Robust Bayesian nonlinear mixed‐effects modeling of time to positivity in tuberculosis trials

Early phase 2 tuberculosis (TB) trials are conducted to characterize the early bactericidal activity (EBA) of anti‐TB drugs. The EBA of anti‐TB drugs has conventionally been calculated as the rate of decline in colony forming unit (CFU) count during the first 14 days of treatment. The measurement of CFU count, however, is expensive and prone to contamination. Alternatively to CFU count, time to positivity (TTP), which is a potential biomarker for long‐term efficacy of anti‐TB drugs, can be used to characterize EBA. The current Bayesian nonlinear mixed‐effects (NLME) regression model for TTP data, however, lacks robustness to gross outliers that often are present in the data. The conventional way of handling such outliers involves their identification by visual inspection and subsequent exclusion from the analysis. However, this process can be questioned because of its subjective nature. For this reason, we fitted robust versions of the Bayesian nonlinear mixed‐effects regression model to a wide range of TTP datasets. The performance of the explored models was assessed through model comparison statistics and a simulation study. We conclude that fitting a robust model to TTP data obviates the need for explicit identification and subsequent “deletion” of outliers but ensures that gross outliers exert no undue influence on model fits. We recommend that the current practice of fitting conventional normal theory models be abandoned in favor of fitting robust models to TTP data.     

A Flexible Nonparametric Test for Ordered and Umbrella Alternatives

A flexible and robust test for the ordered and umbrella alternatives is proposed in this paper. A two-step procedure is presented to make the proposed test be easily applicable. Type I error and power of the given approach are thoroughly investigated by extensive Monte Carlo studies.     

Long maternal working hours were linked to obesity,underweight and stunting in children under age 5 in China

This study assessed the relationship between maternal working hours and stunting, underweight and obesity in children under age 5 in China, using data from the China Nutrition and Health Survey (CNHS) conducted in 2002 and multivariable logistic regression. We found that maternal work hours 25–40 or >40 h per week were associated with a higher risk for underweight and stunting (under growth) in children under age 5. The association between working 25–40 h per week and stunting was somewhat stronger for children from low-income families and the effect of working >40 h per week on underweight was larger among children from mothers with lower education, although with marginal significance (90% confidence). In contrast, we found that long maternal work hours (>40 h per week) were associated with a lower risk for overweight and obesity in children under age 5. This association was stronger among children from mothers with lower education.     

策墨林活佛系统的沉浮与清代中晚期的西藏摄政制度

有清一代,出于安抚蒙藏各部的需要,清朝政府对西藏的管理极为重视。虽然延续了元明 以来“群分而众建之”的治藏政策,但在具体的实施过程中,进行了很多的尝试,最后确立了由达赖喇嘛 执掌政教大权的政教合一制度。西藏的摄政制度也由此派生出来,而成为政教合一制度最重要的组成部 分。有资格出任摄政的四大林活佛之一的策墨林活佛系统,在西藏历史上曾经产生过十分重要的影响, 它的一世、二世、三世均出任过西藏摄政和甘丹赤巴,并兼任八世和十世达赖喇嘛经师,为密切中央政府 和西藏之间的联系、保持西藏政局稳定和抵抗外敌入侵方面做出了巨大的贡献。本文试图对该活佛系统 的传承加以介绍,并透过这一活佛系统对清代中晚期的西藏摄政制度做一些分析。     

吸烟对免疫功能的影响

本文就烟草在吸燃过程中产生的有害物质对免疫功能的影响,并阐述吸烟对人体的危害。     

中泰铁路面临的挑战及对策分析

从英拉政府时期的高铁换大米方案到巴育军政府时期的新铁路方案,中泰铁路前后经历了中泰高铁缘起、中泰高铁曲折发展、中泰高铁向中泰铁路转变、中泰铁路发展筹备、中泰铁路发展陷入困境和中泰铁路发展缓慢推进等六个阶段的波折变化.中泰两国关于方案本身的分歧,日本高铁的外部竞争和冲击,以及泰国国内政权更迭频繁等因素是造成中泰铁路一波三折的主要原因.基于对中泰铁路建设好事多磨的全面探讨和研究,提出构建政治风险评估和预警机制、创新企业投融资合作模式、加强舆论宣传作用等建议,助力中泰铁路项目平稳推进.     

烟气置换在煤气储气柜拆除工程中的技术研究与应用

为安全拆除煤气储气柜必须先对气柜内原气体实施置换。该文对比分析了三种置换介质,在此基础上确定采用烟气置换的方案,并详细介绍了烟气置换在储气柜拆除工程中的工艺及实施。