https://doi.org/10.33697/ajur.2012.006

After 10 Years: Back to Undergraduate Research Advisors

https://doi.org/10.33697/ajur.2012.007

Author(s):

C. C. Chancey

Affiliation:

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

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The Effects of Hypergravity on Xenopus Embryo Growth and Cardiac Hypertrophy

https://doi.org/10.33697/ajur.2012.008

Author(s):

Bryce Joseph Duchman and Darrell Wiens

Affiliation:

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

ABSTRACT:

All life on earth has developed and evolved in a unity gravity (1G) environment. Any deviation below or above 1G could affect animal development, a period when much change occurs and sensitivity is high. We imposed simulated hypergravity through centrifugation and analyzed the effects on the overall body length and cardiac growth of Xenopus laevis embryos. We predicted that increased contractile force would be required from the heart to adequately circulate blood, dispersing nutrients, and that this would inhibit organism growth and possibly induce a state of hypertrophy. Embryos reaching gastrulation stage were exposed to a 7G or 1G (control) field via centrifugation for 96 hours. We then recorded behavior, mortality and took body length measurements. We found no significant differences in behavior or mortality, however, body length was significantly reduced by an average of 6.8% in the 7G group. We then fixed, embedded, sectioned and stained embryos in order to investigate the dimensions of cardiac tissue and of the cardiac region of the body using image analysis software. We found the 7G group had a significantly reduced average body cross-sectional area (-18%) and yet a significantly larger ventricular cross-sectional area (+36%) when compared to the 1G group. The average ratio of ventricle cross-sectional area to average body cross-sectional area was significantly higher in the 7G group when compared to the 1G. From these data, we conclude that hypergravity has a significant inhibitory impact on the Xenopus laevis embryo growth and causes a significant increase in ventricle size.

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Observing Program Calculator for Eclipsing Binary Star Systems

Appendix: ephemeris calculator

https://doi.org/10.33697/ajur.2012.009

Author(s):

Colby Neal and Michael Braunstein

Affiliation:

Central Washington University, Department of Physics, Ellensburg, Washington 98926 USA

ABSTRACT:

A Microsoft Excel application has been developed to utilize eclipsing binary elements to calculate binary ephemerides that are useful in a program of observing binary systems. Binary star systems consist of two stars orbiting a common center of mass. Consistent monitoring of eclipsing binary stars is important for establishing fundamental astronomical parameters, such as mass and composition of the stellar system. The application that was developed supports effective use of resources in such monitoring applications. The main quantities computed by the application at the time of the eclipse include: local time, Julian date, starting Epoch, altitude of the system, phase of the moon, Local Mean Sidereal Time, and Local Hour Angle. Other quantities computed by the application include current Universal Time (UT), UT/Local Time correction, Julian Date, and current moon phase/percent illuminated. The observing application has been demonstrated to be effective in practical application to obtain differential photometry data for SV Camelopardalis, a system of interest because of variability in its period caused by a third body. The application can be easily modified for use with other highly periodic astronomical systems, for instance transits of extrasolar planets.

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Isospectral Domains in Euclidean 3-Space

https://doi.org/10.33697/ajur.2012.010

Author(s):

Christopher Cox

Affiliation:

Department of Mathematics, Iowa State University, Ames, Iowa 50011 USA

ABSTRACT:

The question as to whether the shape of a drum can be heard has existed for around fifty years. The simple answer is ‘no’ as shown through the construction of isospectral domains. Isospectral domains are non-isometric domains that display the same spectra of frequencies of sound. These frequencies, deduced from the eigenvalues of the Laplacian, are determined by solving the wave equation in a domain omega , where alpha-omega is subject to Dirichlet boundary conditions. This paper presents methods to expand the already existing two dimensional transplantation proof into Euclidean 3-space and, through these means, provides a number of three dimensional isospectral domains.

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Memory Accuracy for Emotional and Neutral Narratives: Investigating the Influence of Suggestive Misinformation on the Frequency of False Memories

https://doi.org/10.33697/ajur.2012.011

Author(s):

Laura E. Paige and Elizabeth A. Kensinger

Affiliation:

Psychology Department, Boston College, Chestnut Hill, Massachusetts 02467 USA

ABSTRACT:

Memory is a reconstructive process, impressionable and not always vigilant in detecting devices working against its accuracy. False memory occurs when memory for an event is infiltrated by new information or alterations are made to the information that was previously stored. The present study investigated the effect of emotional valence on false memory occurrence through the misinformation effect – memory errors that arise as a consequence of exposure to misleading information – by presenting participants with narratives in one of three valence conditions (negative, positive, neutral) and subjecting them to suggestive questions providing credulous misinformation following a one-hour delay. Results revealed that when collapsing across negative and positive conditions, overall false memory occurrences were significantly reduced for these narratives compared to the neutral condition. Some of the effects of emotion on memory accuracy were more pronounced for negative information than for positive or neutral information; response rates in the negative condition, as compared to the two other valence conditions, revealed an increase in hits and a decrease in false alarms suggesting negative valence enhances discriminability.

