Post-concussion syndrome. Post-concussion syndrome, also known as postconcussive syndrome or PCS, is a set of symptoms that may continue for weeks, months, or a year or more after a concussion â a mild form of traumatic brain injury (TBI).
The Equatorial (Celestial) Coordinate System. Equatorial coordinates, also called simply celestial coordinates, are the standard coordinate system for the sky. It is meant for the fixed sphere of the stars within which the Earth and Sun move.
In geographical information systems, absolute coordinates reference the position of a point or other feature on a map using a specific datum within a known coordinate system. For example, a point on the globe may be referenced by its latitude and longitude with respect to the intersection of the Equator and the Prime Meridian, designated as 0 degrees latitude and 0 degrees longitude.