[Editors] MIT Research Digest, July 2008
Elizabeth Thomson
thomson at MIT.EDU
Tue Jul 1 16:50:19 EDT 2008
For Immediate Release
TUESDAY, JUL. 1, 2008
Contact: Elizabeth A. Thomson, MIT News Office
T. 617-258-5402 E.: thomson at mit.edu
======================================
MIT Research Digest, July 2008
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A monthly tip-sheet for journalists of recent research advances
at the Massachusetts Institute of Technology.
Latest research news: http://web.mit.edu/newsoffice/research.html
RSS -- research feed: http://web.mit.edu/newsoffice/mitresearch-rss.xml
IN THIS ISSUE: Sichuan Earthquake * No Numbers * Wheelchair Design
Searching for Planets * Audio-Game * Nanostripes & Drug Delivery
Trading CO2 * X-ray Nanomirrors * Super-Sensitive Detector
Martian Impact * Novel Solar Dish * Solar Collaboration
Optical Tug * Protein Probe * Harnessing the Sun * Genetic Foil
Flexible Airport Design * Colorectal Cancer Drug * Bacterial
Communication
Solar Textiles * Eradicating TB * Teacher-Testing
Crab Pulsar * Inflammation, Cancer Link * Brain Imaging Mystery
SICHUAN EARTHQUAKE
A new MIT analysis of the setting for May’s devastating earthquake in
China shows that the quake resulted from faults with little seismic
activity, and that similar events in that area occur only once in
every 2,000 to 10,000 years, on average. However, the researchers
caution that because earthquakes can sometimes occur in clusters,
people should still be wary of another possible large-scale
earthquake. The magnitude 7.9 quake struck Sichuan province on May
12. More than 69,000 people have been confirmed dead so far, and more
than 374,000 injured. Clark Burchfiel, Schlumberger Professor of
Geology, and Leigh Royden, professor of geology and geophysics in the
Department of Earth, Atmospheric and Planetary Sciences at MIT, have
been doing extensive research in that region of China and the Tibetan
plateau for more than two decades, but had found no hints that
suggested such a large earthquake might strike the area. They and
several colleagues have published a paper analyzing the causes of the
quake that appears in the July issue of GSA Today, a publication of
the Geological Society of America. The research was funded by the NSF.
PHOTOS AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/quake-china-0630.html
NO NUMBERS
An Amazonian language with only 300 speakers has no word to express
the concept of "one" or any other specific number, according to a new
study from an MIT-led team. The team, led by MIT professor of brain
and cognitive sciences Edward Gibson, found that members of the
Piraha tribe in remote northwestern Brazil use language to express
relative quantities such as "some" and "more," but not precise
numbers. It is often assumed that counting is an innate part of human
cognition, said Gibson, "but here is a group that does not count.
They could learn, but it's not useful in their culture, so they've
never picked it up." The study, which appeared in the June 10 online
edition of the journal Cognition, offers evidence that number words
are a concept invented by human cultures as they are needed, and not
an inherent part of language, Gibson said.
PHOTO AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/language-0624.html
WHEELCHAIR DESIGN
Throughout the developing world, 20 million people need wheelchairs
but are unable to get them. And even the lucky ones who do get them--
usually through charitable donations--often get chairs designed for
the smooth floors and sidewalks of the industrialized world, which
can be difficult or even impossible to use on the unpaved roads and
narrow hallways that people often face. Amos Winter, an MIT graduate
student in mechanical engineering, has spent much of the last three
years trying to address these problems by working with wheelchair
workshops in various countries in Africa and Asia to help develop new
designs. His focus has been on chairs that work better under the
rough conditions they face in each location, that can be made locally
with readily available materials and by local workers, and that are
rugged enough to stand up to the rough roads, gear-clogging dust and
wet and muddy conditions they often face. Last semester, for the
second time, Winter also taught a class on wheelchair design for the
developing world. The 22 students in this year's class split into
five teams and each came up with new variations on how to help bring
mobility to people whose lives could be dramatically changed by it.
