WASHINGTON: US President Barack Obama on Tuesday praised the work of budding a Indian-American teenage scientist who used machine learning to teach a computer to identify potential drugs for cancer, tuberculosis and Ebola.Anvita Gupta, 17, of Scottsdale, Arizona, winner of Third Place Medal of Distinction for Global Good, was one of the participants of the fifth White House Science Fair which was attended by several other Indian-origin teenagers -Trisha Prabhu from Illinois, Sahil Doshi from Pittsburgh, Nikhil Behari from Pennsylvania and Ruchi Pandya from San Jose.When Gupta explained how she had used an algorithm to help identify possible new drugs to treat Ebola, cancer and tuberculosis, Obama turned to the press, grinned and said, "I don't know what you all have been doing. But this is what she has been doing"."It is unbelievable what so many of these young people have accomplished at such an early age," Obama said after his personal interaction and viewing of some of the exhibits on display.This year's White House Science Fair has a specific focus on diversity and includes more than 100 students from 30 states, representing more than 40 science competitions and organisations.Thirty-five student teams exhibited their projects. Obama personally viewed 12 of these exhibits. Prabhu showcased her computer program 'Rethink' that alerts users when an outgoing message contains language that is potentially abusive and hurtful.Ninth-grader Doshi exhibited the design of his innovative carbon-dioxide powered battery called PolluCell.Behari showcased the easy-to-use security system developed by him which is versatile and effective in protecting online data.Pandya exhibited the one-square centimetre carbon nanofibre electrode-based biosensor that has the potential to improve cardiac health diagnostics for patients around the world.