Sigma Xi Undergraduate Research Forum 1997


Session 1: 1:45-3:15pm

Concurrent paper session 1a: Olin Hall, Room 216, 1:45-3:15pm

Dr. Larry Wohl, chair

NMR, CD, and Computational Studies of the Major Helix from Chicken Cystatin

Brent Goplen (advisor: Ellis Bell) 1:45pm

Previous studies of the folding of the thiol protease inhibitor cystatin have suggested that the first helix of the structure plays a major role in the overall folding of the protein. To further examine the stability of this helix a series of biophysical and computational studies have been undertaken. The stability in solution of a peptide, synthesized using standard fmoc synthesis, to correspond to the sequence of the helix, has been studied by both circular dichroism and proton NMR using a series of solvent denaturants [guanidine hydrochloride] and temperatures [5oC to 65oC]. Although the NMR studies yield no definitive data in the absence of the helix potentiating cosolvent, trifluoroethanol, the CD studies using the 222nm band associated with alpha helix formation indicate that this helix is particularly stable. The role that various hydrophobic and hydrophilic residues, selected on the basis of their positions relative to adjacent residues in the overall structure, may play in this stability has been examined, by computer mutation, using molecular modeling simulations. These studies support the contention that this helix may act as a nucleation site for the folding of cystatin.

Melanoma Adhesion to Lung Endothelial Tissue

Jessica Hatlevig (advisor: William Heidcamp) 2:00pm

Research efforts on cancer have concentrated on the investigation of the adhesion mechanisms surrounding B16 melanoma in mice. This investigation measures the attachment of B16 melanoma to lung endothelial cells and the role of fibronectin. Fibronectin is thought to be a main contributor to the attachment of melanoma cells onto the endothelial cell surface. The lung endothelial cultrures were established to study fibronectin in vitro. Once a culture was established, the B16 mouse melanoma cells were co-cultured adjacent to normal lung endothelial cells. Focal adhesions between melanoma and endothelia are identified and quantified by fluorescenct tags, immunolocalization of fibronectin, and image analysis.

A Comparative Historical Study of Elevation Determination

Bob Fossum (advisor: Bob Douglas) 2:15pm

Various methods have been used to determine elevation throughout history. Three distinct eras can be noted: Barometer and Compass(1850s), Benchmarks(1950s), and GPS or Global Positioning System(1990s). Through librar research, the process by which each method was completed was determined. Next, field research located benchmarks placed on the landscape during the 1950s. With these locations identified, a reading with a GPS unit was taken to verify these 1950 elevations with 1990's technology.

Employment Subsidies for Disadvantaged Workers and Their Effects

Jesse I Christianson (advisor: Larry Wohl) 2:30pm

This paper will examine the government's attempts to encourage employment among the chronically difficult to employ. The findings of studies of these attempts have been less than encouraging. Evidence that the subsidization may actually make it more difficult for disadvantaged workers to become employed was shown in an experiment in Dayton, Ohio. The two subsidized groups were hired at a significantly lower rate than the null group. This would suggest that the vouchers hurt rather than helped the employment chances of the disadvantaged worker pool.

Welfare Reform Efforts

Kristi Maidment (advisor: Larry Wohl) 2:45pm

There is no perfect solution to reform welfare, but there have been many programs which have attempted to improve the welfare system. Some have proven effective and others have not. It is important be aware of these attempts and their effectiveness when designing new programs. This paper will investigate welfare reform efforts at the federal, state and local government levels, and evaluate the effectiveness of each alternative approach. Recommandations will be offered on common design features that seem to be successful.

Discrimination and the Wage Gap

Stacey Willemsen (advisor: Larry Wohl) 3:00pm

The wage differential for males and females is a topic of debate for many people. Although there is a substantial wage gap, it does not exist solely as a result of discrimination. Women's choices of occupation, along with a weak attachment to the labor force, have a large impact on the wage differential. However, after correcting for these different characteristics, discrimination still appears to be a factor. Several policies which could alleviate discrimination include comparable worth, education policy, full-employment policy, and family-friendly policy.

