Anna Sasser and Crystal Schulte
The Influence of Pyrene on Muscle Metabolism and Contractile Ability in Rana Pipiens
Biology Department (GRD)
Faculty Mentor :  Dr. Erich K. Stabenau

Polycyclic aromatic hydrocarbons (PAHs) are carcinogens found in Illinois River sediment. This study used in-water column exposures to determine the effect of pyrene on muscle tissue contractility in leopard frogs. The results show that pyrene causes a significant decrease in muscle contractile tension, which limits exercise tolerance. Data indicate that oxygen is both loaded and delivered to the tissues, that glycogen stores were not significantly affected as a result of the treatment, and that there is no significant difference in contractile length between control and pyrene-exposed animals.  Mitochondrial oxygen consumption was significantly lower in pyrene-exposed frogs compared to that of control. Future studies could examine how decreased mitochondrial oxygen consumption correlates to the decreased exercise tolerance and muscle contractile tension observed in pyrene-exposed frogs.

Jennifer N. Steele
Characterization of Mercury-resistant Bacteria Isolated from Hatchery-reared Rainbow Trout
Biology Department (GRD)
Faculty Mentor :  Dr. Keith Johnson

Environmental mercury (Hg) levels have resulted in federal advisories for fish consumption.  Due to environmental Hg exposure through food and water contamination, Hg-resistant bacteria have colonized the fish intestinal tract.  Previous research provides a correlation between Hg and antibiotic resistance (Ab^R) within microbes.  Rainbow trout gastrointestinal tract (GI) bacteria were used to characterize Hg^R microflora for Ab^R.  GI-Hg^R strains were isolated and characterized using 16S rDNA cloning and sequencing.  Isolates were identified as Pseudomonas, Acinetobacter, Staphylococcus, and Shewanella.  Resistance to differing concentrations of Hg and varying antibiotics were assessed.  The mercury resistance gene is being cloned and sequenced.

Ashlyn Borges
Emiquon: Landscape Scale Differences in Organic Matter Content Following 80 Years of Agriculture
Biology Department
Faculty Mentor :  Dr. Sherri Morris

This study examines the impacts of 80+ years of agriculture on former lakebed soils.  Composited samples were collected from two agricultural sites on former lakebeds and an adjacent wetland site.  Soils were analyzed for bulk density, total carbon and nitrogen content, and net nitrogen mineralization rates.  Carbon content did not differ significantly.  Nitrogen content differed significantly at 0-10 and 0-50 cm depths.  Carbon to nitrogen ratio significantly differed at 0-10 cm. Significantly greater N mineralization and nitrification in wetland than either former lakebed soils. Results suggest that 80+ years of agriculture significantly altered nitrogen turnover dynamics at the Emiquon site.

Collin R. Diedrich and Pamela R. Hesker
Mitochondrial Oxygen Consumption in Fischer Rats Following Cocaine/Hypoxic Exposure
Biology Department
Faculty Mentor :  Dr. Erich K. Stabenau

Cocaine use is prevalent, as 34.9 million Americans have used it (NIDA, 2005).  Cocaine exposure causes hypoxia, brain cellular water flux, and cerebral atrophy.  Given that alterations to mitochondrial respiration cause limitations to regulatory volume mechanisms (Patel, 1998), the purpose of this study was to examine mitochondrial respiratory rates from rats exposed to cocaine/hypoxic conditions.  Fischer rats were exposed to cocaine/hypoxia for three consecutive days.  Following a latency period, brain mitochondrial oxygen consumption was measured.  Cocaine/hypoxic treatment significantly increased mitochondrial O₂ consumption in juvenile animals, whereas adult female and male rats displayed no significant differences between the treatments.

Debra Engel
Soil Organic Dynamics in the Developing Soils of Mt. St. Helens
Biology Department
Faculty Mentor :  Dr. Sherri Morris

Biology Department, Bradley University; Department of Plant Pathology, University of California at Riverside; USDA Forest Service, Pacific Northwest Research Station; Biology Department, Bradley University.

Soil organic matter plays an important role in nutrient storage and soil quality.  The eruption of Mount St. Helens provides an opportunity to examine changes in soil organic matter following disturbance.  Soil samples were taken across a disturbance gradient and C incubations were established.  The most disturbed site had the greatest initial soil respiration rate.  It is unexpected that CO2 release from these soils was so high as they have little C content.  Large pools of active fraction C suggest high rates of nutrient turnover in shallow soils so nutrient limitations for plants becoming established in these soils are reduced. 

Bryce Callighan
Isolation and Characterization of Polyketide Synthase Domains from Fusarium
Biology Department
Faculty Mentor :  Dr. Keith Johnson

Fusarium verticillioides mycotoxins (e.g. fumonisins and fusarins) that contaminate grain are synthesized by an enzyme family known as polyketide synthases (PKSs).  Degenerate PCR primers that target a conserved portion of the PKS ketosynthase (KS) domain were used to isolate KS gene fragments from F. proliferatum and F. subglutinans genomic DNA. In each species, five novel KS fragments have been isolated using these primers.  We conducted a phylogenetic analysis of the new KS sequences and available KS sequences from fungal PKSs of known and unknown function, and identified species specific PKSs as well as potential PKSs homologues in Fusarium.

Nicholas Jones
Functional Characterization of Differently Regulated Fusarium Verticillioides Genes
Biology Department
Faculty Mentor :  Dr. Keith Johnson

Fusarium verticillioides infects corn and produces secondary metabolites (e.g. fumonisins) that are toxic to animals and linked to human cancer. A better understanding of the genetic regulation of the F. verticillioides-plant disease process and fumonisin production will aid in developing new fungal-damage limitation strategies. Our approach has been to develop vectors that specifically disrupt candidate regulatory genes previously identified by sequence similarity in EST libraries and differential expression studies. Mutant fungi generated by transformation with these vectors will be compared to the wild-type strain under a variety of growth conditions in order to elucidate each gene’s function.

