At the Cleveland Clinic, technician Larry Raber and physician Mei Lu practice the ultrasound technique to measure CCSVI in patients with MS on medical student Claudiu Diaconu. Cleveland Clinic Center for Medical Art & Photography hide caption

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Emergency personnel attend to a shooting victim outside a Safeway in Tucson, Ariz. Rep. Gabrielle Giffords (D-AZ), and others were shot as the congresswoman was meeting with constituents. First responders to the scene used special first aid kits to help treat victims until medical personnel arrived. James Palka/AP hide caption

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A traveler passes an automated external defibrillator at O'Hare International Airport in Chicago. Tim Boyle/Getty Images hide caption

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Gabrielle Giffords traveled by ambulance, private jet and helicopter from the University Medical Center in Tucson to a rehabilitation hospital in Houston on Friday. John Moore/Getty Images hide caption

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A study that measured antibodies and the disease history of more than  200 kids found that two doses of vaccine were 98 percent effective in  preventing chickenpox compared with 86 percent for a single dose. AP hide caption

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