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Modeling And Prioritizing Interventions Using Pollution Hotspots For Reducing Nutrients, Atrazine And E. Coli Concentrations In A Watershed, Olufemi Abimbola, Aaron Mittelstet, Tiffany L. Messer, Elaine Berry, Ann Van Griensven Jan 2021

Modeling And Prioritizing Interventions Using Pollution Hotspots For Reducing Nutrients, Atrazine And E. Coli Concentrations In A Watershed, Olufemi Abimbola, Aaron Mittelstet, Tiffany L. Messer, Elaine Berry, Ann Van Griensven

Biosystems and Agricultural Engineering Faculty Publications

Excess nutrients and herbicides remain two major causes of waterbody impairment globally. In an attempt to better understand pollutant sources in the Big Sandy Creek Watershed (BSCW) and the prospects for successful remediation, a program was initiated to assist agricultural producers with the implementation of best management practices (BMPs). The objectives were to (1) simulate BMPs within hotspots to determine reductions in pollutant loads and (2) to determine if water-quality standards are met at the watershed outlet. Regression-based load estimator (LOADEST) was used for determining sediment, nutrient and atrazine loads, while artificial neural networks (ANN) were used for determining E. …


A Model For Crafting Diversity, Inclusion, Respect, And Equity (Dire) Policy Statements Toward Catalyzing Organizational Change, Carolyn Gentle-Genitty, Breanca Merrit, Ann C. Kimble-Hill Jan 2021

A Model For Crafting Diversity, Inclusion, Respect, And Equity (Dire) Policy Statements Toward Catalyzing Organizational Change, Carolyn Gentle-Genitty, Breanca Merrit, Ann C. Kimble-Hill

Founder’s College - Scholarship and Professional Work

In light of the Black Lives Matter movement, the Science, Technology, Engineering, and Mathematics (STEM) community has had to reflect on how their organizations can address their disparities in identity representation. To that end, the ACS Committee on Minority Affairs (CMA) has been called upon to advise various levels of the chemistry enterprise in their interventions, such as structured and actionable policy statements. As a result, this work was created to provide a model for all organizations to write catalytic diversity, inclusion, respect, and equity (DIRE) policy statements. The model herein acknowledges active tensions and leverages theory, analysis, and practical …


Combined Coagulation-Microfiltration Process For Dye Wastewater Treatment, Alexander Ekenatanse Eguagie, Yung-Tse Hung, Howard Hao-Che Paul Jan 2021

Combined Coagulation-Microfiltration Process For Dye Wastewater Treatment, Alexander Ekenatanse Eguagie, Yung-Tse Hung, Howard Hao-Che Paul

Civil and Environmental Engineering Faculty Publications

The performance of combined coagulation-microfiltration process for the removal of dyes in a binary mixture of dye wastewater of varied concentrations and fruit drink wastewater at three different strengths; low (10ppm), medium (50ppm) and high (100ppm) was investigated. Synthetic dye wastewater was prepared in the laboratory while fruit drink wastewater was purchased from the grocery store. Color removal efficiency was also investigated for the three coagulants; Ferric Chloride, Aluminum Sulfate and Ferrous Sulfate. Transmittance and Absorbance values were used as indices to measure the efficacy of the combined coagulation- microfiltration process.

Transmittance and absorbance values of 99.8% and 0.001 respectively …


Algae-Based Beneficial Re-Use Of Carbon Emissions Using A Novel Photobioreactor: A Techno-Economic And Life Cycle Analysis, Michael H. Wilson, Aubrey Shea, John Groppo, Czarena Crofcheck, David Quiroz, Jason C. Quinn, Mark Crocker Jan 2021

Algae-Based Beneficial Re-Use Of Carbon Emissions Using A Novel Photobioreactor: A Techno-Economic And Life Cycle Analysis, Michael H. Wilson, Aubrey Shea, John Groppo, Czarena Crofcheck, David Quiroz, Jason C. Quinn, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

Despite the many advantages of microalgae, the feasibility of large-scale cultivation requires significant amounts of carbon dioxide (CO2) to enable high growth rates. A synergistic union typically proposed for the supply of CO2 is the coupling of algal cultivation with emissions from power plants. This study investigates the sustainability of a novel microalgae platform coupled with coal-based flue gas. The proposed system consists of a novel photobioreactor (PBR) for the production of biomass followed by a two-stage dewatering process. A systems model, which quantifies the CO2 and energy consumption of the proposed system, was developed, and the minimum biomass selling …