PHOTO AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/itw-wheelchairs-tt0521.html
SEARCHING FOR PLANETS
A planet-searching satellite planned by scientists from MIT, the
Harvard-Smithsonian Center for Astrophysics and NASA-Ames is one of
six proposed spacecraft concepts that NASA has picked for further
study as part of its Small Explorer satellite program. The planet-
searching satellite would have the potential to discover hundreds of
“super-Earth” planets, ranging from one to two times Earth's
diameter, orbiting other stars.The six projects were selected from
among 32 proposals submitted to NASA in January. Each of the six will
receive $750,000 for a detailed six-month feasibility study. In early
2009, two of the projects will get the go-ahead for development at a
cost of no more than $105 million, excluding the launch vehicle, with
the first launch as early as 2012. The proposed satellite, called the
Transiting Exoplanet Survey Satellite (TESS), would use a set of six
wide-angle cameras with large, high-resolution electronic detectors
being developed in cooperation with MIT's Lincoln Laboratory, to
provide the first-ever spaceborne all-sky survey of transiting
planets around the closest and brightest stars. Plans for TESS are
being led by senior research scientist George R. Ricker at the MIT
Kavli Institute for Astrophysics and Space Research.
MORE: http://web.mit.edu/newsoffice/2008/tess-0603.html
AUDIO-GAME
A new computer game developed by MIT and Singaporean students has
taken the video out of videogames, making it possible for visually
impaired people to play the game on a level field with their sighted
friends. The game, called AudiOdyssey, simulates a deejay trying to
build up a catchy tune and get people dancing. By swinging the remote-
control device used by the Nintendo Wii, which senses motion, the
player can set the rhythm and lay down one musical track after
another, gradually building up a richer musical track. Eitan Glinert,
a recent graduate student in computer science at the Singapore-MIT
Gambit Game Lab established by MIT and the Media Development
Authority of Singapore, worked with a team of seven other students
to develop the prototype for AudiOdyssey in the summer of 2007, and
has since been testing it with various groups of players. Since not
everyone has access to the Wii controller, the game is also designed
to be playable using a regular keyboard. AudiOdyssey is available for
free download (Windows only) at gambit.mit.edu/loadgame/audiodyssey.php.
IMAGES AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/audio-game-0513.html
NANOSTRIPES & DRUG DELIVERY
In work that could at the same time impact the delivery of drugs and
explain a biological mystery, MIT engineers have created the first
synthetic nanoparticles that can penetrate a cell without poking a
hole in its protective membrane and killing it. The key to their
approach? Stripes. The team found that gold nanoparticles coated with
alternating bands of two different kinds of molecules can quickly
pass into cells without harming them, while those randomly coated
with the same materials cannot. The research was reported in a recent
advance online publication of Nature Materials. “We've created the
first fully synthetic material that can pass through a cell membrane
without rupturing it, and we've found that order on the nanometer
scale is necessary to provide this property,” said Francesco
Stellacci, an associate professor in the Department of Materials
Science and Engineering and co-leader of the work with Darrell
Irvine, the Eugene Bell Career Development Associate Professor of
Tissue Engineering. The research was funded by the NSF, the NIH and
the Packard Foundation.
IMAGES AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/nanocell-0609.html
TRADING CO2
In a bid to control greenhouse gas emissions linked to climate
change, the European Union has been operating the world's first
system to limit and to trade carbon dioxide. Despite its hasty
adoption and somewhat rocky beginning three years ago, the EU “cap-
and-trade” system has operated well and has had little or no negative
impact on the overall EU economy, according to an MIT analysis. The
MIT results provide both encouragement and guidance to policy makers
working to design a carbon dioxide (CO2)-trading scheme for the
United States and for the world. A key finding may be that everything
does not have to be perfectly in place to start up similar systems.
