33 resultados para Improved Borsch-Supan Method
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Dissertação para obtenção do Grau de Mestre em Biotecnologia
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This Thesis describes the application of automatic learning methods for a) the classification of organic and metabolic reactions, and b) the mapping of Potential Energy Surfaces(PES). The classification of reactions was approached with two distinct methodologies: a representation of chemical reactions based on NMR data, and a representation of chemical reactions from the reaction equation based on the physico-chemical and topological features of chemical bonds. NMR-based classification of photochemical and enzymatic reactions. Photochemical and metabolic reactions were classified by Kohonen Self-Organizing Maps (Kohonen SOMs) and Random Forests (RFs) taking as input the difference between the 1H NMR spectra of the products and the reactants. The development of such a representation can be applied in automatic analysis of changes in the 1H NMR spectrum of a mixture and their interpretation in terms of the chemical reactions taking place. Examples of possible applications are the monitoring of reaction processes, evaluation of the stability of chemicals, or even the interpretation of metabonomic data. A Kohonen SOM trained with a data set of metabolic reactions catalysed by transferases was able to correctly classify 75% of an independent test set in terms of the EC number subclass. Random Forests improved the correct predictions to 79%. With photochemical reactions classified into 7 groups, an independent test set was classified with 86-93% accuracy. The data set of photochemical reactions was also used to simulate mixtures with two reactions occurring simultaneously. Kohonen SOMs and Feed-Forward Neural Networks (FFNNs) were trained to classify the reactions occurring in a mixture based on the 1H NMR spectra of the products and reactants. Kohonen SOMs allowed the correct assignment of 53-63% of the mixtures (in a test set). Counter-Propagation Neural Networks (CPNNs) gave origin to similar results. The use of supervised learning techniques allowed an improvement in the results. They were improved to 77% of correct assignments when an ensemble of ten FFNNs were used and to 80% when Random Forests were used. This study was performed with NMR data simulated from the molecular structure by the SPINUS program. In the design of one test set, simulated data was combined with experimental data. The results support the proposal of linking databases of chemical reactions to experimental or simulated NMR data for automatic classification of reactions and mixtures of reactions. Genome-scale classification of enzymatic reactions from their reaction equation. The MOLMAP descriptor relies on a Kohonen SOM that defines types of bonds on the basis of their physico-chemical and topological properties. The MOLMAP descriptor of a molecule represents the types of bonds available in that molecule. The MOLMAP descriptor of a reaction is defined as the difference between the MOLMAPs of the products and the reactants, and numerically encodes the pattern of bonds that are broken, changed, and made during a chemical reaction. The automatic perception of chemical similarities between metabolic reactions is required for a variety of applications ranging from the computer validation of classification systems, genome-scale reconstruction (or comparison) of metabolic pathways, to the classification of enzymatic mechanisms. Catalytic functions of proteins are generally described by the EC numbers that are simultaneously employed as identifiers of reactions, enzymes, and enzyme genes, thus linking metabolic and genomic information. Different methods should be available to automatically compare metabolic reactions and for the automatic assignment of EC numbers to reactions still not officially classified. In this study, the genome-scale data set of enzymatic reactions available in the KEGG database was encoded by the MOLMAP descriptors, and was submitted to Kohonen SOMs to compare the resulting map with the official EC number classification, to explore the possibility of predicting EC numbers from the reaction equation, and to assess the internal consistency of the EC classification at the class level. A general agreement with the EC classification was observed, i.e. a relationship between the similarity of MOLMAPs and the similarity of EC numbers. At the same time, MOLMAPs were able to discriminate between EC sub-subclasses. EC numbers could be assigned at the class, subclass, and sub-subclass levels with accuracies up to 92%, 80%, and 70% for independent test sets. The correspondence between chemical similarity of metabolic reactions and their MOLMAP descriptors was applied to the identification of a number of reactions mapped into the same neuron but belonging to different EC classes, which demonstrated the ability of the MOLMAP/SOM approach to verify the internal consistency of classifications in databases of metabolic reactions. RFs were also used to assign the four levels of the EC hierarchy from the reaction equation. EC numbers were correctly assigned in 95%, 90%, 85% and 86% of the cases (for independent test sets) at the class, subclass, sub-subclass and full EC number level,respectively. Experiments for the classification of reactions from the main reactants and products were performed with RFs - EC numbers were assigned at the class, subclass and sub-subclass level with accuracies of 78%, 74% and 63%, respectively. In the course of the experiments with metabolic reactions we suggested that the MOLMAP / SOM concept could be extended to the representation of other levels of metabolic information such as metabolic pathways. Following the MOLMAP idea, the pattern of neurons activated by the reactions of a metabolic pathway is a representation of the reactions involved in that pathway - a descriptor of the metabolic pathway. This reasoning enabled the comparison