Research
Roundup
$1.26
Million to Study Microfluidic Systems | $2.84
Million to Improve Reliability of Computers | National
Technology Lab for Adult Education | "Fuzzy"
Molecules Assemble into Distinct Lattices | Mild
Head Injury Increases Brain's Vulnerability
$1.26
Million to Study Microfluidic Systems
Researchers
at Penn have received a three-year, $1.26 million grant, part of
a push to develop minute, fluid-based systems that could be used
to safely detect minuscule quantities of airborne pathogens, analyze
blood in real time and inconspicuously monitor the safety of food
and water.
The
grant, to a Penn team led by Dr. Haim H. Bau, professor of mechanical
engineering and applied mechanics, comes from the Defense Advanced
Research Projects Administration, which is interested in furthering
the development of such microfluidic devices. Microfluidic systems
are intriguing to the military and others because they would allow
for real-time, inexpensive testing of samples, in some cases continuously
and remotely, without a need for skilled personnel.
Dr.
Bau and Penn colleagues Dr. Irwin M. Chaiken, research professor
of medicine and rheumatology, and Dr. Howard H. Hu, associate professor
of mechanical engineering and applied mechanics, will model the
transport of liquids, particles, macromolecules and cells in microconduits
and study their effect on biological interactions. The fluids and
particles will be driven and stirred by electrical and magnetic
forces.
In
order to test their ideas, the team will fabricate prototypes with
low-temperature co-fired ceramic tapes. In a prior DARPA-supported
effort, a Penn team demonstrated the applicability of the ceramic
tape technology for the fabrication of microfluidic systems.
"These
tapes allow one to fabricate devices and systems rapidly and inexpensively,"
Dr. Bau said. "We can literally go from a design to a prototype
in a matter of days."
$1.26
Million to Study Microfluidic Systems | $2.84 Million
to Improve Reliability of Computers | National Technology
Lab for Adult Education | "Fuzzy" Molecules
Assemble into Distinct Lattices | Mild Head Injury
Increases Brain's Vulnerability
$2.84
Million to Improve Reliability of Computers
Computer
scientists at Penn and other institutions have received a $2.84
million grant to boost the dependability of the specialized minicomputers
embedded in electronic devices from toasters to passenger jets.
The
three-year award, from the U.S. Department of Defense's Army
Research
Office, brings external funding awarded to Penn's embedded systems
research group within the last 18 months to more than $6 million.
"These
tiny embedded computers can literally make the difference between
life and death, so their reliability is crucial," said Dr.
Lee, principal investigator and professor of computer and information
science at Penn. "Even though they're small, these computers
are growing more complex, meaning the number of problems that can
develop in them is also growing."
Dr.
Lee and his peers will examine ways to engineer reliability and
reusability into embedded computers' software during the earliest
stages of design. Among their goals: developing an integrated approach
to development of reliable embedded systems that takes into account
real-time issues and resource constraints the system will face,
such as energy consumption, memory size and weight of the final
product.
Embedded
computers are ubiquitous, found in products ranging from dishwashers
to automobile transmissions to cellular phones. They underpin much
of modern medicine; equipment like heart-lung machines, infusion
pumps, defibrillators, dialysis machines and mammography machines
are all rife with embedded systems. "Embedded systems are becoming
increasingly networked, meaning the failure of one can cause many
others to fail," Dr. Lee said.
Lee's
Penn colleagues on the ARO grant include Dr. Rajeev S. Alur, Dr.
Carl A. Gunter and Dr. Sampath Kannan, each a professor of computer
and information science, and Dr. Oleg Sokolsky, research assistant
professor of computer and information science. Others on the project
include Dr. Robert P. Cook at Georgia Southern, Dr. Elsa Gunter
at NJIT and Dr. Kang G. Shin at Michigan.
$1.26
Million to Study Microfluidic Systems | $2.84 Million
to Improve Reliability of Computers | National Technology
Lab for Adult Education | "Fuzzy" Molecules
Assemble into Distinct Lattices | Mild Head Injury
Increases Brain's Vulnerability
National
Technology Lab for Adult Education
Educational
researchers at the national Center on Adult Literacy at Penn have
been awarded a three-year, $2.4 million grant from the U.S. Department
of Education to foster the use of technology, including distance
learning, the Internet and CDs, in adult education and literacy
programs nationwide.
The
goal of the project, TECH.21, is to make it possible for program
directors and practitioners to know what is available and make the
best choices for their students. Adult education and literacy teachers
and learners from nine sites across the country will experiment
with educational technologies designed to improve learning. The
principle site of the National Technology Laboratory will be at
Penn.
NCAL's
partners in this technology initiative include the Sacramento County,
Office of Education/Outreach and Technical Assistance Network, the
Public Broadcasting Service and the National Adult Education Professional
Development Consortium.
$1.26
Million to Study Microfluidic Systems | $2.84 Million
to Improve Reliability of Computers | National Technology
Lab for Adult Education | "Fuzzy" Molecules
Assemble into Distinct Lattices | Mild Head Injury
Increases Brain's Vulnerability
"Fuzzy"
Molecules Assemble into Distinct Lattices
Physicists
at Penn have determined that adding a "fuzz" of chemical
chains to colloidal molecules can lead them to form a predictable
array of lattices. The entropy-driven phenomenon represents a way
in which the power of entropy might be harnessed by scientists for
constructive purposes.
