881 resultados para Dynamic Spatial Performance


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OBJECT The authors developed a new mapping technique to overcome the temporal and spatial limitations of classic subcortical mapping of the corticospinal tract (CST). The feasibility and safety of continuous (0.4-2 Hz) and dynamic (at the site of and synchronized with tissue resection) subcortical motor mapping was evaluated. METHODS The authors prospectively studied 69 patients who underwent tumor surgery adjacent to the CST (< 1 cm using diffusion tensor imaging and fiber tracking) with simultaneous subcortical monopolar motor mapping (short train, interstimulus interval 4 msec, pulse duration 500 μsec) and a new acoustic motor evoked potential alarm. Continuous (temporal coverage) and dynamic (spatial coverage) mapping was technically realized by integrating the mapping probe at the tip of a new suction device, with the concept that this device will be in contact with the tissue where the resection is performed. Motor function was assessed 1 day after surgery, at discharge, and at 3 months. RESULTS All procedures were technically successful. There was a 1:1 correlation of motor thresholds for stimulation sites simultaneously mapped with the new suction mapping device and the classic fingerstick probe (24 patients, 74 stimulation points; r(2) = 0.98, p < 0.001). The lowest individual motor thresholds were as follows: > 20 mA, 7 patients; 11-20 mA, 13 patients; 6-10 mA, 8 patients; 4-5 mA, 17 patients; and 1-3 mA, 24 patients. At 3 months, 2 patients (3%) had a persistent postoperative motor deficit, both of which were caused by a vascular injury. No patient had a permanent motor deficit caused by a mechanical injury of the CST. CONCLUSIONS Continuous dynamic mapping was found to be a feasible and ergonomic technique for localizing the exact site of the CST and distance to the motor fibers. The acoustic feedback and the ability to stimulate the tissue continuously and exactly at the site of tissue removal improves the accuracy of mapping, especially at low (< 5 mA) stimulation intensities. This new technique may increase the safety of motor eloquent tumor surgery.

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Air Traffic Control Laboratory Simulator (ATC-lab) is a new low- and medium-fidelity task environment that simulates air traffic control. ATC-lab allows the researcher to study human performance of tasks under tightly controlled experimental conditions in a dynamic, spatial environment. The researcher can create standardized air traffic scenarios by manipulating a wide variety of parameters. These include temporal and spatial variables. There are two main versions of ATC-lab. The medium-fidelity simulator provides a simplified version of en route air traffic control, requiring participants to visually search a screen and both recognize and resolve conflicts so that adequate separation is maintained between all aircraft. The low-fidelity simulator presents pairs of aircraft in isolation, controlling the participant's focus of attention, which provides a more systematic measurement of conflict recognition and resolution performance. Preliminary studies have demonstrated that ATC-lab is a flexible tool for applied cognition research.

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Training designed to support and strengthen higher-order mental abilities now often involves immersion in Virtual Reality where dangerous real world scenarios can be safely replicated. However despite the growing popularity of advanced training simulations, methods for evaluating their use rely heavily on subjective measures or analysis of final outcomes. Without dynamic, objective performance measures the outcome of training in terms of impact on cognitive skills and ability to transfer newly acquired skills to the real world is unknown. The relationship between affective intensity and cognitive learning provides a potential new approach to ensure the processing of cognitions which occur prior to final outcomes, such as problem-solving and decision-making, are adequately evaluated. This paper describes the technical aspects of pilot work recently undertaken to develop a new measurement tool designed to objectively track individual affect levels during simulation-based training.

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The effects of the hydrological regime on temporal changes to physical characteristics of substratum habitat, sediment texture of surface sediments (<10 cm), were investigated in a sub-tropical headwater stream over four years. Surface discharge was measured together with vertical hydraulic gradient and groundwater depth in order to explore features of sediment habitat that extend beyond the streambed surface. Whilst the typical discharge pattern was one of intermittent base flows and infrequent flow events associated with monsoonal rain patterns, the study period also encompassed a drought and a one-in-a-hundred-year flood. Rainfall and discharge did not necessarily reflect the actual conditions in the stream. Although surface waters were persistent long after discharge ceased, the streambed was completely dry on several occasions. Shallow groundwater was present at variable depths throughout the study period, being absent only at the height of the drought. The streambed sediments were mainly gravels, sand and clay. Finer sediment fractions showed a marked change in grain size over time, although bedload movement was limited to a single high discharge event. In response to a low discharge regimen (drought), sediments characteristically showed non-normal distributions and were dominated by finer materials. A high-energy discharge event produced a coarsening of sands and a diminished clay fraction in the streambed. Particulate organic matter from sediments showed trends of build-up and decline with the high and low discharge regimes, respectively. Within the surface sediment intersticies three potential categories of invertebrate habitat were recognised, each with dynamic spatial and temporal boundaries.

