briefs
Pictured is a diagram for a queueing theoretic
model describing how upstream components
compete in a bottleneck to produce proteins.
Queueing theory helps
physicist understand
protein recycling
John Aigner, a doctoral student of entomology in the College of Agriculture and Life Sciences, fills
a foil roasting pan with water and dish soap. Set the pan out overnight with a light shining on it to
trap stink bugs.
Homemade stink-bug
traps squish competition
A Virginia Tech team of
researchers has proven that
homemade, inexpensive stinkbug traps crafted from simple
household items outshine pricier
models designed to kill the invasive,
annoying bugs.
Researchers found that the best
way to get rid of the pests is to fill a
foil roasting pan with water and dish
soap and put a light over the pan
to attract the bugs in an otherwise
dark room. The homemade trap
eliminated 14 times more stink bugs
than store-bought traps that cost up
to $50, the study found, and may
cost nothing, since it’s composed of
items most people already own.
Though the solution is not new
and has been promoted on YouTube
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and other websites, this is the first
time it was actually tested in a
scientific experiment.
To conduct the study, John
Aigner, a doctoral student in
the Department of Entomology,
and Tom Kuhar, an entomology
professor and Extension specialist,
enlisted the help of citizen scientists
— homeowners who were annoyed
by the infestation of stink bugs in
their houses — to evaluate different
types of traps for ridding homes of
bugs. The study was conducted in 16
houses over two years.
Unfortunately, the traps are
practical only in homes, and do not
offer a solution for farmers in the
mid-Atlantic region, who have faced
millions of dollars in damage to their
crops since the brown marmorated
stink bug invaded the mid-Atlantic
region in the late 2000s.
Most of us have had the
experience of getting stuck in a long
check-out line.
For Will Mather, an assistant
professor of physics and an instructor
with the College of Science’s
Integrated Science Curriculum,
studying lines, or queues, has been
crucial in trying to understand how
cells deal with bottlenecks that limit
the recycling of proteins.
The work has received attention
from the National Science
Foundation in the form of a
$960,000 grant.
Mather tries to extend an
understanding of waiting in line to
how cells operate, especially as it
relates to protein “traffic jams” inside
cells.
“If you consider the analogy of a
subway, it’s a fairly apt one,” Mather
said. “A subway can deal with a
certain number of customers with its
limited number of outlets. If the flow
is correct, the system works fine. If
people arrive in bunches, it can jam
the system. The same is true in cells.”
In the subway analogy, enzymes
act as gatekeepers, while proteins are
the customers. The proteins are trying
to be recycled so they can be made
into other proteins, but the enzymes
can handle only so much traffic.
Proteins that wind up in a “traffic jam”
are either not recycled or need to find
alternative pathways.
“What we’re doing now is using
a common bacterium, E. coli, and
fluorescent proteins to see how
circuits behave in individual cells in an
effort to understand the effect of these
pathways,” Mather said.
Mather seeks to discover the
mechanism behind how cells naturally
alleviate bottlenecks by directing their
proteins to different “servers” to be
recycled. He expects this research will
produce quantitative models for these
bottlenecks, and ultimately create new
molecular tools that will allow for the
construction of large, scalable biocircuits in bacteria.
Two wasps imported from Mexico
were used to combat an expensive
pest in India. The Acerophagus
papayae was found to be effective
against the papaya mealybug and
saved farmers and consumers
millions of dollars.
Virginia Tech-led pestcontrol measure saves
$309 million for Indian
farmers, consumers
Virginia Tech researchers who
first discovered a devastating pest in
India and devised a natural way to
combat it have now put an economic
value on their counterattack: up to
$309 million the first year and more
than $1 billion over five years.
That’s the amount of damage
the papaya mealybug would have
wreaked on farmers and consumers
in India without scientists’
intervention.
The papaya mealybug ripped
through crops, including papaya,
eggplant, and tomato in southern
India, causing mold and stunted
growth, before Rangaswamy “Muni”
Muniappan of Virginia Tech
identified the pest and spearheaded
the natural control program.
For a relatively modest cost of
$200,000 during the first year of the
intervention, devastation that would
have totaled from $524 million to
$1.34 billion over five years was
prevented, Muniappan and other
scientists reported in the February
2014 issue of the journal Crop
Protection.
“India’s first efforts to eradicate
the papaya mealybug failed,” said
Muniappan, who heads up Virginia
Tech’s federally funded Integrated
Pest Management Innovation Lab
program, a venture that works in
developing countries to minimize
crop losses, increase farmer income,
and decrease pesticide use. “The
government and farmers tried
spraying pesticides, but crop losses
kept getting larger. It was clear to us
that this was a case not for poisons
but for natural, biological controls.”
