CHICAGO, Nov. 27 (UPI) -- U.S. scientists say they found metabolically active bacteria in the brine of an Antarctic lake sealed for thousands of years under more than 65 feet of ice.
Researchers at the University of Illinois at Chicago, writing in the Proceedings of the National Academy of Sciences, said the finding sheds light on the limits of life in extreme environments.
The brine has been isolated from the surface environment, and from any external sources of energy, for at least 2,800 years, they said.
"This provides us with new boundary conditions on the limits for life," researcher Peter Doran said. "The low temperature or high salinity on their own are limiting, but combined with an absence of solar energy or any new inputs from the atmosphere, they make this a very tough place to make a living."
The findings were unexpected because of the extremely salty, dark, cold, isolated ecosystem within the ice, scientists said.
The brine is oxygen-free, slightly acidic, and contains high levels of organic carbon and molecular hydrogen, the scientists said.
"Geochemical analyses suggest that chemical reactions between the brine and the underlying sediment generate nitrous oxide and molecular hydrogen," researcher Fabien Kenig said. "The hydrogen may provide some of the energy needed to support microbes."
Satellites used to track global smog level
TEL AVIV, Israel, Nov. 27 (UPI) -- Israeli researchers say using a trio of NASA satellites has allowed them to measure levels of air pollution over the world's largest cities.
On-the-ground monitoring stations do not always provide the most accurate picture of global smog created by traffic, industry and other human activities, they said.
Using eight years of data collected by the satellites, the researchers at Tel Aviv University tracked pollution trends for 189 cities where the population exceeds 2 million.
More than 50 of these metropolitan areas, including New York, Tokyo and Mumbai, have populations that exceed 5 million.
The researchers used data gathered by three aerosol-monitoring satellites, called MODIS-Terra, MODIS-Aqua, and MISR, which NASA launched from 2000 through 2002.
Northeastern China, India, the Middle East and Central Africa are currently experiencing the most increases in air pollution, the researchers said.
Among the cleanest cities were Houston, with a 31 percent decrease over the time period; Curitiba, Brazil, with a 26 percent decrease; and Stockholm, Sweden, with a 23 percent decrease, they said.
Research leader Pinhas Alpert said he believes this satellite-based monitoring method will hold countries accountable for their emissions and encourage more environmentally friendly practices.
Study: Seeing not the same as noticing
LOS ANGELES, Nov. 27 (UPI) -- Psychology researchers in California say tests show people often do not recall things, even important items, they've seen or walked by hundreds of times.
For the study at the University of California, Los Angeles, 54 people who work in a building were asked if they knew the location of the fire extinguisher nearest their office.
Although many of the participants had worked in their offices in the building for years and had passed a number of the bright red extinguishers several times a day, 24 percent knew their locations.
Yet when asked to find a fire extinguisher, researchers found, everyone was able to do so within a few seconds, with most of the participants saying they were surprised they had never noticed them.
"Just because we've seen something many times doesn't mean we remember it or even notice it," UCLA psychology Professor Alan Castel said.
Not noticing things isn't necessarily bad, he said, particularly when those things are not important in your daily life.
"It might be a good thing not to burden your memory with information that is not relevant to you," he said.
But safety information, like knowing where fire extinguishers are or what to do in an emergency, could be vital, he said.
"We don't notice something if we're attending to something else," Castel said. "Fire extinguishers are bright red and very conspicuous, but we're almost blind to them until they become relevant."
Flu outbreaks predicted like the weather?
BOULDER, Colo., Nov. 27 (UPI) -- U.S. scientists say techniques used in weather forecasting can be used to generate local forecasts of seasonal influenza outbreaks.
Researchers at Columbia University in New York and the National Center for Atmospheric Research in Boulder, Colo., said predicting the timing and severity of flu outbreaks would help health officials and the general public better prepare for them.
The peak of flu season can vary widely from region to region and from year to year, but the new forecast system can provide "a window into what can happen week to week as flu prevalence rises and falls," Columbia environmental health sciences Professor Jeffrey Shaman said.
Wintertime U.S. flu epidemics tend to occur following very dry weather, the researchers said, and a prediction model incorporating this finding used estimates of flu-related sickness from the winters of 2003-04 to 2008-09 in New York City to retrospectively generate weekly flu forecasts in a test, an NCAR release reported Tuesday.
The researchers said the technique could predict the peak timing of the outbreak more than seven weeks in advance of the actual peak.
"Analogous to weather prediction, this system can potentially be used to estimate the probability of regional outbreaks of the flu several weeks in advance," NCAR scientist Alicia Karspeck said.
In the future flu forecasts could conceivably be disseminated on local television news program along with the weather report, Shaman said.
"Because we are all familiar with weather broadcasts, when we hear that there is an 80 percent chance of rain, we all have an intuitive sense of whether or not we should carry an umbrella," he said. "I expect we will develop a similar comfort level and confidence in flu forecasts and develop an intuition of what we should do to protect ourselves in response to different forecast outcomes."