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Diffusion of Water and Diatomic Oxygen in Poly(3-hexylthiophene) Melt: A Molecular Dynamics Simulation Study

https://doi.org/10.33697/ajur.2012.012

Author(s):

Julia Deitz, Yeneneh Yimer, and Mesfin Tsige

Affiliation:

Department of Polymer Science, University of Akron, 302 Buchtel Common, Akron, Ohio 44325 USA

ABSTRACT:

Diffusion behavior of water, diatomic oxygen, and a mixture of both into a poly(3-hexylthiophene)[P3HT] melt were investigated using Molecular Dynamics Simulation. Once simulations were complete, the data was analyzed to determine the diffusion coefficient of those molecules in P3HT using Fick’s law. The diffusion coefficient values were then plotted as a function of concentration and temperature to determine if trends existed. For both water and oxygen, no dependence was observed of the diffusion coefficient on concentration and temperature for the ranges studied. However, a variation in the diffusion coefficient on concentration was observed due to the expected inhomogeneity of the P3HT melt. In the presence of O2, the diffusion of H2O decreased significantly by a factor between four and five, while in the presence of H2O, the diffusion of O2 slightly decreased.

https://doi.org/10.33697/ajur.2012.001

After 10 Years: Back to Where We Began

https://doi.org/10.33697/ajur.2012.002

Author(s):

C. C. Chancey

Affiliation:

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

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A New Vectorization Technique for Expression Templates in C++

https://doi.org/10.33697/ajur.2012.003

Authors and Affiliations:

J. Progsch and Y. Ineichen
Department of Computational Science, ETH-Zürich, CAB H 83.2, Universitätstrasse 6, 8092 Zürich SWITZERLAND

A. Adelmann
Paul Scherrer Institute, 5232 Villigen PSI, SWITZERLAND

ABSTRACT:

Vector operations play an important role in high performance computing and are typically provided by highly optimized libraries that implement the Basic Linear Algebra Subprograms (BLAS) interface. In C++ templates and operator overloading allow the implementation of these vector operations as expression templates which construct custom loops at compile time and providing a more abstract interface. Unfortunately existing expression template libraries lack the performance of fast BLAS implementations. This paper presents a new approach – Statically Accelerated Loop Templates (SALT) – to close this performance gap by combining expression templates with an aggressive loop unrolling technique. Benchmarks were conducted using the Intel C++ compiler and GNU Compiler Collection to assess the performance of our library relative to Intel’s Math Kernel Library as well as the Eigen template library. The results show that the approach is able to provide optimization comparable to the fastest available BLAS implementations, while retaining the convenience and flexibility of a template library.

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Determining the Efficacy of IonatorEXP™ Activated Tap Water on Growth of Staphyloccocus aures and Escherichia coli.

https://doi.org/10.33697/ajur.2012.004

Author(s):

Sara Schiedler, Rachelle Peterson, and Sasha Showsh (Department of Biology)

Thao Yang (Department of Chemistry)

Affiliation:

University of Wisconsin, PO Box 4004, Eau Claire, Wisconsin 54702 USA

ABSTRACT:

The efficacy in growth inhibition of Staphylococcus aureus and Escherichia coli of the IonatorEXP™ activated tap water was compared to plain tap water, Quatsyl™, and Butchers Neutral Disinfectant™. Treatment with Quatsyl™ or Butchers Morning Mist™ Neutral Disinfectant resulted in complete inhibition of growth for both S. aureus and E.coli. Treatments with IonatorEXP™ activated tap water, performed as directed by the manufacturer, or plain tap water, resulted in no observable inhibition of growth for either of the bacterial strains tested. This observation is not unexpected given that analysis of pH, conductivity and H2O2 on IonatorEXP™ activated tap water were statistically the same values as those determined for plain tap water that was not activated by the IonatorEXP™.

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A Multi-Objective, Linked-Simulation-Optimization of Henry’s Saltwater Intrusion Problem using HST3D and Box’s Method

https://doi.org/10.33697/ajur.2012.005

Author(s):

Emily Curtis and Robert Willis

Affiliation:

Department of Environmental Resources Engineering, Humboldt State University, Arcata, California 95521 USA

ABSTRACT:

A multi-objective linked simulation and optimization (LSO) model for a three dimensional saltwater intrusion problem has been developed. The LSO employs HST3D and Box’s algorithm. The weighting method of multi-objective optimization solves the multi-objective planning problem. The model is capable of determining the optimal pumping rates that minimize the saline concentration at the well sites, as well as, the cost associated with pumping, while satisfying an exogenous water demand. The model is valid for a wide range of applications as explicitly defined by the simulation model. The application of the model was limited to a modified version of Henry’s saltwater intrusion problem. Henry’s problem was modified to include a third spatial dimension and well sites. The multi-objective optimization yielded explicit tradeoff information between the two objectives.

https://doi.org/10.33697/ajur.2011.016

Editorial: The Lessons of Pittsburgh

https://doi.org/10.33697/ajur.2011.017

Author(s):

C. C. Chancey

Affiliation:

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

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The ERC Mechanism and the Formation of Abnormal Product in the Stevens Rearrangement

https://doi.org/10.33697/ajur.2011.018

Author(s):

Soumendranath Bhakat

Affiliation:

Nutanpalli, P.O. Suri, Dist. Birbhum, West Bengal, Pin: 731101 INDIA

ABSTRACT:

To explain the new abnormal product of the Stevens Rearrangement which is not explainable by different existing mechanisms like “radical pair mechanism”; “ionic pair mechanism”, I proposed a new mechanism scheme entitled the ERC (Elimination Recombination Coupling) mechanism and a new abnormal product of the Stevens Rearrangement. This mechanism also maintains parity between the “radical pair mechanism” and the “ionic pair mechanism.

