Adolescence methamphetamine use is an issue of considerable concern due to its correlation with later delinquency, divorce, unemployment and health problems. Understanding how adolescents initiate methamphetamine abuse is important in developing effective prevention programs. We formulate a mathematical model for the spread of methamphetamine abuse using nonlinear ordinary differential equations. It is assumed that susceptibles are recruited into methamphetamine use through imitation. An epidemic threshold value, Ra\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal {R}}_a$$\end{document}, termed the abuse reproduction (...) number, is proposed and defined herein in the drug-using context. The model is shown to exhibit the phenomenon of backward bifurcation. This means that methamphetamine problems may persist in the population even if Ra\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal {R}}_a$$\end{document} is less than one. Sensitivity analysis of Ra\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal {R}}_a$$\end{document} was performed to determine the relative importance of different parameters in methamphetamine abuse initiation. The model is then fitted to data on methamphetamine users less than 20 years old reporting methamphetamine as their primary substance of abuse in the treatment centres of Cape Town and parameter values that give the best fit are chosen. Results show that the proportion of methamphetamine users less than 20 years old reporting methamphetamine as their primary substance of abuse will continue to decrease in Cape Town of South Africa. The results suggest that intervention programs targeted at reducing adolescence methamphetamine abuse, are positively impacting methamphetamine abuse. (shrink)

Accountability is of universal interest to the business ethics community, but the emphasis to date has been primarily at the level of the industry, organization, or key individuals. This paper unites concepts from relational and felt accountability and team dynamics to provide an initial explanatory framework that emphasizes the importance of social interactions to team accountability. We develop a measure of team accountability using participants in the USA and Europe and then use it to study a cohort of 65 teams (...) of Irish business students over three months as they complete a complex simulation. Our hypotheses test the origins of team accountability and its effects on subsequent team performance and attitudinal states. Results indicate that initial team accountability is strongly related to team trust, commitment, efficacy, and identifying with the team emotionally. In established teams, accountability increases effort and willingness to continue to collaborate but did not significantly improve task performance in this investigation. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Studying Penguins to Understand BirdsJacinta O. A. Tan (bio), Anne Stewart (bio), Ray Fitzpatrick (bio), and Tony Hope (bio)Keywordsanorexia nervosa, treatment decision-making, competence, valuesWe are grateful to Grisso, Appelbaum, Charland, and Vollmann for their thoughtful commentaries on our paper. We would like to respond by picking up on some of the points they make, although we do not address all the issues raised.Our general aims in the paper (...) are less immediately pragmatic than are the central concerns of Grisso and Appelbaum. Our interest is primarily in a number of ethical, and related conceptual, issues that arise from empirical data. In the long run, of course, we believe that these ethical and conceptual issues are important to the care of people with mental disorders, but our focus is philosophical.Our central interest is what justifies overriding treatment refusal. We are unhappy with a "status" approach according to which, for example, the mere fact that a person suffers a mental disorder provides grounds for overriding her wishes. Such an approach, it seems to us, fails to identify reasons, and discriminates against those with mental disorder, a view shared by the Law Commission (The Law Commission 1995). We are, on the other hand, attracted by the approach that grounds any overriding of treatment refusal on lack of capacity (or competence) to make treatment decisions. The concept of capacity has been well developed through legal cases and conceptual analysis, not least by Grisso and Appelbaum themselves. We were struck, however, first through clinical experience, and subsequently from the pilot study reported in our paper, that many patients with anorexia nervosa who refuse treatment do not necessarily lack capacity, using the current criteria, and yet show features or give reasons that raise serious doubts as to whether it is right to respect their refusal of treatment.To avoid reliance on a "status" approach, the issue with which we are grappling is whether the concept of capacity (and therefore lack of capacity) can be developed to encompass some of our findings, and whether it is ethically right to do so. Charland makes the important point that the concept of competence, or capacity, has both a descriptive and a prescriptive component. It is for this reason that the question of whether, for example, we should extend the criteria for capacity is part of the question of when it is morally right to override treatment refusal.Grisso and Appelbaum suggest that our work advances "our thinking about appreciation, rather than requiring that we add new elements" (2006, 297). From our perspective, and at this stage, it is a secondary issue whether we are suggesting a development of appreciation, or a new element (e.g., "pathological values"). The primary issue for us is whether the reasons for refusal to which we draw attention provide grounds for overriding refusal, and if they do how they can be characterized in [End Page 299] such a way as to avoid the ever-present danger of simply overriding autonomy in a patient's best interests.We chose to study anorexia nervosa for various reasons, but we expect that the issues raised have a more general relevance (such as to substance abuse and impulse control disorders as Grisso and Appelbaum and Charland suggest). We do not expect the results to be relevant to all, or even most, mental disorders. Our main interest is not the specific management of people with anorexia, but how the data challenge, and help to develop, the concept of capacity, and the ethical analysis of overriding patient refusal of treatment. Our paper aims to address what we understand Charland to be referring to by the "pretheoretical desiderata" (2006, 283) of the concept of capacity. One reason why we chose anorexia as the focus of this work is because it is different from many mental disorders in the issues that it raises. In this it is, perhaps, rather like studying penguins to better understand the concept of bird just because penguins, although clearly birds, have unusual features.We agree, therefore, with Grisso and Appelbaum's caution that it would be unwise to jump in and change the MacCAT-T on the basis of the results... (shrink)

