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Articles 391 - 420 of 3436

Full-Text Articles in Physical Sciences and Mathematics

High-Velocity Impact Dissociation Of Molecular Species In Spacecraft-Based Mass Spectrometers, Brandon M. Turner Aug 2022

High-Velocity Impact Dissociation Of Molecular Species In Spacecraft-Based Mass Spectrometers, Brandon M. Turner

Theses and Dissertations

Mass spectrometers have proven to be vital to understanding the Solar System and the planets within it. Spacecraft containing mass spectrometers have been sent to numerous remote places and have determined important information about the atmospheric composition of Venus, Earth, Mars, Jupiter, and Saturn, along with other celestial bodies. Such results have shown a variety of small neutral molecules, such as CH4 NH3, H2O, CO2, and CO, neutral radicals such as atomic O, H, and N, and a host of small ions, such as H+, N+, and NH4+. Closed ion source inlets, which allow for the detection of these small …

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The Discovery Of Novel 14-3-3 Binding Proteins Atg9a And Ptov1 And Their Role In Regulating Cancer Mechanisms, Colten Mitchell Mcewan Aug 2022

The Discovery Of Novel 14-3-3 Binding Proteins Atg9a And Ptov1 And Their Role In Regulating Cancer Mechanisms, Colten Mitchell Mcewan

Theses and Dissertations

14-3-3 proteins are among a family of phospho-binding proteins that are known to regulate many essential cellular mechanisms. By binding to sites of phosphorylation, 14-3-3s are integrated into multiple signaling pathways that govern critical processes, such as apoptosis, cell cycle progression, autophagy, glucose metabolism, and cell motility. These processes are crucial for tumorigenesis and 14-3-3 proteins are known to play a central role in facilitating cancer progression. In this study, my colleagues and I discover two novel 14-3-3 interacting proteins, ATG9A and PTOV1, that are both vital to essential cellular functions and describe various mechanisms that these two proteins regulate. …

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Experimental Design And Construction Of The First Rotor Induced Collision Cell (Ricc) For Studying High Velocity Molecular Impacts, Abraham Lehi De La Cruz Hernandez Aug 2022

Experimental Design And Construction Of The First Rotor Induced Collision Cell (Ricc) For Studying High Velocity Molecular Impacts, Abraham Lehi De La Cruz Hernandez

Theses and Dissertations

The identification and characterization of molecular biomarkers using mass spectrometry on an orbiting or fly-by spacecraft is one of the preferred analytical techniques in the search for life beyond the Earth. However, analysis is complicated by unwanted molecular dissociation occurring when sampled native molecules impact the instrument at high velocity. The mechanisms of chemical changes produced in high velocity impacts have been studied experimentally in some cases; however, there are significant experimental limitations to these techniques. Here I present the design, construction, and testing of a new experimental technique to produce high velocity molecular and microparticle collisions under a controlled …

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Data Assimilation And Parameter Recovery For Rayleigh-Bénard Convection, Jacob William Murri Aug 2022

Data Assimilation And Parameter Recovery For Rayleigh-Bénard Convection, Jacob William Murri

Theses and Dissertations

Many problems in applied mathematics involve simulating the evolution of a system using differential equations with known initial conditions. But what if one records observations and seeks to determine the causal factors which produced them? This is known as an inverse problem. Some prominent inverse problems include data assimilation and parameter recovery, which use partial observations of a system of evolutionary, dissipative partial differential equations to estimate the state of the system and relevant physical parameters (respectively). Recently a set of procedures called nudging algorithms have shown promise in performing simultaneous data assimilation and parameter recovery for the Lorentz equations …

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Vector-Valued Mock Theta Functions, Clayton Williams Aug 2022

Vector-Valued Mock Theta Functions, Clayton Williams

Theses and Dissertations

Ramanujan introduced his now celebrated mock theta functions in 1920, grouping them into families parameterized by an integer called the order. In 2010 Bringmann and Ono discovered generalizations of Ramanujan's mock theta functions for any order relatively prime to 6; this result was later strengthened by Garvan in 2016. It was also shown that by adding suitable nonholomorphic completion terms to the mock theta functions the family of mock theta functions corresponding to a given order constitute a complex vector space which is closed under the action of the modular group. We strengthen the Bringmann, Ono, and Garvan result by …

