La paléosismologie, spécifiquement les tranchées paléosismiques, a été l’outil de recherche conventionnel par excellence et plus amplement utilisées dans les études focalisées sur l’estimation de l’aléa sismique. Plus récemment, l’intérêt sur l’activité sismique tout au long des systèmes de failles associées aux limites de plaques, a conduit à la caractérisation du remplissage sédimentaire des bassins en environnement côtier avec un fort potentiel de préservation et donc d’enregistrement des déformations et perturbations liées à une activité tectonique.Le travail présenté dans ce mémoire a pour objective de développer une analyse du risque naturel, particulièrement le risque de séismes et tsunamis dans la bordure nord de Venezuela, sur la trace sous-marine active de la faille décrochante d’El Pilar.Dans ce contexte la texture, minéralogie et géochimie de la séquence sédimentaire d’un petite appendice de la fosse de Cariaco appelé golfe de Cariaco, a été étudié à partir des différentes techniques (analyse de taille de particules, fluorescence X semi-quantitative, mesures de perte à feu, Pyrolise Rock-Eval et propriétés magnétiques). Comme résultat d’une caractérisation détaillée des sédiments et d’un control chronologique détaillé basé sur la datation radiocarbonique et la correction de l’effet réservoir (potentiellement accumulé sur les différents fractions organiques datées), nous avons mis en évidence un particulier dépôt silto-argileux, fortement détritique, d’une ample distribution spatiale, dont l’âge le plus probable correspond au séisme historique de 1853, qui a affecté la ville de Cumaná. Les analyses géochimiques révèlent que ce dépôt de texture homogène précède une augmentation relative du Br (cts/s) à la surface. On interprète la conjugaison de ces deux singularités comme la conséquence d’un glissement sous-marin et d’une modification morphologique majeure concomitante dans le seuil qui connecte la fosse et le golfe de Cariaco. Dans cette chaine d’événements, ce dépôt serait le produit de la décantation du sédiment en suspension remobilisé et l’augmentation du Br est la manifestation d’un changement hydrogéochimiquemarqué pour une majeure influence marine sur le golfe. Pour établir un point de référence pour l’évaluation du potentiel et de la qualité d’enregistrement de l’activité sismique dans le golfe de Cariaco, un deuxième site lié à la plaque Caraïbe fait partie de cette recherche. Il s’agit de l’arc des Petites Antilles, siège d’une activité sismique et volcanique importante, résultat d’une subduction. Les carottes ici prélevées et étudiées avec la même approche sédimentologique, ont enregistré la trace d’un événement sismique récent, plus probablement le séisme de Redonde de 1974. Cet événement correspond à un dépôt silto-sableux, non stratifié et acoustiquement transparent. Les profils sismiques montrent que la relation géométrique de faciès similaires (de faible énergie) avec l’escarpement co-sismique, implique une origine séisme-induite, a différence des turbidités, dont leur origine peut être influencée par la superposition complexe de plusieurs mécanismes déclencheurs. / Paleoseismological researches, especially through paleoseismic trenches, have been widely developed during the last decades, and are presently commonly used for seismic hazards assessment. Beside, and more recently, the recording of earthquakes and related phenomena (gravity reworking, tsunamis) by sedimentary fills became a precious complement. Along plate boundaries and associated major active faults, the search and characterization of sediments with a strong potential for preservation of earthquakes-disturbances or specific layers has been developed; the here-presented results belong to this approach.The research presented in this dissertation aims to develop an analysis of natural risk, specifically tsunamis and seismic risk, on northern boundary of Venezuela, along the submarine active trace of the El Pilar strike slip fault.In this context, the texture, mineralogy and the geochemistry of the sedimentary sequence in the Gulf of Cariaco (built upon the fault) have been studied from different techniques (particle-size analysis, semi-quantitative XRF analysis, loss on ignition, Rock-Eval Pyrolysis and magnetic properties). From detailed characterization of sediments and an extensive chronological control, based on radiocarbon dating (including a local reservoir effect estimation), we found evidences of a particular siliciclastic fine-grained deposit, widely distributed, which probably corresponds to the 1853 major catastrophic earthquake and associated tsunamis which affected the Cumana town. The geochemical analyses reveal that this deposit of homogeneous texture is followed by an abrupt relative increase of Br at the surface. We interpret this singular combination as a consequence of a submarine landslides and subsequent morphological modification at the connection between the Cariaco trench and the Gulf of Cariaco. This deposit can be the result of the settling of remobilized suspended sediment and the Br increase is the indicator of a hydrogeochemical change indicated by important marine influence on the gulf.In order to establish a point of reference for the evaluation of the potential sedimentary record of the seismic activity in the Gulf of Cariaco, a second site related to the Caribbean Plate boundaries is analysed and discussed in this work. Sedimentation within the Lesser Antilles Arc was chosen as offering a comparable seismic activity but a strongly different sedimentary environment. In this zone of seismic and volcanic activity, consequence of a subduction, we collected and analysed cores with the same sedimentological approach, searching and characterizing recent earthquake record. The most recent one probably corresponds to the 1974 Redonda event. High resolution seismic profiles across active faults indicate precise direct geometrical relationship of specific turbidite-type layers with scarps genesis.