Altered Skeletal Muscle Excitation-Contraction Coupling In The R6/2 Transgenic Mouse Model For Huntington's Disease, Daniel R. Miranda Jan 2021

Altered Skeletal Muscle Excitation-Contraction Coupling In The R6/2 Transgenic Mouse Model For Huntington's Disease, Daniel R. Miranda

Browse all Theses and Dissertations

Huntington’s disease (HD) has classically been categorized as a neurodegenerative disorder. However, the expression of the disease-causing mutated huntingtin gene in skeletal muscle may contribute to the symptoms of HD, namely those that involve involuntary muscle contraction. In the R6/2 transgenic mouse model of HD, we previously observed ion channel defects that could contribute to involuntary muscle contraction. Here, in R6/2 muscle we investigated the consequence of these ion channel defects on action potentials (APs), the first step in excitation-contraction (EC) coupling. We found that the ion channel defects were associated with depolarizing the baseline membrane potential during AP trains. …


Biom 4110/6110: The Science Of Medicine (Syllabus), Bradford D. Pendley Jan 2021

Biom 4110/6110: The Science Of Medicine (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Integration of fundamental principles from physics, chemistry, biology and mathematics, and applications of these principles to solve problems in medicine.


Comparison Of Direct-Reading And Gravimetric Methods Of Particle Measurement In A Science Building, Silpakorn University, Aungsiri Tipayarom, Prayad Sangngam, Siraphop Pinitkarn Jan 2021

Comparison Of Direct-Reading And Gravimetric Methods Of Particle Measurement In A Science Building, Silpakorn University, Aungsiri Tipayarom, Prayad Sangngam, Siraphop Pinitkarn

Applied Environmental Research

This study aimed to develop relationships between particulate matter (PM) concentrations obtained from a direct-reading instrument to those from a gravimetric method. TSI DustTrak II Aerosol Monitors (Model 8530), a direct-reading instrument for PM10 and PM2.5 measurement, together with personal air pumps connected to a Sensidyne cyclone and a SKC Personal Environmental Monitor (PEM) for gravimetric PM10 and PM2.5 measurements respectively were deployed in the Faculty of Science building, Silpakorn University, Nakhon Pathom, Thailand. Comparison of the results from each instrument indicated that PM10 and PM2.5 concentrations obtained from the TSI DustTrak were higher. The linear relationship from ordinary least …


Low Illumination Video Enhancement Based On Machine Learning, Mohsine Taarji Jan 2021

Low Illumination Video Enhancement Based On Machine Learning, Mohsine Taarji

All ETDs from UAB

ow-brightness and image noise are common problems in computer vision that prohibit useful information extraction from video sequences. This problem is caused by insufficient illumination, low-quality cameras, external disturbances, and other factors. Dark image enhancement requires improvement of intensity and saturation; the missing data could be replaced by matching image regions using image feature detector-descriptor pairs. We proposed new metrics for evaluating image descriptors with regard to their uniqueness. Also, we developed new image enhancement techniques based on HSV color space. The idea behind the first contribution of our dissertation is to find the best descriptor that match pixels from …


Identification And Mitigation Of Harmful Algal Blooms In Mantua Reservoir, Jeffrey Kennedy, Timothy Place, Tyler Wallace, Steven White, Carolina Williams Jan 2021

Identification And Mitigation Of Harmful Algal Blooms In Mantua Reservoir, Jeffrey Kennedy, Timothy Place, Tyler Wallace, Steven White, Carolina Williams

Civil and Environmental Engineering

Cyanobacteria, also known as blue-green algae, are capable of emitting cyanotoxins which are harmful to humans and animals. Harmful Algal Blooms (HABs) occur when cyanobacteria multiply to great densities. Mantua Reservoir in Box Elder County, UT, experiences seasonal HABs, which has resulted in seasonal reservoir closures.

The EnVision team investigated the cause of HABs at Mantua Reservoir by collecting samples from the reservoir’s known point sources and frequently visited recreation areas. The samples were analyzed to determine total phosphorus, nitrate, and cyanotoxin concentrations. The team concluded that excessive phosphorus loading in the reservoir is most culpable for the annual HABs …


Comparison And Evaluation Of Two Sensors For Dynamic Measuring Of Foam Level In Single-Use Bioreactors, Alyssa Cisneros, Harley Cragun, Crystal Rain Fowler, Mikelle Kearnes, Annika Saunders Jan 2021

Comparison And Evaluation Of Two Sensors For Dynamic Measuring Of Foam Level In Single-Use Bioreactors, Alyssa Cisneros, Harley Cragun, Crystal Rain Fowler, Mikelle Kearnes, Annika Saunders

Biological Engineering

Single Use Bioreactors (SUBs) are used for microbial cell culture for many industries, such as cell cultures of pilot-studies, food, and cosmetics1. Foaming in bioreactors is common and is responsible for the fouling of equipment.

