A normative approach to radicalization in social networks

In recent decades, the massification of online social connections has made information globally accessible in a matter of seconds. Unfortunately, this has been accompanied by a dramatic surge in extreme opinions, without a clear solution in sight. Using a model performing probabilistic inference in large-scale loopy graphs through exchange of messages between nodes, we show how circularity in the social graph directly leads to radicalization and the polarization of opinions. We demonstrate that these detrimental effects could be avoided by actively decorrelating the messages in social media feeds. This approach is based on an extension of Belief Propagation (BP) named Circular Belief Propagation (CBP) that can be trained to drastically improve inference within a cyclic graph. CBP was benchmarked using data from Facebook and Twitter. This approach could inspire new methods for preventing the viral spreading and amplification of misinformation online, improving the capacity of social networks to share knowledge globally without resorting to censorship.Comment: 23 pages, 8 figures, 1 supplementary materia

Ly49E Expression on CD8αα-expressing intestinal intraepithelial lymphocytes plays no detectable role in the development and progression of experimentally induced inflammatory bowel diseases

The Ly49E NK receptor is a unique inhibitory receptor, presenting with a high degree of conservation among mouse strains and expression on both NK cells and intraepithelial-localised T cells. Amongst intraepithelial-localised T cells, the Ly49E receptor is abundantly expressed on CD8 alpha alpha-expressing innate-like intestinal intraepithelial lymphocytes (iIELs), which contribute to front-line defense at the mucosal barrier. Inflammatory bowel diseases (IBDs), encompassing Crohn's disease and ulcerative colitis, have previously been suggested to have an autoreactive origin and to evolve from a dysbalance between regulatory and effector functions in the intestinal immune system. Here, we made use of Ly49E-deficient mice to characterize the role of Ly49E receptor expression on CD8 alpha alpha-expressing iIELs in the development and progression of IBD. For this purpose we used the dextran sodium sulphate (DSS)- and trinitrobenzenesulfonic-acid (TNBS)-induced colitis models, and the TNF Delta ARE ileitis model. We show that Ly49E is expressed on a high proportion of CD8 alpha alpha-positive iIELs, with higher expression in the colon as compared to the small intestine. However, Ly49E expression on small intestinal and colonic iIELs does not influence the development or progression of inflammatory bowel diseases

Enquêter dans les partis politiques:Perspectives comparées

Ce dossier se situe à la croisée de deux mouvements récents qui traversent la science politique française. Le premier tient au constat que l’étude des partis politiques s’est largement transformée ces dernières années. D’abord, cet objet « canonique » a fait l’objet d’une attention renouvelée, et en particulier un nombre important de thèses, récemment soutenues ou en cours, y sont consacrées. Ensuite, ces travaux, émanant donc pour une large part de jeunes chercheur(se)s, ont pour point commun de s’appuyer sur des enquêtes, entendues au sens large comme des méthodes de production de données originales, que celles-ci soient qualitatives (par observations et entretiens) ou quantitatives (passation de questionnaires auprès d’adhérents d’un parti politique, par exemple). Cette multiplication de travaux empiriques sur les partis permet une confrontation des expériences d’enquête, afin de réfléchir collectivement à ces pratiques de recherche, pour elles-mêmes mais aussi pour ce qu’elles nous apprennent de l’objet de recherche parti politique (...)

A Cell Wall Proteome and Targeted Cell Wall Analyses Provide Novel Information on Hemicellulose Metabolism in Flax

International audienceExperimentally-generated (nanoLC-MS/MS) proteomic analyses of four different flax organs/tissues (inner-stem, outer-stem, leaves and roots) enriched in proteins from 3 different sub-compartments (soluble-, membrane-, and cell wall-proteins) was combined with publically available data on flax seed and whole-stem proteins to generate a flax protein database containing 2996 nonredundant total proteins. Subsequent multiple analyses (MapMan, CAZy, WallProtDB and expert curation) of this database were then used to identify a flax cell wall proteome consisting of 456 nonredundant proteins localized in the cell wall and/or associated with cell wall biosynthesis, remodeling and other cell wall related processes. Examination of the proteins present in different flax organs/tissues provided a detailed overview of cell wall metabolism and highlighted the importance of hemicellulose and pectin re-modeling in stem tissues. Phylogenetic analyses of proteins in the cell wall proteome revealed an important paralogy in the class IIIA xyloglucan endo-transglycosy-lase/hydrolase (XTH) family associated with xyloglucan endo-hydrolase activity. Immunolocalisation, FT-IR microspectroscopy, and en-zymatic fingerprinting indicated that flax fiber primary/S1 cell walls contained xyloglucans with typical substituted side chains as well as glucuronoxylans in much lower quantities. These results suggest a likely central role of xyloglucans and endotransglucosylase/hydrolase activity in flax fiber formation and cell wall remodeling processes. Molecular & Cellula

