U.S. Economic Growth
It can be enhanced by improving workers' skills, supporting research and development and encouraging investment in capital that applies technological innovations
Volume 258, Issue 6
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Features
"Snurps"
The name stands for small nuclear ribonucleoproteins, particles that help to remove meaningless Hintrons" from the messages issued by a cell's genes. Without them cellular activity would grind to a halt
Particle Accelerators Test Cosmological Theory
Is there a limit to the number of families of elementary particles? Debris from the big-bang origin of the universe suggests there is, and accelerators are reaching the energies required to confirm the limit
Perovskites
Many of the new high-temperature superconductors belong to a family of ceramics called perovskites. The adaptable perovskite structure gives rise to materials that have a wide array of electrical properties
Bacteria as Multicellular Organisms
They differentiate into various cell types and form highly regular colonies that appear to be gUided by sophisticated temporal and spatial control systems
Polynyas in the Southern Ocean
They are vast gaps in the sea ice around Antarctica. By exposing enormous areas of seawater to the frigid air, they help to drive the global heat engine that couples the ocean and the atmosphere
The Neurobiology of Feeding in Leeches
A single neurotransmitter, serotonin, orchestrates feeding behavior in the medicinal leech. The discovery may illuminate how neurochemicals control behavior in other animals
Early Iron Smelting in Central Africa
More than 2,500 years ago the people near Lake Victoria began smelting iron in tall furnaces that produced a remarkable heat. The authors unravel the workings of this ancient technology