981 resultados para simple linear regression
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Diante de uma discussão não consensual a respeito da existência ou não de um trade-off entre inflação e desemprego (curva de Phillips), esta dissertação analisa a evolução desta relação na economia brasileira no período 1980-2010 através de duas análises diferentes: A primeira é uma análise considerada estática, realizada com a utilização de uma regressão linear simples. A segunda consiste em uma análise dinâmica, onde é utilizada uma regressão com coeficientes time-varying, com a estimação dos coeficientes sendo realizada com a aplicação do filtro de Kalman. Os resultados econométricos mostraram que a relação entre inflação e desemprego de fato se alterou ao longo do período analisado: A curva de Phillips se torna horizontal após o Plano Real e fica levemente positiva após o Regime de Metas de Inflação. Sendo assim, este trabalho basicamente se divide em duas partes: A primeira consiste de uma contextualização teórica da relação entre inflação e desemprego e do regime de metas de inflação. A segunda parte traz a análise econométrica, onde é descrita a evolução do trade-off. Diante dos resultados encontrados, são apresentadas suas possíveis causas e é realizada uma análise qualitativa da atual política monetária praticada pelo Banco Central do Brasil.
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Interest rate risk is one of the major financial risks faced by banks due to the very nature of the banking business. The most common approach in the literature has been to estimate the impact of interest rate risk on banks using a simple linear regression model. However, the relationship between interest rate changes and bank stock returns does not need to be exclusively linear. This article provides a comprehensive analysis of the interest rate exposure of the Spanish banking industry employing both parametric and non parametric estimation methods. Its main contribution is to use, for the first time in the context of banks’ interest rate risk, a nonparametric regression technique that avoids the assumption of a specific functional form. One the one hand, it is found that the Spanish banking sector exhibits a remarkable degree of interest rate exposure, although the impact of interest rate changes on bank stock returns has significantly declined following the introduction of the euro. Further, a pattern of positive exposure emerges during the post-euro period. On the other hand, the results corresponding to the nonparametric model support the expansion of the conventional linear model in an attempt to gain a greater insight into the actual degree of exposure.
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OBJECTIVE: To assess a new impunity index and variables that have been found to predict variation in homicide rates in other geographical levels as predictive of state-level homicide rates in Brazil. METHODS: This was a cross-sectional ecological study. Data from the mortality information system relating to the 27 Brazilian states for the years 1996 to 2005 were analyzed. The outcome variables were taken to be homicide victim rates in 2005, for the entire population and for men aged 20-29 years. Measurements of economic and social development, economic inequality, demographic structure and life expectancy were analyzed as predictors. An "impunity index", calculated as the total number of homicides between 1996 and 2005 divided by the number of individuals in prison in 2007, was constructed. The data were analyzed by means of simple linear regression and negative binomial regression. RESULTS: In 2005, state-level crude total homicide rates ranged from 11 to 51 per 100,000; for young men, they ranged from 39 to 241. The impunity index ranged from 0.4 to 3.5 and was the most important predictor of this variability. From negative binomial regression, it was estimated that the homicide victim rate among young males increased by 50% for every increase of one point in this ratio. CONCLUSIONS: Classic predictive factors were not associated with homicides in this analysis of state-level variation in Brazil. However, the impunity index indicated that the greater the impunity, the higher the homicide rate.
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RESUMO - Objetivos: Caracterizar a evolução do consumo de medicamentos da área cardiovascular entre 2002 e 2011. Caracterizar a evolução dos internamentos com diagnóstico principal cardiovascular, da taxa de mortalidade intra-hospitalar e da idade média dos doentes no episódio de internamento. Estabelecer relação entre o consumo de medicamentos e os episódios de internamento. Metodologia: Por consulta à base de dados do Infarmed, determinar a evolução do consumo de medicamentos por distrito de Portugal continental, medido em embalagens consumidas/1000 habitantes. Por consulta à base de dados de GDH, determinar a evolução do nº de internamentos por doença cardiovascular dos residentes em cada distrito, determinado em internamentos/1000 habitantes. Determinar a evolução da taxa de mortalidade dos episódios, avaliada em mortes/ 100 episódios. Determinar a evolução da idade média. Correlação estatística entre o consumo e nº internamentos, mortalidade e idade. Regressão linear simples entre o consumo e nº internamentos, mortalidade e idade. Resultados: O consumo de cardiotónicos e antiarrítmicos diminuiu, -26,45% e -16,48%, respetivamente. O consumo de anti hipertensores, vasodilatadores e antidislipidémicos aumentou, respetivamente, 78,73%; 11,18% e 180,91%. A incidência de EAM aumentou 0,03%, a de IC 0,97% e a de AVC diminuiu -21,42%. A mortalidade diminuiu para EAM, IC e AVC, respetivamente, -31,48%; -18,03% e -15,06%. A idade média de ocorrência de EAM manteve-se, a de IC aumentou 2,2 anos e a de AVC aumentou 1,5 anos. 23,9% da variação da incidência de AVC pode ser explicada pelo consumo. A variação da taxa de mortalidade por EAM, IC e AVC que pode ser explicada pelo consumo é de 30,9%; 13,0% e 32,9%. O consumo explica 48,3% e 73,5%, da variação da idade média de ocorrência de internamentos por IC e AVC, respetivamente. Os anti hipertensores e os antidislipidémicos são as subclasses com correlação estatisticamente significativa mais relevante com a diminuição da taxa de mortalidade e aumento da idade média. Conclusão: O consumo explica sensivelmente 50% do aumento da idade média, e em menor percentagem a evolução do nº de internamentos e da taxa de mortalidade. As subclasses dos anti hipertensores e dos antidislipidémicos são as principais responsáveis pelo aumento do consumo, mas também são as que tem correlação estatisticamente significativa mais forte com os ganhos em saúde.
