907 resultados para General Linear Methods
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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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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The GxE interaction only became widely discussed from evolutionary studies and evaluations of the causes of behavioral changes of species cultivated in environments. In the last 60 years, several methodologies for the study of adaptability and stability of genotypes in multiple environments trials were developed in order to assist the breeder's choice regarding which genotypes are more stable and which are the most suitable for the crops in the most diverse environments. The methods that use linear regression analysis were the first to be used in a general way by breeders, followed by multivariate analysis methods and mixed models. The need to identify the genetic and environmental causes that are behind the GxE interaction led to the development of new models that include the use of covariates and which can also include both multivariate methods and mixed modeling. However, further studies are needed to identify the causes of GxE interaction as well as for the more accurate measurement of its effects on phenotypic expression of varieties in competition trials carried out in genetic breeding programs.
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RESUMO - INTRODUÇÃO: A equidade em cuidados de saúde constitui uma prioridade das políticas de saúde, tendo vários estudos descrito uma iniquidade que geralmente favorece os indivíduos com maior rendimento e nível educacional. Este estudo visa caracterizar as desigualdades socioeconómicas na utilização de cuidados de saúde na população com 65 ou mais anos de idade, dadas as suas características, maior vulnerabilidade e crescente peso demográfico na população. METODOLOGIA: Através de dados do INS, procedeu-se à análise univariada e multivariada por regressão linear múltipla para avaliação das desigualdades socioeconómicas na utilização de cuidados de saúde em 8698 indivíduos. RESULTADOS: Identifica-se um padrão de desigualdade na utilização de cuidados de saúde – indivíduos com maior rendimento e nível de escolaridade utilizam em média mais consultas de especialidade; ocorrendo o inverso nas consultas de CSP. Com ajustamento pela necessidade, através do estado de saúde auto-reportado, observa-se um padrão de iniquidade no sexo masculino relativamente às consultas em geral e consultas de CSP. DISCUSSÃO E CONCLUSÕES: A iniquidade na utilização de cuidados de saúde, apesar de não constituir a única causa, pode determinar maior iniquidade em saúde, pelo que é relevante o seu estudo. Os resultados alcançados podem ser justificados pelas características do SNS, assim como pelas isenções de taxas moderadoras, rede social, outros indicadores económicos, ou ainda pelo próprio contexto de vida do individuo. Torna-se fundamental prosseguir a investigação acerca da equidade, assim como promover uma ampla reflexão sobre os desafios futuros do sistema de saúde, que permitam preservar a sua sustentabilidade e princípios fundadores.
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RESUMO - Contexto: O presente estudo teve como objetivo apurar a demora média (DM) em doentes admitidos com pneumonia adquirida de comunidade (PAC), nos hospitais públicos portugueses, que tiveram alta durante os anos de 2009, 2010 e 2011, identificar se esta é influenciada por um grupo de fatores selecionados para o efeito e determinar se existe margem para a reduzir nos hospitais com uma DM mais elevada, através da comparação da mesma com as respetivas taxas de readmissão até 30 dias após a alta. Metodologia: Para responder aos objetivos definidos recorreu-se à base de dado dos resumos de alta, referente aos anos de 2009, 2010 e 2011, tendo-se selecionado, para o efeito, todos os episódios de internamento com diagnóstico de admissão de PAC. O estudo considerou como medidas “chave” a DM e a taxa de readmissão até 30 dias após alta. Para identificar a influência de um conjunto de fatores na duração de internamento utilizaram-se duas abordagens: análise descritiva dos dados e análise estatística dos dados, com recurso a uma Regressão Linear Múltipla. Numa última fase e com recurso à análise descritiva dos resultados obtidos, procedeu-se à comparação da taxa de readmissão até 30 dias após alta, por hospital, com as DM de internamento que mais se distanciaram das DM nacional e corrigida da população em estudo. Resultados: Constatou-se que a no tratamento da PAC, em Portugal, entre 2009 e 2011, não sofreu em termos globais grandes oscilações, tendo registado um valor de 9,47 dias nos três anos em análise. Concluiu-se ainda existir uma elevada variabilidade da DM entre hospitais e por hospital. Apesar das limitações identificadas verificou-se que os fatores idade, sexo, quantidade de diagnósticos adicionais, quantidade de procedimentos, destino após alta e tipo de hospital têm influência sobre a duração de internamento dos doentes admitidos com PAC. Por fim conclui-se que os cinco hospitais com DM mais baixa apresentam, de uma forma geral e com exceção do hospital 44, uma taxa de readmissão até 30 dias após alta inferior aos hospitais com DM mais elevada. Conclusão: Os resultados apurados apontam no sentido de existir margem para reduzir a DM no tratamento da PAC, nos hospitais que registaram valores mais elevados entre 2009 e 2011, permitindo que os mesmos obtenham resultados mais custo-efetivos sem piorar os resultados em saúde, medidos pela taxa de readmissões até 30 dias após a alta e, simultaneamente garantindo que a qualidade dos cuidados prestados e a segurança do doente se mantêm nos níveis desejados e exigidos. Sugere-se, no entanto, que em estudos futuros se detalhem algumas das matérias abordadas neste estudo com o objetivo de completar ou corroborar os resultados apresentados.
