February 16, 2006

The Nose Knows: Thomas Hoye uses chemistry to outfox the sea lamprey

Office of the Vice President for Research: The sea lamprey has been around for 400 million years, so it's a safe bet the parasitic eel-like fish comes equipped with top-of-the-line survival tools. But the scourge of the Great Lakes may finally have met its match.

Chemistry professor Thomas Hoye and several graduate students in his lab are members of a University research team intent on converting one of the lamprey's most powerful assets into a liability. They are collaborating with a group led by Peter Sorensen, a professor in the Department of Fisheries, Wildlife, and Conservation Biology, to develop a species-specific, nontoxic synthetic chemical attractant (pheromone) as a means of controlling the sea lamprey population.

An ocean native, the lamprey invaded the Great Lakes early in the 20th century and soon decimated stocks of lake trout, whitefish, chub, and other commercially valuable species. Although it spends only about a year of its life as an adult parasite, each lamprey kills on average 40 pounds of fish, according to the Great Lakes Fishery Commission, which is responsible for sea lamprey control. Last year alone, the U.S. and Canada spent more than $16 million on lamprey control, primarily through the use of lampricides that kill the larvae but also some innocent species.

As adult lampreys near the end of their lives, they have only a few weeks in which to migrate from their normal habitat in lakes or coastal waters to freshwater streams where they spawn. However, only about one in 10 freshwater streams provides a suitable spawning ground and nursery habitat for larval lampreys, which spend three to 20 years burrowed into the streambed. Adults locate these streams by following the scent of a powerful pheromone emitted by the toothless, blind larvae.

Read the full article: http://www.research.umn.edu/spotlight/hoye.html

Read more about this topic at:

Sorensen PW, Fine JM, Dvornikovs V, Jeffrey CS, Shao F, Wang J, et al. Mixture of new sulfated steroids functions as a migratory pheromone in the sea lamprey. Nature Chemical Biology 2005;1(6):324-328.
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Fine JM, Sorensen PW. Biologically relevant concentrations of petromyzonol sulfate, a component of the sea lamprey migratory pheromone, measured in stream water. J.Chem.Ecol. 2005 Sep;31(9):2205-2210.
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Sorensen PW, Stacey NE. Brief review of fish pheromones and discussion of their possible uses in the control of non-indigenous teleost fishes. New Zealand Journal of Marine & Freshwater Research 2004 Aug;38(3):399-417.
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February 9, 2006

Corn on the Job: Shri Ramaswamy's research advances our understanding of the interaction of water and corn-based plastics

Office of the Vice President for Research: What goes around, comes around. In the late 1960s polymers were the hot thing. Twenty years later, the material was, well no longer so hot. Plastics were an inexpensive commodity, mostly a world of oil-based resins, pressed, extruded, or blow molded to shape using low-cost, high-speed production techniques.

Now the field has come alive again. For proof, look no further than the 2005 Minnesota State Fair. Hundreds of thousands of people at this year's State Fair picked up that most ubiquitous of giveaways: the plastic carry-bag. Most were of the normal, petroleum-based plastic variety, functional to be sure, perhaps even colorful. But sooner or later, those bags, having done their job, will land unceremoniously in waste bins—and eventually in landfills.

But clogging landfills is not the only possible destiny for some fairgoers' bags. The bags that Shri Ramaswamy and his colleagues at the College gave away had another attribute: They contained plastics derived from agricultural products, and were (and are) biodegradable. They were made with poly lactic acid (PLA), which is one of the biobased polymers recently introduced in the marketplace. "These corn derived plastics essentially degrade within 30 days. So if you have the right conditions—temperature, humidity, and bugs [bacteria], which are typical of industrial compost sites—they go completely back to water and lactic acid and leave no solid waste pollution," Ramaswamy explains.

The use of bio-based PLA plastics in the food industry is growing faster than a Chia Pet soaked in Miracle-Gro. Consumers value "green" plastics for their ecological benefits. With the advancement in technology, and given today's oil prices, bio-based polymers are very cost competitive to conventional petroleum-based polymers. Researchers at the University of Minnesota are working to improve the properties and performance of the bio-based polymers.

Ramaswamy and his colleague, Professor Rich Cairncross from Drexel University, recently received a grant to study one of the problems associated with the type of plastic made from corn-derived PLA. The project is an investigation into the moisture transport and degradation kinetics of PLA products. "I'm working on the use of this plastic in water bottles," says Ramaswamy. "Being bio-based, PLA interacts with moisture and transmits water easily. This is one of the reasons why PLA degrades so quickly and completely. At the same time, ease of transport of moisture through PLA can pose problems in long-term storage and use in applications such as water bottles. The water will evaporate out of the bottle, right through the bottle walls."

