national academy of sciences

Researchers find 3,000-Year-Old Microbes in Mars-Like Antarctic Environment

Researchers drilling into Lake Vida, an Antarctic “ice-block” lake, have found the lake isn’t really an ice block at all. In the December 16 issue of the Proceedings of the National Academy of Sciences, the team reveals that Antarctic Lake Vida may represent a previously unknown ecosystem, a frigid, “ice-sealed,” lake that contains the thickest non-glacial lake ice cover on Earth and water seven times saltier than seawater. Because of the arid, chilled environment in which it resides, scientists believe the lake may be an important template for the search for evidence of ancient microbial life on Mars and other icy worlds.

Satellite Could Help Predict Hantaviral Transmission Risk

Researchers report that satellite imagery could be used to determine areas at high-risk for exposure to Sin Nombre virus (SNV), a rodent-born disease that causes the often fatal hantaviral pulmonary syndrome (HPS) in humans. According to the researchers, satellite imaging detects the distinct environmental conditions that may serve as a refuge for the disease-carrying deer mice. Higher populations of infected deer mice increase the risk of HPS to humans.

Large-scale climate changes occur naturally, new research says

A Canadian researcher has found new evidence that — contrary to previous belief — the past 6,000 years have been marked by large-scale climate changes occurring naturally, on a regular basis. He and his research team have documented four abrupt climate shifts over the past 5,500 years in western Canada, occurring on average every 1,220 years. Until now the last 6,000 years has been considered climatically stable, with the main evidence of large-scale shifts being found in the Greenland ice cores and sediments from the Atlantic Ocean. The team’s findings are reported in the current issue of the Proceedings of the National Academy of Sciences.

Little Yellow Molecule Comes Up Big

Bilirubin has been a mystery of a molecule, associated with better health if there’s just a little more than normal, but best known for being at the root of the yellow color in jaundice and, at high levels, for causing brain damage in newborns. In the current online edition of the Proceedings of the National Academy of Sciences, a research team from Johns Hopkins reports that bilirubin and the enzyme that makes it appear to be the body’s most potent protection against oxidative damage.

Statistics Help Infants Build Knowledge of Visual World

A baby’s first look at the world is likely a dizzying array of shapes and motion that are meaningless to a newborn, but researchers at the University of Rochester say they have now shown that babies use relationships between objects to build an understanding of the world. By noting how often objects appear together, infants can efficiently take in more knowledge than if they were to simply see the same shapes individually, says the paper published in the current issue of Proceedings of the National Academy of Sciences.

Scientists Eavesdrop on Cellular Conversations by Making Mice ‘Glow’

Scientists have coupled the protein that makes fireflies glow with a device similar to a home video camera to eavesdrop on cellular conversations in living mice. The team’s research will allow scientists to study how cellular proteins talk to one another. These communications trigger changes that regulate a healthy body and cause disease when the signals go awry. The findings may speed development of new drugs for cancer, cardiovascular diseases and neurological diseases.

Gut Bacteria Interact with Intestine to Regulate Blood Supply

Bacteria aren’t always bad. In fact, they can be extremely helpful partners. According to research at Washington University School of Medicine in St. Louis, microbes found naturally in the mouse and human gut interact with intestinal cells, called Paneth cells, to promote the development of blood vessels in the intestinal lining. “This study provides insights into the mutually beneficial partnerships forged between mammals and their native microbes,” says the principal investigator. “These symbiotic relationships probably are most important in the gut, which contains the largest and most complex collection of bacteria.”

Bacterial protein kills tumors

The use of live bacteria to treat cancer goes back a hundred years. But while the therapy can sometimes shrink tumors, the treatment usually leads to toxicity, limiting its value in medicine. Now, researchers at the University of Illinois at Chicago have isolated a protein secreted by bacteria that kills cancer cells but appears to have no harmful side effects. Tested in mice injected with human melanomas, the protein shrank the malignancies, but, in contrast with other studies using whole bacteria, caused no deaths or adverse reactions in the laboratory animals.

Scientists decipher tooth decay bug’s genome

Researchers in Oklahoma have deciphered the complete genome sequence of Streptococcus mutans, the main organism implicated in causing tooth decay. The work, supported by the National Institute of Dental and Craniofacial Research, has been made freely available online. Said one of the team members involved in the four-year effort: “Building on this basic research may one day lead us to new approaches for preventing and treating tooth decay.” Added another: “By targeting the adherence genes, for example, we might be able to develop a way of preventing S. mutans from sticking to teeth.”

Cutting calories slows aging of the heart

Keep eating like that and I'll outlive you for sure.To remain young at heart, eat less. That’s the message drawn from new research out of the University of Wisconsin-Madison, where a team of scientists studied middle-aged mice that were put on a calorie-restricted diet. What they found were signs of a remarkable uptick in heart health in old age. “It looks like caloric restriction just retarded the whole aging process in the heart,” said one of the researchers. The new study provides evidence that — even starting in middle age — cutting calories can confer significant health benefits for the heart and extend its working life. It does so, according to the team’s results, by exerting influence on the genetic program that governs heart cells.