‘Twin Sister’ mechanism prevents formation of genetic mutations

Twenty thousand hits per day — that’s the average dose of damage sustained by the genes within each cell of our body. How are innumerable mutations avoided? In a new study, researchers have proved the existence of a vital repair mechanism used by cells to correct this damage and showed that it’s responsible for about 85% of what are termed “last-resort” repairs. Genes can be damaged by a variety of factors, such as ultraviolet light, cigarette smoke, or certain types of viruses. Such damage, if left unrepaired, can cause mutations, which can lead to disease. The “first resort” for genetic repair is most often a mechanism that works on an “all or nothing” basis: when unable to precisely correct the damage, it stops in its tracks, leading to what can be an even more harmful effect ? the death of the cell. Fortunately, nature has provided cells with two alternative, last-resort repair systems that can take command when the first rescue mechanism fails.

Asian dust storm causes plankton to bloom in the North Pacific

The plankton, my friend, is blowin' in the wind...In the spring of 2001, two robotic Carbon Explorer floats recorded the rapid growth of phytoplankton in the upper layers of the North Pacific Ocean after a passing storm had deposited iron-rich dust from the Gobi Desert. The carbon measurements, reported in the October 25 issue of Science, are the first direct observation of wind-blown terrestrial dust fertilizing the growth of aquatic plant life.

NASA Music Out of this World

With scientific instruments on NASA’s Voyagers, Galileo, Cassini and more than two dozen other spacecraft, University of Iowa physicist Dr. Don Gurnett has been recording waves that course through the thin, electrically charged gas pervading the near-vacuum of outer space. Gurnett converted the recorded plasma waves into sounds, much as a receiver turns radio waves into sound waves. “I’ve got a cardboard box full of cassette tapes of sounds that I’ve collected over nearly 40 years,” he said. Gurnett’s tapes have inspired a 10-movement musical composition called “Sun Rings.” The Grammy-nominated Kronos Quartet will premiere “Rings” this month.

Experimental ‘Gene Switch’ Increases Lifespan

By experimentally switching genes off or on at specific stages in an animal’s lifecycle, California scientists have discovered that vigor and lifespan can be significantly extended with no side effects. Many researchers believe that increasing lifespan will dampen reproduction. But the new study of the tiny roundworm commonly known as C. elegans shows that silencing a key gene only in adulthood increases longevity with no effect on reproduction.

Snuff, smoking hold adjacent risks

As tobacco companies campaign to promote smokeless tobacco as a safer alternative to cigarettes, many smokers who take up snuff in an effort to quit instead end up using both products, according to a Florida researcher. Further, nonsmokers who use snuff are more likely than those who don’t to eventually begin smoking.

Acidic aerosols greatly increase secondary aerosol formation

Atmospheric particles that become acidic through exposure to such pollutants as sulfuric acid can lead to vast increases in the formation of secondary organic aerosols, a new study indicates. Such aerosols are major components of the unsightly haze that hangs over cities and oil refineries and even affects otherwise pristine U.S. national parks.

Better detection, not global warming, behind iceberg increase

I've been here all along.Contrary to an opinion held by some researchers, a new analysis of more than 20 years of historical data has found no evidence that the increasing number of large icebergs off Antarctica’s coasts is a result of global warming trends. “The dramatic increase in the number of large icebergs as recorded by the National Ice Center database does not represent a climatic change,” said Brigham Young University’s David Long. “Our reanalysis suggests that the number of icebergs remained roughly constant from 1978 to the late 1990s.” Using BYU’s supercomputers, Long enhanced images of the waters around Antarctica transmitted by satellite. Comparing this data to records from the federal government’s National Ice Center, which tracks icebergs larger than ten miles on one side, he determined that previous tracking measures were inadequate, resulting in a gross undercounting.

Mild Injury May Render Brain Cells Vulnerable to Immune Attack

A seemingly mild “insult” to the brain could sensitize neurons to attack by immune system proteins that are otherwise protective, researchers have found. The finding could explain why sufferers of Alzheimer’s and other neurodegenerative diseases significantly worsen following such insults. The scientists believe that drugs to selectively inhibit the immune proteins could reduce the rate of neural damage in a wide range of neurodegenerative diseases. Such drugs could also protect other organs against damage from autoimmune diseases such as lupus and rheumatoid arthritis, in which the immune system attacks body tissues.

Researchers Discover ‘Doorways’ Into Brain Cells

Come on in, we saved a place for youBrain cell membranes have established “doorways” that accept or reject molecules trying to pass into the cell, researchers have founbd. The discovery fundamentally changes how researchers think about the behavior of neurons. It had been long believed that surface molecules such as receptors are enveloped right where they rest in the fatty membrane, to be drawn into the cell’s interior.

NASA to Develop Biohazard ‘Smoke’ Detector

Researchers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., have demonstrated a prototype device that automatically and continuously monitors the air for the presence of bacterial spores. The result is a novel alarm capability reminiscent of smoke detectors. Current methods for detecting bacterial spores, such as anthrax, require a trained operator. The large number of trained monitors required, with associated costs, limits widespread implementation of these methods.

Men more dependent on exercise than women

Women may worry more about their weight, but it’s men who are more likely to become hooked on exercise, a study shows. College dudes are more likely to exercise to excess — and get tense and irritable if they were deprived of their workouts. The research among 408 university students also found that men who worked out for the benefit of feeling better physically and mentally — rather than to look better or improve their performance — were more likely to become dependent on the need to exercise excessively.

Isoflavone-enriched soy fails to increase bone density in young women

In a study sure to disappoint the soy industry, researchers say they’ve found that soy protein enriched with isoflavones appears to have no effect on bone mineral content and bone mineral density in young women. Isoflavones are chemicals made by plants, possibly to protect them against oxidation and organisms that might attack them, and soy beans are an especially good source. Isoflavones such as genistein are structurally similar to human estrogens and for that reason have some estrogen-like properties. Scientists and drug companies have become increasingly interested in them over the past few years since the naturally occurring chemicals seem to produce positive effects in bone without the negative impact, such as cancer, that estrogens are believed to have on reproductive organs in some women.

Anchorage Area Fault May Be Due for 6 or 7 Magnitude Quake

A new study by the U.S. Geological Survey (USGS) shows that the Castle Mountain fault in south-central Alaska may be ready to produce a strong magnitude 6 to 7 earthquake. Peter Haeussler, the principal investigator in the study, said his research demonstrated that major earthquakes occurred on this fault on average every 700 years or so in the last 2,700 years, and that the last significant earthquake along the fault occurred about 650 years ago. The Castle Mountain fault is the only active fault that comes to the earth’s surface in the Anchorage region, and the eastern part of the fault produced light to moderate magnitude 5.7 and 4.6 earthquakes in 1983 and 1996.

Progress Made by Seismologists in Identifying Violations of Nuclear Test Ban

Detection techniques and technology have improved so much in recent years that seismologists now say they are able to detect and identify virtually all events that might be nuclear explosions of possible military significance under the Comprehensive Test Ban Treaty. Verification was a major issue in the U.S. Senate debate in 1999, in which American ratification of the treaty was defeated.