Physical Sciences and Mathematics Commons^™

Particle Dynamics In Anti-De Sitter Space By Eih Method, Jiusi Lei

Dissertations, Theses, and Capstone Projects

Following the work of Einstein, Infeld and Hoffmann, we show that particle dynamics in Anti-de Sitter spacetime can be built up by regarding singularities in spacetime manifold as the source of particles.

Since gauge fields play a foundational role in the action, the singularities are chosen to be point-like instantons. Their winding number, defined by an integration on the spheres surrounding those singularities, will turn out to be related to their masses. And their action, derived from the Chern-Simons forms, will be a co-adjoint orbit action, with group element g ∈ SO(4, 2) describing the collective coordinates of the particle. …

An Accurate Solution Of The Self-Similar Orbit-Averaged Fokker-Planck Equation For Core-Collapsing Isotropic Globular Clusters: Properties And Application, Yuta Ito

Dissertations, Theses, and Capstone Projects

Hundreds of dense star clusters exist in almost all galaxies. Each cluster is composed of approximately ten thousand through ten million stars. The stars orbit in the clusters due to the clusters' self-gravity. Standard stellar dynamics expects that the clusters behave like collisionless self-gravitating systems on short time scales (~ million years) and the stars travel in smooth continuous orbits. Such clusters temporally settle to dynamically stable states or quasi-stationary states (QSS). Two fundamental QSS models are the isothermal- and polytropic- spheres since they have similar structures to the actual core (central part) and halo (outskirt) of the clusters. The …

Asymmetric Alpha-Stannylation Of Heterocycles And Their Subsequent Use In Cross-Coupling Reactions, Haoran Zhao

Dissertations, Theses, and Capstone Projects

α-Substituted oxygen-containing heterocycles are commonly present in biologically active molecules. Statistics shows that at least one α-substituted ether moiety appears in over 20% of the top 200 small-molecule pharmaceuticals. This project illustrates a reliable regioselective method to introduce simple cyclic ethers towards the diversification of small molecules. Aryl halides bearing various functional groups were well tolerated independent of their electronic properties. It was found that cyclohexyl spectator ligands on tin selectively slows transmetallation of undesired units, circumventing the competitive transfer of n-butyl group from ⁿBu₃SnR reagents. Compared to the normally used ⁿBu₃SnR reagents, Cy …

Excitons In Self-Assembled Hybrid Systems Of Molecular Aggregate Light-Harvesting Nanotubes: Charge-Transfer Substrates And Solution-Stabilized Nanocomposites, Kara Ng

Dissertations, Theses, and Capstone Projects

Delocalized Frenkel excitons-coherently-shared excitations among chromophores-are responsible for the remarkable effciency of supramolecular light-harvesting aggregates within photosynthetic organisms. Despite tremendous progress towards a deeper understanding of these photosynthetic complexes, as well as progress in the development of organic solar cells, the possibility of using bio-inspired molecular nanostructures for large-scale solar energy conversion has not been realized yet. The persistent limitations in translating natures design principles for applications in optoelectronic devices have been the supramolecular structures fragility, and the Frenkel excitons delicate nature. The structural instability, both dis-assembly and spontaneous re-assembly of aggregates. Analysis of the absorption spectrum of a model …

Pointing The Zinc Finger On Protein Folding: Energetic Investigation Into The Role Of The Metal-Ion In The Metal-Induced Protein Folding Of Zinc Finger Motifs, Inna Bakman-Sanchez

Dissertations, Theses, and Capstone Projects

Interactions between inorganic metal-ion cofactors and organic protein scaffolds are important for the proper structure and function of metalloproteins. Zinc finger proteins (ZFPs) are an example of proteins with such crucial metal-protein interactions. Incorporation of the Zn(II)-ion into ZFPs allows for their correct folding into structures that can carry out vital biological functions which include gene expression and tumor suppression. In addition, engineered ZFPs have shown to be promising genetic therapeutics in the clinic. And yet, there is still a gap in a quantitative understanding of the energetic contribution of the metal-protein interactions towards the structure and function of these …

