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991.
In this study, a variance‐based global sensitivity analysis method was first applied to a contamination assessment model of Listeria monocytogenes in cold smoked vacuum packed salmon at consumption. The impact of the choice of the modeling approach (populational or cellular) of the primary and secondary models as well as the effect of their associated input factors on the final contamination level was investigated. Results provided a subset of important factors, including the food water activity, its storage temperature, and duration in the domestic refrigerator. A refined sensitivity analysis was then performed to rank the important factors, tested over narrower ranges of variation corresponding to their current distributions, using three techniques: ANOVA, Spearman correlation coefficient, and partial least squares regression. Finally, the refined sensitivity analysis was used to rank the important factors.  相似文献   
992.
Despite underlying regularities in the age profile of migration, there is mounting evidence of cross‐national variations in the ages at which migration occurs. Explanations for these differences have variously been sought by reference to cultural, social, and economic factors, and through analysis of reasons for moving. There is also a growing body of work linking migration events to particular transitions in the life course. We set out a conceptual framework that links contextual factors to the age structure of migration through life‐course transitions that act as proximate determinants of the age at migration. We propose metrics to capture the prevalence, timing, and spread of four key life‐course transitions: education completion, labor force entry, union formation, and first childbearing. We then seek to quantitatively establish the link between these indicators and the age and intensity of internal migration at its peak for a global sample of 27 countries. Correlation and factor analysis reveal substantial diversity in the timing and spread of transitions to adult roles, and show that cross‐national differences in the age profile of migration closely parallel variations in the age structure of the life course for over two‐thirds of countries. Migration age profiles are aligned with transitions to adulthood for both sexes but most strongly among women.  相似文献   
993.
994.
Recently, numerous cases of dermatitis induced by dimethylfumarate (DMFu) have been reported in Europe. DMFu has been used to prevent mold development in various items, although it is not registered as a biocide. In France, from October 2008 to December 2009, more than 100 cases were reported. Despite a ban on articles containing DMFu and the removal of potentially contaminated products, some people were still suffering from dermatitis or other health problems. The French Agency for Food, Environmental and Occupational Health & Safety was mandated to assess whether the existence in the past of DMFu‐contaminated items in dwellings could continue to pose a threat to the health of inhabitants. A risk assessment was performed based on the classical risk analysis approach for environmental contaminants. Hazard assessment of DMFu with regard to its sensitizing properties was performed, based on human case reports collected in France between January 2009 and February 2010. For around half of the 132 individual cases reported, the causal link to DMFu was considered at least probable. An Organisation for Economic Co‐Operation and Development (OECD) local lymph node assay performed in a study on mice showed strong sensitizing potential for DMFu. Exposure was assessed by measuring DMFu in items sampled in preselected dwellings. These investigations demonstrated that DMFu exposure can persist after removal of the primary contaminated items. We therefore concluded that there was clearly a risk of skin reactions in patients previously sensitized to DMFu. Furthermore, the available data do not support the existence of significant health effects through the respiratory route.  相似文献   
995.
The 2005 Canada‐wide legalization of same‐sex marriage provided same‐sex couples with access to an institution they had previous been excluded from. Yet not all couples choose to marry. In this paper, we examine why this is the case, considering the role of personal, political, and historical factors. We draw on 22 interviews with people in common‐law same‐sex relationships in Toronto to examine how they understand their relationship within the new context of marriage equality. We find that participants feel they are held accountable to marriage as a default relationship legitimacy norm, indicating that this new institutional access is accompanied by a set of social expectations. Despite their awareness of the need to navigate a social context favoring marriage, participants individualize their relationship decisions as personal rather than political. Participants often contradict themselves as they articulate what marriage means to them, suggesting that, in this period of legal and social transition, people are negotiating multiple meanings, societal messages, and traditions when it comes to making sense of their relationship. We discuss the implications of these findings for LGBQ activism and the framing of sexuality‐based inequalities in Canadian society.  相似文献   
996.
