The Cutting Edge: COMPUTING / TECHNOLOGY / INNOVATION : Worms, Water in Soil Studied Closely
A soil scientist at the University of Minnesota is discovering what fans of Frank Herbert’s classic science-fiction novel, “Dune,” have known for some time: There is a relationship between worms and the flow of water.
Earthworms affect the flow of water through the soil in ways that are just beginning to be understood. Sometimes they mean less runoff of applied chemicals, less erosion and less surface water pollution. In other cases, slimy worm holes can be direct conduits to ground water. Soil scientist Satish Gupta and his team are now developing computer models that may help generate specific recommendations to farmers to reduce the chances of ground-water contamination.
Gupta has found that the burrows of night crawlers are the most important water carriers. These burrows can go three feet straight down and are as wide as a pencil. The team also found that the deepest continuous worm holes, or macropores, are found in fields that contain dairy manure. This means dairy areas will likely have more conduits for water, which can result in a good or bad influence on the flow of potential contaminants into the ground water.
Tracking worm holes, however, isn’t easy. There can be hundreds or even thousands of burrows in a cubic yard of soil. One method is to take three-foot-deep soil cores and take them apart in the laboratory. Different colors of paint are squirted into each hole with a hypodermic syringe. A more high-tech method involves sending core samples in for a CT-scan, creating a three-dimensional view without disturbing the soil. Under development are computer models that may help generate specific recommendations to farmers to reduce the chances of ground-water contamination.
Have a (Pig) Heart: Researchers at Duke University Medical Center have altered the genetic makeup of pig organs to make them more “human.” Long term, that would be good news for people who need organ transplants, since those needing transplants currently outnumber donors by more than 10 to 1.
Normally, when an organ from one species is transplanted into another, it is rapidly rejected. But the Duke team has found that inserting human genes into fertilized pig eggs and then implanting them in host mothers result in a “transgenic” pig that can produce human proteins.
The human proteins in the pig’s organs, in turn, inhibit the first and most powerful rejection response, which occurs in the blood vessels lining the “foreign” organ. So far the “humanized” pig parts have only been tested on baboons. But human trials are expected to begin within several years. Pigs are considered good donors because their organs are about the same size as human organs, they are easy to breed and they don’t carry diseases that would harm humans.
These Lilies Are in Hot Water: Consider the lilies of the field, particularly the Easter lily. Easter lilies are a $6.5-million industry in Humboldt and Del Norte counties, which happen to be the only areas of the United States where the bulbs are grown. Some 65,000 boxes of Easter lily bulbs are shipped annually to greenhouses around the world. But the Easter lily has a foe, a microscopic soil worm called the lesion nematode. Pesticides
that would control the soil worms also result in environmental pollution. So growers have been looking for non-chemical answers to the pest problem. One promising approach appears to be simply dipping the bulbs in hot water before they are planted. Becky Westerdahl, a scientist at UC Davis, has found that bulbs that were dipped in hot water ranging from 123 to 135 degrees Fahrenheit were free of nematodes when they were planted. Westerdahl is currently researching the ideal water temperature and the ideal length of time for the bulb to remain in the water. She is also looking at the length of time and amount of land that would need to be left fallow for nematodes to starve to death.
Vaporize Blood Clots: Scientists at Los Alamos National Laboratory are adapting computing techniques developed in nuclear weapons research to learn more about the use of lasers to remove blood clots.
Blood clots can form suddenly within arteries of the heart, cutting off vital oxygen and nutrients to as much as half of the heart. The result can be heart failure and sudden death. One way to remove those life-threatening clots could be to vaporize them with laser energy--an approach being taken by the Oregon Medical Laser Center at Providence St. Vincent Medical Center in Portland. The laser procedure, laser thrombolysis, could become a practical complement to open-heart surgery, balloon angioplasty and clot-dissolving drugs.
In laser thrombolysis, a cardiologist threads a catheter that contains an optical fiber through an artery near the hip to the site of the blood clot at the heart. A laser fires a millionth-of-a-second pulse through the optical fiber to vaporize the clot. The procedure also removes the blood platelets that formed the clot in the first place.
But researchers still do not know exactly how the technique works. That’s where Los Alamos comes in. Detailed modeling of the laser thrombolysis process requires many of the same capabilities used to predict how nuclear weapon designs produce explosions that vaporize targets. Palomar Medical Technologies of Beverly, Mass., is developing the lasers and catheters used in the process.
