2012 Student Research Symposium Abstract Booklet

Student Research Symposium • Abstract Booklet

Research Experience for High School Students and

School for Science and Math Research III

Student Research SymposiumAbstract Booklet


SYMPOSIUM SCHEDULE

8:30 ........................ Poster Session 1 ............................................ MRBIII Lobby



1:30 ........................ Keynote Address ................................... MRBIII Room 1220

2:30 ........................ Reception and Awards .......................... MRBIII Room 1220

Braxton Bakerfi eldMaximillian CarterJonathan DaviesTatyana HaddockRanine HaidousAndrew Courtland

HaworthFrank JiangSagar KanumallaChuyun KimAvinaash KorrapatiHavisha Munjal

Jordan SalterAloukika ShahDelaney WilliamsGuangze Zheng

Zachary AndersonCarson BryantIrtiqa FaziliRegan GivensAbhinav GoyalMelissa Guo

Kelli KleinSamuel KlockenkemperConnor MuellerAndrew MullengerMohan RaviMelenka Reed

Jacob SeloffNishant SubramaniZoe Turner-YovanovitchBenjamin WellsMichelle Won

Today’s keynote speaker, George Hornberger, Ph. D., is a Vanderbilt University Distinguished Professor of Civil and Environmental Engineering and Earth and Environmental Sciences. He also is the Director of the Vanderbilt Institute for Energy and Environment with research focuses on studies of environmental impacts of individual, institutional, and societal choices related to energy, water, and climate. Dr. Hornberger received his Ph. D. in Hydrology from Stanford University and currently holds the Craig E. Philip Chair in Engineering.

Tom BuWilliam CoxElena DikovaNavleen Kaur GillScherly GomezAditya Gudibanda

Busra GungorArun Christian HabermannRoya HuangNora MayChirayu Patel

Meera PatelIgor PolosukhinLogan SweetRachel WatersWilliam YangJenny Zheng

Vanderbilt Center for Science Outreach • Summer 2012

Department Student Name, Program*............... Faculty Mentor...............................................Page

Student Research Experience Introduction ................................................. 2

Anesthesiology Guangze Zheng, REHSS ................. Kevin Currie .........................................................3

Biochemistry Mohan Ravi, REHSS ...................... Larry Marnett ......................................................3

Biological Sciences Navleen Kaur Gill, REHSS ............. Patrick Abbott ......................................................4 Scherly Gomez, SSMV .................... Julian Hillyer .......................................................4 Roya Huang, REHSS ...................... Shin Yamazaki .....................................................5 Jordan Salter, REHSS .................... Carl Johnson ........................................................5 Jacob Seloff, SSMV ........................ Kathy Friedman ...................................................6 William Yang, REHSS .................... Shin Yamazaki .....................................................6

Biomedical Engineering Regan Givens, REHSS.................... Melissa Skala........................................................7 Zoe Turner-Yavanovitch, SSMV .... Kevin Seale ...........................................................7

Cancer Biology Irtiqa Fazili, REHSS ....................... Simon Hayward .................................................. 8 Busra Gungor, SSMV ..................... Hal Moses ........................................................... 8 Connor Mueller, REHSS ................ Simon Hayward ...................................................9

Cell & Developmental Biology Ranine Haidous, SSMV .................. William Tansey ....................................................9

Chemical & Biomolecular Engineering Jonathan Davies, SSMV ................. Scott Guelcher ....................................................10 Nora May, REHSS .......................... Paul Laibinis ......................................................10

Chemistry Aditya Gudibanda, SSMV .............. Jens Meiler ......................................................... 11 Andrew Mullenger, REHSS ........... John McLean ..................................................... 11

Electrical Engineering William Cox, SSMV ........................ Yaqiong Xu ......................................................... 12 Logan Sweet, REHSS ..................... Yaqiong Xu ......................................................... 12

* REHSS - Research Experience for High School Students SSMV - School for Science and Math at Vanderbilt

TABLE OF CONTENTS


Hearing & Speech Sciences Tatyana Haddock, REHSS ............. Melanie Schuele ................................................. 13 Avinaash Korrapati, REHSS .......... Melanie Schuele ................................................. 13 Rachel Waters, SSMV .................... Alexandra Key ....................................................14

Mechanical Engineering Zachary Anderson, SSMV .............. Jason Valentine..................................................14 Brazton Brakefi eld, SSMV.............. Greg Walker ....................................................... 15 Melissa Guo, SSMV ........................ Nilanjan Sakar ................................................... 15 Frank Jiang, REHSS ...................... Nabil Simaan......................................................16 Chirayu Patel, REHSS .................... Deyu Li ...............................................................16 Nishant Subramani, REHSS .......... Nilanjan Sakar ................................................... 17 Delaney Williams, REHSS ............. Nabil Simaan...................................................... 17

Medicine C. Bryant & B. Wells, REHSS ......... Thomas Aune .....................................................18 Elena Dikova, REHSS .................... Pierre Massion ...................................................18 Arun C. Habermann, REHSS ......... Timothy Blackwell .............................................19 Andrew C. Haworth, REHSS ......... Charles Hong .....................................................19 Meera Patel, SSMV......................... Richard Peek ..................................................... 20 Igor Polosukhin, REHSS ................ Rasul Abdolrasulnia ......................................... 20 Melenka Reed, SSMV ..................... Pamela Hull .......................................................21

Molecular Physiology & Biophysics Sagar Kanumalla, REHSS .............. Alyssa Hasty .......................................................21 Kelli Klein, REHSS ......................... Kate Ellacot ....................................................... 22 Aloukika Shah, REHSS .................. Roger Cone ........................................................ 22 Jenny Zheng, SSMV ....................... David Wasserman ..............................................23

Opthamology Tom Bu, REHSS ............................. John Penn ..........................................................23 Michelle Won, REHSS ................... Rebecca Sappington.......................................... 24

Pediatrics Havisha Munjal, SSMV .................. Mark Denison ................................................... 24

Pharmacology Carter Maximiliian, SSMV ............. Ron Emerson .....................................................25 Abhinav Goyal, SSMV .................... Qi Zhang .............................................................25

Physics & Astronomy Chuhyun Kim, REHSS ................... Rich Hagland .................................................... 26

Radiology & Radiological Sciences Samuel Klockenkemper, SSMV ..... Bruce Damon .................................................... 26

TABLE OF CONTENTS


This summer, the Vanderbilt Center for Science Outreach (CSO) enrolled 20 high school students from Middle Tennessee and beyond – extending as far as New Jersey, Oman, Puetro Rico and Germany – to participate in the Research Experience for High School Students, an intense six-week advanced science experience. In addition, 22 students from the School for Science and Math at Vanderbilt (SSMV), a unique four-year, interdisciplinary, research-centered learning experience for students from Metropolitan Nashville Public Schools, spent the summer completing Research III as part of the SSMV curriculum. These 42 students were mentored by Vanderbilt University and Medical Center faculty in 36 laboratories spanning 18 different departments. The young scientists-in-training attended weekly meetings to extend their critical thinking skills and develop the research posters being presented today. They have also developed the requisite skills required for independent research projects.

The summer research staff in the CSO would like to thank all of the participating faculty, laboratory staff, postdoctoral fellows, and graduate and undergraduate students for providing mentorship, assistance, and insight into the world of scientifi c discovery. We would also like to acknowledge the many contributions of the entire Center for Science Outreach and the School for Science and Math at Vanderbilt.

STUDENT RESEARCH EXPERIENCE

Director, Center for Science OutreachVirginia Shepherd

Administrative Offi cerCenter for Science Outreach

Joe Lopez

Associate Directors,Center for Science Outreach

Chris Vanags

Director, Interdisciplinary Science and Research Program

Tiffany Ellis Farmer

Scientist-in-the-Classroom Partnerships Coordinator

Jeannie Tuschl

IT CoordinatorGabe Sterling

Scientists in ResidenceSean CarmodyJulia Dobish

Sydika McKissicJosh Swartz

Data Management SpecialistGreta Clinton-Selin

Instructors, School for Science and MathJonathan Creamer

Mary Loveless

Admissions and Administration,School for Science and Math

Amanda Dixon

Teaching Assistant,School for Science and Math

Ryanne Hilbert

Educational ConsultantHarvey Sperling

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Summer Research Coordinator andScientist in Residence, Interdisciplinary Science and Research Program

Kimberly Xaviera Mulligan

Director, School for Science and MathAngela Eeds


Do G Protein Coupled Receptors Inhibit “Low Threshold Exocytosis” Of Catecholamines Elicited By The Stress Mediator PACAP?

Guangze Zheng, Mark Jewell, Kevin Currie

Graded catecholamine release from adrenal chromaffi n cells allows for diverse regulation of both normal metabolic/cardiovascular functions and the “fi ght or fl ight” stress response. This scaled output is made possible by precise regulation of the exocytotic trigger mechanism, in part by G protein coupled receptors (GPCRs). On the cellular level, calcium entry through calcium channels triggers exocytosis of catecholamine by binding to SNARE associated proteins. The Currie lab and others have shown that inhibitory Gi/o- type GPCRs and associated Gβγ subunits inhibit Cav2 Ca2+ channels and potentially SNARE proteins to regulate exocytosis, however the cellular context in which these two inhibitory pathways converge remains unclear. The neuropeptide PACAP is released during high frequency stimulation from splanchnic nerve terminals innervating the adrenal medulla, and may be a unique secretagogue that bypasses Cav2 Ca2+ channels. Accordingly, the lab is interested in PACAP as a useful tool to isolate the inhibitory function of Gβγ subunits on SNARE proteins. The goals of the present study are to 1) test the hypothesis that PACAP stimulates exocytosis in part by recruitment of CaV3 (T-type) Ca2+ channels, and 2) test whether DAMGO, a Gi/o- type GPCRs agonist, modulates exocytosis in PACAP treated cells. Using carbon fi ber amperometry, it was shown that a brief application of PACAP (100 nM) stimulates sustained catecholamine release. Consistent with the amperometry data, ratiometric calcium imaging suggests that PACAP increases the intracellular

