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1.
The extent of carcinogen regulation under existing U.S. environmental statutes is assessed by developing measures of the scope and stringency of regulation. While concern about cancer risk has played an important political role in obtaining support for pollution control programs, it has not provided the predominant rationale for most regulatory actions taken to date. Less than 20% of all standards established to limit concentrations of chemicals in various media address carcinogens. Restrictions on chemical use are more frequently based on concerns about noncancer human health or ecological effects. Of the chemicals in commercial use which have been identified as potential human carcinogens on the basis of rodent bioassays, only a small proportion are regulated. There is an inverse relationship between the scope of regulatory coverage and the stringency of regulatory requirements: the largest percentages of identified carcinogens are affected by the least stringent requirements, such as information disclosure. Standards based on de minimis cancer risk levels have been established for only 10% of identified carcinogens and are restricted to one medium: water. Complete bans on use have affected very few chemicals. The general role that carcinogenicity now plays in the regulatory process is not dramatically different from that of other adverse human health effects: if a substance is identified as a hazard, it may eventually be subject to economically achievable and technically feasible restrictions.  相似文献   
2.
The goal of Louisiana's 1990–1991 comparative risk project, also called the Louisiana Environmental Action Plan (LEAP), was to incorporate risk assessment into state environmental planning and policymaking. Scientists, government officials, and citizens were brought together to estimate the relative risk to human health, natural resources, and quality of life posed by 33 selected environmental issues. The issues were then ranked according to their relative estimated risks. It was hoped that this ranking of "comparative risks" would enable state policymakers to target the most important environmental problems and allocate scarce public resources more rationally and efficiently. As a result of the project, the governor issued an Executive Order forming a permanent Public Advisory Committee to continue this type of comparative risk assessment in Louisiana.  相似文献   
3.
Tattling on siblings was observed in 40 families with 2- and 4-year-old children. All but 5 children reported sibling misbehaviour to parents with younger siblings tattling largely to recruit parental help in resolving conflict issues, and older siblings tattling both in the context of conflict and merely to inform parents of their siblings' misbehaviour. Parents rarely reprimanded children for tattling, but either ignored it, or responded to information in tattlers' reports regardless of context or whether older or younger children tattled. Children did not tattle equally on all sibling transgressions, but emphasized physical aggression and property damage, issues that also elicited parental discipline. Tattling is discussed in relation to children's understanding of the dynamics and moral standards of family life.  相似文献   
4.
土地是人类赖以生存和发展的物质基础。近二十年来,土地单纯作为自然资源的价值发生了深刻的变化,已成为影响经济和政治活动的重要因素。基于土地的经济和社会价值的与日俱增,土地政策的重要性也越来越受到学者的重视,因此关于土地改革的政策研究也成为热点。  相似文献   
5.
为了提升城市户外广告环境品质,改进规划工作的不足,提出以公共政策为导向的户外广告规划研究方法。在《深圳市户外广告设置指引》的编制实践中,通过多视角的目标建构、"规范"加"规划"的导控策略以及"手册式"的成果表达手段,取得了良好的实践效果。因此提出:为了提高户外广告规划成果的可操作性,增强实施实效性,必须正确认识户外广告的双重属性,将规划工作从传统的技术导向转变为以公共政策导向,做到导控中的因势"利导"与"力导"。  相似文献   
6.
皮亚杰首次利用实验方法,从个体心理发展的微观角度,揭示了儿童的道德责任的发生过程和机制。道德责任是个体社会化的产物,经历了由他律的客观责任向自律的主观责任的进化。真正的道德责任产生于协作。皮亚杰的道德责任发生论对道德教育理论与实践的启示是:道德教育必须以自由为基础,充分利用学生的自主活动,才能教会学生负责。  相似文献   
7.
孔子仁道观的建立源自对"仁"的阐发,具有主体性、社会互动性和超越性等特性,并广泛地涉及到道德主体、道德互动、道德判断、道德能力、道德修养、道德境界和道德健康等哲学命题,构起了内涵丰富的仁道观。基于当今公民道德面临的新情况、新问题,重新审视这些特性,对当今加强公民道德建设不无启迪,主要包括:尊重道德主体的主体性;充分发挥道德行为过程中的社会互动功能;努力提高道德能力;不断提升道德境界和积极培养道德健康等等。这些都是当今加强公民道德建设中值得关切的问题,应当努力的方向和可供选择的路径。  相似文献   
8.
利用生存分析研究寿险退保问题是一个很好的工具,因为可以将寿险保单的持续期(persistency duration)视为生存期长,而将保单的退保或失效看作一个“保单生命”的结束,这其中的保单退保或失效就成为生存研究的目标事件。而导致保单失效的因素会有很多,只有通过利用Cox比例危险模型拟合寿险退保数据以分析影响客户退保的原因,并在对Cox模型的比例危险假设进行检验时,发现部分影响因素并不遵守此前提条件,从而推理得到这些影响因素在不同的时间段对客户退保的影响方式不同。也就是说,其影响有短期效应和长期效应之分。  相似文献   
9.
Abstract

In this article, we have considered the problem of estimation of population variance on current (second) occasion in two occasion successive (rotation) sampling. A class of estimators of population variance has been proposed and its asymptotic properties have been discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion and the Singh et al. (2013) estimator. Optimum replacement policy is discussed. It has been shown that the suggested estimator is more efficient than the Singh et al. (2013) estimator and a usual unbiased estimator when there is no matching. An empirical study is carried out in support of the present study.  相似文献   
10.
ABSTRACT

This paper addresses the problem of estimation of the population mean on the current (second) occasion in two-occasion successive sampling. Utilizing the readily available information on several auxiliary variables on both occasions and the information on the study variable from the previous occasion, an estimation procedure of the population mean on the current occasion has been proposed. Theoretical properties of the proposed estimator have been investigated. Optimum replacement policy to the proposed estimator has been discussed. The proposed estimator has been compared empirically with the sample mean estimator, when there is no matching and the optimum estimator which is a linear combination of the means of the matched and unmatched portions of the sample at the current occasion. Appropriate recommendations have been made for practical applications.  相似文献   
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