Empathie mémorielle et transferts littéraires

L’exposé (Séminaire Schwarz-Bart, février 2020) converti ici en article, s’appuie, notamment, sur l’ouvrage Causes Communes, Des Juifs et des Noirs (Stock, 2011). Il traite du transfert mémoriel dans le parcours et l’œuvre d’André Schwarz-Bart, en particulier à travers le roman Un plat de porc aux bananes vertes signé par André et Simone Schwarz-Bart (Seuil, 1967). S’appuyant sur le concept de « mémoire multidirectionnelle » de Michael Rothberg et celui de « Relation » d’Édouard Glissant, l’auteure de l’article voit dans l’approche d’André Schwarz-Bart de l’esclavage des Noirs, plutôt qu’une capacité de l’appréhender à partir du drame qui serait central de la Shoah, celle du pouvoir de rencontrer l’Autre, du « Moi à dire Tu ».Nicole Lapierre’s presentation at the Schwarz-Bart Seminar of February 2020, which this paper is based on, draws on the book Causes Communes, Des Juifs et des Noirs (Stock, 2011). It addresses the transfer of memory through the work of André Schwarz-Bart, in particular in the novel Un plat de porc aux bananes vertes by André and Simone Schwarz-Bart (Seuil, 1967). Drawing on Michael Rothberg’s concept of “multidirectional memory” and Édouard Glissant’s concept of “Relation”, the author of the article sees, in André Schwarz-Bart’s exploration of Black slavery, the power to meet the Other, of the «Me to say You», rather than an approach of the tragedy from a Shoah-centric perspective

Visible light reduces C. elegans longevity.

The transparent nematode Caenorhabditis elegans can sense UV and blue-violet light to alter behavior. Because high-dose UV and blue-violet light are not a common feature outside of the laboratory setting, we asked what role, if any, could low-intensity visible light play in C. elegans physiology and longevity. Here, we show that C. elegans lifespan is inversely correlated to the time worms were exposed to visible light. While circadian control, lite-1 and tax-2 do not contribute to the lifespan reduction, we demonstrate that visible light creates photooxidative stress along with a general unfolded-protein response that decreases the lifespan. Finally, we find that long-lived mutants are more resistant to light stress, as well as wild-type worms supplemented pharmacologically with antioxidants. This study reveals that transparent nematodes are sensitive to visible light radiation and highlights the need to standardize methods for controlling the unrecognized biased effect of light during lifespan studies in laboratory conditions

Development of a CHO production medium utilizing proteomic and metabolomics analysis

productivity. Metabolomics and proteomic analysis was conducted on two medium formulations with disparate growth and production characteristics. Medium formulation 1 (M1) demonstrates moderate peak VCD with a high specific productivity (qP) over a 14 day growth performance assay utilizing a recombinant IgG producing CHO-S cell line and DG44 cell line. Medium formulation 2 (M2) demonstrates a high peak VCD with moderate qP under the same conditions and cell line. A comparative analysis of metabolite abundance and enzyme regulation identified that M1 had greater flux in the sorbitol pathway verses glycolysis, the TCA cycle was upregulated to a greater degree than M2. A Design of Experiment (DoE) study was developed to increase the specific productivity of M1 without decreasing the VCD to M2 levels resulting in a superior volumetric titer. Simultaneously, we utilized traditional empirical approaches to increase the qP of M2 in a parallel set of experiments. We describe here the path to develop the medium, metabolic and proteomic pathways which were found to be important, and a comparison of results based on the traditional empirical path verses the hypothesis based advanced cellular analytics path

Clostridium difficile Toxin B causes epithelial cell necrosis through an autoprocessing-independent mechanism

Clostridium difficile is the most common cause of antibiotic-associated nosocomial infection in the United States. C. difficile secretes two homologous toxins, TcdA and TcdB, which are responsible for the symptoms of C. difficile associated disease. The mechanism of toxin action includes an autoprocessing event where a cysteine protease domain (CPD) releases a glucosyltransferase domain (GTD) into the cytosol. The GTD acts to modify and inactivate Rho-family GTPases. The presumed importance of autoprocessing in toxicity, and the apparent specificity of the CPD active site make it, potentially, an attractive target for small molecule drug discovery. In the course of exploring this potential, we have discovered that both wild-type TcdB and TcdB mutants with impaired autoprocessing or glucosyltransferase activities are able to induce rapid, necrotic cell death in HeLa and Caco-2 epithelial cell lines. The concentrations required to induce this phenotype correlate with pathology in a porcine colonic explant model of epithelial damage. We conclude that autoprocessing and GTD release is not required for epithelial cell necrosis and that targeting the autoprocessing activity of TcdB for the development of novel therapeutics will not prevent the colonic tissue damage that occurs in C. difficile - associated disease

Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography

Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N2-fixing root nodules on diverse and globally distributed angiosperms in the “actinorhizal” symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%–98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses

EgMYB2, a new transcriptional activator from Eucalyptus xylem, regulates secondary cell wall formation and lignin biosynthesis

International audienceEgMYB2, a member of a new subgroup of the R2R3 MYB family of transcription factors, was cloned from a library consisting of RNA from differentiating Eucalyptus xylem. EgMYB2 maps to a unique locus on the Eucalyptus grandis linkage map and co-localizes with a quantitative trait locus (QTL) for lignin content. Recombinant EgMYB2 protein was able to bind specifically the cis-regulatory regions of the promoters of two lignin biosynthetic genes, cinnamoyl-coenzyme A reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD), which contain MYB consensus binding sites. EgMYB2 was also able to regulate their transcription in both transient and stable expression assays. Transgenic tobacco plants over-expressing EgMYB2 displayed phenotypic changes relative to wild-type plants, among which were a dramatic increase in secondary cell wall thickness, and an alteration of the lignin profiles. Transcript abundance of genes encoding enzymes specific to lignin biosynthesis was increased to varying extents according to the position of individual genes in the pathway,whereas core phenylpropanoid geneswere not significantly affected. Together these results suggest a role for EgMYB2 in the co-ordinated control of genes belonging to the monolignol-specific pathway, and therefore in the biosynthesis of lignin and the regulation of secondary cell wall formation

Des livres et des idées - Biennale des sciences humaines et sociales 2012

"L\u27édition de sciences humaines et sociales : le cœur en danger", ainsi Sophie Barluet intitulait-elle son rapport commandé par le ministère de la Culture et de la Communication, remis en 2004. Si la question du devenir des sciences humaines et sociales n\u27est pas réductible à sa seule présence sur les tables des libraires, la vitalité du secteur est sans cesse questionnée, depuis la mort des Pères : Sartre, Foucault, Barthes, Bourdieu, Derrida…, depuis la chute du mur de Berlin, et la prégnance – comme allant de soi - du capitalisme (financier), et l\u27effacement du politique, depuis le 11 septembre 2001, entrée fracassante dans le XXIe siècle, comme il y eut Sarajevo un siècle plus tôt, depuis le bouleversement des techniques de lecture et de publication (numérique). Pour autant, la pensée est toujours féconde. De jeunes chercheurs interrogent l\u27histoire et le colonialisme pour comprendre les révolutions du Moyen-Orient, sondent l\u27économie et la finance, analysent nos sociétés. Pour autant, l\u27édition critique traduit, découvre, parfois survit, les chercheurs publient ; voir, à ce propos, l\u27ouvrage de Sophie Noël : L\u27édition indépendante critique : engagements politiques et intellectuels (Presses de l\u27enssib, novembre 2012), ainsi que les trois volumes Faire les sciences sociales aujourd\u27hui publiés par les éditions de l\u27EHESS (octobre 2012). C\u27est pour donner la parole à ceux et celles qui nous aident à comprendre le monde que l\u27enssib, avec la librairie Passages, l\u27école des hautes études en sciences sociales (EHESS) et la bibliothèque municipale de Lyon, en collaboration avec la Fondation de la Maison des sciences de l\u27homme (FMSH), ont organisé cette première biennale des sciences humaines et sociales, dont le thème (générique) est "penser la crise"