ANESTHESIOLOGY

BIOCHEMISTRY

Quantifi cation Of Reactive Oxidant Induced DNA Damage

Mohan S. Ravi, Sarah C. Shuck, Orrette R. Wauchope, Phillip J. Kingsley, and Lawrence J. Marnett

Free radicals are ubiquitous in everyday lives since exposure to sources of reactive oxygen species (ROS) range from environmental carcinogens to endogenous sources like respiration and infl ammation. ROS can form reactive aldehydes when reacting with lipids, forming malondialdehyde (MDA), and DNA, forming base propenals. These aldehydes react with DNA bases 2’-deoxyadenosine (dA) and 2’deoxyguanosine (dG), mutagenic DNA adducts like M1dG and OPdA can form. While DNA adduct levels produced from ROS reactions have been strongly linked with carcinogenesis, the mechanism of and sources for the formation of DNA adduct OPdA have been less studied. To increase the understanding of the induction of this important class of DNA adducts, OPdA levels induced by MDA were investigated both in vitro and in vivo. To perform these studies, MDA was synthesized and employed to treat purifi ed calf thymus DNA in vitro and in RKO cells in cellular systems, with adduct prevalence assessed using LC-MS-MS and HPLC assays. Similar concentrations through induction pathways as M1dG were hypothesized and, consistent with this hypothesis, a dose-dependent increase in OPdA in DNA treated with MDA and peroxynitrite, an agent known to produce base propenal was detected. MDA gave rise to the M1dG adduct with greater effi ciency than peroxynitrite and subsequently quantifi ed to 7 adducts/105 bases. The higher induction of OPdA adducts from MDA than peroxynitrite in cellular systems suggests that even low reactive oxidants derived from oxidative DNA damage may contribute to a larger mutagenic burden of the cell. This leads to further questions on the relative potency and functionality of OPdA as a biomarker of carcinogenetic developments.

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BIOLOGICAL SCIENCES

Allocation And Analysis Of Aphid Lethal Paralysis Virus And Rhopalosiphum Padi Virus In Pemphigus Obesinymphae And P. Populi-Caulis Aphids

Navleen Gill, Sarah Lawson, Patrick Abbot

Dicistroviruses belong to the Picornavirus family, many of which are terrible pathogens for economically important arthropods. Colony collapse disorder has been linked to the dicistrovirus, Israeli acute paralysis virus. Despite the importance, little is known about the natural populations of these viruses in insect hosts. This project investigates Aphid lethal paralysis virus (ALPV) and Rhopalosiphum padi virus (RhPV), both of which infect many aphid species. Both pathogens are deleterious to the recipient and result in the aphid exhibiting distinct behavior: aphids infected with RhPV do not respond to healthy aphids and those infected with ALPV are paralyzed and die within hours. Specifi c questions this experiment aimed to answer included: What is the incidence of dicistroviruses in natural populations of aphids? Is there evidence of host-plant dependent infection, and evidence of spatial aggregation? Are dicistroviruses vertically transmitted in aphids? Is there evidence of non-random associations across and within aphid species? Because this pathogen is lethal it was hypothesized that the virus will be rarely encountered. Using PCR screens, assaying the presence or absence in aphids, examining the discrete trends in transmission was possible. Only 15 out of 65 tested samples were infected. Because the viruses were so common, no particular pattern in the distribution of the virus across the aphid species examined was found. Also, there was no correlation between specifi c stages of the insect and proliferation of ALPV and RhPV. Increasing the sample size and examining the distinctive behaviors of aphids would further the ability to discover more about this unique classifi cation of virus.

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BIOLOGICAL SCIENCES

The Effects Of Infection On Mosquito Heart Physiology

Scherly N. Gomez, Tania Y. Estévez-Lao, and Julián F. Hillyer

The mosquito dorsal vessel, a muscular tube extending the body’s length, is subdivided into the aorta and heart. The heart, through wave-like contractions, propels hemolymph (blood) in the anterograde (towards the head) and retrograde directions (towards the tip of abdomen). Here, the effects of infection on the heart physiology of female Anopheles gambiae were examined. Mosquitoes were infected with Escherichia coli, Micrococcus luteus, Staphylococcus aureus and Staphylococcus epidermidis, and imaged through the cuticle. Visualization of heart contractions showed that after 24 hours of infection, the contraction rate of infected mosquitoes was lower than uninfected mosquitoes. However, after fi ve days of infection, the heart rate of infected mosquitoes was similar to uninfected mosquitoes, except for S. aureus infected mosquitoes. An immune response that mosquitoes mount against bacteria is the production of nitric oxide (NO) through nitric oxide synthase (NOS). In vertebrates, NO is also known to decrease heart rates by relaxing cardiac muscle. Using Real-Time PCR, we assessed the expression of NOS and showed that NOS is more highly expressed in infected mosquitoes compared to uninfected mosquitoes. In summary, we found that with an infection, the mosquito heart contraction rate decreases, possibly due to the production of NO.

Student Research Symposium • Abstract Booklet 5

BIOLOGICAL SCIENCES

Effects Of Environmental Enrichment On Weight Gain Associated With High-Fat Diet

Roya Huang, Julie S. Pendergast, Shin Yamazaki

A high-fat diet is a major cause of obesity. Mouse studies have found that a high-fat diet also leads to more frequent daytime activity and a phase change in the circadian rhythm of the liver. The aim of this study was to test the effects of non-food environmental enrichment on the weight gain, activity patterns, and circadian rhythm of mice. Our hypothesis was that environmental enrichment would lead to less weight gain. To test this hypothesis, we set up wild-type C57BL6/J male mice in control cages (no enrichment) and in cages enriched by the additions of: either 1) nesting hut with nesting paper, 2) locked running wheel which could act as a climbing structure, or 3) free running wheel on which the mouse could run. All mice were in a 12-12 light-dark cycle and ate normal chow for one week and high-fat diet for the second week. We found that the control mice gained an average of 15% of their body mass during the second week. Mice with a nesting hut and nesting paper gained 12%, mice with a locked running wheel gained 10%, and mice with a free running wheel gained 7%. These data suggest that environmental enrichment incorporating exercise decreases the tendency to mice to gain weight from a high-fat diet.

BIOLOGICAL SCIENCES

Response of Circadian Temperature Compensation Mutants To Environmental Changes

Jordan Salter, Yao Xu, Katie Campbell, Carl Johnson

The circadian rhythm is an organism’s internal clock, which regulates when processes such as sleep are performed. Research in Carl Johnson’s lab has shown that, when faced with changes in temperature, the period (the amount of time it takes for the cycle to repeat) changes very little because the regulators of these rhythms are able to compensate for temperature. The purpose of this experiment was to test the ability of other environmental factors, e.g. light color and pH value, to affect the ability of different genetic mutants of cyanobacteria, a single-celled organism with an easily studied circadian rhythm, to compensate for changes to the environment. This serves as a small-scale test to see if environmental factors are able to change the rhythm’s period at different temperatures in organisms. This experiment monitors the change in period of the rhythm in environments with different pH and light. The cyanobacteria was exposed to different colors of light and grown in petri dishes with different pH levels. Both of these factors affect the cell’s ability to photosynthesize, so a change in period would suggest that a cell’s ability to receive energy affects its circadian rhythm; a cell deprived of nutrients would not be able to compensate for temperature. The results of this experiment showed that if a mutant of cyanobacteria cannot compensate for temperature, it cannot compensate for pH or light.


BIOLOGICAL SCIENCES

Examining Sequences That Stimulate Telomere Addition Following DNA Double-Strand Breaks In Saccharomyces Cerevisiae

Jacob Seloff, Ann Ding, Udo Obodo, Margaret Platts, and Katherine Friedman

The end-replication problem present in semiconservative DNA replication machinery has required the development of maintaining the ends of linear chromosomes, or telomeres, which distinguish normal chromosome ends from broken DNA ends and prevent end-to-end fusions. The most common mechanism for proper telomere maintenance is the employment of telomerase, an enzyme that elongates chromosomes by adding telomere sequences to the end of existing DNA strands. One minimally studied role of telomerase is its ability to create a new telomere upon chromosome breakage. The repair of spontaneous or induced DNA damage by homologous recombination in Saccharomyces cerevisiae normally suppresses chromosome rearrangements. However, other pathways that act upon chromosome breaks can result in abnormalities termed gross chromosomal rearrangements. One of these pathways, de novo telomere addition, occurs when the end of a broken chromosome is stabilized by addition of a telomere at a non-telomeric site via the recruitment of telomerase. Through previous study, an 83 base-pair, telomere-like sequence has been shown to suggest higher than normal levels of de novo telomere addition through a mechanism that requires the Rap1 protein. Through the construction of several mutations, this project examines the contribution of the telomere-like sequence to de novo telomere addition at this site.

BIOLOGICAL SCIENCES

High-Fat Diet Alters Feeding Behavior

William Yang, Julie Pendergast, and Shin Yamazaki

Studies have examined that a high-fat diet (HFD) increases the locomotor activity of nocturnal mice during the light phase of the day. The exposure to HFD also causes a phase advance in the liver, an important organ in regulating daily biological processes. In this study, we investigated the effects of high-fat diet on the feeding activity of mice to determine a possible cause for the advanced phase of the liver. Two PER1 C57BL/6J mice were (1) raised in our breeding colony (2) weaned at 3 weeks old (3) group-housed. Mice (at age 2-5 months) were singly housed in cages with locked wheels and fed with regular chow (13.4% kcal from fat, LabDiet 5L0D). They were then placed in a light-tight box with controlled lighting settings of 12 hours of light and 12 hours of dark (12L:12D). After 3 days, the food was replaced with HFD (45% kcal from fat; Research Diets D01060502). Using a motion sensing video recorder focused on the food grating, we were able to collect data of the specifi c feeding times. Similar to the effects of HFD on locomotor activity, we found HFD also increased the feeding activity of mice especially during the light phase of the day. As a result, we conclude that the increase in feeding activity due to HFD is a possible cause for the advanced phase of the liver.


