Exhibit 24.1

POWER OF ATTORNEY

Each person whose signature appears below does hereby make, constitute and appoint each of Kenneth D. Tuchman, Regina M. Paolillo, Margaret B. McLean, and Marc C. Arseneau, acting individually, as such person’s true and lawful attorney-in-fact and agent, with full power of substitution, resubstitution and revocation to execute, deliver and file with the U.S. Securities and Exchange Commission, and the securities regulatory agency in each other country where a registration or filing may be necessary or advised in connection with any offering of the Company’s securities, including but not limited to: Argentina, Brazil, Bulgaria, Canada, Ireland, Mexico, the Philippines, Singapore, the United Arab Emirates, and the United Kingdom, for and on such person’s behalf, and in any and all capacities,

granting unto each of said attorneys-in fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done as fully to all intents and purposes as such person might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent or such person’s substitute or substitutes may lawfully do or cause to be done by virtue hereof.