Reliability models for categorical data

As assumed hypothetical consensus category corresponding to a case being classified provides a basis for assessment of reliability of judges. Equivalent judges are characterised by the joint probability distribution of the judge assignment and the consensus category. Estimates of the conditional probabilities of judge assignment given consensus category and of consensus category given judge assignments are indices of reliability. All parameters can be estimated if data include classifications of a number of cases by 3 or more judges. Restrictive assumptions are imposed to obtain models for data from classifications by two judges. Maximum likelihood estimation is discussed and illustrated by example for the 3 or more judges case.     

Differential equation models for statistical functions

Differential equations have been used in statistics to define functions such as probability densities. But the idea of using differential equation formulations of stochastic models has a much wider scope. The author gives several examples, including simultaneous estimation of a regression model and residual density, monotone smoothing, specification of a link function, differential equation models of data, and smoothing over complicated multidimensional domains. This paper aims to stimulate interest in this approach to functional estimation problems, rather than provide carefully worked out methods.     

Convergence of Heavy-tailed Monte Carlo Markov Chain Algorithms

Abstract.  In this paper, we use recent results of Jarner & Roberts ( Ann. Appl. Probab., 12, 2002, 224) to show polynomial convergence rates of Monte Carlo Markov Chain algorithms with polynomial target distributions, in particular random-walk Metropolis algorithms, Langevin algorithms and independence samplers. We also use similar methodology to consider polynomial convergence of the Gibbs sampler on a constrained state space. The main result for the random-walk Metropolis algorithm is that heavy-tailed proposal distributions lead to higher rates of convergence and thus to qualitatively better algorithms as measured, for instance, by the existence of central limit theorems for higher moments. Thus, the paper gives for the first time a theoretical justification for the common belief that heavy-tailed proposal distributions improve convergence in the context of random-walk Metropolis algorithms. Similar results are shown to hold for Langevin algorithms and the independence sampler, while results for the mixing of Gibbs samplers on uniform distributions on constrained spaces are rather different in character.     

Convergence of Slice Sampler Markov Chains

We analyse theoretical properties of the slice sampler. We find that the algorithm has extremely robust geometric ergodicity properties. For the case of just one auxiliary variable, we demonstrate that the algorithm is stochastically monotone, and we deduce analytic bounds on the total variation distance from stationarity of the method by using Foster–Lyapunov drift condition methodology.     

A Comparative Pharmacokinetic Estimate of Mercury in U.S. Infants Following Yearly Exposures to Inactivated Influenza Vaccines Containing Thimerosal

The use of thimerosal preservative in childhood vaccines has been largely eliminated over the past decade in the United States because vaccines have been reformulated in single‐dose vials that do not require preservative. An exception is the inactivated influenza vaccines, which are formulated in both multidose vials requiring preservative and preservative‐free single‐dose vials. As part of an ongoing evaluation by USFDA of the safety of biologics throughout their lifecycle, the infant body burden of mercury following scheduled exposures to thimerosal preservative in inactivated influenza vaccines in the United States was estimated and compared to the infant body burden of mercury following daily exposures to dietary methylmercury at the reference dose established by the USEPA. Body burdens were estimated using kinetic parameters derived from experiments conducted in infant monkeys that were exposed episodically to thimerosal or MeHg at identical doses. We found that the body burden of mercury (AUC) in infants (including low birth weight) over the first 4.5 years of life following yearly exposures to thimerosal was two orders of magnitude lower than that estimated for exposures to the lowest regulatory threshold for MeHg over the same time period. In addition, peak body burdens of mercury following episodic exposures to thimerosal in this worst‐case analysis did not exceed the corresponding safe body burden of mercury from methylmercury at any time, even for low‐birth‐weight infants. Our pharmacokinetic analysis supports the acknowledged safety of thimerosal when used as a preservative at current levels in certain multidose infant vaccines in the United States.     

Leveraging the common and outsourcing the distinct: institutional difference and multinational company identity in emerging economies

ABSTRACT

This paper explores the challenges of outsidership faced by multinational companies (MNCs) accessing emerging economies. The paper departs from popular conceptualisations of culture drawing instead on social identity theory as part of an institutions-based view, to explain how employing a singularities approach can allow the identification of commonalities of Indianness and Australianness that can be leveraged to ameliorate negative socially embedded business norms that pose a challenge to MNC success in emerging economies. This study shows that despite recognised formal (regulatory) and informal (cultural) differences, managers of Australian MNCs operating in India were able to innovatively identify and exploit cultural commonalties/singularities to ease cultural adjustment and mitigate intergroup conflict, allowing them to achieve an innovative institutional fit. The paper discusses how, using this approach, sole-venture MNCs can access many of the benefits provided by collaborative entry modes while preserving MNC identity. We further propose that the singularities approach can provide a valuable starting point to develop culturally appropriate competence training initiatives.     

Employment status of women with disabilities from the Behavioral Risk Factor Surveillance Survey (1995-2002)

Among working aged adults (18-64) with disabilities, three out of 10 (32%) work full or part-time, compared to eight out of 10 (81%) of those without disabilities [9]. In addition, 24.7% of women with a severe disability and 27.8% of men with a severe disability are employed, while women with a non-severe disability have an employment rate of 68.4% and men with a non-severe disability have an employment rate of 85.1% [14]. This study examined data from the Behavioral Risk Factor Surveillance Survey from 1995-2002 to determine whether or not disparities exist in the rate of unemployment for women with disabilities, compared to men with disabilities and women and men without disabilities. In addition, regression analysis looked at the how disability and gender predict the outcome of unemployment. Results showed that there has been essentially no change with regard to employment for any of these populations. In addition, disability and gender were found to be the strongest predictors of unemployment for women with disabilities. Possible explanations were discussed as to the reasons for the results and issues were presented for future research.     

The self-perceptions and interpersonal relationships of persons with significant physical disabilities: a qualitative pilot study

This exploratory, qualitative research was conducted to obtain the perspectives of people with significant physical disabilities regarding factors that have facilitated and hindered the development of a positive self-concept, participation in the broader society, and the formation of interpersonal relationships. The sample was high achieving in terms of education and/or career and attributed positive self-perceptions and their success in the broader society and interpersonal relationships to the attitudes and perceptions regarding their abilities, talents, and potential modeled in supportive family relationships. Females reported the influence of significant others most often, and males the effectiveness of their personality characteristics. Societal barriers, both practical and attitudinal, were reported along with the process for developing a positive selfperception despite these.