of different pathways, the automatic classification of pathways, and a classification of organisms based on their biochemical machinery. The three levels of classification (from bonds to metabolic pathways) allowed to map and perceive chemical similarities between metabolic pathways even for pathways of different types of metabolism and pathways that do not share similarities in terms of EC numbers. Mapping of PES by neural networks (NNs). In a first series of experiments, ensembles of Feed-Forward NNs (EnsFFNNs) and Associative Neural Networks (ASNNs) were trained to reproduce PES represented by the Lennard-Jones (LJ) analytical potential function. The accuracy of the method was assessed by comparing the results of molecular dynamics simulations (thermal, structural, and dynamic properties) obtained from the NNs-PES and from the LJ function. The results indicated that for LJ-type potentials, NNs can be trained to generate accurate PES to be used in molecular simulations. EnsFFNNs and ASNNs gave better results than single FFNNs. A remarkable ability of the NNs models to interpolate between distant curves and accurately reproduce potentials to be used in molecular simulations is shown. The purpose of the first study was to systematically analyse the accuracy of different NNs. Our main motivation, however, is reflected in the next study: the mapping of multidimensional PES by NNs to simulate, by Molecular Dynamics or Monte Carlo, the adsorption and self-assembly of solvated organic molecules on noble-metal electrodes. Indeed, for such complex and heterogeneous systems the development of suitable analytical functions that fit quantum mechanical interaction energies is a non-trivial or even impossible task. The data consisted of energy values, from Density Functional Theory (DFT) calculations, at different distances, for several molecular orientations and three electrode adsorption sites. The results indicate that NNs require a data set large enough to cover well the diversity of possible interaction sites, distances, and orientations. NNs trained with such data sets can perform equally well or even better than analytical functions. Therefore, they can be used in molecular simulations, particularly for the ethanol/Au (111) interface which is the case studied in the present Thesis. Once properly trained, the networks are able to produce, as output, any required number of energy points for accurate interpolations.
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Void formation during the injection phase of the liquid composite molding process can be explained as a consequence of the non-uniformity of the flow front progression. This is due to the dual porosity within the fiber perform (spacing between the fiber tows is much larger than between the fibers within in a tow) and therefore the best explanation can be provided by a mesolevel analysis, where the characteristic dimension is given by the fiber tow diameter of the order of millimeters. In mesolevel analysis, liquid impregnation along two different scales; inside fiber tows and within the open spaces between the fiber tows must be considered and the coupling between the flow regimes must be addressed. In such cases, it is extremely important to account correctly for the surface tension effects, which can be modeled as capillary pressure applied at the flow front. Numerical implementation of such boundary conditions leads to illposing of the problem, in terms of the weak classical as well as stabilized formulation. As a consequence, there is an error in mass conservation accumulated especially along the free flow front. A numerical procedure was formulated and is implemented in an existing Free Boundary Program to reduce this error significantly.
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Sustainable Construction, Materials and Practice, p. 426-432
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Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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ABSTRACT: Financing is a critical factor in ensuring the optimal development and delivery of a mental health system. The primary method of financing worldwide is tax-based. However many low income countries depend on out-of-pocket payments. There is a report on Irish Health Care funding but none that deals exclusively with mental health care. This paper analyses the various financial models that exist globally with respect to financing the mental health sector, examines the impact of various models on service users, especially in terms of relative ‘financial burden’ and provides a more detailed examination of the current mental health funding situation in Ireland After extensive internet and hardcopy research on the above topics, the findings were analysed and a number of recommendations were reached. Mental health service should be free at the point of delivery to achieve universal coverage. Government tax-based funding or mandatory social insurance with government top-ups, as required, appears the optimal option, although there is no one funding system applicable everywhere. Out-of-pocket funding can create a crippling financial burden for service users. It is important to employ improved revenue collection systems, eliminate waste, provide equitable resource distribution, ring fence mental health funding and cap the number of visits, where necessary. Political, economic, social and cultural factors play a role in funding decisions and this can be clearly seen in the context of the current economic recession in Ireland. Only 33% of the Irish population has access to free public health care and the number health insurance policy holders has dramatically declined, resulting in increased out-of-pocket payments. This approach risks negatively impacting on the social determinants of health, increasing health inequalities and negatively affecting economic productivity. It is therefore important the Irish government examines other options to provide funding for mental health services.
