|Greenhouse Real, |
and Black Holes!
|Increase in Greenhouse Gases Seen From Space|
|By Patricia Reaney |
LONDON March 14, 2001 (Reuters) - Scientists dispelled any lingering doubts about the increase of greenhouse gases in the atmosphere Wednesday with new evidence from satellites orbiting the Earth.
Until now researchers have depended on ground-based measurements and theoretical models to gauge the change in greenhouse gases, believed by scientists to be the cause of global warming and major climate disruption.
New sets of data taken 27 years apart from two satellites orbiting the Earth have now provided the first observational evidence from space of a rise in greenhouse gases.
"We've seen greenhouse gas increases that we can link to a change in outgoing long-wave radiation, which is believed to force the climate response," said Dr. Helen Brindley, an atmospheric physicist at Imperial College in London.
By comparing the two sets of data, Brindley and her colleagues have shown a change in greenhouse gas emissions from Earth over 27 years which is consistent with ground-based measurements.
REAL DIFFERENCES OVER 27 YEARS
The comparison of the data, reported in the science journal Nature, shows real differences over 27 years in the outgoing long-wave radiation which can only be due to greenhouse gases.
The scientists compared data for a region over the Pacific Ocean and the entire globe to calculate the differences in the levels of atmospheric methane, carbon dioxide (CO2), ozone and chlorofluorocarbons.
"Because we know where in the spectrum certain greenhouse gases are observed, when we look at the changes between the two periods we can say that change is due to changes in CO2 or methane," Brindley said in a telephone interview.
"There has been quite a significant change over the past 30 years, particularly in methane."
One of the most powerful greenhouse gases, methane, is emitted from landfill sites and disused mines.
The scientists took into account the influence of clouds and seasonal variations, so the changes they observed could only be explained by long-term changes in greenhouses gases, they said.
"It's the first time that we have seen observationally that these changes are really having an effect on the radiative forcing of the climate," said Brindley.
Radiative forcing is the measure of the climate effects of greenhouse gases.
"Since these are the models used to predict future climate and influence policy decisions, it is imperative that they can accurately simulate measurements of what is considered to be the driving mechanism behind climate change," said Professor John Harries, the first author of the Nature study.
Without significant reductions in greenhouse gas emissions, scientists estimate the Earth's temperature and sea levels will rise, leading to increased flooding and drastic climate changes.
Industrialized nations agreed to cut their emissions of greenhouse gases under a plan agreed in Kyoto, Japan in 1997 but talks in the Hague in November to finalize details broke down.
|Tourists Head for Mir Re-entry Site|
|MOSCOW March 16, 2001 (AP) -- After reluctantly deciding to dump the aging Mir space station, Russian controllers chose a spot for re-entry along a swath of the South Pacific, far, far from the nearest inhabited land. |
But it's not off-limits to determined tourists.
Herring Media Group, a Sausalito, Calif.,-based public relations firm, has chartered a plane for space enthusiasts and television crews to fly to the site -- a trip Russia's space agency director compares to a suicide jump off a bridge.
Organizers claim the flight is safe, and want to film the spectacle of burning space station debris streaking toward Earth. The 143-ton cluster will be the largest man-made object ever to enter the atmosphere.
Once the pride of the Soviet Union, Mir is scheduled to come down March 22 in a target zone about halfway between Australia and Chile, according to Russia's Mission Control.
More than 50 people have paid about $6,500 each, slightly more for a window seat, to see the historic event, according to company director Marc Herring. The price includes a few nights on the Pacific Island of Fiji before and after the show, a steak barbecue to honor Herring's Texas roots, drinks on the plane and a promised "bash'' once the station is down. Four Russian cosmonauts will be on board to see the fiery death of their former home in space, which they dubbed an "apartment.''
"We'll see a bright, meteor-like object on the horizon with a smoke trail coming toward us, then a series of explosions of the pressurized vessels and a glow as the station fragments into multiple parts and rains down,'' Herring said.
Russian Aerospace Agency Director Yuri Koptev maintains any trip to the target zone would be foolhardy, stressing that the area was chosen to minimize risk to people and property on Earth. Still, the space agency can't stop people from going there.
