Digital Commons Network^™

Post-Operative Vision Loss Following Cataract Surgery: Lessons Learned From An Eight-Year Analysis, Thanigasalam Thevi

Manipal Journal of Medical Sciences

Background: Cataract is an ageing process and surgery is the only mode of restoring vision. Patients who undergo surgery have only one aim in mind, which is improvement in their visual acuity (VA). However, some patients do not achieve this aim for improved vision after having undergone the surgery. Reasons for worsening vision after cataract surgery should be identified to counsel the patients on the possibility of poorer outcomes so that patients are prepared for such eventualities should they happen. Objective: While cataract surgery restores vision in most, a subset of patients experience worsening vision post-operatively. We investigated various reasons …

Percutaneous Tracheostomy; As It Stands Today, Devaraja K

Manipal Journal of Medical Sciences

Conventionally, tracheostomy includes surgical creation of tracheo-cutaneous communication. It is done either to bypass the upper airway obstruction or to facilitate optimal mechanical ventilation and early weaning off the ventilator support in neurologically unstable patients. For many years now, percutaneous tracheostomy has been proposed as an alternative to open surgical tracheostomy in ventilator-dependent patients. This review briefly narrates the principles and procedure of percutaneous tracheostomy. In addition, the article sheds light on a few critical problems that one could encounter during the process and discusses countermeasures to overcome those difficulties. Finally, the role of intra-procedure bronchoscopy or ultrasonography and of …

A Rare Case Of Chorioretinitis Sclopetaria- A Pellet In A Haystack, Yogish Kamath

Manipal Journal of Medical Sciences

Chorioretinitis sclopetaria is a rare event with a poor visual prognosis, with less than a hundred cases reported worldwide. We report a case of an 8-year-old boy who presented with swelling and decreased vision in the left eye after an alleged fall. On examination, the affected eye showed periorbital ecchymosis, ptosis, subconjunctival haemorrhage, hyphema, and an afferent pupillary defect. A CT scan showed a foreign object lodged in the left orbit which was removed surgically. This case report intends to describe the rare occurrence of chorioretinitis sclopetaria in a child, wherein the history of gun pellet injury, elicited in retrospect, …

Post-Coarctectomy Syndrome And The Use Of Gabapentin For Gi Ileus: A Case Report, Vinay Krupadev

Manipal Journal of Medical Sciences

Post-coarctectomy syndrome is a complication of aortic arch repair that occurs due to a sudden increase in reperfusion of the body’s vasculature following surgery. One complication related to postcoarctectomy syndrome is ileus which can prolong a patient’s ICU stay and delay discharge home. While traditionally supportive care has been used to resolve this condition, this case highlights the use of gabapentin as a relatively novel treatment for post-coarctectomy syndrome gastrointestinal ileus.

An Investigation Of Sensory Percepts Elicited By Macro-Sieve Electrode Stimulation Of The Rat Sciatic Nerve, Nikhil Shiva Chandra

McKelvey School of Engineering Graduate Student Theses & Dissertations

Intuitive control of conventional prostheses is hampered by their inability to replicate the rich tactile and proprioceptive feedback afforded by natural sensory pathways. Electrical stimulation of residual nerve tissue is a promising means of reintroducing sensory feedback to the central nervous system. The macro-sieve electrode (MSE) is a candidate interface to amputees’ truncated peripheral nerves whose unique geometry enables selective control of the complete nerve cross-section. Unlike previously studied interfaces, the MSE’s implantation entails transection and subsequent regeneration of the target nerve. Therefore, a key determinant of the MSE’s suitability for this task is whether it can elicit sensations at …

Hyperlocal Air Quality Exposure Assessment To Support Health Studies, Pradeep Prathibha

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hyperlocal air pollution exposure is driven by local emission sources, meteorology, and the built environment, with traffic-related emissions modulating primary and secondary pollutant concentrations against a variable background of similar contaminants from other sources. Recent studies show that intra-urban air quality has temporally persistent patterns that sharply vary 5-8 times within a city block; currently, regulatory ambient air quality monitoring (2-5 fixed-site monitors per 1000 km2 in U.S. census urban areas) cannot capture exposure at this spatial resolution. This dissertation aims to advance methods relying on fixed-site and mobile measurements using high-time resolution aerosol instruments as well as low-cost sensors …

