The Patient Record in Epidemiology
The most accurate estimates of the rate of many diseases come from studies based on a huge collection of patient records at the Mayo Clinic. The records are indexed for retrieval by diagnosis
Features
An Early Habitat of Life
Microorganisms may have flourished on tidal mud Bats 3.5 billion years ago. The environment can be reconstructed from sedimentary deposits in Australia, but the evidence of life remains tentative
Gravitational Waves from an Orbiting Pulsar
Einstein's 1915 prediction that an accelerating mass should radiate energy in the form of gravitational waves is supported by evidence that a pulsar's orbit around a companion star is slowly shrinking
Neuropeptides
They are short chains of amino acids that are active in the nervous system. In some cases they transmit signals between nerve cells and also serve the body as a hormone
The Acoustics of Violin Plates
Modern tests of the vibrational properties of the unassembled top and back plates of a violin reveal something of what violinmakers do by "feel" and lead to the making of consistently good violins
Vitruvius' Odometer
A machine for measuring mileage that the Roman engineer described but may never have seen proved puzzling to Leonardo 1,500 years later. It may have been invented by Archimedes during the first Punic War
Quantum Logic
In the quantum theory classical patterns of inference break down. Mathematical structures called lattices can model alternative roles for the words "and" and "or" that may fit the world more coherently
Image Processing by Computer
When the information in an image is expressed in digital form, it can be manipulated mathematically rather than optically. By such methods a blurred photograph can sometimes be restored to clarity
Departments
50 and 100 Years Ago: October 1981
Science and the Citizen, October 1981
- Letters
Letters to the Editors, October 1981
- Recommended
Books, October 1981
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist, October 1981
- Departments
The Authors, October 1981
Bibliography, October 1981