Al Ferof ridden by Ruby Walsh jumps a fence in the Racing Post Arkle Challenge Trophy Steeple Chase run during day one of the Cheltenham Festival at Cheltenham Racecourse on March 13, 2012 in Cheltenham, England. (Julian Finney/Getty Images)

Pakistani vendors wash oranges at their roadside stall on the outskirts of Islamabad, Pakistan, March 13, 2012. (Anjum Naveed/AP Photo)

Two of three polar bear cubs born in November last year, play in the snow at the Moscow Zoo, in Moscow, March 13, 2012. The cubs have only recently been revealed to the public as they have mostly stayed in the seclusion of their den. (Alexander Zemlianichenko/AP Photo)

Tony Odong, a 12-year old victim of nodding syndrome, sits in front of his home playing with a dead chicken found nearby in Pader, Uganda, March 8, 2012. The cause of nodding syndrome is not yet known by scientists despite years of research. Ugandan Ministry of health statistics indicate that over 3,000 children have been affected by the disease and some 170 other children have died since 2009. (Xinhua/Yuan Qing Press/Corbis)

Relatives of Mohamed Dahir cry at his funeral in Gaza City. An Egyptian-brokered truce arrives between Israel and militant groups in the Gaza Strip after four days of violence that killed 25 Palestinians, Gaza Strip, March 13, 2012. (Majdi Fathi/Demotix/Corbis)

Hostesses walk outside the Great Hall of the People during the closing ceremony of the Chinese People's Political Consultative Conference, March 13, 2012 in Beijing, China. Known as 'liang hui,' or 'two organizations', it consists of meetings of China's legislature, the National People's Congress, and its advisory auxiliary, the Chinese People's Political Consultative Conference. (Feng Li/Getty Images)

People watch as two loggerhead sea turtles are released back into the wild at Bill Baggs Cape Florida State Park after they underwent rehabilitation at Miami Seaquarium March 13, 2012 in Key Biscayne, Florida. The two loggerhead sea turtles weighing in at 90 lbs and 125 lbs were both found weak in the wild, covered in parasites and facing buoyancy issues. (Joe Raedle/Getty Images)

Afghans burn an effigy depicting U.S. President Barack Obama following Sunday's killing of civilians in Panjwai, Kandahar by a U.S. soldier during a protest in Jalalabad east of Kabul, Afghanistan, March 13, 2012. (Rahmat Gul/AP Photo)

Models walk the runway wearing Korhani fall 2012 collection at David Pecaut Square on March 12, 2012 in Toronto, Canada. (George Pimentel/WireImage/Getty Images)

A South Korean activist wears a mask depicting a cluster munition as police officers stand guard during a campaign to ban land mine and cluster munitions in Cambodia, near the Foreign Ministry in Seoul, South Korea, March 13, 2012. Activists call people's attention to the victims of land mines. (Lee Jin-man/AP Photo)

Jason Ryles and Will Chambers of the Storm pass the ball during a Melbourne Storm NRL training session at Gosch's Paddock on March 13, 2012 in Melbourne, Australia. (Scott Barbour/Getty Images)

Danny Cooper, of Chilton County, Ala. waves to motorists outside a polling place, March 13, 2012, in Vestavia Hills, Ala. Alabama voters would be deciding Tuesday whether Mitt Romney has deep South appeal, if it's time for Newt Gingrich to go forward or go home, and whether Rick Santorum can trim the Republican field. (David Goldman/AP Photo)