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Variational And Covariational Reasoning Of Students With Disabilities, Lauren Rigby Aug 2022

Variational And Covariational Reasoning Of Students With Disabilities, Lauren Rigby

Theses and Dissertations

Mathematics education reform has led to more conceptually focused instruction in the classroom. Yet, students with disabilities are receiving fewer chances than other students to engage in meaningful mathematics. Furthermore, a research divide between mathematics education and special education in mathematics has led to significant gaps in research on the individual and conceptual understanding of students with disabilities. Through task-based interviews and classroom observations, this study begins the process of closing this research gap through an examination of students' understanding of variational and covariational reasoning. Data suggest that the participants, two students with disabilities, increased their conceptual understanding in a …

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Using Machine Learning To Classify Volleyball Jumps, Miki Jauhiainen Aug 2022

Using Machine Learning To Classify Volleyball Jumps, Miki Jauhiainen

Theses and Dissertations

In this study, inertial measurement units (IMUs) were used to train a random forest classifier to correctly classify different jump types in volleyball. Athlete motion data were collected in a controlled setting using three IMUs, one on the waist and one on each ankle. There were 11 participants who at the time played volleyball at the collegiate level in the United States, seven male and four female. Each performed the same number of jumps across the eight jump types--five BASIC jumps and three each of the other seven--resulting in 26 jumps per subject for a total of 286. The data …

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On Continuity Of Multiplication In The Fundamental Group, Eric Steadman Aug 2022

On Continuity Of Multiplication In The Fundamental Group, Eric Steadman

Theses and Dissertations

For a topological space X, the fundamental group can be topologized as a quotient of the path space with the compact-open topology. For one-dimensional or planar Peano continua, the fundamental group with this topology is a topological group if and only if it is semilocally simply connected. In particular, we demonstrate that the group operation is not continuous in this setting.

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Fabrication And Characterization Of Dna Templated Electronic Nanomaterials And Their Directed Placement By Self-Assembly Of Block Copolymers, Dulashani Ruwanthika Ranasinghe Weerakkodige Aug 2022

Fabrication And Characterization Of Dna Templated Electronic Nanomaterials And Their Directed Placement By Self-Assembly Of Block Copolymers, Dulashani Ruwanthika Ranasinghe Weerakkodige

Theses and Dissertations

Bottom-up self-assembly has the potential to fabricate nanostructures with advanced electrical features. DNA templates have been used to enable such self-assembling methods due to their versatility and compatibility with various nanomaterials. This dissertation describes research to advance several different steps of biotemplated nanofabrication, from DNA assembly to characterization. I assembled different nanomaterials including surfactant-coated Au nanorods, DNA-linked Au nanorods and Pd nanoparticles on DNA nanotubes ~10 micrometer long, and on ~400 nm long bar-shaped DNA origami templates. I optimized seeding by changing the surfactant and magnesium ion concentrations in the seeding solution. After successful seeding, I performed electroless plating on …

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Atomic Layer Deposition And High Sensitivity-Low Energy Ion Scattering For The Determination Of The Surface Silanol Density On Glass And Unsupervised Exploratory Data Analysis With Summary Statistics And Other Methods, Tahereh Gholian Avval Jul 2022

Atomic Layer Deposition And High Sensitivity-Low Energy Ion Scattering For The Determination Of The Surface Silanol Density On Glass And Unsupervised Exploratory Data Analysis With Summary Statistics And Other Methods, Tahereh Gholian Avval

Theses and Dissertations

With the increasing importance of hand-held devices with touch displays, the need for flat panel displays (FPDs) will likely increase in the future. Glass is the most important substrate for FPD manufacturing, where both its bulk and surface properties are critical for its performance. Many properties of the glass used in FPDs are controlled by its surface chemistry. Surface hydroxyls are the most important functional groups on a glass surface, which control processes that occurs on oxide surfaces, including wetting, adhesion, electrostatic charging and discharge, and the rate of contamination. In this dissertation, I present a new approach for determining …

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Quantifying Protein Quality To Understand Protein Homeostasis, Hsien-Jung Lavender Lin Jul 2022

Quantifying Protein Quality To Understand Protein Homeostasis, Hsien-Jung Lavender Lin

Theses and Dissertations

Proteins are the center of all biochemical reactions in living organisms. Proteins need to be present at the right time, in the right place, with the correct concentration and have the right shape to carry their designated function. Protein homeostasis is when all proteins in the proteome are in functional balance, and such balance is maintained by synthesis, folding, and degradation machinery. When protein homeostasis is lost, organisms start to age and develop diseases. To truly unveil disease mechanisms and provide more efficient means for treatment and prevention, we need a holistic understanding of the mechanism of protein homeostasis. Currently, …

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Reconstructing Historical Earthquake-Induced Tsunamis: Case Study Of 1820 Event Near South Sulawesi, Indonesia, Taylor Jole Paskett Jul 2022

Reconstructing Historical Earthquake-Induced Tsunamis: Case Study Of 1820 Event Near South Sulawesi, Indonesia, Taylor Jole Paskett

Theses and Dissertations

We build on the method introduced by Ringer, et al., applying it to an 1820 event that happened near South Sulawesi, Indonesia. We utilize other statistical models to aid our Metropolis-Hastings sampler, including a Gaussian process which informs the prior. We apply the method to multiple possible fault zones to determine which fault is the most likely source of the earthquake and tsunami. After collecting nearly 80,000 samples, we find that between the two most likely fault zones, the Walanae fault zone matches the anecdotal accounts much better than Flores. However, to support the anecdotal data, both samplers tend toward …

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Quantifying Protein Quality To Understand Protein Homeostasis (Supplemental Data), Hsien-Jung Lavender Lin Jul 2022

Quantifying Protein Quality To Understand Protein Homeostasis (Supplemental Data), Hsien-Jung Lavender Lin

ScholarsArchive Data

This data set includes the supplementary data for chpaters 3 and 4 in the dissertation Quantifying Protein Quality to Understand Protein Homeostasis. It includes various excel worksheets that were used to generate the data reported in the dissertation. We make this data available to the public so anyone who wants to reproduce the results has the resources and access to other perspectives that weren't discussed in depth in the dissertation. Chapter 3 used mass-spectrometry to quantify the surface accessibility differences in human serum albumin (HSA)between patients with and without rheumatoid arthritis (RA). We found certain residues are less reactive …

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The Telsam Protein Polymer Significantly Improves The Speed And Propensity Of Crystallization Of Target Proteins, Seyedeh Sara Soleimani Jun 2022

The Telsam Protein Polymer Significantly Improves The Speed And Propensity Of Crystallization Of Target Proteins, Seyedeh Sara Soleimani

Theses and Dissertations

While conducting pilot studies into the usefulness of fusion to TELSAM polymers as a potential protein crystallization strategy, we observed novel properties in crystals of two TELSAM–target protein fusions, as follows. (i) A TELSAM–target protein fusion can crystallize more rapidly and with greater propensity than the same target protein alone. (ii) TELSAM–target protein fusions can be crystallized at low protein concentrations. This unprecedented observation suggests a route to crystallize proteins that can only be produced in microgram amounts. (iii) The TELSAM polymers themselves need not directly contact one another in the crystal lattice in order to form well-diffracting crystals. This …

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Efficient And Adaptive Decentralized Sparse Gaussian Process Regression For Environmental Sampling Using Autonomous Vehicles, Tanner A. Norton Jun 2022

Efficient And Adaptive Decentralized Sparse Gaussian Process Regression For Environmental Sampling Using Autonomous Vehicles, Tanner A. Norton

Theses and Dissertations

In this thesis, I present a decentralized sparse Gaussian process regression (DSGPR) model with event-triggered, adaptive inducing points. This DSGPR model brings the advantages of sparse Gaussian process regression to a decentralized implementation. Being decentralized and sparse provides advantages that are ideal for multi-agent systems (MASs) performing environmental modeling. In this case, MASs need to model large amounts of information while having potential intermittent communication connections. Additionally, the model needs to correctly perform uncertainty propagation between autonomous agents and ensure high accuracy on the prediction. For the model to meet these requirements, a bounded and efficient real-time sparse Gaussian process …

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Understanding College Students' Use Of Written Feedback In Mathematics, Erin Loraine Carroll Jun 2022

Understanding College Students' Use Of Written Feedback In Mathematics, Erin Loraine Carroll

Theses and Dissertations

Many teachers want to help their students develop a growth mindset about their ability to do mathematics. Research has shown, however, that teachers simply do not know how to promote growth mindsets in their classrooms. Existing research suggests that one way teachers can support students' development of a growth mindset is through the written feedback they provide students. This study combines the research done on students' mindsets and written feedback to examine the interaction between student mindset and written feedback by analyzing written feedback provided to students in a College Algebra class and how students used that feedback based on …

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Patterned And Infiltrated Vertically Aligned Carbon Nanotube Ultra-Black Materials, Kevin Laughlin Jun 2022

Patterned And Infiltrated Vertically Aligned Carbon Nanotube Ultra-Black Materials, Kevin Laughlin

Theses and Dissertations

Ultra-black materials reflect less than 1% of incident light, and are used in a wide variety of applications from low signal detector systems, to jewelry. The darkest ultra-black materials are made with vertically aligned carbon nanotubes (VACNTs). One downside to these VACNT based ultra-black material, is they are extremely fragile, and the types of surfaces they can be grown on is limited. Here I created a strengthened ultra-black material that can withstand light handling and drying from water exposure, and can be transferred to other substrates while remaining ultra-black. I also present theoretical models with supporting data on how to …

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Quantum Decoherence In Time-Dependent Anharmonic Systems, Ty Beus Jun 2022

Quantum Decoherence In Time-Dependent Anharmonic Systems, Ty Beus

Theses and Dissertations

This dissertation studies quantum decoherence in anharmonic oscillator systems to monitor and understand the way the systems evolve. It also explores methods to control the systems' evolution, and the effects of decoherence when applicable. We primarily do this by finding the time evolution of the systems using their Lie algebraic structures. We solve for a generalized Caldirola-Kanai Hamiltonian, and propose a general way to produce a desired evolution of the system. We apply the analysis to the effects of Dirac delta fluctuations in mass and frequency, both separately and simultaneously. We also numerically demonstrate control of the generalized Caldirola-Kanai system …

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Towards Color-Based Two-Hand 3d Global Pose Estimation, Fanqing Lin Jun 2022

Towards Color-Based Two-Hand 3d Global Pose Estimation, Fanqing Lin

Theses and Dissertations

Pose estimation and tracking is essential for applications involving human controls. Specifically, as the primary operating tool for human activities, hand pose estimation plays a significant role in applications such as hand tracking, gesture recognition, human-computer interaction and VR/AR. As the field develops, there has been a trend to utilize deep learning to estimate the 2D/3D hand poses using color-based information without depth data. Within the depth-based as well as color-based approaches, the research community has primarily focused on single-hand scenarios in a localized/normalized coordinate system. Due to the fact that both hands are utilized in most applications, we propose …

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Synthesis And Applications Of Α,Β-Dehydroamino Acid-Containing Peptides, Diego A. Moya Jun 2022

Synthesis And Applications Of Α,Β-Dehydroamino Acid-Containing Peptides, Diego A. Moya

Theses and Dissertations

Yaku’amide A (YA) is a linear anticancer peptide that is rich in bulky dehydroamino acids (ΔAAs) and β-hydroxyamino acids (β-OHAAs). In our recent total synthesis of YA, we featured a one-pot anti dehydration–azide reduction–O→N acyl transfer process for the stereospecific construction of Z- and E- ∆Ile residues. Despite previous total syntheses and our efforts, the synthesis of YA remains lengthy. Via computational studies, we identified two analogue peptides that closely resemble the conformation of YA. The use of simpler and symmetrical bulky ΔAAs such as dehydrovaline (ΔVal) and dehydroethylnorvaline (ΔEnv) as surrogates of ∆Ile, along with azlactone chemistry for their …

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Two New Late Quaternary Avifaunas From The East-Central Great Basin With The Description Of A New Species Of Falco, Steven D. Emslie, Jim I. Mead Jun 2022

