A modified random-effect procedure for combining risk difference in sets of 2×2 tables from clinical trials

Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however, the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual data and the differences among the results. This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University.     

跨文化沟通与国际经济

搞好跨文化沟通是国际经济活动成功的重要条件.本文以西欧、美国、阿拉伯国家和日本为对象探讨其文化差异和沟通的途径.     

关于全面建设小康社会的思考

全面建设小康社会具有新的时代内涵。全面建设小康社会应力争处理好发展、改革和稳定的关系,处理好农业、农村、农民问题,处理好发展经济与人口、资源、环境的关系,高度重视就业问题和收入分配差距问题。     

唐代文学中灾异观念的表现

灾异观念是天人感应学说的重要内容,唐人因为推崇汉朝,对来自汉朝的思想观念接受较多,灾异观念在唐代甚为流行,其表现形式与汉朝略有不同。对文学创作的影响主要表现在政论、对策和诗歌中,该观念对唐代文学的作用小于瑞应和封禅。     

构建以人为本的英语教学模式

传统的英语教育模式忽视了学生的个性意识、个性特点和个性需要,违背了人本主义的教育教学理念。如何提高教学效率一直是外语教师主要探讨的问题。文章运用人本主义的教学理念,结合实际探讨了如何构建以人为本的新型教学模式以改进英语教学,提高教学效率。以人为本的新型教学模式包括:创立民主愉悦的课堂教学环境、构建个性化的学习空间、设计师生共同探索的教学活动、建立协作性的教学模式。     

商标权保护与平行进口问题研究

文章从国际货物贸易中的专利平行进口问题的含义,重点在于对“权利穷竭”原则与“地域性”原则两种理论依据进行相关内容分析。通过分析世界各国对待商标平行进口的态度,对当前中国知识产权领域商标平行进口立法方向做出自己的判断。     

婚龄性别比失衡对社会运行和发展的影响——来自吉林省延边朝鲜族自治州农村地区的调查分析

婚龄性别比失衡问题到底有什么样的社会影响?这些社会影响的性质、影响范围以及具体表现又是怎样?为了回答这些问题,我们对延边地区进行了实地调查和深度访谈,发现该地区的婚龄男女性别比失衡相当明显。在这些地区,由于婚龄女性人口的大量向城市(国外)流动,当地的很多成年男性到了婚龄,都面临着无妻可娶的窘境。由此,对社会造成了一些负面的影响,社会运行和发展出现了一定程度上的离轨。     

意象是心灵上的图画

探讨了意象的渊源及其互为影响、超越时空的意象差异、不同语境的理解与阐释以及意象作为文艺作品生命的细胞,并分析了它们在跨文化交流中所起的作用。     

Statistics for weighing benefits and harms in a proposed genetic substudy of a randomized cancer prevention trial

Summary.  When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes.     

英汉习语的文化翻译

由于文化背景的不同,英汉两种语言的习语文化内涵也有差异。该文先从思维方式、风俗习惯、宗教神话和地域环境四方面讨论了英汉习语文化内涵的不同,然后分析了引起习语翻译障碍的原因,依据等效翻译理论对习语翻译的方法作了简要探讨。