2018 Postdoctoral Research Symposium

2018 Postdoctoral Research Symposium

The 2018 Postdoctoral Research Symposium was held on Friday, May 25th at the NC State McKimmon Center. The Symposium included over 60 presenters from seven institutions and centers. Keynote speaker Jamie Vernon of Sigma Xi spoke to attendees about the importance of science communication. See below for pictures of the event.

Postdoc Research Symposium 2018

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Presenters

Mr. Mohamed Saveer Ahmed
Dr. Mauriell Amechi
Dr. Rishi Aryal
Dr. Aurore Canoville
Dr. Stefanie Chen
Dr. Pandiyarajan Chinnayan Kannan
Dr. Hsuan Chou
Dr. Ashley Elias
Dr. Yuan Fang
Dr. Josefina Patricia Fernandez Moreno
Dr. Melina Florez-Cuadros
Dr. Nathaniel Grubbs
Dr. Lucie Guertault
Dr. Drew Hackney
Dr. Linna Han
Dr. Emily Harrison
Dr. Eduardo Hatano
Dr. Melanie Hedgespeth
Jaret Hodges
Dr. Allyn Howlett
Dr. Qandeel Hussain
Dr. Chinmay Jena
Dr. Younggeon Jin
Dr. Katherine Kennedy
Dr. Hiroki Kittaka
Dr. Amanda Krentzel
Dr. Alma Laney
Dr. Zheng Li
Dr. Xuefeng Li
Ms. Shuang Liu
Dr. Ana Martins
Dr. Alsayed Mashaheet
Ms. Panita Maturavongsadit
Dr. Michael McLaren
Dr. Bhalchandra Mirlekar
Dr. Marie Mooney
Dr. Roberto Mota
Dr. Ismaeel Muhamed
Dr. Bita Nickkholgh
Dr. Feng Pan
Dr. Lizhi Pan
Dr. Cameron Parsons
Dr. Tahira Pirzada
Dr. Deepti Pradhan
Dr. Keshav Raghuvanshi
Dr. Hector Rendon
Dr. Luis Rivera-Burgos
Dr. Avinash Rustagi
Dr. Sheila Saia
Dr. Elena Schroeter
Hasan Shahariar
Dr. Michael Sidorov
Dr. Kunwar Singh
Dr. Shilpa Sivashankar
Dr. Bridget Smith
Dr. Teng Su
Dr. Qingyu Tang
Dr. Nadja Vielot
Dr. Glenn Watson
Dr. Hui-Yin Wu
Dr. Xiao Xiao
Dr. Xinyu Zhang
Dr. Yuchen Zhao
Dr. Ce Zheng
Dr. Cheng Zhu

Abstracts

Mr. Mohamed Saveer Ahmed

College of Agricultural and Life Sciences
NC State University

Chemosensory mediated sex- and stage-specific recognition in the bed bug, Cimex lectularius

Problem Statement
The common bed bug, Cimex lectularius is an obligate blood-feeding human ectoparasite that has become global pest and poses enormous threat to public health. Many factors may have led to this outbreak but the development of resistance against commonly used insecticides is one of the important contributors. Alternative approaches such as development of novel, non-insecticidal control strategies are essential.

Because bed bugs rely on their sense of smell (olfaction) to locate aggregation sites, mating partner and human hosts (for blood meal), odorants can be used to control bed bugs. Using behavioral, analytical and electrophysiological methods, these studies will further enhance our understanding of the fundamentals of bed bug chemosensory mediated behaviors as well as the specific role of odorants that mediate these behaviors.

Broader implications of the research
These studies will further enhance our understanding of the fundamentals of bed bug
chemosensory mediated behaviors as well as the specific role of odorants that mediate these
behaviors that may facilitate the development of effective odorant-based bed bug traps for better surveillance and control.

Keywords
Behavioral ecology; chemical ecology; Cimex lectularius

Dr. Mauriell Amechi

UNC-Chapel Hill

Exploring how Underrepresented Minority PharmD Candidates were Exposed to and Gained Interest in Pharmacy

Problem Statement
Racial and ethnic health disparities persist in the United States despite urgent calls for action (Nkansah, Youmans, Agness, & Assemi, 2009; U.S. Department of Health and Human Services [HHS], 2017; HHS, Office of the Secretary, Office of the Assistant Secretary for Planning and Evaluation, & Office of Minority Health, 2015). Leaders across healthcare disciplines, government agencies, and professional organizations have called greater attention to the shortage of diverse, competent, and compassionate health professionals dedicated to working in cross-cultural contexts. Broadening diversity and participation in health occupations like pharmacy is critical. Studies link a diverse health sciences workforce with health equity within communities racially and ethnically underserved. The purpose of this exploratory study was to understand the pre-pharmacy experiences of underrepresented minority students (URM). One central research question guided this work: How are URM students exposed to and gain interest in pharmacy education and health professions?

While previous quantitative studies offer a broad, macro-level analysis of the general pathway to pharmacy, enabling factors that motivate underrepresented minority students to pursue careers in pharmacy are less understood. This phenomenological study explored how underrepresented minority students gained exposure to and interest in pharmacy education and health professions. Findings, based on 20 in-depth interviews, suggest the importance of: a) participation in health professions/STEM pipeline programs, b) early immersion/work experiences, and c) motivation from family, friends, and institutional agents in the pharmacy field.

Broader implications of the research
Findings from this study contribute to the literature in at least three significant ways. First, unlike prior research in this area, which mostly assessed the impact of pipeline programs (e.g., Awé & Bauman, 2010), the current inquiry shed light on the confluence of other sociological factors, notably supportive networks of family, friends, and professional colleagues. Second, our investigation adds to evidence regarding the role and significance of health science/STEM pipeline programs in broadening participation among URM students (e.g., Awé & Bauman, 2010; Schultz et al., 2011). Third, given the underutilization of qualitative approaches in pharmacy (Rosenthal, 2016), this study represents one of the first qualitative explorations of underrepresented minority students’ pathways to pharmacy. Hence, this study provides unique and contextualized insights regarding the lived experiences of participants and their journey into the field. As more colleges and universities implement new strategies to recruit underserved students, these findings will be especially useful to stakeholders in the health science and STEM fields.

Keywords
Pathways to Pharmacy; Underrepresented minority students; Student recruitment

Dr. Rishi Aryal

College of Agricultural and Life Sciences
NC State University

Differential Gene Expression During Flower and Fruit Development of the Blueberry cv. O’Neal

Problem Statement
Every year blueberry industry suffers from severe crop loss due to floral damage by late-season frosting and fruit damage during machine harvest. Modulation of the flowering time and fruit firmness has been a major focus of the blueberry breeding programs. In this study, we investigated the genetic regulation of flower and fruit development in a commercially important blueberry cultivar.

• A total of 219,842 transcripts were assembled from 1.8 billion RNAseq reads using CLC genomics
• We identified 7,398 and 6,734 genes that are differentially expressed during flower and fruit development respectively.
• There were 2701 genes deferentially expressed during breaker stage when the fruit starts softening.
• Glycan degradation pathway genes are enriched during fruit softening stage.

Broader implications of the research
Our study provides candidate blueberry genes that regulate fruit ripening and flower development in blueberry. These resources can be useful for breeding superior blueberry cultivars that are resistant to frost damage as well as suitable for mechanical harvesting.

Keywords
Blueberry; ISOseq; RNAseq; mechanical harvest; flower development

Dr. Aurore Canoville

College of Science
NC State University

New data on the skeletal distribution, microstructure, and chemistry of medullary bone in modern birds – Paleobiological implications

Problem Statement
Medullary bone is a specialized tissue produced by female birds during the egg-laying cycle. This gender-specific bone tissue acts as a labile reservoir of calcium for the eggshell formation.
In the literature, it is commonly described as a highly vascularized and strictly woven bone tissue, deposited in the cavity of long limb bones. This bone tissue has also been defined by a unique molecular composition. Some of its molecular markers, such as the glycosaminoglycan keratan sulfate (KS), have not been reported in the calcified matrix of other bone types.
Using these microstructural and chemical criteria, medullary bone-like tissues have been reported in several specimens of non-avian dinosaurs. However, medullary bone’s definition mostly results from its study in domestic bird species that are not representative of bird diversity. Moreover, some avian pathological bone tissues meet the microstructural criteria, thus casting doubt on previous observations of medullary bone in the fossil record.

With a sample of over 60 bird species, our work constitutes the first taxonomically comprehensive study of medullary bone. Using micro-computed tomography and histochemical techniques (chemical staining and immunochemistry), we assess the skeletal distribution of medullary bone and evaluate the extent of microstructural and chemical variation of this bone tissue in modern birds.

