The Pingding segment of the Altyn Tagh Fault (91E): Holocene slip-rate determination from cosmogenic radionuclide dating of offset fluvial terraces

International audienceMorphochronologic slip-rates on the Altyn Tagh Fault (ATF) along the southern front of the Pingding Shan at 90.5E are determined by cosmogenic radionuclide (CRN) dating of seven offset terraces at two sites. The terraces are defined based upon morphology, elevation and dating, together with fieldwork and high-resolution satellite analysis. The majority of the CRN model ages fall within narrow ranges (<2 ka) on the four main terraces (T1, T2, T3 and T3′), and allow a detailed terrace chronology. Bounds on the terrace ages and offsets of 5 independent terraces yield consistent slip-rate estimates. The long-term slip-rate of 13.9+/-1.1 mm/yr is defined at the 95% confidence level, as the joint rate probability distribution of the rate derived from each independent terrace. It falls within the bounds of all the rates defined on the central Altyn Tagh Fault between the Cherchen He (86.4E) and Akato Tagh (88E) sites. This rate is 10 mm/yr less than the upper rate determined near Tura at 87E, in keeping with the inference of an eastward decreasing rate due to progressive loss of slip to thrusts branching off the fault southwards but it is greater than the 9+/-4 mm/yr rate determined at 90E by GPS surveys and other geodetic short-term rates defined elsewhere along the ATF. Whether such disparate rates will ultimately be reconciled by a better understanding of fault mechanics, resolved transient deformations during the seismic cycle or by more accurate measurements made with either approach remains an important issue

Applications of Morphochronology to the Active Tectonics of Tibet

The Himalayas and the Tibetan Plateau were formed as a result of the collision of India and Asia, and provide an excellent opportunity to study the mechanical response of the continental lithosphere to tectonic stress. Geophysicists are divided in their views on the nature of this response advocating either (1) homogeneously distributed deformation with the lithosphere deforming as a fluid continuum or (2) deformation is highly localized with the lithosphere that deforms as a system of blocks. The resolution of this issue has broad implications for understanding the tectonic response of continental lithosphere in general. Homogeneous deformation is supported by relatively low decadal, geodetic slip-rate estimates for the Altyn Tagh and Karakorum Faults. Localized deformation is supported by high millennial, geomorphic slip-rates constrained by both cosmogenic and radiocarbon dating on these faults. Based upon the agreement of rates determined by radiocarbon and cosmogenic dating, the overall linearity of offset versus age correlations, and on the plateau-wide correlation of landscape evolution and climate history, the disparity between geomorphic and geodetic slip-rate determinations is unlikely to be due to the effects of surface erosion on the cosmogenic age determinations. Similarly, based upon the consistency of slip-rates over various observation intervals, secular variations in slip-rate appear to persist no longer than 2000 years and are unlikely to provide reconciliation. Conversely, geodetic and geomorphic slip-rate estimates on the Kunlun fault, which does not have significant splays or associated thrust faults, are in good agreement, indicating that there is no fundamental reason why these complementary geodetic and geomorphic methods should disagree. Similarly, the geodetic and geomorphic estimates of shortening rates across the northeastern edge of the plateau are in reasonable agreement, and the geomorphic rates on individual thrust faults demonstrate a significant eastward decrease in the shortening rate. This rate decrease is consistent with the transfer of slip from the Altyn Tagh Fault (ATF) to genetically-related thrust mountain building at its terminus. Rates on the ATF suggest a similar decrease in rate, but the current data set is too small to be definitive. Overall, the high, late Pleistocene-Holocene, geomorphic slip velocities on the major strike-slip faults of Tibet, suggests that they absorb as much of India's convergence relative to Siberia as the Himalayan Main Frontal Thrust on the southern edge of the plateau

An international parentage and identification panel for the domestic cat (Felis catus)

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations

Localization of Secondary Metabolites in Marine Invertebrates: Contribution of MALDI MSI for the Study of Saponins in Cuvierian Tubules of H. forskali