We elucidate the epistemological futility of using concepts such as unconscious thinking in research. Focusing on Newell & Shanks' (N&S's) use of the lens model as a framework, we clarify issues with regard to unconscious-thought theory (UTT) and self-insight studies. We examine these key points: Brunswikian psychology is absent in UTT; research on self-insight did not emerge to explore the unconscious; the accuracy of judgments does not necessitate the unconscious; and the prescriptive claim of UTT is unfounded.

This full-length study of Plato's dialogue Phaedrus, now in paperback, is written in the belief that such concerted scrutiny of a single dialogue is an important part of the project of understanding Plato so far as possible 'from the inside' - of gaining a feel for the man's philosophy. The focus of this account is on how the resources both of persuasive myth and of formal argument, for all that Plato sets them in strong contrast, nevertheless complement and reinforce each (...) other in his philosophy. Not only is the dialogue in its formal structure a dovetail of myth and argument, but the philosophic life that it praises is also shaped by an acknowledgement of the limitations of argument and the importance of mythical understanding. By means of this correlation of form and content Plato invites his readers, through the very act of reading, to take a first step along the path of the philosophical life. (shrink)

Based on the proceedings of a 1985 conference held in the U.K., this volume embraces most of the important concerns in AI today, emphasizing common techniques and methodologies rather than applications. Topics covered include building efficient computational logic, planning and design, the representation of uncertain knowledge, user modelling, and psychological and philosophical issues. Papers on perception, theorem proving, expert systems, robotics, and data bases are also included. Each section is preceded by an introduction which draws comparisons between various papers.

Subjects classified visible 2-digit numbers as larger or smaller than 55. Target numbers were preceded by masked 2-digit primes that were either congruent (same relation to 55) or incongruent. Experiments 1 and 2 showed prime congruency effects for stimuli never included in the set of classified visible targets, indicating subliminal priming based on long-term semantic memory. Experiments 2 and 3 went further to demonstrate paradoxical unconscious priming effects resulting from task context. For example, after repeated practice classifying 73 as larger (...) than 55, the novel masked prime 37 paradoxically facilitated the “larger” response. In these experiments task context could induce subjects to unconsciously process only the leftmost masked prime digit, only the rightmost digit, or both independently. Across 3 experiments, subliminal priming was governed by both task context and long-term semantic memory. (shrink)

This paper forms an introduction to this issue, the contents of which arose directly or indirectly from a conference in May 2001 on Corruption of scientific integrity? — The commercialisation of academic science. The introduction, in recent decades, of business culture and values into universities and research institutions is incompatible with the openness which scientific and all academic pursuit traditionally require. It has given rise to a web of problems over intellectual property and conflict of interest which has even led (...) to corporate sponsors’ suppressing unfavourable results of clinical trials, to the detriment of patients’ health. Although there are those who see the norms of science developing to recognise the importance of instrumental science aiming at specific goals and of knowledge judged by its value in a context of application, none justifies the covert manipulation of results by vested interest. Public awareness of these problems is growing and creating a climate of opinion where they may be addressed. We suggest a way forward by the introduction of nationally and internationally-accepted guidelines for industrial collaboration which contain proper protections of the core purposes of universities and of the independence of their research. Some codes suggested for this purpose are discussed. We note that some universities are moving to adopt such codes of conduct, but argue the need for strong support from the government through its funding bodies. (shrink)