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RESUMO: A avaliação da satisfação dos utentes tem tido uma importância crescente na avaliação da qualidade em saúde e na orientação do planeamento e da gestão dos processos e dos recursos da saúde. Os Hospitais de Dia, unidades funcionais que se assumem como uma alternativa moderna à hospitalização tradicional, com maior eficiência e ganhos na qualidade assistencial dos utentes, devem também ser capazes de se auto-avaliar, de forma a detectarem os aspectos menos correctos da sua actuação e a procurar o aperfeiçoamento permanente de todos os aspectos do seu funcionamento. Este trabalho pretendeu avaliar o grau de satisfação dos utentes do Hospital de Dia das Especialidades Médicas do Hospital de Egas Moniz (HDEM), Centro Hospitalar de Lisboa Ocidental. O estudo, que obteve parecer favorável por parte da Comissão de Ética e foi autorizado pelo Conselho de Administração do Centro Hospitalar Lisboa Ocidental, foi um estudo descritivo transversal, utilizando uma perspectiva quantitativa. A amostra seleccionada foi de conveniência, constituída pelos utentes que utilizaram o HDEM num período de 14 dias úteis, 3 a 24 de Junho de 2011. As dimensões da satisfação que foram avaliadas foram a satisfação global, a qualidade global, a satisfação relativa aos profissionais de saúde, a satisfação relativa às instalações, a satisfação relativa aos serviços prestados e ainda a recomendação do serviço a familiares e amigos e os aspectos sócio-demográficos dos utentes do HDEM. Foi construído um questionário com 39 itens (38 de resposta fechada e uma de resposta aberta), agrupados em 13 questões. Para a sua construção foram consultados muitos outros questionários destinados a avaliar a satisfação dos utentes com a prestação dos serviços de saúde. O questionário foi submetido à apreciação por investigadores e outros profissionais, aperfeiçoado e pré-testado antes da sua utilização. A validação do questionário incluiu a determinação da consistência interna através do coeficiente alfa de Cronbach, que foi boa ou muito boa, e a determinação da validade, através do método de Kaiser-Meyer-Olkin (KMO), que foi boa ou muito boa. A amostra foi constituída por 136 indivíduos, 61,8% dos quais eram do sexo feminino. O grupo etário mais representado foi o das idades entre os 35 e os 44 anos, seguido dos grupo etário entre os 45 e os 54 anos e entre os 55 aos 64 anos. A maioria dos participantes eram casados ou a viver em união de facto, tinham o ensino secundário ou uma licenciatura e eram trabalhadores no activo. Os resultados do estudo permitiram concluir que os utentes do HDEM que fizeram parte do estudo apresentaram níveis elevados de satisfação em todos os aspectos avaliados. Os maiores níveis de satisfação dos utentes disseram respeito à actuação dos profissionais de saúde e os mais baixos, apesar de positivos, tiveram a ver com aspectos muito particulares das instalações físicas do HDEM, como as condições da sala de espera e as instalações sanitárias. Outro aspecto que motivou algumas críticas por parte dos utentes foi o horário de funcionamento, tendo havido sugestões para o seu alargamento.
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Dissertation to obtain the Master Degree in Biotechnology
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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RESUMO: A Diabetes Mellitus é uma doença metabólica crónica, com deficiência a nível do metabolismo dos hidratos de carbono, lípidos e proteínas, resultante de deficiências na secreção ou ação da insulina, ou de ambas, que quando não tratada antecipadamente e de modo conveniente, pode ter consequências muito graves. Dado a incidência a nível mundial da Diabetes Mellitus, torna-se de elevada importância avaliar toda a sua envolvência e estudar bem quais os critérios a ter em consideração. Este trabalho propõe-se estudar para além dos parâmetros bioquímicos relacionados com a doença - Glicose e Hemoglobina Glicada A1c (HbA1c), analisar os resultados dos últimos cinco anos (2008-2012) dos ensaios interlaboratoriais do PNAEQ, do Departamento de Epidemiologia, do Instituto Nacional de Saúde Dr. Ricardo Jorge. Foram também analisadas as metodologias utilizadas e as variações interlaboratoriais, de forma a entender qual ou quais são os parâmetros mais adequados para o seu diagnóstico e controlo. Este estudo utilizou a população de laboratórios portugueses, públicos e privados, de Portugal Continental e Ilhas, um laboratório de Angola e outro de Macau que se inscreveram no PNAEQ nestes cinco anos, sendo a amostra composta pelo n.