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Cellular Biology I (Chancellor West) 

9:15am: How Do We Make Neurons: An In Depth Characterization of in vitro Neurogenesis

Emily Puleo (University of Virginia)

Neurogenesis and the development of different neural cell types involves highly regulated, complex processes that are not fully understood. In vitro systems allow us to quickly screen perturbations to neurodevelopmental pathways. We use an in vitro model of neurogenesis to study the effects of retinoic acid (RA), a key modulator of neurogenesis, on neurodevelopment. RA mediates vitamin A functions necessary for growth and development, and cells treated with RA are expected to differentiate into neural progenitors. RA and vitamin A are implicated in Alzheimer’s and Parkinson’s diseases as they are known to prevent the diseases by preventing formation of plaques. A 14-day cell culture with varying concentrations of RA was collected at days 6 and 14 and subsequently stained for antibodies and run on a mass-cytometer to obtain 39 simultaneous measurements per cell. The UMAP force-directed algorithm was applied to create a map which clusters cell populations based on marker similarity. These clusters are the result of unprecedented molecular resolution. Cell populations are identified based on a cluster’s marker profile. Compiling all samples yields populations of neural, mesoderm and glial progenitors. Neural populations are identified by NeuN, Dcx, and MAP2 markers. Mesoderm and glial populations are identified similarly through marker expression. UMAP analysis identified early and late-stage cell populations of in vitro neurogenesis. Increasing concentrations of RA push cells to a neural fate and lack of RA produces mesoderm and neural subtypes. These experiments illustrate the effects of RA in generating various neural subtypes and identify its role in neurogenesis.

9:35am: Novel Functions of Human Binding Proteins in DNA Repair

Nathan Matzko (Clemson University)

Homologous Recombination (HR) is a crucial DNA repair pathway that resolves double stranded breaks in DNA by utilizing the homologous sister chromatid of the damaged DNA as a template for repair. While single-stranded binding proteins (SSBs) play crucial roles in HR, many SSBs, like human SSB1 and SSB2, are not fully biochemically characterized. Here, we present novel functions of human SSB1 and SSB2, linking these proteins in second end capture in the HR repair pathway. 

9:55am: Structural Studies of Two tRNA-Synthetases

Meghan Pressimone (Wake Forest University)

X-Ray crystallography permits deeper understanding of protein structure and function beyond experimental assays. Such is the case of Mycoplasma penetrans methionyl-tRNA synthetase (MpMetRS), a homodimer comprising both an aminoacylation domain and an appended aminotransferase domain. It has been determined that the transferase domain of MpMetRS is capable of supplying methionine for aminoacylation activity, but the orientation of these domains is unknown, and may reveal the evolutionary rationale for the linking of the domains.  A second tRNA-modifying enzyme, Burkholderia cenocepacia tRNA-isoleucine lysidine synthetase (BcTilS), is of interest because of evolutionary mutants that increased bacterial fitness when TilS activity was actually decreased. Computational modeling and tRNA mutation experiments suggest a crucial recognition point at the 3-70 tRNA Ile base pair, and crystallizing the enzyme, especially with tRNA, would better aid these conclusions.  In pursuing crystallography of BcTilS and MpMetRS, proteins have been overexpressed, purified, and screened both in-house and with high throughput screening at the Hauptman-Woodward Medical Research Institute. Through screening thousands of solutions varying in buffer, salt, pH, and additives, deceptively promising salt crystals have precipitated for MpMetRS, leaving Cryo Electron Microscopy as the final means of obtaining the structure. Nevertheless, BcTilS has presented significant promise towards the structure since crystals were replicated and partially optimized from a unique screening condition.

Ecological Studies (Chancellor East)

9:15am: Forest Interception of Airborne Ammonia/Ammonium from Hog Waste Lagoons in Eastern North Carolina

Daniel Amparo (North Carolina State University)

A significant amount of emissions from hog waste lagoons consist of nitrogen-based compounds, such as ammonia gas and ammonium particulate matter. These compounds are carried by the wind and are deposited onto nearby areas of land. Forests have the potential to act as a natural barrier to intercept ammonia/ammonium released into the air from hog waste lagoons. An understanding of the extent of forest interception of ammonia/ammonium could provide beneficial social and economic benefits to society. The parameters of interest were the concentration of ammonia gas and analyzing the N- 15 isotopic signature in foliar pine needle samples. Ammonium data was collected with Radiello passive samplers, a polyethylene cartridge that allows ammonia gas to diffuse and adhere to its surface as ammonium ions. Hog diets consist of a larger percentage of stable N-15 isotopes that can be detected in N-15 isotopic analysis of pine needle samples. An initial sampling phase was conducted to provide a qualitative representation of ammonium and N-15 partitioning throughout a specific forested region neighboring the hog waste lagoon of interest. The samples were collected, prepared, and shipped to the Cornell Stable Isotope Laboratory (COIL). The results were recorded and mapped out using ArcMap. Further research will consist of an extensive examination of the forest’s ability to intercept ammonia gas at further distances from hog waste lagoons. This will be conducted by using a greater number of passive samplers, foliar samples, and a grid sampling approach.

