https://doi.org/10.33697/ajur.2006.006

Guest Comment: Early Years Are Important in the STEM Pipeline

https://doi.org/10.33697/ajur.2006.007

Author(s):

Robert D. Koob

Affiliation:

Department of Chemistry, University of Northern Iowa, Cedar Falls, Iowa 50614 USA

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Using Molecular Dynamics Simulations to Model the DC Electrical Behavior of Confined Layers

https://doi.org/10.33697/ajur.2006.008

Authors and Affiliations:

Nathan G. Beougher, Jason McIntosh, Jason A. Djuren, and M.W. Roth
Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614 USA

Carlos Wexler
Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211 USA

Carl Thurman
Department of Biology, University of Northern Iowa, Cedar Falls, Iowa 50614-0421 USA

ABSTRACT:

A Molecular Dynamics (MD) computer simulation is utilized to qualitatively understand the DC electrical conduction behavior of pentadecane (CH) layers confined between two graphite slabs as related to the dynamics of the layer. At low temperatures the patch remains together and perpendicular to the confining layers. Then, as temperature is increased, tilting of the molecules begins. The molecules tend to remain straight as they tilt with increasing temperature which, in our model, affects the capacitance somewhat but the resistance little. As temperature is increased further, the molecules exhibit gauche defects which accompany patch collapse. During patch collapse, the system shows dramatic changes in its calculated DC resistance and capacitance. Calculated specific capacitance values are in remarkable agreement with recent experimental measurements. Results for two different confining layer separations are discussed as well as future work related to lipid bilayer systems.

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Visualizing Bond Types with Electron Density Models: How Informative is Electronegativity?

https://doi.org/10.33697/ajur.2006.009

Author(s):

Heath D. Stotts and J. Conceicao

Affiliation:

Division of Natural Sciences, Northwestern Oklahoma State University, 709 Oklahoma Blvd., Alva, Oklahoma 73717 USA

ABSTRACT:

Electron densities are used to visualize pure covalent, polar covalent and ionic bonds in binary compounds. The rationale for this study stems in part from the observations that within the same bond type, for example pure covalent, a variety of bond properties exist. Simple ΔEN predictions by Pauling do not adequately explain differences within the same bond type, nor determine covalent or ionic bonding. In this study, a series of electron density maps for binary compounds have been calculated to compare the characteristics of the maps to ΔEN predictions.

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Comparing 6th Grade Science Classrooms: Inner-City versus Suburb

https://doi.org/10.33697/ajur.2006.010

Author(s):

Nida Syed

Affiliation:

Department of Behavioral Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128-1491 USA

ABSTRACT:

Do teachers in the inner-city have different expectations of their students than teachers in the suburbs? Ethnographic studies of the classroom such as one by Wilcox in 1982 suggest they do. Wilcox describes education as “primarily a process of cultural transmission”. In other words, schools in a particular setting or neighborhood aim to instill in their students the cultural norms and behaviors accepted and expected in that setting. This project is an ethnographic study of two sixth grade science classrooms; one in an urban inner-city Detroit, Michigan neighborhood and one in the neighboring suburb of Dearborn. The study examines the way the two classrooms are run by the teachers and their teaching styles by comparing the types of assignments that are given to students and the implications they have on the students’ learning development. Other factors such as a comparison of school funding per pupil and the effect it has on the availability of resources necessary for learning in each classroom were also examined. We found that the Dearborn school students learned how to work individually and in groups whereas the Detroit school students learned only how to work in groups. We also found that Dearborn students were encouraged to read out loud to the class individually whereas Detroit students were often read to by the teacher. 

https://doi.org/10.33697/ajur.2006.001

Guest Comment: Set Theoretic Concepts in Computer Science and Engineering—A Connection between Mathematics and Computing

https://doi.org/10.33697/ajur.2006.002

Author(s):

Dele Oluwade

Affiliation:

College of Science & Technology, P.O. Box 20253, University of Ibadan, Ibadan, Oyo 200005 NIGERIA

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A Joint Source-Channel Steganography Decoding Paradigm and It’s Implications on Capacity

https://doi.org/10.33697/ajur.2006.003

Author(s):

Ishtiaq Saaem and Hong Man

Affiliation:

Visual Information Environment Lab (VIEL), Department of Electrical and Computer Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 USA

ABSTRACT:

Steganography has become extremely popular lately as a means of achieving security for many multimedia applications. However, research on stego-attack mechanisms has also kept pace with this development. Robustness to such stego-attacks usually requires a compromise in stego-capacity. In this paper we propose a joint source-channel coding paradigm for attack robustness with small overhead. We test our framework using a least significant bit based embedding algorithm and random additive attacks. Our results lead us to believe that the joint source-channel coding paradigm has significant potential in this area.

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Evaluating Arm Movement Imitation

https://doi.org/10.33697/ajur.2006.004

Authors and Affiliations:

Alexandra Constantin
Baxter Hall, Williams College, Williamstown, Massachusetts 01267 USA
Maja J. Matarić
Computer Science Department, University of Southern California, Los Angeles, California 90089 USA

ABSTRACT:

In this paper, we present a metric for assessing the quality of arm movement imitation. We develop a joint-rotational-angle-based segmentation and comparison algorithm that rates pairwise similarity of arm movement trajectories on a scale of 1-10. We describe an empirical study designed to validate the algorithm we developed, by comparing it to human evaluation of imitation. The results provide evidence that the evaluation of the automatic metric did not significantly differ from human evaluation.

