Perspectives Online, The Magazine of The College of Agriculture and Life Sciences. Summer 2009 Issue

Poised for Impact - The College of Agriculture and Life Sciences is well represented as the Graduate Student Research Symposium emphasizes public benefits of NCSU research. By Terri Leith


Posters depicting more than 150 research projects were displayed at the 2009 Graduate Student Research Symposium. Photo by Becky Kirkland

The third week of March was designated Graduate Education Week by the N.C. State University Graduate School, and a highlight of the week was the Graduate Student Research Symposium. The fourth annual poster exhibit of graduate student research projects was held March 18 at McKimmon Center. Dr. Terri Lomax, vice chancellor for research and graduate studies, called the symposium, “a gathering of the best of the best.”

Noting the practical application of many of the research projects, she said, “We’re showing the range of research we do here at N.C. State – everything from destroying asteroids to designing a better hospital gown.”


Among the participants were 36 entries from CALS exhibitors, including Mary Helen Jones.
Photo by Becky Kirkland
Indeed, the logo of Graduate Education Week bore the legend NCSU Graduate Education – the Original Economic Stimulus Plan – Serving North Carolina Since 1894.

And in keeping with the university’s land-grant mission, service to North Carolina was a dominant theme at the research symposium. Like a gold star, a red graphic image of the state was displayed on many posters of research addressing and impacting issues and challenges facing the state.

Among the symposium exhibits were 36 entries from the College of Agriculture and Life Sciences, more than from any other participating college at the university. Seven are featured here.

Plant-based pest repellent packs a punch


Brooke Bissinger participated in a study of a locally developed product that has potential for health benefits and economic returns.
Photo by Becky Kirkland

One poster displaying the red state-impact graphic was that of Brooke Bissinger, third-year Ph.D. student in entomology. Her project, mentored by CALS entomologist Dr. Michael Roe, compared the efficacy of the plant-based insect repellent BioUD to other commercially available repellents, including DEET, against arthropods such as mosquitoes and ticks.

Bissinger says this applied research promises both health and economic impacts.

“This and earlier research in Dr. Roe’s lab have led to a product that can be purchased and used to protect people from blood-feeding arthropods,” she said. “This is a locally discovered product that people in North Carolina can use, and its sale has the potential to economically benefit the state and N.C. State University.”

“Although DEET is a very safe repellent, many people are concerned that it causes health problems and therefore may avoid using repellents,” she said. “We wanted to provide an acceptable plant-based repellent to help these people protect themselves from arthropods that may carry and transmit human disease organisms.”

Among the pertinent findings and results were that BioUD, which contains 7.75 percent of the active ingredient 2-undecanone (originally derived from the leaves of wild tomato plants), was as repellent or more repellent than 25 and 30 percent DEET in field trials against mosquitoes. Moreover, it was as or more repellent than 98 percent DEET against three species of ticks in lab trials.

“BioUD was also as or more repellent than all of the other commercially available repellents on the market that are EPA-approved or are recommended by the Centers for Disease Control and Prevention for use against ticks against the two species that we tested,” said Bissinger. “We were pleased with the results from our mosquito trials but were really surprised by how well BioUD worked against ticks.”

And the research goes on. “We are currently testing a second compound found in the leaves of the wild tomato plant,” she said. “It may lead to a next-generation version of BioUD that is even more repellent than the current one. I am also interested in determining how repellents work against ticks on a molecular level.”

Bissinger, who is from Durham, holds a bachelor’s degree in environmental studies from Warren Wilson College and master’s in entomology from N.C. State. She plans to do post-doctoral research and hopes ultimately to be a researcher for the USDA or be a research professor at a university.

She is also eager to share the benefits of the research with the public. “A number of people have asked about where they could purchase BioUD,” she said. “It is available at Triangle Nutrition at 8801 Lead Mine Road in Raleigh, at Wal-Mart in the camping section or on bioud.com.”

Green energy source has potential to save some green


The research of Jiele Xu (left) aims for improvement of the overall process of ethanol production from switchgrass.
Photo by Becky Kirkland

Renewable energy research project” — the phrase alone speaks volumes about what the discoveries from such a study could yield. That phrase is how third-year Ph.D. student Jiele Xu refers to his symposium entry, more formally called “Alkaline Pretreatment of Switchgrass for Ethanol Production.” Xu conducted the research working with Dr. Jay Cheng in the CALS Department of Biological and Agricultural Engineering.

