Search results for "light"
showing 10 items of 3575 documents
Pulvérisation ciblée sur les tâches d’adventices détectées par drône en colza
2019
L’idée de cartographier les zones infestées par les adventices pour restreindre la surface traitée, et donc les quantités d’herbicides utilisées, méritait d’être testée. Depuis l’acquisition des données par drone, en passant par le traitement des images, jusqu’à l’exploitation de la carte par le pulvérisateur au champ. C’est pourquoi, Terres Inovia a décidé de collaborer avec AIRINOV pour conduire un essai sur colza en vue de la pulvérisation ciblée sur les tâches d’adventices détectées préalablement par drone. Cette étude exploratoire avait pour objectif de vérifier l’intérêt, la faisabilité, la pertinence et l’efficacité d’une telle technique. Elle s’inscrit dans le projet européen H2020 …
Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector
2010
The ANTARES high energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the atmospheric muon flux and the associated depth-intensity relation are measured and compared with previous measurements and Monte Carlo expectations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is presented.
A numerical study of tropical cross-tropopause transport by convective overshoots
2007
Abstract. Observations obtained during the Tropical Convection, Cirrus and Nitrogen Oxides (TROCCINOX) golden day have revealed the presence of ice particles up to 410 K (18.2 km) 2 km above the local tropopause. The case was investigated using a three-dimensional quadruply nested non-hydrostatic simulation and Meteosat Second Generation (MSG) observations. The simulation reproduced the measurements along the flight track fairly well. A reasonable agreement with MSG observations was also achieved: the 10.8-μm brightness temperature (BT) minimum of 187 K was reproduced (a value 6 K colder than the environmental cold-point temperature) as was the positive BT difference between the 6.2- and 10…
Weed seeds ability to emerge on the soil surface
2015
International audience; Annual weeds have to produce seeds each year to maintain their populations. These seeds fallon the soil surface. Seeds exposed to light during their moistening (i.e. caused by rain) bettergerminate than seeds in the darkness (i.e. buried). However, rare studies quantified the unique andcombined effects of light, moisture and burial depth on the germination process. We investigated,in a greenhouse experiment in 2014, the impact of seed moisture (Moistened vs. Dried), lightduring moistening (Darkness vs. Light) and burial depth (Buried vs. Surface) on germination of 12annual weed species contrasted on their seed traits and germination periods (Alopecurusmyosuroides Hud…
Ecological role of mycotoxins produced by Fusarium graminearum : consequences of the presence of deoxynivalenol (DON) in crop residues on the soil mi…
2012
Fusarium graminearum is a plant pathogenic fungus, causing devastating disease “Fusarium head blight” (FHB) in cereals including wheat and maize. It also contaminates the grains with mycotoxins including deoxynivalenol (DON) which are toxic to human and animals. This disease has resulted in the serious losses in grain yield and quality. We established through a first bibliographic review that during off season fungus survives saprophytically on the crop residues (ecological habitat) and serves as primary inoculum for the next season crop. However, we noticed also that the literature was poor about the role mycotoxins could play in the establishment of F. graminearum in such a habitat. The m…
Pheromonal imprinting in Drosophila melanogaster: preadult exposure affects free flight odor tracking in adult
2021
International audience
Programme-cadre FENOIR (Figurations de l’environnement nocturne des territoires réunionnais). Rapport d’étape pour le Parc national de La Réunion
2022
Soumise à une importante poussée démographique, l’île de La Réunion a vu sa population urbaine fortement augmenter – passant de 44 % de la population totale en 1975 à 95 % en 2015. Directement corrélée aux formes et dynamiques spatiales de l’urbanisation, l’empreinte lumineuse sur l’île a connu une mutation radicale ces dernières années : son emprise et sa pression ont considérablement augmenté sur l’ensemble du territoire, depuis la côte jusqu’à l’intérieur même du Parc national de La Réunion qui recouvre plus de 76 % du territoire insulaire (42 % pour la zone cœur). Acteur incontournable des enjeux environnementaux sur l’île, le Parc national a mené très tôt des actions autour des effets …
The starry sky, a territorial commons?
2021
International audience; Flagstaff, Arizona, United States, April 15, 1958: the city council adopts the ordinance n°440 which aims at “preventing a rapid deterioration of the visibility of the starry sky”. This regulation results from the mobilization of the Lowell Observatory astronomers against certain public lighting devices. Through this political act, the elected officials place their city at the epicenter of an emergent international movement: the ‘Dark-sky movement’. The first replica of this movement is felt in 1972 in Tucson, Arizona. From a discomfort perceived by astronomers from the Lowell and Kitt Peak observatories, the idea of ‘light pollution’ emerges and begins to spread thr…
Fenêtres sur ciel étoilé
2019
International audience; L’engouement pour la création de réserves de « protection du ciel étoilé » s’étend à un nombre croissant de pays. Impulsé par les milieux de l’astronomie professionnelle et amateur, relayé par d’autres protagonistes publics et privés impliqués dans la réussite et la valorisation de la démarche, cet élan a notamment pris corps autour d’observatoires scientifiques de montagne. Figures emblématiques de l’histoire de l’aménagement de la montagne, ces observatoires ouvrent aussi un espace d’intermédiation entre nos sociétés contemporaines, technicistes et sophistiquées, et des mécanismes célestes porteurs d’enjeux environnementaux concrets.
Getting night lighting right taking account of nocturnal urban uses for better-lit cities
2018
Translated by Oliver Waine; International audience; Innovation in contemporary urban lighting has increasingly been driven by issues of sustainability. While environmental concerns focus attention on energy savings and reducing light pollution, taking account of how people use public spaces is important too, as artificial light can then be adjusted to actual needs. Following the pioneering work of Roger Narboni and Luc Gwiazdzinski, Samuel Challéat and Dany Lapostolle make the case for dedicated nocturnal city planning.