BIOMEDICAL ENGINEERING

BIOMEDICAL ENGINEERING

Hexagonal Microfl uidic Device: A New Method For Capturing And Culturing Bacteria

Zoe Turner-Yovanovitch, Thomas F. Byrd, and Kevin T. Seale

Although the current knowledge of bacteria is vast, there still exist an uncountable number of bacteria that have yet to be identifi ed and categorized. The core of this problem lies with the current methods for culturing bacterial colonies, most commonly, the petri dish. In this setting, where all different species of bacteria are placed together, competition arises and the slower growing, less adaptive bacteria that may even be prey to other, larger, bacteria die out and are never identifi ed. This research presents a new method for the capturing and culturing of different bacteria from a local water sample. A microfl uidic device with small hexagonal traps was fabricated and used to trap free-living bacteria. The bacteria were nourished with a media derived from the original sample and observed growing in the hexagons, showing that bacteria can be cultured this way.

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The Effects Of Varying Glucose Concentrations On Cellular Glycolytic Rates

Regan Givens, Alex Walsh, Melissa Skala

Cancer has been around for centuries, and many scientists have examined how cancer cells react to various treatments. Normal cells go through cellular respiration which is a process in which glucose and oxygen are used to produce energy for the cell. Cancer cells consume more glucose than normal cells however these cells are applicable to the Warburg Effect meaning that instead of going through oxidative phosphorlyation, similar to normal cells, cancer cells goes through the lactic acid cycle. Both normal and cancer cells produce NADH in glycolysis, but only normal cells produce FAD in the Krebs cycle.

The objective of this study was to analyze and compare metabolism rates of cancer cell lines that were grown in media with varying glucose concentrations. It was hypothesized that as the concentration of glucose increased, the redox ratio measured in the cancer cell lines would also increase. At increased glucose concentrations, higher rates of glycolysis were expected leading to an increase in the amount of NADH and decrease in the amount of FAD. Multiple cancerous cell lines were grown in vitro with media containing glucose at the following concentrations: 0 mM, 2.5 mM, 5 mM, 7.5 mM, 10 mM, 15 mM, and 22.7 mM. Cellular NADH and FAD were imaged by fl orescence microscopy. The optical redox ratio, fl uorescence intensity of NADH divided by the fl uorescence of FAD, compared the metabolic rates of the tumor cells grown with varying amounts of glucose. It was determined that the media containing no glucose had the biggest effect on the glycolytic rates of cancer cells, while the other concentrations appeared to have similar redox ratios.


CANCER BIOLOGY

Role Of Lipid Metabolism In Prostate Differentiation And Disease

Irtiqa Fazili, Anne Wang, Douglas W. Strand, Ming Jiang, Simon W. Hayward

Obesity and type 2 diabetes are now recognized as comorbidities for benign prostatic hyperplasia (BPH), an enlargement of the transitional zone of the prostate that results in considerable pain and diffi culty with urination. Data suggest that PPARγ2 regulates prostatic differentiation through increased lipid metabolism and that lipid metabolism genes are expressed in specifi c cellular compartments in the prostate. We hypothesize that lipid metabolism is essential for normal prostate differentiation and is altered in human BPH resulting in cellular changes. It is currently unknown whether the prostate responds to the hyperinsulinemia and hyperglycemia resulting from type 2 diabetes by becoming lipogenic (like adipose and liver) or insulin resistant (like skeletal muscle). This is primarily due to an insuffi cient understanding of the normal metabolism of energy by prostate. Histochemical and immunohistochemical studies on human normal and BPH tissues were performed to assess the localization of lipid droplets and various proteins involved in lipid metabolism. The data suggest that prostate basal cells normally harbor neutral lipids and express lipogenic genes such as SCD1 that are regulated by insulin. Furthermore, we show that neutral lipids, SCD1 and PPARg2 are decreased in BPH and that other lipid metabolic genes implicated in infl ammation like CD36 are increased, suggesting that the prostate is becoming insulin insensitive, which may lead to infl ammation and hyperplasia.

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CANCER BIOLOGY

Uncovering The Role Of TGFβ And BMP In Triple Negative Breast Cancer Stem Cells

Busra Gungor, Philip Owens, and Harold L. Moses

Triple negative breast cancer is diagnosed in approximately 400,000 women worldwide and is considered to be the most diffi cult breast cancer subtype to treat due to lack of targeted therapy. Increasing evidence has shown that cancer stem cells (CSC) are responsible for tumor re-initiation and enhance metastasis. It was hypothesized that inhibiting the CSC will prevent tumor self-renewal and growth. In order to test CSC self-renewal, mammospheres from different human breast cancer cell lines were grown and quantifi ed to

determine the effects of Transforming Growth Factor β (TGFβ) and Bone Morphogenetic Protein (BMP) stimulation. Cancer stem, differentiated progenitor, and epithelial-mesenchymal-transition (EMT) markers were evaluated for differential gene expression. Both TGFβ and BMP stimulation were suffi cient to enhance

the stem cell phenotype. Interestingly, one cell line (HCC1937) had diminished response to TGFβ/BMP stimulation. HCC1937 cells were observed to be highly enriched for stem cell/EMT gene expression, which

indicated that lack of response may be due to saturation in TGFβ/BMP signaling. Inhibition of BMP signaling with a kinase inhibitor DMH1 reduced tumor volume in a dose-dependent response in three human stem-

like cell lines. These results reveal that targeting the CSC via TGFβ/BMP may be a promising therapeutic approach for breast cancer.


CANCER BIOLOGY

The Role Of Proinfl ammatory Chemokines In BPH Pathogenesis

Connor Mueller, Mary Herrick, Omar E. Franco, Simon W. Hayward

Benign prostatic hyperplasia (BPH) is a major cause of morbidity in the adult male population. Some form of BPH affects over half of men above the age of fi fty. Enlargement of the prostate can lead to increased urinary frequency, urgency, and ria. While the cause of BPH is still unclear, increased infl ammation is closely associated with the severity of BPH. The infl ammatory response involves a biochemical cascade that results in the recruitment of neutrophils and macrophages, epithelial proliferation, and stromal reaction. However, it is unclear whether infl ammation is a cause or an effect of prostatic growth. Chronic infl ammation can have harmful effects on the infl amed tissue and is implicated in a number of human diseases including BPH. Infi ltration of infl ammatory cells is accompanied by increased expression of many pro-infl ammatory cytokines. The purpose of this project was to understand the responses of prostate epithelia and stroma to local expression of cytokines in vivo. It was hypothesized that interleukin 17 (IL17) serves as a crucial link between infl ammation and BPH pathogenesis. To test this concept tissue recombinants previously prepared using the human prostatic epithelial cell line NHPrE1 and rat urogenital sinus mesenchyme (UGM - a prostatic inducer) in a sub-renal capsule model xenograft model were utilized. In this model recombinants demonstrated increased growth in the IL17-overexpressing samples. Stromal expansion and alterations in differentiation profi le were detected using the stromal markers α-smooth muscle actin (αSMA), vimentin, and the proliferation marker Ki67. Macrophage infi ltration was monitored using F4/80 staining. The identifi cation of increased numbers of macrophages and phenotypic stromal changes in grafts over expressing IL17 demonstrated the shift in cell type that accompanies infl ammation and the stromal alterations associated with clinical BPH. The data support the concept that the proliferation of epithelial cells and associated stromal changes seen in BPH can be driven by IL17. As the role of IL17 becomes better understood, anti-infl ammatory drugs could be developed to target the chemokine’s activity to prevent chronic infl ammation and reduce hyperplasia.

Functional Dissection Of The Central Domain Of c-Myc Through Characterization Of Novel Interacting Proteins

Ranine A. Haidous, Soumyadeep Dey, and William P. Tansey

c-Myc is an oncoprotein transcription factor that controls the expression of genes necessary for cell growth and hyperproliferation. Overexpression of c-Myc, or expression at inappropriate times, triggers cells to grow irrepressibly—resulting in tumorigenesis. Generally, c-Myc can be partitioned into three fundamental domains: an amino-terminal transcriptional activation domain, a carboxy-terminal DNA-binding domain, and a central domain of unknown function. Recent evidence in the Tansey laboratory revealed that this domain of Myc plays an important role in regulating gene expression, manipulating Myc by proteolysis, and oncogenic transformation, but the underlying molecular mechanisms are unknown. To address this defi cit, a two-hybrid assay identifi ed a number of novel potential proteins that specifi cally interact with the central domain of c-Myc. A quantitative two-hybrid analysis was performed, with the objective of identifying molecules that interact most robustly with this central domain. This research identifi ed four proteins that bind to the central portion of Myc with apparent high affi nity and specifi city. Interestingly, these proteins established links to gene expression, cell cycle progression, DNA repair, and apoptosis, suggesting that they may be linked to known functions of the c-Myc central domain. Future studies will expose the connection between these c-Myc interactors and their function in mammalian cells.

CELL & DEVELOPMENTAL BIOLOGY


CHEMICAL & BIOMOLECULAR ENGINEERING

Characterization Of Macrophage Behavior In The Human Immunoresponse And Bone Remodeling

Jonathan P. Davies, E. Margarita Prieto, and Scott A. Guelcher

Macrophages play a versatile role in the human body, including the human immunoresponse and bone remodeling. This study focused on the response to external stimuli of two kinds of macrophages: osteoclasts and derivations of Human Monocytes. Part One of this study aimed at determining if bacterial biofi lms modify the immunoresponse of macrophages in wound healing. Macrophages were treated with media pre-conditioned by bacteria (biofi lm and planktonic) and mesenchymal stem cells. The macrophages were then Triple Stained, testing for Phagocytosis and Reactive Oxygen Species (ROS) production. Part Two adapted a protocol to examine osteoclasts’ resorption of implant materials, based off previous research (Hsu, 2011; Collin-Osdoby, 2012). Osteoclasts were fi ltered by size through a Serum Gradient and seeded onto the materials; then TRAP stained and imaged to quantify cellular differentiation and material resorption. From Part One, an increase in phagocytic activity was detected after treatment during 16 hrs by both planktonic and biofi lm media. No differences were observed in ROS, or phagocytic activity at any other time point. It is recommended to further test other variations of the conditioned media, due to the limiting monocyte supply. In Part Two, portions of the resorption protocol were adapted; in the future, it is recommended to develop material testing.

Preparation And Use Of Microcontact Printing Masters Formed Using Liquid Microdroplet Arrays

Nora May and Paul E. Laibinis

Microcontact printing is a technique used to direct the placement of chemicals onto a solid surface into specifi ed patterns for use across a wide range of areas. The approach is being used at Vanderbilt in the imaging of tissue samples by mass spectrometry, where higher resolution is desired as are smaller feature sizes. For patterning, a rubbery, silicone-based stamp made of polydimethylsiloxane (PDMS) is used in the printing process. These PDMS stamps are commonly made by photolithography, requiring specialized equipment that are often available only through clean room facilities. The photolithography process also limits the user to the formation of rectangular features within the PDMS stamp. As an alternative, this work has explored the use of a robotically-controlled, microdroplet deposition approach for generating patterns within PDMS for microcontact printing. By changing the surface chemistry of the substrate employed in the microdroplet printing process, the size and shape of the droplets could be varied as a way to change the pattern within the PDMS stamp. Mixed self-assembled monolayers (SAMs) formed from 11-mercapto-undecanoic acid and dodecanethiol were used to alter the substrate wettability from hydrophilic to hydrophobic in a controlled way. The resulting microdroplets could be varied in their diameters from 250 to 50 microns in size by using substrates of increasing hydrophobicity. The microdroplet patterns were transferred into PDMS with high fi delity by applying the PDMS prepolymer to patterns printed using solutions of betaine. The features within the PDMS stamps could be varied in their density by changing the pitch of the microdroplet deposition and maintained the non-rectangular curved shapes associated with the droplets. The microdroplet-based features incorporated within the PDMS stamps were useful in microcontact printing, as demonstrated by their use to generate patterns with controlled variations in wettability and for selectively depositing materials onto surfaces. Patterns with features as small as 50 microns in diameter were made possible by this approach, where the use of self-assembled monolayers allowed features roughly 100 microns smaller than that available previously to be generated, offering possibilities for performing imaging studies of tissues by mass spectrometry at previously unavailable resolutions.

CHEMICAL & BIOMOLECULAR ENGINEERING


CHEMISTRY

The Implementation Of Paired Descriptor Functions To Improve Quantitative Structure Activity Relationship Models For Drug Discovery

Aditya Gudibanda, Edward W. Lowe, Jr., and Jens Meiler

One of the major challenges that we face today is the discovery of new drugs. Pharmaceutical companies have libraries of millions of compounds of possible drug leads, and these libraries are tested through the brute force method of high throughput screening (HTS), which runs assays on all these compounds to see which have the desired biological activity. However, this method is ineffi cient in that it involves no prioritization of small molecules, leading to a waste of time and resources. To solve this problem, methods have been developed in the fi eld of computational chemistry that predict the activity of a molecule based on its structure using Quantitative Structure Activity Relationships (QSAR). An algorithm is trained to correlate the complex relationship between molecular structure and biological activity, to predict the activity of untested molecules. Research in the laboratory of Jens Meiler has demonstrated the success of this approach, and has also led to the discovery of novel biologically active compounds. The algorithm used by this approach uses descriptor functions, which are tools that mathematically describe the constitution and confi guration of molecules. Here we present a novel class of descriptor functions that signifi cantly improves the performance of these QSAR models.

11

CHEMISTRY

Experimental Determination Of A Consistent Method For NiNTA Slide Synthesis

Andrew Mullenger, Keersten Davis, Dr. David Wright

The process of functionalizing surfaces with various compounds is often quite unreliable. Many times the chemistry dictates that the entire surface of a particle or other substrate should be covered by the intended coating, and yet analysis shows that only a fraction of the surface has been functionalized. Such is the case when attempting to coat a glass substrate with nickel (II) nitrilotriacetic acid (NiNTA). Several procedures have been developed that should, theoretically, allow for complete coverage of the glass surface. However analysis by inductively coupled plasma-optical emission spectroscopy (ICP-OES) of the concentration of nickel present on the slides often yields contrasting results. The purpose of this study was to establish a set of conditions that would allow for complete functionalization of a glass substrate with NiNTA. Contact angle and ICP-OES measurements were used to characterize the degree of functionalization. Ongoing research into the development of rapid diagnostic tests for malaria currently uses the established method for slide synthesis, but a defi nitive method for NiNTA funcitonalization would greatly assist this groundbreaking research. It was determined that epoxy-terminated SAM in place of glutaraldehyde and aminopropyltriethoxysilane (APTES) yielded cover slips that were more uniformly coated with NiNTA.


ELECTRICAL ENGINEERING

Creation Of A Graphene-MoS2 Junction

Will Cox, Roel Flores, Nathan Fisher, Logan Sweet, and Yaqiong Xu

Graphene is a recently discovered two-dimensional material that has proved to have an immense array of interesting physical and electrical properties. Molybdenum disulphide (MoS2), a material potentially useful in nanotechnology, when isolated to a single monolayer pieces, also has interesting electrical properties. An interface between these two materials is what we propose to fabricate, and it is expected to have characteristics of a Schottky barrier, namely current rectifi cation and a low voltage drop. A PDMS stamping technique was used to deposit multi-layered fl akes onto a Si/SiO2 wafer with pre-pattered gold electrodes, and then a laser thinning process was carried out to cleave off successive layers of the fl ake. Then a standard micromechanical cleavage technique was carried out to deposit single layer graphene on a PMMA/glass substrate, and fi nally a mechanical transfer method was applied to align the piece of single layer graphene on top of the piece of laser-thinned MoS2.We aimed to take Electrical and Photocurrent measurements to test the design and effi ciency of our device. In this study we hoped to determine if a graphene-MoS2 junction is a viable Schottky barrier, and could be widespread in future electronics.

12

ELECTRICAL ENGINEERING

Electronic And Photocurrent Properties Of Graphene

Logan Sweet, Zina Jarrahi, Roel L. Flores, Alex Huffstutter, Yunhao Cao, Will Cox, Yaqiong Xu

Graphene, a two-dimensional allotrope of carbon, has recently become an important material in nanoelectronics research. Graphene has been shown to have high electron mobility. In order to test its resistance, chemical vapor deposition (CVD) grown graphene was transferred to gold electrodes on a pre-fabricated silicon device. The graphene was then checked for true single layer and quality of structure using Raman spectroscopy. By scratching and swabbing away excess graphene on the device, each electrode was separated from the large area fi lm of transferred graphene, leaving only a strip connecting each electrode. The resistance of the graphene between the electrodes was measured and photocurrent measurements were taken on the produced graphene ribbons. Even though it is atomically thin, graphene can still be used as an excellent conductor. Due to its electronic properties and unique physics, graphene is a candidate for the creation of smaller, faster electronics.


HEARING & SPEECH SCIENCES

Lexical Semantic Organization Of Children With Hearing Loss: A Clozure Task

Tatyana Haddock, Emily Lund, C. Melanie Schuele

Children with hearing loss develop their lexicon at a slower rate than children with normal hearing. This investigation used extensive data to evaluate how children with hearing loss complete nursery rhymes when prompted on a standardized clozure task. Eight monolingual and eight bilingual children with hearing loss participated in this study. An experimenter started various nursery rhymes, and children were asked to fi ll in the blank with the word they thought best fi t the phrase. Children’s responses were coded for lexical-semantic categories. Children with hearing loss did not exhibit knowledge of nursery rhymes as well as expected for children with normal hearing. Analysis of child errors indicated that children with hearing loss do not show the same lexical organization as children with normal hearing for example, children with hearing loss did not provide primarily syntactic answers. The results of this pilot study indicate that children with hearing loss may organize their lexicon differently than children with normal hearing.

Utilizing Eye Gaze As A Measure Of Visual Attention To Print In Children With Hearing Loss

Avinaash Korrapati, Krystal L. Werfel, Zachary P. Barnett, C. Melanie Schuele

Previous studies have reported that children with normal hearing spend much less time looking at print than at illustrations during storybook reading. However, children are more likely to attend to print when storybooks have high print salience. Little is known about attention to print for children with hearing loss. The purpose of this study was to investigate visual attention to print during storybook reading in preschool children with and without hearing loss. Preschoolers with and without hearing loss participated in storybook reading sessions. One book with high print salience and one book with low print salience were displayed on a computer screen while a female voice read the text. Visual attention to print was tracked using a Tobii X50 eye tracking system. Eye gaze analysis indicated that children with hearing loss actually focused more on contextualized print than children without hearing loss. Moreover, both groups paid almost an equal amount of attention on regular print. Concerning print salience, both children with and without hearing loss were found to focus more on print with higher print salience than lower print salience.




Understanding Syntactic Processing And Phonological Awareness In Specifi c Language Impairment

Rachel Waters, Reyna Gordon, and Alexandra Key

Specifi c Language Impairment (SLI) is an unexplained disorder that affects language and communication skills with normal nonverbal abilities and no cause by any other disorder such as autism or dyslexia. This study looks to understand the difference of children with SLI and children with typical development in both the syntactical and phonological aspects. Syntax, the way sentences are made up of words, may be measured by the P600 component using EEG. It is believed that the P600 component in children with typical development is more defi ned, showing a more acute detection of syntactic violation in sentences. Phonology, the way words are made up of sounds, is measured using behavioral tests such as the CTOPP (Comprehensive Test of Phonological Profi ciency). It is believed that children with SLI, when compared to children with typical development, will have lower scores on the CTOPP. Another aim of this study is to fi nd a relationship between syntactic processing and phonological awareness using a fi t-to typical approach, where syntactic processing and phonological awareness are expected to have a positive relationship. Preliminary data shows that children with typical development have a defi ned P600 component as well as average or above average scores on the CTOPP.

