Digital Commons Network^™

Structural Mechanisms Of F-Actin Mechanochemical Regulation And Flexible Network Assembly, Matthew J. Reynolds

Student Theses and Dissertations

The actin cytoskeleton integrates physical and chemical cues from a cell's environment to instruct its behavior, coordinating processes including cell migration, organelle dynamics, and endocytosis. Actin-binding proteins (ABPs) specify actin filament (F-actin) organization to build micron-scale networks which power these cell dynamics. Interactions between ABPs and F-actin are regulated by both biochemical processes and mechanical forces. The mechanisms mediating this interplay remain unclear at the protein structural level. Newly polymerized F-actin hydrolyzes bound ATP to produce metastable ADP-Pi–F-actin, which persists for minutes before phosphate release to yield long-lived ADP–F-actin. I determined cryo-EM structures of both ADP–F-actin and ADP-Pi–F-actin with sufficient …

Fate, Phases, And Form In Vertebrate Organ Morphogenesis-Uncovering A Role Of Morphogenesis At The Supracellular Scale, Sichen Yang

Student Theses and Dissertations

How morphology unfolds from fertilization to birth is one of the most fundamental questions in the life sciences. Self-organization in embryonic development, whereby organs robustly adopt forms through intrinsic processes, is a central feature that remains enigmatic. To achieve greater clarity of such processes, new conceptual and experimental approaches may be needed. Much of work in developmental biology in the past three to four decades has focused on cell and subcellular levels of organization. In line with work of some key conceptual thinkers, we revisit the notions of epigenetics. Rather than confining it to the molecular mechanisms of chromatin remodeling, …

Towards A Better Understanding Of Facial Movements: Computational Models For Perception, Characterization, And Neural Production, Yanis Tazi

Student Theses and Dissertations

Facial movements are the primary medium for non-verbal communication and involve a complex orchestration of muscles controlled by the brain. The ability to interpret and produce these movements enables the expression of a wide range of emotions and social cues, all essential for social interactions. Despite their significance, the neural mechanisms governing facial movements remain poorly understood, hindered by the complexity of muscle coordination and the limitations of traditional, subjective, and labor-intensive analysis methods. To objectively understand facial motor control, this research adopts a three-pronged approach: 1) Developing and interpreting computational models within a novel multi-task training framework to simultaneously …

The Role Of Gram - Negative Anaerobes In Hidradenitis Suppurativa, Samuel Clay Williams

Student Theses and Dissertations

Hidradenitis Suppurativa is a chronic autoinflammatory disease with unknown triggers.New evidence in the last five years has begun to clarify two parts of the pathogenesis of the disease. These two parts are the fundamental role of keratinocyte inflammation from early through late-stage disease and the role of the microbiome as an antigenic and infectious trigger of pathogenesis. Gram-negative anaerobic bacteria (GNA) such as Prevotella, Porphyromonas, and Fusobacterium are commonly identified in HS lesions, and their prevalence in lesions is associated with HS disease severity. Additionally, newly epithelialized structures called "dermal tunnels" are found in severe disease and are associated with …

Recombination And Excision: Dna Repair Proteins In Prokaryotic Host-Virus Conflicts, Amer Azim Hossain

Student Theses and Dissertations

Bacteriophages, or simply phages, are viruses that infect bacteria. They are the most abundant biological entity on our planet and outnumber bacteria 10:1 in the ocean. In response to this threat, bacteria have evolved a diverse battery of immune systems that prevent infection, which in turn has resulted in the development of numerous counter-defense mechanisms by phages. This evolutionary arms race drives molecular innovations and presents exciting avenues for the discovery of new molecular biology and new biotechnology tools, such as restriction enzymes and CRISPR-Cas9. My thesis investigates how mechanisms of DNA repair, specifically recombination and base excision, have been …

Molecular Mechanisms Of Sensing And Synergy By Anti-Bacteriophage Immune Systems In Staphylococcus, Dalton Van Banh

Student Theses and Dissertations

Viruses parasitize every known life form on the planet for their propagation and spread. To deal with this constant assault, organisms across all domains of life have evolved immune strategies in the form of genetically encoded systems to defend themselves. Immunity can be conceptualized as occurring in three fundamental stages. First, the immune system must identify an invading pathogen— either directly via recognition of a pathogen-associated molecular pattern (PAMP), or indirectly by sensing the perturbation of homeostasis during the process of infection ("guard hypothesis"). Second, this information must be converted into molecular signals to be transmitted to the appropriate compartment …