Kendra Kearns
Does a Common Industrial Contaminant Effect Human Sex Hormones?
Biology Department
Faculty Mentor :  Dr. Barbara Frase

Nonylphenol is used in manufacturing processes. In water supplies, levels of 1ppm are reported. Nonylphenol is a hormone-mimicking chemical; induces sex changes in some hermaphroditic organisms and disrupts normal gamete formation in lower invertebrates. My experiment focused on the effects of nonylphenol on human estrogen. For my experiment, I inserted ERE and a reporter gene, which results in fluorescence, into E. coli plasmid by transfection. There were four treatments; control group, with nonylphenol, with estrogen, and with nonylphenol and estrogen. Since the reporter gene is downstream from ERE, relative amounts of fluorescence in treatments and control will elucidate mechanisms of the hormone-mimicry.

Kate Lippert-Koch, Laura Hutchens, Karyn Olszak, ,Karaleigh Porteus, Erica Pozzie, and Colleen Wittenberg
Effects of Reinforcement  Magnitude on Alcohol Self-Administration in Rats
Psychology Department
Faculty Mentor :  Dr. Forrest Files

Previous research has shown that large reinforcers, in terms of quantity, maintain more responding than do small reinforcers. This has been shown to be true with food and water reinforcement. The present study was conducted to determine whether a large alcohol reinforcer would maintain more responding than a smaller alcohol reinforcer. During daily 30-min experimental sessions, rats were given a choice between 0.1 mls vs. 0.3 mls of a 10% alcohol solution. Results showed that the rats preferred the larger quantity.

Kimberly Lang and Anna Abts
Ecological Controls of the Phytochemistry of the Invasive Plant Alliaria petiolata
Biology Department
Faculty Mentor :  Dr. Kelly McConnaughay

Alliaria petiolata (garlic mustard) is an invasive plant species that may cause a decrease in biodiversity, increases in species extinctions, or alterations in ecosystem functions.  Garlic mustard produces a set of chemicals that are toxic to living organisms and believed to contribute to the plant’s success as an invasive species.  We examined variability in plant growth, and tissue carbon, nitrogen and glucosinolate contents in natural populations of garlic mustard from five distinct sites from a local forest.  We hypothesized that carbon and nitrogen availabilities in the environment modulate internal C and N availability, which in turn modulate glucosinolate production.

Richard Lee and Joseph Wych
Growth Responses of Soybeans to Nighttime Carbon Dioxide Enrichment
Biology Department
Faculty Mentors:  Dr. Sherri Morris and Dr. Kelly McConnaughay

Whole ecosystem responses to elevated [CO₂] depend on an expensive technique called free air carbon dioxide enrichment (FACE).  As plants do not acquire CO₂ at night, many FACE sites limit elevated [CO₂] to daytime hours in order to reduce costs.  Recently, a few studies report significant growth responses to elevated nighttime [CO₂].  Our research evaluates whether elevated nighttime [CO₂] significantly affects biomass accrual and allocation in soybean plants.  Our results show that soybean exhibits increased growth in elevated daytime [CO₂], whereas elevated nighttime [CO₂] reduces growth.  Studies ignoring differences in nighttime [CO₂] may overestimate growth responses to rising atmospheric [CO₂].

Nathan Mellor
Changes in Ecosystem Carbon Following Afforestation of Native Prairie
Biology Department
Faculty Mentor :  Dr. Sherri Morris

The Nebraska National Forest was sampled to evaluate changes in carbon following land-use change. Litter and soil samples were taken from native prairie, cedar and pine plantations. Cedars contained the largest amount of total soil carbon and pines the greatest litter carbon. Pine stands contain more soil carbon from the pines than the original prairie suggesting greater carbon loss over the years since they were planted. While total carbon may not differ between cedar and pine stands, residence times and placement do. We must know the size, location and residence times of carbon in ecosystems if they are to be used as sinks.

Robert Puhr and Stephanie Gove
The Impacts of Restoration on Ecosystem Function in Illinois Hill Prairies
Biology Department
Faculty Mentor :  Dr. Sherri Morris

Our research focused on measuring changes in ecosystem function following restoration of hill prairies in the Illinois River basin . We hypothesized that restoration would alter ecosystem functions, such as erosion control and productivity, and these changes would benefit the Illinois River . Soil and plant diversity data were collected on four restored hill prairies. Our data show that all prairies have high aggregation and soil carbon.  While soil characteristics did not differ, aboveground diversity differed across sites.  These results indicate that prairies may have characteristics that make them less susceptible to erosion. Further studies are needed to evaluate differences in diversity.

Colleen Wittenberg
Impact of Vegetation on Active Fraction Carbon Pools
Biology Department
Faculty Mentor :  Dr. Sherri Morris

We are investigating the degree to which plant inputs change soil organic matter dynamics.  Our research examines three vegetative types and examines carbon dynamics under each.  Soil samples were taken from Glycine max, Panicum virgatu, Miscanthus sinesnsis planted on the same agricultural field in Champaign , IL .  Carbon mineralization incubations were established for all soils. Carbon dioxide release was sampled periodically with an infrared gas analyzer. Results to date show that soils underlying switchgrass had the greatest CO₂ release. These results suggest that growing switchgrass for biomass fuel may increase soil carbon over crops that are commonly grown in agricultural systems.