Deep-learning segmentation of fascicles from microCT of the human vagus nerve

IntroductionMicroCT of the three-dimensional fascicular organization of the human vagus nerve provides essential data to inform basic anatomy as well as the development and optimization of neuromodulation therapies. To process the images into usable formats for subsequent analysis and computational modeling, the fascicles must be segmented. Prior segmentations were completed manually due to the complex nature of the images, including variable contrast between tissue types and staining artifacts.MethodsHere, we developed a U-Net convolutional neural network (CNN) to automate segmentation of fascicles in microCT of human vagus nerve.ResultsThe U-Net segmentation of ~500 images spanning one cervical vagus nerve was completed in 24 s, versus ~40 h for manual segmentation, i.e., nearly four orders of magnitude faster. The automated segmentations had a Dice coefficient of 0.87, a measure of pixel-wise accuracy, thus suggesting a rapid and accurate segmentation. While Dice coefficients are a commonly used metric to assess segmentation performance, we also adapted a metric to assess fascicle-wise detection accuracy, which showed that our network accurately detects the majority of fascicles, but may under-detect smaller fascicles.DiscussionThis network and the associated performance metrics set a benchmark, using a standard U-Net CNN, for the application of deep-learning algorithms to segment fascicles from microCT images. The process may be further optimized by refining tissue staining methods, modifying network architecture, and expanding the ground-truth training data. The resulting three-dimensional segmentations of the human vagus nerve will provide unprecedented accuracy to define nerve morphology in computational models for the analysis and design of neuromodulation therapies

Building a multi-scaled geospatial temporal ecology database from disparate data sources: fostering open science and data reuse

Although there are considerable site-based data for individual or groups of ecosystems, these datasets are widely scattered, have different data formats and conventions, and often have limited accessibility. At the broader scale, national datasets exist for a large number of geospatial features of land, water, and air that are needed to fully understand variation among these ecosystems. However, such datasets originate from different sources and have different spatial and temporal resolutions. By taking an open-science perspective and by combining site-based ecosystem datasets and national geospatial datasets, science gains the ability to ask important research questions related to grand environmental challenges that operate at broad scales. Documentation of such complicated database integration efforts, through peer-reviewed papers, is recommended to foster reproducibility and future use of the integrated database. Here, we describe the major steps, challenges, and considerations in building an integrated database of lake ecosystems, called LAGOS (LAke multi-scaled GeOSpatial and temporal database), that was developed at the sub-continental study extent of 17 US states (1,800,000 km² ). LAGOS includes two modules: LAGOS[subscript]GEO , with geospatial data on every lake with surface area larger than 4 ha in the study extent (~50,000 lakes), including climate, atmospheric deposition, land use/cover, hydrology, geology, and topography measured across a range of spatial and temporal extents; and LAGOS[subscript]LIMNO , with lake water quality data compiled from ~100 individual datasets for a subset of lakes in the study extent (~10,000 lakes). Procedures for the integration of datasets included: creating a flexible database design; authoring and integrating metadata; documenting data provenance; quantifying spatial measures of geographic data; quality-controlling integrated and derived data; and extensively documenting the database. Our procedures make a large, complex, and integrated database reproducible and extensible, allowing users to ask new research questions with the existing database or through the addition of new data. The largest challenge of this task was the heterogeneity of the data, formats, and metadata. Many steps of data integration need manual input from experts in diverse fields, requiring close collaboration.Keywords: LAGOS, Integrated database, Data harmonization, Database Ecoinformatics, Macrosystems ecology, Landscape limnology, Water qualityKeywords: LAGOS, Integrated database, Ecoinformatics, Data harmonization, Water quality, Data sharing, Landscape limnology, Macrosystems ecology, Database documentation, Data reus

W.E.B. Du Bois, le «problème» noir et la «question» juive

W. E. B. Du Bois, das Schwarzen- „Problem und die Juden-Frage” Im Rückblick auf das Werk von W. E. B. Du Bois und insbesondere auf dessen Analyse des Rassismus auf der Grundlage der Farbenlinie (color line) zeigt dieser Artikel, wie die „Entdeckung der jüdischen Frage“ ihn dazu gebracht hat, seine Vision des Schwarzenproblems zu erweitern und eine Form des Essentialismus zugunsten einer universellen Kritik der rassistischen Vorurteile zu verlassen.W. E. B. Du Bois, of the black “ problem” and the Jewish “ question” Referring to the work by W. E. B. Du Bois, and in particular his analysis of racism based on the colour line, this article shows how the “discovery of the Jewish question” led him to broaden his vision of the black problem and to emerge from a form of essentialism to the benefit of a universalising criticism of racial prejudices.Revenant sur l’oeuvre de W. E. B. Du bois, et notamment sur son analyse du racisme fondée sur la ligne de séparation des couleurs (color line), cet article montre comment la «découverte de la question juive» l’a conduit à élargir sa vision du problème noir et à sortir d’une forme d’essentialisme, au profit d’une critique universalisante des préjugés raciaux.Lapierre Nicole. W.E.B. Du Bois, le «problème» noir et la «question» juive. In: Revue des sciences sociales, N°42, 2009. Étrange étranger. pp. 104-109