• The goal of the project is to test and develop two possible dynamic foam level sensors for the 30 and 300L SUBs

Objectives:

1. Manufacture a scalable foam sensor housing unit

2. Create a program that allows for ease of sensor use when implemented into controller

3. Safe for biological cultures

4. Test the system to ensure accurate and simple sensor output …


Computational Model Of Angiogenesis In Wet Age-Related Macular Degeneration, Kelsey Bradshaw, Michael Cotner, Jacilyn Fielding, Andrew Kjar, Teren Teeples Jan 2021

Computational Model Of Angiogenesis In Wet Age-Related Macular Degeneration, Kelsey Bradshaw, Michael Cotner, Jacilyn Fielding, Andrew Kjar, Teren Teeples

Biological Engineering

Age-Related Macular Degeneration (AMD)

• Leads to vision loss and blindness

• Localized to subretinal layers (Figure 1.)


Electrocoagulation For Removal Of Nitrates From Fgd Wastewater, Jacob Watkins, Julissa Van Renselaar, Amanda Moravek, Tallon Beckstrom, Shaylynn Cannon Jan 2021

Electrocoagulation For Removal Of Nitrates From Fgd Wastewater, Jacob Watkins, Julissa Van Renselaar, Amanda Moravek, Tallon Beckstrom, Shaylynn Cannon

Biological Engineering

Flue gas desulfurization (FGD) processes are often utilized to mitigate pollution from coal-based plants by removing sulfur oxides¹. However, FGD wastewater streams still contain pollutants such as nitrates that must undergo further treatment². The Environmental Protection Agency (EPA) has Effluent Limitation Guidelines (ELG) that dictate the allowable concentrations of the contaminants in FGD wastewater effluent. While common treatment approaches can meet these requirements, efficiency drops with chemical concentration flux, which is a common situation with FGD wastewater. A novel method that could both meet ELG requirements and handle chemical concentration flux is electrocoagulation (EC). EC is able to target a …


Long Short-Term Memory With Spin-Based Binary And Non-Binary Neurons, Meghana Reddy Vangala Jan 2021

Long Short-Term Memory With Spin-Based Binary And Non-Binary Neurons, Meghana Reddy Vangala

Electronic Theses and Dissertations, 2020-2023

Research in the field of neural networks has shown advancement in the device technology and machine learning application platforms of use. Some of the major applications of neural network prominent in recent scenarios include image recognition, machine translation, text classification and object categorization. With these advancements, there is a need for more energy-efficient and low area overhead circuits in the hardware implementations. Previous works have concentrated primarily on CMOS technology-based implementations which can face challenges of high energy consumption, memory wall, and volatility complications for standby modes. We herein developed a low-power and area-efficient hardware implementation for Long Short-Term Memory …


An Improvement Of Data Analytics Detection Rules In The Internal Audit Of The Procurement And Inventory Processes, Penpak Rangsipunyaporn Jan 2021

An Improvement Of Data Analytics Detection Rules In The Internal Audit Of The Procurement And Inventory Processes, Penpak Rangsipunyaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Data analytics is a powerful tool to deliver value-added internal audit results as it reduces execution time and increases efficiency, effectiveness, and assurance level compared with the audit sampling approach. Because detection rules are criteria applied in the data analytics method to discover anomalies in the business transactions. Therefore, this project aims to improve the anomaly detection rules in the procure-to-pay and inbound inventory processes for an audit firm based in Thailand to provide internal audit services for clients in the manufacturing business. The sub-processes cover (1) process governance, (2) vendor selection, evaluation, and master data maintenance, (3) ordering, (4) …


Material Handling System For An Advanced Flexible Manufacturing Environment, Con Cronin Jan 2021

Material Handling System For An Advanced Flexible Manufacturing Environment, Con Cronin

