Insights
The end of the big chill
A new
study of glacial retreat shows that much of the world emerged from the
last ice age simultaneously, according to two leading climate change
scientists at Columbia University and the University of Maine. The
exceptions were areas of the North Atlantic, which remained in a deep
freeze 2,500 years longer.
The
end of the recurring, 100,000-year glacial cycles is one of the most
prominent and readily identifiable features in records of the Earth's
recent climate history. Yet one of the most puzzling questions has been
why different parts of the world, most notably Greenland, appear to have
warmed at different times and at different rates after the end of the
last ice age.
The
new study, reported recently in the journal Science, suggests that most
of the Earth did, in fact, begin warming at the same time, roughly
17,500 years ago. In addition, scientists suggest that ice core records
from Greenland, which show that average temperatures there did not warm
appreciably until about 15,000 years ago, may have remained in a
hypercold state largely as a result of events triggered by warming
elsewhere.
The
research, led by Joerg Schaefer from the Lamont-Doherty Earth
Observatory, a member of the Earth Institute at Columbia University, and
George Denton of UMaine's Climate Change Institute, relied on a method
known as cosmogonic or surface-exposure dating, which enabled the
scientists to determine how long rock surfaces have been exposed since
the glaciers retreated.
As
cosmic rays penetrating the Earth's atmosphere strike the scoured rock,
they form an isotope of the element beryllium at a known rate. By
measuring the minute amounts of beryllium in rock samples from glacial
moraines in California and New Zealand, and comparing these data to
previously published results from Wyoming, Oregon, Montana Argentina,
Australia and Switzerland, the scientists were able to narrow down when
glaciers around the world began to retreat. Additional studies from
tropical South America and southern Tibet also produced similar results.
Tiny Trouble
Marine scientist Peter Jumars wants to learn how centimeter-long opossum
shrimp carry out their daily, round-trip migrations from the shelter of
the ocean floor to open water.
So
does the U.S. Department of Defense.
Jumars, a University of Maine professor of marine sciences and
oceanography at the Darling Marine Center in Walpole, Maine, has a grant
from the military's Defense University Research Instrumentation Program
to continue his groundbreaking work in the utilization of sonar
technology to establish reliable techniques for monitoring the movements
of opossum shrimp.
Jumars' research has revealed some exciting data about the biology and
ecological importance of the fast-moving shrimp, which are a major
source of food for small cod and other fish. The research is important
for national defense purposes because the movements of large numbers of
opossum shrimp and other small organisms can interfere with the
military's use of sonar for detecting and identifying underwater mines.
"I
basically study what the people who identify undersea mines call noise.
Their noise has become my signal," said Jumars.
"Office of Naval Research Program officers have been impressed by how
dense the swarms of migrating shrimp can be. This is definitely not a
small problem when it comes to using acoustics for local area search,
and the shrimp are certainly something cod care about."
Tagging cancer cells
Extremely small tumors are
notoriously difficult to detect, and pose a potentially lethal threat to
cancer patients, even after surgery. But by using an amazingly tiny
technology being perfected by University of Maine researchers, doctors
may soon be able to pinpoint even the most minuscule cancerous cells
while the patient is still on the operating table.
UMaine Chemical and Biological Engineering Assistant Professor Michael
Mason is developing an improved screening technique in which
nanometer-size metal particles are used to "tag" cancer cells, allowing
surgeons to identify cancerous tissue more quickly and efficiently.
Metallic nanoparticles are guided by attached biomolecules that are
attracted to specific molecules on the surface of cancer cells. The
technique is sensitive enough to reveal even a single cancer cell.
Michael Mason and his team will provide the foundation for cellular and
tissue trials that will be conducted later this year by Dr. Peter Allen
at Memorial Sloan-Kettering Cancer Center in New York, which funded the
UMaine research.
Wild at heart
Maine's wild blueberries continue to prove that they are more than just
a splash of tasty color in muffins and pancakes. Research conducted at
the University of Maine suggests that a serving of wild blueberries can
go a long way toward a healthier heart.
Research conducted by UMaine Professor of Clinical Nutrition Dorothy
Klimis-Zacas and her team — postdoctoral fellow Anastasia Kalea and
graduate student Kate Clark — shows that compounds found in wild
blueberries may reduce the chances of cardiovascular disease by altering
the composition and structure of arterial components, which may prevent
LDL cholesterol from binding to blood vessels. By decreasing the
vulnerability of the arterial wall to stress and inflammation,
antioxidants in wild blueberries may help to create a less favorable
environment for fatty buildup that can cause reduced blood flow and
heart attacks.
The
study, published in the Journal of Nutritional Biochemistry, is the
latest of several research projects by Klimis-Zacas that examine the
effects of colorful, antioxidant-rich foods like wild blueberries on
human health. Her previous work has shown that Maine's favorite berry,
when eaten regularly, also may play a role in helping arteries relax and
in reducing hypertension.
In physical education, A is for aerobic
Physical education in grades 4–8
can increase youngsters' aerobic capacities, no matter their age, sex or
level of participation in sports, according to preliminary findings of a
study conducted by University of Maine researchers.
