2236-3459 2236-3459 S2236-34592013000200175 10.1590/S2236-34592013000200009 Brazil 00 08 2013 00 08 2013 17 40 175 195

13 24 24 15-29 16 1 1 19-39 1 1 9-43 14 32 32 77-108