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Start Over Author "Grimaud F" Publisher oxford university press
4 results on '"Grimaud F"'

1. Absolute earthquake locations using 3-D versus 1-D velocity models below a local seismic network: example from the Pyrenees

Author

Agence Nationale de la Recherche (France), Theunissen, T., Chevrot, S., Sylvander, Matthieu, Monteiller, V., Calvet, M., Villaseñor, Antonio, Benahmed, S., Pauchet, Hélène, Grimaud, F., Agence Nationale de la Recherche (France), Theunissen, T., Chevrot, S., Sylvander, Matthieu, Monteiller, V., Calvet, M., Villaseñor, Antonio, Benahmed, S., Pauchet, Hélène, and Grimaud, F.

Abstract

Local seismic networks are usually designed so that earthquakes are located inside them (primary azimuthal gap < < 180 degrees) and close to the seismic stations (0-100 km). With these local or near-regional networks (0 degrees-5 degrees), many seismological observatories still routinely locate earthquakes using 1-D velocity models. Moving towards 3-D location algorithms requires robust 3-D velocity models. This work takes advantage of seismic monitoring spanning more than 30 yr in the Pyrenean region. We investigate the influence of a well-designed 3-D model with station corrections including basins structure and the geometry of the Mohorovicic discontinuity on earthquake locations. In the most favourable cases (GAP < 180 degrees and distance to the first station lower than 15 km), results using 1-D velocity models are very similar to 3-D results. The horizontal accuracy in the 1-D case can be higher than in the 3-D case if lateral variations in the structure are not properly resolved. Depth is systematically better resolved in the 3-D model even on the boundaries of the seismic network (GAP > 180 degrees and distance to the first station higher than 15 km). Errors on velocity models and accuracy of absolute earthquake locations are assessed based on a reference data set made of active seismic, quarry blasts and passive temporary experiments. Solutions and uncertainties are estimated using the probabilistic approach of the NonLinLoc (NLLoc) software based on Equal Differential Time. Some updates have been added to NLLoc to better focus on the final solution (outlier exclusion, multiscale grid search, S-phases weighting). Errors in the probabilistic approach are defined to take into account errors on velocity models and on arrival times. The seismicity in the final 3-D catalogue is located with a horizontal uncertainty of about 2.0 +/- 1.9 km and a vertical uncertainty of about 3.0 +/- 2.0 km.

Published
2018

2. The Pyrenean architecture as revealed by teleseismic P-to-S converted waves recorded along two dense transects

Author

Chevrot, S., Sylvander, Matthieu, Diaz, J., Ruiz Fernández, Mario, Paul, A., Cougoulat, G., Péquegnat, C., Wolyniec, D., Delmas, P., Grimaud, F., Benahmed, S., Pauchet, Hélène, De Saint Blanquat, M., Lagabrielle, Yves, Manatschal, Gianreto, Chevrot, S., Sylvander, Matthieu, Diaz, J., Ruiz Fernández, Mario, Paul, A., Cougoulat, G., Péquegnat, C., Wolyniec, D., Delmas, P., Grimaud, F., Benahmed, S., Pauchet, Hélène, De Saint Blanquat, M., Lagabrielle, Yves, and Manatschal, Gianreto

Abstract

© The Authors 2014. Between 2011 and 2013, two dense transects were deployed across the central and western Pyrenees to get better constraints on the deep lithospheric architecture and discriminate the competing models of the structure and formation of the Pyrenees. Each transect recorded the regional and global seismicity during a period of approximately 1 yr. Here, we exploit the records of teleseismic compressional waves and of their conversions to shear waves on internal discontinuities in order to map lithospheric interfaces beneath the two transects. The migrated sections, obtained by performing common conversion point stacks, are in remarkable agreement with the results of the ECORS-Pyrenees and ECORS-Arzacq deep seismic surveys. However, the migrations of converted waves reveal new details of the deep lithospheric architecture that could not be seen with the active source experiments. The new images provide clear and definite evidence for the subduction of a thinned Iberian crust down to at least ~70 km depth, a result that has important implications for the formation of the Pyrenees. The subduction of the Iberian lithosphere leads to reconsider the amount of convergence between Iberia and Europe during the Cenozoic. A recent regional P-wave tomography, relying on the data of the PYROPE and IBERARRAY temporary experiments, revealed the segmentation of lithospheric structures by inherited Hercynian NE-SW transfer faults that were reactivated during the Albian rifting. Ourmigration images are consistent with this model, and give further support to the idea that the Pyrenees were produced by the tectonic inversion of a segmented hyperextended rift that was buried by subduction beneath the European Plate.

Published
2015

3. Clinical and immunological features of antiphospholipid syndrome in the elderly: a retrospective national multicentre study.

