University of Illinois at Chicago
University of Illinois at Chicago: UIC INDIGO (INtellectual property in DIGital form available online in an Open environment)Not a member yet
21439 research outputs found
Sort by
The Microbial Ecology of Biological Soil Crusts Within a Temperate Coastal Dune Ecosystem
No full textBiological soil crusts (or biocrusts) are a consortium of phototrophic microorganisms, bacteria, fungi, lichens and mosses, each embedded within a self-aggregated soil matrix found among the first few millimeters of the soil surface. Referred to as the “living skin” of the Earth, biocrusts are known for their ecological contributions to dryland biogeochemical cycling, soil stability, and their influence on soil water dynamics. They colonize a significant proportion of arid and semi-arid ecosystems and our understanding of the global relevance of biocrusts has increased exponentially over the last few decades. However, biocrusts are not limited to only dryland ecosystems, with recent research showing biocrust to be present throughout a variety of temperate ecosystems that host nutrient-poor, excessively drained soils with limited vascular plant establishment. Though it’s suspected that temperate biocrusts share many of the same ecological functions as their dryland counterparts, our current knowledge on the ecology of biocrusts within temperate biomes is limited, resulting in their absence in consideration from ongoing land management efforts.
With the combination of field data collection, genomics, and the implementation of robust computational analyses, my thesis work explores the spatial and microbial ecology of biocrusts within a US federally-preserved temperate coastal dune ecosystem. For my first chapter, I conducted a field study to survey biocrusts within the Miller Woods dune complex, located within the Indiana Dunes National Park. My objective was to understand how biocrusts were distributed among a complex dune system and how their distribution was related to differences in dune morphology and their surrounding above-ground community. For my second chapter, I collected samples of biocrusts, their adjacent sub-surface soil, and non-crusted soils throughout Miller Woods to understand the influence biocrusts have on the surface and underlying soil microbiome. Overall, my thesis work introduces biocrusts as important members of coastal dune ecosystems found along the southern shore of Lake Michigan
Age-Associated Differential Salivary Immune Profiles in Post-Non-Surgical Periodontal Therapy Subjects
No full textPeriodontal Disease (PD) is the second most prevalent oral condition worldwide and has been linked with other systemic conditions. This inflammatory disease primarily occurs due to biofilm dysbiosis with periopathogens that triggers the host immune system to elicit exaggerated responses. Aging has been reported to affect the immune system, leading to increased effects on age-related diseases, including PD. Examining how aging affects immunobiology of PD and its resolution can uncover novel mechanisms that may cater towards the treatment of aging subjects. Saliva and gingival crevicular fluid (GCF) can allow us to monitor immune changes non-invasively by evaluating the biomarkers involved in the disease process. The objective of this study is to dissect mechanisms of immune perturbation in geriatric and young-middle age PD patients before and after non-surgical periodontal therapy (NSPT, scaling and root planing). Periodontally healthy young and geriatric patients were included as control groups. Clinical parameters including probing depth (PPD), bleeding on probing (BOP), & plaque index (PI) were measured pre- & post-NSPT. Salivary immune cells were assessed by flow cytometry and GCF cytokines were quantified by multiplex. To measure the bacterial burden, key virulence factors of A. actinomycetemcomitans and P. gingivalis were quantified by RT-qPCR. Our results show reduction of clinical parameters for both, young-middle aged (YMA) and geriatric (G) groups post-NSPT. However, NSPT significantly reduces bacterial burden in young subjects but not in geriatric patients. GCF assessment by periotron also indicates significantly higher reduction in YMA group post-therapy compared to geriatric PD subjects. This correlates with salivary cytology showing differential impact of NSPT on immune cell abundance with less reduction in geriatric subjects compared to YMA cohort showed significant reduction in these inflammatory T cells and concomitant increase in immunoregulatory Tregs (CD4+IL-10+). Overall, we noticed less reduction in clinical parameters of PD, poor bacterial clearance, higher inflammatory cells, and low immunosuppressive T cell abundance in geriatric PD subjects indicating age-associated immune profiles that can be used to non-invasively monitory therapy outcomes.
