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A.
Smarter Radiation Detection Technologies for Cargo Containers
Narrator: This is Science Today. Nuclear physicists at the Lawrence Livermore National Laboratory are working on developing smarter radiation detection technologies for cargo containers entering U.S. seaports. Dennis Slaughter says high sensitivity is key because the radiation that comes from a nuclear weapon is quite weak.
Slaughter: The problem is, its weaker than a whole lot of background sources present in the environment and its weaker than the radioactivity in a lot of legal shipments. Radioactive pharmaceuticals, various commercial cargo materials if you gather together thirty tons of some of this stuff, the radioactivity signals pretty large. And the radioactivity due to a nuclear weapon is a lot less than that.
Narrator: Slaughter says the obvious concern is the possibility of false alarms.
Slaughter: Were trying to build a system where the radiation we see is really distinctive, not like natural background, so that we can be sure that if we say, that's it, we think theres one there, that we wont be wrong about that any more than about one time in a thousand.
Narrator: Technical obstacles include figuring out how to detect nuclear materials even if terrorists have shielded the materials with lead. For Science Today, I'm Larissa Branin.
B.
A University-Business Partnership Opens Up New Frontiers of Research
Narrator: This is Science Today. The University of California , Santa Barbara and a private satellite company called Terra Image USA have formed a partnership that will open up new frontiers of research. David Siegel, a geography professor and director of the university's Institute for Computational Earth System Science, explains that because of prohibitive costs, researchers and students were not able to utilize very high-resolution satellite images.
Siegel: A single scene, which is a snapshot taken from space on a sixty kilometer by sixty kilometer basis can cost anywhere from a couple thousand to eight thousand dollars. And if you want to do science at the cutting edge, you need to have enough of those that you can resolve temporal change. You want to see how cities grow, you want to see how forests go through their seasonal cycles. Change is a fundamental part of this, so for a variety of reasons, it was priced out of the scales that academic researchers can use it.
Narrator: Having virtually unlimited access to this sophisticated technology will also benefit students. For Science Today, I'm Larissa Branin.
C.
A Non-Invasive Technique May Offer Early Detection of Alzheimer's Disease
Narrator: This is Science Today. Arterial spin labeling is a non-invasive MRI technique that measures the supply of blood flow in the brain. Norbert Schuff, an associate professor of radiology at the University of California , San Francisco , has been using this technique in a study to measure blood flow in areas of the brain affected by degenerative disease.
Schuff: It takes less time and since its non-invasive, you can repeat it over and over again. So, since there's no risk to a patient's health from injections or accumulation of radioactive trace in your body, we can do it over and over again. So, even if the first scanner is not doing very well, we can repeat it and actually, even more important we can do it in such a way that we can measure how blood flow changes in very short time frames.
Narrator: The researchers found that arterial spin labeling could actually distinguish between Alzheimer's disease and frontotemporal dementia, which in the early stages, is difficult to do.
Schuff: So, we believe that measuring blood flow might be an even earlier marker of Alzheimers disease or other neurodegenerative diseases than looking at brain shrinkage.
Narrator: For Science Today, I'm Larissa Branin.
D.
What Would You Do If You Encountered a Mountain Lion?
Narrator: This is Science Today. Reports of fatal mountain lion attacks in recent years have put people living near mountain lion territory on edge. But wildlife expert Walter Boyce of the University of California , Davis says worry and anxiety caused by mountain lions are really out of proportion to the risk.
Boyce: Mountain lion attacks are very rare. Those of us that spend a lot of time out in the environment looking for lions still have a hard time finding them and we don't see them very often. In the vast majority of the time, lions are doing everything they can to avoid us.
Narrator: Boyce explains that most human-lion encounters are what are called simple sightings people are hiking or out in the woods and all of a sudden, a lion appears. Usually, the lion goes one way and the person goes another with no threat. But on occasion, a lion may act in a threatening way.
Boyce: If a lion does appear threatening to you, what you want to do is act big and yell at it. You want to be the aggressive, dominant animal in this case and again, in the vast majority of the time, the lion will turn and run away.
Narrator: For Science Today, I'm Larissa Branin.
E.
An Updated, High-Tech Version of the White Cane for the Blind
Narrator: This is Science Today. A computer engineer at the University of California , Santa Cruz has developed what's called a virtual white cane, which is an assisted technology device for the blind. Roberto Manduchi says in its ultimate form, the device would look like a flashlight and would be carried by the blind to help navigate their surroundings.
Manduchi: If you talk with blind people, they love the white cane, so its not clear if well be able to replace that. The white cane is very economical, it never runs out of power, you can fold it and put in your pocket. Being white, it is something that allows other people to notice you and therefore to behave accordingly.
Narrator: But, Manduchi adds that the white cane does have its limitations; it bumps into things and cannot navigate at a distance.
Manduchi: So if I'm in an unknown environment and I'd like to know where the door is, or where the staircase is, that white cane is not going to help us. The device were building has much longer range, it is not invasive, it doesn't bump into things. So, it does have a number of features that the white cane doesn't have.
Narrator: For Science Today, I'm Larissa Branin.
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