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INTRODUCTION: Bacterial meningitis has great social relevance due to its ability to produce sequelae and cause death. It is most frequently found in developing countries, especially among children. Meningococcal meningitis occurs at a high frequency in populations with poor living conditions. This study describes the temporal evolution of bacterial meningitis in Salvador, Brazil, 1995-2009, and verifies the association between its spatial variation and the living conditions of the population. METHODS: This was an ecological study in which the areas of information were classified by an index of living conditions. It examined fluctuations using a trend curve, and the relationship between this index and the spatial distribution of meningitis was verified using simple linear regression. RESULTS: From 1995-2009, there were 3,456 confirmed cases of bacterial meningitis in Salvador. We observed a downward trend during this period, with a yearly incidence of 9.1 cases/100,000 population and fatality of 16.7%. Children aged <5 years old and male were more affected. There was no significant spatial autocorrelation or pattern in the spatial distribution of the disease. The areas with the worst living conditions had higher fatality from meningococcal disease (β = 0.0078117, p < 0.005). CONCLUSIONS: Bacterial meningitis reaches all social strata; however, areas with poor living conditions have a greater proportion of cases that progress to death. This finding reflects the difficulties for ready access and poor quality of medical care faced by these populations.
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Introduction Congenital syphilis is an important health problem in Brazil. This study assessed measures aimed at the prevention and control of syphilis in the State of Mato Grosso and its capital, Cuiabá. Methods A descriptive study cross-sectional and of time trends assessing the congenital syphilis was performed in Cuiabá and Mato Grosso between 2001 and 2011. We compared maternal sociodemographic characteristics and health care utilization related to cases of congenital syphilis during the periods from 2001 to 2006 and from 2007 to 2011. We assessed the temporal trends in this disease's incidence using a simple linear regression. Results Between 2001 and 2006 in Mato Grosso, 86.8% of the mothers who had live births with congenital syphilis received prenatal care, 90.6% presented with a nontreponemal test reagent at delivery, 96.2% had no information regarding a treponemal confirmatory test at delivery, and 77.6% received inadequate treatment for syphilis; additionally, 75.8% of their partners were not treated. There was a statistically significant reduction in prenatal visits (p = 0.004) and an increase in the proportion of mothers reactive to nontreponemal tests at delivery (p = 0.031) between the two periods. No other variables were found to differ significantly between the periods. In Cuiabá, we observed a similar distribution of variables. In the state and in the capital, the increasing trend of congenital syphilis was not statistically significant. Conclusions The high incidence of congenital syphilis in Mato Grosso and the low levels of health care indicators for pregnant women with syphilis suggest the need to improve the coverage and quality of prenatal care.
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AbstractINTRODUCTION:Studies that generate information that may reduce the dengue death risk are essential. This study analyzed time trends and risk factors for dengue mortality and fatality in Brazil from 2001 to 2011.METHODS:Time trends for dengue mortality and fatality rates were analyzed using simple linear regression. Associations between the dengue mortality and the case fatality rates and socioeconomic, demographic, and health care indicators at the municipality level were analyzed using negative binomial regression.RESULTS:The dengue hemorrhagic fever case fatality rate increased in Brazil from 2001 to 2011 (β=0.67; p=0.036), in patients aged 0-14 years (β=0.48; p=0.030) and in those aged ≥15 years (β=1.1; p<0.01). Factors associated with the dengue case fatality rate were the average income per capita (MRR=0.99; p=0.038) and the number of basic health units per population (MRR=0.89; p<0.001). Mortality rates increased from 2001 to 2011 (β=0.350; p=0.002).Factors associated with mortality were inequality (RR=1.02; p=0.001) high income per capita (MRR=0.99; p=0.005), and higher proportions of populations living in urban areas (MRR=1.01; p<0.001).CONCLUSIONS:The increases in the dengue mortality and case fatality rates and the associated socioeconomic and health care factors, suggest the need for structural and intersectoral investments to improve living conditions and to sustainably reduce these outcomes.