Using similar techniques, we also studied the bone pathologies of 20 bird specimens, in order to test the hypothesis that medullary bone is chemically different from avian pathological bone tissues.

Our results reveal that the skeletal distribution of medullary bone varies between bird species. This bone tissue can be found in most skeletal elements and is uniformly present in the proximal part of the tibiotarsus of all studied specimens during the laying cycle.
Our preliminary chemical analyses reveal that some avian pathological bone tissues may contain keratan sulfate, complicating the reliability of chemical approaches to identify medullary bone.

Broader implications of the research
The data of this groundwork will be used to reassess previous identifications of medullary bone-like tissues in non-avian dinosaurs.

Keywords
Medullary bone; histochemistry; bone pathologies; Dinosauria; gender identification

Dr. Stefanie Chen

College of Sciences
NC State University

Dr. Pandiyarajan Chinnayan Kannan

College of Engineering
NC State University

Gradient Hydrogel Coatings for Biomedical Applications

Problem Statement
Demonstration of a synthetic platform to generate surface-anchored stiffness gradients using biocompatible hydrogels that can be employed in the creation of artificial implants, e.g., tendons and ligaments.

Broader implications of the research
A successful outcome of this project will have a tremendous impact on both basic and applied science especially in the area of chemical and biomedical engineering.

Keywords
Hydrogels, surface-attached polymer networks, thin films, artificial implants, stiffness gradients, cross-link density

Dr. Hsuan Chou

College of Agricultural and Life Sciences
NC State University

Effects of diurnal thermal fluctuation into uncomfortably warm temperatures on life history and transcriptomic response in mayfly Neocloeon triangulifer

Problem Statement
In freshwater ecosystems, organisms experience thermal change on different temporal scales – (e.g. daily, seasonally, annually) which may differentially affect physiological processes, developmental trajectories and life history outcomes. As thermal regimes change, it is likely that some species are experiencing portions of their life cycle where daily high temperatures are outside of the thermal acclimation zone. The fitness consequences of exposure to diurnally fluctuating temperatures that place organisms under transient thermal stress are largely unknown. Moreover, the physiological processes that occur under chronic but transient thermal stress are poorly understood despite the fact that this situation may be perhaps the most relevant to organisms as conditions warm. As the global climate changes and human activities increase the temperature freshwater ecosystems, it is imperative that we develop a better understanding of how thermal change experienced at different temporal scales affects aquatic life.

Here we rear mayfly Neocloeon triangulifer, an emerging aquatic insect model for environmental studies under two sets of diurnal fluctuating temperatures to better understand its life history outcomes and transcriptomic responses to chronic daily forays into uncomfortably warm temperatures.

Previous static life cycle rearing experiments with N. triangulifer identified temperatures associated with excellent survival (18-26°C ), markedly reduced survival and fitness (28°C) and chronic lethality (30°C) (Kim et al., 2017). We used this information to create diurnally fluctuating rearing conditions (mean ± 2.5°C, e.g. 5°C amplitude) that enabled us to ask if life history outcomes differ when temperatures are experienced in a static vs. fluctuating manner.

Life history outcomes did not differ between static and fluctuating temperatures at 22°C, whereas at 26°C, fitness was reduced in oscillating conditions relative to static.

We used an RNA-SEQ approach to compare gene expression profiles of mature larvae sampled at the low and warm temperatures of their respective daily thermal regimes to better understand how short- term forays into sub-optimal (warm) conditions affected gene expression. We also made comparisons of gene expression profiles across thermal regimes to better understand how signatures of transient but chronic thermal challenge are retained at the mRNA level even at “recovery” temperatures. Our results suggest thermal fluctuation to uncomfortable temperatures has an effect on chitin catabolism, cuticle development and energy metabolism.

Broader implications of the research
Our study shows that N. triangulifer larvae do not recover from daily forays into challenging temperatures. We link these results to life history outcomes and fitness measures. In addition, data also highlights the role of molting in mediating thermal performance. This study not only helps better understand how a modestly increased daily thermal fluctuation affects gene expression, biological processes and ultimately life history outcomes in N. triangulifer but also raises our awareness of climate change impact on living organisms.

Keywords
Mayfly; thermal stress; life history; RNAseq; molting

Dr. Ashley Elias

College of Science
NC State University

Genomic survey of sex determination systems in cichlids reveals an evolutionary hot-spot

Problem Statement
Despite sex determination being a fundamental process in sexually reproducing species, there is striking diversity, particularly among fish, in the mechanism. Studying sex chromosomes is essential to understand gene and chromosome evolution, but they present unique challenges for sequencing.

The research presented includes two comparative genomic strategies to characterize new sex determination genomic regions and gain insight into how new sex determination alleles evolve, and how they alter the evolution of the chromosomes they reside upon. In one species, a novel approach was used that enabled the characterization of the sex determination system with relatively low coverage sequencing. This strategy will be broadly applicable for rapid characterization of sex chromosomes in species where sex reversal is possible. Another model system this research is developing involves multiple genetic factors segregate and interact to direct sexual development. While individuals of a species will develop phenotypically as either male or female, multiple genetic types of males and females may exist. Using a pooled sequencing strategy, the genomes of four sex genotypes that produce two sexes were compared. Two sex determination regions were identified at different locations in the genome, the sequence variation between sex alleles at each region was cataloged, and possible sex determiners in those refined mapping intervals were identified. Notably, these identified genomic regions lack sex determination genes previously found in other vertebrates. Interestingly, the sex determination regions identified in in different species overlap. The same region of the genome has been recruited as a sex chromosome in cichlids repeatedly and independently, suggesting that some chromosomes are more likely to be used for sex determination.

Broader implications of the research
This work has implications for studying the evolution of sex determination, aquaculture, and studying gene interactions and networks more broadly. Genetic mapping of sex determination is valuable for understanding the evolution of sex determination and sex chromosomes. The species studied provide snapshots of possible transitions from one mode of sex determination to another. Through this work we hope to identify additional sex determination genes and interactions. This work will also provide insight into sexual development and disease. This research may provide insight into the continuum of sex differences in humans, and challenge long held notions of the evolution and development of sex and sexual dimorphism.

Aquaculture is important worldwide, with over 350 species cultivated. Tilapia, a cichlid, is one of the fastest growing fish farming sector and the most widely grown (85 countries). There is a lot of interest in controlling and manipulating sex ratios. Balanced sex ratios are needed for broodstock management, while monosex farming is of interest where one sex is more valuable due to differences in growth, timing of maturation, color or shape. In tilapia growth dimorphism favoring males and previous farming practices have included: manual separation, hybridization between species, and sex reversal using hormones. A broader study into sex determination in related species could have impacts on these aquaculture practices.

The development of this model system will provide the unique ability to address broad questions about evolutionary transitions and gene interactions. With multiple genetic switches interacting in different combinations to produce a fundamental trait and effects throughout an organism, we can ask questions about the developmental regulation of genes and gene networks.

Keywords
Genomics; fish; cichlids; sex determination; sequencing

Dr. Yuan Fang

College of Natural Resources
NC State University

Impacts of Urbanization on Terrestrial Water Balance in the United States

Problem Statement
More than 2 billion additional urban residents are forecasted by 2050 globally, indicating a steadily urban growth (UNPD 2017). The land devoted to urban had grown by over 34% during 1980 to 2000 and was projected to increase by nearly 100% by 2030, rising to about 1.2 million square kilometers (Alig et al. 2004, Seto et al. 2012). Land cover changes associated with urbanization have a profound effect on watershed water balances due to the introduction of impervious surfaces, removal of deep-rooted vegetation and alterations to the drainage network (Haase 2009b). It has been increasingly important to understand the impacts of urbanization on ecosystem water balance. Several studies have examined the functional effects of urban growth on the ecosystem (Haase 2009a, Caldwell et al. 2012), but very few studies evaluated the impacts of future urbanization on water balance regardless of climate change at the terrestrial united states.

This study aims to 1. Evaluate the urbanization impacts on water yield and evapotranspiration (ET) at multiple spatial scales: from the single watershed, regional, and national undercurrent mean climate. 2. Discover the key variables control the water balance change under urbanization. We examine the landcover data in year 2006/2011 (NLCD) and 2040 (ICLUS). The ET and water yield are projected by Water Supply Stress Index (WaSSI) model. The primary finding is that climate (e.g. dry vs. wet) and changes in leaf area index (LAI) control the magnitude of change in water balance (e.g. water yield).

