ACKNOWLEDGEMENTS
We thank the researchers who collected and reported the field data, our
institutions and the many colleagues who helped us in different ways
during this project for their comments and suggestions, especially to
Professor Dr. Marcus Aguiar. EDB is grateful for the Ph.D. degree
scholarship provided by Capes (Coordenação de Aperfeiçoamento de Pessoal
de Nível Superior). EDB and SBLA acknowledge the computational support
from Professor Carlos M. de Carvalho at LFTC-DFis-UFPR.