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Physiological Versus Perceived Foot Temperature, and Perceived Comfort, during Treadmill Running in Shoes and Socks of Various Constructions

https://doi.org/10.33697/ajur.2011.019

Author(s):

Rachel M. Barkley, Mike R. Bumgarner, and Erin M. Poss (Biochemistry, Cell and Molecular Biology Program)

David S. Senchina (Biology Department)

Affiliation:

Drake University, Des Moines, Iowa 50311 USA

ABSTRACT:

The purpose of this investigation was to determine whether people could accurately perceive physiological foot temperature during brief bouts of treadmill running in different combinations of shoe and sock models, and also how perception of comfort was influenced. Sixteen young adult males (21.3  0.8 years, 181.8  1 cm, 74.6  1.5 kg) participated in two separate studies where they alternated running and resting for 10 min each with temperature probes attached at two sites on the lateral dorsal aspect of the right foot. Subjects reported perceptions of foot comfort and temperature after each run using 10 cm visual analogue scales. In the first experiment, different sock models were tested with the same shoe model; in the second experiment, different shoe models were tested with the same sock model. Foot temperature did not differ statistically as a function of shoe or sock model in either experiment. Subjects did not perceive any difference in foot temperature in the shoe experiment, but perceived their foot as being cooler when wearing either a polyester sock or a calf compression sleeve and more comfortable when wearing shoes with less mass. Taken together, the results suggest that subjects’ perceptions of foot temperature may not coincide with physiological foot temperature and are more strongly influenced by sock characteristics than shoe characteristics. Further, shoe mass (but not sock fiber weave or composition) may impact comfort perception by subjects.

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Determination of Cadmium and Lead in Northern Pike from the Missouri River

https://doi.org/10.33697/ajur.2011.020

Author(s):

Jennifer Even and Shahrokh Ghaffari

Affiliation:

Ohio University-Zanesville, Zanesville, Ohio 43701 USA

ABSTRACT:

Lead and cadmium are trace metals which accumulate in the body and are extremely toxic in living organisms. The purpose of this study was to find organ(s) with the greatest concentrations of these elements. In this study liver, gill, intestines, and kidney of five samples of Northern Pikes were analyzed. After the organs were dried and digested using nitric acid the anodic stripping voltammetry method was employed to analyze this samples. This method was used for its low detection limit of 10-9 to 10-10 M. However, no trace of either lead or cadmium was found in all 60 samples analyzed. Lack of detectable amount of both lead and cadmium is attribute to; first, Northern Pikes are not bottom dweller and thus would not be highly exposed to sediments that most commonly contain trace metals, second, the absence of a major industry which typically produces these contaminates in this area.

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Conic Sections in the Double-Slit Experiment

https://doi.org/10.33697/ajur.2011.021

Author(s):

Joe Hughes and Frederic Liebrand

Affiliation:

Walla Walla University, 204 S. College Avenue, College Place, Washington 99324 USA

ABSTRACT:

The use of conic sections in obtaining the locations of double-slit maxima is absent in many undergraduate treatments [1-3]. However, their inclusion is not conceptually difficult and increases the understanding not only of interference phenomena, but also of the underlying geometry. This paper illustrates how elliptic and hyperbolic conic sections arise naturally in a conceptual analysis of the double slit.

https://doi.org/10.33697/ajur.2011.011

Editorial: A Lack of Sustained Focus on STEM Education in the US

https://doi.org/10.33697/ajur.2011.012

Author(s):

C. C. Chancey

Affiliation:

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

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Algorithms for Collective Construction of 2D Block Structures with Holes

https://doi.org/10.33697/ajur.2011.013

Author(s):

Zachary Fitzsimmons and Robin Flatland

Affiliation:

Department of Computer Science, Siena College, Loudonville, New York 12211 USA

ABSTRACT:

In this paper we present algorithms for collective construction systems in which a large number of autonomous mobile robots transport modular building elements to construct a desired structure. We focus on building block structures subject to some physical constraints that restrict the order in which the blocks may be attached to the structure. Specifically, we determine a partial ordering on the blocks such that if they are attached in accordance with this ordering, then (i) the structure is a single, connected piece at all intermediate stages of construction, and (ii) no block is attached between two other previously attached blocks, since such a space is too narrow for a robot to maneuver a block into it. Previous work has consider this problem for building 2D structures without holes. Here we consider 2D structures with holes. We model the problem as a graph orientation problem and describe an O(n2) algorithm for solving it. We also describe how this partial ordering may be used in a distributed fashion by the robots to coordinate their actions during the building process.

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A deterministic model for (n = 2) competitive products in a market system

https://doi.org/10.33697/ajur.2011.014

Author(s):

M. C. Kekana and O. D. Makinde

Affiliation:

Tshwane University of Technology, Private Bag X680, Pretoria 0001, Staatsartillerie Road, Pretoria West, Republic of South Africa

ABSTRACT:

We proposed a new deterministic model for the dynamics of two competitive products in a given market system. The model was analyzed qualitatively to determine the stability of its equilibrium under the influence of factors such as advertisement, personal interaction, immigration and emigration. Numerical verification of the analytical results is performed and presented graphically.

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Using Web 2.0 Data to Estimate Alcohol-Related Travel

https://doi.org/10.33697/ajur.2011.015

Author(s):

William Conroy and Duncan Smith

Affiliation:

Department of Geography, University of Washington, Box 353550, Smith Hall 408, Seattle, Washington 98195 USA

ABSTRACT:

Using ArcGIS, the locations of pubs, clubs, and bars were geocoded onto the street network of Seattle. Upon calculating the density of these drinking establishments throughout the city, the six densest areas, representing nightlife districts, were converted to polygons. Using publicly available check-in data from Gowalla, user check in data within these six polygons was obtained. After cross referencing the Gowalla users’ legal names with the Washington State Voter Registration Database, straight line distances between their legal addresses and bars patronized were calculated. As a result, distance traveled profiles were calculated for each nightlife district.

https://doi.org/10.33697/ajur.2011.006

Editorial: “The World Festival of Science — Could this go viral?”

https://doi.org/10.33697/ajur.2011.007

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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Sizing Up Outer Billiard Tables

https://doi.org/10.33697/ajur.2011.008

Authors and Affiliations:

Filiz Doǧru
Department of Mathematics, Grand Valley State University, 1 Campus Drive. Allendale, Michigan 49401 USA

Samuel Otten
Division of Science & Mathematics Education, Michigan State University, 116 North Kedzie Hall, East Lansing, Michigan 48824 USA

ABSTRACT:

The outer billiard dynamical system models the motion of a particle around a compact domain, such as a planet orbiting a star. When considering outer billiards in hyperbolic space, an interesting problem is to determine precisely the conditions in which an orbiting particle breaks orbit and escapes to infinity. Past work has classified triangular and Penrose kite billiard tables according to whether or not their orbiting particles escape. This article presents a classification of regular polygonal tables.

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Using Ohm’s Law to Calibrate a Picoammeter to 0.4 Pico-ampere Precision

https://doi.org/10.33697/ajur.2011.009

Author(s):

Joseph Hashem, Tiankuan Liu, Zhihua Liang, and Jingbo Ye

Affiliation:

Department of Physics, Southern Methodist University, Dallas, Texas 75275 USA

ABSTRACT:

We present an experimental method based on Ohm’s Law to calibrate the Keithley 6485 picoammeter with the calibration error less than 0.4 pico-ampere (pA), which is specified as the highest sensitivity of this instrument. The maximum calibration difference between the measurement current and the calibration current in the picoammeter’s 2 nano-ampere (nA) range is 0.25 pA. This difference is far less than the highest accuracy, 0.4 pA, specified by the instrument. Measurement errors are estimated and discussed.

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Designing and Constructing a Controlled-Flow Apparatus to Study the Effect of Surface Flow Velocity on the Quality of Electropolishing of Niobium

https://doi.org/10.33697/ajur.2011.010

Authors and Affiliations:

Tina Wang
Chemical and Biological Engineering Department, Princeton University, Princeton, New Jersey 08544 USA

Michael J. Kelley
Applied Science, Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 USA

ABSTRACT:

The focus of this project was to design and construct a model controlled-flow apparatus to study electropolishing of one cm2 niobium coupons at surface flow rates typical of cavity processing. A simulation of the apparatus was constructed using CFDesign, a flow and thermal simulation software, to ensure that the selected dimensions may be expected to provide steady-state, laminar flow across the surface of the niobium coupon. Based on these dimensions, a sample system and apparatus was produced to determine the correct reservoir elevation heights for the desired flow rates for fluid viscosities represented in the mixed acid electrolyte. From the CFDesign simulations, it was found that the flow channel supplied laminar flow rates when the center of the niobium coupon was located 40 mm downstream from the inlet stream. The corresponding system, based on the CFDesign simulations, showed that the reservoir elevation heights for flow rates of 0 cm/s to 5 cm/s ranged from 0 to 1.27 cm. The correlation between pressure heads and flow rates has been analyzed and an equation for flow rate was determined using experimental results. The detailed dimensions regarding the flow channel and information regarding the respective pressure heads serve as resources to finding the optimal flow rate for electropolishing the niobium cavities. Although previous research has found a correlation between the quality of electropolishing and internal surface flow rates, research facilities, including Jefferson Lab, did not have the equipment to pursue further analysis. Each nine-cell niobium cavity costs over $50,000, so it is cost prohibitive to use real cavities to conduct early stage research. The prototype built through this research work provides a cost effective alternative. It can be used to validate some of the theoretical results obtained through simulation. In addition, the device allows for easy variable measurements that are either difficult or impractical with an enclosed niobium cavity, as sensors can be embedded into the device in the construction stage. Moreover, the data collected through our experiment furthers superconducting radiofrequency (SRF) technology by allowing Jefferson Lab to design a more effective electropolishing process. 