Broader implications of the research
The cumulative impact of land use change is likely to impair the urban water balance, which possibly leads to an increased risk of flood and water pollution produced by increasing runoff. A decreasing in ET will likely increase the summer temperature. Our research may contribute to the future water management and hydrological changes evaluation.

Keywords
WaSSI; water balance; hydrology; urban; landcover change

Dr. Josefina Patricia Fernandez Moreno

College of Agricultural and Life Sciences
NC State University

THE HORMOMETER: Single-locus multi-hormone reporters for comprehensive plant phenotyping. A synthetic-biology approach

Problem Statement
The study of hormones interaction and crosstalk to coordinate and integrate tightly the plant responses under different situations such as plant grow, plant development, plant defense or plant adaptation is limited. Even though there is individual information available for most of the major plant hormones (obtained by reductionist approaches), there is very little information about how they interact together. One of the major reasons of why these holistic studies have not being achieved is the lack of a proper system for hormone sensor multiplexing; that is, to combine them with compatible reporters in a way that allow us to visualize and quantify their presence at the same time with a high spatial and temporal resolutions. Nowadays, thanks to the new synthetic biology methodologies that allow generate complex combinations there is an open door to address such difficulty. In this frame, my project is focused in the development of such tool using one of the SynBio platforms available for plants.

First, we found a fast and low cost way to clone repetitive promoters in a week, rather than months like the time required for the current methodologies. For this purposes, we also design a strategy to synthetize the different repeats to be cloned.

Second, we are generating an extended collection of phytobricks including hormone-inducible promoters, minimal synthetic promoters, synthetic terminators, subcellular compartment signals and fluorescent proteins. These bricks are specially designed to prevent silencing issues when they are combined into the plant. The importance of this collection is based in the fact that there are available just a few bricks to be used in synthetic biology, especially promoters and terminators; so we are going to increase substantially the possibilities of the field with this collection.

Third, we are assembling individual transcriptional sensors for each one of the major plant hormones. These, could be used individually or in combination with others to address individual or more complex studies (reductionist or holistic approaches, respectively).

Fourth, we are making ‘The Hormometer’, a combination of sensors for the nine major plant hormones. This tool will allow us to trace the presence of the nine hormones at once in different parts of the plant. Initially, and as a proof of concept, we are generating a 3-hormones module containing the three major hormones involved in plant development: auxins, ethylene and cytokinins.

Fifth, we are also generating transgenic plant lines for Arabidopsis and tomato species containing these sensors and they are going to be characterized at different levels.

Broader implications of the research
The Hormometer is conceived to be a universal tool that scientist from diverse plant fields can use to understand not only hormonal interactions under different plant processes, but also to investigate the molecular mechanisms underlying some of these processes. This could be especially useful, for example, in the study of plant defense against pathogens where several hormones are involved and there is not much information of how they co-work and interact. Moreover, deciphering the molecular mechanisms also will allow defining targets of interest to generate resistant lines.

In addition, we are generating the first reporters for some of the major plant hormones, which will help to study in detail the function of these hormones. Finally, the collection of phytobricks will represent an excellent repository that other groups interested in plant synthetic biology could use to generate their favorite constructs for their own purposes.

Keywords
Plant hormones; Reporter genes; Synthetic Biology; Holistic approaches

Dr. Melina Florez-Cuadros

College of Agricultural and Life Sciences
NC State University

Improvement to the Screwworm Eradication Program with a “male-only” transgenic strain

Problem Statement
Part of the New world screwworm life cycle happened in mammals living tissue. Infestations can be fatal. Livestock is greatly affected by this parasite, with significant economic losses for the industry. The New World screwworm eradication program was created in the ’60s using Gamma rays for sterilizing screwworm flies, exterminating the population of the parasite in the US in less than 10 years. To keep the screwworm out of the country, a biological barrier was created in US-Mexico border releasing millions of sterile flies weekly. Due to the success of the program, the eradication continued in Central America and a new biological barrier was created the Panama-Colombia border. But, the process of sterilizing flies with Gamma rays is expensive and dangerous for the personal executing the task, and the population control efficiency can be greatly increase releasing males only. Thus, my project focus on create a genetically modified screwworm fly line that produces only males, for improving the efficiency of the eradication program, as well as decreasing feeding costs in half because no females will be reared.

• New World screwworm is an external parasite of mammals
• An eradication program was created and successfully has been controlling screwworm in the US and Central America
• Gamma rays are used to sterilize millions of flies. Sterile flies -male and females- are released and will mate with wild screwworm giving no offspring. In this approach, only sterile males are needed to eradicate population.
• The sterilization process is expensive, not ecofriendly, and inefficient.
• A genetically modified screwworm line is being created that will generate males only. Thus, when these males are releasing no offspring is produce.

Broader implications of the research
The New World screwworm eradication program is being on for more than 50 years now, successfully keeping the country without the pest. However, new technologies can be used to accomplish the goal but with less money and environment costs. In addition, I am using a genetic approach call phi C 31 integrase for the first time in screwworm.

Keywords
New World screwworm; phi C 31 integrase; eradication; genetic modification

Dr. Nathaniel Grubbs

College of Agricultural and Life Sciences
NC State University

The ABCs of Beetle Proteins

Problem Statement
Most ATP-Binding Cassette (ABC) proteins use ATP as an energy source to actively transport molecules across cellular membranes. These molecules can included toxins, which are pumped out of cells to ensure survival. This means that ABC proteins can play a role in helping pest insects resist pesticides, so it is important to study members of this protein family in these insects.

We focused on identifying the ABC proteins of two pest beetles. In the small hive beetle, Aethina tumida, a pest of bee hives, we searched for ABC proteins in the genome sequence, which had been recently assembled. In the western corn rootworm, Diabrotica virgifera virgifera, we obtained RNA sequencing data, which we then used to identify the rootworm’s complement of ABC proteins. We then used this data to make comparisons with the complement of ABC proteins from other insect species to identify species-specific changes to the members of the ABC protein family.

Broader implications of the research
The patterns of differences in the makeup of ABC proteins in pest species may be able to provide us useful clues to toxins they are resistant or susceptible to. Some ABC proteins may also be useful targets for some pest control methods. Knowing the ABC family members found in each species is the first step in using this protein family to make informed decisions about developing or improving how we manage these pests.

Keywords
Phylogenetic Analysis; Pest Control; Resistance; RNAseq; Beetles

Dr. Lucie Guertault

College of Agricultural and Life Sciences
NC State University

Is a Linear Model suitable for Predicting Cohesive Soil Detachment?

Problem Statement
Prediction of cohesive soil detachment is required for many engineering applications such as erosion of streambanks, watersheds or earthen structures. The most commonly used model assumes a linear relationship between the shear stress and the erosion rate of cohesive material. While the linear relationship proved to fit well when applied to a narrow range of shear stress, its suitability over a large range has been questioned in recent studies, but has not been heavily explored due to a lack of data.

Laboratory Jet Erosion Tests were performed on cohesive sediment samples to generate erosion data for large ranges of shear stresses. A series of statistical tests were used to evaluate the suitability of a linear relationship for modeling erosion rates. The assumption of linearity was statistically rejected for most of the trials. For a few trials, however, the limited information obtained precluded any conclusion concerning a non-linear behavior. While a linear relationship was typically not suitable for large ranges of shear stress, results affirmed that it was a good approximation over restricted ranges. The analysis also showed that linear erosion models that are adjusted to a limited range of shear stress do not predict accurate erosion rates outside of this range, demonstrating the limited extrapolation potential of the linear model.

Broader implications of the research
If a linear model is used to predict erosion rates for a practical application, it is highly recommended to determine model parameters using calibration data that was obtained in conditions similar to this application

Keywords
Cohesive Sediment Detachment; Linear model; Jet Erosion Tests; Statistical Analysis

Dr. Drew Hackney

College of Engineering
NC State University

Reconstruction of Back Face Deformation During Ballistic Impact Using Fiber Bragg Grating Response

Problem Statement
Current methods to test and validate prospective body armor designs, such as Kevlar vests, are outdated and rely on 1970’s technology. Testing standards require all data to be collected after the end of the impact event, which excludes the collection of any data during the impact event. This results in the dynamic, real time response of armor under test not being fully understood leading conservative standards and over-engineered, heavy final designs.

Our work allows for the real-time measurements of armor deformation and response to impact. For the first time, we’ve been able to measure the armor response using an integrated sensing suite that can be used in test environments that realistically reflect operational armor use. Our sensing suite has been able to reconstruct the magnitude of armor deformation to within 5% of actual measured values.