Concurrent paper session 1b: Olin Hall, Room 220, 1:45-3:15pm

Dr. Lawrence Potts, chair

The Construction of a High-Vacuum Plasma Chamber

Michael R Bukowski (advisor: Dr. Lawrence W. Potts) 1:45pm

In the course of our surface studies, we dicovered a need to prepare ultra-clean metal oxide surfaces. To Acomplish this we have designed and built a vacuum plasma chamber. The base pressure for this chamber is 5 x 10-7 Torr, which is ahieved using a turbo-molecular pump. The Plasma is generated at .3 Torr by appling a radio frequency field to ultra-pure water vapor. In this paper we will present the basic design and discuss the performance of this aparatus.

Water Plasma Treatments of Thin Polymer Films

Corey Bloom (advisor: Dr. Lawrence Potts) 2:00pm

Using a plasma apparatus we have designed and built, we have been able to plasma treat thin polymer films. Through the use of Fourier Transform Infrared (FTIR) Reflectance Spectroscopy it is possible to study the effects of these plasma treatments. Specifically we are able to monitor the oxidation and ablation of thin cast films of polystyrene in a water plasma. The conditions for treatments have been 300 millitorr water pressure with 20 watts of radio frequency power for times of up to 20 minutes. Reflectance IR spectra of films taken before and after exposure to the plasma reveal changes in thickness as well as chemical composition.

Synthesis of Low Molecular Weight Polyacrylamides

Jennifer Marohn and Stephanie Truhlar (advisor: Dr. Lawrence Potts) 2:15pm

Commercial polyacrylamides (PAm) are often contaminated with acrylic acid groups and may contain condensed imide rings. In our laboratory we observed unusual results during a chemisorption study which prompted an anaylsis of our commercial PAm. Because of unassignable peaks in the commercial PAm 13C spectra, we decided to synthesize PAm to try and minimize impurities. This work is a report of our preparation of extremely clean PAm, data of its viscosity average molecular weight, and a comparison of 13C spectra of synthesized and commercial PAm.

13C NMR and IR Characterization of Acrylamide Polymers and Copolymers

Sarah Marohn (advisor: Dr. Lawrence Potts) 2:30pm

We have used high resolution nuclear magnetic resonance (NMR) and infrared (IR) spectroscopies to characterize the structures and functional groups of polyacrylamide (PAm) and poly(acrylic acid) (PAA) copolymers. By comparing data from highly pure (PAm), synthesized in our lab, with data from commercially available polymers and copolymers, we are able to connect the various resonances in the 13C NMR spectra with specific features in these polymers and copolymers.

13C NMR Studies of Polyacrylic Acid: Chemical shifts changes induced by solution pH and evidence of a polymer phase change

Kimberly J. Miller and Stephanie Endsley (advisor: Dr. Lawrence Potts) 2:45pm

As a part of our studeis of acylic acid and acrylamide copolymers, we have investigated the sensitivity of 13C NMR chemical shifts to solution pH. The general phenomenon is that the carboxylate carbon shifts to lower fields with increased acidity. We have also discovered the apparent formation of an oriented polymer phase in highly acidic solution of polyacrylic acid.

Concept and Design of a Liquid Seismometer

Jason E. Smerdon (advisor: Chuck Niederriter) 3:00pm

Research has been conducted exploring the concept and design of a liquid seismometer. Specifically, ground displacements and velocities have been measured using a transparent liquid contained in a cylinder as an inertial reference frame. To monitor ground behavior, the reflection and/or refraction characteristics of the liquid can be exploited by directing a diode laser along the cylinder's axis of symmetry. Thus, as the liquid is disturbed, the displacement of the laser can be monitored with a phototransitor to obtain a signal that is directly proportional to the ground displacement. The design will be discussed with some consideration of the basic mechanical construction, however, strongest emphasis will be placed on the characterization of the device. This will include a presentation of damping and free oscillation data for several different liquids and container dimensions. A cross sectional analysis of the laser intensity has also been completed, and will be included in the report. Thus, the general presentation will focus on the possibilities and shortcomings of the design, as well as a comparison to basic specifications of a traditional mechanical seismometer.

Poster session: 3:15-3:45pm

The posters will be exhibited in the lobbies on the ground floor, second floor, and third floor of Olin Hall. Student researchers will be present to discuss their posters. Refreshments will be served. Dr. William Heidcamp is the poster session chair.

Diminishing Postive Body Esteem as a Function of the Media Portrayal of the Idealized Female Body and Levels of Self-Consciousness

Korinne Cikanek (advisor: Dr. Miri Goldstein)

The effects of media's portrayal of the ideal female body and levels of self-consciousness on women's body images were investigated. Thirty-two females watched one of two television clips (Baywatch or ER). They then completed several questionnaires, either in the presence or absence of a mirror, assessing body image and state of self-consciousness (SC). Baywatch was hypothesized to increase SC and generate greater body dissatisfaction. The results did not support these hypotheses. The lack of significant findings due to the mirror's failure to manipulate self-consciousness and the inability of the video to influence body dissatisfaction were discussed.

Subcloning the H1flk-3 gene from the Arabidopsis thaliana

Cara Brown and Tom Grys (advisor: Dr. Colleen Jacks)

We have isolated and subcloned the Rev 3 fragment from Arabidopsis thaliana. Using pre-prepared DNA that contained the Rev 3 gene, we ran a low melting agarose gel. From this gel, we selected and cut out the bands that seemed to possess the Rev 3 fragment. The DNA from these bands were ligated and transformed into Escherichia coli cells. Certain colonies of E. coli cells that were thought to hold the target Rev 3 fragment were grown and cut with one of two restriction enzymes. After running the cut DNA on a gel, a Southern blot revealed that several of our transformed bacterial colonies contained the Rev 3 gene.

Effects of Depth of Processing and Modality on False Memory Creation

Carmen Westerberg (advisor: Dr. Miriam Goldstein)

A false memory effect has been shown for lists of words of related items (Roediger and McDermott, 1995). The present study examined whether the false memory effect is moderated by the modality of word presentation and depth of processing. Participants were assigned to either a deep or shallow condition, and were presented with four lists auditorily and four lists visually. Results showed that more false memories were produced in the auditory condition than the visual condition, and also more false memories were created in the shallow depth of processing condition than the deep depth of processing condition. No interaction between these variables was found. The results deomonstrate that items processed deeply will be remembered more accurately as well as items processed visually. However, these results were only marginally significant. Further analysis is needed to examine the strength of these results.

A Retrospective Analysis of Time Loss Trends in Women's Basketball

Shelle Newcomb (advisor: Bruce Van Duser)

This study retrospectively examined time loss in sports participation due to lower extremity injuries in Division III female basketball athletes over the past ten years. Dependent variables consisted of the total time loss and the relative time loss (number of days loss / number of athletes). The results of this study reflect a trend of decreasing time loss which may be associated with improvements in training room prevention and treatment procedures.

Effect of Delayed and Immediate Suggestions on Accuracy of Recall

Dawn Kelling (advisor: Dr. Mark Kruger)

Zaragoza and Lane (1994) conducted an experiment which showed that subjects given misleading information after a slide sequence believed that they remembered seeing the suggested information. The present study sought to replicate and extend these findings by examining the effect of retention intervals of suggestions. College students (N=60) viewed slides and received misleadin and neutral information immediately or two days later. The results revealed that subjects remembered seeing suggested information but failed to show that retention intervals produced greater suggestibility.

Rad Free Non-Isotopic Detection and the Arabidopsis thaliana Genome

Jeremiah Depta and Ross Detert (advisor: Dr. Colleen Jacks)

We used the Rad Free non-isotopic detection system created by Schleicher and Scheull for analyzing a particular genome, in our case Arabidopsis thaliana, through a Southern blot. With a wide intercalation window, the Rad-Free system allows labeling of the proper probes, by the tricyclic compound psoralen biotin, to occur with minimal room for error. The probes, which have now been labeled by the Rad-Free system, can be used to detect the genome on the Southern transfer, with the addition of the enzyme, streptavidin alkaline phosphatase. The Starlight Substrate system is used to detect the DNA sequences that are the same as the probe. The Starlight reacts with the alkaline phosphatase. This reaction produces light which is registered on a piece of x-ray film. From this we can see approximately how many copies of the S15 gene are contained within the A. thaliana genome.

Relationship Between Hand Grip Strength and Total Body Strength

Carrie E. Pearson and Alissa Midthune (advisor: Bruce Van Duser)

This study examined the relationship between handgrip (HG) and total body strength in 20 college students. Dynamometers measured HG, upper back, lower back, and leg strength. Absolute body strength (ABS) and relative body strength (RBS) were calculated. A Pearson product correlation analysis revealed that HG was significantly related to ABS (R2=0.9284), and RBS (R2=0.8082). The results of this study indicate that handgrip strength is a good predictor of over all strength.

