630 resultados para 4D Geodesy


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Dissertação de mestrado integrado em Engenharia Civil

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Los sistemas de agua dulce constituyen fuentes vitales para el desarrollo de la vida. Entre otras causas, el excesivo y poco controlado uso de pesticidas por las prácticas agrícolas modernas ha contribuido con la degradación de estos ecosistemas en la provincia de Córdoba (Secretaría de Ambiente, 2008). Los pesticidas son compuestos tóxicos y químicamente estables en el ambiente. Diversas especies microbianas presentan la capacidad para mineralizar dichos compuestos, siendo uno de los mecanismos de descomposición más importante. En el presente trabajo se pretende (1) Detectar y cuantificar principios activos de pesticidas en diferentes aguas ambientales de la región centro-sur de la provincia de Córdoba; (2) Aislar y caracterizar especies bacterianas a partir de muestras de aguas superficiales y subterráneas de la región que demuestren ser eficientes en la biodegradación de diferentes pesticidas. Para ello, se estudiará la presencia de 10 pesticidas organoclorados y organofosforados (lindano, 2,4D, DDT, p,p-DDE, �-endosulfán, �-endosulfán, clorpirifós, dimetoato) y herbicidas (atrazina) en muestras de agua superficiales y subterráneas (8 - 12m de profundidad) de la región agrícola centro-sur de Córdoba. Se establecerán diferentes puntos de muestreo en las principales cuencas hidrográficas: Río Tercero y Embalse de Río Tercero, Canal Desviador de Bell Ville, Laguna La Salada, Río Saladillo, Río Carcarañá y Río Cuarto. La determinación de pesticidas se realizará mediante Cromatografía de Gases (GC). Conjuntamente, se realizará el aislamiento de microorganismos a partir de las muestras de agua suplementadas con diferentes concentraciones de pesticidas (López et al., 2005) y se procederá a la caracterización morfológica y bioquímica (Lechevalier, 1989). Se realizarán curvas de crecimiento (DO600) y se determinará la viabilidad celular mediante el método de recuento en placa. El potencial catabólico de cada aislamiento se determinará analizando la concentración residual de pesticidas en el sobrenadante de los cultivos (Benimeli et al, 2003) y mediante ensayos de resting-cell (Hernández et al, 2008). Finalmente se realizará la caracterización genética (Weisburg, 1991) de los aislamientos que demuestren una mayor eficiencia en la biodegradación de pesticidas. El presente estudio pretende abordar una temática prioritaria como es la contaminación ambiental de ecosistemas acuáticos de la provincia de Córdoba. la detección de principios activos de pesticidas sería, por lo tanto, un indicador de contaminación de origen antropológica y brindaría información respecto al deterioro de la calidad del agua. Por otra parte, el aislamiento de bacterias adaptadas a las condiciones ecológicas de la región y capaces de metabolizar eficientemente diferentes pesticidas como fuentes de carbono y energía sería beneficioso para su utilización en futuros ensayos de biorremediación.

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FUNDAMENTO: O índice de dilatação transitória pode ser determinado através de teste ergométrico ou estresse farmacológico. Desconhece-se se o tipo de estresse tem impacto sobre os valores médios do índice de dilatação transitória. OBJETIVO: Comparar os valores médios do índice de dilatação transitória na cintilografia com 99mTc-sestamibi, em pacientes submetidos a teste ergométrico em esteira, versus estresse com dipiridamol. O objetivo secundário foi avaliar o impacto sobre o valor médio do índice exercido pelas características demográficas, pelos fatores de risco para doença arterial coronariana e a gravidade da isquemia. MÉTODOS: O estudo transversal incluiu 200 pacientes, entre 40 e 70 anos, portadores ou não de fatores de risco para cardiopatia isquêmica, com ou sem diagnóstico prévio de cardiopatia isquêmica. A separação entre grupos foi sequencial. O software 4D-MSPECT calculou o índice de dilatação transitória e forneceu um sistema de escores para análise da perfusão. RESULTADOS: O valor do índice de dilatação transitória médio do grupo submetido a teste ergométrico foi de 1,06 (±0,23). O do grupo submetido ao estresse com dipiridamol foi de 1,10 (±0,22);(p = 0,200). Não houve associação entre o tipo de estresse e os valores médios do índice de dilatação transitória. Encontrou-se associação entre os valores médios do índice e a faixa etária somente para os pacientes do grupo do teste ergométrico (p = 0,009). CONCLUSÃO: Os resultados do nosso estudo demonstram que o índice de dilatação transitória não difere quando os pacientes são submetidos a estresse pelo teste ergométrico em esteira ou estresse farmacológico pelo dipiridamol.

