A Commentary on Althusser's 1963 Presentation of Bourdieu and Passeron

The commentary provides contextual information about the seminar which Bourdieu and Passeron gave in the École Normale Supérieure on 6 December 1963. It appears that the intended series of seminars was curtailed, perhaps because the initial seminar of 6 December exposed the extent to which Althusser was formally managing the intentions of his guest speakers and resisting the implications of their ongoing research on students and their studies. The commentary argues that the conflict between Althusser and Bourdieu/Passeron was inter-generational in that Althusser’s attitudes had been shaped by his experience as a victim of Nazi oppression whereas those of Bourdieu/Passeron were defined, instead, by their unwilling participation in the French colonial oppression of indigenous Algerians. Althusser was intent on examining philosophically the validity of various contemporary versions of social science whereas Bourdieu and Passeron were engaged in educational research which was scrutinizing sociologically the validity of precisely this supposedly detached philosophical perspective. In short, the commentary is aligned with the Bourdieu/Passeron position in that it seeks to offer an historical sociology of the encounter of December 1963

Evaluation des rôles relatifs d’une bande enherbée et d’un fossé filtrant dans un ouvrage de traitement des eaux de ruissellement de voirie

International audienceIn order to determine the relative importance of a vegetative filter strip and a biofiltration swale in a treatment train for road runoff, US EPA SWMM was used to model infiltration and runoff from the filter strip. The model consists of a series of subcatchments representing the road, the filter strip and the side slopes of the swale. Simulations were carried out for different rain scenarios representing a variety of climatic conditions. In addition, a sensitivity analysis was conducted for the model's different parameters (soil characteristics and initial humidity, roughness, geometry…). This exercise showed that for the system studied, the majority of road runoff is managed by the filter strip rather than the biofiltration swale, an effect observed especially during periods of low-intensity rainfall. Additionally, it was observed that the combination of infiltration of road runoff in the filter strip and direct rainfall on the system leads to a significant and variable dilution of the runoff reaching the swale. This result has important implications for evaluating the treatment efficiency of the system.Afin de déterminer l'importance relative d'une bande enherbée dans un ouvrage combiné bande enherbée-fossé de biofiltration de traitement des eaux de ruissellement de voirie, le ruissellement et l'infiltration au niveau de la bande enherbée ont été modélisés avec US EPA SWMM. Le modèle consiste en une série de sous-bassins versants représentant la route, la bande enherbée et le talus du fossé. Des simulations ont été menées pour différents scenarios de pluies représentant une variété de conditions climatiques et en menant une analyse de sensibilité sur les différents paramètres du modèle (nature du sol, humidité initiale, rugosité, géométrie…). Cet exercice a montré que pour le système étudié, la grande majorité de l'eau est gérée par la bande enherbée et non pas par le fossé de biofiltration dans lequel peu d'eau arrive, notamment quand l'intensité de la pluie est faible. De plus, il a été observé que la combinaison de l'infiltration de l'eau de voirie sur la bande enherbée et de l'apport en précipitation directe sur l'ouvrage conduit à une dilution significative et variable de l'eau atteignant le fossé. Ces résultats ont des implications importantes pour l'évaluation de l'efficacité épuratoire du système

Dynamique du piégeage des micropolluants métalliques au sein des zones humides artificielles traitant des eaux pluviales urbaines strictes : Etude de cas à Strasbourg, Moulins-lès-Metz et Leuville-sur-Orge

Colloque avec actes et comité de lecture. internationale.International audienceStormwater constructed wetlands (SCW) in Strasbourg (Alsace, France), Moulin-lès-Metz (Lorraine, France), and Leuville-sur-Orge (Ile-de-France, France) receive and treat exclusively runoffs from urban catchments but with different soil uses. Made up of sedimentation ponds and a vertical subsurface flow constructed wetland, the treatment facilities lead to trap several trace metal pollution. Each site belongs to different hydroclimatic areas (modified oceanic, modified continental and semi-continental) and was designed for different purposes (watercourse protection in Strasbourg and in Leuville-sur-Orge, protection of drinking water wells in Moulins-lès-Metz). The aim of this study is to explore trace metals (Cd, Cu, Pb and Zn) behaviours in these SCW. We investigated trace metal trapping by determining concentrations in the systems compartments (filters media and plants). Then trace metal speciation was determined through sequencial extractions of the sediment and filter media. This allowed to determine their forms in soils and to anticipate their behaviour during physical and chemical condition changes. This study permits to obtain first results for the metals stability, to highlight a decrease of the concentrations through the SCW depth (from surficial sediment to clean filter media) and to observe a negligible metal trap in plants (mainly in roots)

