L'émergence du développement durable au regard des mutations de l'histoire urbaine

National audienceAlors que la ville classique devait être belle en respectant les conventions de bienséance et que la ville moderne devait être radieuse en ordonnant ses besoins, la ville contemporaine doit être durable en assurant son lien avec la nature. depuis l'époque industrielle, l'entassement des habitants et l'engorgement des voies appellent des réformes rationnelles qui rendent la ville plus fluide, plus saine et plus naturelle. Les motifs et les projets du développement durable s'inscrivent aujourd'hui dans la continuité de ces discours

Etude bibliographique des zoonoses en Italie

Cette étude des zoonoses en Italie s'inscrit dans le cadre de la création d'une banque de données informatiques présentant la situation sanitaire des différents pays du monde. L'auteur contribue à réactualiser les risques sanitaires encourus en Italie, selon une présentation synthétique. Le recensement de chacune des zoonoses bactériennes, virales et parasitaires, est mené en développant, à partir des données disponibles à ce jour, leur étude épidémiologique, leurs aspects socio-économiques et les mesures de prophylaxie et de lutte appliquées ou conseillées par les services vétérinaires italiens. Parmi l'ensemble des zoonoses étudiées, certaines se détachent par leur caractère de gravité et/ ou leur fréquence et constituent les affections contre lesquelles les autorités sanitaires concentrent leurs efforts; il s'agit plus particulièrement de la brucellose, la tuberculose, des rickettsioses (fièvre boutonneuse et fièvre Q), la leishmaniose et l'hydatidose. Outre leurs aspects épidémiologiques, cette thèse fait l'état des lieux des différents programmes de lutte et de prévention engagés et permet ainsi la mise en évidence des risques encourus par l'homme vis-à-vis de l'animal et de ses produits, sans oublier l'importance du rôle joué par les autorités sanitaires dans leur prévention

Une ethnographie sensible des places Schuman (Grenoble) et des Terreaux (Lyon) : les facteurs lumineux des ambiances publiques nocturnes

Programme de recherche ACI "ville"/ Ministère de l'Enseignement Supérieur et de la Recherche subvention n°45 du 15 mars 2000 .Les nouvelles formes d'éclairage urbain impulsées par les concepteurs lumières invitent à étudier les usages nocturnes de l'espace public au-delà des thématiques sécuritaires ou esthétiques. En quoi les dispositifs qu'ils mettent en oeuvre affectent-ils le caractère public d'un lieu ? Comment usages de l'espace-au sens de conduites en public-, qualités spatiales et effets lumineux interagissent-ils dans la construction d'ambiances nocturnes ? S'appuyant sur les travaux de la microsociologie urbaine consacrés aux espaces publics et sur la notion d'ambiance, cette ethnographie sensible porte sur 2 places à l'architecture et aux fonctions urbaines différentes mais dont la mise en lumière répond à un double principe commun : éclairage indirect et constellation ou trame lumineuse au sol. LE RENOUVEAU DES PRATIQUES D’ECLAIRAGE URBAIN EN QUESTION(S) Eclairage et usages de l’espace urbain : état des lieux Parti-pris de recherche : publicité et ambiances La publicité des espaces, une qualité construite L’efficace sensori-moteur de l’environnement sensible La notion d’ambiance : interactions entre environnement sensible et pratiques sociales METHODE : UNE ETHNOGRAPHIE SENSIBLE DES ESPACES PUBLICS NOCTURNES Caractérisation architecturale et paysagère Caractérisation lumière Caracterisation des conduites publiques PLACE DES TERREAUX Un lieu historique, un espace public central Environnement sensible et conduites PLACE SCHUMAN 1. Un lieu de passage dans le nouveau quartier d’affaires de grenoble 2. Environnement sensible et conduite

The Planetary Mass Companion 2MASS1207-3932 B: Temperature, Mass and Evidence for an Edge-On Disk

We present J-band imaging and H+K-band low-resolution spectroscopy of 2MASS1207-3932 AB, obtained with VLT NACO. For the putative planetary mass secondary, we find J = 20.0+/-0.2 mag. The HK spectra of both components imply low gravity, and a dusty atmosphere for the secondary. Comparisons to synthetic spectra yield Teff_A ~ 2550+/-150K, and Teff_B ~ 1600+/-100K, consistent with their late-M and mid-to-late L types. For these Teff, and an age of 5-10 Myrs, evolutionary models imply M_A ~ 24+/-6 M_Jup and M_B ~ 8+/-2 M_Jup. Independent comparisons of these models to the observed colors, spanning ~I to L', also yield the same masses and temperatures. Our primary mass agrees with other recent analyses; however, our secondary mass, while still in the planetary regime, is 2-3 times larger than claimed previously. This discrepancy can be traced to the luminosities: while the absolute photometry and Mbol of the primary agree with theoretical predictions, the secondary is ~ 2.5+/-0.5 mag fainter than expected in all bands from I to L' and in Mbol. This accounts for the much lower secondary mass (and temperature) derived earlier. We argue that this effect is highly unlikely to result from a variety of model-related problems, and is instead real. This conclusion is bolstered by the absence of any luminosity problems in either the primary, or in AB Pic B which we also analyse. We therefore suggest grey extinction in 2M1207B, due to occlusion by an edge-on circum-secondary disk. This is consistent with the observed properties of edge-on disks around T Tauri stars, and with the known presence of a high-inclination evolved disk around the primary. Finally, the system's implied mass ratio of ~0.3 suggests a binary-like formation scenario. (abridged)Comment: Accepted by The Astrophysical Journal, 43 pages text + 16 figs + 1 tabl

Controverses autour de l’axe héliothermique : l’apport de la simulation physique à l’analyse des théories urbaines

Les techniques contemporaines de modélisation et de simulation appliquées à l'architecture sont souvent mises en avant pour la restitution visuelle des environnements bâtis disparus au moyen d'images de synthèse photo réalistes. Ces techniques informatiques offrent bien d'autres possibilités pour l'analyse historique. En particulier, les outils de simulation physique développés pour l'étude des projets contemporains d'architecture et d'aménagement urbain, peuvent s'appliquer très à propos pou..

