Digital Commons Network^™

Multiscale Modeling Of Cardiac Growth And Baroreflex Control, Hossein Sharifi

Theses and Dissertations--Mechanical and Aerospace Engineering

The heart functions within a complex system that adapts its function to any alteration in loading via several mechanisms. For example, the baroreflex is a short-term feedback loop that modulates the heart's function on a beat-to-beat basis to control arterial pressure. On the other hand, cardiac growth is a long-term adaptive response that occurs over weeks or months in response to changes in left ventricular loading. Understanding the mechanisms that drive ventricular growth and biological remodeling is critical to improving patient care. Multiscale models of the cardiovascular system have emerged as effective tools for investigating G&R, offering the ability to …

Nanopesticide Influence On Nitrogen Cycling In Soils, Jacob Richardson

Theses and Dissertations--Biosystems and Agricultural Engineering

Nanotechnology has several applications in the agricultural industry, as the small size of nanoparticles and high reactivity enables targeted delivery of pesticides and fertilizers to the intended crop. Copper-based nanopesticides such as Kocide, are proposed as a more efficient method for targeted pest control. Despite the potential benefits of nanopesticides, little is known regarding the transport and implications of nanopesticides under long-term inundation conditions often found in downstream wetlands. Specifically, the impact of nanopesticides on microbial nitrogen processes in wetland environments remains unknown. Therefore, this thesis explores the impact of nanopesticides, specifically Kocide, on microbial nitrogen cycles in agricultural and …

Impact Of Physicochemical Characteristics And Distillation Parameters On The Biomethane Potential Of Bourbon Stillage, Danielle Hockensmith

Theses and Dissertations--Biosystems and Agricultural Engineering

Bourbon, or whiskey, production in Kentucky has been estimated to double within the next five years and an increase in the main by-product from bourbon distillation, stillage. Stillage is composed mostly of water along with the fermented grains after distillation. Stillage is expensive to dispose of and difficult to store due to the high biodegradability, posing a risk to the environment given the low pH and high chemical oxygen demand (COD). Anaerobic digestion has been identified as a potential solution for stillage valorization, but little research has been performed. Stillage from different mash bills has varying physicochemical properties, total solids …

Fate And Transport Of Emerging Contaminants Entering, Leaving, And Flowing Past Wastewater Treatment Plants In Central Kentucky, Kyra Sigler

Theses and Dissertations--Biosystems and Agricultural Engineering

Per- and polyfluoroalkyl substances (PFAS) and neonicotinoid insecticides are two classes of emerging contaminants that have been recently detected in many environmental compartments. Both have been associated with negative impacts on humans and the environment. Wastewater treatment plants (WWTPs) have been identified as likely hotspots for introduction of these contaminants into the environment. Thus, the aim of this study was to investigate the occurrence of PFAS and neonicotinoids in two WWTPs in Central Kentucky. Polar organic chemical integrative samplers (POCIS) were deployed in WWTP influent and effluent and placed upstream and downstream of the effluent mixing zone (EMZ) for two …

Microalgae Immobilization With Filamentous Fungi: Process Development For Sustainable Food Systems, Suvro Talukdar

Theses and Dissertations--Biosystems and Agricultural Engineering

Demand for sustainable food sources has increased because of the rapid growth of the world's population.  In this study, microalgae cells of Haematococcus pluvialis were immobilized using the edible fungal strain Aspergillus awamori for potential food applications. The study investigated the impact of fungal loading, pellet geometry, and initial microalgae cell concentration on the immobilization performance and product characteristics. It was found that higher fungal loading and larger fungal pellets contributed to increased immobilization performance while increased initial microalgae concentration inhibited the process. Larger fungal pellets had decreased biomass density, which led to decreased surface concentration of immobilized microalgae but …

Fate And Transport Of Nanopesticides In Agricultural Field Plots In Central Kentucky, William D. Rud

Theses and Dissertations--Biosystems and Agricultural Engineering

Due to a growing world population, pesticide applications are necessary part to increasing agricultural production on the same arable land, but this has created environmental contamination, human toxicity, and endangerment to non-target species (i.e, honeybees, monarch butterflies) from bulk pesticide application. Nanoengineered particles or ENP are a potential solution with increased efficiency, longer duration, and enhanced stability of pesticides due to their unique formulations at smaller sizes. However, the potential long-term impact to agroecosystems is still unknown. Therefore, the goal of this project was to evaluate the fate, transport, impact, and persistence of two commercially available nanopesticides (copper hydroxide and …