https://doi.org/10.33697/ajur.2011.001

Editorial: “The Most Terrifying Problem in American University Education…”

https://doi.org/10.33697/ajur.2011.002

Author(s):

C. C. Chancey

Affiliation:

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

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Investigation of the Effect of Concentration on Molecular Aggregation of Cyanine Dyes in Aqueous Solution

https://doi.org/10.33697/ajur.2011.003

Author(s):

John Kunzler, Leen Samha, Renwu Zhang, and Hussein Samha

Affiliation:

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

ABSTRACT:

The aggregation of the cyanine dye, 3,3’-disulfobutyl-5,5’-dichloro thiacarbocyanine triethylamine, (NK-3796) in aqueous solution was investigated using absorption and emission spectroscopy. The equilibrium, n(monomer) ⇆ n(dimer) ⇆ (H-aggregate)n , was observed over a series of dye concentrations ranging from 10-4 mM to 0.1mM. At concentrations <10-3 mM, the dye exists in solution mostly in the monomeric form. However, dimers become more significant when the concentration of the dye exceeds 10-2 mM. Unlike the substituted dye in the 9th position, the NK-3796 dye tends to form H-aggregates at higher concentration (>10-1 mM). Monomers and dimers exhibit strong emission in the visible region. Also notable, is that the emission from the H-aggregates was very weak due to self quenching.

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An Interruption in the Highway: New Approach to Modeling Car Traffic

https://doi.org/10.33697/ajur.2011.004

Author(s):

Amin Rezaeezadeh

Affiliation:

Physics Department, Sharif University of Technology, Tehran, Iran

ABSTRACT:

A very common phenomenon in car traffic is investigated in this article. The problem is one-dimensional. We find the wave equation of the traffic, and illustrate a simulation using Matlab 7.6

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Design Optimization for DNA Nanostructures

https://doi.org/10.33697/ajur.2011.005

Author(s):

Jacob Girard, Andrew Gilbert, Daniel Lewis, and Mary Spuches

Affiliation:

Department of Mathematics, Saint Michael’s College, One Winooski Park, Colchester, Vermont 05439 USA

ABSTRACT:

This paper is concerned with minimizing the cost of self-assembling DNA nanostructures by minimizing the number of different components used in the construction. We first describe the nanostructures, then give a combinatorial formalization of the assembly process and demonstrate that the octet truss provides an accurate geometric framework for current branched junction molecule assembly. We choose the octet truss because it is highly symmetric and has an appropriate number of edges for the application. We develop a method of differentiating among branched junction molecules, the basic building blocks of the nanostructures, within this structure. In the mathematical model, we represent the branched junction molecules graphically with „tiles‟. We use this approach to find the minimum number of tiles necessary to construct Platonic and Archimedean solids naturally occurring within the octet truss. This will be useful and cost efficient for the chemists and biologists who actually build these branched junction molecules because once a branched junction molecule is created, a lab can make many copies of it.

https://doi.org/10.33697/ajur.2010.011

Editorial: Science makes the pie bigger

https://doi.org/10.33697/ajur.2010.012

Author(s):

C. C. Chancey

Affiliation:

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

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Forensic Identification of Salvia divinorum and Salvinorin A

https://doi.org/10.33697/ajur.2010.013

Author(s):

Dana Nontell and Douglas Armstrong

Affiliation:

Department of Physical Sciences, Olivet Nazarene University, Bourbonnais, IL 6091

ABSTRACT:

Salvia divinorum is a member of the mint family that is growing in popularity in the United States and many other countries as a hallucinogenic drug. Because of this, numerous studies have been conducted in identifying the plant material. Some of the most common methods include UV/Vis, TLC, and GC/MS. This article discusses these methods, as well as two other common identification methods proven to be ineffective towards salvia. An extraction method is also discussed.

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Odor and the Effects of Schema Activation on Recognition Memory

https://doi.org/10.33697/ajur.2010.014

Authors and Affiliations:

Kelly Appino, Claire Svec, Brandon Tankard, Amy A. Overman
Department of Psychology, Elon University, Elon, North Carolina 27244, USA

Joseph D. W. Stephens
Department of Psychology, North Carolina A & T State University, Greensboro, North Carolina 27411 USA

ABSTRACT:

This study investigated whether schema-consistent odors affect recognition memory. Forty-two undergraduate students read a story about baking in the presence of an odor that was either baking-related (schema-consistent) or not (schema-inconsistent). Further, the story contained information that was both inconsistent, and consistent, with baking. Participants were then tested on recognition of information from the story. It was predicted that participants who smelled the schema-consistent odor would be more likely to falsely recognize new (i.e., not in the story) schema-consistent information than those who smelled the schema-inconsistent odor. The results indicated that all participants were more likely to falsely recognize new schema-consistent information than schema-inconsistent information. However, odor had no statistically significant effects on recognition.