“This important public policy experiment is not perfect, but it is
far more than any other nation or set of nations has done to control
greenhouse-gas emissions--and it works surprisingly well,” said A.
Denny Ellerman, senior lecturer in the MIT Sloan School of
Management, who performed the analysis with Paul L. Joskow, the
Elizabeth and James Killian Professor in the Department of
Economics.This report was commissioned by the Pew Center for Global
Climate Change. The more extensive research project on which it is
based is funded by the Doris Duke Charitable Foundation. The full
report, The European Union's Emissions Trading System in Perspective,
is available at http://www.pewclimate.org/eu-ets.
MORE: http://web.mit.edu/newsoffice/2008/emissions-0610.html
X-RAY NANOMIRRORS
A new way of bending X-ray beams developed by MIT researchers could
lead to greatly improved space telescopes, as well as new tools for
biology and for the manufacture of semiconductor chips. X-rays from
space provide astronomers with important information about the most
exotic events and objects in our universe, such as dark energy and
black holes. But X-rays are notoriously difficult to collect and many
interesting cosmic sources are faint.Now an MIT team has fabricated a
new, highly efficient nanoscale Venetian-blind-like device that
contains thousands of ultrasmooth mirror slats per millimeter for use
in future improved space-based X-ray telescopes. The so-called
Critical-Angle Transmission (CAT) gratings feature dense arrays of
tens-of-nanometer-thin, freely suspended silicon structures that
serve as efficient mirrors for the reflection and diffraction of
nanometer-wavelength light--otherwise known as X-rays. New instrument
designs based on these gratings could also lead to advances in fields
beyond astrophysics, from plasma physics to the life and
environmental sciences, as well as in extreme ultraviolet
lithography, a technology of interest to the semiconductor industry.
The concept behind CAT gratings might also open new avenues for
devices in neutron optics and for the diffraction of electrons, atoms
and molecules. Based on an invention by Ralf Heilmann and Mark
Schattenburg of the Space Nanotechnology Laboratory at the MIT Kavli
Institute of Astrophysics and Space Research, the fabrication
challenges were overcome by graduate student Minseung Ahn of the
Department of Mechanical Engineering, with funding from NASA and a
Samsung Fellowship.
PHOTO AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/nanomirrors-0609.html
SUPER-SENSITIVE DETECTOR
Using carbon nanotubes, MIT chemical engineers have built the most
sensitive electronic detector yet for sensing deadly gases such as
the nerve agent sarin. The technology, which could also detect
mustard gas, ammonia and VX nerve agents, has potential to be used as
a low-cost, low-energy device that could be carried in a pocket or
deployed inside a building to monitor hazardous chemicals. “We think
this could be applied to a variety of environmental and security
applications,” said Michael Strano, the Charles and Hilda Roddey
Associate Professor of Chemical Engineering and senior author of a
paper describing the work published recently in the online edition of
Angewandte Chemie. To build their super-sensitive detector, Strano
and his team used an array of carbon nanotubes aligned across
microelectrodes. Each tube consists of a single-layer lattice of
carbon atoms, rolled into a long cylinder with a diameter about
1/50,000 of the width of a human hair, which acts as a molecular
wire. When a particular gas molecule binds to the carbon nanotube,
the tube's electrical conductivity changes. Each gas affects
conductivity differently, so gases can be identified by measuring the
conductivity change after binding. The work was funded by the
Department of Homeland Security under contract to the Federal
Aviation Administration and MIT's Institute of Soldier
Nanotechnologies. Additional funding came from the DOE and the
Defense Advanced Research Projects Agency.
