Still-births among the offspring of male radiation workers at the Sellafield nuclear reprocessing plant: detailed results and statistical aspects

Summary. This study investigates whether there was evidence of increasing risk of still-birth with increasing paternal exposure to ionizing radiation received during employment at the Sellafield nuclear installation before the child was conceived. A significant positive association is found between the total paternal preconceptional exposure to external ionizing radiation and the risk of still-birth (after adjustment for year of birth, social class, birth order and paternal age, odds ratio at 100 mSv 1.24 (95% confidence interval 1.04–1.45)). A summary of the principal scientific findings of this study has been published in the Lancet . This paper describes in detail the statistical methods that were used in the investigation and presents the results in full.     

Führung durch Selbstführung

This paper outlines the conceptual bases, strategies, and psychological attributes of leadership by self-leadership. In addition, relations to other theories of leadership are drawn. Dimensions and correlates of self-leadership competence are described and discussed. Various approaches for developing self-leadership competence are discussed as well.     

Empirical likelihood confidence intervals for the mean of a population containing many zero values

If a population contains many zero values and the sample size is not very large, the traditional normal approximation‐based confidence intervals for the population mean may have poor coverage probabilities. This problem is substantially reduced by constructing parametric likelihood ratio intervals when an appropriate mixture model can be found. In the context of survey sampling, however, there is a general preference for making minimal assumptions about the population under study. The authors have therefore investigated the coverage properties of nonparametric empirical likelihood confidence intervals for the population mean. They show that under a variety of hypothetical populations, these intervals often outperformed parametric likelihood intervals by having more balanced coverage rates and larger lower bounds. The authors illustrate their methodology using data from the Canadian Labour Force Survey for the year 2000.     

Stjepan Metrović and Michel Maffesoli's 'implosive' defence of the Durkheimian tradition: theoretical convergences around Baudrillard's thesis on the 'end' of the social

This paper critically examines Metrovi? and Maffesoli's attempt to understand postmodernity through Émile Durkheim's nonrational link between society, religion and morality. Metrovi? (1991, 1997) and Maffesoli's (1996) work draws upon this emotional element when attempting to refute Baudrillard's (1983) cognitively focused, if implicit, critique of the Durkheimian tradition. Despite their best intentions, Metrovi? and Maffesoli still fail to exploit the partialities of Baudrillard's critique to the full. While both have some appreciation of the link between emotion and religion as found in Durkheim's The Elementary Forms of Religious Life (1912) they, nevertheless, fall short of grasping its full conceptual importance. This leads them to an implicit acceptance of Baudrillard's thesis on the ‘end’ of the social. This pitfall could have been avoided if Metrovi? and Maffesoli had built their respective analyses of the postmodern condition on a closer reading of The Elementary Forms. Reading this text alongside those other insights on emotion and social life as contained within Durkheim and Mauss's Primitive Classification (1903) and Talcott Parsons's subsequent writings on the sociological problem of religion, would have helped to distance the work of Metrovi? and Maffesoli from that of Baudrillard, and allowed them to offer a stronger and more comprehensive defence of the said tradition.     

Implied Preference for Seismic Design Level and Earthquake Insurance

Seismic risk can be reduced by implementing newly developed seismic provisions in design codes. Furthermore, financial protection or enhanced utility and happiness for stakeholders could be gained through the purchase of earthquake insurance. If this is not so, there would be no market for such insurance. However, perceived benefit associated with insurance is not universally shared by stakeholders partly due to their diverse risk attitudes. This study investigates the implied seismic design preference with insurance options for decisionmakers of bounded rationality whose preferences could be adequately represented by the cumulative prospect theory (CPT). The investigation is focused on assessing the sensitivity of the implied seismic design preference with insurance options to model parameters of the CPT and to fair and unfair insurance arrangements. Numerical results suggest that human cognitive limitation and risk perception can affect the implied seismic design preference by the CPT significantly. The mandatory purchase of fair insurance will lead the implied seismic design preference to the optimum design level that is dictated by the minimum expected lifecycle cost rule. Unfair insurance decreases the expected gain as well as its associated variability, which is preferred by risk-averse decisionmakers. The obtained results of the implied preference for the combination of the seismic design level and insurance option suggest that property owners, financial institutions, and municipalities can take advantage of affordable insurance to establish successful seismic risk management strategies.     

The Effect of Repetition on Infants' Imitation From Picture Books Varying in Iconicity

Although picture‐book reading is commonplace during infancy, little is known about the impact of this activity on learning. A previous study showed that 18‐ and 24‐month‐olds imitated a novel action sequence presented in a book that was illustrated with realistic color photos, whereas they failed to imitate from books illustrated with less realistic drawings. In the research reported here, we hypothesized that increasing infants' exposure to a picture book would increase learning from books illustrated with both color photos and drawings. Independent groups of 18‐and 24‐month‐olds were exposed to a picture book either twice in succession or 4 times in succession. The results showed that, regardless of the iconicity of the illustrations, increasing the number of reading sessions significantly improved the infants' imitation scores, compared to age‐matched, no‐demonstration controls. The results are discussed in relation to representational insight and cognitive flexibility.     

A class of count models and a new consistent test for the Poisson distribution

We define a class of count distributions which includes the Poisson as well as many alternative count models. Then the empirical probability generating function is utilized to construct a test for the Poisson distribution, which is consistent against this class of alternatives. The limit distribution of the test statistic is derived in case of a general underlying distribution, and efficiency considerations are addressed. A simulation study indicates that the new test is comparable in performance to more complicated omnibus tests.