Machine Learning Applications For Drug Repurposing, Hansaim Lim

Dissertations, Theses, and Capstone Projects

The cost of bringing a drug to market is astounding and the failure rate is intimidating. Drug discovery has been of limited success under the conventional reductionist model of one-drug-one-gene-one-disease paradigm, where a single disease-associated gene is identified and a molecular binder to the specific target is subsequently designed. Under the simplistic paradigm of drug discovery, a drug molecule is assumed to interact only with the intended on-target. However, small molecular drugs often interact with multiple targets, and those off-target interactions are not considered under the conventional paradigm. As a result, drug-induced side effects and adverse reactions are often neglected …

Unclonable Secret Keys, Marios Georgiou

Dissertations, Theses, and Capstone Projects

We propose a novel concept of securing cryptographic keys which we call “Unclonable Secret Keys,” where any cryptographic object is modified so that its secret key is an unclonable quantum bit-string whereas all other parameters such as messages, public keys, ciphertexts, signatures, etc., remain classical. We study this model in the authentication and encryption setting giving a plethora of definitions and positive results as well as several applications that are impossible in a purely classical setting.

In the authentication setting, we define the notion of one-shot signatures, a fundamental element in building unclonable keys, where the signing key not only …

Understanding Atmospheres Across The Stellar-Substellar Boundary, Eileen C. Gonzales

Dissertations, Theses, and Capstone Projects

Complexities in the atmospheres of sources that straddle the boundary between low-mass stars and planets drive the spectral features we observe and the fundamental parameters that we derive. In an effort to understand the underlying cause of these spectral features, this work examines low-mass stars and brown dwarfs using two approaches: distance-calibrated spectral energy distributions (SEDs) and atmospheric retrievals. SEDs allow for the determination of semi-empirical fundamental parameters, while atmospheric retrievals allow us to derive the atmospheric structure and composition, as well as extrapolated fundamental parameters for a source. Low-metallicity and high surface gravity sources, known as subdwarfs, are the …

An Empirical Study Of Refactorings And Technical Debt In Machine Learning Systems, Yiming Tang, Raffi T. Khatchadourian, Mehdi Bagherzadeh, Rhia Singh, Ajani Stewart, Anita Raja

Publications and Research

Machine Learning (ML), including Deep Learning (DL), systems, i.e., those with ML capabilities, are pervasive in today's data-driven society. Such systems are complex; they are comprised of ML models and many subsystems that support learning processes. As with other complex systems, ML systems are prone to classic technical debt issues, especially when such systems are long-lived, but they also exhibit debt specific to these systems. Unfortunately, there is a gap of knowledge in how ML systems actually evolve and are maintained. In this paper, we fill this gap by studying refactorings, i.e., source-to-source semantics-preserving program transformations, performed in real-world, open-source …

The Relationship Between Impact Energy And Glass Fracture Via .177 Caliber Steel Bbs, Jocenel Beach

Student Theses

Fractured glass is often found at shooting scenes and can provide useful information for crime scene reconstruction. Mechanical glass fracture from a projectile impact can result in different types of fracture patterns. The degree of fracture depends on several factors including: type of glass, the thickness of the glass, curvature (if any), distance from the muzzle, contact angle, and type of projectile. Correlating impact energy to the degree of glass fracture can provide useful information regarding the muzzle-to-target distance for a particular firearm/ammunition combination. This research focuses on the projectile impact velocity of .177 steel BBs shot from a pneumatic …

Protocol For A National Probability Survey Using Home Specimen Collection Methods To Assess Prevalence And Incidence Of Sars-Cov-2 Infection And Antibody Response, Aaron J. Siegler, Patrick S. Sullivan, Travis Sanchez, Ben Lopman, Mansour Fahimi, Charles Sailey, Martin Frankel, Richard Rothenberg, Colleen F. Kelley, Heather Bradley

Publications and Research

Purpose: The U.S. response to the SARS-CoV-2 epidemic has been hampered by early and ongoing delays in testing for infection; without data on where infections were occurring and the magnitude of the epidemic, early public health responses were not data-driven. Understanding the prevalence of SARSCoV- 2 infections and immune response is critical to developing and implementing effective public health responses. Most serological surveys have been limited to localities that opted to conduct them and/or were based on convenience samples. Moreover, results of antibody testing might be subject to high false positive rates in the setting of low prevalence of immune …

