Posters from the annual student research session where DePauw students can demonstrate their collaborative work with faculty or internship experiences.
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Semi-Synthetic Development of Mithramycin Analogues
Sterling Brooks, Allison Foster, and Daniel Scott
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A Parallel Genetic Algorithm For Tuning Neural Networks
Nathan Chadderdon, Ben Harsha, and Steven Bogaerts
One challenge in using artificial neural networks is how to determine appropriate parameters for network structure and learning. Often parameters such as learning rate or number of hidden units are set arbitrarily or with a general "intuition" as to what would be most effective. The goal of this project is to use a genetic algorithm to tune a population of neural networks to determine the best structure and parameters. This paper considers a genetic algorithm to tune the number of hidden units, learning rate, momentum, and number of examples viewed per weight update. Experiments and results are discussed for two domains with distinct properties, demonstrating the importance of careful tuning of network parameters and structure for best performance.
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Majority of Cells Lining the Walls of the 3rd Ventricle in the Adult Rat Brain are not Neural Progenitor Cells
C. Hasken, S. Vermilyea, M. Hendrickson, and R. Kalil
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Measuring Immune Responsiveness in Xenopus laevis Using Phytohaemagglutanin (PHA)
Kevin Kinney, Skyler Majors, Madelyn Lee, Scott Espich, and Erika Kischuk
Phytohaemagglutanin (PHA) is a red kidney bean extract that has been used to stimulate an immunological T cell response in a variety of animals. This procedure has become very popular method to analyze an individual animal’s ability to trigger an immunological response.(Brown 2014) PHA skin testing has been used in a variety of avian, mice, lizard, and amphibian species where it is injected into the muscle, skin, or webbing of an animal and then recording the amount of swelling before and after the injection.(Smits 1999) We are using the amphibian Xenopus laevis to test 1) their immune reaction under normal conditions and 2) to test how stress effects their immune reaction. In our control non-stress experiment to discover if PHA actually causes swelling, we found that significant swelling occurs at all time points in comparison to the saline injected foot. In the stress versus non-stress PHA experiments, we found no significant variation between the stressed versus non-stress, but still a significant difference between PHA versus saline injection.
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Skin Graft Acceptance Rates in Xenopus laevis
Madelyn Lee, Scott Espich, Erika Kischuk, Skyler Majors, and Kevin Kinney
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Probe Location within Interfacial Layer of CTAB Reverse Micelle System
Jonathan Li and Bridget L. Gourley
To understand the chemistry of the interfacial region of reverse micelles (RM), we studied RM system made with the cationic surfactant cetyltrimethylammonium bromide (CTAB), alkanol cosurfactants dissolved in cyclohexane with water core. Spectroscopic methods, specifically UV-Vis absorption of Coumarin 343 (C343) as a probe molecule, were used to determine basic properties of RM systems. However, the probe location was difficult to determine because the spectrum (absorbance), when dissolved in RM solution, didn’t match the spectra in any of the pure components. Our data suggests that the interfacial layer of RM cannot be thought of behaving only the characteristic of single one of the components; rather, it behaves as a mixture of multiple components with unique characteristics. The interfacial layer appears to have roughly three distinct regions. By combining two components at a time, our data shows that C343 is most likely to reside in the middle or outer interfacial regions, which is surprising because C343 is polar enough that it would be expect to preferentially migrate into the water core
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Anticancer Drug Delivery via Unique Properties of Gold Nanoparticles
Sam Lohmar, Jeffrey Schulte, and Daniel Scott
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Dynamical Behavior of Probe Molecules and Dominant Role of Cosurfactants in Reverse Micelles
Jia QI and Bridget L. Gourley
Reverse micelles (RM) are nanopools of water surrounded by surfactant molecules in a non-polar solvent. Our studies investigated properties of RM probe molecules in the interfacial boundary between water and non-polar solvents. Reichardt’s dye, a probe molecule, was used to uncover properties of RM. UV/vis spectroscopy of Reichardt’s dye reveals information about polarity and the dye’s approximate residential location and also helps confirm molecular orbital energy diagram. We discovered an interesting phenomenon with Reichardt’s dye in RM. Surprisingly, the UV/vis spectrum of Reicahrdt’s dye in CTAB RM with octanol as a cosurfactant exhibits decreasing absorbance and a blue shift. Reichardt’s dye in solely octanol shows an irreversible color change and similar UV/vis spectrum. Consequently, we conclude that Reichardt’s dye resides near the interfacial layer/solvent boundary. Other cosurfactants do not result in the time dependent behavior suggesting a more dynamic interaction between octanol and Reichardt’s dye.
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Tandem Cancer Drug Delivery via Gold Nanoparticle Targeting Platforms
Jeffrey Schulte, Sam Lohmar, and Daniel Scott
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Automatic Animation of Molecular Motion using Python and Cinema 4D
Diana Zajac, Nathaniel Smith, and Dan Gurnon
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Kinematics and Economy of Novel Barefoot Running
Aaron Zell and Patrick Babington
The purpose of the study was to compare key physiological, anthropometric, and kinematic attributes between barefoot and shod runners while also comparing these variables to the running economy of their respective conditions. We hypothesize that when running in the acute barefoot condition participants will exhibit significant biomechanical, physiological, and kinematic differences compared to the shod condition that may be correlated with a superior or inferior running economy. Male (4) and female (5) test subjects (19.2±0.83 years, 171.06±6.89 cm, 71.09±14.52 kg) participated in two separate testing sessions. The first session involved collecting the weight, height, sitting height, ankle and hip widths, hamstring flexibility, and body fat percentage preceding a maximal oxygen consumption test. The second session required subjects to run at a variety of submaximal velocities while they were recorded with high speed video. Kinematic variables were measured using Dartfish Video Analysis Software. Results showed that VO2 was greater when shod than barefoot at 2.68 m/s, but shod running required less oxygen at 3.58 m/s. There was no difference at 3.13 m/s. Body composition was the only physiological variable that correlated with economy. Knee angle decreased and stride frequency increased when switching from shod to barefoot running. These findings suggest that as habitually shod runners begin barefoot running they adapt to increased ground reaction forces by incorporating greater knee flexion and a faster stride frequency. These changes may cause a decrease in economy at slower speeds and an improvement in economy at greater velocities.
