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).
Nimbostratus clouds are smooth layers of gray, which often cannot be seen clearly because of the precipitation falling from them. Low clouds: Stratus, cumulus and stratocumulus clouds are based at altitudes of 6,000 feet or lower. Stratus clouds appear as smooth, even sheets; light rain and drizzle often fall from them; light snow or freezing drizzle during the winter. Fog is merely a stratus cloud reaching to, or forming on the ground.