Browsing by Issue Date, starting with "2016-05"
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- Cognitive predictors of balance in Parkinson’s diseasePublication . Fernandes, Ângela; Mendes, Andreia; Rocha, Nuno; Tavares, João Manuel R. S.Postural instability is one of the most incapacitating symptoms of Parkinson's disease (PD) and appears to be related to cognitive deficits. This study aims to determine the cognitive factors that can predict deficits in static and dynamic balance in individuals with PD. A sociodemographic questionnaire characterized 52 individuals with PD for this work. The Trail Making Test, Rule Shift Cards Test, and Digit Span Test assessed the executive functions. The static balance was assessed using a plantar pressure platform, and dynamic balance was based on the Timed Up and Go Test. The results were statistically analysed using SPSS Statistics software through linear regression analysis. The results show that a statistically significant model based on cognitive outcomes was able to explain the variance of motor variables. Also, the explanatory value of the model tended to increase with the addition of individual and clinical variables, although the resulting model was not statistically significant The model explained 25-29% of the variability of the Timed Up and Go Test, while for the anteroposterior displacement it was 23-34%, and for the mediolateral displacement it was 24-39%. From the findings, we conclude that the cognitive performance, especially the executive functions, is a predictor of balance deficit in individuals with PD.
- Physical activity and self-esteem during pregnancyPublication . Santos, Paula Clara; Ferreira, Marta Isabel; Teixeira, Ricardo João; Couto, Miriam; Montenegro, Nuno; Mota, JorgeThe aims of this paper are to examine the accomplishment of the recommendations of physical activity (PA) practice in accordance with the recommendations of the American College of Sports Medicine (ACSM); verify if the sociodemographic variables (SDV) influence women’s self-esteem; investigate if there are differences in pregnant women’s self-esteem who practiced or not structured physical activity (SPA) before pregnancy, and of pregnant women who met the recommendations or not during pregnancy. A sample of 44 pregnant women was evaluated in two stages: between the 10th and 13th week of pregnancy (1st trimester- 1T) and between the 20th and 23rd week of gestation (2nd trimester - 2T). The PA was assessed by accelerometry and self-esteem was assessed using the Rosenberg Self-Esteem Scale. Sociodemographic variables and SPA before pregnancy were assessed through a self-administered questionnaire. Over 60% of the sample did not meet recommendations for PA practice in any of the trimester. There were no significant differences between self-esteem for each of the SDV, with the exception of the higher monthly income (1T) and marital status (2T), associated with better self-esteem. There were significant differences in self-esteem among pregnant women or unstructured PA performed before pregnancy (1T and 2T). The completion, or not, of ACSM recommendations did not seem to impact on self-esteem during pregnancy. Most pregnant women did not met the ACSM recommendations for PA practice. It was found that marital status and higher incomes have influenced positively self-esteem, as well as the practice of SPA, before pregnancy.
- Multimodal interaction and serious game for assistive robotic devices in a simulated environmentPublication . Faria, Brigida Monica; Dias, Daniel; Reis, Luís Paulo; Moreira, António PauloSports and physical activities allow people with disabilities to have better quality of life. The proposed work aimed to develop a multimodal interaction platform of robotic devices in a simulated environment for users to train different interface options. The suggested scenarios allow a user to interact with an Intelligent Wheelchair (IW) and with an Intelligent Robotic Ramp (IRR) performing different tasks individually or with a multiplayer option. The main objective of this multimodal interaction platform is to allow users, with severe disabilities, to move around and inclusive to play the Boccia Game more independently and autonomously. A preliminary set of experiments with 27 volunteers tested the scenarios and the multimodal interface for driving the intelligent wheelchair and to maneuver the IRR. The results show excellent performance when users maneuver the IRR in which the success achieved 90%. All dimensions of CEGEQ questionnaire presented good results. Therefore the solution created is quite satisfactory for a user point of view.
- Genetic variants at the Wnt/[beta]-catenin and oestrogen receptor signalling pathways are associated with low bone mineral density in dancersPublication . Amorim, Tânia; Durães, Cecília; Maia, José; Machado, José Carlos; Nogueira, Luísa; Adubeiro, Nuno; Flouris, Andreas D.; Metsios, George S.; Marques, Franklim; Wyon, Matthew; Koutedakis, YiannisResearch suggests that dancers are at higher risk of developing low bone mineral density (BMD) compared with the general population. However, the associated factors contributing to low BMD in dancers are not fully understood. We aimed to assess the association of single-nucleotide polymorphisms (SNPs) in the Wnt/b-catenin and oestrogen receptor (ER) signalling pathways with low BMD in dancers.
