907 resultados para stacking fault


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On December 4th 2007, a 3-Mm3 landslide occurred along the northwestern shore of Chehalis Lake. The initiation zone is located at the intersection of the main valley slope and the northern sidewall of a prominent gully. The slope failure caused a displacement wave that ran up to 38 m on the opposite shore of the lake. The landslide is temporally associated with a rain-on-snow meteorological event which is thought to have triggered it. This paper describes the Chehalis Lake landslide and presents a comparison of discontinuity orientation datasets obtained using three techniques: field measurements, terrestrial photogrammetric 3D models and an airborne LiDAR digital elevation model to describe the orientation and characteristics of the five discontinuity sets present. The discontinuity orientation data are used to perform kinematic, surface wedge limit equilibrium and three-dimensional distinct element analyses. The kinematic and surface wedge analyses suggest that the location of the slope failure (intersection of the valley slope and a gully wall) has facilitated the development of the unstable rock mass which initiated as a planar sliding failure. Results from the three-dimensional distinct element analyses suggest that the presence, orientation and high persistence of a discontinuity set dipping obliquely to the slope were critical to the development of the landslide and led to a failure mechanism dominated by planar sliding. The three-dimensional distinct element modelling also suggests that the presence of a steeply dipping discontinuity set striking perpendicular to the slope and associated with a fault exerted a significant control on the volume and extent of the failed rock mass but not on the overall stability of the slope.

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Direct absolute dating of the Penninic Frontal Thrust tectonic motion is achieved using the Ar-40/Ar-39 technique in the Pelvoux Crystalline Massif (Western Alps). The dated phengites were formed syn-kinematically in shear zones. They underline the brittle-ductile stretching lineation, pressure-shadow fibres and slickensides consistent with underthrusting of the European continental slab below the propagating Penninic Thrust. Chlorite-phengite thermobarometry yields 10-15 km and T similar to 280 degrees C, while Ar-40/Ar-39 phengite ages mainly range between 34 and 30 Ma, with one younger age at 27 Ma. This Early Oligocene age range matches a major tectonic rearrangement of the Alpine chain. Preservation of prograde Ar-40/Ar-39 ages is ascribed to passive exhumation of the Pelvoux shear zone network, sandwiched between more external thrusts and the Penninic Front reactivated as an E-dipping detachment fault. Partial resetting in the Low Temperature part of argon spectra below 24 Ma is ascribed to brittle deformation and alteration of phengites.

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La E/S Paralela es un área de investigación que tiene una creciente importancia en el cómputo de Altas Prestaciones. Si bien durante años ha sido el cuello de botella de los computadores paralelos en la actualidad, debido al gran aumento del poder de cómputo, el problema de la E/S se ha incrementado y la comunidad del Cómputo de Altas Prestaciones considera que se debe trabajar en mejorar el sistema de E/S de los computadores paralelos, para lograr cubrir las exigencias de las aplicaciones científicas que usan HPC. La Configuración de la Entrada/Salida (E/S) Paralela tiene una gran influencia en las prestaciones y disponibilidad, por ello es importante “Analizar configuraciones de E/S paralela para identificar los factores claves que influyen en las prestaciones y disponibilidad de la E/S de Aplicaciones Científicas que se ejecutan en un clúster”. Para realizar el análisis de las configuraciones de E/S se propone una metodología que permite identificar los factores de E/S y evaluar su influencia para diferentes configuraciones de E/S formada por tres fases: Caracterización, Configuración y Evaluación. La metodología permite analizar el computador paralelo a nivel de Aplicación Científica, librerías de E/S y de arquitectura de E/S, pero desde el punto de vista de la E/S. Los experimentos realizados para diferentes configuraciones de E/S y los resultados obtenidos indican la complejidad del análisis de los factores de E/S y los diferentes grados de influencia en las prestaciones del sistema de E/S. Finalmente se explican los trabajos futuros, el diseño de un modelo que de soporte al proceso de Configuración del sistema de E/S paralela para aplicaciones científicas. Por otro lado, para identificar y evaluar los factores de E/S asociados con la disponibilidad a nivel de datos, se pretende utilizar la Arquitectura Tolerante a Fallos RADIC.

