994 resultados para temporal stability
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OBJETIVO: Analisar a capacidade preditiva de índice cognitivo funcional para mortalidade entre idosos. MÉTODOS: Estudo de coorte realizado com 1.667 idosos acima de 65 anos residentes no município de São Paulo, SP, no período 1991-2001. O índice cognitivo funcional foi construído a partir da orientação temporal e funções executivas (fazer compras e tomar medicação), controlado por variáveis sociodemográficas, hábitos de vida, morbidade, autopercepção de saúde, internação, edentulismo e suporte social. Os óbitos ocorridos no período foram investigados com familiares em entrevistas domiciliares, em cartórios e registros da Fundação Seade (até 2003). Foram calculados riscos relativos brutos e ajustados com respectivos intervalos com 95% de confiança por meio de análise bivariada e múltipla com regressão de Poisson, adotando-se p<0,05. RESULTADOS: No modelo multivariado final os fatores de risco independentes identificados pelo índice foram: perda parcial da orientação temporal ou funções executivas (RR=1,37; IC 95%: 1,03;1,83); perda total da orientação e parcial das funções (RR=1,71; IC 95%: 1,24;2,37); perda parcial da orientação e total das funções (RR=1,76; IC 95%: 1,35;2,28); perda total da orientação e das funções (RR=1,64; IC 95%: 1,30;2,06), Quanto às condições de saúde: internação (RR=1,45; IC 95%: 1,22;1,73); diabetes (RR=1,20; IC 95%: 1,00;1,44); edentulismo total (RR=1,34; IC 95%: 1,09;1,66). Relacionamento mensal com parentes foi identificado como fator protetor (RR=0,83; IC 95%: 0,69;1,00). CONCLUSÕES: O Índice Cognitivo Funcional pode auxiliar clínicos e planejadores em decisões sobre estratégias de seguimento e prevenção de causas tratáveis de déficit cognitivo e perda funcional para diminuir a mortalidade entre os idosos.
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Clustering analysis is a useful tool to detect and monitor disease patterns and, consequently, to contribute for an effective population disease management. Portugal has the highest incidence of tuberculosis in the European Union (in 2012, 21.6 cases per 100.000 inhabitants), although it has been decreasing consistently. Two critical PTB (Pulmonary Tuberculosis) areas, metropolitan Oporto and metropolitan Lisbon regions, were previously identified through spatial and space-time clustering for PTB incidence rate and risk factors. Identifying clusters of temporal trends can further elucidate policy makers about municipalities showing a faster or a slower TB control improvement.
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Background: Temporal lobe epilepsy (TLE) is a neurological disorder that directly affects cortical areas responsible for auditory processing. The resulting abnormalities can be assessed using event-related potentials (ERP), which have high temporal resolution. However, little is known about TLE in terms of dysfunction of early sensory memory encoding or possible correlations between EEGs, linguistic deficits, and seizures. Mismatch negativity (MMN) is an ERP component – elicited by introducing a deviant stimulus while the subject is attending to a repetitive behavioural task – which reflects pre-attentive sensory memory function and reflects neuronal auditory discrimination and perceptional accuracy. Hypothesis: We propose an MMN protocol for future clinical application and research based on the hypothesis that children with TLE may have abnormal MMN for speech and non-speech stimuli. The MMN can be elicited with a passive auditory oddball paradigm, and the abnormalities might be associated with the location and frequency of epileptic seizures. Significance: The suggested protocol might contribute to a better understanding of the neuropsychophysiological basis of MMN. We suggest that in TLE central sound representation may be decreased for speech and non-speech stimuli. Discussion: MMN arises from a difference to speech and non-speech stimuli across electrode sites. TLE in childhood might be a good model for studying topographic and functional auditory processing and its neurodevelopment, pointing to MMN as a possible clinical tool for prognosis, evaluation, follow-up, and rehabilitation for TLE.
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TLE in infancy has been the subject of varied research. Topographical and structural evidence is coincident with the neuronal systems responsible for auditory processing of the highest specialization and complexity. Recent studies have been showing the need of a hemispheric asymmetry for an optimization in central auditory processing (CAP) and acquisition and learning of a language system. A new functional research paradigm is required to study mental processes that require methods of cognitive-sensory information analysis processed in very short periods of time (msec), such as the ERPs. Thus, in this article, we hypothesize that the TLE in infancy could be a good model for topographic and functional study of CAP and its development process, contributing to a better understanding of the learning difficulties that children with this neurological disorder have.
