Dose Response for Infectivity of Several Strains of Campylobacter jejuni in Chickens

Although some major risk studies have been done for Campylobacter jejuni, its dose response is not well characterized. Only a single human study is available, providing dose-response information for only a single isolate. As substantial heterogeneity in infectivity has been acknowledged for other pathogens, it remains unknown how well this single study represents the dose-response relation for this pathogen. As future human challenge studies with Campylobacter are unlikely, we have to find other means of studying its infectivity. Several dose-response studies have been done using chickens as host organisms. These studies may be used to obtain quantitative information on the variation in infectivity among different isolates of this pathogen. A hierarchical Bayesian model is well suited to describe heterogeneity, and we demonstrate how the beta-Poisson model of microbial infection may be adapted to allow for within- and between-isolate variation. Isolates tested in chickens can be categorized into two distinct groups: lab-adapted and fresh isolates, and we show how the hierarchical dose-response model can be used to quantitatively describe their differences. Fresh isolates show higher colonization potential and less within-isolate variation than lab isolates. The results indicate that Campylobacter jejuni is highly infectious in chickens. Different isolates show great variation in infectivity, especially between lab and fresh isolates, indicating that human clinical (volunteer) studies on infectivity must be interpreted cautiously.     

Reflections on the study of burnout

Four papers on burnout appear in this issue of Work & Stress. This commentary gives an indication of how they add to the pool of knowledge regarding the prevalence of burnout and its chronic nature. A lapse common to most papers on this subject is then discussed: the lack of attention to burnout's relationships with other negative affective states, primarily depression. Finally, some of the major similarities and differences among various measures of burnout represented in this special edition are discussed. The concluding comment addresses future theoretical challenges to burnout researchers.     

Empirical evidence on preference formation

To explain the empirical fact that different individuals have different individual welfare functions, a theory of preference formation has been developed by the first author. The theory essentially states that an individual's welfare function is identical to the distribution of consumption patterns the individual has observed over time. This includes both his own consumption and the consumption by others in his social reference group. The paper reviews the evidence collected with respect to directly measured individual welfare functions in Europe. Evidence obtained in related research by economists, psychologists, and sociologists is also discussed.     

Organizing for strategic management

In this paper, the author—a well-known Dutch academic and consultant—discusses the factors which make ‘strategic management’ effective. Among these, a dominant factor is the organization climate which, in its turn, is determined by the quality of the managers and the availability of alternatives. He suggests that to improve the organization climate in which strategic management can be effective, the quality of the managers is a crucial factor. The scope for alternatives is an important constraint. This article assesses common problems and failures in strategic management and gives some suggestions for organizing it, including the use of consultants and the role of formal procedures.     

Predicting supportive behavior of parents and siblings to a family member with intellectual disability living in institutional care

This feasibility study examines whether the theory of planned behavior can predict supportive behavior provided by either parents to their offspring-or adult siblings to their brothers and sisters-with an intellectual disability living in 2 Israeli institutional care facilities. Participants were 67 parents and 63 siblings who were interviewed at baseline regarding their intentions to visit their offspring or sibling in the institutional care facility, to contact the caregiving staff, and to accept visits at home. Parents' and siblings' behavior regarding visitation and supportive behavior was examined after 6 months by caregiving staff. Core findings indicated that subjective norms in siblings and parents predicted frequency of home visits. Perceived behavioral control predicted frequency of contact between siblings and staff. Differences between parents and siblings regarding their supportive behaviors are discussed with respect to social work practice.     

Lot sizing with storage losses under demand uncertainty

We address a variant of the single item lot sizing problem affected by proportional storage (or inventory) losses and uncertainty in the product demand. The problem has applications in, among others, the energy sector, where storage losses (or storage deteriorations) are often unavoidable and, due to the need for planning ahead, the demands can be largely uncertain. We first propose a two-stage robust optimization approach with second-stage storage variables, showing how the arising robust problem can be solved as an instance of the deterministic one. We then consider a two-stage approach where not only the storage but also the production variables are determined in the second stage. After showing that, in the general case, solutions to this problem can suffer from acausality (or anticipativity), we introduce a flexible affine rule approach which, albeit restricting the solution set, allows for causal production plans. A hybrid robust-stochastic approach where the objective function is optimized in expectation, as opposed to in the worst-case, while retaining robust optimization guarantees of feasibility in the worst-case, is also discussed. We conclude with an application to heat production, in the context of which we compare the different approaches via computational experiments on real-world data.     

Politics of geographic exclusion: deinstitutionalization,hegemony and persons with intellectual disability in Israel

Deinstitutionalization is a core policy for the development of services for people with intellectual disabilities (ID) in western countries. Nonetheless, although a western country, deinstitutionalization is not well advanced in Israel. In order to shed light on this phenomenon, we explore the hegemony of ID as reflected in Israeli legislation. The analysis shows a biomedical hegemony; ID is depicted as a form of medical and social deviance. Israel’s legislation reflects paternalistic views of persons with ID, who are largely seen as vulnerable objects of pity, to be cared for and protected.     

Israeli policy toward veterans with disabilities: a snapshot and insights of the proposed reform

The policy toward Israeli veterans with disabilities is based on the Invalids Law (Benefits and Rehabilitation) of 1949 . This legislation has served as the foundation for an intricate disability policy, providing benefits and psychosocial services for veterans with disabilities. Sixty two years later, in light of the emergence of a new social model and disability rights conceptualization, there is a need to reevaluate the current legislation and policy. In this article the authors present the essence of the current Israeli disability policy and explore the applications of a proposed reform aimed at adapting the disability policy and services to the new principles of the social model of disability.     

Why do some Irish drink so much? Family, historical and regional effects on students’ alcohol consumption and subjective normative thresholds

This paper studies determinants of drinking behavior and formation of subjective thresholds of acceptable drinking behavior using a sample of students in a major Irish University. We find evidence of strong associations between amounts of alcohol students consume and drinking of their fathers and older siblings. In contrast, we find little evidence of impacts of other non-drinking aspects of family background on students’ drinking. Parental and older sibling drinking appears to affect subjective attitudes of students towards what constitutes problem drinking behavior. We investigated historical origins of drinking behavior including the role of the Church, English cultural influences, the importance of the brewery and distilling industry, and the influence of weather. We find relatively strong influences of the Catholic Church and English colonial settlement patterns on Irish drinking patterns but little influence of Irish weather. Historical licensing restrictions on the number of pubs and off-license establishments also appear to matter.