Search results for "Mono"
showing 10 items of 6843 documents
Alignement moléculaire par impulsions laser ultrabrèves : Mesures & Applications
2009
The interaction of an intense ultrashort laser pulse with a molecular sample leads, after the end of the pulse, to molecular alignment at specific time under field-free conditions. This thesis is dedicated to the measurements and applications of this effect. The degree of alignment is determined through the variation of the refractive index induced by the rearrangement of the molecular dipoles. A two-dimensional technique allowing to measure molecular alignment on a single-shot basis is reported in this document. The alignment is then exploited in order to determine physical quantities which are usually difficult to estimate through others methods. The "cross-defocusing technique" has been …
Sur le rôle des singularités hamiltoniennes dans les systèmes contrôlés : applications en mécanique quantique et en optique non-linéaire.
2012
This thesis has two goals: the first one is to improve the control techniques in quantum mechanics, and more specifically in NMR, by using the tools of geometric optimal control. The second one is the study of the influence of Hamiltonian singularities in controlled systems. The chapter about optimal control study three classical problems of NMR : the inversion problem, the influence of the radiation damping term, and the steady state technique. Then, we apply the geometric optimal control to the problem of the population transfert in a three levels quantum system to recover the STIRAP scheme.The two next chapters study Hamiltonian singularities. We show that they allow to control the polar…
High-Pressure Raman Scattering of CaWO4 Up to 46.3 GPa: Evidence of a New High-Pressure Phase
2014
International audience; The high-pressure behavior of CaWO4 wasanalyzed at room temperature by Raman spectroscopy.Pressure was generated using a diamond-anvil cell and Ne aspressure-transmitting medium. The pressure range of previousstudies has been extended from 23.4 to 46.3 GPa. Theexperiments reveal the existence of two reversible phasetransitions. The first one occurs from the tetragonal scheelitestructure to the monoclinic fergusonite structure and isobserved at 10 GPa. The onset of a previously unknownsecond transition is found at 33.4 GPa. The two high-pressurephases coexist up to 39.4 GPa. The Raman spectra measuredfor the low-pressure phase and the first high-pressure phase arecons…
Impacts de l'occupation du sol sur les ressources en eau du complexe Mono-Couffo (Afrique de l'Ouest)
2009
International audience; En Afrique de l'ouest en général et au Bénin comme au Togo en particulier, les cours d'eau sont des pôles particulièrement attractifs pour la population du fait de la diversité des activités socio-économiques qu'ils permettent. Mais, les variations pluviométriques et la pression humaine de ces dernières années, sur le complexe Mono-Couffo ont eu une influence négative sur les ressources en eau et les écosystèmes en particulier. Les données utilisées sont : la pluviométrie, les débits (Athiémé et Lanta), la superficie des unités d'occupation du sol, la turbidité, le taux de dépôts solides (TDS) et la production halieutique. Ces données ont permis d'analyser d'une part…
Impact de la variabilité climatique sur les apports liquides dans la basse vallée du Mono (Bénin, afrique de l'ouest)
2009
International audience; Les effets de la variabilité climatique et leur conséquence sur les ressources en eau devient une question de plus en plus préoccupante pour les gestionnaires dans le contexte de la Gestion Intégrée des Ressources en Eau (GIRE) dans de nombreuses régions de l'Afrique de l'Ouest en général et du Bénin en particulier. Les données utilisées sont : précipitations, évapotranspiration et débit du bassin-versant du Mono à Athiémé sur la période 1970-2005. La détermination des précipitations de l'ensemble du bassin est faite en fonction des coordonnées géographiques et de l'altitude. L'analyse statistique de ces données a permis de faire ressortir d'une part la tendance du r…
Networks of Seed Storage Protein Regulation in Cereals and Legumes at the Dawn of the Omics Era
2012
BAP GEAPSI CT2 (BAP); International audience; Finely regulated and orchestrated events occur during seed development and germination in different cell organelles (mitochondria, peroxisomes, plastids, vacuoles, endoplasmic reticulum, oil bodies and nuclei). Therefore, some of the ongoing investigations pass through sub-cellular organelle purifications for a deeper comprehension of these complex developmental processes. In seed biology, recent ambitious efforts in proteomics have been directed toward organelle isolation from seeds and high-throughput protein separation and identification by mass spectrometry at defined developmental stages. The construction of reference maps allowed identifyi…
Medicago truncatula
2012
In plants, long distance transport of sugars from photosynthetic source leaves to sink organs comprises different crucial steps depending on the species and organ types. Sucrose, the main carbohydrate for long distance transport is synthesized in the mesophyll and then loaded into the phloem. After long distance transport through the phloem vessels, sucrose is finally unloaded towards sink organs. Alternatively, sugar can also be transferred to non‐plant sinks and plant colonization by heterotrophic organisms increases the sink strength and creates an additional sugar demand for the host plant. These sugar fluxes are coordinated by transport systems. Main sugar transporters in plants compri…
Towards human exploration of space: the THESEUS review series on cardiovascular, respiratory, and renal research priorities
2016
International audience; The THESEUS project (Towards Human Exploration of Space: aEUropean Strategy) was initiated within the seventh FrameworkProgramme by the European Commission. This project aimed toprovide a cross-cutting, life science-based roadmap for Europe’sstrategy towards human exploration of space, especially for deepspace missions and its relevance to applications on Earth. Toaddress these challenges, relevance of space research on thecardiovascular system, the lungs and kidneys, was discussed in anexpert group and its principal conclusions will be presented in thisarticle.
Trehalose and trehalose-6-phosphate induce stomatal movements and interfere with ABA-induced stomatal closure in grapevine
2015
Aims: The effects of trehalose and trehalose-6-phosphate (T6P), among other sugars, were assessed on grapevine stomatal movements. Methods and results: Epidermal peels were used to assess the effects of sugars. Low concentrations of trehalose and T6P (1 μM) induced an osmotic-independent reduction of the stomatal aperture in light conditions. Furthermore, ABA-induced stomatal closure was reduced by sugar application in association with lower accumulation of reactive oxygen species in guard cells. Similar effects, although weaker, were observed in response to the disaccharides sucrose and maltose, but not in response to the monosaccharides fructose and glucose. Conclusion: This study clearly…
Prévalence de pathogènes humains dans les sols français, effet des facteurs pédoclimatiques, biologiques et du mode d'utilisation des sols
2013
Soil contamination by bacterial pathogens can occur through manure, sewage sludge spreading or irrigation using waste water treatment plants effluents. Agricultural soils may act as reservoirs for these pathogens, play a significant role in their dissemination, leading to the potential contamination of food and water resources. Health risk associated with the occurrence of pathogens in environmental matrices has to be thoroughly evaluated. In this context, the objectives of this work were: i) to determine the prevalence of two pathogenic bacterial species (Listeria monocytogenes and Enterococcus faecalis) in a large collection of French soils originated from a systematic soil survey of the …