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OBJETIVO: Analisar as tendências de asma em crianças e adolescentes entre 1998 e 2008 no Brasil. MÉTODOS: Foram analisados os dados de prevalência de asma da Pesquisa Nacional por Amostra de Domicílios, dos anos de 1998, 2003 e 2008. A amostra foi constituída por 141.402, 144.443 e 134.032 indivíduos em 1998, 2003 e 2008, respectivamente, e a análise foi ajustada pelo desenho amostral. As tendências de asma foram descritas por sexo, regiões do Brasil e local de residência, em crianças (zero a nove anos) e adolescentes (dez a 19 anos). RESULTADOS: A prevalência de asma entre crianças foi 7,7% em 1998, 8,1% em 2003 e 8,5% em 2008, com um incremento anual de 1%. O maior aumento anual foi observado nas regiões Sudeste e Norte (1,4%). Entre o grupo de adolescentes, a prevalência de asma foi de 4,4% em 1998, 5,0% em 2003 e 5,5% em 2008, com aumento de 2,2% ao ano. Na região Nordeste, o aumento anual na prevalência de asma foi de 3,5%. Os maiores incrementos foram observados entre os meninos e entre moradores da zona rural. CONCLUSÕES: Apesar de a asma apresentar um decréscimo em países emergentes, no Brasil os resultados apontam um incremento da asma entre crianças e adolescentes no período de 1998 e 2008, especialmente na zona rural.
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The theory and applications of fractional calculus (FC) had a considerable progress during the last years. Dynamical systems and control are one of the most active areas, and several authors focused on the stability of fractional order systems. Nevertheless, due to the multitude of efforts in a short period of time, contributions are scattered along the literature, and it becomes difficult for researchers to have a complete and systematic picture of the present day knowledge. This paper is an attempt to overcome this situation by reviewing the state of the art and putting this topic in a systematic form. While the problem is formulated with rigour, from the mathematical point of view, the exposition intends to be easy to read by the applied researchers. Different types of systems are considered, namely, linear/nonlinear, positive, with delay, distributed, and continuous/discrete. Several possible routes of future progress that emerge are also tackled.
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OBJETIVO: Estimar a prevalência da anemia em crianças, sua tendência temporal e identificar fatores associados. MÉTODOS: Estudo de corte transversal, de base populacional, envolvendo 1.108 crianças, com idade entre seis e 59 meses, de ambos os sexos, do Estado da Paraíba, em 2007. A hemoglobina foi analisada em sangue venoso com contador automático. Foram considerados para anemia valores < 11,0 g/dL, forma leve 9-11g/dL, moderada 7-9 g/dL e grave < 7,0 g/dL. As condições socioeconômicas e demográficas das crianças foram obtidas por meio de questionário aos pais ou responsáveis. As proporções foram comparadas pelo teste do qui-quadrado de Pearson, e a associação entre as concentrações de hemoglobina e potenciais fatores de riscos foi testada pelo modelo de regressão de Poisson. A tendência temporal da anemia foi avaliada pelo incremento/redução na prevalência de anemia nos anos de 1982, 1992 e 2007. RESULTADOS: A prevalência de anemia foi de 36,5% (IC95% 33,7;39,3). Observa-se que 1,3% (IC95% 0,7;1,8) foi na forma grave, 11,1% (IC95% 9,4;13,5) na forma moderada e 87,6% (IC95% 79,1;91,2) na forma leve. Houve um incremento de 88,5% nos casos de anemia no período entre 1982 e1992 e uma estabilização na prevalência entre 1992 e 2007. A análise ajustada no modelo de Poisson mostrou maior suscetibilidade à anemia nas crianças de seis a 24 meses de idade, naquelas amamentadas por seis meses ou mais, que co-habitavam com mais de quatro pessoas no mesmo domicílio e moravam em casas com menos de cinco cômodos. CONCLUSÕES: A alta prevalência de anemia mostra que continua sendo um importante problema de saúde pública no Estado da Paraíba. Apesar da estabilização na prevalência entre 1992 e 2007, a anemia apresenta-se em elevado patamar, o que impõe medidas mais efetivas de prevenção e controle.
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Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Automação e Electrónica Industrial
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Renewable energy sources (RES) have unique characteristics that grant them preference in energy and environmental policies. However, considering that the renewable resources are barely controllable and sometimes unpredictable, some challenges are faced when integrating high shares of renewable sources in power systems. In order to mitigate this problem, this paper presents a decision-making methodology regarding renewable investments. The model computes the optimal renewable generation mix from different available technologies (hydro, wind and photovoltaic) that integrates a given share of renewable sources, minimizing residual demand variability, therefore stabilizing the thermal power generation. The model also includes a spatial optimization of wind farms in order to identify the best distribution of wind capacity. This methodology is applied to the Portuguese power system.
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OBJETIVO Analisar a tendência da mortalidade por acidentes de motocicleta no Brasil. MÉTODOS Estudo descritivo de séries temporais sobre a taxa de mortalidade de acidentes de motocicleta no Brasil, segundo unidades federativas e faixas etárias entre 1996 e 2009. Os dados de óbitos foram obtidos no Sistema de Informação sobre Mortalidade do Ministério da Saúde e da população no Instituto Brasileiro de Geografia Estatística. Taxas de mortalidade padronizadas foram calculadas no período para o Brasil como um todo e Unidades Federativas. Variações anuais das taxas de mortalidade foram estimadas pelo método de Prais-Winsten de regressão linear. RESULTADOS A taxa de mortalidade por acidentes de motocicleta aumentou de 0,5 para 4,5/100.000 habitantes de 1996 a 2009 (aumento de 800% no período e 19% ao ano). Estados com maiores taxas em 2009 foram: Piauí, Tocantins, Sergipe e Mato Grosso. As maiores taxas de crescimento foram observadas nos Estados das regiões Norte, Nordeste e Centro-Oeste. CONCLUSÕES Houve grande aumento das taxas de mortalidade por acidente de motocicleta em todo o Brasil no período, principalmente nos Estados do Nordeste.
