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...
It is because Mercury s color and the surface are very similar to the Moon. They both are rocky gray and have broken up craters. However, there are some differences between them. The moon, unlike Mercury, has lot of darker areas, or what astronomers call seas.It is because the Moon has a lot of lava flows that creates those dark areas. Also, the Moon has more variety of colors compared to Mercury.he moon, unlike Mercury, has lot of darker areas, or what astronomers call seas. It is because the Moon has a lot of lava flows that creates those dark areas. Also, the Moon has more variety of colors compared to Mercury.