14

MECHANICAL ENGINEERING

Characterization Of An Impedance Matched Zero-Index Metamaterial

Zach Anderson, Parikshit Moitra, and Jason Valentine

Current retrieval methods for many optical properties, such as refractive index, assume a natural material; however, with the design and fabrication of a zero-index metamaterial, the same assumptions cannot be made as in classical electromagnetics. To measure these optical properties, different techniques have to be implemented. In this project, an impedance matched zero-refractive index metamaterial (ZIM) in the optical frequency range was characterized using transmission measurements at varying incidence angles. These measurements were taken using a six-inch general purpose integrating sphere in the near infrared region. Results include the transmission spectrum of an impedance-matched zero-index metamaterial from which both components of the refractive index, ε and μ, can be calculated, unlike in most other retrieval methods. The advantages of creating a ZIM include the possibility of point source directive emission and the tunneling of electromagnetic radiation.



The Effect Of Cerium Concentration On YBO3:Ce

Braxton Brakefi eld, Sadie Gollub, and Greg Walker

Phosphors are novel materials with applications in lighting, temperature sensing, and radiation sensing. One phosphor, YBO3:Ce, has the potential to be used as a radiation sensor, but there is very little research into the optimal concentration of Cerium. With too little Cerium, there is the possibility for more luminescence centers; if there is too much Cerium, concentration quenching can occur, thereby reducing the effectiveness of the phosphor. Samples with varying Cerium concentrations from 0.5% to 15% were prepared by combustion synthesis, using glycine as fuel. Their photoluminescence spectra were obtained and their intensities compared analytically. The decay times of the emissions were also obtained using a photomultiplier tube, and then compared analytically. The optimal concentration of Cerium in YBO3 was found to be 4% based on the intensity measurements; furthermore the decay time started to decrease after 4% as well. This phosphor, with a Cerium concentration of 4%, can now be used to its full extent as a radiation sensor.


Interfacing Of Kinect Motion Sensor And NAO Humanoid Robot For Imitation Learning

Melissa Guo, Shuvajit Das, Jake Bumpus, Esubalew Bekele, and Nilanjan Sarkar

Given the 1 in 88 children prevalence rate in the US, autism spectrum disorder (ASD) is considered a public health emergency. Children affected by ASD generally have diffi culty interacting in social environments. The disorder has no cure, and traditional intervention often involves private time with a trained therapist, which is costly and time-consuming. However, it has been shown that some children with ASD interact better with robots than with humans. Compared to humans, robots express no emotion, which ensures that children with ASD are not overwhelmed by their interactions. In order to advance human-robot interactions specifi cally for autism treatment, a robot imitation learning platform was developed using the Xbox 360 Kinect and the Aldebaran NAO humanoid robot. The robot imitated movements made by a human based on full body tracking data from the Kinect sensor in real-time. It was shown that the NAO robot can successfully imitate human actions and gestures within its joint and workspace limits. In the future, a learning algorithm will be applied to facilitate autonomous recognition of and reaction to gestures detected by the Kinect. This will lead to improved human-robot interaction technology and eventually to a viable treatment method for children with autism.



Design And Evaluation Of Retinal Models For Robotic Ophthalmic Procedures

Frank Jiang, Haoran Yu, Nabil Simaan

This study investigates optimal protocols for creating retinal models used for the refi nement of robot-assisted surgery. Robots are currently being designed to limit complications of retinal surgery and to enable new procedures. However, their implementation requires the construction of retinal models on which the robots’ effi cacy and feasibility can fi rst be tested. This study addresses two separate models for different types of retinal surgery—branch retinal vein occlusion and epiretinal membrane peeling. The fi rst model is developed to investigate robot-assisted, image-guided micro-vascular retinal interventions. The optimal fabrication conditions for agar models of the retina were investigated while maximizing contrast for optical coherence tomography (OCT). A recipe of coffee creamer and agar was used. Results showed that a recipe with roughly one part creamer for every part agar produces optimal visibility under an OCT probe. The second model is for testing robot-assisted epiretinal membrane peeling. The model mimics epiretinal membranes by using a newly reported method in the literature. Coats of liquid skin bandage were used for fabrication of these membranes on agar plates. A robotic actuation mechanism for micro-tweezers used to peel epiretinal membranes was designed using Pro-Engineer and subsequently tested. Results showed that both the actuation mechanism and the membranes can be used effectively, though further refi nement is possible. These models are expected to enhance the precision and effectiveness of robot-assisted retinal surgery.

16


Small Molecule Absorption In Polydimethylsiloxane

Chirayu Patel, Bryson Brewer, Deyu Li

Polydimethylsiloxane (PDMS) is a material that has come to dominate the world of microfl uidics. Unlike silicon, glass, and other traditional micromachining materials, PDMS can be used to quickly fabricate new microfl uidic devices via soft-lithography. The ability to be used in rapid prototyping, combined with its biocompatibility, optical transparency, and low cost, makes PDMS extremely useful to microfl uidics researchers. The porous nature of PDMS makes it permeable to some small molecules. This permeability can be useful in applications such as microextractions. On the other hand, in the case that one would want to separate two cell populations this feature would cause small hydrophilic compounds to be absorbed into the PDMS, which in many cases is not preferred. As a result, a better understanding of factors affecting small molecule absorption in PDMS is vital for better design and use of microfl uidic devices. By using fl uorescent dyes it was determined if the duration of time a device was cured during fabrication reduced absorption. The fl uorescent dye Rhodamine B was placed into a device that had been cured with heat for varying lengths of time: 0 hours, 2 hours, and 24 hours. The device was then imaged every 3 minutes for 3 hours. The results indicated that with more thermal aging, the PDMS absorbed slightly smaller amounts of the Rhodamine B fl uorophore. With these observations, devices can be fabricated with a more effective method that allows results involving small molecules to be more accurate. It also opens up a new window for biological research that can now be done with devices with higher small molecule retention rates.



Development Of A Virtual Reality Environment For Rehabilitation In Teenagers With Autism Spectrum Disorder

Nishant Subramani, Esubalew Bekele, Nilanjan Sarkar

Autism spectrum disorder (ASD) is associated with impairments in social interaction and verbal and non-verbal communication. Traditional human-centric therapeutic techniques are costly and time-intensive and thus not available for the larger population. These methods include using applied behavior analysis therapy, a technique that gives patients 30 hours of behavior intervention a week. Other techniques include using dietary changes such as gluten-free diets and biomedical interventions such as chelation, a drug that rids the body of metal toxins. Emerging technologies such as virtual reality (VR) technology, if shown useful, can assist traditional therapies. The goal is to create a virtual cafeteria environment to facilitate rehabilitation processes through the participant’s social interaction with the avatars.

The virtual cafeteria offers numerous social challenges for children with ASD to tackle. The virtual cafeteria environment allows for a different viewpoint on therapeutic methods in giving the participant a more convenient setting for interaction depicting the person to person interaction in a very real manner. A virtual reality environment has been created to facilitate rehabilitation processes for teenagers with ASD. A total of 12 characters (avatars) were rigged and animated for the virtual social communication goal. The overall task logic and protocols are yet to be implemented. In addition, natural language processing, speech recognition, eye tracking and peripheral physiological signal monitoring are yet to be integrated as part of the overall closed-loop adaptive system for more realistic and meaningful social interaction and communication.

17


Investigation Of Anatomical Constraints Of The Facial Recess And Electrode Impedance During Cochlear Implant Surgery

Delaney Williams, Jason Pile, Nabil Simaan

Electrode array insertion is a critical part of cochlear implant (CI) surgery during which trauma to intracochlear anatomy may occur. The electrode array is inserted into the scala tympani through the facial recess. Consequently, the facial recess determines the limits of allowable surgical instrument movement and tilting. In this study, the anatomical constraints that the facial recess imposes on straight instruments were investigated. The sensitivity of impedance measurements to change in distance from physical walls was also investigated. These experiments are meant to help engineers develop new robotic technologies for reducing trauma during CI surgery. For the workspace study ten cadaver temporal bones, an NDI tracking camera and device and MATLAB were used to conduct the anatomical constraint experiments. A custom made digitization probe was inserted into the facial recess and cochleostomy and subsequently swept around the area to characterize available workspace. The data was processed using MATLAB to obtain a polar plot representing available workspace. For the impedance sensitivity study a functional CI, a container with saline solution and a Tefl on peg, a microscope with image capturing capabilities, and a computer with FlyCap 2 and CIM software were utilized. The electrode array was inserted into the container, and moved towards a Tefl on peg. The electrical impedance was recorded by the CIM software and a photograph was of the array and peg was taken. After conducting experiments on ten cadaver bones, the results showed that tests on more bones need to be done to validate the study further. Results from the impedance experiments show that within a millimeter distance, there is a clear trend in proximity to a wall and impedance of an electrode.


MEDICINE

Methotrexate Decreases NF-κB Activity Via JNK Induction

Carson J. Bryant*, Benjamin C. Wells*, Charles F. Spurlock, III, Thomas M. Aune* These authors contributed equally to this work.

Rheumatoid arthritis (RA) is a chronic, infl ammatory disease characterized by disabling erosion of the small and large joints. Methotrexate (MTX), the anchor drug in the treatment of RA, is a highly effective therapy, yet its mechanism of action is incompletely understood. The aim of this study was to better understand how MTX mitigates the chronic NF-κB activity found in RA. Levels of NF-κB, a well-defi ned pro-infl ammatory biomarker, were examined in Jurkat T cells stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin. Sub-micromolar doses of methotrexate substantially decrease the activity of NF-κB. This is mediated, in part, through MTX-dependent production of reactive oxygen species and c-Jun-N-terminal kinase (JNK) activation. While adenosine supplementation reduced NF-κB activity in tissue culture, treatment with adenosine receptor antagonists only partially blocked these MTX-mediated effects. Treatment with JNK inhibitors or free radical scavengers signifi cantly abrogated reduction of NF-κB. These results indicate that superoxide generation and JNK induction may play a signifi cant role in the immunomodulatory effects of MTX.

