A Brentwood man was arrested Friday by FBI agents for attempting to join a branch of al-Qaida in Yemen, as well as for conspiring with a previously arrested Babylon man to wage "violent jihad," officials said. Marcos Alonso Zea, 25, pleaded not guilty in federal court in Central Islip to a five-count indictment accusing him of conspiracy to commit murder in a foreign country, and attempting to provide material support to terrorists. The other three counts, to which Zea also pleaded not guilty, involved obstruction of justice and attempted obstruction of justice in an effort to conceal his terrorist activities,...