Urban aerosols survey LIDAR and numerical model

In this paper, we present a new methodology for urban aerosol survey, coupling Lidar measurements and numerical models. The aim of this study is build a continuous survey of aerosol impact on the local and regional scale

Nature-based tourism elicits a phenotypic shift in the coping abilities of fish

Nature-based tourism is gaining extensive popularity, increasing the intensity and frequency of human-wildlife contacts. As a consequence, behavioral and physiological alterations were observed in most exposed animals. However, while the majority of these studies investigated the effects of punctual exposure to tourists, the consequences of constant exposition to humans in the wild remains overlooked. This is an important gap considering the exponential interest for recreational outdoor activities. To infer long-term effects of intensive tourism, we capitalized on Odontostilbe pequira, a short-lived sedentary Tetra fish who spends its life close to humans, on which it feeds on dead skin. Hence, those fish are constantly exposed to tourists throughout their lifecycle. Here we provide an integrated picture of the whole phenomenon by investigating, for the first time, the expression of genes involved in stress response and neurogenesis, as well as behavioral and hormonal responses of animals consistently exposed to tourists. Gene expression of the mineralocorticoid (and cortisol) receptor (mr) and the neurogenic differentiation factor (NeuroD) were significantly higher in fish sampled in the touristic zone compared to those sampled in the control zone. Additionally, after a simulated stress in artificial and controlled conditions, those fish previously exposed to visitors produced more cortisol and presented increased behavioral signs of stress compared to their non-exposed conspecifics. Overall, nature-based tourism appeared to shift selection pressures, favoring a sensitive phenotype that does not thrive under natural conditions. The ecological implications of this change in coping style remain, nevertheless, an open question

Intérêt de la médicalisation d'un rassemblement de foule (l'exemple du festival des Terre Neuvas à Bobital en 2007)

RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Atmospheric aerosol size retrieval from LIDAR data applying genetic algorithm approach

International audienceIn this paper we present a novel approach using a genetic algorithm (GA) to solve the LIDAR "ill-problem". It is inverting aerosol size distribution from multi-wavelengths Lidar data in the UV-VIS-IR spectral range. This method do not need any predefined size distribution shape and is also running with data having poor S/N. Numerical convergence test of the GA have been done on both simulated data and on Lidar field measurements performed during the French POVA Campaign. It shows that size distribution is retrieved in millisecond rage, which represent a considerably decreasing in computing time consuming. Comparison between GA size distribution retrieval and SMPS ground-based measurements has been done showing an excellent agreement

LIDAR applications for air quality monitoring : case of aerosol characterisation and industrial site survey of gaseous leaks

It has been demonstrated the feasibility of an ambient air on-line remote characterisation of nanoparticles atmospheric aerosol size distribution combining 4 wavelength LIDAR and a specific genetic algorithm. Results obtained on a demonstrator-based instrument had shown field measurement ability. Based on modification of a commercial instrument, it has also been demonstrated the feasibility of an automatic 3D survey of diffuse emissions in a large industrial site

Lidar remote sensing of laser-induced incandescence on light absorbing particles in the atmosphere

International audienceCarbon aerosol is now recognized as a major uncertainty on climate change and public health, and specific instruments are required to address the time and space evolution of this aerosol, which efficiently absorbs light. In this paper, we report an experiment, based on coupling lidar remote sensing with Laser-Induced-Incandescence (LII), which allows, in agreement with Planck's law, to retrieve the vertical profile of very low thermal radiation emitted by light-absorbing particles in an urban atmosphere over several hundred meters altitude. Accordingly, we set the LII-lidar formalism and equation and addressed the main features of LII-lidar in the atmosphere by numerically simulating the LII-lidar signal. We believe atmospheric LII-lidar to be a promising tool for radiative transfer, especially when combined with elastic backscattering lidar, as it may then allow a remote partitioning between strong/less light absorbing carbon aerosols

Caractérisation physico-chimique des particules atmosphériques

Si la pollution gazeuse est de mieux en mieux évaluée, les particules restent difficiles à quantifier de manière précise car les paramètres les caractérisant sont beaucoup plus complexes que dans le cas des polluants gazeux. En effet, l’évolution temporelle de la concentration massique s’avère être un indicateur très insuffisant en termes d’impact sanitaire et d’autres paramètres doivent être pris en compte : - les éventuels composés chimiques adsorbés à leur surface dont certains sont toxiques (mutagènes, cancérigènes…) ; - leur distribution de taille afin de quantifier les fractions inhalées ; - leur spatialisation et leur évolution dans la colonne atmosphérique compte tenu de l’impact des échanges verticaux sur l’exposition des populations. Dans cette optique, de nouvelles méthodologies de caractérisation physicochimique des particules atmosphériques ont été mises en place, puis validées lors de campagnes de mesures spécifiques

A Perovskite Oxide Interface Layer in a Perovskite Active Layer Solar Cell

International audienc