Skip to main content

Features

The Census of 1970

The early figures from the 19th count of the U. S. population show a reduced rate of growth, large migrations to the West and South and a continued shift of whites to the suburbs and blacks to cities

By Philip M. Hauser

The Induction of Interferon

A synthetic RNA called poly l:C may provide broad-spectrum protection against virus diseases. It makes cells form interferon, the protein that defends other cells against infection by viruses

By Alfred A. Tytell and Maurice R. Hilleman

A New Class of Diode Lasers

Minute sandwich-like heterostructures composed of two or more different semiconducting materials show great promise as cheap, efficient carrier-wave generators for use in mass communications

By Izuo Hayashi and Morton B. Panish

Pathways in The Brain

New techniques combining various staining methods with electron and light microscopy make it possible to investigate in detail the connections among nerve cells and the circuitry of the brain

By Lennart Heimer

The Sacred Source of the Seine

The spring that gives rise to the river was once the sanctuary of Sequana, a Celtic goddess of healing. A unique accumulation of 2,000-year-old wood sculpture has been uncovered at the site

By Simone-Antoinette Deyts

Supernova Remnants

Radiation emitted by the debris left over from catastrophic stellar explosions may yield clues to many astronomical puzzles

By Paul Gorenstein and Wallace Tucker

A Grazing Ecosystem in the Serengeti

Large herds of zebras, wildebeests and Thomson's gazelles migrate in succession across the plains of Tanzania. These migrations are synchronized with the availability of specific tissues of grasses

By Richard H. V. Bell

Photons as Hadrons

Photons with a billion times more energy than photons of visible light exhibit properties once thought to belong solely to hadrons:the class of particles that includes the proton and the neutron

By David E. Yount and Frederick V. Murphy

Departments

  • 50 and 100 Years Ago: July 1971

  • Science and the Citizen: July 1971

  • Letters

    Letters to the Editors, July 1971

  • Recommended

    Books - July 1971

  • Mathematical Recreation

    Mathematical Games - July 1971

  • Amateur Scientist

    The Amateur Scientist - July 1971

  • Departments

    The Authors - July 1971

  • Bibliography - July 1971

Purchase To Read More

Already purchased this issue? Sign In to Access
Select Format
July 1971

See the World from a Different Perspective

Subscribe to Scientific American MIND