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Explicit Solutions of the Wave Equation on Three Dimensional Space-Times: Two Examples with Dirichlet Boundary Conditions on a Disk

https://doi.org/10.33697/ajur.2006.005

Author(s):

Daniel Boykis and Patrick Moylan

Affiliation:

Physics Department, The Pennsylvania State University, Abington College, Abington, Pennsylvania 19001 USA

ABSTRACT:

We study solutions of the wave equation with circular Dirichlet boundary conditions on a flat two-dimensional Euclidean space, and we also study the analogous problem on a certain curved space which is a Lorentzian variant of the 3-sphere. The curved space goes over into the usual flat space-time as the radius R of the curved space goes to infinity. We show, at least in some cases, that solutions of certain Dirichlet boundary value problems are obtained much more simply in the curved space than in the flat space. Since the flat space is the limit R → ∞ of the curved space, this gives an alternative method of obtaining solutions of a corresponding problem in Euclidean space. 

https://doi.org/10.33697/ajur.2005.018

Editorial: AJUR and the Flat World

https://doi.org/10.33697/ajur.2005.019

Author(s):

C. C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

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Aggregation of Cyanine Dye in Bilayer Vesicles of Phospholipids

https://doi.org/10.33697/ajur.2005.020

Author(s):

Casey McCullough, Matthew Heywood, and Hussein Samha

Affiliation:

Division of Chemistry, Southern Utah University, 351 W. Center Street, SC 215, Cedar City, Utah 84720 USA

ABSTRACT:

The effect of phospholipid, 1,2-Dipalmitoyl-sn-glycero-3-Phosphocholine (DPPC) on the spectroscopy of the cyanine dye, 1-ethyl-1’-octadecyl-2,2’-cyanine iodide (PIC-18), has been investigated using UV-Vis spectroscopy. Vesicles of DPPC containing PIC-18 in the molar ratio of 1:3 (dye/phospholipids) were prepared in aqueous solution. J-aggregates of PIC-18 were detected in the bilayer wall of the vesicles. When an aqueous solution of mixed PIC-18/DPPC vesicles is treated with excess DPPC vesicles that are prepared separately, the dye molecules in the mixed vesicles underwent a rapid (aggregate)n’ n (monomer) equilibrium as the  appearance of only one isosbestic point in the absorbance of the dye indicates. The equilibrium constant was calculated at room temperature (Keq = 6.7×10-2). An aggregation number of 4 was calculated for the dye in the bilayer vesicles.

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JAR1, a Dominant Gene Conferring Resistance to Amphotericin B in Saccharomyces cerevisiae

https://doi.org/10.33697/ajur.2005.021

Author(s):

Joyce Iwema, Katherine Force, and Robin Pals-Rylaarsdam

Affiliation:

Biology Department, Trinity Christian College, 6601 West College Drive, Palos Heights, Illinois 60463 USA

ABSTRACT:

Infectious diseases are the cause of death for over 1 million people a year in the United States alone. Drug resistance in infectious microbes is an increasing problem. This study focuses on antibiotic resistance in fungal infections, using Saccharomyces cerevisiae as the model of study. Spontaneous mutations in this yeast resulted in a yeast strain with the ability to grow in the presence of the antifungal drug amphotericin B. This yeast isolate, named JAR1, was genetically analyzed to determine how many mutated genes were responsible for the resistant phenotype, and whether the allele was dominant or recessive. The results indicate that the ability of JAR1 to grow in the presence of amphotericin B is due to a single dominant mutation.

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Construction of Higher Orthogonal Polynomials Through a New Inner Product, ‹·,·›p, In a Countable Real Lp-space

https://doi.org/10.33697/ajur.2005.022

Author(s):

Femi O. Oyadare

Affiliation:

Department of Mathematics, University of Ibadan, Ibadan, Oyo State, NIGERIA

ABSTRACT:

This research work places a new and consistent inner product ‹·,·›p on a countable family of the real Lp function spaces, proves generalizations of some of the inequalities of the classical inner product for ‹·,·›p provides a construction of a specie of Higher Orthogonal Polynomials in these inner-product–admissible function spaces, and ultimately brings us to a study of the Generalized Fourier Series Expansion in terms of these polynomials. First, the reputation of this new inner product is established by the proofs of various inequalities and identities, all of which are found to be generalizations of the classical inequalities of functional analysis. Thereafter two orthogonalities of ‹·,·›p (which coincide at p = 2) are defined while the Gram-Schmidt orthonormalization procedure is considered and lifted to accommodate this product, out of which emerges a set of higher orthogonal polynomials in Lp[-1,1] that reduce to the Legendre Polynomials at p = 2. We argue that this inner product provides a formidable tool for the investigation of Harmonic Analysis on the real Lp function spaces for p other than p = 2, and a revisit of the various fields where the theory of inner product spaces is indispensable is recommended for further studies.

