280 research outputs found
Un plaidoyer en faveur de la recherche polaire : Lorius C., Gendrin R., 1997, L'Antarctique, Paris : Flammarion, coll. Dominos
No full textBenjamin Didier. Un plaidoyer en faveur de la recherche polaire : Lorius C., Gendrin R., 1997, L'Antarctique, Paris : Flammarion, coll. Dominos. In: Mappemonde 54, 1999/2. Les outre-mers français. p. 48
The complete mitochondrial genome of yellow-bibbed lory, Lorius chlorocercus (Psittaciformes Psittacidae), with its phylogenetic relationship
No full textIn this study, the complete 17,855 bp mitochondrial genome of Lorius chlorocercus was obtained using sanger sequencing. It consists of 13 protein-coding genes, 22 tRNAs, 2 ribosomal RNAs, and a control region. The overall base composition is 22.5% T, 33.18% C, 30.42% A, and13.9% G. The phylogenetic tree was constructed using neighbour-joining (NJ) method based on 19 parrot species. Phylogenetic analysis showed that L. chlorocercus was closest to Melopsittacus undulates. The complete mitogenome data would be useful for further study on the molecular evolution of L. chlorocercus
Climatic Interpretation of a Continuous Deuterium Profile Obtained from the Vostok Ice Core, Antarctica (160 000 Years) (Abstract)
No full textOceanic studies have convincingly demonstrated that there is a link between the Pleistocene ice ages and the variations in the elements of the Earth’s orbit (Imbrie and others 1984). In contrast, the climatic conditions which prevailed over continental areas have been far less well documented and then rarely on a quantitative basis.In this context, the 2083 m ice core recovered by the Soviet Antarctic Expeditions at Vostok (East Antarctica) is of fundamental importance because it covers fully the last glacial-interglacial cycle, back to the ice age which preceded the last interglacial (∽160 ka B.P.). Potentially it allows access to many climatic and climate-related parameters as illustrated by the oxygen-18 data we have recently published (Lorius and others 1985), from 10Be measurements (Yiou and others 1985, Raisbeck and others 1987), from aerosol concentration (De Angelis and others 1987) and from CO2 measurement (Barnola and others 1988, this volume).Our first isotopic data set was largely discontinuous over the last 100 ka (only about 7% of the core was analyzed), but continuous beyond that time. Sampling of the ice was completed later, in the field, and we now have continuous deuterium data for the whole core (total ice recovery is about 85%), combining the data of the 2083 m core below 138 m and a complementary data set above. The core chronology was established using a two-dimensional ice-flow model and, for snow accumulation, taking into account change with time (Lorius and others 1985).There is a general correspondence between this curve and the previously published δ18O record (Lorius and others 1985). However, there is obviously far more information in this continuous δD record, which we will examine from the deduced temperature record.</jats:p
Climatic Interpretation of a Continuous Deuterium Profile Obtained from the Vostok Ice Core, Antarctica (160 000 Years) (Abstract)
No full textOceanic studies have convincingly demonstrated that there is a link between the Pleistocene ice ages and the variations in the elements of the Earth’s orbit (Imbrie and others 1984). In contrast, the climatic conditions which prevailed over continental areas have been far less well documented and then rarely on a quantitative basis.
In this context, the 2083 m ice core recovered by the Soviet Antarctic Expeditions at Vostok (East Antarctica) is of fundamental importance because it covers fully the last glacial-interglacial cycle, back to the ice age which preceded the last interglacial (∽160 ka B.P.). Potentially it allows access to many climatic and climate-related parameters as illustrated by the oxygen-18 data we have recently published (Lorius and others 1985), from 10Be measurements (Yiou and others 1985, Raisbeck and others 1987), from aerosol concentration (De Angelis and others 1987) and from CO2 measurement (Barnola and others 1988, this volume).
Our first isotopic data set was largely discontinuous over the last 100 ka (only about 7% of the core was analyzed), but continuous beyond that time. Sampling of the ice was completed later, in the field, and we now have continuous deuterium data for the whole core (total ice recovery is about 85%), combining the data of the 2083 m core below 138 m and a complementary data set above. The core chronology was established using a two-dimensional ice-flow model and, for snow accumulation, taking into account change with time (Lorius and others 1985).