Applying Hermetic Storage And Multiple Abiotic-Stressed Germinations To Actuate Desirable Effects In Wheat Phytochemistry, Food, And Biological Functionalities, Bababode Kehinde

Theses and Dissertations--Biosystems and Agricultural Engineering

Wheat is one of the most widely consumed staple foods in the world, supplying both nutritional and caloric requirements for billions of people. The rising global population and increased food demand behooves all stakeholders across the wheat supply chain to significantly increase their output and efficiency. Beyond the target for increased farm yields, dietary, nutritional, and health requirements along with their continuous supply must be satisfied with improved storage and processing schemes. Post-harvest changes in wheat can result in a significant reduction in its quality. Such losses could be qualitative and/or quantitative, impacting its physical, physiological, organoleptic, and nutritional attributes. …

Defect State Study And Surface Patching In Zno Nanoparticles Via Nano- Bio Interaction With Dna Bases, Ummay Honey

Graduate Theses/Dissertations

First, this thesis investigates the structural and optical properties of hydrothermally synthesized ZnO nanostructures, focusing on the effects of varying annealing temperatures on their properties. Structural characterizations using micro-Raman spectroscopy, X-ray diffraction (XRD), and morphological study called scanning electronic microscopy (SEM) show changes in crystallinity and intensity with different annealing temperatures. Optoelectronic characterization using photoluminescence spectroscopy reveals changes in luminescence properties near the ultraviolet region with temperature variation and in the visible emission area region. These results provide insights into how annealing temperature can affect the surface layer of ZnO nanostructures and can be applied to improve performance in electronic …

Synthesis, Characterization, And Application Of Chitosan Nanoparticles For In Vitro Studies On Hela Cancer Cells, Rejeena Jha

Graduate Theses/Dissertations

Chitosan is a fibrous substance that is derived from chitin, a natural substance in the shells of crustaceans. It possesses all the necessary qualities for being used as carrier for the transport of drugs and genes into tumor, such as biodegradability, biocompatibility, hydrophilicity, and non-toxicity and cationic in nature. Ionic gelation method was used to synthesize chitosan (CS) nanoparticles (NPs). Ionic gelation is a very benign process chemically that requires mixing a CS aqueous solution with a sodium tripolyphosphate (TPP) aqueous solution at room temperature. In addition, a surfactant polyethylene oxide (PEO) alone and a diblock copolymer of PEO and …

Aortic Remodeling Kinetics In Response To Coarctation-Induced Mechanical Perturbations, Arash Ghorbannia, Mehdi Maadooliat, Ronald K. Woods, Said H. Audi, Brandon J. Tefft, Claudio Chiastra, El Sayed H. Ibrahim, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

Background: Coarctation of the aorta (CoA; constriction of the proximal descending thoracic aorta) is among the most common congenital cardiovascular defects. Coarctation-induced mechanical perturbations trigger a cycle of mechano-transduction events leading to irreversible precursors of hypertension including arterial thickening, stiffening, and vasoactive dysfunction in proximal conduit arteries. This study sought to identify kinetics of the stress-mediated compensatory response leading to these alterations using a preclinical rabbit model of CoA.

Methods: A prior growth and remodeling (G&R) framework was reformulated and fit to empirical measurements from CoA rabbits classified into one control and nine CoA groups of various severities …

New Species Of Birds Reported In Arkansas Since 2009, R. Tumlison, R. Kannan

Journal of the Arkansas Academy of Science

We update our state of knowledge regarding the 20 new species of birds (and 1 new species name based on a change in taxonomy) discovered in Arkansas since the last update in 2009. These are based on records of the Arkansas Audubon Society and those posted on eBird. New species include 3 from Order Anseriformes, 1 Pelicaniformes, 1 Falconiformes, 1 Gruiformes, 4 Charadriiformes, 1 Apodiformes, and 10 Passeriformes. Historic distributions of the new species include Atlantic, Pacific, and Gulf Coasts, as well as interior origins. The current count of extant species of birds observed in Arkansas now stands at 425.

