SPICES: Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems

SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450 - 900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/22, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5-10 AU) from nearby stars ($<$25 pc) with masses ranging from a few Jupiter masses to Super Earths ($\sim$2 Earth radii, $\sim$10 M$_{\oplus}$) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System

Analyse des performances d'apprentissage d'odeurs florales et pheromonales chez l'abeille

* Inra Poitou-Charentes, ERIST, Route de Saintes BP 6, 86600 Lusignan (FRA) Diffusion du document : Inra Poitou-Charentes, ERIST, Route de Saintes BP 6, 86600 Lusignan (FRA) Diplôme : Maîtris

Étude des macro-invertébrés des milieux aquatiques dans un territoire à vocation agricole en cours d’urbanisation

Le plateau de Saclay est actuellement en remaniement fort quant au mode d’occupation du sol depuis la mise en place du projet de cluster scientifique de rayonnement international. Dans ce contexte, ce projet a visé à mettre en place un protocole d’échantillonnage qui permettra de pouvoir caractériser les mares sur la base de l’étude de leur faune résidente, tout particulièrement les Arthropodes voyant tout ou partie de leur cycle de vie s’y dérouler. L’approche d’identification morphologique a été comparée à celle basée sur le séquençage d’une portion du gène mitochondrial CO1. La caractérisation des mares à partir des individus séparés via la méthode morphologique classique a été ensuite comparée à celle obtenue via du séquençage de masse par la méthode de metabarcoding. Les mares ont ensuite été comparées en intégrant le contexte paysager selon la nature de l’occupation du sol sur une zone tampon de 50 m. Il est alors apparu que l’identification des individus appartenant au Ordres des Coléoptères, des Diptères, des Hémiptères et des Odonates permet de caractériser les mares en minimisant la pression d’étude et de collecte. Le cycle de vie de la mare, représenté par son assèchement total ou partiel durant une période de l’année, est un des traits majeurs à prendre en compte. De plus, le contexte paysager joue un rôle majeur dans leur caractérisation, tout particulièrement la présence de massif boisé et d’espaces verts. Les données biotiques obtenues pourront dans le futur être analysées pour caractériser les réseaux trophiques. Les taxons rencontrés pourront de plus être mis en relation avec les contaminants de l’eau et des sédiments, qui ont été mesurés en parallèle des relevés des Invertébrés aquatiques lors des campagnes de 2016 et 2017

Compared sensitivities of VLT, JWST and ELT for direct exoplanet detection in nearby stellar moving groups

In the context of exoplanet detection, a large majority of the 400 detected exoplanets have been found by indirect methods. Today, progress in the field of high contrast and angular resolution imaging has allowed direct images of several exoplanetary systems to be taken (cf. HR 8799, Fomalhaut and β Pic).[SUP]1-4[/SUP] In the near future, several new instruments are going to dramatically improve our sensitivity to exoplanet detection. Among these, SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) at the VLT, MIRI (Mid Infra-Red Instrument) onboard JWST and EPICS at the ELT will be equipped with coronagraphs to reveal faint objects in the vicinity of nearby stars. We made use of the Lyon group (COND) evolutionary models of young (sub-)stellar objects and exoplanets to compare the sensitivities of these different instruments using their estimated coronagraphic profiles. From this comparison, we present a catalogue of targets which are particularly well suited for the different instruments

Apprentissage olfactif et discrimination chez l'abeille domestique

National audienc

Extra-solar planet imaging: ground vs space based coronagraphs

International audienc

Extra-solar planet imaging: ground vs space based coronagraphs

International audienc

Changes in odor background affect the locomotory response to pheromone in moths

Many animals rely on chemical cues to recognize and locate a resource, and they must extract the relevant information from a complex and changing odor environment. For example, in moths, finding a mate is mediated by a sex pheromone, which is detected in a rich environment of volatile plant compounds. Here, we investigated the effects of a volatile plant background on the walking response of male Spodoptera littoralis to the female pheromone. Males were stimulated by combining pheromone with one of three plant compounds, and their walking paths were recorded with a locomotion compensator and analyzed. We found that the addition of certain volatile plant compounds disturbed the orientation toward the sex pheromone. The effect on locomotion was correlated with the capacity of the plant compound to antagonize pheromone detection by olfactory receptor neurons, suggesting a masking effect of the background over the pheromone signal. Moths were more sensitive to changes in background compared to a constant background, suggesting that a background odor also acts as a distracting stimulus. Our experiments show that the effects of odorant background on insect responses to chemical signals are complex and cannot be explained by a single mechanism

An approach to evaluate which in vitro model and exposure method is more predictive for in vivo biological responses

The growing utilization of nanomaterials (NMs) in nanotechnology products lead to a potential increase of exposure, thus raising concerns about workers and public’s health risks. The major route of exposure is inhalation, but so far occupational and environmental atmosphere are not well characterized in terms of NMs. Despite the lack of epidemiological data on the relation between exposure to NMs and human health effects, their potential toxicity has been studied on cell cultures and animal models. Among these studies, most results are from in vitro experimentations due to the difficulty to perform in vivo studies for the enormous number of existing NMs and the necessity to reduce number of animals used in experimentations (3R rules). Nevertheless, results from animal experimentations remain the most reliable. Even if, pushed by the necessity to reduce the number of animals used in experimentation, new in vitro models and exposure methods are and have been developed, suggesting the more and more relevant alternatives to animal experimentation. Thus, many studies show that newly developed co-culture or 3D in vitro models have different nanotoxicity responses compared to classical mono-culture models. Moreover, studies using new devices allowing exposure of cells to aerosols of NMs show different nanotoxicity responses compared to exposure to suspensions of NMs. However, which of these models and exposure methods is more predictive for in vivo responses is yet to be defined. In order to better define which in vitro model and which exposure method is more predictive for in vivo pulmonary nanotoxicity data, three different methodologies will be implemented

Lin could act as secondary cue to maintain the orientation after loss of odor.

<p>On the left: time plots of the evolution of speed during two-phase experiments (median in black; first and third quartiles in grey). The horizontal bars show PV (grey) and pheromone (white) presentations. The vertical grey dashed lines delimit the 10-s time windows before and after the loss of Phero in a neutral background (<i>N</i> = 24), the loss of Phero in a Lin background (<i>N</i> = 26) or the loss of Lin during Phero presentation (<i>N</i> = 24), and chosen to calculate and compare the median speeds, straightness (str) and orientation index (oi) presented in the corresponding box plots (Right). Box plot legends as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052897#pone-0052897-g003" target="_blank">Figure 3</a>.</p