Chemical risk communication through the Internet in Spain

In this work, some corporate websites of the chemical industry of Tarragona (Spain) are studied, analysing how the chemical trade associations and companies present information and/or encourage dialogue with the community on issues relating to the chemical risk and their environmental, health and safety (EHS) performance. The results suggest that the chemical industry in Tarragona uses the corporate websites mainly to disseminate information about its EHS commitments and performance, but they do not encourage dialogue with the community through the Internet.     

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.     

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.     

学习智障对我国企业竞争力弱化之影响

本文从系统的观点出发 ,运用反馈机制原理 ,对企业竞争优势弱化现象进行了较为系统、深入的分析 ,提出学习智障对企业竞争力的雪崩效应模型和组织学习力的滚雪球效应模型 ,以探索强化企业竞争优势的途径     

Perception and control of occupational injury risks in fishery--a pilot study

The frequency of occupational accidents in fishery is high in most fishery nations. Implementation of safety measures has, however, been limited. The purpose of the present cross-sectional study was to explore Swedish fishermen's attitudes towards occupational risks and accident control. Information was acquired through a questionnaire distributed to a convenience sample of 92 fishermen. Indices were built, containing variables relevant to perceived risk levels in connection with work, perceived manageability of risks, activity in safety work, technical knowledge and individual attitudes towards risks. The results did not support earlier findings of low risk awareness and risk acceptance among fishermen. Perceived manageability of risks but not perceived risk level, accident experience or risk acceptance, were significantly associated with activity in safety work. The results suggest that safety work might benefit from efforts to develop fishermen's understanding of how the development of hazardous situations can be prevented or managed. The results do not support strategies for accident control in fishery based solely on increasing risk awareness.     

ERP系统的评价方法

ERP－Enterprise Resource Planning即企业资源计划系统，是运用信息技术，包含成功的管理思想和管理方法的软件系统，可以帮助企业实现规范化，合理化管理，正逐渐成为现代企业的运行模式。面对加入WTO，引入ERP管理系统成为中国企业提高管理水平的大势所趋。而ERP的导入会给企业带来巨大的变化，所以，对于一个即将导入或正在导入ERP的企业，如何选择适合自身的ERP系统是一个首要的问题。本文综合分析了ERP系统的定量评价方法，它可以帮助企业结合自身特点对ERP系统进行评价，为ERP系统选择提供依据。     

价值多元化视阈下大学生核心价值认同危机与重构

中国社会正处于一个急剧转型时期，人们的生活方式发生了极大变化，出现了许多认同危机，特别是核心价值认同危机。然而，核心价值认同是关系到社会安定和发展的一个重要的心理和文化因素。大学生是推动社会前进的重要力量和潜在力量，因此，考察大学生核心价值认同危机的表现形式，分析产生核心价值认同危机的原因，提出以社会主义核心价值体系重塑大学生价值认同对构建社会主义和谐社会具有重要的现实意义。     

Human immunodeficiency virus risk: is it possible to dissuade people from having unsafe sex?

Summary. The cumulative number of human immunodeficiency virus (HIV) infections worldwide has reached 60 million in little over 30 years. HIV continues to spread despite a detailed understanding of the manner in which it spreads and measures which can prevent spread. Some governments have been highly successful in containing the spread of HIV through blood products and from mother to child and among injecting drug users. Lack of political will, lack of resources or challenges to widely accepted scientific evidence have held back similar interventions in other countries. It has proved much more difficult to reduce the sexual transmission of HIV in both high and low income countries. A wide range of strategies has been identified but it remains unclear which strategies deserve priority and what methods of promoting them have the greatest effect. There is ample evidence that awareness of HIV and changes in sexual behaviour have occurred widely but the penetration of information remains poor in some vulnerable groups especially adolescents and women in poorer countries. Further obstacles face those who have information about the risk. The subordinate position of women and a desire for large families are important obstacles to condom negotiation and use. Urbanization, poverty, conflict and declining public services all exacerbate unsafe sexual behaviour. We argue that so-called 'structural' interventions directed at these wider contexts of unsafe behaviour merit greater attention. Such approaches have the added benefit of being less susceptible to 'risk compensation' which has the potential to undermine strategies directed at reducing the transmission efficiency of HIV.     

Modeling for Risk Assessment of Neurotoxic Effects

The regulation of noncancer toxicants, including neurotoxicants, has usually been based upon a reference dose (allowable daily intake). A reference dose is obtained by dividing a no-observed-effect level by uncertainty (safety) factors to account for intraspecies and interspecies sensitivities to a chemical. It is assumed that the risk at the reference dose is negligible, but no attempt generally is made to estimate the risk at the reference dose. A procedure is outlined that provides estimates of risk as a function of dose. The first step is to establish a mathematical relationship between a biological effect and the dose of a chemical. Knowledge of biological mechanisms and/or pharmacokinetics can assist in the choice of plausible mathematical models. The mathematical model provides estimates of average responses as a function of dose. Secondly, estimates of risk require selection of a distribution of individual responses about the average response given by the mathematical model. In the case of a normal or lognormal distribution, only an estimate of the standard deviation is needed. The third step is to define an adverse level for a response so that the probability (risk) of exceeding that level can be estimated as a function of dose. Because a firm response level often cannot be established at which adverse biological effects occur, it may be necessary to at least establish an abnormal response level that only a small proportion of individuals would exceed in an unexposed group. That is, if a normal range of responses can be established, then the probability (risk) of abnormal responses can be estimated. In order to illustrate this process, measures of the neurotransmitter serotonin and its metabolite 5-hydroxyindoleacetic acid in specific areas of the brain of rats and monkeys are analyzed after exposure to the neurotoxicant methylene-dioxymethamphetamine. These risk estimates are compared with risk estimates from the quantal approach in which animals are classified as either abnormal or not depending upon abnormal serotonin levels.     

The Burden of Risk: Who Dies Because of Cars?

This article argues that those interested in social policy should by definition be interested in issues of transport policy. It analyses data on road traffic fatalities and suggests, in the light of this evidence, that those who benefit least from the motor vehicle seem disproportionately likely, given their relative exposure to the risk, to die in road traffic accidents.