Session 1: 1:45-3:15pm

Concurrent paper session 1a: Nobel Hall  Room 201  1:45-3:15 p.m.

The Synthesis of Substituted Aryl Diazonium Salts for the Rapid Detection of Cyanide by Surface Enhanced Raman Scattering (SERS) Spectroscopy

The precious metal mining industry has a high need to measure the concentrations of many of the waterborne chemicals used in the mining process.  Perhaps the highest need is for the measurement of cyanide concentrations.  Current methods for monitoring cyanide, however, are labor intensive, slow, and not always accurate.  Here we propose a new method for measuring cyanide concentrations using Surface Enhanced Raman Scattering (SERS) Spectroscopy, because many compounds exhibit a Raman enhancement when they are absorbed at a silver surface. An ideal receptor molecule would attach to the silver surface and would contain a binding site specific for cyanide. With these criteria in mind, we synthesized three target compounds, aryl diazonium salts, which fit all of these specifications.   All three derivatives exhibited the properties of successful cyanide detectors, indicating that this substrate could very well be used in a detection system.
 

Polyacrylamide on an Aluminum Oxide Surface

In our research we have found that the hydrolysis of polyacrylamide to form a polyacrylamide polyacrylic acid copolymer is catalyzed by an aluminum oxide surface.  FT-IR results have shown that a significant amount of polyacrylamide will react in as little time as an hour.
(CH₂CHCONH₂)_n + Al₂O₃ Yields (CH₂CHCO2H)_n + Al₂(OH)_n
The hydrolysis process, we have found, is much more favorable on this basic surface than it was on the acidic surfaces used in previous experiments.

Towards the Structural Biology of the Cytomegalovirus UL97 Gene Product

The purpose of this study is to investigate the structure and function of the cytomegalovirus UL97 gene product.  An analysis of sequence homology suggests that UL97 appears to be a novel tyrosine kinase.  The putative structure of the kinase domain has been modeled.  Polymerase chain reaction (PCR) was used to amplify the UL97 gene of cytomegalovirus.  The homology models and PCR trials will be presented and further studies will be discussed.
 

Mechanism of Hydrolysis of Toluene Sulfonates

Kelly Devine, Patrick Rider (advisor:  Allan Splittgerber)   2:15 p.m.

The mechanism of hydrolysis of two toluene sulfonate esters have been studied by measuring rates of reaction under various conditions.  These reactions have been thought to involve sulfene intermediates.  The rate data for both reactions studied is completely consistent with the presence of a sulfene intermediate.  The proposed mechanism, kinetic data for hydrolysis of phenyl-p-nitro-alpha-toluene sulfonate (old data), and data for hydrolysis of p-nitrophenyl-p-nitro-alpha-toluene sulfonate (new data) will be discussed.
 

Comparison of Coomassie Brilliant Blue and Zincon as Protein Assay Reagents

Coomassie Brilliant Blue is a protein binding reagent with characteristic  sensitivity for dilute proteins and a correlation between the assay slope and the number of bound sites.  Unfortunately, assays are run at low pH and various slopes and sensitivities occur for different proteins. Zincon, a similar reagent, was examined for its usefulness.  A correlation between slope and the number of bound sites was found, but problems arose with light sensitivity and buffer activity.
 

Preparation and Multinuclear NMR Analysis of Tris(1,1,1-trifluoro-2,4-pentanedionato)cobalt(III)

Ashley W. Jensen  (advisor:  Brian A. O'Brien )    2:45 p.m.

An improved procedure for the preparation of tris(1,1,1-trifluoro-2,4-pentanedionato)cobalt(III) from cobalt(II) carbonate, in which the use of t-butyl alcohol as a component of the solvent allows substitution of 10% hydrogen peroxide for the 90% hydrogen peroxide used in a literature procedure, is described.  The product is a mixture of mer and fac isomers that can be separated by silica gel chromatography with toluene as the eluent. ¹H, ¹³C, and ¹⁹F NMR analyses clearly illustrate the threefold rotational symmetry of the fac isomer and the lack of symmetry of the mer isomer.  These and other features of the NMR spectra will be discussed.
 

Flavanolignans: Synthesis and Antimicrobial Activity

Jeffrey B. Johnson  (advisor:  Brian A. O'Brien)   3:00 p.m.

This presentation will present an overview of the synthesis and characaterization of the flavanolignans Hydnocarpin-D and 7,3',4'-trihydroxyflavanolignan, as well as their natural product parent compound.  This includes multiple synthetic steps,  several methods of purification as well as intensive NMR study.  In addition,  the biological activity of these compounds has been tested, and their potential as antimicrobial agents will be discussed.
 
