NASA: Dark energy stifles universe growth
WASHINGTON, Dec. 16 (UPI) -- U.S. astronomers say they have, for the first time, clearly observed the effects of "dark energy" on the most massive collapsed objects in the universe.
National Aeronautics and Space Administration astronomers using the agency's Chandra X-ray Observatory tracked how dark energy has stifled the growth of galaxy clusters. Combining that information with previous studies, scientists say they have obtained the best clues yet about what dark energy is and what the destiny of the universe might be.
NASA said the study strengthens the evidence that dark energy is the cosmological constant. "Although it is the leading candidate to explain dark energy, theoretical work suggests it should be about 10 raised to the power of 120 times larger than observed," space agency scientists said. Therefore, alternatives to general relativity, such as theories involving hidden dimensions, are being explored.
"This result could be described as 'arrested development of the universe'," said Alexey Vikhlinin of the Smithsonian Astrophysical Observatory, who led the research. "Whatever is forcing the expansion of the universe to speed up is also forcing its development to slow down."
Added William Forman, a co-author of the study, "For years, scientists have wanted to start testing how gravity works on large scales and now, we finally have."
The work will be published in two separate papers in the Feb. 10 issue of The Astrophysical Journal.
New method of killing bacteria is created
CHAMPAIGN, Ill., Dec. 16 (UPI) -- U.S. scientists say they have developed a method of "fooling" a bacterium's evolutionary machinery into programming its own death.
Researchers at the University of Illinois and the University of Massachusetts at Amherst said their achievement shows a synthetic "hole punching" anti-microbial depends upon the presence of phosphoethanolamine -- a cone-shaped lipid found within Gram-negative bacterial membranes.
"The basic idea is for an antimicrobial to target something in a bacteria that, in order to gain immunity, would require the bacteria to kill itself through a suicide mutation," said UI Professor Gerard Wong, corresponding author of the study.
"It's a Catch-22," he added. "Some mutations bacteria can tolerate, and some mutations they cannot tolerate. In this case, the bacteria would have to go through a mutation that would kill it, in order to be immune to these anti-microbials. The anti-microbial reorganizes PE lipids into holes in the membrane; the perforated membranes leak, and the bacteria die."
The study that included graduate student and lead author Lihua Yang, as well as Professors Dallas Trinkle, John Cronan Jr. and Gregory Tew has been accepted for publication in the Proceedings of the National Academy of Sciences and is currently available on the journal's Web site.
Global warning might increase corn pests
WEST LAFAYETTE, Ind., Dec. 16 (UPI) -- U.S. scientists say climate change could produce warmer growing seasons that could result in an increase in pests that feed on corn and other crops.
Warmer growing seasons and milder winters could allow some insects to expand their territory and produce an extra generation of offspring each year, said Purdue University Associate Professor Noah Diffenbaugh.
"The greatest potential range expansion was seen with the corn earworm, which is known to infest other high-value crops such as sweet corn and tomatoes," said Diffenbaugh, interim director of the Purdue Climate Change Research Center. "Warming could allow populations to survive the winter in the upper Midwest … as well as areas of the West where other high-value crops are grown."
Diffenbaugh noted the United States contributes nearly half of the world's total corn production.
"The world depends on U.S corn production for a variety of uses," he said. "Ethanol production and a growing world population are increasing demand for corn. Expansion of the pests' ranges could have substantial impacts through decreased yields and increased costs for seed and pest management."
The research that included Purdue Professors Christian Krupke and Corinne Alexander, as well as Michael White from Utah State University, was recently published in the online edition of the journal Environmental Research Letters.
FDA criticizes medication information
WASHINGTON, Dec. 16 (UPI) -- The U.S. Food and Drug Administration says it has found flaws in the printed consumer medication information voluntarily provided with new prescriptions.
The FDA said a study of the information provided by retail pharmacies showed it does not consistently provide easy-to-read, understandable information about the use and risks of medications.
The FDA said its study -- Expert and Consumer Evaluation of Consumer Medication Information -- "showed that while 94 percent of consumers received such information with new prescriptions, only about 75 percent of the information met the minimum criteria for usefulness."
"The current voluntary system has failed to provide consumers with the quality information they need in order to use medicines effectively and safely," said Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research. "We need to work with pharmacy operators, drug manufacturers, healthcare professionals and consumers to come up with a sensible, comprehensive and more effective solution," said Woodcock.
"Specifically," the FDA said, "CMI should include the drug name and uses, how to monitor for improvement in the condition being treated, contraindications, symptoms of serious or frequent adverse reactions and what to do, and certain general information, including statements encouraging patients to talk to their health care professional."