Theses

A Flexible Manufacturing System (FMS) is a method of production that is designed to easily adapt to changes in the type and quantity of the product being manufactured. Machines and computerised systems can be configured to manufacture a variety of parts and to handle the changing levels of production that is required. The aim of this project was to investigate the current manufacturing processes of Kostal Ireland GmbH with the aim of developing a bespoke prototype material handling system to achieve flexible manufacturing. Kostal Ireland GmbH currently do not have the ability to change their manufacturing operations easily when a …


Develop Biochar-Based Controlled Release Nitrogen Fertilizers, Zhisheng Cen Jan 2021

Develop Biochar-Based Controlled Release Nitrogen Fertilizers, Zhisheng Cen

Electronic Theses and Dissertations

The current efficiency of conventional nitrogenous fertilizers (e.g. urea, ammonium sulfate, etc.) in agricultural practices is low, fluctuating from 30 to 40%. Approximately 60% of nitrogenous fertilizers were wasted due to vaporization into the air, runoff or leaching into water systems. The lost nitrogen (N) resulted in not only high production cost but also serious environmental problems, such as greenhouse gas (N2O) emission in the atmosphere, algal blooms, oxygen depletion, fish kills, and loss of biodiversity in surface water due to eutrophication or pollution. To address these problems, this study aimed to utilize low-cost biochar-based materials to develop a controllable, …


Nitrate And Phosphate Removal From Denitrification Bioreactors Using Woodchips, Steel Chips And Agricultural Residue Media, Abdoul Aziz Kouanda Jan 2021

Nitrate And Phosphate Removal From Denitrification Bioreactors Using Woodchips, Steel Chips And Agricultural Residue Media, Abdoul Aziz Kouanda

Electronic Theses and Dissertations

Nitrate and phosphate present in agricultural subsurface drainage water can impact surface water quality thus impacting the environment and human health by causing eutrophication and Methemoglobinemia in young infant. Biological denitrification and phosphate adsorption filters are treatments options that can help reduce nitrate and phosphate concentration from agricultural subsurface drainage before it can be discharged in surface water. The first objective of this dissertation was to determine the Michaelis-Menten kinetics model parameters for nitrate removal in bioreactors using the fresh, aged, and composted woodchips. The composted woodchips achieved a denitrification rate 2.4 times higher than the fresh woodchips which was …


Material Analysis Of 3d Welded 5356 Aluminum Alloy, Ryan Fouts Jan 2021

Material Analysis Of 3d Welded 5356 Aluminum Alloy, Ryan Fouts

Electronic Theses and Dissertations

Metal 3D printing has been reserved for aerospace and high-end automotive industries because of its cost. A gas metal arc welder (GMAW) on a rugged 3D printer frame could make metal additive manufacturing an option for more industries and consumers. 3D welded aluminum has not been examined in depth as an option for additive manufacturing (AM). Extensive tests are necessary to determine the correct settings to use a metal inert gas (MIG) welder for AM. Porosity within the welded material must be evaluated to better understand the additive process. The material properties of 3D welded aluminum will be tested and …


Rational Design Of Advanced Functional Materials For Electrochemical Devices, Shun Lu Jan 2021

Rational Design Of Advanced Functional Materials For Electrochemical Devices, Shun Lu

Electronic Theses and Dissertations

In recent years, there has been a fast-growing trend in developing urea (CO(NH2)2) as a substitute H2 carrier in energy conversion due to its high energy density, nontoxicity, stability, and nonflammability. Urea, a byproduct in the metabolism of proteins and a frequent contaminant in wastewater, is an abundant compound that has demonstrated favorable characteristics as a hydrogen-rich fuel source with 6.7 wt % gravimetric hydrogen content. Also, there is 2-2.5 wt % urea from mammal urine; therefore, 0.5 million ton of additional fuels will be produced per year just from human urine (240 million ton each year). Electrochemical oxidation has …


Biomechanical Investigation Of Plant Vascular Tissue For Bio-Inspired Design And Flexible Composites, Mukesh Roy Jan 2021

Biomechanical Investigation Of Plant Vascular Tissue For Bio-Inspired Design And Flexible Composites, Mukesh Roy

Electronic Theses and Dissertations

Since the inception of evolution, nature has continuously optimized all the natural materials. These optimizations are so efficient that scientists and engineers have started taking inspiration from nature. Such inspiration-based solutions provide sustainable development of new materials with enhanced structural properties and functionalities (such as stiffness, stability, toughness, self-healing etc.). This variety of properties and functionalities is mainly due to the hierarchical organization of such components. Abstraction of the hidden cues of the hierarchical organization, principles and underlying structure-function relations are some of the critical approaches of bioinspired materials design. Inspiration from animals and plants has helped develop the design …