 

Concurrent paper session 2a: Nobel Hall  Room 222  2:15-3:15 p.m.

Keith Carlson, Chair

Evaluation of Epitope Specificity of Antibody Generated by Infection or Immunization with Neisseria meningitidis Serogroup B

Jennifer Keis   (advisor:  William Heidcamp)  2:00 p.m.

N. meningitidis serogroup B causes 33% of meningococcal disease in the United States, and there is no vaccine currently available against this group, as its polysaccharide capsule closely resembles glycoproteins found in human tissue.  The focus of vaccine development has shifted to the outer membrane proteins (OMP). Using Western blots and ELISAs we examined antibody specificity to the four variable regions (VRs) of the class 3 OMP. Eight paired human serum samples were obtained from patients in Brazil during a bacterial meningitis epidemic.  All patients except one displayed antibody to the class 3 OMP of the group B type 4b Brazilian epidemic strain.  The patient who showed no antibody to the prototype 4b strain did exhibit antibody to the strain containing the type 4b VR4.  The other seven patients each showed antibody to more than one VR; not one of the eight produced antibody to the class 3 protein of a heterologous type 15 strain.  No patient produced antibody to all four VR, and all showed antibody to at least one VR: No immunodominance of any one VR was seen. The peptide sequence corresponding to the VR1 regions for serotype 4 was examined to determine if a peptide alone can mimic the VR closely enough to be used as a vaccine or as a tool to assay VR-specific responses.

Investigation of a possible role for CD44 in repression of metastatic potential of murine melanoma by the Adenvirus E1A 12S gene product

 Tim Wilson (advisor:  William Heidcamp)  2:15 p.m.

CD44 is a cell adhesion receptor implicated in melanoma metastasis. Stable Adenovirus E1A 12S transfection confers a poor metastatic phenotype in vivo onto highly metastatic cells. Murine melanomas expressing high metastasis, poor metastasis, and E1A repressed phenotypes, were assayed for CD44 expression and distribution.  Little difference in full-length CD44 expression was found among the cell lines assayed.
 

Chondroitin Sulfate Assembly sites, CD44, and Tumorgenicity: A Correlation

Beth A. Peter  (advisor:  William Heidcamp)  2:30 p.m.

CD44 is an adhesion recptor molecule found in high abundance on the membrane of highly metastatic tumor cells.  Adhesion recptor molecules in aggressive melanoma strains form cell surfacen attachments with other cells.  These metastatic cells have chondroitin sulfate proteoglycan constituents attached to the exterior portion of the CD44 variant exons as part of the extracellular matrix.  This study corrleates tumorgenicityand the presence of absence of CD44 variant isoforms 4,6, and 7-8 through soft agar assays, immunoprecipitations, SDS-PAGE, and Western Blotting.
 

Hydroacoustic Survey and GIS Modeling of the Kenai River

Dan Engel  (advisor:  Mark Bjelland)  2:45 p.m.

To aid in sonar counts of sockeye salmon, it is necessary to have an accurate map of a riverbed.  Water depths across the river are correlated with their respective GPS data points, and are mapped with GIS software to create two- and three- dimensional maps of a section of the Kenai River.
 

Walk, Wade, or Swim? Evidence of Vertebrate Locomotion in a 300 Million Year Old Lake

Brooke Swanson  (advisor:  Keith Carlson)  3:00 p.m.

Trackways contribute to paleobiological interpretations by adding behavioral and ecological information unavailable from skeletal fossils. This study focuses on a recently discovered vertebrate trackway north of Perry, Oklahoma. The tracks are found on a single dolomite bedding plane in the Early Permian Wellington Formation. In excess of 1400 reptile and amphibian tracks have been documented within which 16 terrestrial vertebrate trackways can be discerned, representing a minimum of 4 ichnotaxa. In addition to the abundance and diversity of tracks, the track producing layer is easily traceable one-half mile to the north and south. This is the first Permian trackway site reported from Oklahoma.

In the past, there has been confusion concerning the paleoenvironment of this region during the Early Permian. The gray, flat lying shales and dolomites of this part of the Wellington Formation have cyclic depositional patterns and other sedimentologic features that have led some workers to the interpretation of a marginal marine paleoenvironment. Alternate interpretations are that this sequence represents a lacustrine or estuary environment, supported by the occasional occurrence of a nonmarine fauna of insects, vertebrates, and plants. The trackway data contributes to a reinterpretation based on insect, plant, and vertebrate fossils and on sedimentologic features.
 