Short-Term Memory And Olfactory Signal Processing, Lijun Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Modern neural recording methodologies, including multi-electrode and optical recordings, allow us to monitor the large population of neurons with high temporal resolution. Such recordings provide rich datasets that are expected to understand better how information about the external world is internally represented and how these representations are altered over time. Achieving this goal requires the development of novel pattern recognition methods and/or the application of existing statistical methods in novel ways to gain insights into basic neural computational principles. In this dissertation, I will take this data-driven approach to dissect the role of short-term memory in olfactory signal processing in …

Process Information And Creative Mindsets: An Examination Of Their Role In The Evaluation Of Creativity, Brendon Michael Cummiskey

Arts & Sciences Graduate Student Theses and Dissertations

Evaluating creativity is a key role for any organization interested in innovation and how that evaluation occurs has been a focal point of researchers. Although creativity scholars have made strides in understanding creativity evaluations, questions remain about the role that process information plays in the evaluation. While most creativity research involves some type of outcome, such as an idea or product, the evaluators often have no description of the creator’s work process or any understanding of the idea or product’s creation. In this dissertation, I build upon the existing evaluation literature and critically examine how process information may influence the …

Dissecting The Molecular Mechanism Of Familial Cardiomyopathies, Sarah Ruth Clippinger Schulte

Arts & Sciences Graduate Student Theses and Dissertations

Familial cardiomyopathies, including hypertrophic (HCM), restrictive (RCM) and dilated cardiomyopathy (DCM), are the leading cause of sudden cardiac death in young people. These diseases, which are characterized by altered cardiac contractility and remodeling of the heart, can lead to heart failure. These diseases are primarily caused by point mutations in sarcomeric proteins that generate or regulate heart contraction, such as troponin T. In the heart, the troponin complex together with tropomyosin lie along the actin filament and regulate myosin’s ability to bind actin and produce force. Here I show how mutations in troponin T affect contractility at the molecular level …

Structural Variants Are A Major Source Of Gene Expression Differences In Humans And Often Affect Multiple Nearby Genes, Alexandra Jane Scott

Arts & Sciences Graduate Student Theses and Dissertations

Structural variants (SVs), including copy number variants (CNVs), balanced rearrangements, and mobile element insertions (MEIs), are an important source of diversity in the human genome but their functional effects are not well understood. SVs are technically difficult to detect and genotype1, and mapping is dependent on deep whole genome sequencing (WGS) which was, until recently, unaffordable for large cohorts. For these reasons SVs are not included in most genome-wide studies of functional variants, despite the fact that SVs are known causal agents in multiple clinical disorders2-16. However, recent advancements in high-throughput sequencing technologies that allow for widespread use of WGS, …

Evaluating Recognition Memory Models From An Individual Differences Perspective, Kyle Gramer Featherston

Arts & Sciences Graduate Student Theses and Dissertations

Although recognition memory models have been thoroughly compared in various recognition memory paradigms, the relative reliability and validity of their parameters have not been thoroughly assessed using an individual differences approach. In two studies, I evaluated three models: the dual-process signal detection (DPSD) model, the continuous dual process (CDP) model, and the unequal variance signal detection (UVSD) model. In Study 1, participants performed a remember-know procedure that also included confidence ratings. When model parameters were estimated twice in the same individual, both key parameters from the DPSD model were reliable within an individual, whereas the CDP version of familiarity was …

A Systematic Study Of Neutron Production In Two Versions Of The Mevion Proton-Therapy System, Nima Tatari

Arts & Sciences Graduate Student Theses and Dissertations

This thesis presents a study of neutron production in two types of proton-therapy systems: passive scattering Mevion S250, and active scanning Mevion S250i. The scattering system has been operating at Washington University in St. Louis since 2013. The scanning system was installed in the same building in 2020. The scanning system has the advantage of producing fewer neutrons due to a focused scanned beam and the absence of beam scatterers, collimators, and a static brass aperture. A systematic particle transport Monte Carlo analysis using the Geant4 toolkit has been performed to track the neutrons produced in various components of each …

Identification Of Multi-Tissue Protein Quantitative Trait Loci And Causal Inference Of Protein Effects In Neurological And Other Complex Human Diseases Via Mendelian Randomization, Chengran Yang