ACBP In Regulation Of Survival Of Lung Cancer Cells

Elena Dikova, Fredrick Haris, Pierre Massion

Background: Previous efforts in the lab were able to uncover a proteomic signature using MALDI-MS. One of the overexpressed proteins identifi ed is acyl-coenzyme A binding protein (ACBP). ACBP was found to be augmented early in the development of cancerous tumors, and has since been discovered to be ubiquitously expressed in non-small cell lung cancer cell lines. Functionally, ACBP is a protein which binds to hydrophobic ligands, and plays an important part in the regulation of lipid homeostasis within the cell. Because lipids are so important to the normalcy of cellular metabolism, ACBP is critical to the cell viability. We want to determine the functional implications of ACBP upregulation in lung cancer. To this end, we have perturbed ACBP protein levels using shRNA. Hypothesis: We propose that the blocking of ACBP activity would interfere with important cancer cell metabolic pathways and would result in the decreased proliferation and survival via down-regulation of AKT survival pathway and induction of apoptosis in lung cancer cells. Objective: ACBP was knocked-down in lung cancer squamous cell line H520 using an shRNA approach and the effects of ACBP on cell proliferation, AKT phosphorylation (a survival pathway) and induction of poly-ADP ribose polymerase (PARP)-cleaved (a marker of apoptosis) were evaluated. Methods: Using samples from H520 cells, in which ACBP has been downregulated, Western blot analysis was performed to confi rm that ACBP was knocked-down. The Western blot analysis was done using anti-ACBP antibody according to a previous protocol. Similar experiments have been performed looking at PARP-cleaved, and phospho-AKT, and actin. Cell proliferation was evaluated using WST-1 assay. Results: The intial expiriments showed that ACBP was down-regulated in H520 cells by specifi c shRNA. We confi rmed ACBP down-regulation on the protein level by utilizing Western blot analysis looking at ACBP expression normalized to actin. Blocking of ACBP expression dramatically decreased proliferative cell function. Phospho-AKT levels and PARP-cleaved were modulated in ACBP defi cient H520 cells. However, additional expirements and testing of different shRNA constructs might be needed to derive a decisive conclusion on the link between ACBP and pro-survival/apototic pathways. Conclusion: It was expected that there would be a signifi cant decrease in ACBP expression in the down regulated cell line that would result in downregulation of cell proliferation mediated via attenuation of pro-survival and activation of pro-apoptotic pathways. Downregulation of ACBP expression and associated cell proliferation were confi rmed. This leads us to conclude that blocking of ACBP slows growth of squamous lung carcinoma cells. Thus, ACBP might be a valuable therapeutic target and its downregulation would be detrimental to lung cancer survival.

18

MEDICINE


MEDICINE

IL-5 Mediated Eosinophils Increase Metastasis In A Mouse Model Of Lung Cancer

Chris Habermann, Taylor P. Sherrill, Linda Gleaves, and Timothy S. Blackwell

Tumor associated eosinophilia has been observed in various human tumors including in the lung. However, the role of eosinophils in lung tumorigenesis and the mechanisms of recruitment of these cells during the disease remain undefi ned. IL-5 has been recognized as a major chemokine involved in recruitment of eosinophils and potentially in their maturation. Therefore, it was hypothesized that defi ciency of IL-5 in mice will impair recruitment/maturation of eosinophils and reduce lung tumorigenesis. A model of lung cancer metastasis was created by injecting Lewis Lung Carcinoma (LLC) or B16F10 (melanoma) cells by tail vein injection (IV) into mice defi cient in IL-5 (IL-5 KO) or WT controls (both on C57B6 background). It was found that by Day 14 after injection of 2.5x105 LLC or 1.25 x105 B16F10 cells, IL-5-defi cient mice had a marked decrease in the number of lung eosinophils compared to the WT controls. These changes were accompanied with a statistically signifi cant reduction in numbers of lung tumors in IL-5 KO mice. Depletion of IL-5 in mice by treatment with IL-5 blocking antibodies reduced lung eosinophils and decreased numbers of LLC or B16F10 tumors in the lung. In contrast, reconstitution of IL-5 by giving back recombinant IL-5 through IV injection prior to the injection of LLC or B16F10 cells increased numbers of lung tumors in IL-5 KO mice. Taken together, it was determined that IL-5 supports metastasis of Lewis Lung Carcinoma (LLC) or B16F10 (melanoma) tumors to the lungs most likely through recruitment of eosinophils.

In Vivo Zebrafi sh-based Screen For Novel Bone Morphogenetic Protein Inhibitors And Natural Therapeutic Compounds

Court Haworth, Jamie Rickmyre, Charles Williams, Charles C. Hong

Many proteins important to development participate in the BMP, FGF, Nodal, and Wnt signaling pathways. These proteins more specifi cally regulate dorsal-ventral polarity in addition to anterior and posterior structures. If these signaling pathways are disrupted, they can lead to diseases including cancers and incorrect bone formation. Using zebrafi sh embryos as a model for humans, it is possible to screen for novel compounds, obtained from the Vanderbilt compound library, that affect dorsal-ventral polarity. When using in vivo screening, the bioactivity, off-target side effects, and toxicity can be determined from the beginning of development, rather than spending money developing the drug, only to determine during testing that one of these factors is too signifi cant for the drug to be effective.

Multiple possible BMP Inhibitors have been identifi ed, so in addition to screening for new potential therapeutic compounds, it is possible to test BMP Inhibitors for potency and consistency. The aim of these studies was to identify possible treatments for BMP-related diseases such as certain types of cancer, and Fibrodysplasia Ossifi cans Progressiva (FOP). The compound that has consistent dorsalization across a range of concentrations without killing the fi sh can be identifi ed as a selective BMP Inhibitor and developed to use as a drug to counter inappropriate bone formation in patients with FOP. When adding these compounds to BRE (BMP responsive element)-GFP fi sh, tissues where BMP signaling is active will glow green, and the BMP inhibitor drugs will reduce this signal. Cave compounds were screened for dorsoventral patterning defects, suspended animation/developmental timing, and pigmentation defects. Some of the compounds were found to cause these defects and are currently being retested. In addition, two BMP Inhibitors were found to be selective and potent dorsalizers (compound 1 and 2).

MEDICINE


MEDICINE

Helicobacter pylori Reciprocally Alters The Junction-Regulating Adhesion Proteins BVES, POPDC2, And POPDC3 In A Non-

Tumorigenic Murine Gastric Epithelial Cell Line (MGEC)

Meera V. Patel, Lydia E. Wroblewski, Christopher S. Williams, Shenika V. Poindexter, David M. Bader, and Richard M. Peek

Background: The molecular pathways that drive Helicobacter pylori-induced gastric adenocarcinoma are incompletely defi ned. Epithelial-mesenchymal transition (EMT), a change in cell morphology owing to H. pylori-induced translocation of tight junction proteins, mediates cancer metastasis. An inverse relationship between BVES expression and EMT has been recently observed in colorectal cancer. This study examined H. pylori regulation of BVES and two related domain members POPDC2 and POPDC3 in gastric epithelium. Methods: Immunofl uorescence was used to determine BVES localization. mRNA expression was analyzed using real-time RT-PCR in H. pylori-infected and uninfected primary murine cells (MGEC), human gastric cancer cells (AGS and MKN28), and human colonic cancer cells (Caco-2). Results: BVES was localized to the membrane of uninfected MGEC and Caco2 cells. AGS and MKN28 cells exhibited decreased BVES transcription levels when compared to non-cancerous MGEC cells, and transcription was modifi ed by increasing cell confl uence. Co-culture of MGEC and Caco2 cells with H. pylori decreased expression of BVES and POPDC3 and reciprocally increased POPDC2 expression. Conclusions: Loss of BVES occurs in gastric cancer cells. BVES is localized at the membrane, and H. pylori alters the expression of BVES, POPDC2, and POPDC3 suggesting that manipulation of this regulatory protein may exert oncogenic effects.

20

MEDICINE

Presence Of Functional GSTM1 Is Associated With Activation Of NF-kB In Airway Epithelial Cells And Neutrophillic

Lung Infl ammation In Human Atopic Asthmatics

Igor V. Polosukhin, Rasul Abdolrasulnia, Brian W. Christman, Timothy S. Blackwell, Ryszard Dworski

Rationale: Bronchial asthma is one of the leading diseases in the USA. Glutathione S-transferase M1 (GSTM1) plays a major role in the detoxifi cation of metabolites of oxidative stress thus contributing to infl ammation in asthma. We hypothesize that GSTM1 is associated with activation of Nuclear Factor (NF)-κB in airway epithelium and neutrophilic infl ammation in atopic asthma. Objective: To defi ne the effect of functional GSTM1 on NF-κB activation in airway epithelial cells and lung infl ammation provoked by allergen in human atopic asthmatics. Methods: Bronchial biopsies and bronchoalveolar lavage (BAL) samples were obtained from 12 asthmatics with GSTM1 null genotype (GSTM1–) and 13 asthmatics with GSTM1 wild genotype (GSTM1+) at baseline and 24 hours after segmental allergen challenge. Paraffi n tissue sections were immunostained with antibody against phospho-p65 (Ser276). Percentage of positive airway epithelial cells was calculated and p65-associated immunofl uorescent signal was measured. Absolute numbers of neutrophils and eosinophils in 1 ml of BAL fl uid were calculated for each study participant at baseline and after allergen challenge. Results: Substantial NF-κB pathway activation in airway epithelial cells and neutrophil accumulation in the lungs were detected in GSTM1+ patients but not in GSTM1– patients in response to segmental allergen challenge. Summary and Conclusions: The GSTM1+ genotype is associated with activation of NF-κB in airway epithelial cells and increased airway neutrophilia provoked by allergen in human atopic asthmatics in vivo. Our fi ndings support substantial role of GSTM1 gene in the development of lung infl ammation in atopic asthmatics. Future investigations are necessary to identify high-risk genotypes to develop effective and safe chemopreventive agents for individuals who are genetically susceptible to the adverse effects of air pollution.


