Vol. 157 No. #11

More Stories from the March 11, 2000 issue

  1. Earth

    Pollution Keeps Rain up in the Air

    New satellite data indicate that aerosol pollution can break up water droplets in clouds and stop rain.

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  2. Materials Science

    Rice hulls could nourish Silicon Valley

    Scientists are developing ways to extract and purify the silicon that occurs naturally in rice hulls.

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  3. Planetary Science

    Meteoric wallop may have diversified life

    A new study suggests that the evolutionary burst on Earth some 540 million years ago occurred around the time that cosmic debris began pummeling our planet at an increasing rate.

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  4. Health & Medicine

    Cell transplants combat diabetes in mice

    Scientists have successfully reversed diabetes in mice by harvesting immature pancreatic cells that make insulin from one mouse, growing them in culture, and transplanting them into a mouse with the disease, which then recedes.

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  5. Health & Medicine

    HIV sexual spread exploits immune sentinels

    The virus that causes AIDS latches onto a protein called DC-SIGN to hitch a ride on immune cells in mucus membranes and spread through the body.

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  6. Earth

    Hey polluters! This billboard’s for you

    Motorists generally like and respond to personalized billboard messages about when an engine tune-up may be warranted.

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  7. Brain cells work together to pay attention

    Cells in the brain's cortex may coordinate their electrical activity as attention shifts from visual to tactile information.

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  8. Animals

    Hormone still rules no-tadpole frogs

    Coqui frogs may skip the tadpole stage, but within the egg, they undergo a metamorphosis ruled by thyroid hormone.

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  9. Tough talk for depressed husbands

    Positive comments directed by depressed men to their wives often elicit negative responses from the women, a conversational style that may contribute to the men's mood problems.

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  10. Listen to the shapes

    People use still-unspecified acoustic cues to discern the shapes of hidden, vibrating plates.

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  11. Progestin adds to breast cancer risk

    Women taking estrogen are more prone to get breast cancer if they are also taking the hormone progestin.

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  12. Alcohol can induce fainting spells

    Alcohol imbibed in modest quantities can disrupt the reflex that maintains blood pressure when a person stands up quickly, which may account for why some people faint when they down a few drinks and then stand up.

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  13. Animals

    Pregnant—and Still Macho

    Some of the basic theories of sexual behavior and sexual selection are getting attention thanks to a burst of new studies in the topsy-turvy social world of the seahorse, where the males get pregnant.

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  14. Health & Medicine

    Is Snoring a DiZZZease?

    Snoring may trigger high blood pressure, which can lead to heart disease or stroke.

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  15. Chemistry

    Where the Gems Are

    By using a novel tool to figure out an emerald’s oxygen-isotope ratio, gemologists can now determine which mine the precious stone came from and, possibly, gain insights into the formation and history of these coveted gems.

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