º de participações. No programa de Química Clinica foram distribuídas 38 amostras e no programa de HbA1c foram distribuídas 22 amostras. Para a glicose, o nível de desempenho nos ensaios é na globalidade das amostras de Excelente, no entanto verifica-se que sempre que a concentração da amostra é de nível patológico, que a maioria dos ensaios o desempenho foi inferior – Bom. O método de eleição e com CV% mais baixos foi o método da hexoquinase. Para a HbA1c, o nível de desempenho nos ensaios é na globalidade das amostras de Excelente. O método de eleição e com CV% mais baixos foi o método de HPLC. O CV% para a glicose ronda desde 2010 a 2012, os 3% e para a HbA1c foi de aproximadamente 4,0% em 2012. A HbA1c tem mostrado ser uma ferramenta muito útil, importante e robusta na monitorização da Diabetes, sendo hoje em dia quase sempre requisitada em análises de rotina a diabéticos de modo a prevenir complicações que possam vir a acorrer. No futuro poderá ser um importante, senão o parâmetro de futuro, para o diagnóstico da Diabetes, no entanto, mesmo já tendo sido muito trabalhada a sua padronização, ainda existem questões por responder como quais são na realidade todos os seus interferentes, qual a verdadeira relação da HbA1c com a glicose média estimada, em todas as populações e com estudos epidemiológicos. Também a própria educação do diabético e clínico deve ser aprimorada, pelo que neste momento as PTGO e os doseamentos de glicose em jejum devem ser utilizados e encontrando-se a Norma da DGS N.º 033/2011 de acordo com as necessidades e com o estado da arte deste parâmetro. A implementação da glicose média estimada será uma mais-valia na monitorização dos diabéticos pelo que deverá ser uma das prioridades a ter em conta no futuro desta padronização, uniformizando a decisão clinica baseada nela e minimizando a dificuldade de interpretação de resultados de laboratório para laboratório. --------------ABSTRACT: Diabetes Mellitus is a chronic metabolic disease, with a deficit in the metabolism of carbohydrates, lipids and proteins, resulting from deficiencies in insulin secretion or action, or both, which if, when not early treated in a proper way, may result in very serious consequences. Given the worldwide incidence of diabetes mellitus, it is highly important to evaluate all its background and study specifically all the criteria to take into consideration. The aim of this thesis is to study and evaluate beyond the biochemical parameters related to the disease - Glucose and Glycated Haemoglobin A1c (HbA1c), analyze the results of the last five years (2008-2012) of the PNAEQ interlaboratorial tests, in the Department of Epidemiology of National Institute of Health Dr. Ricardo Jorge. It is also intended to analyze the methodologies used and the interlaboratorial variations, in order to understand the most suitable parameters for the diagnosis and control. This study was based in a population of Portuguese laboratories, public and private, of Portugal mainland and islands, a laboratory of Angola and other from Macau, who enrolled in PNAEQ in these five years, and the sample was composed by the n. º of holdings. In the Clinical Chemistry Program there were distributed 38 samples and in the program HbA1c were distributed 22 samples. For glucose, the level of performance in the total nº of the samples was Excellent; however, it was found that when the concentration level of the sample was pathological, in most of the tests the performance was Good. The most preferred method with the lowest CV% is the hexokinase method. For the HbA1c, as a whole, the samples’ tests were Excellent, at the level of performance. The method of election with the lower CV% was the HPLC. The CV% for glucose was around 3%, from 2010 to 2012 and the HbA1c was approximately 4.0% in 2012. The HbA1c method has demonstrated to be a very useful tool, important and robust for monitoring diabetes, being nowadays, almost always required in routine analysis to prevent future complications. In the future it may be an important parameter, if not the most important, for the diagnosis of diabetes. However, despite it has already been standardized, there are still some questions that need to be answered, such as, which are in fact all their interferences, which is the true connection of HbA1c, when compared with the estimated average glucose, in all populations and epidemiological studies. Moreover, the education of the patient and the doctor concerning diabetes should be improved. Nowadays, the Oral Glucose Tolerance Test (OGTT) and fasting glucose determinations should be used and, the needs and the state of the art of this parameter, should be in accordance with the Standard DGS N. º 033/2011. The Implementation of the estimated average glucose will be an added value in monitoring diabetics and, therefore, should be a priority to consider in its future standardization and clinical decision based on it, will be uniform and the difficulty of interpreting results from laboratory to laboratory will be minimal.
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21st Annual Conference of the International Group for Lean Construction – IGLC 21 – Fortaleza, Brazil