97 research outputs found
Le référentiel taxonomique Florical et les caractéristiques de la flore vasculaire indigène de la Nouvelle-Calédonie
The taxonomic reference base Florical and characteristics of the native vascular flora of New Caledonia. The floristic inventory presented here comprises the evolving computerised database Florical (http://www.botanique.nc/herbier/florical). As of the date of publication, it lists all native vascular plant species (as well as infraspecific taxa) present in the territory of New Caledonia, whether validly published or in press, along with their basionym, organised according to the most recent classifications systems (APG III 2009 for the angiosperms, Smith et at [2006] for the ferns and lycophytes, and Mabberley [2009] for the gymnosperms), accompanied by their status (native or endemic) and the various vegetation types in which they occur. After a brief historical review of our knowledge of New Caledonian botany, the characteristics (richness, composition and endemism) of the different taxonomic groups (ferns and lycophytes, gymnosperms and then angiosperms -mono- and dicotyledons) are analyzed, followed by an assessment of the distribution of these groups among the vegetation types. The vascular flora of New Caledonia is characterised by its high level of richness (3371 species, including 3099 for the flowering plants alone), despite the absence or under-representation of some taxa that are abundantly represented elsewhere in the tropics, and especially by its remarkable distinctiveness (with endemism at the species level reaching 74,7%, and 77.8% for the flowering plants). The flora stands out by the presence of several relictual taxa and a high level of speciation among certain groups, despite the fact that the island was re-colonised relatively recently following the total submersion of its much older basement during the Paleocene and the Oligocene. Details of the measures taken to conserve this extraordinary natural heritage show that only 3.4% of the territory's total surface area is effectively protected. Despite the undeniable progress made in recent years by the authorities concerned, significant work remains to be done, especially in the northern Province
Physics beyond the standard model with kaons at NA62
The NA62 experiment at CERN Super Proton Synchrotron was designed to measure BR(K+ \u2192 \u3c0+\u3bdv\u304) with an in-fight technique, never used before for this measurement. This decay is characterised by a very precise prediction in the Standard Model. Its branching ratio, which is expected to be less than 10-10, is one of the best candidates to indicate indirect effects of new physics beyond SM at the highest mass scales. NA62 result on K+ \u2192 \u3c0+\u3bdv\u304 from the full 2016 data set is described. Also a search for an invisible dark photon A\u2032 has been performed, exploiting the efficient photon-veto capability and high resolution tracking of the NA62. The signal stems from the chain K+ \u2192 \u3c0+\u3c00 followed by \u3c00 \u2192 A\u2032\u3b3. No significant statistical excess has been identified. Upper limits on the dark photon coupling to the ordinary photon as a function of the dark photon mass have been set, improving on the previous limits over the mass range 60 - 110 MeV/c2
Measurement of the reaction gamma*p->phi p in deep, inelastic e(+)p scattering at HERA
The production of phi mesons in the reaction e(+)p --> e(+)phi p (phi --> K+K-), for 7 phi p cross section rises strongly with W. This behaviour is similar to that previously found for the gamma*p --> rho(0)p cross section. This strong dependence cannot be explained by production through soft pomeron exchange, It is, however, consistent with perturbative QCD expectations, where it reflects the rise of the gluon momentum density in the proton at small x. The ratio of sigma(phi)/sigma(rho(0)), which has previously been determined by ZEUS to be 0.065 +/- 0.013 (stat.) in photoproduction at a mean W of 70 GeV, is measured to be 0.18 +/- 0.05 (stat.) +/- 0.03 (syst.) at a mean Q(2) of 12.3 GeV2 and mean W of approximate to 100 GeV and is thus approaching at large Q(2) the value of 2/9 predicted from the quark charges of the vector mesons and a flavour independent production mechanism
Deuxième conférence internationale sur l'écologie des milieux serpentiniques, Nouméa, 31 juillet-5 août 1995 : résumés = Second international conference on serpentine ecology, Noumea, july 31-august 5, 1995 : abstracts
L'étude porte sur l'analyse des variations de teneurs en nickel, manganèse et cobalt dans les tissus foliaires de 12 espèces croissant naturellement sur 5 catégories de sols issus de roches ultramafiques. La variation des teneurs en ces 3 éléments au sein d'une même espèce sur différents substrats traduit la différence de concentrations de ces éléments sous forme assimilable dans le sol. Elle rend compte par là même des risques de toxicité plus ou moins importants pour les plantes. Ces risques sont en ce qui concerne le nickel relativement faibles sur oxisols gravillonnaires ou cuirassés, et élevés sur oxisols colluvio alluviaux hydromorphes. En dépit de teneurs en nickel total élevées, ils apparaissent moins importants sur oxisols remaniés d'érosion que sur sols colluvio alluviaux hydromorphes. Les risques de toxicité en manganèse sont les plus importants sur oxisols colluvionnés de piedmont et les plus faibles sur sols bruns hypermagnésiens et sur oxisols remaniés d'érosion. Ils sont intermédiaires sur oxisols colluviaux hydromorphes et sur oxisols gravillonnaires ou cuirassés, mais varient beaucoup dans ces 2 cas d'une station à l'autre. Les teneurs en cobalt dans les espèces analysées sont relativement faibles sauf pour les Cunoniacées et ne permettent pas de préjuger de l'existence de risques de toxicité dans l'une ou l'autre catégorie de sol. Il apparaît que les variations de teneurs en nickel ou manganèse foliaire de certaines espèces des maquis miniers, et notamment de celles qui ont la capacité d'absorber et de tolérer des quantités relativement importantes de ces éléments dans leurs tissus, apportent des indications sur les risques de toxicité en ces éléments du sol. (Résumé d'auteur
Effect of monoamine oxidase A and B and of catechol-O-methyltransferase inhibition on L-DOPA-indnced circling behavior
The effect of enzyme-inhibiting adjuvants on L-DOPA + benserazide-induced contralateral turning in unilateral 6-hydroxydopamine (6-OHDA)-lesioned rats was studied. Both the number of turns and the duration of turning were examined. Inhibition of MAO-A with 10 mg/kg Ro 41-1049 increased both parameters; inhibition of COMT with 30 mg/kg Ro 40-7592 had a similar effect. In contrast, inhibition of MAO-B with 10 mg/kg Ro 19-6327 did not change turning behavior. A further potentiation of turning behavior was observed after the combined administration of both the MAO-A and COMT inhibitor. MAO-A inhibition in conjunction with MAO-B inhibition prolonged the duration of L-DOPA-induced turning but had no effect on the number of turns. However, in conjunction with COMT inhibition, 10 mg/kg of the MAO-B inhibitor, Ro 19-6327, significantly affected both the number and duration of turning behavior. An even further potentiation of turning behavior was observed after the combined administration of all three enzyme-inhibitors
Monitoraggio dello stato di conservazione sulle opere del Parmigianino mediante misurazione dell’apparenza della superficie pittorica e implicazioni illuminotecniche
Spatial-resolution of Limited Streamer Tubes With Analog Strip Readout
We have studied the achievable spatial resolution of a streamer tube chamber with pickup strips orthogonal to the signal wires and analog readout. The measurement has been performed in real experimental conditions with 135 GeV/c muons at CERN. Using a new algorithm to determine the center of the induced charge on the strips, we have obtained for 1 cm wide strips a spatial resolution better than 500 ÎĽm after averaging over all strips. The intrinsic resolution averaged over a single strip is better than 350 ÎĽm
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