Sigma Xi Undergraduate Research Forum 1996


Friday, May 3, 1996


Session I

Room: Olin 220

Convener: Dr. Tom Gover

1:45 p.m. Kinetics of the Binding of Coomassie Blue Dye to Ovalbumin

Rachel Roberts

Advisor: Dr. A. Splittgerber

The Coomassie Blue Assay is commonly used for quantitive estimation of many types of proteins. In most cases, an increase in absorbance is observed in mixing protein and dye. This reaction is complete within five minutes. For some proteins, such as ovalbumin, the time course of reaction of dye with protein is much longer. The time course of the ovalbumin protein was fitted to an exponential rate equation, rate constants, and other parameters were extracted. These topics will be discussed in terms of the mechanism of the dye-protein binding reaction.

2:00 p.m. A Kinetic Study of the Oxidation of Calcon Dye in Highly Alkaline Solution.

JennySue Abbott

Advisor: Dr. Allan Splittgerber

It has been known for some time that the compound known as Calcon (Eriochrome Blue-Black R) is not stable in aqueous solution at highly alkaline pH values. This has been attributed to air oxidation of the compound. In this study we have carried out kinetic studies of the conversion of Calcon to its (supposedly) oxidized product at a series of pH values and at different dye concentrations. Results will be discussed with respect to possible reaction products and possible mechanism of conversion.

2:15 p.m. Comparative Absorbances of Coomassie Brilliant Blue at Various pH's

Lynn E.M. Cordes & Thomas H. Ehrich

Advisor: Dr. Allan Splittgerber

Protein assays commonly use Coomassie Brilliant Blue (CBB) in spectral measurements. The object of our research was to optimize the assay with respect to pH and wavelength conditions. Absorbance spectra of various concentrations of the protein Bovine Serum Albumin (BSA) in CBB were taken at varying pH's across several wavelengths ranging from 560nm to 650nm. Phosphoric Acid was used to modify the pH which ranged from pH 0.80 to 1.00. From this data we determined that the ideal pH and wavelength for BSA assays is at pH 0.92, 590nm.

2:30 p.m. The Kinetic Study of the Binding of Coomassie Blue to Chymotrypsin

Todd Allen Mayer

Advisor: Dr. Allan Splittgerber

The mixing of a protein with Coomassie Brilliant Blue usually results in an increase in absorbance which reaches a maximum within 5 minutes. With some proteins, such as Chymotrypsin, a much longer time course is followed. We followed the time course of binding of the dye Coomassie Brilliant Blue to the protein Chymotrypsin. The time course fits best to a triple exponential rate equation. The parameters of the rate equation determined by the fitting procedure are discussed in terms of the mechanism of dye-protein binding.

2:45 p.m. Classical Mechanics from a Differential Manifold Perspective

John A. Vano

Advisor: Dr. Jeff Rosoff

This paper presents the reader with a brief overview of basics of differential geometry motivated by application to physical examples. After introducing the concept of a differential manifold and its related structures, the laws of mechanics (in the form of Lagrange's Equations) are formulated for the configuration space of an N-particle system. Using this formulation, several examples of classical systems are illustrated.

3:00 p.m. Self-Associate Minimal Surfaces

Mark Tomforde

Advisor: Dr. Michael Hvidsten

The Weierstrass representation formula is a well-known method for generating minimal surfaces. It involves creating an object in a six-dimensional space and then projecting this object onto a three-dimensional subspace in order to form a minimal surface. This presentation will involve a discussion of attempts to create other minimal surfaces, called associate surfaces, by rotating the six-dimensional object prior to projection.

Session II

Room: Olin 103

Convener: Dr. William Heidcamp

1:45 p.m. Mutations in Two Highly Conserved Regions of the Potential RNA Helicase Gene, ARB9, do not Eliminate Wild-Type Function.

