ABSTRACT This paper presents a comparative analysis of the electrode impedance for a vertical rod buried in a homogeneous ground where the soil electrical parameters (resistivity and permittivity) are frequency-dependent in relation to the impedances obtained with frequency-constant parameters. In this study, it is taken into account that vertical rod can be seen as a short transmission line whose electrical parameters (resistance, inductance, capacitance and conductance) are distributed along its length. Thus, the rod impedance is computed as being the harmonic impedance of the transmission line as a function of frequency. Once the rod impedances are obtained, and using the Vector Fitting technique, equivalent electrical circuits are obtained directly in time domain. The advantage of this type of representation is that equivalent circuit can be easily incorporated into EMTP-type programs for the electromagnetic transient analysis. In this model, the grounding potential rise (GPR) generated due to a lightning stroke at the rod can be calculated. Additionally, an impulsive current source, representing a lightning stroke, is injected at the top of a transmission tower whose the grounding system is composed by a vertical rod, and the transient voltages at the cross-arms and tower base are calculated. The results show that the voltages are significantly modified by the presence of the soil with frequency-dependent parameters, especially their voltage peaks, and that an accurate analysis of the transient in power systems must take this phenomenon into account.

RESUMEN Este articulo presenta un estudio comparativo de la impedancia de un electrodo vertical enterrado en un suelo homogéneo donde los parámetros eléctricos (resistividad y permisibilidad) son dependientes de la frecuencia en relación con las impedancias obtenidas con los parámetros del suelo constantes. Este estudio, considera que el electrodo vertical se modela como una línea de transmisión (LT) corta cuyos parámetros eléctricos (resistencia, inductancia, capacitancia y conductancia) se distribuyen a lo largo de su longitud. De esta manera, la impedancia del electrodo se calcula como la impedancia armónica de la LT en función de la frecuencia. Una vez que se obtienen las impedancias de aterramiento del electrodo, y utilizando la técnica del Vector Fitting, circuitos eléctricos equivalentes son obtenidos directamente en el dominio del tiempo. La ventaja de usar este tipo de representación es que el circuito equivalente puede insertarse fácilmente en software de tipo EMTP, para realizar análisis de los transitorios electromagnéticos. De esta manera, se pueden calcular la elevación del potencial en el aterramiento para una descarga atmosférica incidente en el electrodo. Adicionalmente, se inyecta una descarga atmosférica en la parte superior de la torre de transmisión cuyo sistema de puesta a tierra está compuesto por un electrodo vertical, y se calculan las tensiones transitorias en los brazos y la base de la torre. Los resultados muestran que las tensiones se modifican significativamente por la presencia del suelo con parámetros dependientes de la frecuencia, especialmente en los picos, y que un análisis preciso de los transitorios electromagnéticos en los sistemas eléctricos debe tener en cuenta este fenómeno.

RESUMO Diferentemente de outras variáveis mais comuns relacionadas à saúde, a aptidão cardiorrespiratória (ACR) não é medida constantemente na população em geral. Sua omissão caracteriza numa perda de informação relevante. Com isso os objetivos do presente estudo foram: a) caracterizar a ACR da população brasileira de 20 a 59 anos, desenvolvendo valores normativos através de uma equação para estimar o consumo máximo de oxigênio (VO2Máx) sem a realização de exercícios; e b) verificar a associação de menores níveis de ACR com a prevalência de doenças crônicas. Ao todo, 32.531 indivíduos compuseram a amostra oriunda da Pesquisa Nacional de Saúde (PNS-IBGE-2013). Apenas variáveis auto-relatadas foram incluídas a partir da equação de Wier et al. (2006): sexo, idade, nível de atividade física e Índice de Massa Corporal. A média de VO2Máx foi estimada como 44,6; 39,3; 34,8 e 30,6 ml/kg/min (homens) e 34,5; 29,6; 25,4 e 21,1 ml/kg/min (mulheres) com idades 20-29; 30-39; 40-49 e 50-59. Os valores de percentil 20 e 80 foram estabelecidos como os extremos de muito baixa e muito alta ACR. A baixa aptidão demonstrou significativamente 33% maiores chances de prevalência de doença cardiovascular, 89% de diabetes mellitus e 67% de hipertensão arterial independentemente de sexo, idade, e presença de obesidade, o que parece corroborar a qualidade da equação utilizada.

ABSTRACT Unlike other more common health-related variables, cardiorespiratory fitness (CRF) is not frequently measured in the general population. This omission characterizes a loss of relevant information. Thus, the objectives of the present study were: a) to characterize the CRF of the Brazilian population aged 20 to 59 years and to develop normative values using a non-exercise equation for predicting maximal oxygen uptake (VO2max), and b) to verify the association between lower levels of CRF and the prevalence of chronic diseases. A total of 32,531 individuals from the National Health Survey (NHS-IBGE-2013) composed the sample. Only self-reported variables were included in the equation of Wier et al. (2006): sex, age, physical activity level, and body mass index. The mean predicted VO2max was 44.6, 39.3, 34.8 and 30.6 ml/kg/min for men, and 34.5, 29.6, 25.4 and 21.1 ml/kg/min for women aged 20-29, 30-39, 40-49 and 50-59 years, respectively. The 20th and 80th percentiles were established as the extremes (very low and very high CRF). Participants with low fitness had a 33% higher chance of cardiovascular disease, an 89% higher chance of diabetes mellitus, and a 67% higher chance of hypertension, regardless of sex, age and presence of obesity, which seem to corroborate the quality of the equation.

