327 research outputs found
Magnetic dephasing in mesoscopic spin glasses
We have measured Universal Conductance Fluctuations in the metallic spin
glass Ag:Mn as a function of temperature and magnetic field. From this
measurement, we can access the phase coherence time of the electrons in the
spin glass. We show that this phase coherence time increases with both the
inverse of the temperature and the magnetic field. From this we deduce that
decoherence mechanisms are still active even deep in the spin glass phase
Origin of micropores In late jurassic (Oxfordian) micrites of the eastern Paris basin, France
Porous micritic facies, either primary chalks or resulting from secondary destructive micritization, can constitute important hydrocarbon or water reservoirs. Characterization of reservoir properties and the understanding of factors which controlled the distribution of porosity are of primary interest to evaluate the prospective reserves. Middle and late Oxfordian limestones of the eastern Paris Basin show several horizons with porosities higher than 20%. The porosity is mainly microporous and located either within secondary micritized grains or in the micritic matrix. Using SEM, cathodoluminescence, as well as confocal microscopy, stable oxygen and carbon isotope ratios, and petrophysical measurements, a scenario for the evolution of the micropores is proposed. Lime mudstones to packstones constitute the majority of the high-porosity facies (HPFs). Inner lagoonal deposits are more micritized and thus more porous than grainstones, and facies rich in leiolitic oncoids and echinoid clasts are less impacted by micritization. Micritization was responsible for an increase of the intragranular porosity in most grain types. During both eogenesis and shallow burial, mineralogical stabilization dissolved aragonitic particles and allowed precipitation of calcite rhombs. This process was probably enhanced below surfaces of subaerial exposure. During burial, Ostwald ripening allowed the growth of larger micrite crystals at the expense of smaller ones during early Berriasian and late Aptian recharges of deep aquifers when the northern margin of the basin was exposed. Overgrowths on micrite crystals were more important in intervals strongly affected by chemical compaction, which favored oversaturation of waters with respect to calcite. In low-porosity horizons (LPFs), the dense micritic texture of oncoids and the monocrystalline architecture of echinoid clasts prevented an intense micritization, while the strong chemical compaction enhanced poronecrosis. Telogenetic fracturing created new fluid pathways that favored inputs of meteoric fluid in porous micrite and allowed the continuation of Ostwald ripening during Cenozoic times. As a whole, mesogenetic inputs of waters undersaturated with respect to calcite in deep aquifers during exposure of basin margins are a more efficient process than early subaerial exposure for enhancing aggrading neomorphism and appearance of microporous micrites. Initial mineralogical heterogeneities also impact the intensity of chemical compaction and thus the stratigraphical distribution of microporous limestones
Os públicos do teatro comunitário: um estudo de caso na PELE - Espaço de Contacto Social e Cultural
International audienc
Pautas de distribuciĂłn espacial y modelizaciĂłn mediante SIG del habitat de Larvas de Solea solea, Pleuronectes flesus y limanda en la parte oriental del Canal de la Mancha durante la primavera
The spring distribution of larval fish stages of flatfishes in the Dover Strait (eastern English Channel) was studied in 1995 and 1999. Fish larvae were identified and sorted according to developmental stages in order to study their ontogenic distribution. The French coastal waters are characterised by an unstable tide-dependent front, which influences larval dispersion. In spring, the French coastal waters have a high phytoplanktonic production. They have higher temperatures, lower salinities and differences in current intensity compared with the central English Channel waters. Generalised Additive Models (GAM) combined with Geographic Information Systems (GIS) were used to model the potential habitats of life stages considering data from three major surveys in this area. The models were developed by coupling presence-absence models with non-null abundance models. The potential habitat of larval stages was then mapped using a geostatistical method (kriging). This revealed different species strategies in which young stages were abundant in central waters and older ones were distributed mainly along the French and Belgian coasts. It is concluded that the central English waters are important for young stages after hatching and that coastal waters are essential nurseries for future juveniles. The models of three flatfish species having similar life cycle strategies are presented here: Limanda limanda, Platichthys flesus and Solea solea.Durante 1995 y 1999 se estudió la distribución primaveral de los estadios larvarios de peces planos en el Estrecho de