Martha and Alvaro Galvis used to travel from New Hampshire to Boston to watch the marathon every year. Both were hurt in the bombing two years ago. Jesse Costa/WBUR hide caption

toggle caption Jesse Costa/WBUR

Dennis Aabo Sorensen tests a prosthetic arm with sensory feedback in a laboratory in Rome in March 2013. Patrizia Tocci/Lifehand 2 hide caption

toggle caption Patrizia Tocci/Lifehand 2

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