Possible Asian Origin for Apes
Paleontologists have discovered a new species of early primate in central Burma, offering fresh evidence that the ancestor of all monkeys and apes may have been from Asia, rather than Africa.
The new species, called Bahinia pondaungensis, was a small, insect-eating tree-dweller weighing about one pound, according to a report published in the Oct. 15 issue of the journal Science.
The Burmese-French scientific team found fossilized teeth and jawbone fragments from Bahinia in Burma's Pondaung Formation, along with the jawbone of a more advanced primate. The fossils are about 40 million years old.
Team leader Jean-Jacques Jaeger, of the Universite Montpellier-II, said the new fossil was definitely anthropoid--an ancestor of modern monkeys and apes--and showed strong similarities to a more fragmentary fossil found in China.
The combined evidence from the sites, as well as other discoveries in Burma, Thailand and China, suggest that anthropoids may have originated in Asia.
Until recently, Africa was regarded not only as the cradle of humanity, but also as the world's richest source of anthropoid remains.
Moon Crash Produced No Water
Is there water on the moon? The mystery remains unsolved. The July 31 kamikaze dive of NASA's Lunar Prospector into the moon's south pole did not produce a discernible signature of water, researchers reported last week after completing their analysis.
A global array that included the Hubble Space Telescope and other spacecraft in Earth orbit, as well as ground-based observatories, was aimed toward the region of the expected impact.
Sensitive spectrometers searched for ultraviolet emission lines from hydroxyl (OH) molecules that should be a byproduct of any icy rock and dust kicked up by the 354-pound spacecraft as it ended its mission with a bang.
Based on earlier detection of large amounts of hydrogen measured indirectly from lunar orbit, some scientists had hypothesized that ancient cometary impacts had delivered tons of ice that now lies buried in permanently shadowed regions of the moon's poles.
"There are several possible explanations why we did not detect any water signature," said Ed Barker, assistant director of the McDonald Observatory, operated by the University of Texas at Austin.
The spacecraft might have missed the target area, or hit a rock or dry soil instead of ice.
The crash might have lacked the energy required to separate water from hydrated minerals if they were tightly bound in rock.
The observing telescopes might have missed the plume raised by the impact. Or there is no water at all--only pure hydrogen.
Rating Radical Cancer Therapy
A growing number of women with advanced breast cancer are opting to undergo a radical and experimental treatment that involves extremely high doses of chemotherapy followed by a bone marrow transplant. There is no proof that the toxic and debilitating therapy increases women's chances of survival, but many women and their doctors demand it because there is no known cure for advanced breast cancer, defined as cancer that has spread to other regions of the body or has recurred after initial treatment.
Now a study of almost 1,200 women who had the therapy is providing a partial answer to the question of whether some women, at least, stand to be helped by the treatment, and describes those women who are so unlikely to be helped that they probably should not bother.
Physicians at 63 hospitals in North America, Brazil and Russia tracked how the women fared in the years after treatment.
They found that several factors significantly add to the odds that a woman will die from her cancer within three years despite the treatment.
* Women older than 45: 17 percent increased risk of death within three years.
* Those whose tumors are not sensitive to estrogen ("estrogen receptor negative"): 31 percent.
* Those who have already undergone adjuvant chemotherapy: 31 percent.
* Those who go less than 18 months before cancer recurs after initial adjuvant chemotherapy: 99 percent.
* Those who have metastasis to the liver: 47 percent.
* Those who responded poorly to standard chemotherapy: 65 percent.
On the positive side, women with tumors that were sensitive to estrogen and who took the drug tamoxifen after their bone marrow transplant reduced their chances of dying within three years by 40 percent.
All told, the researchers report in the Oct. 13 Journal of the American Medical Association, women with none of the above risk factors had a 43 percent chance of surviving three years after the bone marrow procedure, compared with a 4 percent chance for women with four or more of the risk factors.
The researchers conclude that women considering a bone marrow transplant for breast cancer should be apprised of their true prognosis, based on data like those collected in the report.
With further studies, they say, it should be possible to identify women who stand to benefit from bone marrow transplants and to avoid putting other women through the ordeal unnecessarily.