Carl Sherman

Advisor: Dr. Cathy Asleson

ARB9, a gene required for telomere localization in eukaryotes, has been shown to be homologous to a class of proteins known as DEAD (Aspartic Acid - Glutamic Acid - Alanine - Aspartic Acid) Box helicases. Yeast arb9 mutants show an aberrant bud shape phenotype when undergoing cell division as well as mislocalization of the protein Rap1p, a protein known to associate with the telomere. We transformed three arb9 mutant alleles, created by site-directed mutagenesis, into a S. cerevisiae strain carrying a disrupted arb9 gene, and we analyzed the phenotypes for the occurrence of the aberrant-shaped buds. These mutant alleles contain a point mutation in each of three highly conserved regions known to be important for RNA helicase activity in organisms with a homologous gene. We found that mutations in two of the regions complemented the disruption, restoring wild-type phenotype. The third mutant, however, showed the aberrant-shaped bud phenotype in two of five transformants. These results indicate that at least two conserved regions may not be important to the function of the gene product, casting doubt on the conclusion that the ARB9 gene product functions as an RNA helicase.

2:00 p.m. Microclimates, Plant Community Composition, and Deer Browse along

Edge-to-Interior Gradients in an Old-Growth Forest in Southeastern Minnesota.

Kristen S. Paap

Advisor: Dr. Timothy W. Sipe

The edge between a forest and cropland shows sharply contrasting microclimates, plant species composition, wildlife use, and community and ecosystem structure than the forest interior. To characterize these trends and the relationships between them, transects were established from the forest edge extending 50m into the forest interior. Air temperature, relative humidity, PPF, solar radiation, woody stem densities, woody vegetation species composition, and availability and use of browsable tips by white-tailed deer were measured along the transects. Preliminary results show microclimatic edge-to-interior gradients for all variables, with the greatest change within the first 20m from the forest edge. Deer browse was highest at the edge, and decreased along the transect. Further analysis will determine relationships between (1) microclimatic patterns and woody plant community, and (2) woody community composition and deer browse patterns.

2:15 p.m. The Effects of Three Planting Techniques on Seedling Microclimate During Forest Restoration in an Abandoned Field

Rebecca M. Hoffman

Advisor: Dr. Timothy W. Sipe

The success of invading tree species in a grassland depends on microenvironmental factors, competition, and herbivory. A forest restoration project in an abandoned field at Nerstrand Big Woods State Park uses competition mats and herbivory protection tubes to aid the survival and growth of seedlings. These treatments may significantly alter seedling microclimate, substantially changing seedling growth and survival. Differences among the treatments in solar radiation, air temperature, and soil temperature were measured with a datalogger and microclimatic sensors in the fall and spring. Results suggest that microclimatic differences are of a magnitude that alters seedling success.

2:30 p.m. GFP Incorporation into Mouse Melanoma

Eric Armstrong

Advisor: Dr. William Heidcamp

A fluorescent protein was expressed in melanoma cells after cDNA transfection. The protein was inserted into a B16 strain of mouse melanoma along with G418 antibiotic resistance. Clones of transfected cells were selected via antibiotic resistance and analyzed for their fluorescent activity.

2:45 p.m. The Meiofauna of Industrialized Rivers in Northern Minnesota

Jennifer Dean, Amy Dewey, Nat Hemstad

Advisor: Dr. Myron Anderson

Meiofauna, microscopic animals that inhabit interstitial spaces among particles of bottom substrates in aquatic systems, were sampled from three rivers in northern Minnesota. Questions asked were: (1) How many and what kinds of meiofauna inhabit these rivers? (2) What is their horizontal and vertical distribution? (3) Can they be used as bioindicators of industrial pollution? Results indicated that similar kinds of meiofauna occurred in all three rivers but total numbers and diversity profiles differed considerably.

3:00 p.m. Does the Anticonvulsant Drug Phenytoin Induce Apoptosis in Myeloma Cells?

Gerhardt Wagner

Advisor: ?

For the past 25 years, phenytoin has been reported to alter the body's immune system. The therapeutic range for phenytoin in human serum is 10-20 ug/mL. However, there is a narrow margin between the therapeutic and the toxic level which can first be seen at 30 ug/mL. Phenytoin, an anti-epileptic drug, was tested for growth-inhibitory effects on a mouse cell line, MOPC-315. The rate at which these cells grew decreased as the concentration of phenytoin increased (10 ug/mL to 100 ug/mL).


