|
A.
Engineers Work to Develop Nanodevices for Cancer Detection and Treatment
Narrator: This is Science Today. Developing devices that are a hundred thousand times thinner than a human hair to track down cancer cells and deliver targeted anti-cancer drugs may seem like science fiction, but University of California at Riverside engineers are working on just that. Mihri Ozkan is hoping to combine her research of micro-electrical arrays, or the signals cells emit, with nanodevices to deliver anti-cancer drugs.
Ozkan: What we're trying to find out is actually to define signature patterns for breast cancer, for example, versus a healthy breast cell and differences between a prostate cancer cell. We are trying to, at the nanoscale, develop smart nanoscale particles, which can basically target and which can image and which can also deliver drugs to the spots that we want.
Narrator: Ozkan's research is part of a consortium that forms the Center for Cancer Nanotechnology Excellence, a new, nationally-funded center based at the University of California , San Diego . For Science Today, I'm Larissa Branin.
B.
Kids on the Witness Stand Likely to Tell the Truth
Narrator: This is Science Today. Over the last thirty years, there has been an increase in the number of court cases involving children – some as young as two years of age. But how competent are children as witnesses in the court? Research from the University of California , San Diego has found that kids on the stand are likely to tell the truth – even if their parents ask them to lie. Kang Lee, an associate professor of psychology, led the study.
Lee: It tells us the competence examination that's in place in our courtroom has some impact on the child's truthfulness when they are giving testimony.
Narrator: Lee says this kind of finding is not only useful for the courts, but also for the entire process of criminal investigations.
Lee: Not just the judge who would ask kids about the implications of lying or the importance of truth telling, but also you can ask the police, the social workers to ask these kinds of questions before they actually engage in interviews in the kids about what's happening.
Narrator: The laboratory-based study included over 200 children and one parent per child. For Science Today, I'm Larissa Branin.
C. Fish Evolve Longer Lifespan by Evolving a Longer Reproduction Period
Narrator: This is Science Today. Guppies living in environments with a large number of predators live longer than those in low-predation areas because they evolved a longer reproductive period. Biologist David Reznick of the University of California , Riverside says their study of the small freshwater fish supports a hypothesis that natural selection introduces changes in only a specific segment of an organism's lifespan.
Reznick: So, all of the increase in lifespan was strictly in the reproductive lifespan and that's consistent with theory because what natural selection predicts is that it only can act on the part of the lifespan of the animal that can contribute to fitness that can contribute to the production of offspring.
Narrator: The researchers then found that the post-reproductive lifespan was the same for guppies in both high and low-predation environments.
Reznick: So, what this tells us is that the guppies do, in a sense, what we predict. We would predict that there would be no differences among these populations in the post-reproductive lifespan because that part of the lifespan has nothing to do with fitness.
Narrator: For Science Today, I'm Larissa Branin.
D. A Potential New Target for Obesity Drugs
Narrator: This is Science Today. A brain protein already known to play a crucial role in the ‘feast or fast” signaling that controls the urge to eat, has also been found to impact the body's baseline regulation of energy balance. Christian Vaisse, an assistant professor of medicine at the University of California , San Francisco , discovered that mutations in the protein – called the melanocortin 4 receptor – disrupts this energy balance.
Vaisse: All this amount of energy has to be directly compensated by an equal amount of food intake and when I say equal, it has be at least as much as you expend, which is necessary for survival. If your input is lower than your expenditure, you'll die. If your intake is a little bit higher, your storage is going to increase, so your fat mass is going to increase and it will lead to obesity.
Narrator: This discovery identifies a potential new target for obesity drugs.
Vaisse: Understanding the genetic make up and understanding what the molecular systems are that they are made of, will eventually help us to find drugs to modulate it.
Narrator: For Science Today, I'm Larissa Branin.
E. Physicists Seek to Better Understand the Earth's Core
Narrator: This is Science Today. Determining the melting point of iron is essential to determine temperatures at the boundaries of the Earth's core, as well as the crystal structure of the solid inner core. Various experiments have been conducted to find out, but there wasn't consensus. Now, scientists at the Lawrence Livermore National Laboratory have used what's called a two-stage gas gun to determine the melting point to be just over 87 hundred degrees Fahrenheit. Lab physicist Neil Holmes co-led the study.
Holmes: We're measuring the melting indirectly. What we know is that solids support, basically the same kind of sound waves we see in seismology. And what you see when it melts, there's an abrupt change in velocity and so we're using that as a measure of how the iron melts.
Narrator: Holmes and his colleagues have been trying to measure the temperature for fifteen years.
Holmes: It's a very hard problem – it's one of the easiest problems to ask and one of the hardest ones to solve. So a long-term goal of the work in the group is to determine a solidly grounded way to measure the temperature as well.
Narrator: For Science Today, I'm Larissa Branin.
|
