1.03-1.25,P=0.022)为新生儿发生AKI的独立相关因素。死亡率、长期LMV只与AKI(Ⅱ+Ⅲ)阶段相关(P0.05),而LOS无论调整前后均只与AKI(Ⅱ+Ⅲ)阶段相关(P0.05)。结论:PCIU治疗的AKI新生儿死亡率增加,菌血症、较低基线估计肾小球滤过率和最大钠浓度与急性肾损伤独立相关。