BACKGROUND: Several species of sea cucumbers of the family Holothuriidae possess a particular mechanical defense system called the Cuvierian tubules (Ct). It is also a chemical defense system as triterpene glycosides (saponins) appear to be particularly concentrated in Ct. In the present study, the precise localization of saponins in the Ct of Holothuria forskali is investigated. Classical histochemical labeling using lectin was firstly performed but did not generate any conclusive results. Thus, MALDI mass spectrometry Imaging (MALDI-MSI) was directly applied and completed by statistical multivariate tests. A comparison between the tubules of relaxed and stressed animals was realized. RESULTS: These analyses allowed the detection of three groups of ions, corresponding to the isomeric saponins of the tubules. Saponins detected at m/z 1287 and 1303 were the most abundant and were apparently localized in the connective tissue of the tubules of both relaxed and stressed individuals. Saponins at m/z 1125 and 1141 were detected in lower amount and were present in tissues of relaxed animals. Finally, saponin ions at 1433, 1449, 1463 and 1479 were observed in some Ct of stressed holothuroids in the outer part of the connective tissue. The saponin group m/z 14xx seems therefore to be stress-specific and could originate from modifications of the saponins with m/z of 11xx. CONCLUSIONS: All the results taken together indicate a complex chemical defense mechanism with, for a single organ, different sets of saponins originating from different cell populations and presenting different responses to stress. The present study also reflects that MALDI-MSI is a valuable tool for chemical ecology studies in which specific chemical signalling molecules like allelochemicals or pheromones have to be tracked. This report represents one of the very first studies using these tools to provide a functional and ecological understanding of the role of natural products from marine invertebrates

Fast reproducible identification and large-scale databasing of individual functional cognitive networks

<p>Abstract</p> <p>Background</p> <p>Although cognitive processes such as reading and calculation are associated with reproducible cerebral networks, inter-individual variability is considerable. Understanding the origins of this variability will require the elaboration of large multimodal databases compiling behavioral, anatomical, genetic and functional neuroimaging data over hundreds of subjects. With this goal in mind, we designed a simple and fast acquisition procedure based on a 5-minute functional magnetic resonance imaging (fMRI) sequence that can be run as easily and as systematically as an anatomical scan, and is therefore used in every subject undergoing fMRI in our laboratory. This protocol captures the cerebral bases of auditory and visual perception, motor actions, reading, language comprehension and mental calculation at an individual level.</p> <p>Results</p> <p>81 subjects were successfully scanned. Before describing inter-individual variability, we demonstrated in the present study the reliability of individual functional data obtained with this short protocol. Considering the anatomical variability, we then needed to correctly describe individual functional networks in a voxel-free space. We applied then non-voxel based methods that automatically extract main features of individual patterns of activation: group analyses performed on these individual data not only converge to those reported with a more conventional voxel-based random effect analysis, but also keep information concerning variance in location and degrees of activation across subjects.</p> <p>Conclusion</p> <p>This collection of individual fMRI data will help to describe the cerebral inter-subject variability of the correlates of some language, calculation and sensorimotor tasks. In association with demographic, anatomical, behavioral and genetic data, this protocol will serve as the cornerstone to establish a hybrid database of hundreds of subjects suitable to study the range and causes of variation in the cerebral bases of numerous mental processes.</p

Suggestions concernant le réaménagement des carrières en eau

L'intégration harmonieuse des carrières en eau dans les paysages f luviatiles, leur réaménagement à des fins halieutiques ou touristiques, voire conservatoires, nécessite la prise en compte de l'état présent de leur environnement, mais surtout de ses potentialités. Les suggestions concernent: — la taille et la forme des plans d'eau à modeler après extraction des graves et maintien en eau ; — la définition des profils des berges permettant un développement rapide de la végétation et la réinstallation d'une faune diversifiée; — le choix des essences végétales à introduire, en particulier dans les vallées de la Somme, de l'Oise et de l'Aisne et les techniques à employer, exprimés sur la base de l'étude d'une vingtaine de cas situés dans les vallées de la Somme et de l'Oise

