ABSTRACT
Dengue fever, a disease caused by a vector-borne flavivirus, is endemic to tropical countries, but its occurrence has been reported worldwide. This study aimed to understand important factors contributing to the spatial and temporal patterns of dengue occurrence in São Paulo, the largest municipality of Brazil. The temporal assessment of dengue occurrence covered the 2011-2016 time period and was based on climatological data, such as the El Niño indices and time series statistical tools such as the continuous wavelet transformation. The spatial assessment used Landsat 8 data for years 2014-2016 to estimate land surface temperature and normalized indices for vegetation, urban areas, and leaf water. Results from a cross correlation for the temporal analysis found a relationship between the sea surface temperature anomalies index and the number of reported dengue cases in São Paulo (r = 0.5) with a lag of +29 (weeks) between the climatic event and the response on the dengue incidence. This relationship, initially nonlinear, became linear after correcting for the lag period. For the spatial assessment, the linear stepwise regression model detected a low relationship between dengue incidence and minimum surface temperature (r = 0.357) and no relationship with other environmental parameters. The poor relationship might be due to confounding effects of socioeconomic factors as these seem to influence the spatial dynamics of dengue incidence. More testing is needed to validate these methods in other locations. Nevertheless, we presented possible tools to be used for the improvement of dengue control programs.
ABSTRACT
O objetivo deste estudo foi avaliar os efeitos do Método Pilates sobre a variabilidade da frequência cardíaca, na flexibilidade e nas variáveis antropométricas em indivíduos sedentários. O presente estudo contou com 14 voluntárias do sexo feminino, na faixa etária entre 40 e 55 anos, que realizaram 20 sessões de exercícios do Método Pilates, duas vezes por semana, com duração de 45 minutos cada sessão, dividida em três fases: repouso, exercício e recuperação. As variáveis estudadas foram: os dados antropométricos, flexibilidade avaliada utilizando o teste de sentar-e-alcançar com o Banco de Wells, e intervalos R-R usando um cardiotacômetro. O processamento dos sinais da frequência cardíaca foi efetuado em ambiente MatLab 6.1®, utilizando a TWC. Os dados coletados foram submetidos ao teste de normalidade de Shapiro Wilk e foi utilizado o teste de Wilcoxon e Anova One Way (α = 0,05). Nos resultados, observou-se que não houve diferenças significativas entre os valores antropométricos e de frequência cardíaca, porém houve aumento da flexibilidade com o treinamento. Comparando a primeira e a Artigo original vigésima sessão com relação aos parâmetros low frequency (LF), high frequency (HF), e relação LF/HF, não houve diferença na fase de repouso e foram constatadas diferenças significativas de LF (p = 0,04) e HF (p = 0,04) na fase de exercício e diferença significativa de LF/ HF (p = 0,05) na fase de recuperação. Comparando os parâmetros nos períodos de repouso, exercícios e recuperação durante a primeira sessão e durante a vigésima sessão, não houve diferença significativa nos parâmetros LF, HF e LF/HF. Pode-se concluir que, em relação à flexibilidade, foi observada uma melhora significativa, enquanto a análise da frequência cardíaca caracterizou a intensidade do exercício de 50% da capacidade funcional das voluntárias. Em relação aos parâmetros LF, HF e LF/HF foram observados um aumento da variabilidade da frequência cardíaca, provavelmente produto da atividade do Método Pilates. A Transformada Wavelet (TWC) mostrou-se um Método adequado para as análises da variabilidade da frequência cardíaca. (AU)
The aim of this study was to evaluate the effects of the Pilates method on cardiovascular system through heart rate analysis with Continuous Wavelet Transformation (CWT). In the present study, 14 women, 40 to 55 years old, performed 20 sets of Pilates method exercises twice a week with duration of 45 minutes each set divided in three phases: rest, exercise and recovery. The studied variables were anthropometric data, flexibility which was evaluated using the sit-and-reach test (bench of wells), heart frequency which was monitored through a model s810i (Polar) cardiotachometer and the RR intervals were stored. The signals processing of the FC was computed in MatLab 6.1® environment, utilizing the CWT. The collected data were analyzed using Shapiro Wilk normality test and Wilcoxon and Anova One Way (α = 0.05) tests to compare the parameters. There were no significant differences between anthropometric values and heart rate; however there was an increase in flexibility. Comparing the parameters during the phases rest, exercise and recovery in the first and later in the last session, it was not observed statistically significant changes in heart frequency. Regarding to low frequency (LF), high frequency (HF) and LF/HF parameters, there was no significant difference. Significant differences of LF (p = 0.04) and HF (p = 0.04) were reported in exercise phase and significant difference (p = 0.05) in recovery phase. There was no significant difference in LF, HF and LF/HF parameters in the resting periods, exercises and recovery in the first and twentieth set. In relation to flexibility, a significant improvement was observed, while the heart rate analysis characterized the intensity of the exercise of fifty per cent of the functional capacity of the subjects. In relation to LF, HF and LF/HF parameters, a VFC increase was reported, result of Pilates method activity. The CWT showed itself an adequate method for the heart rate frequency analysis. (AU)