Some remarks on the duality of continuous time markov chains

A simple proof of Siegmund's result on the relation between dual q-matrices and dual transition functions for Markov chains is given. A byproduct is a uniqueness result for minimal solutions of stochastically monotone q-matrices.     

Race–gender Differences in Risk and Protective Factors among Youth in Residential Group Homes

Analysis reported here examined youth in residential group home placements in order to better understand how sexual behaviors, drug use, and environmental experiences differ by race and gender subgroups. Data were collected from 336 youth aged 14–21 residing in one of 41 group homes in Maryland. Chi square and logistic regression analyses were done to determine differences on study variables among the race-gender groupings. Results demonstrate not only significant health concerns overall but notable differences were also found between race-gender subgroups. Findings suggest that found race-gender subgroup differences might be informative for tailoring programming for youth of residential group home settings.     

On the construction of a class of efficient row-column designs

In this paper a method for the construction of a class of row-column designs with good statistical properties and high efficiency is presented. The class of designs produced is shown to exhibit balance, orthogonality and adjusted orthogonality. The efficiencies of these designs are investigated in detail, and they are shown to be very high, and possibly maximal in some cases.     

The Social Model of Disability and the Disappearing Body: towards a sociology of impairment

What is the case for and how would one begin to construct a sociology of impairment? This paper argues that the realignment of the disability/impairment distinction is vital for the identity politics of the disability movement. The body is at the heart of contemporary political and theoretical debate, yet the social model of disability makes it an exile. The transformation of the body from a reactionary to an emancipatory concept implies a sociology of impairment. This paper explores the contribution that post-structuralism and phenomenology might make to this end.     

THE DIFFUSION OF MEDICAL TECHNOLOGY: SOCIAL NETWORK ANALYSIS AND POLICY RESEARCH

The purpose of this article is to demonstrate how social network analysis can be used to provide information for policy decisions pertaining to physicians' adoption and utilization of new medical technology. Interviews and hospital records were used to obtain data on refenals, consultations, discussions, and on-call coverage; utilization of a computer-based hospital information system; and personal and practice characteristics from 24 physicians who belong to a private group practice. The results of a block-model analysis suggest that the physician's relative position in the network is an important determinant of his/her participation in the diffusion process. A number of policy implications related to the introduction of new medical technology into practice settings are discussed.     

Moments of the sampled autocovariances and autocorrelations for a Gaussian white-noise process

Cumulants, moments about zero, and central moments are obtained for the mean-corrected serial covariances and serial correlations for series realizations of length n from a white-noise Gaussian process. All first and second moments (and some third, fourth, and higher moments) are given explicitly for the serial covariances; and the corresponding moments for the serial correlations are derived either explicitly or implicitly.