August 22, 1997
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Contents of this News Tip:
Huddled over a twenty-gallon tank, counting thousands of tiny swimmers,
National Science Foundation (NSF)-funded psychologist Karen Hollis of
Mount Holyoke College in Massachusetts got more than she bargained for.
Working to prove a principle that psychologists had suspected for decades
but hadn't confirmed experimentally, Hollis proved that classical conditioning
helps animals survive and reproduce. In the image of the well-known dog
experiments of Ivan Pavlov, who taught canines to associate one specific
tone with the arrival of food, Hollis demonstrated that conditioned animals
can increase their reproductive success, as measured by the number of
offspring they produce. Her choice of animal to work with? Blue gourami
fish.
Hollis set up fish tanks and conditioned male blue gourami to expect
the arrival of a female after a specific signal. She videotaped the fish
to see if they mated, and whether they produced offspring, called fry.
As Hollis expected, the fish who could anticipate a female's arrival mated
more often and produced more fry than unconditioned fish, experimentally
proving concepts first set forth by Pavlov.
Hollis' research results are published in the September issue of the Journal
of Comparative Psychology. [Cheryl Dybas]
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Scientists have discovered how three genes work together to regulate
the development of nerve cells--fundamental new knowledge that could boost
efforts in related areas, including cancer research.
In a recent issue of the journal Cell, researchers report on
studies funded by the National Science Foundation that allowed them to
figure out which genes regulate the development of photoreceptor neurons
in fruit flies. Photoreceptor neurons convert light signals into chemical
signals that the brain can understand.
According to biologists Zhi-Chun Lai of Penn State and Richard Carthew
of the University of Pittsburgh, fruit fly genes are very similar to their
corresponding human genes; at the cellular level, there is virtually no
difference between human cells and fruit fly cells.
External signals tell developing cells what kind of cell to become
by initiating a cascade of internal molecular reactions called the "signal
transduction pathway." Cancer can result if errors occur in this pathway,
giving a cell the signal to divide instead of the signal to become, in
this case, a neuron. Up until a few years ago, the scientists explain,
it was thought that developing cells always received positive signals,
but now evidence is building that the message sometimes carried by the
signal transduction pathway is a negative one. [Cheryl Dybas]
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While some parts of the United States have been sweltering under the
summer sun, the South Pole just recorded the coldest July ever. The average
monthly temperature for July at the U.S. Amundsen-Scott South Pole Station
was -66 degrees Celsius (-86.8 degrees Fahrenheit), breaking the record
of -64.3 C (-83.7 F) set in July, 1965. The lowest temperature recorded
during this past July was -77.9 C (-108.2 F). Temperature records have
been kept continuously since January, 1957.
"These very cold days provide the best conditions for astronomical
observations--clear skies and low wind. On the down side, power usage
is at a maximum and vehicle operation is almost impossible." South Pole
meteorologist Matt Wolf, one of 28 people spending the winter at the research
station, noted.
The year-round research station, run by the National Science Foundation,
supports on-going studies in astronomy, astrophysics, atmospheric sciences,
and other disciplines. [Lynn Simarski]
NSF is making a transition to a new form of electronic distribution
of news materials. We will eventually replace the current "listserve" with
a new Custom News Service. From the toolbar on NSF's home page, (URL: http://www.nsf.gov),
you can sign up to receive electronic versions of all NSF materials (or
those of your own choosing). NSF is an independent federal agency responsible
for fundamental research in all fields of science and engineering, with
an annual budget of about $3.3 billion. NSF funds reach all 50 states,
through grants to more than 2,000 universities and institutions nationwide.
NSF receives more than 50,000 requests for funding annually, including
at least 30,000 new proposals. Also see NSF news products at: http://www.eurekalert.org/,
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