Identification of T-DNA instertion in S15 gene.

Ryan Nelson and Eric Refsland (advisor: Dr. Colleen Jacks)

The purpose of our research was to identify the subpool of Arabidopsis thaliana which contained an insertion in the S15 ribosomal gene from Agrobacterium tumifaciens. We did this by combining several techniques, such as DNA isolation, restriction enqme digestion, PCR, agarose gel electrophoresis, and Southern blot analysis.

Species Richness and Tree Seedling Dispersions in a New England Forest

Jessica R. Rigelman (advisor: Dr. Timothy Sipe)

The present forests of Massachusetts are recovering from three categories of historical land-use: woodlot, pastured, and plowed fields. This study investigates the effects former human land-uses on vascular plant species richness, its spatial pattern, and the variation in seedling dispersions. Total species richness declines from woodlot>pastured>plowed. Spatial variability in richness decreases from woodlot>plowed>pastured. Seedling dispersions are most aggregated in the pastured sites and least in woodlots. The patterns of richness and seedling dispersion are thought to reflect light levels and the degree of microenvironmental heterogeneity within sites.

Eyewitness Memory for Focal and Nonfocal Colors

Kyle Lehenbauer and Tara Madsen (advisor: Barbara Simpson)

This study investigated how well people recall focal versus nonfocal colors in eyewitness situations. Following a video containing four short scenes, subjects' memories were tested. The colors of tablecloths in each scene was varied. Subjects correctly recalled the focal colored tablecloths more often than the nonfocal colored tablecloths. When subjects did make errors, they were far more likely to report that they saw a focal color than a nonfocal color. Errors in memory were interpreted as consequences of a physiologic predispostion to focal colors.

Soil spatial heterogeneity in pit-and-mound complexes across three land-uses

Winfield Scott Heath II (advisor: Dr. Timothy W. Sipe)

Pit-and-mound complexes, which are caused by trees falling over, are known to be a source of soil disturbance. This study attempted to ascertain the effects of the structure of these complexes on soil characteristics. We also examined the relative impacts that the complexes had on secondary growth forest soils. We found that the top of the mounds were more basic and the impact of the complexes was most visible in the pastured sites.

Longitudinal Analysis of Aerobic Fitness in Members of a Fitness Center

Alea Reeves (advisor: Bruce Van Duser)

Blair and Paffenbarger (1989) reported that all cause mortality is linked to low fitness in all ages. This study compared maximal oxygen uptake (VO2max) of members at a large fitness center to VO2max values reported by Blair and Paffenbarger (B&P). Center members were placed into trained, untrained lean, and untrained fat categories. Results revealed that VO2maxs in all three categories were slightly higher and followed the same trend that B&P reported.

Brain Dominance Does Not Affect Athletic Capability

Ashley Baker and Sarah A. Peterson (advisor: Bruce Van Duser)

This study examined the effect of brain hemisphere control on athletic capability. Eight left brained and eight right brained men participated. Handedness, eyedness, and surveys assessed brain dominance. Athletic capabilities included reaction time (RT), balance (BA), and bilateral transfer (BL). A MANOVA revealed no significant differences (p>0.05) in RT, BA, and BL between the two groups. Results of this study indicate that brain dominance does not influence athletic capabilities and may not affect performance.

Relationship of Anxiety and Activity In Members of a Corporate Fitness Center

Rachel Cox (advisor: Bruce Van Duser)

This study examined the relationship between activity and anxiety in members of a large fitness center. Sixty center members, 22 to 65 years old, voluntarily completed surveys regarding anxiety and activity. To quantify scores, survey responses were ranked by a 5 point system. A Pearson Product Moment correlational analysis revealed no significant relationship between activity and anxiety (R2 = -0.20). The results of this study indicate that activity levels do not decrease anxiety.

