L'agentivité en question : étude des pratiques discursives des femmes enceintes sur les forums de discussion

International audienceSur les forums doctissimo.fr sur l'accouchement, les participantes produisent des discours d'opposition au pouvoir médical ; elles estiment être privées de leur capacité d'agir par la normalisation et la technicisation de l'accouchement. Elles développent alors des pratiques discursives collectives pour élaborer une puissance d'agir dans un but de réappropriation du processus de la naissance. L'étude de ces pratiques par lesquelles les femmes enceintes sur les forums utilisent, construisent et parfois refusent leur agentivité permet de comprendre comment les rapports de pouvoirs genrés sont construits ou destabilisés dans les discours. Je mènerai une étude qualitative de messages recueillis sur les forums doctissimo.fr concernant la naissance en croisant les perspectives de l'anthropologie linguistique, de l'analyse du discours et des études de genre. Après avoir proposé une conception de l'agentivité qui réunisse matérialité linguistique et pensée des rapports de domination, je montrerai comment les internautes construisent et performent en ligne des pratiques langagières de résistance au pouvoir médical et de réappropriation du corps. Cette agentivité doit cependant être nuancée par l'importance accordée dans leurs discours à la naturalité du processus de l'accouchement : des entités comme le bébé, le corps ou la nature sont également dotés d'une puissance d'agir par ces femmes. Le concept d'agentivité, considéré dynamiquement au sein des interactions, permet d'étudier les processus discursifs de création collective de pouvoirs mais aussi les mécanismes d'intériorisation et de reproduction des dominations

Circonscriptions et réseaux de voies : un angle mort de la Géographie Historique

International audienceThis paper examines two aspects of the relation to space and territory : networks and grids. Over the past one hundred and fifty years, historigraphy has focused either on constituencies or on means of communication and transport, but has largely overlooked the relationship between the two. A detailed examination of historical practices reveals that the introduction of the planimetry of ditstricts (between 1680 and 1850 in the case of France) coincided with the construction of both objects. Based on several case studies at the level of cantons, the findings suggest that there are a number of significant links between district boundaries and means of transport. This raises the question of common or separate histories (or temporalities) and the importance of mapping ond planimetrics conceived as the combination or association of different objects in the 18th century.L'objectif de cet article est de proposer la mise en place de réflexions articulant maillages et treillages, alors que l'historiographie dominante sépare ces deux aspects de la relation aux territoires. En effet, une lecture de l'historiographie des 150 dernières années montre que les réflexions dominantes portent soit sur les circonscriptions, soit sur les voies de communication, mais n'essayent pas, en règle générale de penser leur relation. Pourtant, une observation soucieuse des pratiques anciennes montre que la période de mise en place d'une planimétrie des circonscriptions, soit pour la France une période qui court de 1680 à 1850, est celle d'une co-construction de ces objets sur le terrain. Une série de cas pris à l'échelle cantonale permet de démontrer diverses formes d'association sur le long terme entre voies de communication et limites de circonscription. Se posent alors des questions de différentes natures, d'une part sur les temporalités communes ou disjointes entre voies et circonscriptions, d'autre part sur l'importance de la planimétrie en tant que mise en cohérence d'objets différents au XVIIIe siècle

Le canton d'hier à aujourd'hui : étude cartographique d'un maillage

Between 1800 and 1999, the number of canton passes from 3043 to 3694 cantons. At the same time, the average surface of these districts passes from 178 to 48 km2. If we accumulate all the modifications which know the cantonal limits during these two hundred years we find more than 3000. The canton is thus an eminently changeable district, what allows to return on the image of fixedness which is attached to it. Maps present the set of these transformations. Beyond these results, the survey presented here aimed at understanding better the spatial nature of the modifications which affect the cantonal weft, as long within the framework of a relation in the big balances of the national territory, that in that of the relationship in the other level of district, or in that of the relations between the city and the countryside.Entre 1800 et 1999, le nombre de canton passe de 3043 à 3694 cantons. Dans le même temps, la superficie moyenne de ces circonscriptions passe de 178 à 48 km2. Si l'on cumule l'ensemble des modifications que connaissent les limites cantonales durant ces deux cents années on en trouve plus de 3000. Le canton est donc une circonscription éminemment changeante, ce qui permet de revenir sur l'image de fixité qui lui est attachée. Des cartes présentent l'ensemble des ces mutations. Au-delà de ces résultats, l'enquête présentée ici a visé à mieux comprendre la nature spatiale des modifications qui affectent la trame cantonale, tant dans le cadre d'une relation aux grands équilibres du territoire national, que dans celui du rapport aux autres circonscriptions, ou dans celui des relations ville-campagne

One-electron oxidation and reduction of glycosaminoglycan chloramides: a kinetic study.

Hypochlorous acid and its acid-base counterpart, hypochlorite ions, produced under inflammatory conditions, may produce chloramides of glycosaminoglycans, these being significant components of the extracellular matrix (ECM). This may occur through the binding of myeloperoxidase directly to the glycosaminoglycans. The N-Cl group in the chloramides is a potential selective target for both reducing and oxidizing radicals, leading possibly to more efficient and damaging fragmentation of these biopolymers relative to the parent glycosaminoglycans. In this study, the fast reaction techniques of pulse radiolysis and nanosecond laser flash photolysis have been used to generate both oxidizing and reducing radicals to react with the chloramides of hyaluronan (HACl) and heparin (HepCl). The strong reducing formate radicals and hydrated electrons were found to react rapidly with both HACl and HepCl with rate constants of 1-1.7 x 108 and 0.7-1.2 x 108 M-1 s-1 for formate radicals and 2.2 x 109 and 7.2 x 10 8 M-1 s-1 for hydrated electrons, respectively. The spectral characteristics of the products of these reactions were identical and were consistent with initial attack at the N-Cl groups, followed by elimination of chloride ions to produce nitrogen-centered radicals, which rearrange subsequently and rapidly to produce C-2 radicals on the glucosamine moiety, supporting an earlier EPR study by M.D. Rees et al. (J. Am. Chem. Soc. 125: 13719-13733; 2003). The oxidizing hydroxyl radicals also reacted rapidly with HACl and HepCl with rate constants of 2.2 x 108 and 1.6 x 108 M-1 s-1, with no evidence from these data for any degree of selective attack on the N-Cl group relative to the N-H groups and other sites of attack. The carbonate anion radicals were much slower with HACl and HepCl than hydroxyl radicals (1.0 x 105 and 8.0 x 10 4 M-1 s-1, respectively) but significantly faster than with the parent molecules (3.5 x 104 and 5.0 x 10 4 M-1 s-1, respectively). These findings suggest that these potential in vivo radicals may react in a site-specific manner with the N-Cl group in the glycosaminoglycan chloramides of the ECM, possibly to produce more efficient fragmentation. This is the first study therefore to conclusively demonstrate that reducing radicals react rapidly with glycosaminoglycan chloramides in a site-specific attack at the N-Cl group, probably to produce a 100% efficient biopolymer fragmentation process. Although less reactive, carbonate radicals, which may be produced in vivo via reactions of peroxynitrite with serum levels of carbon dioxide, also appear to react in a highly site-specific manner at the N-Cl group. It is not yet known if such site-specific attacks by this important in vivo species lead to a more efficient fragmentation of the biopolymers than would be expected for attack by the stronger oxidizing species, the hydroxyl radical. It is clear, however, that the N-Cl group formed under inflammatory conditions in the extracellular matrix does present a more likely target for both reactive oxygen species and reducing species than the N-H groups in the parent glycosaminoglycans. © 2013 Elsevier Inc. All rights reserved

Irradiation-induced Ag nanocluster nucleation in silicate glasses: analogy with photography