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INTRODUCTION: This study was developed to evaluate the situation of leprosy in the general population of the municipality of Buriticupu, State of Maranhão, Brazil. METHODS: We used the method of active search to identify new cases from 2008 to 2010. Bacilloscopy of intradermal scrapings was performed in all patients with skin lesions compatible with leprosy, and histopathological examination in those who had doubts on the definition of the clinical form. RESULTS: The study included 19,104 individuals, with 42 patients diagnosed with leprosy after clinical examination, representing a detection rate of 219.84 per 100,000 inhabitants. The predominant clinical presentation was tuberculoid with 24 (57.1%) cases, followed by borderline with 11, indeterminate with four, and lepromatous with three cases. The study also allowed the identification of 81 patients with a history of leprosy and other skin diseases, such as pityriasis versicolor, dermatophytosis, scabies, vitiligo, and skin carcinoma. The binomial test showed that the proportion of cases in the headquarters was significantly higher than that in the villages (p = 0.04), and the generalized exact test showed that there was no association between age and clinical form (p = 0.438) and between age and gender (p = 0.083). CONCLUSIONS: The elevated detection rate defines the city as hyperendemic for leprosy; the active search for cases, as well as the organization of health services, is an important method for disease control.
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Introduction Here, we evaluated sweeping methods used to estimate the number of immature Aedes aegypti in large containers. Methods III/IV instars and pupae at a 9:1 ratio were placed in three types of containers with, each one with three different water levels. Two sweeping methods were tested: water-surface sweeping and five-sweep netting. The data were analyzed using linear regression. Results The five-sweep netting technique was more suitable for drums and water-tanks, while the water-surface sweeping method provided the best results for swimming pools. Conclusions Both sweeping methods are useful tools in epidemiological surveillance programs for the control of Aedes aegypti.
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RESUMO: Introdução: As benzodiazepinas são os fármacos ansiolíticos e hipnóticos mais utilizados. O elevado consumo destes fármacos tem representado uma preocupação devido aos efeitos secundários do seu uso prolongado e dependência. Portugal tem a maior utilização de benzodiazepinas na Europa. Este estudo pretende analisar a alteração do padrão de prescrição de benzodiazepinas após uma intervenção com clínicos gerais. Métodos: A intervenção consistiu numa sessão educacional a um grupo de clínicos gerais. Foi comparado o padrão de prescrição de benzodiazepinas dos médicos intervencionados com o de um grupo de médicos não intervencionado da mesma região e com o de um grupo de médicos não intervencionados de outra região. Analisaram-‐se as prescrições de 12 meses antes e depois da intervenção. A análise do padrão de prescrição utilizou como metodologia a Dose Diária Definida (DDD) e a Dose Diária Definida por 1000 pacientes por dia (DHD). A análise estatística recorreu a métodos de regressão segmentada. Resultados: Houve uma diminuição no padrão de prescrição de benzodiazepinas no grupo intervencionado após a intervenção (p=0.005). Houve também uma redução no padrão de prescrição no grupo não intervencionada da mesma região (p=0.037) e no grupo não-intervencionado da região diferente (p=0.010). Analisando por género, prescritores do género feminino prescrevem uma quantidade maior de benzodiazepinas. Os clínicos gerais do género feminino intervencionados tiveram a maior redução na prescrição após a intervenção (p=0.008). Discussão: Os dados demonstraram que a intervenção reduziu a prescrição de benzodiazepinas após a intervenção. A diminuição geral do padrão de prescrição poderá ser explicada pelo efeito de Hawthorne ou pela contaminação entre os três grupos de clínicos gerais. Os dados disponíveis não explicam as diferenças nos padrões de prescrição por género. Conclusão: Este estudo demonstra como uma única intervenção tem um impacto positivo na melhoria dos padrões de prescrição. A replicação desta intervenção poderá representar uma oportunidade para alterar a prescrição de benzodiazepinas em Portugal. -----------------------------ABSTRACT: Introduction: Benzodiazepines are the most utilized anxiolytic and hypnotic drugs. The high consumption of benzodiazepines has been a concern due to the reported side effects of long-‐term use and dependence. Portugal has the highest benzodiazepine utilisation in Europe. This study aims to analyse the change in General Practitioners’ (GPs) benzodiazepine prescription pattern after na intervention period. Methods: An educational session was delivered to a group of intervened GPs. The benzodiazepine prescription pattern of the intervened group was compared to the pattern of a non-‐intervened matched group from the same region, and to the pattern of another non-‐intervened matched group from a diferente region. The research time frame was 12 month before and after intervention. The analysis of the prescription trends used the Defined Daily Dose (DDD) and Defined Daily Dose per 1000 patients per day (DHD) methodology. The statistical methods consisted of segmented regression analysis. Results: There was a decrease in benzodiazepine prescription pattern of intervened GPs after intervention (p=0.005). There