| 1. |
- Journeau, C., et al.
(författare)
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European Research on the Corium issues within the SARNET network of excellence
- 2008
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Ingår i: International Conference on Advances in Nuclear Power Plants, ICAPP 2008. - 9781605607870 ; , s. 1172-1181
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Konferensbidrag (refereegranskat)abstract
- Within SARNET, the corium topic covers all the behaviors of corium from early phase of core degradation to in or ex-vessel corium recovery with the exception of corium interaction with water, direct containment heating and fission product release. The corium topic regroups in three work packages the critical mass of competence required to improve significantly the corium behavior knowledge. The spirit of the SARNET networking is to share the knowledge, the facilities and the simulation tools for severe accidents, so to reach a better efficiency and to rationalize the R&D effort at European level. Extensive benchmarking has been launched in most of the areas of research. These benchmarks were mainly dedicated to the recalculation of experiments, while, in the next periods, a larger focus will be given to integral experiments or reactor applications. Eventually, all the knowledge will be accumulated in the ASTEC severe accident simulation code through physical model improvements and extension of validation database. This paper summarizes the progress that has been achieved in the frame of the networking activities. A special focus is placed on the melt pool and debris coolability and corium-concrete interaction, in which, the effects due to multidimensional geometries and heterogeneities has been shown, during SARNET, to play a crucial role and for which further research is still needed.
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| 2. |
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| 3. |
- Kuttippurath, J., et al.
(författare)
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Intercomparison of ozone profile measurements from ASUR, SCIAMACHY, MIPAS, OSIRIS, and SMR
- 2007
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 112:D9
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Tidskriftsartikel (refereegranskat)abstract
- The airborne submillimeter radiometer ( ASUR) was deployed onboard the Falcon research aircraft during the scanning imaging absorption spectrometer for atmospheric cartography ( SCIAMACHY) validation and utilization experiment ( SCIAVALUE) and the European polar stratospheric cloud and lee wave experiment ( EuPLEx) campaigns. A large number of ozone profile measurements were performed over a latitude band spanning from 5 degrees S to 80 degrees N in September 2002 and February/March 2003 during the SCIAVALUE and around the northern polar latitudes in January/February 2003 during the EuPLEx. Both missions amassed an ample microwave ozone profile data set that is used to make quantitative comparisons with satellite measurements in order to assess the quality of the satellite retrievals. In this paper, the ASUR ozone profile measurements are compared with measurements from SCIAMACHY and Michelson interferometer for passive atmospheric sounding ( MIPAS) on Environmental Satellite and optical spectrograph and infrared imager system ( OSIRIS) and submillimeter radiometer ( SMR) on the Odin satellite. The cross comparisons with the criterion that the ASUR measurements are performed within +/- 1000 km and +/- 6 hrs of the satellite observations show a good agreement with all the four satellite sensors. The differences in data values are the following: -4 to +8% for ASUR-SCIAMACHY ( operational product, v2.1), within +/- 15% for ASUR-SCIAMACHY ( scientific product, v1.62), up to +6% for ASUR-MIPAS ( operational product v4.61) and ASUR- MIPAS ( scientific product v1-O(3)-1), up to 17% for ASUR- OSIRIS ( v012), and -6 to 17% for ASUR- SMR ( v222) between the 20- and 40- km altitude range depending on latitude. Thus, the intercomparisons provide important quantitative information about the quality of the satellite ozone profiles, which has to be considered when using the data for scientific analyses.
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| 4. |
- Gongora, Jaime, et al.
(författare)
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Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA
- 2008
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 105:30, s. 10308-10313
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Tidskriftsartikel (refereegranskat)abstract
- European chickens were introduced into the American continents by the Spanish after their arrival in the 15th century. However, there is ongoing debate as to the presence of pre-Columbian chickens among Amerindians in South America, particularly in relation to Chilean breeds such as the Araucana and Passion Fowl. To understand the origin of these populations, we have generated partial mitochondrial DNA control region sequences from 41 native Chilean specimens and compared them with a previously generated database of approximate to 1,000 domestic chicken sequences from across the world as well as published Chilean and Polynesian ancient DNA sequences. The modern Chilean sequences cluster closely with haplotypes predominantly distributed among European, Indian subcontinental, and Southeast Asian chickens, consistent with a European genetic origin. A published, apparently pre-Columbian, Chilean specimen and six pre-European Polynesian specimens also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing no support for a Polynesian introduction of chickens to South America. In contrast, sequences from two archaeological sites on Easter Island group with an uncommon haplogroup from Indonesia, Japan, and China and may represent a genetic signature of an early Polynesian dispersal. Modeling of the potential marine carbon contribution to the Chilean archaeological specimen casts further doubt on claims for pre-Columbian chickens, and definitive proof will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia.
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| 5. |
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| 6. |
- Slater, Graham J., et al.
(författare)
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Evolutionary History of the Falklands Wolf
- 2009
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 19:20, s. R937-R938
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Baxter, Charles J, et al.
