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71.
The skin is a route of exposure that needs to be considered when conducting a risk assessment. It is necessary to identify the potential for dermal penetration by a chemical as well as to determine the overall importance of the dermal route of exposure as compared with inhalation or oral routes of exposure. The physical state of the chemical, vapor or liquid, the concentration, neat or dilute, and the vehicle, lipid or aqueous, is also important. Dermal risk is related to the product of the amounts of penetration and toxicity. Toxicity involves local effects on the skin itself and the potential for systemic effects. Dermal penetration is described in large part by the permeability constant. When permeability constants are not known, partition coefficients can be used to estimate a chemical's potential to permeate the skin. With these concepts in mind, a tiered approach is proposed for dermal risk assessment. A key first step is the determination of a skin-to-air or skin-to-medium partition coefficient to estimate a potential for dermal absorption. Building a physiologically-based pharmacokinetic (PBPK) model is another step in the tiered approach and is useful prior to classical in vivo toxicity tests. A PBPK model can be used to determine a permeability constant for a chemical as well as to show the distribution of the chemical systemically. A detailed understanding of species differences in the structure and function of the skin and how they relate to differences in penetration rates is necessary in order to extrapolate animal data from PBPK models to the human. A study is in progress to examine anatomical differences for four species.  相似文献   
72.
This paper presents empirical evidence that an individual's decision to drive while drunk is negatively affected by the expected full price of driving drunk. The analysis uses a unique data set containing information on self-reported drunk driving matched to state-level drunk driving policies as well as to state excise taxes on beer. These are hypothesized and found to affect drunk driving. Further, we find interesting racial differences but surprisingly small differences by gender in the effect of socioeconomic and policy variables on drunk driving propensities.  相似文献   
73.
The authors consider the issue of map positional error, or the difference between location as represented in a spatial database (i.e., a map) and the corresponding unobservable true location. They propose a fully model‐based approach that incorporates aspects of the map registration process commonly performed by users of geographic informations systems, including rubber‐sheeting. They explain how estimates of positional error can be obtained, hence estimates of true location. They show that with multiple maps of varying accuracy along with ground truthing data, suitable model averaging offers a strategy for using all of the maps to learn about true location.  相似文献   
74.
Recent scholarship on the 'Americanization' of economic and cultural practices emphasize that the Europeans were not passive victims of this 'colonizing' project but selectively appropriated or even completely rejected aspects of it. This paper extends these insights to a scientific field. It describes the failed attempt to export to NATO a theory-based, computer-dependent model of operations research which embedded civilian scientists deeply in the military decision-making process. This conception of operations research and its related social practices was blocked by the British, who rejected a model of operations research which called for a training in advanced mathematics and computing, and who insisted that NATO maintain a strict civil/military divide. 'Americanization' was a negotiated and contested project which, while stimulating an awareness for change in Europe, did not necessarily determine its trajectory.  相似文献   
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信息化、网络化的发展带来了社会价值的多元化,人们的观念不断更新,从工作、学习到娱乐,从经济、政治到文化都发生了一次根本性的变革.这一切都给正在处于认识能力低、情绪不稳定、心理与生理不成熟的青少年带来了极大的发展机遇的同时也给其带来了困惑与迷茫.而传统的思想教育显得空洞乏味,失去了对青少年的吸引力,面对现状无法担负起这时代的重任.为了使青少年思想教育回归生活,立足于普世中的价值,本文就青少年思想教育存在的现状及其出路,提出了一些浅略的见解.  相似文献   
77.
This article overviews prevention and early intervention approaches focusing specifically on their relevance to the health of children and young people in Australia. Australian public health has a sound track record although concealed within the aggregate profile are a number of sub-populations with poorer health indicators. Recognition of this has increased efforts to improve the health of children and young people especially in exploring the impact of social environments within the communities where children are raised. This paper examines emerging research in this area drawing out key lessons and learning from Australian experience in the field of early intervention and prevention in community settings.  相似文献   
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Book reviews     
Nathan Glazer Ethnic Dilemmas Harvard, Harvard University Press. 1985

Giddens, Anthony The Constitution of Society, Berkeley, University of California, 1985, pp.XXXVII, 402. Notes, glossary, diagrams, bibliographic notes and index.

Jeremy Rifkin Declaration of a Heretic. Boston. London, Melbourne and Henley, Routledge and Kegan Paul, 1985, pp.X,140.

Ted Benton The Rise and Fall of Structural Marxism: Althusser and his Influence, New York, St.Martin's Press, 1984, pp. VII,259.

Raymond L. Garthoff Détente and Confrontation Washington, The Brookings Institution, 1985, pp.XVI,1126.

Joseph J. Collins The Soviet Invasion of Afghanistan. A Study in the Use of Force in Soviet Foreign Policy, Massachusetts/Toronto, D.C. Heath and Company/Lexington, 1986, pp. XV, 195.

Jan Shipps Mormonism: The Story of a New Religious Tradition, Chicago, University of Illinois Press, 1985, pp.211.

Robert Jay Lifton Home from the War: Vietnam Veterans: Neither Victims nor Executioners, New York, Basic Books, 1985, pp.478  相似文献   

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