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Biophysical Chemistry 110 (2004) 83–92
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OBJECTIVE To analyze temporal trends and distribution patterns of unsafe abortion in Brazil. METHODS Ecological study based on records of hospital admissions of women due to abortion in Brazil between 1996 and 2012, obtained from the Hospital Information System of the Ministry of Health. We estimated the number of unsafe abortions stratified by place of residence, using indirect estimate techniques. The following indicators were calculated: ratio of unsafe abortions/100 live births and rate of unsafe abortion/1,000 women of childbearing age. We analyzed temporal trends through polynomial regression and spatial distribution using municipalities as the unit of analysis. RESULTS In the study period, a total of 4,007,327 hospital admissions due to abortions were recorded in Brazil. We estimated a total of 16,905,911 unsafe abortions in the country, with an annual mean of 994,465 abortions (mean unsafe abortion rate: 17.0 abortions/1,000 women of childbearing age; ratio of unsafe abortions: 33.2/100 live births). Unsafe abortion presented a declining trend at national level (R2: 94.0%, p < 0.001), with unequal patterns between regions. There was a significant reduction of unsafe abortion in the Northeast (R2: 93.0%, p < 0.001), Southeast (R2: 92.0%, p < 0.001) and Central-West regions (R2: 64.0%, p < 0.001), whereas the North (R2: 39.0%, p = 0.030) presented an increase, and the South (R2: 22.0%, p = 0.340) remained stable. Spatial analysis identified the presence of clusters of municipalities with high values for unsafe abortion, located mainly in states of the North, Northeast and Southeast Regions. CONCLUSIONS Unsafe abortion remains a public health problem in Brazil, with marked regional differences, mainly concentrated in the socioeconomically disadvantaged regions of the country. Qualification of attention to women’s health, especially to reproductive aspects and attention to pre- and post-abortion processes, are necessary and urgent strategies to be implemented in the country.
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A QoS adaptation to dynamically changing system conditions that takes into consideration the user’s constraints on the stability of service provisioning is presented. The goal is to allow the system to make QoS adaptation decisions in response to fluctuations in task traffic flow, under the control of the user. We pay special attention to the case where monitoring the stability period and resource load variation of Service Level Agreements for different types of services is used to dynamically adapt future stability periods, according to a feedback control scheme. System’s adaptation behaviour can be configured according to a desired confidence level on future resource usage. The viability of the proposed approach is validated by preliminary experiments.
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OBJECTIVE To analyze the temporal evolution of maternal mortality and its spatial distribution.METHODS Ecological study with a sample made up of 845 maternal deaths in women between 10 and 49 years, registered from 1999 to 2008 in the state of Rio Grande do Sul, Southern Brazil. Data were obtained from Information System on Mortality of Ministry of Health. The maternal mortality ratio and the specific maternal mortality ratio were calculated from records, and analyzed by the Poisson regression model. In the spatial distribution, three maps of the state were built with the rates in the geographical macro-regions, in 1999, 2003, and 2008.RESULTS There was an increase of 2.0% in the period of ten years (95%CI 1.00;1.04; p = 0.01), with no significant change in the magnitude of the maternal mortality ratio. The Serra macro-region presented the highest maternal mortality ratio (1.15, 95%CI 1.08;1.21; p < 0.001). Most deaths in Rio Grande do Sul were of white women over 40 years, with a lower level of education. The time of delivery/abortion and postpartum are times of increased maternal risk, with a greater negative impact of direct causes such as hypertension and bleeding.CONCLUSIONS The lack of improvement in maternal mortality ratio indicates that public policies had no impact on women’s reproductive and maternal health. It is needed to qualify the attention to women’s health, especially in the prenatal period, seeking to identify and prevent risk factors, as a strategy of reducing maternal death.
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Renewable energy sources (RES) have unique characteristics that grant them preference in energy and environmental policies. However, considering that the renewable resources are barely controllable and sometimes unpredictable, some challenges are faced when integrating high shares of renewable sources in power systems. In order to mitigate this problem, this paper presents a decision-making methodology regarding renewable investments. The model computes the optimal renewable generation mix from different available technologies (hydro, wind and photovoltaic) that integrates a given share of renewable sources, minimizing residual demand variability, therefore stabilizing the thermal power generation. The model also includes a spatial optimization of wind farms in order to identify the best distribution of wind capacity. This methodology is applied to the Portuguese power system.