Read the full article: http://www.research.umn.edu/spotlight/ramaswamy.html

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Bandyopadhyay, A.; Ramarao, B. V.; Ramaswamy, Shri. Transient moisture diffusion through paperboard materials. Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2002), 206(1-3), 455-467.
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Ramaswamy, S.; Gupta, M.; Goel, A.; Aaltosalmi, U.; Kataja, M.; Koponen, A.; Ramarao, B. V. The 3D structure of fabric and its relationship to liquid and vapor transport. Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2004), 241(1-3), 323-333.
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Bandyopadhyay, A.; Ramarao, B. V.; Ramaswamy, Shri. Transient moisture diffusion through paperboard materials. Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2002), 206(1-3), 455-467.
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December 31, 2005

Engineering Novel Approaches to Bacterial Infections: The field of protein engineering sheds light on the prevention and treatment of bacterial diseases

Office of the Vice President for Research: Because of an unexpected influenza (flu) virus vaccine shortage this year, many Americans must forego their annual flu shot. Media continue to report on availability of the remaining vaccine and how to prepare for the flu season. For the moment, illnesses caused by another type of infectious agent, bacterial pathogens, are receiving far less attention. However, infectious diseases caused by bacteria are a concern for public health officials and can pose significant risk to the public. For example, Wisconsin and, to a lesser extent North Dakota and Minnesota, have observed a recent spike in the number of cases of whooping cough , a highly contagious bacterial disease affecting the lungs and producing a severe, uncontrollable cough that can last for weeks. Whooping cough derives its name from a high-pitched whooping sound that can sometimes be heard, particularly in young children, when breathing in after a coughing episode.
In the University's Department of Chemical Engineering and Materials Science, newly arrived assistant professor Jennifer Maynard is using protein engineering to study the bacterium that causes whooping cough, Bordetella pertussis. A chemical engineer with a strong background in biology, Maynard uses recent advances in genetic engineering to design more sophisticated strategies to treat people with active disease and to discover better vaccine technologies to prevent disease.
Over the past 15 years, scientists have learned how to artificially alter proteins or recombine portions of proteins to produce a desired effect, such as improved function, in a field known as protein engineering. Protein engineering relies on recombinant DNA techniques to make targeted changes at the DNA level that will produce a tailor-made protein possessing one or more favorable characteristics.
Much of Maynard's research focuses on using protein engineering to artificially construct antibodies, which are proteins naturally produced by the body's immune system as a defense against foreign invasion. Antibodies are highly specific and targeted in their action; each antibody can recognize and bind to only a single foreign substance. Protein engineering techniques allow scientists like Maynard to build specific antibodies that can bind to a particular bacterial target and to find those that can defend against bacterial infection. Administration of such engineered antibodies to a patient with a bacterial infection could represent a new therapy for the treatment of bacterial disease.

Read the full article: http://www.research.umn.edu/spotlight/maynard.html

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Maynard J, Adams EJ, Krogsgaard M, Petersson K, Liu CW, Garcia KC. High-level bacterial secretion of single-chain alphabeta T-cell receptors. J.Immunol.Methods 2005 Nov 30;306(1-2):51-67.
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Maynard J, Petersson K, Wilson DH, Adams EJ, Blondelle SE, Boulanger MJ, et al. Structure of an autoimmune T cell receptor complexed with class II peptide-MHC: insights into MHC bias and antigen specificity. Immunity 2005 Jan;22(1):81-92.
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Presta LG. Selection, design, and engineering of therapeutic antibodies. J.Allergy Clin.Immunol. 2005 Oct;116(4):731-736. Quiz page 737.
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Deploying a Driver-Assistance System for Rural Snowplows: Craig Shankwitz designs smart snowplows to keep Minnesota roads clear

Office of the Vice President for Research: When researchers at the University of Minnesota's Intelligent Vehicles Laboratory set out to build a better snowplow, they faced the challenge of integrating many different technologies into a single system that would make plow drivers' jobs easier and safer. A pair of new research reports offers ITS professionals a valuable window into the design and eventual deployment of this system, from vehicle design through initial field testing to final operational use in two Minnesota counties.

The Minnesota team, led by IV Lab director Craig Shankwitz, designed its advanced snowplow to enable vehicle operation in white-out conditions by using a high-accuracy differentially corrected Global Positioning System receiver working in concert with high-resolution digital maps of plow routes. Knowing the exact position of the vehicle in relation to the road and surrounding landmarks enabled a variety of navigational assistance technologies, including a head-up display (HUD) unit to show road boundaries and obstacles projected over the driver's view through the windshield. The HUD also integrated data from radar sensors, allowing the driver to see other vehicles around the plow. Steering feedback and a vibrating seat to warn of lane departure were also implemented based on the navigation system.

The advanced snowplow was tested by plow operators in two Minnesota counties featuring very different geography and snow conditions. St. Louis County, near Lake Superior, experiences heavy lake-effect snowfalls and is heavily wooded, with thick conifer forests near the highway on which the plow was operated. Polk County, on the other hand, experiences less snowfall but lies on the heavily cultivated plains and has few forests, contributing to frequent blowing snow that reduces visibility. In the final analysis, these geographic differences proved significant, as the Polk County testers found the system more useful than the St. Louis County testers, who chose to abandon the system after a year of testing. Polk County subsequently requested the St. Louis County unit and put it to use on its roads.

Read the full article: http://www.research.umn.edu/spotlight/shankwitz.html

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Gorjestani A, Alexander L, Newstrom B, Cheng P M, Sergi M, Shankwitz C, et al. Driver Assistive System for Snowplows. 2003;MN/RC-2003-13:pp72
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Alec Gorjestani, Bryan Newstrom, Craig Shankwitz, Max Donath. Advanced range sensor processing using DGPS and a geospatial database. 2001 IEEE Intelligent Transportation Systems Proceedings, Aug 25-29 2001 Oakland, CA; 2001.
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Learn more at the Minnesota Specialty Vehicle Initiative web site: http://www.its.umn.edu/research/ivifieldtest/index.html