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  1. Follow that Fossil!

    The Denver Museum of Nature and Science offers an introduction to the process of finding fossils and learning from them about the past. The museum’s Web site describes the prospecting, excavation, preparation, and exhibition of various types of plant and animal specimens. Go to: http://www.dmns.org/denverbasin2/fossil/

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  2. Astronomy

    Dying star illuminates its own shroud

    Images of a planetary nebula, taken by the Hubble Space Telescope in 1997 but only recently assembled as a color composite, show a shroud of material cast off and ionized by the dying, sunlike star Henize 3-401.

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  3. Archaeology

    The Original Cocoa Treat: Chemistry pushes back first use of the drink

    Analysis of residues from ancient Maya vessels has revealed that the pots held cocoa almost 1,000 years before its previously known earliest use.

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  4. 19089

    As I recall, neural networks also require, from time to time, periods of very low input in order to maintain their learning efficiencies. Neural-network researchers call these periods sleep, yet these networks obviously don’t require glycogen to function. Thus, it always seemed to me that sleep is probably more of a requirement of the neurons’ […]

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  5. Health & Medicine

    Sleepy Heads: Low fuel may drive brain’s need to sleep

    A new study supports the hypothesis that dwindling energy stores in the waking brain induce sleep.

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  6. Physics

    Heavy Suspicion: Elemental discoveries trace to fake data

    A prominent physicist has lost his job following allegations that he fabricated the evidence underpinning his team's now-discredited discovery of elements 116 and 118.

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  7. Health & Medicine

    Mixed Blessing: Unusual gene helps heart, hurts immunity

    People carrying a variant of a gene that encodes an immune protein called toll-like receptor 4 have a weaker defense against infections but appear to be less prone to heart disease.

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  8. 19088

    This article touches on one of the dirty little secrets of beauty products: By and large, they are a chemical stew with ingredients that would require EPA warnings if used in industrial settings. I’m amazed that EPA doesn’t regulate the volatiles in nail salons. Steve SchlosserSaratoga, Calif.

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  9. Health & Medicine

    More than Skin Deep? Beauty products may damage fetal development

    A new report shows that many cosmetics contain phthalates—a class of chemicals known to cause developmental deformities in animals.

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  10. Health & Medicine

    Disabled Defense: HIV protein counters immune-cell gene

    Immune cells contain a protein that can inhibit HIV replication if the AIDS virus lacks a key protein.

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  11. 19087

    While reading that the cranial crest of the pterosaur Thalassodromeus helped regulate body temperature, I pondered another potential use. While gliding near the water, its crested head might act as a rudder for the large-wingspan animal. Perhaps the crest also included nerves that allowed Thalassodromeus to sense fleeing fish. Steve M. AdamsPlano, Texas Perhaps the […]

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  12. Paleontology

    Skimming the Surface: Flying reptile may have scooped its meals

    Fossils unearthed in Brazil strengthen the idea that some species of ancient flying reptiles snatched their meals on the fly, snapping up fish as they swooped low over the water's surface.

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