The Nanomechanics Of Protocadherin 15, A Protein Essential For Human Hearing, Camila M. Villasante

Student Theses and Dissertations

Mechanical force controls the opening and closing of mechanotransductive ion channels atop the hair bundles in the inner ear. A mechanical element called the gating spring modulates the mechanotransduction channel's open probability by changing the force transmitted to the channels. The molecular identity of the gating spring is yet unconfirmed, but a leading candidate is the filamentous tip link connecting the mechanotransduction channel to the tallest neighboring stereocilium. The tip link is essential to mechanotransduction: when it is broken, mechanotransduction is abolished, and when it is allowed to regenerate, mechanotransduction returns. Each tip link comprises four protein molecules: a dimer …

Investigating The Supracellular Processes Underlying Emergent Material Phase Properties During Embryonic Skin Morphogenesis, Karl H. Palmquist

Student Theses and Dissertations

During embryonic development, vertebrate tissues are sculpted by the coordinated behaviors of cells.Vertebrate organs are complex, typically requiring the orchestrated dynamics of hundreds to thousands of cells. Yet, due to their functional significance, the mechanisms underlying organ formation are robust.This implies the need for mechanisms to constrain critical processes during embryogenesis. While much of developmental biology has focused on the aspects of self-organization that relate to patterns of chemicals and molecules across a tissue and their relationship to gene regulatory networks, less attention has been given to the physical mechanisms at play. In particular,it is poorly understood how, in complex …

Plaster Creek Stewards Curb-Cut Rain Garden Social Impacts Study, Eleanor Vander Ark, Laura Luchies

Watershed Reports

As one method of minimizing pollutants in Plaster Creek, Plaster Creek Stewards (PCS) has installed Curb-Cut Rain Gardens (CCRGs) in the downstream neighborhoods of the Plaster Creek Watershed. CCRGs sit in the parkway between the sidewalk and the street, are planted with native plants, and have a cut in the curb to allow the influx of rainwater from the street. These gardens divert polluted rainwater from the creek by catching the water closer to where it falls and allowing it to filter into the ground.

As part of a grant from the Michigan Department of Environment, Great Lakes, and Energy …

Human Inborn Errors Of Immunity: Tuberculosis, Autoimmunity, And Beyond, Masato Ogishi

Student Theses and Dissertations

Tuberculosis (TB), a multi-organ infectious disease caused by virulent mycobacteria, most predominantly M. tuberculosis, remains one of the deadliest infectious diseases in human history. Bacillus Calmette-Guérin (BCG) vaccine, first implemented medically in 1921, has remained the only available vaccine for TB, although its protective effect is moderate. TB occurs in 5-10% of individuals exposed to those pathogens, while 90-95% remain asymptomatic (i.e.,latent infection or spontaneous clearance). This surprisingly large inter-individual variability has long attracted the attention of human geneticists. Classical twin-based genetic studies have demonstrated the presence of a substantial genetic risk of developing TB disease between monozygotic twins. Later, …

Llu Dentistry - Volume 33, Number 1, Loma Linda University School Of Dentistry

Articulator (Dentistry)

In this Issue

6 | Dean's Message
8 | Service Learning - Caring for those in Cuba
12 | Homecoming Recap
20 | Dean's Circle Breakfast | Mission Inn
21 | Mission Emphasis Breakfast
22 | Honoring Class Gathering
24 | Alumnus of the Year - Dr. John Kershner
25 | Institute for Health Policy and Leadership
26 | $4M National Cancer Institute Grant Awarded to Dr. Chi Viet
28 | Dental Hygiene class graduates in China
30 | DDS Class of 2024 Profile
32 | LLUSD Continuing Education
34 | CDA Reception
40 | President's Award
41 | Prince …

Integrating Higher Order Fear-Based Psychopathology And Rdoc’S Acute Threat Subconstruct, Travis Cole

Graduate Research Theses & Dissertations

Fear-based psychopathology consistently pushes the categorical boundaries established by current diagnostic systems such as the Diagnostic and Statistical Manual of Mental Disorders, 5th edition text revision. While classified by their differing phenotypic symptoms, physiological processes such as fear potentiated startle (FPS) and fear load are common, well-established underlying mechanisms of fear-based psychopathology and represent a prominent target for intervention. The shared mechanisms and symptom overlap among fear-based disorders lend evidence to the examination of symptoms based on a dimensional classification system. One such system, the Hierarchical Taxonomy of Psychopathology (HiTOP) is a quantitative, bottom-up approach to mental illness classification that …