Room: Olin Lobby

3:15 p.m. - 3:45 p.m.

A stratigraphic and sedimentological study of the Cretaceous strata at New Ulm, Minnesota.

Jonathon Blaha

Advisor: Dr. Keith J. Carlson

The sandstone and shale sequences of Cretaceous age occurring at New Ulm, Minnesota are marginal deposits from the epicontinental Cretaceous interior seaway. A variety of sedimentary structures can be used to determine the depositional history of these rocks. The sandstones are crossbedded, allowing the paleocurrent directions to be determined. The sandstone and shale layers contain plant fragments, indicating non marine deposition. Outcrops were measured and described and stratigraphic columns were constructed to establish the distribution and lithology of the strata. Microscopic and sieve analyses were used to determine the depositional environment of the sandstone. These data were graphed and compared to depositional models. This study shows that the strata are non marine and were deposited adjacent to the Cretaceous sea by fluvial processes.

Psychological and Physiological Effects of Music on Musicians and Non-Musicians

Betsy Brandl

Advisor: Dr. Mark Kruger

The purpose of this study was to measure the physiological responses of musicians and non-musicians to music or no music conditions after a mild stressor. A total of seventeen subjects were tested: nine non-musicians and eight musicians. Sedative music was played in the music condition and physiological responses of subjects were measured at three time intervals. Physiological data was assessed with the Speilberger Sate Anxiety Inventory and a mood assessment inventory of sixteen different moods or emotions. Analysis of the data produced no significant results however several promising trends occurred. Musicians displayed a lower degree of rated anxiety in the music conditions than non-musicians. Musicians' muscle tension decreased in the presence of music while non-musicians' tension increased. Musicians heart rates increased in the music conditions, and non-musicians heart rates remained stable.

Correlation of religiousness and transcendent experiences

Darcie Gilbertson

Advisor: Dr. Mark Kruger

A correlational evaluation of transcendent experiences (with respect to descriptive qualities and frequency) and religiousness was taken with a sample (N=32) of general psychology students. Previous study of the phenomenon of transcendent experiences (t-experiences) has not been undertaken. Overall religiousness was not found to be a significant determinant of transcendental experiences or frequency. Types of t-experiences were found to coincide with extrinsic religiousness. T-experiences were defined as 'the feeling one has when one is brought to a heightened sense of awareness, participation in, or removal from, the experience at hand.' Categories were divided into eight separate categories. Religiousness was evaluated in terms of intrinsic and extrinsic values using Allport's Religious Orientation Scale.

Does phenytoin, an anticonvulsant drug, affect cell division?

Stephanie Martin

Advisor: Dr. John Lammert

Phenytoin (PHT) is a drug often used to control epileptic seizures. However, PHT can cause birth defects by inducing suppression of essential prostagladin synthesis. Prostaglandins are also important in cell division of the protozoan Tetrahymena. I gre Tetrahymena at 28^0C in proteose-peptone broth containing varying concentrations of PHT. These data show that PHT does have an effect on the growth rate of Tetrahymena.

The Relationship Between Gold and Sulfide Mineralization in Quartz Veins of the Felsic Porphyry of the Virginia Horn Area, Northeastern Minnesota

Michele Mykris

Advisor: Dr. James Welsh

Hydrothermal quartz-carbonate veins and alteration are associated with gold-bearing Archean porphyry bodies of the Virginia Horn. Evidence suggests that hydrothermal alteration was contemporaneous with shear structures in the porphyry. Examination of the polished thin sections of these rocks using reflected light microscopy has revealed the presence of minute blebs of a bright yellow metal in association with sulfide crystals. This type of mineralization is similar to that of gold. Electron microscopic study of these minerals is currently underway.

Perception of Groups as a Function of In-group and Out-group outcomes.

Jenifer J. O'Leary

Advisor: Dr. Mark Kruger

The experiment examined the effects of mainipulated affective state on impression formation of three out-groups by an in-group member. Thirty-five college students were given one of four gender specific scenarios to read which manipulated the in-group and out-group outcomes (+/+, +/-, -/+, and -/- respectively). After completion of the reading task, all Ss answered the same battery of likert scaled questions to determine their perceptions of all four groups. Results indicated that only the in-group outcome affects resulting out-group perception.

