L’expressivisme moral : une conclusion de la critique darwinienne de Sharon Street ?

Un des objectifs de la critique darwinienne de Sharon Street est de montrer que nous devons opter pour l’antiréalisme – plutôt que le réalisme – comme théorie métaéthique appropriée pour décrire le phénomène moral. Plus encore, parmi les théories antiréalistes, Street cherche à défendre que c’est le constructivisme humien que nous devrions privilégier. Dans cet article, je cherche à évaluer la possibilité que l’expressivisme moral soit également une conclusion de la critique darwinienne. Pour ce faire, j’explique en quoi nous pouvons de manière légitime considérer que le constructivisme humien est une théorie expressiviste, dans la mesure où nous nous limitons aux deux thèses que je considère comme étant constitutives de l’expressivisme : l’internalisme motivationnel et la conception humienne des jugements normatifs. C’est de cette manière qu’il est possible de soutenir que l’expressivisme moral est une conclusion de la critique darwinienne

Non-Naturalism and the Metaphysics of Normative Properties

Normative non-naturalists seem to be committed to a supervenience relation about the normative. This means that the normative necessarily varies with the non-normative, such that the normative features of a person or a thing cannot change if the non-normative features of that person or that thing do not change either. Furthermore, according to normative non-naturalists, normative properties are metaphysically discontinuous with non-normative properties, as the former are irreducible to the latter and cannot be exhaustively understood in terms of the latter. However, it is not clear that normative non-naturalists can explain the necessary connection between the normative and the non-normative they themselves seem to maintain; this is the core of the problem of supervenience. In order to respond to the problem of supervenience, non-naturalists could either try to explain the necessary connection between the normative and the non-normative, or deny that this necessary connection between the normative and the non-normative holds. I first define normative non-naturalists theoretical commitments and give a few reasons to take this view seriously (Chapter 1), and then I explain how the problem of supervenience against non-naturalism should be understood (Chapter 2). Then, I argue that there are issues with the most convincing attempts to explain the necessary connection between the normative and the non-normative (Chapter 3) and with the most convincing attempts to deny this necessary connection (Chapter 4). My conclusion is then that non-naturalists do not have a convincing response to the problem of supervenience

Automated measurement of Drosophila wings

BACKGROUND: Many studies in evolutionary biology and genetics are limited by the rate at which phenotypic information can be acquired. The wings of Drosophila species are a favorable target for automated analysis because of the many interesting questions in evolution and development that can be addressed with them, and because of their simple structure. RESULTS: We have developed an automated image analysis system (WINGMACHINE) that measures the positions of all the veins and the edges of the wing blade of Drosophilid flies. A video image is obtained with the aid of a simple suction device that immobilizes the wing of a live fly. Low-level processing is used to find the major intersections of the veins. High-level processing then optimizes the fit of an a priori B-spline model of wing shape. WINGMACHINE allows the measurement of 1 wing per minute, including handling, imaging, analysis, and data editing. The repeatabilities of 12 vein intersections averaged 86% in a sample of flies of the same species and sex. Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. Wing shape retains some phylogenetic structure, although some species have shapes very different from closely related species. The WINGMACHINE system facilitates artificial selection experiments on complex aspects of wing shape. We selected on an index which is a function of 14 separate measurements of each wing. After 14 generations, we achieved a 15 S.D. difference between up and down-selected treatments. CONCLUSION: WINGMACHINE enables rapid, highly repeatable measurements of wings in the family Drosophilidae. Our approach to image analysis may be applicable to a variety of biological objects that can be represented as a framework of connected lines

Incremental and Decremental Maintenance of Planar Width

We present an algorithm for maintaining the width of a planar point set dynamically, as points are inserted or deleted. Our algorithm takes time O(kn^epsilon) per update, where k is the amount of change the update causes in the convex hull, n is the number of points in the set, and epsilon is any arbitrarily small constant. For incremental or decremental update sequences, the amortized time per update is O(n^epsilon).Comment: 7 pages; 2 figures. A preliminary version of this paper was presented at the 10th ACM/SIAM Symp. Discrete Algorithms (SODA '99); this is the journal version, and will appear in J. Algorithm

Evaluation of glare reducing skin coatings as utilized in athletics

For many years, athletes have been wearing a black substance under their eyes. The ability of this substance to enhance an athlete\u27s performance has never been tested. This paper will address the ability of this substance to increase contrast sensitivity. Three different glare reducing skin coatings were photometrically tested to determine the product with the lowest gloss index. Utilizing the Arden Plates, contrast sensitivity (CS) was measured on 55 subjects ages 22-40 in a high glare environment both with and without the most effective glare reducing product. When wearing the glare reducing skin coating, subject\u27s CS increased significantly at the spatial frequency of 0.8 cpd, under our test conditions

Flip Graphs of Degree-Bounded (Pseudo-)Triangulations

We study flip graphs of triangulations whose maximum vertex degree is bounded by a constant $k$. In particular, we consider triangulations of sets of $n$ points in convex position in the plane and prove that their flip graph is connected if and only if $k > 6$; the diameter of the flip graph is $O(n^2)$. We also show that, for general point sets, flip graphs of pointed pseudo-triangulations can be disconnected for $k \leq 9$, and flip graphs of triangulations can be disconnected for any $k$. Additionally, we consider a relaxed version of the original problem. We allow the violation of the degree bound $k$ by a small constant. Any two triangulations with maximum degree at most $k$ of a convex point set are connected in the flip graph by a path of length $O(n \log n)$, where every intermediate triangulation has maximum degree at most $k+4$.Comment: 13 pages, 12 figures, acknowledgments update