Concurrence et nuisibilite des mauvaises herbes dans des cultures annuelles en relation avec le desherbage

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 81973 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Proposition d’un méta-modèle basé sur les Topic Map pour la structuration et la recherche d’information

International audienceNous présentons ici un état d’avancement de nos travaux dans le domaine du Web Sémantique à la lumière d’une application industrielle. Après avoir replacé notre approche parmi celles du Web Sémantique, nous présenterons HyperTopic, un métamodèle générique inspiré des Topic Maps pour la réalisation d’applications permettant de structurer et de rechercher un ensemble de ressources présentant des similarités « fonctionnelles » pour des utilisateurs partageant des préoccupations communes

Cognitive Interactions in the Semantic Web

International audienceThe advancement of a Semantic Web both entails and promotes new collaborative practices in Web content management, e.g. for e-business applications. These practices involve cognitive interactions which must be taken into account in the aims of the Semantic Web, and encouraged by using and completing its standards, with a Knowledge Engineering approach

Cognitive Interactions in the Semantic Web

The advancement of a Semantic Web both entails and promotes new collaborative practices in Web content management, e.g. for e-business applications. These practices involve cognitive interactions which must be taken into account in the aims of the Semantic Web, and encouraged by using and completing its standards, with a Knowledge Engineering approach. General Terms: Human Factors

Les Topic Maps sont-ils un bon candidat pour l’ingénierie du Web Sémantique ?

International audienceL’avènement d’un Web sémantique fait émerger des nouvelles pratiques dans l’organisation des contenus sur le Web. Ces pratiques mettent en jeu un ensemble d’interactions cognitives qu’il convient de canaliser et de favoriser pour donner au Web sémantique les possibilités des ambitions qu’on lui prête. Après avoir brièvement situé ces ambitions et les interactions cognitives en jeu nous présenterons les Topic Maps comme formalisme de représentation des connaissances capable de répondre à une partie des objectifs du Web sémantique

Cadmium accumulation and buffering of cadmium-induced stress by arbuscular mycorrhiza in three <i>Pisum sativum</i> L. genotypes

The role of arbuscular mycorrhiza in reducing Cd stress was investigated in three genotypes of Pisum sativum L. (cv. Frisson, VIR4788, VIR7128), grown in soil/sand pot cultures in the presence and absence of 2—3 mg kg-1 bioavailable Cd, and inoculated or not with the arbuscular mycorrhizal fungus Glomus intraradices. Shoot, root and pod biomass were decreased by Cd in non-mycorrhizal plants. The presence of mycorrhiza attenuated the negative effect of Cd so that shoot biomass and activity of photosystem II, based on chlorophyll a fluorescence, were not significantly different between mycorrhizal plants growing in the presence or absence of the heavy metal (HM). Total P concentrations were not significantly different between mycorrhizal and non-mycorrhizal plants treated with Cd. From 20—50-fold more Cd accumulated in roots than in shoots of Cd-treated plants, and overall levels were comparable to other metal-accumulating plants. Genetic variability in Cd accumulation existed between the pea genotypes. Concentration of the HM was lowest in roots of VIR4788 and in pods of VIR4788 and VIR7128. G. intraradices inoculation decreased Cd accumulation in roots and pods of cv. Frisson, whilst high concentrations were maintained in roots and pods of mycorrhizal VIR7128. Shoot concentrations of Cd increased in mycorrhizal cv. Frisson and VIR4788. Sequestration of Cd in root cell walls and/or cytoplasm, measured by EDS/SEM, was comparable between non-mycorrhizal pea genotypes but considerably decreased in mycorrhizal cv. Frisson and VIR7128. Possible mechanisms for mycorrhiza buffering of Cd-induced stress in the pea genotypes are discusse

Cadmium accumulation and buffering of cadmium‐induced stress by arbuscular mycorrhiza in three Pisum sativum L. genotypes

The role of arbuscular mycorrhiza in reducing Cd stress was investigated in three genotypes of Pisum sativum L. (cv. Frisson, VIR4788, VIR7128), grown in soil/sand pot cultures in the presence and absence of 2-3 mg kg−1 bioavailable Cd, and inoculated or not with the arbuscular mycorrhizal fungus Glomus intraradices. Shoot, root and pod biomass were decreased by Cd in non‐mycorrhizal plants. The presence of mycorrhiza attenuated the negative effect of Cd so that shoot biomass and activity of photosystem II, based on chlorophyll a fluorescence, were not significantly different between mycorrhizal plants growing in the presence or absence of the heavy metal (HM). Total P concentrations were not significantly different between mycorrhizal and non‐mycorrhizal plants treated with Cd. From 20-50‐fold more Cd accumulated in roots than in shoots of Cd‐treated plants, and overall levels were comparable to other metal‐accumulating plants. Genetic variability in Cd accumulation existed between the pea genotypes. Concentration of the HM was lowest in roots of VIR4788 and in pods of VIR4788 and VIR7128. G. intraradices inoculation decreased Cd accumulation in roots and pods of cv. Frisson, whilst high concentrations were maintained in roots and pods of mycorrhizal VIR7128. Shoot concentrations of Cd increased in mycorrhizal cv. Frisson and VIR4788. Sequestration of Cd in root cell walls and/or cytoplasm, measured by EDS/SEM, was comparable between non‐mycorrhizal pea genotypes but considerably decreased in mycorrhizal cv. Frisson and VIR7128. Possible mechanisms for mycorrhiza buffering of Cd‐induced stress in the pea genotypes are discusse

CKIP-1 regulates mammalian and zebrafish myoblast fusion

Multinucleated muscle fibres arise by fusion of precursor cells called myoblasts. We previously showed that CKIP-1 ectopic expression in C2C12 myoblasts increased cell fusion. In this work, we report that CKIP-1 depletion drastically impairs C2C12 myoblast fusion in vitro and in vivo during zebrafish muscle development. Within developing fast-twich myotome, Ckip-1 localises at the periphery of fast precursor cells, closed to the plasma membrane. Unlike wild-type myoblasts that form spatially arrayed multinucleated fast myofibres, Ckip-1-deficient myoblasts show a drastic reduction in fusion capacity. A search for CKIP-1 binding partners identified the ARPC1 subunit of Arp2/3 actin nucleation complex essential for myoblast fusion. We demonstrate that CKIP-1, through binding to plasma membrane phosphoinositides via its PH domain, regulates cell morphology and lamellipodia formation by recruiting the Arp2/3 complex at the plasma membrane. These results establish CKIP-1 as a regulator of cortical actin that recruits the Arp2/3 complex at the plasma membrane essential for muscle precursor elongation and fusion