Arts & Sciences Graduate Student Theses and Dissertations

Alzheimer disease (AD) is the most common neurodegenerative disease, affecting 6.2 million people mostly aged 65 years or older in the United States as of early 2021. AD has been widely studied and characterized worldwide, but there is still no effective treatment or cure. Even the latest FDA-approved treatment, Aducanumab, cannot stop decline or improve cognition. To develop a truly effective treatments, researchers keep discovering genetic and molecular mechanisms underlying the disease. Protein biomarkers are keys to bridge the mechanisms to disease. Here, I first used a high-throughput proteomic dataset from three tissues (CSF, plasma, and brain) with array-based genotype …

Influence Of Aging And Cerebrovascular Disease On Neuroimaging Measures Of Alzheimer Disease, Lauren Nicole Koenig

Arts & Sciences Graduate Student Theses and Dissertations

The overall goal of this dissertation is to gain a better understanding of how Alzheimer disease relates to normal aging and cerebrovascular disease to impact neuroimaging measures in a clinically meaningful way. Both aging and cerebrovascular disease are known to influence measures of Alzheimer disease, making it difficult to separate what changes are attributable specifically to Alzheimer disease. We hypothesize that a better understanding of these relationships will allow future studies to appropriately take these factors into account. In Chapters 2 and 3 we attempt to separate out the influences of normal aging and Alzheimer disease on measures of atrophy. …

Role Of Interferon Receptors In Sting-Associated Autoinflammatory Disease In Mice, William Alexander Stinson

Arts & Sciences Graduate Student Theses and Dissertations

Over the past decade, the cGAS-STING pathway has emerged as a principal component of innate DNA sensing. Its activation of type I interferon (IFN) elicits host immune activation and in the absence of cGAS or STING, mice are rendered critically susceptible to infection by viruses and bacteria. Breakdowns in the molecules that regulate this pathway can promote unrestrained cGAS-STING activation and the development of various forms of autoimmune disease. For instance, gain-of-function mutations in STING cause autoinflammatory lung disease in mice and STING-associated vasculopathy with onset in infancy (SAVI) in humans. However, our understanding of the mechanisms that underlie STING-dependent …

Regulatory Effects Of The E. Coli Recbcd Nuclease Domain On Dna Unwinding Kinetics, Nicole Fazio

Arts & Sciences Graduate Student Theses and Dissertations

I have examined the effects of deleting the nuclease domain of the E. coli helicase RecBCD on the rates of ATP-independent DNA melting, single stranded (ss) DNA translocation, and double stranded (ds) DNA unwinding by RecBCD. The canonical role of the nuclease domain is DNA degradation, but the removal of this domain showed unexpected effects on other RecBCD activities including DNA binding, melting, and unwinding. This thesis presents a mechanistic study of DNA unwinding by RecBCD and a RecBCD variant with the nuclease domain deleted (RecBΔnucCD). I examined the rates of ssDNA translocation and dsDNA unwinding by RecBCD and RecBΔnucCD …

Genetic Risk Factors For Neurodevelopmental Disorders: Insights From Hipsc-Cerebral Organoids, Michelle L. Wegscheid

Arts & Sciences Graduate Student Theses and Dissertations

Neurofibromatosis type 1 (NF1) is a common neurodevelopmental disorder (NDD) characterized by remarkable phenotypic variability, where affected children manifest a spectrum of central nervous system (CNS) abnormalities, including brain tumors, impairments in attention, behavior, learning disabilities, and an increased incidence of autism spectrum disorder (ASD). A significant barrier to the implementation of precision medicine strategies for children with NF1 is a lack of prognostic risk factors to guide clinical management. However, emerging population-based genotype-phenotype association studies have suggested that the germline NF1 gene mutation may represent one clinically actionable risk factor for NF1-associated neurodevelopmental abnormalities. As a critical step in …

The Potential Of Mental Health Policy Implementation: Methods And Applications, Meagan Renee Pilar

