Human effects on the Great Barrier Reef
Stewart Fallon of the Laboratorys
Center for Accelerator Mass Spectrometry collaborated with researchers
from Australian National University and the Australian Institute
of Marine Science to study the geochemistry of coral in the Great
Barrier Reef. In the February 13, 2003, issue of Nature,
they published findings concluding that in the 150 years since the
first Europeans settled along the Australian coast, the settlers
land-use practices have led to a major degradation of the semiarid
region and resulted in substantially increased amounts of sediment
entering the Great Barrier Reef.
The researchers studied coral
by measuring barium content within the coral skeleton, using a technique
called laser ablation inductively coupled plasma spectrometry. Barium
deposits can provide good records of how much sediment enters the
reef. The barium comes loose from fine-grained particles in a low-salinity
region of the estuary and is carried with a flood plume into the
coral skeleton. Measurements of a 5.3-meter core from the Havannah
coral reef showed a significant increase in barium beginning around
1870, about two decades after European settlers arrived in northern
Queensland and began clearing land for raising sheep and cattle.
The Nature report
warns that reducing sediment discharges must be a high priority
if coral reefs are to survive the lethal combination of human-use
effects and rapid climate change.
Contact: Stewart Fallon (925) 422-4396 (email@example.com).
More discoveries about neutron stars
An international group of
researchers, which includes Laboratory astrophysicist Diego Torres,
has shown through computer simulations that accreting neutron stars
can be a source of high-energy neutrinos. The neutrinosparticles
that rarely interact with other matterare produced in amounts
significant enough that they are expected to be detected by next-generation
A neutron star is one possible
end-point in the evolution of a massive star. In some binary star
systems, two neutron stars are so close together that the strong
gravity from one can steal gas from the other. The gas transfer
onto a neutron star is accretion; it is a turbulent, shiny event.
Neutron stars have long been
viewed as physics laboratories in space because they provide insights
into the nature of matter and energy. Torres and his colleagues
believe that astronomers will be able to use IceCubean international
high-energy neutrino observatory being built for installation in
the deep ice below the South Poleto detect neutron star neutrinos.
This would mark the beginning of multiparticle astronomy, where
photons in all wavelengths and neutrinos are detected at the same
include scientists from Northeastern University, Instituto Argentino
de Radioastronomia, and the Max Planck Institut für Kernphysik.
Their research is presented in the May 20, 2003, edition of Astrophysical
Contact: Diego Torres (925) 423-0750 (firstname.lastname@example.org).
Containment of a fowl disease
A partnership of researchers from Livermore, the University of California
at Davis, the California Animal Health and Food Safety Laboratory,
and the U.S. Department of Agriculture has developed a rapid diagnostic
assay to detect Exotic Newcastle Disease (END), a virus that has
been attacking poultry in California and Nevada. The new assay,
which is faster and more precise, is based on DNA fingerprinting
methods that Livermore perfected for use in detecting bioterrorism.
It can provide test results overnight, in contrast to the 6 to 12
days previously needed to identify infected birds.
The test is based on the polymerase chain reaction, a method of
multiplying DNA. Livermore scientists use powerful computers to
compare the multiplied DNA sequences of a pathogen with those of
close genetic kin to discover the DNA regions, or signatures, that
are unique to the pathogen. Scientists can then design an assay
that includes fluorescent probes that signal the presence of a signature.
Developing an assay for END was challenging because its chromosome
is made of RNA rather than DNA and because close cousins of the
virus were hard to find. These are very interesting pathogens,
says Paula McCready, head of Livermores DNA signature team.
They mutate quickly so its difficult to find those regions
that are unique to the virus.
Use of the new test spared 170,000 layer hens in Riverside County
from euthanasia. The assay showed that the quarantined hens did
not have END but were instead infected with a nonvirulent strain.
Contact: Paula McCready (925) 422-5721 (email@example.com).