Oral Sessions

Session 1:

Professor Jean-Claude Thill

Associate Professor Kent Brintnall 

Assistant Professor In Hong Yang 

Postdoctoral Researcher Ticiana Della Justina Farias

Director Brad Yeckley 

Session 2:

Professor Jay Wu

Professor Min Shin 

Assistant Professor Jaewon Oh 

Collagenous connective tissue is critical for the survival of multicellular organisms and has many biomedical applications within a multibillion-dollar industry. The secret to discovering a new generation of biomedical applications of collagenous tissue may lie in echinoderms, a group of marine invertebrates including sea stars, sea cucumbers, brittle stars, sea urchins, and sea lilies. Echinoderms are capable of reversibly controlling the pliability of certain connective tissue components (i.e., tendons and ligaments) that are composed of mutable collagenous tissue (MCT). These changes in tensile strength are rapid and appear to be directly controlled by the nervous system. The MCT’s variable tensility allows echinoderms to perform unique functions, including energy-saving posture maintenance, autotomy, and asexual reproduction. It is known that the nervous system controls the MCT via neurosecretory juxtaligamental cells, which, in turn, release softening or stiffening substances, of which only a few have been purified and characterized. The genomic underpinnings of MCT biology remain largely unknown. Therefore, we propose to identify the putative MCT-related genes in echinoderms and investigate the biology of their juxtaligamental cells in greater depth. Our research will be the first step in improving our knowledge about MCT's molecular control mechanism, with the ultimate goal of unlocking new biomaterial applications. In this project, we use transmission electron microscopy (TEM) to identify and describe Ophiomastix wendtii’s juxtaligamental cells and RNA-seq to find and annotate up and down-regulated genes in the tissues surrounding those glands. Our findings will be presented along with future research perspectives. 

This study investigates the variations in the output signal of 3D-printed PVDF-TrFE single-layer sensors in shear mode owing to varied geometries and electrode materials, with applications in hydraulic systems, open channels, etc. Square (30mm x 30mm x 0.4mm) and rectangular (30mm x 15mm x 0.4mm) samples are printed with the Prusa i3 MK3 3D printer using an extruded PVDF-TrFE filament of 1.75 diameter. The samples are corona-poled with a voltage of 25 kV under room temperature and coated separately with 50 microns of gold, silver, and platinum, using the AJA sputter coater. Other samples of the two geometries with brush-painted silver electrodes are considered for further comparison. Flickering and deflection up to 5mm are performed as initial sensitivity tests for the sensors. For the signal output, a setup consisting of a sensor at a time connected with DS1052E digital oscilloscope temporarily sealed to the middle of an elevated acoustic tube of 50mm internal diameter sealed at one end and on the other connected with 2446J-16 ohms JBL speaker which in turn connected with a Model SR830 DSP lock-in amplifier. Shear stresses due to the transient airflow generated in the tube by the speaker via a directed series of frequencies at corresponding voltages from the amplifier are measured by the sensors laid along the airflow direction in the middle of the acoustic tube. It is hypothesized that the rectangular sensor sputter-coated with the silver electrode gives the highest signal response and output above 50 mV, succeeded by rectangular sensors with gold and platinum electrodes. Consequently, a rectangular PVDF-TrFE sensor with a sputter-coated silver electrode hypothetically proves to be the most suitable for measuring stress in shear mode. Experimental processes are ongoing to scrutinize the hypothesis and further investigations to verify scalability and versatility with a different flow material.

The decline in public transportation use in U.S. cities like Charlotte, North Carolina, marked by a 75% drop in bus ridership from 2014 to 2022, highlights the need for an efficient, inclusive transit system. Transportation behaviors are influenced by urban design; pedestrian-friendly environments increase public transit use, while car-dependent designs contribute to its decline. The study proposes pedestrian-oriented urban designs and smart transit technology to enhance transit efficiency. An innovative on-demand bus system is expected to address transportation disparities, particularly in underserved communities. Employing community surveys in Charlotte, an AI-based bus arrival time prediction model, and TRANSIT-GYM and SUMO software for CO2 emission simulations, our research reimagines buses as IoT devices, integrating real-time demands with operations. This includes a commuter-focused mobile app and a cloud-based scheduling platform. Preliminary findings show significant public transit challenges in Charlotte, particularly in low-income areas. We predict bus arrival times with less than 40 seconds error using a neural network with over 2 million data points. Additionally, urban design simulations reveal that areas like Charlotte's South End can substantially reduce emissions through increased bus usage, with a potential decrease in daily emissions by 10.18% at double bus utilization and 21.45% at 50% utilization. This emphasizes the importance of urban design in transit system efficiency. This study contributes to urban planning, transportation engineering, AI, and environmental sustainability, aiming to make public transit more accessible and appealing across demographics, enhancing inclusivity and accessibility. In order to revitalize public transit systems, smart technologies, and urban design are emphasized. The outcomes advocate sustainable urban design and intelligent transportation solutions to influence urban transportation policy.