Author

Grimaud F, Yelnik C, Pineton de Chambrun M, Amoura Z, Arnaud L, Costedoat Chalumeau N, Hachulla E, Lambert M, Roriz M, Sibilia J, Papo T, and Sacre K

Subjects
Aged, Antibodies, Antiphospholipid immunology, Antiphospholipid Syndrome drug therapy, Antiphospholipid Syndrome immunology, Autoantibodies, Female, France, Humans, Male, Middle Aged, Retrospective Studies, Symptom Assessment, beta 2-Glycoprotein I immunology, Anticoagulants therapeutic use, Antiphospholipid Syndrome diagnosis, Platelet Aggregation Inhibitors therapeutic use
Abstract

Objective: APS mainly affects women who are of child-bearing age. We aimed to describe the clinical and immunological features of APS patients diagnosed after the age of 60., Methods: The Elderly-Phospholipid study is a national, multicentre, retrospective study involving all APS (2006 Miyakis criteria) patients followed in five French tertiary university centres including four national referral lupus and APS centres. Clinical and serological data of patients in whom APS onset occurred after the age of 60 were analysed and compared with patients included in the Euro-Phospholipid cohort., Results: Forty-four patients (30 women (68.2%); 68.7 (7) years at diagnosis; 72.7% of primary APS) were included in the Elderly-Phospholipid study. Stroke was the most common manifestation at diagnosis (38.6%) and during follow-up (11.4%). LA, aCL and anti-β2-glycoprotein I antibodies were detected in 70.4%, 72.7% and 65.9% of patients, respectively; 43.2% of patients were triple-positive for aPL antibodies. All patients were treated with antithrombotic treatment including antiplatelet agents (31.8%) and/or oral anticoagulants (77.3%). Over a 5.3 (3.8) years follow-up, nine (20.5%) patients displayed a new arterial (n = 8) or venous (n = 1) thrombotic event. Only three (6.8%) patients developed major bleeding. As compared with Euro-Phospholipid APS patients (mean age of 34 (13) years at disease onset), patients in the Elderly-Phospholipid study were more frequently male (P < 0.05) and had a higher frequency of primary APS (<0.05), stroke (<0.0001) and LA (P < 0.05)., Conclusion: APS patients with elderly onset share a distinct disease profile, with a higher frequency of LA, triple aPL positivity and arterial thrombosis., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Published
2019
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4. Proteome and phosphoproteome analysis of starch granule-associated proteins from normal maize and mutants affected in starch biosynthesis.

Author

Grimaud F, Rogniaux H, James MG, Myers AM, and Planchot V

Subjects
1,4-alpha-Glucan Branching Enzyme genetics, 1,4-alpha-Glucan Branching Enzyme metabolism, Phosphorylation, Plant Proteins genetics, Starch Phosphorylase genetics, Starch Phosphorylase metabolism, Starch Synthase genetics, Starch Synthase metabolism, Zea mays enzymology, Mutation, Plant Proteins metabolism, Proteomics, Starch biosynthesis, Zea mays genetics, Zea mays metabolism
Abstract

In addition to the exclusively granule-bound starch synthase GBSSI, starch granules also bind significant proportions of other starch biosynthetic enzymes, particularly starch synthases (SS) SSI and SSIIa, and starch branching enzyme (BE) BEIIb. Whether this association is a functional aspect of starch biosynthesis, or results from non-specific entrapment during amylopectin crystallization, is not known. This study utilized genetic, immunological, and proteomic approaches to investigate comprehensively the proteome and phosphoproteome of Zea mays endosperm starch granules. SSIII, BEI, BEIIa, and starch phosphorylase were identified as internal granule-associated proteins in maize endosperm, along with the previously identified proteins GBSS, SSI, SSIIa, and BEIIb. Genetic analyses revealed three instances in which granule association of one protein is affected by the absence of another biosynthetic enzyme. First, eliminating SSIIa caused reduced granule association of SSI and BEIIb, without affecting GBSS abundance. Second, eliminating SSIII caused the appearance of two distinct electrophoretic mobility forms of BEIIb, whereas only a single migration form of BEIIb was observed in wild type or any other mutant granules examined. Third, eliminating BEIIb caused significant increases in the abundance of BEI, BEIIa, SSIII, and starch phosphorylase in the granule, without affecting SSI or SSIIa. Analysis of the granule phosphoproteome with a phosphorylation-specific dye indicated that GBSS, BEIIb, and starch phosphorylase are all phosphorylated as they occur in the granule. These results suggest the possibility that starch metabolic enzymes located in granules are regulated by post-translational modification and/or protein-protein interactions.

Published
2008
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