January Gallery

Strait of Olkhon, Lake Baikal

Lake Baikal. View of the Strait of Olkhon, on the west coast of Lake Baikal, Russia. The land on the horizon is Olkhon Island. Baikal is the largest reservoir of fresh water in the world, containing about 23, 000 cubic kilometres, or about 20% of the world's total supply. The lake is about 620 km long and up to 72 km wide, and is located in a rift valley in Siberia. Its maximum depth is about 1940 metres. Hot vents deep in the lake have created a unique ecosystem in its waters

© RIA NOVOSTI/SCIENCE PHOTO LIBRARY

Angina pectoris

Angina pectoris. Illustration of a heart diseased with the cardiac condition angina pectoris. The heart is outlined in blue, with the aortic arch at top (red) and coronary arteries at lower frame. A spasm is occurring (centre right, orange) where a coronary artery branch has become pinched between the left atrium and ventricle of the heart. Angina pectoris refers to a pain in the chest due to in- sufficient oxygen reaching the heart muscle. It is caused by coronary artery disease: fat deposits (yellow) develop on the inner walls of the artery (atherosclerosis) decreasing blood flow. Angina pectoris is a common condition, occurring earlier in men. Drug treatment or surgery may be required

© JOHN BAVOSI/SCIENCE PHOTO LIBRARY