Experimental study of reinforced soil bunds subjected to horizontal impact

14th International Congress of Rock Mechanics and Rock Engineering, FOZ DO IGUACU, BRESIL, 13-/09/2019 - 18/09/2019Rockfall phenomenon is a common event in mountainous areas and presents a serious risk to the nearby buildings or infrastructure. Different protection measures may be taken depending on the site conditions. A reinforced soil bund can be effective in stopping blocks with relatively high speed and kinetic energy. This article presents the response of three reinforced soil bunds subjected to horizontal impacts. The tests are dimensioned in a reduced scale with a factor of 1/3 by following specific similarity rules and assumptions. A rectangular shape with ratio height/width equal to 2 is chosen aiming to have a lower footprint than the dominating trapezoidal shape of existing soil bunds. In order to find the most efficient design, different reinforcement patterns are installed in each bund. The failure mechanisms and the role of the reinforcements are observed with several instrumentations

Comportement de l'interface barre - scellement d'un ancrage passif scellé au rocher : étude numérique

La compréhension du comportement des ancrages passifs scellés au rocher nécessite de définir celui de l'interface barre-scellement. Sollicitée en cisaillement, différents mécanismes de rupture interviennent suivant les conditions de confinement. Or les modèles issus des études expérimentales se limitent à un comportement tangentiel sans considérer l'influence de paramètres comme l'épaisseur de scellement ou la rigidité de la roche. Cette étude présente une approche numérique pour étudier le comportement tangentiel de l'interface barre-scellement en tenant compte du comportement radial. Pour cela, des essais d'arrachement sur de faibles longueurs de barres scellées ont été reproduits numériquement. Une attention particulière a été portée à la définition du comportement du matériau de scellement afin de reproduire les différents mécanismes de rupture possibles. Pour décrire le comportement en traction, ainsi que celui en compression, l'effet d'échelle a été pris en compte. La confrontation entre les résultats numériques et expérimentaux permet de valider ce modèle numérique. Ce dernier va être utilisé pour effectuer une étude paramétrique du comportement tangentiel de l'interface en faisant varier les conditions de confinement

Amélioration de la détermination des propriétés de résistance de l'interface béton-rocher et des discontinuités des fondations rocheuses des barrages poids

CIGB 2018, 26è Congrès des Grands Barrages, Vienne, AUTRICHE, 01-/07/2018 - 07/07/2018La détermination des caractéristiques mécaniques régissant la stabilité d'un barrage existant peut s'avérer complexe notamment en ce qui concerne les discontinuités présentes en fondation et à l'interface barrage-fondation. Ces caractéristiques sont la résistance à la traction, la cohésion et l'angle de frottement. Fort de ce constat, IRSTEA et EDF ont lancé des travaux de recherche ces dernières années de manière d'une part à créer des données utiles à la compréhension des mécanismes de rupture et d'autre part à proposer des méthodologies d'estimation des caractéristiques mécaniques utilisables directement par l'ingénierie. Le présent article donne les principaux résultats des essais de traction et de cisaillement sur des interfaces béton-rocher. Ces résultats pourraient faire l'objet d'échange et de partage avec les ingénieries intéressées par le sujet. L'article présente également des méthodologies de détermination des caractéristiques de discontinuités rocheuses en cisaillement ainsi que des caractéristiques de résistance à la traction de l'interface béton-rocher. Des perspectives sont proposées quant à de futures actions de recherche prometteuses telles que la caractérisation de la cohésion apparente des discontinuités rocheuses et l'estimation de la géométrie du contact barrage-fondation par des méthodes non-destructives

Retrospective French nationwide survey of childhood aggressive vascular anomalies of bone, 1988-2009

