中国农业转基因生物安全政策模式的选择

美国学者Robert L．Paarlberg认为农业转基因生物安全政策模式主要有这样四种：鼓励式的（promotional）、禁止式的（preventive）、允许式的（permissive）、预警式的（precautionary）。通过分析,笔者认为,可以根据国务院在2001年颁布《农业转基因生物安全管理条例》为界,把中国农业转基因生物安全政策模式的选择划分为两个阶段：第一阶段（1996—2001年）,中国采取了允许式的农业转基因生物安全政策;第二阶段（2001年至今）,中国采取了预警式的农业转基因生物安全政策。     

Modified quasi-profile likelihoods from estimating functions

We discuss higher-order adjustments for a quasi-profile likelihood for a scalar parameter of interest, in order to alleviate some of the problems inherent to the presence of nuisance parameters, such as bias and inconsistency. Indeed, quasi-profile score functions for the parameter of interest have bias of order O(1)$\mathrm{O}(1)$, and such bias can lead to poor inference on the parameter of interest. The higher-order adjustments are obtained so that the adjusted quasi-profile score estimating function is unbiased and its variance is the negative expected derivative matrix of the adjusted profile estimating equation. The modified quasi-profile likelihood is then obtained as the integral of the adjusted profile estimating function. We discuss two methods for the computation of the modified quasi-profile likelihoods: a bootstrap simulation method and a first-order asymptotic expression, which can be simplified under an orthogonality assumption. Examples in the context of generalized linear models and of robust inference are provided, showing that the use of a modified quasi-profile likelihood ratio statistic may lead to coverage probabilities more accurate than those pertaining to first-order Wald-type confidence intervals.     

吕集版本考述

吕温是中唐进步的文学家、政治家和思想家。其独具一格的诗文创作在中唐文坛是举世瞩目的。本文试对其诗文集的版本渊源嬗变作一番考察,认为其文集版本自明清以来可大致归类为两大系统,即冯本和吴本系统。     

铜在8—羟基喹啉修饰铅笔芯电极上的伏安特性

本文用8-羟基喹啉修饰的铅笔芯电极研究了铜的阶梯阳极溶出伏安特性并将此法用于人发中微量铜的测定。实验指出,在此修饰电极上,铜的阶梯溶出峰有两个,1~#峰电位在-0.03V,2~#峰电位在0.27V 处。同样的试液和条件下,1~#峰总比2~#峰的峰电流大。实验研究了测定铜的最佳条件,并测得铜的浓度在4.0×10~(-8)～1.6×10~(-6)mol·L~(-1)范围内,1~#峰的峰高与浓度呈良好的线性关系,最低检测限为2×10~(-8)mol.L~(-1)。2~#峰高与铜的浓度在6.0×10~(-8)～1.6×10~(-6)mol·L~(-1)范围内也有较好的线性关系,也可用于测定铜。本文还分析了铜在修饰电极上的反应机理。@韦璐$本文用8-羟基喹啉修饰的铅笔芯电极研究了铜的阶梯阳极溶出伏安特性!并将此法用于人发中微量铜的测定。实验指出,在此修饰电极上,铜的阶梯溶出峰有两个,1~#峰电位在-0.03V,2~#峰电位在0.27V 处。同样的试液和条件下,1~#峰总比2~#峰的峰电流大。实验研究了测定铜的最佳条件,并测得铜的浓度在4.0×10~(-8)～1.6×10~(-6)mol·L~(-1)范围内,1~#峰的峰高与浓度呈良好的线性关系,最低检测限为2×10~(-8)mol.L~(-1)。2~#峰高与铜的浓度在6.0×10~(-8)～1.6×10~(-6)mol·L~(-1)范围内也有较好的线性关系,也可用于测定铜。本文还分析了铜在修饰电极上的反应机理。     

