Impact de pulvérisations de deltaméthrine dans un foyer de leishmaniose de Bolivie

Une unique pulvérisation domiciliaire de K-Othrine à 0,025 g/m2, en début de saison humide, contrôle efficacement les populations domestiques et péridomestiques de #Lutzomyia longipalpis, le vecteur de la leishmaniose viscérale, dans un village submontagnard de la province Nord-Yungas, Bolivie. Ce phlébotome est éliminé des habitations et des poulaillers durant, respectivement, 9 et 10 mois. Par contre, l'impact des traitements sur #Lu. nuneztovari anglesi, le vecteur présumé de la leishmaniose tégumentaire, est beaucoup moins marqué. Il se traduit, plus par une baisse de 50 % du taux de gorgement des populations capturées dans les maisons, que par une diminution de leur densité, difficile à apprécier du fait des variations saisonnières naturelles, et de l'absence de témoin représentatif. Ce résultat n'est pas inattendu, étant donné la forte exophilie de #Lu. n. anglesi$ dans la région. (Résumé d'auteur

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Rotational Raman Lidar to measure the Atmospheric Temperature in the upper troposphere and lower stratosphere

International audienceMeasurement of the vertical temperature profile within the UTLS presents a major challenge in geophysics to study microphysical phenomena and dynamic processes in particular to detect gravity waves between 2 km and 30 km of altitude. Theoretically, a Lidar method using the anti-Stokes rotational lines of N2 and 02 Raman spectrum should enable the validity range for the temperature profile to be extended to below 30 km by eliminating the particle contribution. In practice, this method uses the variation with the temperature of the envelop of the intensities of the backscattered rotational Raman spectrum, or more precisely the variations of the ratio of the intensities at two lines close-by wavelengths. For each temperature of the gas, the ratio of the fluxes through two narrow and close-by filters takes a definite value directly related to the temperature. The difficulty of eliminating the near-by contribution of the Mie backscattering was solved by adding a Notch filter to produce a rejection factor of 108 at the central wavelength. The theoretical calculation of the method led to an analytic calibration function which, once adjusted, can provide the temperature profile in the upper troposphere and lower stratosphere. We will also consider the technical evolutions of this optical device with a Fabry-Perot interferometer, a diffraction grating and a new detector

High spectral resolution lidar using spherical Fabry-Perot to measure aerosol and atmospheric molecular density

In theory, the HSRL method should expand the validity range of the atmospheric molecular density and temperature profiles of the Rayleigh LIDAR in the UTLS below 30 km, with an accuracy of 1 K, while suppressing the particle contribution. We tested a Spherical Fabry-Perot which achieves these performances while keeping a big flexibility in optical alignment. However, this device has some limitations (thermal drift and a possible partial depolarisation of the backscattered signal)

High Spectral Resolution Lidar using Spherical Fabry-Perot to measure Aerosol and Atmospheric Molecular Density in the upper troposphere and lower stratosphere

International audienceMeasurement of the vertical temperature profile within the UTLS presents a major challenge in geophysics to study microphysical phenomena and dynamic processes in particular to detect gravity waves between 2 km and 30 km of altitude. Theoretically, the use of an HSRL method should enable the validity range for the molecular density and temperature profiles from Rayleigh LIDAR to be extended to below 30 km by eliminating the particle contribution. In practice, a spectral separation of a few picometres requires a special filtering system. In the context of this work, we tested the use of a Spherical Fabry-Perot which achieves these performances while maintaining a high level of flexibility in terms of optical alignment. However, the first tests have shown that this filtering device has some technical limitations (thermal drift and possibly partial depolarization of the backscattered signal)

Ground-based Rayleigh-Mie Doppler wind lidar: design, observations and proposal for ADM-Aeolus cal/val

International audienceA unique Rayleigh-Mie Doppler wind lidar, measuring Doppler shift between the emitted and backscattered light by means of a Fabry-Perot interferometer is deployed at Observatory of Haute-Provence (Southern France) and at Reunion island (tropical Indian Ocean). The technique was shown capable of wind measurements between 5 and 50 km with accuracy better than 1 m/s up to 30 km. The system consists of a monomode Nd:Yag laser operating at 532 nm, three telescopes and a double-edge Fabry-Perot interferometer. The laser light is sent alternatively in the vertical as well as zonal and meridional directions at 45 • from the zenith using a rotating mirror. The two components of the horizontal wind are obtained from the measurement of the Doppler shift of the return signal spectrally filtered by a double-edge Fabry-Pérot etalon. The vertical pointing is used to obtain zero Doppler shift. After demonstration of the method in 1989 at Observatory of Haute-Provence the measurements were used for studying mesoscale wind fluctuations and intertia-gravity waves in the mid-stratosphere as well as for constructing wind climatology up to 50 km altitude. A new system, featuring a more compact design was installed at Maïdo observatory at Reunion island (22 • S). The design of the instrument, the results of observations and comparisons against GPS radiosondes are presented. The European Space Agency (ESA) Atmospheric Dynamic Mission (ADM-Aeolus) aimed at providing global observations of wind in the lower and middle atmosphere using 355 nm Doppler lidar ALADIN is expected to be launched in late-2015. A similarity of the measurements techniques exploited by ALADIN system and by the French ground-based Doppler lidar makes the latter an attractive mean for Aeolus validation. We present a proposal for ADM-Aeolus cal/val activities based on the operations of two wind lidars operating at mid-latitude and tropical sites. These activities include a pre-cal/val phase aimed at development of a spatial-temporal collocation criteria for gound-based/satellite measurement match. An advantage of the Doppler lidar with respect to conventional GPS radiosondes is that the lidar provides continuous high-resolution wind measurements that can be used to determine temporal collocation criteria for validation of ADM-Aeolus. The spatial collocation criteria will be defined using a dense radiosonde network in Europe

