The US President Barack Obama will nominate Federal Reserve Vice-Chair Janet Yellen to be the next head of the US Central Bank today. According to a White House official, if confirmed by Congress, Ms Yellen will replace Ben Bernanke who has held the post for eight years. She has been his Deputy for the last two years and will become the first woman to head the Federal Reserve. Ms Yellen and Mr. Bernanke are due to appear with the President today.