Éditeur(s) : HAL CCSD Wiley-VCH Verlag
Résumé : International audience
Deciphering the assembly history of the Milky Way is a formidable task, which becomes possible only if one can produce high-resolution chrono-chemo-kinematical maps of the Galaxy. Data from large-scale astrometric and spectroscopic surveys will soon provide us with a well-defined view of the current chemo-kinematical structure of the Milky Way, but will only enable a blurred view on the temporal sequence that led to the present-day Galaxy. As demonstrated by the (ongoing) exploitation of data from the pioneering photometric missions CoRoT, Kepler, and K2, asteroseismology provides the way forward: solar-like oscillating giants are excellent evolutionary clocks thanks to the availability of seismic constraints on their mass and to the tight age-initial-mass relation they adhere to. In this paper we identify five key outstanding questions relating to the formation and evolution of the Milky Way that will need precise and accurate ages for large samples of stars to be addressed, and we identify the requirements in terms of number of targets and the precision on the stellar properties that are needed to tackle such questions. By quantifying the asteroseismic yields expected from PLATO for red-giant stars, we demonstrate that these requirements are within the capabilities of the current instrument design, provided that observations are sufficiently long to identify the evolutionary state and allow robust and precise determination of acoustic-mode frequencies. This will allow us to harvest data of sufficient quality to reach a 10% precision in age. This is a fundamental pre-requisite to then reach the more ambitious goal of a similar level of accuracy, which will only be possible if we have to hand a careful appraisal of systematic uncertainties on age deriving from our limited understanding of stellar physics, a goal which conveniently falls within the main aims of PLATO's core science.
ISSN: 0004-6337

hal-01541393
https://hal.archives-ouvertes.fr/hal-01541393
ARXIV : 1706.3778
BIBCODE : 2017AN....338..644M
DOI : 10.1002/asna.201713385

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : National audience
The sources of exposure during diseases due to Aspergillus fungi in cystic fibrosis patients are still poorly explored. We assessed home fungal exposure in patients suffering from cystic fibrosis and analysed its impact on the presence of Aspergillus biological markers, the colonisation of airways, as well as the sensitization and Aspergillus serology. Between March 2012 and August 2012, 34 patients benefited from a visit performed by a home environment medical adviser including sampling for mycological analysis. The number of colonies of Aspergillus was not significantly different in the various sampling sites (P = 0.251), but the number of non-Aspergillus colonies was much higher in the kitchen (P = 0.0045). Subsequently, home fungal exposure was compared between the groups “absence of Aspergillus-related markers” and “presence of Aspergillus-related markers”. Home exposure to Aspergillus (P = 0.453) and non-Aspergillus (P = 0.972) flora was not significant between the 2 groups. Within this series of 34 patients that should be expanded, we note an absence of clear relationship between home exposure and the Aspergillus-linked markers in patients suffering from cystic fibrosis. This result should be taken into account regarding too restrictive hygiene advices provided to families, given the fact that fungal exposure can also results from activities performed away from home.
La source d’exposition au cours des pathologies aspergillaires du patient atteint de mucoviscidose reste encore peu explorée. Nous avons évalué l’exposition fongique domiciliaire chez des patients atteints de mucoviscidose, et analysé son impact sur la présence de marqueurs biologiques aspergillaires, colonisation des voies aériennes, ainsi que sensibilisation et sérologie anti-aspergillaire. Trente-quatre patients ont bénéficié d’une visite par un conseiller médical en environnement intérieur entre mars et août 2012, comprenant des prélèvements à visée mycologique. Le nombre de colonies aspergillaires ne différait pas significativement d’un site de prélèvement à l’autre (p = 0,251), mais le nombre de colonies non aspergillaires était significativement plus important dans la cuisine (p = 0,0045). L’exposition fongique domiciliaire a ensuite été comparée entre les groupes « marqueurs aspergillaires absents » et « marqueurs aspergillaires présents ». L’exposition domiciliaire à une flore aspergillaire (p = 0,453) et non aspergillaire (p = 0,972) ne différait pas significativement entre les 2 groupes. Sur cette série de 34 patients qui mérite d’être élargie, on note une absence de lien évident entre l’exposition domiciliaire et la pathologie aspergillaire. Ce résultat doit rendre prudent sur des conseils d’hygiène parfois très contraignants donnés aux familles, l’exposition fongique étant également importante dans le cadre des activités extra-domiciliaires.
ISSN: 1156-5233

hal-01158660
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660/file/Exposition%20domiciliaire%20aux%20moisissures%20postprint%20MYCMED-S-14-00173.pdf
DOI : 10.1016/j.mycmed.2015.03.005