9 resultados para numeri primi criteri divisibilità Euclide Goldbach Eulero Lagrange Mersenne Fürstenberg
em Scielo Saúde Pública - SP
Resumo:
OBJECTIVE - To analyze the trends in risk of death due to cardiovascular diseases in the northern, northeastern, southern, southeastern, and central western Brazilian geographic regions from 1979 to 1996. METHODS - Data on mortality due to cardiovascular, cardiac ischemic, and cerebrovascular diseases in 5 Brazilian geographic regions were obtained from the Ministry of Health. Population estimates for the time period from 1978 to 1996 in the 5 Brazilian geographic regions were calculated by interpolation with the Lagrange method, based on the census data from 1970, 1980, 1991, and the population count of 1996, for each age bracket and sex. Trends were analyzed with the multiple linear regression model. RESULTS - Cardiovascular diseases showed a declining trend in the southern, southeastern, and northern Brazilian geographic regions in all age brackets and for both sexes. In the northeastern and central western regions, an increasing trend in the risk of death due to cardiovascular diseases occurred, except for the age bracket from 30 to 39 years, which showed a slight reduction. This resulted from the trends of cardiac ischemic and cerebrovascular diseases. The analysis of the trend in the northeastern and northern regions was impaired by the great proportion of poorly defined causes of death. CONCLUSION - The risk of death due to cardiovascular, cerebrovascular, and cardiac ischemic diseases decreased in the southern and southeastern regions, which are the most developed regions in the country, and increased in the least developed regions, mainly in the central western region.
Resumo:
OBJECTIVE: To assess the trends of the risk of death due to circulatory (CD), cerebrovascular (CVD), and ischemic heart diseases (IHD) in 11 Brazilian capitals from 1980 to 1998. METHODS: Data on mortality due to CD, CVD and IHD were obtained from the Brazilian Health Ministry, and the population estimates were calculated by interpolation with the Lagrange method based on census data from 1980 and 1991 and the population count of 1996. The trends were analyzed with the multiple linear regression method. RESULTS: CD showed a trend towards a decrease in most capitals, except for Brasília, where a mild increase was observed. The cities of Porto Alegre, Curitiba, Rio de Janeiro, Cuiabá, Goiânia, Belém, and Manaus showed a decrease in the risk of death due to CVD and IHD, while the city of Brasília showed an increase in CVD and IHD. The city of São Paulo showed a mild increase in IHD for individuals of both sexes aged 30 to 39 years and for females aged 40 to 59 years. In the cities of Recife and Salvador, a reduction in CD was observed for all ages and both sexes. In the city of Recife, however, an increase in IHD was observed at younger ages (30 to 49 years), and this trend decreased until a mild reduction (-4%) was observed in males ³ 70 years. CONCLUSION: In general, a reduction in the risk of death due to CD and an increase in IHD were observed, mainly in the cities of Recife and Brasília.
Resumo:
OBJETIVO: Analisar tendências do risco de morte por doenças circulatórias (DC) em 13 estados do Brasil, no período de 1980 a 1998. MÉTODOS: Dados de mortalidade por DC, isquêmicas do coração (DIC) e cerebrovasculares (DCbV) nos 13 estados foram obtidos do Ministério da Saúde. Estimativas das populações, de 1980 a 1998, foram calculadas por meio de interpolação, pelo método de Lagrange, com base nos dados dos Censos de 1970, 1980, 1991 e contagem populacional de 1996. As tendências foram analisadas pelo modelo de regressão linear múltipla. RESULTADOS: A mortalidade por DC mostrou tendência de queda na maioria dos estados. Observou-se aumento, nos homens, em Pernambuco, para todas as faixas etárias, em Goiás, a partir de quarenta anos e na Bahia e Mato Grosso, a partir dos cinqüenta anos. Nas mulheres, aumento em Mato Grosso, a partir dos trinta anos, em Pernambuco, a partir dos quarenta anos, e em Goiás, nas faixas etárias entre trinta e 49 anos. Em Goiás, nas outras faixas etárias, o aumento foi discreto. Para as DIC, aumento da mortalidade para todas as faixas etárias em Mato Grosso e Pernambuco, e a partir dos quarenta anos, na Bahia, Goiás e Pará. Para as DCbV, aumento da mortalidade para todas as faixas etárias em Mato Grosso e Pernambuco, e a partir dos quarenta anos na Bahia e em Goiás. CONCLUSÃO: Observou-se importante aumento do risco de morte para as doenças circulatórias nos estados menos desenvolvidos do Brasil.