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A high-resolution three-dimensional (3-D) seismic reflection survey was conducted in Lake Geneva, near the city of Lausanne, Switzerland, as part of a project for developing such seismic techniques. Using a single 48-channel streamer, the 3-D site with an area of 1200 m x 600 m was surveyed in 10 days. A variety of complex geologic structures (e.g. thrusts, folds, channel-fill) up to similar to150 m below the water bottom were obtained with a 15 in.(3) water gun. The 3-D data allowed the construction of an accurate velocity model and the distinction of five major seismic facies within the Lower Freshwater Molasse (Aquitanian) and the Quaternary sedimentary units. Additionally, the Plateau Molasse (PM) and Subalpine Molasse (SM) erosional surface, "La Paudeze" thrust fault (PM-SM boundary) and the thickness of Quaternary sediments were accurately delineated in 3-D.

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RESUME : Bien que les propriétés physiques de la structure de l'ADN aient été intensivement étudiées pendant plus de 50 ans il y a encore beaucoup de questions importantes qui attendent des réponses. Par exemple, qu'arrive-t-il à la structure de la double hélice d'ADN nue (sans protéines liées) lorsqu'elle est fortement courbée, de la même manière que dans les nucléosomes? Cet ADN nu est-il facilement plié (il reste dans le régime élastique) ou réduit-il la contrainte de flexion en formant des sites hyperflexibles «kinks» (il sort du régime élastique en cassant l'empilement des paires de bases à certains endroits) ? La microscopie électronique peut fournir une réponse à cette question par visualisation directe des minicercles d'ADN de la longueur d'un tour de nucléosome (environ 90 paires de bases). Pour que la réponse soit scientifiquement valide, on doit observer les molécules d'ADN lorsqu'elles sont en suspension dans la solution d'intérêt et sans que des colorations, produits chimiques ou fixatifs n'aient été ajoutés, étant donné que ceux-ci peuvent changer les propriétés de l'ADN. La technique de la cryo-microscopie électronique (cryo-EM) développée par le groupe de Jacques Dubochet au début des années 80, permet la visualisation directe des molécules d'ADN suspendues dans des couche minces vitrifiées de solutions aqueuses. Toutefois, le faible contraste qui caractérise la cryo-EM combinée avec la très petite taille des minicercles d'ADN rendent nécessaire l'optimisation de plusieurs étapes, aussi bien dans la préparation des échantillons que dans le processus d'acquisition d'images afin d'obtenir deux clichés stéréo qui permettent la reconstruction 3-D des minicercles d'ADN. Dans la première partie de ma thèse, je décris l'optimisation de certains paramètres pour la cryoEM et des processus d'acquisition d'image utilisant comme objets de test des plasmides et d'autres molécules d'ADN. Dans la deuxième partie, je .décris comment j'ai construit les minicercles d'ADN de 94 bp et comment j'ai introduit des modifications structurelles comme des coupures ou des lacunes. Dans la troisième partie, je décris l'analyse des reconstructions des rninicercles d'ADN. Cette analyse, appuyée par des tests biochimiques, indique fortement que des molécules d'ADN sont capables de former de petites molécules circulaires de 94 bp sans dépasser les limites d'élasticité, indiquant que les minicercles adoptent une forme circulaire régulière où la flexion est redistribuée le long la molécule. ABSTRACT : Although physical properties of DNA structure have been intensively studied for over 50 years there are still many important questions that need to be answered. For example, what happens to protein-free double-stranded DNA when it is strongly bent, as in DNA forming nucleosomes? Is such protein-free DNA smoothly bent (i.e. it remains within elastic limits of DNA rigidity) or does it release its bending stress by forming sharp kinks (i.e. it exits the elastic regime and breaks the stacking between neighbouring base-pairs in localized regions)? Electron microscopy can provide an answer to this question by directly visualizing DNA minicircles that have the size of nucleosome gyres (ca 90 bp). For the answer to be scientifically valid, one needs to observe DNA molecules while they are still suspended in the solution of interest and no staining chemicals or fixatives have been added since these can change the properties of the DNA. CryoEM techniques developed by Jacques Dubochet's group beginning in the 1980's permit direct visualization of DNA molecules suspended in cryo-vitrified layers of aqueous solutions. However, a relatively weak contrast of cryo-EM preparations combined with the very small size of the DNA minicircles made it necessary to optimize many of the steps and parameters of the cryo-EM specimen preparation and image acquisition processes in order to obtain stereo-pairs of images that permit the 3-D reconstruction of the observed DNA minicircles. In the first part of my thesis I describe the optimization of the cryo-EM preparation and the image acquisition processes using plasmid size DNA molecules as a test object. In the second part, I describe how I formed the 94 by DNA minicircles and how I introduced structural modifications like nicks or gaps. In the third part, I describe the cryo-EM analysis of the constructed DNA minicircles. That analysis, supported by biochemical tests, strongly indicates that DNA minicircles as small as 94 by remain within the elastic limits of DNA structure, i.e. the minicircles adopt a regular circular shape where bending is redistributed along the molecules.

