Russia's Volga River travels 2,300 miles through the country's heartland. It is the source of Russia's power, spanning from imperial times to the present. Here, a cruise ship travels down the Moscow-Volga canal, heading into the river. Anne Garrels/NPR hide caption

itoggle caption Anne Garrels/NPR

Texas-based Valero Energy -- which owns gas stations across the country, like this one in Sacramento,Calif. -- has contributed about half of the roughly $10 million behind California's Proposition 23 campaign. Rich Pedroncelli/AP hide caption

itoggle caption Rich Pedroncelli/AP

The Food and Drug Administration has approved Nuedexta to treat a condition known as emotional incontinence. Courtesy of Avanir hide caption

itoggle caption Courtesy of Avanir