A Hydrologic Climate Study For An Arid Region, Ali Alsubeai Jan 2021

A Hydrologic Climate Study For An Arid Region, Ali Alsubeai

Electronic Theses and Dissertations

Water is the most precious natural resource in arid regions due to the limitation of water resources, expanding population, and increasing volumes of industrial and domestic waste. The purpose of this research was to evaluate methods to estimate water quantity in an arid region. The research consisted of three separate studies. In the first study, hydrologic models used to estimate water quantity were evaluated for suitability of use in arid regions. Most hydrologic models that have been used in arid regions were originally developed for humid regions. Rainfall events in arid regions can be characterized as short-term, high intense rainstorms …


Picosecond Pulsed Electric Fields And Promise In Neurodegeneration Research, Martina Zamponi, Ross Petrella, Peter A. Mollica Jan 2021

Picosecond Pulsed Electric Fields And Promise In Neurodegeneration Research, Martina Zamponi, Ross Petrella, Peter A. Mollica

School of Medical Diagnostics & Translational Sciences Publications

The delivery of pulsed electric fields to biological cells for regenerative research and therapeutic applications is a field that has been widely explored. Picosecond pulsed electric fields have been shown to induce intracellular effects and directly target cell membrane proteins as well as being able to induce cell permeabilization and death by apoptosis. Additionally, ultrashort pulses can be focused and delivered in a noncontact manner for possible targeting of deep and inaccessible tissues. The unique characteristics of picosecond pulses make them a possible approach for treatment of Huntington's and Alzheimer's diseases, both characterized by progressive neuronal degeneration and death, and …


The Mechanics And Multiphysics Of Biomimetic Discrete Exoskeleton Substrates, Hessein Ali Jan 2021

The Mechanics And Multiphysics Of Biomimetic Discrete Exoskeleton Substrates, Hessein Ali

Electronic Theses and Dissertations, 2020-2023

Biological structures have inspired synthetic materials with unparalleled performances such as ultra-lightweight design, tunable elasticity, camouflaging, and antifouling. Among biological structures, exoskeletal scales that cover the exterior surfaces of fishes, fur, and many reptiles. These exoskeletal scales had appeared in the earliest stages of evolution of complex multicellular life and continued their existence in spite of millions of years of evolutionary pressures. This makes them an attractive candidate for biomimicry to produce high performance multifunctional materials with applications to soft robotics, wearables, energy efficient smart skins, antifouling surfaces and on-demand tunable materials. Canonically speaking, biomimetic samples can be fabricated by …


The Effects Of Critical Micelle Concentration And Environmental Factors On Oil Separation In Simulated Bilgewater Emulsions, Kelsey Rodriguez Doran Jan 2021

The Effects Of Critical Micelle Concentration And Environmental Factors On Oil Separation In Simulated Bilgewater Emulsions, Kelsey Rodriguez Doran

Electronic Theses and Dissertations, 2020-2023

Improved bilgewater treatment is necessary because of technological challenges often faced when meeting existing ocean discharge criteria regulations. Since bilgewater is a waste mixture including hydraulic oils, cleaning agents, and seawater, the success of its management is largely attributed to understanding oil-in-water emulsion characterizations. However, the study of bilgewater emulsions is complex due to the multivariate nature of real-shipboard samples. The objective of this study is to develop the relationship between parameters commonly found in bilgewater and emulsion stability. This work is a continuation of a 3-year research project supported by the Strategic Environmental Research and Development Program (SERDP). Previous …


Multi-Functional Fluorescence Microscopy Via Psf Engineering For High-Throughput Super-Resolution Imaging, Jinhan Ren Jan 2021

Multi-Functional Fluorescence Microscopy Via Psf Engineering For High-Throughput Super-Resolution Imaging, Jinhan Ren

Electronic Theses and Dissertations, 2020-2023

Image-based single cell analysis is essential to study gene expression levels and subcellular functions with preserving the native spatial locations of biomolecules. However, its low throughput has prevented its wide use to fundamental biology and biomedical applications which require large cellular populations in a rapid and efficient fashion. Here, we report a 2.5D microcopy (2.5DM) that significantly improves the image acquisition rate while maintaining high-resolution and single molecule sensitivity. Unlike serial z-scanning in conventional approaches, volumetric information is simultaneously projected onto a 2D image plane in a single shot by engineering the fluorescence light using a novel phase pattern. The …


