Women chant slogans and wave the Egyptian flag during a rally March 11 to support national unity of Muslims and Christians in Cairo's Tahrir Square, the focal point of the uprising that ousted Hosni Mubarak.
Charles Lotter is an operator of Tower Bridge in London and can work all night if a bridge lift is required. Sleep experts say that even people who routinely work night shifts will experience times when they get sleepy in the middle of the night.
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The Deepwater Horizon oil rig burns in the Gulf of Mexico, April 21, 2010. Investigations before and after the disaster found the agency responsible for overseeing the industry quite friendly with those it regulated.