High spectral resolution lidar using spherical Fabry-Perot to measure aerosol and atmospheric molecular density

The 28th International Laser Radar Conference (ILRC 28)International audienceIn theory, the HSRL method should expand the domain of validity of the atmospheric molecular density and temperature profiles of the Rayleigh LIDAR. This, in the UTLS under 30 km with the accuracy of 1 K, while suppressing the particulate contribution. We tested a Spherical Fabry-Perot which achieves these performances while keeping a big flexibility in optical alignment. Performances and limitations of this device will be shown

Lidar vent UV avec une architecture robuste comprenant un interféromètre Quadri Mach-Zehnder pour la calibration/validation et la future génération d'Aeolus

International audienceWind speed measurement with on-board system has many applications in aeronautics (Gust Load alleviation, Haps, etc.) and space (Weather forecast). The molecular wind lidar is developed for those purposes as it sent laser pulses into the atmosphere to determine, with a spectral analyzer, the wind speed from the Doppler shift induced by the molecules of the atmosphere. In this paper we present the lidar architecture developed at ONERA, that uses a Quadri Mach-Zehnder (QMZ) as a spectral analyzer and a UV fiber laser, designed for gust load alleviation application. We discuss about the advantages of such architecture for wind measurement from space. Simulations of the performances have been performed in the case of Calibration/Validation (Cal/Val) of Aeolus, showing standard deviation on wind speed measurement less than 2 m/s up to 17 km of altitude for the optimized hybrid fiber laser of 10 W laser average power and a pulse repetition frequency (PRF) of 5 kHz. Simulations that evaluates the performances for Aeolus measurement with minor changes in the lidar architecture have been computed, with results showing that requirements are fulfilled up to 22.5 km of altitude with the optimized hybrid fiber laser of 10 W and 3 kHz PRF.La mesure de la vitesse du vent avec système embarqué a de nombreuses applications en aéronautique (atténuation des charges de rafales, Haps, etc.) et spatial (Prévisions météorologiques). Le lidar vent moléculaire est développé dans ce but car il envoie des impulsions laser dans l'atmosphère pour déterminer, avec un analyseur spectral, la vitesse du vent à partir du décalage Doppler induite par les molécules de l’atmosphère. Dans cet article nous présentons l'architecture lidar développée à l'ONERA, qui utilise un Quadri Mach-Zehnder (QMZ) comme analyseur spectral et un laser à fibre UV, conçu pour l'allègement des charges de rafales. Nous discutons des avantages d’une telle architecture pour la mesure du vent depuis l’espace. Des simulations des performances ont été réalisées dans le cas de Calibration/Validation (Cal/Val) d'Aeolus, montrant un écart type sur la mesure de la vitesse du vent inférieur à 2 m/s jusqu'à 17 km d'altitude pour l'optimisation laser à fibre hybride d'une puissance moyenne laser de 10 W et d'une fréquence de répétition d'impulsions de 5 kHz. Des simulations qui évaluent les performances de la mesure d'Aeolus avec des changements mineurs dans l'architecture lidar ont été réalisées, avec des résultats montrant que les exigences sont remplies jusqu'à 22,5 km d'altitude avec le laser à fibre hybride de 10 W et 3 kHz PRF

UV spectroscopy of artificial meteors (200–400 nm)

International audienceThe high energy of meteoroid entering the Earth atmosphere presumably results in UV radiation. However, ground-based observations are impaired by the atmospheric absorption below 400 nm. Artificial meteors are produced in a high enthalpy wind tunnel, and observed with a [200–400] nm fiber-fed spectrometer in order to analyse for the first time the UV emission of meteors. Similarly to visible observations, several atomic lines of Fe and Mg are detected. Contrary to observations in the visible wavelength range, Si is also clearly detected in all tested samples. Carbon is not detected in atomic lines. As the strongest emission lines are detected between 220 and 330 nm, we recommend that future meteor dedicated space-based UV instruments focus on this particular wavelength interval

Detection of spectral UV from meteors by a nanosatellite

International audienceHere, we present a cubesat space mission concept devoted to the UV detection of meteors from space. Space observations have the advantages of being able to continuously observe meteors independently of weather conditions on large portions of the atmosphere and, specifically, to perform ultra-violet light measurement as it is above the ozone layer. The UV spectrum is interesting for the detection of chemicals such as iron, carbon and hydroxide that can yield a signature of elements present during the solar system's formation