[1] UIB, CSIC, IFISC, E-07122 Palma de Mallorca, Spain
[2] CIC, CONICET La Plata, Ctr Invest Opt, RA-1897 Gonnet, Argentina
[3] UNLP, Fac Ingn, Dept Ciencias Basicas, RA-1900 La Plata, Argentina
[4] Univ Autonoma Madrid, E-28049 Madrid, Spain
[5] Banco Cent Brasil SBS Quadra 3, BR-70074900 Brasilia, DF, Brazil
[6] Univ Catolica Brasilia, Brasilia, DF, Brazil
[7] PUCV, Inst Fis, Valparaiso 2340025, Chile
[8] Univ Fed Minas Gerais, Inst Ciencias Exatas Fis, BR-31270901 Belo Horizonte, MG, Brazil
[9] Univ Buenos Aires, Fac Ciencias Exactas & Nat, Inst Calculo, Chaos & Biol Grp, RA-1428 Buenos Aires, DF, Argentina