Identification of the H1-2 "sense" construct in pBI 121

Kathryn Fraser and Beth Peter (advisor: Dr. Colleen Jacks)

Histones organize DNA strands into nucleosomes by forming molecular bonds where DNA is attatched. Researchers believe differences in histone structure may play a role in different eukaryote traits through the alteration of transcription activities. In conjunction with the Arabidopsis thaliana genome project, our goal involved cloning the histone H1-2 "sense" fragment into vector pBI121 for future study with agrobacterium. This project involved isolation of the H1-2 fragment cut with Sac1 and BamH1. Following the isolation, the ligation of the H1-2 fragment into pBI121 occured, and transformation of E. coli with H1-2/pBI121 ligations was successful. Afterwards, colony screening using plasmid extraction and DNA tests for the H1-2 gene using electrophoresis and Southern blot analysis verfied the ligation.

Characterization of the H1flk-3 gene in Arabidopsis Thaliana

Kelle McManus, Christian Erickson (advisor: Dr. Colleen Jacks)

Three Linked genes of unknown function have been isolated in thesearch for H1 histone genes in Arabidopsis thaliana. We are studying the h1flk-3 gene with partial sequence already known. We plan to determine the function and regulation of the H1flk-3 gene. The entire sequence obtained from the Genome Project showed that the gene contained eight introns and nine exons along with upstream sequences. From this a restriction map was developed and predicted and expected cuts were compared. Sequencing results confirmed our conclusions.

EM Morphology of Mouse Melanoma

Joleen Hubbard (advisor: Dr. William Heidcamp)

B16 mouse melanoma cells were injected intraperitonially into C57B syngeic mice. Tumors were collected two-three weeks after injection and prepared for routine and immunological electron microscopy. Sectons were stained with standard lead uranium or reacted with immunogold techniques for fibronectin. Sections were examined for attachment to the extracellular matrix and/or normal tissue.

Expression of GFP in B16 Melanoma

Matthew Detert and Andrew Hyser (advisor: Dr. William Heidcamp)

Previous studies have produced a transgenic melanoma containing green fluorescent protein (GFP). These B16 melanoma cells were cultured gentimycin and used in the isolation of GFP. Cellular protein was extracted and isolated in bulk. In order to distinguish between autofluorescence of B16 and expression of GFP, the presence and amount of GFP expression was determined by Western Blot.

Comparison of Various Methods of Measuring Body Composition

Becky Johnson (advisor: Bruce Van Duser)

Various methods are used to assess body composition (BC), however hydrostatic weighing (HW) is considered to be the gold standard. The purpose of this study was to compare various methods of BC measures to HW. Methods of BC measurement consisted of HW, skinfolds, girth, and height techniques. Data analysis is in progress and will compare mean values to HW.

Visualizing a Hydrodynamic Model of Accretion Disks in Cataclysmic Variable Star Systems

Nathan A. Miller (advisor: Dr. Matt A. Wood, Florida Institute of Technology)

We present the results of a hydrodynamic model of accretion disks in short-period mass-transferring binary star systems using IBM Data Explorer to visualize and animate the data. Surfaces of constant density are displayed as three- dimentional objects. Cross-sections taken vertically and horizontally through the disk illustrate the interior thermal structure of the disk. The visualizations clearly show spiral density waves which appear to be quasi-static in the co-rotating frame of reference, and which therefore may be a possible mechanism for generating the quasi-periodic brightness variations observed in cataclysmic variable star systems.

Melanoma Characteristics through Light Microscopy

DeAnn Ryberg (advisor: Dr. William Heidcamp)

Mouse melanoma injected via a tail vein has been a model system for the study of cancer metastasis. By injecting B16 melanoma cells into the tail vein, abdominal cavity, and skin of mice a variety of tumors were obtained. This study represnts a histological analysis ofthe growth of the tumors during the first three weeks in the lungs,skin, and abdominal cavity of mice.

Retrieval-Induced Forgetting Effects

Jenifer Breutzmann (advisor: Dr. Mark Kruger)

Twenty-two subjects were shown a short slide sequence including objects from two categories: college sweatshirts and popular magazines. Half of the subjects were subsequently asked questions three times about one-half of the sweatshirts to practice retrieiving these times from their long-term memory While subjects' recall for the unpracticed items was inhibited as expected, the memory of the exerimental group for the practiced objects was not significantly better than that of the control subjects.

