986 resultados para Temporal fluctuations


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A epilepsia do lobo temporal (ELT) é o tipo de epilepsia refractária mais comum nos adultos. O compromisso da memória verbal nos doentes com ELT à esquerda é relativamente consensual. No entanto, no que concerne a outras funções como é o caso da atenção, funções executivas, rendimento intelectual e linguagem, o consenso não é tão generalizado. Nesta investigação fomos estudar o perfil neuropsicológico dos défices cognitivos apresentados por doentes com epilepsia do lobo temporal e clarificar o impacto da cronicidade da doença na cognição. Para esta investigação analisámos retrospectivamente um grupo de 76 doentes com epilepsia refractária, 48 doentes com epilepsia do lobo temporal (23 com foco à direita e 25 com foco à esquerda) e 28 doentes com epilepsia extratemporal. Aplicámos uma bateria de provas utilizada no âmbito do programa da Cirurgia da Epilepsia do Hospital de Egas Moniz, em Lisboa. Os resultados mostram que a bateria aplicada apresenta consistência interna no âmbito da avaliação dos doentes com ELT. Encontrámos que os doentes com ELT à direita e à esquerda apresentam um padrão generalizado de défices, sobreponíveis aos apresentados pelos doentes com epilepsia extratemporal, o que pode ser indicador de compromisso noutras áreas cerebrais para além do hipocampo. Um achado que consideramos pertinente foi o facto da memória verbal com interferência (memória a longo termo) não mostrar alterações nos doentes com ELT tanto à direita como à esquerda, sugerindo que esta função não está comprometida na ELT. Os nossos resultados mostram ainda que os doentes com ELT lateralizada à esquerda apresentam maior compromisso cognitivo do que os doentes com lateralização à direita. Por último, para além do padrão generalizado de défices cognitivos, também conseguimos observar o impacto da doença ao nível das variáveis sócio-demográficas.

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Foram recolhidos praticamente todos os dados da concentração de CO2 à superfície do mar (fCO2 (SO)) e temperatura à superfície do mar (TSM) obtidos por Embarcações de Observação Voluntária, para o Oceano Atlântico Norte (10º N – 80º N). Foram ainda recolhidos dados das concentrações atmosféricas de CO2 (fCO2 (ATM)), em estações fixas ao longo da bacia, para realizar o estudo do sequestro oceânico de CO2. Após uma seleção minuciosa e uma uniformização exaustiva, os dados foram armazenados por "sectores" 5º latitude x 5º longitude x mês. Em seguida foi obtida uma boa série de dados (2002 – 2007) para sectores que representavam a região das latitudes baixas (10º N-35º N), médias (35º N- 50º N) e altas (50º N-80º N). Para o período 2002 – 2007, o padrão regional da variação da fCO2 (SO) é controlado pela TSM nas latitudes baixas e médias, e pela dinâmica do oceano (absorção de CO2 (SO)) nas latitudes altas. Foi verificado um crescimento generalizado da fCO2 (ATM), TSM e fCO2 (SO) (excepto latitudes altas). Contudo para 2002 – 2007, a fCO2 (SO) está a aumentar mais lentamente do que para 1970 - 2006 [5]. A ΔfCO2 é principalmente influenciada pela fCO2 (SO) e pelos factores físicos que controlam o seu padrão de variação regional. A região das altas latitudes é a zona de maior sequestro de CO2 liquído da bacia. Nas latitudes médias e altas verifica-se um aumento do poder de sequestro para 2002 – 2007, o que que representa uma inflexão à tendência verificada em 1993 - 2005 [93]. Este factor pode estar relacionado com a mudança do índice da Oscilação do Atlântico Norte. A Zona Económica Exclusiva Portuguesa engloba a região que actua como o maior sumidouro de CO2 e o seu poder de sequestro oceânico de CO2 está a aumentar.

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Marine protected areas (MPAs) have been widely proposed for conservation purposes and as a tool for fisheries management. The Arrábida Marine Park is the first MPA in continental Portugal having a management plan, fully implemented since 2009. The main objective of this study was to evaluate the effect of protection measures on rocky reef fish assemblages and target invertebrates through before-after and control-effect (no-take vs. fished areas) underwater visual surveys and analysis of landings trends. Second, we used surveys before, during and after implementation of the management plan to understand fishers‟ preferences for fishing grounds and adaptation to the new rules, and evaluated the reserve effect through analysis of both ecological responses and fishing effort density. Third, we identified the main oceanographic drivers influencing the structure of reef fish assemblages and predicted the community structure for the last 50 years, in light of climatic change. Overall results suggest positive responses in biomass but not yet in numbers of some commercial species, with no effects on non-target species. The reserve effect is reinforced by the increase in landings of commercial species, despite increased fishing effort density in some areas, especially with octopus traps. Fishing grounds are mainly chosen based on the distribution of target species and associated habitats, but distance to port, weather conditions and safety also influence fishers‟ choices. Moreover, different fisheries respond differently to the protection measures, and within each fishery, individual fishers show distinct strategies, with some operating in a broader area whereas others keep preferred territories. Our results also show that wind stress and temperature are the main oceanographic drivers for rocky reef fish assemblages, with tropicalization of assemblages and polewards movements of species over the last 50 years consistent with temperature trends. We believe this study provides significant lessons for marine conservation and management of coastal systems.

