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81.
82.
A quantitative microbial risk assessment (QMRA) according to the Codex Alimentarius Principles is conducted to evaluate the risk of human salmonellosis through household consumption of fresh minced pork meat in Belgium. The quantitative exposure assessment is carried out by building a modular risk model, called the METZOON-model, which covers the pork production from farm to fork. In the METZOON-model, the food production pathway is split up in six consecutive modules: (1) primary production, (2) transport and lairage, (3) slaughterhouse, (4) postprocessing, (5) distribution and storage, and (6) preparation and consumption. All the modules are developed to resemble as closely as possible the Belgian situation, making use of the available national data. Several statistical refinements and improved modeling techniques are proposed. The model produces highly realistic results. The baseline predicted number of annual salmonellosis cases is 20,513 ( SD 9061.45). The risk is estimated higher for the susceptible population (estimate  4.713 × 10−5; SD 1.466 × 10−5  ) compared to the normal population  (estimate 7.704 × 10−6; SD 5.414 × 10−6)  and is mainly due to undercooking and to a smaller extent to cross-contamination in the kitchen via cook's hands.  相似文献   
83.
Event history models, also known as hazard models, are commonly used in analyses of fertility. One drawback of event history models is that the conditional probabilities (hazards) estimated by event history models do not readily translate into summary measures, particularly for models of repeatable events, like childbirth. In this paper, we describe how to translate the results of discrete-time event history models of all births into well-known summary fertility measures: simulated age- and parity-specific fertility rates, parity progression ratios, and the total fertility rate. The method incorporates all birth intervals, but permits the hazard functions to vary across parities. It can also simulate values for groups defined by both fixed and time-varying covariates, such as marital or employment life histories. We demonstrate the method using an example from the National Survey of Family Growth and provide an accompanying data file and Stata program.  相似文献   
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85.
Despite known risks associated with aberrant social skill development, there has been a relative dearth of literature on typical developmental changes in social skills over time. In this study, we examine systematic changes in social skills from kindergarten (typical age of 5–6 years) to third grade (typical age of 8–9 years), and focus on systematic heterogeneity across these developmental trajectories. Data came from the National Head Start—Public School Early Childhood Transition Demonstration Project (N = 6964). Mixture models provide evidence for multiple classes of individuals representing heterogeneity in the development of social skills. Classes were defined as a majority class (whose trajectories remained relatively stable over time), an increasing class (whose trajectories increased at a faster rate than the majority class), and a decreasing class (whose trajectories decreased at a faster rate than the majority class). Developmental trends accounted for a substantial proportion of the variance in social skill components. Implications and limitations of the study are discussed.  相似文献   
86.
Most principal–agent literature of nonprofit organizations has focused on the relationship between board members and managers. However, in addition to the role as an agent of the board, the manager also performs a role as principal with respect to the nonprofit employees. By using a discrete choice experiment, we identify the objectives of managers and employees in nonprofit organizations and assess the presence of agency problems in this relationship. Our sample consists of 76 headmasters, 161 teachers, and 39 administrative employees in 74 secondary nonprofit schools in Belgium. We find that the six objectives set out in the experiment play an important role for both headmasters and subordinate staff. However, the results also indicate that some of these objectives are significantly more important for the headmasters. In sum, our results suggest that agency theory and stewardship theory are not necessarily in conflict with each other but can be combined into a more general governance framework for nonprofit organizations. Consequently, we argue that incentive structures that incorporate different types of objectives can facilitate the recruitment and retention of employees in nonprofit organizations.  相似文献   
87.
This study focuses on the economically disadvantaged position of refugees. We use survey data of refugees from Somalia, Iran, Afghanistan, Iraq, and the former Yugoslavia in the Netherlands, to analyze refugees’ odds of employment and their occupational status. In line with human capital and social capital theory, we find that host country specific education, work experience, language proficiency, and contacts with natives are positively related to the chances of employment and occupational status. The study shows that health problems, integration courses, and the time spent in refugee reception centers form important additional explanations of the economic integration of refugees.  相似文献   
88.
Will paper recycling reduce the environmental impact of the European pulp and paper sector? If so, is maximal paper recycling the best policy to optimize the life cycle of the pulp and paper sector? We explore these questions using an approach that combines materials accounting methods and optimization techniques. Environmental impact data are inputs for a linear programming network flow model to find optimal configurations for the sector. These configurations consist of a mix of different pulping technologies, a geographical distribution of pulp and paper production, and a level of recycling consistent with the lowest environmental impacts. We use the model to analyse scenarios with different recycling strategies. Recycling offers a reduction in environmental impact in regions with a high population and a large production of paper and board products. Regions with a large production of graphic products should focus on cleaner virgin pulp production with energy recovery. We conclude that relocation of paper production also offers a reduction in environmental impact. However, the severe effects on the economy make this policy less attractive than a combination of recycling, cleaner pulp production and energy recovery.  相似文献   
89.
This article extends the debate begun in the June 1992 issue of EMJ when the authors first criticized Michael Porter's explanatory framework in his Competitive Advantage of Nations (1990), over the role of national culture on the competitive advantage of nations. In this paper, Frans van den Bosch and Arno van Prooijen stress that Europe is a locus of competitive advantage if one is prepared to pay attention to the possibility of ‘European Management’ as a potential asset of European firms. In this connection, the transnationalization of European firms is of importance.  相似文献   
90.
This article summarizes the results of a socioeconomic model of basic needs that was applied to four countries—Brazil, Colombia, India, and Kenya. A modeling approach was thought necessary in order to make more precise the concept of basic needs. Although the work has not been entirely successful in doing that, from the policy experiment attempted, and given the limitations of the models used, we believe that an approach centered on the provision of basic needs will help the poorest satisfy their needs more quickly than is possible under alternative approaches.  相似文献   
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