Brazilian Archives of Biology and Technology, Vol 52, Iss 4, Pp 835-839 (2009) Brazilian Archives of Biology and Technology, Volume: 52, Issue: 4, Pages: 835-839, Published: AUG 2009 Brazilian Archives of Biology and Technology v.52 n.4 2009 Brazilian Archives of Biology and Technology Instituto de Tecnologia do Paraná (Tecpar) instacron:TECPAR