Lactose tolerance. Map of Eurasia, African and Australia, showing the varying tolerance for lactose, the milk sugar found in dairy products from cow's milk (lower centre). Tolerance varies from complete (100 percent, white) to zero percent (dark blue), with varying shades between (see key at right). Lactose intolerance is due to an inability to metabolize lactose because the enzyme lactase is not present. Ingesting dairy products when intolerant can produce gastrointestinal discomfort, gas, bloating, cramps or diarrhoea. Tolerance is high in north-western Europe, but can be very low in some African and Asian countries.
Science Photo Library was founded in 1981 by Michael Marten, one of the authors of "Worlds Within Worlds", a book exploring different ways to observe the universe - from electron micrographs, to images of earthrise taken from the Apollo spacecraft. When Marten started receiving requests for the beautiful images in the book, he had an idea of setting up Science Photo Library.
Since then, Science Photo Library has continued to work alongside world acclaimed photographers and the leading science and medical experts to provide a central source of the best science and specialist imagery available. Although the collection started with scientific images, it has grown to encompass all aspects of science and their impact on everyday life.
Shop with Confidence (Fine Art America Return Policy)
Our return policy is very simple:
If you're not happy with a purchase that you made on FineArtAmerica.com, for any reason, you can return it to us within 30 days of the order date. As soon as it arrives, we'll issue a full refund for the entire purchase price. Please note - Fine Art America does not reimburse the outgoing or return shipping charges unless the return is due to a defect in quality.