<p>Abstract</p> <p>Objective</p> <p>To document the epidemiological, clinical, histological and radiological characteristics of aggressive vascular abnormalities of bone in children.</p> <p>Study design</p> <p>Correspondents of the French Society of Childhood Malignancies were asked to notify all cases of aggressive vascular abnormalities of bone diagnosed between January 1988 and September 2009.</p> <p>Results</p> <p>21 cases were identified; 62% of the patients were boys. No familial cases were observed, and the disease appeared to be sporadic. Mean age at diagnosis was 8.0 years [0.8-16.9 years]. Median follow-up was 3 years [0.3-17 years]. The main presenting signs were bone fracture (n = 4) and respiratory distress (n = 7), but more indolent onset was observed in 8 cases. Lung involvement, with lymphangiectasies and pleural effusion, was the most frequent form of extraosseous involvement (10/21). Bisphosphonates, alpha interferon and radiotherapy were used as potentially curative treatments. High-dose radiotherapy appeared to be effective on pleural effusion but caused major late sequelae, whereas antiangiogenic drugs like alpha interferon and zoledrenate have had a limited impact on the course of pulmonary complications. The impact of bisphosphonates and alpha interferon on bone lesions was also difficult to assess, owing to insufficient follow-up in most cases, but it was occasionally positive. Six deaths were observed and the overall 10-year mortality rate was about 30%. The prognosis depended mainly on pulmonary and spinal complications.</p> <p>Conclusion</p> <p>Aggressive vascular abnormalities of bone are extremely rare in childhood but are lifethreatening. The impact of anti-angiogenic drugs on pulmonary complications seems to be limited, but they may improve bone lesions.</p

The retrospective analysis of Antarctic tracking data project

The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations

The retrospective analysis of Antarctic tracking data project

The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations.Supplementary Figure S1: Filtered location data (black) and tag deployment locations (red) for each species. Maps are Lambert Azimuthal projections extending from 90° S to 20° S.Supplementary Table S1: Names and coordinates of the major study sites in the Southern Ocean and on the Antarctic Continent where tracking devices were deployed on the selected species (indicated by their 4-letter codes in the last column).Online Table 1: Description of fields (column names) in the metadata and data files.Supranational committees and organisations including the Scientific Committee on Antarctic Research Life Science Group and BirdLife International. National institutions and foundations, including but not limited to Argentina (Dirección Nacional del Antártico), Australia (Australian Antarctic program; Australian Research Council; Sea World Research and Rescue Foundation Inc., IMOS is a national collaborative research infrastructure, supported by the Australian Government and operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent), Belgium (Belgian Science Policy Office, EU Lifewatch ERIC), Brazil (Brazilian Antarctic Programme; Brazilian National Research Council (CNPq/MCTI) and CAPES), France (Agence Nationale de la Recherche; Centre National d’Etudes Spatiales; Centre National de la Recherche Scientifique; the French Foundation for Research on Biodiversity (FRB; www.fondationbiodiversite.fr) in the context of the CESAB project “RAATD”; Fondation Total; Institut Paul-Emile Victor; Programme Zone Atelier de Recherches sur l’Environnement Antarctique et Subantarctique; Terres Australes et Antarctiques Françaises), Germany (Deutsche Forschungsgemeinschaft, Hanse-Wissenschaftskolleg - Institute for Advanced Study), Italy (Italian National Antarctic Research Program; Ministry for Education University and Research), Japan (Japanese Antarctic Research Expedition; JSPS Kakenhi grant), Monaco (Fondation Prince Albert II de Monaco), New Zealand (Ministry for Primary Industries - BRAG; Pew Charitable Trusts), Norway (Norwegian Antarctic Research Expeditions; Norwegian Research Council), Portugal (Foundation for Science and Technology), South Africa (Department of Environmental Affairs; National Research Foundation; South African National Antarctic Programme), UK (Darwin Plus; Ecosystems Programme at the British Antarctic Survey; Natural Environment Research Council; WWF), and USA (U.S. AMLR Program of NOAA Fisheries; US Office of Polar Programs).http://www.nature.com/sdataam2021Mammal Research Institut

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation