Student Presenter: Valeria Acuna

Student Project Title: Protein-Protein Surface Modeling of DSB Repair Complexes

Student Project Abstract: Double-strand breaks (DSBs) in DNA are extremely problematic; require intricate, complicated repair; and have an unknown mechanism. Lack of repair results in loss of a region of chromosome, while incorrect repairs result in cancer development. In order to prevent cancer development, the mechanism must be understood. Comparing computational data with experimental results will give better insights as to what is happening among the protein complexes involved with DSB repair. Computational techniques being used include protein-protein docking and homology modeling. Protein-protein docking is a snapshot of two proteins interacting with each other and will be used to look at a combination of the yeast proteins RAD52, MST1, and HIP1. These yeast structures were generated using homology modeling, which entails taking a primary protein sequence and deducing possible protein structures. In the future, these computational methods could predict the outcomes of yeast experimentation with mutational analysis. Once the mechanism is well understood, further studies may find a way to ensure DSB are repaired correctly.

Student Presenter: Gwenyth Amborski

Student Project Title: Differences in MicroRNA Expression in Cutaneous Squamous Cell Carcinoma by Anatomical Site

Student Project Abstract: Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer. Only 2-6% of cSCC metastasize but metastatic cSCC leads to an estimated 3,932 to 8,791 deaths in the United States each year. The most common sites for primary cSCCs that become metastatic cSCC are on the ear, lip, and temple. Primary cSCCs at other sites, like limbs and the trunk, are less likely to metastasize. MicroRNAs (miRNAs) are non-coding RNAs linked with the 3’-UTR region of target mRNAs. They function in the regulation of gene expression and are important to proliferative signaling, apoptosis, and angiogenesis. Changes in normal miRNAs expression have been found in every cancer and are also associated with metastasis. We hypothesize that expression of miRNAs will be unique based on the location of the primary tumor and this may reveal miRNAs important in metastasis. In previous studies, we measured miRNAs isolated from cSCCs at sites associated with metastasis (aggressive sites), cSCCs at sites not associated with metastasis (non-aggressive sites), and non-tumorous skin tissue. Multiple miRNAs showed differences between the groups. The goal of this project is to determine whether five miRNAs: miR-21, miR-31, let-7g, miR-93, and miR-22 show differences in expression in tumors between the aggressive versus non-aggressive sites. To test this, I made cDNA with TaqMan Advanced cDNA Synthesis Kit from RNAs from tumors not previously tested and performed Quantitative Real-Time PCR with TaqMan Probes for the five miRNAs: miR-21, miR-31, let-7g, miR-93, and miR-22. RNU6B was used as a control to normalize the results of the qPCR. Thirty tissue samples consisting of nine normal, eight aggressive, and thirteen nonaggressive sites were examined. Preliminary results on 21 tumors show that not all of the miRNAs may show expected expression differences between the tumor sites. Ongoing studies will examine additional tumors to establish the statistical significance of miRNA expression between tumor sites. Further studies investigating the expression of different miRNAs will be useful in concluding the role of miRNAs in aggressive versus non-aggressive tumor sites.

Student Presenter: Cole Anderson

Student Project Title: Timecourse of KLF-2 Expression After Murine Intracranial Hemorrhage

Student Project Abstract: Anderson, CP, Dornbos, D, Wheeler DG, Hoang N, Gnyawali S, Nimjee, SM, and Powers CJ

Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, 43210.

Introduction/Background:

Stroke is the leading cause of combined death and disability in the United States. Aneurysmal subarachnoid hemorrhage (aSAH) accounts for approximately half of all strokes and commonly results in death (33-45%) from delayed cerebral ischemia (DCI) within 30 days. We have analyzed miR levels in cerebrospinal fluid (CSF) of aSAH patients and found that miR-92a is increased early and decreases over time. miR-92a targets the transcription factor Kruppel-like factor 2 (KLF2) in endothelial cells, decreasing endothelial nitric oxide synthetase (eNOS) which is critically important in cellular response to ischemia. Based on this data, we hypothesized that increased abundance of miR-92a early after aSAH sensitizes the brain to ischemia by down-regulating KLF2 and downstream eNOS.

Methods:

Forty two C57/BL6 mice were randomized into two groups (ICH and non-injured control) and 3 mice/group were sacrificed every 24 hours to 7 days immediately after magnetic resonance imaging (MRI). After the carotid artery was isolated in anesthetized mice, the external carotid was ligated distally; a knot place around the proximal end, and blood flow was stopped by vessel clipping. An incision allowed a filament to be inserted until perforation of the blood vessel occurred and treatment began 10 minutes after injury. Controls received all procedures except perforation. At time of sacrifice, brains were harvested, sectioned, and stained for KLF2 and images analyzed using ImageScope software.

Results:

Data analysis revealed a significant increase in KLF2 with injury at three time points (Days 3, 5, and 6) compared to 7 days.

Conclusions:

We identified three time points after injury in a murine intracranial hemorrhage model at which KLF2 was significantly increased compared to 7 days. Our next step is intra-cerebroventricular injection of miR-92a injection in lentiviral vector to over-express miR-92a in C57/BL6 mice to correlate miR-92a and KLF2 in mouse brain.

Student Presenter: Wesley Barnhart

Student Project Title: Effects of acute pain and pain-related fear on risky decision making and effort during cognitive tests

Student Project Abstract: Introduction: Both the experience of acute pain and pain-related fear negatively impact cognition and behavior; however, to date little research has examined their impacts on risky decision making and effort. The present study investigated the effects of acute pain and pain-related fear on risky decision making and effort during cognitive tests.

Method: Levels of pain-related fear were assessed. Healthy participants experienced acute pain induced via cold pressor task, and then were randomly assigned to one of four conditions to induce pain-related fear: pain threat with no control (n = 24), pain threat with control (n = 24), cognitive threat (n = 22), and control (n = 25). Participants then completed measures of effort (Word Memory Test [WMT], self-reported effort) and risky decision making (Iowa Gambling Task [IGT], Balloon Analogue Risk Task [BART]).

Results: Collapsed across condition, participants did not learn to decide advantageously on the IGT following an acute pain experience. However, higher levels of pain during the cold pressor task predicted less risky decisions on the BART. Participants in the two pain threat conditions self-reported lower effort on cognitive tests, yet no group-based differences were seen in WMT performance. Greater pain-related fear predicted greater self-reported effort and better WMT performance, but no effects were seen on decision making task performance.

Conclusions: The experience of pain and the threat of additional pain can lead to changes in risky decision making and effort on cognitive tasks. This threat of additional pain could activate underlying pain-related fear, creating hypervigilance to and avoidance of pain that affects subsequent task performance. Implications for research and clinical evaluation of acute pain and pain-related fear are discussed.

Student Presenter: Jeremy Bilfield

Student Project Title: A Bayesian Reanalysis of Correlations between Cortical Thickness and Strategic Choices in Economic Games

Student Project Abstract: Yamagishi et al. 2015 examined correlations between dorsolateral prefrontal cortex (DLPFC) thickness and giving in two economic games (dictator and ultimatum) and strategic behavior in a Machiavellian game (MG). THEIR Results showed DLPFC thickness was correlated with selfish behavior in the dictator game (DG) and strategic behavior in the MG. If DLPFC thickness is a sign of increased control, it implies that the selfish behavior seen in the DG is a result of such control. This, in turn, suggests prosocial behavior may not require planned control. These findings run counter to the usual interpretation of human behavior in economic games (that prosocial behavior requires control), and the significance level of their findings was higher than prescribed by recent literature (Benjamin et al., 2017). I reexamined the data from a Bayesian perspective and present a number of Bayesian model fits to the data. I fit two linear models to the residual differences for a linear regression of the cortical region data adjusting for age, sex, and intracranial volume. One model accounted for differences resulting from both games and the other model presumed the game had no effect. The Bayes factor for these models showed only slight anecdotal evidence for the former model and a 95% posterior credible set of the means included 0. This suggests the thickness of the DLPFC does not correlate or predict performance economic games in either a positive or negative fashion. Thus my models support neither the idea prosocial nor selfish behavior require cognitive control.

Student Presenter: Fernando Blank

Student Project Title: Morphological variation in retinal architecture of diurnal and nocturnal frogs

Student Project Abstract: Photon availability under different light regimes selects for differences in the optical and neural components of the visual system. With respect to animal models of research of visual pathologies, nocturnal and fossorial murine models may not mimic the optical, cellular, biochemical, or physiological processes of the diurnal human eye. Previous findings in our lab have shown that nocturnal and diurnal frog species differ in their optical anatomy, photoreceptor outer segment dimensions, and physiological sensitivity. Herein, we examined the inner nuclear layer (INL) and outer nuclear layer (ONL) to determine if these differences are reflected in the cellular architecture of the retina. We used 1 mm-thick plastic sections of retina to count the number of cells in the INL and ONL of four species of frogs (two diurnal species and two nocturnal species). Morphological analysis did not show a significant difference in cone to rod ratio within the ONL. However, there were significant differences between species in regard to the INL, with O. pumilio and M. viridis showing hypertrophy. Therefore, the INL of diurnal species have a significantly higher number of cells than those of nocturnal species (p<0.001). Ultimately, our results indicate that visual circuitry in the retina of diurnal species is potentially 2.5xs greater than in nocturnal species.

In the future, we plan to characterize the various cells of the INL to see if the observed hypertrophy is limited to a specific cell type, and if it is associated with a specific class of retinal photoreceptor. Most biomedical research on the visual system is performed on nocturnal rodent species; Thus, these data are critical for providing a framework for nocturnal versus diurnal retinal differences that could affect clinically relevant research with humans.

Student Presenter: Simon Bogason

Student Project Title: BiSb Nernst-Ettingshausen Coolers

Student Project Abstract: Conventional active cooling systems such as air conditioning and water heat pumps are cumbersome and involve moving parts, meaning they are prone to wear over time. Active cooling can also be created using thermoelectric materials without any moving parts. Some semimetals, such as bismuth antimony, can become a heat pump by using the Hall Effect, this is called a Nernst-Ettingshausen cooler. The Hall Effect is characterized by an electromagnetic force applied to a charged particle moving through a magnetic field. When a current is passed along the x axis through a semimetal sample placed in a magnetic field along the y axis, the electromagnetic force pushes traveling electrons to one side of the sample in the z axis. The travel of electrons acts as a heat pump and creates a temperature gradient across the sample. The cooler side could be used as a cooling system without any moving parts. A drawback is that a Nernst-Ettingshausen cooler is relatively inefficient as a heat pump, meaning it requires more input energy to transfer a set amount of heat. Further research is required to seek semimetal alloys that can achieve a greater efficiency. This research seeks to create two semimetal samples, Bi95Sb5 and pure Bi, then test their cooling characteristics. A sample is placed in a vacuum chamber with a controlled ambient temperature. Electric current is passed through the sample and a magnetic field is applied across the sample. The resulting temperature gradient in the sample is then measured. This experiment is repeated by procedurally varying current and ambient temperature, while magnetic field is maintained constant. The cooling performance is greatly affected by the ambient temperature and current. By studying the temperature gradient while increasing current and ambient temperature, it may be possible to observe a trend or optimal parameters for cooling. The results could provide insight into the feasibility of bismuth as a material for Nernst-Ettingshausen and other solid-state cooling applications.

Student Presenter: Olivia Britt

Student Project Title: Evaluating Education: Analyzing Pre-Service Teachers' Assessments in Light of Equity Pedagogy and Mathematical Practices

Student Project Abstract: Recent studies have shown that students in some teacher education courses are lacking in incorporating certain aspects of equity pedagogy and mathematical practices into their assessments of children's mathematical content knowledge and reasoning skills. In particular, individuals were surveyed from an Early Childhood Education program at a regional campus of a large Research I institution, and the survey results suggest that these pre-service teachers were struggling to demonstrate their ability to encourage input from a diverse array of mathematical competencies as well as give students voice and incorporate their ideas in future lessons. In addition, these pre-service teachers seemed to struggle with demonstrating certain mathematical practices in their assessments, including evaluating their students on their ability to construct arguments and critique those of others. The data collected suggests these pre-service teachers are not instinctively choosing to seek out and give weight to the arguments of their own students. Instead, it appears that they are using a narrow perspective in approaching their own mathematical content as well as in interpreting their students’ logical reasoning without input from the students themselves. Toward the end of the study, we conclude that this could be a result of an incomplete content knowledge on the part of the pre-service teachers, or it could be related to their lack of familiarity with or understanding of equity pedagogy. A few promising teacher responses, on the other hand, are evidence that some pre-service teachers have a firm basis in pedagogical content knowledge grounded in equity pedagogy and are able to align the two in a way that supports the whole individual of a young learner.

Student Presenter: Wyatt Bunstine

Student Project Title: Exploring Automatic Sample Characterization using image Recognition and Motion Control Software

Student Project Abstract: Sample characterization is an important part of materials research. Much of the visual sample characterization done in our lab is done by hand; researchers manually examine samples under a microscope, looking for desirable or undesirable features, such as color contrast, size, uniformity, and documenting them one by one. Using servos and image recognition software, this visual characterization can be automated to characterize samples more effectively and efficiently.

The software that I developed uses a combination of two ideas to fully automate the process of sample characterization under an optical microscope. The first key idea is that, visually speaking, a computer should be able to interpret an image as effectively, if not more, compared to the human eye because the characterization process is largely reliant on the color contrast between different parts of a sample. The second idea is that manually moving the microscope allows for significant overlap of examined areas. While this may not be a problem qualitatively, it does waste time. The opposite of this can also occur, where parts of a sample are not examined because of user error. These issues can be eliminated when a machine is allowed to control the movement of the sample. Using servos and simple logic, areas of sample with desired features can be thoroughly examined without unnecessary overlap.

Combining these two ideas allows for a fully automated system for characterizing samples. This presents many advantages; first and foremost, it reduces the time researchers must spend characterizing samples. It also eliminates human error; a machine will always find and characterize sample in the same way since it can guarantee that every part of a sample is examined as thoroughly as any other part. This standardization of the sample characterization process presents advantages as well, such as allowing for samples to be compared with each other with more consistency; samples will not be unfairly judged because the quality of their characterization differs

This software will streamline the process of sample characterization as well as standardize it. In my research poster, I’ll present a more indepth look at how the program works, the logic behind the image recognition algorithm, specific examples where this program would be effective as well as other important details. This will save researchers’ time and increase the reliability of sample characterization.

Student Presenter: Trent Cash

Student Project Title: Various Measures of Socioeconomic Status As Predictors of Formal and Informal Home Literacy Environments

Student Project Abstract: Individual differences in literacy during early childhood are important predictors of later reading ability (Sénéchal & LeFevre, 2002) and cognitive achievements (Downer & Pianta 2006). These differences in early literacy have been shown to be associated with various forms of literacy opportunities in the home, collectively known as the home literacy environment (HLE; Sénéchal & LeFevre, 2002). HLE includes both an informal aspect, which involves “those [activities] for which the primary goal is the message contained in the print,†� and a formal aspect, which entails “those [activities] for which parent and child focus on the print†� (Sénéchal & LeFevre, 2002, p. 1). Each aspect of HLE is correlated with different aspects of future literacy. HLE, however, does not exist in a vacuum; it is associated with multiple family-level variables, most notably socioeconomic status (SES). Like HLE, SES can be conceptualized in many ways. The researchers hypothesized that different aspects of SES would be differentially related to HLE, and that Informal HLE would be more strongly predicted by income-related measures, whereas Formal HLE would be more strongly predicted by education-related measures. To disentangle this complex association between SES and HLE, the researchers administered surveys to the parents of 393 preschool-aged children in Columbus to document their Informal HLE, Formal HLE, and multiple aspects of their SES, including income, income-to-needs ratio, and parental education. Multiple regression was used to predict Informal and Formal HLE from the various SES measures. Results indicated that income (β=.182, p=.010), income to needs ratio (β=.179, p=.014), and maternal education (β=.207, p=.013) are unique, significant predictors of Informal HLE. No measures of SES were significant predictors of Formal HLE. The results suggest that SES plays a role in Informal HLE, but also suggest that SES is not a catch-all predictor of HLE and that factors not explored in this study may predict both Informal and Formal HLE. Although the results do not fully support hypotheses, they suggest the existence of complex associations between SES and HLE that must be understood in order to develop initiatives that address the underlying causes of disparities in early childhood literacy.

Student Presenter: Andrew Cypcar

Student Project Title: Hydrogen atom abstraction reactivity of distorted dicopper(III) bis-μ-oxo complexes

Student Project Abstract: With diminishing liquid petroleum resources, methane has become an important component to support our continuing need for hydrocarbons and their derived products. However, conversion of methane to a portable fuel like methanol is extremely difficult due to the high C-H bond dissociation energy of methane (104 kcal/mol). Nature accomplishes this challenging task with an enzyme particulate methane monooxygenase (pMMO), which selectively oxidizes methane to methanol at ambient conditions with oxygen as the sole oxidant. The origin of this exceptional reactivity is currently unknown.

We propose pMMO’s unique distorted dicopper(III) bis-μ-oxo core is a contributing factor to the high hydrogen atom abstraction reactivity. Inspired by pMMO, we synthesized three bisoxazoline (BOX) copper(I) precursors with different steric hindrances. Upon addition of oxygen, all three copper(I) precursors activate oxygen by four electrons and generate a series of dicopper(III) bis-μ-oxo cores with different degrees of distortion. The unique C2 symmetry of BOX ligand allows us to control the distortion of dicopper(III) bis-μ-oxo cores by asserting steric bulks that lead to (a) increase of N-Cu-Cu-N dihedral angle or (b) increase of Cu2O2 hinge angle (butterfly distortion). Hydrogen atom abstraction reactivity of distorted dicopper(III) bis-μ-oxo cores with different C-H bond substrates was probed with low-temperature UV-Vis spectroscopy, and the products of the reaction was analyzed by GC-MS. While the twisted and control experiment show no reactivity towards C-H substrates, the “bridged butterfly†� core oxidizes relatively strong C-H substrates, such as cyclohexadiene and dihydroanthracene, and oxidation products are detected by GC-MS. DFT calculations were performed to help us understand the enhanced reactivity of this “bridged butterfly†� core. The computational and experimental study of these synthetic models suggests a “bridged butterfly†� distortion of the dicopper-oxo core is a strong contributing factor to the high hydrogen atom abstraction reactivity observed in pMMO.

Student Presenter: Kyle Deistler

Student Project Title: Developing a novel model of retinal light damage in chicks to test the neuroprotective efficacy of different pharmacological agents

Student Project Abstract: Many retinal diseases, such as retinitis pigmentosa, age-related macular degeneration, and solar retinopathy are caused by the progressive loss of photoreceptors. It is important to model these diseases in order to study their progression and to develop potential treatments that can be used to reverse their effects. This investigation worked to develop model of retinal light damage in chicks to mimic the effects of selective photoreceptor cell death found in many of these diseases. Chicks have long been a model for human eye research due to their larger relative size making them easier to handle and their inherent semi-regenerative capabilities. Chicks were exposed to bright light for varying amounts of time to induce photoreceptor cell damage via an oxidative stress pathway. Dark adaptation periods and dilating eye drops were also used to maximize photoreceptor cell sensitivity and exposure to light treatment. Chicks were dark adapted up to five days and subsequently exposed to bright light for up to five days without inducing significant photoreceptor cell damage. Focal, laser induced, damage was also utilized in tandem with dark adaptation and bright light to further increase the potential for photoreceptor cell death. Currently, varying lengths of retinal laser exposure are being tested to determine a minimal quantity of light exposure necessary to induce significant, repeatable photoreceptor cell death. After this protocol has been finalized, the model will be used to study the efficacy of different neuroprotective agents at preventing photoreceptor cell death after retinal light damage. This model will open new avenues for further study of retinal degenerative diseases by offering opportunities to investigate a wider range of diseases through different in vivo models. Ultimately, it is our hope that by developing this model, we will be able to better study a range of retinal degenerative diseases for the development of novel treatment options for patients.

Student Presenter: Rachel Doberstein

Student Project Title: The characterization of BRIP1 missense variants

Student Project Abstract: The gene encoding a DNA repair helicase known as BRIP1 has been identified as a possible breast and ovarian cancer susceptibility gene. It is known that cells without functional BRIP1 protein are unable to properly repair interstrand crosslink DNA damage and frameshift or stop mutations can result in a complete loss of protein. However, very little is known about the role of missense variants in BRIP1 and the risk for breast and ovarian cancer. The purpose of this project is to characterize the function of 21 unique variants of unknown significance within the BRIP1 gene to elucidate the role of these variants in cancer risk. Cell lines have been genetically engineered through the use of CRISPR-Cas9 to express wild-type missense variants and null BRIP1. Additionally, cell lines are being genetically engineered to stably express the 21 BRIP1 variants by transfecting BRIP1 null HeLa and HEK293 cell lines with plasmids containing the variant. Western blot analysis is being done to screen the stable clones for relative protein expression to select for the cells that integrated the plasmid at endogenous levels. The function of the BRIP1 mutant proteins are being tested by inducing DNA damage with interstrand crosslinking agents Mitomycin C (MMC) and Cisplatin and the sensitivity to the damage is being determined by CellTiter-Glo® luminescent cell viability assays, crystal violet clonogenic growth assays, cell cycle analysis, and karyotype. Results have shown that clones containing loss-of-function missense alleles have an increased sensitivity to MMC and Cisplatin-induced DNA damage as seen by decreased cell viability, increased G2/M accumulation in cell cycle and increased chromosomal aberrations by karyotype. Since BRIP1 helicase functions as a dimer, some missense mutations result in a dominant negative function which creates an increased sensitivity to MMC and cisplatin, even when expressed in the presence of wildtype protein. In conclusion, this data shows that these missense variants are important for protein function and may increase one's risk for early-onset breast and ovarian cancer.

Student Presenter: Marissa Farinas

Student Project Title: Treatment of T cells from Multiple Sclerosis patients with novel STAT3 inhibitor improves Teff:Treg balance

Student Project Abstract: Multiple Sclerosis (MS) is an immune-mediated chronic CNS disorder in which the body’s immune system attacks the fatty myelin sheath surrounding neurons, resulting in poor neuronal signaling. Myelin-specific CD4+ T effector (Teff) cells are pathogenic while T regulatory (Treg) cells beneficially suppress Teff cells in MS and its murine model, experimental autoimmune encephalomyelitis (EAE). We examined the Interleukin-6 (IL-6)/STAT3 pathway in MS pathogenesis, as dysregulation of this pathway has been observed in MS patients. IL-6 is a cytokine that initiates the transcription factor STAT3 to activate Th17 cells, thus releasing the proinflammatory cytokine IL-17. Th17 cells are a subset of CD4 Teff cells and are highly encephalitogenic when injected into wild type (WT) recipient mice. Moreover, IL-6 suppresses the generation of inducible Tregs (iTreg), resulting in an overreactive immune response to myelin antigens, or autoimmunity. We developed a small molecule inhibitor, LLL12b, of STAT3. We hypothesized that by inhibiting the IL-6/STAT3 pathway, the Teff:Treg balance of CD4 T cell responses would normalize and the progression of the disease in the EAE model of MS and in humans would be suppressed. We previously tested LLL12b in mice with EAE and found that the Teff:Treg imbalance of myelin-specific CD4 T responses was repaired and EAE was suppressed. In this study, we examined the effects of LLL12b on CD4 T cells from MS patients. Human PBMCs from 22 treatment-naïve MS patients were activated with αhCD3 for 3 days, in the presence of different concentrations of LLL12b or vehicle control (DMSO). IL-17 production in supernatants was determined by ELISA. Our data show that LLL12b significantly suppressed IL-17 production in human CD4 Teff cells from MS patients, suggesting LLL12b has the capacity to inhibit the effector function of effector/memory CD4 T cells from MS patients. Meanwhile, we also determined LLL12b significantly promoted iTreg development of CD4 T cells from the same 22 treatment-naïve MS patients via flow cytometry, indicating LLL12b has the capacity to normalize the Teff:Treg balance in human patients. Together, these data suggest the novel small molecule STAT3 inhibitor LLL12b has great therapeutic potential for MS.

Student Presenter: Sarah Greenbaum

Student Project Title: Drone SAR

Student Project Abstract: Radar imaging systems perform ground mapping through range measurements of the environment, requiring a large antenna aperture to create cross-range resolution. Synthetic Aperture Radar (SAR) is commonly used as an alternative to large antennas and is leveraged on aerial platforms. SAR platforms are typically satellites, airplanes, or large fixed-wing drones. The Drone SAR project seeks to introduce SAR capability to small, more agile, low-cost quadcopter drone platforms. The goal of the Drone SAR project is to develop a ground-mapping radar system on a small UAV to have sub-meter resolution at a range exceeding 50 meters and operate in darkness, fog, and smoke.

The team selected an Ancortek 980 AD transceiver with a bandwidth of 400 MHz which allowed 0.375-meter nominal range resolution. The transceiver used a linear FM chirp waveform and stretch processing, with a center frequency of 9.8 GHz. A GPS unit, with U-blox RTK package, was used to measure the transceiver position at each pulse. A Raspberry Pi was employed as a system controller, and a modified DJI app was used to remotely trigger the Raspberry Pi, transceiver, and GPS data collection. Time, position, and radar data were stored to a memory card for post-processing. The transceiver, antenna, GPS module, and Raspberry Pi were mounted to a Matrice 100 drone. Tests with the radar unit mounted to a computer-controlled rail were conducted to calibrate system delays and FM chirp rate.

For field testing, transceiver and GPS data were collected in a circular flight over a corner reflector. A simulation of the same scene was made in MATLAB. Using back-projection and autofocus software, an image of the reflector was computed and compared to the simulation. The result successfully distinguished the reflectors from the background and geo-located the reflector to within 80 cm of its true location. Continuing work is addressing three extensions. First, we seek to extend state-of-the-art autofocus algorithms for application to the drone imaging geometry, where a planar wave-front approximation fails. Second, we will employ flight paths that enable three-dimensional imaging. Third, we will replace the DJI app with a wireless Wi-Fi link to the Pi.

Student Presenter: Nick Harvey

Student Project Title: Determining the acid preference of methyl ammonium lead halide perovskites

Student Project Abstract: Research in renewable energy materials has been of growing interest in recent years. Perovskites are at the forefront of this growth, due to the perovskites abilities to be used in high-efficiency solar cells. My research is focused on synthesizing methylammonium lead halide perovskites and determining the preferred halide in acid solutions. By testing these systems for halide preference we can determine the thermodynamically favored products.

Student Presenter: Zhang Jing

Student Project Title: Motor Learning Comparison between Rotarod and Wheel Running Training on Spinal Cord Injured Mice

Student Project Abstract: Spinal cord injury (SCI) affects over 240,000 people in the US, and results in severe permanent functional impairment. Locomotor training, a rehabilitation for human SCI, has been developed for experimental research in mice with SCI to test rehabilitation-induced neuroplasticity and motor learning. Two training parameters may be important – short precise training or extensive generalized training. Rotarod training in uninjured mice, requiring precise, rapid steps on rotating rod, induces greater neuroplasticity in the brain, and increased motor skills, than untrained mice (Yang, et al, 2014). Alternatively, wheel running provides extensive, generalized locomotor activity at will, and increased myelinating cells in the uninjured brain (Xiao, et al, 2016). The greater plasticity in both paradigms supports a motor learning study comparing precision Rotarod training and general wheel running training. Adult female mice (C57BL6/J n=3; PDGFRα-creERT2:mT/mG n=4) received moderate-severe contusion SCI (75 kdyne impact) using a computerized, contusion device. After 35-days of recovery, mice completed 14 days of Rotarod (n=4) training, or wheel running (n=3). Rotarod training was 60 minutes per session, with speeds increasing from the previous day to challenge the mice but still allow successful stepping. Outcome measures included start time, speed, step count per minute, trial duration and fall assessment. Wheel running occurred overnight in Activity Boxes for 12-hour with a suspended wheel containing a rotation counter to track activity. Automatically derived measures included rotation count, vertical activity count and movement time. To characterize recovery, Basso Mouse Scale of locomotion (BMS), plantar heat sensory test (PH), and Grid Walk precise paw placement test were performed chronic SCI before training, mid training and post training. Both training paradigms promoted learning, although improvements after wheel running were greater than Rotarod. Wheel running increased total revolutions (mean percent change 254%±109), while Rotarod training increased speed (131%±56) and total steps (75%±32). There were no differences in recovery-based outcomes (BMS, PH). However grid walk analysis is underway. These findings show that motor learning occurs later after SCI and learning may be greater in long duration training SCI. For human SCI, recovery may be improved by novel training paradigms. Further studies are needed to address myelin formation.

Student Presenter: Lillian Kleban

Student Project Title: Chemical Weathering of Volcanic Ash as a Carbon Sink

Student Project Abstract: CO2 in the atmosphere over geologic timescales is greatly affected by the weathering of silicate and phosphate rocks. Weathering of Ca-Mg phases is significant because it results in precipitation of Ca Mg carbonates and removal to marine sediments, thereby affecting long term CO2 uptake. Weathering of iron or phosphate phases is important because these reactions release nutrients that promote plant growth and take up CO2 as organic carbon in the short term. My project investigated the dissolution kinetics of volcanic ash from five different eruptions (Mount St. Helens, USA eruption, Mt. Pinatubo, Philippines eruption, and Eyjafjallajökull, Iceland, Mt. Pacaya, Guatemala, and Tungurahua, Ecuador eruptions) in synthetic sea water and in freshwater solutions, with and without the addition of iron oxidizing bacteria. Bulk ash composition determined by x-ray fluorescence ranged from basaltic andesite, to trachy-andesite, andesite and trachydacite. Over the course of 9 months, the solutions were sampled periodically via syringe, filtered, and analyzed with a Skalar San++ nutrient analyzer to determine concentrations of silica and phosphate. The samples were also analyzed for iron by use of the ferrozine method; however, the concentrations of iron were too low to be detected (LOD=3 ppb). Phosphate concentrations were close to the detection limit and varied over time. The silica concentrations increased gradually over time and dissolution rates were estimated from a linear fit of the data. Samples with or without bacteria exhibited similar rates of Si dissolution. The highest dissolution rate was 47 ppb Si/day from Icelandic abiotic freshwater ash sample, a fine-grained trachy-andesite. The lowest release rate was 2.4 ppb Si/day from the freshwater abiotic Tungurahua ash, a fine-grained andesite. Differences in dissolution rates of the ash samples were related to the differences in surface area and particle size of the ash. Faster dissolution rates are associated with greater surface area and smaller particle size. Results are consistent with the results of a similar experiments from our group in which ash from the same eruptions was dissolved in deionized water at varying acidity.

Student Presenter: Julian Lee

Student Project Title: Elucidating the Structure of Human Plastins

Student Project Abstract: Plastins are a conserved family of actin-bundling proteins that assist in several critical cellular functions including motility and cell division. There are three human plastin isoforms: I-Plastin expressed primarily in the intestinal, inner ear, and kidney epithelia; L-Plastin expressed in leukocytes; and T-Plastin ubiquitously expressed in solid tissues. L-Plastin and T-Plastin are of particular interest as they are dysregulated in various cancers where ectopic expression of L-Plastin promotes metastasis, while ectopic expression of T-Plastin has been linked to a poor prognosis. Plastins’ primary function is the non-covalent crosslinking of actin filaments into tight bundles. This bundling is negatively regulated upon binding of Ca2+ to EF-hand motifs within the N-terminal regulatory domain. C-terminal to the regulatory domain is the actin-binding core consisting of two actin-binding domains (ABD1 and 2) each capable of binding to an actin filament. The structures of the A. thaliana and S. pombe actin binding cores have been determined by X-ray crystallography. However, only segments of the human plastin isoform structures have been solved, which hampers understanding of plastin function and regulation. In one case, the structure of the L-, but not the T-Plastin headpiece is known. This complicates cross-examination of the two structures to discern their distinct roles and regulations controlling cytoarchitectural plasticity and cancer metastasis. The purpose of this study is to characterize the calcium-dependent regulation of T- and L-Plastins by structural and biochemical approaches. To this end, both crystallography and NMR techniques are utilized to explore the structure of T-Plastin and L-Plastin while focusing on the T-Plastin regulatory domain and the binding core of L-Plastin. Regarding NMR, a 2D spectrum of a 15N-labeled T-Plastin headpiece has been obtained. In parallel, we obtained protein crystals of the L-Plastin binding core, the headpiece through ABD1 for T-Plastin, and a combination of S5D and Calmodulin. Work continues to optimize the crystallization conditions for the acquired crystals. We anticipate that solving the structure of human plastins will elucidate the function and regulation of these proteins and lead to a more thorough understanding of plastin’s roles in cancer cell cytoarchitectural plasticity and metastasis.

Student Presenter: Daniel Lesman

Student Project Title: Exon skipping using an AAV-U7snRNA approach and its therapeutic implication for Duchenne Muscular Dystrophy.

Student Project Abstract: Duchenne Muscular Dystrophy (DMD) is a recessive X-linked degenerative muscle disorder affecting 1 / 5,200 males. DMD usually occurs due to mutations in the DMD gene that disrupt the reading frame. DMD encodes for dystrophin, a protein that links the F-actin cytoskeleton to the plasma membrane through its actin binding domains (ABD). Because of this, such domains were thought to be crucial for dystrophin function. However, recent evidence is challenging this dogma as proteins missing part of ABD1 were demonstrated to be highly functional. We have in the past developed a therapeutic vector inducing such protein lacking part of ABD1. Under this project we intend to develop another exon skipping vector inducing such proteins in order to potentially treat a sub population of DMD patients (~4% of patients). We developed a complex of proteins and antisense sequences (U7snRNA) mediating exon skipping. The advantage of our approach is that the antisense sequence is embedded, thereby protecting it from degradation and causing accumulation in the nucleus where splicing occurs. Moreover, when embedded into an Adeno-Associated Virus (AAV), these U7snRNAs can be permanently expressed. We transfected myotubes with a variety of plasmids to determine the best way to skip DMD exons. Our preliminary results support the ability of U7snRNA to mediate exon skipping. We are currently screening additional U7snRNA that mediates exon skipping. Cloning of the best candidates into a single AAV plasmid will then be performed to produce AAV. This AAV will be used in patient cell lines harboring mutation within exon encoding for the ABD1 domain. These results suggest that this U7snRNA vector offers a therapeutic approach for patient harboring mutations within exons encoding for ABD1 (~4% of patients), an area of the gene largely ignored by the current therapeutic approaches.

Student Presenter: Xiaoyu Liang

Student Project Title: The Impact of Gene Flow on Species Tree Inference

Student Project Abstract: Evolution of species is taking place over time. The understanding of the natural world has a significant impact on various fields, from general public opinion to expert study of the constantly evolving ecosystem in which we live. The research conducted here focuses on the misspecification of current models used for estimating the history of species evolution by investigating the effect of migration, or gene flow, between distinct species. We study the speciation process in general, by considering models that include both coalescence (to capture within-species genetic variation) and divergence over time (to capture the process of speciation). In the research, we will implement simulation studies to analyze the performance of several algorithms (MP-EST, ASTRAL, maximum likelihood, SVDQuartets, and a distance method) that are currently used for inference of species phylogenies to identify the shortcomings of these current methods. We apply these methods to data simulated under a paraphyletic model, an isolation-migration model, and an ancestral model for both 4 taxa and 10 taxa. The distance from the estimated species tree generated by each method to the true model species tree is used to measure the efficiency of each of the algorithms. Under the current models, our goal is to evaluate how significant gene flow is in the isolation-migration, paraphyletic, and ancestral models as well as the impact it has on the estimated phylogenetic tree.

Student Presenter: Sidney Long

Student Project Title: Dirofilaria immitis: Cryopreservation for Diagnostic Teaching

Student Project Abstract: Proper diagnosis of Dirofilaria immitis is critical as the disease can be fatal and expensive to treat. Furthermore, undiagnosed infected dogs serve as the primary source of infection. Diagnostics are confounded by antibody-antigen blocking, causing false negative antigen testing. Therefore, detection of microfilaria is an important diagnostic skill in veterinary medicine. However, finding a supply of blood containing microfilaria when scheduled to teach the technique presents a challenge. To address this issue, we evaluated the use of cryopreserved microfilaria-infected blood in two standard diagnostic tests, Modified Knott’s and carbonate filter tests. The specific aims included 1) determine if cryopreserved D. immitis microfilaria could be detected in the assays and 2) compare the morphology of the microfilaria following cryopreservation over time. With this information, teaching laboratories could utilize cryopreserved microfilaria-infected blood in lieu of freshly collected microfilaria-containing blood. Whole blood containing microfilaria of either JYD or MO isolates were used. One aliquot of fresh blood was removed, designated as a baseline and immediately evaluated using the two diagnostic techniques. The remaining blood was mixed 1:1 with Glycerolyte 57 solution, divided into aliquots and frozen at -20C for later processing on days 7, 21, and 70 post-freezing. The quantity and morphology of the microfilaria were compared. After freezing, the microfilaria were detected in lower yields. Interestingly, the Glycerolyte also preserved the red blood cells, making the cells more difficult to lyse, resulting difficulty reading the slide due to the intact cells. These results provide evidence that using cryopreservation to store blood containing microfilaria for teaching diagnostic techniques will work; however, the overall concentration of microfilaria on the slide will be less, and individual microfilaria will be more difficult to see. Despite the changes in slide quality, students were able to correctly identify microfilaria from a cryopreserved sample, even though the microfilaria measurements did not match reference values.

Student Presenter: Ryan Messer

Student Project Title: Base Excision Repair as a Catalyst for Retroviral Integration

Student Project Abstract: Oxidative damage of DNA by reactive oxygen species is widespread and unavoidable in cells. The primary mechanism to resolve this damage is through the base excision repair (BER) pathway. BER involves excising the damaged DNA base, removing the residual backbone, polymerizing across the gap, and ligating the DNA. Interestingly, oxidative BER is hypothesized to play a role in the retroviral life cycle. An siRNA screen revealed that decreasing BER protein levels reduced HIV-1 infectivity. Additionally, BER gene deficient cells transduced with lentiviral particles revealed that oxidative BER is necessary for efficient retroviral complementary DNA (cDNA) integration. In this study we use biochemical assays to understand this mechanism on a molecular level. The preintegration complex, containing integrase monomers, viral DNA, and various cofactors, is modeled in these assays by an intasome. Retrovirus prototype foamy virus (PFV) intasomes are comprised of a catalytic tetramer of integrase and two DNA oligomers which mimic the cDNA ends. The reaction between the intasome and target DNA yields products which can be analyzed by gel electrophoresis. Gap DNA BER intermediates can be used as target DNA to reveal integration patterns that may occur within the BER pathway. We found that intermediates in the oxidative BER pathway show an increase in total integration activity compared to fully complementary, duplex DNA. In addition, these events result in site-specific integration at the DNA lesion. This suggests that oxidative BER intermediates are more favorable targets for intasome integration.

Student Presenter: Armin Munir

Student Project Title: Segmented Filament Bacteria in a Lupus Mouse Model

Student Project Abstract:

Background:

Commensal organisms are a critical component to the host organism. Segmented Filament Bacteria (SFB) are commensal organisms found in many mammalian species. SFB has been shown to exacerbate autoimmune disease but has not been implicated in the pathogenesis of Systemic Lupus Erythematosus (SLE). The focus of our study was to understand the relationship between the microbiota and disease of lupus.

Methods:

To determine the effect of SFB on lupus, we used a lupus mouse model of (NZM2410) that is prone to developing lupus manifestations such as immune complex glomerulonephritis. NZM2410 mice were orally inoculated with SFB (n=10) or without SFB-containing (n=10) fecal homogenates. SFB-primer PCR analysis was used to confirm the presence of SFB after inoculation. Serum was collected monthly and mice were euthanized at either 26 or 30 weeks. Kidney damage was accessed via histopathological stains. Immunohistochemistry (IHC) was performed on kidney and small intestine tissue to assess the presence of specific immune cells as well as permeability of the intestine. To analyze changes in the microbiome of SFB colonized mice, fecal bacterial DNA was analyzed using 16S rRNA Deep Sequencing.

Results:

Significantly increased glomeruli size was observed in SFB-inoculated mice via H&E. PAS staining showed more hyaline deposits in SFB-exposed mice, and Jones staining revealed spike formations in the glomerular basement membrane of SFB mice; all of which are indicative of lupus-like glomerulonephritis. Furthermore, we observed an increased level of fluorescence intensity of C3 and IgG in the glomeruli of SFB-inoculated mice. Inflammatory myeloid cells were increased in the kidney of SFB mice. The tight junction Zo-1 was decreased in the small intestine of mice inoculated with SFB, indicating elevated intestinal permeability better known as “leakiness†�. There were significant differences in the intestinal microbial composition in SFB-exposed mice. These differences were evident down to the Family taxonomic level and either indicated a disease-driven and/or SFB-influenced commensal change.

Conclusion:

These findings suggest that SFB can act as a “pathobiont†� in lupus. SFB may have no role in disease in wildtype mice, but our findings suggest that SFB can exacerbate the disease progression of lupus in mice.

Student Presenter: Jazmyn Mustafa

Student Project Title: Transforming fMRI Ballet Data into Intersubject Correlation Maps to Better Characterize Autism Spectrum Disorders

Student Project Abstract: Intersubject correlation maps (ISCs) quantify brain similarities using the Pearson Correlation Coefficient. Recent studies suggest that individuals with autism spectrum disorders (ASD) show more variable ISC patterns compared to typically developing (TD) individuals. In fact, past research attributes reduced ISCs in individuals with ASD to impaired social cognition, or how thinking works in situations where understanding the motivations and emotions of others is needed. In order to explore the underlying mechanisms involved in various social brain areas of participants with ASD, we used functional Magnetic Resonance Imaging (fMRI) to study the brain activity of ASD individuals as well as age and IQ matched TD participants while they watched ballet dances in a fMRI scanner. In this study, we analyzed previously collected fMRI data with a new version of the Intersubject Correlation Toolbox in Matlab. We calculated ISC maps for each group as well as a comparison map of the two groups that was visualized using BrainVoyager QX software. The ISC difference maps displayed distinctions in ASD social brain areas compared to those of TD participants. We then utilized the Talairach Client and found regions in the left cuneus, middle frontal gyrus, and two clusters in the middle temporal gyrus where greater ISC was found in ASD participants compared to TD controls. Ultimately, our findings support past research focusing on cortical differences in ASD populations and encourage more fMRI data to be analyzed with the open source software.

Student Presenter: Daniel Pharis

Student Project Title: Fabrication and Analysis of Graphene and Iron Oxide Heterostructures

Student Project Abstract: Graphene, or single atom thick layers of graphite, is a promising material for future electronics. The properties of graphene are fairly well understood, but recent work focusing on combining graphene with other materials has created new heterostructures with unique properties. Here we present the results of placing graphene on superparamagnetic iron oxide nanoparticles (SPIONs). SPIONs make extremely small, local, magnetic fields which can be aligned. By placing graphene on SPIONS, we can determine the effects of these local magnetic fields on graphene. To do this, graphene is exfoliated, then transferred to SiO2 coated in SPIONs. The graphene is then shaped into a Hall bar and gold contacts are attached to the graphene. These are used to measure voltages across different points on the graphene. The SPIONs near the graphene are also imaged to determine their distribution, which could affect results. The difficulty of device fabrication means that only one device has been successfully fabricated so far. Preliminary results from this device do not show a strong SPIONs and graphene interaction. The results from this device lay the foundation for further calculations of the magnetic field of the SPIONs to be implemented to check the magnitude of the interaction. These calculations could be used for analyzing results from future devices.

Student Presenter: Charis Ramsing

Student Project Title: Characterization of Rice Blast Disease Resistance Mediated by Partial Resistance (R) Genes in Rice

Student Project Abstract: The purpose of this research is to characterize Rice Blast disease resistance genes mediated by partial resistance genes in rice. The Rice Blast disease, caused by the fungal organism Magnaporthe oryzae, is known to cause yield losses of over $66 billion each year and devastate enough rice to feed 60 million people. Currently there are no viable methods of controlling the disease, as fungicides are expensive, cultural methods ineffective, and the fungus has quickly overcome race specific host resistance. In this study, rice plants were bred to contain race non-specific genes that are broad spectrum and therefore much more challenging to overcome. Fixed lines of these crosses were grown and genotyped to both confirm the presence of the resistance gene as well as homozygous dominance. The confirmed rice plants were transplanted and will be inoculated with 5 M. oryzae isolates to screen for resistance. Rice crosses able to provide resistance to more than 3 isolates of M. oryzae will be submitted to further trials for longevity and dispersed to breeders to produce durable resistance to the Rice Blast disease.

Student Presenter: Deja Rush

Student Project Title: Synthesis and Characterization of a Modified MMP-Degradable Peptide for Detection of Cell Secreted Protease Activity Using Fluorescent Peptide Zymography

Student Project Abstract: Statistics have established that metastasis contributes to 90% of cancer-related deaths. Some of the initial steps of metastasis including cancer cell migration and invasion, are regulated by a family of endoproteases called matrix metalloproteinases (MMPs). MMPs play a significant role in extracellular matrix degradation and remodeling and are upregulated during cancer progression.

Current methods implemented to detect MMP activity include substrate zymography, a modified SDS-PAGE technique, and degradable fluorescent peptides. The substrate zymography technique is limited by the number of substrates that can be successfully incorporated into polyacrylamide gels. It can therefore only be used to detect a few proteases. The drawback to using degradable fluorescent peptides is the inability to detect specific proteolytic activity.

We are proposing a novel method that takes advantage of an azido-PEG3-maleimide crosslinker to covalently incorporate thiol-modified fluorescent peptides into substrate zymography gels to simultaneously detect activity of multiple MMPs and expand the library of detectable proteases.

This was accomplished by synthesizing and characterizing a general MMP fluorescent sensor peptide (PLGL). Ellman’s and degradation assays were performed to determine the peptide concentration and sensitivity to cleavage by various proteases respectively. The PLGL peptide was then covalently incorporated into polyacrylamide gels and used to detect cellular MMP activity in various cancer cell lines and tissue homogenates through changes in fluorescent intensity.

The data gathered demonstrates that the PLGL peptide can be incorporated into the peptide zymography gel system and simultaneously detect the activity of various proteases (i.e. MMP-1, -2, -8, -9, and -13). Furthermore, the PLGL peptide can successfully detect a greater number of enzymes than traditional zymographic techniques.

Student Presenter: Katarina Schneiderman

Student Project Title: Environmental enrichment reduces vulnerability to repeated traumatic brain injury

Student Project Abstract: Traumatic brain injury (TBI) is a major public health issue, affecting approximately two million people in the United States each year. Insult causes damage to microvasculature and cellular structures, prompting a rapid neuroimmune response characterized by inflammation and metabolic dysfunction. This series of events precipitates further damage to the nervous system and renders it more vulnerable to subsequent TBI. Repeated injury prior to the recovery of normal metabolic physiology generates more severe functional and histological pathology. Since insult has long-lasting consequences for behavior, cognition, and brain health, discerning neuroprotective strategies for recovery is of large societal importance. Housing mice in enriched environments, characterized by larger living quarters, varied toys, space for climbing and hiding, and social stimulation, has been shown to confer motor, cognitive, and histological benefits after injury in animal models of TBI. We hypothesized that housing animals in enriched environments after a mild TBI would render animals less vulnerable to a subsequent brain injury. Young adult mice received a mild, closed-head injury and were then housed in enriched or standard housing environments. One week later, mice underwent a more severe controlled cortical impact injury and were assessed for cognitive deficits, anxiety- and depression-like behaviors, motor deficits, and tissue damage. Our preliminary data suggest that housing brain injured mice in an enriched environment improves motor function, modulates depressive- and anxiety-like behaviors, and improves memory in a fear conditioning task compared to standard housing. These preliminary trends suggest that not only is recovery improved after intense physical and cognitive rehabilitation immediately after injury, but vulnerability to repeated injury may also be ameliorated.

Student Presenter: Nicholas Soulas

Student Project Title: The effect of hippocampal neural stem and progenitor cell specific VEGF knockdown on the activation of microglia in the dentate gyrus in a mouse model of traumatic brain injury.

Student Project Abstract: Traumatic brain injury (TBI) is a growing concern in the world, due to potentially irreversible neurological defects that result from the trauma itself and subsequent inflammatory changes 1. One of the areas of the brain that is particularly sensitive to TBI is the dentate gyrus of the hippocampus, which is not only involved in the formation of memories, but is also one of the two areas of the brain found to harbor neural stem cells. Neural stem and progenitor cells (NSPCs) help the brain to possibly recover from injury by producing new neurons through a process called neurogenesis 2. Recently, it has also been discovered that NSPCs secrete growth factors, in particular Vascular Endothelial Growth Factor (VEGF) 3. We hypothesize that NSPC-secreted VEGF is important in mitigating the effects of TBI. To test this hypothesis, we first used a lateral fluid percussive injury model on wild type C57/Bl6 mice and found that VEGF is indeed upregulated in the dentate gyrus of injured mice compared to the sham control mice. We then used VEGFfl/fl Nestin-Cre/ERT2 transgenic mice to test the importance of NSPC derived VEGF. When treated with tamoxifen, these mice selectively knock down the expression of VEGF in neural stem cells. These transgenic mice were separated into three subgroups: injured mice (which receive craniectomies and fluid percussion), sham controls (which receive craniectomies only) or naïve controls (which do not receive either craniectomy or fluid percussion). Three days after injury, all mice were euthanized and the brains were removed and sectioned for histology. Preliminary results from quantification of immunofluorescent staining indicates a strong inflammatory response in the dentate gyrus of injured mice. These pilot tests have paved the way for larger trials that are currently underway to confirm our initial findings and test for possible functional differences in memory after TBI in mice that lack NSPC-specific VEGF.

Student Presenter: Lindsay Strehle

Student Project Title: Adapting Touchscreen Technology for a Balb/c Cancer Survivor Model to Assess Cognitive Disturbances

Student Project Abstract: Many cancer patients suffer from a wide range of collateral issues from their treatments, such as emotional and cognitive disturbances. There are a wide variety of rodent models and paradigms in practice today to biologically investigate effects of the tumor itself and subsequent treatments, but few detect clinically-relevant, subtle impairments in cognition. Here, we aim to master and adapt a visual discrimination task that utilizes a clinically-relevant touchscreen platform to detect subtle executive function changes in female Balb/c mice for future application to our breast cancer survivor model. In this preliminary study, 8-week-old BALB/c female mice were food restricted, trained to use the touchscreens and reward mechanism to criteria, and then progressed to the visual discrimination task. After learning the “correct stimuli†�, the cognitive flexibility of the mice was assessed by challenging them to learn the previously incorrect stimuli as the new correct stimuli (i.e., reversal learning). Through adjustments of other visual discrimination protocols tailored to the C57BL/6 strain of mice, a new protocol has been adapted for BALB/c mice, taking into account their anxiety-like phenotype. Future application of this protocol comparing tumor survivor mice to controls aims to advance the mechanistic understanding of subtle cognitive changes that affect cancer patients and survivors alike.

Student Presenter: Joseph Sudar

Student Project Title: A closer look at the mechanical process of hearing mediated by prestin and cadherin-23

Student Project Abstract: From listening to music, to learning in a classroom, or even to being alerted of the presence of a predator, hearing is an extremely important sense. There are many complex pieces to hearing. The cochlea, located in the inner ear, contains organ of Corti, which is home to the inner and outer hair cells of the inner ear. The Inner hair cells are responsible for the conversion of physical stimuli to an electrical impulse that can be interpreted by the brain, while the outer hair cells (OHCs) are responsible for the amplification of sound. OHCs change in size based on changes in voltage and this action is mediated by the motor protein Prestin. Found along the walls of OHCs, the mode by which Prestin mediates the shape change is unknown. In a first project, and to gain further insight into Prestin’s function, molecular dynamics (MD) simulations were carried out using a homology model of Prestin. This model was then coarse-grained (CG), decreasing the size of the system and allowing for longer simulations to be carried out using the MD engine Gromacs. After preparing the system with polarized CG water, +1.0 V, -1.0 V, +500mV, and -500mV simulations were ran for varying times. Analyses of these simulations aimed at revealing structural changes upon voltage application are under way. In a second project, we focused on a filament protein called the Tip Link, which is essential for hearing. It is made up of two proteins, Cadherin-23 and Protocadherin-25. These are made up of extracellular cadherin (EC) repeats, Cadherin-23 having 27 and Protocadherin-15 having 11 EC repeats. Knowing the structure of the Tip Link will result in a deeper understanding of the process of hearing. The structures are solved in small sections, such as EC 10 to 12 of Cadherin-23. Using the drop-by-drop refolding method and size exclusion chromatography, EC 11 to 12 was refolded, and it appeared to be a dimer. Many crystal screens were set up and small crystals were produced. Further work to obtain the structure of the EC11 to 12 and to validate the dimeric state is ongoing.

Student Presenter: Elizabeth Troiano

Student Project Title: Exploring the coherence of speech sounds at the beginning versus the end of a sentence

Student Project Abstract: Understanding speech is easy for most people, despite the fact that speech sounds can be very different. For example, in the word “start,†� combining the “t†� and “a†� sounds together is like combining the bang of a drum with the blare of a trumpet. At a concert, those instruments, when played in succession, come together to form a song. Do they come together better at the end of the melody than at the beginning? We asked this question of speech sounds. Do they stick together better as a sentence goes on? We created two sentences, one containing a key word toward the beginning, and the other containing it toward the end. For example, if the key word was “start,†� the early sentence would be, "My start did not earn me any points in the first round." The late sentence would be, "The announcer told them to start around the corner." The sentences were presented in the participant’s left ear, but the “s†� of the key word was presented in their right ear (taking the “s†� off of the key word “start†� leaves “dart,†� which also fits in the sentences above). The task was for participants to repeat the sentence they heard in their left ear, with the focus being whether they said the target word with or without the “s.†� Pilot data suggest that there is no overall difference between responses to early and late sentences, indicating that speech sounds are as coherent at the beginning of a sentence as they are at the end. However, there are large individual differences between participants, suggesting that coherence of speech sounds in general is stronger for some people than others.

Student Presenter: Alexander Vaeth

Student Project Title: Determination of the influence of SnO2 nanowire amount on resistive-type gas sensors

Student Project Abstract: This project involved the study of metal-oxide nanowires (NW) as resistive-type gas sensors and how the fabrication method impacted the sensor’s performance. The goals were to develop a method of growing ZnO NWs and determine the optimal number of nanowires for a sensor. The growth of ZnO NWs involved a vapor-liquid-solid (VLS) technique where source material was placed in the center of a tube furnace with a gold-coated Si substrate downstream. ZnO NW growth was observed using a graphite and ZnO source powder, a temperature gradient of 750oC, an upright growth substrate, and Ar gas flow at a pressure of 50 torr. Further research into the parameters for longer and more numerous NW growth is needed. Ethanol, Methanol, DI water, and Dimethylformamide (DMF) were tested as solutions for transferring the NWs to a substrate with electrodes. DMF was determined to be the most appropriate solution for NW deposition. Solutions with suspended SnO2 nanowires were dropped onto the sensor substrate, which consisted of Pt electrodes on an alumina substrate. Sensors were tested in a sealed probe station with Au-coated W probes to measure resistance. At a temperature of 350oC, a series of gases were introduced to the chamber. N2 was flowed for one hour, then 21% O2 for another hour, then back to N2. The change in resistance with atmosphere determined the sensors response value. Determination of an optimum number of NWs for a sensor involved testing the sensor after every 0.5 µL of solution. This method for testing amounts showed that adding successive drops did not guarantee more material on the sensor, meaning the amount of material deposited from successive drops was random. A different approach was then taken where a sensor with high material coverage versus one with lower coverage were tested. No trend of NW amount on gas sensing properties was observed, but the data suggested that more material on the sensor resulted in a lower baseline resistance and larger response values. Further tests are required to determine if there indeed is a trend.

Student Presenter: Prescott Vayda

Student Project Title: Application of X-ray Computed Tomography reveals a (fool’s) gold mine of exceptionally preserved fossils in the Silica Shale (Devonian) of Ohio

Student Project Abstract: The Silica Shale of northwestern Ohio contains a diverse assemblage of Middle Devonian fossils, many of which are pyritized. Body fossils have been collected from this unit for more than a century, and large collections of shelly taxa exist in museums, in universities, and privately. Study of a varied array of samples from the Silica Shale using X-ray Computed Tomography (XCT) reveals that internal soft tissues of shelly taxa are commonly replicated by pyrite. In addition, large numbers of pyritized trace fossils have been imaged in some layers. XCT scanning reveals the Silica Shale to be a remarkably rich Konservat-lagerstätte. So far, this nondestructive method has allowed visualization of the internal soft tissues of trilobites, brachiopods, and corals. Imaging the nonbiomineralized anatomy of shelly organisms, together with traces, provides new perspectives on the paleobiology and taphonomy of Silica Formation taxa, and provides new information about the bioturbation of bottom muds. Pyrite replication evidently began quickly after death. Approximately half of enrolled trilobites (Phacops) have preserved guts, whereas outstretched trilobites rarely show remains of the digestive system, leading to the inference that enrolled specimens were corpses, whereas most outstretched trilobites were probably molts. Most brachiopods (including Mucrospirifer, Paraspirifer, and Pseudoatrypa) have preserved brachidia, and a few have pyritized muscles and organs. Rugose corals (including Heliophyllum) have pyritized structures resembling mesenteries. The surprising results of XCT scanning on fossils from the Silica Formation suggests that other deposits containing pyritized fossils might be far richer in paleontological and sedimentational information than historically suspected.

Student Presenter: Selina Vickery

Student Project Title: Chemotherapy-related Anxiety-like Behavior and Cytokine Expression in Mice

Student Project Abstract: Anxiety is a common side effect associated with chemotherapy treatment, and in patients, can last years beyond the completion of treatment. Chemotherapy treatments activate the immune system in both patients and rodent models, including increasing inflammatory signals (e.g., cytokines) within the brain. Cytokines, which are secreted by immune cells and affect the function of the cells around them, are associated with changes in anxiety-like behavior in rodents. This experiment tested the hypothesis that anxiety-like behavior is associated with an increase in cytokine production in the central nervous system following chemotherapy treatment. Forty healthy, female 7-8-week-old Balb/c mice received a total of six injections of either 30 mg/kg paclitaxel chemotherapy or vehicle, which were administered every other day over two weeks. Half of the mice were euthanized three days post-treatment (“short-term†�; n=10/treatment). The second half was euthanized 12 days post-treatment (“long-term†�; n=10/treatment). All mice underwent open field and step down behavioral testing to measure anxiety-like behaviors prior to tissue collection. mRNA was extracted from the prefrontal cortex, hippocampus, and hypothalamus, which are brain regions associated with anxiety-like behaviors. Using qRT-PCR, expression of inflammatory cytokines and Itgam, a surface marker for microglia, was measured. Behavioral testing revealed evidence of fatigue short-term and anxiety long-term following chemotherapy treatments. Chemotherapy did not result in changes in mRNA expression for Il-6, Il1beta, Tnfalpha or Itgam. No correlations between cytokines and behavior were found. In conclusion, the anxiety-like behavior observed in chemotherapy-treated mice long-term is similar to persistent anxiety affecting patients post-treatment. In the future, analysis of cytokine expression at an earlier time point, as well as upregulation in different cytokines, may be done to investigate further correlations with chemotherapy-related anxiety-like behavior.

Student Presenter: Ismoni Walker

Student Project Title: Perceptions of Marital Conflict from 9 Months to 7.5 Years Postpartum

Student Project Abstract: This study sought to better understand change in marital conflict by examining 65 first time, dual-earner mothers’ and fathers’ responses to the Marital Agendas Protocol (MAP) (Notarius & Vanzetti, 1983) at nine months and seven and a half years postpartum. Specifically, this study used Pearson correlations and independent samples t-tests to address the following questions: 1) do mothers’ and fathers’ ratings of problematic issues in their relationship remain stable over time, 2) were there gender differences between mothers’ and fathers’ ratings of problematic issues in their relationship, 3) were mothers’ and fathers’ ratings of problematic issues in their relationship associated. Results indicated that of the 14 potential issues listed on the MAP survey, mothers had eight remain stable (money, in-laws, sex, religion, alcohol and drugs, work/careers, rec/free time and friends) and 6 increase in severity (commitment to the relationship, communication, child, household tasks, jealousy and trust, and time spent together) from nine months to seven and a half years postpartum. Fathers had ten remain stable (money, in-laws, sex, religion, alcohol and drugs, commitment to the relationship, work/careers, household tasks, rec/free time, and friends) and four increase in severity (communication, child, jealousy and trust, and time spent together) from nine months to seven and a half years postpartum. Additionally, mothers and fathers tended to be similar in their rankings of problematic issues by time point more than within person over time. If marital conflict stability and change over the early years of parenthood can be better understood, data can be used by interventionists to provide conflict resolution skills to couples facing marital conflict.

Keywords: Marital conflict, transition to parenthood, dual-earner

Student Presenter: Samantha Walkin

Student Project Title: Impact of eccentric-focused downhill treadmill training on locomotor recovery after spinal cord injury

Student Project Abstract: Scientific understanding of spinal cord injury (SCI) and recovery continues to grow, yet a cure for the vast sensorimotor deficits remains elusive. Clinical treadmill treatment for SCI is commonly studied in animal models on a flat treadmill. However, our lab hypothesized that eccentric-focused downhill (DH) training, a novel and challenging intervention, will greatly improve locomotor recovery after SCI. Adult, male and female mice were used in trained (SCI+DH, n=7) and untrained (SCI only, n=6) groups. The mice underwent a moderate (75 kilodyne) thoracic contusion injury using a computer-driven device. At 36 days after SCI, mice walked on a DH treadmill at 6-10 meters/min for two, 10-minute bouts separated by 20 minutes of rest daily for 14 days. Kinematic videos were collected pre-injury, 35 days after SCI (before DH training), and at end of training. 2D kinematics quantified gait patterns using pelvis, hip, knee, ankle, and toe linear and angular excursion across the four phases of the step cycle. Overall, the kinematics did not show differences in timing (swing and stance duration and percent toe drag) or distance (step length), but differences between the two groups were shown in limb movement patterns. SCI+DH group showed significantly lower hip heights (closer to the floor) than the SCI only group during all gait phases (p<0.05), demonstrating an improvement in the animal’s hindlimb weight support directly under the body with increased muscular effort. Additionally, the SCI+DH group had significantly smaller knee angles than the SCI only group at swing initiation (p<0.05), demonstrating the animal can walk without overextending its hind limbs. These two improvements correspond as when the hindquarters are closer to the floor at swing initiation the limb does not lift as high during swing phase and therefore created a smaller knee excursion. These results show improvement in the overall locomotion of the SCI+DH group as they are more similar to their non-injured locomotor pattern than the untrained group. Eccentric-focused DH treadmill training may be an effective clinical intervention to improve movement patterns.

Student Presenter: Rebecca Weiss

Student Project Title: Influences of Muscle Control Patterns on Post-Operative Outcomes of Total Knee Replacement

Student Project Abstract: Osteoarthritis (OA) is a disease that is becoming increasingly more prevalent due to heavier and aging populations. Effects of OA in the knee range from weakness and instability to loss of motion, resulting in difficulty performing everyday tasks such as walking, stair negotiation, and chair rise. The end-stage treatment of knee OA is total knee replacement (TKR). Although the procedure is extremely common, 1 in 5 individuals who receive TKR report poor function post-operatively. Many factors have been studied to find the cause of these suboptimal results, however, the root cause has not been pinpointed. Recent work has investigated neuromuscular control patterns, specifically how simultaneous muscle contractions, or synergies, may provide insight to post-operative function. Those studies suggest individuals who report poor outcomes post-TKR display a lower number of synergies (n=2-3) than individuals with better outcomes (n=4-5). Despite other research suggesting that the condition of the non-operated limb may influence post-operative recovery, no studies have been conducted to explore the neuromuscular control of the non-operated limb and analyze it in this context. The purpose of this project was to investigate the neuromuscular control of the non-operated limb before and after surgery and determine the relationship between the number of synergies and post-operative function.

I analyzed previously collected gait data to calculate muscle synergies of TKR patients pre-operatively, and 6-months and 24-months post-operatively. Fifteen subjects (M/F 4/11; 60.2±6.8 y) were included based on quality of gait and electromyography (EMG) data at all 3 timepoints. The EMG data were filtered, rectified, and smoothed to create linear envelopes, then normalized to the maximum activation within each trial. Synergies were calculated using non-negative matrix factorization and averaged for each subject at each timepoint. Preliminary findings show that there is not a significant difference (p = 0.173) in the number of synergies before (n=2.7±.036) and 24-months after (n=2.9±0.57) surgery in the non-operated limb. However, data analysis is ongoing and will explore the relationship between synergies, in both number and characteristics, and functional and self-reported outcomes. The results of this study could inform post-operative rehabilitation to target the non-operated limb in addition to the operated limb.