145 research outputs found
Proposition de candidature de la coupe de Thuoux (France) pour le GSSP de la base de l'étage Oxfordien
La coupe de Thuoux, localisée en France dans le Bassin du Sud-Est, (coordonnées : 44°30'55"E; 5°42'25"N) satisfait à la majorité des critères demandés pour devenir le GSSP de la base de l'étage Oxfordien. La sédimentation est continue à l'échelle de l'horizon ammoniti-que et en particulier des horizons à Paucicostatum (MARCHAND, 1979) et à Thuouxensis (FORTWENGLER & MARCHAND, 1994a). Dans cette coupe, il y a un mélange constant entre les ammonites boréales (Car-dioceratinae) et les ammonites subboréales et sub-méditérranéennes (Hecticoceratinae, Peltoceratinae et Perisphinctinae) ce qui autorise de larges corrélations géographiques. De plus, la présence simultanée de ces 4 sous-familles permet un découpage temporel très précis et permet aussi de proposer des corrélations temporelles entre l'Europe Occidentale, le nord de l'Amérique (grâce aux Cardioceratinae) et l'Amérique du Sud (grâce aux Peltoceratinae). La forte épaisseur des sédiments à Thuoux a aussi permis des études sédimentologiques et une calibration astronomique de l'Oxfordien inférieur (BOULILA, 2008 ; BOULILA et al., 2008). Enfin, plus d'une trentaine de coupes ont été analysées en détail autour de Thuoux, ce qui augmente la fiabilité des résultats obtenus sur la coupe où la base de l'Oxfordien est visible (FORTWENGLER, 1989 ; FORTWENGLER & MARCHAND, 1994a, b, c, d).The Thuoux section, located in South-Eastern Basin of France (coordinates: 44°30'55"E; 5°42'25"N), is a section that satisfies numerous demanding criteria as reference section (GSSP) for the base of the Oxfordian stage. Sedimentation was continuous in that the abundant ammonitic fauna yields no detectable hiatuses. The stratigraphic boundary is located between the Lamberti Zone and the Mariae Zone or more precisely between the Paucicostatum horizon (MARCHAND, 1979) and the Thuouxensis horizon (FORTWENGLER & MARCHAND, 1994a). In this section, there is a perfect mixing bet-ween Boreal ammonites (Cardioceratinae) whose species are used as stratigraphic markers and Sub-mediterranean/Subboreal ammonites (Hecticoceratinae, Peltoceratinae and Perisphinctinae) that provi-de further possibilities for wide correlation of this boundary. Finally, parallel ammonite zonations have been established with great precision (biohorizons and sometimes "sub-biohorizons") in various areas of France, with different palaeoenvironments. The Thuoux section permits correlations with central and eastern Europe as well as North America, based on Cardioceratinae successions, and with South Ameri-ca, using Peltoceratinae. Thickness of the Callovian-Oxfordian transitional beds in the Thuoux section has allowed detailed sedimentological studies and astronomical calibration of the Lower Oxfordian (BOULILA, 2008; BOULILA et al., 2008). The Thuoux section is located at the centre of a set of more than thirty sections where the base of the Oxfordian stage is visible (FORTWENGLER, 1989; FORTWENGLER & MARCHAND, 1994a, b, c, d)
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Validation of the French Version of the Child Post-Traumatic Stress Reaction Index: Psychometric Properties in French Speaking School-Aged Children
Background: Although the reliable and valid Child Post-Traumatic Stress Reaction Index (CPTS-RI) is a widely used measure of posttraumatic stress disorder (PTSD) symptoms in children, it has not been validated in French-speaking populations. The present study aims to assess the psychometric properties of the CPTS-RI in three samples of French-speaking school-children. Methods: Data was obtained from three samples. Sample 1 was composed of 106 children (mean (SD) age = 11.7(0.7), 50% females) victims of an industrial disaster. Sample 2 was composed of 50 children (mean (SD) age = 10.8(2.6), 44% females) who had received an orthopaedic surgical procedure after an accident. Sample 3 was composed of 106 children (mean (SD) age = 11.7(2.2), 44% females) admitted to an emergency department after a road traffic accident. We tested internal consistency using Cronbach's alpha. We examined test-retest reliability using intraclass correlation coefficient. In order to assess the convergent validity of the French version of the CPTS-RI and the Clinician Administered PTS Scale-Child and Adolescent (CAPS-CA), spearman-correlation coefficient was computed. To verify the validity of the cut-off scores, a ROC curve was constructed which evaluated the sensitivity and specificity of each score compared to the diagnosis with the CAPS-CA. We also used principal components analysis with varimax rotation to study the structure of the French version of the CPTS-RI. Results: Cronbach's alpha coefficient was 0.87 for the French version of the CPTS-RI. Two-week test-retest intraclass correlation coefficient (n = 30) was 0.67. The French version of the CPTS-RI was well correlated with the CAPS-CA (r = 0.76, p24 for the CPTS-RI, the sensitivity and specificities were 100% and 62.6%, respectively. The French version of the CPTS-RI demonstrated a three-factor structure. Conclusions: The CPTS-RI is reliable and valid in French-speaking children
PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY FOR EMBOLIGENIC ARTERIAL LESIONS AFTER RADIOTHERAPY OF AXILLARY ARTERIES
Nest grouping patterns of bonobos (Pan paniscus) in relation to fruit availability in a forest-savannah mosaic
A topic of major interest in socio-ecology is the comparison of chimpanzees and bonobos’ grouping patterns. Numerous studies have highlighted the impact of social and environmental factors on the different evolution in group cohesion seen in these sister species. We are still lacking, however, key information about bonobo social traits across their habitat range, in order to make accurate inter-species comparisons. In this study we investigated bonobo social cohesiveness at nesting sites depending on fruit availability in the forest-savannah mosaic of western Democratic Republic of Congo (DRC), a bonobo habitat which has received little attention from researchers and is characterized by high food resource variation within years. We collected data on two bonobo communities. Nest counts at nesting sites were used as a proxy for night grouping patterns and were analysed with regard to fruit availability. We also modelled bonobo population density at the site in order to investigate yearly variation. We found that one community density varied across the three years of surveys, suggesting that this bonobo community has significant variability in use of its home range. This finding highlights the importance of forest connectivity, a likely prerequisite for the ability of bonobos to adapt their ranging patterns to fruit availability changes. We found no influence of overall fruit availability on bonobo cohesiveness. Only fruit availability at the nesting sites showed a positive influence, indicating that bonobos favour food ‘hot spots’ as sleeping sites. Our findings have confirmed the results obtained from previous studies carried out in the dense tropical forests of DRC. Nevertheless, in order to clarify the impact of environmental variability on bonobo social cohesiveness, we will need to make direct observations of the apes in the forest-savannah mosaic as well as make comparisons across the entirety of the bonobos’ range using systematic methodology
Integrated process for extraction and formulation in emulsions of active molecules from fresh passion fruits (Passiflora edulis Sims)
Intensified green processes were investigated to extract several classes of active molecules from fresh purple passion fruits, and to prepare emulsions directly by extrusion for the fruit comprehensive utilization. A thermo-mechanical treatment was carried out through a discontinuous process from the edible part and through a continuous process by twin-screw extrusion using the whole fruit. Only mechanical energy was applied to the materials to generate a liquid fraction (filtrate) and a solid residue. Lipid contents of the obtained filtrates ranged from 0.5 to 2.6 g/100 g close to the extractible lipophilic part. Polyphenols extraction was improved when using the whole fruit and with the addition of water in extrusion. In-situ emulsions with droplets sizes between 2 and 8 μm were obtained. Emulsions obtained after extrusion showed an enhanced stability. This way represents a green alternative method to solvent extractions applied to the different parts of the fruit, and leads to bio-based emulsions enriched in vegetable oil, natural antioxidants and emulsifiers, such as phospholipids, proteins, polysaccharides, pectins and polyphenols
Semi‐Siccative Oils and Bioactive Fractions Isolated from Reunion Island Fruit Co‐Product: Two Case Studies
Semi-Siccative Oils and Bioactive Fractions Isolatedfrom Reunion Island Fruit Co-Product: Two Case StudiesAlice Delvar, Pascale de Caro,* Yanis Caro,* Alain Shum Cheong Sing, Rudy Thomas,and Christine RaynaudThis paper focused on the use of agro-industrial wastes of strawberry guava (Psidiumcattleianum) and passion fruit (Passiflora edulis) generated by the agriculturalindustry on Reunion Island, according to two routes: extraction of semi-siccative oilsfrom the seeds and extraction of bioactive compounds from residual pulp and peels.Oil content, fatty acid, carotenoids, tocopherol, and sterol concentrations aredetermined in the seed oils obtained by four different extraction processes usingSoxhlet extraction, extraction by hexane and ethanol, mechanical pressing andsupercritical-carbon dioxide (SC-CO2) extraction. The oil extraction yields ranged from15 to 30% w/w for strawberry guava and passion fruit, respectively. Both oils areclassified as semi-siccative and had a similar total unsaturated fatty acid content(88%) with a prevalence of linoleic acid (70–78%). High contents in phytosterols andinα-tocopherol are particularly detected in strawberry guava oil. The antioxidantactivities of the bioactive compounds extracted by water and ethanol from pulp