Biosecurity in the potato fields
Potato wart, a highly contagious fungal
disease of potatoes, can not only ruin a potato crop, it can destroy the
agricultural value of the soil it infects for decades. So virulent that
it has been listed as a threat to the nation's biosecurity by the
federal government, potato wart has had a devastating impact on European
agriculture and can be found just beyond Maine's borders in isolated
areas of Newfoundland, Canada.
University of Maine researchers Laurie Connell
and Rosemary Smith are combining their expertise in molecular biology
and sensor development to help combat the dangerous disease. With a
four-year, $800,000 grant from the United States Department of
Agriculture Biosecurity Program, Connell and Smith are working with
Steven Woods of the Canadian Food Inspection Agency to create a fast and
effective device for detecting potato wart in soil.
The mobile, hand-held sensor currently being
developed will use groundbreaking techniques in nanotechnology to
identify the RNA sequence specific to the potato wart pathogen,
providing faster, more accurate results than the field identification
techniques currently in use. The new sensor, which utilizes a bridge of
gold nanoparticles that reacts to specific molecular configurations,
could provide researchers with an important new tool for detecting a
broad range of potential toxins and pathogens in the field.
Connell and Smith are developing the
specialized surfaces and attachment methods required for the
nanoparticles and streamlining the process for extracting the potato
wart pathogen from the soil. The project promises to greatly improve the
chances of early detection of the disease, which is critical to its
control.
Toddler talk
Toddlers who speak slower and have long pauses
between words may be more likely to have a reading disability later in
life, according to a new study published in the American Journal of
Speech-Language Pathology.
Looking for predictors of developmental reading disability in 2
1/2-year-olds, researchers at the University of Maine, Hofstra
University and Lehman College analyzed the speech of youngsters
considered at low and high risk for reading disability. Those considered
high risk had at least one parent with reading disability.
Of the 18 children at high risk, half were
identified as having a reading disability once they were evaluated in
grade school. The 10 children at low risk did not have the developmental
disorder. Recordings made years earlier showed that the children with
reading disability spoke fewer syllables per second, spending more time
pausing.
The goal is to help identify precursors of
reading disability to implement intervention strategies. Presently, most
children are diagnosed with the disorder after they enter a school
reading program.
Arresting Protesters
Social Dissent sometimes leads to
confrontations with the police and possible arrest. Studies of social
movements have examined the types of police response to such protest.
But according to a University of Maine sociologist, the criminal justice
treatment of protesters — what happens to them after their arrest — also
is significant in understanding the social control of dissent.
"Protest prosecutions create a very public and
potentially dramatic stage for repression and dissent to play out," says
Steven Barkan, writing in the international journal Mobilization.
"Neither social movements nor law in the United States and other
democracies can be fully understood without appreciating the dynamics
and outcomes of the prosecutions and trials of political activists."
After a protest arrest occurs, prosecutors and
judges respond to legal misconduct and political threat, while protest
defendants struggle to balance the needs of their cause and their own
political convictions with concerns for their personal welfare.
Barkan proposes eight hypotheses on the
factors that determine whether a political or legal defense will better
serve protesters and their causes. The hypotheses are informed by his
years of research examining many aspects of political justice, including
its dissimilar consequences for the Southern civil rights and Vietnam
antiwar movements.
Media and the military
A study of a decade of news coverage of U.S.
military interventions around the world beginning in the early 1980s
shows that American public opinion was most favorable when the Pentagon
insisted on media pools, according to a professor of journalism at the
University of Maine.
In a military media pool, a small number of
participating reporters agree to share their coverage with other news
outlets. Military censors clear their reports.
Shannon Martin's research involved the content
analysis of nearly 20,000 media articles and transcripts covering U.S.
military intervention from the 1980s–90s. Her goal was to determine if
there is a correlation between the characterization of the intervention
by pool reporters and the shifts in public opinion during the U.S. troop
deployments to Bosnia and Herzegovina, Grenada, Haiti, Iraq, Lebanon,
Libya, Panama and Somalia.
Message managers know that the public considers the reasons for military
deployment as important as the results of the action. The way that
action is framed affects public opinion about the "rightness" of the
military intervention.
Martin found that when U.S. media were
constrained by military pooling, the news corps characterized the
military intervention as facilitating local change in government and
public opinion was initially favorable. When the media were not
constrained by military pooling, intervention was characterized as part
of a humanitarian effort and public opinion was less favorable.
The tactic suggests savvy agenda framing and
agenda setting among military operations planners who organize the media
pools, says Martin, who published her findings in the Journal of Peace
Research.
Forests and amphibians
Major habitat changes appear to affect
juvenile amphibians more than adults, a finding that is particularly
pertinent for species at risk of extinction, according to a recent
University of Maine study.
The study of the effects of forestry
treatments on a Maine amphibian community focused on five types of frogs
and four kinds of salamanders common in the North Woods. The study was
conducted in the university's two forests in Orono, Maine, as part of
the Land-use Effects on Amphibian Populations project (LEAP) of UMaine,
the University of Missouri – Columbia and the University of Georgia.
All of the study species had higher juvenile
captures in uncut and partial-cut tracts compared to clear cuts. In
particular, the number of wood frog juveniles was significantly higher
and the animals larger in uncut and partial-cut areas.
The University of Maine study corroborated
previous research that found fewer amphibians in clear cuts, with adult
green frogs and American bullfrogs showing more tolerance for canopy
removal.