- Impact of using solar heat pumps for domestic hot water in Portuguese residential buildingsPublication . Monteiro, Joaquim; Castro, OlgaIn recent years, we have seen an improvement of existing facilities in dwellings in Portugal. Within the heat pumps systems, there is a special type known as direct expansion heat pump assisted by Solar Collector (DX-SAHP). It was calculate the SPF indicator for 30 regions of Portugal. It was analyses the potential of reductions of CO2 and primary energy use for the retrofitting of DHW preparation systems. It was found that the performances of this type of equipment are benefiting from the Portuguese climate conditions, especially in the South and in the Autonomous Regions. Best SPF was obtained for Beja. It was found in all regions of the high potential for reducing CO2 emissions and verifying a potential significant reduction of primary energy consumption.
- Análise do Planning Target Volume e Órgãos de Risco, com diferentes energias de fotões em 3D-CRT, no Cancro do PulmãoPublication . Ferreira, Marta Patrícia Varzim MirandaObjetivo: Este estudo tem como principal objetivo analisar a presença de um benefício na distribuição das isodoses (cobertura do Planning Target Volume – PTV), assim como nas doses recebidas pelos órgãos de risco, utilizando feixes de baixa energia 6 MV (megavolt) em comparação com feixes de alta energia, 18 MV, no planeamento do tratamento de Radioterapia (RT) com Three-Dimencional Conformal Radiotherapy (3D-CRT) em pacientes com Carcinoma de Pulmão. Materiais e Métodos: A amostra incluiu 15 pacientes com diagnóstico de Carcinoma do Pulmão. Foram realizados dois planeamentos dosimétricos, idênticos para cada doente, com energias de 6 MV e de 18 MV. Posteriormente foram avaliados os histogramas de dose volume (DVH’s) de todos os órgãos de risco (OAR’s), bem como a cobertura, o índice de conformidade (IC) e o índice de homogeneidade (IH) relativos ao PTV. Os dados foram analisados estatisticamente através do programa Statistical Package for the Social Science. Resultados: Através da análise dos dados recolhidos é possível afirmar que com a energia de 6 MV obtiveram-se melhores resultados nos seguintes parâmetros de avaliação do PTV: índice de conformidade e índice de homogeneidade, em comparação com os planos de energia de 18 MV. Também se verificou que a energia de 6 MV apresentou valores mais baixos relativamente aos órgãos de risco. Através da análise diferencial, percebeu-se que vários são os parâmetros dos quais se verificam diferenças estatisticamente significativas, entre os dois planeamentos, sendo a energia de 6 MV a que apresenta melhores resultados. Conclusões: Através dos resultados obtidos neste estudo pode-se constatar que estes vão de encontro, a outros anteriormente publicados, podemos então concluir que a energia 6 MV apresenta melhores valores, com diferenças estatisticamente significativas, em particular para o tratamento do cancro do pulmão, em relação à energia 18 MV. Contudo o que não quer dizer que não se possa usar energia de 18 MV no tratamento do cancro do pulmão, principalmente nos casos de tumores do mediastino.
- Qualidade de imagem em mamografia: apresentação do músculo grande peitoral na incidência oblíqua médio-lateralPublication . Mota, Joana; Ventura, Sandra Moreira RuaA mamografia é, atualmente, o principal método de diagnóstico imagiológico da patologia mamária, sendo, por isso, essencial a produção consistente de imagens mamográficas de elevada qualidade. Assim, e uma vez que a mamografia visa a maximização da visualização do tecido mamário, o principal objetivo deste estudo consiste em investigar a apresentação mamográfica do músculo grande peitoral na incidência oblíqua médio-lateral (OML) da mama. Pretendeu-se relacionar os padrões técnicos de aquisição de imagem à forma de apresentação do referido músculo, avaliando-os de acordo com os atuais critérios de qualidade de imagem. As imagens mamográficas foram recolhidas a partir de duas instituições hospitalares de referência do Porto, sendo posteriormente efetuada uma análise e tratamento estatístico dos indicadores qualitativos e quantitativos de qualidade das mesmas. Numa análise global por instituição, e tendo por base estes indicadores, a instituição que utiliza uma angulação fixa do potter-bucky, independentemente do biótipo corporal da paciente, apresentou resultados melhores, indicando assim que a existência de falhas devido a erros de posicionamento é menor por comparação aos critérios de qualidade padrão. Constatou-se, portanto, que a angulação do potter-bucky tem um impacto relevante e estatisticamente significativo na qualidade das imagens mamográficas.