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La tolerancia a fallos es una línea de investigación que ha adquirido una importancia relevante con el aumento de la capacidad de cómputo de los súper-computadores actuales. Esto es debido a que con el aumento del poder de procesamiento viene un aumento en la cantidad de componentes que trae consigo una mayor cantidad de fallos. Las estrategias de tolerancia a fallos actuales en su mayoría son centralizadas y estas no escalan cuando se utiliza una gran cantidad de procesos, dado que se requiere sincronización entre todos ellos para realizar las tareas de tolerancia a fallos. Además la necesidad de mantener las prestaciones en programas paralelos es crucial, tanto en presencia como en ausencia de fallos. Teniendo en cuenta lo citado, este trabajo se ha centrado en una arquitectura tolerante a fallos descentralizada (RADIC – Redundant Array of Distributed and Independant Controllers) que busca mantener las prestaciones iniciales y garantizar la menor sobrecarga posible para reconfigurar el sistema en caso de fallos. La implementación de esta arquitectura se ha llevado a cabo en la librería de paso de mensajes denominada Open MPI, la misma es actualmente una de las más utilizadas en el mundo científico para la ejecución de programas paralelos que utilizan una plataforma de paso de mensajes. Las pruebas iniciales demuestran que el sistema introduce mínima sobrecarga para llevar a cabo las tareas correspondientes a la tolerancia a fallos. MPI es un estándar por defecto fail-stop, y en determinadas implementaciones que añaden cierto nivel de tolerancia, las estrategias más utilizadas son coordinadas. En RADIC cuando ocurre un fallo el proceso se recupera en otro nodo volviendo a un estado anterior que ha sido almacenado previamente mediante la utilización de checkpoints no coordinados y la relectura de mensajes desde el log de eventos. Durante la recuperación, las comunicaciones con el proceso en cuestión deben ser retrasadas y redirigidas hacia la nueva ubicación del proceso. Restaurar procesos en un lugar donde ya existen procesos sobrecarga la ejecución disminuyendo las prestaciones, por lo cual en este trabajo se propone la utilización de nodos spare para la recuperar en ellos a los procesos que fallan, evitando de esta forma la sobrecarga en nodos que ya tienen trabajo. En este trabajo se muestra un diseño propuesto para gestionar de un modo automático y descentralizado la recuperación en nodos spare en un entorno Open MPI y se presenta un análisis del impacto en las prestaciones que tiene este diseño. Resultados iniciales muestran una degradación significativa cuando a lo largo de la ejecución ocurren varios fallos y no se utilizan spares y sin embargo utilizándolos se restablece la configuración inicial y se mantienen las prestaciones.

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An alternative model for the geodynamic evolution of Southeast Asia is proposed and inserted in a modern plate tectonic model. The reconstruction methodology is based on dynamic plate boundaries, constrained by data such as spreading rates and subduction velocities; in this way it differs from classical continental drift models proposed so far. The different interpretations about the location of the Palaeotethys suture in Thailand are revised, the Tertiary Mae Yuam fault is seen as the emplacement of the suture. East of the suture we identify an Indochina derived terrane for which we keep the name Shan-Thai, formerly used to identify the Cimmerian block present in Southeast Asia, now called Sibumasu. This nomenclatural choice was made on the basis of the geographic location of the terrane (Eastern Shan States in Burma and Central Thailand) and in order not to introduce new confusing terminology. The closure of the Eastern Palaeotethys is related to a southward subduction of the ocean, that triggered the Eastern Neotethys to open as a back-arc, due to the presence of Late Carboniferous-Early Permian arc magmatism in Mergui (Burma) and in the Lhasa block (South Tibet), and to the absence of arc magmatism of the same age East of the suture. In order to explain the presence of Carboniferous-Early Permian and Permo-Triassic volcanic arcs in Cambodia, Upper Triassic magmatism in Eastern Vietnam and Lower Permian-Middle Permian arc volcanites in Western Sumatra, we introduce the Orang Laut terranes concept. These terranes were detached from Indochina and South China during back-arc opening of the Poko-Song Ma system, due to the westward subduction of the Palaeopacific. This also explains the location of the Cathaysian West Sumatra block to the West of the Cimmerian Sibumasu block.

