Science: Update

THE WORLD'S oceans are leaking away, according to geologists in Tokyo who calculate that in a billion years our planet could be as dry and barren as Mars.

Shigenori Maruyama, of the Tokyo Institute of Technology, who led the team, says that his calculations suggest that the oceans are leaking into the Earth's mantle, where the enormous "plates" of the continents meet, five times more quickly than they are being replenished by volcanic hot spots and mid-ocean ridges where molten rock is forced upwards from the mantle.

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THOUSANDS OF men living in Scotland are to be interviewed as part of a survey into possible causes of the dramatic fall in sperm counts seen over recent decades. Scientists at the Medical Research Council's reproductive biology unit in Edinburgh are collaborating with researchers at the University of Edinburgh to gather a sample of at least 1,200 men aged between 21 and 31. In addition to completing a questionnaire, the men will be asked to send a semen sample through the post for scientists to assess its sperm quality. Several studies have shown that sperm counts are in decline throughout the world and may be the result of unknown factors operating very early in a boy's development, possibly even in the womb before birth.