Broader implications of the research
Our results will lead to a modern, up to date testing standard, resulting in more appropriately designed armor that is lighter without sacrificing its protective qualities.

Keywords
Fiber Bragg grating; Kevlar; Ballistic Impact; Shape Reconstruction

Dr. Linna Han

College of Science
NC State University

Dr. Emily Harrison

UNC-Chapel Hill

Dr. Eduardo Hatano

College of Agricultural and Life Sciences
NC State University

Dr. Melanie Hedgespeth

College of Natural Resources
NC State University

Jaret Hodges

Duke University

Sex differences in the right tail of cognitive abilities

Problem Statement
Are there cognitive differences between high IQ boys and girls that could explain why boys tend to be over represented in STEM degree programs and later STEM careers?

Academic tilt describes how an individual’s performance varies between subject and can possibly explain the gap in STEM representation. High IQ boys tend to be more “tilted” towards quantitative ability than girls with the same IQ. Further, as IQ increases, the difference in academic tilt between boys and girls increases as well. This research provides one possible explanation to what is an extremely complex issues. From a methodological standpoint, this research incorporated novel data visualization methods in the form of split violin plots. Further, this research utilizes a sample of over 2 million students to draw conclusions.

Broader implications of the research
The research provides a possible explanation to partially explain the gap in STEM fields. Its not so much that girls are not as good at math as boys, its that girls that are strong quantitative performers are just as likely to be strong verbal performers. This result can at least provide some partial explanation as to why there is greater gender parity in fields that rely on quantitative and verbal reasoning such as law and medicine rather than fields such as computer science.

Keywords
Gender; intelligence; gap

Dr. Allyn Howlett

Wake Forest University

Postdoctoral Research, Instruction and Mentoring Experience (PRIME)

Problem Statement
The Sullivan Report (2004) highlights concerns that a major impediment to health equity in the US is the paucity of underrepresented (UR) minorities in the medical and allied health professions.

  • North Carolina is populated by rural African American families (17% of North Carolinians) and the fastest growing Hispanic American population in the country (>600% increase in the last decade), and yet the percentage of these populations in the health care professions fails to keep pace with these population statistics.
  • The partnership of Wake Forest University School of Medicine (WFSM) and Winston-Salem State University (WSSU) will contribute to overcoming this disparity by training translational scientists as medical educators for the health professions.

Broader implications of the research

  • By recruiting PRIME scholars from a diverse population of applicants, the PRIME program will support the career development of UR biomedical academic researchers.
  • By training educator-researchers to work with diverse populations of students, the PRIME program will enhance the learning environment and support the career pathways of UR medical and allied health professionals.

Keywords
Academic Careers; Postdoctoral Training Programs; Workforce Development

Dr. Qandeel Hussain

College of Humanities and Social Sciences
NC State University

Dr. Younggeon Jin

College of Veterinary Medicine
NC State University

Knockout of CLC-2 Reveals Critical Functions of Adherens Junction in Colonic Homeostasis and Tumorigenicity

Problem Statement
Intestinal epithelial integrity is critical for maintaining a barrier between noxious contents within the intestinal lumen and the body. This is dependent on the adherens junctions (AJs) and the tight junctions (TJs) that make up the apical junctional complex linking the single layer of epithelial cells that line the gut. Although a wide range of gastrointestinal disease etiologies reduced intestinal integrity, the mechanism of regulation of epithelial barrier have not studied well.

The small and large intestines have region-specific differences in apical junctional complex structure and function. For instance, the large intestine has notable elevations in the expression of the AJ proteins E-cadherin and -catenin compared to the small intestine. However, the mechanisms of AJ regulation in colonic mucosa have not been studied. Therefore, there is a critical gap in our scientific knowledge of the mechanisms of AJ regulation of mucosal barrier, particularly in the colon. In this study, we investigated the role of ClC-2 in the regulation of colonic homeostasis and tumorigenicity following experimental colitis. Our findings indicate that the absence of ClC-2 results in less differentiated colonic crypts and increased tumorigenicity following colitis via dysregulation of the AJ E-cadherin/β-catenin complex, associated with β-catenin-initiated TCF/LEF1 signaling activation.

Broader implications of the research
In conclusion, the present data demonstrate that knockout of ClC-2 resulted in disruption of AJ proteins, with a possible compensatory response of interdigitation of the lateral epithelial membranes, as seen on TEM. These findings enabled us to further explore the role of AJs in colonic crypt differentiation and tumorigenicity. As far as differentiation, nuclear localization of β-catenin resulted in reduced differentiation of mature colonocytes, but not other cell types. Of further interest, these effects were not seen in the small intestine, indicating an increased importance of ClC-2 AJ regulation in the colon. Our studies also highlighted the potential for progression of colitis-associated cancer in the presence of unstable AJs. Our studies may also point to potential clinical uses of ClC-2 as a prognostic marker or as a target for therapy in patients with inflammatory bowel disease at risk of the associated colorectal cancer.

Keywords
Adherens junction; colonic homeostasis; colonoids; chloride channel ClC-2; colonic tumorigenicity.

Dr. Katherine Kennedy

College of Veterinary Medicine
NC State University

A Comparative assessment of prognostic genomic signatures in Diffuse Large B-Cell Lymphoma in people and dogs

Problem Statement
Non-Hodgkins lymphomas are a diverse yet related group of malignancies representing the 7th and 3rd most common tumors in humans and dogs respectively. With standard-of-care therapy there is a wide range of progression-free-survival in both species. In human medicine, there are multiple factors that serve as prognostic indicators of how a patient will respond to therapy. Genomic signatures, such as the breakage of the cMYC locus, are examples of prognostic indicators in people, but similar factors have not yet been identified in veterinary medicine.

Our research has identified a molecular genomic signature that can identify dogs that will respond poorly to the current standard of care treatment in Non-Hodgkins Lymphoma. Additionally, we demonstrate that genomic signatures present in human lymphoma are also present in canine lymphoma. In the future, we plan on assessing the prognostic value of these aberrations.

Broader implications of the research
Our research supports the further use of spontaneously occurring canine disease (in this case lymphoma) as a model to study human disease.

Keywords
lymphoma, diffuse large b-cell lymphoma, canine

Dr. Hiroki Kittaka

College of Veterinary Medicine
NC State University

The Role of Endogenous Lipids in Pain and Itch

Problem Statement
Pain is a sensation to detect and then avoid harmful stimuli, such as heat, pressure and acid. Itch is a sensation which makes us scratch on the surface of our bodies, caused by substances from outside to be removed, such as insect bites, plant components (pollens or lacquers), food allergens, and some medicine. Interestingly, when we are sick, painful and itchy substances are produced from inside of our bodies, for example, histamine, serotonin, and leukotrienes. In this study we focus on sphingosine-1-phosphate (S1P), one of endogenous compound, and investigate if S1P has effects on our itch and pain sensations.

• We stimulated sensory neurons by S1P and evaluated neuronal responses by a calcium imaging technique.
• We used mice to evaluate pain and itch behaviors because human and mouse are thought to have similar somatic sensations.
• We found that S1P induces both pain and itch sensations.
• We found that at least 2 important ion channels, TRPV1 (a receptor for chili) and TRPA1 (a receptor for wasabi), mediate S1P-induced neuronal responses.
• TRPV1 is involved in S1P-induced pain and itch sensations in vivo and in vitro.

Broader implications of the research
S1P in produced by endothelial cells, erythrocytes and/or mast cells. Our study implies that these cells might release S1P in some disease condition and cause or modulate our pain and/or itch sensations. Therefore, we are planning to investigate the role of endogenously released S1P by using chronic disease models.

Keywords
Neuron; Sphingosine-1-phosphate (S1P); pain; itch; ion channels

Dr. Amanda Krentzel

College of Science
NC State University

Dr. Alma Laney

College of Agricultural and Life Sciences
NC State University

Development of full-length infectious clones of barley yellow dwarf viruses

Problem Statement
Barley yellow dwarf is a chronic problem for small grain producers and causes high losses in some years whereas other years have minimal losses. The disease is caused by several related positive-sense RNA viruses that are transmitted by sap sucking insects known as aphids. In the US, one species, known as Barley yellow dwarf virus-PAV (PAV), is the primary species found in wheat. However, in Kansas it was recently discovered that another species, Barley yellow dwarf virus-PAS (PAS), was also common in both single and mixed infections with PAV. PAS isolates from other parts of the US and world are not commonly found in wheat. This Kansas PAS isolate is genetically distinct from other US isolates which could help explain why it is common in Kansas wheat fields. To determine why this Kansas isolate is so common, the PAS and PAV isolates from Kansas and other parts of the US will be biologically characterized and infectious clones developed for functional characterization.

