Detecting homogeneous segments in DNA sequences by using hidden Markov models

In recent years there has been a rapid growth in the amount of DNA being sequenced and in its availability through genetic databases. Statistical techniques which identify structure within these sequences can be of considerable assistance to molecular biologists particularly when they incorporate the discrete nature of changes caused by evolutionary processes. This paper focuses on the detection of homogeneous segments within heterogeneous DNA sequences. In particular, we study an intron from the chimpanzee α-fetoprotein gene; this protein plays an important role in the embryonic development of mammals. We present a Bayesian solution to this segmentation problem using a hidden Markov model implemented by Markov chain Monte Carlo methods. We consider the important practical problem of specifying informative prior knowledge about sequences of this type. Two Gibbs sampling algorithms are contrasted and the sensitivity of the analysis to the prior specification is investigated. Model selection and possible ways to overcome the label switching problem are also addressed. Our analysis of intron 7 identifies three distinct homogeneous segment types, two of which occur in more than one region, and one of which is reversible.     

The meaning of empowerment: the interdisciplinary etymology of a new management concept

Empowerment has become a widely used management term in the last decade or so, though, in practical terms, it shares the ambiguity of its predecessors in the HRM tradition. This paper sets out to unravel the web of meaning surrounding empowerment to show what a contested concept it is, and hence why its application in organizational settings is fraught with misunderstanding and tension. It does so by taking an approach that contributes to the examination of HRM discourse and management rhetoric. To demonstrate the ambiguity of empowerment as a concept, the paper reviews the various ways in which the term has been used across non-management disciplines (women, minority groups, education, community care, politics), culminating with a review of the use of empowerment in contemporary management theory. The paper concludes that organizations and managers have chosen to coin a phrase which is open to different, sometimes contradictory, meanings and which, when applied, evokes both subjective attitudes and objective behaviour, means different things in varying contexts, and is affected fundamentally by individual differences in perception and experience. Unless organizations offer clear operational definitions when using empowerment, instead of purely acquiescing to a vague and seductive version of the concept, they are abdicating responsibility for the unpredictable consequences that result.     

Bayesian Analysis of DNA Profiling Data in Forensic Identification Applications

The utilization of DNA evidence in cases of forensic identification has become widespread over the last few years. The strength of this evidence against an individual standing trial is typically presented in court in the form of a likelihood ratio (LR) or its reciprocal (the profile match probability). The value of this LR will vary according to the nature of the genetic relationship between the accused and other possible perpetrators of the crime in the population. This paper develops ideas and methods for analysing data and evaluating LRs when the evidence is based on short tandem repeat profiles, with special emphasis placed on a Bayesian approach. These are then applied in the context of a particular quadruplex profiling system used for routine case-work by the UK Forensic Science Service.     

Psychiatric Disorder Dramaturgically Considered*

This paper reports the results of an investigation into the empirical applicability of conceptualizing mental illness as dramaturgic incompetence and a corresponding attempt to operationalize dramaturgical thought. It was found that dramaturgic incompetence and subsidiary components were strongly associated with degree of psychiatric disturbance and general diagnosis as determined by psychiatric staff. It also was found that attainment of psychiatric identities proceeded through a series of stages consisting of performative incompetence, empathic incompetence, motive incompetence, meaning loss, and identity loss. This sequence was particularly evident in cases of psychosis.