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...
1. Penumbral Lunar Eclipse. The Moon passes through Earth's penumbral shadow. These events are of only academic interest because they are subtle and hard to observe. (click for photo example) 2. Partial Lunar Eclipse. A portion of the Moon passes through Earth's umbral shadow. These events are easy to see, even with the unaided eye. (click for photo example) 3. Total Lunar Eclipse. The entire Moon passes through Earth's umbral shadow. These events are quite striking due to the Moon's vibrant red color during the total phase (totality).