Dover (parte oriental del Canal de la Mancha).Las larvas de peces fueron identificadas y separadas en función de su estadio de desarrollo con objeto de estudiar su distribución ontogénica. Las aguas costeras francesas se caracterizan por un frente de marea inestable, que influencia la dispersión larvaria. Durante la primavera, dichas aguas presentan una elevada producción fitoplanctónica. Asimismo, presentan altas temperaturas, bajas salinidades y diferencias en la intensidad de la corriente, comparado con las aguas centrales del Canal de la Mancha. A partir de datos obtenidos en tres amplias campañas en este área, se utilizaron Modelos Aditivos Generalizados (GAM) con Sistemas de Información Geográfica (SIG) para modelizar los hábitats potenciales de los estadios larvarios. Los modelos se desarrollaron uniendo modelos de “presencia-ausencia” con modelos de “abundancia no nula”. A continuación, usando métodos geoestadísticos (kriging) se representó el mapa del hábitat potencial de los estadios larvarios. Esto reveló diferencias en las estrategias de aquellas especies cuyos primeros estadios son abundantes en las aguas centrales y cuyos estadios más avanzados están distribuidos principalmente a lo largo de la costa francesa y belga. Se mostró la importancia de las aguas centrales del Canal de la Mancha para las larvas lecitotróficas, y como las aguas costeras son áreas de cría esenciales para los futuros juveniles. Aquí se presentan los modelos para tres especies de peces planos que tienen estrategias de vida similares: Limanda limanda, Platichthys flesus and Solea solea
Impact of respiratory viruses in intensive care unit patient with community-acquired pneumonia : a one-year retrospective single-centre study.
International audienc
Cellular Cardiomyoplasty: Clinical Application
Myocardial regeneration can be induced with the implantation
of a variety of myogenic and angiogenic cell
types. More than 150 patients have been treated with
cellular cardiomyoplasty worldwide, 18 patients have
been treated by our group. Cellular cardiomyoplasty
seems to reduce the size and fibrosis of infarct scars, limit
postischemic remodelling, and restore regional myocardial
contractility. Techniques for skeletal myoblasts culture
and ex vivo expansion using autologous patient
serum (obtained from plasmapheresis) have been developed
by our group. In this article we propose (1) a total
autologous cell culture technique and procedures for cell
delivery and (2) a clinical trial with appropriate endpoints
structured to determine the efficacy of cellular
cardiomyoplasty
Efficacy of transcranial direct current stimulation (tDCS) in reducing consumption in patients with alcohol use disorders: study protocol for a randomized controlled trial
Impact of basin burial and exhumation on Jurassic carbonates diagenesis on both sides of a thick clay barrier (Paris Basin, NE France).
27 pagesInternational audienceSeveral diagenetic models have been proposed for Middle and Upper Jurassic carbonates of the eastern Paris Basin. The paragenetic sequences are compared in both aquifers to propose a diagenetic model for the Middle and Late Jurassic deposits as a whole. Petrographic (optical and cathodoluminescence microscopy), structural (fracture orientations) and geochemical (δ18O, δ13C, REE) studies were conducted to characterize diagenetic cements, with a focus on blocky calcite cements, and their connection with fracturation events. Four generations of blocky calcite (Cal1-Cal4) are identified. Cal1 and Cal2 are widespread in the dominantly grain-supported facies of the Middle Jurassic limestones (about 90% of the cementation), whereas they are limited in the Oxfordian because grain-supported facies are restricted to certain stratigraphic levels. Cal1 and Cal2 blocky spars precipitated during burial in a reducing environment from mixed marine-meteoric waters and/or buffered meteoric waters. The meteoric waters probably entered aquifers during the Late Cimmerian (Jurassic/Cretaceous boundary) and Late Aptian (Early Cretaceous) unconformities. The amount of Cal2 cement is thought to be linked to the intensity of burial pressure dissolution, which in turn was partly controlled by the clay content of the host rocks. Cal3 and Cal4 are associated with telogenetic fracturing phases. The succession of Cal3 and Cal4 calcite relates to the transition towards oxidizing conditions during an opening of the system to meteoric waters at higher water/rock ratios. These meteoric fluids circulated along Pyrenean, Oligocene and Alpine fractures and generated both dissolution and subsequent cementation in Oxfordian vugs in mud-supported facies and in poorly stylolitized grainstones. However, these cements filled only the residual porosity in Middle Jurassic limestones. In addition to fluorine inputs, fracturation also permitted inputs of sulphur possibly due to weathering of Triassic or Purbeckian evaporites or H2S input during Paleogene times
Enrichissement en Ꙍ3 de prépupes d'Hermetia illucens (L. 1758) à partir de coproduits d'oléagineux.
