4,201 research outputs found
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On the assimilation of Martian total ozone retrievals
The technique of data assimilation gives us an opportunity to further our understanding of important photochemical processes in the Martian atmosphere, through the creation of a reanalysis product that can be used to investigate the temporal and spatial agreement between model and observations and determine any possible causes of identified differences. In this study [1], we have assimilated, for the first time, total ozone retrievals into a Mars Global Circulation model (GCM) to study the ozone cycle
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First ozone reanalysis on Mars using SPICAM data
To further our understanding of important photochemical processes in the Martian atmosphere, a synthesis can be used to investigate the temporal and spatial agreement between model and observations and determine any possible causes of identified differences. In this study [1], we have assimilated, for the first time, total ozone into a Mars Global Circulation model (GCM) to study the ozone cycle
Status report on survey and alignment activities @ GANIL-SPIRAL2 facilities (CEA/CNRS, Caen, France)
International audienceThe over 30 years old GANIL laboratory (heavy ionsnational accelerator) is still delivering beams that interestthe nuclear physicist community. That is why AGATA(Advanced GAmma Tracking Array, a Europeancollaboration of 12 countries) settled at GANIL for a 4years campaign. This π gamma-ray detector requested aquite strong effort in term of 3D positioning metrologyand in term of environment adaptation.Furthermore, since 2013, GANIL is constructing andinstalling the SPIRAL2 facility: a superconducting linearaccelerator and experimental areas that represent 150mlong beam lines. Two injectors (ions, protons anddeutons), a RFQ, a medium energy beam line, a 30m longLINAC (26 supraconducting accelerating cavities) andhigh energy beam lines supplying two experimental hone dedicated to neutron and the other containing S3(Super Separator Spectrometer).This project requested full time survey and alignmentwork from the underground network linked to historicalGANIL coordinates system to the process installation stiin progress
Heredity of seventeen isozyme loci in cassava (Manihot esculenta Crantz)
L'électrophorèse sur gel d'amidon a été utilisée pour évaluer le polymorphisme isoenzymatique chez deux espèces de manioc. Les extraits bruts ont été obtenus à partir de feuilles et de pollen. Dix enzymes ont été examinés pour leur polymorphisme dans une collection de germplasm de 365 cultivars plus 109 échantillons sauvages, la plupart d'Afrique. L'hérédité de ces allozymes a été examinée en utilisant treize descendances intra et interspécifiques. 17 locus polymorphes ont été trouvés pour les dix systèmes enzymatiques, avec 59 allèles. Tous les marqueurs ont montré une hérédité disomique et trois groupes de liaison ont été identifiés. (Résumé d'auteur
Tapping Thermodynamics of the One Dimensional Ising Model
We analyse the steady state regime of a one dimensional Ising model under a
tapping dynamics recently introduced by analogy with the dynamics of
mechanically perturbed granular media. The idea that the steady state regime
may be described by a flat measure over metastable states of fixed energy is
tested by comparing various steady state time averaged quantities in extensive
numerical simulations with the corresponding ensemble averages computed
analytically with this flat measure. The agreement between the two averages is
excellent in all the cases examined, showing that a static approach is capable
of predicting certain measurable properties of the steady state regime.Comment: 11 pages, 5 figure
Survey and alignment concept for the SPIRAL2 accelerator (status report)
International audienceThe SPIRAL2 project located at the GANIL facility (Caen, France) has been studied since the beginning of 2003, and is now under construction. This project aims at delivering rare (radioactive) isotope beams with intensities not yet available with presently running machines. An important aspect of this project is that it is foreseen to deliver up to five different beams in parallel to the users. This paper is a status report on the survey and alignment techniques selected for installation of the SPIRAL2 accelerator device
The initial geodetic survey for the SPIRAL2 process installation
International audienceThe SPIRAL2 project located at the Grand Accélérateur National d'Ions Lourds (GANIL facility - Caen, France) has been studied since the beginning of 2003, and is now under construction. This project aims at delivering rare (radioactive) isotope beams with intensities not yet available with presently running machines. An important aspect of this project is that it is foreseen to deliver up to five different beams in parallel to the users. This paper is focused mainly on the initial geodetic survey for the SPIRAL2 process installation. The positioning of the process and by extension of the buildings is subject to an important constraint due to the future connection of the radioactive beam line to the existing accelerator (see Fig.3). In order to reach the performances, a geodetic reference network (surface network) linked to the local survey network of the existing accelerator is designed [1]. The surface network will be transferred to the floor of the SPIRAL2 accelerator tunnel (9m under the ground), in order to define the underground reference network for the process setup. Final goal of the initial geodetic survey is to align process components of accelerator according to design within required tolerances
Tapping Spin Glasses
We consider a tapping dynamics, analogous to that in experiments on granular
media, on spin glasses and ferromagnets on random thin graphs. Between taps,
zero temperature single spin flip dynamics takes the system to a metastable
state. Tapping, corresponds to flipping simultaneously any spin with
probability . This dynamics leads to a stationary regime with a steady state
energy . We analytically solve this dynamics for the one dimensional
ferromagnet and spin glass. Numerical simulations for spin glasses and
ferromagnets of higher connectivity are carried out, in particular we find a
novel first order transition for the ferromagnetic systems.Comment: 5 pages, 3 figures, RevTe
Understanding the pharmacokinetics of Coartem®
Artemether and lumefantrine (AL), the active constituents of Coartem® exhibit complementary pharmacokinetic profiles. Artemether is absorbed quickly; peak concentrations of artemether and its main active metabolite, dihydroartemisinin (DHA) occur at approximately two hours post-dose, leading to a rapid reduction in asexual parasite mass and a prompt resolution of symptoms. Lumefantrine is absorbed and cleared more slowly (terminal elimination half-life 3-4 days in malaria patients), and accumulates with successive doses, acting to prevent recrudescence by destroying any residual parasites that remain after artemether and DHA have been cleared from the body. Food intake significantly enhances the bioavailability of both artemether and lumefantrine, an effect which is more apparent for the highly lipophilic lumefantrine. However, a meal with only a small amount of fat (1.6 g) is considered sufficient to achieve adequate exposure to lumefantrine. The pharmacokinetics of artemether or lumefantrine are similar in children, when dosed according to their body weight, compared with adults. No randomized study has compared the pharmacokinetics of either agent in pregnant versus non-pregnant women. Studies in healthy volunteers and in children with malaria have confirmed that the pharmacokinetic characteristics of crushed standard AL tablets and the newly-developed Coartem® Dispersible tablet formulation are similar. Studies to date in healthy volunteers have not identified any clinically relevant drug-drug interactions; data relating to concomitant administration of HIV therapies are limited. While dose-response analyses are difficult to undertake because of the low rate of treatment failures under AL, it appears that artemether and DHA exposure impact on parasite clearance time while lumefantrine exposure is associated with cure rate, consistent with their respective modes of action. In conclusion, knowledge of the pharmacokinetic profiles of artemether and lumefantrine is increasing within a range of settings, including infants and children. However, additional data would be warranted to better characterize artemether and lumefantrine pharmacokinetics in patients with hepatic impairment, in pregnant women, and in patients undergoing HIV/AIDS chemotherapy
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