Nanoplasmonic Colorimetric Sensors For Detection Of Ammonia From Water And Urine, Zuriel Caribe Jan 2021

Nanoplasmonic Colorimetric Sensors For Detection Of Ammonia From Water And Urine, Zuriel Caribe

Electronic Theses and Dissertations, 2020-2023

Motivated by the need for inexpensive, simple, and portable devices for aqueous chemical analysis, we developed a nanoplasmonic colorimetric sensor capable of direct detection of wide range of chemicals. This novel sensor exploits the plasmonic resonance of metallic nanostructures with natural light to transduce changes in the chemical environment to changes in color, thus offering a simple route for real-time, in-situ, and low-cost analysis of aqueous chemical species. Due to its environmental and medical relevance, we chose aqueous ammonia to analyze and determine the efficacy and limit of detection of this sensing platform. For the metallic nanostructures we selected aluminium …


Investigating The Removal Of Total Trihalomethanes In Tray And Spray Aeration Processes At Two Central Florida Groundwater Treatment Facilities, Zachary Protas Jan 2021

Investigating The Removal Of Total Trihalomethanes In Tray And Spray Aeration Processes At Two Central Florida Groundwater Treatment Facilities, Zachary Protas

Electronic Theses and Dissertations, 2020-2023

An investigation has been completed that assessed the efficiency of tray and spray aeration processes on the removal of regulated total trihalomethanes (TTHMs) at two publicly owned potable groundwater treatment facilities located in Polk County, Florida: the Providence and Van Fleet water treatment plants (WTPs). Finished water from each of these facilities was fed to a pilot-plant that could be operated as either a tray, spray, or combined configuration. A series of four pilot aerator configurations were tested at each WTP. Test 1 evaluated the tray aerator operated in a recirculated multiple-pass mode. It was shown that three passes across …


Development Of Quantitative Intensity-Based Single-Molecule Assays, Benjamin Croop Jan 2021

Development Of Quantitative Intensity-Based Single-Molecule Assays, Benjamin Croop

Electronic Theses and Dissertations, 2020-2023

Fluorescence microscopy has emerged as a popular and powerful tool within biology research, owing to its exceptional signal contrast, specificity, and the versatility of the various microscope designs. Fluorescence microscopy has been used to study samples across orders of magnitude in physical scale ranging from tissues to cells, down to single-molecules, and as such has led to breakthroughs and new knowledge in a wide variety of research areas. In particular, single-molecule techniques are somewhat unique in their ability to study biomolecules in their native state, which enables the visualization of short-lived interactions and rare events which can be highly relevant …


Actin Cytoskeleton Dynamics And Organization Modulated By Macromolecular Crowding, Cation Interaction, And Nanomaterials, Jinho Park Jan 2021

Actin Cytoskeleton Dynamics And Organization Modulated By Macromolecular Crowding, Cation Interaction, And Nanomaterials, Jinho Park

Electronic Theses and Dissertations, 2020-2023

The assembly of actin, the essential cytoskeleton protein, into filaments and bundles/networks is important in various cellular processes including cell movement and morphogenesis. Actin bundle formation occurs in crowded intracellular environments with the aid of actin-crosslinking proteins. The role of actin-crosslinking proteins such as fascin and a-actinin in bundle formation has been investigated, however, how intracellular environments affect actin crosslinker-induced bundle formation is unknown. In the first two parts of this dissertation, we explore the effects of macromolecular crowding and cation interactions on the organization and mechanics of actin crosslinker-induced bundles. To determine how changing environmental conditions modulate actin bundling, …


Modulation Of Actin Filament Severing And Mechanics By Gelsolin In Varying Ph Conditions, Claire Toland Jan 2021

Modulation Of Actin Filament Severing And Mechanics By Gelsolin In Varying Ph Conditions, Claire Toland

Electronic Theses and Dissertations, 2020-2023

Actin is an essential cytoskeletal protein that plays a critical role in cell mechanics, structure and organization with the help of actin binding proteins (ABPs). Gelsolin is a calcium-dependent ABP that severs actin filaments and caps them at their barbed end, regulating cell motility and signaling through dynamic actin cytoskeleton remodeling. A recent study has indicated that low pH stabilizes the active conformations of gelsolin. Additionally, the binding of gelsolin to the barbed end of an actin filament induces a conformational change that propagates along the actin filament. However, it has not been well understood how the complex intracellular environments …