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Biological Sciences / Doctoral / Doctor of Philosophy

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In this thesis, we present a new approach to rendering deforming textured surfaces that takes into account variations in elasticity of the materials represented in the texture. Our approach is based on dynamically warping the parameterisation so that parameterisation distortion in a deformed pose is locally similar to the rest pose; this similarity results in apparent rigidity of the mapped texture material. The warps are also weighted, so that users have control over what appears rigid and what not. Our algorithms achieve real-time generation of warps, including their application in rendering the textured surfaces. A key factor to the achieved performance is the exploitation of the parallel nature of local optimisations by implementing the algorithms on the GPU. We demonstrate our approach with several example applications. We show warps on models using standard texture mapping as well as Ptex. We also show warps using static or dynamic/procedural texture detail, while the surface that it is mapped on deforms. A variety of use-cases is also provided: generating warps for looping animations, generating out-of-core warps of film-quality assets, approximating high-resolution warps with lower-resolution texture-space Linear Blend Skinning and dynamically preserving texture features of a model being interactively edited by an artist.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Cancer therapies have evolved continuously, with the newest class being immunotherapies targeting the PD‐L1/PD‐1 pathway. This pathway is often overexpressed in malignancies, which allow the aberrant cells to evade the body’s natural immune response that would normally eliminate them. The novel therapies currently being investigated are monoclonal antibodies that target either the PD‐L1 on the tumor cell or the PD‐1 on the lymphocyte. Considering there are significant toxicities with these therapies, namely gastrointestinal and endocrine adverse effects, a predictive tool that could allow physicians which patients are likely to respond to these immunotherapies could spare patients unnecessary therapy and potential economic harm. Since repetitive imaging of patients with cancer is necessary to monitor treatment response, advanced imaging analysis techniques on standard of care images, such as CT scans may provide insights into tumor patterns that could help to predict treatment response. Quantitative texture analysis (QTA) of computed tomography scans has been used in various settings to examine tissue heterogeneity as a predictive biomarker of response; we hypothesized that QTA may have potential value in predicting tumor response to immunotherapy. We performed a QTA on standard of care CT scans from patients to determine if a unique textural imaging signature could be identified that would serve as a predictive biomarker for response to PD‐L1/PD‐1 therapies in subjects with solid tumor malignancies in the lungs, liver, and lymph nodes. This study examined the diagnostic standard of care CT scans of the chest, abdomen, and pelvis (CT CAP) at baseline and follow‐up, which were acquired as part of routine clinical care for tumor staging and treatment response in 20 subjects whose personal health care information was removed prior to analysis. Regions of interest (ROI) were drawn around all identifiable tumor lesions on baseline CT scans provided that tumors were of reasonable size (>10 mm in diameter) and conspicuity. CT texture analysis was performed on these lesions to obtain a histogram readout of tumor texture based upon tissue densities on a per pixel bases. The output values from the QTA platform provided an estimate of tumor signal properties as expressed as the mean pixel density, standard deviation, entropy, kurtosis, skewness, and mean positive pixel values. Each subject was designated as achieving either a RECIST based treatment response or not. Statistical modeling was then conducted using regression techniques. There was no identifiable signature when examining all of the lesions together, but there were statistically significant correlations noted between QTA and RECIST responses for lung‐based lesions. The QTA derived mean pixel density parameter was a major component of separating out responders from non‐response. Of the 14 lung lesions (8 responder vs. 6 nonresponder) there was a significant difference in the mean density with a threshold cutoff of 11.91 (p < 0.0001). A Mann‐Whitney U‐test was performed on the total data set yielding a Z statistic of 2.6 (p=0.0092). Despite the relatively small number of patients in this initial study, there were promising findings regarding the mean density of lesions, suggesting that texture analysis can be used to predict if patients respond to PD‐L1/PD‐1 inhibitors. Further investigation is warranted in a larger population that can be differentiated by tumor type to validate these results.