Rare Birds In Arkansas: Historical Observations And New Records, R. Tumlison, R. Kannan

Journal of the Arkansas Academy of Science

Diligent members of birding communities are quick to report rare sightings of birds, which often lead to multiple observations and photographic documentation. Verified reports and images of birds in Arkansas are curated by the Arkansas Audubon Society (AAS), which has led to an appreciation of which species are common versus rare. We gathered historic (literature) and more recent unpublished records of rare birds (those with fewer than 10 reports, per AAS) to document the historic and current state of knowledge of those species. Currently, there are a total of 425 species of birds reported in Arkansas, of which 54 are …

Citizen Science: Role Of Inaturalist In Biodiversity Documentation And Education In Arkansas, K. Baker, L. Barnes, S. Rana, J. Jackson, R. Kannan

Journal of the Arkansas Academy of Science

iNaturalist is a global online digital platform for documenting and fostering interest in biodiversity, with Research Grade (RG) entries being vetted and scientifically valid observations. Here we present a review of the role of approximately 16,000 Arkansans using the iNaturalist tool for recording 445,000 verifiable observations comprising 10,800 species, with 40 percent RG, and one third of observations still pending confirmation. Overall, plants lead in RG observations followed by invertebrates and birds. Within these groups, reptiles lead in proportion of RG observations, followed by birds and amphibians. Less charismatic or infrequently encountered organisms are less represented. Arkansas ranks about average …

Energy Content Of Grasshoppers (Orthoptera: Acrididae) In The Diet Of Scaled Quail (Callipepla Squamata) In Southeastern New Mexico, J.L. Hunt, M.E. Grilliot, T.L. Best, C.M. Wilkerson, A.F. Huitt

Journal of the Arkansas Academy of Science

Grasshoppers (Orthoptera: Acrididae) are common insects that are important food items for many kinds of wildlife, including many species of upland game birds such as scaled quail (Callipepla squamata). We analyzed the energy content of grasshoppers obtained from the crops of scaled quail collected from plainsmesa sand-scrub in Lea and Eddy counties, New Mexico. Grasshoppers were removed from crops and dried for 48 hours at 60°C to remove moisture and standardize masses. Grasshoppers were then pulverized and analyzed for gross caloric value (i.e., energy content) in an oxygen bomb calorimeter. Energy content of grasshoppers from New Mexico averaged 19.2 J/kg …

Analysis Of The Physical Discomfort Of Earplugs Experienced By A Group Of Workers In Canadian Companies And Identification Of The Influencing Variables, Bastien Poissenot-Arrigoni, Alessia Negrini, Djamal Berbiche, Franck Sgard, Olivier Doutres

Études primaires

Earplugs are widely used to prevent noise induced hearing loss. However, the discomforts they induce negatively impacts their effectiveness by influencing their consistent and correct use. The physical earplugs discomfort is related to the user perception resulting from biomechanical and thermal interactions between the earplug and the earcanal. Its main attributes are “physical annoyance”, “pain”, “pressure” and “irritation". The (dis)comfort results from the complex interactions between the wearer, his/her earplug, and his/her work environment, which form the concept of triad. This study aims at improving our understanding of the physical discomfort of earplugs by identifying the triad characteristics that have …

Investigation Of Mechanical Regulation On Stat3 Activity And Mmp Production, Jaxson R. Libby

Honors Theses and Capstones

Transcription factor, STAT3, is inappropriately expressed in cancer cells, and has contrasting activation in 2D versus 3D microenvironments. 2D plates are often used for drug screening and do not always recapitulate in vivo responses. To combat inaccurate 2D drug studies, a 3D hydrogel was created to support the growth of cancer cells into a tumor-like environment. The hydrogel consists of a biocompatible dextran homopolysaccharide, cell adhesion RGD sequences, and crosslinker MMP labile peptides. A pH dependent reaction couples the RGD sequences to dextran then the polymers are crosslinked into a gel. Crosslinking is accomplished using terminal cysteine peptide sequences, allowing …

Using Paired-Agent Imaging To Track Changes In Head And Neck Cancers After Undergoing Photodynamic Therapy Treatment, Reeham M. Choudhury

Dartmouth College Master’s Theses

Head and neck cancers affect thousands of people across the world, and photodynamic therapy (PDT) has been shown to have great potential to treat said cancers in a noninvasive manner. However, imaging head and neck cancers has been difficult, and molecular changes caused by PDT are not well-understood. Therefore, we propose the use of paired-agent imaging (PAI) to track changes in these cancers after after PDT treatment. For these studies, we primarily used benzoporphyrin derivative monoacid (BPD) for our photosensitizer, which is activated by a 690 nm laser. We first looked at changes in EGFR expression in vitro, and …

Livestock Wastewater And Air Quality Management Using Microalgae, Capacitive Deionization, And Biofilters, Augustina Kwesie Osabutey