 

Poster Session       Nobel Hall Lobby      3:15-3:45 p.m.

James Welsh, Chair

Cesium and Potassium Phthaloylphosphanides

Ryan C. Nelson, Jeffrey B. Johnson  (advisor:  Brian A. O'Brien)

An array of structurally diverse phthaloylphosphanides [1,2-C₆H₄(C=O)₂P^- M⁺ and ring-substituted derivatives] has been prepared by reaction of diethyl phthalate or ring-substituted diethyl phthalates with phosphane in a tertiary alcohol solvent in the presence of one molar equivalent of alkali (Cs⁺, K⁺/18-crown-6,or K⁺) alkoxide base. The reactions proceed rapidly and in good yield, and isolation of the products is straightforward. Spectroscopic and chemical characterization of the phthaloylphosphanides will be  presented, and differences in properties induced by  the various substituent groups will be described.  Details of the synthetic procedures will be presented, with emphasis on a particularly effective route in  which cesium t-amyloxide is used as the base
 

Mineralization of Collagen Fibers by Bioactive Glass Stimulated Chondrocytes

Laura Owen  (advisor:  Ellis Bell)

Interest in artificial tissue generation has stimulated interest in examining the formation of interfaces between cartilage/collagen and developing bone. The specific aim of this project was to determine whether bioactive glass would either provide a source of ions for the mineralization process or would stimulate chondrocyte cells directly to enhance mineralization. We have demonstrated that kokubo bioactive glass stimulates chondrocyte differentiation and that the stimulation requires direct contact with the glass.
 

Preparation of Asymmetric Titanium Trisphenolate Complexes

Gina Kime  (advisor: Gretchen Hofmeister)

Plasma-produced polymer thin films have been found to afford some corrosion protection in some cases.  We are currently trying to understand the film formation process.  Do the films build up as islands that grow, or in a layer-by-layer constant coverage process?  Thus far we have developed a reliable and repeatable process for creating thin films.  We coat
aluminum plated slides with a thin polymer film in a plasma chamber, leaving part of the slide uncoated.  We are able to make measurements of thickness and coverage using the scanning tunneling microscope.
 

Proteases in Plant Development: Possibilities of GMO’s and Pest Resistance

Jason Christiansen  (advisor:  Ellis Bell)

Soybean cyst nematodes have a thiol protease located in their digestive system that destroys soybean plants.  It is possible that a thiol protease inhibitor could prevent the damage.  The possibility for a TG soybean plant resistant to the nematode thus exists.  The purpose of this study is to determine which types of proteases are important in the development of the soybean plant. Proteins from various tissues are extracted and analyzed for protease activity.  Seeds and seedlings are the only tissues to show protease activity and have a relatively high affinity for substrate binding.
 

Papain Activiy in the Presence of Cystatin and Hydroxyapatite

Aaron Johnson  (advisor:  Ellis Bell)

Protease activity must be crucial for the structural rearrangements in the extracellular matrix necessary for bone and tooth synthesis.  Hydroxyapatite is a main mineral component of bone and teeth and it is known that it affects protease activity in some ways.  This project investigates the affects of both hydroxyapatite and the thiol protease inhibitor cystatin on the thiol protease papain.  The protease activity was measured by the degradation of the dye-linked substrate protein azocasein.  Papain activity was found to obey Michaelis-Menten kinetics with this substrate.  Papain was shown to bind hydroxyapatite in solution, but the association was very weak.  The results of the incubation with cystatin and hydroxyapatite were inconclusive.  Cystatin seems to have little effect at low azocasein concentration, but at higher concentration, protease inhibition occurs, seemingly the cause of both cystatin and hydroxyapatite and most pronounced in the presence of both.
 

Session 2: 3:45-5:00pm

Concurrent paper session 2a: Olin Hall  Room 220  3:45-5:15 p.m.

Dennis Henry, Chair

Divisibility Properties of a Tribonacci Sequence

Andrew Shallue  (advisor:  John Holte)  3:45 p.m.

Many are familiar with the numerous nice properties of the Fibonacci sequence.  This presentation will extend some of these properties to the Tribonacci sequence defined by T_n = T_n-1 + T_n-2 + T_n-3.  Specifically we investigate the degree of divisibility of T_n by 2, the patterns that result, and the consequences for "tribonomial coefficients."
 

Investigations of Anomalous Magnetic Fields in a Classroom

Jessica Midgarden  (advisor:  Dennis Henry)   4:00 p.m.