• A genetically divergent isolate of Barley yellow dwarf virus-PAS is common in Kansas wheat fields whereas other PAS isolates are not commonly found in wheat.
• The biological characteristics of each isolate will be determined to provide a baseline for further testing.
• Full-length infectious clones of these isolates will be developed to facilitate functional characterization of the divergent portions of the genomes using the previously acquired baseline information as a reference.

Broader implications of the research
This newly discovered Barley yellow dwarf virus-PAS isolate from Kansas is an emerging pathogen in wheat and could represent a threat to other wheat growing regions in the US. Understanding why this isolate is common in Kansas will provide crucial data to develop effective control strategies, including breeding for resistance.

Keywords
Virus-vector interactions; infectious clones; functional and biological characterization

Dr. Zheng Li

College of Engineering
NC State University

Dr. Xuefeng Li

College of Natural Resources
NC State University

A improved method for measuring production, mortality and decomposition of mycorrhizal fungi in forests

Problem Statement
great uncertainty exists in quantifying production, mortality and decomposition in forests due to methodology limitation.

The exisiting method for measuring mycorrhizal production and mortality failed to assess amount of mycorrhizal fungi decomposed during sampling intervals. Our method can addess this problem by integrating a decomposition experiment into the widely accepted mass balance model.

Broader implications of the research
Help to better understand the contribution of mycorrhizal fungi to forest net primary production and below ground carbon cycling processes

Keywords
mycorrhizal fungi; forest; production; mortality; improved method

Ms. Shuang Liu

College of Agricultural and Life Sciences
NC State University

Dr. Alsayed Mashaheet

Virginia Tech University

Saving the nation’s boxwood from boxwood blight could be easy with anti-desiccants

Problem Statement
Boxwood blight is a devastating, very contagious disease, threatening home, public, and national historic gardens, as well as boxwood production and marketing industry. The disease is extremely difficult to prevent, contain or control. Spraying the plants with Film-forming Anti-desiccants (ATs) could safely and effectively prevent and contain the disease, and save the priceless boxwood in our gardens. Yet, anti-desiccants have not been tested as boxwood blight control.

Research gap: Boxwood blight is a serious disease threatening home, national and historic gardens, requiring an effective and safe control to replace fungicides.

Hypothesis: Film-forming Anti-desiccants are commonly used for maintaining leaf moisture in boxwood leaves in winter by forming a thin transparent film on the leaves, which could also prevent the spores of the fungus from reaching the healthy plants, and could coat spores on diseased plants preventing them from spreading to healthy plants.

Methodology: Under completely contained conditions (Biosafety Level-2), the effect of a film-forming anti-desiccant (Pinolene) on the disease severity and spore production was investigated for two disease cycles.

Findings: Pinolene provided near-complete protection against the disease when applied before inoculation, coated and contained spore when applied after disease developed, providing a safe, cheap and effective treatment that could replace fungicides.

Broader implications of the research
Film-forming Anti-desiccants are a smart solution to a serious problem. They provide protection against boxwood blight that is as effective as fungicides but is safer and more durable.

Keywords
Fighting Boxwood blight; Protecting historic boxwood; Fungicide alternative; Smart Agriculture

Ms. Panita Maturavongsadit

UNC-Chapel Hill

Dr. Michael McLaren

College of Veterinary Medicine
NC State University

Correcting Experimental Biases in Measurements of Microbial Community Composition

Problem Statement
Measurements of microbial communities, or microbiomes, using DNA sequencing suffer from unknown, experiment-specific biases that make results incomparable between experiments and preclude the development of reliable microbiome-based clinical diagnostics. We hypothesized that these biases could be measured and corrected for to calibrate community measurements across experiments.

We tested this hypothesis using two published microbiome sequencing datasets of constructed “mock” communities with known species composition. In both datasets, the bias of a particular species and experimental methodology was consistent across samples, and calibration of microbiome measurements increased agreement to the true composition near to the limits of random experimental error for three different experimental methodologies.

Broader implications of the research
Current efforts to address bias aim to standardize protocols across labs; however, standards can impose undesirable restrictions on researchers and cannot be applied across different sequencing methods (such as 16S amplicon versus shotgun metagenomic sequencing). Our results suggest bias measurement and calibration may be a feasible alternative strategy.

Keywords
microbiome; microbial communities; DNA sequencing; metagenomics

Dr. Bhalchandra Mirlekar

UNC-Chapel Hill

IL-35+ B Cells Establish Immunosuppressive Network in Pancreatic Ductal Adenocarcinoma

Problem Statement
Role of immuno-suppressive B cells in development of pancreatic cancer.

Breg and CD4+ T cells from pancreatic tumor bearing mice secrete IL-35 and IL-10.
IL-35 also limits CD4+ T cells to produce IFN-γ and TNF-α and CD8+ T cell activity.
B cell-specific production of IL-35 leads to expansion of IL35+ Tregs and suppression of anti-tumor immunity.

Broader implications of the research
Our findings reveal a potential novel function of B cell derived IL-35 in the pathogenesis of pancreatic cancer and could provide therapeutic insight for patient treatment.

Keywords
B cell, IL-35; pancreatic cancer

Dr. Marie Mooney

Duke University

Dr. Roberto Mota

UNC-Chapel Hill

Development of the First Animal Model of Dyslipidemia, Atherosclerosis, and Diabetes in Obese Rats

Problem Statement
Cardiovascular disease accounts for 2,200 deaths per day in the US. Diabetic patients have aggressive forms of artery disease, with increased risk of serious complications in other organs. When diabetic patients have increased fat in their diet, fat deposits in their arteries and decreases the amount of blood that is delivered to important organs. We want to develop the first experimental small animal model of diabetes, obesity and increased fat deposition in the arteries to be able to accurately study life-threatening complications that occur in human patients. This project will allow us to genetically manipulate rats that are obese and diabetic by increasing the amount of fat deposits in their body. Our animal model will help to better diagnose and treat patients that are diabetic, obese and have fat depositions in their arteries and are at very high risk of suffering serious complications.

• Currently no small animal model appropriately resembles human diabetic atherosclerosis
• Modifying lipid metabolism in Zucker Diabetic Fatty rats will promote dyslipidemia and develop atherosclerosis
• We genetically modified lipid metabolism, by knocking out apoE gene using CRISPR/Cas9 system
• Our animal model is diabetic, obese, dyslipidemic and atherosclerosis-prone

Broader implications of the research
We efficiently created the first apoE KO ZDF CRISPR founders with different mutations in apoE gene. Our findings suggest the effective knockout of the apoE gene in ZDF rats to create the first polygenic rat model to study vasculopathies in diabetes. Future studies will evaluate our animal model longitudinally and further evaluate accelerated development of type-2 DM and atherosclerosis.

Keywords
rat model; diabetes; atherosclerosis; obesity; dyslipidemia

Dr. Ismaeel Muhamed

Comparative Medicine Institute & College of Engineering
NC State University,UNC-Chapel Hill

Fibrin nanoparticles coupled with keratinocyte growth factor enhance dermal wound healing rate

Problem Statement
Six million Americans suffer from chronic non healing wounds and annual cost of treatment is 20 billion USD. The goal of wound management and therapy is to assist wound closure and restore tissue function. Currently fibrin sealants are sold commercially to seal blood loss, but the agents are viscous and delay wound healing. I have engineered biocompatible and biodegradable fibrin nanoparticles that can carry wound healing agents to speed up wound healing rates.

Current FDA approved fibrin sealants are dense and affect in situ wound healing rates. I have prepared nano sized fibrin clots that are biodegradable and can carry wound healing factors to enhance wound healing rates.The fibrin nanoclots are prepared in a low cost microfluidic device and industry scale high throughput production is feasible. Additionally, the cost of recombinant human growth factors is getting inexpensive as they are produced in bacterial systems. The idea is to prepare a band-aid like biomaterial supplemented with our nanoparticle that can enhance the rate of wound healing.

Broader implications of the research
Fibrin nanoparticle is versatile that it can carry antimicrobial agents, dermal wound healing tissue, endothelial factors and neuropeptides. Research is being conducted on the versatility and application of my particle in other research areas.

