by Doug Prince
In this issue:
A Sharper Image
"Welcome to the Citadel of Xenon," says Bill Hersman as he opens the door to a room in the basement of DeMeritt Hall. It sounds as though it should be the palace of a mythical warrior princess, but it turns out to be an ordinary laboratory. On a workbench in the center of the room is a contraption made of plywood, duct tape and glass tubing--Hersman's prototype for an instrument that will give physicians a clearer view inside their patients' bodies.
Hersman is a UNH nuclear physicist, accustomed to fundamental research. But over the past few years, he has been working on a practical medical problem: expanding the capabilities of MRI (magnetic resonance imaging) technology.
MRI scanners enable doctors to see inside a human body, but don't give a very clear picture of the lungs. That's because lungs are filled with air instead of water like other parts of the body. MRI scanners rely on the ability of water's hydrogen atoms to act as tiny magnets, which emit detectable signals when the patient is placed inside a large magnet. Normally, an MRI signal from gas in the lungs would be 10,000 times weaker than the signal emitted by ordinary tissue. "Most patients can't lie still for the months it would take for that faint signal to transmit a readable image," Hersman says.
In recent years, a new technique has emerged for imaging lungs. Patients inhale a harmless noble gas, such as helium, whose atomic nuclei have been magnetized. When a few of these magnetized nuclei (about 2 percent) are made to point in the same direction--to be polarized--the MRI signal increases to normal levels. Today there are three centers in the world using helium in this way.
The form of helium used for lung MRIs does not occur naturally, and it's very expensive. A single liter of the stuff--enough for one deep breath--costs several hundred dollars. Xenon, on the other hand, is cheap; it can be extracted from the air. However, it's not used for MRIs because its nuclear magnets are three times smaller than those of helium.
This is where Hersman's nuclear physics comes in. The machine he is building in the Citadel of Xenon will make 70 to 80 percent of the nuclei in a sample of xenon line up at magnetic attention when a laser is beamed at them. Their signals can then be detected by a modified MRI imager. This imager uses a magnetic field about 1,000 times weaker than today's MRI behemoths, which cost more than a million dollars and fill an entire room.
One of the most useful applications could be a bedside MRI scanner for patients with chronic obstructive pulmonary disease, who are often too sick to be moved. Another application might be to study the effects of zero gravity on the lungs of astronauts. And geologists could use a low-field MRI device to evaluate the properties of rocks.
Is this the beginning of a new field of research? Hersman can't say. "I'll only know how important it is after the contribution is made," he says.
Help Wanted: Engineers
New Hampshire is going to need a lot more engineers to keep the engine of its economy on track. And not just engineers, but also college graduates in computer science and mathematics to fill a variety of jobs in the state's expanding high-tech industries.
That's the conclusion reached by Ross Gittell, an associate professor in the Whittemore School of Business and Economics, and Brian Gottlob '85G, president of the consulting firm PolEcon, in a report prepared for the New Hampshire Education Forum. They warn that a shortage of college-educated workers is slowing the growth of the state's economy.
"This is the main reason why the state lost its number-one rank (among the 50 states) in the percentage of employment in high-tech industries last year," Gittell says. "It was caused by an inadequate supply of skilled labor."
The problem is that New Hampshire colleges are producing too few qualified graduates to fill the increasing number of high-tech jobs. Last year, USNH graduated a total of 217 students with four-year degrees in math, computer science or engineering, and all of the other colleges in the state graduated about 276 more. But New Hampshire businesses are creating about a thousand openings in those fields each year. And according to the study, the number of high-tech degrees awarded each year is declining, not increasing.
That pattern is not limited to New Hampshire; it's occurring in most states. But Gittell notes that the effects are more severe here for two reasons. "First, because high-tech industries are such a dominant factor in the state's economy. Second, because New Hampshire already lags behind the rest of the nation in the number of high-tech degrees awarded per 1,000 high-tech jobs. For the U.S., that number is 118.4; for the New England region, it is 93.3; and for New Hampshire, it is 69.5."
Until now, New Hampshire companies have been able to make up for the shortage of high-tech graduates within the state by recruiting college-educated workers from elsewhere, particularly from other New England states. But since those states now have strong economies, low unemployment rates and aging populations, Gittell predicts that fewer college graduates will want to move to New Hampshire for the sake of a job. "In the future, more than two-thirds of new skilled workers in New Hampshire will have to come from in-state institutions of higher education," he says.
What can be done to make sure those workers will be available? These are some of the report's recommendations:
Do the Numbers
When he was growing up in China, Yeping Li often heard the saying, "If you can do well in math, physics and chemistry, you can go around the world without fear." Since then, he has gone around the world, from China to UNH, where he is an assistant professor of mathematics. An expert in mathematics education, he believes the saying he learned in his youth may help explain the discrepancy between Asian and American scores on international math tests. While several Asian countries always rank at the top, the U.S. is often near the bottom. In 1995, the U.S. placed 19th out of 21 industrialized countries.
The Chinese clearly place a high value on math skills. "In America, people will say, 'I'm not good in math,'" Li notes, "but people will not tell you, 'I cannot read a newspaper.'"
Research shows that Americans tend to believe mathematical ability is innate, whereas the Chinese believe it is acquired through effort.
East and West also differ in teacher training and curriculum development. Even in the first grade, most Chinese children learn math from a trained math teacher (lecturing to a class of 40 to 50 attentive students). Li has found that Asian textbooks contain more difficult problems than U.S. textbooks and that American ninth-graders learn roughly the same material Chinese students get in seventh grade.
"Cross-cultural studies can provide a mirror to help us reflect on our own educational practices," says Li. When Asian countries look in the mirror, they, too, may see things that need to be changed. Asian students have excelled in traditional problems requiring pure math skills, Li notes. But in some tests, Americans have done better with problems requiring them to put their computation into context. (An example: recognizing that storing 22 tapes in boxes of 5 each would require 5 boxes, not 4.4 boxes.) In fact, Li's research shows that American textbooks place more emphasis on conceptual learning and applied math than Asian textbooks.
To improve American math instruction, Li believes that systematic change will be necessary. Simply copying a practice from another culture may not work: just imagine delivering a math lecture to a class of 50 American first-graders. He recommends that schools provide an environment where teachers can collaborate more in planning and curriculum development. In China, teachers have much more time for these activities, since the typical workload is only about three to four classes a day. More collaboration between parents and teachers would also help. And he urges parents to maintain a positive attitude toward math, recognizing that "effort, not innate ability, is needed to succeed in school math."
Li, who has been on both sides of the cross-cultural looking glass, still sees "more questions than answers." Undaunted, he smiles and adds, "There is much work to be done."
--Virginia Stuart '75, '80G
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