Science News, Vol 169

Some items from vol. 169 of Science News ... posting for The Political Cat while she's out of town ...

cancerRoss Cagan, a developmental biologist at Washington University School of Medicine in St. Louis, has shown that cells on a tumor's outer layer that come in contact with healthy cells receive a chemical signal (a protein called cadherin) that causes them to lose the surface proteins that keep them anchored. They then become motile, and while most of them die, those that mutate successfully and stay alive can form tumours elsewhere in the body. Hopefully, this will lead to a way of stopping the motility of these cells and the metastasizing of tumours.

brain development Gail A. Wasserman of Columbia University's College of Physicians and Surgeons has shown that water contaminated with manganese can limit the intellectual development of children exposed to it. The WHO (World Health Organisation) standard for manganese contamination is 500 mcg per liter of drinking water. However, contamination in wells in Bangladesh far exceeded that amount. Manganese in water is more readily absorbed in the body than manganese in food. Some U.S. well water exceeds these manganese concentrations. However, because manganese imparts a foul taste to water and stains porcelain, it is more likely that consumers in developed countries will avoid it.

astronomyThe Milky Way is apparently cannibalising nearby collections of stars, according to astronomers who have been combing through distance measurements recorded by the Sloan Digital Sky Survey. Heather Morrison of Case Western Reserve University in Cleveland and Robert Lupton of Princeton University have both reported such cannibalistic activity on the part of our home galaxy.

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