PHOTOS, IMAGE AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/nanotube-0605.html
MARTIAN IMPACT
A new analysis of the topography and gravity of Mars by researchers
at MIT and NASA has solved one of the biggest remaining mysteries in
the solar system — why the planet Mars has two completely different
kinds of terrain, in its northern and southern hemispheres. In the
process, they have identified what appears to be by far the largest
impact scar found anywhere. The giant basin that covers about 40
percent of the surface of Mars, sometimes called the Borealis Basin,
is actually the remains of a colossal impact very early in the solar
system’s formation, the new analysis shows. The basin, 8,500 km
across and 10,600 km long, is about the size of the combined area of
Asia, Europe and Australia, and about four times wider than the next-
biggest impact basins known. The northern-hemisphere basin on Mars is
one of the smoothest surfaces found anywhere in the solar system, and
some geologists think it may once have contained an ocean in the
early days of the planet. The southern hemisphere is high, rough,
heavily cratered terrain. Until now, nobody really knew why the two
halves were so different. The new findings are reported in the
journal Nature by MIT postdoctoral researcher Jeffrey Andrews-Hanna,
Maria Zuber, MIT’s E.A. Griswold Professor of Geophysics, and Bruce
Banerdt of NASA-JPL. Two other papers in the same issue provide a
theoretical analysis of the kind of impact that would have been
required to create it.
PHOTOS, IMAGES AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/mars-basin-0625.html
NOVEL SOLAR DISH
A team led by MIT students recently successfully tested a prototype
of what may be the most cost-efficient solar power system in the
world--one the team believes has the potential to revolutionize
global energy production.The system consists of a 12-foot-wide
mirrored dish that team members have spent the last several weeks
assembling. The dish, made from a lightweight frame of thin,
inexpensive aluminum tubing and strips of mirror, concentrates
sunlight by a factor of 1,000--creating heat so intense it could melt
a bar of steel. To demonstrate the system’s power, Spencer Ahrens,
who just received his master’s in mechanical engineering from MIT,
stood in a grassy field on the edge of the campus recently holding a
long plank. Slowly, he eased it into position in front of the dish.
Almost instantly there was a big puff of smoke, and flames erupted
from the wood. Success! Burning sticks is not what this dish is
really for, of course. Attached to the end of a 12-foot-long aluminum
tube rising from the center of the dish is a black-painted coil of
tubing that has water running through it. When the dish is pointing
directly at the sun, the water in the coil flashes immediately into
steam. Someday soon, Ahrens hopes, the company he and his teammates
have founded, called Raw Solar, will produce such dishes by the
thousands.
MORE: http://web.mit.edu/newsoffice/2008/solar-dish-0618.html
SOLAR COLLABORATION
As part of the MIT Energy Initiative (MITEI), MIT and Bosch, a
leading global supplier of technology and services, are forming an
energy research collaboration aimed at exploring new materials and
concepts for efficient energy-conversion and energy-storage systems.
With the collaboration, Bosch becomes a Sustaining Member of MITEI,
which was formally established in November 2006 to address global
energy issues. The MITEI-Bosch collaboration will focus on three
areas: The atomistic modeling and computational search for new
materials in electrochemical energy storage and electromechanical
actuation, nano-structured thermoelectric materials for residential
heat and electricity co-generation, and ultra-efficient thin-film
solar cells.
MORE: http://web.mit.edu/newsoffice/2008/bosch-0623.html
OPTICAL TUG
MIT researchers have developed a novel technique to measure the
strength of the bonds between two protein molecules: Gently tugging
them apart with light beams. This is the first time that such light
beams, known as optical tweezers, have been used to measure
interactions between single protein molecules. “It’s really giving us
a molecular-level picture of what’s going on,” said Matthew Lang, an
assistant professor of biological and mechanical engineering and
senior author of a paper on the work appearing in the June 30
advanced online issue of the Proceedings of the National Academy of
Sciences.Last fall, Lang and others demonstrated that light beams
could be used to pick up and move individual cells around the surface
of a microchip. The current research was funded by the Nicholas
Hobson Wheeles Jr. Fellowship, the W.M. Keck Foundation, and the
Westaway Research Fund.