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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

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Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

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Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

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Tese de doutoramento, Geografia (Geografia Física), Universidade de Lisboa, Instituto de Geografia e Ordenamento do Território, 2014

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Geographical and temporal variations in the start dates of grass pollen seasons are described for selected sites of the European Pollen Information Service. Daily average grass pollen counts are derived from Network sites in Finland, the Netherlands, Denmark, United Kingdom, Austria, Italy and Spain, giving a broad longitudinal transect over Western Europe. The study is part of a larger project that also examines annual and regional variations in the severity, timing of the peak and duration of the grass pollen seasons. For several sites, data are available for over twenty years enabling long term trends to be discerned. The analyses show notable contrasts in the progression of the seasons annually with differing lag times occurring between southern and northern sites in various years depending on the weather conditions. The patterns identified provide some insight into geographical differences and temporal trends in the incidence of pollinosis. The paper discusses the main difficulties involved in this type of analysis and notes possibilities for using data from the European Pollen Information service to construct pan European predictive models for pollen seasons.

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Tese de doutoramento, Informática (Ciências da Computação), Universidade de Lisboa, Faculdade de Ciências, 2015

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Detailed surveys of depth and velocity are undertaken to describe hydro-ecological status of rivers. Fieldwork for these surveys is time consuming and expensive. This paper aims to describe the methodology applied in order to determine the most suitable depth sampling strategy for effective field data collection and river representation in time and space at the Leigh Brook river site, Worcester, UK. The accuracy of three different sampling strategies for predicting depth at non-measured points has been compared and the mesohabitats that better characterise depth changes due to variations in discharge have been identified. The results show that depth changes due to discharge change are mainly located at shallow and deep glide mesohabitat types. The analysis for the comparison of sampling strategies indicates that grid sampling strategies give better results than regular transects. Since the results also show that higher errors in predictions are obtained in the deepest areas, higher sampling densities should be applied in these locations.

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This thesis takes a theoretical and practical approach to data visualization, focusing in particular on interactive timelines as a means to mapping historical/cultural narratives. It seeks to understand how timelines can efficiently communicate a historical narrative, enhancing the topic’s comprehension whilst relating it to the surrounding context. For this purpose, an interactive timeline on Design in Portugal from 1900 to present, was conceptualized and developed. The research adopted a descriptive methodology. The theoretical framework depicts the basic concepts, models and taxonomies associated to timelines, which derive from the main studies available on the matter. From this, a model for the analysis of three case studies – Idea Line (2002), The Path of Protest (2011) and British History Timeline (2006) – was proposed. The selection criteria shows that they refer to interactive timelines depicting a historical narrative, in addition to being as heterogeneous as possible with respect to the themes presented and conveyed purposes. The comparative analysis produced a set of thoughts, conclusions and principles, subsequently considered and applied in the development of the timeline presented. The results of this study point to the decisive role of visual setup of the time axis and user tasks in the interpretation of information. The effective implementation of the timeline Design in Portugal: from 1900 to present, contributes to the study of timelines as information devices with its own characteristics and capabilities, promotes associated research and theoretical systematization and, on a pragmatic note, helps creating the basis for the gathering, compilation and presentation of relevant information on design in Portugal, providing the academic and professional community with an effective tool for referring and learning

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Existing Workflow Management Systems (WFMSs) follow a pragmatic approach. They often use a proprietary modelling language with an intuitive graphical layout. However the underlying semantics lack a formal foundation. As a consequence, analysis issues, such as proving correctness i.e. soundness and completeness, and reliable execution are not supported at design level. This project will be using an applied ontology approach by formally defining key terms such as process, sub-process, action/task based on formal temporal theory. Current business process modelling (BPM) standards such as Business Process Modelling Notation (BPMN) and Unified Modelling Language (UML) Activity Diagram (AD) model their constructs with no logical basis. This investigation will contribute to the research and industry by providing a framework that will provide grounding for BPM to reason and represent a correct business process (BP). This is missing in the current BPM domain, and may result in reduction of the design costs and avert the burden of redundant terms used by the current standards. A graphical tool will be introduced which will implement the formal ontology defined in the framework. This new tool can be used both as a modelling tool and at the same time will serve the purpose of validating the model. This research will also fill the existing gap by providing a unified graphical representation to represent a BP in a logically consistent manner for the mainstream modelling standards in the fields of business and IT. A case study will be conducted to analyse a catalogue of existing ‘patient pathways’ i.e. processes, of King’s College Hospital NHS Trust including current performance statistics. Following the application of the framework, a mapping will be conducted, and new performance statistics will be collected. A cost/benefits analysis report will be produced comparing the results of the two approaches.