LOS ANGELES (Reuters) -- Scientists from five nations gathered at a "mission control center" at the University of California at Los Angeles (UCLA), anxiously waiting for the Mars Polar Lander mission to touch down on Friday.
Lander Like New BabyThe team's first task is to assess the area where the lander has set down, mainly from pictures sent back through NASA's Deep Space Network of giant tracking stations.
"The lander is like a new baby. It's just been born and you want to make sure everything is working well. We want to be cautious at first. We'll be monitoring really closely those first couple of days, not doing as much science as we'd like. But then, once we get our confidence up, we'll start doing a lot," Paige said.
Martian days, or "sols," are 37 minutes longer than Earth's. The day of the landing is referred to as sol 0. While NASA scientists hope everything goes well, the agency is prepared for set-backs and delays. In a press release it said that "a highly optimistic scenario" might include landing and getting basic spacecraft operations going on sol 0. "And then perhaps exercising the robotic arm for the first time on sol 2."
It warned, however, "If the flight team has to deal with any spacecraft anomalies...science operations such as exercising the robotic arm might be delayed up to perhaps a week."
But if everything goes well and the Mars Polar Lander touches down with the help of its cluster of retro rockets after a journey of 11 months, it will start sending signals from experiments that will be analyzed by the international team of experts.
The Russian Academy of Science's Space Research Institute "Lidar" experiment is the first to be sent into space on a United States craft. Using pulses of light from a laser it will measure the amount of dust and ice in the lower Martian atmosphere about one to two miles above the surface.
MOSCOW -- There are only half as many scientists in Russia today as there were nine years ago, admitted the science minister, Mikhail Kirpichnikov, last week. But he said that Russia was not the only country to suffer from a brain drain, and that only 1.6 per cent of those who left science had also left the country. Speaking in the State Duma, the lower chamber of parliament, Kirpichnikov said there had been no brain drain in the past two years. One reason was that in 1999 scientists' salaries had passed the Russian average for the first time. The Duma had increased the state budget for science by 2.5 billion rubles (US$100 million) for 2000.
ZURICH, Switzerland (AP) -- Juergen Moser, an American mathematician recognized worldwide for proving a theory on the workings of the solar system, has died. He was 71. Moser died of cancer last Friday in Zurich, family members said at his home in the Zurich suburb of Schwerzenbach. "He was one of the leading mathematicians of the postwar era," Konrad Osterwalder, a colleague at Switzerland's prestigious Federal Institute of Technology, wrote in an obituary in the daily Neue Zuercher Zeitung. In 1994, Moser was awarded the Wolf Prize in Mathematics for his work in the 1960s analyzing the stability of the solar system. Moser is credited with proving a general theory on celestial mechanics by the Russian mathematician Andrei N. Kolmogorov that the gravitational pull of distant planets may have no apparent effect on elliptical orbits in space. Kolmogorov offered no proof, but his student, V.I. Arnold, provided one and Moser another. As a result the theory is known as Kolmogorov-Arnold-Moser. Moser's work was important to the understanding of the solar system and to the development of particle accelerators, which have allowed scientists to test many theories about nature's tiniest building blocks. Born July 4, 1928, in Koenigsberg, then an eastern outpost of Germany and now the Russian city of Kaliningrad, Moser studied at the University of Goettingen in West Germany before going to the United States on a Fulbright fellowship in 1953. Moser, who became a U.S. citizen, was a research associate at New York University in 1957 when he left to become visiting professor at the Massachusetts Institute of Technology. He returned to New York University in 1960, becoming a professor at the Courant Institute of Mathematical Sciences. He was the institute's director from 1967 to 1970 and remained a professor there until 1980. Moser then went back to Europe, becoming a teacher and researcher at the Swiss technology institute. He served as director of its Research Institute for Mathematics until 1995, when he was made professor emeritus. From 1983 to 1986, he was president of the International Mathematical Union.
Brains Of Those In Certain Professions Shown To Have More Synapses
CHAMPAIGN, Ill. -- Education not only makes a person smarter, it may generate a specific type of synapse in the prefrontal cortex of the brain, Illinois and Russian neuroscientists say.
