Posters from the annual student research session where DePauw students can demonstrate their collaborative work with faculty or internship experiences.
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AROutcrop: an augmented reality mobile application for teaching geology in the field
Zachary Wilkerson, M. Scott Wilkerson, and Chad Byers
Augmented reality (AR) provides an immersive environment where computer-generated textural and/or graphical information overlay natural features in real-time. Such computer-generated objects/data have the potential to supplement or “augment” reality in ways that enhance geoscience comprehension in the field. For example, when instructors stand at a distance from an outcrop and explain the features present, students sometimes struggle to recognize the subtle rock textures and fabrics that define the stratigraphic units and structures present, instead seeing only an amorphous mass of rock. AR technology might allow students to use their own mobile devices to better recognize, interpret, and comprehend the geology around them. We created an AR app (AROutcrop) for Android mobile devices to evaluate the advantages/disadvantages of using AR approaches to teach geology in the field. Specifically, AROutcrop accesses the device’s picture library to auto-recognize outcrops from photos and overlay various AR objects (2-D interpretations and 3-D models) in the real-time view within the device’s camera environment. Students can use their mobile device to interact with various AR objects by: 1) clicking on AR objects to open a window with text, graphics, and data describing the geology of each feature, 2) collecting a “rock sample” from the outcrop by placing an AR 3-D photogrammetry model of an actual rock specimen from the outcrop on the ground where students can walk around the AR “sample” and magnify it for more in-depth study, and 3) overlaying and georeferencing (e.g., resizing, translating, rotating, etc.) a 2-D AR geologic interpretative image over the entire outcrop to highlight specific features and/or rock layers. Preliminary trials of AROutcrop at a nearby quarry suggest that this novel approach has the potential to not only improve student learning and comprehension, but also to encourage students to engage in critical-thinking processes, to make careful observations while in the field, and to become better consumers of scientific knowledge.
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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.
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Where has all the leaf litter gone?....
Charlotte Buehler, Chad Byers, and Summer Drake
What Affects the Amount of Leaf Litter in a Forest?
Decomposition rates of leaf litter?
Abiotic soil conditions (pH, calcium content, other nutrients)?
Abundance of earthworms?
Abundance of millipedes?
Abundance of macroinvertebrates (beetles, crickets, spiders)?
Forest composition (maples, oaks, elms)?
Other abiotic factors (microclimate, microtopography, moisture)?
Leaf chemistry (tannin content, lability, recalcitrance)?
Other biotic factors (bacteria, fungi, mycorrhizae)? -
Invertebrate & Leaf Litter Dynamics in the DePauw University Nature Park and Arboretum
Karl Koehler, Libby Sue Allard, and Kyra Dawn Reed
Our study focuses on the interaction between invertebrate abundance and the decomposition of leaf litter. The decomposition of leaf litter plays a major role in the nutrient cycling process, which is critical to the health of an ecosystem (Spurr and Barnes 1980). The dynamics between invertebrates and leaf litter are of particular importance because invertebrates are good indicators of the activity of the decomposer community. Abiotic factors such as soil pH and temperature are also important influences on decomposition rates (Bornebusch 1930; Petersen & Luxton 1982; Seastedt 1984). Our goal was to determine the nature of this interaction. Ultimately, this information could provide us with a more accurate illustration of the efficiency and health of the Nature Park and Arboretum ecosystems.
We hypothesized that certain invertebrates would appear in high abundance in specific areas. If these proved to be invertebrates integral in the decomposition process then there would be a noticeably high amount of decomposition of litter in these areas.
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Patterns and processes of recovery in and around an Indiana limestone quarry
Dana A. Dudle, Vanessa L. Fox, Bryan Helm, David Pope, and Aaron Randolph
Introduction
Here we present baseline data on forest songbird communities in the DePauw Nature Park. Our goal was to survey the songbird population and assess the quality of forest habitat in the park.Methods
We set up study plots in three forested sites: Arboretum (ARB), Quarry South (QS), and Quarry Hillside (QH). We surveyed bird populations using the territory-mapping method. Each site was surveyed four times during May and June between 6 and 10 a.m. During each survey, we recorded locations of songbirds. Clusters of observations over multiple visits were used to identify songbird territories. Population sizes for songbird species were estimated based on the number of territories within each site.We searched for and monitored nests following BBIRD protocol. Nests were checked every 3 to 5 days to monitor their contents and determine their fate. Successful nests produced at least one host edgling whereas failed nests had no fledglings. Causes of nest failure included predation, parasitism by Brown-headed Cowbirds, abandonment, and weather. We estimated daily nest survival rates using the Mayfield method.
Results and Discussion
The three sites supported a variety of songbird species that are typical of eastern deciduous forests.One of the most intriguing results was the presence of Cerulean Warblers at QS. The Cerulean Warbler is a species of significant conservation concern and requires large tracts of mature closed-canopy forest for nesting habitat, and populations may be declining due to loss of habitat. Their distributions are patchy within suitable habitat but reasons for this patchy distribution are unknown. The presence of Cerulean Warblers at QS appeared to be unrelated to differences in forest composition or structure but attests to the importance of maintaining the forest within its existing condition to continue to provide habitat for this bird species.
The dense growth of shrubs in the forest at QH provided suitable nesting habitat for the Indigo Bunting. Indigo Buntings usually occur in early-successional habitats such as open meadows. They were common in edge habitat in the ARB, next to the powerline and athletic fields. Indigo Buntings were more widely distributed throughout the forest habitat of QS. The distribution of this bird species across a variety of habitats (edge, meadows, and closed-canopy forests) provides an opportunity for future research on fitness consequences of habitat selection within an easily accessible environment close to campus.
Acadian Flycatchers occurred at all three sites. This bird species nests in large trees located along moist forest ravines. We monitored 13 Acadian Flycatcher nests and found fairly high levels of breeding productivity. Half of the nests failed due to predation or Brown-headed Cowbird parasitism, but the estimated rate of daily nest survival of 95.5% may be sufficient to support a healthy self-sustaining population. The Acadian Flycatcher is another appropriate species for additional research since it was common at all three sites and their nests tend to be accessible.
Wood Thrushes are common in eastern deciduous forest habitat, and their large bulky nests tend to be easy to find and monitor. Wood Thrushes were common at QH but were almost absent in the other sites, and their nests were difficult to find. The differences in forest structure and composition between the sites do not necessarily explain these results, but the Wood Thrush’s unusual distribution merits closer attention in the future. Overall, the forest habitat in the DePauw Nature Park provides valuable habitat for a variety of songbirds, several of which are of significant conservation concern.
