The credibility of health economic models for health policy decision-making: the case of population screening for abdominal aortic aneurysm

<i>Objectives</i>: To review health economic models of population screening for abdominal aortic aneurysm (AAA) among elderly males and assess their credibility for informing decision-making. <i>Methods</i>: A literature review identified health economic models of ultrasound screening for AAA. For each model focussing on population screening in elderly males, model structure and input parameter values were critically appraised using published good practice guidelines for decision analytic models. <i>Results</i>: Twelve models published between 1989 and 2003 were identified. Converting costs to a common currency and base year, substantial variability in cost-effectiveness results were revealed. Appraisals carried out for the nine models focusing on population screening showed differences in their complexity, with the simpler models generating results most favourable to screening. Eight of the nine models incorporated two or more simplifying structural assumptions favouring screening; uncertainty surrounding these assumptions was not investigated by any model. Quality assessments on a small number of parameters revealed input values varied between models, methods used to identify and incorporate input data were often not described, and few sensitivity analyses were reported. <i>Conclusions</i>: Large variation exists in the cost-effectiveness results generated by AAA screening models. The substantial number of factors potentially contributing to such disparities means that reconciliation of model results is impossible. In addition, poor reporting of methods makes it difficult to identify the most plausible and thus most useful model of those developed

Theoretical and Pedagogical Applications of Discourse Analysis to Professional Writing.

This dissertation attempts to show the utility of discourse analysis for professional writing. The articles collected here fall into three categories: Chapter One provides an overview of the need for a discourse analysis approach in writing research; Chapters Two and Three demonstrate applications of Speech Act Theory to problems in tone; and Chapters Four, Five and Six suggest the role that cohesion and coherence play in professional writing. Chapter One notes that, with the emphasis on process, discourse based research has largely fallen out of favor with writing specialists. Despite this lack of enthusiasm, this chapter demonstrates the importance of discourse knowledge in the writing process of expert writers and suggests areas of discourse research which could enhance writing pedagogy. Chapters Two and Three begin with the observation that advice about tone is often too vague and unprincipled to truly benefit novice writers. Chapter Two illustrates that advice about the use of syntactic positioning of pronouns for manipulating tone (called the you-perspective) can be better understood by looking at two types of speech acts: directives and commissives. Chapter Three demonstrates that advice about the use of explanations in refusal letters (called negative messages) can be better understood by examining the felicity conditions on the speech act of refusing, also taken from Speech Act Theory. Chapters Four, Five and Six explore theories of cohesion and coherence and their importance in enhancing the quality of professional writing. Chapter Four notes that current theories of cohesion are inadequate for describing well-written professional texts and proposes a Repetition theory of cohesion based on perceptual principles. Two types of repetition are distinguished: semantic and formal. Chapter Five illustrates the variety of formal cohesive devices used in professional writing, but which are excluded from current theories of cohesion. Finally, Chapter Six explores the distinction between cohesion and coherence. A Fulfillment theory of coherence is proposed. Two coherence conditions on cohesion (i.e., repetition) are also proposed: the Redundancy Condition on semantic cohesion and the Similarity Condition on formal cohesion

Tribute to Madame Justice Bertha Wilson, Foreword, and Preface

On behalf of the Government of Canada, I am pleased to convey my best wishes to all those participating in \u27The Democratic Intellect Symposium being hosted by Dalhousie Law School in honour of Madame Justice Bertha Wilson\u27s contribution to the law and to the life of Canada

Trinification with sin^2\theta_W^0=3/8 and seesaw neutrino mass

We realize a supersymmetric trinification model with three families of $({\bf 27}_{\rm tri}+{\bf 27}_{\rm tri} +\bar{\bf 27}_{\rm tri})$ by the $Z_3$ orbifold compactification with two Wilson lines. It is possible to break the trinification group to the supersymmetric standard model. This model has several interesting features: the {\it hypercharge quantization}, $\sin^2\theta_W^0=\frac38,$ naturally light neutrino masses, and introduction of R-parity. The {\it hypercharge quantization} is realized by the choice of the vacuum, naturally leading toward a supersymmetric standard model.Comment: 15 page

Branching Rules for Supercuspidal Representations of SL_2(k)

The restriction of a supercuspidal representation of SL_2(k), for k a local nonarchimedean field, to a maximal compact subgroup decomposes as a multiplicity-free direct sum of irreducible representations. We explicitly describe this decomposition in the case that the residual characteristic is odd, and determine how the spectrum of this decomposition varies as a function of the parameters describing the supercuspidal representation.Comment: 30 pages; minor reorganization to previous version. Accepted to Journal of Algebr

Higgsino mass matrix ansatz for MSSM

An ansatz, Det. $M_{\tilde H}=0,$ for the Higgsino mass matrix in string orbifold trinification is suggested toward the minimal supersymmetric standard model(MSSM). Small instanton solutions effective around the GUT scale can fulfil this condition. An argument that the couplings contain a moduli field is given for a dynamical realization of this Higgsino mass matrix ansatz.Comment: 15 pages of LaTeX fil

Analyzing Multidisciplinary Team Effectiveness in an Engineering Environment: A Case Study of the West Point Steel Bridge Design Team

The West Point Steel Bridge Design Team is a group of five undergraduate seniors working to design and build a steel bridge for the annual ASCE Steel Bridge Competition. The purpose of our group’s research is to discover how multidisciplinary teams perform in academically competitive environments. This project provides a unique opportunity in the field of multidisciplinary collaborative work because the team’s success can be objectively measured against this year’s competitors and the team’s performance in previous years. The traditional structure of the West Point team consisted of three-to-five civil engineering majors. This year’s team includes a law and legal studies major and five civil engineers, two of which recently switched from systems engineering. Past designs have relied heavily on the work of previous years, which has led to stagnant performance at competitions. Our hypothesis is that by entering different perspectives into the group at an early stage, a revolutionary approach will ensue and overall performance will increase. The team did not completely disregard the designs and methods of previous teams, but the reliance on their decision-making process was more heavily scrutinized with the current multidisciplinary team. Our research is not solely limited to competitive performance. We also analyzed the decision-making process of this year’s team in comparison to previous years. While data on decision-making is not readily available, both the faculty advisor and two current team members who served on the team last year were able to provide personal insight into how the teams compare. Ultimately, this research seeks to provide groups in similar academically competitive environments an indication of whether a multidisciplinary composition will provide benefit to their team’s performance.Cockrell School of Engineerin