MEXICO CITY (AP) — The dismemberment slayings of four youths whose bodies were left cut to pieces in plastic bags has horrified the central Mexican city of Cuernavaca.Prosecutors say the four range in age from 14 to 21, and say that a threatening note from a drug gang was left near the bodies.The Morelos state prosecutors office said in a statement the bodies were found early Thursday on a street in Cuernavaca.That is the same city where the slaying of a poet's son prompted a national protest movement against violence.Poet Javier Sicilia said Friday the slayings prove that little or nothing has changed in the year since his son died and the government continues to fail to prevent or investigate such crimes.