Color distortions have long been observed in TV monitors at specific locations in Olin Hall 220.  Abnormally large magnetic fields, reaching ten times the Earth's ambient, were measured at one such location.  Likely field sources have been identified in concentrations of pipes, rods and ductwork in the ceiling of the computer lab below.  Field measurements near these ferromagnetic objects reached 40 times the Earth's background.  The locations of these structures correlate well with the high-field classroom locations.
 

Sound Distribution Of An Organ Pipe

Jonathan Skovholt  (advisor:  Tom Huber)   4:15 p.m.

Our research goal is to understand the sound distribution within an organ pipe.  We are starting by studying the sound distribution of a cylindrical pipe driven by a sine sound wave.   We have constructed a computer controlled sampling device that will map out the sound distribution.  Preliminary results will be presented.
 

Monte Carlo Simulation of Scattering

Larry Engelhardt  (advisor:  Tom Huber)   4:30 p.m.

The purpose of this research is to develop a Monte Carlo simulation that can be used to model both acoustical and optical scattering experiments that are being performed in the Gustavus physics department.  In Monte Carlo simulations, random numbers are used along with probabilities of interest to determine the positions at which scattering events occur and the scattered angles.  We will discuss the motivation for the project as well as its status.
 

Low-Coherence Optical Reflectometer

Christopher Holstrom  (advisor:  Steve Mellema)   4:45 p.m.

We have constructed a low-coherence optical reflectometer. The apparatus employs optical heterodyning in a modified Mach-Zehnder interferometer using a diode laser, acousto-optic modulator (AOM), photodiode detector and a high-frequency lock-in amplifier. The samples to  be studied are reflective objects inside sample  cells filled with an aqueous suspension of  polystyrene spheres. An image of the reflective object will be constructed pixel-by-pixel by moving the detector through the profile of the beam.
 

Concurrent paper session 2b: Nobel Hall, Room 222, 3:45-5:15 p.m.

Nancy Butler, Chair

Evidence of the Mozart Effect through the Analysis of Alpha-Wave Activity

Heather M. Nelson  (advisor:  Michael Ferragamo)   3:45 p.m.

The goal of this study was to replicate the Mozart Effect under the methods prescribed by Rausher et.al (1995) by requiring subjects to complete spatial reasoning tasks under two audio conditions.  Alpha-wave activity of subjects was analyzed in an attempt to provide a physiological correlation to the phenomenon.  It was observed that subjects performed better on tests while listening to music rather than silence.  There was also an observed decrease in alpha-wave activity while performing with music.
 

Neural Modeling of Echolocation in the Big Brown Bat

Christine Torborg  (advisor:  Michael Ferragamo)  4:00 p.m.

Electrophysiological recordings from the inferior colliculus and auditory cortex of the big brown bat, Eptesicus fuscus, indicate that individual neurons respond to a frequency-modulated emission with a characteristic latency. Using this information, we are developing a model that processes auditory temporal information and are testing the mean performance of populations of neurons at both recorded brain levels.  Our simulations reveal that relatively few cells are required to produce good temporal performance.
 

Reproductive Potential of Gleditsia tricanthos

Nathan Keller, Emily Orling  (advisor:  Cindy Johnson-Groh)   4:15 p.m.

This study examines the relationships between pod storage, herbivory, and germination of Gleditsia tricanthos.  Pods were collected and counted during 1999-2000.  Individual trees are capable of producing over 8,000 pods.  Pods containing an average of 15.3 seeds were stored under three regimes.  Pods were examined for signs of herbivory.  The pods stored outside had the highest number of viable seeds.  Pods stored inside had fewer viable seeds and higher herbivory.  Germination of seeds was high (58-100%) for all storage regimes.
 

The Distribution and Abundance of Underground Gametophytes in Eight Species of Botrychium (Moonwort Ferns)

 Laura C. Schoessler, Chanda Riedel, Krissa C. Skogen   (advisor:  Cindy Johnson-Groh)    4:30 p.m.

 Botrychium species reproduce through production of underground gametophytes which grow from spores.  The distribution of underground gametophytes has not been extensively studied.  In this study we compare the distribution of eight species:  Botrychium virginianum, B. mormo, B. montanum, B. lanceolatum, B. gallicomontanum, B. campestre, B. "fennestratum", and B. "tetra".  For each species, forty-nine soil samples were collected in a spoke-like pattern.  Gametophytes were isolated from the soil samples using a centrifugation technique which allows gametophytes (and other organic material) to float in a sucrose solution.  The underground distribution of Botrychium is patchy and not regularly distributed.  The average abundance was 529.5 gametophytes/m2.  Forty percent of samples contained underground structures.  The results indicate that most species of Botrychium have a large bank of underground structures to regenerate the aboveground population.