Pour un nouveau discernement éthique à l’égard des pratiques d’assistance médicale à la procréation : le métabolisme symbolique du don de la vie

Les critiques d’ordre éthique faites à l’assistance médicale à la procréation (AMP) ne tiennent généralement pas compte de l’extraordinaire efficacité des nouvelles techniques procréatives face à la souffrance des couples stériles. Mais, marquée par l’impératif technicien qui la pousse à explorer tous les possibles techniques, la médecine procréative constitue également — et paradoxalement — une puissante source de souffrances elle-même. Un nouveau discernement éthique est nécessaire, à la fois conscient des réussites de l’AMP et soucieux de ne pas tomber dans une logique utilitariste.Ethical objections formulated against medically assisted procreation usually do not take into account the extraordinary success of the new procreative techniques so far as sufferings undergone by sterile couples are concerned. Since procreative medicine is, however, under the technical imperative which urges it on to explore every technical possibility, it itself constitutes as well — and paradoxically — a powerful source of suffering. A new ethical discernment is necessary, which would prove to be both aware of the successes of medically assisted procreation and concerned not to fall into a utilitarian logic

EXAFS study of lead-free relaxor ferroelectric BaTi(1-x)Zr(x)O3 at the Zr K-edge

Extended X-ray absorption fine structure (EXAFS) experiments at the Zr K-edge were carried out on perovskite relaxor ferroelectrics BaTi(1-x)Zr(x)O3 (BTZ) (x = 0.25, 0.30, 0.35), and on BaZrO3 for comparison. Structural information up to 4.5 A around the Zr atoms is obtained, revealing that the local structure differs notably from the average Pm-3m cubic structure deduced from X-ray diffraction. In particular, our results show that the distance between Zr atoms and their first oxygen neighbors is independent of the Zr substitution rate x and equal to that measured in BaZrO3, while the X-ray cubic cell parameter increases linearly with x. Furthermore, we show that the Zr atoms tend to segregate in Zr-rich regions. We propose that the relaxor behavior in BTZ is linked to random elastic fields generated by this particular chemical arrangement, rather than to random electric fields as is the case in most relaxors.Comment: 13 pages, 12 figures, 4 tables. Submitted to Phys. Rev.

Investigation of the Jahn-Teller Transition in TiF3 using Density Functional Theory

We use first principles density functional theory to calculate electronic and magnetic properties of TiF3 using the full potential linearized augmented plane wave method. The LDA approximation predicts a fully saturated ferromagnetic metal and finds degenerate energy minima for high and low symmetry structures. The experimentally observed Jahn-Teller phase transition at Tc=370K can not be driven by the electron-phonon interaction alone, which is usually described accurately by LDA. Electron correlations beyond LDA are essential to lift the degeneracy of the singly occupied Ti t2g orbital. Although the on-site Coulomb correlations are important, the direction of the t2g-level splitting is determined by the dipole-dipole interactions. The LDA+U functional predicts an aniferromagnetic insulator with an orbitally ordered ground state. The input parameters U=8.1 eV and J=0.9 eV for the Ti 3d orbital were found by varying the total charge on the TiF$_6^{2-}$ ion using the molecular NRLMOL code. We estimate the Heisenberg exchange constant for spin-1/2 on a cubic lattice to be approximately 24 K. The symmetry lowering energy in LDA+U is about 900 K per TiF3 formula unit.Comment: 7 pages, 9 figures, to appear in Phys. Rev.

France:: Social science education in France – A fragmented educational landscape in transition

Purpose: After a short historical presentation, this country report highlights current developments of social science education in France and clarifies its general status in the French school system, giving not only information about the curricula baselines, but also on current reforms, shifts and conflict lines among practitioners and researchers. Design/methodology/approach: This article is based on a synopsis of both official documents and evaluation reports published by the French Ministry of Education and other public organs and scientific data such as empirical case studies. Findings: Social sciences education falls under broad purposes such as educating citizens and preparing the future workforce. History, geography and civics are more established and taught to more students than other more recent subjects like Sciences économiques et sociales (Economic and social sciences), all of those subjects raising broader research questions

VOGEL, Christine, Der Untergang der Gesellschaft Jesu als europäisches Medienereignis (1758-1773). Publizistische Debatten im Spannungsfeld von Aufklärung und Gegenaufklärung

Issu d’une thèse de doctorat soutenue pendant le semestre d’hiver 2003/ 2004 à l’université de Gießen, l’ouvrage à recenser expose, dans l’optique d’une histoire culturelle, les étapes qui conduisirent de l’« affaire jésuite » du Portugal (1758-1761) à la suppression de la Compagnie de Jésus en 1773. Le choix de l’échelle et de la perspective d’étude donne son originalité à ce traitement d’un moment incontournable de l’histoire des jésuites. En effet, le parti est pris de s’attaquer à un « év..