This study was conducted to analyse the course and the outcome of the liver disease in the co-infected animals in order to evaluate a possible synergic effect of human parvovirus B19 (B19V) and hepatitis A virus (HAV) co-infection. Nine adult cynomolgus monkeys were inoculated with serum obtained from a fatal case of B19V infection and/or a faecal suspension of acute HAV. The presence of specific antibodies to HAV and B19V, liver enzyme levels, viraemia, haematological changes, and necroinflammatory liver lesions were used for monitoring the infections. Seroconversion was confirmed in all infected groups. A similar pattern of B19V infection to human disease was observed, which was characterised by high and persistent viraemia in association with reticulocytopenia and mild to moderate anaemia during the period of investigation (59 days). Additionally, the intranuclear inclusion bodies were observed in pro-erythroblast cell from an infected cynomolgus and B19V Ag in hepatocytes. The erythroid hypoplasia and decrease in lymphocyte counts were more evident in the co-infected group. The present results demonstrated, for the first time, the susceptibility of cynomolgus to B19V infection, but it did not show a worsening of liver histopathology in the co-infected group.

In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

O estudo avaliou a associação entre poluição do ar e óbitos por doenças respiratórias, considerando susceptibilidade diferencial segundo sexo. Foram utilizados óbitos diários por doenças respiratórias (CID-10, J00-J99), níveis de PM10, SO2, O3 e indicadores meteorológicos de Volta Redonda, Rio de Janeiro, Brasil, de janeiro de 2002 a dezembro de 2006. A associação foi estimada por MAG de regressão de Poisson, onde para lag 1, o aumento do risco dos óbitos por PM10 foi de 10,01% (IC95%: 1,81-18,88%) no total da população feminina e 10,04% (IC95%: 0,90-20,02%) em idosas. No total da população masculina, para lag 9, o aumento do risco de óbitos por PM10 foi de 8,25% (IC95%: 0,86-16,18%) e de 10,80% (IC95%: 2,18-20,15%) para os idosos. Para exposição ao SO2 e O3, o risco foi significativo no total da população masculina e em idosos respectivamente. Os resultados reforçam a necessidade de estudos adicionais, centrando-se na modificação dos efeitos da poluição do ar sobre a saúde.

This study analyzed the association between air pollution and deaths from respiratory diseases, considering differential susceptibility according to gender. The authors used daily deaths from respiratory diseases (ICD-10, J00-J99), PM10, SO2, and O3 levels, and meteorological indicators in Volta Redonda, Rio de Janeiro State, Brazil, from January 2002 to December 2006. The association was estimated by Poisson regression using generalized additive models, where the increase in risk of deaths from PM10 to lag 1 was 10.01% (95%CI: 1.81-18.88%) in the total female population and 10.04% (95%CI: 0.90-20.02%) in elderly women. The increase in risk of deaths from PM10 to lag 9 was 8.25% in the total male population (95%CI: 0.86-16.18%) and 10.80% (95%CI: 2.18-20.15%) in elderly men. For exposure to SO2 and O3, the risk was significant in the total male population and the elderly, respectively. The results emphasize the need for further studies, focusing on modification of the effects of air pollution on health.

O estudo avaliou a associação entre poluição do ar e óbitos por doenças respiratórias, considerando susceptibilidade diferencial segundo sexo. Foram utilizados óbitos diários por doenças respiratórias (CID-10, J00-J99), níveis de PM10, SO2, O3 e indicadores meteorológicos de Volta Redonda, Rio de Janeiro, Brasil, de janeiro de 2002 a dezembro de 2006. A associação foi estimada por MAG de regressão de Poisson, onde para lag 1, o aumento do risco dos óbitos por PM10 foi de 10,01% (IC95%: 1,81-18,88%) no total da população feminina e 10,04% (IC95%: 0,90-20,02%) em idosas. No total da população masculina, para lag 9, o aumento do risco de óbitos por PM10 foi de 8,25% (IC95%: 0,86-16,18%) e de 10,80% (IC95%: 2,18-20,15%) para os idosos. Para exposição ao SO2 e O3, o risco foi significativo no total da população masculina e em idosos respectivamente. Os resultados reforçam a necessidade de estudos adicionais, centrando-se na modificação dos efeitos da poluição do ar sobre a saúde.

This study analyzed the association between air pollution and deaths from respiratory diseases, considering differential susceptibility according to gender. The authors used daily deaths from respiratory diseases (ICD-10, J00-J99), PM10, SO2, and O3 levels, and meteorological indicators in Volta Redonda, Rio de Janeiro State, Brazil, from January 2002 to December 2006. The association was estimated by Poisson regression using generalized additive models, where the increase in risk of deaths from PM10 to lag 1 was 10.01% (95%CI: 1.81-18.88%) in the total female population and 10.04% (95%CI: 0.90-20.02%) in elderly women. The increase in risk of deaths from PM10 to lag 9 was 8.25% in the total male population (95%CI: 0.86-16.18%) and 10.80% (95%CI: 2.18-20.15%) in elderly men. For exposure to SO2 and O3, the risk was significant in the total male population and the elderly, respectively. The results emphasize the need for further studies, focusing on modification of the effects of air pollution on health.