"People used to kill themselves by jumping from the Brooklyn Bridge,'' Koptev said. "Apparently these people are driven by a spirit of adventure, but we would recommend that they not go there.''
But Herring said the plane, either a jet or a turboprop, should never be closer than about 200 miles from the falling space junk.
A navigator will call Russian Mission Control on a satellite phone minutes before the station breaks up, when the final re-entry coordinates are known, and the pilot can skedaddle out of range if necessary, he said.
"It's the sort of thing you shouldn't try at home,'' Herring quipped.
The unoccupied station still contains a guitar cosmonauts strummed to pass time during their record-setting long stays in space. Russian Orthodox icons adorn the walls, just as Russian ships were decorated in past centuries. The station carries a library of more than 400 books, including Russian classics, detective stories and technical manuals.
These items will likely incinerate in a puff in the upper atmosphere, but about 1,500 chunks of metal weighing a total of about 27.5 short tons are expected to survive re-entry, according to Russian space officials.
When the unoccupied U.S. Skylab space station fell to Earth in 1979, debris came down on a sparsely populated area in western Australia, creating sonic booms and whirring noises audible to people on the ground as it fell. No one was hurt.
Web chatrooms are buzzing with comments on Mir's demise. One contributor asked if anybody had purchased "Mir insurance,'' recalling that Skylab insurance was sold in the 1970s. Another much-discussed topic: dangerous microbes on the station spreading to earth.
Molds and bacteria live on the station, and one particularly virulent strain has corroded Mir's windows. But the germs pose no danger to Earth's environment, Russian space officials say.
In the months before the Skylab's demise, two American computer specialists established a firm called Chicken Little Associates, offering to predict, for a fee, the likelihood of the station hitting a particular house or point on the Earth's surface. The chances were all minuscule.
This time around in Moscow, the Troika Dialog brokerage, which usually places bets on the gyrations of the Russian stock market, is sponsoring a contest to guess how close the Mir will come to the hometown of one its chief analysts, Tom Adshead, from Christchurch, New Zealand.
New Zealand is not under the station's flight path, and the brokerage stressed the contest was in jest.
|Galileo Spacecraft Gets a Final NASA Mission|
|WASHINGTON March 16, 2001 (REUTERS) - The intrepid Galileo spacecraft, which has been orbiting Jupiter for more than five years, will observe the Jovian moons before being sent on a death plunge into the crushing pressure of the giant planet's atmosphere in 2003, NASA said on Thursday. |
This marks a third -- and final -- mission extension for Galileo, which was launched in October 1989 aboard the space shuttle Atlantis. NASA said the little spacecraft will make five more fly-bys of Jupiter's moons before its final dive into the solar system's largest planet.
"We're proud that this workhorse of a spacecraft has kept performing well enough that we can ask it to keep serving science a little longer,'' Jay Bergstralh, NASA's acting director of solar system exploration, said in a statement.
NASA said Galileo should pass on May 25 about 76 miles above the moon Callisto, the second-largest of Jupiter's 28 known moons. The effects of Callisto's gravity will send the space probe on a swing in August and October over both polar regions of Io, an intensely volcanic moon.
Galileo is due to take pictures, measure magnetic forces and study dust and smaller particles, NASA said. The spacecraft also will examine the extent of past and present volcanism on Io, seek to determine whether Io generates its own weak magnetic field, and study a doughnut-shaped ring that encircles Jupiter and contains electrically charged gases, NASA said.
WEALTH OF DATA
In 2002, Galileo will continue studies of Jupiter's massive magnetic field, before swinging that November closer to Jupiter than ever before, dipping within about 300 miles of the moon Amalthea, the space agency said.
Scientists will use Galileo measurements to determine the mass and density of Amalthea, which is less than one-tenth the size of Io and less than half as far from Jupiter.
Galileo's final orbit will take an elongated loop away from Jupiter. Then in August 2003, the spacecraft will head back for a direct impact and burn up as it plows into Jupiter's atmosphere, NASA said.
Galileo has amassed a wealth of information during its trek. It has produced evidence that the moon Europa has a melted salt water ocean under the ice layer on its surface, and that moons Ganymede and Callisto also boast layers of liquid salt water.
|Man Survives Fall But Lands Beside Corpse|
|LONDON March 14, 2001 (Reuters) - A British man who jumped off a cliff survived a fall of nearly 400 feet -- but landed on a ledge next to a badly decomposed body. |
Rescuers said the 22-year-old man had suffered serious and extensive injuries and it was miraculous that he was still alive after falling such a distance.