Ethanol can be produced, through yeast fermentation, from sugars that are abundant in biomass. Switchgrass is a native perennial grass, hardy and adaptable, with a high biomass yield. Basically, the scientists seek to increase the sugar yield of switchgrass for more efficient and cost-effective ethanol production.

Switchgrass, as a lignocellulosic biomass, has a recalcitrant structure that makes it difficult for enzymes to get access to the inside carbohydrates and cut them into sugar monomers, Xu explained. “Therefore, pretreatment of the raw biomass is essential as it helps break down the lignocellulosic structure to expose the carbohydrates, substantially improving the enzymatic digestibility of switchgrass.”

With the improved digestibility comes improvement in the overall process of ethanol production from the switchgrass, including the cost.

Xu uses sodium hydroxide (NaOH) solution to pretreat the switchgrass and studies the combination of three parameters — temperature, time and the NaOH concentration — to maximize the pretreatment effectiveness. NaOH pretreatment helps to disrupt chemical bonds that hold the biomass components tightly together, thus loosening the structure for better enzyme access, Xu said.

“It breaks up the tough structure, so that more sugars will be available for ethanol production,” he said. “NaOH pretreatment is explored in this research because it is potentially cost-effective. If its cost-effectiveness can be substantially improved, ethanol fuel can be much more competitive in the fuel market, thus making the entire transportation sector more ‘green.’”

The research also underscores the efficacy of lignocellulosic-based versus corn-based ethanol production. In the United States, corn is currently the predominant feedstock for ethanol production, Xu said. “However, corn-based ethanol production will inevitably impose a negative impact on our food security and the environment,” he said, noting that corn is also used for food and feed, and the agricultural inputs for its growth — fertilizer, pesticide and herbicide — are intensive.

“So now, people are more and more interested in using another kind of feedstock — lignocellulosic biomass such as trees, grass, agricultural residues — for ethanol production, because it is abundant, can be produced locally and requires much less agricultural inputs for its growth.

“Ethanol is one of the best alternative energy [sources] to power our cars and trucks,” said Xu. “Actually, half of the gasoline sold in the United States today is blended with ethanol to up to 10 percent.”

The benefits of ethanol fuel include renewable and domestic production – and a reduced carbon footprint. And that corresponds to another timely need for this kind of research, Xu said — coping with global warming.

“If the ethanol cost is low enough to compete with fossil fuels, the demand for green ethanol will explode, thus decreasing the combustion of dirty fossil fuels and reducing the emission of greenhouse gases,” he said. “As we know, ethanol is theoretically carbon neutral. Plants take up CO2, a major greenhouse gas causing global warming, for its growth. After biomass is converted to ethanol and burned for energy, the CO2 goes back to the atmosphere, which forms a closed-loop recycling of CO2. No net CO2 is generated during the process.”

Furthermore, the biomass grown for ethanol production could potentially benefit the environmental quality of North Carolina, because swine wastewater can be used as a nutrient source for biomass growth, Xu said. “Actually a colleague of mine is working on ethanol production from coastal Bermuda grass, which is used by farmers as a part of nutrient management plans for the treatment of swine waste in many swine farms in the South and Southeast.”

Xu works as a research assistant for his adviser in the BAE department and expects to graduate in December. He is a native of Shanghai, “a beautiful and dynamic city on the east coast of China,” where he received his bachelor’s degree from Tongji University and master’s degree from East China University of Science and Technology, both in environmental engineering. His ultimate career goal is “to begin my own business in China someday to use biomass-based renewable energy technologies to create good jobs in rural China to help people there lead a better life.”

Study concurrently reveals water pollutant origins and antibiotic resistance trends


Lloyd Liwimbi has a goal of devising better ways to manage and use agricultural wastes while minimizing pollution in water.
Photo by Becky Kirkland

The research of Lloyd Liwimbi provides new information on both the environmental impacts of animal waste and the rates of development of antibiotic-resistant bacteria.

Liwimbi, a second-year master’s degree candidate and research assistant in the CALS Department of Soil Science, presented the symposium entry “Microbial Source Tracking Based on the Distribution of Antibiotic Resistance Genes.” Working with adviser Dr. Alexandria Graves, he has sought to identify host sources of fecal pollution found in a Sampson County creek, based on the distribution in the creek of antibiotic resistance genes recovered from E. coli. The location was chosen because of the swine production in the area, where animal waste from swine treated with antibiotics may reach nearby surface waters.