"There clearly were more synapses found in subjects with intellectually skilled professions, such as engineering or teaching," said James E. Black, who is part of a team examining post-mortem brain tissue at the University of Illinois Beckman Institute for Advanced Science and Technology. "With our approach, however, we can't determine if extra professional experience actually caused new synapses to form, or if people with more synapses tended to choose challenging professions." The team's preliminary findings were presented in late October at the 29th annual meeting of the Society for Neuroscience in Miami.
Black and his Russian colleagues used an electron microscope that allowed for a systematic count of brain cells (neurons) and synapses (the connections between neurons) in 16 healthy people. Based on family interviews, the subjects were then divided by their profession and amount of education, with a high-level category corresponding to skilled occupations requiring more than a high school degree. The researchers examined tissue from the uppermost layers of the prefrontal cortex - an area of the brain used in complex reasoning - and counted two different types of synapses. They also examined the same types of synapses in occipital cortex, an area involved in simple visual perception.
Subjects with more professional training had 17 percent more synapses for each neuron than did their less educated counterparts. Synapse formation is thought to be a means of storing the information obtained through experience.
"The animal literature strongly indicates that experience can drive the formation of new synapses," said Black, a physician and professor of clinical psychiatry at the U. of I. at Chicago and a professor of neuroscience and psychology on the Urbana-Champaign campus.
A study by Arnold Scheibel of UCLA found a correlation between education and neuron branching in another brain region, a finding that would support the synapse data. "Because humans learn an enormous amount of information during development, there is good reason to think that they store this information in the form of new synaptic connections between neurons," Black said.
No significant differences were found in the subjects' occipital cortex or in the numbers of the second type of synapse, suggesting that professional training may affect only certain types of synapses.
The study is part of a larger project examining brain changes that may be related to schizophrenia, which affects synapses in the prefrontal cortex. While schizophrenia can greatly interfere with a person's quality of life, Black said, new medications offer a good possibility of recovery.
The research team includes Dr. Natalya Uranova and colleagues in Moscow, and Black, Anna Klintsova and William T. Greenough of the U. of I.
WASHINGTON, (Reuters) -- Bacteria may lurk underneath the surface of a frozen Antarctic lake, having survived for millions of years without light or outside oxygen, researchers report. Three separate studies in this week's issue of the journal Science show evidence of bacteria in Lake Vostok, a large lake found only in 1974 in Antarctica. The finding adds support to the possibility that life may exist on other planets. For example, a frozen lake on Jupiter's moon Europa has a slushy lake that scientists think is a likely haven for life. David Karl of the University of Hawaii and John Priscu of Montana State University looked at ice drilled out from about 11,700 feet below the surface of the lake. They found DNA from bacteria in what they believe to be lake water that was once thawed and re-froze. An analysis that Priscu's team did on the DNA indicates that although the bacteria have been isolated for millions of years, they are biologically similar to known organisms. "Our research shows us that the microbial world has few limits on our planet," Priscu said in a statement. Scientists have found bacteria thriving in ice, in steaming undersea vents and in hot sulfur springs. They have been found living under huge pressure buried deep inside the Earth, and far from light at the bottom of the ocean. "If a similar ice layer is present under the surface of Europa's icy oceans, it may also harbor life," Chris McKay, a planetary scientist at NASA Ames Research Center in Moffett Field, California, said in Radar and sonar mapping suggests that liquid water may exist at the bottom of Lake Vostok, perhaps warmed by the pressure of thousands of feet of ice above or by geothermal sources below. Russian teams have drilled into the ice covering the lake, but stopped several hundred meters above what was believed to be the level of liquid water, for fear of contaminating it. International researchers have been debating how best to proceed. "We don't know what's in Lake Vostok, and we may never know, if we don't get the contamination issues solved," Karl said.
Team Led By MSU Biologist Finds Bacteria Deep In Antarctic Ice
And if microbes exist on other planets, such as in the frozen ocean thought to exist on Jupiter's moon Europa, finding them could be similar to hunting for them in Lake Vostok, the scientists say.