"To live at all is a miracle but to land so close to a dead body is just amazing," a coastguard spokesman told Reuters.
The drama began when police and coastguards were called to Shakespeare Cliff at Dover on England's southeast coast on Tuesday night when the man was spotted behaving erratically.
Despite their attempts to calm him he leapt over the cliff edge. "The man survived the plunge but landed close to another body. It was very much decomposed," the spokesman said.
The grisly find was made by a paramedic who went to the aid of the man as he lay injured on the ledge about 30 feet from the bottom of the white chalky cliff.
The man was taken to hospital with multiple injuries but his condition was stable, officials said.
A spokesman for Dover police said officers did not know the identity of the dead man.
|Study Backs Freud Repression Theory|
|By ALEX DOMINGUEZ |
Associated Press Writer
March 14, 2001 - An experiment found that people can push an unwanted memory out of their minds, lending credence to Sigmund Freud's theory of repression.
In the study, college students who had memorized pairs of words were later shown half of the pair and were asked to either say the corresponding word or try to forget the second word.
The more the participants were asked to put words out of their minds, the less likely they were to recall the word later, even when paid to remember the word.
The University of Oregon study is one of two on memory appearing in Thursday's issue of the journal Nature. In the second study, which was conducted on rats, researchers found that the growth of new neurons in a part of the brains known as the hippocampus is necessary to form memories relating two events separated over time.
Martin Conway, a psychologist at the University of Bristol in England, said in an accompanying commentary that the Oregon research supports Freud's theory about the mind's ability to repress thoughts, especially painful or disturbing ones.
"Even more surprising is that this occurs for unrelated pairs of words,'' Conway said. "How much stronger must this inhibition be for objects central to our thoughts and emotions.''
Michael Anderson, who led the study of 32 students, said the participants were about 10 percent less likely to remember the second word after 16 attempts to repress the memory, a figure he said he expected would climb if repression continued.
The work supports the findings of a colleague who found that children were less likely to remember abuse at the hands of a parent or guardian than a stranger, possibly because they had to forget in order to be able to cope with their daily routine, Anderson said.
However, the researcher admitted that memorizing word pairs is far from the type of memory associated with painful events such as child abuse.
"What we really need to do is see if the same effect occurs for emotionally more significant material,'' Anderson said. "That's a very important step we have to take. I wouldn't really say we've solved the repression problem here. It's just a good start.''
In the rat study, Tracey Shors of Rutgers University said rats were not as likely remember the connection between two events separated by time if given a drug that cuts the production of neurons in the hippocampus, an area of the brain used in the formation of some types of memory.
Eighteen rates were given the drug.
The brains of both rats and humans have a hippocampus, and the study is the first to show in mammals that new neurons are used in memory formation, though previous work has shown the connection in birds, Shors said.
Shors said previous work has shown that the learning of certain tasks made cells in the hippocampus live longer. The current work found that these cells are needed for some types of memory.
Jeffrey Mackliss, a neurobiologist at Harvard Medical School, said the experiment supports both the concept that the production of neurons is necessary for some types of memory formation and the idea that it may one day be possible to treat some diseases of the nervous system with neurons.
|Tuna Makes Bad Burgers|
|CHICAGO March 13, 2001 (AP) — Tuna burgers may be hazardous to your health, according to a government study that traced food-poisoning outbreaks in North Carolina to the relatively new menu item. |
Made with ground tuna, the burgers may be especially susceptible to contamination with histamine, a chemical produced by bacteria.
The grinding process can mix bacteria into the fish or increase the tuna's temperature through friction, the researchers reported in Wednesday's Journal of the American Medical Association.
Affected fish may appear and smell normal, and cooking does not destroy the toxicity.
"A simple and cost-effective test that is sensitive enough to detect contamination before a health problem occurs is needed,'' said the researchers, led by Karen Becker of the Centers for Disease Control and Prevention.
From 1994 to 1997, North Carolina averaged no more than four cases a year of histamine, or scombroid, poisoning. But in an eight-month period in 1998-99, 22 cases involving tuna were reported. All but one were linked to restaurants. Eighteen of the patients had eaten tuna burgers.