Evaluating The Impacts Of Microplastics On The Soil Biochemical Environment And Cherry Tomato (Solanum Lycopersicum) Productivity, Kenny Famakinwa

All Graduate Theses, Dissertations, and Other Capstone Projects

Microplastics are a global contaminant with serious consequences for ecosystems and human health, yet their effects on terrestrial soil and plants are poorly understood. We conducted the systematic research to reveal the impact of polyethylene microplastics (PE MPs), polypropylene (PP) MPs and Mixture of PE + PP, size (0.1 – 1 vs 2 – 3.5 mm), concentration (1% vs 5%) on soil biochemical and physiochemical of tomato (Solanum lycopersicum L) health. The results showed that the addition of MPs resulted in elevated soil pH, particularly at 5% concentration and size 2 – 3.5mm. There was a remarkable 30.6 – 47% …

Probable Extirpation Of The Jackrabbit (Lepus Californicus) From Arkansas, D.B. Sasse

Journal of the Arkansas Academy of Science

The black-tailed jackrabbit (Lepus californicus) was first documented in Arkansas during the modern era in Franklin County in 1927. Over the next few decades records were reported from multiple counties in northwest Arkansas and the species was locally common in Benton, Crawford, and Washington counties in the 1950s. The last Arkansas record documented in the scientific literature was from 1968 and since then there have only been three credible reports, with the last being from the late 1980s. The Arkansas Game and Fish Commission solicited reports of jackrabbits from the public and failed to find evidence of them from a …

Ultrastructure Of The Biflagellated Spermatozoon In The Western Siren, Siren Nettingi (Caudata: Sirenidae), Using Scanning Electron Microscopy, S.E. Trauth

Journal of the Arkansas Academy of Science

I investigated the ultrastructure of the biflagellated spermatozoon of the Western Siren, Siren nettingi, using scanning electron microscopy from salamanders collected in northeastern Arkansas. My primary goal in this study was to reveal the general morphology of the distinctive sperm cell components (two axonemes, two undulating membranes, and two axial fibers), which run nearly the entire length of the spermatozoon. These remarkable gamete structures are found in members of the salamander family Sirenidae and do not conform to spermatozoal ultrastructure of any other salamander species. Moreover, the biflagellated sperm are the end product of an extraordinary assemblage of complex maturation …

History And Distribution Of The Wood Stork (Mycteria Americana) In Arkansas, R. Tumlison, L. Serviss

Journal of the Arkansas Academy of Science

Wood Storks (Mycteria americana) were thought to be common visitors to Arkansas in the early 1900s, but observations declined mid-century. Surveys of citizen science data and other online sources indicate that numbers of unique observations and total counts of birds have increased since 2000. Storks do not breed here, but have been reported in 34 of 75 counties, and appear mostly in August and September. Birds apparently originate from Mexico. Number of observations have increased since 2016, but many of those observations include only a few birds rather than larger flocks.

An Annotated Checklist Of The Camel Crickets (Insecta: Orthoptera: Rhaphidophoridae) Of Arkansas, H.W. Robison, C.T. Mcallister

Journal of the Arkansas Academy of Science

A total of 14 native species of camel crickets and one introduced taxon representing three genera (Ceuthophilus, Phrixocnemis, and Diestrammena) of the orthopteran family Rhaphidophoridae, are herein reported from Arkansas. The most diverse genus was Ceuthophilus, with 13 native species, while Phrixocnemis had one native species, and Diestrammena, formerly Tachycines, was represented by one introduced species. This updated checklist is intended to be of use to entomologists, naturalists, professional biologists, and resource managers in evaluating the biodiversity of Arkansas. State distributional maps are provided for each species listed by county, and habitats are discussed in which each species was taken …

Fish Leeches Of Arkansas, D.J. Richardson, W.E. Moser, C.T. Mcallister, S.P. Lawson, H.W. Robison

Journal of the Arkansas Academy of Science

Recent collection within Arkansas greatly enlarges the knowledge concerning hosts and distributions of fish leeches within the state. The natural history of the 6 species of fish leeches known from Arkansas (Placobdella montifera, Placobdella pediculata, Cystobranchus klemmi, Cystobranchus verrilli, Myzobdella lugubris, and Myzobdella reducta) is reviewed and updated and molecular data are provided.