MEDICINE

Perceived Barriers And Facilitators To HPV Vaccination In African American Girls Ages 11-18

Melenka Reed and Pamela C. Hull

INTRODUCTION: Among African American women, there is a higher incidence rate of cervical cancer, as well as a higher mortality rate. Since 2006, two vaccines have been approved that prevent the two high-risk types of HPV that cause about 70% of all cervical cancer cases. By increasing HPV vaccine uptake among African American girls and women, the disparities in cervical cancer incidence and mortality may improve. PURPOSE: to identify barriers and facilitators to vaccination as perceived by African American girls between the ages of 11 and 18, focusing on the differences in responses between girls who had completed the vaccine as compared with girls who were still undecided about vaccination. METHODS: two focus groups were conducted as part of a larger study, one with vaccinated girls and one with girls who were undecided about the vaccine. The girls responses to questions regarding perceived barriers and facilitators to vaccination were analyzed using ATLAS.ti and the two groups were compared. RESULTS: Preliminary results suggest that vaccinated girls perceive money and fear of adverse side effects as barriers, while the undecided group perceives fear of pain and side effects as barriers. Both groups perceive cancer prevention as an advantage of vaccination.

Unique Population Of Immune Cells In Adipose Tissue After Gastric Bypass Surgery In Mice

Sagar Kanumalla, Corey Webb, Alyssa Hasty

Over the past 5 years, scientifi c inquiry has shown that diabetic patients who receive roux-en-Y gastric bypass (RYGB) start to show normal glucose levels and no longer need diabetes medications within just 3-4 days post-surgery. The objective of this study was to establish a link between RYGB and improved metabolism for reasons other than decreased consumption of food and weight loss, using the mouse model. The key question is how RYGB improves metabolism even before weight loss. It is known that weight loss leads to a decrease in white adipose tissue (WAT) in mice. It was hypothesized that changes in WAT macrophage content reduce WAT infl ammation and that apoptosis of WAT macrophages may be the mechanism by which they are reduced. It is important to note that macrophages increase as WAT expands. The purpose of the study was to determine whether reductions in infl ammation in WAT are the driving force behind the sudden return to a normal glycemic state. There were 3 groups of mice from which WAT tissue was taken – RYGB, Sham, and Sham Pair-Fed. The pair-fed group was used as a way to examine whether changes in metabolism were functions of direct weight loss or other factors that RYGB alone could induce. The goals of the study were to: 1) demonstrate whether WAT macrophages decreased in mice that underwent RYGB; 2) determine whether infl ammation had indeed been reduced; and 3) establish this in turn happened due to apoptosis. A 2-part method was utilized – the fi rst part was gene expression, which showed whether the amount of transcripts for genes of interest had changed. This showed whether macrophages, infl ammation, and cell death had increased. Quantifi cation of gene expression involved 3 steps: RNA isolation, cDNA synthesis from this RNA, and polymerase chain reaction (PCR). The second part of the method was histology/microscopy which demonstrated the quantity of cells and if apoptosis had occurred. Ultimately, gene expression showed that there was no signifi cant difference in macrophages or infl ammation in tissue from mice that underwent sham surgery and mice that underwent gastric bypass. However, while imaging for cell counts in adipose tissue from RYGB mice, an interesting distribution of granular immune cells was found. These cells remain unidentifi ed but present an intriguing future direction for this project and the lab as a whole. While it was not shown that RYGB impacted WAT macrophages or infl ammation, the population of unidentifi ed granular cells and the fact that they only appeared in tissue of mice that underwent RYGB present the opportunity for an exciting further study and may possibly have medical signifi cance.

MOLECULAR PHYSIOLOGY & BIOPHYSICS



S100B’s Role In Obesity-Related Hypothalamic Infl ammation

Kelli Klein, Laura Hunt, Misty Thompson, Kate Ellacott

In 2008, more than 1.4 billion adults, 20 and older, were overweight. Of these over 200 million men and nearly 300 million women were obese. In the periphery, obesity is associated with chronic low-grade infl ammation which in turn is linked to cardiovascular disease, diabetes, and a variety of cancers. Mounting evidence shows that obesity is also associated with astrogliosis and increased peripheral immune cell entry into the central nervous system (CNS) which may cause an increased risk of chronic and acute neurological disorders. Little is known about the mechanism underlying this phenomenon, although it is hypothesized S100B plays an important role. S100B has been linked to infl ammation in the periphery and has been identifi ed as toxic at high concentrations, but the role of S100B specifi cally in neuroinfl ammation as a result of obesity has yet to be elucidated. It was hypothesized that in obesity astrocytes secrete S100B, which then acts on the endothelial cells of the blood brain barrier (BBB), thus enabling peripheral immune cells to gain entry. Using immunohistological staining, western blotting, and real time PCR, S100B was observed to be more abundant in mice with diet induced obesity (DIO) than in their lean counterparts. Additionally, S100B expression showed colocalization with astrocytes, suggesting that S100B may play an important, although toxic, role in CNS injury as a result of obesity.

22


Specifi city Profi ling of Positive Allosteric Modulators Of The Melanocortin-4 Receptor

Aloukika Shah, Julien Sebag, Savannah Williams, Roger Cone

The melanocortin-4 (MC4) receptor is a central player in the regulation of food intake and energy expenditure. Mutations of this receptor are known to cause inherited human obesity. For these reasons, the MC4 receptor is a potential drug target to treat both obesity and cachexia. However, past attempts to develop orthosteric agonists targeting the MC4 receptor have failed due to unacceptable side effects. The Cone laboratory (Vanderbilt University) adopted a different approach and successfully identifi ed 62 positive allosteric modulators which potentiate MC4 receptor signaling, but theoretically should cause little to no side effects by conserving a physiological spacio-temporal activation of the targeted receptor. These modulators however, could potentially stimulate other G protein coupled receptors (GPCRs) on the cells and possibly cause adverse side effects. To determine the specifi city of these molecules, their effect on other GPCRs endogenously expressed in HEK293 cells must be measured. For this specifi city profi ling, fi ve GPCRs were selected based on their reported expression levels measured by a microarray analysis in the HEK293 cells (Atwood et al., 2011). Of these fi ve, four (Prostaglandin E receptor 2, Prostaglandin F, Hypocretin Orexin receptor type 2, and adenosine A2B) are G(s) coupled receptors for which cAMP concentration was measured using a cAMP-dependent luciferase reporter. Cellular activity of Acetylcholine which couples to G(q) proteins was measured by recording intracellular calcium release using a Fluo-8 calcium dye. MC4 receptor specifi city of the allosteric modulators was determined based on a lack of potentiation of the other GPCRs used for profi ling. Several compounds with specifi city for MC4 as well as some molecules with satisfying selectivity were successfully identifi ed.



Investigation Of Hepatic Gluconeogenic And Lipogenic Pathways In Integrin α1β1 Knockout Mice On A High Fat Diet

Jenny Zheng, Ashley Williams, and David Wasserman

Mice with hepatic insulin resistance exhibit selective insulin resistance in which both hyperglycemia and hypertriglyceridemia occur. Total insulin resistance is a recent phenomenon: insulin still fails to suppress gluconeogenesis, but without manifestation of hypertriglyceridemia. Previous studies from our lab show that integrin α1β1 null mice on a high fat (HF) diet exhibit increased hepatic glucose output during an insulin clamp coupled with decreased hepatic triglyceride accumulation compared to high fat fed WT mice. This leads us to believe that integrin α1β1 null mice on a high fat diet are a unique model of total hepatic insulin resistance. However, the mechanism whereby HF fed itgα1-/- mice develops total insulin resistance remains unclear. The objective of this study was to investigate downstream targets of the gluconeogenic and lipogenic pathways in itgα1-/- in hopes of identifying where the two pathways diverge. If a marker is found, hepatic glucose output could be more closely studied without the interference of increased lipogenic action. qPCR was performed for PEPCK and G6PASE of the gluconeogenic pathway revealing a higher mRNA content of PEPCK in high fat fed itgα1+/+. ACC, FAS, and SREBP-c1 were also assessed using rtPCR. Plasma triglycerides assessed in an assay were elevated in high fat fed itgα1-/- mice compared to high fat fed itgα1+/+.

Effects Of Vascular Endothelial Growth Factor On The Resistance Of Human Retinal Microvascular Endothelial Cells

Tom Bu, Gary McCollum, Colin Bretz, Sai H. Presley, John S. Penn

Hypothesis: Transendothelial cell electrical resistance in HRMEC monolayers is a reliable indicator of vasopermeability in diabetic retinopathy. Purpose: Important features of diabetic retinopathy (DR) are increased retinal vascular permeability and edema, which may lead to vision loss. In order to study retinal vascular permeability, an experimental method is needed to study permeability changes in retinal endothelial cell monolayers that are induced by DR relevant stimuli, and to test agents that could potentially block these changes. Retinal vascular endothelial growth factor (VEGF) is increased in DR and correlates with increased retinal permeability. The purpose of this project is to develop an in vitro high throughput method to test the effect of VEGF on the permeability of retinal endothelial cell monolayers. Data gathered from these in vitro studies may be useful for testing potential chemotherapies for effi cacy against vascular permeability. Methods: Human retinal microvascular endothelial cells (HRMECs) at passage 6 were cultured in tissue fl asks coated with attachment factor and with endothelial basal medium supplemented with 10% fetal bovine serum (FBS) and EGM single quots (Cambrex; Walkersville, MD). This medium is known as HRMEC “growth medium.” Seventy-thousand cells were seeded onto a 0.4 µm PET track-etched membrane cell culture insert (Becton Dickinson; Franklin Lakes NJ) and cultured in growth medium for 5-6 days to reach 100% confl uency. The cells were treated with 2% FBS growth medium, 2% FBS growth medium+25ng/ml VEGF or 2% FBS growth medium+ 50ng/ml VEGF for 0 to 12 hours. Transendothelial electrical resistance (TEER) was measured at 0, 0.5, 1.0, 2, 4, and 12 hours using a Epithelial Voltohmmeter equipped with current-passing and voltage-measuring electrodes (World Precision Instruments; Sarasota, FL). Resistances of the time-matched 2% FBS growth medium treated groups were subtracted from the VEGF treated groups. Results: HMRECs treated with 2% FBS growth medium+VEGF produced signifi cantly less resistance than those treated with 2% FBS growth medium. The electrical resistance decreased with increased duration of VEGF treatment. Conclusions: Using an in vitro method to assess electrical resistance, it was demonstrated that HRMEC monolayers treated with VEGF demonstrate increased permeability. Testing the effects of potential anti-permeability agents on transendothelial resistance of cultured HRMEC monolayers may produce data that are reliable indicators of effi cacy against vascular permeability.