n recent years, the term ‘currency manipulation’ has sparked attention in policy and scholarly debates as the US Treasury Department has been accusing countries involved in this “unethical or unfair currency practice”. According to the US Treasury Department, currency manipulation is a designation that is used to label countries that deliberately or artificially make their currency weaker to make export cheaper and import expensive. A crucial question is if this is an unfair practice why do countries engage in it? A weaker currency of a country could also be attributed to “quantitative easing”. This macroeconomic process leads to a weak currency when the Central Bank of a nation lowers the interest rate to increase borrowing and encourage spending. The study used a panel data which is a combination of cross-sectional data for twenty-five (25) countries which are G22 countries with Switzerland, Saudi Arabia and Turkey (excluding Poland and US) and times series quarterly data (September 2000 – August 2020). For this balanced panel, the study employed Fixed Effect Models (FEM), Random Effect Models (REM) and the Robust Standard Error Models (RSE) for estimation and interpretation. However, the Robust Standard Error Model was extended to include country-specific random intercepts and country-specific fixed effects. These clustered data analysis methods produce unbiased estimates, have strengths of correcting omitted variable biases and heterogeneity shrinkages. Although coefficients may be unbiased, autocorrelation may render estimates inefficient. Overall, the study demonstrated that quantitative easing which leads to devaluation of currencies of countries might also be a factor for the US to label countries as currency manipulators. Therefore, it is imperative for the US to understudy the monetary policy of a country before labelling it as a currency manipulator.

The ongoing collaborative effort in Mecklenburg County to assess and reduce food insecurity, titled “State of the Plate”, has examined statistical trends in food insecurity through survey data, and analyzed interviews and surveys with organizational leaders within the food system. In the current phase, we spoke directly with a diverse group of participants from various backgrounds to discuss their thoughts on what the food system needs, and their current beliefs on healthy eating. We worked with these community members to gain more perspective on what barriers individuals who are food insecure feel affect them the most through small focus groups that began in March 2023, and continued until July, with 6 total events being held. These “community conversations” were recorded and transcribed for clarity and coded for recurring themes. This data, while still preliminary, highlights a recurring narrative of marginalized groups feeling isolated from access to the food system, including food assistance programs or efforts due to cultural and historical associations, lack of education, and language barriers, among other obstacles. Additionally, there is a recurring narrative of feelings regarding powerlessness and exhaustion for many struggling with food security. Overall, within many of the barriers individuals face, the emotional and psychological effects seemed to be stressed by participants, yet are not sufficiently being addressed by current interventions. We are working to communicate the results from this study with community members, organizations, and policy leaders to begin building sustainable solutions that increase accessibility and well-being within the Mecklenburg County community. 

Millions of Americans are killed annually due to antibiotic resistant infections. Bacteria can evolve quickly to avoid antibiotic mechanisms and easily spread resistance genes. This occurs so rapidly that new antibiotics are often rendered ineffective before or within the same year of Food and Drug Administration approval for widespread use. This is accelerated with the overuse and misuse of antibiotics in healthcare and in agriculture. There is a critical need for novel antibiotics that use a combination of antibacterial mechanisms which are more difficult for bacteria to evolve to avoid. Silver has been used for its bacteriostatic and bactericidal properties for centuries, and has been incorporated into wound creams and dressings, food packaging, and in both home and industrial appliances to prevent contamination. Furthermore, silver nanomaterials have been gaining interest. DNA-templated silver nanoclusters are biocompatible antibacterial agents with tunable bacteriostatic and bactericidal properties while remaining non toxic to mammalian cells. 

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer in the USA where pancreatic cancer alone ranks third as a cancer related mortality. The aggressiveness of this cancer subtype and challenges in early diagnosis and treatment result in poor prognosis with a 5-year survival rate of 9%. Thus, detection of PDAC in early stage and treatment are necessary. In clinics, combination of multiple drugs like gemcitabine plus nab-paclitaxel, FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) showed promises, however, they have safety and ratiometric delivery limitation. These drawbacks can be avoided with nanoplatforms to deliver single or combinatorial drugs to improve spatiotemporal and ratiometric delivery with less chemotherapy related toxicities. Mesoporous silica nanoparticles (MSNs) – a nanoparticle-based drug delivery system – have demonstrated promising improvement in delivering multiple chemotherapeutic drugs combination due to their high drug loading capacity due to high surface area with porosity, functionalization tunability, and biocompatibility. We have developed gemcitabine resistant murine and human pancreatic cell lines to examine the effectiveness of mesoporous silica nanoparticles loaded with gemcitabine and cisplatin (cisPt) in different ratio. The cytotoxicity study via MTS assay showed that MSNs carrying gemcitabine and cisPt can bypass the gemcitabine resistance mechanism to kill the pancreatic cancer cells compared to single cytotoxic drug. The cytotoxicity studies have been conducted with different ratios of gemcitabine to cisPt and synergistic effect of drugs is ratio dependent. We envision that using nanocarriers like MSNs in the treatment of pancreatic ductal adenocarcinoma can be valuable tool to circumvent the drug resistance in clinical settings for patients with improved therapeutic outcomes.

Our study comprehensively approaches the development question in sub-Saharan Africa (SSA) from two complementary angles. The first study takes a macro approach to critically analyze how and to which extent INGO interventions influence socioeconomic development in SAA from 1990 to 2020. The second study focuses instead on the Millennium Corporation Challenge (MCC); analyzing how its conditional aid approach affects poverty reduction, and institutional performance in SSA. The first study adopts a mixed method with a quantitative analysis using the Human Development Index (HDI) for dependent variables and as a proxy measurement of socioeconomic development. The adopted statistical model is a Time Series Cross-Sectional (TSCS) Analysis. The second study uses difference-in-difference (DiD) to measure the effect of the Millennium Challenge Corporation (MCC) on Institutional Performance and poverty reduction in SSA. Preliminary findings suggest that MCC conditional aid programs seem to positively influence institutional performance in recipient countries. However, the impact of INGOs on the HDI appears varied, more mitigated, and inconclusive.