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Biological features and social preferences have been studied separately as factors influencing human strategic behaviour. We run two studies in order to explore the interplay between these two sets of factors. In the first study, we investigate to what extent social preferences may have some biological underpinnings. We use simple one-shot distribution experiments to attribute subjects one out of four types of social preferences: Self-interested (SI), Competitive (C), Inequality averse (IA) and Efficiency-seeking (ES). We then investigate whether these four groups display differences in their levels of facial Fluctuating Asymmetry (FA) and in proxies for exposure to testosterone during phoetal development and puberty. We observe that development-related biological features and social preferences are relatively independent. In the second study, we compare the relative weight of these two set of factors by studying how they affect subjects’ behaviour in the Ultimatum Game (UG). We find differences in offers made and rejection rates across the four social preference groups. The effect of social preferences is stronger than the effect of biological features even though the latter is significant. We also report a novel link between facial masculinity (a proxy for exposure to testosterone during puberty) and rejection rates in the UG. Our results suggest that biological features influence behaviour both directly and through their relation with the type of social preferences that individuals hold.

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This paper examines whether the degree of confidence and overconfidence in one's ability is determined biologically. In articular, we study whether foetal testosterone exposure correlates with an incentive-compatible measure of confidence within an experimental setting. We find that men (rather than women) who were exposed to high testosterone levels in their mother's womb are less likely to overestimate their actual performance, which in turn helps them to gain higher monetary rewards. Men exposed to low prenatal testosterone levels, instead, set unrealistically high expectations which results in self-defeating behaviour. These results from the lab are able to reconcile hitherto disconnected evidence from the field, by providing a link between traders'overconfidence bias, long-term financial returns and prenatal testosterone exposure.

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OBJECTIVES: The purpose of this study was to compare a novel compressed sensing (CS)-based single-breath-hold multislice magnetic resonance cine technique with the standard multi-breath-hold technique for the assessment of left ventricular (LV) volumes and function. BACKGROUND: Cardiac magnetic resonance is generally accepted as the gold standard for LV volume and function assessment. LV function is 1 of the most important cardiac parameters for diagnosis and the monitoring of treatment effects. Recently, CS techniques have emerged as a means to accelerate data acquisition. METHODS: The prototype CS cine sequence acquires 3 long-axis and 4 short-axis cine loops in 1 single breath-hold (temporal/spatial resolution: 30 ms/1.5 × 1.5 mm(2); acceleration factor 11.0) to measure left ventricular ejection fraction (LVEFCS) as well as LV volumes and LV mass using LV model-based 4D software. For comparison, a conventional stack of multi-breath-hold cine images was acquired (temporal/spatial resolution 40 ms/1.2 × 1.6 mm(2)). As a reference for the left ventricular stroke volume (LVSV), aortic flow was measured by phase-contrast acquisition. RESULTS: In 94% of the 33 participants (12 volunteers: mean age 33 ± 7 years; 21 patients: mean age 63 ± 13 years with different LV pathologies), the image quality of the CS acquisitions was excellent. LVEFCS and LVEFstandard were similar (48.5 ± 15.9% vs. 49.8 ± 15.8%; p = 0.11; r = 0.96; slope 0.97; p < 0.00001). Agreement of LVSVCS with aortic flow was superior to that of LVSVstandard (overestimation vs. aortic flow: 5.6 ± 6.5 ml vs. 16.2 ± 11.7 ml, respectively; p = 0.012) with less variability (r = 0.91; p < 0.00001 for the CS technique vs. r = 0.71; p < 0.01 for the standard technique). The intraobserver and interobserver agreement for all CS parameters was good (slopes 0.93 to 1.06; r = 0.90 to 0.99). CONCLUSIONS: The results demonstrated the feasibility of applying the CS strategy to evaluate LV function and volumes with high accuracy in patients. The single-breath-hold CS strategy has the potential to replace the multi-breath-hold standard cardiac magnetic resonance technique.

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L'objectiu és una aplicació que permeti realitzar el càlcul del volum de terres disponibles en el subsòl d'un àrea seleccionada. L'objectiu final del projecte serà crear un Sistema d'Informació Geogràfica SIG que ajudi a valorar quines parcel¿les de l'àrea seleccionada són les que disposen de més volum de terres per iniciar la seva explotació. Per a això, es disposa del programari gvSIG i les seves extensions (SEXTANTE) i de tota la informació que es pugui obtenir sobre els SIG, Cartografia, Geodèsia... Per dur a terme aquest projecte es necessita tenir experiència en Bases de dades, Programació Orientada a Objectes i seria recomanable tenir coneixements sobre Enginyeria del Programador. El projecte se centrarà en la utilització de gvSIG, com un exemple concret de programari SIG de lliure accés, solució desenvolupada per la ¿Conselleria d%o2019Obris Publiquis de la Generalitat Valenciana¿. Una part d'aquest projecte consistirà a avaluar aquest programari. El resultat final serà l'obtenció dels coneixements necessaris per poder treballar amb dades espacials a més d'una aplicació SIG per al càlcul del volum de terres d'un àrea seleccionada.