Ancient Bedrock Valleys in Southern Minnesota

Geoff Goodwin

Advisor: Dr. Keith Carlson

The Des Moines Lobe in Minnesota has had an important role in shaping the fluvial environments in much of the state. Drainages existed in preglacial, interglacial, and postglacial periods, and these drainages have left a sinuous pattern of ancient bedrock valleys. These valleys have been cut through the bedrock and have eventually been filled in with glacial drift. The bedrock valleys are important clues on what drainages patterns existed prior to the Des Moines Lobe glaciation, as well as patterns during and after glaciation. Present day river valleys have exposed some of the bedrock valleys, allowing for observation.

Preparation and Characterization of Trifluoromethylated Aromatic Compounds as Precursors for Ring-substituted Phthaloylphosphides

Matthew P. Shores, Dimitri M. Drekonja

Advisor: Dr. Brian A. O'Brien

The preparation of the title compounds has been accomplished through a variety of synthetic techniques. Here we detail the rationale for choice of the various synthetic pathways which were used to prepare these compounds, and present details of the syntheses and purifications. Details of infrared, 13C NMR, and 1H

NMR spectral analyses will also be presented.

Preparation and Characterization of Percursors for Triflouromethyl-substituted Phthaloylphosphides

Matthew P. Shores, Dimitri M. Drekonja

Advisor: Brian A. O'Brien

The preparation of these title compounds has been accomplished through a variety of synthetic techniques. Here we detail the rationale for choosing the various synthetic pathways which were used to prepare these compounds, and present details of the actual syntheses and purifications themselves. Details of infrared, 13C NMR, and 1H NMR spectral analyses will also be presented.

Growth Characteristics of Melanoma

Kimberly Smith

Advisor: Dr. William Heidcamp

B16F, and GFP transfected cells were cultured with RPMI media supplemented with calf serum and antibiotics. A growth curve was established. Log phase cells were injected into C57 Black and albino mice either i.p. or through a tail vein. Subsequently, the mice were sacrificed and tumor subclones established.

A Spatial Analysis of Wheat Production in Minnesota

Rachel A. Frojen

Advisor: Dr. Robert Douglas

This study shows that during the last two decades, wheat production has become more geographically concentrated in Minnesota, even as the total amount of acreage planted in wheat has decreased. But where in the state has this concentration occurred, and why in these areas? The objectives of this study are two-fold: first, to specifically measure the changing geographic concentration of wheat production in Minnesota and second, to test a number of hypotheses related to this changing concentration. First, the study employs the location quotient technique to measure the changing concentration of wheat production in Minnesota counties for the years 1974, 1987, and 1992. The U.S. Census of Agriculture is the data source. Second, regression and correlation analyses are used to test two hypotheses, namely, that as the number of farms in a county decreases, the concentration of wheat production in that county increases, and that as the average county farm size increases, the production of wheat in that county also becomes more concentrated.

Changing Recruiting Patterns of Big Ten Men's Basketball Programs

Aaron W. Sickman

Advisor: Dr. Robert Douglas

Sports geography deals with the spatial organization of athletic competition. Although most geographers have largely ignored the spatial aspects of sports, there is justification for a subfield of sports geography. Big Ten Men's Basketball recruiting is an aspect of college sports that can be studied geographically. College basketball recruiting has gone from signing student athletes in close geographic proximity to a nearby university to searching the United States and foreign countries for top players. Two hypotheses were developed for testing: one, that over time, Big Ten Men's Basketball recruiting would be spatially expanding, i.e. university recruiting "areas" would be increasing in size. And two, that as the larger United States cities have increased in size, so have their recruiting contributions to Big Ten Men's Basketball programs. Data was collected from the men's basketball rosters of Big Ten schools at three different time periods, 1980, 1987, and 1995. Maps of this data were made to visually show the spatial correspondence of the home towns of these basketball players and the Big Ten University they attended for the three different time periods. A mean center statistic was also used to confirm the hypothesis that recruiting areas have been expanding over time. Lastly, regression and correlation analysis were employed to examine the changing recruiting areas and the population growth of major United States cities.