was also a decrease in benzodiazepine prescription pattern for the non-‐intervened group from the same region (p=0.037) and for the non-‐ intervened group from a diferente region (p=0.010). Concerningthe analysis by gender, female gender prescribed a higher amount of benzodiazepines. The intervened female gender prescribers presented the highest decrease in prescription trend after intervention (p=0.008). Discussion: The data demonstrated that the intervention was effective in reducing benzodiazepine prescription after intervention. The general decrease in prescription trend might be explained by a Hawthorne effect or a contamination effect between the three groups of GPs. The available data couldn´t explain the diferences in prescription patterns by gender. Conclusion: This study demonstrates how a single intervention has a positive impact on improving prescription trends. The replication of this intervention might be an opportunity to changing the worrying benzodiazepine utilisation in Portugal.
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OBJECTIVE: To investigate and characterize the professional stereotypes associated with general medicine and surgery among Brazilian medical residents. METHODS: A randomized sample of residents of the General Medicine and Surgery Residence Programs were interviewed and their perceptions and views of general and surgical doctors were compared. RESULTS: The general practitioner was characterized by the residents in general to be principally a sensitive and concerned doctor with a close relationship with the patient; (45%); calm, tranquil, and balanced (27%); with intellectual skills (25%); meticulous and attentive to details (23%); slow to resolve problems and make decisions (22%); and working more with probabilities and hypotheses (20%). The surgeon was considered to be practical and objective (40%); quickly resolving problems (35%); technical with manual skills (23%); omnipotent, arrogant, and domineering (23%); anxious, stressed, nervous, and temperamental (23%); and more decided, secure, and courageous (20%). Only the residents of general medicine attributed the surgeon with less knowledge of medicine and only the surgeons attributed gender characteristics to their own specialty. CONCLUSION: There was considerable similarity in the description of a typical general practitioner and surgeon among the residents in general, regardless of the specialty they had chosen. It was interesting to observe that these stereotypes persist despite the transformations in the history of medicine, i.e. the first physicians (especially regarding the valorization of knowledge) and the first surgeons, so-called "barber surgeons" in Brazil (associated with less knowledge and the performance of high-risk procedures).
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PURPOSE: To find out the prevalence of hypertension in employees of the Hospital and relate it to social demographic variables. METHODS: Blood pressure measurement was performed with a mercury sphygmomanometer, using an appropriate cuff size for arm circumference, weight, and height in a population sample of 864 individuals out of the 9,905 employees of a University General Hospital stratified by gender, age, and job position. RESULTS: Hypertension prevalence was 26% (62% of these reported being aware of their hypertension and 38% were unaware but had systolic/diastolic blood pressures of >140 and/or >90 mm Hg at the moment of the measurement). Of those who were aware of having hypertension, 51% were found to be hypertensive at the moment of the measurement. The prevalence was found to be 17%, 23%, and 29% (P <.05) in physicians, nursing staff, and "others", respectively. The univariate analysis showed a significant odds ratio for the male gender, age >50 years, work unit being the Institute of Radiology and the Administration Building, educational level
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As a renewable energy source, the use of forest biomass for electricity generation is advantageous in comparison with fossil fuels, however the activity of forest biomass power plants causes adverse impacts, affecting particularly neighbouring communities. The main objective of this study is to estimate the effects of the activity of forest biomass power plants on the welfare of two groups of stakeholders, namely local residents and the general population and we apply two stated preference methods: contingent valuation and discrete choice experiments, respectively. The former method was applied to estimate the minimum compensation residents of neighbouring communities of two forest biomass power plants in Portugal would be willing to accept. The latter method was applied among the general population to estimate their willingness to pay to avoid specific environmental impacts. The results show that the presence of the selected facilities affects individuals’ well-being. On the other hand, in the discrete choice experiments conducted among the general population all impacts considered were significant determinants of respondents’ welfare levels. The results of this study stress the importance of performing an equity analysis of the welfare effects on different groups of stakeholders from the installation of forest biomass power plants, as their effects on welfare are location and impact specific. Policy makers should take into account the views of all stakeholders either directly or indirectly involved when deciding crucial issues regarding the sitting of new forest biomass power plants, in order to achieve an efficient and equitable outcome.
