The Growth of Core Regions in the Third World
They contain much of the industry and most of the major cities. Since 1950 core regions in developing nations have been gaining population at a rate that poses grave social and economic problems
Volume 252, Issue 4
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Features
The Earth's Hot Spots
These plumes of hot rock welling up from deep in the mantle are a key link in the plate-tectonic cycle. The marks they leave on passing plates include volcanoes, swells and midocean plateaus
The Release of Acetylcholine
The compound carries a nerve impulse across a synapse. Recent studies of the electric fish Torpedo suggest that the source of the acetylcholine emitted by a neuron is the cytoplasm rather than the synaptic vesicles
Elementary Particles and Forces
A coherent view of the fundamental constituents of matter and the forces governing them has emerged. It embraces disparate theories, but they may soon be united in one comprehensive description of natural events
Compartmentalization of Decay in Trees
Animals heal, but trees compartmentalize. They endure a lifetime of injury and infection by setting boundaries that resist the spread of the invading microorganisms
The Clouds of Magellan
The nearest neighbors of our galaxy have had a turbulent history. Close encounters with each other and with the Milky Way have split the smaller cloud and drawn out an enormous stream of hydrogen gas
Anesthesiology
Rendering the patient insensitive to pain is still an essential part of the anesthesiologist's work; another major function is to maintain the stability of the patient's vital-organ systems
The Parsons Steam Turbine
Invented in 1884 by Charles A. Parsons, son of an aristocrat and scientist, it revolutionized shipping and the generation of electric power. Many of Parsons' innovations are still in use