Large-scale multiple testing under dependence

Summary.  The paper considers the problem of multiple testing under dependence in a compound decision theoretic framework. The observed data are assumed to be generated from an underlying two-state hidden Markov model. We propose oracle and asymptotically optimal data-driven procedures that aim to minimize the false non-discovery rate FNR subject to a constraint on the false discovery rate FDR. It is shown that the performance of a multiple-testing procedure can be substantially improved by adaptively exploiting the dependence structure among hypotheses, and hence conventional FDR procedures that ignore this structural information are inefficient. Both theoretical properties and numerical performances of the procedures proposed are investigated. It is shown that the procedures proposed control FDR at the desired level, enjoy certain optimality properties and are especially powerful in identifying clustered non-null cases. The new procedure is applied to an influenza-like illness surveillance study for detecting the timing of epidemic periods.     

The Sociology of Death

The understanding of death, dying and bereavement in relation to society is indebted to a number of disciplines – anthropology, history, psychology and sociology are surveyed. Theories and methods used by sociologists of death, dying and bereavement are briefly outlined, followed by a number of key debates and challenges: denial, taboo and sequestration; death and the media; how to integrate scholarship in collective memory and Holocaust studies; theorising contemporary rites of passage; the lack of comparative research; and the need to focus on the meaning and organisation of death for those who encounter it most directly; namely, the poor, displaced and elderly. A brief discussion of undergraduate and postgraduate teaching is followed by the conclusion that any promise of a general sociology conducted in the light of mortality has been eclipsed by yet another specialism, the sociology of death.     

Toward a capabilities perspective of the small firm

This paper attempts to explain the competitive advantages of the small firm in the capabilities perspective. It begins by identifying the kinds of strategic assets possessed by small firms. It argues that entrepreneurship and a simple capital structure are the sources of dynamism for small firms. The relationship between the small firm's resources and its capabilities are then critically examined. In particular, the analysis focuses on the influences of strategic assets on the organizational flexibility – a significant source of competitive advantage enjoyed by small firms. The competitive attributes of small firms are further discussed in terms of firm's internal and external capabilities. Finally, the relationship between the small firm's capabilities and the choice of technology strategies is examined.     

Risk Analysis of PCB Exposure via the Soil–Food Crop Pathway, and Alternatives for Remediation at Serpukhov, Russian Federation

A risk assessment was conducted to determine the likelihood of certain health risks resulting from exposure to soils and food crops contaminated with polychlorinated biphenyl (PCBs). PCBs have contaminated soils, river sediments, and air in the past as a result of industrial activities at a capacitor plant located in the City of Serpukhov, Russian Federation. This risk assessment and suggestions for remediation are designed to aid in decision-making efforts by a joint Russian–American research team developing a community, national, and international response to industrial contamination. Bobovnikova et al. ( The Science of the Total Environment 139/140 , 357–364, [1993]) have reported that PCBs are elevated in soils and sediments, breast milk, and locally grown foods in the Serpukhov area. Data from these and other investigators have been used in this risk assessment to calculate a potential cancer risk resulting from exposure to PCBs. Our assessment indicates that members of the local population may be at increased risk of cancer, and possibly other adverse health effects, as a result of PCB contamination of their environment. Because previously unassessed environmental contamination is a common problem in the former Soviet Republics, as well as many other areas of the world, we believe this type of evaluation, using known methods, can serve as a model for assessment efforts in other parts of the globe and result in remediative efforts in regions constrained by faltering economies.     

Canadian Biotechnology Start-Ups, 1991–1997: The Role of Incumbents'' Patents and Strategic Alliances in Controlling Competition

Fligstein (1996) contends that organizations act to exploit the institutional context in which they are embedded so as to stabilize the competition they face. Drawing on Fligstein's theoretical analysis, we conceptualize incumbent biotechnology firms' patenting and alliance-building activities as attempts to stabilize and control potential competition and analyze how these activities shape rates of founding in the Canadian biotechnology industry. We find that increases in the level and concentration of incumbents' patenting discourage founding, particularly in human application sectors of the industry where development and approval processes are more costly and time consuming. Incumbents' horizontal alliances depress start-ups; vertical alliances stimulate start-ups. Our findings highlight how technology appropriation and strategic alliances structure the competitive dynamics and evolution of high-technology, knowledge-intensive industries.