in the News
in global climate prediction
Bala Govindasamy, Ken Caldeira, and Philip Duffy of Livermores
Atmospheric Science Division reported in a recent issue of Geophysical
Research Letters that cooling temperatures recorded on Earth from
1000 to 1900 could be attributed to changes in land use instead
of to natural variations in climate.
leader of Livermores climate and carbon-cycle modeling group,
said that the main way humans influence climate is by burning
fossil fuels, which make greenhouse gases. But we also suspected
that large-scale changes in land use contributed to climate changes.
To test their theory, the researchers performed computer simulations
of two scenarios for climate development: one simulating natural
vegetation conditions and one accounting for deforestation caused
by agricultural land use.
the 900-year period covered by the simulations, the regions that
cooled more were the ones where there was deforestation and dense
human activity. Over land in the U.S., there was a cooling of
about 0.41 kelvin. The researchers explained that the darker colors
of forests tend to absorb sunlight, thus trapping heat on Earth,
while the fields of grain or corn in agricultural land are lighter-hued
and reflect solar rays back into space. Duffy said, People
talk about planting trees as a way to slow global warming, [but
our study] suggests that may not work. It. . .might not be a good
commented, This is an example of inadvertent geoengineeringwe
changed the reflectivity of the Earth and have probably caused
a global cooling in the past. This is now probably being overwhelmed
by our greenhouse gas emissions.
Contact: Philip Duffy (925) 422-3722 (email@example.com).
plague detection system gets results fast
a DNA-based test system developed at Livermore, biologists at
Northern Arizona University were able to detect an outbreak of
plague in prairie dogs so quickly that they could issue health
warnings within hours.
If we hadnt gotten the warning out, someone could
have gotten sick, said Paul Keim, a microbiology professor
who used the test. The speed of the test made all the difference.
outbreak was the first time that the Livermore detection system
was used to test for a disease in the environmentin this
case, Yersinia pestis, the bacteria that cause plague, which is
carried to fleas from prairie dogs. The system could accurately
and speedily test for Y. pestis bacteria because it was based
on the bacterias DNA signature, which had been developed
by Livermore scientists. Flea samples were subjected to the test
and within six hours, the testing team had four positive readings
and had initiated a series of preventive messages to the public.
development of the Y. pestis signature is part of Livermores
work on methods to monitor, detect, and counter infectious diseases
or bioterrorism agents. Of its use in the plague outbreak, Livermore
biomedical scientist Paula McCready said, Its very
exciting, and it made all
the hard work we went through worthwhile. We did a lot of analysis
to make sure these DNA signatures were unique to Yersinia pestis
and nothing else in the environment.
The use of genetic signatures to speedily monitor the spread
of infectious diseases is based on a DNA detection method called
polymerase chain reaction, or PCR. Because at least some
of a pathogens genes and its DNA are unique to it, PCR can
be used to detect even a single germ in a very specific fashion,
said Keim. The basic technology has been applied to many
different diagnostic problems, but you have to know what the specific
DNA codes are for each. Without these, it is like a computer without
software. LLNL provided the DNA codes to detect plague.
Contact: Paula McCready (925) 422-5721 (firstname.lastname@example.org).
will extend life of cruise missile warhead
at the National Nuclear Security Administration of the Department
of Energy have approved an agreement, signed by the directors
of the Livermore, Los Alamos, and Sandia national laboratories,
to assign the responsibility of refurbishing the W80 warhead to
Livermore. Originally developed at Los Alamos, the W80 is carried
by cruise missiles.
Alamos weapons scientists will continue to be responsible for
the Mod 0 and Mod 1 warheads in the stockpile. Livermore, together
with Sandia/California, will develop the next round of modifications,
dubbed Mod 2 and Mod 3, as well as all future changes to extend
the stockpile life of the warhead.
assignment of responsibilities seeks to accomplish a more
balanced workload at the nuclear laboratories and tend to the
current needs of the national stockpile. The effort is expected
to last five years, and an estimated 30 Livermore researchers
will form the core group for the refurbishment project.
Contact: Don Johnston (925) 423-4902 (
stars individually imaged by Hubble
the June meeting of the American Astronomical Society in Pasadena,
California, Michael Gregg of the Institute of Geophysics and Planetary
Physics at Livermore and the University of California at Davis
presented some exciting images of stars. They were pictures he
had taken of individual stars in a galaxy called NGC3379, located
about 30 million light years from Earth. The pictures resulted
from a collaboration in which Gregg, colleagues from the Space
Telescope Science Institute, the Universidad Catolica de Chile,
and the University of Hertfortshire, England, used the Hubble
Space Telescopes near-infrared camera and multiple-object
spectrograph to capture images.
images help astronomers determine star composition and formation.
This knowledge allows them to compare the galaxy in which the
stars are found with the Milky Way and other nearby galaxies.
star pictures, the first instance of individual stars being resolved
in infrared at such great distance, also show that the NGC3379
contains variable stars, which change in brightness over time.
Some of them were no longer visible in images taken three months
later. Because NGC3379 is an elliptical galaxy, one that is thought
to contain few variable stars, Gregg said that current assumptions
about elliptical galaxy evolution may need to be revised.
Contact: Michael Gregg (925) 413-8946 (email@example.com).
communications links in free space
Defense Advanced Research Projects Agency (DARPA), a principal
research and development organization for the Department of Defense,
has funded the first phase of a project to develop powerful new
capabilities for free-space communications, such as data transmission
from Earth stations to satellites. Called Coherent Communications,
Imaging, and Targeting (CCIT), the project would enable secure
communications at speeds of several gigabits over ranges greater
than 1,000 kilometers. And the transmitted three-dimensional images
would be aberration-free.
is the lead organization for the $9.5-million Phase I work, which
will be performed over two years. The team includes researchers
from academic institutions and companies in microelectromechanical
systems (MEMS), photonics, and aerospace. The team is responsible
for modeling; coordinating MEMS development; integrating MEMS,
photonics, and high-speed electronics into a prototype system;
and demonstrating the concept. DARPA expects that the innovations
and integrations achieved by this work will provide systems useful
late into this century.
Eddy Stappaerts, the CCIT program manager at Livermore, The
CCIT program has the potential to be a major development in secure,
free-space communications for a range of military applications
as well as having a significant impact in the commercial arena.
Contact: Eddy Stappaerts (925) 422-7307 (firstname.lastname@example.org).