The Preparation of Titanium Centered Lewis Acid Catalysts

JennySue Abbott (advisor: Dr. Gretchen Hofmeister)

The goal of this project has been to synthesize new titanium compounds which we hope will be good Lewis acid catalysts. There are several characteristics that are desirable in these new compounds. Firstly, the compound must be monomeric, so the ligands that are bound to the titanium metal center must be bulky enough to prevent dimerization. Secondly, we want to control the electronics of the metal center. The titanium must be electropositive to act in a catalytic manner. The range of reactions that could be catalyzed by these titanium compounds is very broad. At present, we are testing one new compound, titanium (bis)-salicylate binaphtholate, for catalytic activity in the alkylation of bezaldehyde.

Geology of the Good Thunder Quadrangle located south of North Mankato

Jason Meek (advisor: Mark Johnson and Keith Carlson)

The Good Thunder Quadrangle is located south of West Mankato, Mn. in Blue Earth County. Research in the Good Thunder Quadrangle embodied a critical study of both the geomorphology and the geology in order to produce a complete geologic map of the area. This area is covered predominantly by glacial drift deposits located stratigraphically on the eroded top of the sedimentary layers deposited by three major marine transgressions during Cambrian and Ordovician times (Webers, 1972).

A structure-contour mapping project of the Jordan Sandstone-Oneota Dolomite contact near St. Peter, MN.

Jon Turner (advisor: Kieth Carlson and Mark Johnson)

The Cambrian age Jordan Sandstone and the Ordovician age Oneota Dolomite are both sedimentary Paleozoic rocks which were accumulated in the Hollandale embayment. The nature of the contact is one of importance, especially because it marks the Cambrian-Ordovician boundary. Local faulting in these sedimentary layers has been observed at other locations. Also, elevation differences of the contact at localities in the area may be indicative of a fault. Research and mapping have indicated that the elevation differences are attributed to the regional dipping of the hollandale embayment.

Measuring Bin Class Hopping in Linux

Antony Sargent (advisor: Max Hailperin)

By modifying the Linux Operating System, we have been able to collect some information about physical memory allocations. We were interested in whether the strategy that Linux uses turns out to be a "good" one in terms of efficient use of the computer's cache memory. Our results show that it usually does a good job. Furthermore, this is relevant since Linux's strategy might be used to good effect in some new computer hardware trends.

Velocity of Slide Motion: A Comparison of Professional & Student Trombonists

Amanda Ludeman (advisors: Mark Kruger & Mark Lammers)

Nine full-time professional and eleven student trombone players participated in a study on the motion of the trombone slide. A sonic ranger was used to record the position and velocity of the trombone slide during two musical exercises and one randomly ordered sequence of notes. The random sequence of notes was included to test the effects of familiarity or expertise on the observed motion. Professionals moved slide faster than students. The consistency of velocity across types of music was greater for professionals than for students. The implications of the findings for understanding expertise and for teaching the trombone are discussed.

Session 2: 3:45-5:15pm

Concurrent paper session 2a: Olin Hall, Room 103, 3:45-5:15pm

Dr. Cindy Johnson-Groh, chair

In Vitro and In Vivo Growth of Melanoma

Kimberly J. Smith (advisor: William Heidcamp) 3:45pm

B16 mouse melanoma was obtained and studied in vitro for growth characteristics and adhesion capabilities. Markers were then studied for cell labeling during in vivo studies. IP and tail vein injections were performed to study metastasis and adhesion in vivo.

Phenology Studies of Two Species of Moonworts in Minnesota

Jennifer Lee (advisor: Dr. Cindy Johnson-Groh) 4:00pm

Moonworts, members of the genus Botrychium subgenus Botrychium, are found in a variety of habitats worldwide. As the phenology of moonworts is poorly understood, the goal of this research was to monitor the phenology of two species of moonworts in Minnesota including, B. gallicomontanum and B. mormo. Five permanent study plots were monitored for population size. Individual plants were measured and the condition of the plant was recorded, every two weeks from April 1 until September 22, 1996.

Is a Single-Site Sampling Protocol Sufficient for the Determination of Stream Biotic Integrity?

Matthew L. Anderson, Keith Fredricks (advisor: Bob Bellig) 4:15pm

Macroinvertebrate and fish communities were compared at three sites within the Rush River in Sibley County, MN. The sites showed no visible human influence and appeared to be representative of the stream. Comparisons were made using a variety of river sampling techniques and through the use of statistical analyses. Differences in community compositions among the three sites were significant, calling into question the accuracy of single-site sampling as a means of diagnosing stream quality.