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Noetherian Rings—Dimension and Chain Conditions

https://doi.org/10.33697/ajur.2005.023

Author(s):

Abhishek Banerjee

Affiliation:

57/1/C, Panchanantala Lane, Behala, Calcutta 700034, INDIA

ABSTRACT:

In this paper we look at the properties of modules and prime ideals in finite dimensional noetherian rings. This paper is divided into four sections. The first section deals with noetherian one-dimensional rings. Section Two deals with what we define a “zero minimum rings” and explores necessary and sufficient conditions for the property to hold. In Section Three, we come to the minimal prime ideals of a noetherian ring. In particular, we express noetherian rings with certain properties as finite direct products of noetherian rings with a unique minimal prime ideal, as an analogue to the expression of an artinian ring as a finite direct product of artinian local rings. Besides, we also consider the set of ideals I in R such that M ≠ I M for a given module M and show that a maximal element among these is prime. In Section Four, we deal with dimensions of prime ideals, Krull’s Small Dimension Theorem and generalize it (and its converse) to the case of a finite set of prime ideals. Towards the end of the paper, we also consider the sets of linear dependencies that might hold between the generators of an ideal and consider the ideals generated by the coefficients in such linear relations.

https://doi.org/10.33697/ajur.2005.012

Editorial: Teaching Something New — Nanoscience

https://doi.org/10.33697/ajur.2005.013

Author(s):

C. C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

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Design, Construction and Testing of a Desktop Supersonic Wind Tunnel

https://doi.org/10.33697/ajur.2005.014

Author(s):

Vi H. Rapp, Jennifer Jacobsen, Mark Lawson, Andrew Parker, Kuan Chen

Affiliation:

Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112 USA

ABSTRACT:

A mobile and affordable, miniature wind tunnel to aid students in studying high-speed compressible flows was constructed and tested. Millimeter-sized nozzles of different contours were fabricated to produce supersonic flows at Mach 2. The complete system consists of a converging-diverging nozzle, a load cell, pressure and temperature sensors, a tank to store high-pressure gases, and a computer-aided data acquisition system. The wind tunnel system is mounted to a cart, making it convenient to move. This test facility allows students to study and test supersonic flows in a safer environment while eliminating the high costs for a full-sized facility. Gas pressure was measured at various locations in the nozzle. A load cell consisting of four cantilever beams was constructed and used to determine the thrust of the nozzle. Data collected from each nozzle was compared to numerical simulations. In all cases, the simulations were in good agreement with the experimental data.

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Effects of a Glutamine Supplement on the Skeletal Muscle Contractile Force of Mice

https://doi.org/10.33697/ajur.2005.015

Author(s):

Derek Waddell and Kim Fredricks

Affiliation:

Department of Biology, Viterbo University, 921 S. 7th Street La Crosse, Wisconsin 54601 USA

ABSTRACT:

L-glutamine is the most abundant amino acid found in human muscle and plays an important role in protein synthesis. It is, therefore, believed that by increasing L-glutamine levels, protein metabolism can be increased, resulting in skeletal muscle growth. The goal of this research was to determine if increased L-glutamine levels enhanced muscle growth in mice. Comparisons between the contractile force of the gastrocnemis muscles of a control group and a group that received the supplement through their water supply were intended to determine if muscle growth occurred. T-tests were used to compare the contractile forces of the experimental and control mice. There was a significant difference between the contractile forces of the experimental and control groups. This suggests that L-glutamine supplementation increased the muscle growth of the experimental mice.

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Optimization of the Split-Operator Method for Modeling of Quantum System Time Evolution

https://doi.org/10.33697/ajur.2005.016

Author(s):

D. V. Vlasov

Affiliation:

Physics Faculty, Dept. of Theoretical Physics, Herzen State Pedagogical University of Russia, St.-Petersburg 191186, Russia

ABSTRACT:

A continuing and important problem in modeling physical processes deals with creating optimum calculation algorithms. These algorithms should provide the necessary precision yet not demand a lot of storage and time for evaluations. In the present paper the numerical integration of the non-stationary Schrödinger equation (NSSE) is considered. There are many numerical methods of integration of this equation to the present moment. In this paper, we explore the split-operator method (SOM) and consider a way of lessening time computing expenses in view of specificity of the given method. We also consider the choice of optimum discretization steps in coordinate and momentum space. The computer application that we outline is applicable, in method and preparation, to the solution more difficult problems, and it has been applied to simple chemical reactions. We use standard atomic units to simplify equations in the analysis that follows.

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Computer-Mediated Communication: Development of an Intranet for a University Academic Department

https://doi.org/10.33697/ajur.2005.017

Author(s):

Oyenike Olufunmilayo Samantha Laoye

Affiliation:

Department of Computer Science, University of Ibadan, Ibadan, Nigeria

ABSTRACT:

The Intranet has been said to be one of the most important technological developments in Computer Communications. Whilst it is now a common, rapidly growing resource in the business world for the dissemination of information, it is yet to be fully explored in educational institutions. Intranets have an enormous potential to transform education in interesting and challenging ways as they offer an exciting approach for improving and facilitating innovative ways of supporting communication and also for accessing teaching and learning resources. This paper discusses the importance and usefulness of Computer-Mediated Communication in the enhancement of human communications and the focus is on the application of the Intranet (a form of Computer-Mediated Communication) in the context of campus-based university education. This is illustrated by means of a case study and a realistic example i.e. the development of an Educational Intranet (CS.IntraNet) for the Department of Computer Science, University of Ibadan, Nigeria.

https://doi.org/10.33697/ajur.2005.007

Editorial: Benchmarks for Undergraduate Science

https://doi.org/10.33697/ajur.2005.008

Author(s):

C. C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

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Long Term Metabolic and Health Effects of a Low-Carbohydrate, High-Fat, High-Protein Diet in Mus musculus: A Nineteen Week Longitudinal Study

https://doi.org/10.33697/ajur.2005.009

Author(s):