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This paper considers a class of dynamic Spatial Point Processes (PP) that evolves over time in a Markovian fashion. This Markov in time PP is hidden and observed indirectly through another PP via thinning, displacement and noise. This statistical model is important for Multi object Tracking applications and we present an approximate likelihood based method for estimating the model parameters. The work is supported by an extensive numerical study.

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A Ilha Grande situa-se na chamada Costa Verde do Estado do Rio de Janeiro, tem a totalidade de seu território protegido legalmente e vem sendo alvo de especuladores e investidores cujos interesses são, principalmente, explorar o potencial natural do bioma de Mata Atlântica. Observa-se um processo de transformação local em diversos aspectos que englobam o meio ambiente e a sociedade, como a degradação ambiental e o deslocamento da comunidade tradicional. O Poder Público manteve-se distante ou mesmo ausente por décadas, o que possibilitou a instalação de problemas ambientais e a configuração de conflitos na esfera do planejamento e gestão. Considerando-se a relevância socioambiental deste território insular e, em especial, com a implantação do Centro de Estudos Ambientais e Desenvolvimento Sustentável (CEADS) da Universidade do Estado do Rio de Janeiro (UERJ) na Enseada de Dois Rios, o presente estudo tem como objetivo identificar a dinâmica ambiental estabelecida na ilha. Os aspectos relacionados ao uso e ocupação do solo e à fragilidade ambiental são fundamentais para a análise integrada, para a compreensão da configuração atual do território e para a formulação de diretrizes de desenvolvimento adequadas à complexa realidade da Ilha Grande, cuja atividade econômica está pautada no turismo. Identificou-se como as principais causas dos problemas ambientais e dos conflitos de gestão: o caótico ordenamento do território, a falta de infraestrutura de serviços, a dificuldade de mobilização social, a falta de integração entre as políticas públicas e competências administrativas, a precariedade da fiscalização, a impunidade aos que não cumpriram a normatização em vigor e, a não observância da fragilidade ambiental do geossistema Ilha Grande.

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Identifying key marine megavertebrate habitats has become ever more important as concern increases regarding global fisheries bycatch and accelerated climate change. This will be aided by a greater understanding of the patterns and processes determining the spatiotemporal distribution of species of conservation concern. We identify probable foraging grounds for leatherback turtles in the NE Atlantic using monthly landscapes of gelatinous organism distribution constructed from Continuous Plankton Recorder Survey data. Using sightings data (n = 2013 records, 1954 to 2003) from 9 countries (UK, Ireland, France, Belgium, The Netherlands, Denmark, Germany, Norway and Sweden), we show sea surface temperatures of approximately 10 to 12 degree C most likely indicate the lower thermal threshold for accessible habitats during seasonal foraging migrations to high latitudes. Integrating maps of gelatinous plankton as a possible indicator of prey distribution with thermal tolerance parameters demonstrates the dynamic (spatial and temporal) nature of NE Atlantic foraging habitats. We highlight the importance of body size- related thermal constraints in structuring leatherback foraging populations and demonstrate a latitudinal gradient in body size (Bergmann's rule) where smaller animals are excluded from higher latitude foraging areas. We highlight the marine area of the European continental shelf edge as being both thermally accessible and prey rich, and therefore potentially supporting appreciable densities of foraging leatherbacks, with some suitable areas not yet extensively surveyed.

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A novel resonator-based bandpass Σ-Δ modulator with an in-built variable centre frequency feature is presented. This structure is designed by analytically determining and subsequently verifying through behavioural level simulations the necessary compensation hardware to be placed in the feedback to ensure stability and good dynamic range performance.

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Tese de Doutoramento, Ciências do Mar (Ecologia Marinha)

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The motility of T cells depends on the dynamic spatial regulation of integrin-mediated adhesion and de-adhesion. Cathepsin X, a cysteine protease, has been shown to regulate T-cell migration by interaction with lymphocyte function associated antigen-1 (LFA-1). LFA-1 adhesion to the ICAM-1 is controlled by the association of actin-binding proteins with the cytoplasmic tail of the beta(2) chain of LFA-1. Cleavage by cathepsin X of the amino acid residues S(769), E(768) and A(767) from the C-terminal of the beta(2) cytoplasmic tail of LFA-1 is shown to promote binding of the actin-binding protein alpha-actinin-1. Furthermore, cathepsin X overexpression reduced LFA-1 clustering and induced an intermediate affinity LFA-1 conformation that is known to associate with a-actinin-1. increased levels of intermediate affinity LFA-1 resulted in augmented cell spreading due to reduced attachment of T cells to the ICAM-1-coated surface. Gradual cleavage of LFA-1 by cathepsin X enables the transition between intermediate and high affinity LFA-1, an event that is crucial for effective T-cell migration.

