Humberto Gerardo Mendoza knows what it feels like for students who participate in the annual Rio Grande Valley Regional Science and Engineering Fair at the University of Texas at Brownsville. Mendoza, 24, a UTB alumnus and a medical student at UTMB, was twice named the science fair’s grand champion when he was a student at Brownsville’s Hanna High School. He will graduate from UTMB in June 2015 and wants to enter an internal medicine residency and seek a fellowship in cardiology.