Donald Harris, Christopher Bell, Misty Retzlaff, Stephanie Toering, Elizabeth Wurdak, and David Mitchell

Affiliation:

College of St. Benedict and St. Johns University, Collegeville, Minnesota 56321 USA

ABSTRACT:

This study was designed to investigate the long-term metabolic adaptations and health effects of a low-carbohydrate, high-fat/protein diet in mice. One-month-old male ICR mice were fed a control, conventional high-carbohydrate diet (n=21) or an experimental low-carbohydrate, high-fat, high-protein diet (n=20). One pair of mice per group was euthanized at two-week intervals for five months for tissue analysis. Basic metabolic data, body and tissue weights, blood and plasma metabolite and lipid profiles, liver glycogen and protein content, and liver serine dehydratase and glucose-6-phosphate dehydrogenase activities were analyzed. The low-carbohydrate group gained significantly more weight (p<0.005 after 4 weeks) than the normally growing control group. Although ketosis was initially stimulated in the low-carbohydrate group, enzyme and tissue analysis suggest that gluconeogenic activity was sufficient to alleviate the effects of severe dietary carbohydrate restriction and allow for glucose metabolism close to that demonstrated in the control group.

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Remote Sensing Calibration of Casey Lake and Silver Lake

https://doi.org/10.33697/ajur.2005.010

Author(s):

Krista Ellyson and Mark D. Ecker

Affiliation:

Mathematics Department, University of Northern Iowa, Cedar Falls, IA 50614-0506 USA

ABSTRACT:

This project examines two Iowa lakes to explore the feasibility of using remote sensing technologies for assessing water quality in lieu of actual ground samples. We demonstrate that a principal component analysis of the more than 20,000 remote sensed pixels can be used in a regression analysis to accurately predict total phosphorus levels in Casey Lake on three distinct times in the summer of 2004.

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Theoretical Considerations for a Geosynchronous, Earth-Based Gravity Wave Interferometer

https://doi.org/10.33697/ajur.2005.011

Author(s):

William P. Griffin

Affiliation:

Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

ABSTRACT:

We investigated theoretical considerations in the design of an Earth-based laser interferometer for detecting gravitational waves. Our design envisages a ground-based tracking station in communication with two geosynchronous satellites. We assumed linearized gravitational waves in a Schwarzschild spacetime geometry outside the Earth. Our initial calculations show that such a design is sufficiently sensitive to successfully detect gravitational waves near Earth.

https://doi.org/10.33697/ajur.2005.001

Integrating Undergraduate Science Research: A Commentary to Undergraduate Research Faculty

https://doi.org/10.33697/ajur.2005.002

Authors and Affiliations:

Larry E. Davis, Department of Biology, College of St. Benedict-St. Johns University, Collegeville, Minnesota 56321 USA

Robert L. Eves
Department of Physical Science, Southern Utah University, Cedar City, Utah 84720 USA

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On Solving Systems of ODEs Numerically

https://doi.org/10.33697/ajur.2005.003

Author(s):

Temple H. Fay, Stephan V. Joubert, and Andrew Mkolesia

Affiliation:

Department of Mathematical Technology, Tshwane University of Technology, Private Bag x680, Pretoria 0001 SOUTH AFRICA

ABSTRACT:

Many beginning courses on ordinary differential equations have a computer laboratory component in which the students are asked to solve initial value problems numerically. But little attention in texts is given to the question of how accurate such solutions are. In this article we offer a simple procedure that not only can provide a measure of accuracy, but also often produces superior numerical results.

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Awareness, Partisanship and the Post-Convention Bounce: A Memory-Based Model of Post-Convention Presidential Candidate Evaluations Part II—Empirical Results

https://doi.org/10.33697/ajur.2005.004

Author(s):

Justin Grimmer

Affiliation:

Department of Mathematics and Computer Science, Wabash College, Crawfordsville, Indiana 47933

ABSTRACT:

This paper continues an analysis, begun in the December 2004 issue, that employed panel data to estimate the effects of awareness and political partisanship on post-convention candidate evaluations. The derivation of a theoretical framework was discussed in Part 1 [1]. Empirical results using data from the US presidential election of 2000 are discussed in the present article. We find that partisans of the opposite party were more resistant to the convention message of Bush than Gore, that awareness played a greater role in determining a predicted post-convention change for Gore, and that Gore’s message was received and accepted at a higher rate than Bush’s message.

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Isometries, Tessellations and Escher, Oh My!

https://doi.org/10.33697/ajur.2005.005

Author(s):

Melissa Potter and Jason M. Ribando

Affiliation:

Department of Mathematics, University of Northern Iowa, Cedar Falls, Iowa 50614-0506 USA

ABSTRACT:

Motivated to better understand the wonderful artistry and hyperbolic tessellations of M.C. Escher’s Circle Limit prints, we study the isometries of the hyperbolic plane and create tessellations of the Poincaré disk using the Euclidean tools of compass and straightedge.