To meet the growing demand for fish in human nutrition, aquaculture is developing increasingly from marine fishery products (i.e. fish meal and fish oil). New environmentally sustainable protein and lipid resources are recommended for this sector and insects, particularly black soldier fly (BSF), Hermetia illucens (L. 1758), are considered as promising candidates for fish feed production. BSF larvae convert organic materials into high-valued protein and lipid, their nutritional composition is related to their diet and could therefore be manipulated. The key issue in fish nutrition will be the fatty acid composition of BSF larvae that are characterized by high saturated fatty acids (SFAs) level (> 60%) with lack of essential polyunsaturated fatty acids. This study aimed to adjust the fatty acid profile of BSF larvae by manipulating their food on focusing on diet formulation with local oilseed cakes for essential ω3 fatty acid (ALA: α-linolenic acid, C18:3n3) enrichment. Selected populations (100 individuals/population) of 7 days old BSF larvae were reared on Chicken feed (CF) diets enriched with flax and rape cakes at six incorporation rates (10 - 20 - 40 - 60 - 80 - 100%), the CF was used as the control diet and all diets were tested in triplicate (n = 3). The first prepupae appeared from 15 rearing days on all diets with an average weight of 195 mg excepted for full oil cake diets showing longer prepupal collection time (7 days) and lower average weight (116 mg). Oil cakes incorporation shows an impact on the prepupae fatty acid profiles. The results show that progressive oil cakes diets incorporation decreased saturated fatty acids from 75.86 ± 0.34% to 56.10 ± 0.74%. Simultaneously, rape cake incorporation leads mainly to oleic acid (C18:1n-9) enrichment which not sought in fish nutrition and low ALA rate from 1.16 ± 0.25% to 2.42 ± 0.12% but Flax cake incorporation increase ALA enrichment up till 15.27 ± 0.02% favorable to fish needs allowing a potential increase BSF meal incorporation in fish feed. This research therefore presents a model of progressive prepupae oil enrichment from oilseed coproducts for application in fish feed.INSEC
FFREE: a Fresnel-FRee Experiment for EPICS, the EELT planets imager
The purpose of FFREE - the new optical bench devoted to experiments on
high-contrast imaging at LAOG - consists in the validation of algorithms based
on off-line calibration techniques and adaptive optics (AO) respectively for
the wavefront measurement and its compensation. The aim is the rejection of the
static speckles pattern arising in a focal plane after a diffraction
suppression system (based on apodization or coronagraphy) by wavefront
pre-compensation. To this aim, FFREE has been optimized to minimize Fresnel
propagation over a large near infrared (NIR) bandwidth in a way allowing
efficient rejection up to the AO control radius, it stands then as a
demonstrator for the future implementation of the optics that will be common to
the scientific instrumentation installed on EPICS.Comment: 12 pages, 15 figures, Proceeding 7736120 of the SPIE Conference
"Adaptive Optics Systems II", monday 28 June 2010, San Diego, California, US
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