The Effect of Land use on the Photosynthetic Rates and Biomass Allocation of Acer rubrum and Quercus rubra Seedlings

Jennifer K. Dean (advisor: Timothy W. Sipe) 4:30pm

Photosynthetic light response curves, field photosynthesis, and biomass allocation of Acer rubrum and Quercus rubra seedlings were examined in response to formerly plowed, pastured, and woodlot sites. Light response curves show 10% greater photosynthesis rates for the woodlot and pastured sites than plowed at light levels exceeding 300 mmol m-2 s-1. Q. rubra photosynthesis rates were 25 - 30% higher than A. rubrum at light levels greater than 50 mmol m-2 s-1. The field photosynthesis rates and light levels followed parallel trends with plowed > pastured > woodlot. Growth rates and root:shoot ratio were not significantly different among sites.

Phenytoin inhibits synthesis of nitric oxide by lipopolysaccharide-stimulated macrophages

Marc Newell (advisor: John M. Lammert) 4:45pm

Phenytoin, a commonly used antiepileptic drug, has been reported to alleviate the symptoms of rheumatoid arthritis. This study investigates the effect phenytoin has on a known inflammatory mediator, nitric oxide. Macrophage-like mouse cells of the J774.1A line were stimulated into releasing nitric oxide by being incubated with lipopolysaccharide, a substance present in the outer membrane of Gram-negative bacteria. These lipopolysaccharide-stimulated cells were also incubated with increasing concentrations of phenytoin. After 48 hours incubation, the amount of nitric oxide released by the cells was colormetrically determined upon reaction with the Greiss reagent. As the concentration of phenytoin was increased, the amount of nitric oxide decreased correspondingly. These data suggest that phenytoin may reduce inflammation in arthritic joints by inhibiting the release of inflammatory mediators.

Tumorous Fish and Deformed Frogs: Is There a Connection? A Case Study In Sibley Co. MN

Sheila Tanata (advisor: Robert Bellig) 5:00pm

Deformed frogs recently discovered in Sibley Co., MN have gained national attention. Considerable resources are currently being expended to determine the cause. Interestingly, the fathead minnow (Pimephales promelas) collected from a stream in the same area (High Island Creek) was found to have an abnormally high incidence of epidermal papillomas, a tumor often associated with environmental pollution. I report here the first evidence that another ectotherm may be negatively impacted from that locale.

Concurrent paper session 2b: Olin Hall, Room 216, 3:45-5:00pm

Dr. Mark Kruger, chair

Individual Differences in Arousal: Examining the Effect of Affect Structure on Physiological Arousal and Coping Style

Lia Keller (advisor: Miri Goldstein) 3:45pm

Goldstein (1996) found that individuals experiencing mixed emotions exhibited greater affective responses than those with a dependent affect strucutre. The present study extended these findings by examing affect structure's effect on physiologcial arousal and coping style. Individuals completed personality questions including the PANIM, Stimulus Screening Scale, COPE and Arousal Predisposition scale. Participants heart rate was monitored while they viewed film clips eliciting disgust and amusement followed by a mood questionnaire.

Performance on a Procedural Memory Task of a Patient with a Traumatic Brain Injury.

Chris Choukalas 4:00pm

A case study focusing on the memory difficulties of a patient at the St. Peter Regional Treatment Center is described. Encoding difficulties were evident. Nonetheless, the subject improved on two timed memory tasks over the course of the observation period. The results are discussed in the context of current research on implicit and explicit learning and comparisons are made with Brenda Milners patient H.M.

Depression, Approval, and Three Measures of Attachment as Predictors of Relationship Satisfaction

Chris Choukalas (advisor: Dr. Mark Kruger) 4:15pm

This study set out to examine the relationship between depression, approval, characteristic attachment style, and relationship satisfaction. Analysis revealed correlations between three different measures of attachment style, correlations between satisfaction, parental approval of relationship, and particular attachment characteristics. Significant differences in the way Ss characterize each relationship, along the lines of attachment theory were found. The results suggest that, though traditional measures of attachment style characterize Ss into discrete categories which pervade all relationships (Hazan & Shaver, 1987), people may classify the nature of their attachment differently in each relationship.