IMAGE AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/protein-binding-0630.html
PROTEIN PROBE
MIT researchers have designed a new type of probe that can image
thousands of interactions between proteins inside a living cell,
giving them a tool to untangle the web of signaling pathways that
control most of a cell’s activities. “We can use this to identify new
protein partners or to characterize existing interactions. We can
identify what signaling pathway the proteins are involved in and
during which phase of the cell cycle the interaction occurs,” said
Alice Ting, the Pfizer-Laubach Career Development Assistant Professor
of Chemistry and senior author of a paper describing the probe
published online June 27 by the Journal of the American Chemical
Society. The new technique allows researchers to tag proteins with
probes that link together like puzzle pieces if the proteins interact
inside a cell. The probes are derived from an enzyme and its peptide
substrate. If the probe-linked proteins interact, the enzyme and
substrate also interact, which can be easily detected. The research
was funded by the NIH and the McKnight, Dreyfus and Sloan Foundations.
MORE: http://web.mit.edu/newsoffice/2008/protein-interaction-0627.html
HARNESSING THE SUN
Ask any scientist to name Earth's most abundant source of energy, and
the answer comes quickly: sunlight. In one hour, the sun strikes
Earth with enough energy to power the entire planet for a year.
"There's nothing that compares to the sun. Everything else pales in
comparison," says Daniel Nocera, the Henry Dreyfus Professor of
Energy in MIT's Department of Chemistry. With gas and oil prices at
all-time highs, it's only logical for scientists to try to harness
some of that solar energy. To that end, three MIT researchers are
building a device that mimics photosynthesis--the process plants use
to capture and store the sun's vast energy. "To turn sunlight into
fuel, that's a chemistry process," says Jonas Peters, MIT's Keck
Professor of Energy and Chemistry. "Nature has come up with an
elaborate chemical solution, and it looks like we're going to need an
elaborate chemical solution as well, and we need to do it
efficiently." MIT chemists including Nocera, Peters and Christopher
Cummins are part of a National Science Foundation-funded solar
project, in collaboration with Caltech. The researchers are also part
of MIT's recently announced Solar Revolution Project, which aims to
transform solar power into an affordable, mainstream energy solution
in the near future.
PHOTO AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/chem-solar-0620.html
GENETIC FOIL
MIT biologists have discovered that proliferating cells shift the
output of their genes to evade regulation by microRNAs, tiny
molecules that normally suppress tumor growth.The work, which could
potentially lead to new cancer diagnostics and treatments by helping
to explain how some cells avoid regulatory controls when they are
rapidly dividing, appears in the June 20 issue of Science. Led by
Chris Burge, associate professor of biology and biological
engineering, in collaboration with the lab of Institute Professor
Phillip Sharp, the researchers studied T lymphocytes, a type of
immune cell. Normal T cells start dividing rapidly when they
encounter their target antigen (for example, a specific bacterium or
virus). The research was funded by the Knut and Alice Wallenberg
Foundation, the Cancer Research Institute, the Gina De Felice and
Robert M. Lefkowitz Fund, the U.S. Public Health Service, the
National Cancer Institute and the National Human Genome Research
Institute.
MORE: http://web.mit.edu/newsoffice/2008/mirna-0620.html
FLEXIBLE AIRPORT DESIGN
The leading low-cost airlines with a preference for small,
inexpensive airports are now the largest airlines in the United
States and Europe, according to an MIT expert on airport design and
operations, who said that airport planners in major metropolitan
areas need to accept this paradigm shift and build flexibility into
airport design. Professor Richard de Neufville of MIT's Department of
Civil and Environmental Engineering said that airport planners have
been slow to grasp the reality that the business model of their
largest customers has changed dramatically. Low-cost airlines require
terminals half the size of legacy airlines, because they use space
more intensively -- for instance, several gates share a single
waiting area -- and the terminals contain few or no retail shops and
restaurants. The reduced commercial activity results in fewer airport
employees going through security checks, which provides the
additional benefit of cutting passenger turnaround time in half.
