A.
Microbes at Work Cleaning Up the Environment
Narrator: This is Science Today. Some bacteria have been found to actually improve water quality by protecting themselves from potentially toxic nanoparticles in their own environment. A team of University of California researchers found that bacteria from an abandoned mine in Wisconsin excrete microbial proteins that cause metal nanoparticles to accumulate. Physicist Peter Weber of the Lawrence Livermore National Laboratory explains.
Weber: It turns out that they're taking sulfate from the water and they're reducing it and making zinc sulfide particles. And so they're cleaning up the water by removing that sulfate from the water and at the same time, they're taking out the heavy metals that are coming from the mine.
Narrator: This research is being driven by the U.S. Department of Energy's need to develop new technologies for cleaning up water.
Weber: So the interest is to go in there and see what's happening naturally and how that can be harnessed to clean up the environment.
Narrator: For Science Today, I'm Larissa Branin.
B.
Researchers Study the Link Between Chronic Stress and Obesity
Narrator: This is Science Today. Glucocorticoid receptors are adrenal stress hormones that are found in every cell type in the body. Dr. Mary Ann Dallman, a stress and physiology expert at the University of California, San Francisco, has been studying the association between glucocorticoids and chronic stress and how they may be contributing to rising obesity rates.
Dallman: In the body, the elevated glucocorticoids secreted with stress decrease protein synthesis and increase fat synthesis and increase glucose synthesis – all very sensible if you need to get away from stress.
Narrator: That's because in an evolutionary sense, energy stored in fat can be used to flee from danger or to get through times without regular food supplies.
Dallman: It's marvelous evolutionarily, because there hasn't been the enormous availability of corner food stores and McDonald's and endless inexpensive food that there is in our society.
Narrator: But chronic stress encountered in modern society, such as on the job, is not so easy to run away from. For Science Today, I'm Larissa Branin.
C. Dust-Size Particles Detected by a New Radiation Detection System
Narrator: This is Science Today. An instrument under development at the Lawrence Livermore National Laboratory can detect dust-size particles for possible explosives, narcotics or biological threat agents. Staff scientist George Farquar says the instrument uses a system called Single-Particle Aerosol Mass Spectrometry, or SPAMS.
Farquar: The general principle of the instrument is it draws in single particles, aerosols – it sizes them with a series of lasers and tracks their speed so we can fire an ionization laser at it where we effectively blow the particle up and from the products of that reaction and the laser and the particle, we're able to back calculate and determine what was in the original particle.
Narrator: One of the possible uses would be at airport security checkpoints.
Farquar: We're currently looking for funding to develop a type of hand wand you could attach to this so we could get particles off of individual bags. So that if you had a piece of luggage, you could scan that individually, suck the particles off and draw it into the instrument.
Narrator: For Science Today, I'm Larissa Branin.
D.
Understanding Behavioral Problems in Dogs
Narrator: This is Science Today. If you own a dog with a behavioral disorder – such as noise phobia, separation anxiety or aggression, you may wonder if you're doing something wrong. But Steve Hamilton, a geneticist and psychiatrist at the University of California, San Francisco, says it may be in their genes.
Hamilton : It's probably fairly common that dogs suffer from behavior disorders, much like in humans. My advice would be not to assume that it's something due to maltreatment necessarily or something that you're doing that may play a role. But also may be something that just happens to be occurring in this dog for a variety of reasons, including perhaps genetic endowment.
Narrator: Hamilton is co-leading the Canine Behavioral Genetics Project in an effort to better understand the genetics behind panic and anxiety-related disorders – not just in dogs, but in humans, too.
Hamilton : As a human psychiatrist and human geneticist, one of my long-term goals is to determine whether what we learn from the genetics of the dog can teach us something about the genetics of humans with regard to mental disorders.
Narrator: For Science Today, I'm Larissa Branin.
E. The Effects of Secondhand Smoke During Lung Development
Narrator: This is Science Today. For fifteen years, researchers at the University of California , Davis have been studying how air pollution affects lung structure and function. Kent Pinkerton, director of the UC Davis Center for Health and the Environment, is particularly interested in understanding how particles are deposited in the lungs, how they change location and what their fate may be over time.
Pinkerton: And especially, how that may impact on a rapidly growing lung system in the neonatal stage and I think this is an area where we can do a tremendous amount of research.
Narrator: In fact, Pinkerton's research group recently described in unprecedented anatomical and biochemical detail how cigarette smoke can damage the lungs of unborn and newborn children. In particular, Pinkerton found that environmental tobacco – or secondhand smoke – affects a critical period of lung development, when millions of tiny cells called alveoli are being formed. For Science Today, I'm Larissa Branin.