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La resolució de la problemàtica exposada al llarg d'aquest treball s'aborda en dues fases. Una primera constitueix un estudi teòric dels diversos conceptes implicats: SIG, cartografia, geodèsia i GPS, amb especial atenció al tipus de receptors GPS disponibles al mercat. La segona part és eminentment pràctica i està formada per l'exposició de la solució adoptada per a respondre a les necessitats de l'empresa

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L¿objectiu del projecte es estudiar el que és i el que no és un sistema d¿informació geogràfica,conèixer la tecnologia associada a aquests sistemes, així com el tipus i format de les dades que fan servir. Tanmateix, l¿estudi no és només teòric i, per conèixer els mecanismes de automatització que ofereix GeoMedia, s¿implementa una petita eina de gestió de vèrtexs geodèsics centrada al territori de Catalunya que fa servir Oracle, com a gestor de bases de dades.

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Els Sistemes d'Informació Geogràfica s'han convertit en quelcom molt important en els darrers temps gràcies al desenvolupament de les tecnologies sobre les que es recolzen. Aquest projecte tracta sobre ells, i ho fa des de dos vessats: el teòric i el pràctic. En la part teòrica del projecte es farà una revisió del que són per a què serveixen els Sistemes d'Informació Geogràfica. Per a entendre'ls amb més garanties es tracten lleugerament alguns conceptes genèrics sobre geodèsia i cartografia. La part pràctica del projecte descriu de quina forma s'ha creat un Sistema d'Informació Geogràfica que permet el tractament de dades d'Haití i que facilita la creació de mapes diversos. Addicionalment, per a veure una utilitat real del que es pot fer amb ells, es descriu també de quina forma s'ha dissenyat una aplicació que permet realitzar el càlcul de rutes òptimes entre dos punts, partint com a base de la xarxa de carreteres d'Haití. Per a finalitzar, es descriu de quina manera s'ha implementat un control de trams de carretera intransitables, els quals no seran considerats en el càlcul de les rutes.

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PURPOSE: The origin of the slow component is not fully understood. The mechanical hypothesis is one of the potential factors, because an increase in external mechanical work with fatigue was previously reported for a constant velocity run. The purpose of this study was to determine whether a change in mechanical work could occur during the development of the VO2 slow component under the effect of fatigue. METHODS: Twelve regional-level competitive runners performed a square-wave transition, corresponding to 95% of the speed associated with peak VO2 obtained during an incremental test. The VO2 response was fit with a classical model including two exponential functions. A specific treadmill with three-dimensional force transducers was used to measure the ground reaction force. Kinetic work (W(kin)), potential work (W(pot)), external work (W(ext)), and an index of internal work (W(int)) per unit of distance were quantified continuously. RESULTS: During the slow component of VO2, a significant increase in W (P< 0.01), no change in W, and a significant decrease in W and W index (P< 0.05, P< 0.001, respectively) were observed. CONCLUSION: The present study showed that the slow component of VO2 did not result partly from a change in mechanical work under the effect of fatigue. Nevertheless, the decrease in stride frequency (P< 0.001) and contact time (P< 0.001) suggested an alternative mechanical explanation. The slow component during running may be due to the cost of generating force or to alterations in the storage and recoil of elastic energy, and not to the external mechanical work.

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España Virtual es un proyecto de I+D, subvencionado por el [CDTI] dentro del programa Ingenio 2010, orientado a la definición de la arquitectura, protocolos y estándares de la futura Internet 3D, con un foco especial en lo relativo a visualización 3D, inmersión en mundos virtuales, interacción entre usuarios y a la introducción de aspectos semánticos, sin dejar de lado el estudio y maduración de las tecnologías para el procesamiento masivo y almacenamiento de datos geográficos. Con una duración de cuatro años, el proyecto está liderado por Elecnor DEIMOS y cuenta con la participación del Centro Nacional de Información Geográfica (IGN/CNIG), Indra Espacio, Androme Ibérica, GeoSpatiumLab, DNX, [Prodevelop], Telefónica I+D y una decena de prestigiosos centros de investigación y universidades nacionales. En este contexto Prodevelop y el Ai2 (Instituto de Automática e Informática Industrial) entran a participar en el proyecto gracias a la Asociación gvSIG con el objetivo de impulsar el desarrollo de la visualización 3D , incorporación de nuevos estándares y mejoras en los ya existentes, así como la evolución de funcionalidades, sobre todo en el ámbito de los servicios remotos y mejoras del rendimiento a través de sistemas de cacheado de datos. También se pretende servir como plataforma para el volcado de resultados en los diferentes activos experimentales realizados por otros socios del proyecto. Para la consecución de objetivos se definen diferentes paquetes de trabajo que va a trabajar sobre nuevos tipos de datos, acceso a datos 3D multirresolución, integración de datos geográficos al vuelo, componentes de visualización 2D, 3D y 4D, algoritmia multirresolución y efectos audiovisuales inmersivos. Concretamente y dentro de estos paquetes de trabajo se presentarán los avances realizados e integrados dentro de gvSIG Desktop v2.0, y otras funcionalidades gvSIG sobre dispositivos móviles

