La mondialisation, facteur d’homogénéité ou d’hétérogénéité dans le rapport tourisme et nature ? (France/Chine)

National audienc

La mondialisation, facteur d’homogénéisation ou de régionalisation du rapport nature-tourisme ? Un regard croisé sur les civilisations occidentales et chinoises

International audienceThe contemporary world is marked by the access to tourism in emerging countries, especially in China. This mutation raises the question of the modalities of the appropriation of tourism. In attempt to answer this question, we will focus on the nature component, which has played an important role in the genesis and development of tourism in the West and also has influenced the Chinese history (first landscape civilization from the Fifth century). Do we observe a transfer of practices and representations, betraying a gap in time (prevalence of temporality) ; a highlighting of specific national cultural (predominance of spatiality) ; or a syncretism inclined to create new models, the result of interbreeding ? The study will focus on French and Chinese domestic tourism, using surveys and historical and contemporary iconographic documents (photographs, paintings, postcards).Le monde contemporain est marqué par l'accès au tourisme des sociétés des pays émergents, et notamment la Chine. Cette mutation pose la question des modalités de l'appropriation du tourisme. Pour tenter d'y répondre, nous nous intéresserons à la composante nature, qui a joué un rôle important dans la genèse et le développement du tourisme en Occident et a aussi influencé l'histoire de la Chine (première civilisation paysagère dans le monde, dès le ve siècle). Observe-t-on un transfert de pratiques et de représentations, trahissant un décalage dans le temps (prédominance de la temporalité) ; une mise en exergue des spécificités culturelles nationales (prédominance de la spatialité) ; ou encore un syncrétisme enclin à créer de nouveaux modèles, fruit d'un métissage ? L'étude portera sur les tourismes intérieurs chinois et français, en exploitant des enquêtes et documents iconographiques historiques et contemporains (photos, tableaux, cartes postales)

Processus de patrimonialisation de la nature et dynamiques touristiques : un phénomène de co-constitution mondial ? Comparaison entre la France et la Chine

International audienc

Cathodoluminescence-based nanoscopic thermometry in a lanthanide-doped phosphor

Crucial to analyze phenomena as varied as plasmonic hot spots and the spread of cancer in living tissue, nanoscale thermometry is challenging: probes are usually larger than the sample under study, and contact techniques may alter the sample temperature itself. Many photostable nanomaterials whose luminescence is temperature-dependent, such as lanthanide-doped phosphors, have been shown to be good non-contact thermometric sensors when optically excited. Using such nanomaterials, in this work we accomplished the key milestone of enabling far-field thermometry with a spatial resolution that is not diffraction-limited at readout. We explore thermal effects on the cathodoluminescence of lanthanide-doped NaYF$_4$ nanoparticles. Whereas cathodoluminescence from such lanthanide-doped nanomaterials has been previously observed, here we use quantitative features of such emission for the first time towards an application beyond localization. We demonstrate a thermometry scheme that is based on cathodoluminescence lifetime changes as a function of temperature that achieves $\sim$ 30 mK sensitivity in sub-$\mu$m nanoparticle patches. The scheme is robust against spurious effects related to electron beam radiation damage and optical alignment fluctuations. We foresee the potential of single nanoparticles, of sheets of nanoparticles, and also of thin films of lanthanide-doped NaYF$_4$ to yield temperature information via cathodoluminescence changes when in the vicinity of a sample of interest; the phosphor may even protect the sample from direct contact to damaging electron beam radiation. Cathodoluminescence-based thermometry is thus a valuable novel tool towards temperature monitoring at the nanoscale, with broad applications including heat dissipation in miniaturized electronics and biological diagnostics.Comment: Main text: 30 pages + 4 figures; supplementary information: 22 pages + 8 figure

Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection

Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at separations between 1 and 100 mas remain mostly unknown due to intrinsic observational limitations. [...] The Southern MAssive Stars at High angular resolution survey (SMASH+) was designed to fill this gap by providing the first systematic interferometric survey of Galactic massive stars. We observed 117 O-type stars with VLTI/PIONIER and 162 O-type stars with NACO/SAM, respectively probing the separation ranges 1-45 and 30-250mas and brightness contrasts of Delta H < 4 and Delta H < 5. Taking advantage of NACO's field-of-view, we further uniformly searched for visual companions in an 8''-radius down to Delta H = 8. This paper describes the observations and data analysis, reports the discovery of almost 200 new companions in the separation range from 1mas to 8'' and presents the catalog of detections, including the first resolved measurements of over a dozen known long-period spectroscopic binaries. Excluding known runaway stars for which no companions are detected, 96 objects in our main sample (DEC < 0 deg; H<7.5) were observed both with PIONIER and NACO/SAM. The fraction of these stars with at least one resolved companion within 200mas is 0.53. Accounting for known but unresolved spectroscopic or eclipsing companions, the multiplicity fraction at separation < 8'' increases to f_m = 0.91 +/- 0.03. The fraction of luminosity class V stars that have a bound companion reaches 100% at 30mas while their average number of physically connected companions within 8'' is f_c = 2.2 +/- 0.3. This demonstrates that massive stars form nearly exclusively in multiple systems. Additionally, the nine non-thermal (NT) radio emitters observed by SMASH+ are all resolved [...]Comment: 57 pages, 20 figures, 7 tables; accepted for publication in ApJ

Patrimonialisation de la nature et dynamiques touristiques : spécificités et singularités d’un « modèle » chinois contemporain

Des analyses conduites depuis plusieurs années sur les relations existantes entre la patrimonialisation de la nature et l’essor du tourisme en Occident nous ont menés à constater une co-constitution, comparable à ce qui fut observé dans le cadre de la mise en patrimoine des objets culturels. Ce phénomène s’explique par l’apport du regard extérieur, non utilitaire, de spectateur qui émerge avec la naissance d’un nouveau type de déplacement : le voyage d’agrément. Afin de savoir si ce lien fondamental qui a contribué à définir le patrimoine naturel en Occident et plus particulièrement en France émane d’un processus universel favorisé par la mondialisation en cours, il convient de le comparer à ce qui se produit dans des pays accédant nouvellement au tourisme. La Chine, qui nourrit une relation particulière à la nature pour être la plus ancienne civilisation paysagère du monde et qui développe aujourd’hui massivement des pratiques touristiques domestiques, ouvre le champ de cette investigation. Cette analyse comparative nous permettra d’observer que la corrélation entre tourisme et patrimonialisation de la nature est bien présente en Chine, comme elle l’est en France, mais elle n’en efface pas les spécificités locales. Elle relève d’un phénomène de co-constitution qui se profile entre universalisme et singularités culturelles, économiques et sociales

Tryptophan metabolism and bacterial commensals prevent fungal dysbiosis in Arabidopsis roots

In nature, roots of healthy plants are colonized by multikingdom microbial communities that include bacteria, fungi, and oomycetes. A key question is how plants control the assembly of these diverse microbes in roots to maintain host–microbe homeostasis and health. Using microbiota reconstitution experiments with a set of immunocompromised Arabidopsis thaliana mutants and a multikingdom synthetic microbial community (SynCom) representative of the natural A. thaliana root microbiota, we observed that microbiota-mediated plant growth promotion was abolished in most of the tested immunocompromised mutants. Notably, more than 40% of between-genotype variation in these microbiota-induced growth differences was explained by fungal but not bacterial or oomycete load in roots. Extensive fungal overgrowth in roots and altered plant growth was evident at both vegetative and reproductive stages for a mutant impaired in the production of tryptophan-derived, specialized metabolites (cyp79b2/b3). Microbiota manipulation experiments with single- and multikingdom microbial SynComs further demonstrated that 1) the presence of fungi in the multikingdom SynCom was the direct cause of the dysbiotic phenotype in the cyp79b2/b3 mutant and 2) bacterial commensals and host tryptophan metabolism are both necessary to control fungal load, thereby promoting A. thaliana growth and survival. Our results indicate that protective activities of bacterial root commensals are as critical as the host tryptophan metabolic pathway in preventing fungal dysbiosis in the A. thaliana root endosphere

Receptor for advanced glycation endproducts (RAGE) deficiency protects against MPTP toxicity

Copyright © 2011 Elsevier Inc. All rights reserved.Peer reviewedPublisher PD