Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm characterized by rapid and irregular beating.
Emperor penguin - Aptenodytes forsteri. This is the largest species of penguins. Emperor penguins are only found on and around the Antarctic continent, on the thick pack ice and rarely on mainland. They have a pale yellow, open (breast and chin patch are one) patch on chin and breast. A long, thin and curved bill, typical for fish eaters. Very dark grey back and blue black head.
1 Emperor penguins owe their scientific name (Aptenodytes forsteri) to their discoverer, the first natural scientist to reach Antarctica, the German Johann Reinhold Forster. 2  Forster came to Antarctica in 1770, on Captain James Cook's ship, and saved Cook's life during the voyage.