(författare)
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The metabolic response of heterotrophic Arabidopsis cells to oxidative stress
- 2007
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Ingår i: Plant Physiology. - Rockville, USA : American Society of Plant Biologists. - 0032-0889 .- 1532-2548. ; 143:1, s. 312-25
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Tidskriftsartikel (refereegranskat)abstract
- To cope with oxidative stress, the metabolic network of plant cells must be reconfigured either to bypass damaged enzymes or to support adaptive responses. To characterize the dynamics of metabolic change during oxidative stress, heterotrophic Arabidopsis (Arabidopsis thaliana) cells were treated with menadione and changes in metabolite abundance and (13)C-labeling kinetics were quantified in a time series of samples taken over a 6 h period. Oxidative stress had a profound effect on the central metabolic pathways with extensive metabolic inhibition radiating from the tricarboxylic acid cycle and including large sectors of amino acid metabolism. Sequential accumulation of metabolites in specific pathways indicated a subsequent backing up of glycolysis and a diversion of carbon into the oxidative pentose phosphate pathway. Microarray analysis revealed a coordinated transcriptomic response that represents an emergency coping strategy allowing the cell to survive the metabolic hiatus. Rather than attempt to replace inhibited enzymes, transcripts encoding these enzymes are in fact down-regulated while an antioxidant defense response is mounted. In addition, a major switch from anabolic to catabolic metabolism is signaled. Metabolism is also reconfigured to bypass damaged steps (e.g. induction of an external NADH dehydrogenase of the mitochondrial respiratory chain). The overall metabolic response of Arabidopsis cells to oxidative stress is remarkably similar to the superoxide and hydrogen peroxide stimulons of bacteria and yeast (Saccharomyces cerevisiae), suggesting that the stress regulatory and signaling pathways of plants and microbes may share common elements.
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| 8. |
- Charles, Nicolas, et al.
(författare)
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Lyn Kinase Controls Basophil GATA-3 Transcription Factor Expression and Induction of Th2 Cell Differentiation
- 2009
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Ingår i: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 30:4, s. 533-543
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Tidskriftsartikel (refereegranskat)abstract
- T helper 1 (Th1)-Th2 cell balance is key to host defense and its dysregulation has pathophysiological consequences. Basophils are important in Th2 cell differentiation. However, the factors controlling the onset and extent of basophil-mediated Th2 cell differentiation are unknown. Here, we demonstrate that Lyn kinase dampened basophil expression of the transcription factor GATA-3 and the initiation and extent of Th2 cell differentiation. Lyn-deficient mice had a marked basophilia, a constitutive Th2 cell skewing that was exacerbated upon in vivo challenge of basophils, produced antibodies to a normally inert antigen, and failed to appropriately respond to a Th1 cell-inducing pathogen. The Th2 cell skewing was dependent on basophils, immunoglobulin E, and interleukin-4, but was independent of mast cells. Our findings demonstrate that basophil-expressed Lyn kinase exerts regulatory control on Th2 cell differentiation and function.
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| 9. |
- Gustafson, J., et al.
(författare)
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Sensitivity of catalysis to surface structure: The example of CO oxidation on Rh under realistic conditions
- 2008
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 78:4
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Tidskriftsartikel (refereegranskat)abstract
- Using a combination of surface x-ray diffraction and mass spectrometry at realistic pressures, the CO oxidation reactivity of Rh(111) and Rh(100) model catalysts has been studied in conjunction with the surface structure. The measurements show that the presence of a specific thin surface oxide is crucial for the high activity of the Rh based CO oxidation. As this oxide is readily formed on all Rh facets, we conclude that the specific Rh crystal planes exposed during catalysis will not directly influence the reactivity. This is fortified by the very close similarity between the Rh(111) and the Rh(100) results.
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| 10. |
- Hesselson, Stephanie E, et al.
(författare)
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Genetic variation in the proximal promoter of ABC and SLC superfamilies : liver and kidney specific expression and promoter activity predict variation
- 2009
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:9, s. e6942-
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Tidskriftsartikel (refereegranskat)abstract
- Membrane transporters play crucial roles in the cellular uptake and efflux of an array of small molecules including nutrients, environmental toxins, and many clinically used drugs. We hypothesized that common genetic variation in the proximal promoter regions of transporter genes contribute to observed variation in drug response. A total of 579 polymorphisms were identified in the proximal promoters (-250 to +50 bp) and flanking 5' sequence of 107 transporters in the ATP Binding Cassette (ABC) and Solute Carrier (SLC) superfamilies in 272 DNA samples from ethnically diverse populations. Many transporter promoters contained multiple common polymorphisms. Using a sliding window analysis, we observed that, on average, nucleotide diversity (pi) was lowest at approximately 300 bp upstream of the transcription start site, suggesting that this region may harbor important functional elements. The proximal promoters of transporters that were highly expressed in the liver had greater nucleotide diversity than those that were highly expressed in the kidney consistent with greater negative selective pressure on the promoters of kidney transporters. Twenty-one promoters were evaluated for activity using reporter assays. Greater nucleotide diversity was observed in promoters with strong activity compared to promoters with weak activity, suggesting that weak promoters are under more negative selective pressure than promoters with high activity. Collectively, these results suggest that the proximal promoter region of membrane transporters is rich in variation and that variants in these regions may play a role in interindividual variation in drug disposition and response.
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