Hen-Durance Training—Effects Of An Exercise Regimen On Laying Hen Muscle Architecture And Fracture Prevalence, Grace A.T. Hong, Bret W. Tobalske, Nienke Van Staaveren, Emily M. Leishman, Tina M. Widowski, Donald R. Powers, Alexandra Harlander

Faculty Publications - Department of Biological & Molecular Science

Domestic chickens kept for egg laying navigate inclines such as ramps in some commercial housing systems to aid in transitions between housing tiers. Laying hens use their wings and hindlimbs in a locomotion called wing-assisted incline running (WAIR) to ascend steep inclines. There is a potential relationship between the strength of the main flight muscles and the health of the keel bone from which they originate. We sought to test the effects of a controlled, WAIR-based exercise regimen during rearing on keel bone health and muscle properties of white- and brown-feathered laying hens. The WAIR exercise regimen, which consisted of …

The Professional Identity Of Stem Faculty As Instructors Of Course-Based Research Experiences, Quinn Vega

Department of Biology Faculty Scholarship and Creative Works

The professional identity of scientists has historically been cultivated to value research over teaching, which can undermine initiatives that aim to reform science education. Course-Based Research Experiences (CRE) and the inclusive Research and Education Communities (iREC) are two successful and impactful reform efforts that integrate research and teaching. The aim of this study is to explicate the professional identity of instructors who implement a CRE within an established iREC and to explore how this identity contributes to the success of these programs. 97 CRE instructors from the Science Education Alliance (SEA) iREC participated in a 2-year, multi-stage, qualitative research project …

Intuition And Insight In Art Therapy, Samantha Mach

Art Therapy | Doctoral Dissertations

The main goal of this research is to explore the unconscious phenomena of Intuition and Insight in art therapy. I define Intuition as knowledge that has been there all along and Insight as an inner sense of knowing and a space of no-thought. It is my belief that these unconscious processes lay at the heart of art and art-making and may therefore strengthen the therapeutic process. In order to investigate this hypothesis, I turned to the phenomenological analysis of qualitative interviews and found that seven themes emerged from the data collected: Prologue, Untethered, Interrelatedness, Deliverance, Concede, Divulge, Art as Allied, …

Using Fishing Industry Input And Fishery-Dependent Data To Improve Understanding Of Offshore Fishing Activity And Business Operations, Julia C. Livermore Sheehan

Open Access Dissertations

As the US Blue Economy expands, the commercial and recreational fishing industries in Southern New England face a plethora of challenges. Demand for ocean space is increasing with the expansion of offshore wind development, proposals for additional marine monuments and sanctuaries, and plans for offshore aquaculture farms. Spatial conflicts are therefore increasing, while climate change is driving physical oceanographic changes and biological responses in species at all levels of the food web, resulting in shifts in species distributions and therefore fishing grounds. These challenges contribute to the conditions that businesses must adapt to in order to survive. Therefore, fishing businesses …

Altered Transcriptional Regulation Is An Early Driver Of Disease In An In Vitro Model Of C9orf72 Als/Ftd, Michelle Jean Gregoire

Open Access Dissertations

Neurodegenerative disorders affect millions of people worldwide and are only expected to increase in prevalence as the world’s population ages. The progressive loss of neurons, their structure, and function can lead to detrimental effects as neurons are responsible for the integration of signals in the brain and spinal cord. Despite the association of genetic mutations leading to neurodegeneration, the etiology of many of the disorders is unknown. Understanding how cellular pathologies affect different subsets of neurons is a major goal in the field of cell and molecular neuroscience. Similarly, understanding the mechanisms that may drive these pathologies is of interest …

Development And Evaluation Of Novel Electrode Designs And Gels For Use In Electroencephalography, Jay Vincelli

Open Access Dissertations

This dissertation addresses the challenge of improving spatial resolution and signal quality in electroencephalography (EEG), focusing on tripolar concentric ring electrodes (TCREs) and conductive gels. The research aimed to develop standardized evaluation methods for TCREs, optimize gel performance, and explore non-invasive EEG techniques for studying brain activity in octopuses.