Electronic Theses and Dissertations

Wastewaters play a significant role in the negative impact of phosphorus on the environment, such as eutrophication. However, phosphorus is a limiting nutrient essential for life which has gained global attention on productive technologies for phosphorus recovery. Several technologies have been developed for phosphorus removal and recovery from wastewater to help alleviate phosphorus loss to the environment. Capacitive deionization technology, which was earlier developed for water desalination and ion removal, is actively being explored for its ability to remove phosphorus from wastewater. This review describes capacitive deionization technology (CDI) and its various types. Significant attention is given to the use …

Assessing The Economic Feasibility Of Capturing And Utilizing Carbon Dioxide From Ethanol Production In South Dakota, Makiah Stukel

Electronic Theses and Dissertations

Since the Industrial Revolution, anthropogenic greenhouse gas (GHG) emissions have spiked dramatically, prompting discussions on climate change. Mitigating climate change requires significant reductions in global carbon dioxide (CO2) emissions as CO2 is the most abundant anthropogenic GHG. A process that assists in offsetting the exponential growth in CO2 emissions is carbon capture and storage (CCS). Integrating carbon capture technology into the ethanol industry can provide an economically feasible way to achieve net reductions in CO2 emissions. The proposed work investigates the economic viability of applying CCS technologies to the 16 ethanol facilities in South Dakota (SD) and quantifies the potential …

Effectiveness Of Atmospheric Cold Plasma In Inactivating Microorganisms, Nadee Shanika Kaluwahandi

Electronic Theses and Dissertations

In the food processing industry, Cold Plasma (CP) is an emerging green process with a number of potential applications. Cold plasma has mostly been used to reduce microbial counts in foodstuffs and biological materials as well as in different levels of packaging, particularly in cases where there is thermal sensitivity. Recent studies have demonstrated that CP technology is being developed for use in the food and agriculture industries. The primary focus is on the interactions between reactive species and food-borne microbes to inactivate them. The literature review discusses both proven and potential applications for cold plasma in food processing, as …

High Throughput Cellular Screening Technologies For Engineering Enhanced-Solubility And Deimmunized Biologics, Andrew Y. Chang

Dartmouth College Ph.D Dissertations

High throughput cell-based screening methodologies have become core development tools for the generation and engineering of various biotherapeutics. For example, SpCas9 variants for use in CRISPR-Cas9 therapeutics have been engineered for enhanced specificity using a high throughput directed evolution approach in E. coli. Additionally, antibodies are routinely discovered and engineered for high affinity binding using yeast surface display. These high throughput techniques typically involve generation of large protein libraries which require innovative screening strategies depending on the target protein’s function. In this thesis work, we describe high throughput protein library screening approaches to address recombinant biologic aggregation and immunogenicity …

Leveraging Data Science To Promote Sustainable Resource Recovery From Organic Waste Streams In Rural Regions, Mohammed Tamim Zaki

Graduate Theses, Dissertations, and Problem Reports (ETD)

Conventional organic waste management practices such as landfilling contribute to global warming and degrade environmental and human health. Alternatively, organic waste can be treated to recover energy, nutrients, and carbon through resource recovery technologies. Data science could benefit such technologies by improving their efficiency through data-driven process modeling along with reducing environmental and economic burdens via life cycle assessment (LCA) and techno-economic analysis (TEA), respectively.

A critical review of 616 peer-reviewed articles published during 2002–2022 was conducted on the use of data science methods in resource recovery from organic waste. Although applications of machine learning (ML) methods have drastically increased …

A Comparison Of Feature Selection Methodologies And Learning Algorithms In The Development Of A Dna Methylation-Based Telomere Length Estimator, Trevor Doherty, Emma Dempster, Eilis Hannon, Jonathan Mill, Richie Poulton, David Corcoran, Karen Sugden, Ben Williams, Avshalom Caspi, Terrie E. Moffitt, Sarah Jane Delany, Therese Murphy Dr

Articles

The field of epigenomics holds great promise in understanding and treating disease with advances in machine learning (ML) and artificial intelligence being vitally important in this pursuit. Increasingly, research now utilises DNA methylation measures at cytosine–guanine dinucleotides (CpG) to detect disease and estimate biological traits such as aging. Given the challenge of high dimensionality of DNA methylation data, feature-selection techniques are commonly employed to reduce dimensionality and identify the most important subset of features. In this study, our aim was to test and compare a range of feature-selection methods and ML algorithms in the development of a novel DNA methylation-based …