This study reviews theories on striving for closure in adolescent networks related to trust issues of adolescents and further examines whether adolescents in mixed‐gender and single‐gender classes are different in striving for closure. Stochastic actor‐based models for network dynamics are applied to test our hypotheses based on longitudinal friendship nominations of 406 Taiwanese adolescents in mixed‐gender, all‐boy, and all‐girl classes. The results show that adolescents strive for closure through connections of friends' friends. Further, the results reveal that while the tendency toward closure is stronger for girls in mixed‐gender classes, such tendency toward closure is stronger in all‐boy classes than in all‐girl classes. Testing effects between types of classes supports the indications of variances in striving closure.  相似文献   
997.
This article examines the quantitative interrelations between sectoral composition of public spending and equilibrium (in)determinacy in a two‐sector real business cycle model with positive productive externalities in investment. When government purchases of consumption and investment goods are set as constant fractions of their respective sectoral output, we show that the public‐consumption share plays no role in the model's local dynamics, and that a sufficiently high public‐investment share can stabilize the economy against endogenous belief‐driven cyclical fluctuations. When each type of government spending is postulated as a constant proportion of the economy's total output, we find that there exists a trade‐off between public consumption versus investment expenditures to yield saddle‐path stability and equilibrium uniqueness. (JEL E32, E62, O41)  相似文献   
998.
Has the progress of output convergence changed within the United States? This article examines the output convergence among U.S. states for the last five decades by making several improvements over the extant literature. By applying a battery of convergence tests designed to capture nonlinear transitional dynamics to real output per worker data (i.e., nominal values deflated by state‐level price), we find that output convergence has not been a feature of the continental United States since the 1970s. Instead, output convergence has proceeded among four subgroups within which constituent states have certain characteristics in common. Our regression analysis suggests that state‐level characteristics related to technology and human capital play a crucial role in accounting for the formation and composition of convergence clubs, in agreement with the recent theoretical models of growth and development (e.g., Aghion et al. 2009; Gennaioli et al. 2013b). The level of technology, proxied by patents, turns out to be a consistently significant determinant even after controlling for endogeneity, suggesting that frictions in the diffusion of technology and human capital may have led to clustering of states with different levels of productivity. Our results therefore cast doubt on the common view that diffusion of knowledge and technology across state borders is frictionless. (JEL O47, O51)  相似文献   
999.
Policies to reduce carbon emissions by vehicles, such as fuel economy standards and gasoline taxes, have impacts on vehicle weight and thus on safety. This paper develops a model that separately identifies the impact of vehicle weight on mortality and selection effects that impact accident propensity. The main results are that (1) the safety externalities associated with heavy vehicles are greater than the environmental ones; (2) under fuel economy standards, vehicle weights have recently decreased with little likely effect on accident deaths; and (3) similar environmental benefits could be combined with substantial reductions in deaths by implementing higher gasoline taxes. (JEL H23, D62)  相似文献   
1000.
Speaking to the debate on the nature of critique, this article is about the struggle to produce an account when listening to and retelling stories. It begins with the disconcertment over listening to a coherent story that emerges in interviews about the development of performance indicators for Dutch hospital care. The indicators are presented as solutions to the problem of unruliness in the healthcare world. Drawing on Helen Verran's work on generative critique I slow down the ‘problem‐solution‐found’ plot. Instead of contrasting the apparently coherent stories with the complexities of an ‘underlying’ practice of healthcare, I hold on to my initial disconcertment so that ‘fleetingly subtle’ interruptions become entry points for generative critique. Taking Eduardo Viveiros de Castro's understanding of the relation that fear and laughter have to alterity, I show how fear and laughter permit generative critique within seemingly coherent stories. In the case of indicator development, the interviewees ‘laugh away’ what they consider alter from quality and safety in healthcare: having no control over what is going on, polyglotism instead of a common language, and inaction as opposed to taking one's time. Paying attention to disconcerting interruptions generates sensitivity and questions rather than yet another set of (critical) problem‐solution‐found answers. How can ridiculed (laughed away) subjectivity be acknowledged as important entry points for including alterity in supervision? And how to position the acknowledgement, not as an antidote, but as a way of rendering the fear of alterity generative? Nurturing sensitivities is crucial for keeping open, which means resisting both the sticky tendency of normalizing accounts and the fallacy of misplaced concreteness. I conclude that keeping open by re‐imagining critique resonates with the creativity of collective life in actual times and places. Thereby it offers a promising potential for doing worlds differently.  相似文献   
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