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Self Assembly of Cyanine Dye on Clay Nanoparticles

https://doi.org/10.33697/ajur.2005.006

Author(s):

Andrew Dixon, Clint Duncan, and Hussein Samha

Affiliation:

Department of Physical Science, Southern Utah University, Cedar City, Utah 84720 USA

ABSTRACT:

The effect of Ca-montmorillonite (clay) on the aggregation behavior of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), in aqueous solutions has been investigated using UV-vis spectroscopy. The absorbance of the monomeric dye in aqueous solutions is compared with the absorbance of the aggregates formed after adding the clay. The appearance of a sharp “red-shifted” band centered at 574 nm, after the addition of clay to the aqueous solutions of the dye, indicates the formation J-aggregates on the charged surfaces of the clay particles. The spontaneous and quantitative transformation of monomers into J-aggregates was controlled by the concentration of the clay in the solution. Successive addition of clay to the dye solution causes an increase in the absorbance intensity of the J-band and consequently, a decrease in the absorbance intensity of the monomer. These changes occur linearly which suggests that the dye monomers are quantitatively being converted to J-aggregates.

https://doi.org/10.33697/ajur.2004.019

Guest Comment: The Drake University Conference on Undergraduate Research in the Sciences

https://doi.org/10.33697/ajur.2004.020

Author(s):

Heidi Sleister, Department of Biology, Charles Nelson, Department of Physics and Astronomy, Maria Bohorquez, Department of Chemistry

Affiliation:

Drake University, 2507 University Avenue, Des Moines, Iowa 50311-4505 USA

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J-Aggregates of Cyanine Dyes in Aqueous Solution of Polymers: A Quantitative Study

https://doi.org/10.33697/ajur.2004.021

Author(s):

Wesley Tillmann and Hussein Samha

Affiliation:

Division of Chemistrym, Southern Utah University, 351 W. Center Street, SC 215 Cedar City, Utah 84720 USA

ABSTRACT:

The effect of polyvinylsulfate (PVS) on the spectroscopy of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), has been investigated using UV-vis spectroscopy. J-aggregates of the PIC dye were formed upon addition of PVS to the monomers of the dye in solution. The appearance of only one isosbestic point in the UV-vis spectra suggests that the dye monomers are quantitatively converted to J-aggregates and equilibrium was reached. Using Benisi-Hildebrand kinetics, aggregation number of 4 was calculated for the dye. In addition, a 1:2 mole ratio of PIC/PVS was calculated at the maximum capacity of the polymer.

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Exactness, Tor and Flat Modules Over a Commutative Ring

https://doi.org/10.33697/ajur.2004.022

Author(s):

Abhishek Banerjee

Affiliation:

Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700108 INDIA

ABSTRACT:

In this paper, we principally explore flat modules over a commutative ring with identity. We do this in relation to projective and injective modules with the help of derived functors like Tor and Ext. We also consider an extension of the property of flatness and induce analogies with the “special cases” occurring in flat modules. We obtain some results on flatness in the context of a noetherian ring. We also characterize flat modules generated by one element and obtain a necessary condition for flatness of finitely generated modules.

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Awareness, Partisanship and the Post-Convention Bounce: A Memory-Based Model of Post-Convention Presidential Candidate Evaluations Part 1—Introduction & Theoretical Analysis

https://doi.org/10.33697/ajur.2004.023

Author(s):

Justin Grimmer

Affiliation:

Department of Mathematics and Computer Science, Wabash College, Crawfordsville, Indiana 47933 USA

ABSTRACT:

This paper employs panel data to estimate the effects of awareness and political partisanship on post-convention candidate evaluations. The theoretical framework proposed by John Zaller (1992) is employed; however, a functional form that differs greatly from Zaller’s proposed model is derived from Zaller’s assumption and then estimated using standard OLS regression. I find that partisans of the opposite party were more resistant to the convention message of Bush than Gore, awareness plays a greater role in determining predicted post-convention change for Gore, and that Gore’s message was received and accepted at a higher rate than Bush’s message.

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Thermal Desorption in Pure Hexane and Hexane/Butane Mixtures on Graphite

https://doi.org/10.33697/ajur.2004.024

Author(s):

Cary L. Pint

Affiliation:

Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

ABSTRACT:

The results of an extensive study of desorption in hexane (monolayer and submonolayer) and hexane/butane mixtures initially adsorbed onto the graphite basal plane is presented. Molecular dynamics (MD) simulations are utilized to carry out atomistic simulations at temperatures 300≤T≤700 for all three cases studied. Results from submonolayer and monolayer hexane indicate that the desorption energy needed for the system to proceed with the desorption process is independent of the system’s coverage, which is in good agreement with experimental results. It is also found that simulations of desorption of hexane/butane mixtures yield a high ratio of butane molecules being desorbed from the surface at lower temperatures (300 K), suggesting a strong dependence of the desorption barrier upon alkane chain length. The results are discussed and compared to previous experimental and theoretical results.

https://doi.org/10.33697/ajur.2004.012

June 2002 through June 2004

https://doi.org/10.33697/ajur.2004.013

Author(s):

C.C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

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Analysis of the Merden Lake Esker, Stearns County, Minnesota: A New Interpretation

https://doi.org/10.33697/ajur.2004.014

Author(s):

Aaron C. Hirsch and Larry E. Davis

Affiliation:

Division of Natural Sciences, College of St. Benedict / St. John’s University, Collegeville, Minnesota 56321 USA

ABSTRACT:

A gravel pit in south central Stearns County, Minnesota exposes sand and gravel of the Merden Lake esker which is thought to have been deposited by a subglacial stream associated with the Wisconsinan-aged Superior Lobe of the Laurentide ice sheet. An analysis of these sediments was conducted from samples collected through a vertical trench on an east-facing exposure of the gravel pit. A total of 12 distinct stratigraphic horizons were recognized. Each horizon was described in terms of overall color, grain size, and lithology, carbonate content, and sedimentary structures. A total of 436 clasts (>3 cm) were collected for lithology studies. Trench samples were collected across each horizon for grain size sieve analysis. Clasts were dominated by basalt (37.6%), granite (28.2%), gabbro (14.5%), quartzite (6.2%), diorite (3.5%), mica schist (3%), and andesite (1%). Minor components consisted of pisolitic claystone, shale, sandstone, limestone, dolostone, ironstone, bauxite, quartz, agate, and amethyst. The sedimentology provides an overall color of yellowish-orange to brown. Many of the large clasts (>5 cm) contained a rind of calcareous-cemented course sand. Several large (18-35 cm) armored clay balls were collected from the basal horizon. Grain size ranged from boulders (up to 37 cm in diameter) to clays. Average cobble size was 10.48 cm. The dominant grain size through the trench was 1-2 mm. Sedimentary structures included graded beds, minor cross bedding, and imbrication. Superior Lobe lithologies are dominated by red volcanics and sedimentary rocks from the Middle Proterozoic Keeweenawan Superior Group and have an overall brown to reddish-gray appearance. Rainy (Wadena) Lobe lithologies are dominated by Precambrian igneous and metamorphic rocks from southwest Ontario and northwest Minnesota and have an overall yellowish to yellow-brown appearance. Sedimentological analysis of the Merden Lake esker indicates its characteristics are more consistent with subglacial stream deposition within the Pierz Sublobe of the Rainy Lobe of the Laurentide ice sheet.

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Numerical Investigation of a Class of Nonlinear Schrödinger Equations

https://doi.org/10.33697/ajur.2004.015

Author(s):

Christopher Ventura

Affiliation:

Pacific University, 2043 College Way, Forest Grove, Oregon 97116

ABSTRACT:

This paper numerically investigates the space-localized spherically symmetric, stationary, and singularity-free solutions of the Nonlinear Schrödinger equation when the nonlinearity is a step function. Previously no-node solutions have been obtained analytically. Here, it is shown that localized stationary solutions with one node and two nodes also exist.

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Interactions among Land, Water, and Vegetation in Shoreline Arthropod Communities

https://doi.org/10.33697/ajur.2004.016

Author(s):

Randall D. Willoughby and Wendy B. Anderson

Affiliation:

Department of Biology, Drury University, 900 N. Benton Avenue, Springfield, Missouri 65802 USA

ABSTRACT:

We investigated the distribution and abundance of terrestrial spiders as a function of their distance from a body of water and the structure of vegetation that would provide suitable habitat. We hypothesized that spiders would prefer to be located near the water to catch abundant aquatic emergent insects. In Montana along the Upper Missouri River, and in Missouri at various locations around Table Rock Lake, transect lines were run from the water’s edge to 25 meters inland. At five-meter intervals, in one square meter plots, the number of spiders, number of prey and type, and vegetation type and structure were recorded. In both Montana and Missouri, spider distribution was more strongly associated with available vegetation structure than with distance from shore. This suggests that, although prey availability may be important for predator distribution, suitable habitat is as strong or stronger a determinant for web building spiders.

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Application of Green Chemistry: A Miniaturized Procedure for Analysis of Dissolved Phosphate

https://doi.org/10.33697/ajur.2004.017

Author(s):

Nadia Kamal and Clay Runck

Affiliation:

Department of Biological Sciences, Benedictine University, 5700 College Road, Lisle, Illinois 60532 USA

ABSTRACT:

The objective of this study was to determine if the volume of sample used for analysis of soluble reactive phosphate (SRP) could be reduced from 100 mL (as per a widely used standardized procedure) to 50 or 10 mL to reduce the amount of hazardous waste generated from routine analysis of SRP in water samples from rivers, streams, and ponds in an urbanized landscape, in accordance with the principles of “green chemistry” and the Pollution Prevention Act of 1990. The ascorbic acid-molybdate blue method of Murphy and Riley (1962) was used to determine the concentration of SRP in water samples collected from the East Branch of the DuPage River and from two ponds on the campus of Benedictine University. Mean concentration of SRP determined using a 10 mL sample volume of DuPage River water (x = 1,051 μg PO4-P/L) was significantly greater than the 100 and 50 mL sample volumes, which were not significantly different from each other (x = 1,002 μg PO4-P/L); however, the difference in SRP concentration between 10 mL and 100 and 50 mL sample volumes was only 5%. There was no significant effect of sample volume on SRP concentration for slough or storm water pond samples, but these two pond systems had a low SRP concentration (<3 μg PO4-P/L). The relationship between absorbance and SRP concentration in the ascorbic acid-molybdate blue method was examined between 0 and 2,000 μg PO4-P/L; absorbance was asymptotic between 500 and 2,000 μg PO4-P/L. The results of this study show that the sample volume for analysis of SRP in DuPage River water with the ascorbic acid-molybdate blue method can be reduced by 50% (i.e., reduced from 100 mL to 50 mL) without loss of accuracy, but that samples must be diluted to reduce the concentration of SRP to within the limits of the procedure. The reduction in sample volume represents a substantial reduction in the volume of hazardous waste that is generated, and the overall cost per sample, for routine analysis of SRP in the DuPage River.

