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.     

西法何以未能东鉴--庞德与中国近代的法律改革浅析

庞德作为中国近代被政府聘请的最后一位外国法律专家,被南京国民政府视为合适人选有其内在原因.庞德的社会学法学的理论、社会利益学说与国民政府的国家、社会本位论有相似之处.庞德在华担任司法部和教育部顾问期间对中国的法制建设及法学教育提出了诸多有见地的建议,但最终收效甚微.笔者认为,除了政局动荡、法制建设缺乏稳定的环境这一因素外,法律文化的不同、宪政运动的失败、司法独立精神的缺乏及社会结构的落后是使其改革建议无法有效实施的更深层次原因.在法制建设蓬勃发展的今天,庞德的改革建议仍有其进步意义,值得我们借鉴.     

反腐败的国内立法问题研究

当前腐败问题的滋生蔓延,与法律规范真空太多、腐败分子有空子可钻有很大的关系。反腐败面临的重重困难,迫切需要有专门的反腐败法律和法律体系的支持。通过借鉴国外和中国古代的立法经验,从如何建立反腐败的法律体系、如何完善反腐败的法律条款等方面提出了一些见解。     

滑稽模仿之法律地位初探——由《馒头》案引发的思考

滑稽模仿在我国的法律地位尚不明确.滑稽模仿能否被认定为合理使用存在理论上的争议.建议将一定的滑稽模仿纳入合理使用的范畴,在具体认定时,综合考虑四个要素:使用的目的和性质、原作的性质,使用的数量、对原作价值和市场的影响.同时应进一步完善关于保护作品完整权的规定.     

善意取得制度研究

善意取得制度意在对特定类型的非正常的利益变动,做出价值判断,进行利益衡平。那么,善意取得制度对何种类型非正常的利益变动进行衡平?又是如何进行衡平的呢?这就引出了善意取得制度的构成要件及其效力问题。笔者正是从这两方面着手对善意取得制度基础理论和实践应用提供一孔之见。     

法律专业英语教学应考虑的三个问题

法律专业英语教学应考虑以下三个方面:特定的教学主体、得当的教学内容以及有效的教学模式,同时要注意三者之间的系统性,以及三者内部各部分之间的呼应,以期很好地开展法律英语教学.     

The impact of sales promotions on store performance: a structural vector autoregressive approach

The present paper analyses the impact of sales promotions on store performance, in the short and long term, from the retailer's point of view. Relationships among promoted and regular sales in the hypermarkets of a large-scale retail chain of national importance, are investigated by means of a structural vector autoregressive model (SVAR). Statistically significant effects of sales promotions in the heavy household section on store sales are found in the short-run; these promotions produce additional sales and thus act as an attractive factor. Promotions in textile category, on the contrary, produce an immediate negative effect on net sales. In the long run, negative statistically significant effects on regular sales are detected when promotions are repeatedly implemented within perishables category.     

论我国青少年法的基本特点

目前,具有中国特色的青少年法律体系在我国已具雏形,青少年法制建设取得了长足的进展。对我国青少年法的基本特点进行概要的分析,旨在为保护青少年合法权益、有效预防青少年违法犯罪提供必要的参考。     

依法办报和质量立刊:高校报刊工作的两个基本点——“‘三标一体’教育质量模型与高校报刊工作”系列研究之一

"依法办报(刊)"和以"质量立(报)刊",是高等学校报刊工作必须遵循的两个基本点;忽略了其中的任何一点,高等学校的报刊工作必然就会遭受挫折。推而广之,一个企业,一所学校,一家报刊,都只有紧紧抓住"依法……"和"质量……"这两个基本点,才能在竞争激烈的当今社会,真正占有自己的一席之地———这就是重庆文理学院"三标一体"教育质量模型先进管理理念的精华之所在。     

Generalized additive models for location, scale and shape

Summary.  A general class of statistical models for a univariate response variable is presented which we call the generalized additive model for location, scale and shape (GAMLSS). The model assumes independent observations of the response variable y given the parameters, the explanatory variables and the values of the random effects. The distribution for the response variable in the GAMLSS can be selected from a very general family of distributions including highly skew or kurtotic continuous and discrete distributions. The systematic part of the model is expanded to allow modelling not only of the mean (or location) but also of the other parameters of the distribution of y , as parametric and/or additive nonparametric (smooth) functions of explanatory variables and/or random-effects terms. Maximum (penalized) likelihood estimation is used to fit the (non)parametric models. A Newton–Raphson or Fisher scoring algorithm is used to maximize the (penalized) likelihood. The additive terms in the model are fitted by using a backfitting algorithm. Censored data are easily incorporated into the framework. Five data sets from different fields of application are analysed to emphasize the generality of the GAMLSS class of models.