Search results for "Feuille"
showing 10 items of 15 documents
Fossiliferous Holocene tufa of Mende (Lozère, southern France): implication for the Atlantic vegetation of the Causses Basin
2016
International audience; Tufas bearing plant macroremains are uncommon in the Causses Basin (southern France). Here, we report anew fossiliferous tufa deposits at Mende, in Lozère. This palaeontological site is the first Quaternary tufa from thenorthern part of the Causses Basin that yields such an abundance of plant macroremains. The radiocarbon dating showsthat these Holocene deposits are related to the Atlantic period. Geomorphology and mineralogy show that theplant-bearing deposit is a calcareous tufa only composed by calcite, deposited near to an outlet of cool water, linked tothe karstic hydrological system of the Causse de Mende. The flora exposed in this article is dominated by angio…
Côté mauvaises herbes, tir de barrage sur trois envahissantes
2006
National audience; Les plantes envahissantes sont évoquées à la conférence sur les zones non agricoles de l'AFPPà Avignon les 11 et 12octobre 2006. La situation à leur égard en France et en Europe est présentée, notamment les dispositions réglementaires et l'identité des 34 principales espèces. Deux communications traitent de l'ambroisie à feuille d'armoise Ambrosia artemisiifolia. Un point sur les méthodes de lutte mécanique, chimique, etc.) insiste sur l'intérêt de la prévention (enherbement, etc.)et de la concertation entre acteurs agricoles et non agricoles. Des essais de lutte chimique (glyphosate ou glufosinate-ammonium en 2004 et 2005, les montrent équivalents et intéressants en débu…
Tardi, de l'Histoire au feuilleton
2010
International audience
Effet d'une carence en soufre combinée à un stress hydrique chez le pois protéagineux : Etude des mécanismes moléculaires mis en jeu dans les organes…
2019
Pea (Pisum sativum L.) is a grain legume crop that produces seeds rich in proteins for food and feed and, thanks to its symbiosis with nitrogen-fixing bacteria, enriches the soil with nitrogen. The wider development of pea cultivation is therefore a major agroecological challenge. Water stress combined with sulfur deficiencies in soils (S is a macroelement necessary for plant defense reactions) are two abiotic stresses that interact in the current context of climate change. However, the molecular mechanisms underlying pea adaptation to water stress and their modulation by sulfur nutrition remain to be elucidated. The objectives of this thesis were, first, to describe the impact of an intera…
Gibbs and harmonic measures for foliations with negatively curved leaves
2013
In this thesis we develop a notion of Gibbs measure for the geodesic flow tangent to a foliated bundle over a compact and negatively curved basis. We also develop a notion of F-harmonic measure and prove that there exists a natural bijective correspondence between the two. For projective foliated bundles with sphere-fibers without transverse invariant measure, we show the uniqueness of these measures for any Hölder potential on the basis. In that case we also prove that F-harmonic measures are realized as weighted limits of large balls tangent to the leaves and that their conditional measures on the fibers are limits of weighted averages on the orbits of the holonomy group.
Effect anti inflammatory and anti obesity of the polyphenolic extracts of carob leaves "Ceratonia siliqua" and cladode "Opuntia ficus-indica"
2018
In the present study, we have investigated the effects of polyphenol-rich infusions from carob leaves and OFI-cladodes on inflammation associated with obesity and dextran sulfate sodium (DSS)-induced ulcerative colitis in Swiss mice. In vitro studies revealed that aqueous extracts of carob leaves and OFI-cladodes exhibited anti-inflammatory properties marked by the inhibition of , TNF-α and nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells concomitant with NF-κβ nucleus translocation inhibition. For in vivo investigations, Swiss male mice were subjected to control or high fat diet (HFD). At the 4th week after the start of study, animals received or not 1% i…
Interaspecific chemical variability and highlighting of chemotypes of leaf essential oils from Ravensara aromatica Sonnerat, a tree endemic to Madaga…
2006
Ravensara aromatica Sonnerat is a tree endemic to Madagascar. The essential oil extracted from the leaves is used in aromatherapy. Previous chemical studies have generated some confusion with regard to the chemical composition of this essential oil. In order to eliminate this uncertainty, we undertook a systematic evaluation of the chemical composition of essential oils from leaves of this species. The study focused on 28 individual samples formally identified as R. aromatica. The essential oils were obtained by hydrodistillation and analysed by GC and GC–MS. It was possible to distinguish four groups of trees through principal components analysis and agglomerative hierarchical clustering a…
Partially hyperbolic diffeomorphisms with a compact center foliation with finite holonomy
2011
The thesis classifies partially hyperbolic diffeomorphisms with a compact center foliation with finite holonomy. Under the further assumption of a one-dimensional unstable bundle we show the following: If the unstable bundle is oriented then the system fibers over a hyperbolic toral automorphism. We further establish that the system has a dense orbit of center leaves. During the proof we show a Shadowing Lemma and the dynamical coherence without restrictions of the dimensions.
Volumes transverses aux feuilletages d'efinissables dans des structures o-minimales
2003
Let Fλ be a family of codimension p foliations defined on a family Mλ of manifolds and let Xλ be a family of compact subsets of Mλ. Suppose that Fλ, Mλ and Xλ are definable in an o-minimal structure and that all leaves of Fλ are closed. Given a definable family Ωλ of differential p-forms satisfaying iZ Ωλ = 0 forany vector field Z tangent to Fλ, we prove that there exists a constant A > 0 such that the integral of on any transversal of Fλ intersecting each leaf in at most one point is bounded by A. We apply this result to prove that p-volumes of transverse sections of Fλ are uniformly bounded.
Résistances aux herbicides : panics dans le riz !
2014
SPE GEAPSI CT1; Des difficultés de désherbage à l’aide d’herbicides inhibiteurs de l’ALS (groupe B du HRAC) ayant été notées en riziculture, en Camargue (France), sur des panics, l’hypothèse d’une sélection de résistance a été étudiée. Des prélèvements ont été effectués sur 28 parcelles à raison d’une feuille de 40 plantes différentes par parcelle. Des tests ADN ont permis d’identifier les espèces en présence. Puis des tests PCR ont permis de rechercher la présence de mutations entraînant des résistances aux herbicides inhibiteurs de l’ALS. Vu le nombre d’analyses à réaliser (7 codons sur 40 plantes x 28 parcelles), le séquençage « 454 » a été utilisé. Deux espèces de panics ont été identif…