Fabrication, properties, and tritium recovery from solid breeder materials

The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Experimental Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 133 refs., 1 fig

Crystal structure of nucleotide-free dynamin

Dynamin is a mechanochemical GTPase that oligomerizes around the neck of clathrin-coated pits and catalyses vesicle scission in a GTP-hydrolysis-dependent manner. The molecular details of oligomerization and the mechanism of the mechanochemical coupling are currently unknown. Here we present the crystal structure of human dynamin 1 in the nucleotide-free state with a four-domain architecture comprising the GTPase domain, the bundle signalling element, the stalk and the pleckstrin homology domain. Dynamin 1 oligomerized in the crystals via the stalks, which assemble in a criss-cross fashion. The stalks further interact via conserved surfaces with the pleckstrin homology domain and the bundle signalling element of the neighbouring dynamin molecule. This intricate domain interaction rationalizes a number of disease-related mutations in dynamin 2 and suggests a structural model for the mechanochemical coupling that reconciles previous models of dynamin function

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Identification biochimique de clones et de lignées d'asperge III. Caractérisation des hybrides de clones hétérozygotes

National audienceIsoenzyme patterns of peroxidase and acid phosphatase have been studied in the cladophylls of 5 hybrids between heterozygous clones. Isoenzymes have been separated by electrofocusing in polyacrylamide gel with a pH gradient of 3.5 to 9.5 or 4 to 6.5. Cathodic peroxidases, anodic peroxidases and acid phosphatases were expressed independently. In each of these categories, the distribution of the different patterns of isoenzymes was of 1-1 or 1-2-1 type (with some patterns grouped together) : each hybrid can thus be characterized by examination of 20 plants. By revealing the diversity of the genetic inheritance of heterozygous parental clones, the study of hybrids has confirmed the existence of linkages between genes coding for certain isopcroxidascs and the allelism of genes coding for various sets of isoenzymes.La distribution des isoenzymes de la peroxydase et de la phosphatase acide a été étudiée dans le feuillage de 5 hybrides entre clones hétérozygotes. Les isoenzymes ont été séparées par électrofocalisation sur gel de polyacrylamide en gradient de pH 3,5 à 9,5 ou 4 à 6,5. Peroxydases cathodiques, peroxydases anodiques et phosphatases acides s’expriment de façon indépendante. Dans chacune de ces catégories, la distribution des divers diagrammes d’isoenzymes est du type 1-1 ou 1-2-1 (moyennant certains regroupements) : de ce fait, l’examen de 20 plantes permet de caractériser chaque hybride. En explicitant la diversité du patrimoine génétique des clones hétérozygotes parentaux, l’étude des hybrides a confirmé l’existence de linkages entre les gènes codant pour certaines isoperoxydases et l’allélisme des gènes codant pour divers groupes d’isoenzymes

Caractérisation de Lactuca sativa L. et des espèces apparentées par électrofocalisation des estérases

Les isoenzymes des estérases foliaires de Lactuca sativa et des espèces apparentées (L. aculeata, L. serriola, L. saligna, L. virosa) ont été séparées par électrofocalisation sur gel de polyacrylamide en gradient de pH 4 à 6,5. La variabilité des estérases est faible au sein de chaque espèce. L. sativa et L. serriola présentent des diagrammes très voisins qui confirment leur proche parenté ; L. aculeata apparaît proche de L. serriola ; L. saligna et L. virosa sont très distinctes des trois autres espèces. Les diagrammes d’estérases permettent de tester le caractère hybride des plantes issues de croisements interspécifiques (L. sativa x L. virosa).Isoenzymes of foliar esterases from Lactuca sativa and related species (L. aculeata, L. serriola, L. saligna, L. virosa) have been separated by electrofocusing on polyacrylamide gel in a pH gradient of 4 to 6.5. Esterases presented a low variability within each species. L. sativa and L. serriola showed closely related diagrams which confirm their genetic closeness ; L. aculeata appeared near L. serriola, L. saligna and L. virosa were very distinct from the other three species. The esterase diagrams could be used to test the hybrid character of plants issued from interspecific crosses (L. sativa x L. virosa)

Caractérisation de Lactuca sativa L. et des espèces apparentées par électrofocalisation des estérases

National audienceIsoenzymes of foliar esterases from Lactuca sativa and related species (L. aculeata, L. serriola, L. saligna, L. virosa) have been separated by electrofocusing on polyacrylamide gel in a pH gradient of 4 to 6.5. Esterases presented a low variability within each species. L. sativa and L. serriola showed closely related diagrams which confirm their genetic closeness ; L. aculeata appeared near L. serriola, L. saligna and L. virosa were very distinct from the other three species. The esterase diagrams could be used to test the hybrid character of plants issued from interspecific crosses (L. sativa x L. virosa).Les isoenzymes des estérases foliaires de Lactuca sativa et des espèces apparentées (L. aculeata, L. serriola, L. saligna, L. virosa) ont été séparées par électrofocalisation sur gel de polyacrylamide en gradient de pH 4 à 6,5. La variabilité des estérases est faible au sein de chaque espèce. L. sativa et L. serriola présentent des diagrammes très voisins qui confirment leur proche parenté ; L. aculeata apparaît proche de L. serriola ; L. saligna et L. virosa sont très distinctes des trois autres espèces. Les diagrammes d’estérases permettent de tester le caractère hybride des plantes issues de croisements interspécifiques (L. sativa x L. virosa)

Caracteristiques minimales d'un ordinateur et de son logiciel de base pour executer la phase numerique de NEPTUNIX 2

FortranSIGLEAvailable from CEN Saclay, Service de Documentation, 91191 - Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc