Transcranial Doppler Assessment of Cerebral Flow Velocity During Cognitive Tasks Roger E. Kelley, MD; Jen Y. Chang, MS; Nancy J. Scheinman, PhD; Bonnie E. Levin, PhD; Robert C. Duncan, PhD; and Shih-Chang Lee, PhD Background and Purpose: The purpose of this study was to assess the ability of transcranial Doppler ultrasonography to detect selective circulatory changes during cognitive activity. Methods: We measured cerebral artery flow velocity in 21 normal volunteers by transcranial Doppler ultrasonography during rest followed by cerebral activation. Mean and peak systolic
Neptune has dark storms and eight named moons, although there are more than 8 moons. Source(s): My memory http://burro.astr.cwru.edu/stu/neptune_m...
Full Moon: Occurs when the earth, moon and sun âline upâ so that the moon is on the opposite side of the earth. The entire sunlit part of the moon is facing earth, so it appears large, round and bright. New Moon: Occurs when the earth, moon and sun âline upâ so that the moon is between the earth and sun. The entire sunlit part of the moon is on its back side (the half we cannot see from earth), so the moon appears dark and barely visible. Tides: The rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon, the sun and the rotation of the earth.