Phase I trial design for drug combinations with Bayesian model averaging

Various statistical models have been proposed for two‐dimensional dose finding in drug‐combination trials. However, it is often a dilemma to decide which model to use when conducting a particular drug‐combination trial. We make a comprehensive comparison of four dose‐finding methods, and for fairness, we apply the same dose‐finding algorithm under the four model structures. Through extensive simulation studies, we compare the operating characteristics of these methods in various practical scenarios. The results show that different models may lead to different design properties and that no single model performs uniformly better in all scenarios. As a result, we propose using Bayesian model averaging to overcome the arbitrariness of the model specification and enhance the robustness of the design. We assign a discrete probability mass to each model as the prior model probability and then estimate the toxicity probabilities of combined doses in the Bayesian model averaging framework. During the trial, we adaptively allocated each new cohort of patients to the most appropriate dose combination by comparing the posterior estimates of the toxicity probabilities with the prespecified toxicity target. The simulation results demonstrate that the Bayesian model averaging approach is robust under various scenarios. Copyright © 2015 John Wiley & Sons, Ltd.     

Uniform Tail Asymptotics for the Sum of Two Correlated Classes with Stochastic Returns and Dependent Heavy Tails

Consider a continuous-time risk model with two correlated classes of insurance business and risky investments whose price processes are geometric Lévy processes. By assuming that the correlation comes from a common shock, and the claim sizes are heavy-tailed and pairwise quasi-asymptotically independent, we investigate the tail behavior of the sum of the stochastic present values of the two correlated classes, and a uniform asymptotic formula is obtained.     

证伪：社会科学研究的可能与必然 兼与张杨商榷

本文针对张杨《证伪在社会科学中可能吗？》一文展开争鸣与论述,指出证伪是理论检验的必然结果之一,相对于证实而言,证伪更有效、更可靠。本文还就张杨文中对波普尔证伪理论的误解做了澄清,指出波普尔的证伪并非“单个反例证伪”,证伪、可证伪性、证伪主义三者之间也存在着明显的区别,不能加以混淆。文章就张文提出的证伪在社会科学中面临的四个挑战做出一一回应：（1）“迪昂奎因命题”不能成为证伪的诘问;（2）穆勒命题不能挑战证伪主义;（3）统计陈述不是概率陈述;（4）限界条件与证伪的结合使社会科学的理论更加科学。     

Dose‐Response Models Incorporating Aerosol Size Dependency for Francisella tularensis

The effect of bioaerosol size was incorporated into predictive dose‐response models for the effects of inhaled aerosols of Francisella tularensis (the causative agent of tularemia) on rhesus monkeys and guinea pigs with bioaerosol diameters ranging between 1.0 and 24 μm. Aerosol‐size‐dependent models were formulated as modification of the exponential and β‐Poisson dose‐response models and model parameters were estimated using maximum likelihood methods and multiple data sets of quantal dose‐response data for which aerosol sizes of inhaled doses were known. Analysis of F. tularensis dose‐response data was best fit by an exponential dose‐response model with a power function including the particle diameter size substituting for the rate parameter k scaling the applied dose. There were differences in the pathogen's aerosol‐size‐dependence equation and models that better represent the observed dose‐response results than the estimate derived from applying the model developed by the International Commission on Radiological Protection (ICRP, 1994) that relies on differential regional lung deposition for human particle exposure.     

地区间个人收入差距的状况及特点(英文)

在地区收入差距的文献中,一直缺乏从个人收入角度出发的研究;而关于个人收入分配的研究,也很少考察地区差异。文章使用2005年全国1％人口普查数据,从个人收入角度描述了全国及（几种不同定义下的）地区间的个人收入差距,并分析了影响个人收入差距的因素,得到了一些有意义的结果。     

让民族音乐之花在校园绽放

文章阐述了弘扬民族音乐的重要意义,分析了目前高校民族音乐教育的现状,指出了弘扬民族音乐对培养德智体美全面发展的大学生的重要作用,并阐述了在校园普及民族音乐的方法.重点围绕构建民族音乐教育体制,开设相关民族音乐课程,让学生了解民族音乐,加强学生的民族音乐文化基础.通过多样的教学形式,把民间文化请进课堂,把课堂搬到民间,让学生在原生文化场景中感受民族民间音乐的独特性.     

高等职业院校英语教学模式的探索

高等职业教育英语教学应改革传统模式,有效地运用现代教育技术手段,使课堂教学与开放式自主学习相结合,光盘多媒体教学与网络教学相结合,将现代教育技术手段及口语教学方法带入英语课堂。     

基于行程时间可靠性的随机交通网络均衡模型

考虑现实条件下交通网络的不确定性状态,提出了从确定型网络到不确定型网络状态下出行者路径选择行为的改变,及基于行程时间可靠性的路径选择模型。并将可靠行程时间的路径选择行为纳入到随机交通网络平衡分配模型中,证明了模型的等价性和唯一性。在一个小型测试网络上对模型分配结果进行了测试,测试结果与经验相吻合,表明模型具有较好的现实可行性。     

军事委婉语的语言学分析

军事委婉语不仅仅是修辞现象,是语言学现象,更是一种社会现象。军事委婉语多为特定的政治目的服务,充分认识其构造方式、语义特征、语用原则、语用功能等有助于我们揭开军事委婉语的表象,认知其真实含义。这对了解军事委婉语的社会功效具有非常重要的现实意义。