A. Lack of Vigorous Activity the Main Cause for Adolescent Obesity

Narrator: This is Science Today. A lack of vigorous activity is the primary reason for obesity in adolescents ages 11 to 15. Dr. Kevin Patrick, a professor of family and preventive medicine at the University of California, San Diego, led a study of 900 adolescents.

Patrick: We think it’s one of the largest to look at diet and activity factors with both self-report and objective measurements of activity – especially a very multi-cultural, multi-ethnic group of kids.

Narrator: Patrick used an activity monitor called an accelerometer for a week and found that the average adolescent watched about four hours of TV per day and participated in very little vigorous physical activity.

Patrick: That’s the type of exercise that really causes somebody to break a sweat – get real active and get out there and do something. Kids just don’t walk as much as they used to, they don’t get out and ride their bike. Of course, there are logical reasons – parents are concerned about safety and concerned about other issues, but this really gets into the question of how we design and manage our environments.

Narrator: For Science Today, I’m Larissa Branin.

B. Time: The Principal Issue in Countering Biological Terrorism

Narrator: This is Science Today. When it comes to improving biological counter terrorism efforts, the principal issues are to respond to an event quickly – whether with antibiotics or antivirals.

Fitch: The efficacy of doing that rolls off very fast with time and so antibiotics against the bacterium that causes the plague have to be administered roughly a day after people are exposed or develop symptoms. That’s not a lot of time, especially if you’re looking at someone who’s deliberately trying to make people sick because you could be dealing with thousands of people at a time, which is not at all like a typical outbreak.

Narrator: Pat Fitch manages the Chemical and Biological National Security Program at the Lawrence Livermore National Laboratory.

Fitch: And so we’ve put a lot of energy and so have the federal sponsors, into ways to shorten that time, how long before we know we have an event that we need to be responding to and what can we do in response.

Narrator: Fitch adds that the technologies developed at the Lab to counter chemical and bioterrorism are also useful to counter infectious diseases like SARS. For Science Today, I’m Larissa Branin.

C. Primitive Instincts May Lead to Safer Baby Product Designs

Narrator: This is Science Today. It seems babies and toddlers are hard-wired to be attracted to glossy, reflective surfaces. Psychologist Richard Coss of the University of California, Davis says this innate sense is a holdover from when early primates sought water for survival.

Coss: Detecting water was absolutely essential, whether it’s a reflective surface or the sparkle that might occur when wind is blowing against the water. And of course, we have very sensitive sparkle detectors because they use these in psychological research with little flashing lights and even in young infants, your attention is attracted to something that glistens or just gives a little flash of light. So that’s probably capturing some of this natural property of water detection.

Narrator: Coss’ research of infants’ reactions to textures and patterns identified another ancestral holdover – a wariness of python and leopard patterns.

Coss: We have six-month old infants showing signs – not being fearful – but just of caution. So it’s possible we could think of textures that you could use for ringing the edges of pools, so children pause or maybe don’t go into the pool directly.

Narrator: For Science Today, I’m Larissa Branin.

D. Why Ethanol Use May Do More Harm than Good

Narrator: This is Science Today. A new report by researchers at the University of California, Berkeley, has concluded that the use of ethanol from corn as a gasoline additive will do more harm than good to the environment. Geoengineering professor Tad Patzek, who led the study, says that using ethanol as a gasoline additive is like burning the same amount of fuel twice to drive a car once.

Patzek: You burn as much fossil fuel to obtain ethanol as you then can get from burning it for the second time, and therefore to the extent that a car burns ethanol from corn, you actually double the emissions.

Narrator: Patzek’s findings come at a critical time in the United States. An energy bill has been passed that will double the amount of ethanol to be used as a gas additive to 5 billion gallons a year by 2012.

Patzek: Remember by that adding additives, or oxygenates into gasoline, we are complicating the system. And in fact, adding ethanol is the ultimate complexity, because we are running away in the opposite direction.

Narrator: For Science Today, I’m Larissa Branin.

E. Putting ‘Waste Heat’ to Better Use

Narrator: This is Science Today. With today’s power system, about two-thirds of the energy consumed by power plants isn’t converted to electricity; it instead escapes as waste heat. Chris Marnay, a staff scientist at the Lawrence Berkeley National Laboratory says placing power generation where heat is needed, rather than where it can be conveniently discarded, could drastically improve efficiency.

Marnay: If the power generation were much closer to the loads or if the power generation were configured somehow that we could capture more of that waste heat, then the overall process can be much more efficient, even if the conversion to electricity is less efficient.

Narrator: Marnay says that using waste heat to drive cooling and heating systems in buildings could be a great way to displace the use of natural gas and save electricity.

Marnay: So by displacing the electricity that would be used to cool the building, you’re really having a major beneficial effect on the power system because at the same time that you’re supplying the need to the building, you’re also lowering the load on the power system.

Narrator: For Science Today, I’m Larissa Branin.