AMBER : a near infrared focal instrument for the VLTI

10 pagesInternational audienceAMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels

Le déficit en vitamine C est-il un facteur de risque d'hémorragie intracérébrale spontanée?

Le déficit modéré en vitamine C favorisait la survenue des hématomes cérébraux. Dans une étude cas témoins prospective réalisée au CHU de Rennes, le taux de vitamine C plasmatique a été mesuré chez 65 patients ayant une hémorragie intracérébrale spontanée et chez 65 témoins appariés. Le taux de vitamine C était de 6,43mg/L+-3,62 chez les cas contre 10,21 mg/L+-3,7 chez les témoins. L'hypertension artérielle, la consommation d'alcool et l'IMC apparaissaient comme des facteurs de risque d'hémorragie cérébrale profonde alors que les hématomes lobaires prédominaient chez les sujets âgés. Un taux de vitamine C= 75 years had more lobar than deep intracerebral hemorrhages. Vitamin C depletion was not associated with acute and at 3 months mortality but was associated with longer length of hospital stay. Vitamin C depletion is spontaneous intracerebral hemorrhage risk factor. There are probably multiple physiopathological mechanisms like vitamin C implication in blood pressure regulation and collagen synthesis.RENNES1-BU Santé (352382103) / SudocSudocFranceF

L’AFS a 20 ans. Origine, histoire et devenir d’une association professionnelle

À l’automne 2020, Muriel Darmon, alors présidente de l’Association française de sociologie (AFS), propose aux ancien·nes président·es de publier sur le site internet de l’association des témoignages de leur mandat. Débute alors un travail mémoriel visant à renseigner l’histoire de l’association, qui trouve un premier aboutissement dans ce numéro de Socio-logos. Un groupe « Histoire de l’AFS » se forme en effet peu après au sein du Comité exécutif afin, après s’être adjoint les forces du RT 49..

Multi-genome metabolic modeling predicts functional inter-dependencies in the Arabidopsis root microbiome

International audienceBackground: From a theoretical ecology point of view, microbiomes are far more complex than expected. Besides competition and competitive exclusion, cooperative microbe-microbe interactions have to be carefully considered. Metabolic dependencies among microbes likely explain co-existence in microbiota. Methodology: In this in silico study, we explored genome-scale metabolic models (GEMs) of 193 bacteria isolated from Arabidopsis thaliana roots. We analyzed their predicted producible metabolites under simulated nutritional constraints including "root exudate-mimicking growth media " and assessed the potential of putative metabolic exchanges of by- and end-products to avoid those constraints. Results: We found that the genome-encoded metabolic potential is quantitatively and qualitatively clustered by phylogeny, highlighting metabolic differentiation between taxonomic groups. Random, synthetic combinations of increasing numbers of strains (SynComs) indicated that the number of producible compounds by GEMs increased with average phylogenetic distance, but that most SynComs were centered around an optimal phylogenetic distance. Moreover, relatively small SynComs could reflect the capacity of the whole community due to metabolic redundancy. Inspection of 30 specific end-product metabolites (i.e., target metabolites: amino acids, vitamins, phytohormones) indicated that the majority of the strains had the genetic potential to produce almost all the targeted compounds. Their production was predicted (1) to depend on external nutritional constraints and (2) to be facilitated by nutritional constraints mimicking root exudates, suggesting nutrient availability and root exudates play a key role in determining the number of producible metabolites. An answer set programming solver enabled the identification of numerous combinations of strains predicted to depend on each other to produce these targeted compounds under severe nutritional constraints thus indicating a putative sub-community level of functional redundancy. Conclusions: This study predicts metabolic restrictions caused by available nutrients in the environment. By extension, it highlights the importance of the environment for niche potential, realization, partitioning, and overlap. Our results also suggest that metabolic dependencies and cooperation among root microbiota members compensate for environmental constraints and help maintain co-existence in complex microbial communities

Genome-resolved metatranscriptomics reveals conserved root colonization determinants in a synthetic microbiota

International audienceThe identification of processes activated by specific microbes during microbiota colonization of plant roots has been hampered by technical constraints in metatranscriptomics. These include lack of reference genomes, high representation of host or microbial rRNA sequences in datasets, or difficulty to experimentally validate gene functions. Here, we recolonized germ-free Arabidopsis thaliana with a synthetic, yet representative root microbiota comprising 106 genome-sequenced bacterial and fungal isolates. We used multi-kingdom rRNA depletion, deep RNA-sequencing and read mapping against reference microbial genomes to analyse the in planta metatranscriptome of abundant colonizers. We identified over 3,000 microbial genes that were differentially regulated at the soil-root interface. Translation and energy production processes were consistently activated in planta, and their induction correlated with bacterial strains’ abundance in roots. Finally, we used targeted mutagenesis to show that several genes consistently induced by multiple bacteria are required for root colonization in one of the abundant bacterial strains (a genetically tractable Rhodanobacter). Our results indicate that microbiota members activate strain-specific processes but also common gene sets to colonize plant roots

Clinical presentation, evolution, and prognosis of precursor B-cell lymphoblastic lymphoma in trials LMT96, EORTC 58881, and EORTC 58951

In children, lymphoblastic lymphomas represent 30% of Non-Hodgkin lymphomas (NHL), and approximately 15% are precursor B-cell lymphomas (PBLL). Our study evaluated their main clinical characteristics, evolution, and prognosis in three trials. From 1989 to 2008, 53 children with PBLL (median age 7·75 years) were included in three protocols: Malignant Lymphoma Therapy (LMT) 96, European Organization for Research and Treatment of Cancer (EORTC) 58881, and EORTC 58951 using Berlin-Frankfürt-Münster-derived acute lymphoblastic leukaemia (ALL) therapy. There were 10 stage I disease, 9 stage II, 9 stage III and 25 stage IV. Clinical presentation was heterogeneous with a majority of bone lesions and cutaneous or subcutaneous manifestations. At diagnosis 23 patients had bone marrow involvement, and only three had central nervous system involvement. The median follow-up was 74 months. At last follow-up, 45 patients were in continuous complete remission, whereas eight had progressed or had relapsed (7 Stages IV and 1 Stage III) and died. Two patients had a secondary neoplasia, and are still alive. Disease stage was a major prognostic factor, with better overall survival (OS) and event-free survival (EFS) (P < 0·05) rates observed in patients with Stage I to III as compared to those with Stage IV. Treatment with protocols derived from ALL therapy are efficient with an 82% EFS and an 85% OS at 5 years

Active polarimetric imager for detection of static and moving manufactured objects in natural environment

International audienc