Brad C. Johnson

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THE question of the roles of heredity and environment is of prime importance to the understanding of the nature of chronic diseases. Genetic mechanisms must be known not only for a better understanding of pathogenesis but, to the extent to which genetic forces are operative, also to identify susceptible persons prior to the onset or full development of the(More)
M ANY factors have been tentatively identified as correlates of blood pressure. These include age, sex, race, body build or obesity, dietary components, particularly sodium, and genetic susceptibility. While there is general agreement that each of these factors plays some role, the exact quantitative nature of this role is a subject of controversy. Some of(More)
We prospectively studied the pathogenic significance of Moraxella (Branhamella) catarrhalis isolated from 212 patients of community practitioners in Australia. This organism was most commonly isolated during winter and early spring, and 92% of isolates were beta-lactamase producers. On the basis of predetermined clinical and microbiological criteria, 42% of(More)
Randomized nomination sampling (RNS) is a rank-based sampling technique which has been shown to be effective in several nonparametric studies involving environmental and ecological applications. In this paper, we investigate parametric inference using RNS design for estimating the unknown vector of parameters θ in the proportional hazard rate and(More)
In this paper, we consider design-based estimation using ranked set sampling (RSS) in finite populations. We first derive the first and second-order inclusion probabilities for an RSS design and present two Horvitz–Thompson type estimators using these inclusion probabilities. We also develop an alternate Hansen–Hurwitz type estimator and investigate its(More)