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...
At the exact time of the New moon the moon is to close to the sun to see at all. Blue Moon - Today we consider the Blue Moon to be when a full moon occurs twice in one month. This is a relatively new concept for the term. Originaly a blue moon was considered to be when a full moon occured 4 times in a season. A season usualy has 3 full moons. The term has became popular when referring to any rare event. Black Moon - This is a term that is not used frequently and has no exact definition. Some sources use this term when there are 2 new moons in one month similar to the blue moon which is 2 full moons in a month.