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Anàlisi de les diferents funcionalitats de l'aplicació Geomedia 3D i la seva utilitat dins del terreny dels sistemes d'informació geogràfica.

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This paper presents a new registration algorithm, called Temporal Di eomorphic Free Form Deformation (TDFFD), and its application to motion and strain quanti cation from a sequence of 3D ultrasound (US) images. The originality of our approach resides in enforcing time consistency by representing the 4D velocity eld as the sum of continuous spatiotemporal B-Spline kernels. The spatiotemporal displacement eld is then recovered through forward Eulerian integration of the non-stationary velocity eld. The strain tensor iscomputed locally using the spatial derivatives of the reconstructed displacement eld. The energy functional considered in this paper weighs two terms: the image similarity and a regularization term. The image similarity metric is the sum of squared di erences between the intensities of each frame and a reference one. Any frame in the sequence can be chosen as reference. The regularization term is based on theincompressibility of myocardial tissue. TDFFD was compared to pairwise 3D FFD and 3D+t FFD, bothon displacement and velocity elds, on a set of synthetic 3D US images with di erent noise levels. TDFFDshowed increased robustness to noise compared to these two state-of-the-art algorithms. TDFFD also proved to be more resistant to a reduced temporal resolution when decimating this synthetic sequence. Finally, this synthetic dataset was used to determine optimal settings of the TDFFD algorithm. Subsequently, TDFFDwas applied to a database of cardiac 3D US images of the left ventricle acquired from 9 healthy volunteers and 13 patients treated by Cardiac Resynchronization Therapy (CRT). On healthy cases, uniform strain patterns were observed over all myocardial segments, as physiologically expected. On all CRT patients, theimprovement in synchrony of regional longitudinal strain correlated with CRT clinical outcome as quanti ed by the reduction of end-systolic left ventricular volume at follow-up (6 and 12 months), showing the potential of the proposed algorithm for the assessment of CRT.

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Purpose: The objective of this study is to investigate the feasibility of detecting and quantifying 3D cerebrovascular wall motion from a single 3D rotational x-ray angiography (3DRA) acquisition within a clinically acceptable time and computing from the estimated motion field for the further biomechanical modeling of the cerebrovascular wall. Methods: The whole motion cycle of the cerebral vasculature is modeled using a 4D B-spline transformation, which is estimated from a 4D to 2D + t image registration framework. The registration is performed by optimizing a single similarity metric between the entire 2D + t measured projection sequence and the corresponding forward projections of the deformed volume at their exact time instants. The joint use of two acceleration strategies, together with their implementation on graphics processing units, is also proposed so as to reach computation times close to clinical requirements. For further characterizing vessel wall properties, an approximation of the wall thickness changes is obtained through a strain calculation. Results: Evaluation on in silico and in vitro pulsating phantom aneurysms demonstrated an accurate estimation of wall motion curves. In general, the error was below 10% of the maximum pulsation, even in the situation when substantial inhomogeneous intensity pattern was present. Experiments on in vivo data provided realistic aneurysm and vessel wall motion estimates, whereas in regions where motion was neither visible nor anatomically possible, no motion was detected. The use of the acceleration strategies enabled completing the estimation process for one entire cycle in 5-10 min without degrading the overall performance. The strain map extracted from our motion estimation provided a realistic deformation measure of the vessel wall. Conclusions: The authors' technique has demonstrated that it can provide accurate and robust 4D estimates of cerebrovascular wall motion within a clinically acceptable time, although it has to be applied to a larger patient population prior to possible wide application to routine endovascular procedures. In particular, for the first time, this feasibility study has shown that in vivo cerebrovascular motion can be obtained intraprocedurally from a 3DRA acquisition. Results have also shown the potential of performing strain analysis using this imaging modality, thus making possible for the future modeling of biomechanical properties of the vascular wall.