A novel planar EEG phantom was developed, enabling systematic evaluation of TCREs and gels. Sixteen commercial EEG gels were assessed using this phantom, revealing significant performance variations with TCREs. Based on these findings, a custom high-impedance gel was formulated specifically for TCREs. Additionally, the potential of TCREs for non-invasive EEG techniques …

Respiratory-Motion Matched Attenuation Correction For Dual-Gated Cardiac Single Photon Emission Computed Tomography (Spect), Christina Xing

Physics Theses - Archive

Cardiac and respiratory dual-gated single-photon emission computed tomography (SPECT) is a promising technique for minimizing the motion artifacts in myocardial perfusion imaging (MPI). However, attenuation correction (AC) for dual-gated SPECT using an attenuation map averaged over the respiratory cycle may lead to mismatched attenuation correction artifacts. In this study, we propose a respiratory motion-matched attenuation correction (RMM-AC) to further improve dual-gated SPECT. For each respiratory gate, RMM-AC uses an attenuation map that matches the SPECT image in a 4D reconstruction framework. Filtered backprojection reconstruction without AC (FBP-nAC) and 4D reconstruction with the attenuation map averaged over all respiratory gates (AVE-AC) …

Boiling Behind Bars: Exploring The Hidden Toll Of Extreme Heat On Mental Health In Texas Prisons, Sandra K. Miller

Social Work Theses - Archive

The State of Texas supports the largest prison system in the US and held 132,859 people in 100 units scattered across the state as of December 2023. Approximately 70% of Texas prison beds are not air conditioned, despite the state’s reputation for dangerously hot, humid summers. The State has officially recorded temperatures inside Texas prison facilities as high as 120 degrees with heat index values of over 150. Although there is a growing body of research on the negative physiological and psychological consequences of extreme heat among the general public, little is known about the physical and emotional toll of …

Sympathetic-Cardiovascular Stress Reactivity In Adults With Major Depressive Disorder, Ashley Darling

Kinesiology Dissertations - Archive

Major depressive disorder (MDD) is a mood disorder characterized by persistently depressed mood and/or anhedonia that causes significant functional impairment in daily life. MDD affects nearly 15% of adults in their lifetime, and since 2019, prevalence estimates have increased up to ~30% in young adults (18-25 years old). In addition to its debilitating effects on daily functioning, epidemiological studies link MDD to ~3 times greater risk of cardiovascular disease (CVD), followed by accelerated CVD progression and mortality. Although the mechanisms contributing to MDD-CVD comorbidity are unclear, there is evidence of stress system dysfunction in adults with MDD.

Accordingly, the aim …

Calix[4]Arene Structure And Function In Sensors, Deuteration Of Cystine Derivatives, And Purification Of Pyrimidine-Based Antibiotics, Ryan P. Madigan

Chemistry & Biochemistry Dissertations - Archive

Calixarenes are cyclic oligomers known for their unique molecular architecture that provides a versatile platform for applications in supramolecular chemistry. These molecules have exceptional binding ability to cations in solution, while also having multiple methods for tunability to change selectivity of cation. When coupled with fluorescent molecules, this serves as a binding domain which can be tuned to develop highly selective chemosensors. Neutrinoless double beta decay is a proposed particle phenomenon in which two neutrons spontaneously convert to two protons and eject 2 electrons, without the ejection of two neutrinos. In a model system, Xenon can be utilized as the …

Solution Combustion Synthesis And Characterization Of Fumarolic Mineral Dolerophanite, Copper (Ii) Oxide Sulfate, Eric J. Cyganowski

Chemistry & Biochemistry Theses - Archive

Dolerophanite Cu₂OSO₄ is a rare mineral found almost exclusively in the fumaroles of volcano systems and is sensitive to temperature and humidity conditions. It has a monoclinic C2/m crystal structure characterized by two-dimensional layers composed of sulfate anions dispersed amongst copper (II) oxide backbones. There has been recent interest in dolerophanite due to the magnetic properties of its Kagome-like lattice as well as its potential use as a photocatalyst or Li-ion battery electrode. Literature on the material however has been limited by the available synthesis strategies. As such, this thesis work presents a novel strategy …

Weaving Empire: The Role Of Wool, The Subjugated, The Enslaved, And The Convicted In Building The British Empire, 1699-1860, Lisa Y. Gabbert

History Dissertations - Archive

A bright red woolsack comprised of wool clippings from across England sits prominently in the House of Lords. King Edward III originally commissioned the cushion for the Speaker to sit upon while conducting Parliamentary business to signify the importance of the commodity. In 1699, as British trade and territorial interests expanded, Parliament issued the Wool Act. It outlined the expectations and limitations of wool production and exchange in British controlled territories. While the British economy benefitted from commodities such as tobacco, sugar, and cotton which was largely produced by convict and enslaved laborers in its colonies, wool remained an essential …