Definition. 1  Troponins are specific proteins found in heart muscle. Troponin testing is done to diagnose heart attacks (myocardial infarctions). 2  When heart muscle is damaged, as in a myocardial infarction (MI), troponins leak out of cells and into the bloodstream.
Variable Ratio Schedule (VR) This is going to be a little confusing at first, but hang on and it will become clear. A variable ratio schedule (VR) is a type of operant conditioning reinforcement schedule in which reinforcement is given after an unpredictable (variable) number of responses are made by the organism. This is almost identical to a Fixed-Ratio Schedule but the reinforcements are given on a variable or changing schedule.
VR is a natural evolution of the experience we at PlayStation strive to deliver to gamers, Andrew House said. Sony expects 50 games to be released between PlayStation VR's launch in October and the end of 2016. 20 of those titles are playing at GDC, but Sony didn't reveal a full list.