9:35am: Quantifying Spatial Distributions and Benthic Footprints of Artificial Reefs on the Southeastern USA Continental Shelf

D’amy Steward (Duke University)

Artificial reefs are commonly deployed to enhance fish habitat and provide fishing and diving opportunities. Despite the widespread occurrence of artificial reefs, relatively little is understood about their spatial distributions and how much area of the seafloor these reefs cover. To help fill these knowledge gaps, we quantified the spatial distribution and benthic coverage (‘footprint’) of artificial reefs along the continental shelf of the southeastern United States (Florida, Georgia, South Carolina, North Carolina) using data from the respective state agencies. Specifically, we examined the distribution of artificial reefs by geography, depth, material, and structure type. We then estimated the minimum, mean, and maximum coverage of artificial reefs across the southeastern USA using multiple quantitative approaches. By increasing knowledge and understanding of the distribution and associated attributes of artificial reefs, this research may help inform future designs, deployments, regulation, and restoration along US coastlines.

9:55am: Magnetic Map Sense of Gulf Flounder (Paralichthys albigutta)

EmmaLi Tsai (University of North Carolina at Chapel Hill)

Gulf Flounder, a species of migratory flatfish found in coastal waters spanning from North Carolina to the Gulf of Mexico, travel significant distances (10s-100s km) from shallow coastal nursery areas to reach deepwater spawning sites. However, the sensory basis guiding this movement remains a mystery. Previous research suggests that some aquatic animals can sense the Earth’s magnetic and use that ability both to determine direction (a magnetic compass sense) and as a “magnetic map” for determining position, similar to a GPS used by humans. We aimed to determine if Gulf Flounder possess a “magnetic map sense,” which would allow them to use the Earth’s magnetic field to guide their migration from spawning grounds to feeding areas and back. To search for the presence of a magnetic map sense, we exposed flounder to one of two artificially-generated magnetic fields that replicate magnetic fields located north (near New Jersey) and south (near Jamaica) of the experimental site of Morehead City, NC. Juvenile flounder were placed in a small orientation arena and allowed to swim freely in either the New Jersey or the Jamaica field for 1.5 hrs. Video analysis indicated that flounder tested in the northern magnetic field of New Jersey significantly oriented towards magnetic SE, and flounder tested in the southern magnetic field of Jamaica exhibited random orientation. Results from these two treatments were significantly different. These results provide evidence for a magnetic map sense in Gulf Flounder, adding flounder to the growing list of marine migrants that utilize this cue.

Identity and the Mind (Hill Ballroom Central)

9:15am: Cultivating Computing Identity: How Children Come to Be, Know, and Do in Computer Science

Carter Zenke (Duke University)

As states begin to mandate computer science (CS) instruction for ever-earlier ages, it is critical to establish a shared language—among teachers, policymakers, and researchers—regarding how students come to learn computer science. This language should equip policymakers to remove systemic barriers, help teachers to humanize their students, and encourage researchers to establish best practices. This presentation argues that the concept of a “computing identity,” coupled with an understanding of how children come to develop this construct, will best unify educational stakeholders across these goals. To propose a useful model of computing identity, this presentation will first draw from literature on established disciplinary identities, such as math identity and STEM identity. Then, it will delve into two ethnographic portraits of high-school students who participated in a computer science curriculum designed to help the students see themselves as, and be recognized as, computer scientists. In merging the literature on disciplinary identity with this rich ethnography of student experiences, this presentation opens a space for conceptualizing computing identity and the conditions that cultivate it. As a test-case for the construct’s usefulness, the presentation will conclude by discussing how computing identity has been used to frame the development of North Carolina’s first elementary CS curriculum, to be implemented in all classrooms by 2021.

9:35am: The Relationship Between Self-Reported Sense of Parental Competency and Postpartum Depression Risk in First-Time Mothers

Zoe White (Florida State University)

The postpartum period raises physical and emotional challenges to new mothers resulting a low sense of competency (LSOC) as they navigate the transition into parenthood. Mothers who report a LSOC are at risk for PPD. Evidence of the relationship between LSOC and PPD over time is lacking. This study explores the correlation between LSOC and PPD over the first months of motherhood. It is hypothesized that LSOC will increase over the four months thus reducing the risk for PPD. Methods: Visits were conducted with first-time mothers (N=36) at 1 and 4 months postpartum. The Parenting Sense of Competence (PSOC) scale provided a measure of LSOC and the Patient Heath Questionnaire-2 (PHQ-2) was used to screen for risk of PPD. Demographic characteristics and birth history were also collected via questionnaire. Average PSOC scores and PHQ-2 scores were compared at the 1- and 4-months visits to examine correlation over time. Results: Seven mothers screened at risk for PPD at 1-month postpartum (19.4%) and the PSOC average was 76.6 (Scores ranged from 45-99). To date, 26 mothers have completed the 4-month visit, 15.4% screened at risk for PPD and the average PSOC is 83.4 (Scores ranged from 65-100). Conclusions: This study explores the relationship between LSOC and PPD in first-time mothers as they adapt to parenthood. Preliminary results indicate that maternal LSOC increases and risk for PPD decreases in the first four months postpartum, supporting the hypothesis of this study. Future research should examine how educational interventions for first-time mothers can act as a mediator for PPD risk by increasing LSOC.

