Probabilistic Modeling of the Fate of Listeria Monocytogenes in Diced Bacon During the Manufacturing Process

To assess the impact of the manufacturing process on the fate of Listeria monocytogenes, we built a generic probabilistic model intended to simulate the successive steps in the process. Contamination evolution was modeled in the appropriate units (breasts, dice, and then packaging units through the successive steps in the process). To calibrate the model, parameter values were estimated from industrial data, from the literature, and based on expert opinion. By means of simulations, the model was explored using a baseline calibration and alternative scenarios, in order to assess the impact of changes in the process and of accidental events. The results are reported as contamination distributions and as the probability that the product will be acceptable with regards to the European regulatory safety criterion. Our results are consistent with data provided by industrial partners and highlight that tumbling is a key step for the distribution of the contamination at the end of the process. Process chain models could provide an important added value for risk assessment models that basically consider only the outputs of the process in their risk mitigation strategies. Moreover, a model calibrated to correspond to a specific plant could be used to optimize surveillance.     

Bayesian Development of a Dose‐Response Model for Aspergillus fumigatus and Invasive Aspergillosis

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromized hosts, most often consecutive to the inhalation of spores of Aspergillus. However, the relationship between Aspergillus concentration in the air and probability of IA is not quantitatively known. In this study, this relationship was examined in a murine model of IA. Immunosuppressed Balb/c mice were exposed for 60 minutes at day 0 to an aerosol of A. fumigatus spores (Af293 strain). At day 10, IA was assessed in mice by quantitative culture of the lungs and galactomannan dosage. Fifteen separate nebulizations with varying spore concentrations were performed. Rates of IA ranged from 0% to 100% according to spore concentrations. The dose‐response relationship between probability of infection and spore exposure was approximated using the exponential model and the more flexible beta‐Poisson model. Prior distributions of the parameters of the models were proposed then updated with data in a Bayesian framework. Both models yielded close median dose‐responses of the posterior distributions for the main parameter of the model, but with different dispersions, either when the exposure dose was the concentration in the nebulized suspension or was the estimated quantity of spores inhaled by a mouse during the experiment. The median quantity of inhaled spores that infected 50% of mice was estimated at 1.8 × 10⁴ and 3.2 × 10⁴ viable spores in the exponential and beta‐Poisson models, respectively. This study provides dose‐response parameters for quantitative assessment of the relationship between airborne exposure to the reference A. fumigatus strain and probability of IA in immunocompromized hosts.     

Does the Representation of Household Behavior Matter for Welfare Analysis of Tax-benefit Policies? An Introduction

A widely shared intuition holds that individual control over money matters for the decision process within the household and the subsequent distribution of resources and welfare. As a consequence, there are good reasons to depart from the unitary model of the household and to explore the possibilities offered by models of the family accounting for several decision makers in the household and for the potential impact of tax reforms on the balance of power. This paper summarizes both the methodological and empirical findings presented in the next three papers of this special issue of the Review of the Economics of the Household. This series of contributions primarily entails a concrete comparison of the policy implications of the choice between the unitary and a particular multi-person representation: the collective representation. On the one hand, it suggests a methodology to implement the collective model of labor supply in a realistic context where participation is modeled together with working hours, and where the full tax-benefit system is accounted for. On the other hand, the empirical part relies on comprehensive simulations of tax reforms in Belgium, France, Germany, Italy, Spain, and the United Kingdom, and allows to quantify the distortions that may affect policy recommendations based on the unitary model.

Chinese and English Infants' Tone Perception: Evidence for Perceptual Reorganization

Over half the world's population speaks a tone language, yet infant speech perception research has typically focused on consonants and vowels. Very young infants can discriminate a wide range of native and nonnative consonants and vowels, and then in a process of perceptual reorganization over the 1st year, discrimination of most nonnative speech sounds deteriorates. We investigated perceptual reorganization for tones by testing 6‐ and 9‐month‐old infants from tone (Chinese) and nontone (English) language environments for speech (lexical tone) and nonspeech (violin sound) tone discrimination in both cross‐sectional and longitudinal studies. Overall, Chinese infants performed equally well at 6 and 9 months for both speech and nonspeech tone discrimination. Conversely, English infants' discrimination of lexical tone declined between 6 and 9 months of age, whereas their nonspeech tone discrimination remained constant. These results indicate that the reorganization of tone perception is a function of the native language environment, and that this reorganization is linguistically based. Supplementary materials to this article are available on the World Wide Web at http:www.infancyarchives.com     

Metaconfirmation

When is it possible to decide that a theory is confirmed by the available evidence? Probabilities seem first to be the good framework for addressing this question. But the philosophers of science did not succeed in building any probabilistic criterion of confirmation beyond dispute. We examine two of the main reasons for this failure. First, the principles of adequacy used by philosophers are often logically inconsistent with each other. We show in the paper how to build consistent subsets of these principles. We identify three main subsets which embody the principles of adequacy for two main kinds of confirmation, namely the relative confirmation and the absolute confirmation. Second, we prove the impossibility of building any probabilistic criterion for absolute confirmation.     

Development,a Question of Opportunity? A Critique of the 2006 World Development Report: Equity and Development

The World Bank's World Development Report 2006 addresses equity and development, defining equity as respect for equal opportunities combined with the avoidance of absolute deprivation. Equity has up to now remained a marginal issue in development economics. This detailed analysis endeavours to place the subject within the context of the evolution of World Bank thinking and policies. The wealth of the concept is illustrated, the downside being the difficulty in defining it accurately. We also emphasise the gap between the prospects opened up by such an enlargement of development goals and the report's policy recommendations, which are generally merely an extension of the World Bank's traditional analyses.     

德里达：解构与理性

德里达因为解构而闻名于世,也因为解构而常常遭到误解。解构不同于批判,也并非是对在西方传统中教养形成的价值和思维方式进行极端而粗暴的摧毁(destruction)。相反,解构应被视作一种狡黠的活动,这种活动的结果就是在哲学思想所赖以建立的地面之上无限度地滑动。并非作为某种非理性主义者,也并非简单的“理性的批判”,德里达力图扰乱理性的活动,使之名誉扫地,使之浸入“书写”之中,也就是说浸入虚构、滑稽模仿之中。解构首先是一种复杂化、进行普遍追问的实践。通过返回到文本、表达式、语言行动,解构所追求的是一种实用类型的认识。这样,解构丰富了我们的概念,丰富了我们的理性实践。