When Daniel A. Colón-Ramos, Ph.D., arrived from Puerto Rico to begin his Harvard undergraduate career in 1994, things didn’t exactly go as planned. Moving to the campus early for a summer program, he took a taxi from Logan Airport into Cambridge. But once in his dorm room, he set down his bags and lay on the bed feeling dizzy—and by the time his roommate arrived, Colón-Ramos recalled, “I told him, ‘I’m dying. You have to take me to the hospital.’ ”