First appraisal to define prospective seismogenic sources from historical earthquake damages in southern Upper Rhine Graben

The southern portion ofthe Upper Rhine Graben, a major oblique rift among France, Germany and Switzerland, shows a weak instrumental seismic record despite its remarkable physiographic imprint within the Northern Alpine foreland. Since traces of active deformation can be found in this region and based on experience in other European areas with high seismic hazard and dense population, we searched for past earthquakes recorded in historical catalogues. Based on the fact that tectonic deformation cumulates through geological time and considering that long-term effects tend to leave characteristic signatures on present-day landscape arrangement, our goal was to identify faults that could have caused the damage of recorded historical events. We isolated five main earthquakes, ofmoderate Richter magnitude, essentially located on the E flank of the graben (as is the case with recent seismic activity). To such events, we were able to associate a specific prospective structure through the use ofa procedure thus far successfully employed in Southern European contexts. We concentrated on three events which showed (a) notable sensitivity to the density of the historical felt reports and (b) accordance with on-going subtle deformation pattern. Another, most relevant earthquake (M 5.5) yielded a promising match with the known deformation network in the region. As a template to better constrain earthquake cycle and damage potential, historical seismicity offers an invaluable tool, since it contains a specific record, although not always unambiguous. Cross-checking such data with pertinent geological information allows to devise a realistic fault geometry capable of being responsible for a specific seismic event

Geomorphic expression of the southern Central Andes forebulge (37 degrees S, Argentina)

Abstract We present a geomorphologic analysis of an east-west transect located east of the southern Andes of Argentina (~37 degrees S). We observe a succession of zones that underwent erosion and deposition during the Pleistocene. If the proximal Andean foothills are incised, a proximal depozone receives sediments feeding the megafan of the Rio Colorado on the Chadileuvu plain. More distally, the abandoned palaeo-valleys and bending of the valley floors reflect a localized uplift. Further to the east, another depozone corresponds to the Pampa Deprimida lowland. This pattern is consistent with the presence of a classical flexural geometry of the lithosphere. The distal uplift of the foreland corresponds in terms of location, length (150 km) and amplitude (240 m) to the Andean forebulge modelled by a geophysical approach. In this study, we identify the morphological imprint of this bulge and show its effect on the fluvial activity

Géodynamique andine : résumés étendus = Andean geodynamics : extended abstracts

Dans la région de Chos Malal, le bassin de Neuquen est affecté d'une déformation chevauchante d'âge Paléocène-Eocène. La tectonique tégumentaire a fait intervenir au moins trois niveaux de décollement. Dans un domaine au nord, le socle est affecté de chevauchements profonds, réactivant des failles normales d'âge jurassique. Quelques failles de transfert jurassiques, de direction NE, ont été réactivées sous forme de rampes latérales. La formation du Tromen, volcan quaternaire, a modifié le schéma structural. (Résumé d'auteur

Active deformation of the northern front of the Eastern Great Caucasus

ACTInternational audienc

Geomorphology of the Northern Great Caucasus : investigating depth geometries from surface data

ACTInternational audienc

Flavin nucleotides act as electron shuttles mediating reduction of the [2Fe-2S] clusters in mitochondrial outer membrane protein mitoNEET

MitoNEET, a primary target of type II diabetes drug pioglitazone, has an essential role in regulating energy metabolism, iron homeostasis, and production of reactive oxygen species in mitochondria. Structurally, mitoNEET is anchored to the mitochondrial outer membrane via its N-terminal transmembrane α-helix. The C-terminal cytosolic domain of mitoNEET hosts a redox active [2Fe-2S] cluster via three cysteine and one histidine residues. Here we report that the reduced flavin nucleotides can rapidly reduce the mitoNEET [2Fe-2S] clusters under anaerobic or aerobic conditions. In the presence of NADH and flavin reductase, about 1 molecule of flavin nucleotide is sufficient to reduce 100 molecules of the mitoNEET [2Fe-2S] clusters in 4 minutes under aerobic conditions. The electron paramagnetic resonance (EPR) measurements show that flavin mononucleotide (FMN), but not flavin adenine dinucleotide (FAD), has a specific interaction with mitoNEET. Molecular docking models further reveal that flavin mononucleotide binds mitoNEET at the region between the N-terminal transmembrane α-helix and the [2Fe-2S] cluster binding domain. The closest distance between the [2Fe-2S] cluster and the bound flavin mononucleotide in mitoNEET is about 10 Å, which may facilitate rapid electron transfer from the reduced flavin nucleotide to the [2Fe-2S] cluster in mitoNEET. The results suggest that flavin nucleotides may act as electron shuttles to reduce the mitoNEET [2Fe-2S] clusters and regulate mitochondrial functions in human cells