MEXICO CITY (Reuters) - Mexican authorities said on Sunday they had captured a leader of the Juarez Cartel wanted by the United States government who took the helm after the organization's long-time chief was nabbed last year. The leader, Jesus Aguayo, was detained on Friday by Federal troops in Villa Ahumada in the northern state of Chihuahua, which borders the United States and has played host to some of the worst drug trafficking-related violence in the country.