Extraction and Characterization of Alkaloids from Solanaceae

Ryan D. Else and Aaron P. Erdmanczyk

Advisor: Dr. Brian O'Brien

Alkaloids comprise the largest single class of secondary plant substances, and often possess high physiological activity. These compounds are generally present in trace amounts, and their isolation is often challenging. We are developing a small-scale procedure for isolation and characterization of the alkaloid solanine from Solanum tuberosum (potato); similar efforts are underway for alkaloids of the common nightshade, Solanum nigrum. Spectral and chemical techniques which we are using for characterization of the compounds will be discussed.

Session III

Room: Olin 216

Convener: Dr. Charles Niederriter

3:45 p.m. Visualization of Objects Traveling with Relativistic Velocities

John A. Vano

Advisor: Dr. Tom Huber

When first introducing students to Special Relativity, the standard example of a fast moving meter stick is often misleadingly used to describe how the Lorentz contraction would alter the appearance of the meter stick. In this talk I will discuss the difference between an object's physical location and its apparent location. Transformations which incorporate effects such as aberration of light and Lorentz contraction have been incorporated into a computer program which will be used to demonstrate several interesting results concerning the appearance of objects at relativistic speeds. These results should be particularly interesting for those unfamiliar with the nature of light aberration.

4:00 p.m. Angular Resolved Scattering

Karl Erickson

Advisor: Dr. Paul Saulnier

Angular resolved measurements of scattered light as a function of scatterer size and density were made. By varying the scatterer size (0.064um, 0.528um, 4.329um) and density (1%, 0.1%, 0.01%, 0.001%), it was determined that the Mie Theory is more representative of the data than the Rayleigh or Rayleigh-Debye models. It should be noted that the Rayleigh models only held for the smallest scatterer size and lower densities. All theories failed to represent the data as the density increased.

4:15 p.m. Examination of Scattering Parameters

Erik R. Rasmussen

Advisor: Dr. Paul Saulnier

The scattering parameters, extinction mean free path length and transport mean free path length, were examined for various scattering concentrations and scatterer sizes. The theory relating to these parameters was compared to the empirical results.

4:30 p.m. Polymer Thin Film Growth Using a Plasma Technique

Jason Hiltner

Advisor: Dr. Charles Niederriter

Thin polymer films were grown on an aluminum substrate using a plasma technique. The process involves vaporizing aluminum and condensing it on a microscope slide. This acts as a substrate for growth of the film in a plasma of ethylene. Various techniques are being used to characterize the rate and manner in which the film grows. FTIR spectroscopy is used to determine the chemical nature of the film. Scanning tunneling microcopy is used to determine how the film coats the surface. Interferometry is used to determine the thickness of the film. We have combined these techniques to allow us to investigate the process of film growth. Specifically, the interdependencies of rate of growth, thickness homogeneity (island formation), chemical composition, and growth environment are being investigated and will be discussed.

4:45 p.m. Sensitive Environment Mapping of the Minnesota River Valley

Eric Nuebel

Advisor: Bob Bellig

This is a sensitive environment map envisioned to increase preparedness in the event of a spill. The map that I am producing combines locations of items such as: sensitive or endangered species, potential spill sources such as storage tanks, water intakes, highways and railways where hazardous materials are commonly transported, and water access points. The visualization provided by the map enables users to anticipate danger sites and produce spill management plans, as well as protective procedures in the event of a spill.

5:00 p.m. Depositional History and Paleoclimatic Implications of a Colluvial Fan near

Ottawa, Minnesota

Tim Armato

Advisor: Dr. Mark Johnson

Alluvial fans occur adjacent to gully mouths along the scarps of the Minnesota River valley. Because these landforms occur after the River Warren ceased to flow, they are younger than 11,000 years before present (YBP) and perhaps younger than 9,200 YBP. The stratigraphy of a fan excavated by the Unimin Corporation near Ottawa, Minnesota reveals a sequence of fluvial and colluvial sediment. Including the modern soil, there are least two well developed paleosols. The presence of developed soils, in association with the other sediments, suggests prolonged periods of both intense erosion, and slope stability. Well documented climate changes during the Holocene in the Midwest may be responsible for destabilizing the slopes and promoting erosion.

