UPI NewsTrack Health and Science News

Study: Fog declines along California coast

BERKELEY, Calif., Feb. 16 (UPI) -- A University of California-Berkeley study suggests foggy conditions have declined during the past century along California's redwood coast.

The scientists, led by postdoctoral scholar James Johnstone, said the decline in fog potentially endangers coastal redwood trees that are dependent on cool, humid summers. The researchers said it is unclear whether the diminished foggy conditions are part of a natural cycle or the result of human activity.

"Since 1901, the average number of hours of fog along the coast in summer has dropped from 56 percent to 42 percent, which is a loss of about three hours per day," Johnstone said. "A cool coast and warm interior is one of the defining characteristics of California's coastal climate, but the temperature difference between the coast and interior has declined substantially in the last century, in step with the decline in summer fog."

Professor Todd Dawson, the study's co-author, said coastal redwoods and other ecosystems along the U.S. West Coast might be increasingly drought-stressed, with a summer climate of reduced fog frequency and greater evaporative demand.

"Fog prevents water loss from redwoods in summer, and is really important for both the tree and the forest," said Dawson. "If the fog is gone, we might not have the redwood forests we do now."

The study appears in the online early edition of the Proceedings of the National Academy of Sciences.

Study identifies gene linked with ADHD

BETHESDA, Md., Feb. 16 (UPI) -- A U.S.-led multinational research team says it analyzed data from more than 6,000 people to find a gene linked to attention-deficit/hyperactivity disorder.

Researchers from the United States, Colombia, Germany, Norway and Spain said they discovered ADHD is linked with the Latrophilin 3 gene after examining data from members of 18 ADHD-afflicted families in an isolated region of Colombia.

The scientists said they then replicated their finding in five samples of people from Germany, Norway, Spain and the United States. Their samples comprised 2,627 people with ADHD and 2,531 people without the disorder.

The team said subsequent brain-imaging studies showed the LPHN3 gene is expressed in areas of the brain associated with attention and influences the metabolism of groups of nerve cells associated with ADHD.

The researchers said their findings could lead to novel drug treatments, as well as a mechanism to identify those likely to develop ADHD. In addition, they said their discovery could help identify ADHD patients who would be more likely to show a therapeutic response to stimulant medication.

The study led by Maximilian Muenke and Mauricio Arcos-Burgos of the U.S. National Institutes of Health appears in the early online edition of the journal Molecular Psychiatry.

Mars Express begins Phobos flybys

PARIS, Feb. 16 (UPI) -- The European Space Agency says its Mars Express spacecraft started a series of flybys of Phobos Tuesday, researching the origin of the mysterious Mars moon.

The ESA said the study will include a March 3 record low pass, with the spacecraft passing just 31 miles above the moon's surface.

The latest Phobos flyby research started Tuesday at 12:52 a.m. EST, when Mars Express drew to within 616 miles of Phobos' airless surface, ESA scientists said, noting the flybys will continue at varying altitudes until March 26 when Phobos moves out of range.

"Because Mars Express is in an elliptical and polar orbit with a maximum distance from Mars of about 10,000 kilometers (6,200 miles), we regularly pass Phobos," said Olivier Witasse, the ESA's Mars Express project scientist.

"Heavy emphasis is being placed upon the closest flyby because it is an unprecedented opportunity to map Phobos' gravity field," the space agency said. "This will allow scientists to infer the moon's internal structure."

Narcolepsy may be autoimmune disorder

LAUSANNE, Switzerland, Feb. 16 (UPI) -- Swiss scientists say they have identified immune molecules that target a natural protein in the body to produce narcolepsy in some individuals.

University of Lausanne researchers say their finding suggests the sleep disorder might be an autoimmune disorder.

Individuals with narcolepsy suffer from excessive daytime sleepiness and attacks of muscle paralysis triggered by strong emotions -- a condition known as cataplexy. It has been thought narcolepsy is an autoimmune disorder, but that has never been definitively proven.

The new research led by Associate Professor Mehdi Tafti has identified autoantibodies, rather than a protein from an infectious agent, that target the natural protein Trib2 in narcolepsy patients with cataplexy.

The study appears in the early online edition of the Journal of Clinical Investigation.