Program 631,
  May 30, 2000


A. The Domino Effect of Extinction

Narrator: This is Science Today. Researchers looking into how the global biosphere recovers following an extinction event, discovered that the time scale for recovery is approximately ten million years. James Kirchner of the University of California, Berkeley says that's much longer than previously thought and goes to show that extinction has a domino effect.

Kirchner: Because individual species are so interdependent, the elimination of one species will have knock on effects through many others - through everything that feeds on it, everything that in other ways, depends on that species.

Narrator: Kirchner and his colleagues used analysis techniques from astrophysics to determine the rate of extinction compared to the rate of evolution over the past 535 million years.

Kirchner: No one had been able to do that before because the mathematical techniques you need to be able to draw those connections, given the uneven spacing of the fossil record, are available in astrophysics. And no one in paleontology was aware of those.

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

B. The Benefits of a Smoke-free Workplace

Narrator: This is Science Today. A University of California, Berkeley study looking into the benefits of a smoke-free workplace, found that aside from the obvious health benefits for the employee, there's also direct benefits for the employer. Joel Moskowitz was lead investigator of the study.

Moskowitz: In the long term, employers have a lot to gain as well. One of the things we know about smokers is that they have higher rates of absenteeism due to various illnesses that they're more likely to contract. So their workers are much more productive, which is contrary to I think what some people's thinking - this hassle factor - the smokers have to go outside and may waste more time.

Narrator: The study also found smokers in non-smoking workplaces were more likely to quit than those in environments with no anti-smoking regulations.

Moskowitz: So, you're saving a lot of lives and reducing a lot of disease and disability. Other studies have shown that smokers will smoke fewer cigarettes, too, if they're in workplaces that restrict smoking.

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

C. Understanding Anxiety Disorders

Narrator: This is Science Today. Anxiety disorders affect approximately twenty million Americans. Lynn Martin, a clinical research specialist at the University of California, San Francisco, says it's natural to have some anxiety and fear ....

Martin: It's when it gets to be excessive, to cause a person significant distress in their life or to lead to impairment in functioning in any part of one's life - school work, home, relationships, that we begin to think of it as an anxiety disorder.

Narrator: Anxiety disorders include obsessive-compulsive disorder, phobias, traumatic stress and panic disorders and even excessive worry, known as generalized anxiety disorder.

Martin: And we're currently doing a research study on generalized anxiety and the phone is ringing off the hook with people who have high anxiety and excessive worry and it's usually worry about two or more things in one's life that one realizes one doesn't need to be worrying about.

Narrator: Public awareness of anxiety disorders is crucial since a lack of understanding prevent less than half of those affected from seeking treatment. For Science Today, I'm Larissa Branin

D. What Athletes Should Know About Leg Pain

Narrator: This is Science Today. Leg pain in athletes is often caused by stress fractures or shin splints but the source of pain can sometimes be a disorder called chronic compartment syndrome. Dr. Robert Pedowitz, a professor of sports medicine at the University of California, San Diego, says in terms of treatment, it's important to know the difference.

Pedowitz: Because the treatment is very different in a stress fracture versus a chronic compartment syndrome. One of the areas of research here at UCSD has been in developing techniques for making the diagnosis of chronic compartment syndrome.

Narrator: This disorder occurs when pressure within the muscle during exercise goes beyond a certain threshold, restricting blood flow and causing pain.

Pedowitz: So we have provided an evaluation service where we actually measure the pressure within the muscle by putting tiny catheters within the muscle and then we monitor the pressure before, during and after exercise. I suspect more patients in the past haven't had the surgery that can fix their problem because they never had the diagnosis established.

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

E. Obesity And Childhood Diabetes

Narrator: This is Science Today. In the last decade, there's been an almost sixteen-fold increase in cases of children with Type 2, or adult onset, diabetes. Dr. Kenneth Jones, who heads the University of California, San Diego's Division of Endocrinology and Diabetes, says parents of obese children or those who have a family history of diabetes, should be aware of the symptoms.

Jones: Increased frequency in urination, volume of urination, urinating at night and the younger patients return to bed wetting after being dry for periods of years and increased thirst are probably the major things that the parents need to look for.

Narrator: As in adults, the first line of defense is diet and exercise.

Jones: And this gets us to the issue of the increasing epidemic and is it caused by the increasing frequency of obesity in this country and what do we need to do about that? And certainly this is going to be a major public health problem over the coming years. If we are to arrest this epidemic of obesity, we need to attack it early.

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



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