Search results for "Persistance"
showing 7 items of 7 documents
Étude de la biologie d'une messicole en régression: le bleuet (Centaurea cyanus L.)
2011
Agroecosystems are currently experiencing high biodiversity loss, in particular among the plant species specifically adapted to this habitat. This decline results from cropping systems that have been intensified in Western Europe since the 1950s. The cornflower (Centaurea cyanus L.), considered as emblem of the flora associated with traditional cereals, appears as a species that may be at risk and should be monitored. Indeed, cornflower can serve as a host to predators of crop pests and is strongly attractive for the pollinators. This study examines the biological factors that could potentially cause the decline of this species: spatial distribution, potential for growth, population's genet…
La persistance de la performance des fonds de pension individuels britanniques : une étude empirique sur des fonds investis en actions et des fonds o…
2003
Dans ce présent cahier de recherche, nous nous proposons d’étudier la stabilité des performances de certains fonds de retraite anglais à cotisations définies : les fonds de pension individuels (Personal Pension Scheme). Il s’agit de fonds – pratiquant une gestion active - investissant principalement dans les actions britanniques et de fonds détenant majoritairement des obligations anglaises durant la période novembre 1990 – novembre 2000. Les données sur les fonds de pension individuels proviennent de la base de données UK PENSION de Standard & Poor’s Fund Services et sont de fréquence mensuelle. Nous utilisons des tests paramétriques de l’existence de la persistance, plusieurs mesures de p…
Persistance and adaptation of Listeria monocytogenes in the soil : role of the communication system Agr
2014
Listeria monocytogenes is a ubiquitous bacterium responsible for listeriosis, a food-borne disease. This pathogen has been isolated from various environments of which the telluric environment. The presence of L. monocytogenes in soil can increase health hazards due to the risk of transfer to vegetables, animals and animal products and water. Considering the role of soil in the circulation of pathogens from farm environment to plant and animal products and eventually to foodstuff, it is critical to identify intrinsic and extrinsic factors that drive the fate of L. monocytogenes in soil. Genome-wide and transcriptomic analyses found that an important part of the genome of L. monocytogenes (7.…
Approche adaptative de simplification géométrique temps réel de modèles 3D distribués pour la visualisation et l'interaction à distance
2010
National audience; Deux moyens permettent aujourd'hui d'accéder visuellement à des données 3D volumineuses à distance : le premier consiste à transférer les données entre le serveur et le poste client/utilisateur, le second consiste à générer et à transférer des " photographies" de ces données 3D qui restent alors localisées sur le serveur. Le goulot d'étranglement principal dans les deux cas est la bande passante du réseau qui ne permet pas de transférer des volumes de données importants. Bien plus, la visualisation de plusieurs centaines de giga-octets d'informations nécessite de grandes capacités de stockage (disque dur ou mémoire) et des équipements de visualisation très performants (ca…
Persistance et adaptation de Listeria monocytogenes dans le sol : rôle du système de communication Agr
2014
Listeria monocytogenes is a ubiquitous bacterium responsible for listeriosis, a food-borne disease. This pathog•en has been isolated from varions environments of which the telluric environment. The presence of L. monocytogenes in soi! can increase health hazards due to the risk of transfer to vegetables, animais and animal products and water. Considering the role of soil in the circulation of pathogens from fann environment to plant and animal products and eventually to foodstuff, it is critical to identify intrinsic and extrinsic factors that drive the fate of L. monocytogenes in soi!. Genome-wide and transcriptomic analyses found that an important part of the genome of L. monocytogenes (7…
Assessment wine aroma persistence by using an in vivo PTR-ToF-MS approach and its relationship with salivary parameters
2019
To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for th…