Climate change may be faster than expected
OAK RIDGE, Tenn., Oct. 13 (UPI) -- A team of U.S. scientists has, for the first time, successfully incorporated the nitrogen cycle into global climate change simulations.
The experiment's findings at the Oak Ridge National Laboratory and the National Center for Atmospheric Research bring into question previous assumptions regarding carbon feedback.
The researchers say they determined the rate of climate change during the next century could be faster than previously anticipated when the requirement of plant nutrients are included in the climate model.
"We've shown that if all of the global modeling groups were to include some kind of nutrient dynamics, the range of model predictions would shrink because of the constraining effects of the carbon nutrient limitations, even though it's a more complex model," Oak Ridge scientist Peter Thornton said.
By taking the natural demand for nutrients into account, the authors demonstrated the stimulation of plant growth during the coming century might be two to three times smaller than previously predicted. Since less growth implies less carbon dioxide absorbed by vegetation, the CO2 concentrations in the atmosphere are expected to increase.
The detailed report is available in the journal Biogeosciences.
Depression linked to inflammatory protein
INDIANAPOLIS, Oct. 13 (UPI) -- U.S. researchers found depression leads to elevated levels of an inflammatory protein in the body.
The study, published in Brain, Behavior and Immunity, found depressive symptoms associated with increases over time in interleukin-6, an inflammatory protein that predicts cardiovascular events. The study determined levels of interleukin-6 were not related to later increases in depressive symptoms.
"There is two-way communication between the brain and the immune system, so we had to determine whether activation of the body's immune system sent a signal to the brain to affect mood and behavior or whether the depression activated the immune system," study leader Dr. Jesse Stewart of Indiana University - Purdue University Indianapolis said in a statement. "The link to cardiovascular disease demonstrates that there may be physical as well as mental health reasons to treat depression."
The study involved 263 healthy men and women ages 50-70, who were tested at baseline and again six years later to determine their levels of depressive symptoms and interleukin-6.
Levels of C-reactive protein -- another inflammatory protein -- were also measured but were not found to be related to depression.
USGS warns of giant invasive snakes
RESTON, Va., Oct. 13 (UPI) -- U.S. Geological Survey scientists say five giant non-native snake species would pose high ecosystem risks if they become established in the United States.
The USGS report is based on the biology and known natural history of non-native boa, anaconda and python species that are invasive or potentially invasive in the United States. Two of the species are documented as reproducing in the wild in South Florida, with population estimates for Burmese pythons in the tens of thousands.
The five most potentially dangerous species were identified by the USGS as Burmese pythons, both northern and southern African pythons, boa constrictors and yellow anacondas.
"This report clearly reveals that these giant snakes threaten to destabilize some of our most precious ecosystems and parks, primarily through predation on vulnerable native species," said herpetologist Robert Reed, a coauthor of the report.
The report notes there are no control tools yet that seem adequate for eradicating an established population of giant snakes once they have spread over a large area.
"We have a cautionary tale with the American island of Guam and the brown tree snake," said Reed. "Within 40 years of its arrival, this invasive snake has decimated the island's native wildlife -- 10 of Guam's 12 native forest birds, one of its two bat species and about half of its native lizards are gone."
The 300-page USGS report is available at http://pubs.usgs.gov/of/2009/1202/pdf/OF09-1202.pdf.
Model predicts hurricane power outages
BALTIMORE, Oct. 13 (UPI) -- U.S. and South Korean scientists say they've created a statistical program that can predict potential power outages in advance of hurricanes and other storms.
"Hurricanes have caused severe damage to electric power systems throughout the world, and electric power is critical to post-hurricane disaster response, as well as to long-term recovery for impacted areas," study co-author Seth Guikema of Johns Hopkins University said. "Effectively predicting and managing power outage risk can dramatically improve the resilience of infrastructure systems and speed up restoration of electric power."
The program is based on data from power outages following Hurricanes Katrina (10,105 outages), Ivan (13,568 outages), Dennis (4,840 outages) and other events in the Gulf Coast region since the mid-1990s, the researchers said.
The researchers said their new modeling approach takes into account more environmental and power system infrastructure factors than previous analyses, providing "more accurate predictions of the number of power outages in each geographic area of a utility company's service area and a better understanding of the response of the (utility company's) system."
The study that included Seung-Ryong Han of Korea University and Steven Quiring of Texas A&M appears in the journal Risk Analysis.