Arts & Sciences Graduate Student Theses and Dissertations

Mental illness affects roughly 20% of the world in some capacity and can be debilitating. Though a large emphasis has historically been placed on individual-level interventions (e.g., therapy or medication), mental health policies present an opportunity to intervene on a large scale, with the potential to enhance impact and equity. This dissertation contributes to the mental health policy research literature in three main ways—(1) exploring factors affecting policymakers’ overall support of mental health policies; (2) assessing the use and quality of quantitative and qualitative methods within this field; and (3) exploring implementation determinants and outcomes, as well as strategies used …

Defining The Role Of Elastic Fibers In Tendon Mechanics, Jeremy D. Eekhoff

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tendons serve as a linking component of the musculoskeletal system by transferring forces between muscle and bone. As such, the structural proteins of the tendon extracellular matrix are of vital importance for the tissue to function properly and maintain its mechanical integrity. Collagen is the principal constituent of tendon and makes up its aligned hierarchical organization. Other structural proteins, such as elastin, are in comparison understudied and not well understood in relation to tendon function. Elastin, the main component of elastic fibers, has unique mechanical properties including high extensibility, fatigue resistance, and elasticity; these properties are important for elastin-rich tissues …

Human Plcg2 Haploinsufficiency Results In A Novel Immunodeficiency, Joshua Brandon Alinger

Arts & Sciences Graduate Student Theses and Dissertations

NK cells are critical for the recognition and lysis of herpesvirus-infected cells. Patients with NK cell immunodeficiency may suffer from unusually severe and/or recurrent herpesvirus infections; however, the genetic cause is frequently unknown. PLCG2 encodes a signaling protein in NK cell and B cell receptor signaling, in which dominant-negative or gain-of-function mutations may cause cold urticaria, antibody deficiency, or autoinflammation. However, loss-of-function mutations and PLCG2 haploinsufficiency have never been reported in human disease. We examined 2 families with autosomal dominant NK cell immunodeficiency with dual high-dimensional techniques, mass cytometry and whole-exome sequencing, to identify the cause of disease. We identified …

Examining Individual Differences In Forgetting From Long-Term Memory, Christopher Lee Zerr

Arts & Sciences Graduate Student Theses and Dissertations

Forgetting reflects the decreased likelihood of memory retrieval over time. With a few exceptions, although the mean likelihood of retrieval (or retention) across experimental conditions may differ markedly, rates of forgetting across those conditions do not differ. Similarly, although groups (e.g., young and old adults) may differ in the amount retained at a given point in time, the rates of forgetting tend not to differ across groups. In contrast, recent work suggests that individual differences in rates of forgetting may emerge when more sensitive statistical analyses are used on person-level performance. Some person-level variables purported to influence forgetting rate include …

Photoacoustic Imaging Of Colorectal Cancer And Ovarian Cancer, Xiandong Leng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoacoustic (PA) imaging is an emerging hybrid imaging technology that uses a short-pulsed laser to excite tissue. The resulting photoacoustic waves are used to image the optical absorption distribution of the tissue, which is directly related to micro-vessel networks and thus to tumor angiogenesis, a key process in tumor growth and metastasis. In this thesis, the acoustic-resolution photoacoustic microscopy (AR-PAM) was first investigated on its role in human colorectal tissue imaging, and the optical-resolution photoacoustic microscopy (OR-PAM) was investigated on its role in human ovarian tissue imaging.Colorectal cancer is the second leading cause of cancer death in the United States. …

Developments In Proteomics, Trans-Splicing Technology And Endogenous Transcript Manipulation, Justin Alexander Melendez

Arts & Sciences Graduate Student Theses and Dissertations

Technological innovation drives scientific discovery, unlocks new avenues of research, and allows us to ask questions in ways that were previously unavailable. With each technological advance, our ability to perturb and explore biological systems has grown in ways previously unimagined. The theme of my thesis is the development of new technologies in biology. To this end, I have worked on three technologies that contribute to the areas of protein sequencing, RNA barcoding for trans-splicing and single-cell applications, and a new method for transcriptional knockdown. In my first project, digital analysis of proteins by end sequencing (DAPES), we set out to …

Addressing Pragmatic Challenges In Utilizing Ai For Security Of Industrial Iot, Maede Zolanvari

McKelvey School of Engineering Graduate Student Theses & Dissertations

Industrial control systems (ICSs) are an essential part of every nation's critical infrastructure and have been utilized for a long time to supervise industrial machines and processes. Today’s ICSs are substantially different from the information technology (IT) devices a decade ago. The integration of internet of things (IoT) technology has made them more efficient and optimized, improved automation, and increased quality and compliance. Now, they are a sub (and arguably the most critical) part of IoT's domain, called industrial IoT (IIoT).