Analysis Of Surface Temperature Trends Of Global Lakes Using Satellite Remote Sensing And In Situ Observations, Christal Jean Soverall, Zahida Yasmin, Mahoutin Godnou, Wen Yong Huang, Ryan Chen, Abdou Bah, Hamidreza Norouzi, Reginald Blake

Publications and Research

Even though lakes make up a small percentage of the water bodies on the global land surface, lakes provide critically important ecosystem services. Unfortunately, however, several lake surface areas around the globe have been changing with many of them drastically decreasing due to climate variability and local mismanagement at the basin-scale level. Lake Surface Water Temperature (LSWT) is recognized as a critical indicator of climate change in lakes. The changes in water and the surrounding land temperatures may be an indicator of climate variability if there is consistency between changes in both temperatures. This project focuses on the application of …

Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus

Theses and Dissertations

This paper investigates how the snow-albedo feedback mechanism of the arctic is changing in response to rising climate temperatures. Specifically, the interplay of vegetation and snowmelt, and how these two variables can be correlated. This has the potential to refine climate modelling of the spring transition season. Research was conducted at the ecoregion scale in northern Alaska from 2000 to 2020. Each ecoregion is defined by distinct topographic and ecological conditions, allowing for meaningful contrast between the patterns of spring albedo transition across surface conditions and vegetation types. The five most northerly ecoregions of Alaska are chosen as they encompass …

Qwasi: The Quantum Walk Simulator, Warren V. Wilson

Theses and Dissertations

As quantum computing continues to evolve, the ability to design and analyze novel quantum algorithms becomes a necessary focus for research. In many instances, the virtues of quantum algorithms only become evident when compared to their classical counterparts, so a study of the former often begins with a consideration of the latter. This is very much the case with quantum walk algorithms, as the success of random walks and their many, varied applications have inspired much interest in quantum correlates. Unfortunately, finding purely algebraic solutions for quantum walks is an elusive endeavor. At best, and when solvable, they require simple …

Method Development For Identifying Counterfeit Cigarettes Using Environmental Pollen Analysis, Tiffany Chan

Student Theses

Cigarette counterfeiting negatively impacts government revenue and undermines tobacco control policies. Tracking geographical origins and potential trade routes of counterfeit cigarettes is important for investigation illegal trade in tobacco products. Traditional pollen extraction techniques provide clear residues of pollen trapped on tobacco leaves and used for geographical identification; however, such methods are time-consuming and utilize concentrated chemicals. This study developed a simple, fast and environmentally friendly method for extraction of pollen grains used in differentiating genuine and counterfeit cigarettes. Experimental factors that may affect pollen recovery including number of cigarettes, extraction solution, and extraction temperature, were optimized. The optimum parameters …

Evolutionary Algorithms Converge Towards Evolved Biological Photonic Structures, Mamadou Aliou Barry, Vincent Berthier, Bobo D. Wilts, Marie-Claire Cambourieux, Pauline Bennet, Rémi Pollès, Olivier Teytaud, Emmanuel Centeno, Nicolas Biais, Antoine Moreau

Publications and Research

Nature features a plethora of extraordinary photonic architectures that have been optimized through natural evolution in order to more efciently refect, absorb or scatter light. While numerical optimization is increasingly and successfully used in photonics, it has yet to replicate any of these complex naturally occurring structures. Using evolutionary algorithms inspired by natural evolution and performing particular optimizations (maximize refection for a given wavelength, for a broad range of wavelength or maximize the scattering of light), we have retrieved the most stereotypical natural photonic structures. Whether those structures are Bragg mirrors, chirped dielectric mirrors or the gratings on top of …

Globe Observer Data: 2016–2019, Helen M. Amos, Matthew J. Starke, Tina M. Rogerson, Marilé Colón Robles, Travis Anderson, Rebecca Boger, Brian A. Campbell, Russanne D. Low, Peder Nelson, David Overoye, Jessica E. Taylor, Kristen L. Weaver, Trena M. Ferrell, Holli Kohl, Theresa G. Schwerin