A novel interleukin-10 DNA mucosal delivery system attenuates intestinal inflammation in a mouse model

Inflammatory bowel diseases (IBD) describe a group of complex intestinal disorders characterized by inflammation in the gastrointestinal tract. Current treatments for IBD include the use of anti-inflammatory drugs; furthermore, recombinant lactic acid bacteria have been used as a therapeutic vehicle for anti-inflammatory agents in IBD models. Interleukin-10 (IL-10) is one of the most important anti-inflammatory cytokines; however, its oral administration is limited because it is quickly degraded in the gastrointestinal tract and systemic treatments have led to undesirable side effects. In this study, an engineered invasive strain of Lactococcus (L.) lactis producing Fibronectin Binding Protein A (FnBPA+), from Staphylococcus aureus capable of delivering, directly inside eukaryotic cells, an eukaryotic DNA expression vector containing the ORF coding for IL-10 of Mus musculus (pValac:il-10) was developed and its functionality was evaluated using in vitro and in vivo assays. Functionality of the plasmid and the invasive strain was demonstrated by transfection and invasiveness assays using cell cultures and in vivo in mice by fluorescence microscopy. TNBS inoculated mice that received this novel strain showed lower damage scores in their large intestines (at both macroscopic and microscopic levels), lower microbial translocation to liver, and increased anti-inflammatory/pro-inflammatory cytokine ratios compared to mice that received L. lactis FnBPA+ without the pValac:il-10 plasmid. The effectiveness was demonstrated of this novel DNA delivery therapeutic strategy in the prevention of inflammation using a murine model of colitis.Fil: del Carmen, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia para Lactobacilos (i); ArgentinaFil: Zurita-Turk, Meritxell. Universidade Federal Do Minas Gerais; Brasil;Fil: Alvarenga Lima, Fernanda. Universidade Federal Do Minas Gerais; Brasil;Fil: Coelho Dos Santos, Janete. No especifíca;Fil: Leclercq, Sophie Yvette. No especifíca;Fil: Chatel, Jean-Marc. Institut National de la Recherche Agronomique; Francia;Fil: Azevedo, Vasco. Universidade Federal Do Minas Gerais; Brasil;Fil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia para Lactobacilos (i); ArgentinaFil: Miyoshi, Anderson. Universidade Federal Do Minas Gerais; Brasil;Fil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia para Lactobacilos (i); Argentina. Universidad Nacional de Tucuman. Facultad de Medicina. Departamento de Investigacion. Catedra de Metodologia de la Invest.cientifica; Argentin

Lactococcus lactis carrying the pValac DNA expression vector coding for IL-10 reduces inflammation in a murine model of experimental colitis

Background: Inflammatory bowel diseases (IBD) are intestinal disorders characterized by inflammation in the gastrointestinal tract. Interleukin-10 is one of the most important anti-inflammatory cytokines involved in the intestinal immune system and because of its role in downregulating inflammatory cascades, its potential for IBD therapy is under study. We previously presented the development of an invasive strain of Lactococcus lactis (L. lactis) producing Fibronectin Binding Protein A (FnBPA) which was capable of delivering, directly to host cells, a eukaryotic DNA expression vector coding for IL-10 of Mus musculus (pValac:il-10) and diminish inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse model of intestinal inflammation. As a new therapeutic strategy against IBD, the aim of this work was to evaluate the therapeutic effect of two L. lactis strains (the same invasive strain evaluated previously and the wild-type strain) carrying the therapeutic pValac:il-10 plasmid in the prevention of inflammation in a dextran sodium sulphate (DSS)-induced mouse model. Results: Results obtained showed that not only delivery of the pValac:il-10 plasmid by the invasive strain L. lactis MG1363 FnBPA+, but also by the wild-type strain L. lactis MG1363, was effective at diminishing intestinal inflammation (lower inflammation scores and higher IL-10 levels in the intestinal tissues, accompanied by decrease of IL-6) in the DSS-induced IBD mouse model. Conclusions: Administration of both L. lactis strains carrying the pValac:il-10 plasmid was effective at diminishing inflammation in this murine model of experimental colitis, showing their potential for therapeutic intervention of IBD.Fil: Zurita Turk, Meritxell. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: del Carmen, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Santos, Ana C. G.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Pereira, Vanessa Bastos. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Cara, Denise C.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Leclercq, Sophie Y.. Fundaçao Ezequiel Dias. Laboratório de Inovaçao Biotecnológica; BrasilFil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Azevedo, Vasco. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Chatel, Jean-Marc. Universidade Federal do Minas Gerais; BrasilFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Miyoshi, Anderson. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; Brasi

