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241.
The introduction of classical swine fever virus (CSFV) into a country free of disease without vaccination may have huge consequences in terms of both disease spread and economic losses. More quantitative insight into the main factors determining the probability of CSFV introduction (PCSFV) is needed to optimally use resources for the prevention of CSFV introduction. For this purpose a spreadsheet model was constructed that calculates the annual PCSFV into member states of the European Union (EU). The scenario pathway approach was used as most probabilities in the model are very small. Probability distributions were used to take into account inherent variability of input parameters. The model contained pathways of CSFV introduction including the import of pigs and pork products, returning livestock trucks, and contacts with wild boar. All EU member states were included as possible sources of CSFV. Default results for the Netherlands showed a mean overall annual PCSFV of approximately 0.06, indicating that the Netherlands can expect CSFV introduction on average once every 18 years from the pathways and countries included in the model. Almost 65% of this probability could be attributed to the pathway of returning livestock trucks. The most likely sources of CSFV introduction were Germany, Belgium, and the United Kingdom. Although the calculated probabilities were rather low when compared with expert estimates and recent history, the most likely causes of CSFV introduction indicated by the model were considered to be realistic. It was therefore concluded that the model is a useful tool to structure and analyze information for decision making concerning the prevention of CSFV introduction.  相似文献   
242.
In this paper, multicultural primary school classes in Norway and the Netherlands are compared in terms of language teaching and learning. Drawing on observations, interviews, and school and policy documents, four dimensions of comparison are discussed. First, we deal with the different ways in which separate language classes for language minority pupils were organized in the two cases. Secondly, the different ways of teaching and the underlying views on learning language are characterized. Thirdly, we analyse how these ways of teaching affect on language minority pupils. Fourthly, we address the question as to how these approaches relate to the educational policies, traditions and discourses of the respective countries.  相似文献   
243.
Foot-and-mouth disease (FMD) is a viral disease of domesticated and wild cloven-hoofed animals. FMD virus is known to spread by direct contact between infected and susceptible animals, by animal products such as meat and milk, by the airborne route, and mechanical transfer on people, wild animals, birds, and by vehicles. During the outbreak of 2001 in the Netherlands, milk from dairy cattle was illegally discharged into the sewerage as a consequence of transport prohibition. This may lead to contaminated discharges of biologically treated and raw sewage in surface water that is given to cattle to drink. The objective of the present study was to assess the probability of infecting dairy cows that were drinking FMD virus contaminated surface water due to illegal discharges of contaminated milk. So, the following data were collected from literature: FMD virus inactivation in aqueous environments, FMD virus concentrations in milk, dilution in sewage water, virus removal by sewage treatment, dilution in surface water, water consumption of cows, size of a herd in a meadow, and dose-response data for ingested FMD virus by cattle. In the case of 1.6 x 10(2) FMD virus per milliliter in milk and discharge of treated sewage in surface water, the probability of infecting a herd of cows was estimated to be 3.3 x 10(-7) to 8.5 x 10(-5), dependent on dilution in the receiving surface water. In the case of discharge of raw sewage, all probabilities of infection were 100 times higher. In the case of little dilution in small rivers, the high level of 8.5 x 10(-3) is reached. For 10(4) times higher FMD virus concentrations in milk, the probabilities of infecting a herd of cows are high in the case of discharge of treated sewage (3.3 x 10(-3) to 5.7 x 10(-1)) and very high in the case of discharge of raw sewage (0.28-1.0). It can be concluded that illegal and uncontrolled discharges of contaminated milk into the sewerage system may lead to high risks to other cattle farms at 6-50 km distance of the location of discharge within one day. This clearly underlines current measures that prohibit such discharges, and also asks for strict control. This risk assessment clearly demonstrated the potential significance of FMD virus transmission via water, and the results will be useful on an international scale, and could also serve as a basis for other FMD risk-assessment models.  相似文献   
244.
Studies of industrial rationality should be reconsidered given the thoroughgoing changes under way. We have switched from a Taylorist rationality based on Scientific Management, which claimed to fit production into a single viewpoint, to a dissemination of the sources of the directions to be followed and an overall destabilization of any attempt at rationalization, and as a consequence, to a looser sense of rationality even among engineers. But this does not at all benefit wage-earners. Often without bearings, they have to cope with instructions; but have a harder time doing so whenever their organization provides them with few tools for coping and whenever the instructions, or part of them, are contradictory.  相似文献   
245.
Brief therapy has often been regarded as “problem solving therapy.” This article discusses the development of a solution-focused approach to clinical practice. Solution-focused therapeutic tasks and interventions are described.  相似文献   
246.
Collective violence is often social control: self-help by a group. It typically defines and responds to conduct as deviant. When unilateral and nongovernmental, it appears in four major forms—lynching, rioting, vigilantism, and terrorism—each distinguished by its system of liability (individual or collective) and degree of organization (higher or lower). Following Donald Black's paradigm of pure sociology, the central assumption is that collective violence varies with its location and direction in social space—the conflict structure. I offer ten propositions that predict and explain the likelihood and severity of collective violence in general and the four forms of collective violence in particular. Conflict structures with a high degree of relational distance, cultural distance, functional independence, and inequality between the adversaries are associated with collective violence in general. Each of the four forms depends on the degree of social polarization between the parties as well as the continuity of the deviant behavior to which the violence responds. Earlier versions of this paper were presented at the Annual Meeting of the American Sociological Association, Pittsburgh, Pennsylvania, August 1992, and the Centennial Congress of the International Institute of Sociology, University of Paris (Sorbonne), Paris, June 1993.  相似文献   
247.
This paper introduces and characterises a class of inequality measures which extends the Atkinson family. This class contains canonical forms of all aggregative inequality measures, each bounded above by one, provides a new dominance criterion for ordering distributions in terms of inequality and offers some new graphical procedures for analysts. The crucial axiom for the characterisation is an alternative to the standard additive decomposition property that we call ‘multiplicative decomposability,’ where the within-group component is a generalised weighted mean with weights summing exactly to one. An erratum to this article can be found at  相似文献   
248.
This paper explores the interrelationship between agricultural policies and development by means of a dynamically recursive, computable general equilibrium model applied to Sri Lanka. The agricultural policies investigated include elimination of the food subsidy, land reform, and technical change in agriculture. The goals considered are the levels and growth rates of GNP and employment, the distribution of income, and the real income level of the lowest income group. The study provides a quantitative assessment of the association between policies and goals and identifies the key economic mechanisms in this association.  相似文献   
249.
Ups and Downs in the Pulse of Science and Technology   总被引:1,自引:0,他引:1  
  相似文献   
250.
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