The winning intervention
centered on three parasitic wasps
from Mexico, natural enemies of the
mealybug that the U.S. government
first employed in Florida after the
pest spread there in the late 1990s.
The wasp lays its eggs inside the
mealybug larvae, and when the eggs
hatch, the young wasps eat the larvae.
The paper’s authors include
Stephanie Myrick of Virginia Tech’s
College of Agriculture and Life
Sciences and representatives from
Tamil Nadu Agricultural University
in India.
Virginia Tech RESEARCH
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Plastics to dust: Easyto-compost plastic bags
closer to mainstream
Wolfgang Glasser said he was
hesitant when a start-up company
asked him to be its chief scientific
officer. But then the professor
emeritus of sustainable biomaterials
realized that cycleWood Solutions
Inc. could make his dream —
biodegradable plastics from a
plentiful natural resource — a reality.
During his three decades with
Virginia Tech’s College of Natural
Resources and Environment, Glasser
worked with many students as
they advanced the field of natural
polymers. But the most recent
breakthroughs came in partnership
with two University of Arkansas
The single-use bags are made with
components that can be composted
just like any other plant-based material.
Summer 2014
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M.B.A. graduates, who came up with
a plan to use lignin, a natural polymer
that helps form the cell walls of plants,
for biodegradable plastic bags.
“They went to National Science
Foundation for a Small Business
Innovation Research grant,” Glasser
said. “The NSF wanted them to have
a lignin chemist on staff, and that
is how I became the chief scientific
officer of cycleWood Solutions.”
Glasser began working with lignin
because it was plentiful and cheap.
It could be used to make “green”
polymers — those from a renewable
source rather than from petroleum.
“My ‘a-ha’ moment came when,
in addition to viewing lignin from
a resource viewpoint, I realized its
environmental benefits,” he recalled.
“It could be compostable. Plastic bags
and bottles needn’t last forever.”
That’s where cycleWood
Solutions comes in. The company
has produced single-use plastic bags,
trash can liners, and meat bags, and is
testing cups and plates. “The bags are
made with natural components and
can be composted just like any other
plant-based material,” said Glasser.
While a professor at Virginia
Tech, Glasser worked on various
issues involving lignin structure,
delignification chemistry, and
structure-property relationships of
lignin-based materials, including
thermosets and thermoplastics. He
was founder and director of the
Biobased Materials Center, which
became one of Virginia Tech’s first
Technology Development Centers,
between 1986 and 1991.
Senior analytical chemist Jody Smiley (left) explains an analytical process to graduate students in Andrea Dietrich’s Civil and Environmental Engineering Techniques for Environmental Analysis class. Dietrich received a $50,000 National Science Foundation Rapid Response Research grant to study
the chemical that contaminated the drinking water of more than 300,000 West Virginians.
West Virginia chemical
spill into Elk River
contaminated air, too
In the months since the January
2014 chemical spill into West
Virginia’s Elk River, new findings
reveal the nature of the chemicals
that were released into the water and
then into the air in residents’ houses.
The spill occurred upstream from
the West Virginia America Water
intake, treatment, and distribution
center.
Some 300,000 residents were
affected.
When civil and environmental
engineering professor Andrea
Dietrich’s team first started, its goal
was to conduct detailed scientific
investigations to determine the
long-term fate of the chemicals in the
drinking water distribution system
and in the environment.
But as the ban was lifted on
drinking water use, the Virginia
Tech researchers realized that West
Virginians were still complaining of a
licorice odor in their homes.
“Like for many contaminants
in water, chemicals leave the water
and enter the breathing air, so that
inhalation becomes a route for
human exposure as well as drinking
the water,” said Daniel Gallagher,
also a faculty member in Virginia
Tech’s Via Department of Civil and
Environmental Engineering and a
member of the research team.
The Virginia Tech researchers
were able to pinpoint the
concentrations of contaminants
in the air by using olfactory gas
chromatography, which allowed
measurement of two isomers found
in 4-methylcyclohexane methanol (or
MCHM), the major component in
the crude mix of the Elk River spill.
Only one of the isomers has the
characteristic licorice-like odor.
Researchers determined the
licorice odor of MCHM is readily
detectable even when the water
concentration meets the health
guideline level.
An “important implication of the
findings,” Dietrich said, “is the critical
need to independently measure the
concentrations of the cis- and the
trans-isomers, as was done in this
study.”
She said the licorice odor will be
proportional to the amount of the
trans-isomer, not the total amount of
MCHM.
Dietrich is an expert on water
quality and treatment, as well as its
taste and odor assessment.
She travels internationally to
speak and train on detecting tastes
and odors in drinking water.
Virginia Tech RESEARCH
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