| 1. |
- Journeau, C., et al.
(author)
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European Research on the Corium issues within the SARNET network of excellence
- 2008
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In: International Conference on Advances in Nuclear Power Plants, ICAPP 2008. - 9781605607870 ; , s. 1172-1181
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Conference paper (peer-reviewed)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. |
- Bessueille, Laurence, et al.
(author)
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Plasma membrane microdomains from hybrid aspen cells are involved in cell wall polysaccharide biosynthesis
- 2009
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In: Biochemical Journal. - : Portland Press Ltd.. - 0264-6021 .- 1470-8728. ; 420, s. 93-103
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Journal article (peer-reviewed)abstract
- Detergent-resistant plasma membrane microdomains [DRMs (detergent-resistant membranes)] were isolated recently from several plant species. As for animal cells, a large range of cellular functions, such as signal transduction, endocytosis and protein trafficking, have been attributed to plant lipid rafts and DRMs. The data available are essentially based on protcomics and more approaches need to be undertaken to elucidate the precise function of individual populations of DRMs in plants. We report here the first isolation of DRMs from purified plasma membranes of a tree species, the hybrid aspen Populus tremula x tremuloides, and their biochemical characterization. Plasma membranes were solubilized with Triton X-100 and the resulting DRMs were isolated by flotation in sucrose density gradients. The DRMs were enriched in sterols, sphingolipids and glycosylphosphatidylinositol-anchored proteins and thus exhibited similar properties to DRMs from other species. However, they contained key carbohydrate synthases involved in cell wall polysaccharide biosynthesis, namely callose [(1 -> 3)-beta-D-glucan] and cellulose synthases. The association of these enzymes with DRMs was demonstrated using specific glucan synthase assays and antibodies, as well as biochemical and chemical approaches for the characterization of the polysaccharides synthesized in vitro by the isolated DRMs. More than 70% of the total glucan synthase activities present in the original plasma membranes was associated with the DRM fraction. In addition to shedding light on the lipid environment of callose and cellulose synthases, our results demonstrate the involvement of DRMs in the biosynthesis of important cell wall polysaccharides. This novel concept suggests a function of plant membrane microdomains in cell growth and morphogenesis.
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| 3. |
- Charles, Nicolas, et al.
(author)
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Lyn Kinase Controls Basophil GATA-3 Transcription Factor Expression and Induction of Th2 Cell Differentiation
- 2009
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In: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 30:4, s. 533-543
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Journal article (peer-reviewed)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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| 4. |
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| 5. |
- Cuburu, Nicolas, et al.
(author)
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Sublingual immunization with nonreplicating antigens induces antibody-forming cells and cytotoxic T cells in the female genital tract mucosa and protects against genital papillomavirus infection.
- 2009
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In: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 183:12, s. 7851-9
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Journal article (peer-reviewed)abstract
- We have recently reported that the sublingual (s.l.) mucosa is an efficient site for inducing systemic and mucosal immune responses. In this study, the potential of s.l. immunization to induce remote Ab responses and CD8(+) cytotoxic responses in the female genital tract was examined in mice by using a nonreplicating Ag, OVA, and cholera toxin (CT) as an adjuvant. Sublingual administration of OVA and CT induced Ag-specific IgA and IgG Abs in blood and in cervicovaginal secretions. These responses were associated with large numbers of IgA Ab-secreting cells (ASCs) in the genital mucosa. Genital ASC responses were similar in magnitude and isotype distribution after s.l., intranasal, or vaginal immunization and were superior to those seen after intragastric immunization. Genital, but not blood or spleen, IgA ASC responses were inhibited by treatment with anti-CCL28 Abs, suggesting that the chemokine CCL28 plays a major role in the migration of IgA ASC progenitors to the reproductive tract mucosa. Furthermore, s.l. immunization with OVA induced OVA-specific effector CD8(+) cytolytic T cells in the genital mucosa, and these responses required coadministration of the CT adjuvant. Furthermore, s.l. administration of human papillomavirus virus-like particles with or without the CT adjuvant conferred protection against genital challenge with human papillomavirus pseudovirions. Taken together, these findings underscore the potential of s.l. immunization as an efficient vaccination strategy for inducing genital immune responses and should impact on the development of vaccines against sexually transmitted diseases.
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| 6. |
- Gongora, Jaime, et al.
