The U.S. economy added  117,000 jobs in July, lowering the unemployment rate to 9.1 percent. The new figures from the Bureau of Labor Statistics bring a flicker of optimism to the markets after the worst day on  Wall Street in three years. The European debt crisis conflated with fears the U.S. may be entering another recession has lead to a violent investor sell off around the world. Asian markets all closed down around  4 percent, and U.S. futures have been volatile this morning.  Louise Story, Wall Street and finance reporter for  The New York Times,  has the latest.