From biomedical engineering and medical device development to genetic research
and biological process technology, IT researchers play a major role in the growing
field of biotechnology. Here is a look at 13 of the most innovative projects
underway.
Two billion years of continental motion,
climatic changes, and magnetic field shifts are locked
inside the rocks forming the layered strata of the earth's
crust. To Bruce
Moskowitz, one possible
key to this wealth of geologic history lies in the fossilized
magnetic skeletons of magnetotactic bacteria.
As he talks about his work, Moskowitz holds an old black and white
photo encased in a cracked frame, glancing at it with a certain
fondness. The photo depicts a bacterium magnified a hundred thousand
times. A typical magnetotactic bacterium is tiny—about two microns
long, 25 times smaller than a single human hair.
The bacterium resembles a translucent hot dog bun with a flagellum,
except for one strange feature—a string of about
ten flat black squares running along what would be its
spine. Those dark cubes, Moskowitz explains, are tiny
magnets the bacterium uses for “magneto-navigation,”
employing the earth's magnetic field as a navigational
tool, just as ancient mariners used the stars. The cell
passively aligns itself with the Earth's magnetic field,
leading the bacterium downward toward sediments and
away from potentially toxic concentrations of oxygen
in the surface waters.
"Essentially, they grow their own compasses,” explains
physics professor Dan
Dahlberg, who studies the bacteria along with Moskowitz and
geophysics professor Subir
Banerjee.
Dahlberg, Moskowitz, and former graduate student Roger Proksch
produced the first detailed magnetic images and cross-sections of
the bacteria at the physics department's Magnetic Microscopy Center.
The information revealed in those images may help explain how tiny
magnetic particles switch their magnetization, says Dahlberg.
According to Moskowitz, the fossilized remains of magnetotactic
bacteria provide equally important insights. By analyzing the remains,
which are sealed in sedimentary rock with their magnetic alignments
intact, paleomagnetists can calculate the latitude at which the
bacteria were fossilized and compare that measurement to the location
where the remains were unearthed.
"It gives you the geologic history of plate motions back two
billion years,” says Moskowitz. “It can basically produce
paleographic maps that, through time, can assemble the continents."
But geologists aren't the only ones interested in magnetotactic
bacteria. “These bacteria have broad cross-disciplinary appeal,”
says Dahlberg. “Geologists are interested in their relationship
to geomagnetic history. [Physicists are] interested in them as a
model for the general problem of magnetic reversal. And biologists
are interested in understanding their evolution and environmental
significance."
Magnetotactic bacteria were thrust into the international limelight
in August 1996, when several NASA scientists published a paper in
the journal Science claiming they had discovered evidence of life
on Mars. According to the article, one of the major pieces of evidence
was the discovery of small bits of magnetite distributed throughout
an alleged Martian stone.
"I thought it was interesting they were basically using evidence
from magnetotactic bacteria . . . as one of the cornerstones for
making this claim,” says Moskowitz, who “wasn't particularly
convinced” that the particles were the remains of ancient bacteria
on Mars.
The fossils may also yield information about climatic change over
long periods of time, says Moskowitz, and may suggest the natural
ebb and flow of weather patterns.
"One can look at the geographical factors that control climate
and try to decouple these from human factors, such as global warming,”
he says. “We can see whether any of these changes are actually
important."
