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  1. Astronomy

    Ordinary matter: Lost and found

    Astronomers believe they have finally found the whereabouts of most of the ordinary matter in the universe.

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  2. Health & Medicine

    Abortion-cancer link is rejected

    A workshop report concludes that abortions do not increase a woman's chance of developing breast cancer.

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  3. Math

    Scrambled Grids

    Amazingly simple mathematical operations can lead to intriguingly complex results. Consider, for instance, the iterative geometric process of creating flaky pastry dough. Flatten and stretch the dough, then fold it over on top of itself. Do it again and again and again. Repeating the pair of operations–stretch and fold–just 10 times produces 1,024 layers; 20 […]

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  4. Humans

    From the August 23, 1930, issue

    alt=”Click to view larger image”> STRICTLY AMERICAN Indian architects and sculptors of the American tropics in prehistoric times had strikingly original ideas. On the cover you see the entrance to the beautiful Temple of the Warriors at Chichen Itza, in Yucatan. The Toltecs, who conquered the Mayas at Chichen Itza, remained in the city and […]

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  5. Animals

    Vampire bats don’t learn from bad lunch

    For the first time, a mammal has flunked a controlled test for developing a food aversion after getting sick just once, and that unusual creature is the common vampire bat.

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  6. Health & Medicine

    Protective virus ties up HIV docking sites

    A harmless virus that seems to keep HIV infections from progressing to AIDS appears to do so by occupying key molecular receptors on immune cells.

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  7. Physics

    New approach smooths wrinkle analysis

    A simple new theory of wrinkle formation predicts basic traits of wrinkled surfaces, such as how close together the folds will be, without miring scientists in impossible-to-solve equations.

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  8. 19230

    I read this article with both amazement and bemusement. The technique you describe has been in practice for decades, but without a computer. Samuel T. Orton realized that dyslexics needed to be explicitly taught letter-sound relationships, a knowledge that most of us acquire automatically. I have been in private practice as an educational therapist for […]

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  9. Brain training aids kids with dyslexia

    Preliminary brain-imaging evidence indicates that after completing an intensive reading-remediation program, children with dyslexia not only read better but also exhibit signs of increased activity in key brain areas as they read.

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  10. Math

    Goldbach’s Prime Pairs

    Like the elements in chemistry, prime numbers serve as building blocks in the mathematics of whole numbers. Evenly divisible only by themselves and one, primes are a rich source of speculative ideas that mathematicians often find simple to state but difficult to prove. The Goldbach conjecture is a prime example of such a conundrum. In […]

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  11. 19229

    The hominid dating puzzle is continually being pieced together due to interdisciplinary work between anthropologists and geologists. I would note, however, that radiation decays (not accumulates) at a known rate in buried minerals, per the radiation half-life law. Bruce M. RuckerBerkeley, Calif.

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  12. Anthropology

    Ancient people get dated Down Under

    New dating analyses indicate that people reached southeastern Australia between 50,000 and 46,000 years ago and that two human skeletons previously unearthed there were buried about 40,000 years ago.

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