Publications and Research

This technical report summarizes the GLOBE Observer data set from 1 April 2016 to 1 December 2019. GLOBE Observer is an ongoing NASA‐sponsored international citizen science project that is part of the larger Global Learning and Observations to Benefit the Environment (GLOBE) Program, which has been in operation since 1995. GLOBE Observer has the greatest number of participants and geographic coverage of the citizen science projects in the Earth Science Division at NASA. Participants use the GLOBE Observer mobile app (launched in 2016) to collect atmospheric, hydrologic, and terrestrial observations. The app connects participants to satellite observations from Aqua, Terra, …

Mapping Gadolinium Contrast In A Complex Ionic And Photosynthesis Environment Of Pineapple By Near-Infrared And X-Ray Imaging, Subhendra Sarkar, Zoya Vinokur, Chen Xu, Tetiana Soloviova, Amina Shahbaz, Aldona Gjoni

Publications and Research

This work explores the diffusivity of a lanthanide complex, Eovist (Gadolinium-Ethoxy Benzyl Diethylenetriamine pentaacetate) that is stable in neutral media but is not in acidic environment. In the current work an acidic fruit model like pineapple that is rich in transition metals was used and a possible transmetallation reaction among Eovist and transition metal complexes was tested using X-ray imaging. Another goal of this work was to perturb the usual and the unusual photosynthesis systems that pineapple has maintained for millions of years during the evolution of circadian genes for efficient water conservation by dark photosynthesis. To detect such photosynthesis …

Eco 230 / Mgt 230 Introduction To Economic And Managerial Statistics, George Vachadze

Open Educational Resources

Development and application of modern statistical methods, including such elements of descriptive statistics and statistical inference as correlation and regression analysis, probability theory, sampling procedures, normal distribution and binomial distribution, estimation, and testing of hypotheses.

A Differential-Algebraic Criterion For Obtaining A Small Maximal Cohen-Macaulay Module, Hans Schoutens

Publications and Research

We show how for a three-dimensional complete local ring in positive characteristic, the existence of an F-invariant, differentiable derivation implies Hochster’s small MCM conjecture. As an application we show that any three-dimensional pseudo-graded ring in positive characteristic satisfies Hochster’s small MCM conjecture.

Circuits With Broken Fibration Symmetries Perform Core Logic Computations In Biological Networks, Ian Leifer, Flaviano Morone, Saulo D. S. Reis, José S. Andrade Jr., Mariano Sigman, Hernán A. Makse

Publications and Research

We show that logic computational circuits in gene regulatory networks arise from a fibration symmetry breaking in the network structure. From this idea we implement a constructive procedure that reveals a hierarchy of genetic circuits, ubiquitous across species, that are surprising analogues to the emblematic circuits of solid-state electronics: starting from the transistor and progressing to ring oscillators, current-mirror circuits to toggle switches and flip-flops. These canonical variants serve fundamental operations of synchronization and clocks (in their symmetric states) and memory storage (in their broken symmetry states). These conclusions introduce a theoretically principled strategy to search for computational building blocks …

Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey

Publications and Research

La(Fe,Si)₁₃–based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)₁₃, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of …

A Comparison Of Tribal Sovereignty, Self-Determination, And Environmental Justice At The Epa’S Onondaga Lake And Tar Creek Superfund Sites, Thomas Clark

Dissertations, Theses, and Capstone Projects

The Environmental Protection Agency’s Superfund program mandates that Native American tribes are afforded the same treatment as states in the implementation of environmental remediation projects; however, the degree of coordination and consultation between the EPA and sovereign tribal governments varies widely between sites. Two of the Superfund program’s highest profile sites with Native American interest, northeast Oklahoma’s Tar Creek and central New York’s Onondaga Lake, are characterized by such a disparity in tribal participation. While Oklahoma’s Quapaw Tribe would ultimately enter into a number of cooperative agreements with the EPA for direct control over remedial projects, New York’s Onondaga Nation …

Structural Studies Of Peptide Toxins And Their Binding Properties Towards The Voltage Sensing Domain Of Nav1.7, Ryan Schroder

Dissertations, Theses, and Capstone Projects

Voltage gated sodium channels (VGSCs) are essential to the propagation of nerve cell impulses and thus communication in the nervous system. VGSCs are comprised of four repeating units of six transmembrane helices. Of the six transmembrane helices, the first four (called S1-S4) comprise the voltage sensing domain (VSD) and the last two (S5-S6) comprise the pore domain (PD)¹. The Human voltage-gated sodium channel Na_V1.7 has been shown to play a vital role in the nerve pathways that induce pain response². Many of the currently available pain therapeutic drugs are opiates, derivative molecules of opium. …

