Spotlight on Research
Mason Researchers Work with NASA in Bay Restoration
With an initial grant of $100,000, researchers from George Mason’s Department
of Environmental Science and Policy (ESP) and Center for Earth Observing and Space
Research began work last August to support National Aeronautics and Space Administration
(NASA) participation in the Chesapeake Bay Restoration Initiative. The research
will be performed on yearly contracts with funding that could reach $500,000,
says Chris Jones, ESP’s interim director.
The researchers hope to map environmental activity in the bay, collecting data
on biological communities, phytoplankton, chlorophyll content, bacterial abundance,
and estuarine eutrophication. The data will be analyzed and integrated into the
NASA geographic information system (GIS) for environmental management.
“We’re getting some powerful GPS [global positioning system] equipment
in this first contract,” says Jones. The equipment will allow researchers
to record the longitude and latitude of locations where they find samples in the
field. Those coordinates will then be stored in a central database, he adds. Should
someone want to build a parking lot near the water, those coordinates could be
plugged into the GIS to show the biological communities in the area. “Let’s
say they come up with an endangered species, then they know they have to be careful
when constructing the parking lot,” says Jones.
Remote sensing, or the use of satellite imagery, is another way to get information
into the GIS, says Jones. The satellite images can be referenced to longitude
and latitude, so researchers can match what is seen from the satellite with conditions
on the ground. Remote sensing allows researchers to look at the various wave lengths
in the spectrum of radiation coming from an object and at the ratios in that spectrum.
“Then you have to do some kind of ground truthing,” says Jones. “In
other words, you have to go in the field and determine, for example, that if the
water is this brown, then the water is 10 parts per million sediment.” By
correlating the remotely sensed data and the ground truthing, the information
could be extrapolated in the future to a much larger area than is actually measured.
—Lynn Burke
Orangutans Show Ability to Discriminate Quantity
In groundbreaking research conducted by Robert Shumaker, director of cognitive
behavioral research at the Krasnow Institute for Advanced Study, orangutans have
shown that they can judge differences in quantity.
Shumaker, who is also a biologist at the National Zoo, conducted the research
at the zoo with a 23-year-old male orangutan named Azy and his 21-year-old sister,
Indah. The findings were published in the December Journal of Comparative Psychology.
In the experiments, Shumaker presented the subject ape with two sets of one
to six grapes. The ape was allowed to choose one of the sets, which was then removed;
the ape received the remaining grapes. The reversed reinforcement contingency
meant that the only way for the ape to optimize performance (that is, have more
grapes) was by choosing the smaller quantity first at all times.
Both orangutans demonstrated the ability to differentiate all quantities ranging
from one to six and solved the reinforcement contingency that was in place. Azy
reached a score of 100 percent accuracy, and Indah reached a high score of 95
percent.
Chimpanzees previously tested by other researchers on the same task never learned
to optimize their performance when presented with arrays of foods.
“The results suggest a cognitive difference between chimpanzees and orangutans,”
Shumaker says. “Chimpanzees, who live in a complex and competitive social
environment, benefit from being impulsive in their decisions about food. Orangutans,
who are much more solitary than chimpanzees and rarely have direct competition
for their food, are able to be more contemplative about their decisions.”
The research is part of the ongoing Orangutan Language Project, which began
in 1995. This cognition project is the only one in the world that the public may
observe as it is conducted. Visitors can watch Shumaker give the orangutans their
lessons at the zoo’s Think Tank exhibit.
Shumaker’s research was featured in a Dec. 21 segment called “Orangutans
Outsmart Chimps?” on National Public Radio’s Morning Edition,
which can be found at www.npr.org.
—Robin Herron
“Dog Nose” Research Supports Man’s Best Friend
For many years, the military has capitalized on dogs’ keen sense of smell,
training them to search for land mines, which can then be defused. But more efficient
and less dangerous ways to defuse land mines are being sought.
Both the humanitarian and mathematical aspects of the problem intrigued Edward
Wegman, the Bernard J. Dunn Professor of Information Technology and Applied Statistics
and director of the Center for Computational Statistics, who joined forces with
other researchers in a two-and-one-half-year artificial dog nose project funded
by the Defense Advanced Research Projects Agency. The project involved developing
an artificial chemical-sensing element to detect the weak but distinct odor of
gases a land mine emits as the chemicals in it begin to decompose, which dogs
have been trained to sniff out.
Building on sensor work performed at Tufts University, Wegman and colleagues
from Johns Hopkins University and the Navy Surface Warfare Center focused on the
mathematical job of differentiating the various aromatic chemicals that a sensor
could detect. When the gases react with specially coated fiber optic strands in
a sensor, the fibers reflect light differently depending on the chemical composition
of the gas. The collaborators developed statistical and graphical algorithms for
weighting the response to differentiate the aromatic chemicals.
Their goals were to differentiate the 300 or so aromatic chemicals and dynamically
tune the sensor to a chosen chemical, targeting those chemicals in a decomposing
land mine. The approach was successful at distinguishing the aromatic chemicals;
however, the sensor’s limited sensitivity and the low levels of chemical
concentration limited the artificial dog nose’s ability to detect mines.
The verdict: “The artificial dog nose is not as sensitive as a real dog nose,”
Wegman says, “but a sensor could detect higher concentrations of a chemical.
It could be used as a warning to detect fuel leakage or overheating on an aircraft,
or it could detect aerosols used in chemical or biological warfare.”
—Robin Herron
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