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Longitudinal Light Clock and Zeno’s Paradox

https://doi.org/10.33697/ajur.2010.015

Author(s):

Joshua Fixelle and K. Austin Johnson

Affiliation:

Department of Physics, The Pennsylvania State University, Abington, 1600 Woodland Road, Abington, Pennsylvania 19001, USA

ABSTRACT:

Introductory college text books consider time dilation through the derivation of the transverse light clock. We consider the case of the longitudinal light clock and derive the time dilation formula of special relativity. Our methods yield the same result as derived by the transverse light clock, and help explain the concept of failure of simultaneity.

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Metal Ion Concentration within Algal Tissue of Species Growing in Proximity to Tioga River Outflows Affected by Acid Mine Drainage in Northern Pennsylvania

https://doi.org/10.33697/ajur.2010.016

Author(s):

Cheyenne McKibbin, Kyle Root, and Gregory Carson

Affiliation:

Department of Chemistry and Physics, Mansfield University, Mansfield, Pennsylvania 16933 USA

ABSTRACT:

In this study, two species of algae from two different areas impacted by acid mine drainage (AMD) were analyzed for metal ion accumulation. The two species of algae collected were Klebsormidium and Entransia. Both algal species are located in an area of high metal ion concentrations and low pH (ranging from 2.28 to 2.89). The study assessed the concentration of iron, manganese, zinc, copper and nickel in the algal tissue. Data shows that both Entransia and Klebsormidium are absorbing or adsorbing iron selectively.

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The E3 Ubiquitin Ligase NARF Promotes Colony Formation in vitro and Exhibits Enhanced Expression Levels in Glioblastoma Multiforme in vivo

https://doi.org/10.33697/ajur.2010.017

Author(s):

Tucker W. Anderson, Christopher Wright, and William S. Brooks

Affiliation:

Department of Biology, Freed-Hardeman University, Henderson, Tennessee

ABSTRACT:

The ubiquitin ligase NARF is a newly identified protein belonging to a small family of structurally similar E3 proteins. NARF is a negative regulator of the canonical Wnt-β-catenin pathway, targeting TCF/LEF family members for proteolytic degradation through poly-ubiquitination. We examined the role that NARF plays in cell division and found that overexpression of NARF in a colony forming assay increases colony formation in a RING finger-dependent manner. Furthermore, we demonstrate that NARF transcripts are expressed at a higher level in the grade IV brain tumor glioblastoma multiforme as compared with low grade astrocytomas. Our data thus indicate that NARF is a positive regulator of cell growth and may be involved in the tumorigenic process.

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The Development of a Three-Dimensional Material Point Method Computer Simulation Algorithm for Bullet Impact Studies

https://doi.org/10.33697/ajur.2010.018

Author(s):

M.J. Connolly, E. Maldonado and M.W. Roth

Affiliation:

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

ABSTRACT:

The two-dimensional Material Point Method (MPM) algorithm outlined by Chen and Brannon has been extended to three dimensions. The development of the code is discussed as well as applications for simulating bullet impact on biological and non-biological systems.

https://doi.org/10.33697/ajur.2010.006

Editorial: Complexity in Our Everyday World

https://doi.org/10.33697/ajur.2010.007

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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A Lesson Learned from Outer Billiard Derivatives

https://doi.org/10.33697/ajur.2010.008

Author(s):

Samuel Otten and Filiz Doğru

Affiliation:

Department of Mathematics Grand Valley State University, 1 Campus Drive Allendale, Michigan 49401-6495, USA

ABSTRACT:

As students move onward and upward through collegiate mathematics they are often impressed by the power of advanced techniques (aren’t they?), techniques allowing problems that were previously difficult or near-impossible to be solved with relative ease. For example, once students have learned the residue theorem in complex analysis they are able to elegantly evaluate integrals that were unwieldy in calculus. Among practicing mathematicians there is also a tendency to look to new or powerful results when trying to unlock a problem within one’s own research. This article presents a new theorem concerning derivatives within the outer billiard dynamical system, and in so doing serves as a reminder that higher-powered mathematics are not always needed and do not necessarily produce more satisfying proofs. Sometimes it is beneficial to keep elementary approaches in mind.

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The Applicability of the River Continuum Concept to the Upper Reaches of a Neotropical Lower Montane Stream

https://doi.org/10.33697/ajur.2010.009

Author(s):

Nicholas Skaff

Affiliation:

Department of Biology, Tufts University, Medford, Massachusetts 02155 USA

ABSTRACT:

The applicability of the River Continuum Concept (RCC) to the upper reaches of Quebrada Máquina, a lower montane stream in Monteverde, Costa Rica, was examined. Macroinvertebrate samples were taken from ten points along the stream from first through fourth order segments. The families of the collected individuals were then categorized based on functional feeding group. The similarity between the families found at each collection point was calculated, along with correlations between the functional groups and various stream characteristics. In most cases, RCC predictions did not apply to Quebrada Máquina. The first (first order) and last (fourth order) sample points were 92% similar despite RCC predictions of substantial divergence in relative functional group abundance. This digression from the RCC predictions may be caused by the relatively few differences in stream characteristics between first and fourth order sections. Specifically, the observed similarities and correlations may have been determined by local scale heterogeneity of the stream characteristics.