The
finding, in which researchers led by Penn physicist Dr. Randall
D. Kamien, examined the effects of a halo of polymer limbs on otherwise
spherical molecules suspended in liquid, is the cover story in the
current issue of the Journal of Physical Chemistry B.
Dr.
Kamien's work adds new evidence that entropy is far richer than
the gloomy drive toward universal disorder it was once thought to
be and suggests it could become a player in the world of self-assembling
molecules. Entropy's knack for driving fuzzy molecules into distinct
lattices offers scientists the promise of new materials designed
rationally rather than through trial and error.
"Predicting
the symmetry of the lattice formed by an organic compound is one
of the oldest dreams of synthetic chemists," said Dr. Kamien,
an associate professor of physics and astronomy at Penn. "By
providing an empirical connection between molecular structure and
macroscopic organization, our result will allow chemists to design
new materials from the top down."
Dr.
Kamien's theoretical work focused on colloids, which feature particles
suspended in liquid. Colloids are all around us, from milk to microreactors,
from pie filling to paint. Crystals formed from colloids form the
basis for a new class of functional materials for use in optical
switches, chemical microreactors and molecular sieves; the new finding
suggests the possibility of creating "designer molecules"
to speed this process along.
"The
old view was that the densest packing wins," Dr. Kamien said.
"Our work shows it's not that simple, especially as molecules
grow less dense."
The
molecules in the colloids Dr. Kamien studied were characterized
by a relatively dense core surrounded by a corona of hundreds of
spindly chemical arms. When virtually none of the fuzz was present,
the particles did indeed organize themselves into a face-centered
cubic array.
But
as the fuzz grows in length, to the point that the molecules were
almost all fluff with a very small core, they would form different
arrays of lattices that could be mapped with precise phase diagrams.
At stages where the fuzz was of an intermediate length, Dr. Kamien's
theoretical work predicts a mixture of face-centered cubic and other
lattices corresponding to the length of the fuzz, a prediction consistent
with experimental findings by Penn chemist Dr. Virgil Percec and
others.
Dr.
Kamien's co-author on the Journal of Physical Chemistry B
paper is Dr. Primoz Ziherl, Institut Jozef Stefan in Ljubljana,
Slovenia. Dr. Kamien and Dr. Ziherl's work was supported by the
NSF, the American Chemical Society's Petroleum Research Fund, the
Alfred P. Sloan Foundation and Penn alumnus Larry Bernstein.
$1.26
Million to Study Microfluidic Systems | $2.84 Million
to Improve Reliability of Computers | National Technology
Lab for Adult Education | "Fuzzy" Molecules
Assemble into Distinct Lattices | Mild Head Injury
Increases Brain's Vulnerability
Mild
Head Injury Increases Brain's Vulnerability
They
may want to "shake it off" and get back into the game.
But a single head injury--even a mild one--can put athletes at risk
for further traumatic brain injuries. According to researchers at
the School of Medicine the brain has an increased vulnerability
to severe, perhaps permanent, injury for at least 24 hours following
a concussion.
Their
results, published in the latest issue of the Journal of Neurosurgery,
have serious implications for victims of accidents and abuse, as
well as amateur and professional athletes. The researchers believe
their work provides a new model for looking at repetitive head injuries
(RHI). The prospect that athletes may be returning to the field
too soon after a head injury is alarming, say the researchers. The
research was funded by NFL Charities.
"If
you look a the guidelines for mild head injuries in athletes--from
high school to the pros--you'll see that they are written with little
hard scientific date," said Dr. Tracy K. McIntosh, the Robert
A. Groff Professor in the Department of Neurosurgery and director
of the Penn Head Injury Center. "Our findings represent the
first real attempt to look a the science behind bead injuries--and
we were startled to see how permanent the damage can be."
There
is already a growing body of data that suggests that those that
suffer RHIs in sports may be at greater risk for neurodegenerative
diseases later in life. In fact, the damage to the brain found in
victims of Dementia Pugilistica, or "Punch Drunk Syndrome,"
closely resembles that of Alzheimer's patients.
Although
they do not know the exact mechanism that leads to damage after
repetitive head injuries, Dr. McIntosh and his colleagues are interested
in one brain cell protein that has also been implicated in contributing
to Alzheimer's accumulations of the beta-amyloid precursor protein
(B-APP) was found in great quantities in the neurons of mice that
received RHIs, accompanied by an increase in the amount of dead
or dying neurons. They hypothesize that the damage from injury causes
B-APPs to gradually accumulate in the cytoskeleton of neurons, which
serves as the support structure for the cell as well as the roadway
by which nutrients travel throughout the cell. This roadblock slowly
chokes off the cell and eventually leads to its death.
According
to Dr. McIntosh, traumatic brain injury (TBI) is a "silent
epidemic" in our society. Each year, an estimated two million
cases of TBI occur in the U.S., with approximately 500,000 cases
serious enough to require hospitalization.
$1.26
Million to Study Microfluidic Systems | $2.84
Million to Improve Reliability of Computers | National
Technology Lab for Adult Education | "Fuzzy"
Molecules Assemble into Distinct Lattices | Mild
Head Injury Increases Brain's Vulnerability
Almanac, Vol. 48, No. 15, December 11, 2001
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