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O objetivo desta tese foi analisar os recursos intangíveis de um destino turístico. Foi feito um estudo de desempenho da cidade de Natal tendo como base a teoria das capacidades dinâmicas. Inicialmente, foi desenvolvido um instrumento de pesquisa para oportunizar a construção de um modelo de medida com vistas à captação de variáveis latentes para os recursos intangíveis existentes no setor do turismo em Natal-RN. Em seguida, foi realizada uma análise dos recursos intangíveis que são evidenciados pelos turistas acerca da cidade. Finalmente, foi feita a investigação de um modelo de estrutura que estabeleceu as relações entre as variáveis latentes dos recursos intangíveis e a percepção de desempenho do turismo na cidade de Natal. Procedeu-se uma revisão de literatura para construção de um modelo inicial acerca dos ativos intangíveis dentro da teoria das capacidades e foram relacionados dez recursos, quais sejam: recursos humanos prestadores de serviços; recursos humanos como gestores; cultura local; conservação do meio ambiente; know-how empresarial; inovação empresarial; tecnologia; marca; preço; e promoção. Estes dez recursos, em conjunto, seriam responsáveis pelo desempenho do destino turístico. Após ser realizada uma análise de equações estruturais, apenas quatro recursos manifestaram relações com o desempenho: marca; cultura; conservação do meio ambiente; e preço. Análisando dos dados, verificou-se que a variável desempenho positivo da cidade na ótica do turista se manifestou fortemente e foi influenciada de forma forte pela cultura local, marca e conservação do meio ambiente em conjunto. O preço foi influenciado pelo desempenho positivo mostrando que o turista sente que o preço pago foi satisfatório diante dos atributos do destino Provavelmente, isso seja um ponto positivo muito forte para o destino turístico de Natal, pois, em termos de recursos intangíveis e de juntos formarem capacidades, eles são inimitáveis, raros e são capazes de se ajustarem às mudanças organizacionais e ambientais, para reconfigurar os ativos e as estruturas de um destino, corroborando, assim, com a teoria das capacidades dinâmicas. Esses recursos da cidade de Natal, como destino turístico, são únicos e provavelmente têm um peso muito maior para o desempenho da cidade do que problemas existentes na localidade. Logo, esses atributos devem ser estimulados a continuar crescendo e se modificando de acordo com as exigências atuais e futuras de consumo

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Nowadays, there are many aspect-oriented middleware implementations that take advantage of the modularity provided by the aspect oriented paradigm. Although the works always present an assessment of the middleware according to some quality attribute, there is not a specific set of metrics to assess them in a comprehensive way, following various quality attributes. This work aims to propose a suite of metrics for the assessment of aspect-oriented middleware systems at different development stages: design, refactoring, implementation and runtime. The work presents the metrics and how they are applied at each development stage. The suite is composed of metrics associated to static properties (modularity, maintainability, reusability, exibility, complexity, stability, and size) and dynamic properties (performance and memory consumption). Such metrics are based on existing assessment approaches of object-oriented and aspect-oriented systems. The proposed metrics are used in the context of OiL (Orb in Lua), a middleware based on CORBA and implemented in Lua, and AO-OiL, the refactoring of OIL that follows a reference architecture for aspect-oriented middleware systems. The case study performed in OiL and AO-OiL is a system for monitoring of oil wells. This work also presents the CoMeTA-Lua tool to automate the collection of coupling and size metrics in Lua source code

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The state of Rio Grande do Norte has been undergoing transformations in their territory, they are promoted by the installation of new infrastructure equipment, which in turn cause changes in the dynamic spatial and social hour set, causing new arrangements and new dynamics between cities. The overall goal of the research is to understand, at present, the urban network of the Rio Grande do Norte, from the centers of territory management. The picture presented in the paper reveals a network of cities that has gained a material basis urban, with the installation of new objects macro state structures (roads, ports, wind farms, banks, pipelines, internet access) that enable a relationship more intense between the urban centers of the state and other cities in the world, that the current structure characteristic of the urban network, its global nature, since the possibility of relations between the centers is greater. Such a relationship is indeed possible because the characteristics of the current historical period, with the high density of the tripod technique, science and information controlled by the market. In Rio Grande do Norte intentionality of the new arrangement that is configured is not other but meet market demands

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)