Model Theory Of Groups And Monoids, Laura M. Lopez Cruz

Dissertations, Theses, and Capstone Projects

We first show that arithmetic is bi-interpretable (with parameters) with the free monoid and with partially commutative monoids with trivial center. This bi-interpretability implies that these monoids have the QFA property and that finitely generated submonoids of these monoids are definable. Moreover, we show that any recursively enumerable language in a finite alphabet X with two or more generators is definable in the free monoid. We also show that for metabelian Baumslag-Solitar groups and for a family of metabelian restricted wreath products, the Diophantine Problem is decidable. That is, we provide an algorithm that decides whether or not a given …

The Reduction, Sequestration, And/Or Coordination Of Technetium-99 Utilizing Polyoxometalates And Nanomaterials, Colleen Mb Gallagher

Dissertations, Theses, and Capstone Projects

Research into the sequestration of radionuclides from aqueous media is being conducted due to the contamination of aqueous waste effluents and groundwater with highly toxic long-lived radionuclides. These contaminants are introduced into water and streams from legacy nuclear sites, nuclear reactor operations, nuclear fuel reprocessing, nuclear weapons testing, and plutonium production. A major contributor (~6%) to the waste from thermal neutron fission of uranium-235 is the radionuclide technetium-99 (⁹⁹Tc). It is considered a long-lived radioisotope with a half-life of 2.1x10⁵ years. It is a weak beta emitter with a max energy of 0.29 MeV and is most …

Novel Fast Algorithms For Low Rank Matrix Approximation, John T. Svadlenka

Dissertations, Theses, and Capstone Projects

Recent advances in matrix approximation have seen an emphasis on randomization techniques in which the goal was to create a sketch of an input matrix. This sketch, a random submatrix of an input matrix, having much fewer rows or columns, still preserves its relevant features. In one of such techniques random projections approximate the range of an input matrix. Dimension reduction transforms are obtained by means of multiplication of an input matrix by one or more matrices which can be orthogonal, random, and allowing fast multiplication by a vector. The Subsampled Randomized Hadamard Transform (SRHT) is the most popular among …

Proton Pumping Mechanism In Cytochrome C Oxidase, Xiuhong Cai

Dissertations, Theses, and Capstone Projects

Cytochrome c Oxidase (CcO), is the terminal electron acceptor in the membrane bound aerobic respiratory chain. It reduces O₂ to water. The energy released by this reaction is stored by pumping protons from the high pH, N-side of the membrane to the low pH, P-side. The generated proton gradient provides the motive force for synthesis of ATP by the ATP synthase.

Building a proton gradient across the membrane requires that proton transport must occur along controllable proton pathways to prevent proton leakage to the N-side. It has been suggested that CcO function requires proton transfer channels in both the …

Quadratic Packing Polynomials On Sectors Of R2, Kaare S. Gjaldbaek

Dissertations, Theses, and Capstone Projects

A result by Fueter-Pólya states that the only quadratic polynomials that bijectively map the integral lattice points of the first quadrant onto the non-negative integers are the two Cantor polynomials. We study the more general case of bijective mappings of quadratic polynomials from the lattice points of sectors defined as the convex hull of two rays emanating from the origin, one of which falls along the x-axis, the other being defined by some vector. The sector is considered rational or irrational according to whether this vector can be written with rational coordinates or not. We show that the existence of …

Convexity And Curvature In Hierarchically Hyperbolic Spaces, Jacob Russell-Madonia

Dissertations, Theses, and Capstone Projects

Introduced by Behrstock, Hagen, and Sisto, hierarchically hyperbolic spaces axiomatized Masur and Minsky's powerful hierarchy machinery for the mapping class groups. The class of hierarchically hyperbolic spaces encompasses a number of important and seemingly distinct examples in geometric group theory including the mapping class group and Teichmueller space of a surface, virtually compact special groups, and the fundamental groups of 3-manifolds without Nil or Sol components. This generalization allows the geometry of all of these important examples to be studied simultaneously as well as providing a bridge for techniques from one area to be applied to another.

This thesis presents …