5:15 p.m. Concept and Design of a Liquid Seismometer

Jason Smerdon

Advisor: Charles Niederriter

Research has been conducted exploring the concept and design of a liquid seismometer. While certain benefits of such a design are clear, we are not aware of any previous liquid seismometer designs. Therefore, our approach has consisted of a series of empirical attempts to model the performance of existing mechanical seismometers with our liquid seismometer design. Using a transparent liquid, we plan to exploit its reflection and/or refraction characteristics by employing a small laser. The displacement of the laser (caused by the moving liquid through which the laser is traveling) will be received by a concentric diode array which we have constructed. While the model is still in its preliminary stages, a discussion of its design will include its construction, function, and the benefits of its characteristics.

Session IV

Room: Olin 220

Convener: Dr. Barbara Kaiser

3:45 p.m. Empathy's Effects on Toleration of Differing Attitudes.

Maren Henry

Advisor: Dr. Tim Robinson

Previous research has shown that more dogmatic individuals have larger latitudes of rejection on an opinion scale (Powell 1966, Sherif 1965). In my research, I hypothesized that more empathetic individuals would have smaller latitudes of rejection, thereby indicating a correlation between empathy and tolerance of differing attitudes. My experiment consisted of four questionnaire which measured empathy, latitudes of rejection and political knowledge and were administered to general psychology students. Results are still pending.

4:00 p.m. The Effect of Out-Group Presence on Group Identification

Jennifer English

Advisor: Dr. Mark Kruger

This experiment tested the effect of varying degrees of out-group presence (no known out-group, existence of an out-group known, physical presence of the out-group) on group identification using aspects of Tajfel's Minimal Group Paradigm (Tajfel,1979). Participants were randomly assigned to groups in one of the three conditions of out-group presence. Participants knew group assignment was random, preventing perceived similarity with group members from affecting participants' responses. Group identification was measured using a survey developed by the experimenter which required participants to rate members of both groups on factors associated with group membership. Group identification was predicted to increase as the awareness of the out-group increased. This effect was found only between the control and known existence of out-group conditions.

4:15 p.m. Altruism as Related to Self-Esteem

Marjorie Fink

Advisor: Dr. Tim Robinson

This study examines the relationship between self-esteem and altruistic behaviors by measuring subjects self-esteem before and after they are given the option to help another student. According to the egoistic hypothesis, subjects with lower self-esteem should be more likely to help in order to feel better about themselves, and as a result of the decision to help their self-esteem should increase. In addition, this study also manipulates the ease with which participants can escape from the helping situation. The egoistic hypothesis predicts that subjects with low self-esteem in the difficult escape condition should be the most likely to help, while subjects with high self-esteem in the easy escape condition should be least likely to help since they have the least to gain.

4:30 p.m The Effects of Inhibited Facial Muscular Activity on Affective Responses

Shawn Mayfield

Sponsor: Dr. Tim Robinson

The affective responses of individuals whose facial muscles had been unobtrusively inhibited were investigated in this study as an examination of the facial feedback hypothesis. Previously, a study by Strack, Martin, and Stepper (1988) found support for the facial feedback hypothesis, applied to pleasant stimuli, using a new unobtrusive techniques to manipulate zygomaticus muscle activity without affecting cognitive awareness of the corresponding emotion. Larsen, Kasimatis, and Frey (1992) expanded on the Strack et al. (1988) findings by discovering support for the facial feedback of unpleasant stimuli in relation to inhibited corrugator muscle contractions. The purpose of this study was to determine whether the findings of Strack et al. (1988) and Larsen et al. (1992) generalize to auditory stimuli similar to the way they do for visual stimuli. Subjects were assigned to one of three conditions: pen in lips (inhibition of the zygomaticus muscle), golf tees attached to the brow region (inhibition of the corrugator muscle), or non-dominant hand (control). It was predicted that the two inhibition conditions would be associated with a stronger sadness response to the auditory stories in comparison to the control condition. In addition, it was predicted that the subjects' responses would be consistent between treatment conditions since the facial feedback hypothesis fails to recognize a superior muscle in the inhibition of affective responses.