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On the Number of Rational Iterated Pre-Images of -1 under Quadratic Dynamical Systems

https://doi.org/10.33697/ajur.2010.010

Author(s):

Trevor Hyde

Affiliation:

Department of Mathematics, Amherst College, Amherst, Massachusetts 01002 USA

ABSTRACT:

For the class of functions fc(x)=x^2+c, we prove a conditional bound on the number of rational solutions to fc^N(x) =−1 and make computational conjectures for a bound on the number of rational solutions to  fc^N(x)=a fora in a specific subset of the rationals.

https://doi.org/10.33697/ajur.2010.001

Editorial: The Continuing Surprise: Recent Scientific Advances

https://doi.org/10.33697/ajur.2010.002

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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Traits for predator selection on Pentaclethra macroloba seeds

https://doi.org/10.33697/ajur.2010.003

Author(s):

Gabriela Anhalzer, Michelle Fournier, Tim O’Connor, Louise Stevenson, and Mariel Yglesias

Affiliation:

La Selva Biological Station, Organization for Tropical Studies, Horquetas, Costa Rica

ABSTRACT:

Pentaclethra macroloba (Fabaceae: Mimosoidea) is a dominant species of canopy tree in Costa Rica’s Caribbean lowlands, constituting up to 40% of the local tree population in some areas. It has been suggested that P. macroloba’s dominance is due in part to low post-dispersal seed depredation, as few terrestrial seed predators can tolerate the high concentration of toxic alkaloids and free amino acids. Seeds are not immune from depredation, however. Several species of parrots and squirrels have been observed depredating pre-dehiscent legumes and may present selective pressure on P. macroloba recruitment. In this study, we assessed depredation patterns in P. macroloba to (1) determine if predators use legume and seed traits to select food items, (2) determine if such patterns represent an optimal foraging strategy for vertebrate predators, and (3) explore potential consequences of depredation on P. macroloba. Seed depredation was not correlated with legume valve side, legume size, seed number, or seed compartment size, though seeds at the distal end of legumes were more often extracted. Depredation patterns do not indicate that seed predators are foraging optimally and may be quickly satiated due to their low toxicity tolerance the abundance of seeds. Despite a lack of predator selection of various legume and seed characteristics, legume damage caused by depredation may interfere with the explosive dehiscence of P. macroloba and constitute a significant recruitment barrier.

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KBO Astrometry Using Small Telescopes

https://doi.org/10.33697/ajur.2010.004

Author(s):

Rachel Bowens-Rubin, Katheryn Decker French, Dora Gao, and Christina A Jaworsky

Affiliation:

Department of Earth, Atmospheric, and Planetary Science, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139 USA

ABSTRACT:

CCD images of Makemake (2005 FY9), the second largest Kuiper Belt Object (KBO), were taken with a 14-inch telescope during the summer of 2008. The position of Makemake was found by comparing its position on the frames to UCAC2 stars in the frame. Observations were limited by the tracking capabilities of the telescopes and atmospheric limitations. The average right ascension offset from the ephemeris was found to be 0.0134 0.3394 arcseconds, and the average declination offset was found to be -0.3855 0.4634 arcseconds. It is possible to do KBO astrometry with small telescopes, however several hundred frames are required to equal the quality of observations on larger telescopes.

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Music-elicited EEG Activity and Emotional Responses are Altered in Schizophrenia

https://doi.org/10.33697/ajur.2010.005

Author(s):

Rondell Burge and Aimee Siebert

Affiliation:

Bethel College, 300 East 27th Street, North Newton, KS 67117 USA

ABSTRACT:

Studies of patients with schizophrenia using facial affect recognition and voice discrimination tasks have identified emotional dysfunction as a prominent clinical feature. In the present study we examine whether emotion processing in patients is also impaired in a less explicitly social context — continuous self-report of emotions during music using a two-dimensional (pleasantness X activation) emotion space. Electroencephalographic (EEG) activity was also recorded during this task since previous studies using EEG measures have found underlying cortical processes related to emotion. Twelve patients with schizophrenia and eleven controls listened to five 25-second songs. These songs included J.S. Bach‟s Invention #13 in A minor (BWV 784) (designated the original piece), and four computer-generated pieces of which two were designed to be similar to the original, and two were designed to be different. While no significant effects were found in the activation dimension of the self-report measures, the pattern of pleasantness ratings was significantly less differentiated among songs in the patient group than in controls. EEG asymmetry indices at frontal and central electrodes provided evidence of greater hemispheric activation asymmetry (with higher activation on the left) in controls than in patients, a difference that was significant at the central electrodes (C3 and C4). These findings indicate that individuals with schizophrenia interpret emotion-eliciting music differently than do controls, even in a relatively non-social setting, possibly because of less differentiated hemispheric representations.

https://doi.org/10.33697/ajur.2009.011

Review: Microwave-Promoted Organic Synthesis

https://doi.org/10.33697/ajur.2009.012

Author(s):

Andrew Loftin and Douglas Armstrong

Affiliation:

Department of Physical Sciences, Olivet Nazarene University, Bourbonnais, Illinois 60914 USA

ABSTRACT:

As of the last twenty years a new wave in organic chemistry has started to change the way people think about putting energy into a reaction mixture. Microwave-promoted organic synthesis is a fast, efficient method of heating a system in order to achieve the completion of a desired reaction. There are many different types of reactions that have been attempted using this method, and still many more to be tested. Microwave-promoted organic synthesis can help to produce high yields of products in a short time, while reducing side reactions and making workups easier. This paper discusses the many benefits of microwave-promoted organic synthesis and gives various examples.

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The Free Base Extraction of Harmaline from Penganum harmala

https://doi.org/10.33697/ajur.2009.013

Author(s):

Alyssa Brobst, Jeremy Lewis, Brian Klett, Cathy Haustein, and James Shriver

Affiliation:

Department of Chemistry, Central College, Pella, Iowa 50219 USA

ABSTRACT:

Highly fluorescent and pharmaceutically significant Harmala alkaloids occur in several plants including Syrian Rue (Penganum harmala) and several species of passion flowers. We identified a relatively nontoxic and efficient method for extraction of the major harmala alkaloid components from Syrian Rue seeds using ethyl acetate and sodium bicarbonate. This produced free base harmala alkaloids. Verification was performed qualitatively by using High Performance Liquid Chromatography and NMR analysis.

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An Investigation of the Structure Underlying Irreducible Devisors

https://doi.org/10.33697/ajur.2009.014

Authors and Affiliations:

Hilary Smallwood
Fort Lewis College, 1000 Rim Drive, Durango, Colorado 81301 USA

Drew Swartz
Department of Mathematical Sciences, Indiana University–Purdue University Fort Wayne, 2101 East Coliseum Avenue, Fort Wayne, Indiana 46805 USA

ABSTRACT:

In previous literature Coykendall & Maney, as well as Axtell & Stickles, have discussed the concept of irreducible divisor graphs of elements in domains and ring with zero-divisors respectively, with two different definitions. In this paper we seek to look at the irreducible divisor graphs of ring elements under a hybrid definition of the two previous ones—in hopes that this graph will reveal structure concerning irreducible divisors in rings with zero-divisors. We also compare the three graphs and examine in what respects they are related. Other graph-theoretic properties of this graph will also be discussed.

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Crystallization and Preliminary X-ray Diffraction of a Halophilic Archaeal Malate Synthase

https://doi.org/10.33697/ajur.2009.015

Author(s):

Geoffrey Thomas, Kenneth Lamlenn, and Bruce R. Howard

Affiliation:

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

ABSTRACT:

Malate synthases found in cells of the halophilic Archaea constitute a third isoform of this important metabolic enzyme, in addition to the well characterized A and G isoforms. They share little sequence similarity with these other two isoforms. Database searches using basic local alignments reveal relationships between isoforms A and G, but do not indicate a significant sequence relationship between members of this third isoform and those of isoform G, and only a distant relationship with members of isoform A. This third isoform, which we propose to call isoform H (Halophilic archaeal), is also significantly smaller in size: ~100 residues shorter than isoform A, and ~300 residues shorter than isoform G. Representatives of both isoform A and G have been structurally characterized, but no three-dimensional structural information exists for isoform H. Here we report the crystallization and preliminary X-ray diffraction from a crystal form of an H-isoform member, the malate synthase from the halophilic archaeon Haloferax volcanii, originally isolated from the mud of the Dead Sea. This crystal form diffracts well, and is amenable to single crystal X-ray analysis.

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Gold Nanowires: Their Synthesis and Surface Plasmon Resonances

https://doi.org/10.33697/ajur.2009.016

Author(s):

Ali Faghih and Edo Waks

Affiliation:

Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742 USA

ABSTRACT:

The objective of the project was to fabricate gold nano-rods and study the optical properties of gold nano-particles when coupled to Indium Arsenide quantum dots. The gold nano-rods were synthesized by a seed-mediated growth method using CTAB and BDAC as the surfactants, and the feasibility of changing the aspect ratio of the rods and their Plasmon resonance frequency was studied by varying the concentrations of these two surfactants. Finally, gold nano-rods with longitudinal Plasmon resonance of 940 nm were synthesized. Next, we studied the feasibility of coupling gold nano-wires to indium arsenide quantum dots for investigating their optical properties and studying the spontaneous emission enhancement of InAs QDs in the presence of the plasmon resonances of gold nano-wires. The sample containing nano-wires coupled to quantum dots was excited by red laser, and the emission was passed through a spectrometer and the spectrum was obtained.

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Band Gap Energy in Silicon

https://doi.org/10.33697/ajur.2009.017

Author(s):

Jeremy J. Low, Michael L. Kreider, Drew P. Pulsifer, Andrew S. Jones and Tariq H. Gilani

Affiliation:

Department of Physics, Millersville University, P. O. Box 1002, Millersville, Pennsylvania 17551 USA

ABSTRACT:

The band gap energy, Eg in silicon was found by exploiting the linear relationship between the temperature and voltage for the constant current in the temperature range of 275 K to 333 K. Within the precision of our experiment, the results obtained are in good agreement with the known value energy gap in silicon. The temperature dependence of Eg for silicon has also been studied.