Posters

Stable isotopic indicators of population structure and natal habitats of Asian carps threatening to invade the Great Lakes

Darcy R. Ernat et al. — Thu, 21 Oct 2010 08:19:29 PDT

Understanding early-life habitats is crucial for managing non-indigenous large river fishes such as silver carp that are threatening to invade the Great Lakes and may significantly impact economically valuable Great Lakes fisheries. Silver carp inhabiting the upper Illinois River directly below the electrical deterrent barrier (installed on a canal in the Chicago area that connects the Illinois River with Lake Michigan) possess the greatest potential to invade the Great Lakes. However, adult silver carp inhabiting this reach of the Illinois River may have originated from many points throughout the Mississippi River basin (e.g., Illinois River or Middle Mississippi River), and the relative importance of these potential origination locations is unknown. As such, this study was used to identify natal habitats of adult silver carp in the upper portion of the Illinois River. Based on the stable oxygen and stable carbon isotopes of otoliths (earstones) from individual fish, we have determined that silver carp inhabiting the area below the electric barrier originated from within the Illinois River itself, the Middle Mississippi River, and floodplain lakes along the lower Illinois River valley. Because of the geographically widespread points of origin for individual fish, management efforts for eradication or control of silver carp in the upper Illinois River should be directed at a similarly broad geographic scale. While potentially challenging to implement, large-scale removal of silver carp and the closely related bighead carp in the Illinois and Mississippi Rivers could greatly reduce the probability of these species breaching the electrical barriers and entering the Great Lakes.

Impact Resistance of Intermetallic Bonded Diamond Composites and Polycrystalline Diamond Compacts

Lucas Pulley — Thu, 21 Oct 2010 08:19:28 PDT

Intermetallic-Bonded Diamond composites (IBDs) represent a ground breaking new group of materials patented in 2007 by two SIUC faculty. IBDs consist of diamond and carbide phases embedded into an intermetallic Ni3Al matrix, which can be further alloyed by additional elements such as Mo, B, Ti, W, Fe, Cr, Zr and others. Polycrystalline Diamond Compacts (PDCs), one of today’s industry-leading materials, consist of diamond crystallites held together by Co-alloy. Both the IBDs and PDCs are designed for “high wear” applications with necessary resistance of tools such as in coal mining, machining of materials, oil drilling and others. IBD has a cutting capacity and wear resistance far exceeding current cemented tungsten carbide materials. In previous research, a series of specifically designed IBD composites have been found to exceed the standards of toughness and wear resistance in mining and oil drilling applications, but no systematic research has been done to compare the friction, wear, and toughness properties of IBDs and PDCs. This research project compared selected properties and performance levels of IBD and PDC samples. During impact testing, samples were subjected to impact energies of up to 125 J in order to examine the fundamental differences in the fracture mechanisms using Scanning Electron Microscopy. During friction and wear testing, sample edges were pressed against rotating discs of cast iron, steel, and granite in order to analyze and compare the mechanisms of friction and wear of IBDs and PDCs. Results show that PDCs outperform IBDs in “smooth wear” testing, but IBD is superior in impact resistance and “impact wear” testing. Several industries are currently interested in licensing this promising new material, and this research is a key component for the future applications of IBDs.

Cradle to Grave: A Study of Sustainable Food Practices in a University Setting

Ryan Babich et al. — Thu, 21 Oct 2010 08:19:27 PDT

The goal of this research was to understand the process of food service sustainability through a limited “cradle-to-grave” analysis of Southern Illinois University’s campus dining facilities. The process of researching the dining halls’ sustainability was broken into three separate stages: food mileage analysis, food waste analysis, and vermicomposting analysis.

The first stage examined the food mileage for each food item. Using a mileage calculator and a carbon footprint calculator, we were able to determine miles traveled and the amount of CO2 produced by the university. Results showed that the dining halls were 15.67% sustainable in its food purchasing process. The goal for the university was to obtain a 20% purchase rate of sustainable products. The total carbon foot print for the university is 1538.06 tons of CO2 for 1,990 items. The tonnage output is equivalent to the carbon emissions of 64,085.83 propane cylinders (carbonfund.org). The total mileage of the food items is 775,394.50 miles. With further investigation, the university will be able to find local producers which will increase the percentage of sustainability by reducing the CO2 and mileage output.

The second stage of the research calculated the average amount of waste that was produced per student. SIUC’s dining halls utilize a new trayless system of service, where trays are removed and students have to fill up a plate instead of a tray. This analysis was performed on two separate days for each of the three serving periods to obtain a per student average. After the serving period had ended, the waste was gathered and weighed on a scale. The average food waste produced per student was 1.04 ounces a day. In 2007, the university’s recycling center conducted a plate waste study and calculated food waste to be approximately 4-ounces per person with trays. Currently, the waste produced is very limited. This demonstrates that trayless dining has proven effective and needs to be continued.

The final stage was a vermicomposting analysis in which a pre-composting phase was implemented to increase the amount of food waste that could be reduced within the university dining setting. The amount of time taken for vermicomposting to reduce the food waste was longer than anticipated. The longer time frame translated into additional monies to pay for utilities for the building and payroll for the workers. Vermicomposting, although ecologically friendly, does not appear cost effective.

This study demonstrates how universities can begin the process of sustainability. By using several methods that we have investigated to increase sustainability, food mileage calculations and tray-less dining, universities should be able to implement more sustainable practices in order to encourage making themselves green.