There is a general correspondence between this curve and the previously published δ18O record (Lorius and others 1985). However, there is obviously far more information in this continuous δD record, which we will examine from the deduced temperature record.</jats:p
Isotope climatic record from ice core Dome C
No full textSimple glaciological conditions at Dome C in east Antarctica have made possible a more detailed and accurate interpretation of an ice core to 950 m depth spanning some 32,000 yr than that obtained from earlier ice cores. Dated events in comparable marine core has enabled the reduction of accumulation rate during the last ice age to be estimated. Climatic events recorded in the ice core indicate that the warmest Holocene period in the Southern Hemisphere occurred at an earlier date than in the Northern Hemisphere
Le deuterium : possibilites d'application aux problemes de recherche concernant la neige, le neve et la glace dans l'Antarctique.
No full textCNFRA ; no. 8Text in French
Evolution of climate
No full textLe Dr.Lorius est née en 1932, il est docteur en Physique et travaille au Centre National de la Recherche Scientifique; il a participé à 11 missions polaires en Antarctique et du Groenland. Il parlera de l'évolution du climat, de la pollution de notre atmosphère qui sont parmi les grands soucis de notre époque
First case report of fatal Nocardia nova infection in yellow-bibbed lory (Lorius chlorocercus) identified by multilocus sequencing
No full textAbstract Background Nocardiosis is often a multi-systemic disease in humans and other mammals. Nocardiosis in birds is uncommon. Laboratory identification of Nocardia to the species level is difficult by traditional phenotypic methods based on biochemical reactions and hydrolysis tests, and is most accurately performed by sequencing multiple gene targets. Case presentation We report the first case of fatal Nocardia nova infection in a yellow-bibbed lory nestling in an oceanarium diagnosed by multilocus sequencing. Necropsy examination showed effacement of normal sternal musculature with yellowish, firm aberrant material, and diffuse infiltration of the lungs with nodular, tan to yellow foci. Histologically, severe granulomatous inflammation with marked necrosis was observed in the lung, spleen and sternal musculature. Fine, sometimes Gram-positive, 0.5–1 μm wide, branching and beaded filamentous organisms were visible within the lesions. They were acid-fast on Fite-Faraco stain. Tissue samples obtained from the sternum, liver, right lung and right kidney recovered Nocardia species. Sequencing of four gene loci and phylogenetic analysis of concatenated (gyrB-16S-secA1-hsp65) sequences revealed that the isolate was N. nova. Conclusions We report the first case of N. nova infection in yellow-bibbed lorry (Lorius chlorocercus). The present case is the first one of which the species identity of the isolate was determined by multilocus sequencing. Molecular diagnosis is important for identifying the Nocardia to species level and understanding the epidemiology of nocardiosis in birds
Contribution to the Knowledge of the Antarctic Ice Sheet: A Synthesis of Glaciological Measurements in Terre Adélie
No full textAbstractThis paper is a synthesis of glaciological investigations conducted in Terre Adélie, mainly during the LG.Y. The surface and bedrock profiles have been obtained along a 500 km. line roughly perpendicular to the coast; the mean annual temperature has been studied as a finnction of altitude, and mean accumulation has been related to distance from the coast and surface slope. Stratigraphic studies made at Station Charcot again raise the problem of the determination of mean accumulation in certain parts of the Antarctic plateau; they provide a quadratic relationship between density and depth. The snow-drift studies lead to the Mowing conclusions: wind velocity and density of drifting snow are functions of height above the surface, and the total transport depends on wind velocity. Lastly, measurements have been made of glacier flow near the coast. The paper ends with a schematic study of the mass balance in Terre Adélie; accumulation seems to be slightly larger than ablation, a result that is to be contrasted with the obtervrd coastal retreat near Dumont d’Urille base.</jats:p
Contribution to the Knowledge of the Antarctic Ice Sheet: A Synthesis of Glaciological Measurements in Terre Adélie
No full textAbstractThis paper is a synthesis of glaciological investigations conducted in Terre Adélie, mainly during the LG.Y. The surface and bedrock profiles have been obtained along a 500 km. line roughly perpendicular to the coast; the mean annual temperature has been studied as a finnction of altitude, and mean accumulation has been related to distance from the coast and surface slope. Stratigraphic studies made at Station Charcot again raise the problem of the determination of mean accumulation in certain parts of the Antarctic plateau; they provide a quadratic relationship between density and depth. The snow-drift studies lead to the Mowing conclusions: wind velocity and density of drifting snow are functions of height above the surface, and the total transport depends on wind velocity. Lastly, measurements have been made of glacier flow near the coast. The paper ends with a schematic study of the mass balance in Terre Adélie; accumulation seems to be slightly larger than ablation, a result that is to be contrasted with the obtervrd coastal retreat near Dumont d’Urille base.</jats:p
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