Recommandations ERINOH (volume 2) : méthodologie de diagnostic de l'érosion interne dans les digues en remblai

Colloque National Digues Maritimes et Fluviales de Protection contre les Submersions, Aix-en-Provence, FRA, 12-/06/2013 - 14/06/2013National audienceThe aim of Recommendations theme of ERINOH's French project was to provide three guidelines which gather and capitalize the knowledge gained during these studies. This guide suggests recommendations on reconnaissance and surveillance methods used on dikes and proposes a diagnosis methodology to detect internal erosion on long linear structures. The guide is composed of three parts.The first part is the main text and contains five chapters.Chapter 1 defines the context and stakes of maintenance of earthen dikes, reminds the French 2007 safety regulation demand, clarifies the perimeter and the objectives of the guide and indicates the public preferentially concerned by the guide.Chapter 2 suggests a short description of hydraulic structures (earthen dikes and embankments) preferentially concerned by this guide, e.g. levees and dikes. Internal erosion laws are also reminded in this chapter.Chapter 3 gives a description of material's properties of dikes and their foundation and quickly reminds soil's classifications methods. Relationships between physical properties of materials and geophysical measurements arealso given in this chapter.Chapter 4 provides an inventory of surveillance and reconnaissance methods able to detect anomalies related to leakage or seepage, gives theirs advantages, disadvantages and limits. In this charter, we also present some new developments which will permit to improve robustness of methods or obtain some quantitative hydraulic data.Chapter 5 defines and develops an efficient diagnosis methodology for assessment of the internal erosion risk on dikes. Some erosion criteria are used to lead to the diagnosis.The second part of the guide gathers technical sheets on geophysical and geotechnical methods commonly used on dikes.The third part gathers technical sheets which synthesize onsite investigations realized during ERINOH's program.This communication proposes a summary of the first part of the guide, emphasizing on investigation methods and on technologic advances provided by ERINOH Projects.Le thème Recommandations du Projet National ERINOH (ERosion INterne dans les Ouvrages Hydrauliques) avait pour objectif de produire trois guides permettant de capitaliser les connaissances acquises pendant ces recherches. Le présent guide propose des recommandations sur l'emploi des méthodes de reconnaissance et de surveillance des digues et suggère une méthodologie dediagnostic de l'érosion interne pour ces ouvrages à long linéaire. Le guide est composé de trois parties.La première partie, corps de texte principal de ce guide, est structurée en cinq chapitres.Le chapitre 1 introduit le guide. Il cerne le contexte et les enjeux de la maintenance des ouvrages hydrauliques en remblai, notamment des digues, rappelle les exigences de la réglementation de 2007 et précise le contour et les objectifs du guide ainsi que le public visé.Le chapitre 2 propose une description succincte des ouvrages hydrauliques en remblai préférentiellement visés par le guide. Les lois d'érosion interne sont aussi rappelées dans ce chapitre.Le chapitre 3 aborde une description des propriétés des matériaux constituant les digues et leur fondation et rappelle succinctement les procédés de classification des sols. Les relations entre les propriétés physiques des sols et les grandeurs géophysiques mesurées sont aussi données dans cechapitre.Le chapitre 4 propose un inventaire des méthodes de reconnaissance et de surveillance capables de détecter les anomalies dues aux fuites et précise les avantages, inconvénients et les limites d'emploi. Dans ce chapitre, nousillustrons quelques nouveaux développements qui vont permettre d'améliorer la robustesse des méthodes de détection.Le chapitre 5 développe une méthodologie de reconnaissance et de diagnostic des digues vis-à-vis du risque d'érosion interne. Des critères d'érosion sont exploités pour mener au diagnostic.La seconde partie du guide rassemble des fiches techniques descriptives des méthodes de reconnaissance géophysique et géotechnique.La troisième partie résume, sous la forme de fiches synthétiques, les essais sur sites réalisés pendant le programme ANR ERINOH.La présente communication propose un résumé de la première partie de ce guide, en insistant sur les méthodes d'investigation et sur les avancées méthodologiques apportées par les travaux de recherche dont il est le produit