The precautionary principle

The Precautionary Principle in its simplest form states: "When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically". This Principle is the basis for European environmental law, and plays an increasing role in developing environmental health policies as well. It also is used in environmental decision-making in Canada and in several European countries, especially in Denmark, Sweden, and Germany. The Precautionary Principle has been used in the environmental decision-making process and in regulating drugs and other consumer products in the United States. The Precautionary Principle enhances the collection of risk information for, among other items, high production volume chemicals and risk-based analyses in general. It does not eliminate the need for good science or for science-based risk assessments. Public participation is encouraged in both the review process and the decision-making process. The Precautionary Principle encourages, and in some cases may require, transparency of the risk assessment process on health risk of chemicals both for public health and the environment. A debate continues on whether the Principle should embrace the "polluter pays" directive and place the responsibility for providing risk assessment on industry. The best elements of a precautionary approach demand good science and challenge the scientific community to improve methods used for risk assessment.     

The no-fault principle

The number of claims against doctors and health authorities for negligence, though not on the scale of those in the USA are, nevertheless, increasing. Harry Orriss looks at the recommendations of the Pearson Commission and compares these with compensation schemes in New Zealand and Sweden.     

The Janus face of statistical adjustment: confounders versus colliders

It has long been established that controlling for confounders is essential to delineate the causal relationship between exposure and disease. For this purpose, statistical adjustment is widely used in observational studies. However, many researchers don’t acknowledge the potential pitfalls of statistical adjustment. The aim of the present paper was to demonstrate that statistical adjustment is a double edged sword. By using numerically identical examples, we show that adjustment for a common consequence of the exposure and the outcome can lead to as much bias as absence of necessary adjustment for a confounder.     

The precautionary principle and the environment

The precautionary principle is a response to uncertainty in the face of risks to health or the environment. In general, it involves taking measures to avoid potential harm, despite lack of scientific certainty. In recent years it has been applied, not without difficulties, as a legal and political principle in many countries, particularly on the European and International level. In spite of the controversy, the precautionary principle has become an integral component of a new paradigm for the creation of public policies needed to meet today's challenges and those of the future.     

X线电视系统故障分析及维修

X线电视系统广泛用于现代X线机中,它主要由影像增强器、摄像机和监视器等组成。三者之中任一部分存在故障，将会使X线电视系统无法正常工作。下面列举几例故障现象及其分析过程。     

UPS的工作原理及故障维修

简要介绍不间断电源的工作原理、故障分析和维修方法。     

库尔特血液分析仪系统原理的探讨

介绍库尔特血液分析仪的整机系统原理。     

常用生理参数的测量原理

随着医学事业的发展,监护仪得到广泛的运用,就医用监护仪常用生理参数的工作原理简述如下。     

Savina呼吸机原理和检修

介绍医院常用的SAVINA呼吸机结构、特点和典型故障检修。     

The precautionary principle in environmental science.

Environmental scientists play a key role in society's responses to environmental problems, and many of the studies they perform are intended ultimately to affect policy. The precautionary principle, proposed as a new guideline in environmental decision making, has four central components: taking preventive action in the face of uncertainty; shifting the burden of proof to the proponents of an activity; exploring a wide range of alternatives to possibly harmful actions; and increasing public participation in decision making. In this paper we examine the implications of the precautionary principle for environmental scientists, whose work often involves studying highly complex, poorly understood systems, while at the same time facing conflicting pressures from those who seek to balance economic growth and environmental protection. In this complicated and contested terrain, it is useful to examine the methodologies of science and to consider ways that, without compromising integrity and objectivity, research can be more or less helpful to those who would act with precaution. We argue that a shift to more precautionary policies creates opportunities and challenges for scientists to think differently about the ways they conduct studies and communicate results. There is a complicated feedback relation between the discoveries of science and the setting of policy. While maintaining their objectivity and focus on understanding the world, environmental scientists should be aware of the policy uses of their work and of their social responsibility to do science that protects human health and the environment. The precautionary principle highlights this tight, challenging linkage between science and policy.     

AGFA CR工作原理及故障分析

本文详细介绍了AGFA CR的ADCC工作原理，详细讨论了由于ADCC引起的相关故障现象及解决方法。