Clinical relevance: difference in post-treatment improvements and bacterial clearance are linked to higher immune infiltrate for the geriatric group resulting in impaired resolution of the disease. Stronger responses of the pro- and anti-inflammatory cells of the young-middle aged group influenced the success of the therapy and wound healing
Exploration of Molecular Mechanisms of Aulosirazole and Wheldone for High-Grade Serous Ovarian Cancer
No full textChapter I is a summary of the project that generated this work. It provides
background information and emphasizes the importance of this thesis. Chapter II is
largely a summary of methods and materials behind the data presented in subsequent
chapters. Chapter III describes the mechanism and action of aulosirazole in ovarian
cancer. A majority of Chapter II and Chapter III is adapted from a published manuscript
on aulosirazole for which I am the first author and main driver of research. Chapter IV
presents data on the discovery of molecular mechanism of wheldone, which is
unpublished as of the submission of this manuscript. Chapter V contains a discussion of
these results and future directions to explore. Appendices contain supplemental data and
approvals
The Effects of Glycosaminoglycans on Corneal Mechanical Response
No full textThis study investigates the role of glycosaminoglycans (GAGs) in regulating corneal biomechanics through a series of ex vivo mechanical experiments, including dynamic shear tests, uniaxial and biaxial tensile tests, and transmission electron microscopy (TEM). The findings reveal that corneal collagen crosslinking (CXL) significantly enhances the mechanical properties of the porcine corneal stroma by increasing tensile tangent modulus, shear modulus, and interfibrillar compaction. TEM analysis highlights the depth-dependent ultrastructure of the corneal stroma, with larger collagen fibrils in the anterior region compared to the posterior. It demonstrates that CXL compacts the collagen-proteoglycan matrix without altering fibril diameter.
Uniaxial tests show that enzymatic GAG depletion reduces the stiffening effects of CXL, emphasizing GAGs' role in maintaining corneal strength and resilience. Planar biaxial testing reveals non-linear stress-strain relationships, isotropic behavior under equibiaxial loading, and significant stiffening due to CXL and preconditioning effects. The results also underscore the importance of displacement rates in influencing mechanical response. Additionally, enzymatic digestion confirms the critical role of GAGs in viscoelastic shear properties, with depletion causing substantial reductions in shear modulus and disrupting collagen fibril organization.
This comprehensive assessment highlights the complex interplay between corneal ultrastructure and biomechanics, demonstrating the significance of GAGs and collagen crosslinking in maintaining corneal integrity. The findings provide a foundation for future in vivo studies and contribute to developing advanced therapeutic strategies for corneal disorders
Advancing Resilience in Clusters of Grid-Forming and Grid-Following Inverters
No full textThis dissertation focusses on developing a hybrid multi-time-scale semi supervised distributed control architecture for a network made up of several clusters of grid forming (GFMI) and grid following inverters (GFLI) connected in a modern active power distribution network. The considered modern power distribution network is made up of several clusters of grid forming and grid following inverters. In such a heavily inverter-dominated power system, ensuring reliable and resilient operation of all these inverter-interfaced generation units of limited capacities, is of paramount importance and severity. The system's voltage and frequency must be maintained within permissible limits, thus ensuring an active power balance between demand and supply while providing uninterrupted power to system loads.
This dissertation proposes a control architecture that achieves the resilient operation of inverters subject to steep disturbances originating in the source as well as load side. A self-reconfiguring coordinated mode selection mechanism has been proposed that runs a consensus among all interfaced inverter agents in a cluster. The proposed mechanism elects new (or additional) GFMI source, to support the system’s V-f whenever additional active-reactive power is demanded. It ensures that sufficient GFMI support is available in the network to serve the system loads. Next, a cluster coordinator module has been implemented to regulate the power operation set-points of GFMIs and GFLIs within the cluster. The cluster coordinator aims at optimally dispatching the power set-points to support the system frequency in response to steep disturbances. Moreover, a machine learning-based artificial neural network approach has also been investigated to further enhance the system performance and offer fast frequency restoration. A synchronization mechanism has also been discussed to enable speedy disconnection and interconnection of inverter clusters when commanded by upper layer controllers or in response to grid disturbance events. Finally, a supervisory coordinator has been proposed to enable seamless synchronization and dynamic power sharing among the interconnected inverters. The power optimizers deployed in the cluster coordinator and the supervisory coordinator command the GFMI/GFLI power set-points to attain various control objectives at different time scales. A detailed parametric analysis comparing the performance of the proposed multi-time scale semi-supervised distributed (MT-SSD) control approach with other state-of-the art control approaches is also performed. The comparative analysis results demonstrate an improvement in the overall resiliency of the IBR cluster achieved by implementing the proposed MT-SSD control approach. Next, the implementation feasibility of the discussed MT-SSD control scheme on real-world microgrid systems and the associated communication infrastructure requirements have also been reviewed. Finally, the dissertation concludes by summarizing the key achievements and discussions pertaining to potential future research directions
A Causal Framework for Mining Helpfulness Voting: Learning Information Quality and Community Dynamics
No full textEfficient access to high-quality information is crucial for online platforms that rely on helpfulness votes to evaluate and rank user-generated content. These votes are designed to reflect collective judgments about information quality. However, the voting process is often affected by position bias (where prominently displayed items receive more attention) and herding bias (where users are influenced by previous votes). These biases can distort evaluations, leading to overestimating popular content rather than the most valuable information. This has sparked interest in understanding how these biases interact and reinforce each other and developing more accurate and fairer methods for assessing information quality.