小学英语课堂会话中的语言错误、纠正反馈语和修正后的可理解输出

本文利用10节课堂会话语料探讨了小学课堂会话中学生语言错误、教师纠正反馈语和学生修正后的可理解输出之间的关系。数据表明,优秀教师针对学生语言错误而选用的纠正反馈语是有规律的,他们倾向针对学生的语法错误使用明确纠正法,针对词汇、语音错误使用形式协商法。这种针对性能推动学生产生修正后的可理解输出。     

Who Does the Public Trust? The Case of Genetically Modified Food in the United States

Trust is important for the perception of many types of risk, including those relating to genetically modified (GM) food. Who the public trusts in any given circumstance, however, is not well understood. In this study of public trust regarding GM food, an exploratory factor analysis with Promax rotation reveals public classification of three common institutional types-evaluators, watchdogs, and merchants. The structure of relationships among these stakeholders can act to enable or constrain public support for this new technology. Evaluators-scientists, universities, and medical professionals-are the most trusted. Watchdogs-consumer advocacy organizations, environmental organizations, and media sources-are moderately trusted. Merchants-grocers and grocery stores, industry, and farmers-are least trusted. While the federal government is seen as closest to being an evaluator, it is not highly correlated with any of the factors. The lack of trust in the organizations with the greatest resources and responsibilities for ensuring the safety of GM food should be seen as an important obstacle to the adoption of the technology.     

改型Wiggler自由电子激光谐波产生的非线性理论

建立了改型Ｗｉｇｇｌｅｒ自由电子激光的非线性理论。导出了自洽非线性方程组。用计算机模拟了在改型Ｗｉｇｇｌｅｒ磁场中，电子与光场互作用从线性调制到非线性饱和的演化过程，得到了电子的相空间群聚图、高次谐波的增益、抽取效率和电子束的分布函数。同时还研究了电子束的能散度对高次谐波的增益和效率的影响等。模拟结果证实，改型ｗｉｇｇｌｅｒ自由电子激光是实现短波长相干光辐射的重要途径之一。     

Socio-educational work in at-risk contexts and professional reflexivity: the multi-vision group of “Maestri di Strada”

ABSTRACT

The Association ‘Maestri di Strada’ (MdS) undertakes socio-educational interventions to promote the well-being of young people in the ‘high-risk’ suburbs of Naples. The socio-educational work is not a mere ‘technical-rational’ activity and it relies on the use of ‘self’, which is not an unlimited resource. MdS places great emphasis upon reflexivity after the action and adopts the ‘Multi-Vision Group’ (MVG), which is a modified Balint group, as a support mechanism for its staff. Before trainees begin working, they attend the MVGs, observe them, and provide narrative accounts of the process. In this study, 61 reports prepared by the trainees during an academic year underwent a textual analysis. The aim was to evaluate the reflexive function of the group and the results indicate that, within the MVG, the practitioners express emotions, doubts, and difficulties linked to the job and its high-risk contexts. They show both self-awareness and awareness of the importance of the team, thinking as a community in a cooperative way. These are features related to reflexivity, which is recognised as being crucial for practice; the process of observation and recording also has a high educational importance for the trainees and social work students.     

Maximum likelihood estimators of the location and scale parameters of the exponential distribution from a censored sample

In this note explicit expressions are given for the maximum likelihood estimators of the parameters of the two-parameter exponential distribution, when a doubly censored sample is available.     

Information Processing of Genetically Modified Food Messages Under Different Motives: An Adaptation of the Multiple-Motive Heuristic-Systematic Model

Recent risk management research has noted the importance of understanding how the lay public processes and reacts to risk-related information. Guided by the multiple-motive heuristic-systematic model, this study examines (1) how individuals process messages in the context of genetically modified foods to change their attitudes and (2) how the persuasion process varies across types of motives. In the three treatment conditions of accuracy, defense, and impression motives, the respondents changed their attitudes through either the heuristic or the systematic mode, depending on their motives. The accuracy-motive group appeared to use the systematic processing mode, while the impression-motive group seemed to employ the heuristic processing mode. The empirical findings highlight the importance of incorporating motives to improve our understanding of the process of attitude change in risk management and communication contexts.