There were three main goals for this study, Liwimbi said: to identify the sources of fecal pollution in surface and groundwater, to identify and quantify antibiotic resistance genes in E. coli recovered from water sources and fecal sources, and to evaluate the association of antibiotic resistance genes found in E. coli with the actual phenotypic expression of the resistance.

This work is applied research, he said, and can be used to track sources responsible for fecal pollution in the environment and also to make decisions based on scientific evidence to establish if waste management systems are working properly.

The study can also provide timely answers to questions about antibiotic resistance, Liwimbi said. “We are faced with issues of antibiotic resistance developing at rates that require the need for the development of new antibiotics. There seems to be a lot of finger pointing with regard to who’s at fault. Are physicians responsible for over-prescribing? Is the livestock industry responsible for using antibiotics at subtherapeutic levels?”

This project, he said, essentially provides somewhat of a survey of the antibiotic resistance trends found at a swine farm, including swine houses, lagoons, groundwater and surface water.

There are “serious concerns about the emergence of antibiotic-resistant bacteria and its connection to antibiotic use in the livestock industry,” Liwimbi said. “While the benefits of antibiotic use have helped sustain intensive animal production to meet consumer demands for food products, we still have to consider the implications for the environment. North Carolina is the home of our nation’s second largest swine industry.

“Most of this swine production is restricted to a small geographical area in southeastern North Carolina. This high concentration of swine production may increase the risk of antibiotic resistant bacteria from swine operations reaching the nearby surface waters. As a result, this area is appropriate to evaluate the potential contributions of swine facilities to antibiotic resistant bacteria found in the environment.”

The research so far has been everything he had hoped, Liwimbi said, noting that “we have acquired sound scientific data that gives us an idea of how many sources contribute to antibiotic resistant bacteria recovered from the environment.”

Significantly, he said, the research showed that “swine production is not the major source of fecal pollution in the creek but multiple sources are responsible. This might also be the case for other similar locations dominated by swine. However, considerations should be made for the role of wildlife in transporting E. coli from lagoons to the streams, such as birds, turtles, etc.”

Furthermore, he added, “We were surprised that some resistant genes were more pronounced in wildlife than the livestock where antibiotics are mostly used.”

Liwimbi, who expects to complete his degree this summer, came to N.C. State from Lilongwe, Malawi, in southeast Africa. He holds a diploma in laboratory technology and a bachelor’s degree in environmental science and technology from the University of Malawi. After graduation, he said, “My goal is to return to my hometown to work towards devising better ways to manage and utilize agricultural wastes as organic fertilizers and minimize pollution in surface waters.”

Illuminating the inner workings of cattle


Scott Fry, shown here explaining his project, chose to research the mechanisms involved in copper absorption in cattle because copper deficiency is of practical importance in beef production.
Photo by Becky Kirkland

Those in the beef production industry, whose livelihoods depend on the health and well-being of the animals they raise, could potentially benefit from basic research being undertaken by R. Scott Fry, second year Ph.D. student in the CALS Department of Animal Science, under the supervision of Dr. Jerry Spears and Dr. Melissa Ashwell. His symposium entry is called “Effect of copper deficiency on gene expression profiles of copper transporters and chaperones in the intestine and liver of steers.” It’s a project focused on evaluating mechanisms involved in copper absorption and export in the intestine and liver and the effect of copper deficiency on these pathways.

More simply, Fry said, it’s a study undertaken “to better understand what is going on in the intestines and liver of cattle at the cellular level — a better understanding of how these pathways are functioning in the animal.”

He chose this research topic, he said, because copper deficiency is of practical importance in beef production.

Copper is an essential mineral, and when an animal is copper-deprived, its growth potential and its biological processes that require copper for proper function are hindered, Fry said. “A state of low copper status or deficiency can occur if there is not enough copper in the diet or if dietary antagonists, such as sulfur, iron, molybdenum and zinc, which can reduce copper status, are present in high concentrations.

“The main objective was to determine the effect of a long-term, induced copper deficiency on gene expression profiles in the intestine and liver of Angus steers,” he explained.

Prior to this research, Fry said, “the effects of a copper deficiency on these mechanisms had not been evaluated in cattle. Basic science has become popular in production livestock, so providing this information will enable us to be at the forefront in regard to copper metabolism in the bovine.

“Significant results from this study are that certain, not all, copper transporters and chaperones are affected by a severe, long-term copper deficiency. In the intestine, we found a trend for an up-regulation in two of the transporters that are vital for copper absorption. … In the liver, the expressions of the genes were down regulated due to copper deficiency. The more dramatic changes of these genes occurred in the liver, where copper is stored and processed for release into the general circulation: Gene expression associated with this function in copper-deficient animals was lower, which reflected lower copper concentrations in the blood stream. Thus it appears that a copper deficiency affects copper export from the liver to a greater extent than uptake of copper from the intestine.”

