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SCIENCE FILE | Science in Brief

Ancient Crystals Provide Clues To Deaths of Sea Creatures

October 19, 2000

Thirty-four-million-year-old crystals of calcium carbonate, called otoliths are yielding new insights into the massive die-out of tiny shell-bearing sea creatures in the extinction event at the so-called Eocene/Oligocene boundary. Analysis of the otoliths--taken from the ears of fish by researchers at the University of Michigan and Syracuse University--show that ocean temperatures were about four degrees colder than normal during winters in this geological period, the team reports in today's Nature. Those lower temperatures may have been enough to kill off the marine invertebrates.

The researchers determined the ocean temperatures by measuring the relative proportions of oxygen-16 and oxygen-18 in the calcium carbonate. That ratio varies as water temperature changes.

'Made-to-Order' Baby Brother Helping His Ailing Sister

Doctors declared success Wednesday in the groundbreaking case of an ailing 6-year-old girl who received a transplant of umbilical cord blood from her "made-to-order" baby brother. Molly Nash of Englewood, Colo., received the blood three weeks ago in hopes it would save her life. The girl suffers from Fanconi's anemia, a rare genetic disorder that prevented her body from making bone marrow.

Dr. John Wagner of the University of Minnesota said tests showed the transplant is working. He said the infused cells are taking over the functions of Molly's bone marrow, making platelets and disease-fighting white blood cells. Molly's brother, Adam, was born through test-tube fertilization over the summer after his parents genetically screened and selected an embryo to make sure he would be free of Molly's disease and would be a suitable tissue donor. It was the first known case in which parents created a baby genetically selected to help save a sibling's life.


--Compiled by Times medical writer Thomas H. Maugh II

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