The synthesis of Ag nanoclusters in sodalime silicate glasses and silica was studied by optical absorption (OA) and electron spin resonance (ESR) experiments under both low (gamma-ray) and high (MeV ion) deposited energy density irradiation conditions. Both types of irradiation create electrons and holes whose density and thermal evolution - notably via their interaction with defects - are shown to determine the clustering and growth rates of Ag nanocrystals. We thus establish the influence of redox interactions of defects and silver (poly)ions. The mechanisms are similar to the latent image formation in photography: irradiation-induced photoelectrons are trapped within the glass matrix, notably on dissolved noble metal ions and defects, which are thus neutralized (reverse oxidation reactions are also shown to exist). Annealing promotes metal atom diffusion, which in turn leads to cluster nuclei formation. The cluster density depends not only on the irradiation fluence, but also - and primarily - on the density of deposited energy and the redox properties of the glass. Ion irradiation (i.e., large deposited energy density) is far more effective in cluster formation, despite its lower neutralization efficiency (from Ag+ to Ag0) as compared to gamma photon irradiation.Comment: 48 pages, 18 figures, revised version publ. in Phys. Rev. B, pdf fil

From Dark Matter to the Earth's Deep Interior: There and Back Again

This thesis is a two-way transfer of knowledge between cosmology and seismology, aiming to substantially advance imaging methods and uncertainty quantification in both fields. I develop a method using wavelets to simulate the uncertainty in a set of existing global seismic tomography images to assess the robustness of mantle plume-like structures. Several plumes are identified, including one that is rarely discussed in the seismological literature. I present a new classification of the most likely deep mantle plumes from my automated method, potentially resolving past discrepancies between deep mantle plumes inferred by visual analysis of tomography models and other geophysical data. Following on from this, I create new images of the upper-most mantle and their associated uncertainties using a sparsity-promoting wavelet prior and an advanced probabilistic inversion scheme. These new images exhibit the expected tectonic features such as plate boundaries and continental cratons. Importantly, the uncertainties obtained are physically reasonable and informative, in that they reflect the heterogenous data distribution and also highlight artefacts due to an incomplete forward model. These inversions are a first step towards building a fully probabilistic upper-mantle model in a sparse wavelet basis. I then apply the same advanced probabilistic method to the problem of full-sky cosmological mass-mapping. However, this is severely limited by the computational complexity of high-resolution spherical harmonic transforms. In response to this, I use, for the first time in cosmology, a trans-dimensional algorithm to build galaxy cluster-scale mass-maps. This new approach performs better than the standard mass-mapping method, with the added benefit that uncertainties are naturally recovered. With more accurate mass-maps and uncertainties, this method will be a valuable tool for cosmological inference with the new high-resolution data expected from upcoming galaxy surveys, potentially providing new insights into the interactions of dark matter particles in colliding galaxy cluster systems

Julie De Ganck, Le Sexe, une invention moderne ? Histoire des réactions face aux anomalies sexuelles et à l’hermaphrodisme en Belgique contemporaine (1830-1914)

L’ouvrage de Julie De Ganck se veut une histoire de la médecine belge concernant l’« hermaphrodisme » et les « anomalies sexuelles » couvrant la période allant de 1830 à 1914. Comme l’explique l’auteure, la période voit l’émergence de travaux médicaux sur la question de l’« hermaphrodisme » – ce qui se traduit notamment en Belgique par la publication croissante d’articles d’auteurs européens sur ce thème dans des revues médicales, qui constituent le corpus d’étude de l’ouvrage. L’auteure choi..

Audrey Benoit. 2019. Trouble dans la matière. Pour une épistémologie matérialiste du sexe

L’ouvrage d’Audrey Benoit, Trouble dans la matière, issu de sa thèse de doctorat en philosophie, traite d’une question complexe : comment articuler le matériel et le discursif, et comment penser que c’est « dans le discours que sont produites les conditions matérielles de l’existence sociale » ? (p. 8). Benoit pose le problème à partir de la réflexion féministe sur la construction discursive du sexe, renversement contre-intuitif qui veut que le sexe, loin d’être de la matière corporelle brute..