Sophisticated tests showed histamine levels far above Food and Drug Administration limits.
Most cases were blamed on inadequate refrigeration. One restaurant did not properly sanitize a grinder.
Symptoms may include mouth tingling, an upper body rash, vomiting and heart palpitations. None of the patients suffered serious complications.
On the Net:
|Black Holes Once Ruled the Universe, Astronomers Say|
|By Deborah Zabarenko |
WASHINGTON March 13, 2001 (Reuters) - Astronomers looking back in time reported on Tuesday that the early universe was probably dominated by three things: "black holes, black holes and black holes."
|California to Celebrate Prunes No More|
|YUBA CITY, Calif. March 14, 2001 (Reuters) - Pity the poor prune. Celebrated for years as one of California's most important crops, the prune this year will find itself on the sidelines, wrinkled, dried out and ignored. |
Instead, California's Sept. 8-9 Dried Plum Festival -- formerly known as the California Prune Festival -- will be dedicated to the prune's more presentable persona, the "dried plum."
"This is a change that is going on throughout the United States, so we felt we needed to follow suit," Bree Gianassi, managing director of the California Dried Plum Festival, said on Tuesday.
Hoping to escape the medicinal whiff of the term "prune," U.S. growers won Food and Drug Administration permission to begin marketing the product as "dried plums" to pitch it as a healthy snack.
|Humans Have Apes to Thank for Colorful World|
|By Patricia Reaney |
LONDON March 14, 2001 (Reuters) - Humans have apes and monkeys to thank for their acute sense of color, scientists in Hong Kong said on Wednesday.
If our primate ancestors had not needed to distinguish red from green to survive -- to find tasty ripe fruit and nutritious leaves in forests -- humans may not have evolved with the ability to enjoy such a colorful world.
"We humans owe our unique color vision to our primate ancestors," Nathaniel Dominy, of the University of Hong Kong, said in an Internet interview.
Apes and monkeys from Africa and Asia can see vivid reds, greens and blues just like humans in contrast to all other non-primate mammals. Dominy and his colleague Peter Lucas studied four species of Old World primates in Uganda to find out why.
"Our study is the first to link a nutritional value with primate food colors," said Dominy.
In research reported in the science journal Nature, the scientists monitored the eating habits of primates in the Kibale Forest in Uganda to see how their ability to see colors influenced which fruits or leaves they ate. Distinguishing the healthiest food is essential for primates to survive.
Dominy and Lucas found that apes and monkeys can choose fruit using only yellow/blue vision but the animals had to see red and green to find the most nutritious young leaves which often have a tinge of red that sets them apart from the green forest.
"We found that a primate lacking the ability to discriminate red-green could still detect ripe fruits but not red leaves. There is value to this because young leaves are rich in protein and easier to chew. All primates, even those that eat mostly fruits, have to rely on young leaves during the year when fruits are unavailable," Dominy explained.
But he added that more humans suffer from color blindness than monkeys so we may be losing our ability to distinguish red from green.
Only about three percent of monkeys are red-green color blind compared to eight percent of Caucasian males.
"So it looks like the selective pressure on we humans has been relaxed, perhaps because we have lived outside the forest for some time now," he added.
|Doctor Who Left Towel in Man Pays|
|HOUSTON March 16, 2001 (AP) -- A man suffering from colon cancer received $400,000 in a lawsuit settlement with a doctor who stitched him up after surgery but left a towel in his abdomen. |
William R. Miller Jr. complained of pain after the operation at the University of Texas M.D. Anderson Cancer Center in 1999. Doctors waited 73 days before they performed exploratory surgery and found the towel wrapped around his small intestine.
Miller, 70, settled the medical malpractice suit against Dr. John Skibber before it went to trial this week.
Ben Martin, a Dallas lawyer representing Miller, said the $400,000 settlement was fair, given a section of Miller's small intestine was damaged by the towel and had to be removed during the surgery.
"It was a very unfortunate mistake,'' the doctor's lawyer, Frank Doyle, said. "Dr. Skibber was very apologetic.''
As a standard procedure, the towel had been wrapped around the small intestine to keep it away from the colon during surgery.