Despite this, airport planners continue to design airports as grand
public spaces. The work is reported in a recent issue of the journal
Transportation Planning and Technology. The Government of Portugal
provided some financial support for this research for a study of the
Lisbon airport.
MORE: http://web.mit.edu/newsoffice/2008/airports-0618.html
COLORECTAL CANCER DRUG
A compound that accumulates in cells more readily than a commonly
used colorectal cancer drug may be just as useful in treating
colorectal tumors, but with fewer side effects, MIT researchers have
found. Both compounds are analogues of cisplatin, a potent anticancer
agent, but the newly investigated compound, known as cDPCP, may
better target colorectal cells, potentially sparing other body
tissues from damage. "This compound, the antitumor properties of
which were established in mice over 20 years ago, emerged in our
search for platinum anticancer drug candidates with cellular uptake
properties analogous or superior to those of oxaliplatin," said
Stephen Lippard, the Arthur Amos Noyes Professor of Chemistry and a
member of the David H. Koch Institute for Integrative Cancer Research
at MIT. Lippard is the senior author of a paper on the work appearing
in the June 16 online edition of the Proceedings of the National
Academy of Sciences. The research was funded by the National Cancer
Institute and the NSF.
MORE: http://web.mit.edu/newsoffice/2008/cancer-drug-0617.html
BACTERIAL COMMUNICATION
MIT researchers have figured out how bacteria ensure that they
respond correctly to hundreds of incoming signals from their
environment. The researchers also successfully rewired the cellular
communications pathways that control those responses, raising the
possibility of engineering bacteria that can serve as biosensors to
detect chemical pollutants. The work is reported in the June 13 issue
of Cell. Led by MIT biology professor Michael Laub, the team studied
genomes of nearly 200 bacteria, which can have hundreds of different
pathways that respond to different types of external stimuli.
Nutrients, antibiotics, temperature or light can evoke a variety of
responses, including transcription of particular genes. The research
was funded by the DOE and the NIH.
IMAGE AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/cell-rewire-0612.html
SOLAR TEXTILES
Sheila Kennedy, an expert in the integration of solar cell technology
in architecture who is now at MIT, creates designs for flexible
photovoltaic materials that may change the way buildings receive and
distribute energy. These new materials, known as solar textiles, work
like the now-familiar photovoltaic cells in solar panels. Made of
semiconductor materials, they absorb sunlight and convert it into
electricity. Kennedy uses 3-D modeling software to design with solar
textiles, generating membrane-like surfaces that can become energy-
efficient cladding for roofs or walls. Solar textiles may also be
draped like curtains. "Surfaces that define space can also be
producers of energy," says Kennedy, a visiting lecturer in
architecture. "The boundaries between traditional walls and utilities
are shifting." Principal architect in the Boston firm, Kennedy &
Violich Architecture, Ltd., and design director of its materials
research group, KVA Matx, Kennedy came to MIT this year. She was
inspired, she says, by President Susan Hockfield's plan to make MIT
the "energy university" and by MIT's interdisciplinary energy
curriculum that integrates research and practice.
MORE: http://web.mit.edu/newsoffice/2008/solar-textiles-0609.html
IMAGES, PHOTO AVAILABLE
ERADICATING TB
One of the biggest challenges in fighting tuberculosis is simply
getting patients to take their medicine. MIT students have come up
with a possible solution: A new testing and reporting system that is
easy for patients to use and offers economic incentives such as free
cell phone minutes. Tuberculosis kills an estimated two million
people every year, and treating the disease requires a strict six-
month regimen of antibiotics. If patients abandon the treatment
early, the TB bacteria survive and can become resistant to first-line
antibiotics. "TB is a massive problem, and it's exacerbated by the
fact that people have a lot of trouble staying on their meds," says
Elizabeth Leshen, an MIT sophomore majoring in biological engineering
and member of the team, known as "X Out TB." The students' plan,
which has been field-tested in Nicaragua, combines a newly developed
paper testing strip with a simple text message reporting system to
ensure drug compliance. The team plans to run larger field tests in
Pakistan and Indonesia this summer, in conjunction with local hospitals.
