President Barack Obama will nominate Janet Yellen as chairwoman of the Federal Reserve later today, administration officials said last night, ending an unusually public search to fill one of the most important economic policy-making jobs in the world. Photograph: Mary F Calvert/The New York Times

US president Barack Obama will nominate Fed number two Janet Yellen today to run the world’s most influential central bank, providing some relief to m(...)

Investigators comb the site of the second of two bomb explosions on Boylston Street in Boston. Photograph: Eric Thayer/The New York Times

A letter addressed to US president Barack Obama containing a substance that initially tested positive for the poison ricin was(...)