andpeels are characterized byα,α-diphenyl-β-picrylhydrazyl (DPPH) test. After purificationon polymeric resin, significant antioxidant activities are recorded (half maximalinhibitory concentration (IC50) from 11 to 50 g L-1) and are related to polyphenolcontents (20.7 to 42.5 g gallic acid equivalents (GAE)/100 g dry extract).Practical Applications: There is a great interest on the use of tropical fruit wastesbecause of their large availabilities. Strawberry guava and passion fruit are often usedin the food industry, for juice and jam production. The seeds, pulp, and peel residuesare in fact a by-product of their industrial processing, which should be valuablyprocessed instead of just throwing away. We can state that the extracted seed (richin polyunsaturated fatty acids) of strawberry guava and passion fruit can be used inthe industrial production of emulsions, paints, and varnishes. Within the positiveaspects of the study, one can also distinguish the use of these tropical fruit by-products as beneficial sources of many valuable bioactive compounds, for example,carotenoids, tocopherols, phytosterols, and especially polyphenols, for functionalformulations. Moreover, it may be the experimental basis for further developmentand use in food industr
MRI investigation of granular interface rheology using a new cylinder shear apparatus
The rheology of granular materials near an interface is investigated through
proton magnetic resonance imaging. A new cylinder shear apparatus has been
inserted in the MRI device, which allows the control of the radial confining
pressure exerted by the outer wall on the grains and the measurement of the
torque on the inner shearing cylinder. A multi-layer velocimetry sequence has
been developed for the simultaneous measurement of velocity profiles in
different sample zones, while the measurement of the solid fraction profile is
based on static imaging of the sample. This study describes the influence of
the roughness of the shearing interface and of the transverse confining walls
on the granular interface rheology
Random Convex Hulls and Extreme Value Statistics
In this paper we study the statistical properties of convex hulls of
random points in a plane chosen according to a given distribution. The points
may be chosen independently or they may be correlated. After a non-exhaustive
survey of the somewhat sporadic literature and diverse methods used in the
random convex hull problem, we present a unifying approach, based on the notion
of support function of a closed curve and the associated Cauchy's formulae,
that allows us to compute exactly the mean perimeter and the mean area enclosed
by the convex polygon both in case of independent as well as correlated points.
Our method demonstrates a beautiful link between the random convex hull problem
and the subject of extreme value statistics. As an example of correlated
points, we study here in detail the case when the points represent the vertices
of independent random walks. In the continuum time limit this reduces to
independent planar Brownian trajectories for which we compute exactly, for
all , the mean perimeter and the mean area of their global convex hull. Our
results have relevant applications in ecology in estimating the home range of a
herd of animals. Some of these results were announced recently in a short
communication [Phys. Rev. Lett. {\bf 103}, 140602 (2009)].Comment: 61 pages (pedagogical review); invited contribution to the special
issue of J. Stat. Phys. celebrating the 50 years of Yeshiba/Rutgers meeting
Glutathione Provides a Source of Cysteine Essential for Intracellular Multiplication of Francisella tularensis
Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. Its ability to multiply and survive in macrophages is critical for its virulence. By screening a bank of HimarFT transposon mutants of the F. tularensis live vaccine strain (LVS) to isolate intracellular growth-deficient mutants, we selected one mutant in a gene encoding a putative γ-glutamyl transpeptidase (GGT). This gene (FTL_0766) was hence designated ggt. The mutant strain showed impaired intracellular multiplication and was strongly attenuated for virulence in mice. Here we present evidence that the GGT activity of F. tularensis allows utilization of glutathione (GSH, γ-glutamyl-cysteinyl-glycine) and γ-glutamyl-cysteine dipeptide as cysteine sources to ensure intracellular growth. This is the first demonstration of the essential role of a nutrient acquisition system in the intracellular multiplication of F. tularensis. GSH is the most abundant source of cysteine in the host cytosol. Thus, the capacity this intracellular bacterial pathogen has evolved to utilize the available GSH, as a source of cysteine in the host cytosol, constitutes a paradigm of bacteria–host adaptation
Suivi longitudinal des patients adultes déficitaires en hormone de croissance avant et après traitement hormonal substitutif somatotrope
MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF
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