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.
Sample Schedule A Letter from the Department of Laborâs Office of Disability and Employment Policy: Date. To Whom It May Concern: This letter serves as certification that (Veteranâs name) is a person with a severe disability that qualifies him/her for consideration under the Schedule A hiring authority. Please feel free to contact me at (insert VRC name, number, contact information) if you have any additional questions or concerns.