Two New Late Quaternary Avifaunas From The East-Central Great Basin With The Description Of A New Species Of Falco, Steven D. Emslie, Jim I. Mead

Western North American Naturalist

We report 2 new late Quaternary avifaunas from cave deposits in Snake Valley, White Pine County, eastern Nevada, that provide new records of extinct and extant species in the east-central Great Basin. These avifaunas collectively represent at least 24 species, including the most northern inland record of California Condor (Gymnogyps californianus) in western North America and a new species of kestrel (Falco sp.) described herein. Two extralimital living species also were identified—the Harlequin Duck (Histrionicus histrionicus) and Snowy Owl (Bubo scandiacus)—and are the first fossil records of these species in the Great Basin. …

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The Regulation Of Atg9a-Mediated Aggrephagy By An Ulk1-Independent Atg13-Atg101 Complex, Joshua Youngs Jun 2022

The Regulation Of Atg9a-Mediated Aggrephagy By An Ulk1-Independent Atg13-Atg101 Complex, Joshua Youngs

Undergraduate Honors Theses

Aggrephagy, a type of autophagy, is an essential cellular process by which protein aggregates are collected and broken down in the lysosome. Protein aggregates are implicated in several diseases including Alzheimer’s disease, diabetes, and cancer. Here, we investigate the ATG13-ATG101 protein complex, a sub-complex of the canonical ULK1 complex whose regulatory role in aggrephagy is not completely understood. We also develop a protein fragment complementation (PFC) assay using the biotin ligase TurboID to study the functions of the ATG13-ATG101 complex with increased specificity. We demonstrate that ATG13 is required for optimal degradation of p62-ubiquitin condensates. We also show that a …

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Gas Phase Techniques For The Study Of Biomolecular And Supramolecular Structures And Chemistry, Andrew J. Arslanian Jun 2022

Gas Phase Techniques For The Study Of Biomolecular And Supramolecular Structures And Chemistry, Andrew J. Arslanian

Theses and Dissertations

This dissertation expounds on the investigations of the structure and chemistry of peptides and supramolecular host-guest systems in the gas phase. These investigations used two different kinds of analytical instrument: Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and ion mobility mass spectrometry (IM-MS, IMS). These investigations were complemented by chemical modeling. The FTICR was used to radially trap ions with its 4.7 T magnet, which allowed the ions to undergo sustained off-resonance irradiation collision-induced dissociation (SORI-CID). A subsequent event then measured the collision cross sections (σ) of the targeted precursor ion and one of the selected product ions. These …

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Finding Patterns In The Inertia Of The Distance Squared Matrix Of Unicyclic Graphs, Kellon Sandall, Mark Kempton, Christian Howell Jun 2022

Finding Patterns In The Inertia Of The Distance Squared Matrix Of Unicyclic Graphs, Kellon Sandall, Mark Kempton, Christian Howell

Undergraduate Honors Theses

We analyze the spectrum of the distance squared matrix of a tree and give a relation between the inertia of the distance squared matrix and the structure of the tree. We take the result one step further and consider the addition of exactly one cycle in the tree. We obtain an expression for the inertia of the distance squared matrix of a cycle graph. We obtain a bound on the inertia of the distance squared matrix of an arbitrary unicyclic graph.

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Synthesis Of Yaku’Amide A Analogues And Impact Of Dehydroamino Acids On The Structure And Stability Of Incipient 310 Helical Peptides, Daniel Joaquin Jun 2022

Synthesis Of Yaku’Amide A Analogues And Impact Of Dehydroamino Acids On The Structure And Stability Of Incipient 310 Helical Peptides, Daniel Joaquin

Theses and Dissertations

The first project in this dissertation describes the total synthesis of yaku’amide A analogues. Natural product yaku’amide A possesses potent anticancer activity and exhibits a novel mode of action. However, due to its complex asymmetrical isoleucine dehydroamino acids, the synthesis of this polypeptide poses a unique challenge. Despite the efficient synthesis developed in our lab, the total synthesis of this natural product remains lengthy. In order to simplify the overall synthesis, symmetrical dehydroamino acids were incorporated to replace the dehydroisoleucine residues yielding two analogues of yaku’amide A that closely resembles the conformation of the natural product. Biological testing of the …