Effects of Background Information About the Victim In Sexually Explicit Violence

Rachel Michael (advisor: Dr. Mark Kruger) 4:30pm

This study examines the possibility that contextual information given in sexually explicit, violent media may effect the viewerUs attitudes towards women. This hypothesis is based on the fact that, while never experimentally examined before, such a trend can be inferred from past research on the effects of sexually explicit violence. In this study, subjects watched three scenes of sexually explicit violence, after having been given either positive, negative, or no background information about the victims. The hypothesis, that the background information would lead to different scores on theRape Myth Acceptance Scale, was not supported by the data.

Sedimentology and Depositional History of Sediment Terraces, Minnesota River Valley near St. Peter, Minnesota

Jared Smith (advisor: Mark Johnson) 4:45pm

The Minnesota River Valley was eroded by the River Warren which originated from the outletting of Glacial Lake Agassiz. The lower part of the valley, downstream from Granite Falls, Mn, is characterized by sand-and-gravel terraces deposited during overall downcutting (Johnson and others, in press). The stratigraphy and sedimentology of these terraces has been described by others along the river valley (Johnson and others, in press, Kraatz 1995, Franco and Johnson, 1997). These terraces are then compared sedimentologically and stratigraphically to other terraces both up and downstream of those previously described.

Concurrent paper session 2c: Olin Hall, Room 220, 3:45-5:00pm

Dr. Dennis Henry, chair

Heterodyne Photon Correlation Spectroscopy

Shannon Siefken (advisor: Dr. Paul Saulnier) 3:45pm

An understanding of the wave nature of light is necessary for exploring light scattering phenomena. The concepts of interference, beating, and frequency modulation are presented for their connection to our work in Photon Correlation Spectroscopy (PCS). PCS is a technique for studying the dynamics of particles suspended in a fluid by measuring intensity fluctuation of the scattered light. From this information characteristics of the scatters, such as particle size, can be found.

Low-Coherence Photon Correlation Spectroscopy

Josh Johnson (advisor: Paul Saulnier) 4:00pm

Photon correlation spectroscopy (PCS) is routinely used to investigate the dynamics of colloidal particles undergoing Brownian motion. The technique is applicable to low-density colloidal suspensions where the effects of multiple light scattering are minimal. This paper introduces a new low- coherence PCS technique that allows direct investigation of colloidal suspensions of higher concentration than previously accessible using standard PCS. Low-coherence optical hetero- dyne interferometry is used to suppress the multiple light scattering, allowing preferential detection of low-order scat- tering events.

Synthesis of a Binaphthol Ligand for Complexing to Metal Catalysts

Adrian B. Anderson (advisor: Gretchen E. Hofmeister) 4:15pm

An extremely useful class of molecules for controlling the selectivity or organic reactions is 1,1'-bi-2-naphthol compounds. Binaphthols are frequently used to coordinate to metals in order to impart a particular 3-D structure at the metal. This affects the selectivity of the "ligand metal complex" as a catalyst. My work constitutes the preparation and improvement of a known synthesis of the modified binaphthol, 3,3'-bis(alkylsiloxy)-1,1'-bi-2-naphthol.

Toward the Preparation of an Elusive Trifluoromethylated Phthaloylphosphide

Matthew P. Shores (advisor: Dr. Brian O'Brien) 4:30pm

Phosphines are well known for their pi-acidity. The introduction of electron withdrawing groups such as carbonyl and trifluoromethyl should cause significant perturbation of the pi-acidic behavior of the phosphorus atom. Here we report progress to date on our work toward the preparation and characterization of the potassium-[18]crown-6 salt of 4,5-Bis(trifluoromethyl)phthaloylphosphide. The preparitive reaction sequence and specific reaction mechanisms will be discussed. In addition, we will use IR and 1H, 13C, and 19F NMR spectroscopy for structural analysis of the intermediate products.

A 1H Nuclear Magnetic Resonance Analysis of the Bromination of 1,1,1,2,2,2-Hexafluorodurene

Matthew P. Shores, Kyle Skiermont (advisor: Dr. Brian O'Brien) 4:45pm

Proton NMR analysis of the sequential bromination of 1,1,1,2,2,2-Hexafluorodurene provides information about the relative production and distribution of intermediates. In addition, NMR analysis provides a qualitative determination of the route by which methyl hydrogens are substituted by bromine. Using 1H NMR data as well as steric information and symmetry arguments, we will show how this potentially "messy" reaction actually follows one out of a number of possible sequences.