July 2, 1999
For more information on these science news and feature story tips, please
contact the public information officer at the end of each item at (703)
292-8070. Editor: Cheryl Dybas
Contents of this News Tip:
Researchers funded in part by the National Science Foundation (NSF)
have gone to sea to further study undersea volcanoes to determine how
they affect the ocean floor environment. The scientists will collect specimens
of the unique biota living near the volcanoes.
Two oceanographic research cruises are underway. Aboard the Oregon
State University research vessel Wecoma, scientists are conducting the
latest in a 15-year-long series of surveys along portions of the Juan
de Fuca Ridge. This ridge, a several-hundred-mile-long volcanically active
seam in the earth's crust, lies some 300 miles off the Oregon and Washington
coasts at depths of one to two miles.
Another cruise aboard the University of Washington's research vessel
Thomas G. Thompson will see scientists enter a second phase in establishing
an unmanned long-term seafloor observatory, called the New Millennium
Observatory (NeMO), built into the caldera, or crater, of a huge undersea
volcano along the ridge system. A swarm of earthquakes under this volcano
occurred in January, 1998. It is the most volcanically active site on
the Juan de Fuca Ridge.
The main objective at NeMO is to understand the community of microorganisms
that lives beneath the seafloor and thrives at temperatures that can exceed
212 degrees Fahrenheit. These heat loving creatures have a wide variety
of potential biotechnical and pharmaceutical applications. [Cheryl Dybas]
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As the 20th century draws to a close, little is yet known about the
origins of a staple subsistence crop that feeds an estimated 600 million
Third World people.
The cassava (Manihot esculenta), a bushy plant producing tubers -- starchy
underground stems -- have fed the indigenous people of the Americas for
millennia, and much of Africa since the 17th century.
But now NSF-funded biologists affiliated with Washington University
in St. Louis have written the ultimate "roots" story for this plant. Researcher
Barbara Schaal has pinpointed cassava's origins to the southern border
of the Amazon River basin in Brazil.
Tracing variation in a single gene found in cultivated and wild cassava
using sophisticated DNA sequencing techniques, Schaal identified a cassava
subspecies, still present in the diminishing wilds of the Amazon basin,
as the plant's progenitor.
The find provides important insights into cassava's evolutionary origin.
Schaal's work reveals a wealth of genetic diversity in wild and domesticated
cassava strains, information that plant breeders can use to create hardier
plants that are more resistant to disease.
Cassava ranks sixth among crops in global production. Those living
in the developed world have sampled cassava in tapioca and in flours at
specialty food stores. But the vast majority of consumers are the world's
poor, who grow cassava in small patches of soil. [Cheryl Dybas]
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U.S. students' generally dismal achievement in mathematics, as revealed
in international comparisons, has prompted a national self-examination
for practical answers to the question of how to boost America's rank in
math performance.
In one effort by mathematics educators at the University of Washington-Seattle,
mathematicians and graduate students are comparing the middle school math
curricula materials of Singapore -- whose students are the top math performers
internationally - against two widely used sets of math materials whose
development was supported by the National Science Foundation. This comparative
study will entail a thorough examination of mathematics instructional
materials in grades six through eight.
The researchers are giving particular attention to the treatment of
mathematics topics, the level and sophistication of the treatment and
the contexts in which the topics are presented.
They say results will not spur a "reverse-engineering" of U.S. math
education, but could potentially benefit teachers and administrators who
make selections of math curricula. [Lee Herring] Top of Page
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