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The Patient Record in Epidemiology

The most accurate estimates of the rate of many diseases come from studies based on a huge collection of patient records at the Mayo Clinic. The records are indexed for retrieval by diagnosis...

By Leonard T. Kurland and Craig A. Molgaard

An Early Habitat of Life

Microorganisms may have flourished on tidal mud Bats 3.5 billion years ago. The environment can be reconstructed from sedimentary deposits in Australia, but the evidence of life remains tentative...

By David I. Groves, John S. R. Dunlop and Roger Buick

Gravitational Waves from an Orbiting Pulsar

Einstein's 1915 prediction that an accelerating mass should radiate energy in the form of gravitational waves is supported by evidence that a pulsar's orbit around a companion star is slowly shrinking...

By Joel M. Weisberg, Joseph H. Taylor and Lee A. Fowler


They are short chains of amino acids that are active in the nervous system. In some cases they transmit signals between nerve cells and also serve the body as a hormone

By Floyd E. Bloom

The Acoustics of Violin Plates

Modern tests of the vibrational properties of the unassembled top and back plates of a violin reveal something of what violinmakers do by "feel" and lead to the making of consistently good violins...

By Carleen Maley Hutchins

Vitruvius' Odometer

A machine for measuring mileage that the Roman engineer described but may never have seen proved puzzling to Leonardo 1,500 years later. It may have been invented by Archimedes during the first Punic War...

By André Wegener Sleeswyk

Quantum Logic

In the quantum theory classical patterns of inference break down. Mathematical structures called lattices can model alternative roles for the words "and" and "or" that may fit the world more coherently...

By R. I. G. Hughes

Image Processing by Computer

When the information in an image is expressed in digital form, it can be manipulated mathematically rather than optically. By such methods a blurred photograph can sometimes be restored to clarity...

By T. M. Cannon and B. R. Hunt


  • 50 and 100 Years Ago: October 1981

  • Science and the Citizen, October 1981

  • Letters

    Letters to the Editors, October 1981

  • Recommended

    Books, October 1981

  • Mathematical Recreation

    Mathematical Games

  • Amateur Scientist

    The Amateur Scientist, October 1981

  • Departments

    The Authors, October 1981

  • Bibliography, October 1981

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