- Application of the nZEB methodology in the retrofitting of a typical Portuguese dwelling from the 60's.Publication . Monteiro, Joaquim; Castro, OlgaBuildings and the whole built environment are in a key role when societies are mitigating climate change and adapting to its consequences. More than 50% of the existing residential buildings in EU-25 were built before 1970. Thus, these buildings are of significant importance in reducing energy consumption and CO2 emissions. The existence of more nearly zero energy buildings (nZEB) is a possible solution for this problem. This study aims to analyze the application of the nZEB methodology in the retrofitting of a typical Portuguese dwelling build in 1950. It was shown that the primary energy used can be reduced to a very low value (11,95 kWhep/m2.y) in comparison with the reference consumption (69,15 kWhep/m2.y), with the application of the best construction techniques together with the use of energy from on-site renewable sources.
- Influência do clima e do caudal de ar variável em função da demanda para um sistema centralizado tudo-ar.Publication . Almeida, Marco; Monteiro, Joaquim; Castro, OlgaNa perspetiva da melhoria da eficiência energética e da QAI dos edifícios de serviços existentes e que são climatizados com sistemas centralizados do tipo tudo-ar, foi desenvolvida uma aplicação informática que permite simular o comportamento dinâmico de situações reais de funcionamento relativas ao tratamento de ar. Com vista à redução do consumo energético associado à utilização dos sistemas técnicos de climatização, foi desenvolvido um modelo matemático para os diversos processos físicos que ocorrem numa unidade de tratamento de ar, implementado numa aplicação informática e validado o seu funcionamento através de experiências laboratoriais desenvolvidas numa sala de testes de climatização. O presente estudo permitiu determinar a influência das variáveis, clima e caudal de ar insuflado variável em função da demanda, no consumo energético associado às condições de conforto do ambiente interior para a estação de aquecimento. Foi estimado um aumento de 65% de consumo energético para o clima mais rigoroso de Bragança, acompanhado de um menor potencial de redução de consumo energético (6% em termos médios), relativamente aos outros climas. Relativamente à utilização de estratégias de ventilação controlada pela demanda (DCV), estimaram-se que os potenciais de redução de consumo energético máximos poderão atingir valores de 40% e 39% para Faro e Porto, respetivamente, e de 30% para Bragança. A ferramenta informática desenvolvida poderá ser uma ajuda em análises económicas a efetuar, nomeadamente para renovações de edifícios de serviços existentes.
- Price Forecasting and Validation in the Spanish Electricity Market using Forecasts as Input DataPublication . Ortiz, María; Ukar, Olatz; Azevedo, Filipe; Múgica, ArantzaThe electricity sector has been subjected to major changes in the last few years. Previously, there existed a regulated system where electric companies could know beforehand the amount of energy each generator would produce, hence basing their largely operational strategy on cost minimization in order to increase their profits. In Spain, from 1988 till 1997, electricity prices were established by the ‘Marco Legal Estable’ – Stable Legal Framework –, where the Ministry of Industry and Energy acknowledged the existence of certain generation costs related to each type of technology. It was an industrial sector with no actual competition and therefore, with very few controllable risks. In the aftermath of the electricity market liberalization competition and uncertainty arose. Electricity spot prices became highly volatile due to the specific characteristics of electricity as a commodity. Long-term contracts allowed for hedge funds to act against price fluctuation in the electricity market. As a consequence, developing an accurate electricity price forecasting model is an extremely difficult task for electricity market agents. This work aims to propose a methodology to improve the limitations of those methodologies just using historical data to forecast electricity prices. In this manner, and in order to gain access to more recent data, instead of using natural gas prices and electricity load historical data, a regression model to forecast the evolution of natural gas prices, and a model based on artificial neural networks (ANN) to forecast electricity loads, are proposed. The results of these models are used as input for an electricity price forecast model. Finally, and to demonstrate the effectiveness of the proposed methodology, several study cases applied to the Spanish market, using real price data, are presented.