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Sexually Transmitted Diseases in the AIDS Era

Gonorrhea, syphilis and other infections still exact a terrible toll. Social conditions help to fuel the new epidemics—and only a combination of social and health programs can defeat them...

By Sevgi O. Aral and King K. Holmes

The Number of Families of Matter

How experiments at CERN and SLAC, using electron-positron collisions, showed that there are only three families of fundamental particles in the universe

By Gary J. Feldman and Jack Steinberger

The Physiology of Perception

The brain transforms sensory messages into conscious perceptions almost instantly. Chaotic, collective activity involving millions of neurons seems essential for such rapid recognition

By Walter J. Freeman

X-ray Microscopes

Recent progress has yielded "soft" X-ray instruments whose resolution is 10 times better than that of optical microscopes. They offer a new way to observe minute structures and to perform chemical analysis...

By Malcolm R. Howells, Janos Kirz and David Sayre

The Echidna

This egg-laying mammal, also called the spiny anteater, has lived in relative obscurity in the Australian bush. Now secrets of its natural history and reproductive behavior are being explored...

By Peggy D. Rismiller and Roger S. Seymour

Computers and Architecture

Advanced modeling and rendering algorithms allow designers and clients to walk through buildings long before construction

By Donald P. Greenberg

The Acoustics of the Harpsichord

A complex interplay of string, wood, air and the human ear produces the swirling sound of the harpsichord

By Edward L. Kottick, Kenneth D. Marshall and Thomas J. Hendrickson

In the Beginning…

Scientists are having a hard time agreeing on when, where and—most important—how life first emerged on the earth

By John Horgan


  • 50 and 100 Years Ago: February 1991

  • Iraq's Nuclear Threat

  • The A Team

  • Postal Mortem

  • Disposable Astronomy

  • Charting a more cautious path to space

  • Hubble bags a great white

  • Safe Bytes

  • Superconducting transistors show their speed

  • Nuclear Numbers

  • Life in the Blood

  • Changing Mission

  • An acoustic sensor spies on insects

  • Hole or Doughnut

  • Reach Out

  • Letters


  • Letters to the Editors, February 1991

  • Recommended

    Books, February 1991

  • Mathematical Recreation

    Mathematical Recreations, February 1991

  • Departments

    The Analytical Economist: Don't write off Marx

  • Essay, February 1991

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