Aerobic capacity has been linked to reduced incidence of high blood
pressure, coronary heart disease, obesity and diabetes.
The
study found that students achieved high levels of aerobic performance
with two physical education classes a week. Their increased performance
continued even in the winter months.
"Increased performance continued right through the terrible Maine
winter, when kids are supposed to be much less active," says UMaine
Professor of Education and Special Education Stephen Butterfield. "In
fact, our follow-up data show a leveling off during the summer, with
improvement a couple months after (students) return to school in the
fall."
The
study by Butterfield and his UMaine College of Education and Human
Development colleagues Robert Lehnhard and Craig Mason was done in
collaboration with physical education teacher Robert McCormick at Blue
Hill Consolidated School in Maine.
During a nine-month school year, the aerobic performance of more than
100 students in grades 4–8 was tested five times using a portion of the
Fitnessgram, a series of activities to assess fitness in children. The
researchers administered the Progressive Aerobic Cardiovascular
Endurance Run (PACER) Test to measure the children's aerobic capacity.
"It
is possible that regularly testing children on the PACER teaches
effective pacing strategies, thereby substantially improving performance
on this key fitness component," the researchers wrote in their paper,
presented earlier this year at the national convention of the American
Alliance for Health, Physical Education, Recreation and Dance.
Maine's biggest creepy crawlers
Most
insects we know are minuscule. Theirs is a small world, after all. Yet,
there are giants among them. We asked University of Maine entomologist
Stephen Woods, who oversees the more than 100,000-specimen UMaine Insect
Collection, to list six found in Maine.
Giant
waterbugs — More than 2 inches long, oval in shape, with a piercing beak
that can inflict a painful bite if handled carelessly. These predators
of insects and small fish in ponds are attracted to lights at night.
Giant
silkworm moths — Beautiful, heavy-bodied moths, with 4- to 5-inch
wingspans. One type, the luna moth, is pale green. The moths are
attracted to lights at night.
Dobsonflies — Males are about
3
inches long with mandibular tusks that are quite scary, but harmless.
The immatures, called hellgrammites, are aquatic, preying on other
insects in streams.
Horntails — Stout-bodied sawflies, 1–1.5 inches long with colorful
abdomens. Larvae are wood borers in live trees.
Dragonflies — Many are 3 inches long with wingspans in the 4- to 5-inch
range. Some are brightly colored and all are predators of flying
insects.
Praying mantids — Up to 3 inches long, voracious predators of other
insects. Mostly greenish. The only insects that can look over their
shoulders.
Sea scallop scrutiny
Better understanding of the relationships between different scallop
populations along the Maine coast could help fine-tune management
strategies, according to two University of Maine marine scientists.
Associate professor Paul Rawson and Ph.D. student Erin Owen are studying
the ecology and genetics of sea scallop populations in the context of
various environmental factors. Their research is funded by a two-year
NOAA grant.
In
particular, Rawson and Owen will determine whether the Cobscook Bay sea
scallop population is a separate stock from the population found in
Penobscot Bay.
Scalloping is an economically important fishery in the state, but the
harvest has been steadily declining in recent years. Scallop landings in
Maine dropped in value from more than $15 million in 1981 to less than
$1 million in 2004.
Windows on Maine
Schoolchildren across the state can explore Maine history and
environmental science using Windows on Maine, an interactive Web site
featuring an ever-increasing collection of multimedia resources — video,
images, documents, sound files, maps and simulations.
Windows on Maine is a tool for experiencing and creating new media —
digital image, sound and video. It is intended to help teachers and
students learn and become fluent in new forms of communication and
expression — 21st-century literacy, according to project director
Marilyn Lutz of the University of Maine. UMaine partnered in the project
with the Maine Public Broadcasting Network and the Maine State Museum.
Users
can access two MPBN series — "HOME: the Story of Maine" and "QUEST:
Investigating Our World." Windows on Maine also offers primary resources
from distinguished Maine cultural collections that enrich the broad
themes: forestry and lumbering, fishing and fishermen, hunting and fur
trading, shipping and ship building, and Native American studies.
Collaborators in the project include members of the Digital Maine
Learning Group — Maine State Archives, Northeast Historic Film, the
Maine Historical Society, and the Maine Folklife Center.
Academ-e
Maine's first early college distance education program begins this fall
with the introduction of Academ-e, 14 University of Maine courses open
to high school seniors via online, videoconferencing and in-person
teaching.
Among
the scheduled courses are Calculus, Introduction to Geology, General
Psychology, Survey of Dramatic Literature and Fundamentals of Music.
Most
of the 560 Academ-e students are from public high schools. Also eligible
are students who are home schooled, in adult education diploma or GED
programs, or from independent high schools.
School principals, teachers and guidance counselors nominate qualified
students, according to a formula based on school enrollment (five slots
for the largest schools; three slots for small schools). UMaine Academ-e
scholarships cover half the tuition for each course — currently $552 for
three credits by an in-state student, $736 for four.
Grants from the National Governors Association and Bank of America
partially pay the tuition balance.
