19304 research outputs found
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Robotic Dog Automation & a Digital Pipette Design
No full textDr. Shan's research involves using a robotic dog to collect data on toxic gases, focusing on agricultural settings. The dog is equipped with sensors for VOCs (Volatile Organic Compounds) and CO2, helping monitor air quality in fields. To further this research, we are incorporating machine learning to enable the dog to autonomously navigate predefined paths, reducing the need for manual control and enhancing data collection through real-time network transmission. In parallel, I worked on a digital pipette system that uses a linear actuator and syringe mounted on a robotic arm to automate chemical procedures in labs, improving precision and efficiency.Electrical and Computer Engineering, Department ofHonors Colleg
Daily State-Like Distress Tolerance and Alcohol Use Motivation Among Hazardous Drinkers with Posttraumatic Stress Disorder Symptoms
No full textHazardous drinking and posttraumatic stress disorder (PTSD) are both highly prevalent and frequently comorbid public health conditions that result in more severe clinical and functional outcomes than either individual condition. Therefore, it is a public health priority to identify malleable treatment mechanisms that may underlie or exacerbate the hazardous drinking-PTSD comorbidity to inform evidence-based intervention efforts. Some research suggests that individual differences in distress tolerance (DT) are theoretically relevant to both hazardous drinking and PTSD symptoms. DT reflects the perceived or objective ability to withstand negative affective or bodily states. DT is relatively stable (i.e., it has trait-like qualities), but recent work indicates that it also maintains state-like qualities. Past work has not examined state-like DT in terms of PTSD and hazardous drinking comorbidity. To fill this gap in the literature and facilitate mechanistic knowledge that can inform future treatment development for this population, this project investigated the following primary aims in an ecological momentary assessment (EMA) framework over a 21-day time-sampling epoch: to examine (1) whether state-like lower DT mediates the association between PTSD symptoms at baseline and alcohol use motivation; and (2) whether state-like DT mediates the association between PTSD symptoms at baseline and hazardous drinking. Hypotheses were partially supported, as a statistically significant indirect effect was observed for baseline PTSD symptom severity on alcohol use motivation via momentary DT; however, this indirect effect was not statistically significant for the model examining hazardous drinking behavior
The Correlation Between Household Composition and MoCA Scores in the Vietnamese Older Adult Population
No full textCognitive decline is a growing public health concern among older adults, particularly in underserved populations. This study examines the correlation between household composition, self-rated health, and cognitive function in the Vietnamese older adult population, measured by the Montreal Cognitive Assessment (MoCA). Household composition, including living alone, with family members, or in multigenerational households, may play a critical role in shaping cognitive health through social engagement, emotional support, and daily interactions. The study aims to determine whether different living arrangements are associated with varying MoCA scores, which assess cognitive domains such as memory, attention, language, and executive function. Additionally, the analysis will compare self-rated health scores with MoCA scores to understand how subjective health perceptions align with objective cognitive outcomes. Understanding the relationship between household composition and cognitive function is essential for developing community-based interventions and promoting healthy aging within the Vietnamese community. These findings emphasize the importance of fostering socially supportive environments and could inform future strategies to reduce the risk of cognitive decline among older adults.Social Work, Graduate College ofHonors Colleg
Design for Cyclometalated Platinum Complexes for Enhanced Red Emission
No full textThis research focused on the design and synthesis of cyclometalated platinum complexes to enhance red emission properties. The study investigated Pt complexes featuring phenylisoquinoline (piq) as the cyclometalated ligand and ancillary ligands ipba and acNacF6. The primary objective was to improve the photophysical properties of these complexes, particularly photoluminescence quantum yield, which has been a challenge due to low quantum yields and short photoluminescence lifetimes. The synthesis process involved three key reactions: the formation of Pt-piq dimer, the synthesis of Pt(piq)(ipba), and the synthesis of Pt(piq)(acNacF6). The obtained complexes were characterized using proton and fluorine nuclear magnetic resonance (NMR) spectroscopy to verify their structures. Photophysical measurements, including photoluminescence and absorption spectra, were performed to evaluate the emission properties. Results indicated that adding a CF3 group to the backbone of Pt(piq)(acNacF6) did not significantly improve red emission, and quantum yield remained low due to slow radiative decay (kr). The Pt(piq)(ipba) complex demonstrated successful synthesis using the reaction conditions. In conclusion, while the Pt(piq)(acNacF6) complex did not show promising results, the Pt(piq)(ipba) complex shows potential for further study, particularly in understanding the effects of ancillary ligands on photophysical properties. Further photophysical studies will be conducted to optimize these complexes for enhanced red emission applications.Chemistry, Department ofHonors Colleg