Meanwhile, he said, “We are continuing to evaluate these transporters and chaperones in cattle. More specifically, we are evaluating the effect of breed on those mechanisms. Furthermore, we are evaluating the effect of high dietary iron (antagonist) on these copper pathways in cattle and pigs.”

Fry, who expects to graduate in August 2010, received his 2005 bachelor’s degree in animal science with a minor in agricultural business from the University of Arkansas. Upon graduation he hopes “to obtain a job related to mineral metabolism, whether it is in academia or a position in private industry,” he said. “The ideal position will provide the opportunity to stay current in aspects of mineral metabolism at both the applied and basic level.”

A first-of-its-kind focus on special education in ag education


Agricultural and extension education doctoral student Kristin Stair said her research emerged out of her own experiences as a high-school teacher.
Photo by Becky Kirkland

Kristin Stair’s research on special education in agriculture education is the subject of her symposium entry called “Are we making the grade?” The research, conducted with adviser Dr. Gary Moore, sought to identify confidence levels and instructional strategies of high-school agricultural education teachers working with students with special needs. “Other researchers have looked at smaller scale studies, but this was one of the first on a national level,” Stair said. “It is the first study regarding the confidence and strategies of ag ed teachers on a national level.”

The basic research purpose was to identify what practices teachers are using when working with students with special needs and to identify the confidence levels of teachers when working with students with special needs. “I think that this research is significant to North Carolina because our teachers are working to help develop the future of our state. This is applied research that benefits teacher training and retention in agricultural education,” Stair said.

“In North Carolina, approximately 56 percent of students in career and technical education classes have an IEP [Individualized Education Plan], which means they have a recognized disability,” she said. “Yet most research in the field suggests that teachers are not confident in their abilities to work with students with special needs. I wanted to determine what areas we needed to focus on when we are training teachers so that we can prepare them to work with these students in their classroom.”

Stair said the research “emerged out of my own experiences as a high-school teacher. I had a difficult time knowing how to work with students with special needs and many of my peers felt unprepared to work with this student population. There was very little research in the field so I wanted to conduct research to help us determine what agriculture teachers were doing in their classrooms.”

Among the significant outcomes, she said, was that more than “50 percent of teachers disagreed that they were receiving adequate in-service opportunities and that their teacher training program prepared them to work with students with special needs. Both of these are very important areas to training teachers in techniques that they can use when working with these learners. To me, this indicates a need to do more to help our teachers be successful.

“I think that we have established the need to pursue better educational opportunities to train teacher to work with students with special needs. This research helped to establish a baseline but now I would like to explore the topic in more depth.”

Stair is in her final year of her doctoral program in the CALS Department of Agricultural and Extension Education. Originally from Tennessee, she holds a bachelor’s degree in agricultural information science and education from Mississippi State and a master’s in agricultural and extension education from N.C. State. She hopes to become an assistant professor in agriculture education, focusing on teacher preparation.

Keeping fairy rings off putting greens


Lee Miller’s turfgrass research can yield economic and environmental benefits to the state.
Photo by Becky Kirkland

The red state symbol was prominent on the poster outlining the work of Gerald (Lee) Miller, Ph.D. candidate in the CALS Department of Plant Pathology, because the study promises to benefit the state’s multibillion-dollar turf and lawncare industry. His research, conducted with advisers Dr. Lane Tredway and Dr. Larry Grand, is to identify the pathogens associated with a disease called “fairy ring” on golf putting greens and develop improved control methods.

“Fairy rings are a common and century-old problem in the management of high amenity turfgrasses,” Miller said. “Complaints from golf superintendents of inadequate control are quite common, and control practices that are effective can vary from site to site. Many of these problems are underlined by the biological component of fairy ring pathogens, of which very little is known. Research in this area can shed light on the biology of this pathosystem, which would directly translate into more effective resources for turf managers in controlling this disease.”

Miller said there is a timely need for such research, because “accurate identification of the causal agent is a critical first step in the successful management of any turfgrass disease. However, due to our poor understanding of fairy ring development, no specific management recommendations are available, and golf course superintendents are left to develop programs for their location by trial and error. This undoubtedly leads to fungicide applications at the wrong time or the use of ineffective products. To manage fairy rings effectively with minimal financial and environmental impacts, we must identify the fungi involved, determine the soil temperatures at which they are active and assess their sensitivity to fungicides and other management practices.”

