Sidereal time

Sidereal time  is a timekeeping system that astronomers use to locate celestial objects. Using sidereal time, it is possible to easily point a telescope to the proper coordinates in the night sky. Briefly, sidereal time is a "time scale that is based on Earth's rate of rotation measured relative to the fixed stars".

Viewed from the same location, a star seen at one position in the sky will be seen at the same position on another night at the same sidereal time. This is similar to how the time kept by a sundial can be used to find the location of the Sun. Just as the Sun and Moon appear to rise in the east and set in the west due to the rotation of Earth, somarginal zone. Finally, there is a jeopardized zone which surrounds the entire area. In studies with baboons, the central necrotic area was not affected by recanalization of the vessel after several hours. However, muscle in the other zones which had undergone less severe damage during the ischemic period could be salvaged. A surprising finding was that lysing of the thrombus to produce a perfect arteriograph was insufficient to restore normal flow in the majority of animals. (See Flameng, et al, J. Clin. Invest., Vol. 75, p. 84-90, 1985).
Some further impediment to flow had developed in the area supplied by the vessel during the time that it was occluded. In further studies, it was demonstrated that immediately after removing the obstruction to the vessel, the flow through the damaged