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The Upper Lahul region in the NW Himalaya is located in the transition zone between the High Himalayan Crystalline (HHC) to the SW and the Tethyan Zone sedimentary series to the NE. The tectonic evolution of these domains during the Himalayan Orogeny is the consequence of a succession of five deformation events. An early D1 phase corresponds to synmetamorphic, NE verging folding. This deformation created the Tandi Syncline, which consists of Permian to Jurassic Tethyan metasediments cropping out in the core of a large-scale synformal fold within the HHC paragneiss. This tectonic event is interpreted as related to a NE directed nappe stacking (Shikar Beh Nappe), probably during the late Eocene to the early Oligocene. A subsequent D2a phase caused SW verging folding in the HHC. This deformation is interpreted as contemporaneous with late Oligocene to early Miocene SW directed thrusting along the Main Central Thrust. In the Tethyan Zone, a D2b phase is marked by a decollement thrust, a system of reverse faults, and gentle folds, associated with SW directed tectonic movements. This deformation is related to an imbricate structure, characteristic of a shallow structural level, and developed in the frontal part of a nappe affecting the Tethyan Zone units of SE Zanskar (Nyimaling-Tsarap Nappe). A later D3 phase generated the Chandra Dextral Shear Zone (CDSZ), a large-scale, ductile, dextral strike-slip shear zone, located in the transition zone between the HHC and the Tethyan Himalaya. The CDSZ most likely represents a part of a system of early Miocene extensional and/or dextral, strike-slip shear zones-observed at the HHC-Tethyan Zone contact along the entire Himalaya. A final D4 phase induced large-scale doming and NE:verging back folding.

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The eastern part of the Western Cordillera of Ecuador includes fragments of an Early Cretaceous ( approximate to 123 Ma) oceanic plateau accreted around 85-80 Ma (San Juan unit). West of this unit and in fault contact with it, another oceanic plateau sequence (Guaranda unit) is marked by the occurrence of picrites, ankaramites, basalts, dolerites and shallow level gabbros. A comparable unit is also exposed in northwestern coastal Ecuador (Pedernales unit). Picrites have LREE-depleted patterns, high epsilonNd(i) and very low Pb isotopic ratios, suggesting that they were derived from an extremely depleted source. In contrast, the ankaramites and Mg-rich basalts are LREE-enriched and have radiogenic Pb isotopic compositions similar to the Galapagos HIMU component; their epsilonNd(i) are slightly lower than those of the picrites. Basalts, dolerites and gabbros differ from the picrites and ankaramites by flat rare earth element (REE) patterns and lower epsilonNd; their Pb isotopic compositions are intermediate between those of the picrites and ankaramites. The ankaramites, Mg-rich basalts, and picrites differ from the lavas from the San Juan-Multitud Unit by higher Pb ratios and lower epsilonNd(i). The Ecuadorian and Gorgona 88-86 Ma picrites are geochemically similar. The Ecuadorian ankaramites and Mg-rich basalts share with the 92-86 Ma Mg-rich basalts of the Caribbean-Colombian Oceanic Plateau (CCOP) similar trace element and Nd and Pb isotopic chemistry. This suggests that the Pedernales and Guaranda units belong to the Late Cretaceous CCOR The geochemical diversity of the Guaranda and Pedernales rocks illustrates the heterogeneity of the CCOP plume source and suggests a multi-stage model for the emplacement of these rocks. Stratigraphic and geological relations strongly suggest that the Guaranda unit was accreted in the late Maastrichtian (approximate to 68-65 Ma). (C) 2002 Elsevier Science B.V. All rights reserved.

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L'objectiu final d'aquest projecte és realitzar un Sistema Traçador d' Errors, però potser mésimportant és l'objectiu d'aprendre noves tecnologies, que sovint estan a disposició de l'usuari però l'usuari les desconeix.