Determination of Angptl4 mRNA as a Diagnostic Marker of Primary and Metastatic Clear Cell Renal-Cell Carcinoma

International audienceBACKGROUND: We have previously shown that angiopoietin-like 4 (angptl4) mRNA, a hypoxia-inducible gene, is highly expressed in clear cell renal-cell carcinoma (ccRCC), the most common subtype of RCC for which no specific marker is available. We here investigated whether angptl4 mRNA 1) could be a useful diagnostic and/or prognostic marker of ccRCC in a large and comprehensive retrospective series, 2) induction is dependent on the VHL status of tumors. METHODOLOGY/PRINCIPAL FINDINGS: Using in situ hybridization, we report that angptl4 mRNA is expressed in 100% of both sporadic (n = 102) and inherited (n = 6) primary ccRCCs, without any statistical association with nuclear grade (p = 0.39), tumor size (p = 0.09), stage grouping (p = 0.17), progression-free survival (p = 0.94), and overall survival (p = 0.80). Angptl4 mRNA was also expressed in 26 (87%) of 30 secondary ccRCCs but neither in any other secondary RCCs (n = 7). In contrast, angptl4 mRNA was neither expressed in 94% non-ccRCC renal tumors (papillary RCCs (n = 46), chromophobe RCCs (n = 28), and oncocytomas (n = 9)), nor in non-renal clear cell carcinomas (n = 39). Angptl4 expression was also examined in tumors associated (n = 23) or not associated (n = 66) with VHL disease. 40 (98%) hemangioblastomas expressed angptl4 whereas all pheochromocytomas (n = 23) and pancreatic tumors (n = 25) were angptl4-negative, whatever their VHL status. CONCLUSIONS/SIGNIFICANCE: Angptl4 mRNA expression was highly associated with ccRCC (p = 1.5 10(-49), Chi square test) allowing to define its expression as a diagnosis marker for primary ccRCC. Moreover, angptl4 mRNA allows to discriminate the renal origin of metastases of clear-cell carcinomas arising from various organs. Finally, inactivation of VHL gene is neither necessary nor sufficient for angptl4 mRNA induction

Ten-year survival and complications of total knee arthroplasty for osteoarthritis secondary to trauma or surgery: A French multicentre study of 263 patients

BACKGROUND: Previous surgical procedures raise technical challenges in performing total knee arthroplasty (TKA) and may affect TKA outcomes. Survival rates of TKA done after trauma or surgery to the knee have not been accurately determined in large populations. The objectives of this retrospective study in 263 patients with TKA after knee trauma or surgery and a follow-up of 10 years were to assess survival, functional outcomes, and the nature and frequency of complications. HYPOTHESIS: Knee trauma or surgery before TKA increases the risk of complications and decreases implant survival. MATERIAL AND METHODS: Two hundred and sixty-three patients (122 [47%] females and 141 [53%] males) underwent TKA between 2005 and 2009 at nine centres in France. Mean age at surgery was 61 years. The patients had knee osteoarthritis secondary to a fracture (n=66), osteotomy (n=131), or ligament injury (n=66). Mean time from trauma or surgery to TKA was 145 months (range, 72-219 months). RESULTS: Major complications were infection (n=12, 4.5%), skin problems (n=8, 3%), and stiffness (n=8, 3%). Ten-year survival to implant exchange for any reason was 89%±2.8%. Flexion range increased by 2.5°±17° (p=0.02) to a mean of 110° (range, 30° to 140°); extension range increased by 4°±7° (p<0.001) to a mean of -1.19 (range, -20° to 0°). Of the 263 patients, 157 (60%) reported little or no pain at last follow-up. Mean postoperative hip-knee-ankle angle was 179°±3.2° (range, 171°-188°). CONCLUSION: TKA performed after knee injury or surgery carries a risk of specific complications (infection, skin problems, and stiffness) and may have a lower survival rate compared to primary TKA