OPTHAMOLOGY


OPTHAMOLOGY

Expression Of gp130 In Response To Aging And Ocular Hypertension In The DBA/2 Mouse Model Of Glaucoma

Michelle J. Won, Franklin D. Echevarria, Heather M. Cathcart, and Rebecca Sappington

Glaucoma affects 66 million individuals worldwide, rendering it the second leading cause of blindness. Glaucoma causes blindness through the degeneration of retinal ganglion cells (RGCs), whose axons form the optic nerve. Although age is the primary risk factor for the disease, it is also often associated with increased intraocular pressure (IOP). In addition to degeneration of RGCs, glaucoma also results in a neuroinfl ammatory response characterized by increased reactivity of glial cells, such as microglia, and increased production of infl ammatory cytokines, like interleukin-6 (IL-6). In in vitro models of glaucoma, IL-6 is upregulated by microglial cells and inhibits pressure-induced death of RGCs. IL-6 exerts its effects on target cells through the IL-6 receptor, which contains two subunits: IL-6Rα, the IL-6 binding subunit, and gp130, the signal transductions subunit. Although recent studies have described changes in IL-6Rα expression with age and elevated IOP in vivo, IOP-induced changes in the concentration and localization of gp130 are unknown. Our hypothesis is that under conditions of elevated IOP, expression of gp130 increases in RGCs. Using immunohistochemistry (IHC), we will examine and quantify changes in the expression and localization of gp130 in retina from the DBA/2 mouse model of hereditary glaucoma. As hypothesized, gp130 expression increased in relationship to RGCs exposed to a chronic increase in IOP; however, gp130 intensity overall did not increase in glaucomatous retinas.

24

PEDIATRICS

Recovery of Putative Temperature-Sensitive Mutations In Murine Hepatitis Virus Chimeras Containing Human Coronavirus Nonstructural Protein

5 Substitutions Reveals Conserved Determinants of nsp5 Structure

Havisha Munjal, Christopher C. Stobart, Xiaotao Lu, and Mark R. Denison

Coronaviruses are positive-strand RNA viruses that cause several upper and lower respiratory diseases. A key hallmark of coronavirus infection is the translation of the genome and subsequent processing of replication polyproteins. Nonstructural protein 5 (nsp5) is an essential cysteine protease present in all coronavirus strains that mediates processing at 11 cleavage sites. Recently, temperature-sensitive (ts) mutations have been identifi ed in the nsp5 protease of murine hepatitis virus (MHV), a model system for coronavirus replication. To provide insight into the relationship of nsp5 structure and function across coronaviruses, chimeric MHV viruses have been recovered with the nsp5 substituted from human coronaviruses (HCoVs), HKU1 and OC43 containing previously described MHV ts mutations S133A and V148A in the HCoV nsp5 coding region. Both HKU1 and OC43 chimeras with V148A showed no apparent growth defects at the nonpermissive temperature. However, the OC43 S133A chimera (O5-S133A) had impaired viral replication at the nonpermissive temperature. Virus H5-S133A also had subtle impairments at the nonpermissive temperature. This ongoing study will increase understanding of the conservation of the structure and function of nsp5 proteases among coronavirus strains and may provide novel targets for pan-coronavirus protease inhibitors.


PHARMACOLOGY

Insertion Of A Tag In The 5HT2c-Receptor

Maximilian H. Carter, Randi Ulbricht, and Ron Emeson

5-hydroxytryptamine (5HT) is a monoaminergic neurotransmitter that regulates and facilitates a multitude of sensory and motor processes (Werry, 2008). The 2C subtype of serotonin receptor (5HT2c) mediates the effects of 5HT and is involved in signaling, reward behavior, locomotion, and energy balance (Giorgetti, 2004). Unfortunately, it is diffi cult to characterize this receptor due to a lack of specifi c 5HT2c antibodies and low levels of expression. To allow for effi cient purifi cation and detection of 5HT2c protein, we utilized the biochemical tools of streptavidin (Strep) and histidine repeats (6XHis) by inserting a Strep II and polyhistidine tag (Strep/6xHis) into 5HT2C. The tag was inserted into a cDNA construct that expresses the mouse 5HT2c cDNA near the N-terminus and C-terminus using a modifi ed version of site-directed mutagenesis that allows large insertions, such as the desired 45-nucleotide tag (Geiser, 2001). Both constructs were transfected into mammalian cells in culture for parallel studies of expression and function of the tagged receptor. It is anticipated that at least one of the constructs created will be similar in function and expression to the native, untagged receptor and therefore provide the optimal location for a similar tag in a knock-in mouse model, which is integral for future studies of 5HT2c.

Culturing of Neurons On Graphene Transistors For High Resolution Scanning of Processes

Abhinav Goyal, and Qi Zhang

Like transistors on a microchip, trillions of synapses are the basic computational units in the human brain. Synaptic dysfunction has been widely vindicated in many neurological disorders like Schizophrenia and Alzheimer’s disease. A single neuron can make thousands of synaptic connections with other neurons. Due to their extremely high density and micrometer size, existing measurements, including optical imaging and patch clamp recording, do not have suffi cient spatiotemporal resolutions to study how thousands of synaptic inputs are integrated into one neuron. Recently, graphene, a single layer allotrope of carbon atoms, has emerged to high regard within the fi elds of electrochemistry and physics. Thanks to graphene’s exotic electric properties, it has been shown that optoelectric scanning of neuronal processes growing on graphene is an adequate mean to study neuronal circuitry at synapse level. A variety of culture confi gurations were tested, including astrocyte-conditioned medium and astrocyte banking culture, and neurons with matured synaptic connections have successfully been grown directly on graphene. The normality of those neurons was verifi ed by electrophysiology and optical imaging. This graphene based super-resolution and high throughput screening platform will bring us one step closer to cracking the enigma of neuronal coding in our brain.

PHARMACOLOGY


Smart Windows Using A Nanothermochromic Metamaterial

Chuhyun Kim, Davon W. Ferrara, Robert E. Marvel, Robert H. Magruder III, Richard F. Haglund, Jr.

The objective of this study was to characterize and evaluate nanocomposites of dropcasted, colloidal Au nanorods in a VO2 matrix for use in solar effi cient window coatings. Vanadium dioxide (VO2) fi lms have special thermal and optical properties in that, above a critical temperature of 68°C, VO2 undergoes a semiconductor-to-metal phase transition (SMT) that leads to an increase in refl ectivity. In addition, gold (Au) nanoparticles which exhibit a localized surface plasmon resonance (LSPR) at optical or near-infrared wavelengths can be incorporated into the VO2 fi lm with benefi ts including aesthetics and increased absorption of electromagnetic radiation. Since the Au LSPR is sensitive to changes in the dielectric function of the surrounding medium, Au::VO2 nanocomposites form a nanothermochromic metamaterial capable of selective enhancement of absorption with increasing temperature. For this research, colloidal Au nanoparticles were drop-casted onto plain glass and indium-tin-oxide (ITO) coated glass substrates for cost-effi cient “broadband light harvesting,” followed by electron-beam deposited VO2. The concentrations and volume of gold colloid solutions were altered to vary the distribution of nanoparticles on the substrates. The SMT of the nanocomposite was induced thermally using a Peltier-effect heater. To characterize the samples before and after VO2 deposition, white-light extinction spectroscopy and scanning electron microscopy were used. Results showed signifi cantly improved refl ectivity and absorption in the near-infrared with the nanocomposite compared to the plain fi lm. These results suggest that a nanocomposite composed of VO2 and Au colloids can be optimized to maximize optical transmission at lower temperatures while selectively increasing refl ectivity as the temperature increases. A theoretical model was proposed for optimization.

PHYSICS & ASTRONOMY

RADIOLOGY & RADIOLOGICAL SCIENCES

Skeletal Muscle Blood Flow And Oxygenation Changes Following Brief

Muscle Contractions In Endurance Trained And Sedentary Individuals

Sam Klockenkemper , Theodore F. Towse, and Bruce M. Damon

Exercise training reduces the risk of cardiovascular disease and type II diabetes through adaptations in the peripheral vasculature. Adaptations from training include peripheral improved vascular reactivity, increased vasodilator availability, and increase muscle capillary density. Therefore, the purpose of this study is to compare the blood fl ow and blood composition responses of habitually trained and sedentary individuals using Doppler ultrasound. There will be twelve sedentary and twelve trained subjects matched by age, sex and BMI. Subjects will perform a series of 1-second maximum voluntary contractions in order to isolate the microvasculature and measure how healthy it is functioning. Doppler Ultrasound will be used to measure blood fl ow in the Anterior Tibial artery while the subject’s foot will be strapped into a force boot that measure force output of the dorsifl exion. Trained subjects will have faster and larger post-contraction increase in blood fl ow and blood volume.

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© 2012 Center for Science Outreach

The Vanderbilt Center for Science Outreach (CSO) is dedicated to enhancing scientifi c and technological literacy through the establishment of unique partnerships between university scientists, K-12 educators, students, and the local and global science community.

To uphold this mission, the CSO has developed and implemented various educational programs in partnership with local and national K-12 classrooms. In addition to the Research Experience for High School Students, the CSO also provides other programs, including summer science camps for middle school students; Scientist-in-the-Classroom Partnerships, pairing actual scientists with middle school teachers; professional development programs focusing on connecting scientists with in-service teachers; and the School for Science and Math at Vanderbilt. It is through these programs that the CSO has reached thousands of children and teachers since the early 1990s.

As a national leader in outreach efforts, the CSO is committed to elevating pre-collegiate science expertise and literacy, allowing the next generation to move forward with an increased desire to discover science.

Virginia L. ShepherdDirector, Center for Science OutreachProfessor of Pathology

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2012 Student Research Symposium Abstract Booklet

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