(author)
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Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA
- 2008
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In: 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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Journal article (peer-reviewed)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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| 7. |
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| 8. |
- Paetzold, Martin, et al.
(author)
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Rosetta Radio Science Investigations (RSI)
- 2007
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In: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 128:1-4, s. 599-627
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Research review (peer-reviewed)abstract
- The Rosetta spacecraft has been successfully launched on 2nd March 2004 to its new target comet 67 P/Churyurnov-Gerasimenko. The science objectives of the Rosetta Radio Science Investigations (RSI) experiment address fundamental aspects of cometary physics such as the mass and bulk density of the nucleus, its gravity field, its interplanetary orbit perturbed by nongravitational forces, its size and shape, its internal structure, the composition and roughness of the nucleus surface, the abundance of large dust grains, the plasma content in the coma and the combined dust and gas mass flux. The masses of two asteroids, Steins and Lutetia, shall be determined during flybys in 2008 and 2010. respectively. Secondary objectives are the radio sounding of the solar corona during the superior conjunctions of the spacecraft with the Sun during the cruise phase. The radio carrier links of the spacecraft Telemetry, Tracking and Command (TT&C) subsystem between the orbiter and the Earth will be used for these investigations. An Ultrastable oscillator (USO) connected to both transponders of the radio subsystem serves as a stable frequency reference source for both radio downlinks at X-band (8.4 GHz) and S-band (2.3 GHz) in the one-way mode. The Simultaneous and coherent dual-frequency downlinks via the High Gain Antenna (HGA) permit separation of contributions from the classical Doppler shift and the dispersive media effects caused by the motion of the spacecraft with respect to the Earth and the propagation of the signals through the dispersive media, respectively.
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| 9. |
- Rodriguez, T, et al.
(author)
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Photorealistic 3D reconstruction from handheld cameras
- 2005
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In: Machine Vision and Applications. - : Springer Science and Business Media LLC. - 0932-8092 .- 1432-1769. ; 16:4, s. 246-257
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Journal article (peer-reviewed)abstract
- One of the major challenges in the fields of computer vision and computer graphics is the construction and representation of life-like virtual 3D scenarios within a computer. The VISIRE project attempts to reconstruct photo-realistic 3D models of large scenarios using as input multiple freehand video sequences, while rendering the technology accessible to the non-expert. VISIRE is application oriented and hence must deal with multiple issues of practical relevance that were commonly overlooked in past experiences. The paper presents both an innovative approach for the integration of previously unrelated experiences, as well as a number of novel contributions, such as: an innovative algorithm to enforce closedness of the trajectories, a new approach to 3D mesh generation from sparse data, novel techniques dealing with partial occlusions and a method for using photo-consistency and visibility constrains to refine the 3D mesh.
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| 10. |
- Takahashi Schmidt, Junko, et al.
(author)
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KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems
- 2009
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In: Plant and Cell Physiology. - : Oxford University Press (OUP). - 0032-0781 .- 1471-9053. ; 50:6, s. 1099-1115
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Journal article (peer-reviewed)abstract
- KORRIGAN1 (KOR1) is a membrane-bound cellulase implicated in cellulose biosynthesis. PttCel9A1 from hybrid aspen (Populus tremula L. tremuloides Michx.) has high sequence similarity to KOR1 and we demonstrate here that it complements kor1-1 mutants, indicating that it is a KOR1 ortholog. We investigated the function of PttCel9A1/KOR1 in Arabidopsis secondary growth using transgenic lines expressing 35S::PttCel9A1 and the KOR1 mutant line irx2-2. The presence of elevated levels of PttCel9A1/KOR1 in secondary walls of 35S::PttCel9A1 lines was confirmed by in muro visualization of cellulase activity. Compared with the wild type, 35S::PttCel9A1 lines had higher trifluoroacetic acid (TFA)-hydrolyzable glucan contents, similar Updegraff cellulose contents and lower cellulose crystallinity indices, as determined by C-13 solid-state nuclear magnetic resonance (NMR) spectroscopy. irx2-2 mutants had wild-type TFA-hydrolyzable glucan contents, but reduced Updegraff cellulose contents and higher than wild-type cellulose crystallinity indices. The data support the hypothesis that PttCel9A1/KOR1 activity is present in cell walls, where it facilitates cellulose biosynthesis in a way that increases the amount of non-crystalline cellulose.
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