Évolution de la contribution française à l'upgrade de LHCb

Ce document décrit l'évolution de la contribution française à l'upgrade de LHCb. Il s'inscrit dans le prolongement de la Lettre d'Intention [1], du Framework TDR [2], du document soumis au Conseil scientifique de l'IN2P3 le 21 juin 2012 [3], et des Technical Design Reports soumis au LHCC en novembre 2013 [4, 5]. Ces derniers concernent le détecteur de vertex et les détecteurs utilisés dans l'identification des particules. La contribution française s'est cristallisée autour de quatre grands projets : l'électronique front-end des calorimètres et du trajectographe à fibres scintillantes, le système de déclenchement de premier niveau et la carte de lecture à 40MHz commune à l'ensemble des sous-systèmes. Dans ce document nous décrivons les contributions envisagées et les ressources nécessaires pour mener à bien ces projets

Chronique

Ricard Robert, Cirot Georges, Bonnard Maryvonne, Mapes E. K., Vilar Pierre. Chronique. In: Bulletin Hispanique, tome 41, n°2, 1939. pp. 198-208

Chronique

Ricard Robert, Cirot Georges, Bonnard Maryvonne, Mapes E. K., Vilar Pierre. Chronique. In: Bulletin Hispanique, tome 41, n°2, 1939. pp. 198-208

Geometric and numerical methods in the contrast imaging problem in nuclear magnetic resonance

International audienceIn this article, the contrast imaging problem in nuclear magnetic resonance is modeled as a Mayer problem in optimal control. The optimal solution can be found as an extremal, solution of the Maximum Principle and analyzed with the techniques of geometric control. This leads to a numerical investigation based on so-called indirect methods using the HamPath software. The results are then compared with a direct method implemented within the Bocop toolbox. Finally lmi techniques are used to estimate a global optimum

Robust water diffusion modeling in a structural polymer joint based on experimental X-ray tomographic data at the micrometer scale

Structural bonding is a technique increasingly used in the industrial field. For applications in aggressive environments such as seawater, predicting the effect of moisture on the mechanical behavior of bonded assemblies is of paramount importance. The objective of this work is to analyze water diffusion in an epoxy adhesive material and, more specifically, to propose a robust method for choosing the most appropriate diffusion model. Experimental studies of the water absorption in a two-component epoxy structural adhesive, using gravimetry and X-ray tomography, were first performed. The presence of a population of pore-type defects in the polymeric joint helped to characterize the evolution of water diffusion kinetics. Thus, two diffusion mechanisms were identified: a first one related to the migration of water molecules within the adhesive matrix, and a second one related to the penetration of water into the pores. Then, Dual-Fick and Langmuir models were retained, as the two diffusion models most likely to capture the above mechanisms. Although it was shown that both models could give similar results in terms of global diffusion behavior, the results arising from these two models differ at the local scale, especially for extended periods of time. Therefore, special attention was paid to the second absorption mechanism, and a comparison of waterfronts between theoretical predictions and experimental tomographic data was achieved, leading to the final choice of a Dual-Fick diffusion model

Coral larval settlement preferences linked to crustose coralline algae with distinct chemical and microbial signatures

The resilience of coral reefs is dependent on the ability of corals to settle after disturbances. While crustose coralline algae (CCA) are considered important substrates for coral settlement, it remains unclear whether coral larvae respond to CCA metabolites and microbial cues when selecting sites for attachment and metamorphosis. This study tested the settlement preferences of an abundant coral species (Acropora cytherea) against six different CCA species from three habitats (exposed, subcryptic and cryptic), and compared these preferences with the metabolome and microbiome characterizing the CCA. While all CCA species induced settlement, only one species (Titanoderma prototypum) significantly promoted settlement on the CCA surface, rather than on nearby dead coral or plastic surfaces. This species had a very distinct bacterial community and metabolomic fingerprint. Furthermore, coral settlement rates and the CCA microbiome and metabolome were specific to the CCA preferred habitat, suggesting that microbes and/or chemicals serve as environmental indicators for coral larvae. Several amplicon sequence variants and two lipid classes-glycoglycerolipids and betaine lipids-present in T. prototypum were identified as potential omic cues influencing coral settlement. These results support that the distinct microbiome and metabolome of T. prototypum may promote the settlement and attachment of coral larvae

Coral larval settlement preferences linked to crustose coralline algae with distinct chemical and microbial signatures

International audienceThe resilience of coral reefs is dependent on the ability of corals to settle after disturbances. While crustose coralline algae (CCA) are considered important substrates for coral settlement, it remains unclear whether coral larvae respond to CCA metabolites and microbial cues when selecting sites for attachment and metamorphosis. This study tested the settlement preferences of an abundant coral species (Acropora cytherea) against six different CCA species from three habitats (exposed, subcryptic and cryptic), and compared these preferences with the metabolome and microbiome characterizing the CCA. While all CCA species induced settlement, only one species (Titanoderma prototypum) significantly promoted settlement on the CCA surface, rather than on nearby dead coral or plastic surfaces. This species had a very distinct bacterial community and metabolomic fingerprint. Furthermore, coral settlement rates and the CCA microbiome and metabolome were specific to the CCA preferred habitat, suggesting that microbes and/or chemicals serve as environmental indicators for coral larvae. Several amplicon sequence variants and two lipid classes-glycoglycerolipids and betaine lipids-present in T. prototypum were identified as potential omic cues influencing coral settlement. These results support that the distinct microbiome and metabolome of T. prototypum may promote the settlement and attachment of coral larvae

Germline NLRP1 Mutations Cause Skin Inflammatory and Cancer Susceptibility Syndromes via Inflammasome Activation

Inflammasome complexes function as key innate immune effectors that trigger inflammation in response to pathogen- and danger-associated signals. Here, we report that germline mutations in the inflammasome sensor NLRP1 cause two overlapping skin disorders: multiple self-healing palmoplantar carcinoma (MSPC) and familial keratosis lichenoides chronica (FKLC). We find that NLRP1 is the most prominent inflammasome sensor in human skin, and all pathogenic NLRP1 mutations are gain-of-function alleles that predispose to inflammasome activation. Mechanistically, NLRP1 mutations lead to increased self-oligomerization by disrupting the PYD and LRR domains, which are essential in maintaining NLRP1 as an inactive monomer. Primary keratinocytes from patients experience spontaneous inflammasome activation and paracrine IL-1 signaling, which is sufficient to cause skin inflammation and epidermal hyperplasia. Our findings establish a group of non-fever inflammasome disorders, uncover an unexpected auto-inhibitory function for the pyrin domain, and provide the first genetic evidence linking NLRP1 to skin inflammatory syndromes and skin cancer predisposition