Demise of early Peruvians discovered
GAINESVILLE, Fla., Jan. 21 (UPI) -- U.S. scientists say a series of earthquakes followed by torrential rains caused the demise of coastal Peruvians more than 3,600 years ago.
"This maritime-farming community had been successful for over 2,000 years … and then all of a sudden, 'boom,'" said University of Florida Professor Mike Moseley. "They just got the props knocked out from under them."
Moseley is one of five authors of a paper to appear in the online edition of the Proceedings of the National Academy of Sciences.
The people of the Supe Valley along the central Peruvian coast flourished for about 2,000 years in the arid desert plain adjacent to productive bays and estuaries by fishing, irrigating fruit orchards and growing cotton and vegetables.
But approximately 3,600 years ago, an enormous earthquake or series of earthquakes struck, destabilizing the mountain ranges surrounding the valley, sending massive amounts of debris crashing into the foothills, the scientists said. Subsequent El Ninos brought torrential rains, washing the debris into the ocean.
Strong ever-present onshore winds resulted in massive sand sheets blowing inland, creating a blasting effect that would have made daily life nearly impossible, Moseley said.
What had for centuries been a productive, if arid, region became all but uninhabitable, the scientists said, with the Supe society eventually collapsing, replaced only gradually by societies relying on the much more modern arts of pottery and weaving.
Study: Microbes might affect obesity
PHOENIX, Jan. 21 (UPI) -- U.S. scientists say they have confirmed a link between differing microbial populations in the human gut and body weight.
Researchers from Arizona State University, the Mayo Clinic in Arizona and the University of Arizona said microbes occupying the human gut number in the tens of trillions, helping the body perform a variety of regulatory and digestive functions, many still poorly understood.
The study revealed a link between differing microbial populations in the human gut and body weight among three distinct groups: normal weight individuals, those who have undergone gastric bypass surgery, and patients suffering the condition of morbid obesity -- a serious, often life-threatening condition associated with diabetes, cardiovascular disease, cancer and psychosocial disorders.
The team's central hypothesis that differing microbial populations in the gut allow the body to harvest more energy, making people more susceptible to becoming obese was supported by the study's confirmation that the microbial composition among obese patients appears significantly altered compared with both normal weight individuals and those who have undergone gastric bypass surgery.
The research is reported in the early online edition of the Proceedings of the National Academy of Science.
Bacterium affected by land practices
DARWIN, Australia, Jan. 21 (UPI) -- Australian scientists say they've discovered the pathogenic soil bacterium Burkholderia pseudomallei is influenced by land management practices.
Researchers at the Menzies School of Health Research in Darwin, Australia, said they found the bacterium, which causes the emerging infectious disease melioidosis in humans and animals, is associated with land management changes such as livestock husbandry or residential gardening.
"These findings raise concerns that B. pseudomallei may spread due to the influence of land management changes," said study author Mirjam Kaestli. "This would increase the risk of human and livestock exposure to these potentially deadly bacteria, which are transmitted by contact with contaminated soil or surface water through cuts in the skin or inhalation."
The study appears in the journal PLoS Neglected Tropical Diseases.
New anti-cancer control mechanism found
MONTREAL, Jan. 21 (UPI) -- Canadian medical researchers say they have discovered a new anti-cancer, anti-infection response control mechanism.
Dr. Andre Veillette of the Institute of Research Clinics in Montreal, and his team led by postdoctoral fellow Dr. Mario-Ernesto Cruz-Munoz, said their discovery could have a significant impact on the treatment of cancers and infectious diseases.
The team identified one of the basic mechanisms controlling "natural killer" cell activity. Produced by the immune system, NK cells are responsible for recognizing and killing cancer cells and cells infected by viruses, they said, and NK cell deficiency is associated with a higher incidence of cancers and serious infections.
"Our breakthrough demonstrates that a molecule known as CRACC, which is present at the surface of NK cells, increases their killer function," said Veillette.
Using mice, the researchers showed those lacking the CRACC gene were found to be more susceptible to cancer persistence. Conversely, stimulation of CRACC function was found to improve cancer cell elimination. Thus, they said, stimulating CRACC could boost NK cell activity, helping to fight cancers. In addition, it could improve the ability to fight infections, which are also handled by NK cells.
The findings are detailed in the journal Nature Immunology.