Characterizing CO Fourth Positive Emission in Young Circumstellar Disks

Carbon Monoxide is a commonly used IR/sub-mm tracer of gas in protoplanetary disks. We present an analysis of ultraviolet CO emission in {HST}-COS spectra for 12 Classical T Tauri stars. Several ro-vibrational bands of the CO A^1\Pi - X^1\Sigma^+ (Fourth Positive) electronic transition system are spectrally resolved from emission of other atoms and H_2. The CO A^1\Pi v'=14 state is populated by absorption of Ly\alpha photons, created at the accretion column on the stellar surface. For targets with strong CO emission, we model the Ly\alpha radiation field as an input for a simple fluorescence model to estimate CO rotational excitation temperatures and column densities. Typical column densities range from N_{CO} = 10^{18} - 10^{19} cm^{-2}. Our measured excitation temperatures are mostly below T_{CO} = 600 K, cooler than typical M-band CO emission. These temperatures and the emission line widths imply that the UV emission originates in a different population of CO than that which is IR-emitting. We also find a significant correlation between CO emission and the disk accretion rate M_{acc} and age. Our analysis shows that ultraviolet CO emission can be a useful diagnostic of CTTS disk gas

Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks

The large relative sizes of circumstellar and circumplanetary disks imply that they might be seen in eclipse in stellar light curves. We estimate that a survey of ~10^4 young (~10 Myr old) post-accretion pre-MS stars monitored for ~10 years should yield at least a few deep eclipses from circumplanetary disks and disks surrounding low mass companion stars. We present photometric and spectroscopic data for a pre-MS K5 star (1SWASP J140747.93-394542.6), a newly discovered ~0.9 Msun member of the ~16 Myr-old Upper Cen-Lup subgroup of Sco-Cen at a kinematic distance of 128 pc. SuperWASP and ASAS light curves for this star show a remarkably long, deep, and complex eclipse event centered on 29 April 2007. At least 5 multi-day dimming events of >0.5 mag are identified, with a >3.3 mag deep eclipse bracketed by two pairs of ~1 mag eclipses symmetrically occurring +-12 days and +-26 days before and after. Hence, significant dimming of the star was taking place on and off over at least a ~54 day period in 2007, and a strong >1 mag dimming event occurred over a ~12 day span. We place a firm lower limit on the period of 850 days (i.e. the orbital radius of the eclipser must be >1.7 AU and orbital velocity must be <22 km/s). The shape of the light curve is similar to the lop-sided eclipses of the Be star EE Cep. We suspect that this new star is being eclipsed by a low-mass object orbited by a dense inner disk, girded by at least 3 dusty rings of lower optical depth. Between these rings are at least two annuli of near-zero optical depth (i.e. gaps), possibly cleared out by planets or moons, depending on the nature of the secondary. For possible periods in the range 2.33-200 yr, the estimated total ring mass is ~8-0.4 Mmoon (if the rings have optical opacity similar to Saturn's rings), and the edge of the outermost detected ring has orbital radius ~0.4-0.09 AU.Comment: Astronomical Journal, in press, 13 figure

Accretion and outflow-related X-rays in T Tauri stars

We report on accretion- and outflow-related X-rays from T Tauri stars, based on results from the "XMM-Newton Extended Survey of the Taurus Molecular Cloud.” X-rays potentially form in shocks of accretion streams near the stellar surface, although we hypothesize that direct interactions between the streams and magnetic coronae may occur as well. We report on the discovery of a "soft excess” in accreting T Tauri stars supporting these scenarios. We further discuss a new type of X-ray source in jet-driving T Tauri stars. It shows a strongly absorbed coronal component and a very soft, weakly absorbed component probably related to shocks in microjets. The excessive coronal absorption points to dust-depletion in the accretion stream

Fluxes and gas transfer rates of the biogenic trace gas DMS derived from atmospheric gradients

Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 109 (2004): C08S10, doi:10.1029/2003JC001795.Gas transfer rates were determined from vertical profile measurements of atmospheric dimethylsulfide (DMS) gradients over the equatorial Pacific Ocean obtained during the GasEx-2001 cruise. A quadratic relationship between gas transfer velocity and wind speed was derived from the DMS flux measurements; this relationship was in close agreement with a parameterization derived from relaxed eddy accumulation measurements of DMS over the northeastern Pacific Ocean. However, the GasEx-2001 relationship results in gas transfer rates that are a factor 2 higher than gas transfer rates calculated from a parameterization that is based on coincident eddy correlation measurements of CO2 flux. The measurement precision of both the profiling and eddy correlation techniques applied during GasEx-2001 is comparable; the two gas transfer data sets are in agreement within their uncertainty. Differences in the number of samples and the wind speed range over which CO2 and DMS fluxes were measured are likely causes for the observed discrepancy.Funding for this work came from the Netherlands Organization for Scientific Research (NWO) and from the NOP project 951203: ‘‘Micrometeorology of air/sea fluxes of carbon dioxide. This work was supported by the Global Carbon Cycle project of the NOAA Office of Global Programs grant NA17RJ1223, National Science Foundation grant OCE-9986724, and NSF grant ATM-0120569

AMBER : a near infrared focal instrument for the VLTI

10 pagesInternational audienceAMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels