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Summer 2018 Presentations
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Poster Presentation Schedule Thursday 10am-11am Presenter Name Allis Barker Morgan Childress Harrison Fu Sarah Ghalayini Jaewon Jeong Paul Tholath Dorottya Kacsoh Anling Kaplan Hadley Lyon Morgan Martin Kevin Tang Andrew Teodorescu Ella Vardeman Robert Roundy Annie Schiffer Evan Scope Crafts
Morning Session Thursday 11am-12pm Location Presenter Name 1 Ruth Mizu 3 Jordan Reed 5 Jacoby Robinson 7 Sydney Sharp 9 Smriti Singh 11 Cory Sylber 13 Kerian Thomas 15 Chayla Vazquez 17 Peiyao Wu 19 Jessica Yeung 21 Hyun Seong Seo 23 Kimberly Sharp 25 Emily Shingle 27 Michael Mu 29 Mguyen Nguyen 31 Eden Nitza
Thursday 12:30pm-1:30pm Presenter Name Emily Fan Addiskidan Hundito Somin Kim Noella Masengesho Otgonjargal Altangerel Liam Ashbrook Kathryn Bagger Arianna Borges Justin Burton Min Ji Choi Rita Wang Avery Zearfoss Wenying Zhu Joseph Piccolo Federico Prokopczuk Giveth Rocha
Afternoon Session Thursday 1:30pm-2:30pm Location Presenter Name 1 Tyler Pham 3 Sreesh Sridhar 5 Roysheda Tarver 7 Qihang Zhang 9 Hithardhi Duggireddy 11 Ben Furman 13 Sofia Garrido-Fajardo 15 Alexander Grayson 17 Ryan Johnson 19 Hannah Komanapalli 21 Thomas Kowal-Safron 23 Margaret Kyle 25 Amy Li 27 Afam Maduka 29 Leslie Mora 31
Location 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32
Location 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
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Session 1 10:30-10:45
Presenter
Location
Yi Xie
N304
10:45-11:00
Austyn Wohlers Camila ReedGuevara Aditi Majoe
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11:00-11:15 11:15-11:30 Session 2 1:00-1:15 1:15-1:30 1:30-1:45 1:45-2:00
Title
Becoming Americans: Chinese and African Americans’ Struggle Racial Inclusion and Uplift, 1860-1904 Ways of Reading: The Artist-Reader and the Aesthetics of The
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Seneca on Slavery and Education in the Letters
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Flake Variability and Skill Acquisition in Hand axe Making
Presenter
Location
Title
Brianna Brown
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Angel GonzalezValero Mia Morrell
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The Characterization of poly(A) RNA-Binding Protein, dNab2 linked to Human Intellectual Disability in Drosophila Melanogaster Chimeragenesis of Encapsulin Loop Domains for Modulation o Protein Quaternary Structure
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Soft Particle Clogging in 2D Hoppers
Alexis Palmer
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The Shifting Roles and Responsibilities of Adolescents and Emerging Adults with Type 1 Diabetes mellitus
Oral Presentation Schedule
*Oral Presentation abstracts start on page 35. ** Although students who participated through the SUPERR program are not presenting, their abstracts are listed starting on page 39.
Poster Presentation Abstracts
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PRESENTER: Otgonjargal Altangerel TITLE: Photoelectrochemical Water-Splitting by a Polyoxometalate AUTHORS: Otgonjargal Altangerel, Daniel Collins-Wildman, Craig L.Hill , PhD; Emory University PRESENTATION TYPE: Poster Presentation For centuries, the majority of increasing demand for energy due to population growth and industrial development has been supplied by the unsustainable finite resource of fossil fuels which are harmful to the environment. A large number of efforts to diversify world sources of energy are being made and photoelectrochemical water-splitting has been a promising area of research for energy generation at low cost in an ambient environment. In this study, the polyoxometalate K12Li16Co2[Co4(H2O)16P8W48O184] ¡60H2O (1) has been investigated for its electrochemical activity and stability as a new catalyst for the oxidation of water. This would provide us with additional insight into the mechanism of water oxidation. Co 2+ ions were added to an aqueous solution of a heteropolyanion K28Li5[H7P8W48O184]¡92H2O (P8W48) which was synthesized according to the published procedure to incorporate the ions into the wheel of P8W48. The compound 1 was tested for activity with the stopped-flow technique and has shown some activity. This suggests that 1 can be potentially used in water splitting reaction as a catalyst. For the remaining part of the study, water oxidation reaction is to be tested with 1. Additional tests on 1 are planned to be done to show that it is not Co2+ ions but the polyoxometalate itself that is performing the water oxidation catalysis. These results will be presented at the symposium.
PRESENTER: Liam Ashbrook TITLE: Mental Rotation in Preschool AUTHORS: Liam Ashbrook, Oberlin College; Jillian Lauer, MD, Emory University; Patricia Bauer, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Kathryn Bagger TITLE: Antimicrobial Activity of Ptelea trifoliata Against ESKAPE Pathogens AUTHORS: Kat Bagger, Emory University;; Lisa Giencke, J.W. Jones Ecological Research Center; Tharangamala Samarakoon, PhD, Emory University; Annie Schiffer,Emory Univeristy; Sarah Hanson, Emory University, Afam Maduka, Emory University; Ella Vardeman, University of Georgia; James (T.) Lyles, PhD, Emory University; Monique Salazar, Emory University; Cassandra (L.) Quave, PhD, Emory University PRESENTATION TYPE: Poster Presentation Ptelea trifoliata (Rutaceae), commonly known as Hop Tree, is a deciduous shrub that grows throughout Northern and Central America. Multiple native peoples from Mexico to Milwaukee have been documented using the plant leaves and roots for varying purposes
5 including gastrointestinal and respiratory medicine, drug potency enhancement, and chemical warfare. Previous scientific studies have discovered active agents within the plant, however, no study has explored its potential dermatological effects. Using this knowledge and additional information from the Native American Ethnobotanical Database, P. trifoliata was collected and processed from the Joseph W. Jones Ecological Research Center at Ichauway in Southern Georgia. Processing included separating, drying, and grinding the plant by individual parts (leaves, woody stems, and roots) in order to study possible varying properties in each tissue of the plant. The ground plant material was extracted by double maceration in 80% ethanol and concentrated via in vacuo and lyophilized in order to extract soluble phytochemicals. The P. trifoliata extract was then screened at a concentration of 256 Âľg/mL for growth inhibition against a panel of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) pathogens. Due to increasing resistance to various bacteria, reviewing native pharmacological approaches and modernizing their use could revolutionize public health. In future studies, fractionation of each plant part will occur, along with mass spectroscopy on the largest fraction by weight.
PRESENTER: Allis Barker TITLE: Evolving Symbionts in the Presence and Absence of their Insect Host AUTHORS: D. Allis Barker; Erika M. Diaz; Nicole M. Gerardo; Emory University, Department of Biology PRESENTATION TYPE: Poster Presentation Symbiosis between microorganisms and animals is sometimes obligatory for the survival of either or both organisms. This facultative symbiosis occurs in Anasa tristis squash bugs, which host their symbiotic bacterial fauna in their gut. The gut contains a section called the crypt, which is almost entirely populated by bacteria in the Burkholderia genus. A. tristis is not born with this symbiont. It must pick up Burkholderia from the environment during its growth by ingesting it. This makes the A. tristis model useful in that it is easy to control the strains of Burkholderia individual bugs are exposed to and develop with. Previously, our lab has shown that association with Burkholderia increases A. tristis’s lifespan and decreases time from hatching to maturity. We hope to expand on previous investigations by studying how affecting the Burkholderia populations through manipulating its environment over several generations changes its effects on A. tristis. Insight into how Burkholderia populations mutated through the absence of or constant contact with Anasa tristis have various effects on new generations of A. tristis will build on previously established knowledge about how dynamic symbiotic relationships arise, are lost, and change. PRESENTER: Arianna Borges TITLE: Multimodal Virtual Reality Pediatric Assessment of Concussion: Pediatric DETECT (Brain Buddy) AUTHORS: Arianna Borges, University of Georgia; Lidia Cardelle, Georgia Institute of Technology Michelle; LaPlaca, PhD, Georgia Institute of Technology and Emory University School of Medicine; Nicole Kosoris, Georgia Tech Research Institute; Erik Swanson, Georgia Tech Research Institute; Brian Liu, Georgia Tech Research Institute; Alessio Medda, PhD,
6 Georgia Tech Research Institute; Tamara R. Espinoza, MD, Emory University School of Medicine; Russell K. Gore, MD, Shepard Center; David W. Wright, MD, Emory University School of Medicine and Georgia Institute of Technology PRESENTATION TYPE: Poster Presentation Mild traumatic brain injury (mTBI), or concussion, is a serious condition caused by a hard blow to the head that results in headaches, dizziness, disorientation, nausea, and more. This is especially detrimental to children because they are in crucial developmental periods where a concussion may lead to complications later in life. Because of this, it is especially important to have an objective and reliable pediatric concussion assessment tool that considers the multiple potential signs associated with concussion. Unfortunately, there does not exist a tool that tests the many different ways that a concussion can manifest in a child as well as give an objective assessment in the time frame following the concussion. A pediatric version of the DETECT (Display Enhanced Testing for Cognitive Impairment and mTBI), has been created for kids between the ages of 9 and 12 that engages children in a series of carnival game-like virtual reality (VR) tests. Child DETECT incorporates the key pillars of concussion assessment, neuropsychological (word recall, processing speed, conditional choice, reaction time), balance (nonpostural), and oculomotor (target tracking) testing. Using a Unity programming platform and an Android/Samsung VR Gear system to implement it, this technology is pioneering the use of VR in medicine and will hopefully expand into other neurological areas. Testing is currently underway in non-concussed 9 to 12-year-olds to assess usability and test-retest reliability. It is anticipated that an animated, shortened battery of tests will not only engage children, but will ultimately provide an objective tool for improved clinical management.
PRESENTER: Justin Burton TITLE: Gravitational Waves from Two Black Holes in Orbit AUTHORS: Justin Y. J. Burton, Oxford College of Emory University; Ruomin Zhu, Emory University; Thomas Osburn, PhD, Oxford College of Emory University PRESENTATION TYPE: Poster Presentation This project models the dynamics of a binary black hole system with electrically charged components. These systems radiate gravitational waves, which can be observed by the groundbreaking astronomical observatories such as LIGO (Laser Interferometer GravitationalWave Observatory). The case with only one charged component has been modeled previously. [1] These systems are described by Einstein’s theory of general relativity. Systems with a large difference in mass are investigated to allow for simplification of Einstein’s and Maxwell’s equations through expansion in powers of the small mass-ratio. Utilizing separation of variables, the resulting ordinary differential equations are numerically solved using Python. The numerical solutions are then used to calculate the radiative energy dissipation from the gravitational and electromagnetic waves produced. The rate of energy dissipation is then used to model the inspiral trajectory of the smaller binary component. [1] R. Zhu and T. Osburn, Physical Review D 97, (2018).
7 PRESENTER: Morgan Childress TITLE: Biomechanical Analysis of a Unilateral Knee Exoskeleton AUTHORS: Morgan Childress, Wake Forest University; Bailey McLain, Georgia Institute of Technology; Dawit Lee, Georgia Institute of Technology; Aaron Young, PhD, Georgia Institute of Technology PRESENTATION TYPE: Poster Presentation Exoskeletons are robotic wearable devices that are a new and promising area of research for medical assistance and human augmentation. The biggest advantage of using a powered device compared to a passive exoskeleton is that a powered device is capable of generating power. For lower limb assistance, exoskeletons have been designed to assist hip, knee and ankle joints in different daily tasks such as walking and sit-to-stand motion. These devices can also be designed to assist in specific gait abnormalities. For example, children with cerebral palsy commonly exhibit crouch gait, excessive knee flexion, or genu recurvatum, knee hyperextension. The unilateral knee exoskeleton in this experiment is designed to assist the knee joint in ambulation with such abnormalities. The apparatus utilizes a torque sensor to allow closed-loop torque control to provide flexion and extension torque assistance during early stance phase of the gait cycle. With motion capture, muscle activity using EMG, and biomechanical analysis tools, we aim to analyze the safety and efficacy of the device through muscle activity, kinematics and kinetics with and without the powered exoskeleton on healthy adults. These results will allow us to examine how the unilateral knee exoskeleton alters the human body and gait. Once we understand the interaction between the exoskeleton and adults, we hope to make the knee exoskeleton applicable to children with cerebral palsy.
PRESENTER: Min Ji Choi TITLE: Synthesis and Purification of Disubstituted Thiadiazoles via C-H Activation AUTHORS: Min Ji Choi, Annette Neuman, PhD; Oxford College of Emory University PRESENTATION TYPE: Poster Presentation 1,3,4-Thiadiazoles show biological activities including anticonvulsant, antioxidant, antimicrobial, and anticancer. Disubstituted 1,3,4-thiadiazoles have been synthesized by the thionation and cyclization of substituted hydrazines. However, the classical method requires individual design of hydrazines for each target compound and does not facilitate the preparation of compound libraries with varied substituents. Therefore, we are developing a method to synthesize disubstituted 1,3,4-thiadiazoles via C-H activation. A Pd-catalyzed oxidative coupling of 1,3,4-oxadiazoles with various aryl groups has been recently reported. The purpose of our project was to extend the scope of this reaction to 1,3,4-thiadiazoles. After the synthesis of 2phenyl-1,3,4-thiadiazole according to known literature, the C-H bond of a monosubstituted 1,3,4thiadiazole was substituted with an aryl group using Pd(OAc)2 as a catalyst and Cu(OAc)2 as an oxidant. Formation of the disubstituted thiadiazole was confirmed by liquid chromatography mass spectrometry (LCMS). Purification and optimization of the reaction will be developed in the future.
8 PRESENTER: Evan Scope Crafts TITLE: Multiresolution Methods for Convolutional Neural Networks AUTHORS: Evan Scope Crafts (Mentor List as sole author) PRESENTATION TYPE: Poster Presentation Convolutional neural networks (CNNs) are a machine learning technique that have had success at important problems such as image classification and speech recognition. However, key parts of the design of the networks and their performance are not well understood. A new approach to this problem interprets CNNs as a discretized version of a partial differential equation (PDE). Multiscale methods, which analyze a PDE on a discretized grid, can be applied to CNNs to allow one network to train and evaluate data of different sizes. This project analyzes the performance of different multiscale methods on commonly used CNN network architectures and datasets. Applying these multiscale methods can reduce training times and utilize data of different resolutions as well as provide information on the stability of the CNN.
PRESENTER: Hithardhi Duggireddy TITLE: Unsupervised Clustering of Biomarker State Dynamics in Neurological Disorders AUTHORS: Hithardhi Duggireddy, Emory University; Mark Connolly, Emory University and Georgia Institute of Technology; Luke Drnach, Emory University and Georgia Institute of Technology; Annaelle Devergnas, PhD, Emory University School of Medicine; Babak Mahmoudi, PhD, Emory University School of Medicine; Lena Ting, PhD, Emory University and Georgia Institute of Technology; Robert Gross, MD, PhD, Emory University School of Medicine PRESENTATION TYPE: Poster Presentation Many neurological disorders may be treated using exogenous real-time control of dynamically transitioning states, such as in deep brain stimulation for epilepsy and human-robot interactions for gait disorders. The first step to modulate these dynamic states is to identify them. As the number of states is not known prior, we utilize an unsupervised clustering algorithm, Kmeans, to (1) determine the number of seizure states and gait phases and (2) assign these states to new data. To conduct seizure state analysis, data was collected from local field potential (LFP) recordings from a non-human primate penicillin (NHP-PCN) model of epilepsy to conduct gait phase analysis, motion capture data was used to measure the joint angles of healthy adults walking at constant speed on a treadmill. We then applied K-means to the power of the LFP spectral bands and joint angles to determine the number of discrete clusters and used these as a model to represent seizure states and gait phases. Our results show that K-means identified 2 seizure states and 4 gait phases. Qualitatively, these states correspond to seizure vs. non-seizure in the LFP dataset and swing and double stance for each leg in the gait dataset. Comparison with manually annotated class labels showed K-means had an accuracy of 75% and 68% in the clustering of LFP spectral band data and joint angle data, respectively. These findings suggest that unsupervised clustering can identify an alternative structure to the data that can provide additional insight into the transition between dynamic states.
9 PRESENTER: Emily Fan TITLE: Hiring the Enemy: The Origins of the US Army Air Forces’ Heidelberg Aeromedical Center through the Eyes of its First Director of Research, Howard B. Burchell, MD, PhD, Major USAAF AUTHORS: Emily Fan and Cynthia Patterson, PhD, Emory University PRESENTATION TYPE: Poster Presentation In their push to create a ‘big picture’ account, recent historical discussions of Operation Paperclip, the secret government program that brought German scientists to U.S. soil after the second World War, flatten and telescope the story, losing details of key background events and the intersectionality of the historical characters involved. This research project investigates in depth and detail one specific and little discussed episode that is an important piece of the larger background to the Paperclip program. We focus on the establishment of the U.S. Army Air Forces’ Aeromedical Center in the German city of Heidelberg, with special attention to the cast of characters who created and participated in the center through the late summer and fall of 1945. The experience of Dr. Howard B. Burchell, Major in the U.S.A.A.F. Medical Corps and the first Director of Research at Heidelberg acts as the thread that ties together the military, political, scientific, and medical perspectives of this narrative. His letters to his wife, Margaret (unknown to previous scholars), provide a candid portrayal of the events during this time period. Data collected from archives, interviews, memoirs, oral histories, scholarly monographs, and declassified documents from the military and intelligence committees are carefully crossreferenced with Burchell’s own correspondence to produce a novel account that emphasizes the multifaceted elements of historical analysis, the necessity of deep engagement of sources, and importance of the individual experience.
PRESENTER: Harrison Fu TITLE: Assessing the inflammation response to oral injuries in mice AUTHORS: Harrison Fu, Georgia Tech; Samir Ballestas, MD, Emory University; Yvonne Stephenson, BS, Emory University; Steven Goudy, MD, Emory University
PRESENTATION TYPE: Poster Presentation Cleft lip and/or palate is characterized by an incorrect fusion of tissues in the face and mouth. It is one of the most common birth defects, occurring in about 1:1000 live births. A common problem following palate repair surgery is an oronasal fistula (ONF), where an abnormal passage develops at the surgery site. The purpose of this project is to assess the inflammatory response during the baseline cellular response at ONF site healing. A 1.5mm thermal injury was created on either he hard or soft palate of the mice. Mice were euthanized at days 3, 5, and 7 and their palates were removed for posterior analysis. The RNA was extracted, and quantitative PCR was performed to analyze the gene expression of several cytokines. Hard palate showed a significant increase in inflammatory cytokine expression. On day 3, Interleukin(IL)-4 and IL-6 peaked at 3.3x and 11x control values. On day 7, IL-1 and TNFα peaked at 81x and 6.1x control values. Soft palate showed a smaller increase. IL-1, IL-4, and IL6 peaked on day 3 at 10x, 1.1x, and 5.0x control values. TNFα peaked at 1.4x control values on day 5. Anti-inflammatory cytokine IL-10 peaked at 3.5x and 2.6x control values for hard and soft palate respectively, with both peaks on day 3. In summary, hard palate injuries showed higher
10 inflammatory response compared to soft palate. The understanding of the inflammation process in the ONF model in mice will be useful to assess the effects of potential treatments during the healing process. PRESENTER: Ben Furman TITLE: Enhanced Biological Pacing by EMT Inhibition in TBX Reprogrammed Pacemakers AUTHORS: Ben Furman; Sandra Grijalva, BS, Emory University, Georgia Institute of Technology; Hee Cheol Cho, PhD, Emory University, Georgia Institute of Technology PRESENTATION TYPE: Poster Presentation Prolonged issues with electronic pacemakers, especially in pediatric patients, has led to an in increase in attempts to create biological pacemakers. Our lab has shown that the reexpression of a single transcription factor, TBX 18, in ventricular cardiomyocytes reprograms them into spontaneously beating pacemaker cells. However, TBX 18 is a known promoter of epithelial-mesenchymal transition (EMT), a process in which cells lose intercellular adhesion and become migratory. We hypothesize that EMT negatively impacts TBX 18 reprogrammed pacemakers, as the lack of adhesion and increased migratory behavior will prevent the cells from staying compact and electrically coupled, which is critical for synchronous pacing. To stop EMT, we are examining the effectiveness of natural inhibitors of TGF-B, a mediator of EMT, by testing dominant positive mutants of Smad2, Smad3, Smad7 (TGF-B inhibitors), and two dominant negative mutants of the TGF-B II receptor. We are using cell cultures of primary neonatal rat ventricular myocytes as our model. Plasmids of each of the aforementioned TGF-B inhibitors have been isolated and purified, and the transfection efficiency of the Lipofectamine 3000 reagent has been optimized for primary cardiomyocyte transfection by manipulating the concentration of both the DNA plasmids and the reagent. Following these preliminary steps, we will perform electrophysiological recordings using multiplexed multi-electrode array plates to measure the effects of each of the TGF-B inhibitors on the beating rate and beat rate variability, beating synchronization, conduction velocity and long-term pacing ability of TBX 18 reprogrammed cardiomyocyte monolayers.
PRESENTER: Sofia Garrido-Fajardo TITLE: Antimicrobial Potential of Chionanthus virginicus AUTHORS: Sofia Garrido-Fajardo, Scarsdale High School; Annie Schiffer, Emory University; Sarah Hanson, Emory University; Lisa Giencke, J.W. Jones Ecological Research Center; Tharangamala Samarakoon, PhD, Emory University; Afam Maduka, Emory University; Ella Vardeman, University of Georgia; James Lyles, PhD, Emory University; Kat Bagger, Emory University; Monique Salazar, Emory University; Cassandra Quave, PhD, Emory University PRESENTATION TYPE: Poster Presentation Chionanthus virginicus L. (Oleaceae) is native to eastern United States. It is commonly referred to as the white fringetree. The large shrub can be identified by its olive-like fruit, fringelike flowers and opposite leaves. The shrub grows to about 10 meters tall and the leaves are 10 to 20 centimeters long. The Choctaw tribe used both the roots and bark as a dressing for wounds and to treat infected sores. The bark was also used by the Koasati tribe to make a
11 decoction as a wash for cuts. Lignans present in the plant have been found to display antioxidant activity; specifically phillyrin, PDG (pinoresinol-β-d-glucoside), and PDDG (pinoresinol di-β-dglucoside) neutralized activities of radicals and inhibited peroxidation reactions of linoleic acid emulsions. The root barks are used as homeopathic medicines to treat hepatitis and jaundice. The Quave Research Group cross-referenced a list of plants containing dermatological activity from the Native American Ethnobotanical Database and plants growing at the Joseph W. Jones Ecological Research Center at Ichauway. Over 150 different species of plants were collected from during this expedition. Chionanthus virginicus was separated into different plant tissues, ground, and a double maceration was performed with 80% ethanol. The extract was screened at a concentration of 256 µg/mL against the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens panel. Fractionation by flash chromatography will be undertaken for further chemical analysis by mass spectrometry.
PRESENTER: Sarah Ghalayini TITLE: Functionalization of Encapsulin Nanocompartment with Elastin-Like Polymers AUTHORS: Sarah Ghalayini, Georgia Institute of Technology; Matthew Jenkins & Stefan Lutz, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Alexander Grayson TITLE: Site-Specific Hydration Levels Probed by (2,7)-Diazatryptophan AUTHORS: Alexander Grayson; Ban-Seok Jeong; R. Brian Dyer, PhD, Emory University PRESENTATION TYPE: Poster Presentation Protein-water interactions play a pivotal role in the dynamics, folding, and function of proteins. The level of hydration and how those water molecules interact with the protein helps determine the stability of that conformation as well as which components of the protein are accessible to the environment. The unnatural amino acid (2,7)-diazatryptophan has been found to sense both the environment polarity and the hydration level. A synthetic scheme was devised to produce L-(2,7)-diazatryptophan for Fmoc-mediated peptide synthesis. Then, this amino acid was substituted into Mastoparan-X, an antimicrobial peptide found to interact with lipid membranes, in place of its natural tryptophan residue. Upon peptide interaction with DPPC lipids, the ratio of fluorescence between the N1-H and N2-H species change, with N1-H species increasing and N2-H species decreasing. Further work will be done to test the change in fluorescence of (2,7)-diazatryptophan when Mastoparan-X is inserted into the membrane, using POPC/POPG lipids and increasing the temperature of DPPC lipids.
PRESENTER: Addiskidan Hundito TITLE: Using Patch Clamp Electrophysiology to Study Receptor Activation in Disease.
12 AUTHORS: Addiskidan Hundito, Emory University; Andrew Jenkins, PhD, Emory University PRESENTATION TYPE: Poster Presentation In this study, we aimed to detect functional GABAA receptors in cancer cells. GABA receptors are found throughout the central nervous system and they are the receptors that respond to the inhibitory compound GABA. We hypothesized that GABA receptor activity will be upregulated in cancer cells which gives the cells an advantage and a greater ability to metastasize. We used patch clamp electrophysiology which, in our study, involved taking a 1 micron wide glass electrode and attaching it tightly to a cell. Then a light suction was applied until that section of the membrane was broken and the cell was now in what’s known as “whole cell mode.” Membrane voltage of the cell was set to -60mv. Then, various concentrations of agonists are applied to the cell to measure the corresponding current. This was then used to compare receptor behavior in normal versus cancer cells. In our results we detected varying degrees of channel activation in cancer cell lines. GABAR activation may be important in cancer cell health. Targeting GABAARs may prove a useful method for enhancing chemotherapy efficacy. PRESENTER: Ryan Johnson TITLE: Inosine Labeling Using a Click-Compatible Acrylamide Derivative AUTHORS: Ryan Johnson, Steve Knutson, Jennifer Heemstra, PhD, Emory University PRESENTATION TYPE: Poster Presentation Adenosine-to-inosine (A-to-I) editing is a highly conserved and widespread form of posttranscriptional modification. The deamination of adenosine within RNA transcripts produces significant changes in cellular function and behavior. Accurately identifying the location of edited sites within the transcriptome is necessary to further understand the biological role and cellular dynamics of A-to-I editing. Previous work has demonstrated the selective chemical labeling and pull-down of inosines in RNA transcripts using an acrylamidofluorescein reagent. While effective, this method lacks flexibility in choice of affinity handle and function. To improve upon this motif, we report the synthesis and evaluation of a p-azido-Nphenylacrylamide reagent. This molecule exhibits similar selectivity for inosine, while providing potential for functionalization with numerous affinity handles and probes via click chemistry. PRESENTER: Jaewon Jeong TITLE: Altering Peripheral Immune Cell Infiltration Using Biodegradable Nanoparticles in the Intrahippocampal Kainic Acid Model of Temporal Lobe Epilepsy AUTHORS: Jaewon Jeong, Emory University; Youngjin Jung & Saeyoon Kim, MD, Yeungnam University School of Medicine; Jacob White, BA, Emory University; Dan Xu, PhD, Northwestern University; Irena Balzekas, BSc, Emory University; Sookyong Koh, MD, PhD, Emory University. PRESENTATION TYPE: Poster Presentation Epilepsy affects 1% of the population worldwide and about 40% of patients with epilepsy are resistant to antiepileptic drugs. Injury to the brain stimulates immune response leading to
13 neuroinflammation characterized with increased cytokine and glial activation, breakdown of blood brain barrier (BBB), and infiltration of peripheral leukocytes. This immune response can acutely promote recovery of the brain (Correale and Villa 2004), but continuous neuroinflammation can be harmful to the animals (Elenkov et al. 2005). Mesial temporal lobe epilepsy (MTLE) is the most common form of temporal lobe epilepsy (Falconer et al., 1964; Margerison et al., 1966). Intrahippocampal kainic acid model, or injection of kainic acid directly into the hippocampus of mice, causes pathological changes and a massive immune response that mimics MTLE in humans (Bouilleret 1999). Increased activation of microglia, astrocytes and proinflammatory cytokines has been observed in patients with epilepsy (Choi et al. 2008). Activation of these key immunomodulators are related to increased permeability in the blood brain barrier. The BBB regulates entry of cells and molecules into the CNS and provides a distinctive niche protected from cells and molecules found in the general circulation that could be harmful to the brain. (Choi et al. 2008). In this study, we administered naked (polylactic-coglycolic acid) nanoparticles (PLG) in IHKA mice models to modulate immune cells. We have found that utilizing PLG has significantly decreased the number of seizures and decreased neuroinflammation. Utilizing PLG has also decreased infiltrating immune cells in the brain. PRESENTER: Dorottya Kacsoh TITLE: Learning Infant Cues: Forming Associations Between Sound and Social Reward AUTHORS: Dorottya Kacsoh & Alex Dunlap & Robert C. Liu, PhD, Emory University PRESENTATION TYPE: Poster Presentation There is significant interest in understanding how neural circuits that control parental care integrate new infant-associated sensory cues. In rodents, female mice are able to learn through experience to associate pups with infant-predictive auditory cues that the pups do not intrinsically produce. The auditory cortex enhances these cues over the course of learning, but how that information reaches the canonical subcortical circuit for maternal responsiveness is unknown. To dissect this circuit as learning occurs, we conduct training experiments to track a mouse as it forms an association. To achieve that end, we developed a T-maze to train female mice to choose to approach a novel sound to receive a pup “reward�. Our current maze is large, slowing training and preventing high experimental throughout. Moreover, only 75% of mice can learn the task in our 8-day limit. We sought to develop a novel maze in a smaller rat-sized cage to increase experimental throughput without compromising the percentage of mice that learn the task. Subsequently, silencing brain regions downstream of auditory cortex would allow us to show their necessary contributions to learning infant-associated cues. While our new apparatus reduced the time to do 100 trials by half, the mice (n=3) did not learn over 8 days of training. Their failure to do so may be due to the short distance between our choice arms, which minimizes the cost of choosing incorrectly, impeding learning. Additional mice should be run (e.g. longer or more sessions) to definitively conclude whether this maze design is inadequate. PRESENTER: Anling Kaplan TITLE: Using Electrophysiology to Better Understand the Mechanism of GABAA Receptors in Pathological Sleepiness
14 AUTHORS: Anling Kaplan, Agnes Scott College; Andrew Jenkins, PhD, Emory University School of Medicine PRESENTATION TYPE: Poster Presentation Sleep is necessary for survival – however, its mechanism remains a mystery. Despite years of research, the current understanding of this process is incomplete. In the central nervous system the GABAA receptor is the most abundant inhibitory fast synaptic neurotransmitter receptor. This protein is also critical in binding sedative therapeutics such as benzodiazepines and anesthetics. Recent studies have discovered that there is an endogenous positive allosteric modulation of the GABAA receptors via a substance in the cerebral spinal fluid of patients who suffer excessive daytime sleepiness, which is a hallmark of Idiopathic Hypersomnia and Type 1 Myotonic Dystrophy. The hypothesis of this research is that people who present with a state of reduced arousal, impaired awareness and excessive sleepiness show hyperactive GABAA receptors which are enhanced by endogenous somnogens that are found in the brain. We expressed recombinant GABAARs in HEK293 cells; 2 days after transfection, we measured receptor activation and modulation using whole cell voltage patch clamp electrophysiology. Data was digitized using a 1440 AD converter and stored for offline analysis using MatLab. Significance was set at p < 0.05. Results were analyzed from 5-10 hypersomnolent CSF samples. The percent potentiation of GABAARs, was defined as 100(ICSF- ICTRL) / ICTRL, where ICTRL is the amplitude of the current response of just the GABA, and ICSF is the response to the 1:1 CSF dilution solution containing GABA. Our results support that individuals with pathological sleepiness have enhanced modulation of GABAARs via a substance in their CSF.
PRESENTER: Somin Kim TITLE: Investigating the effects of HDAC inhibitors Trichostatin-A and Valproic Acid on the Development of Myopia and Retinal Degeneration in the Interphotoreceptor Retinoid-Binding Protein Deficient Mouse Model AUTHORS: Kim, SM, Markand, S & Nickerson, J., Emory University PRESENTATION TYPE: Poster Presentation Little is known about the role of histone modifying proteins in the development of myopia and retinal degeneration (RD). Here we begin to phenotypically characterize the effects of two histone deacetylase inhibitors Trichostatin-A (TSA) and Valproic Acid (VPA) in an interphotoreceptor retinoid-binding protein (IRBP) KO mouse model, a model known to rapidly induce myopia and retinal degeneration in mice. To determine how TSA and VPA impact these deteriorative eye conditions, we randomly assigned IRBP KO mice to experimental and control groups. TSA-assigned mice were injected daily with TSA (2.5mg/kg) or vehicle (DMSO), while VPA-assigned mice were injected daily with VPA (350mg.kg) or vehicle (PBS) intraperitoneally using a double-blind system over the course of 5 days. Whole-eye biometry and SD-OCT was utilized to observe retinal layers, and electroretinography (ERG) was performed to provide additional information regarding how retinal function is affected, all of which showed that the chosen dosage of TSA and VPA made no significant improvement to visual function or the myopic phenotype. Immunohistochemistry, enzymatic assays, and western blots were conducted to reveal endogenous levels of HDAC3 deacetylate activity in IRBP KO mice as grounds for a possible underlying mechanism but was revealed that the absence of IRBP does not affect
15 HDAC3 activity or quantity. Data from these experiments will provide critical information on what role epigenetics plays in myopia and RD and the importance IRBP plays in the normal development of the eye. PRESENTER: Hannah Komanapalli TITLE: Effect of Flow on Growth of Endothelial Cells using 3D-Bioprinted Models in Development of Hypoplastic Left Heart Syndrome AUTHORS: Hannah Komanapalli, Undergraduate, Purdue University; Rithvik Sarasani, Undergraduate, Georgia Institute of Technology; Vahid Serpooshan, PhD, Emory University PRESENTATION TYPE: Poster Presentation Hypoplastic Left Heart Syndrome (HLHS) is a congenital heart disease where the left ventricle is underdeveloped, impeding blood flow to the body. Current treatments for HLHS can be invasive to infants and are not a cure. Causes are largely unknown, but studies suggest a lack of blood flow to the developing heart could lead to its underdevelopment. To study whether flow affects growth, 3D printed blood vessels were fabricated using a dual extruder ALLEVI bioprinter. Computer-aided design modelling was used to create 3D construct consisting of a 7×7×5 mm3 cube with an embedded cylinder of 1 mm diameter, serving as blood vessel. Initially, two pluronic inks were used to optimize parameters, followed by printing with gelatin methacrylate (gelMA, for tissue) and pluronic (for vessel). Average diameter of channels ranged from 1.65±0.03 to 2.01±0.02 mm. Pluronic was dissolved in PBS to leave a hollow cylinder mimicking the vessel. The constructs were seeded with HUVECs (1M/construct, injected into channel) and cultured in static (culture plate) and dynamic (bioreactor, flow of 5 mL/min) conditions. Cell viability and growth were assessed for 7 days using AlamarBlue assay and fluorescence microscopy. Our results provide a bioengineering platform to study effects of flow on cellular function in 3D biomimetic microenvironments and can lead to development of new treatments to HLHS and other blood flow-related diseases.
PRESENTER: Thomas Kowal-Safron TITLE: Optimization of Rhodium(III)-Catalyzed Allylic C-H Alkylation of Disubstituted Olefins AUTHORS: Thomas Kowal-Safron and Ashley Zachmann, Caitlin M. B. Farr, Jacob S. Burman, Simon B. Blakey, PhD; Emory University PRESENTATION TYPE: Poster Presentation Selective C-H functionalization is a popular emerging field in organic chemistry research due to the potential for increased efficiency in the syntheses of various pharmaceutically relevant compounds. Recently, advances have been made in allylic C-H functionalization with various nitrogen nucleophiles via Rh(III) catalytic complexes. Herein, an optimized method for the catalytic intermolecular allylic C- H alkylation of the trans-disubstituted olefin substrate 1,3trans-diphenylpropene with various malonate-type carbon nucleophiles via a Rh(III) catalytic complex is reported.
PRESENTER: Margaret Kyle
16 TITLE: The Developmental Impact of a High Fat Diet and Social Stress on Infant Emotional Regulation Neurocircuitry AUTHORS: Margaret Kyle, Andrew Kaldas, Melanie Pincus, PhD, Jodi Godfrey, PhD, Zsofia Kovacs-Balint, PhD, Elyse Morin, Longchuan Li, PhD, Kelly Ethun, PhD, Mark Wilson, PhD & Mar Sanchez, PhD, Emory University/Yerkes National Primate Research Center; Brittany Howell, PhD, University of Minnesota; Martin Styner, PhD, University of North Carolina. PRESENTATION TYPE: Poster Presentation Chronic psychosocial stress is associated with psychopathology in children and comorbid with consumption of highly caloric diets that pose a cumulative risk factor for obesity. It is not well understood, though, how neurobehavioral alterations caused by social stress emerge during development and interact with other risk factors, such as obesogenic diets. This study investigated the potentially synergistic impact of social stress and an obesogenic diet on infant and juvenile brain development longitudinally and the biological mechanisms involved, using a translational macaque model of social subordination stress. Thirty-nine socially-housed rhesus monkey mother-infant pairs (n=19 dominant (DOM), n=20 subordinate (SUB)) were randomly assigned to either a low-calorie diet (LCD) condition, or had access to both LCD and highcalorie diet (HCD) from birth (Choice). Brain structural MRI data was collected at 6 and 16 months of age. Hair cortisol and CRP levels were analyzed at the same ages to examine stressand diet-induced activations of neuroendocrine stress systems and inflammation. Preliminary results show larger amygdala and hippocampus volumes in SUB infants by 6 months of age, effects which persisted at 16 months, suggesting that early neurodevelopmental effects of social subordination are already detected during infancy and are long-lasting. At both 6 and 16 months, subjects with access to the obesogenic diet showed larger overall brain (ICV) volumes. These initial findings indicate that exposure to social subordination and obesogenic diets early in life impacts primate infant structural brain development, resulting in region-specific, non-synergistic effects.
PRESENTER: Amy Li TITLE: A Scalable System for Massive Behavioral Data Collection for Rodents AUTHORS: Amy Li, Yahia Ali, Tony Corsten, Chethan Pandarinath, PhD, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University PRESENTATION TYPE: Poster Presentation To study how the brain executes movements, one of the standard models researchers use is to train non-human primates (NHPs) and conduct multi-electrode recordings as they perform stereotyped behavioral tasks. However, because of the high cost to maintain and train NHPs, study sample sizes are typically small. Here we take an alternative approach of using highthroughput analysis to explore motor regions by developing a scalable rodent paradigm. Our project focuses on developing an inexpensive, scalable system capable of real-time behavioral measurements, which allows massive data collection by training animals in parallel. Our system, MiniTaskRunner, runs on a microcomputer (Raspberry Pi; rPi) that allows precisely-timed behavioral measurements and cue delivery. The software is built around a real-time model (Matlab/Simulink) where the communications between the host computer, rPi, and other
17 hardware devices rely on the utilization of blocks from Matlab Support Package for Raspberry Pi Hardware. During the behavioral experiments, the real-time Simulink model controls the electronic devices included in the behavior box to provide visual and sound stimulus for animals to cue them to interact with a manipulandum and perform supination or pronation behaviors. This model is able to collect data, such as position changes of the manipulandum, from the peripherals at a frequency of 500Hz. The development of such a system allows us and other researchers to collect massive but precise behavioral performance data and, thus, enable researchers to better study motor region related questions. PRESENTER: Hadley Lyon TITLE: Skipping Pain Medication: ATC Opioid Use in African American Patients Treated for Cancer Pain AUTHORS: Hadley Lyon, Agnes Scott College; Kate A. Yeager, RN, PhD, Jinbing Bai RN, MSN, PhD, Emory University PRESENTATION TYPE: Poster Presentation For African Americans (AA) cancer pain relief is sometimes inadequate due to the challenges of taking pain medication. The purpose of this study was to describe reasons why AA cancer patients being treated for pain skip around the clock (ATC) oral opioids. A secondary data analysis of a parent study (1K01NR014673) exploring pain medication adherences was completed. Data included: sociodemographic, clinical, and opioid taking behavior variables. Chisquare, Mann-Whitney U and Kruskal-Wallis tests were used to examine associations between study variables. The sample (n = 105) was primarily older (mean = 56 years), women (63%), and diagnosed with various types of cancer. Most received cancer treatment in the last month (59% chemotherapy, 20% radiation). Average pain score was 4.6/10. Over half skipped their ATC opioids (56%), including 31% who skipped within the last week. Among patients who skipped opioids, reasons included: being busy (21%), away from home (25%), a change in routine (25%), slept through dosage time (52%) and felt like they didn’t need it (57%). Of patients who skipped (n=58), they were more likely to skip if they “felt like they didn’t need it” (p = 0.04). 40% of patients that received chemotherapy recently skipped their medication. Having private insurance (p = 0.02) and having at least some college education (p = 0.001) were associated with not skipping opioids. Further work is needed to understand the paradox of having pain and skipping pain medication as well as other reasons why patients with cancer pain do not obtain adequate pain relief. PRESENTER: Afam Maduka TITLE: Nymphaea odorata: Analyzing Growth Inhibition of ESKAPE Pathogen AUTHORS: Afam Maduka, Emory University; Annie Schiffer, Emory University; Sarah Hanson, Emory University; Lisa Giencke, J.W. Jones Ecological Research Center; Tharangamala Samarakoon, PhD, Emory University; Ella Vardeman, University of Georgia; James Lyles, PhD, Emory University; Kat Bagger, Emory University; Monique Salazar, Emory University; Cassandra Quave, PhD, Emory University PRESENTATION TYPE: Poster Presentation
18 The Joseph W. Jones Ecological Research Center at Ichauway in southern Georgia has a large diversity of flora that have been used for centuries by Native Americans for both food and medicine. Additionally, the plants found in this region have shown some antibacterial activity against skin infections. Nymphaea odorata Aiton (Nymphaceae), also known as the American white water-lily, is a plant that has been shown to have some phenolic compounds, but not many studies have been done on the chemistry or antibacterial activity of the plant. This species is usually found in areas near bodies of water such as a pond or a lake. It was selected for analysis by looking at the Native American Ethnobotany research databases, and also cross referencing similar plants with known medicinal affects. After collecting the plant from a small pond area, the roots and stems/leaves were separated and put in a dryer to remove any water. After the plant material was completely dry, it was ground up, and then double macerated in 80% ethanol for 72. The macerations were then put on a rotovap to remove the solvent and then shell frozen and dried down on the lyophilizer. The extract was screened for growth inhibitory activity at a concentration of 256 Âľg/mL against the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens panel. In the future, flash chromatography and mass spectroscopic analyses will be applied to further examine the chemical makeup of this species.
PRESENTER: Morgan Martin TITLE: In Vitro Analysis of Caspase Activity in Peripheral Blood Mononuclear Cells of Healthy and Latent Mycobacterium-Tuberculosi Infected Individuals AUTHORS: Morgan Martin, Hampton University; Morgan Barham, Cheryl Day, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Noella Masengesho TITLE: C(SP2)-H Functionalization of Dehydroamino Acid Derivatives AUTHORS: Noella Masengesho, Amaan Kazerouni, Simon Blakey, PhD; Emory University PRESENTATION TYPE: Poster Presentation The C-H bond is traditionally considered unreactive due to a similarity in electronegativity of both atoms. This has been a limiting factor in chemical synthesis for many years, not until creative synthetic chemists came up with C-H functionalization discoveries that up to today, are revolutionizing concepts of modern chemical sciences application. C-H functionalization, with help from certain transitional metals as catalysts to form an organometallic intermediate, is a process that transforms a previously inert C-H bond into a more versatile, reactive C-C, C-O, CX, or C-B bond. In this project, substrates for a more controlled C(sp2)-H bond functionalization from dehydroamino acid derivatives are being studied to develop new pathways for late stage peptide diversification.
19 PRESENTER: Ruth Mizu TITLE: Selective Allosteric Modulators of the GluN3 Subunit of the N-Methyl-D-Aspartate Receptor AUTHORS: Ruth Mizu, Zongjian Zhu, MD, PhD; Matthew P. Epplin; David S. Menaldino, PhD; Scott J. Myers,PhD; Gil H. Shaulsky; Hongjie Yuan, MD, PhD; Dennis C. Liotta, PhD; Stephen F. Traynelis, PhD; Emory University PRESENTATION TYPE: Poster Presentation The N-methyl-D-aspartate receptor (NMDAR) is an ionotropic glutamate receptor whose activity is essential for proper synaptic transmission in the brain. NMDARs regulate ion flow across the plasma membrane of nerve cells, which plays an important role in central nervous system development, plasticity, and normal function. The NMDAR contains four subunits. Two GluN1 subunits that bind the neurotransmitter glycine are required for the NMDA receptor, while the other two subunits can be drawn from glutamate binding GluN2A, GluN2B, GluN2C, and GluN2D. Two additional Glycine binding subunits, GluN3A and GluN3B, appear capable of assembling with GluN1 to form a glycine receptor, but their roles are poorly understood. Here we determine the selectivity, site of action, and mechanism of action of the two new GluN3selective allosteric modulators. To ascertain selectivity, Xenopus levis oocytes were injected with RNA for receptors for serotonin, GABAc(Ď ), glycine Îą, purinergic P2x2(human), purinergic P2x2(rat), or GluN1/GluN3A. Two to three days later, agonist-activated currents were recorded from the Xenopus levis oocytes in the absence or presence of 10 uM positive allosteric modulator EU1180-289 and EU1180-437 or negative allosteric modulators EU1180-321 and EU1180-438. Overall, this project evaluates the potential of these agents to be GLuN1/GluN3 selective probes, which might be useful in unravelling the role of these subunits and receptors in neurons. These agents could allow testing of the therapeutic potential for modulation of GluN3containing receptors.
PRESENTER: Leslie Mora TITLE: Probing Sublimated Interstellar Water Ice Analogues Via Submillimeter Spectroscopy AUTHORS: Leslie Mora, Katarina Yocum, Stefanie N. Milam, PhD, Susanna L. Widicus Weaver, PhD; Emory University PRESENTATION TYPE: Poster Presentation The dense molecular clouds of the interstellar medium (ISM) are home to an abundance of molecular species and complex chemistry. Many chemical processes occur in this region and studying these clouds expands our knowledge of processes that form prebiotic molecules. Most of the chemistry in the ISM occurs within icy grains where molecular densities are high enough to drive the formation of complex molecules. In order to better understand the chemical processes that occur in interstellar ices, we are conducting a laboratory study of the ultraviolet irradiation of interstellar ice analogues. This study focused on water ice because it is one of the most abundant ices in the ISM and it is a simple molecule ideal for optimizing our novel laboratory approach. The ices undergo ultraviolet irradiation as well as thermal alterations under simulated interstellar conditions. Our experiment is unique because it employs submillimeter spectroscopy to monitor desorbed gases above laboratory ices while previous studies typically used mass spectrometry. Submillimeter spectroscopy is beneficial because it is noninvasive and
20 the high-quality laboratory data is directly comparable to remote observational data. Using this novel technique, we are working to determine how simple radical species sublimate from the ices where they can undergo further chemistry. Specifically, we are interested in the photochemical formation of OH and H radicals from water ices.
PRESENTER: Michael Mu TITLE: LCMT-1 as an essential component of neuronal development AUTHORS: Michael Mu, Emory University; David C. Pallas, PhD, Emory University School of Medicine Department of Biochemistry and Winship Cancer Institute PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Nguyen Nguyen TITLE: Real Time Detection Algorithm for Invasive Arterial Blood Pressure Metrics Applied to a Pilot Study of Pediatric Cardiac Arrest AUTHORS: Nguyen Nguyen3,4, Kyle Cowdrick1,2,MSE, Erin M. Buckley1,2 Ph.D; (1) Dept. of Biomedical Engineering, Georgia Institute of Technology and Emory University; (2) Dept. of Pediatrics, Emory University School Of Medicine; (3) Dept. of Physics, Mount Holyoke College; (4) Dept. of Computer Science, Mount Holyoke College PRESENTATION TYPE: Poster Presentation Cardiac arrest in children is a devastating event associated with high mortality and poor neurological outcome in survivors. After arrest, the brain experiences hyperemia followed by hypoperfusion, hypometabolism and impaired cerebral autoregulation, i.e. the process by which the cerebrovasculature regulates brain blood flow in response to changes in blood pressure. Unfortunately, evidence-based targeted neuro-protective therapies following cardiac arrest are lacking. Our lab is developing non-invasive optical instrumentation (dubbed frequency domain near infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) that enables real time, bedside quantification of cerebral oxygen metabolism, along with cerebral blood flow, tissue oxygen saturation, and cerebral autoregulation. Given the need for a direct, bedside cerebral monitoring modality post cardiac arrest, we are launching a pilot clinical study at the Pediatric Cardiac Intensive Care Unit at Children’s Healthcare of Atlanta in view of understanding the longitudinal evolution of cerebral injury after cardiac arrest using the aforementioned technologies. Quantification of cerebral autoregulation requires continuous monitoring of arterial blood pressure. Our lab has developed an arterial line transducer circuit to acquire and amplify invasively recorded blood pressure signals. In this project, we implemented a Labview real time feature extraction algorithm for annotating systolic, diastolic and mean arterial blood pressure metrics in order to verify proper performance of the blood pressure acquisition circuit in clinical setting. The accuracy of this algorithm is then evaluated using MIMIC Critical Care Database (an openly available dataset developed by the MIT Lab for Computer Physiology comprising of de-identified health data associated with critical care patients).
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PRESENTER: Eden Nitza TITLE: Population Genetic Structure in Trimerotropis saxatilis Lichen Grasshopper AUTHORS: Eden Nitza, Michael Martin, PhD, Oxford College of Emory University PRESENTATION TYPE: Poster Presentation Habitat fragmentation can limit animal movement, thus decreasing genetic diversity in isolated populations. In Georgia, rock outcrop communities are isolated from each other, potentially leading to a decrease in genetic diversity of rare endemic species such as the lichen grasshopper (Trimerotropis saxatilis). We used amplified fragment length polymorphisms (AFLPs) to describe the population genetic structure of T. saxatilis on and around Arabia Mountain. Five specimens were collected from each of ten sampling locations across Arabia Mountain (n=8), Panola Mountain (n=1), and the Georgia International Horse Park (n=1). Sampling locations on Arabia Mountain were separated by either potential barriers to dispersal (i.e., roads, canopied forest) or suitable dispersal habitats (i.e., bare rock). Genomic DNA was extracted from both femurs using a spin column-based extraction kit. AFLP analysis was conducted according to the protocol outlined by Vos et al. (1995), and consisted of genomic DNA extraction, digestion, ligation, pre-selective polymerase chain reaction (PCR), and selective PCR. The restriction endonucleases EcoRI and MseI were used to digest genomic DNA at the specific cut sites GAATTC and TTAA, respectively. Pre-selective PCRs included primers with a single selective base while selective PCRs included primers with three selective bases. Our results may have important implications for land managers and policy makers as they evaluate conservation priorities for patchily-distributed, specialist species like T. saxatilis.
PRESENTER: Tyler Pham TITLE: Molecular Regulation of Mitochondrial Calcium Transport AUTHORS: Tyler Pham and Jennifer Q. Kwong, PhD; Emory University School of Medicine PRESENTATION TYPE: Poster Presentation The Mitochondrial Calcium Uniporter (MCU) Complex (uniporter) is a Ca2+ transporter responsible for Ca2+ uptake into the mitochondrial matrix. Mitochondrial Ca 2+ has the dual function of both stimulating metabolism and initiating cellular death pathways. Research has shown that uniporter Ca2+ uptake depends on the MCU subunit of the transporter that forms a Ca2+ conducting pore. However, it has been proposed that this Ca 2+ conducting pore also encompasses additional MCUb subunits that hetero-oligomerize with MCU resulting in the suppression of Ca2+ uptake. Our experiments focus on the MCUb subunit because of its similarity in both sequence and structure to MCU but possibly lacks Ca2+ binding capacity. We hypothesize that the differences in the amino acid sequence in a critical domain present in both proteins results in the differences of functionality. Using cell lines expressing mutated variants of MCU and MCUb, compared to normal versions of MCU and MCUb, we have measured Ca 2+ uptake kinetics for each mutated cell line with the goal of identifying the specific portions of the MCUb protein responsible for its functionality. Ultimately, these experiments will aid us in better understanding the uniporter complex regulation.
22 PRESENTER: Joseph Piccolo TITLE: Solid-State Magnetic Tweezer Development: Improving Single-Molecule Techniques for the Study of DNA Mechanics and Gene Transcription AUTHORS: Joseph Piccolo, Daniel Kovari PhD, David Dunlap PhD, Laura Finzi PhD; Emory University PRESENTATION TYPE: Poster Presentation DNA transcription is the foundational biological process to practically all cellular life. Transcription and eventual gene expression is regulated via epigenetic proteins known as transcription factors. In the study of this process, single-molecule techniques are at the forefront of cutting edge research. Within the Finzi Lab, the pairing of tethered particle motion with magnetic tweezer manipulation allows for the study of the physical effect of specific transcription factors on DNA. Under the current setup, magnetic tweezer manipulation is achieved by positioning a set of permanent rare-earth magnets near the sample using motorized mechanical translators. Unfortunately, the electric motor introduces unwanted vibrations into the system, reducing the accuracy of measurements. The Finzi Lab is developing a set of electromagnet tweezers that eliminates physical motion within the system. In order to develop this apparatus, new hardware, including custom electromagnetic solenoids and controls electronics, as well as software systems had to be created. The first aim of this summer’s research was to produce a reliable control circuit, which required perfecting new methods for rapid, low-cost, circuit board fabrication. With a working prototype in-hand, the second aim was to demonstrate the electromagnetic tweezers performance in a side-by-side comparison with the previous mechanical system. PRESENTER: Federico Prokopczuk TITLE: 3D Bioprinting of Nanoparticle-Laden Cardiac Tissue Constructs AUTHORS: Federico Prokopczuk, California State University, Northridge; Huyun Chen, Georgia Institute of Technology; Vahid Serpooshan, PhD, Georgia Institute of Technology and Emory University School of Medicine. PRESENTATION TYPE: Poster Presentation 3D bioprinted cardiac patches are a promising tool to restore lost tissue in patients who suffered a myocardial infarction (i.e., heart attack). These scaffolds, however, face several challenges including possible infections post-implantation, difficulty with in vivo imaging and characterization, and inadequate electrical conductivity, that may hamper their clinical applications. Nanoparticles, particles with at least one dimension smaller than 100nm, have been used in a variety of biomedical applications and have desirable properties for 3D printed constructs. Our study aims to find out whether the application of nanoparticles, specifically super paramagnetic iron oxide particles (SPIONs) and gold nanorods (gold NR), confer properties that will be beneficial in bioprinted cardiac tissue constructs. Using the TSIM modeling software (Advanced Biosystems), we designed and printed cross-hatch constructs to model vascularized cardiac tissue. A range of different models were generated with varying numbers of cross hatches and different sizes of internal channels. Printing parameters were optimized using pluronic F127 and methacrylated gelatin (gelMA) with an ALLEVI 2 bioprinter. We found that altering the printing parameters of the bioinks used created significantly smaller internal channels than
23 expected, around 64% of the expected size. Further, preliminary data showed that nanoparticleembedded constructs exhibited significantly improved CT and MRI imaging qualities, higher antimicrobial properties, and lower electrical impedance. This work informs on the use of nanoparticles in 3D bioprinted cardiac patches and may contribute to their translational applications.
PRESENTER: Derick Rapista TITLE: Effect of Regular Aerobic Exercise on Endothelial Function in Chronic Kidney Disease AUTHORS: Derick Rapista, Emory University; Justin Sprick PhD, Emory University; Doree Morrison, MS, Emory University; Jeanie Park, MD, Emory University PRESENTATION TYPE: Poster Presentation Cardiovascular disease is the leading cause of death in Chronic Kidney Disease (CKD). In addition to conventional risk factors (e.g. blood pressure), the use of non-conventional risk factors may provide further mechanistic insights into the physiology underlying cardiovascular disease risk in CKD. One non-conventional risk factor that has been underexplored in CKD is endothelial dysfunction. Since aerobic exercise has previously been demonstrated to improve cardiovascular disease risk in cardiac patients, we sought to explore the use of exercise in CKD. We hypothesized that 12 weeks of regular aerobic exercise would improve blood pressure and endothelial function in CKD, supporting the use of this therapy in renal disease. 20 CKD patients (stages 3-4) were randomized to receive either stretching or aerobic exercise (cycling) 3 days a week for the duration of 10-12 weeks. Blood pressure and endothelial function were measured pre- and post-intervention via sphygmomanometry and peripheral arterial tone (PAT) technology respectively. In support of our hypothesis, mean arterial pressure (MAP) decreased with exercise from pre- to post-intervention (Exercise; Pre=96.3±3.45mmHg, Post=88.1±2.31mmHg, P=0.004; Stretching; Pre=96.9±3.03mmHg, Post=98.5±4.09mmHg, P=0.523). While not statistically meaningful, we also observed a trend towards improvements in endothelial function, assessed via reactive hyperemia index (RHI) in the exercise group. Future work should continue to explore the use of exercise in CKD, with a larger sample size and additional indices of endothelial function (e.g. flow mediated dilation, biomarkers). In conclusion, this investigation demonstrates the safety and efficacy of regular aerobic exercise in CKD as a method to improve cardiovascular risk factors. PRESENTER: Jordan Reed TITLE: Skin-specific adjuvants improve vaccination outcomes in aged mouse model. AUTHORS: Jordan Reed, Frehiwot Gossaye, Dahnide Williams-Taylor, Richard W. Compans and Elena Vassilieva PRESENTATION TYPE: Poster Presentation The prevention of influenza virus infections is currently among the top public health priorities worldwide. Furthermore, the elderly (65 years and older) are at higher risk of influenza-related complications. An estimated 71-85% of seasonal flu-related deaths and 54-70% of seasonal flu-related hospitalizations occurred in aged populations in 2005-2011 in the U.S. alone. This increase in hospitalizations correlates with immunosenescence, a decreased immune
24 response to infection and vaccination that occurs with age. Current influenza vaccines have low reactogenicity, but also low efficacy in aged people. Immunogenicity can be improved by utilizing skin vaccine delivery and adding safe, immune-boosting adjuvants. Intradermal vaccination takes advantage of the skin’s antigen presenting cells to facilitate stronger immune responses. We used two leading adjuvants identified for use in skin vaccinations, referred to here as compound A and compound B, separately and simultaneously with influenza A/California 07/09 (H1N1) vaccine to measure protective efficacy in the aged mouse model. We found that the two adjuvants, combined 1:5:5 (Vax:A:B) intramuscular (IM) and 1:10:1 (Vax:A:B) intradermal (ID), improved survival from 0% to 100% compared to the vaccine alone. The current strategy to increase vaccine efficacy in the elderly is to give them 4X more antigen when vaccinating. Our data shows the adjuvant combination paired with a normal vaccine dose increases survival to 100% 2 weeks post-challenge versus 75% survival using the current 4X antigen vaccination strategy for aged populations. Weight loss also improved in adjuvant combination groups, with average maximum weight loss 2.5X less than that of 4X vaccine alone. PRESENTER: Jacoby Robinson TITLE: Host-specificity of Escovopsis May Be Partially Mediated by Response to Antifungals AUTHORS: Jacoby Robinson, University of Kansas; Caitlin Conn, PhD, Emory University; Hassan Salem, PhD, Emory University; Nicole Gerardo, PhD, Emory University PRESENTATION TYPE: Poster Presentation Fungus-farming ants have, over the course of 50 million years, developed a highly specific mutualistic relationship with their cultivated fungus which serves as the primary source of food for these colonies. These ants feed and maintain the fungal gardens that are recurrently attacked by a parasitic microfungus from the genus Escovopsis. The infection can spread throughout the garden, killing the fungus, and, in turn, collapse attine colonies subsisting on it. Prior phylogenetic construction indicates that Escovopsis evolution closely follows that of both the cultivar and the attines themselves, thus possibly holding an evolutionary role in the ancient history of this system. Prior research has demonstrated host-specificity of Escovopsis, indicating that it selectively grows toward and infects its native attine cultivar. Escovopsis is highly hostspecific and nonnative cultivars are capable of repelling and suppressing Escovopsis growth. The ability to defend against Escovopsis infection relies heavily on the specific cultivar and Escovopsis species interaction. Defense against the parasite hinges on secretion of inhibitory compounds, however, Escovopsis spp. overcome native cultivar defenses, eventually infecting and destroying the cultivar. In this study, we demonstrate that Escovopsis species vary in their ability to grow and persist in the presence of different classes of antifungals. Combined with a genomic analysis that shows a fluctuating presence of antifungal transporters, it is possible that differences in secreted compound composition, from cultivars, may mediate host specificity of Escovopsis.
PRESENTER: Giveth Rocha TITLE: Understanding the Deep Ancestry of the Indigenous People of North America AUTHORS: Giveth Rocha and John Lindo, PhD, Emory University PRESENTATION TYPE: Poster Presentation
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The evolutionary history of Native Americans, to date, has been limited in scope, both in the data generated and tribe participation. A common theme of research on ancient DNA ancestry has found that the mixing of native and immigrant populations happened much more often than previously suspected, proving a greater exchange of cultures, diseases and genes. However, the evolutionary history of the many tribes of the Americas is poorly understood compared to other continents such as Europe, which have a surplus of evolutionary studies on the whole genome level. Recent advancements and affordability in computational population genetics and genome sequencing, have allowed a deeper understanding of the diversity and complex history of human evolution. Our goal is to apply the latest sequencing and computational methods to a comprehensive sample set of indigenous tribes throughout North America to address evolutionary and anthropological questions centered around regional demographic history, ancient local adaptation, and the effects of European colonization. In doing so, we will create the first deep coverage whole-genome reference panels of indigenous populations from the Americas. This will lead to the identification of ancient ancestral genetic patterns on the regional level and not on the level of the nebulous term “Native American ancestry,� which serves as a racial classification perpetuating the idea of a single homogenous and indistinguishable indigenous lineage. This study will further provide us information on current issues related to cultural change, racial mixing and immigration. PRESENTER: Robert Roundy TITLE: Preliminary Evaluation of Anhedonia and Memory in GALT-Null Rats AUTHORS: Robert Roundy, Kaylie Garcia, Shauna Rasmussen, PhD, Judith Fridovich-Keil, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Annie Schiffer TITLE: Antibacterial Activity of Prunus serotina Bark against ESKAPE Pathogens AUTHORS: Annie Schiffer, Emory University; Sarah Hanson, Emory University; Lisa Giencke, J.W. Jones Ecological Research Center; Tharangamala Samarakoon, PhD, Emory University; Afam Maduka, Emory University; Ella Vardeman, University of Georgia; James T. Lyles, PhD, Emory University; Kat Bagger, Emory University; Monique Salazar, Emory University; Cassandra L. Quave, PhD, Emory University PRESENTATION TYPE: Poster Presentation Prunus serotina Ehrh., commonly known as black cherry, is a tree species in the Rosaceae family common to the Eastern United States. According to the Native American Ethnobotanical Database, the Chippewa Native American people used a poultice of the inner bark of P. serotina as a dermatological aid on old sores and ulcers. Using medicinal practices of the Chippewa tribe as a guide, P. serotina was identified and collected at the J.W. Jones Ecological Research Center in Baker County, Georgia. After separating the specimens into leaves, woody stems, and fruits, each part was ground and extracted through two consecutive 72-hour macerations using 80%
26 ethanol. The extracts underwent in vacuo concentration, shell freezing, and lyophilization in the phytochemistry lab to isolate active compounds. Extracts were collected, and percent yields recorded. The woody stem extract of P. serotina was screened at a concentration of 256 µg/mL against a panel of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) for growth inhibitory effects. The search for new antibacterial agents is critical as the world faces growing antibiotic resistance and increased pathogen resilience. Future directions will involve creating fractions of the extract to further distinguish the compounds in the P. serotina bark. Additionally, the minimum inhibitory concentration (MIC) will be determined for the extract against any pathogen demonstrating >80% inhibition during this screen.
PRESENTER: Hyun Seong Seo TITLE: The Role of PVT-BNST Connectivity in Stress-Induced Depression AUTHORS: Hyun Seong Seo, Sherod Haynes, Larry Young, PhD; Emory University PRESENTATION TYPE: Poster Presentation Social stress is a prevalent issue in society and has been associated with stress-related disorders such as Major Depressive Disorder (MDD). The bed nucleus of stria terminalis (BNST) is a key brain region that has been shown to mediate adaptive responses to stress and may play a causal role in the development of MDD. Furthermore, the paraventricular thalamus (PVT) which encodes information relating to stress habituation through connections downstream to the BNST has also been shown to be involved in stress related disorders. However, the neural mechanisms underlying the onset of these disorders are still minimally understood. The Social Defeat Stress paradigm was used to investigate the circuitry that determines the temporal emergence of depression. We hypothesize that the BNST and PVT have concurrent roles in the temporal emergence of depression. Previous data has shown that there is neuronal hyperactivity in both regions of mice that exhibited depressive–like phenotypes after chronic social defeat. By using temporally specific Designer Receptors Exclusively Activated by Designer Drugs (DREADD), we inhibited BNST projecting PVT neurons during a period of enhanced stress vulnerability to potentially understand the circuitry between the PVT and BNST. By inhibiting these neurons during a specified period of social defeat known as the critical period, we observed social behavioral changes in mice even with the inhibition of PVT neurons connected to the BNST. The development of social avoidance may indicate that the PVT may have a less regulatory role in the manifestation of depressive behavior.
PRESENTER: Kimberly Sharp TITLE: Efficient Synthesis of Sensipar® Using Rhodium-Catalyzed Benzylic and Allylic C–H Amination AUTHORS: Kimberly R. Sharp, Taylor A. F. Nelson, Dr. Simon B. Blakey, PhD; Emory University PRESENTATION TYPE: Poster Presentation Regio- and enantioselective C–H aminations have provided shorter syntheses with reduced waste. To highlight these advancements we envisioned a short modular synthesis of
27 SensiparÂŽ, a common drug used to treat secondary hyperparathyroidism. The synthesis will begin with a previously reported enantioselective benzylic amination developed by the Davies group, followed by an allylic amination method previously reported by our group. Once that product has been successfully synthesized, hydrogenation will yield SensiparÂŽ. Preliminary results from a racemic benzylic amination using Rh2(esp)2 shows desired product. Here we report the ongoing optimization of the benzylic and allylic amination.
PRESENTER: Sydney Sharp TITLE: Targeting Metabolic Pathway to Promote Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes AUTHORS: Sydney Sharp & Sameer Sarma, Emory University School of Medicine PRESENTATION TYPE: Poster Presentation Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are an important cell source for regenerative medicine, disease modeling, drug development, and other clinical applications. Their main limitation is their immature phenotype which does not allow them to be used successfully in these endeavors. There have been many ways to attempt to mature hiPSC-CMs and targeting metabolic pathways could be one of the promising methods. There are widely known pathways that regulate metabolic functions and have been identified for promoting cardiomyocyte maturation during cardiac development. In this study, we used a small molecule agonist of a specific metabolic pathway to enhance the maturation potential of cardiomyocytes. To do this, hiPSCs were cultured and differentiated toward cardiomyocytes using growth factors Activin A and BMP4. Homogenous spheroid cells (3D) were generated using an Aggrewell plate. 3D cardiac spheres were then treated with this small molecule at the early stage. Two weeks after the treatment, cells were analyzed for gene expression and calcium transients. We found that the treatment significantly changed the expression of calcium handlingrelated genes and altered calcium transient kinetics. Therefore, our study identified that targeting metabolic pathway by a small molecule has the potential for use in promoting molecular and functional maturation of cardiomyocytes, thus, giving hiPSC-CMs the ability to play a more critical role in future clinical settings. PRESENTER: Emily Shingle TITLE: Exploring O2 Reactivity Mediated by Iron-Based, Biomimetic Complexes with Redox Active Ligand Backbones AUTHORS: Emily Shingle, Elaine E. L.-N. Liu, John Bacsa, PhD.; Cora E. MacBeth, PhD; Emory University PRESENTATION TYPE: Poster Presentation One of the most abundant and environmentally benign oxidants found in nature is O2. Although within the last two decades more attention has been directed towards utilizing O2 as a greener and more economically viable oxidant, synthetic systems using O2 as the terminal oxidant in catalytic cycles are rare. However, many metalloenzymes systems use O2 for selective oxidation. Therefore, the synthesis of first-row transition metal complexes that can activate O2 is a subject of interest. Iron-containing enzymes make up a majority of the metalloenzymes present
28 in the human body that facilitate O2 activation. Developing biomimetic systems will allow both a better understanding of less well studied enzymatic processes such as cysteine dioxygenase, as well as the synthetic conditions for utilizing O2 as an oxidant. This research investigates the interaction of O2 with iron complexes that have various reactive ligand backbones to test the ligand environment and observe how O2 activation occurs with respect to the metal center. The complex K_2 [Fe^(2+) (HL^iPr)_2] (where L^iPr=(N(o-PhNC(O)^i Pr)(o-PhNHC(O)^i Pr))_2 ] ^(2-)) was synthesized, isolated, and characterized and the O2 reactivity was studied. Analogous, asymmetric iron complexes that combine redox active ligand backbones and biologically relevant ligands, such as thiols that mimic cysteine, were also synthesized and studied.
PRESENTER: Smriti Singh TITLE: Microfluidic Device Sorting of Pediatric ALL Cells AUTHORS: Smriti Singh, Undergraduate PERSE Fellow, Emory University; Sebastian Kahf, Research Specialist, Emory University School of Medicine, Department of Hematology and Medical Oncology; Nicholas Stone, PhD Candidate, Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology; Todd Sulchek, PhD, Woodruff School of Mechanical Engineering, Georgia Institute of Technology PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Sreesh Sridhar TITLE: Novel Curcumin Analogs Selectively Inhibit Colistin Resistant Bacterial Growth AUTHORS: Sreesh Sridhar; Emily K. Crispell, PhD; Jessie E. Wozniak, Spandan Chennamadhavuni, PhD; Dennis C. Liotta, PhD; David S. Weiss, PhD; Emory University PRESENTATION TYPE: Poster Presentation With the increased rate of antibiotic resistant infections found in clinical settings, the need for working antibiotics steadily grows. Colistin is a last-line drug that is used to treat multidrug resistant Gram negative bacteria, however, an increasing amount of bacterial infections now display resistance against colistin. Curcumin, the main component of turmeric, has been shown to inhibit rifampicin resistance in Mycobacterium tuberculosis. Preliminary tests demonstrate curcumin exposure to Enterobacter cloacae and Klebsiella pneumoniae displayed restored colistin susceptibility in colistin resistant strains. Monocarbonyl analogs of the parent curcumin compound illustrate varying degrees of resistance inhibition. Certain analogs demonstrate high rates of killing specifically against resistant strains, lowering colistin MIC to clinically susceptible levels. These results highlight the potential of these curcumin analogs as treatments for colistin resistance against resistant bacteria.
PRESENTER: Cory Sylber TITLE: Role of Scavenger Receptors in DNAzyme Uptake in the Lung
29 AUTHORS: Cory Sylber, Emory University; Bridgette Peake, PhD, Emory University School of Medicine; Cherry Wongtrakool, MD, Emory University School of Medicine PRESENTATION TYPE: Poster Presentation Scavenger receptor (SR) surface proteins are highly conserved motifs and are implicated in the uptake of nanotherapies. Gold nanoparticles functionalized with DNAzymes (DzNP) represent a promising novel nanotherapy for lung diseases such as asthma, particularly because they can be delivered directly to the lung. Our lab has been studying the therapeutic potential of a DzNP targeting GATA-3, a master transcription factor regulating Th2 inflammation, in an animal model of allergic asthma. Although nanotherapy uptake through scavenger receptors has been described in macrophages in other models, the role of SRs in DzNP uptake in the lung is poorly understood. We hypothesize that scavenger receptors mediate DzNP uptake in both airway epithelium and alveolar macrophages. To examine this hypothesis, we will characterize the expression levels of transcripts and distribution of SRs in alveolar macrophages and airway epithelium in vitro using qRT-PCR and histological silver staining. We will employ the known SR-A blockers, dextran sulfate and polyinosinic acid, and concomitantly treat alveolar macrophages and airway epithelium with DzNPs to determine whether DzNP uptake is wholly dependent on scavenger receptor binding. Understanding the impact SRs have on nanoparticle uptake may lead to novel interventions that enhance DzNP uptake through manipulation of SR binding. PRESENTER: Kevin Tang TITLE: Effects of Glucose Levels on Pabpn1 Gene Expression in C2C12 and N2A Cells: Implications for Oculopharyngeal Muscular Dystrophy AUTHORS: Kevin Tang, Emory College of Arts and Sciences; Ayan Banerjee, PhD, Brittney Phillips, PhD, Katherine Vest, PhD, Anita Corbett, PhD, Emory University Department of Biology PRESENTATION TYPE: Poster Presentation RNA-binding proteins are critical for cellular function because they are involved in the control of gene expression. PABPN1 is a nuclear poly(A)-binding protein that regulates poly(A) polymerase (PAP) which determines the length of the poly(A) tail in RNAs and regulates poly(A)-signal (PAS) utilization. A mutation in the PABPN1 gene leading to an expansion of the N-terminal alanine tract causes the muscle disease oculopharyngeal muscular dystrophy (OPMD), which causes weakness in the eyelids, pharynx and proximal limb muscles. Previous research from our group revealed that the levels of PABPN1 protein and Pabpn1 RNA are low in muscles in mice and humans. We also demonstrated that the RNA-binding protein HuR negatively regulates Pabpn1 mRNA in vitro and in vivo. To further understand how Pabpn1 is regulated, we investigated how glucose levels affect gene expression in vitro. We cultured C2C12 myoblasts in high and low glucose growth media and conducted immunoblotting and quantitative reverse transcriptase PCR to determine whether there is a difference in gene expression. C2C12 cells closely mimic the behavior of primary muscle myoblasts and serves as a good in vitro model. The experiment was also conducted in N2A neuroblastoma cells as previous studies have indicated potential brain involvement in OPMD. Overall, we determined that low glucose leads to higher levels of Pabpn1 in C2C12 cells and lower Pabpn1 levels in N2A cells.
30 As such, we have begun to uncover another mechanism that regulates Pabpn1, which could provide insight on future studies investigating potential treatments for OPMD patients.
PRESENTER: Roysheda Tarver TITLE: Expression of Genes Involved in Mitochondrial Protein Synthesis is Altered in Mutants of the SLC25A1 Gene Implicated in 22q11.2 Deletion Syndrome AUTHORS: Roysheda Tarver, Agnes Scott College; Avanti Gokhale, PhD, Emory University; Victor Faundez, MD, PhD, Emory University PRESENTATION TYPE: Poster Presentation Schizophrenia is a chronic psychiatric disorder affecting approximately 1% of the American population. While several genetic and environmental factors are implicated in disease progression, the precise molecular mechanisms that lead to psychiatric phenotypes remain unknown. To better understand disease mechanisms, our lab studied 22q11.2 deletion syndrome (22q11.2DS), caused by the hemizygous deletion of 22q11.2 in 40 to 60 genes on chromosome 22. Nearly 30% of individuals with 22q11.2DS develop the disease, making this polygenic deletion the strongest genetic risk factor for Schizophrenia and an opportune model to study pathogenic mechanisms. Of particular interest is SLC25A1, a citrate transporter localized to the inner mitochondrial membrane and one of the genes hemideleted in 22q11.2DS. Previous research in our lab including genealogical proteomics, functional assays, and bioinformatics revealed that mitochondrial respiration levels and mitochondrial protein synthesis were altered in SLC25A1 deficient cells. Based on this, we predicted that expression of genes encoding subunits of mitochondrial ribosomes and other mitochondrial protein synthesis machinery would be modified in SLC25A1 null cells. To test this prediction we focused on 4 specific mitochondrial ribosomal subunit proteins - MRPL52, MRP63, MRPL38, and MRPL33. Using quantitative Reverse-Transcriptase PCR (qRT-PCR), we measured the expression of MRPL52, MRP63, MRPL38, and MRPL33 in control cell lines and those missing SLC25A1. Based on our proteomic and bioinformatic analysis, we predicted that these 4 markers would have altered expression in cells lacking SLC25A1. This novel data emphasized the connection between mitochondrial function, protein synthesis and pathogenic mechanisms that lead to severe neurological phenotypes.
PRESENTER: Andrew Teodorescu TITLE: Skepticism, Speculation and Scandal: An Event Study of the Teapot Dome Affair AUTHORS: Andrew Teodorescu, Emory University; Caroline Fohlin, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available.
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PRESENTER: Paul Joseph Tholath TITLE: Factors Effecting RNA Duplex Stability AUTHORS: Paul Joseph Tholath; Christopher J Butch, PhD, Emory University; Thomas M Kaiser, PhD, Emory University; Savita Sharma, PhD, Emory University; Dennis C Liotta, PhD, Emory University PRESENTATION TYPE: Poster Presentation Modern biology uses adenosine triphosphate (ATP) as the primary carrier of metabolic energy. Why biology selected NTPs, rather than other energy carriers such as thioesters, NAD, or FAD, among others, is an open question. Further, the selection of ATP over the other NTPs is largely unexplored. We hypothesize that these selections may have initially occurred during an early era of life during which the enzymatic machinery of the cell was less complicated and the influence of the fundamental chemistry of nucleic acids played a more direct role in cellular processes, specifically replication. The chemistry of replication in this context has been thoroughly explored, and efficient replication has been shown to be quite difficult to achieve. Without the sophisticated enzymes to facilitate replication, complementary RNA strands tend to remain annealed to one another, preventing replication from occurring. Consequently, small molecules which changes the equilibrium of RNA complementary strands could significantly alter control of the replication process. Since canonical nucleotides are known to interact with nucleic acid duplexes through non-Watson-Crick base pairing, it is likely that high concentrations of NTPs would affect RNA equilibrium. We designed experiments to analyze the stability and kinetics of RNA duplexes of varying the G-C content, strand length and sequence in the presence of differing concentrations of NTPs. The data was then analyzed to see whether any single nucleotide had a significant impact on the kinetics of deannealing of our system which could explain why it may have evolved to be the energy carrier for biological systems. PRESENTER: Kerian Thomas TITLE: Ionic Effect on Amyloid Self-Assembly AUTHORS: Kerian Thomas, Georgia State University; Chen Liang, Jill E. Smith, PhD, Yilin Zhang, David G. Lynn, PhD, Emory University PRESENTATION TYPE: Poster Presentation The amyloid hypothesis suggests that the assembly of the Aβ peptide causes plaque buildup surrounding neurons in Alzheimer’s patients. Studying the structure of these assemblies lends insight into the mechanism of plaque formation. Multiple environmental factors that have been shown to impact assembly, including; pH, presence of metals like copper, temperature, and presence of salt. In this experiment, we studied the structural progression of the assembly of the nucleating core of Aβ Dutch mutant, Aβ (16-22)E22Q or Ac-16KLVFFA22Q-NH2 in the presence of salt. Sodium chloride has been shown to affect growth of amyloid intermediates in the assembly pathway through various mechanisms. Here, the structural, kinetic, and mechanistic effects of salt was studied utilizing isotope-edited IR and TEM over a series of weeks. In the particle phase salt increases the rate of assembly without affecting morphology. In the amyloid phase, structural transition is kinetically enhanced with new confirmation generated.
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PRESENTER: Ella Vardeman TITLE: Analysis of the Antimicrobial Properties of Pluchea rosea AUTHORS: Ella Vardeman, University of Georgia; Annie Schiffer, Emory University; Sarah Hanson, Emory University; Lisa Giencke, J.W. Jones Ecological Research Center; Tharangamala Samarakoon, PhD, Emory University; Afam Maduka, Emory University; James Lyles, PhD, Emory University; Kat Bagger, Emory University; Monique Salazar, Emory University; Cassandra Quave, PhD, Emory University PRESENTATION TYPE: Poster Presentation Pluchea rosea Godfrey (Asteraceae), also known as Rosy Camphorweed, is a flowering plant found in marshes, wet prairies, and savannas. Pluchea rosea was selected for collection by cross-referencing the Native American Ethnobotanical Database with plants available at the Joseph W. Jones Ecological Research Center in Baker County, Georgia. The Pima Native Americans of Southern and Central Arizona have recorded dermatological applications of related species in the same genus. An infusion of Pluchea sericea Nutt. roots are used to wash the face and sore eyes. A poultice of the roots is also used to treat snake bites on horses. The aerial parts and roots were separated after collection to isolate specific chemical compounds found in each part of the plant. The separated ground plant material was extracted by a double maceration with 80% ethanol and processed to isolate soluble phytochemicals through in vacuo concentration and lyophilization. The dried extracts were screened at a concentration of 256 Âľg/mL for growth inhibitory activity against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter sp.) for growth inhibition. ESKAPE pathogens are prevalent infections throughout the world that have developed multidrug resistance. Analyzing potential sources of defense against a panel of ESKAPE pathogens and other arising antibiotic resistant infections is important for combating multidrug resistance as a global public health threat. Beyond this project, Pluchea rosea will be fractioned via flash chromatography. The fraction with the most mass will be analyzed by mass spectroscopy to characterize specific active compounds.
PRESENTER: Chayla Vazquez TITLE: AIS Changes in Fmr1 KO Neurons and How it Relates to Homeostatic Mechanisms AUTHORS: Chayla Vazquez, Pernille Buelow, Gary Bassell, PhD; Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Rita Wang TITLE: Expression of wzz1 and wzz2 at the Single-Cell Level in Nonmucoid and Mucoid Pseudomonas aeruginosa AUTHORS: Zihuan (Rita) Wang, Ashley R. Cross, Joanna B. Goldberg, PhD, Emory University PRESENTATION TYPE: Poster Presentation
33 Pseudomonas aeruginosa is an opportunistic bacterium and is among the most common pathogens responsible for causing lung infections in people with cystic fibrosis (CF). Once a chronic infection is established, P. aeruginosa converts from a nonmucoid to a mucoid phenotype. Additionally, chronic isolates lose expression of the O antigen. O antigen is a repeat polysaccharide attached to lipopolysaccharide (LPS) and is characterized as long or very long based on the number of subunits present. Each length is controlled by a chain-length control protein: Wzz1 controls long and Wzz2 controls very long. Preliminary experiments have determined that at a population level, nonmucoid strains express both wzz1 and wzz2 while mucoid strains only express wzz2. However, the expression pattern of wzz1 and wzz2 at the single-cell level remains unclear. We hypothesize that individual nonmucoid cells will express only wzz1 or wzz2 while all mucoid cells will only express wzz2 and further that these expression patterns will be maintained overtime. In order to test our hypothesis, we constructed nonmucoid and mucoid P. aeruginosa strains containing the wzz1 and wzz2 promoters fused to two different fluorescent markers. Using these fluorescent promoter fusions, we were able to monitor the growth of each of our strains as well as the expression of each promoter in individual cells overtime using a confocal fluorescent microscope. Unraveling how wzz1 and wzz2 are expressed will provide insight into the chronic adaption of P. aeruginosa to the CF lung. PRESENTER: Peiyao Wu TITLE: Colloidal particles phase transition - what prevents perfect crystallization? AUTHORS: Peiyao Wu, Emory University; James T. Kindt, PhD, Emory University PRESENTATION TYPE: Poster Presentation Gravity influences the behavior of particles in everyday life, but usually its effect on microscopic particles is negligible. Colloidal glass microspheres in water behave in between these two extremes: the force of gravity will keep a single layer of particles resting at the bottom surface of a container filled with water, but the spheres’ thermal energy will be enough to occasionally lift some out of this layer. In recent studies, we used Monte Carlo simulations to study how gravity and thermal energy affect the ordering transition of spheres at the surface. The results from those simulations showed much faster ordering than experiments. We hypothesized that the origin of the difference in behavior was that the particles in the initial simulations were all identical in size (monodisperse) while the experimental samples had a range of sizes (polydisperse). To study polydispersity effects on structure and dynamics, we ran several groups of simulations on mixtures of particles of the same average size but having a Gaussian distribution of particle sizes with standard deviations 5%, 7.5%, and 10 %. Systems with 5% polydispersity behave similarly to monodisperse cases, with domains of hexagonal order growing rapidly in size and spreading across the simulation box. For the mixtures of particle sizes of wider Gaussian distribution, domain growth slowed down significantly after average domain sizes reached 10, in qualitative agreement with experiment. From this we conclude that the degree of polydispersity is very important in determining ordering behavior under gravity. PRESENTER: Jessica Yeung TITLE: Quantifying Emissions of HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) and Analyzing its Environmental and Health Impacts
34 AUTHORS: Jessica Yeung, Emory University; Eri Saikawa, PhD, Emory University PRESENTATION TYPE: Poster Presentation The stratospheric ozone is essential to terrestrial and aquatic ecosystems, crop production, and human health, by absorbing UV radiation. Chlorofluorocarbons (CFCs) are ozone-depleting substances (ODS) that destroy the stratospheric ozone by interaction with chlorine atoms. To regulate major and detrimental ODS like CFCs, the 1987 Montreal Protocol (MP) and its amendments were ratified as a global agreement to protect the stratosphere. With the phase-out of CFC production and consumption from the MP, many countries turned to hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) for their lower ozonedepleting potentials (ODP). For example, HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) is one of the preferred alternatives to the common CFC-11 and is emitted from centrifugal chillers in low-pressure air conditioning systems. In this study, we focus on HCFC-123 emissions because they pose both climate and potential health-related risks, such as acute hepatoxicity, in addition to being an ODS. Furthermore, HCFC-123 emissions data do not exist and the global magnitude and origins of its emissions are not well known. To create HCFC-123 emissions estimates, we utilize the common HFC-134a (1,1,1,2-tetrafluoroethane) as a proxy, due to its similar usage in centrifugalchiller production. Using these emissions in a global 3D chemical transport model – MOZART 4 – and an inverse modeling methodology, we optimize HCFC-123 emissions for several regions using observational data for atmospheric mixing ratios. Providing a more detailed analysis and projection of HCFC-123 emissions estimates is a first step in better understanding the impacts of HCFC-123 and its effects on stratospheric ozone, climate, and human health.
PRESENTER: Avery Zearfoss TITLE: Organocatalytic Radical Hydroarylation for the Synthesis of Substituted Arylethylamines AUTHORS: Avery Zearfoss, Allyson Boyington, Nathan Jui, PhD, Emory University PRESENTATION TYPE: Poster Presentation Arylethylamines are medically relevant molecules with structures similar to neurotransmitters and therefore, are powerful drug precursors. We have developed an inexpensive, facile, and metal-free intermolecular coupling method to synthesize these molecules. This radical photoredox hydroarylation method forms aryl radicles from stable precursors and couples them with olefins to form arylethylamines through a mild, rapid, and direct mechanism. In addition to working with aryl iodides and bromides as radical precursors, we have found that this system is functional with cheap, commercially available aryl chlorides.
PRESENTER: Qihang Zhang TITLE: Impact of Ordinary Differential Equation Discretization on the Training of Deep Residual Networks AUTHORS: Qihang Zhang, Emory University PRESENTATION TYPE: Poster Presentation Deep Neural Networks (DNNs) are a core technique in machine learning that have been applied to various important problems including image classification and object detection. The
35 Residual Network (ResNet) is one of the most widely studied and used DNN architectures due to its benchmark performance as it eases the training process while allowing the network gets deeper. The ResNet utilizes skip connections between network layers to create more predictable performance for arbitrarily deep DNNs. A new way of interpreting this network framework is as a forward Euler discretization of an ordinary differential equation (ODE). By interpolating the trained weights, this interpretation allows us to create networks of varying depth using the same number of weights, reducing training times. This project investigates the performance and stability of networks of different depth with the goal of creating deep stable networks that require minimal training time and give accurate classification results. PRESENTER: Wenying Zhu TITLE: Investigating Cognitive Mechanisms of Source Memory in Rhesus Monkeys (Maccaca mulatta) AUTHORS: Wenying Zhu, Ryan J. Brady, Rober R. Hampton, Phd, Emory University PRESENTATION TYPE: Poster Presentation Recognizing previously encountered items can be controlled by at least two cognitive processes. Familiarity represents the fact that an item has been experienced before, whereas source memory encodes specific information about the context of an encounter. Evidence for source memory in rhesus monkeys is scant, and little is known about the underlying cognitive mechanisms that support the discrimination between contexts. In a series of experiments, we investigated cognitive mechanisms supporting context discrimination in a recognition paradigm. In Experiment 1, Monkeys were shown images associated with two contexts that were separated with a five-minute interval, and recognition memory tests were given after each of the context 2 images. At test, monkeys were presented with four images: one from the first context, one from the second, and two novel images. Monkeys were rewarded for selecting context 1 images. Across sessions, all monkeys showed a shift from selecting context 2 images at test, to selecting the context 1 images. This result demonstrates an ability to discriminate between contexts, akin to source memory. To assess the extent to which this discrimination is supported by active memory mechanisms such as working memory, or a more passive familiarity judgement, followup experiments investigated the effects of various delay intervals and an added concurrent cognitive load between context 2 and recognition tests on accuracy. Preliminary results show that longer time intervals disrupt the monkeys’ performance more than concurrent cognitive load, suggesting that familiarity may play a larger role than working memory.
Oral Presentation Abstracts
PRESENTER: Brianna Brown TITLE: The Characterization of Poly(A) RNA-Binding Protein, dNab2, Linked to Human Intellectual Disability in Drosophila Melonagaster AUTHORS: Brianna Brown1, Binta Jalloh1, Tina Lence2, Jean-Yves Roignant1, Anita Corbett1, and Kenneth Moberg1; (1) Department of Cell Biology, Emory University, Atlanta, GA; (2) Institute of Molecular Biology, Johannes Gutenberg University, Mainz, Germany PRESENTATION TYPE: Oral Presentation The human brain is a complex system that is comprised of billions of neurons. The precise location, connectivity and function of these neurons is critical for brain development and function and are tightly regulated by gene encoding RNA binding proteins. There are over 500 RNA binding protein encoding genes that play important roles in brain development and function. One particular RNA binding protein that has been linked to a Non-Syndromic Autosomal Recessive form of human intellectual disability is ZC3H14. The ZCH143 gene encodes for a poly(A) RNA-binding protein that is ubiquitously expressed in all cell types. To understand the function of this gene we employ Drosophila Melanogaster, or the “fruit fly”, as a model system. Our lab generated a fly missing the ZC3H14 functional ortholog, dNab2, and observed several important phenotypes. dNab2 mutant flies present distinguishable characteristics such as a “wings-held-out” phenotype, reduced survival, brain defects analogous to the hippocampus, and defects in RNA metabolism. Additionally, dNab2 mutants also exhibit a large sex skew ratio that favors the survival of females compared to males. One hypothesis to explain this phenomenon is that sex lethal, a gene that is the master regulator of sex in these flies, is being altered and expressed incorrectly, resulting in the increased death of male flies. This project aims to explore the characterization and effects of a mutated dNab2 gene and the effects of the sex lethal gene and how they play critical roles in the development and survivability of the flies.
PRESENTER: Aditi Majoe TITLE: Flake Variability and Skill Acquisition in Handaxe Making AUTHORS: Aditi Majoe; Dr. Justin Pargeter, Emory University Department of Anthropology; Dr. Dietrich Stout, Emory University Department of Anthropology PRESENTATION TYPE: Oral Presentation Stone tool making, or knapping, is believed to be strongly linked to the evolution of culture and social learning in human beings. Making stone tools such as handaxes has been found to require a combination of substantial motor ability and cognitive capabilities, in addition to several hours of practice. We used debris collected from a longitudinal experiment that involved teaching novices how to make handaxes to study the effect of social learning via instruction from expert to novice knappers. In order to further our understanding of the processes underlying skill-acquisition of toolmaking, it is important to analyze the patterns of morphology of the flakes in lithic assemblages. Handaxe production requires the skillful removal of a few long, large flakes from the core. Our study focused on the quantitative and qualitative characteristics of these large ‘outlier’ flakes. Using photogrammetric methods, and open-source data collection and computing softwares such as R, Image J, and E4, we analyzed flake
37 thickness, width, platform shape, and exterior platform angles among other variables. We used these to understand the correlation between different flake variables and skill-level of the knapper by comparing data between assessments by the same knapper, as well as between novice and expert handaxe-makers. Our study furthered current knowledge of how social transmission affects skill, and the contribution of individual variation to skill acquisition.
PRESENTER: Mia Morrell TITLE: Soft Particle Clogging in 2D Hoppers AUTHORS: Mia Morrell and Eric R. Weeks, PhD, Emory University PRESENTATION TYPE: Oral Presentation We study the outflow of soft, low-friction, hydrogel beads from a quasi-2D hopper, examining the probability of clog formation as a function of hopper exit width. Clogging occurs when an arch forms at the hopper exit. By tilting the hopper chamber, we vary the force of gravity driving the flowing bead system. We find that clogging of soft beads requires the hopper exit to be only slightly larger than the bead diameter, and increasing the force driving the beads towards the exit results in a decreased probability of clogging, holding exit width constant. We find that vibrating the entire hopper system results in decreased clogging probability, an effect that is also displayed in simulations of the system.
PRESENTER: Alexis Palmer TITLE: The Shifting Roles and Responsibilities of Adolescents and Emerging Adults with Type 1 Diabetes mellitus AUTHORS: Alexis Palmer, Cassidy Puckett, PhD; Emory University PRESENTATION TYPE: Oral Presentation Around 1.25 million American children and adults have Type 1 diabetes mellitus, also known as juvenile diabetes. There is research on the importance of patients receiving proper diabetes selfmanagement education in order to ensure that they are able to successfully perform self-care outside of the hospital setting. However, it is common for those with Type 1 diabetes to be diagnosed as a child or young adult, leaving parents/caregivers to have majority of the involvement in the management of the adolescent’s disease. Nevertheless, there is a period of time where the patient with diabetes begins to adopt the role as an independent administrator in their management. I conducted an observational study at the Children’s Healthcare of Atlanta’s Endocrinology clinic. By observing Certified Diabetes Educators (CDE’s), providers (physician and nurse practitioner), and adolescents and emerging adults with Type 1 diabetes and their parents/caregivers during four transition clinic sessions, I was able to explore the process in which there is a shift of roles and responsibilities in management of the disease. The process by which this transition occurs requires a negotiation amongst a number of people including the patients themselves, their caregivers, the healthcare providers, and insurance companies. Each participant involved in this negotiation affects its progression in a different way. I study how transition clinic aims to provide a formal clinical setting for adolescents and emerging adults
38 (AEA) with Type 1 diabetes to undergo a shift of roles and responsibilities surrounding the management of their chronic disease.
PRESENTER: Camila Reed-Guevara TITLE: Seneca on Slavery and Education in the Letters AUTHORS: Camila Reed-Guevara, Undergraduate at Emory University PRESENTATION TYPE: Oral Presentation This paper analyzes the author's original translations of Seneca the Younger’s letters to better understand his philosophical understanding of slavery and education, in the Letters on Ethics to Lucilius. A close reading of these letters demonstrates Seneca’s various positions. First, a philosophical education is the best method by which an individual can achieve a virtuous life. Second, slaves are human beings with the same abilities as freed-people and free-born citizens. While this doesn’t seem radical to a modern reader, this is a major break with the ancient philosophical canon which asserted that anyone who would be in the system of slavery was a “natural” slave. It also indicates that slaves have the ability, and perhaps the divine right, to be educated. Thus, by extension, enslaved people can achieve and demonstrate virtue. Seneca’s philosophy can be read as an advocacy for education for all individuals including the lowest socio-economic strata of any culture. Beyond this, Seneca’s work indicates that slavery, or any form of social death, is an unnatural condition; that is, while unfreedom is created by social and cultural means, slavery does not exist in nature. This, in conjunction with his belief that philosophy is open to all individuals regardless of their social states, creates a vision of the world that was unique in his historical moment. This paper uses original translations to argue for the contemporary value of Senecan philosophy in an attempt to prove the universal equality of humans and the human right to an education.
PRESENTER: Angel Gonzalez-Valero TITLE: Chimeragenesis of Encapsulin Loop Domains for Modulation of Protein Quaternary Structure AUTHORS: Angel Gonzalez-Valero, Matt Jenkins, Stefan Lutz (PhD), Emory University PRESENTATION TYPE: Oral Presentation Similar to membrane-based compartmentalization in eukaryotic cells, prokaryotes can establish physical boundaries within their cellular environment with the help of protein-based encapsulins. Individual encapsulin proteins can self-assemble to form nanocompartments; hollow spheres consisting of either 60 or 180 homomeric subunits. Structure analyses suggest that the E-loop, one of encapsulin’s three distinct structural features, is responsible for conformational changes which give rise to the two distinct quaternary structures of these nanocompartments. This study examines the structural effects of swapped E-loops of encapsulins from Thermotoga maritima (TmE; native 60-mer), Myxococcus xanthus (MxE; native 180-mer), and Pyrococcus furiosus (PfV; native 180-mer). Through extensive multiple sequence alignments across several orthologues of the native encapsulins, a TmE-MxE loop variant was established and cloned. The TmE-MxE loop variant underwent dramatic structural change with a majority of its monomers remaining disassembled.
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PRESENTER: Austyn Wohlers TITLE: Ways of Reading: The Artist-Reader and the Aesthetics of Theft AUTHORS: Austyn Wohlers PRESENTATION TYPE: Oral Presentation Abstract not available. PRESENTER: Yi Xie TITLE: Becoming Americans: Chinese and African Americans’ Struggle for Racial Inclusion and Uplift, 1860-1904 AUTHORS: Yi Xie PRESENTATION TYPE: Oral Presentation This research aims to break the black-and-white racial binary perspective and develop a clearer understanding of the racial dynamics of the second half of the nineteenth century by studying the “Chinese Question” and the “Negro Problem” and the relationship between the two. The major historical legislation indicated the anti-Chinese agitation and resulted in the limited inclusion of African Americans and the complete exclusion of the Chinese in the U.S. The Chinese struggled to reverse the “negroization” of their status and to elevate and stabilize their social standing as racially and culturally superior. Some African Americans strived for their racial uplift by identifying against the Chinese—seeing “Chinaman” as “foreigner,” “interloper," and “invader,” while others identified with Chinese, “proclaim[ing] the brotherhood of man.” An inclusive perspective for the study of the nineteenth-century racial dynamics therefore is necessary. I investigate whether the “Chinese Question” was a question of race or immigration from various points of view, why and how the Chinese and African American questions were conflated, and how dynamic and complex was the relationship between the two. I take a historical and literary approach, analyzing historical newspapers, manuscripts, speeches, and pamphlets. To date, there is limited scholarship that focuses on African American-Chinese relations in the nineteenth century. This research’s grassroots approach will bring new insights to this often-overlooked topic within the nineteenth-century racial dynamics.
SUPERR Abstracts PRESENTER: Hannah Baratz TITLE: Ektacytometry in Sickle Cell Disease AUTHORS: Hannah Baratz, Emory University; Shateesh Chonat, MD, Emory University; David Archer, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available.
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PRESENTER: Kahsavyah Buckley TITLE: Examining the Association of NEDD4-2 and NCC AUTHORS: Kahsavyah Buckley Rickta Mallick, Abinash C. Mistry, and Robert Hoover MD; Emory University School of Medicine PRESENTATION TYPE: Poster Presentation The sodium chloride cotransporter (NCC) is a transmembrane protein located in both the DCT1 and the DCT2 of the nephron. The function of NCC is to reabsorb NaCl from the tubular filtrate. Aldosterone regulates the activity of NCC. However, the effects of aldosterone on NCC are localized exclusively to the DCT2, due to the co-expression of the mineralocorticoid receptor and 11ď ˘-hydroxysteroid dehydrogenase type 2 (11ď ˘HSD2). The epithelial sodium channel (ENaC) is another transmembrane protein that reabsorbs sodium and is localized to the DCT2. Previous research has shown that NCC and ENaC associate with each other and appear to directly bind. NEDD4-2 is an aldosterone-regulated protein that ubiquitinates both NCC and ENaC, resulting in degradation. However, while NEDD4-2 binds directly to ENaC it is unclear whether it directly binds NCC. This is because there is no consensus binding site for NEDD4-2 on NCC. This study examines if the interaction between NEDD4-2 and NCC is direct or indirect. To test this, co-transfections (GST-NCC- C-terminus/ NEDD-2, GST-NCC-N-terminus/NEDD42) and transfections (GST-NCC-C-terminus and GST-NCC-N-terminus) in COS-7 cells were done. These cells do not natively express NCC, ENaC, or NEDD4-2 permitting us to examine direct interactions. Western Blot analysis was done to verify expression of GST-NCC and NEDD4-2. After confirmation of protein expression, a GST pull-down assay will be done to assess the interaction between NCC and NEDD4-2. Specifically, to test whether the N-terminus or C-terminus of NCC binds to NEDD4-2 in the presence or absence of ENaC. Experiments are ongoing to fully characterize this association. PRESENTER: Joseph Elengickal TITLE: Selective CD28 Blockade Increases Immune System Suppression in the Setting of Viral Infection AUTHORS: Joseph Elengickal, University of Georgia; Rebecca Crepeau, PhD; Mandy Ford, PhD; Emory University PRESENTATION TYPE: Poster Presentation Kidney transplantation is a lifesaving therapy for end stage renal disease patients. Immunosuppression is necessary to avoid host rejection but must retain protective immunity. Calcineurin inhibitors have dramatically improved short-term graft survival, but their nephrotoxicity leads to loss of graft function over time. Costimulatory molecules are of interest for immunosuppression as they affect adaptive immune responses. CTLA-4 Ig binds to CD80/CD86, blocking both costimulatory CD28 and coinhibitory CTLA-4 signaling. While drugs using CTLA-4 Ig, abatacept and belatacept, have increased graft function over time, they increase rates of acute rejection and viral reactivation. Recently, anti-CD28 domain antibodies (dAb) that selectively target CD28 and leave CTLA-4 intact are promising new avenues for immunotherapy. This study aims to elucidate the effects of selective CD28 blockade on the anti-viral immune response. Mice were infected with a YFP-labeled recombinant MHV-68, a
41 murine model of EBV, and received either PBS, CTLA-4 Ig, or anti-CD28 dAb and monitored for T and B cell responses. Our results reveal that both dAb and CTLA-4 Ig mice had decreased populations of antigen-specific cells, however the dAb maintained lower populations over time while CTLA-4 Ig approached PBS levels at later time points. Virally infected B cells were found to be increased in dAb treated mice compared to CTLA-4 Ig, suggesting that dAb is a more potent inhibitor as it maintains CTLA-4 coinhibitory signals leading to higher viral load. The effector T cell populations suggest that dAb is more effective in suppressing the T cells leading to weaker immunity to viral infections.
PRESENTER: Spencer King TITLE: Pendrin Gene Ablation Activates NCC and BK Pathway AUTHORS: Spencer King, University of Georgia; Derek T. Pham, Emory University; Susan M. Wall, MD, Emory Univeristy PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Janet Le TITLE: Effects of Different MLP Constructs on ENaC Function AUTHORS: Janet Le, University of Texas at Austin; Chang Song, MD, Emory University; Douglas Eaton, PhD, Emory University PRESENTATION TYPE: Poster Presentation Abstract not available. PRESENTER: Monisha Mistry TITLE: NFkB Mediates Zinc-Deficiency Induced Blood Pressure Increases via the Sodium Chloride Cotransporter AUTHORS: Monisha Mistry, Meagan K. Naraine, Aswathy Cheriyan, Jasmine Williams, Rickta Mallick, Robert S. Hoover, and Clintoria R. Williams; Emory University PRESENTATION TYPE: Poster Presentation Zn2+ deficiency (ZnD) is a common comorbidity with numerous chronic diseases. In these settings, ZnD exacerbates hypertension. The sodium chloride cotransporter (NCC), located in the distal convoluted tubule (DCT) of the renal nephron, plays a critical role in blood pressure (BP) regulation and hypertension. The transcription factor Nuclear Factor kappaB (NFkB) is activated in settings of ZnD and contributes to numerous essential cellular processes. This study’s objective was to determine if NFkB plays a role in ZnD-induced NCC upregulation. We hypothesize that ZnD activates NFkB, which leads to NCC upregulation and BP increases. To this end, wild type (WT) mice were fed a Zn 2+ adequate (ZnA; 50 ppm) or ZnD diet (1 ppm) for 6 weeks. To test the hypothesis, WT mice on a ZnD diet (6 weeks) were administered Caffeic acid phenethyl ester (CAPE), a NFkB inhibitor. Systolic BP was monitored via tail-cuff. In in vitro experiments, WT DCT cells were treated with CAPE for 24 hours prior to inducing ZnD
42 with the intracellular Zn2+ chelator TPEN. NCC mRNA and protein expressions were examined via qRT-PCR, western blot, and immunohistochemistry. NCC activation was assessed by cellular localization via biotinylation and immunofluorescence. Findings show that BP is increased in ZnD mice. This is accompanied by changes in urinary Na + excretion and increased NCC mRNA and protein expression. Notably, ZnD-induced BP increases are reduced by CAPE treatment. Furthermore, CAPE treatment of DCT decreases NCC expression compared to TPEN-treated cells. These results indicate that NFkB plays a role in ZnD-induced NCC upregulation and BP. PRESENTER: Hayley Moyer TITLE: IL-6 Mediated Increases in Renal Sodium Reabsorption via the JAK/STAT Pathway AUTHORS: Hayley C. Moyer, Emory University; Gillian G. Hecht, Emory University; Ashwini Krishnamurthy, Emory University; Rickta Mallick, Emory University; Robert S. Hoover, MD, Emory University and Atlanta Veteran's Administration Medical Center; Brandi M. Wynne, PhD, Emory University PRESENTATION TYPE: Poster Presentation Hypertension is an inflammatory disease characterized by increased sodium (Na +) reabsorption and is a leading cause of death and disability worldwide. The effect of mineralocorticoid receptor (MR) antagonists in reducing blood pressure suggests a role for the MR in hypertension. Interestingly, the classical MR ligand, aldosterone (Aldo) is not always increased during hypertension; however, the pro-inflammatory cytokine interleukin 6 (IL-6) is elevated in hypertensive serum. Previously we have shown that IL-6 increases both MRdependent Na+ uptake in vitro and expression of the Na+ chloride cotransporter (NCC) in vivo. Cytokines produce intracellular effects through multiple pathways, including the Janus Kinase (JAK)/Signal Transducer and Activation of Transcription (STAT) signaling pathway. While multiple isoforms of each of these kinases have been implicated in other IL-6-mediated inflammatory responses in the kidney, no studies have identified the specific JAK/STAT pathway combination that may mediate this process. We hypothesize that the JAK2/STAT3 signaling pathway is involved in MR-mediated activation of NCC. Using a luciferase reporter assay, we show that IL-6 increases mineralocorticoid response element (MRE) activity via JAK2/STAT3 signaling in a cell model of distal convoluted tubule cells (mDCT15). Additionally, we show that IL-6 infusion increases the IL-6 receptor-dependent signaling molecule gp130, and phosphor(T53) NCC. Together, our data suggest a mechanism of IL-6 mediated NCC activation and JAK2/STAT3 activation of the MR, demonstrating an alternative mechanism for increased distal nephron Na+ reabsorption in hypertension.
PRESENTER: Bianca Olivieri TITLE: Patient-provider Race Concordance and Access to Kidney Transplantation AUTHORS: Bianca E. Olivieri1, Laura J. McPherson2, MPH, Reem E. Hamoda2, MPH, Stephen O. Pastan3, MD, Rachel E. Patzer2,4, PhD, MPH, Affiliations: (1) University of Central Florida, Orlando, FL; (2) Department of Surgery, Emory University School of Medicine, Atlanta, GA; (3) Department of Medicine, Renal Division, Emory University School of Medicine, Atlanta, GA; (4) Department of Epidemiology, Rollins School of Public Health, Emory University PRESENTATION TYPE: Poster Presentation
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Although kidney transplantation (KTx) provides significant survival benefits compared to dialysis, many end-stage renal disease (ESRD) patients referred for KTx evaluation at a transplant center do not attend this appointment. Patient-physician race concordant relationships can impact patient satisfaction, adherence and response time in seeking healthcare. Thus, this study investigated the association of patient-provider race concordant relationships with KTx evaluation attendance. A telephone survey was administered to adult ESRD patients referred for KTx evaluation to three Georgia transplant centers in 2016. During the survey, patients identified their race and the race of their kidney doctor. Patient-provider race discordance was defined as the patient reporting a different race than the provider. Evaluation attendance was abstracted from medical records. Multivariable logistic regression was used to assess the association between patient-provider race discordance and evaluation attendance. Of the 457 patients, 43.8% were female and 72.2% were black with an average age of 55.7 years. Approximately two-thirds (69.4 %) of patients reported being in race discordant provider relationships, with black patients more frequently reporting discordant relationships compared to whites (77.9% vs. 41.7%; p <0.01). In multivariable analyses, there was no statistically significant association between patient-provider race discordance and not attending the KTx evaluation (OR 1.31, 95% CI 0.81 2.13). While no statistically significant association was found between race concordance and evaluation attendance, results suggest a lack of racial diversity among ESRD providers. A more diverse provider population may encourage better patient-provider communication and promote culturally sensitive environments to enhance ESRD patient healthcare utilization.
PRESENTER: Aditya Sood TITLE: Metformin Improves Urine Concentration Ability in Humanized Sickle Cell Mice AUTHORS: Aditya Sood, Faten Hassounah, BS, Fitra Rianto, MD, Lauren LaRocque, BS, David R. Archer, PhD, Janet D. Klein, PhD, Jeff M. Sands, MD; Emory University School of Medicine PRESENTATION TYPE: Poster Presentation The kidney’s ability to concentrate urine is normally dependent on the actions of vasopressin, which promotes phosphorylation of the water channel, aquaporin 2 (AQP2), and water reabsorption. One characteristic of sickle cell pathology is an inability to concentrate urine despite normal vasopressin levels. We studied whether an alternate pathway could improve urine concentration in the humanized sickle cell mice. Metformin activates adenosine monophosphateactivated kinase (AMPK). AMPK phosphorylates AQP2 and the UT-A1 urea transporter. Sickle mice given metformin (800 mg/kg/d) by oral gavage daily for 5 days were compared with sickle mice and control mice that did not receive metformin. Urine osmolality in metformin-treated sickle mice (2413 ¹ 176 mOsM) was significantly elevated from untreated levels (1903 ¹ 29 mOsM) (p<0.05;n=8-10/group). Metformin increased urine osmolality within 24 hours and continued to improve over the next 4 days. This was mimicked by an increase in urinary Na, K and Cl levels. In the inner medulla, the ratio of activated pS256-AQP2 to total AQP2 protein was not significantly changed by metformin but trended toward an increase. The pS261-AQP2/total AQP2 ratio remained unchanged. Inner medullary UT-A1 protein abundance was not changed by AMPK stimulation. These results indicate that AMPK activators, such as metformin, might
44 provide promising treatments for polyuria and dehydration from Sickle Cell disease. Since inner medullary AQP2 and UT-A1 protein abundances were statistically unchanged, future studies are needed to examine additional mice to see whether pSer-AQP2 protein is increased in the IM or altered in the cortex. PRESENTER: Grace Xu TITLE: Associations of Age and Gender with Domains of Physical Functioning in Hemodialysis Patients AUTHORS: Grace Xu; Laura Plantinga, PhD; Emory University PRESENTATION TYPE: Poster Presentation To bridge the gaps in dialysis patient-provider communication, the INFORMED pilot study has collected the physical functioning data of dialysis patients. The end goal of the study is to initiate patient-provider conversations on the individualized physical functioning reports. The present study utilizes the preliminary data to examine associations of age and gender with domains of physical functioning. Physical functioning was measured across multiple domains in 41 hemodialysis patients at two clinics. Measures included: Short Physical Performance Battery (SPPB; incorporating balance, gait speed, and lower-body strength; range, 0-12; higher scores=better performance); perceived physical functioning (range, 0-100; higher scores=higher perceived functioning); and any impairment in basic and instrumental activities of daily living (ADLs; %). Paired t-tests and Fisher’s exact tests were performed to compare functioning by age group (dichotomized <60, ≥60) and gender. In this population (mean age, 56.9; 53.7% female, 91.9% black), apart from transferring (17.4% vs. 50.0%, ≥60 vs. <60; p = 0.043), both age groups reported negligible differences in their ADLs; no statistically significant differences were seen in perceived physical functioning. However, their actual physical performance on the SPPB showed demonstrable age-dependent differences (mean score, 8.08 vs. 5.07, p = 0.007). No statistically significant differences by gender were seen for any measure. Results suggest that, while functioning is generally lower in these dialysis patients than in the general population, there are age (but not gender) differences across domains of physical functioning. Therefore, interventions to improve functioning and gauge physical performance in hemodialysis patients should take age into account.