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Nuclear-Free Zones

The failure of recent attempts to revitalize the Nonproliferation Treaty has led to renewed interest in regional multinational pacts as an alternative way of preventing the spread of nuclear weapons

By William Epstein

The Protein Switch of Muscle Contraction

The contraction of muscle is "turned on" when calcium ions trigger changes in the conformation of two regulatory proteins: tropomyosin and troponin. The detailed nature of these changes is now emerging

By Carolyn Cohen

High-Gradient Magnetic Separation

A recent advance in the generation of strong magnetic fields opens the way to removing very weakly magnetic particles from mixtures. One novel application of the new process is purifying wastewater

By Henry Kolm, John Oberteuffer and David Kelland

The Cancer Problem

Almost all cancers appear to be caused by exposure to factors in the environment. The most promising approach to the control of the disease is to identify those factors and eliminate them

By John Cairns

Unusual Mechanisms for the Generation of Lift in Flying Animals

Some birds and insects that hover cannot generate enough lift by means of standard aerodynamics. A close study of hovering shows that they employ two mechanisms that are best described as clap-fling and flip

By Torkel Weis-Fogh

The Subduction of the Lithosphere

The rocky shell of the earth grows outward from mid-ocean ridges. Ultimately it plunges into the mantle below, giving rise to oceanic trenches, earthquakes, volcanoes, island arcs and mountain ranges

By M. Nafi Toksöz

The Synthesis of Diamond at Low Pressure

Natural diamonds and most man-made ones form at high pressure. It is also possible to synthesize diamond by growing it from existing diamonds in a low-pressure gas rich in carbon

By B. V. Derjaguin and D. B. Fedoseev

The Role of Pupil Size in Communication

Changes in attitude can be detected by measuring changes in pupil size. It now appears that enlarged or constricted pupils can also affect the attitude and responses of the person who observes them

By Eckhard H. Hess

Departments

  • 50 and 100 Years Ago, November 1975

  • Science and the Citizen, November 1975

  • Letters

    Letters to the Editors, November 1975

  • Recommended

    Books, November 1975

  • Mathematical Recreation

    Mathematical Games, November 1975

  • Amateur Scientist

    The Amateur Scientist, November 1975

  • Departments

    The Authors, November 1975

  • Bibliography, November 1975

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November 1975

Think Outside the Gift Box