A first informal U.N. Security Council poll on Thursday showed former Costa Rican Vice President Rebeca Grynspan as the early frontrunner to become the next U.N. secretary-general, followed by former Guyanese Foreign Minister Carolyn Rodrigues-Birkett. In the non-binding "straw poll" voting by the ?15 members of the Security Council, Grynspan received 10 "encourage" votes to nine for Rodrigues-Birkett and seven for Argentina's Rafael Grossi, head of the U.N. nuclear watchdog, diplomats said. The candidates are seeking to replace Portugal's Antonio Guterres when he steps down at the year-end after two five-year terms. Guterres' successor faces the task of revitalizing an...