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Tese de Doutoramento em Ciências da Administração
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The currently available clinical imaging methods do not provide highly detailed information about location and severity of axonal injury or the expected recovery time of patients with traumatic brain injury [1]. High-Definition Fiber Tractography (HDFT) is a novel imaging modality that allows visualizing and quantifying, directly, the degree of axons damage, predicting functional deficits due to traumatic axonal injury and loss of cortical projections. This imaging modality is based on diffusion technology [2]. The inexistence of a phantom able to mimic properly the human brain hinders the possibility of testing, calibrating and validating these medical imaging techniques. Most research done in this area fails in key points, such as the size limit reproduced of the brain fibers and the quick and easy reproducibility of phantoms [3]. For that reason, it is necessary to develop similar structures matching the micron scale of axon tubes. Flexible textiles can play an important role since they allow producing controlled packing densities and crossing structures that match closely the human crossing patterns of the brain. To build a brain phantom, several parameters must be taken into account in what concerns to the materials selection, like hydrophobicity, density and fiber diameter, since these factors influence directly the values of fractional anisotropy. Fiber cross-section shape is other important parameter. Earlier studies showed that synthetic fibrous materials are a good choice for building a brain phantom [4]. The present work is integrated in a broader project that aims to develop a brain phantom made by fibrous materials to validate and calibrate HDFT. Due to the similarity between thousands of hollow multifilaments in a fibrous arrangement, like a yarn, and the axons, low twist polypropylene multifilament yarns were selected for this development. In this sense, extruded hollow filaments were analysed in scanning electron microscope to characterize their main dimensions and shape. In order to approximate the dimensional scale to human axons, five types of polypropylene yarns with different linear density (denier) were used, aiming to understand the effect of linear density on the filament inner and outer areas. Moreover, in order to achieve the required dimensions, the polypropylene filaments cross-section was diminished in a drawing stage of a filament extrusion line. Subsequently, tensile tests were performed to characterize the mechanical behaviour of hollow filaments and to evaluate the differences between stretched and non-stretched filaments. In general, an increase of the linear density causes the increase in the size of the filament cross section. With the increase of structure orientation of filaments, induced by stretching, breaking tenacity increases and elongation at break decreases. The production of hollow fibers, with the required characteristics, is one of the key steps to create a brain phantom that properly mimics the human brain that may be used for the validation and calibration of HDFT, an imaging approach that is expected to contribute significantly to the areas of brain related research.
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Inspired by the relational algebra of data processing, this paper addresses the foundations of data analytical processing from a linear algebra perspective. The paper investigates, in particular, how aggregation operations such as cross tabulations and data cubes essential to quantitative analysis of data can be expressed solely in terms of matrix multiplication, transposition and the Khatri–Rao variant of the Kronecker product. The approach offers a basis for deriving an algebraic theory of data consolidation, handling the quantitative as well as qualitative sides of data science in a natural, elegant and typed way. It also shows potential for parallel analytical processing, as the parallelization theory of such matrix operations is well acknowledged.
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BACKGROUND: General anesthetics (GA) are well known for the ability to induce a state of reversible loss of consciousness and unresponsiveness to painful stimuli. However, evidence from animal models and clinical studies show that GA exposure may induce behavioral changes beyond acute effects. Most research and concerns are focused on changes in cognition and memory. METHODS: We will look at effects of GA on behavior that is mediated by the dopaminergic system. RESULTS: Pharmacological resemblance of GA with drugs of abuse, and the complexity and importance of dopaminergic systems in both reward seeking and addictive illnesses make us believe that it deserves an overview about what is already known and what matters to us as healthcare workers and specifically as anesthesiologists. CONCLUSION: A review of available evidence strongly suggests that there may be a link between the effects of GA on the brain and substance abuse, partly explained by their influence on the dopaminergic system.