Brazilian Archives of Biology and Technology, Volume: 54, Issue: 4, Pages: 761-768, Published: AUG 2011 Brazilian Archives of Biology and Technology v.54 n.4 2011 Brazilian Archives of Biology and Technology Instituto de Tecnologia do Paraná (Tecpar) instacron:TECPAR Brazilian Archives of Biology and Technology, Vol 54, Iss 4, Pp 761-768 (2011)