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A laboratory experiment was carried out to study the effects of chemical and physical characteristics of the soil on the phosphate fixing capacity. One hundred samples collected from various localities were at first characterized chemically and their particlesize distribution determined. They were then tested as to their phosphate fixing capacities. The results obtained were statistically analysed by means of both simple linear and multiple correlation. The following conclusions could be drawn: 1. simple linear regression analysis indicated that % C, exchangeable Al+3, CEC, % clay, pH and % sand were the soil characteristics which significantly affected phosphate fixing capacity of São Paulo State soils; 2. multiple linear regression analysis indicated that % C, exchangeable Mg(+2)9 exchangeable- Al+3 and % clay were the soil characteristics which significantly affected the phosphate fixing capacity of São Paulo State soils; 3. the phosphate phonomena fixing as they occur in the soils of the São Paulo State can be best described by the following equation: Y = -2,266 - 3,484 + 3,514 + 5,559 + 1,005 %C Mg+2 Al+3 % clay exchangeable exchangeable 4. phosphate fixation in the soil is affected by the combined effects of both soil chemical and physical characteristics.
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Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n = 24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n = 410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker's measured serum PCB levels and the same worker's cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14-24% of the variance of the Aroclor 1242/LPCB and 22-39% for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB.
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In visceral leishmaniasis, phlebotomine vectors are targets for control measures. Understanding the ecosystem of the vectors is a prerequisite for creating these control measures. This study endeavours to delineate the suitable locations of Phlebotomus argentipes with relation to environmental characteristics between endemic and non-endemic districts in India. A cross-sectional survey was conducted on 25 villages in each district. Environmental data were obtained through remote sensing images and vector density was measured using a CDC light trap. Simple linear regression analysis was used to measure the association between climatic parameters and vector density. Using factor analysis, the relationship between land cover classes and P. argentipes density among the villages in both districts was investigated. The results of the regression analysis indicated that indoor temperature and relative humidity are the best predictors for P. argentipes distribution. Factor analysis confirmed breeding preferences for P. argentipes by landscape element. Minimum Normalised Difference Vegetation Index, marshy land and orchard/settlement produced high loading in an endemic region, whereas water bodies and dense forest were preferred in non-endemic sites. Soil properties between the two districts were studied and indicated that soil pH and moisture content is higher in endemic sites compared to non-endemic sites. The present study should be utilised to make critical decisions for vector surveillance and controlling Kala-azar disease vectors.
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The objective of this work was to test long-term trends in the duration of rice development phases in Santa Maria, RS, Brazil. The duration from emergence to V3 (EM-V3), emergence to panicle differentiation (EM-R1), emergence to anthesis (EM-R4), and emergence to all grains with brown hull (EM-R9) was calculated using leaf appearance and developmental models for four rice cultivars (IRGA 421, IRGA 417, EPAGRI 109, and EEA 406), for the period from 1912 to 2011, considering three emergence dates (early, mid, and late). The trend of the time series was tested with the non-parametric Mann-Kendall test, and the magnitude of the trend was estimated with simple linear regression. Rice development has changed over the last ten decades in this location, leading to an anticipation of harvest time of 17 to 31 days, depending on the cultivar maturity group and emergence date, which is related to trends of temperature increase during the growing season. Warmer temperatures over the evaluated time period are responsible for changing rice phenology in this location, since minimum and maximum daily temperature drive the rice developmental models used.
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The aim of this paper was to estimate the loss caused by rust (Puccinia psidii) to 'Paluma' guava production in orchards located in Rio de Janeiro State. The disease intensity on the reproductive organs of plants was observed during two chemical control experiments carried out in 2003 and 2004. The loss was estimated based on simple linear regression and the production reduction (fruit number and weight ha-1) on the incidence of diseased buds and fruits. In the first experiment, no relationship was established between incidence of diseased buds and loss since there was a delay in spraying and the incidence of buds showing rust was high (mean of 47%) at the beginning of flowering. In the second experiment (2003-2004), spraying occurred at the beginning of the epidemics and there was a linear relationship between incidence of diseased buds and loss, justifying fungicide intervention at this stage. For the fruiting stage, a significant relationship was found between incidence of diseased fruits and loss in both experiments. In the absence of chemical control, rust reduced fruit production by around 90%.
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The aim of this study was to analyze the thickness of the intima-media complex (IMC) using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 ± 0.13 and 0.62 ± 0.16 vs 0.54 ± 0.09 and 0.52 ± 0.11 mm, respectively, P<0.0001). In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39) in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40). In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37), while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10). There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC.
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The objectives of this study were to understand how genotype, storage time, and storage conditions affect cooking time of beans and to indicate storage techniques that do not affect the cooking time. The grains were subjected to five different storage periods and six different storage conditions. The cooking time was estimated using the Mattson Cooker. The data were subjected to analysis of variance and a subsequent adjustment of simple linear regression for deployment of the interactions between the factors. Contrasts were used to determine the best levels of the factor storage condition. Genotype did not impact cooking time when the storage time and storage conditions were considered. Time and storage conditions affect the cooking time of beans in a dependent manner, but time of storage had the biggest influence. The best conditions for long-term storage of beans ensuring a smaller increase in cooking time is plastic storage at low temperatures. Thus, plastic freezer storage is a practical alternative for consumers.