Discovery

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Studying avian TB in a rare wood duck Composites strengthen bridge construction

On the wing

Through a long-standing partnership between ECU and Sylvan Heights Bird Park in Scotland Neck, researchers have sequenced the genome of the white-winged wood duck, which could help in the conservation effort for the rare avian species .

There are only 150-250 of the birds in captive populations, and probably less than 800 in the wild, said Dustin Foote ’16, general curator of the 18acre Sylvan Heights Bird Park . Foote has a master’s degree in biology from ECU and is working on a doctorate .

The white-winged wood duck is one of the rarest at the park . Sylvan Heights owns all the white-winged wood ducks in captivity in North America and has birds on loan to 14 other institutions, he said . The species is native to southeast Asia and is notoriously difficult to survey due to its mottled black-and-white coloring and its preferred habitat .

“They really like these flooded forest environments, and they just disappear when people are trying to do surveys, and so they’re kind of hard to get a good gauge on … but that’s a tiny number of them,” he said . “In a bad year, they could just be gone . ”

Foote’s research on the birds’ genome is aimed at better understanding health issues that affect them, such as avian tuberculosis .

“It really decreases their lifespan … and that’s affecting the longterm sustainability of the captive population, which is going to be a critical component to the future of this species,” Foote said .

Dustin Foote, left, and Chris Balakrishnan examine a bird at Sylvan Heights Bird Park in 2017.

Birds from the wild have also been sequenced, and there’s an environmental monitoring component to explore external factors . Because of the small global population, the species has limited genetic diversity, which could play a role, and the team is looking at how the birds are being raised and housed and how they might be exposed to the disease .

The genomic sequencing is also part of a larger project involving researchers all over the world and recently published in Nature .

“It’s a massive jump in the scale at which we sequence things, and we sequence them to understand where birds came from and what makes birds different from each other, how birds behave, and how to better conserve the bird species that we have,” said Chris Balakrishnan, associate professor in the Department of Biology . His lab has contributed six sequenced genomes, including Foote’s work on the white-winged wood duck, to the more than 250 genomes analyzed in the project . – Jules Norwood

Carbon-fiber bridge coming to the coast

While the entire bridge won’t be built of the black composite material, its use as a reinforcing component should reduce construction and maintenance costs while extending the life of the bridge.

That’s according to Amin Akhnoukh, an associate professor in ECU’s Department of Construction Management. He’s part of two research projects that could shape the way North Carolina builds bridges in the future.

Bridges have traditionally been built with steel rebar and concrete. However, a new replacement bridge that is planned to link Harkers Island to mainland Carteret County will be built using non-corroding, carbon fiberreinforced polymer strands instead of steel.

“There are a lot of corrosion issues for steel and a lot of concrete durability issues in the long term, so we are trying to design the first carbon fiber-reinforced bridge,” Akhnoukh said. “The sections will be smaller because carbon fiber sections are smaller than steel or concrete. It’s lighter, so there won’t be the need for heavy construction equipment. It’s safe in the long term because carbon fiber never corrodes.”

That’s especially important along the coast, where the marine environment can lead to expensive maintenance costs and decrease the lifespan of bridges. The two bridges that link Harkers Island to the mainland are 45 years old. Sections of one of them, the Earl C. Davis Memorial Bridge, are mottled with rust stains.

The new high-rise bridge will be better structurally and will not need the repairs associated with corrosion in traditional steel-reinforced concrete, thus increasing the lifespan of the structure, Akhnoukh said.

Generally made from polyacrylonitrile, carbon fiber was invented in Cleveland, Ohio, in 1958. It’s strong, stiff and light and has been used to build everything from race cars to wedding bands.

“It’s stronger in the short term and better and more durable in the long term,” he said. “In general, it will be much better for the future. There will be lower maintenance costs.” Work on the grant is expected to start in August, correlating with the expected start of construction of the new $47.9 million bridge.

“This is a significant project for NCDOT because it will be our first complete structure reinforced with FRPs (fiber-reinforced polymer),” said Hon Yeung, project team lead for NCDOT.

Akhnoukh is a co-principal investigator on the project, funded for $365,000 by the NCDOT, along with Rudolf Seracino, Mohammad Pour-Ghaz and Giorgio Proestos from N.C. State University.

In a separate grant, Akhnoukh is the principal investigator in a $208,992 grant through NCDOT to look at bridge drainage systems.

– Ken Buday

Amin Akhnoukh of the Department of Construction Management is part of a team looking at the use of carbon fiber in bridge construction. The replacement for the aging Earl C. Davis Memorial Bridge, left, on Harkers Island, will be the state’s first to use carbon fiber reinforcement.