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Improvements in Latent Semantic Analysis

https://doi.org/10.33697/ajur.2004.018

Author(s):

Ryan Lloyd and Cheri Shakiban

Affiliation:

Department of Mathematics, University of St. Thomas, St. Paul, Minnesota 55105-1079 USA

ABSTRACT:

This paper proposes and examines modifications for the method of Latent Semantic Analysis (LSA). Several new local and global weight functions, along with normalization routines, are disclosed. Changes in the general structure of LSA are discussed. An application of LSA, in which the method is used to filter advertisements in e-mail, proves the worthiness of the advancements.

https://doi.org/10.33697/ajur.2004.006

Undergraduate Research Opportunities via Google

https://doi.org/10.33697/ajur.2004.007

Author(s):

C.C. Chancey

Affiliation:

American Journal of Undergraduate Research, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

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Origin Of Calcareous Sediments in the Holocene Pigeon Creek Tidal Lagoon and Tidal Delta, San Salvador Island, Bahamas

https://doi.org/10.33697/ajur.2004.008

Authors and Affiliations:

B. A. Welle, A. C. Hirsch, L. E. Davis
Department of Geology, College of St. Benedict / St. John’s University, Collegeville, Minnesota 56321 USA

A. C. Johnson, G. J. Hunt, and R. L. Eves
Department of Geology, Southern Utah University, Cedar City, Utah 84720 USA

ABSTRACT:

A sedimentological survey of the southwest arm of the Holocene Pigeon Creek tidal lagoon on San Salvador Island, Bahamas was conducted to determine the origin and distribution of calcareous sediments. Transect surveys, surface samples, and sediment cores were collected and examined to determine the abundance and distribution of sediments and sediment producers in the lagoon and associated tidal delta. The study area has three regions: an extensive tidal to shallow, subtidal flat; a tidal channel near the entrance to the lagoon; and a lobate, ebb-dominated tidal delta. Tidal flat sediments were extensively bioturbated and heavily rooted by Thalassia testudinum. Tidal flat sediments ranged from coarse, calcareous sand to calcareous muds, and were rich in gastropod shells, foraminifera, calcareous algae, and pelletal calcareous mud. The tidal flat sediments are assigned to a pellet-lime wackestone to muddy lime packstone lithofacies. Calcareous green algae are the primary producers of calcareous sediments in the lagoon with species of Halimeda and Penicillus being the dominant genera. Surface samples taken from the coarse channel lag of the tidal channel consisted primarily of whole and fragmented bivalves and gastropods. Most of the bivalves were oriented convex upward. Surface samples taken from ripples, mega-ripples, and sand waves of the tidal delta are dominated by well-sorted, well-rounded, and polished sand-size grains (1-2 mm in diameter). This sediment was dominated by bioclasts (bivalves, gastropods, calcareous algae, foraminifera) and minor ooids. Sediments of the tidal channel and tidal delta are assigned to a lime packstone to grainstone lithofacies. The coarsest fraction (> 2 mm) accumulated on the lee slopes and troughs of large, tidal and wave produced ripples. Ripples for both ebb- and flood tides are strongly asymmetrical, but symmetrical ripples are common, indicating that significant migration of the tidal delta does not occur during normal tidal events. A low energy, shallowing upward cycle is well illustrated in the lagoon, and the presence of a depaurperate biofacies and heavily bioturbated and rooted lithofacies typify a carbonate lagoon depositional environment.

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Cadmium Bioaccumulation in Yellow Foxtail (Setaria glauca L. P. Beauv): Impact on Seed Head Morphology

https://doi.org/10.33697/ajur.2004.009

Author(s):

D. K. Kosma, J. A. Long, and S. D. Ebb

Affiliation:

Department of Plant Biology, Southern Illinois University Carbondale, Carbondale, Illinois 62901 USA

ABSTRACT:

Yellow foxtail (Setaria glauca L. P. Beauv) growing on a cadmium-contaminated site was sampled to determine the extent of cadmium bioaccumulation in aerial tissues and the impact of cadmium on growth and development. Water-extractable Cd concentrations in the soil ranged from 5.0 to 18.0 mg L-1. Aerial tissues contained elevated concentrations of Cd (16-48 μg g-1 DW), with mean concentration ratios of >3.0. Since foxtail frequently colonizes disturbed sites, the bioaccumulation of Cd in aerial tissues of foxtail suggests that wildlife feeding upon this plant species could be exposed to elevated Cd levels. A significant negative correlation (r2=0.98) was observed between water-extractable Cd in the soil and seed head length in foxtail, indicative of an adverse effect of Cd on reproductive development. This correlation further suggests seed head length as a biomarker for soluble Cd in contaminated soils.

KEYWORDS:

Cadmium, bioaccumulation, biomarker, phytotoxicity

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Apollonius’ Problem: A Study of Solutions and Their Connections

https://doi.org/10.33697/ajur.2004.010

Author(s):

David Gisch and Jason M. Ribando

Affiliation:

Department of Mathematics, University Northern Iowa, Cedar Falls, Iowa 50614-0506 USA

ABSTRACT:

In Tangencies Apollonius of Perga showed how to construct a circle that is tangent to three given circles. More generally, Apollonius’ problem asks to construct the circle which is tangent to any three objects that may be any combination of points, lines, and circles. The case when all three objects are circles is the most complicated case since up to eight solution circles are possible depending on the arrangement of the given circles. Within the last two centuries, solutions have been given by J. D. Gergonne in 1816, by Frederick Soddy in 1936, and most recently by David Eppstein in 2001. In this report, we illustrate the solution using the geometry software Cinderella™, survey some connections among the three solutions, and provide a framework for further study.