Keywords
wound healing; tissue regeneration; nanoparticles; synthesis; fibrin; microfluidics; growth factor

Dr. Bita Nickkholgh

Wake Forest University

Dr. Feng Pan

College of Science
NC State University

Structure and Dynamics of DNA and RNA Double Helices of CAG and GAC Trinucleotide Repeats

Problem Statement
I studied the structure and dynamics of DNA and RNA double helices of CAG and GAC trinucleotide repeats, which are closely related with the trinucleotide disorders.

A new GPU-enhanced free energy calculation method (ABMD) was used to investigate the free energy landscape of the structures regarding with different types of reaction coordinates. Various kinds of conformation based on the chi torsion angles of the AA mismatch in the structures were characterized and several local minima were found.

Broader implications of the research
To study the stability of the secondary structures that consists of CAG or GAC repeats, we can get to the mechanism during the process of transcription and translation associated with trinucleotide disorders. Also this study provides guidance to explore the hairpin secondary structures.

Keywords
trinucleotide repeats; free energy; hairpin

Dr. Lizhi Pan

College of Engineering
NC State University,UNC-Chapel Hill

Novel Neural Control of Multifunctional Prosthetic Arms based on Internal Musculoskeletal Biomechanical Model

Problem Statement
Electromyography-based pattern recognition (EMG-PR), recently commercialized and considered the state-of-the-art in upper limb prosthesis control, predicts discrete movement classes that differ from the fluid, continuous multi-joint movements of biological limbs.

• We proposed a musculoskeletal model to simultaneously predict hand (MCP) and wrist (flexion/extension) movements from EMG signals.
• The 2-DOF musculoskeletal model was robust against upper limb posture changes.
• We developed a generic 2-DOF musculoskeletal model towards a multi-user neural-machine interface.
• Based on the 2-DOF model, we added a wrist pronation/supination DOF and a corresponding antagonist muscle pair to the musculoskeletal model to simultaneously estimate motion for a hand DOF (MCP) and two wrist DOFs (flexion/extension and pronation/supination) from EMG signals.

Broader implications of the research
The proposed generic robust musculoskeletal model for myoelectric control of a prosthetic hand will allow individuals with upper-limb amputations to perform versatile activities efficiently and will improve their quality of life.

Keywords
Electromyography (EMG); musculoskeletal model; multi-user; robust; neural-machine interface

Dr. Cameron Parsons

College of Agricultural and Life Sciences
NC State University

 

Dr. Tahira Pirzada

College of Engineering
NC State University

3D Composite Nanofiber Aerogels

Problem Statement
We present a cost effective solid templating process to transform Cellulose Acetate and Silica composite nanofibers to 3-dimensional aerogels. By bringing together two different material processing techniques we have introduced a product with enhanced properties that can be used to separate oil and water mixtures.

• This process is cost effective and time saving, involving lesser use of chemicals.
• Presence of fibrous structure in the aerogel strengthens its structure giving it more flexibility at the same time
• Nanofibers are transformed into a 3 dimensional, self supportive network which is otherwise not possible

Broader implications of the research
These aerogels can be used to purify oil and water mixtures.

Keywords
Nanfiber Aerogels; Oil separation; Cellulose acetate-silica composites

Dr. Deepti Pradhan

College of Agriculture and Life Sciences
NC State University

Early stage of Nitrogen fixation in grain legume species

Problem Statement
Nitrogen(N) accumulation is essential for growth of plants and for increased crop yields. The extensive use of N fertilizers has environmental drawbacks, such as denitrification in wet soil and nitrogen leaching from soil following rainfall and irrigation resulting in water pollution. Therefore, enhancing biological nitrogen fixation in cropping systems is an important opportunity to improve their viability. In this respect, the use of grain legumes in crop rotation plays an important role.

• Comparison of nitrogen fixation in legume was studied for the first time.
• Hydroponic system of methodology was followed to compare the physiological potential for the establishment of nitrogen fixation among grain legume species and among cultivars within common beans.
• Finding: among the legumes Cowpea and soybeans were found to have especially active nitrogen fixation very early in seedling establishment.

Broader implications of the research
The difference in physiological potential for initiation of nodules and nitrogen fixation could be helpful in selecting suitable grain legumes for crop rotation systems.

Keywords
Nitrogen; Legumes; hydroponic

Dr. Keshav Raghuvanshi

College of Engineering
NC State University

Dr. Hector Rendon

Laboratory for Analytic Sciences
NC State University

 

Dr. Luis Rivera-Burgos

College of Agricultural and Life Sciences
NC State University

Evaluation of Resistance to Gummy Stem Blight in a Population of RILs of Watermelon x Citron

Problem Statement
For more than 35 years, no watermelon cultivars have been released having high levels of resistance to gummy stem blight (fungal disease) and high-quality fruit to the growers.

• Using novel breeding methods a new population of watermelons segregating for resistance to gummy stem blight and high-quality fruit was developed over 10 years of breeding efforts.
• We identified elite lines with resistance and fruit quality using improved inoculum production methodologies and evaluation in the field and greenhouse.
• Our results provide evidence of improved germplasm for cultivar development of high resistant watermelons of excellent fruit quality for growers worldwide.

Broader implications of the research
We will release improved germplasm with a high level of resistance and excellent fruit quality.
This lines will have a tremendous impact on U.S. farmers economy.

Keywords
Gummy Stem Blight; Germplasm release; Resistance; Watermelon

Dr. Avinash Rustagi

College of Science
NC State University

Electron Hole Liquid in quasi-two dimensional monolayer transition metal dichalcogenides

Problem Statement
Water vapor condensing to liquid water at high density and low temperature is a classic example of a phase transition. An analogous phenomena happens in a class of semiconductors known as monolayer transition metal dichalcogenides (TMDCs). Shining light onto a semiconductor can cause an electron to absorb energy and jump from a low energy state to a high energy state leaving behind a hole, thereby forming an electron-hole pair. This electron-hole pair interacts and can form a bound state known as exciton (just like an electron binds to a proton in a hydrogen atom). When many electron-hole pairs/excitons are created in a system, they can interact and condense to form a Electron-Hole Liquid (EHL). We map out the conditions for the formation of this liquid state in a theoretical phase diagram.

• The electronic and optical properties of a material can change when driving the material out of equilibrium.
• The goal is to study how materials can be tuned for desirable properties by exciting them.
• Can we use this tuning for making multi-functional devices?
• A liquid-like state in a material is not a common phenomena, let alone making one at room temperature
• We have theoretically mapped the phase diagram for such a transition in a monolayer semiconductor, which tells us the conditions under which it can form using tools of many body perturbation theory. We show that monolayer transition metal dichalcogenides can host such an exotic state at and above room temperature.

Broader implications of the research
Our study has provided a complete way of looking at this phenomena and calculating observables in materials. It opens up avenues for tuning material properties by exciting them, thereby adding transient new functionalities to existing devices. It shows that physical phenomena that exist in a classical world have a analogous quantum phenomena.

Keywords
Photoexcitation; Correlation Effects; Phase Transition; Semiconductors

Dr. Sheila Saia

College of Natural Resources
NC State University, US Forest Service

Combining Hydrological Models and Demographics Data to Prioritize Climate Change Preparedness

Problem Statement
Global Change Models project an increase in the frequency and magnitude of storm events in the Southeastern United States in the next several decades. Additionally, urban development in this region is expected to double by 2060 and this growth will likely intensify discrepancies between water supply and demand. Communities unable to adapt to climate-induced changes in water resources may experience adverse social and economic impacts. Therefore, there is a need to (1) combine existing hydrological models and demographics data to identify locations where socially vulnerable communities are in North Carolina and (2) use this information to support flooding and drought preparedness efforts in these communities.

Given the likely impacts of climate and land use change on water resources, there is a need to (1) combine existing hydrological models and demographics data to identify locations where socially vulnerable communities are in North Carolina and (2) use this information to support flooding and drought preparedness efforts in these communities. We use the Soil Water Assessment Tool (SWAT) to project future (2050-2070) stream discharge under four future climate change scenarios. We combine SWAT streamflow projections and social vulnerability index (SoVI) estimates derived from 2014 American Community Survey data for the Upper Yadkin-Pee Dee (UYPD) Watershed, North Carolina, USA. Our results show that mapping techniques based on hydrological outcomes (i.e., percent change in 10-yr flows or percent change in extreme events by subbasin) alone, tend to miss especially vulnerable communities in the UYPD. Therefore, by combining hydrological outcomes and demographics data, we gain important information concerning why communities are at risk of flooding and drought as well as how climate change preparedness efforts may better serve them.

Broader implications of the research
My research will be used to prioritize the location of future county-based climate change preparedness efforts in North Carolina.

