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...
Saturn has 62 confirmed moons of which 9 are waiting to be officially named. Saturn's largest moon Titan is bigger than both Mercury and Pluto. Titan has a very thick atmosphere which is mostly nitrogen. Earth's atmosphere is also mostly nitrogen. Saturn also has many icy moons like Mimas which has a large crater that is 1/4 the diameter of the moon, and Enceladus which has very dark material covering one side and very bright material on the other side.