Prospects for near-infrared characterisation of hot Jupiters with VSI

In this paper, we study the feasibility of obtaining near-infrared spectra of bright extrasolar planets with the 2nd generation VLTI Spectro-Imager instrument (VSI), which has the required angular resolution to resolve nearby hot Extrasolar Giant Planets (EGPs) from their host stars. Taking into account fundamental noises, we simulate closure phase measurements of several extrasolar systems using four 8-m telescopes at the VLT and a low spectral resolution (R = 100). Synthetic planetary spectra from T. Barman are used as an input. Standard chi2-fitting methods are then used to reconstruct planetary spectra from the simulated data. These simulations show that low-resolution spectra in the H and K bands can be retrieved with a good fidelity for half a dozen targets in a reasonable observing time (about 10 hours, spread over a few nights). Such observations would strongly constrain the planetary temperature and albedo, the energy redistribution mechanisms, as well as the chemical composition of their atmospheres. Systematic errors, not included in our simulations, could be a serious limitation to these performance estimations. The use of integrated optics is however expected to provide the required instrumental stability (around 10^-4 on the closure phase) to enable the first thorough characterisation of extrasolar planetary emission spectra in the near-infrared.Comment: 10 pages, 8 figures, Proc. SPIE conference 7013 "Optical and Infrared Interferometry" (Marseille 2008

Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada

Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for four large Sierra Nevada (CA) basins, at inflow points to major reservoirs. Streamflow timing is measured by “center timing” (CT), the day when half the annual flow has passed a given point. We use a physically based hydrology model driven by meteorological input from a global climate model to quantify the natural variability in CT trends. Estimated 50-year trends in CT due to natural climate variability often exceed estimated actual CT trends from 1950 to 1999. Thus, although observed trends in CT to date may be statistically significant, they cannot yet be statistically attributed to external influences on climate. We estimate that projected CT changes at the four major reservoir inflows will, with 90% confidence, exceed those from natural variability within 1–4 decades or 4–8 decades, depending on rates of future greenhouse gas emissions. To identify areas most likely to exhibit CT changes in response to rising temperatures, we calculate changes in CT under temperature increases from 1 to 5°. We find that areas with average winter temperatures between −2°C and −4°C are most likely to respond with significant CT shifts. Correspondingly, elevations from 2000 to 2800 m are most sensitive to temperature increases, with CT changes exceeding 45 days (earlier) relative to 1961–1990

La demande sociale et la sylviculture méditerranéenne

Voyage entre l'imaginaire et l'utilitaire

Présentation des écosystèmes : garrigues, landes et maquis

Texte didactique décrivant les contraintes du climat méditerranéen, les relations biotopes/types de végétation, et les contraintes édaphiques en relation avec les grandes associations de sols en région méditerranéenne

La végétalisation des berges du Rhône canalisé et de ses abords

La végétalisation des berges du Rhône canalisé est délicate mais bénéficie de l'expérience acquise pour les talus routiers. L'article rend compte de la conception et de la réalisation d'un projet précis. Reste posée la question de l'entretien des plantations

Méthodologie d'étude pour une typologie des paysages.

International audienc

Quelques définitions dans le langage courant

International audienc

Factors impacting work success in Veterans with mental health disorders: A Veteran-focused mixed methods pilot study

BACKGROUND: Veterans with mental illness often have poor employment outcomes. OBJECTIVE: This mixed-methods study sought to understand and describe Veteran perspectives of factors that impact their work success. METHODS: A sample of 40 employed and unemployed Veterans with post-traumatic stress disorder (PTSD) or other severe mental illness (SMI) completed a survey of factors that impact vocational functioning and provided narrative accounts of their most successful and challenging work experiences. RESULTS: Personal motivation, self-efficacy, work skills, interpersonal issues, health, and cognitive problems were rated as most impactful on work. There were no significant differences on ratings of work factors based on employment status. Veterans with PTSD reported significantly more barriers to work success compared with Veterans with SMI, notably, cognitive problems, physical health, and psychological stress. Veterans with SMI were more likely to receive VA vocational services and rated this assistance as beneficial to work success. Narrative findings corroborated the survey results, and yielded additional factors, including economic factors, person/job fit, and Veteran-specific issues. CONCLUSIONS: Several factors substantially impact work success in Veterans with mental illness. Veterans with PTSD and SMI experience a distinct set of barriers and facilitators, suggesting the need for tailoring clinical and rehabilitative services

Montagnes et collines à faibles potentialités ligneuses : diagnostic écologique

Synthèse des contributions volontaires présentées sur le thème "diagnostic écologique" du groupe "Montagnes et collines à faibles potentialités ligneuses" de Foresterranée 90 "Espaces naturels : de la friche à la forêt méditerranéenne"