Definitions. 1  Abatements are reductions in tax assessments and are a normal part of the IRS tax administration process. Abatements may occur for a number of reasons. 2  Accrual Accounting is the accounting basis whereby transactions and events are recognized when they occur, regardless of when cash is received or paid.
(March 2008) In United States aviation, a terminal radar service area (TRSA) is a delimited airspace in which radar and air traffic control services are made available to pilots flying under instrument flight rules or (optionally) visual flight rules for the purposes of maintaining aircraft separation.
Torsades de pointes is a distinctive polymorphic ventricular tachycardia in which the QRS amplitude varies and the QRS complexes appear to twist around the baseline. Torsades de pointes is associated with a prolonged QT interval, which may be congenital or acquired.