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Physics of Potassium Ion Channel Inactivation in Neurons

https://doi.org/10.33697/ajur.2004.011

Author(s):

Ryan M. W. Collins

Affiliation:

Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

ABSTRACT:

The electrical signaling capabilities of neurons depend on the flows of ions into and out of their axons. Potassium ions exit an axon’s interior through a potassium channel or pore that connects the intracellular region with the extracellular region. The channel opens, or is activated, allowing potassium ions to exit. The channel then undergoes a blocking transition in which the channel is physically open but is blocked by some part of the larger channel molecule. This blocking process is called inactivation, and the physics by which it might occur forms the topic of our investigation. The N-terminus region of the Drosophila shaker potassium ion channel was identified by Hoshi et al as having an important role in channel inactivation. Using the last 19 amino acids in the N-terminus region, a mass and net charge were calculated. We investigated two forces that might affect the motion of this N-terminus mass (tentatively identified as the blocking or inactivation particle): the magnetic field effects due to potassium ion current in the channel, and an electric force due to the decreasing density of potassium ions from the intracellular region. Time-of-flight calculations were calculated for the inactivation particle. These times will be discussed in terms of typical inactivation processes.

https://doi.org/10.33697/ajur.2004.001

There Is Truth And Beauty In Undergraduate Mathematics Research

https://doi.org/10.33697/ajur.2004.002

Author(s):

Dele Oluwade

Affiliation:

Mathematics and Computational Sciences, American Journal of Undergraduate Research, Dewade Science Clinic, Ibadan, Oyo State NIGERIA

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Isolation of Microsatellite Loci in Sceloporus grammicus (Squamata, Phrynosomatidae)

https://doi.org/10.33697/ajur.2004.003

Author(s):

Patrick H. Degnan and Elisabeth Arévalo

Affiliation:

Department of Biology, Providence College, Providence, RI 02918-0001 USA

ABSTRACT:

The mesquite lizard (Sceloporus grammicus) exhibits multiple Robertsonian chromosomal rearrangements (mainly centric fissions) resulting in several cytotypes. In a transitional environment from oak-pine forests to a drier xeric habitat in central Mexico, two cytotypes (F5: 2n = 34 and FM2: 2n = 46) are known to hybridize. A partial genomic library was constructed from S. grammicus genomic DNA and then screened for microsatellites. Microsatellites are short tandem nucleotide repeats that have near universal occurrence in all eukaryotic genomes. Microsatellites exhibit variable length polymorphisms that can be characterized and utilized as genetic markers for population studies. Thirteen microsatellite arrays were isolated from the S. grammicus genomic library and PCR primers were designed in the flanking regions for the amplification of these alleles. These microsatellite loci would be the primary tool used to answer behavioral, ecological, chromosomal and evolutionary questions that influence the maintenance of this hybrid zone.

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Understanding Layer Promotion and Its Relationship to Melting in Krypton on Graphite Using Artificial Constraints

https://doi.org/10.33697/ajur.2004.004

Author(s):

E.J. Chamberlin and M.W. Roth

Affiliation:

Physics Department, University of Northern Iowa, Cedar Falls, Iowa 50614-0150 USA

ABSTRACT:

Constant particle number, density and temperature (N, ρ, T) Molecular-Dynamics simulations are used to study second layer promotion and melting in a complete monolayer of krypton deposited onto a graphite substrate. In order to study the vertical behavior of the system and its relationship to melting, artificial horizontal constraints are introduced and their effects are systematically monitored. We find that horizontally confining each atom within an impenetrable cylinder increases the melting temperature Tm and causes melting to be less dramatic. The results also suggest that there is a limiting case of there being no transition for a sufficiently small confining cylinder. Vertical excursions of the adsorbate atoms increase at the onset of melting. The system subsequently goes through a vertical transition with increasing temperature, including second layer promotion followed by extinction of the partial second layer and the presence of a sparsely populated first layer and a large population of desorbed atoms. Horizontal confinement stifles true second layer promotion, causing the atoms to spend less time in the second layer at a given temperature and resulting in a thermal blurring of the adlayer, suggesting that in-plane fluctuations are a necessary part of the layer promotion mechanism. Horizontal confinement also raises the temperature where the vertical transition occurs but does not affect its sharpness or temperature extent.

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Isoflavone Content of Kansas Soybeans

https://doi.org/10.33697/ajur.2004.005

Author(s):

M. Swanson, M. Stoll, W. Schapaugh, and L. Takemoto

Affiliation:

Division of Biology and Department of Agronomy, Kansas State University, Manhattan, Kansas 66506 USA

ABSTRACT:

Isoflavones occurring in soybean seed have been thought to have a positive effect on the health of humans, especially in cancer prevention. This positive impact may be a result of their antioxidant properties, estrogenic activity, or a combination of mechanisms. The purpose of this study was to quantify and compare different levels of isoflavones in various Kansas soybean cultivars. Seeds of four different cultivars grown in 2001 at three different locations were analyzed. There were significant differences in total and individual amounts of isoflavones across both cultivars and locations. These results demonstrated a large variation in isoflavone content in different cultivars grown in different locations, suggesting that selection of cultivar and growing location are important parameters in optimizing the isoflavone content of soybeans grown in Kansas.