DOE Pulse - Science and Technology Highlights from the DOE National Laboratories

Close-up of SPEAR3.
(Photo by Peter Ginter)

Jeb Flemming, project lead for the ElectroNeedle platform, holds a test version.

Turning off alcohol abuse


Panayotis (Peter) Thanos

“Stopping alcohol abuse will never be as easy as turning on or off a ‘switch,'” says Panayotis (Peter) Thanos, a neuroscientist at the U.S. Department of Energy's (DOE's) Brookhaven National Laboratory . “But understanding the brain's reward circuits and finding ways to modulate them could play a role in developing successful treatments.”

Through brain-imaging and behavioral studies in animals, Thanos and his colleagues have demonstrated that a variety of brain receptors play a role in excessive drinking — including those for dopamine, one of the brain's primary reward chemicals, and those that trigger the reinforcing properties of marijuana.

Adding more receptors via “ gene therapy” or blocking their ability to send pleasure/reward signals can drastically affect drinking behavior, Thanos' studies have shown.

“When you see a rat that chooses to drink 80 to 90 percent of its daily fluid as alcohol, and then three days later it's down to 20 percent, that's a dramatic drop in alcohol intake.”

Thanos traces his interest in brain chemistry and behavior to an undergraduate class at Queen's University in Canada. He volunteered to work with his professor in the lab and got hooked — on research. After completing his Ph.D. at Eastern Virginia Medical School, he went to Stony Brook University and collaborated with scientists at Brookhaven's Center for Translational Neuroimaging, joining the Lab as a neuroscientist in 1999.

Thanos extends the research opportunity he had as a student to three or four undergraduate students each semester — and sometimes more in the summer. “Even if students have had no prior research experience,” he says, “they can produce great work.”

With many of these students going on to medical school, graduate school, dental and veterinary schools, it's clear that Thanos' ability to spot and spark that motivation pays off for the students as well as their mentor.

Submitted by DOE's Brookhaven National Laboratory

Meteoroid ‘smoke' may influence weather, study finds


This image of a dust cloud from an asteroid plunging into Earth's atmosphere shows some of its unusual properties. The cloud sits vertically with thin wispy layers separated by a few kilometers. It lasted about an hour.

Space-based infrared sensors of the U.S. Department of Defense detected the object 75 kilometers high, descending rapidly off the coast of Antarctica.

DOE visible-light sensors, built by DOE's Sandia National Laboratories, noticed the intruder when it became a fireball. They identified it as an asteroid — not a missile — 56 kilometers above Earth. Five infrasound stations, to detect nuclear explosions anywhere in the world, registered acoustic waves (analyzed at the DOE's Los Alamos National Laboratory), confirming the speeding asteroid.

The debris cloud formed by the disintegrating space rock was imaged by NASA's multi-spectral polar orbiting sensor.

This array of multi-agency sensors worked together to provide basic facts: the time of entry, speed, and size — one of the largest meteoroids to enter Earth's atmosphere in a decade.

But, there was one last sighting: scientists using ground-based lidar detected an irregular cloud of material in the upper stratosphere over Antarctica. These were the first direct measurements of meteoritic “smoke.”

Scientists have paid little attention to meteoroid dust, assuming it did not affect Earth's environment, says Andrew Klekociuk, a scientist at the Australian Antarctic Division. New observations suggest that this micron-sized dust could play a more important climate role, according to Klekociuk and other researchers, including Sandia's Dick Spalding, in an Aug. 25 paper published in the journal Nature.

The asteroid deposited 1,000 metric tons in the stratosphere in seconds, according to data from Sandia sensors, whose primary function is to detect nuclear explosions. The sensor evolution to include meteor fireball observations came when Sandia's Spalding recognized that ground-based data processing might be modified to record the relatively slower flashes of asteroids and meteoroids.

This ability to distinguish a nuclear explosion from an asteroid fireball with equavalent energy provides an additional safety margin for decision makers responding to nuclear threats.

Submitted by DOE's Sandia National Laboratories