The host metabolite D-serine contributes to bacterial niche specificity through gene selection

Escherichia coli comprise a diverse array of both commensals and niche-specific pathotypes. The ability to cause disease results from both carriage of specific virulence factors and regulatory control of these via environmental stimuli. Moreover, host metabolites further refine the response of bacteria to their environment and can dramatically affect the outcome of the host–pathogen interaction. Here, we demonstrate that the host metabolite, D-serine, selectively affects gene expression in E. coli O157:H7. Transcriptomic profiling showed exposure to D-serine results in activation of the SOS response and suppresses expression of the Type 3 Secretion System (T3SS) used to attach to host cells. We also show that concurrent carriage of both the D-serine tolerance locus (dsdCXA) and the locus of enterocyte effacement pathogenicity island encoding a T3SS is extremely rare, a genotype that we attribute to an ‘evolutionary incompatibility’ between the two loci. This study demonstrates the importance of co-operation between both core and pathogenic genetic elements in defining niche specificity

A new multimethod approach for dating cave calcite: application to the cave of Trou du Renard (Soyons, France)

A multimethod approach aimed at characterizing carbonate parietal deposits and at proposing a chronology for these carbonate crusts is described. Dating was performed by radiometric methods (C-14 for recent samples and U series) on samples that had been characterized beforehand using optical and cathodoluminescence microscopy and Fourier transform infrared microspectroscopy. For the U series, high precision on U–Th ages was achieved using liquid phase multicollector inductively coupled plasma mass spectrometry (ICP-MS) applied to large samples, while laser ablation single collector inductively coupled plasma sector field mass spectrometry (ICP-SFMS) provided information on the reliability of the sampling with a high spatial resolution. This methodology, based on the combination of these two techniques reinforced by the information obtained by the calcite characterization methods, was applied to carbonate deposits from the cave of Trou du Renard (Soyons, France). The ages obtained with the two U–Th dating techniques are comparable and illustrate that different laminae were deposited at different rates in the samples. In the future, this procedure, based on the mineralogical and geochemical characterization of the samples and their dating by radiometric methods, will be applied to the layers of parietal carbonates deposited on Palaeolithic decorated walls. When the crystallization is slow, the U/Th dating method by imaging technique is of interest, as well as that by multicollector ICP-MS in liquid phase. The development of robust dating methods on very small quantities of material will make it possible to define the chronological framework of cave rock art.</p

Phosphatase and tensin homologue: a therapeutic target for SMA

Spinal muscular atrophy (SMA) is one of the most common juvenile neurodegenerative diseases, which can be associated with child mortality. SMA is caused by a mutation of ubiquitously expressed gene, Survival Motor Neuron1 (SMN1), leading to reduced SMN protein and the motor neuron death. The disease is incurable and the only therapeutic strategy to follow is to improve the expression of SMN protein levels in motor neurons. Significant numbers of motor neurons in SMA mice and SMA cultures are caspase positive with condensed nuclei, suggesting that these cells are prone to a process of cell death called apoptosis. Searching for other potential molecules or signaling pathways that are neuroprotective for central nervous system (CNS) insults is essential for widening the scope of developmental medicine. PTEN, a Phosphatase and Tensin homologue, is a tumor suppressor, which is widely expressed in CNS. PTEN depletion activates anti-apoptotic factors and it is evident that the pathway plays an important protective role in many neurodegenerative disorders. It functions as a negative regulator of PIP3/AKT pathway and thereby modulates its downstream cellular functions through lipid phosphatase activity. Moreover, previous reports from our group demonstrated that, PTEN depletion using viral vector delivery system in SMN delta7 mice reduces disease pathology, with significant rescue on survival rate and the body weight of the SMA mice. Thus knockdown/depletion/mutation of PTEN and manipulation of PTEN medicated Akt/PKB signaling pathway may represent an important therapeutic strategy to promote motor neuron survival in SMA