Taxol Precursor Production in Physcomitrella patens

Samuel Hughes et al. — Thu, 21 Oct 2010 08:19:26 PDT

Taxol is a cancer fighting drug that was initially isolated from the Pacific Yew. However, the isolation process is not very efficient and the tree is being excessively harvested and faces extinction. To synthetically make Taxol is an inefficient and costly process. If the precursor taxadiene-5 alpha-acetoxy-10 beta-ol can be produced with ease, then the synthetic modification of that precursor would be an efficient way to produce the potent cancer fighting drug. Several genes from the Pacific Yew were isolated and amplified so that they could be inserted into the moss Physcomitrella patens. Using competent E. coli cells as entry vectors, the genes were transferred so that the metabolic pathway responsible for taxadiene-5 alpha-acetoxy-10 beta-ol synthesis could be replicated in Physcomitrella patens. When the final transfer was made to the moss, a transient expression of the genes resulted in small amounts of product being obtained. After gas chromatography mass spectrometry analysis, the chromatogram plots showed a few more promising peaks representing other Taxol precursors. With a permanent transfer to the moss, a much larger sample could be analyzed and more Taxol precursor could be produced.

Waiting for a More Certain Future; Decision Making in a Video Game

Tara Webb — Thu, 21 Oct 2010 08:19:25 PDT

A first-person-shooter video game was adapted for the study of probability discounting, in which an outcome decreases in value as its likelihood decreases, and delay discounting, in which an outcome decreases in value as the delay to its occurrence increases. This novel preparation was designed to address a criticism of previous research in the area. Discounting research using humans has been criticized for using hypothetical outcomes and tasks in which the probabilities and delays are not actually experienced. In the video game preparation, participants fired a weapon that could produce an explosion. The longer that they waited, the higher the likelihood that their weapon would function; after 10 seconds, pulling the trigger was guaranteed to produce an explosion. An impulsive person was predicted to shoot sooner with a greater risk of the weapon not firing, whereas a highly self-controlled person was predicted to shoot later in order to ensure a high probability of damage to the target. The advantages of waiting were systematically changed to either encourage or discourage waiting by modifying the way in which the probability increased. Participants who needed more encouragement to wait were judged to be more impulsive than those who waited without significant encouragement. Students also completed a typical probability discounting task, where they were asked to make hypothetical choices between smaller-certain versus larger-uncertain monetary rewards. There were significant individual differences in the task, and participants completed the task less efficiently than they did in an earlier experiment in which outcome magnitude, not probability, increased over time. Behaving impulsively in the video game was detrimental to the progress of the player, which produced less impulsive behavior as the game progressed. Future analyses will examine correlations between behavior in the video game and choices in the typical questionnaire task.

Loss of Innocence: A Live Production of Bert V. Royal's "Dog Sees God: Confessions of a Teenage Blockhead"

Steve Looten, Jr. — Sat, 10 Apr 2010 05:34:53 PDT

What do you think happens when we die?

“Hecate is the goddess of death…”

“Either you are reborn or you dissolve into nothingness…”

“Maggot food!”

“They go to heaven.”

These are only a few of the answers provided by CB’s friends as he mourns the death of his pet beagle. In “Dog Sees God: Confessions of a Teenage Blockhead,” an unauthorized parody of the Peanuts comic strip by Charles Schulz, playwright Bert V. Royal continues Charlie Brown’s (CB’s) story into adolescence where the beloved blockhead – an icon of American youth – encounters modern threats to childhood’s innocence. Loss of Innocence jumps into Royal’s world and explores how teenage students address alcohol, drugs, sexual activity, and prejudice on a daily basis. The project looks into our generations’ views of morality, insignificance, and rejection – hoping to bridge gaps based on religion, gender, and social differences. This poster presentation outlines Royal’s play, the SIUC staged performance, and the director’s vision that inspired the production.

Modification and Stabilization of MHC Class I Molecules for Use in DNA Vaccine

Gregory Cresswell et al. — Sat, 10 Apr 2010 05:34:49 PDT

Major Histocompatibility Complex class I molecules present antigens to the immune system. A mouse MHC class I gene was modified by linking individual subunits together with a peptide antigen. A disulfide bond, termed the disulfide trap, was added to stabilize the preloaded antigen. The original antigen peptide, SIINFEKL, was modified to test the disulfide trap for stabilization of MHC class I with a modified antigen. The SIINFEKL antigen was modified to SIINHEKL and SIINYEKL. DNA primers were designed to mutate the phenylalanine (F) amino acid to the new histidine (H) or tyrosine (Y). This was done through site directed mutagenesis, transformation, and transfection into tissue culture cells. Modifications of the peptide were tested using cytotoxic T cells that specifically recognized MHC I-SIINFEKL. Cells expressing the disulfide trap proved to be very stable and presented a recognizable antigen to the T cells even when the original peptide had been modified. For the SIINHEKL modification, the disulfide trap model was recognized by the T cells. However, the SIINHEKL without the disulfide trap model was weakly presented to the T cells. Flow cytometry of the tissue cultures showed very similar results. Flow cytometry uses antibodies specific for the MHC I molecule and the antigens being presented. This allows for proper folding of the antigen peptide on the MHC I to be detected. Molecules lacking the disulfide trap were not as stable and did not fold or present peptides well. The SIINYEKL molecule responded in much the same way. This serves as proof of the concept that peptides of our design can be presented efficiently to the immune system with disulfide trap stabilization. Further application of this research may allow DNA vaccines, expressing custom antigens, to be generated.