dr. mccray? >> i want to make a more i guess general background commentary and say that this is probably a familiar story in medical research. concussion has gone, as many people in this room know, has gone truly from total on -- obscurity, 10 or 20 years ago, to now, in a sports setting and to a large extent in the military sector, dominating the national narrative. and the unfortunate position we're in currently i think is we've reached that awkward stage of maturity, call it adolescence, that we've made enormous strides over the last 20 years that puts us in a position to have this discussion today. but at the same time, the topic has been elevated in to the public spotlight such that all the stakeholders, including sports parents, assume we already know the answers to all the critical questions and they want those answers now. and there's perhaps no more unenviable position for a scientist to be in than to have to catch up with the public narrative. i think we've made great strides in changin