In essay one “From Popularity to Meritocracy: Information Monopoly and Evolution of Excellence in Online Communities”, I propose the Evolution of Excellence (EoE), a theoretical framework that explains the position and herding biases along with their monopolistic reinforcement. To quantify these biases, we map the diverse voting behaviors across 120 major StackExchange communities onto two behavioral axes, further clustering the communities into four distinct information categories. We also demonstrate the behavioral evolution of individual communities over the years, highlighting longitudinal insights into the underlying social process. Our findings can help service providers secure community-specific interventions that foster meritocracy by promoting valuable yet under-recognized information without running expensive A/B tests or model training.
In essay two “Finding Information Quality: Counterfactual Voting Adjustment for Quality Assessment and Voting Fairness in Online Platforms with Helpfulness Evaluation”, for fairer assessment of information quality, we propose the Counterfactual Voting Adjustment (CVA), a causal framework that account for the context in which individual votes are cast. Through preliminary and semi-synthetic experiments, we show that CVA effectively models the position and herding biases, accurately recovering the predefined content quality. In real experiment, we demonstrate that reranking content based on the learned quality by CVA exhibits stronger alignment with both user sentiment and quality evaluation assessed by GPT-4o, outperforming system rankings based on aggregated votes and model-based rerankings without causal inference. Beyond the individual quality inference, our embeddings offer comparative insights into the behavioral dynamics of expert user groups across major StackExchange communities
High-throughput Patterning of Labile Proteins for Fabricating Cardiac Micropatterned Co-cultures
No full textReliable in vitro platforms that accurately mimic the heart’s cellular and structural organization are essential for advancing cardiac research, including disease modeling, drug discovery, and regenerative medicine. This thesis represents preliminary work toward developing a high throughput 96-well plate platform designed to model the microenvironment and characteristics of the human heart.
Such platforms serve as a crucial middle ground, bridging the gap between basic two dimensional cultures and the complexities of in vivo studies. By providing controlled environments, they replicate key features necessary for the development of adult-like iPSC-derived cardiomyocytes. This approach builds on the state-of-the-art understanding that co-culturing cardiac fibroblasts (CFs) with cardiomyocytes significantly enhances both the function and maturity of cardiomyocytes. The first goal of the thesis was to develop a robust protocol for patterning labile proteins, specifically fibronectin (FN) and bovine serum albumin (BSA), on a 96-well plate. This protocol enables the spatial organization of iPSC-derived ventricular cardiomyocytes (iPSC-vCMs) and vCFs, mimicking the physical and biochemical cues found in the native cardiac microenvironment.
Subsequently, this thesis investigated how iPSC-vCMs respond to co-culture within this micropatterned platform compared to random co-cultures. This includes analyzing structural and functional maturation markers under varying seeding densities to determine the conditions that most effectively promote cardiomyocyte maturation.
Finally, an exploratory analysis was conducted to evaluate the influence of secreted frizzled related protein 2 (Sfrp2) on iPSC-vCM differentiation. This analysis compared Sfrp2-mediated differentiation to an in-house protocol modeled after commercially available differentiation methods, with the aim of understanding its potential role in improving the maturity of iPSC-vCMs.
In conclusion, this body of work provides a foundation for future studies to refine the platform and explore its applications in cardiac disease modeling, drug discovery, and regenerative medicine
The Role of Internalin B Regulation and Variation in the Vertical Transmission of Listeria monocytogenes
No full textListeria monocytogenes (Lm) is a foodborne pathogen capable of causing severe infection during pregnancy. However, the bacterial strains most likely to cause vertical transmission remain understudied. This work investigates the increased placental and fetal invasion of Lm strain 07PF0776, which exhibits higher surface abundance of the virulence factor Internalin B (InlB) compared to the commonly studied strain 10403S. We identify a post-transcriptional regulatory mechanism involving the small RNA rliB, which reduces inlB expression in 10403S but not 07PF0776. Expanding our analysis to additional Lm strains, we observe a correlation between surface InlB abundance, vertical transmission rates, and rliB sequence variation, suggesting a broader role for inlAB regulation in Lm pathogenesis. In addition, structural polymorphisms in InlB influence its interactions with bacterial wall teichoic acids and host proteoglycans. These findings provide insights into the molecular determinants of pregnancy-associated listeriosis and inform strategies for surveillance and prevention of severe disease
Unofficial Mongolian Translation of the <i>Agreement on Transparency in Matters Related to International Trade and Investment between the United States of America and Mongolia</i>
No full textThis document provides an unofficial Mongolian translation of the Agreement on Transparency in Matters Related to International Trade and Investment between the United States of America and Mongolia, originally signed in 2013 in both English and Mongolian. While the treaty was executed in both languages as equally authentic, the official Mongolian text is not publicly available. This translation has therefore been prepared for educational and reference purposes to increase accessibility for researchers, students, and practitioners. It includes a disclaimer clarifying its unofficial status and a glossary of key legal terms.</p
The Library is Not Enough: Building Data Governance Community at Your Institution
No full textA book chapter done in the ACRL "cookbook/recipe" format. The chapter addresses the need for developing broad engagement across many campus units to manage data and open science practices at the institutional levels. The primary focus is on research data governance. </p
Data sources:
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