Unifying CRM and EWOC designs for phase I cancer clinical trials

The main goal of phase I cancer clinical trials is to determine the highest dose of a new therapy associated with an acceptable level of toxicity for the use in a subsequent phase II trial. The continual reassessment method (CRM) [O’Quigley, J., Pepe, M., Fisher, L., 1990. Continual reassessment method: a practical design for phase I clinical trials in cancer. Biometrics 46, 33–48] and escalation with overdose control (EWOC) [Babb, J., Rogatko, A., Zacks, S., 1998. Cancer phase I clinical trials: efficient dose escalation with overdose control. Statist. Med. 17 (10), 1103–1120] are two model-based designs used for phase I cancer clinical trials. A few modifications of the (original) CRM and EWOC have been made by many authors. In this paper, we show how CRM and EWOC can be unified and present a hybrid design. We study the characteristics of the approach of the hybrid design. The comparisons of the three designs (CRM, EWOC, and the hybrid design) are presented by convergence rates and overdose proportions. The simulation results show that the hybrid design generally has faster convergence rates than EWOC and smaller overdose proportions than CRM, especially when the true maximum tolerated dose (MTD) is above the mid-level of the dose range considered. The performance of these three designs is also evaluated in terms of sensitivity to outliers.     

地方政府支出与农村居民消费需求：基于1998-2007年省级 面板数据的经验分析

 政府支出对居民消费需求产生挤出抑或挤入效应是理论界最近关注的焦点之一。本文在理论诠释地方政府支出对农村居民消费需求的传导机制以及模型建立的理论框架下,通过建立地方政府支出与农村居民消费支出之间的个体固定效应变截距模型,运用我国31个省份1998-2007年的经验数据进行实证检验,结果表明：地方政府财政支农支出对农村居民消费具有显著的挤入效应,而转移性支出与农村居民消费的相关程度并不明显。基于理论分析和实证检验结果,本文最后针对地方政府扩大农村居民消费提出相关建议。     

Prenatal Sex Determination and Sex‐Selective Abortion in Rural Central China

This study analyzes the practice of prenatal sex selection in rural central China. It examines the prevalence and determinants of prenatal sex determination by ultrasound scanning and subsequent sex‐selective abortion. The data are derived from a survey of 820 married women aged 20–44 and from in‐depth interviews with rural women and men, village leaders, family planning managers, and health providers, conducted by the author in one county in central China in 2000. Prenatal sex determination was a widespread practice, especially for second and higher‐order pregnancies. Sex‐selective abortion was prevalent and order of pregnancy, sex of fetus, and sex of previous children were major determinants of the practice. A female fetus representing a high‐order pregnancy in a family with one or more daughters was the most likely to be aborted. Awareness among rural families that in the population at large a future marriage squeeze was likely did not diminish the demand for sex‐selective abortion.     

Ecosystem resilience, specialized adaptation and population decline: A modern Malthusian theory

The purpose of this article is to construct a theoretical framework characterizing the interactions among economic development, ecosystem equilibrium and possible population decline, and to discuss the population dynamics in the very long run. In our framework, economic activities bridge population and environment. On the one hand, human beings reform the environment through economic activities; on the other hand, economic activities decrease environmental resilience and increase the possibility of an environmental change in a discontinuous and irreversible pattern, as described in Arrow et al. (1995). Furthermore, a highly developed economy also causes over-specialization of human adaptation, which tends to exaggerate the impact of an environmental change on human population size. Received: 19 January 1999/Accepted: 3 July 1999     

Internet risks and expert views: a case study of the insider perspectives of youth workers in Hong Kong

This study collects and analyses the viewpoints of front-line youth workers regarding the notion of ‘Internet risks’. Previous studies have examined and discussed various dangers of the Internet. Parental, school, and governmental interventions are often called for by those concerned. The implicit assumption is that these are the people who possess the expertise to tackle the problems at hand. Through participation in three forums focusing on ‘Internet risks’, and in-depth interviews with 10 such ‘experts’ in Hong Kong, the study examines if this is a valid assumption. It finds that experts perceive Internet risks rather differently. In addition to the more conventional views about content, contact and conduct risks, our interviewees are aware that a new order is quickly emerging in the new media environment. Despite being considered as ‘experts’, they do not necessarily know how to tackle the so-called ‘youth-at-risk’. Rather, they are exploring how they would capitalize on the opportunities offered by the developments. The key findings highlight the need to critically review the notion of ‘Internet risks’. As with other risk frameworks, the ultimate aim is to develop intervention programmes. In this regard, risks are often treated as concrete problems that can be solved. Youth experts, however, find that the changing scope, speed and persistence of communication in today's information society present the biggest challenge in youth work. The existing framework of risks was unable to describe and account for such risks. In response, Internet risk has to be reconceptualized so that more updated, relevant and imaginative intervention can be introduced.     

