MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112

The version of record, Rodigas, T. J. et al, 'MagAO Imaging of long-period objects (MILO). II. A puzzling white dwarf around the sun-like star HD 11112', The Astrophysical Journal, 831:177, November 2016, is available online via doi: 10.3847/0004-637X/831/2/177 © 2016. The American Astronomical Society. All rights reserved.HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2\fasec 2 (100 AU) at multiple wavelengths spanning 0.6-4 \microns ~and show that it is most likely a gravitationally-bound cool white dwarf. Modeling its spectral energy distribution (SED) suggests that its mass is 0.9-1.1 \msun, which corresponds to very high-eccentricity, near edge-on orbits from Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is $>2\sigma$ discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.Peer reviewedFinal Published versio

Influence du contrôle comportemental et de la distance psychique sur le choix du mode d’exportation de PME vietnamiennes

Cet article étudie les relations entre les caractéristiques environnementales, individuelles et organisationnelles des PME vietnamiennes et leur comportement d’exportation. Plus précisément, il s’intéresse à l’effet médiateur des contrôles du comportement effectif de l’entrepreneur sur la relation entre les stimuli de distance psychique et le choix du mode d’exportation de PME vietnamiennes. Nous utilisons une base de données de PME manufacturières établies au Viêt Nam et montrons que les contrôles du comportement effectif de l’entrepreneur et les facteurs organisationnels déterminent le choix du mode d’exportation des PME vietnamiennes. Nos résultats ne permettent pas de conclure à une influence de la distance psychique (distance géographique et stimuli de distance psychique) sur le choix du mode d’exportation des PME vietnamiennes. Enfin, les contrôles du comportement effectif de l’entrepreneur ne semblent pas jouer de rôle médiateur ou modérateur dans la relation entre distance psychique et choix du mode d’exportation de ces PME

Detection of Biological Bricks in Space. The Case of Adenine in Silica Aerogel

International audienceSpace missions using probes to return dust samples are becoming more frequent. Dust collectors made of silica aerogel blocks are used to trap and bring back extraterrestrial particles for analysis. In this work, we show that it is possible to detect traces of adenine using surface-enhanced Raman spectroscopy (SERS). The method was first optimized using adenine deposition on glass slides and in glass wells. After this preliminary step, adenine solution was injected into the silica aerogel. Finally, gaseous adenine was successfully trapped in the aerogel. The presence of traces of adenine was monitored by SERS through its characteristic bands at 732, 1323, and 1458 cm −1 after the addition of the silver Creighton colloid. Such a method can be extended in the frame of Tanpopo missions for studying the interplanetary transfer of prebiotic organic compounds of biological interest

GCPBayes pipeline: a tool for exploring pleiotropy at the gene level

International audienceCross-phenotype association using gene-set analysis can help to detect pleiotropic genes and inform about common mechanisms between diseases. Although there are an increasing number of statistical methods for exploring pleiotropy, there is a lack of proper pipelines to apply gene-set analysis in this context and using genome-scale data in a reasonable running time. We designed a user-friendly pipeline to perform cross-phenotype gene-set analysis between two traits using GCPBayes, a method developed by our team. All analyses could be performed automatically by calling for different scripts in a simple way (using a Shiny app, Bash or R script). A Shiny application was also developed to create different plots to visualize outputs from GCPBayes. Finally, a comprehensive and step-by-step tutorial on how to use the pipeline is provided in our group's GitHub page. We illustrated the application on publicly available GWAS (genome-wide association studies) summary statistics data to identify breast cancer and ovarian cancer susceptibility genes. We have shown that the GCPBayes pipeline could extract pleiotropic genes previously mentioned in the literature, while it also provided new pleiotropic genes and regions that are worthwhile for further investigation. We have also provided some recommendations about parameter selection for decreasing computational time of GCPBayes on genome-scale data

Anti-microbial activity of Mucosal Associated Invariant T cells

International audienceMucosal associated invariant T (MAIT) lymphocytes are characterized by two evolutionarily conserved features: an invariant TCRα chain and restriction by the MHC-related protein, MR1. Here we show that MAIT cells are activated by cells infected with different strains of bacteria and yeasts, but not viruses, both in human and mouse. This activation requires cognate interaction between the invariant T cell receptor (TCR) and MR1, which can present a bacteria-derived ligand. In humans, we observe a striking diminution of MAIT cell blood-numbers in patients with bacterial infections such as tuberculosis. In mouse, MAIT cells protect against infections by Mycobacterium and Escherichia coli. Thus, MAIT cells are evolutionarily conserved innate-like lymphocytes that sense and help fight off microbial infections