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).
More specifically, the term stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color from dark gray to nearly white. The word stratus comes from the Latin prefix strato-, meaning layer. Stratus clouds may produce a light drizzle or a small amount of snow. These clouds are essentially above-ground fog formed either through the lifting of morning fog or through cold air moving at low altitudes over a region.