BOZEMAN, MT -- A team led by Montana State University biologist John Priscu has discovered bacteria in an ice core drilled from deep within a frozen Antarctic lake.
The bacteria came from Lake Vostok, a subglacial body of water the size of Lake Ontario resting more than two miles under the East Antarctic ice cap. "From a biologist's perspective, this is the Holy Grail of lake biology," Priscu said before leaving Montana for another field season on the frozen continent. "Our findings indicate that the microbial world has few limits on our planet."
Priscu's team, along with two other groups studying Vostok ice, will publish its findings in the Dec. 10 issue of the journal Science. The team includes seven MSU scientists plus scientists from the University of Alabama, the U.S. Geological Survey and the NASA Ames Research Center. The Vostok ice is among the deepest ever explored for life, Priscu said, and could be a model for searching for life in frozen environments elsewhere in the solar system. "You don't have to leave the planet to study this completely unexplored system, but the samples sure aren't easy to get," Priscu said of the Vostok core, drilled by Russian scientists and distributed through the National Science Foundation.
The clear ice core, 18 inches long and 4 inches wide, was plucked from 3,590 meters (about 11,800 feet) below the surface of the ice sheet and about 150 meters (495 feet) above Lake Vostok. Discovered in 1974, the lake is one of the world's ten deepest bodies of water and one of about 70 lakes underneath the glaciers of central Antarctica.
The bacteria, commonly associated with soils, are related to microbes called proteobacteria and actinomycetes. They could have been blown on bits of soil from the Patagonian deserts onto the East Antarctic ice sheet and then buried, Priscu said. If so, the microbes could be more than half a million years old.
Another possibility is the microbes originated in the lake and became trapped as lake water refroze or accreted to the bottom of the overlying glacier, he said. In either case, the study suggests the lake could support a microbial population, despite a million years of isolation from the atmosphere, according to the article in Science. The MSU-led group was not able to determine whether the microbes were alive or merely trapped in an ancient icy grave. "They could have been alive, but growing so slowly that we could not detect growth rates using our protocols," Priscu said. "If alive, I think they are in a maintenance mode of metabolism, rather than one of active growth." Priscu and his teams have found microbes growing in other Antarctic frozen lakes, but none nearly as deep as Lake Vostok. Microbes are known to hang out in other extreme environments, such as hot vents along undersea trenches, deep in the earth's subsurface and in geothermal pools like those in Yellowstone National Park. And if microbes exist on other planets, such as in the frozen ocean thought to exist on Jupiter's moon Europa, finding them could be similar to hunting for them in Lake Vostok, the scientists say. "Similar to Lake Vostok accretion ice, this ice may retain evidence for life, if present, in the europan ocean," the scientists wrote. Internal energy from the planet could drive an ice system independent of the sun and possibly sustain life in really extreme environments, said MSU earth sciences professor and co-author David Mogk. "I think the message is really, 'Life is where you find it'," Mogk said. "If you find it under nearly 4,000 meters of ice, I mean, that's pretty staggering."
In addition to searching for bacteria, the group studied the ice's unique crystal structure and mineral composition using aspecialized scanning electron microscope. They saw parts of only two large crystals in the sample. The crystals weren't oriented vertically as you would expect in a quiet lake, said MSU civil engineering professor Ed Adams. He'd have to analyze more samples to understand why but suspects sheer stresses could play a role in crystal misalignment. Another possibility is that ice crystals initially nucleate in the lake water and attach to the overlying ice at a random orientation. Adams said the group hopes to get more core samples from the National Science Foundation, which paid for the research along with MSU.
Other MSU scientists who helped with the project are Bob Brown, Cristina Takacs, Craig Wolf and Recep Avci. Additional coauthors are W. Berry Lyons and Kathy Welch from the University of Alabama; Mary Voytek and Julie Kirshtein from the U.S. Geological Survey and Christopher McKay, Space Sciences Division, NASA Ames Research Center.
The original news release can be found at: http://www.montana.edu/wwwpb/univ/lifeice.html
|Продолжение дайджеста за ДЕКАБРЬ 1999 года (часть 2)|