Session V

Room: Olin 103

Convener: Dr. Larry Wohl

3:45 p.m. Sedimentologic Analysis of sand and Gravel Deposits Near Le Sueur, Minnesota

Brian Kraatz

Advisor: Dr. Mark Johnson

The terrace deposits of the Minnesota River Valley near Le Sueur, Minnesota are composed of several different facies of sand and gravel. Detailed sketches of outcrops were made and numerous samples taken to aid in understanding evolution and depositional history. Similar terraces located south of Kasota, Minnesota were interpreted to have been formed during the catastrophic draining of Glacial Lake Agassiz. Alternatively, the terrace sediments have been suggested to be outwash gravels, deposited while the Des Moines Lobe retreated. A third model suggests downcutting originating from the drainage of Glacial Lake Minnesota and a filling period attributed to outwash deposition. The final downcutting was then caused by the catastrophic draining of Glacial Lake Agassiz.

4:00 p.m. The Blue Earth Clay of Blue Earth County, Minnesota: Its Extent, Nature and Geologic History

Tom Marks

Advisor: Dr. Keith Carlson

In 1700, Pierre Le Sueur allegedly mined 30,000 lbs of copper near Mankato, Minnesota. Although later explorers dismissed the presence of copper, one can find a bluish-green clay at the contact between the Cambrian Jordan Sandstone and Ordovician Oneota Dolomite, a marine sequence. While the presence of glauconite in the clay tends to confirm a marine origin, field relationships suggest that the clay weathered out of the dolomite at a later date.

4:15 p.m. The North American Free Trade Agreement and the Labor Market for Truck Drivers

Chris Western

Advisor: Dr. Larry Wohl

Between 1993 and 1995, 80% of all exported Mexican goods traveled by truck to the U.S. under the North American Free Trade Agreement. On December 17, President Clinton revoked the "free-freight" side-agreement of NAFTA and banned all Mexican freight carriers from U.S. highways because of pressure from the Teamsters due to safety concerns, at least allegedly. This presentation will examine the hemispheric free trade pact and its influence on trucking labor demands and requirements.

4:30 p.m. Age Discrimination: Theory, Practice, and Public Policy Implications Concerning America's Aging Labor Force

Dan Drewitz

Advisor: Dr. Larry Wohl

This paper demonstrates how age discrimination can affect the social and economic lives of elderly Americans by examining theory, public policy, and empirical evidence related to an aging labor force. The primary focus of the paper is to determine the origins of age discrimination and relate this to ways in which older workers are discriminated against. The last section examines the role of the Age Discrimination in Employment Act of 1967, as amended, in an attempt to describe how the composition of the labor force has changed and what future legislative actions may be needed to reduce age discrimination.

4:45 p.m. Iron Ore Taxation: A Study of the Appropriation of Public Funds for the Development of Taconite

Dan Friesner

Advisor: Dr. Louis Johnston

The basic premise of this research project was to determine the accuracy of the statement that from 1941-65, $2.3 million was allocated to the Iron Range Resources and Rehabilitation Board to the University of Minnesota for the development of taconite. Using data from the IRRRB and Minnesota Dept. of Revenue, it was found that the total value of the appropriations totaled 1.98 million, or $300,000 short of the original claim. Implications about the impetus for the state's funding of the project have also been discovered.

5:00 p.m. Explaining the Gender Gap in Earnings

Jason Bondhus

Advisor: Dr. Larry Wohl

Since the Equal Pay Act of 1963 was passed, the gender gap in earnings has remained fairly stable, at 70 percent. How much of the gap is due to discrimination? My research compares men and women with the same amounts of human capital to determine any discrimination. Do two doctors with Ph.D.s, a man and a woman get paid the same today? My research looks at the gap across occupations and also the effects of education.