9:55am: Making Music Memories

Bethany Ghent (Clemson University)

Dementia is a disease that destroys the sensory components of the brain over time. To combat the symptoms that hinder activities of daily life, music therapy is a cost-effective and beneficial tool. This project provides an overview of the best methods in delivering music therapy to dementia patients through the analyzation of live performances, individualized audio playlists, and video sessions.

Forests, Floods, and Fluids (Hill Ballroom South)

9:15am: Changing Perceptions of Forest Spaces in the Himalayan Foothills: From Extraction Zone to India’s First National Park

Colin Phelan (Boston College)

My project investigates the creation of Jim Corbett National Park in Uttarkahand, India. Established in 1936 and then-known as Hailey National Park, this national park was the first in both India and in Asia. The thesis project is divided into three chapters. Overall, the thesis analyzes how the forest space which eventually came to be Hailey National Park once served as a forest which provided some of the best commercial timber in all of British India. The first chapter focuses on the 1860s, and the mobilization of the Indian Forest Service; I describe how the service viewed this specific forest region in northern India with purely commercial ambitions in view. My second chapter skips forward a few decades; this chapter focuses on the 1920s and 1930s, and in it I focus on several key actors who contributed to a new understanding of forest spaces within India. In particular, I describe how this forest space shifted into one which concerned the livelihoods of animals. With the establishment of this national park, animals would now receive unabated protection; this reform confronted the long-standing hunting tradition of shikar on the subcontinent, and represented a shifting understanding of natural spaces. My final chapter focuses on the creation of Hailey National Park within a global context. This chapter focuses on influences from both the U.S. and the U.K. in the interwar period and situates the creation of the park not merely as a product of South Asia’s animal protection movement, but as one also influenced by external pressures. By analyzing this forest space’s transformation over time, this project exhibits the changing human relationship to forest spaces, and more broadly, to the environment. 

9:35am: Aerospace Approach to Flood Modelling

Yashvardhan Tomar (Georgia Institute of Technology)

Catastrophic urban flooding due to sustained intense rainfall has been reported in many densely populated regions. Human decision-making with dams and rivers is one reason, because dam operators often trade the risk of dry summer against timely water release unless dam burst risk becomes acute. The presentation will focus on my approach to create a light user-friendly tool that operates on localized geographic information encoded in the form of pre-loaded GIS files for a user’s region of interest. The methodology is based on the concept of “Influence Coefficients” and “Domain of Influence” used in Aerospace supersonic and transonic aerodynamics and aeroelasticity, along with finite difference tools from computational fluid dynamics.   The problem at hand, from an aerospace perspective, is one of quasisteady fluid dynamics (with gradient-based time-delay modelling) under body (gravitational) forces, with a discretized, finite difference approach using mass continuity and momentum conservation. In this talk, I will present my results from a first-order computational prediction technique, followed by a brief discussion on the development of a physical model of gradient-based flows that can be adapted per the nature of flow surface to obtain numerical solutions for discharge velocities in any localized region. 

9:55am: Fluid Management for Passive Sweat Lactate Sensing Devices using Osmotic-Capillary Principles with Self-Powered Microfluidic Pumping

Jennifer Fang (North Carolina State University)

Sweat is an important biofluid source for human health monitoring since it contains analytes and metabolites similar to the ones found in blood. However, collecting information from sweat is still challenging as most commercially available sweat sensing devices operate either invasively or are functional only under active sweating, released via intense physical exertion. These devices cannot actively collect sweat fluid in low humidity conditions. We present and discuss about a new flexible, wearable design prototype that can contribute towards withdrawing sweat non-invasively under low sweating conditions by utilizing the simultaneous action of osmosis, capillary wicking, and evaporation. The device comprises of silicone, paper, and a polyacrylamide hydrogel, equilibrated with glucose solution to obtain a higher osmotic strength than skin. In-vitro analysis on model skin has shown the potential of such devices to provide continuous extraction till ~ 10 hours. Human trial results highlight sweat lactate collection under both resting and non-resting conditions within a period 2 hours. The device shows visual variations in sweat lactate between modes of passive and active sweating during alternating periods of rest and exercise, where with exercise a higher lactate value was achieved. A continuous sweat lactate sensing platform is also being currently established on this paper microfluidic device, using screen printed enzymatic electrochemical sensors for providing near real-time monitoring. Such simple, low cost, continuous sweat sensing platform with specific sensors can either be worn directly onto the skin or be used as a wearable, that will reveal a great deal of health information.