Resumo:
The studies of rare genetic defects, the preliminary results of population-based studies, being validated by the experimental immunocompromised animal models and the current observations accumulated in immunocompromised patients with mycobacterial diseases provide us with insights into the importance of the macrophage activation pathway in controlling human infection with pathogenic and non pathogenic intracellular multiplying mycobacteria. Initial cytokine production by infected macrophages and/or dendritic cells could be crucial in the overall regulation of self cure, acquired protection or immunopathological sequelae expressing the disease. Knowledge of molecular and genetic cross-talks between phagocytic and specialized antigen presenting cells and different mycobacterial products associated with persistence or replication of the intracellular bacteria, could provide further informations on the global immune regulation of the early host responses to infection and the following events. It seems likely that the development of mycobacterial infections in humans will turn out to be as much dependent on the genetic make up of the host as or the virulence of the bacteria.
Resumo:
Teaching classes and events regarding the molecular aspects of drug-receptor interactions is not an easy task. The ligand stereochemistry and the spatial arrangement of the macromolecular targets highly increase the complexity of the process. In this context, the use of alternative and more playful approaches could allow students to gain a more thorough understanding of this important topic in medicinal chemistry. Herein, we describe a practical teaching approach that uses computational strategies as a tool for drug-receptor interaction studies performed for angiotencsin converting enzyme inhibitors (ACEi). Firstly, the students learn how to find the crystallographic structure (enzyme-ligand complex). Then, they proceed to the treatment of crude crystallographic data. Thereafter, they learn how to analyze the positioning of the drug on the active site of the enzyme, looking for regions related to the molecular recognition. At the end of the study, students can summarize the molecular requirements for the interaction and the structure-activity relationships of the studied drugs.
Resumo:
In this study is presented an economic optimization method to design telescope irrigation laterals (multidiameter) with regular spaced outlets. The proposed analytical hydraulic solution was validated by means of a pipeline composed of three different diameters. The minimum acquisition cost of the telescope pipeline was determined by an ideal arrangement of lengths and respective diameters for each one of the three segments. The mathematical optimization method based on the Lagrange multipliers provides a strategy for finding the maximum or minimum of a function subject to certain constraints. In this case, the objective function describes the acquisition cost of pipes, and the constraints are determined from hydraulic parameters as length of irrigation laterals and total head loss permitted. The developed analytical solution provides the ideal combination of each pipe segment length and respective diameter, resulting in a decreased of the acquisition cost.
Resumo:
This work presents a formulation of the contact with friction between elastic bodies. This is a non linear problem due to unilateral constraints (inter-penetration of bodies) and friction. The solution of this problem can be found using optimization concepts, modelling the problem as a constrained minimization problem. The Finite Element Method is used to construct approximation spaces. The minimization problem has the total potential energy of the elastic bodies as the objective function, the non-inter-penetration conditions are represented by inequality constraints, and equality constraints are used to deal with the friction. Due to the presence of two friction conditions (stick and slip), specific equality constraints are present or not according to the current condition. Since the Coulomb friction condition depends on the normal and tangential contact stresses related to the constraints of the problem, it is devised a conditional dependent constrained minimization problem. An Augmented Lagrangian Method for constrained minimization is employed to solve this problem. This method, when applied to a contact problem, presents Lagrange Multipliers which have the physical meaning of contact forces. This fact allows to check the friction condition at each iteration. These concepts make possible to devise a computational scheme which lead to good numerical results.
Resumo:
The pregnancy-induced increase in self-licking observed in rats is important for mammary gland development and lactation. Reproductive experience has epidemiologial implications such as a decrease in the incidence of mammary gland cancer in women and it also influences various behavioral, neurochemical and endocrine parameters. The aim of the present study was to investigate the influence of reproductive experience on grooming behavior patterns during pregnancy in rats. Self-grooming behavior was measured in age-matched virgin, primi- and multigravid (days 7, 8, 9, 19, and 20 of pregnancy) rats. General grooming (head, forelimbs and shoulders) was not significantly different among virgin, primi- and multigravid rats during pregnancy. Confirming previous work, pregnant rats spent significantly more time in specific grooming (mammary glands, nipple lines, genital and pelvic regions) than did virgin animals. In addition, self- licking of mammary glands was significantly increased in multi- as compared to primigravid rats on days 8, 9, 19 and 20 of pregnancy. The increase in mammary gland grooming observed in multigravid rats appears to be a consequence of previous reproductive experience. These data show that reproductive experience modulates mammary gland grooming during pregnancy, possibly contributing to successful reproduction.