Keywords
climate change; land use change; water resources; social vulnerability; soil and water assessment tool

Dr. Elena Schroeter

College of Science
NC State University

A method to concentrate and clean peptides from fossils for mass spectrometry analyses

Problem Statement
Humic substances are break-down products of decaying organic matter that co-extract with proteins from fossils. These dark substances are notoriously difficult to separate from proteins in solution, and create a host of problems when attempting to sequence fossil proteomes.

I introduce a method combining multiple techniques and utilizing recent advances in protein extraction protocols to both concentrate proteins in extracts from fossil specimens and remove these humic substances, producing clean samples that can be analyzed by mass spectrometry (MS) without interference. I employ: 1) a non-demineralizing extraction buffer that eliminates the protein loss observed during the demineralization phase in more routine methods; 2) filter-aided sample preparation (FASP) of peptides, in which extract is both concentrated and digested in one filter, allowing the separation of large humics after digestion; 3) automated stage-tipping, which removes small humics in a process that is uniform and can be performed simultaneously on multiple samples, unlike manual stage-tipping. I apply this method to a 1000 year old moa bone with very high humic acid content, generating samples that were colorless and produced more proteins and more complete protein sequences than previous MS analyses on this same specimen.

Broader implications of the research
Because this method allows better and more sensitive MS analyses of low-abundance proteins in fossils with high humic content, it will widen the range of extinct organisms we can analyze with MS, and increase regions of the proteome we can explore.

Keywords
Proteins; paleoproteomics; fossils; protein extraction; mass spectrometry

Hasan Shahariar

College of Textiles
NC State University

Fabrication of Flexible and Scalable Thermoelectric Cooling Device

Problem Statement
The solid-state thermoelectric device can generate electricity from the temperature differential between the top and bottom surface of the device. The same principle applies to generate a temperature differential across the device by applying a voltage/current to the device. This fundamental principle of physics can be applied to numerous applications to harvest energy from waste heat or cooling a surface without using gas or liquid source. However, the commercial thermoelectric device is very expensive and rigid in its form, thus limited in many applications. My research will make this device flexible and cost-effective, which will create endless opportunities for using this device in different form factor and day-to-day application spaces.

We are developing a novel but scalable fabrication for manufacturing the thermoelectric device. Current technology used for fabrication make the device very expensive more many applications.
This method can be used to make the device flexible and to scale the production to reduce cost.
Our methods combine existing manufacturing process like pick-and-place robots, soldering etc, and utilize commercial materials such as foams, conductive foils, which make it as a ready-process for manufacturing.

Broader implications of the research
My research is creating a process to custom prepare a flexible and low-cost thermoelectric device, which can cool, heat or generate power as designed. Thus, it can create new products, applications and business opportunities in the spaces such as wearables, sensors, medical, energy etc.

Keywords
Thermoelectric Device; Peltier Effect; Cooling; Mass-manufacturing; Low-cost

Dr. Michael Sidorov

UNC-Chapel Hill

 

Dr. Shilpa Sivashankar

College of Engineering
NC State University

Microvasculature-on-chip; a preclinical evaluation tool

Problem Statement
How would you test the drug compatibility? How does drug interact with your blood vessel during normal functioning and when dysfunctional?

The study provides insight into the process variables that are involved in controlling the feature size of GelMA structures fabricated within microchannels. Here, we have successfully built the ECM-like matrix structure with fibroblast (HDFn) cells and the lumen of the blood vessel for fluids to pass through. We have begun to incorporate endothelial cells to line the interface and plan to study drug metabolism, metastasis, and stem cell extravasation.

Broader implications of the research
The model can be used to evaluate the barrier function with and without an endothelial layer by permeation of fluorescently labeled probes and could have a significant impact on improving the predictability of drug screening models and personalized medicine.

Keywords
Microvasculature; microfluidics; tissue-on-chip

Dr. Bridget Smith

College of Humanities and Social Sciences
NC State University

Deconstructing sound change

Problem Statement
/tr/ and /dr/ are now pronounced as ‘chr’ and ‘jr’ (as in train and drain), but we know that they used to be pronounced as /t/ and /d/ (as in tape and day). Can we recover the trajectory of the sound change from a combination of old recordings and articulatory studies using the same sounds from across age groups, and comparing them to other sounds that might undergo the same effects?

Historical sound changes are known to have occurred based on written evidence, in which an earlier spelling is replaced by a differently spelled form in a later stage of the language, or by comparison of related languages which originated from the same parent language. Reconstructed parent languages (e.g., Proto-Indo-European), and the sound changes that they imply, are our best guess at what happened.

Thanks to the invention of recording devices around the beginning of the 20th century, we have a window into the way that people spoke 100 years ago, and can examine the acoustics of a sound change that occurred during this time. Besides tracking the time course of the change, we can use articulatory recordings (ultrasound and lip video) to examine physical differences between pronunciation styles in the modern language, and detect the conditions that allowed this change to occur.

Rather than positing a phonological change, that is, a categorical replacement of t -> ch or d -> j, we can detect a gradual shift in pronunciation, one that is still ongoing for /dr/. We can trace the gradual lengthening of the sounds, and the resulting articulatory changes that emerged.

Broader implications of the research
The results of this research suggest that we approach reconstruction of past sound changes with more nuance, and provide insight into how variability in a synchronically stable linguistic system can develop into diachronic sound change. It also contributes to our understanding of speech processing, in which two equivalent sounds (e.g., ‘dr’ vs ‘jr’) may be perceived as belonging to the same sound category, but conveying very different social meanings.

Keywords
sound change; phonology; acoustic phonetics; articulatory phonetics; affrication

Dr. Teng Su

College of Engineering
NC State University

Smart Nanocarriers for Heart Regeneration

Problem Statement
Heart failure following a myocardial infarction (MI, commonly known as heart attack) continues to be one of the leading causes of death. Many interventional approaches, such as stem cell therapy and gene therapy, have emerged. These approaches, however, are hampered by the low acute/chronical stem cell retention in the recipient myocardium, off-target effect of drug/gene delivery systems, and nucleic acid biodegradation.

The takeway points of my research include:
• Design and fabrication of platelet-mimicking therapeutic nanocarriers (PMNCs) functionalized with both platelet membrane and prostaglandin E2 (PGE2);
• Leveraging both the MI-homing ability of platelets and the PGE2-mediated receptor-ligand interaction to promote the targeted vascular delivery of therapeutic nanoparticles to the scarred heart tissue in a minimally invasive fashion;
• In vitro, our PMNCs exhibited selective binding to the collagen-coated surface. Their uptake into heart muscle cells was significantly higher than that of the nanoparticles without PGE2 decoration;
• In an immunocompetent mouse model of myocardial ischemia-reperfusion, the mice that received tail vein injection with the therapeutic PMNCs exhibited significantly augmented heart function after four weeks of treatment, which was accompanied by the mitigation of heart remodeling and by the increase in cycling heart muscle cells, new blood vessel formation, and heart muscle regeneration.

Broader implications of the research
Our smart nanocarriers provide a new approach to the design and development of targeted nanomedicine for the treatment of ischemic heart disease in a minimally invasive manner and show promise in achieving widespread application in biomedicine, drug delivery, tissue engineering, and personalized regenerative medicine.

Keywords
Targeted drug delivery; nanoparticles; ligand-receptor interaction; cardiac repair

Dr. Qingyu Tang

College of Agricultural and Life Sciences
NC State University

Mechanism of vaccinia viral protein B14 mediated inhibition of IêB kinase â activation

Problem Statement
Activation of the IκB kinase β (IKKβ) is a central event in the NF-κB-mediated canonical proinflammatory pathway. some viruses encode virulence factors that target IKKβ to inhibit NF-κB-mediated antiviral immune responses. One of these factors is the vaccinia viral protein B14 that directly interacts with and inhibits IKKβ. However, the molecular mechanism of vaccinia viral protein B14-mediated inhibition of IκB kinase β activation is elusive.

We mapped the interaction interface on the B14 and IKKβ proteins. We observed that B14 binds to the junction of the kinase domain (KD) and scaffold and dimerization domain (SDD) of IKKβ. Molecular docking analyses identified key interface residues in both IKKβ and B14, which were confirmed by mutational studies to promote binding of the two proteins. During trans-autophosphorylation of the protein kinases in the IKK complex, the activation segments of neighboring kinases need to transiently interact with each other’s active sites, and we found that the B14-IKKβ interaction sterically hinders the direct contact between the kinase domains of IKKβ in the IKK complex, containing IKKβ, IKKα, and NEMO in human cells. We conclude that the binding of B14 to IKKβ prevents IKKβ trans-autophosphorylation and activation, thereby inhibiting NF-κB signaling.