论《畿辅方言》对《汉语方言大词典》修订的作用

清人王树柑《畿辅方言》是清末民初一部记载河北方言的辞书,也是一部研究河北古代方言的专书,在方言学史和汉语词汇史上具有重要地位与价值。《畿辅方言》以词汇研究为视角,对《汉语方言大词典》修订的作用体现在增补词目、补充义项、提前书证、补充书证等四个方面。     

中国本土对话诗学的构建

对话理论、对话诗学的基础是对话哲学,或哲学的对话论转向。在西方,哲学的对话论转向在某种意义上则是以康德的批判哲学为开端的,至海德格尔、伽达默尔的存在论阐释学,特别是巴赫金的对话主义则走向了巅峰。但对话理论在实际的学术世界又是以多维化的面相存在的,如解释学、接受学、阅读学、主体间性、生态论、阴阳交感思想等等,当然还有专门的对话学理论。因此需要从理论上进行新的整合、建构。另外,若从一种平等的关系结构或交流模式来看,中国哲学、诗学中也早就存在相关的对话论了,因此,也有必要建构一种跨文化的、贯通中西的对话理论。至于把这种新的对话理论模式转换成一种对话诗学,就更是一种具有开创性的工作,它是对巴赫金对话诗学的自觉的兼融和超越。     

观念竞合与国际体系的变迁

观念在国际关系中的作用及重要性已是不言而喻。在过去的四百多年里，国家主义和保守主义分别主导、塑造了威斯特伐利亚体系及维也纳体系，而威尔逊式的理想主义虽然塑造了凡尔赛—华盛顿体系，但主导该时期的却是激进主义。直到雅尔塔体系时期，民族主义才终于打败了帝国主义，自由主义则成功战胜了极权主义。因此，国际体系确立的背后是观念分配竞合的结果，是主流观念取向在竞合中占据主导地位的过程。观念作为深层次因素，始终是影响、塑造国际体系的更新与变迁的不可或缺的力量。     

张平小说写作的方向、价值简析

张平小说的一个明显的特征是它的强烈的关注现实的情怀、实实在在的生活的“含金量”和近距离的“纪实品格”。其《法撼汾西》、《天网》、《孤儿泪》、《抉择》、《十面埋伏》、《对面的女孩》都直接取材于现实生活 ,都有大量的现实素材做基础。张平的小说又不同于一般的“社会问题小说” ,它不仅仅限于提出问题 ,而是要积极地干预现实 ,尤其重视对社会正面力量的褒扬和歌颂 ,充满了正面的激情 ,散射出积极的理想主义光彩。张平小说其实正代表着一种文学传统 :为人民代言 ,为老百姓鼓呼。这是中国文学史上的一个优秀的、源远流长的写作传统 ,如儒家的“文以载道”论 ,以《诗经》为开端的现实主义传统 ,屈原的“哀民生之多艰” ,杜甫的“三吏、三别” ,白居易的“惟歌生民病” ,鲁迅的“俯首甘为孺子牛” ,赵树理的全心全意为农民写作、甘当“文摊作家” ,当然 ,还有毛泽东的“文艺为工农兵服务”和我们党后来的一系列类似的文艺政策等等。张平的小说创作正是这一优秀传统的继承和发扬光大。它的出现、成功 ,无疑是对文学领域那种远离“大众生活”的私人化倾向的有力针砭和拨正。代言传统小说 ,过去曾经步入公式化、概念化和庸俗政治化的歧途 ,而张平却未落窠臼 ,他的小说写作已有了一些新的变化 ,如自?     

Health Risk Characterization of Chlorpyrifos Using Epidemiological Dose‐Response Data and Probabilistic Techniques: A Case Study with Rice Farmers in Vietnam

Various methods for risk characterization have been developed using probabilistic approaches. Data on Vietnamese farmers are available for the comparison of outcomes for risk characterization using different probabilistic methods. This article addresses the health risk characterization of chlorpyrifos using epidemiological dose‐response data and probabilistic techniques obtained from a case study with rice farmers in Vietnam. Urine samples were collected from farmers and analyzed for trichloropyridinol (TCP), which was converted into absorbed daily dose of chlorpyrifos. Adverse health response doses due to chlorpyrifos exposure were collected from epidemiological studies to develop dose‐adverse health response relationships. The health risk of chlorpyrifos was quantified using hazard quotient (HQ), Monte Carlo simulation (MCS), and overall risk probability (ORP) methods. With baseline (prior to pesticide spraying) and lifetime exposure levels (over a lifetime of pesticide spraying events), the HQ ranged from 0.06 to 7.1. The MCS method indicated less than 0.05% of the population would be affected while the ORP method indicated that less than 1.5% of the population would be adversely affected. With postapplication exposure levels, the HQ ranged from 1 to 32.5. The risk calculated by the MCS method was that 29% of the population would be affected, and the risk calculated by ORP method was 33%. The MCS and ORP methods have advantages in risk characterization due to use of the full distribution of data exposure as well as dose response, whereas HQ methods only used the exposure data distribution. These evaluations indicated that single‐event spraying is likely to have adverse effects on Vietnamese rice farmers.