In the past, to secure ICSs from malicious outside attack, these systems were isolated from the outside world. However, …

Perspectives In The Mystery Of The Origin Of Arabic Grammar, Hasan Mohammed

Alustath Journal for Human and Social Sciences

This research reviews famous stories in the emerging of grammar so that we can detect the mystery that surrounds that emerging. It seemed that the need of the foreigners to adapt and seize opportunities in the new culture is what led them to try to learn and master the language. They had tremendous efforts in the establishment of Arabic grammar, forcing those who wanted to enter the field of this science to follow the rules on which Arabic syntax was built. Being skilled in Arabic linguistics had been in demand in order to gain opportunities to obtain state jobs and …

Quantitative Characterization Of Microbial Ecologies In Dysbiosis And Infection, Eric Keen

Arts & Sciences Graduate Student Theses and Dissertations

In 1973, Theodosius Dobzhansky famously wrote that nothing in biology makes sense except in the light of evolution. Today, nearly 50 years later, little in microbiology – or in biology, for that matter – makes sense except in the light of genomics. Microbial genomics populates the field with innumerable testable hypotheses for evaluation in vitro and in vivo, allows us to monitor microbial populations in real time and at a massive scale, and underpins our approach to entire domains of microbiology, including microbial evolution. In this Thesis, I present three studies from my graduate research united by their common theme …

Satirizing Empire: Comparing Ancient China And Rome, Di Wang

Arts & Sciences Graduate Student Theses and Dissertations

Comparative scholars of the ancient Mediterranean and East Asian worlds have recently taken a serious interest in the unprecedented and simultaneous emergence of two classical empires: Rome and China. The trend, invigorated by the contemporary geopolitical development of China’s rise as a world empire challenging the post-World War II Western hegemony, has yielded new insights into the many divergences and convergences of the world’s two most enduring political and cultural systems. However, preoccupied with describing the political, cultural institutions and grand narratives of empire, scholarship has largely ignored the detractors of empire, whose ingenious expressions are as enduring as these …

Probing New Physics Beyond The Standard Model Via New Neutrino Interactions, Garv Chauhan

Arts & Sciences Graduate Student Theses and Dissertations

The Standard Model (SM) of Particle Physics provides a self-consistent quantum field theoretic framework to explain three of the four known fundamental forces (electromagnetic, weak, strong) along with classifying all known elementary particles. Since its conception in the 1960s, the SM has been one of the most tested theories of physics and has withstood all experimental batterings. In spite of these successes, there are compelling indications, both experimental and theoretical, that require us to expand our understanding of the nature beyond the SM (BSM). Arguably the most glaring indication of BSM physics is the observation of neutrino oscillations, which implies …

On Arousal And The Internal Regulation Of Brain Function: Theory And Evidence Across Modalities And Species, Ryan Raut

Arts & Sciences Graduate Student Theses and Dissertations

The brain is an organ. It is subject to the same physiological regulatory processes that engage the rest of the body’s organs, sculpted over hundreds of millions of years to sustain life so effectively. The central message of this thesis is that the holistic functioning of the brain, rather than operating at some level above or independent from these systemic regulatory processes, is deeply related to them. In short, as our limited attention spans might suggest: brain function is internally regulated. I propose that this internal regulation is a primary function of intrinsic brain activity. Chapter 2 provides a theoretical …

Quantifying Components Of Protein Translation And Metabolite Heterogeneity In Isogenic Microbial Populations, Alexander Schmitz

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cell-to-cell variation in gene expression and metabolite levels have a significant impact on ensemble productivity of microbial bioproduction. New metabolic engineering tools and approaches are needed that consider cell cultures as an amalgam of uniquely behaving individuals to improve the slow commercialization of metabolically engineered systems. Stochastic cellular process including gene expression, metabolism, and growth lead to phenotypic variation between genetically identical cells. Understanding and the ability to control microbial phenotypic variation is key to improving microbial bioproduction metrics. During protein translation, codon usage strongly influences ensemble gene expression but the effect on the variation of gene expression was not …