Uncategorized

  1. Math

    Testing for Divisibility

    The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4? by 11? In a 1962 Scientific American article, Martin Gardner noted that during the […]

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  2. Earth

    Nature’s Own: Ocean yields gases that had seemed humanmade

    Chemical analyses of seawater provide the first direct evidence that the ocean may be a significant source of certain atmospheric gases that scientists had previously assumed to be produced primarily by industrial activity.

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  3. Astronomy

    X-Ray Chaos: Violence shows itself in a nearby galaxy

    New X-ray observations provide additional evidence that Centaurus A, the nearest radio-wave-emitting galaxy to Earth that has a supermassive black hole, is a maelstrom of violence.

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  4. Earth

    Killer Cocktails: Drug mixes threaten aquatic ecosystems

    Trace amounts of pharmaceutical drugs in waterways may work together to deform and kill native microscopic organisms.

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  5. Not a Turn-On: Alleged X chromosome activator may be a dud

    A gene that helps regulate X chromosome activity in mice doesn't work in people.

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  6. Materials Science

    Spinning Fine Threads: Silkworms coerced to make better silk

    The caterpillars that spin commercial silk can make tougher or more elastic threads, depending on how fast they're forced to spin.

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  7. Ecosystems

    Tougher Weeds? Borrowed gene helps wild sunflower

    Feeding concerns about developing superweeds, a test of sunflowers shows for the first time that a biologically engineered gene moving from a crop can give an advantage to wild relatives under naturalistic conditions.

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  8. Health & Medicine

    Toxin Trumped: New malaria vaccine protects mice

    An experimental vaccine neutralizes a toxic molecule made by malaria-causing parasites.

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  9. 19103

    Your article on microbial-efflux-pump research immediately caused me to relate the phenomenon to immune system response. Have the researchers considered the possibility of such a response triggering the formation of efflux pumps, either specific to the triggering “foreign” body or to a group of bodies similar to the cow pox-small pox link? Robert E. HubbardWinter […]

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  10. Keeping Bugs from Pumping Drugs

    Researchers hope that attacking the machinery some microbes use to pump antimicrobial agents out of their cells may help deal with the increasing problem of drug resistance.

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  11. Physics

    Scaling energy barriers to save data

    Researchers demonstrate a promising new way to make semiconductor-based memory that doesn't erase when the power goes off.

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  12. Physics

    Spectral atom rings in

    Electron waves can generate a phantom atom when a real atom is placed at the right spot inside an elliptical quantum corral, or loop of atoms, arranged on a surface.

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