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The geological evolution of the northern Peru convergent margin can be traced using samples collected during deep-sea dives of the submersible Nautile. In the Paita area (5 degrees-6 degrees S), the sedimentary sequence was intensively sampled along the main scarp of the middle slope area. It consists of Upper Miocene (7-9 Ma) to Pleistocene siltstone, sandstone and rare dolostone. The age distribution of these samples is the basis for a new geologic interpretation of the multichannel seismic line CDP3. Siliceous microfossils (both diatoms and radiolarians) show influence of both cold and temperate waters (local species mixed with upwelling ones). Diatom assemblages studied from the NP1-13 and NP1-15 dives bear a strong resemblance to assemblages from the Pisco Formation of southern Peru. Micropaleontological data from siliceous microfossils, provide evidence for two main unconformities, one is at the base of the Quaternary sequence and the other corresponds to a hiatus of 1 Myr, separating the Upper Miocene (7-8 Ma) sediments from uppermost Miocene (5-6 Ma) sediments. During the past 400 kyr, a wide rollover fold developed in the middle slope area associated with a major seaward dipping detachment fault. A catastrophic debris avalanche occurred as the result of an oversteepening of the landward flank of the rollover fold. The gravity failure of the slope, recognized by SeaBEAM and hydrosweep mapping, displaced enough material to produce a destructive tsunami which occurred 13.8 +/- 2.7 kyr ago.

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This paper is a first draft of the principle of statistical modelling on coordinates. Several causes —which would be long to detail—have led to this situation close to the deadline for submitting papers to CODAWORK’03. The main of them is the fast development of the approach along thelast months, which let appear previous drafts as obsolete. The present paper contains the essential parts of the state of the art of this approach from my point of view. I would like to acknowledge many clarifying discussions with the group of people working in this field in Girona, Barcelona, Carrick Castle, Firenze, Berlin, G¨ottingen, and Freiberg. They have given a lot of suggestions and ideas. Nevertheless, there might be still errors or unclear aspects which are exclusively my fault. I hope this contribution serves as a basis for further discussions and new developments

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Fission-track and (40)Ar/(39)Ar ages place time constraints on the exhumation of the North Himalayan nappe stack, the Indus Suture Zone and Molasse, and the Transhimalayan Batholith in eastern Ladakh (NW India). Results from this and previous studies on a north-south transect passing near Tso Morari Lake suggest that the SW-directed North Himalayan nappe stack (comprising the Mata, Tetraogal and Tso Morari nappes) was emplaced and metamorphosed by c. 50-45 Ma, and exhumed to moderately shallow depths (c. 10 km) by c. 45-40 Ma. From the mid-Eocene to the present, exhumation continued at a steady and slow rate except for the root zone of the Tso Morari nappe, which cooled faster than the rest of the nappe stack. Rapid cooling occurred at c. 20 Ma and is linked to brittle deformation along the normal Ribil-Zildat Fault concomitant with extrusion of the Crystalline nappe in the south. Data from the Indus Molasse suggest that sediments were still being deposited during the Miocene.

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A survey of MPLS protection methods and their utilization in combination with online routing methods is presented in this article. Usually, fault management methods pre-establish backup paths to recover traffic after a failure. In addition, MPLS allows the creation of different backup types, and hence MPLS is a suitable method to support traffic-engineered networks. In this article, an introduction of several label switch path backup types and their pros and cons are pointed out. The creation of an LSP involves a routing phase, which should include QoS aspects. In a similar way, to achieve a reliable network the LSP backups must also be routed by a QoS routing method. When LSP creation requests arrive one by one (a dynamic network scenario), online routing methods are applied. The relationship between MPLS fault management and QoS online routing methods is unavoidable, in particular during the creation of LSP backups. Both aspects are discussed in this article. Several ideas on how these actual technologies could be applied together are presented and compared

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Due to the high cost of a large ATM network working up to full strength to apply our ideas about network management, i.e., dynamic virtual path (VP) management and fault restoration, we developed a distributed simulation platform for performing our experiments. This platform also had to be capable of other sorts of tests, such as connection admission control (CAC) algorithms, routing algorithms, and accounting and charging methods. The platform was posed as a very simple, event-oriented and scalable simulation. The main goal was the simulation of a working ATM backbone network with a potentially large number of nodes (hundreds). As research into control algorithms and low-level, or rather cell-level methods, was beyond the scope of this study, the simulation took place at a connection level, i.e., there was no real traffic of cells. The simulated network behaved like a real network accepting and rejecting SNMP ones, or experimental tools using the API node