Broader implications of the research
This study has provided critical structural and mechanistic information for the future design of new therapeutics to specifically target IKKâ activation for the treatment of these devastating human diseases.

Keywords
B14; IKKβ; protein kinase; vaccinia virus; inflammatory disorders

Dr. Nadja Vielot

UNC-Chapel Hill

U.S. Travelers’ Concern about Zika Infection and Willingness to Receive a Hyptohetical Zika Vaccine

Problem Statement
The ongoing Zika pandemic is an important concern for U.S. travelers, and no commercially available vaccine exists to prevent Zika infection. However, investigational vaccines have demonstrated protective immunity in animal studies, some of which are currently in Phase I human trials. We surveyed travelers living in U.S. states on their awareness and perceptions of Zika and its potential effects on their travel plans. The present study explored U.S. travelers’ concern about Zika infection, and their willingness to receive a hypothetical Zika vaccine.

• Zika vaccines are currently under development, but it is unknown if travelers to Zika-affected locations would be willing to receive it.
• Concern about Zika was the only independent predictor of willingness to receive a Zika vaccine in travelers to U.S. states and to other destinations.
• Targeted communications can educate travelers, particularly those who are pregnant or may become pregnant, about Zika risk to generate demand for Zika vaccination, regardless of intended destination.

Broader implications of the research
While the peak of the Zika epidemic in the Western hemisphere appears to have subsided, Zika endemicity remains a concern as the scientific community explores potential long-term sequelae of Zika infections in infected individuals and infants exposed in utero, including neurological, developmental, and other manifestations. A vaccine could effectively prevent Zika, provided there is sufficient interest to promote enrollment in vaccine trials and willingness to receive a licensed vaccine. Concern about Zika infection might be a key factor in motivating individuals to receive a Zika vaccine, regardless of their intended travel destinations.

Keywords
Zika virus; vaccines; travel; global health; prevention

Dr. Glenn Watson

Duke University

Dr. Hui-Yin Wu

College of Engineering
NC State University

Using Joint Attention for Automated Meeting Video Editing

Problem Statement
It is easy to collect and record our lives on digital devices, but hard to sift through this data to extract the important information. However, the advancement of video processing and machine learning techniques opens the possibility to make this process more automated. We present our work on extracting and processing pose and audio data in recorded corporate meeting videos, and using this data to train a neural network that learns the joint attention of participants in the meeting room. The idea of computationally formalizing joint attention–a concept well-studied in psychology and in film–allowed us to use it as a metric for automated camera selection, and generate edits of corporate meetings for the purpose of summarization and future reference. The outputs of our method are compared to state-of-the-art audio and rule-based approaches against human expert-edited versions on a number of cinematographic criterion such as shot size, pacing, and framing.

• Interdisciplinary combination of psychology, film cognition, and computing techniques to address the problem of automated video editing
• Using machine learning techniques such as neural networks to detect high-level emotive signals such as joint attention
• Training and establishing computational models to conduct difficult tasks such as video editing across multiple meeting recordings from cameras placed at different angles and distances
• Producing video edits of corporate meetings that improve on state-of-the-art audio-based or rule-based techniques, and are comparable to expert human edits

Broader implications of the research
This work would be an important first-step to using machine learning for real-time processing and editing of long-distance video and virtual meetings. We hope the methods developed will be applied to developing more efficient and effective technologies, such as software for video conferences, or design of smart meeting rooms.

Keywords
joint attention; automated video editing; neural networks; pose detection; audio processing

Dr. Xiao Xiao

College of Natural Resources
NC State University

Dr. Xinyu Zhang

College of Engineering
NC State University

 

Dr. Yuchen Zhao

College of Engineering
NC State University

Study of Microstructure Evolution in Austenitic Steel 709 at different temperatures

Problem Statement
As a promising candidate for the fast reactor program, Alloy 709 possesses excellent high temperature thermo-mechanical properties. It was down-selected by the Department of Energy (DOE) with the specific objective of providing advanced structural materials for fast reactors with superior response at high temperatures. The main aim of this study is to characterize the evolution of microstructure of steel 709 at different temperatures under different external loads using in situ diffration measurements.

This study is based on the in situ diffraction measurements during mechanical tests at different temperatures, in the aim of characterizing the evolution of the features related to the microstructure of steel 709, such as the grain orientations, the precipitations and the variation of grain sizes, under external loads at different temperatures

Broader implications of the research
To help us deeply understand the evolution of microstructure about the next generation of high performance stainless steel

Keywords
In situ differaction; tensile test; creep test; grain orientations; precipitations; grain size

Dr. Ce Zheng

College of Engineering
NC State University

Dose Effect on the Irradiation Induced Loop Density & Burgers Vector in Ion-irradiated Alloy T91 Irradiated In-situ in a TEM

Problem Statement
Ferritic/Martensitic (F/M) steel T91 is a promising candidate for structural materials and fuel cladding applications in Gen IV nuclear reactors. However, its radiation tolerance and microstructure evolution under irradiation need to be proved. In-situ TEM observations provide the ability to see the dominant radiation damage as well as the evolution of the microstructure induced by this damage. Such insight is usually missing from static snapshots taken at the end level of radiation.

The formation of resolvable loops results in an increase of radiation-induced dislocation loop density between 0-2 dpa. After that, the build-up of dislocation segments / network by the interaction of dislocation loops at higher doses results in a significant decrease of loop density between 2-10 dpa. The decrease of radiation-induced loop density through interactions of loops with the dislocation network was evidenced by dynamic observations.

The proportion of a <100> loops is similar to a/2 <111> loops at 4 dpa, whereas at 10 dpa the a <100> loops are predominant, indicating a preferred loss of a/2 <111> loops (i) to feed the formation of dislocation network; (ii) to interactions resulting in the formation of a <100> loops; (iii) to the free surfaces. Similar trends were observed in 12Cr F/M steel HT9 in-situ irradiated to 20 dpa at 420-470℃.

Broader implications of the research
In-situ TEM characterization provides dynamic observations for the formation of resolvable dislocation loops and the loss of these loops into the complex network of dislocations. The on-zone STEM imaging makes it easy to identify the Burgers vector of dislocation loops. In total, this research helps to better understand the evolution of radiation-induced microstructure in F/M steel T91.

Keywords
In-situ TEM observation; Radiation damage; dislocation loop morphology

Dr. Cheng Zhu

College of Engineering
NC State University

Single-Droplet Flow Chemistry Platform for High-Throughput Studies of Rhodium-Catalyzed Hydroformylation Reactions

Problem Statement
Hydroformylation reaction is one of the largest-scale applications of homogeneous catalysis in industry where catalysts and ligands play a significant role in tailoring the selectivity and yield of the products. Conventionally, the lab-scale studies of hydroformylation reactions in the presence of toxic and flammable gases (i.e., carbon monoxide and hydrogen) are carried out by batch reactors. Batch reactors suffer from inherent limitations such as inefficient heat and mass transfer, slow sampling rates, and large amount of waste. In addition, large volumes of toxic and flammable gases raise major safety concerns. Recently, flow chemistry has emerged as an efficient technique for continuous synthesis of fine chemicals. My current research focuses on the design and development of flow chemistry strategies for time- and material-efficient screening and optimization of this gas-liquid two-phase reactions under high pressure/temperature conditions.

First, I have designed, developed, and tested a unique automated high-throughput experimental platform for rapid performance evaluation of the complex homogeneous catalytic reactions which are challenging to conduct in batch flasks. A single-droplet tube-in-tube microfluidic reactor is designed to address heat and mass transfer limitations. Second, the autonomous operation of the developed flow chemistry platform enables precise control of the reaction parameters for each experiment and ensures the high reproducibility between runs. Third, the small internal volume of the microreactor along with the reduced reagent volumes enhance significantly the process safety for continuous operations in research labs.

Broader implications of the research
As a case study, I utilize the developed flow chemistry platform for screening and optimization of a library of catalysts and ligands towards high catalytic activity and selectivity for hydroformylation reactions. This experimental setup can be utilized for any gas-liquid or liquid-liquid two phase chemical reactions like methanol oxidation, switchable solvents study or partition coefficient screening of pharmaceutical compounds. It’s a fast high-throughput screening system for catalytic organic synthesis and reaction kinetics.

Keywords
Hydroformylation; Microfluidics; Automation; 1-octene; Phosphine ligands