Images Dated 26th February 2004

Thermogram of man

Thermogram of the head and upper torso of a naked man. Thermography is an imaging technique for mapping the heat distribution over the surface of a body. Here, the colour-coded image shows temperature variation in 0.1 degree celsius steps (see scale at left), where blue corresponds to the colder areas and yellow corresponds to the hotter areas. Thermography has proved useful in manufacturing and medicine (where it may reveal disorders such as tumours and arthritis). It was developed by the military in the 1970's and 1980's to assist night vision; the solid state sensors used in the thermograph can detect infra-red radiation even in darkness and/or smoke

© PASIEKA/SCIENCE PHOTO LIBRARY

Plague bacteria

Plague bacteria. Light micrograph of Gram- stained Yersinia pestis bacteria. This bacterium is the cause of bubonic plague (generally agreed to have been the Black Death of the Middle Ages). The bacteria are rod-shaped, Gram-negative, non- motile bacilli. Y. pestis is primarily carried by fleas on rats. Transfer to humans occurs when the fleas feed on human blood. Infection is rapid, causing swollen lymph nodes, and leading to septicaemia and pulmonary infection. Extensive control measures against rats and their fleas have eliminated plague from Europe, but it still occurs in other regions of the world. Magnification: x1450 when printed 10cm wide

© CNRI/SCIENCE PHOTO LIBRARY