Atherosclerosis in the carotid arteries, two large arteries in the neck that carry blood to the brain, is a major risk factor for ischemic stroke. Symptoms of stroke include: 1  Sudden numbness, weakness, or paralysis of face, arm or leg, especially on one side of the body. carotid endarterectomy is a surgical procedure in which a doctor removes fatty deposits blocking one of the two carotid arteries, the main supply of blood for the brain.
Polar stratospheric cloud. Polar stratospheric clouds or PSCs, also known as nacreous clouds (/ËneÉªkriË.És/, from nacre, or mother of pearl, due to its iridescence), are clouds in the winter polar stratosphere at altitudes of 15,000â25,000 meters (49,000â82,000 ft).
A B-52 Stratofortress soars above Minnesota enroute to Polar Roar, July, 31, 2016. Polar Roar is a mission held in the Arctic Circle that demonstrates the ability to provide a flexible and vigilant long-range global-strike capability. (U.S. Air Force photo/Airman 1st Class Christopher Thornbury) 161102-N-FT178-046 PACIFIC OCEAN (Nov. 2, 2016) An MK 45/5-inch lightweight gun fires off the starboard side of Ticonderoga-class guided-missile cruiser USS Lake Champlain (CG 57) during a pre-action aim calibration fire exercise.