But the findings also showed that uses of
habitat by adult and juvenile amphibians differed. The UMaine
researchers found that juvenile amphibians choose to move through forest
rather than open-canopy areas, and partial canopy removal may reduce the
abundance of many species.
If fewer juvenile amphibians choose to enter
clear cuts, the probability of successful dispersal and the amount of
available habitat are reduced.
The study by UMaine wildlife ecologists David Patrick and Malcolm
Hunter, and wetlands ecologist Aram Calhoun was published in Forest
Ecology and Management.
Fueled by seeds
Working in collaboration with
businesses in northern Maine, University of Maine Cooperative Extension
Crops Specialist Peter Sexton has completed a pilot project that
successfully converted Maine-grown seed crops into 1,000 gallons of
biodiesel. The project offers an exciting glimpse into Maine's potential
as a producer of oilseed for fuel.
Sexton planted 30 acres of oil-rich mustard
and canola in Aroostook County. The experimental plots yielded more than
25 tons of oilseed, which was pressed by CHB Proteins, an independent
mill that is one of several small businesses participating in the
project.
More than 2,000 gallons of raw canola oil was
extracted from the seeds harvested from Sexton's test plots. A portion
of the thick, amber oil was later blended with petroleum-based fuel to
produce the state's first 1,000 gallons of homegrown biodiesel, an
alternative blend that can be used in the same way as traditional diesel
fuel without any engine or burner modifications.
More than half of the biodiesel is being used
for home heating and fueling farm equipment in northern Maine. Already
available at select sites across the state, biodiesel produced elsewhere
is rapidly increasing in popularity as an alternative to all-fossil
fuels produced largely overseas.
While oil from field crops will likely remain
only a small piece of the nation's energy puzzle, Maine has the
potential to greatly increase its oilseed production.
"Within the potato rotation in Maine, if we
produce 10,000 to 15,000 acres of canola, then we could in theory
produce approximately 800,000 to 1,200,000 gallons of biodiesel," says
Sexton.
Assessing aquatic animal health
A more than $396,000 grant from the state's
Marine Research Fund will be used to purchase equipment to facilitate
applied research in marine animal health assessments and investigations
at the university's new Maine Aquatic Animal Health Laboratory (MAAHL).
Several instruments will enable MAAHL to serve
as a magnet research facility for marine researchers. For example, a
Biolog Microbial Identification System will allow for database building
and consistent identification of microbial assemblages of marine aquatic
animals. The system will be key to lobster and mollusk diagnostics and
health assessments. Plans call for the Biolog to eventually be made
available for outside users and sample submissions. The database can be
shared with private and government aquatic animal diagnostic
laboratories, providing a vital tool for bacterial identification.
The Marine Research Fund grant also
facilitates the establishment of the state's first, state-of-the-art
marine samples repository, featuring high-capacity -80C freezers and a
computerized laboratory information management system. The repository
will facilitate comparative studies over time and provide historically
supported scientific data critical for informed ecosystem management.
With a fully equipped lab in place, MAAHL
personnel will be better able to support marine animal health research,
and foster entrepreneurial activity and technology transfer.
MAAHL is a collaborative service of UMaine's
Department of Animal and Veterinary Sciences, Cooperative Extension, and
the Lobster Institute.
Historic heavy metals
More than a century after silver and copper
mines went bust along Egypt Stream in Maine, scientists are finding
elevated levels of heavy metals in adjacent coastal bay sediments.
The findings by University of Maine
researchers illustrate that estuarine sediments provide well-preserved
records of coastal land use history. Despite mixing by worms, these
materials also recorded the deposition of more recent contaminants,
including metal and radiogenic particles from the atmosphere.
In 1877, a vein of silver and copper was
discovered along the banks of the Taunton River. Within eight years,
there were 50 mines in the upland surrounding Taunton Bay, with shafts
up to 24 meters deep. Mining activities in the Egypt Stream watershed in
Hancock County lasted through the early 1900s. The stream feeds Egypt
Bay, part of the Taunton Bay estuary.
Soil samples collected in tailings piles at a
former copper mine in the watershed revealed elevated levels of cobalt,
zinc, silver and cadmium. The surface soils surrounding the historic
mine were not contaminated.
Analysis of sediment from 26–34 cm depths in
Egypt Bay identified heavy metal enrichment comparable to the soils in
the tailings piles. Lead 210 dating of the metal-contaminated silts and
clays determined that they were deposited at the time the historic mines
operated.
Laurie Osher of the Department of Plant, Soil
and Environmental Sciences led the research that involved five UMaine
scientists. Their findings appeared in the journal Estuarine Coastal and
Shelf Science. The research was initiated by former student Lauren
LeClerc.
Genome of deadly fungus sequenced
Researchers around the world now have a
valuable new tool for studying the deadly Batrachochytrium dendrobatidis
fungus, thanks to the efforts of scientists at the Broad Institute,
Timothy James of Duke University and University of Maine researcher
Joyce Longcore.
The fungus' genome sequence consists of more
than 20 million base pairs, offering scientists new insights into the
genetic nature of the pathogen.
One of only a handful of researchers with
expertise in identifying and culturing the unusual group of fungi
collectively known as chytrids, Longcore provided the diploid strain of
B. dendrobatidis that was sequenced by the Broad Institute's Fungal
Genome Initiative team. James extracted the DNA from Longcore's
cultures.
Implicated in amphibian declines around the
world, B. dendrobatidis is the first chytrid to be sequenced. Longcore
was the first to isolate a pure culture of the pathogen nearly a decade
ago. Her research focuses on the relationships between chytrid species;
her lab is the world's leading repository for chytrid fungi strains.
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