This paper explores structuralism as a way to model theories from scientific practice. As a case study I analyzed a theory about the dynamics of the basal ganglia, a part of the brain that is involved in Parkinson's disease. After introducing the case study I explore how to structurally represent qualitative assumptions about disease, intervention and dynamical systems in general. I further explicate the structure of the basal ganglia theory in detail, how it explains Parkinson's disease and how it implies (...) treatments. I close with a consideration of how a structuralist representation could be useful in practice to explore and develop theories with the aid of a computer. (shrink)
One method to determine the asymptotics of particular solutions of a difference equation is by solving an associated asymptotic functional equation. Here we study the behaviour of the solutions in an asymptotic neighbourhood of such individual solutions. We identify several types of attraction and repulsion, which range from almost orthogonality to almost parallelness. Necessary and sufficient conditions for these types of behaviour are given.
I define serendipity as the art of making an unsought finding. And I propose an overview of my collection of serendipities, the largest yet assembled, chiefly in science and technology, but also in art, by giving a list of ‘serendipity patterns’. Although my list of ‘patterns’ is just a list and not a classification, it serves to introduce a new and possibly stimulating perspective on the old subject of serendipity. Knowledge of these ‘serendipity patterns’ might help in expecting also the (...) unexpected and in finding also the unsought. * I acknowledge A. D. de Groot, R. C. M. Noordam, B. P. van Heusden, T. Pinkster, C. J. van den Berg, T. A. F. Kuipers, A. Wegener Sleeswijk and my referee for their suggestions and I dedicate this article to T. A. van Kooten. Cases and studies of serendipidy are welcome. À propos: a travelling serendipity exhibition is available, also for ‘new democracies’: ‘Freedom of opportunity as developed by democracy is the best human reaction to divergent phenomena. We may, in fact, define ‘freedom’ as ‘the opportunity to profit from the unexpected.’ (Langmuir ). (shrink)
This article focuses on maternal-fetal surgery (MFS) and on the concept of clinical equipoise that is a widely accepted requirement for conducting randomized controlled trials (RCT). There are at least three reasons why equipoise is unsuitable for MFS. First, the concept is based on a misconception about the nature of clinical research and the status of research subjects. Second, given that it is not clear who the research subject/s in MFS is/are, if clinical equipoise is to be used as a (...) criterion to test the ethical appropriateness of RCT, its meaning should be unambiguous. Third, because of the multidisciplinary character of MFS, it is not clear who should be in equipoise. As a result, we lack an adequate criterion for the ethical review of MFS protocols. In our account, which is based on Chervenak and McCullough's seminal work in the field of obstetric ethics, equipoise is abandoned. and RCT involving MFS can be ethically initiated when a multidisciplinary ethics review board (ERB), having an evidence-based assessment of the risks involved, is convinced that the value of answering the research hypothesis, for the sake of the health interests of future pregnant women carrying fetuses with certain congenital birth defects, justifies the actual risks research participants might suffer within a set limit of low/manageable. (shrink)
Chervenak and McCullough, authors of the most acknowledged ethical framework for maternal–fetal surgery, rely on the ‘ethical–obstetrical’ concept of the fetus as a patient in order to determine what is morally owed to fetuses by both physicians and the women who gestate them in the context of prenatal surgery. In this article, we reconstruct the argumentative structure of their framework and present an internal criticism. First, we analyse the justificatory arguments put forward by the authors regarding the moral status of (...) the fetus qua patient. Second, we discuss the internal coherence and consistency of the moral obligations those authors derive from that concept. We claim that some of the dilemmas their approach is purported to avoid, such as the debate about the independent moral status of the fetus, and the foundation of the moral obligations of pregnant women (towards the fetuses they gestate) are not, all things considered, avoided. Chervenak and McCullough construct the obligations of physicians as obligations towards entities with equal moral status. But, at the same time, they assume that the woman has an independent moral status while the moral status of the fetus is dependent on the decision of the woman to present it to a physician for care. According to the logic of their own argumentation, Chervenak and McCullough implicitly admit a different moral status of the woman and the fetus, which will lead to different ascription of duties of the physician than those they ascribed. (shrink)
O. Renn, P.-J. Schweizer, M. Dreyer, A. Klinke: Risiko. Über den gesellschaftlichen Umgang mit Unsicherheit Content Type Journal Article DOI 10.1007/s10202-009-0071-9 Authors Stephan Lingner, Europäische Akademie zur Erforschung von Folgen wissenschaftlich-technischer Entwicklungen Bad Neuenahr-Ahrweiler GmbH Wilhelmstr. 56 53474 Bad Neuenahr-Ahrweiler Germany Journal Poiesis & Praxis: International Journal of Technology Assessment and Ethics of Science Online ISSN 1615-6617 Print ISSN 1615-6609 Journal Volume Volume 6 Journal Issue Volume 6, Numbers 3-4.
I discuss van inwagen's "first formal argument" for the incompatibility of causal determinism and freedom to do otherwise. I distinguish different interpretations of the important notion, "s can render p false." I argue that on none of these interpretations is the argument clearly sound. I point to gaps in the argument, Although I do not claim that it is unsound.
Peter van Inwagen’s argument for incompatibilism uses a sentential operator, “N”, which can be read as “No one has any choice about the fact that . . . .” I show that, given van Inwagen’s understanding of the notion of having a choice, the argument is invalid. However, a different interpretation of “N” can be given, such that the argument is clearly valid, the premises remain highly plausible, and the conclusion implies that free will is incompatible with determinism.