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Modeling Inter-Particle Magnetic Correlations In Magnetite Nanoparticle Assemblies Using X-Ray Magnetic Scattering Data, Johnathon Michael Rackham Jun 2022

Modeling Inter-Particle Magnetic Correlations In Magnetite Nanoparticle Assemblies Using X-Ray Magnetic Scattering Data, Johnathon Michael Rackham

Theses and Dissertations

Magnetic nanoparticles are used in nanotechnologies and biomedical applications, such as drug targeting, hyperthermia, MRI contrasting agents, and bio-separation of compound solutions. Magnetite (Fe3O4) nanoparticles stand to be effective in these roles due to the non-toxic nature of magnetite and its ease of manufacture. To this end, a greater understanding of the magnetic behavior of the individual magnetite nanoparticles is needed when a collection of them is used. This research seeks to discover the local magnetic ordering of ensembles of magnetite nanoparticles at various stages of the magnetization process, temperatures above and below their blocking temperature, and for various particle …

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Development Of Cooperative Catalytic Systems And Bimetallic Catalysts For Organic Synthesis, Kelton Guy Forson Jun 2022

Development Of Cooperative Catalytic Systems And Bimetallic Catalysts For Organic Synthesis, Kelton Guy Forson

Theses and Dissertations

The development of new catalysts for organic synthesis is an important pursuit that enables the discovery of new and more efficient reactions and the identification of new reaction mechanisms. Cooperative catalytic systems and bimetallic catalysts represent unique approaches to catalyst development that achieve reactivity that cannot be obtained with a single catalyst or metal. These types of catalysts can activate substrates in unique ways, facilitate reactions under mild conditions, increase substrate scope, and provide access to completely new transformations. The first part of this work describes the development of a cooperative nickel-titanium-catalyzed amination of allylic alcohols. The cooperative effects of …

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Language Learning Using Models Of Intentionality In Repeated Games With Cheap Talk, Jonathan Berry Skaggs May 2022

Language Learning Using Models Of Intentionality In Repeated Games With Cheap Talk, Jonathan Berry Skaggs

Theses and Dissertations

Language is critical to establishing long-term cooperative relationships among intelligent agents (including people), particularly when the agents' preferences are in conflict. In such scenarios, an agent uses speech to coordinate and negotiate behavior with its partner(s). While recent work has shown that neural language modeling can produce effective speech agents, such algorithms typically only accept previous text as input. However, in relationships among intelligent agents, not all relevant context is expressed in conversation. Thus, in this paper, we propose and analyze an algorithm, called Llumi, that incorporates other forms of context to learn to speak in long-term relationships modeled as …

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An Iterative Numerical Method For Multiple Scattering Using High Order Local Absorbing Boundary Conditions, Jonathan Harriman Hale May 2022

An Iterative Numerical Method For Multiple Scattering Using High Order Local Absorbing Boundary Conditions, Jonathan Harriman Hale

Theses and Dissertations

This thesis outlines an iterative approach for determining the scattered wave for two dimensional multiple acoustic scattering problems using high order local absorbing boundary conditions and second order finite difference. We seek to approximate the total wave as it is scattered off of multiple arbitrarily shaped obstacles. This is done by decomposing the scattered wave into the superposition of single scattered waves. We then repeatedly solve the single scattering system for each obstacle, while updating the boundary conditions based off the incident wave and the scattered wave off the other obstacles. We solve each single scattering by enclosing the obstacle …

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A Visual Focus On Form Understanding, Brian Lafayette Davis May 2022

A Visual Focus On Form Understanding, Brian Lafayette Davis

Theses and Dissertations

Paper forms are a commonly used format for collecting information, including information that ultimately will be added to a digital database. This work focuses on the automatic extraction of information from form images. It examines what can be achieved at parsing forms without any textual information. The resulting model, FUDGE, shows that computer vision alone is reasonably successful at the problem. Drawing from the strengths and weaknesses of FUDGE, this work also introduces a novel model, Dessurt, for end-to-end document understanding. Dessurt performs text recognition implicitly and is capable of outputting arbitrary text, making it a more flexible document processing …

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