Word: gradient
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Some insist that climbing brings man closer to God. Jerome is not sure. But he does believe that mountains help man to appreciate both his planet and himself. "Gradient is the elixir of youth," declares a geologist, and he may be right. Flatlands, worn down to sea level by gravity and the forces of time, are old, almost senile. Mountains, no matter how ancient, are new and dynamic. No one can spend much time with them - or with Jerome's high-minded volume - without feeling the same...
...energy. Light striking a pigment molecule causes it to eject a hydrogen ion-or proton-that passes through the cell's membrane. The movement of the positively charged protons through the membrane leaves an excess of negative charge on one side of the membrane. That produces a voltage gradient and results in an electrical current flowing through the membrane. In the process, which involves at least five separate steps, each bacteriorhodopsin molecule pumps out a proton every 250th of a second and provides the energy the organism needs to synthesize adenosinetri-phosphate (ATP), the energy-storing molecule common...
...informosomes was impossible because Kafatos was dealing with such minute amounts of particles. Finally he turned to a method for testing a particle's density devised ten years ago by Harvard's Matthew Meselson, professor of Biology. Particles are placed in a centrifugal tube containing a salt gradient, a solution with various density levels. Kafatos used a centrifuge capable of creating a gravitational field 400,000 times greater than that of the earth. The particles soon settle to the level of the solution which has the same density...
...flight path, the sensor can detect temperature variations as small as a fraction of a degree Fahrenheit in atmospheric carbon dioxide at a range of from 24 to 48 miles. These variations register on three side-by-side cockpit gauges that show the pilot whether a temperature gradient lies directly ahead or 45° to the left or right of his flight path...
...determined, it is relatively easy to detect changes in the spacecraft's known configuration. In June, RSA was employed to discover which of four solar panels on a secret Air Force satellite had not flopped into place. When telemetry failed to confirm that a boom on a gravity gradient satellite had extended, RSA recognized a change in the radar pattern that proved the boom had stretched into place. A study of the radar echoes reflected from the first Nimbus weather satellite provided tumble and spin data that were unavailable from telemetry...