MORE: http://web.mit.edu/newsoffice/2008/tb-cellphone-tt0604.html
TEACHER-TESTING
Teacher certification tests may be undermining American public
education by deterring higher-quality candidates from applying for
teaching jobs, according to a study by MIT labor economist Joshua
Angrist and Jonathan Guryan of the University of Chicago Graduate
School of Business. The study, "Does Teacher Testing Raise Teacher
Quality? Evidence from State Certification Requirements," will appear
in the October issue of The Economics of Education Review. "States
are using increasingly strict licensing provisions to identify and
hire those most qualified to teach. But our results show that testing
has acted more as a barrier to entry into teaching than as a quality
screen," Angrist says.
PHOTO AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/teacher-tests-tt0604.html
CRAB PULSAR
In one of the first significant scientific findings from a huge
collaborative effort to detect gravitational waves, the team
operating the Laser Interferometer Gravity-wave Observatory (LIGO)
reported that the pulsar at the center of the Crab Nebula must have
an extremely smooth surface."This is one of the very first findings
where the sensitivity of the instrument and the kind of analysis
we've done is of more scientific interest," says David Shoemaker,
senior research scientist in the MIT Kavli Institute for Astrophysics
and Space Science and director of the MIT LIGO Laboratory. The report
was posted online in June, and will be submitted for publication in
Astrophysical Journal Letters. The Crab pulsar is a rapidly spinning
ball of ultra-dense matter, called a neutron star, created when a
star died in a massive explosion called a supernova. The remains of
the star collapsed so that its atoms were squeezed into subatomic
particles called neutrons, and the mass of the star -- once a sphere
about a half-million miles across -- was compressed into a ball only
about 6 miles (or 10 km) across.
IMAGE AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/ligo-crab-0603.html
INFLAMMATION, CANCER LINK
Chronic inflammation of the intestine or stomach can damage DNA,
increasing the risk of cancer, MIT scientists have confirmed. The
researchers published evidence of the long-suspected link in a June
online issue of the Journal of Clinical Investigation. In two
studies, the researchers found that chronic inflammation accelerated
tumor formation in mice lacking the ability to repair DNA damage.
"It's something that was expected but it was never formally proven,"
said Lisiane Meira, research scientist in MIT's Center for
Environmental Health Sciences and lead author of the paper. The
results of this work suggest that people with decreased ability to
repair DNA damage might be more susceptible to developing cancer
associated with chronic inflammation such as ulcerative colitis,
Meira said. The research was funded by the NIH.
MORE: http://web.mit.edu/newsoffice/2008/gastric-cancer-0602.html
BRAIN IMAGING MYSTERY
In work that solves a long-standing mystery in neuroscience,
researchers at MIT's Picower Institute for Learning and Memory have
shown for the first time that star-shaped brain cells called
astrocytes--previously considered bit players by most
neuroscientists--make noninvasive brain scans possible. Imaging
techniques such as functional magnetic resonance imaging (fMRI) and
positron emission tomography (PET) have transformed neuorscience,
providing colorful maps of brain activity in living subjects. The
scans' reds, oranges, yellows and blues represent changes in blood
flow and volume triggered by neural activity. But until the MIT
study, reported in the June 20 issue of Science, no one knew exactly
why this worked. "Why blood flow is linked to neuronal activity has
been a mystery," said study co-author Mriganka Sur, Sherman Fairchild
Professor of Neuroscience and head of the Department of Brain and
Cognitive Sciences at MIT. "Previously, people have argued that the
fMRI signal reports local field potentials or waves of incoming
electrical activity, but neurons do not connect directly to blood
vessels. A causal link between neuronal activity and blood flow has
never been shown." This work is supported by the NIH and the Simons
Foundation.
IMAGE AVAILABLE
MORE: http://web.mit.edu/newsoffice/2008/astrocytes-0619.html
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