1. Center for Clinical and Epidemiological Research of University Hospital University of Sao Paulo Sao Paulo Brazil
2. Department of Biological Sciences Federal University of Vale do Sao Francisco Petrolina Brazil
3. Department of Electrical Engineering Federal Institute of Espirito Santo Vitória Brazil
4. Department of Physiological Sciences Federal University of Espírito Santo Vitória Brazil
5. Department of Social Medicine Federal University of Rio Grande do Sul Porto Alegre Brazil
6. Postgraduate Programme in Epidemiology Federal University of Rio Grande do Sul Porto Alegre Brazil