Vol. 163 No. #4

More Stories from the January 25, 2003 issue

  1. Earth

    Snow alga may be sizable carbon sink

    A common microorganism that adds a reddish tinge to some patches of snow may be a significant consumer of planet-warming carbon dioxide.

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  2. Earth

    Contraceptive ring could pose risks after its disposal

    Discarded vaginal contraceptive rings could interfere with fishes' reproduction by releasing estrogen into streams.

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  3. Physics

    Clocking gravity

    The first attempt to measure the speed of gravity finds it roughly equal to that of light, as expected, though not everyone agrees that the method used can actually measure gravity's speed.

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  4. Astronomy

    Sundancing

    Astronomers have solved the mystery of why supergranules—enormous cells of turbulent, charged gas on the sun's surface—appear to move across the sun faster than the sun rotates.

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  5. Goodnight moon, hello Mom

    A national study finds that about 13 percent of U.S. infants now routinely sleep in a bed with their mothers or other adults, intensifying interest in alleged health benefits and risks of bed sharing for babies.

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  6. Earth

    Estrogens classified as carcinogens

    The sex hormones known as steroidal estrogens, which are used in hormone-replacement therapies and birth control pills, have joined a government list of known human carcinogens.

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  7. Paleontology

    Wings Aplenty: Dinosaur species had feathered hind limbs

    A team of Chinese paleontologists has discovered fossils of a small, feathered dinosaur that they say had four wings.

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  8. Astronomy

    In the Beginning: Dark matter builds galaxies, feeds quasars

    Cosmologists say they have found compelling evidence that massive galaxies were already in place when the universe was less than a billion years old.

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  9. Tech

    Fiber Helper: Minuscule controllers may open data floodgates

    A device that fits on the end of optical fibers may make possible the next big boost in Internet speed without new underground cables.

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  10. Health & Medicine

    Too Much of a Good Thing: Excess vitamin A may hike bone-fracture rate

    Dietary studies suggest that people who consume large amounts of vitamin A in foods or multivitamins are more likely to suffer hip fractures than are people who ingest modest amounts.

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  11. Animals

    One-Two Poison: Scorpion starts with a cheap shot

    A South African scorpion economizes as it stings, injecting a simple mix first, followed by a venom that's more complicated to produce.

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  12. Smells Like Emotion: Brain splits duties to sniff out feelings

    A study suggests that a brain structure called the amygdala assesses the emotional intensity of both pleasant and unpleasant sensations, thus challenging prior evidence that it primarily coordinates fear responses.

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  13. Chemistry

    Unnatural Biochemistry: Bacteria make and use an alien amino acid

    Researchers have constructed an organism that synthesizes and incorporates an extra amino acid into its proteins.

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  14. From Bone to Brain: Transplanted male bone marrow makes nerve cells in women and girls

    Transplanted bone marrow can form new nerve cells in the brains of people.

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  15. Astronomy

    Planet Formation on the Fast Track

    New computer simulations suggest that planets as massive as Jupiter may have formed in only a few hundred years rather than several million years, as the leading theory of planet formation requires.

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  16. Health & Medicine

    Getting the Bugs Out of Blood

    Researchers are developing methods for inactivating all sorts of pathogens that could be found in blood, including West Nile virus, an emerging infection recently brought to the United States from Africa.

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