Thus the basic purposes of the research, he said, were to develop procedures for isolation and identification of fairy ring fungi from symptomatic rings, to determine the geographic distribution of fairy ring fungi on golf course putting greens and to develop effective and specific recommendations for control of common fairy ring pathogens.

The environment could also benefit from his findings. “There are environmental and financial concerns over the inputs involved in maintaining and delivering high quality turf,” he said. “This research is aimed at reducing the inputs required for controlling fairy rings on golf putting greens. We have laid the foundation for doing this by properly identifying the pathogens involved. This will lead to further investigation of the biology of the system with the aim of finding alternative control measures.

“We also directly reduced inputs by developing a program that more effectively uses fungicides to break the cycle of fairy ring. This proper use of fungicides has reduced the overall number of applications and total fungicide load needed for fairy ring control. This reduces cost and environmental concerns over fungicide use in treatment of this disease.”

Miller, who is from Jacksonville, Fla., anticipates completion of his Ph.D. in December. He earned his bachelor’s degree in agronomy from N.C. State and his master’s in plant pathology from the University of Georgia. He was a winner of the 2008 Watson Fellowship Program’s $5,000 postgraduate grant, awarded by the Golf Course Superintendents Association of America (GCSAA) to graduate students identified as promising future teachers and researchers in the field of golf course management.

Focusing on families


Wanda Hardison (center) and Mary Helen Jones (left) tell a visitor about their master’s degree research on the impacts of familial discord on child development.
Photo by Becky Kirkland

Mary Helen Jones and Wanda J. Hardison’s symposium presentation, “Children Know When Their Parents are Fighting,” a study of the impact of familial discord on child development, earned a red-state designation because it shed light on the kind of family services that may be needed in the state.

“This project may not have immediate economic impact,” Jones said, “but child outcomes have long-range impact, such as the need for services for children who have internalized or externalized problems and for children who achieve lower academic success. Children who grow up with such issues may need additional services throughout their lives, may drop out of school and not be productively employed.”

They chose this topic, because “family conflict seems so prevalent between generations, between siblings, in divorce/separation, in blended families,” Jones said.

“Many parents don’t seem to see it as a problem, especially if they grew up with high conflict. So is it a problem for growing children? Research says, ‘Yes.’”

Thus the two sought “to create and test strategies for increasing parents’ awareness of children’s reactions to hostile conflict and teach strategies for minimizing hostile conflict between parents or family members,” Hardison said.

Furthermore, she said, “while most people readily acknowledge that domestic violence and abuse are harmful for adults and children, I was really interested to learn how harmful other forms of hostile conflict can be to children’s development.”

Jones said that a substantial body of research shows destructive parental conflict is likely to result in child outcomes, “including internalized problems, such as increased anxiety and depression, and more externalized problems, such as misbehaviors, less social competence and lower school achievement.”

However, said Hardison, the research in “the maladaptive consequences of children exposed to hostile conflict… needed to be translated into easily understood materials for the public.” Therefore, Jones and Hardison determined to both test the effectiveness of findings and translate them into “parent-friendly” educational materials.

One significant finding of their research, Jones said, “was the importance of children being made aware of conflict resolution. Some of the research indicated that even in family situations where there was severe, destructive conflict that impacts on the child might be ameliorated if the child is made aware that his parents have resolved the problem or are optimistic about resolution.”

Said Hardison, “The research shows overwhelmingly that children are aware of the conflict even if unspoken. Research stresses that parents should note that children are very aware and sensing of the emotional environment of the home.

“I should also note, as we did in our educational materials, that every family has conflict. It is normal part of family life. The research shows that respectful conflict, which is productive in solving problems, can demonstrate to children healthy ways to resolve disputes or differences with others.”

The two conducted the study as a joint endeavor for completion of their CALS master’s degrees in human development and family studies. Jones is a Cooperative Extension family and consumer sciences agent in Vance County, and Hardison is a Harnett County family and consumer sciences agent. Their graduate adviser, Dr. Karen DeBord, provided direction for the research.

Ultimately they hope “to make the basic research available to Cooperative Extension family and consumer sciences agents and other family life educators so that it would be accessible to families for use in their daily lives,” said Jones.

“We, as well as others, have much left to do in translating the research into helpful educational pieces for the general public,” Hardison said. “As the stress of our environments and economy continue, there is much need for increasing awareness of this important topic and giving families tools with which to decrease its occurrence.”