Interpreting Disentangled Representations Of Person-Specific Convolutional Variational Autoencoders Of Spatially Preserving Eeg Topographic Maps Via Clustering And Visual Plausibility, Taufique Ahmed, Luca Longo

Articles

Dimensionality reduction and producing simple representations of electroencephalography (EEG) signals are challenging problems. Variational autoencoders (VAEs) have been employed for EEG data creation, augmentation, and automatic feature extraction. In most of the studies, VAE latent space interpretation is used to detect only the out-of-order distribution latent variable for anomaly detection. However, the interpretation and visualisation of all latent space components disclose information about how the model arrives at its conclusion. The main contribution of this study is interpreting the disentangled representation of VAE by activating only one latent component at a time, whereas the values for the remaining components are …

Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad

Dissertations, Master's Theses and Master's Reports

There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …

Treating Contaminated Water: Predicting Reactivities Of Aqueous Organic Contaminants With Hydrated Electrons, And Development Of A Biogarden To Manage Greywater Discharge In Monteverde, Costa Rica, Rose C. Daily

Dissertations, Master's Theses and Master's Reports

Advanced reduction processes (ARPs) that generate highly reactive solvated electrons (e^-_aq) are a promising method for the destruction of conventional and emerging aqueous organic contaminants. While there is a large database of contaminant reactivity with e^-_aq in the literature, there is little information on the detailed elementary mechanisms for reduction of multifunctional group compounds and the impact of those functional groups on reactivity. As it is difficult to determine specific mechanisms through experiments and time consuming to measure reactivity, the development of computational approaches to elucidate mechanisms and predict reactivity is becoming increasingly important. In …

Machine Learning And Deep Learning Approaches For Gene Regulatory Network Inference In Plant Species, Sai Teja Mummadi

Dissertations, Master's Theses and Master's Reports

The construction of gene regulatory networks (GRNs) is vital for understanding the regulation of metabolic pathways, biological processes, and complex traits during plant growth and responses to environmental cues and stresses. The increasing availability of public databases has facilitated the development of numerous methods for inferring gene regulatory relationships between transcription factors and their targets. However, there is limited research on supervised learning techniques that utilize available regulatory relationships of plant species in public databases.

This study investigates the potential of machine learning (ML), deep learning (DL), and hybrid approaches for constructing GRNs in plant species, specifically Arabidopsis thaliana, …

Collagen V Promotes Fibroblast Contractility, And Adhesion Formation, And Stability, Shaina P. Royer-Weeden

Dissertations, Master's Theses and Master's Reports

Ehlers-Danlos syndrome, classical type, (cEDS) is a hereditary connective tissue disorder causing excessive elasticity and fragility of the connective tissue and problems with wound healing. Most cases of cEDS are caused by haploinsufficiency for collagen V. Collagen V regulates collagen fibril diameter. In cEDS fibroblast migration is impaired and integrin expression is altered.

The effects of collagen V on collagen gel ultrastructure and how it alters its mechanical properties were measured using scanning electron microscopy (SEM) and rheology respectively. Fibroblast contractility and adhesion dynamics were investigated to better understand the role of fibroblast disfunction in wound healing in cEDS. To …

Nanomaterials For Cardiovascular Engineering, Roya Bagheri

Dissertations, Master's Theses and Master's Reports

Cardiovascular diseases and disorders (i.e., those related to heart and blood vessels) are the main reasons for mortality worldwide. Nanomaterials, with their unique morphologies and properties, have a great potential for advancing cardiovascular engineering to treat diseases and disorders. In this dissertation, several cardiovascular applications of conductive nanomaterials were investigated. First, a conductive nanomaterial was explored to fabricate biohybrid nanomaterial-cardiomyocyte (CM – heart muscle cell) systems. Using Carbon Nanotube (CNT) forest as a 3D porous and conductive scaffold was investigated. The influence of the CNT forest on the viability, attachment, and spreading of CMs and their genetic information was …

Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane

Dissertations, Master's Theses and Master's Reports

Polymer matrix composite materials are widely used as structural materials in aerospace and aeronautical vehicles. Resin/reinforcement wetting and the effect of polymerization on the thermo-mechanical properties of the resin are key parameters in the manufacturing of aerospace composite materials. Determining the contact angle between combinations of liquid resin and reinforcement surfaces is a common method for quantifying wettability. It is challenging to determine contact angle values experimentally of high-performance resins on CNT materials such as CNT, graphene, bundles or yarns, and BNNT surfaces. It is also experimentally difficult to determine the effect of polymerization reaction on material properties of a …