Mesothelioma Among Brake Mechanics: An Expanded Analysis of a Case-Control Study

The U.S. Environmental Protection Agency has begun discussions to consider its assessment of asbestos toxicity related to mineral form and fiber size. Brake workers are typically exposed to short chrysotile fibers. To explore the mesothelioma risk among brake workers, considering other occupational exposures to asbestos, data from a study that was published previously were obtained and the analysis was extended. The National Cancer Institute provided data from a case-control study of mesothelioma. Because many participants with a history of brake work also had employment in other asbestos-related occupations, mesothelioma cases and controls were compared for a history of brake work, controlling for employment in eight occupations with potential asbestos exposure. A stratified analysis was also performed excluding those with any of the eight occupations. Possible interactions between brake work and other occupational exposures related to risk of mesothelioma were also examined. The odds ratio (OR) for employment in brake installation or repair was 0.71 (95% CI: 0.30-1.60) when controlled for insulation or shipbuilding. When a history of employment in any of the eight occupations with potential asbestos exposure was controlled, the OR was 0.82 (95% CI: 0.36-1.80). ORs did not increase with increasing duration of brake work. Exclusion of those with any of the eight exposures resulted in an OR of 0.62 (95% CI: 0.01-4.71) for occupational brake work. There was no evidence of an interaction between brake work and other occupational exposures. These latter analyses were based on small numbers of exposed cases. The results are consistent with the existing literature indicating that brake work does not increase the risk of mesothelioma and adds to the evidence that fiber type and size are important determinants of mesothelioma risk.     

The Household as an Economic Unit in Arctic Aboriginal Communities,and its Measurement by Means of a Comprehensive Survey

Northern aboriginal communities are widelyrecognized as having mixed, subsistence-basedeconomies. The chief characteristic of thiseconomy, aside from the contribution ofsubsistence harvesting and related activitiesto household well-being, is that the householdoperates as a ``micro-enterprise' that is thebasic unit of production as well asconsumption. This economic form has persistedinto the present day, contrary to thepredictions of many social scientists andpolicy-makers. This paper outlines a model ofthe household in mixed, subsistence-basedeconomies, and describes its characteristicsand activities. While the discussion focuseson northern Canada, the model is thought toapply generally in the circumpolar North. Quantitative measurement of northern aboriginalhousehold characteristics and activities hasbeen limited, however, because national andregional data collection systems are notdesigned specifically to capture thesephenomena. The model is therefore basedprimarily on the results of in-depth casestudies, and the systematic measurement ofsubsistence harvesting. This paper describesthe development, for the first time, of aquestionnaire specifically designed to documentquantitatively the key characteristics of thehousehold economy as part of a comprehensivesurvey of living conditions in the circumpolarArctic.     

National Competitiveness: A Question of Cost Conditions or Institutional Circumstances?

The issue of national competitiveness is a matter of considerable importance to both managers and public policy makers alike. Business scholars reflect this importance by their annual production of international indices of country competitiveness. Nevertheless, the notion of national competitiveness is controversial and has both (i) a narrow, concise conception that relates primarily to cost conditions as determined by exchange rates, and (ii) a broader, more nebulous conception that comprises the institutional and systemic circumstances of an economy, such as legal, governmental, public policy and other factors framing countries' wider business environments. In practical managerial terms, national competitiveness is a combination of both these narrow and broad conceptions. However, exactly how important cost conditions as opposed to institutional circumstances are to national competitiveness from a practical business perspective has never been investigated and is not known. This study uses qualitative and quantitative data gathered from senior firm executives in a specimen economy to find out. Hierarchical regression analyses suggest that institutional circumstances are significantly more important than cost conditions to the competitiveness of an economy from a practical managerial viewpoint.     

Managerial and professional beliefs influencing public health privatization: results of a national survey of local health department directors

This article describes managerial and professional beliefs underlying decisions to privatize public health services. We drew a stratified, nationally representative sample of local health departments and interviewed 347 department directors by telephone. We used logistic regression to establish the independent effects of various beliefs on the decision to privatize. Over half of directors did not believe that there was valid evidence that privatization results in more efficient performance, and those who believed there was such evidence were not more likely to privatize. However, directors held professional and managerial beliefs that influenced their decision to privatize. Directors most likely to privatize were those who believed that local health departments should exclusively focus on the core public health functions, those who asserted that public health should become involved in an increasingly diverse array of social problems, and those who believed that employees should be used on a temporary and contractual, rather than permanent, basis wherever possible.     

Regulation of Carcinogens

We propose a procedure, suitable for regulatory use, for estimating individual and societal risks of carcinogenic materials by using information on interspecies comparisons of carcinogenic potency. The consistent treatment of uncertainties allows evaluation of confidence limits and hence regulatory measures of risk which incorporate safety factors and incentives for better information. Numerical examples are given, together with discussion of the treatment of undetected carcinogens. Applications of the procedure to setting priorities for carcinogenicity testing and to product substitution are mentioned.     

Random effects models for estimation of the probability and time to progression of a continuous biomarker

Biomarkers play a key role in the monitoring of disease progression. The time taken for an individual to reach a biomarker exceeding or lower than a meaningful threshold is often of interest. Due to the inherent variability of biomarkers, persistence criteria are sometimes included in the definitions of progression, such that only two consecutive measurements above or below the relevant threshold signal that “true” progression has occurred. In previous work, a novel approach was developed, which allowed estimation of the time to threshold using the parameters from a linear mixed model where the residual variance was assumed to be pure measurement error. In this paper, we extend this methodology so that serial correlation can be accommodated. Assuming that the Markov property holds and applying the chain rule of probabilities, we found that the probability of progression at each timepoint can be expressed simply as the product of conditional probabilities. The methodology is applied to a cohort of HIV positive individuals, where the time to reach a CD4 count threshold is estimated. The second application we present is based on a study on abdominal aortic aneurysms, where the time taken for an individual to reach a diameter exceeding 55 mm is studied. We observed that erroneously ignoring the residual correlation when it is strong may result in substantial overestimation of the time to threshold. The estimated probability of the biomarker reaching a threshold of interest, expected time to threshold, and confidence intervals are presented for selected patients in both applications.     

Is it time sociology started researching incompetence?

There appears to be a mismatch between apparent incompetence in the world and the amount of sociological research it attracts. The aim of this article is to outline a sociology of incompetence and justify its value. I begin by defining incompetence as unsatisfactory performance relative to standards. Incompetence is thus intrinsically sociological in being negotiated and socially (re)constituted. The next section foregrounds how widespread and serious incompetence is. This renders effective sociological understanding crucial to welfare. The article then systematically analyses uses of the term in the British Journal of Sociology (a good quality general journal) to assess the current state of research. This analysis fully confirms the neglect of incompetence as a research topic. The next section proposes suitable methods for preliminary incompetence research addressing distinctive challenges like the stigma of being incompetent. These sections then allow incompetence to be better contextualised by other contributing concepts like power, bureaucracy and meritocracy. The final section justifies suggestions about directions for future research.