Elucidating the role of divalent metal ions in the stability and behavior of lymphocyte function-associated antigen-1 inserted domain
No full textThe αL-Inserted (αL-I) domain is the external ligand-binding component of lymphocyte function-associated antigen 1 (LFA-1/αLβ2), an integrin expressed on antigen-presenting cells, endothelial cells, and lymphocytes. LFA-1 plays a role in binding ICAM-1, ICAM-2, and ICAM-3, facilitating immune cell migration and adhesion and subsequent signaling events. LFA-1 is a Type-2 integrin that consists of a 180 kDa αL subunit and a 95 kDa β2 subunit. When in the extended open state, LFA-1 binds to ligands via a Mg2+ ion, a physiological requirement for its function. LFA-1 is responsible for leukocyte recruitment to the site of inflammation, T-cell activation, and in mediating both the adaptive and innate immune responses. Recent literature has revealed that LFA-1 binds Mg2+ to co-stimulate and regulate the effector function of CD8+ T cells with low serum magnesium concentrations (hypomagnesia) associated with poorer clinical outcomes in cancer immunotherapy. In this study, I investigated the biophysical and biochemical characteristics of the αL-I domain with a focus on the role of divalent metal ions in its stability. We successfully expressed, refolded, and purified the αL-I domain and discovered that its stability was significantly enhanced in the presence of the Mg2+-supplemented buffer, highlighting the importance of divalent cations in the function of LFA-1. Further studies may explore the influence of varying concentrations of other divalent cations on the stability of LFA-1, with potential implications for therapeutic strategies in cancer treatment and immune dysfunctions.Honors CollegeBiology and Biochemistry, Department o
Simulating mitotic exit: Training the minimal chromatin model on human mitotic chromosomes
No full textAs cells transition from mitosis back into interphase, they undergo several structural changes and must re-establish features of interphase chromosome organization. To study this structural transition, we sought to utilize the Minimal Chromatin Model (MiChroM) at 100kb resolution with mitotic Hi-C data at multiple timepoints beginning from prometaphase arrest. MiChroM energy parameters require optimization for each timepoint in order to generate effective energy landscapes for chromosomes at different stages during the cell cycle. During optimization, the system got trapped in a glassy state while converging to agree with the experimental data. To prevent this issue, we found that several adjustments need to be made to the optimization procedure to obtain convergence for our system. Some of these adjustments include keeping a confinement potential to aid the initial collapse of the chromosome, a reduction of the learning rate, recalculation of parameters for the crosslinking probability function, increasing training of the ideal chromosome to include the entire chain length, and adjusting the confinement potential for our system. Despite these adjustments, we were unable to find a non-glassy solution given the available mitotic data and our model. Future work may explore a different optimization resolution that remains compatible with the resolution of the mitotic data available and a different optimization method may be utilized to obtain parameters for MiChroM. Accurately modeling the mitotic exit is crucial to our understanding of how cells regain the organization necessary for gene regulation and expression in interphase.Honors CollegePhysics, Department o
A Robust Estimation Algorithm for GEV Distribution and Application in Analyzing Extreme Values in Intraday Stock Price Movement
No full textIn this thesis, we introduce a new algorithm for fitting the parameters of the Generalized Extreme Value (GEV) distribution. This algorithm provides estimators with explicitly computable asymptotic normality, addressing a gap in the existing literature. We applied the block maxima method alongside our estimation algorithm to analyze extreme values in the stock market. Specifically, we examined 261 Chinese stocks and 32 U.S. stocks with high trading activity, forming separate pools for analysis. Our study revealed that the GEV distribution effectively models the extreme values in the stock market. The results indicate that stocks in the Chinese pool generally exhibit higher risk levels compared to those in the U.S. pool. Additionally, all U.S. stocks demonstrated stable risk models, whereas of Chinese stocks displayed stability. We also found that the dynamic patterns of risk parameter are different between the two pools. Specifically, in the Chinese stock pool, the risk parameter Value at Risk (VaR) increased after mid-2016, while in the U.S. pool, VaR remained relatively stable with a decrease post mid-2016. During the Chinese stock crash of mid-2015, the U.S. pool was sensitive to the change and reflected this in VaR, whereas the Chinese pool remained robust, likely due to "T+1" trading and "price limit" regulations. We further developed a method for portfolio optimization based on VaR. Our findings suggest that the GEV-based VaR outperforms the traditional normal VaR in terms of portfolio returns. The empirical analysis demonstrated that the GEV-VaR portfolio consistently achieved higher returns compared to the normal-VaR and equal-weighted portfolios. Finally, we discussed various topics, including a robust maximum likelihood estimation algorithm for GEV parameters, methods to mitigate biases inherent in the block maxima method, and techniques for detecting large jumps in stock prices. Our research provides valuable insights into the application of extreme value theory in financial markets, particularly in optimizing portfolios and managing risks
Just Enough Pain: Central American Asylum Seekers with Gang-Based Persecution Claims
No full textMany asylum-seekers, especially those from Central America, seek relief from growing gang violence. However, the current asylum system disfavors these individuals. This research paper will explore why gang-based asylum applications are on the rise, how the current system is antagonistic toward such claims, how attorneys create favorable claims, and how those strategies may perpetuate harmful stereotypes and victim narratives.Comparative Cultural Studies, Department ofHonors CollegePolitical Science, Department o
Environmental entanglements: The fourth space
No full textThe postwar American suburbs, once the symbol of prosperity and domestic idealism, have become fragmented environments defined by ecological harm and social isolation. Plan It is an interactive planning game that reimagines suburban development as a collaborative, site-specific process. Players use environmental data layers such as flood risk, soil quality, and biodiversity to design neighborhoods that are resilient, inclusive, and ecologically responsive. The game assesses these designs through environmental, economic, and social metrics, allowing participants to make informed decisions grounded in local conditions. Serving as a design tool, public engagement platform, and research archive, Plan It reveals how individuals navigate complexity in suburban planning. Through gameplay, it promotes community science and democratized urbanism while challenging conventional development models to envision more sustainable and equitable futures.Honors CollegeArchitecture and Design, Gerald D. Hines College o
Development and Evaluation of a Co-Culture System for Ovarian Cancer Metastasis Using Silicon-Titanium Diboride Micropatterned Substrates
No full textOvarian cancer, the deadliest gynecological malignancy, has a 75% advanced-stage diagnosis rate and an overall survival rate of less than 50%. Understanding ovarian cancer cell aggregation, dissemination, and metastasis within the peritoneal cavity requires robust co-culture models. Current in vitro models, including 2D and 3D co-culture systems, have limitations. While 2D models fail to capture the complexity of cancer cell interactions, 3D models offer better tissue architecture representation but lack precise control over cell placement and tracking individual cell behavior during metastasis. This study evaluates a silicon-titanium diboride (Si-TiB₂) micropatterned substrate fabricated using photolithography, creating circular and linear patterns for co-culturing SKOV-3 ovarian cancer cells and MeT-5A mesothelial cells. Cell viability assays indicated significantly higher viability of SKOV-3 and MeT-5A cells on TiB₂ substrates (84%) than on Si substrates (35%), highlighting the enhanced support provided by TiB₂. Morphological analysis showed that SKOV-3 cells cultured on TiB₂ exhibited greater elongation and migration traits (median length/width ratio of 1.6410) compared to the MeT-5A cells. SKOV-3 cells formed 3D aggregates, favoring TiB₂ over Si regions. Also, F-actin and E-cadherin staining confirmed expression of the cytoskeletal structure and cell-cell adhesion for MeT-5A cells on TiB₂ substrates. To evaluate the feasibility of the co-culture platform, MeT-5A and SKOV-3 cells were co-cultured on patterns with Ethylene Vinyl Acetate (EVA) as a temporary barrier, preventing initial cell mixing and enabling residue-free barrier removal. Time-lapse imaging coupled with fluorescence microscopy was developed to track real-time cell interactions on the substrate. This study demonstrates proof-of-concept for utilizing the Si-TiB₂ micropatterned substrate for co-culture of SKOV-3 and Met-5A cells. It supports high cell viability, and distinct morphological behaviors, providing a robust platform for future investigations of cancer metastasis and the role of the mesothelial environment in cancer progression