Physical Sciences and Mathematics Commons^™

Role Of Amyloid Beta Assembly State In The Human Immune Response, Deepa Viswanathan

Dissertations

Alzheimer’s disease (AD) is a slowly progressing neurodegenerative disease that leads to dementia. Histopathological hallmarks that characterize AD are senile plaques formed by extracellular deposition of Amyloid beta (Aβ) peptide and intracellular aggregates of hyperphosphorylated tau protein. The plaques, which are found in the brain parenchyma, comprise both 40 and 42 residue Aβ. Aggregation of Aβ is an established pathogenic mechanism in AD, but little is known about the initiation of this process in vivo. Several studies have revealed significant inflammatory markers such as activated microglia and cytokines surrounding the plaques. Plaques are a hallmark of AD, but they are …

Activation Of Propargylic Alcohols By Piano-Stool Ruthenium Complexes Bearing Phosphoramidite Ligands, Stephen Andrew Costin

Dissertations

Various piano-stool ruthenium complexes bearing phosphoramidite ligands have been synthesized and characterized spectroscopically and in some cases structurally. Reaction of phosphoramidite ligands with an appropriate metal precursor gives new piano-stool ruthenium complexes [RuCl(L)(arene)(phosphoramidite)], where L = Cl, PPh3, or others. The novel complexes are tested for their ability to activate propargylic alcohols catalytically as well as stoichiometrically. Specifically, catalytic substitution of propargylic alcohols via allenylidene intermediates is envisioned. Stoichiometric reactions designed to form stable, isolable allenylidenes are sought as well. h6-p-cymene complexes of the type [RuCl2(h6-p-cymene)(phosphoramidite)] activate propargylic alcohols in the reaction with carboxylic acids to form b-oxo esters. The …

Study Of 3,3' Vs. 4,4' Dds Isomer Curatives On Physical Properties And Phenyl Ring Motions Of Dgeba Epoxy Via Molecular Dynamics, Deuterium Nmr, And Dielectric Spectroscopy, Samuel James Tucker

Dissertations

The purpose of this research is to develop a multiscale understanding of crosslinked amorphous matrices, connecting molecular level events to macroscopic properties. To accomplish this goal, our methodology was to identify network architectures that influence molecular level energy dissipation through mechanisms such as bond rotations, torsions, and ring flips and then relate those molecular motions to macroscopic properties. Studies were accomplished on two aerospace grade matrices: the epoxy, diglycidyl ether of bisphenol A (DGEBA) cured with two amines, 3,3’- diaminodiphenyl sulfone (33DDS) and 4,4’-diaminodiphenyl sulfone (44DDS). The 33DDS/DGEBA and 44DDS/DGEBA served both to provide a baseline for experimental testing of …

A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves

Dissertations

This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty.

Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors …

Stereo Matching Using A Modified Efficient Belief Propagation In A Level Set Framework, Stephen Goyer Rogers

Dissertations

Stereo matching determines correspondence between pixels in two or more images of the same scene taken from different angles; this can be handled either locally or globally. The two most common global approaches are belief propagation (BP) and graph cuts.

Efficient belief propagation (EBP), which is the most widely used BP approach, uses a multi-scale message passing strategy, an O(k) smoothness cost algorithm, and a bipartite message passing strategy to speed up the convergence of the standard BP approach. As in standard belief propagation, every pixel sends messages to and receives messages from its four neighboring pixels in EBP. Each …

Synthesis And Electrical Properties Of Functional Block Copolymer/Inorganic Nanocomposite Materials, Hongying Chen

Dissertations

Sulfonated poly[styrene-b-ethylene-co-butylene-b-styrene] (sSEBS) block copolymers/inorganic nanocomposite materials were synthesized via in situ formation of inorganic fillers and characterized particularly for their dielectric properties and proton conductivities.

In preparation of sSEBS/SrTiO₃ nanocomposites, titanium (IV) isopropoxide [Ti(OPrⁱ)₄] complex was diffused into sSEBS film, followed by subsequent hydrolysis of [Ti(OPr i)4], diffusion of strontium cations in sSEBS domains, and in situ formation of crystalline SrTiO₃. sSEBS with sulfonation degree of 38.1% and 65.0% were employed, and relevant sSEBS/SrTiO₃ composites contain SrTiO₃ of 10-15 wt%. Elemental composition characterization with ESEM/EDX indicated uniform distribution of …

The Influence Of Nanoporous Crystalline Structure On Low Molecular Weight Mass Transport In Syndiotactic Polystyrene, Justin Paul Brandt

Dissertations

Solid-state structure, crystalline morphology, crystallization kinetics, thermal, free volume, and gas transport properties of semicrystalline syndiotactic polystyrene (sPS) and ethylene vinyl alcohol copolymers (EVOH) have been investigated. Solid-state structure of sPS after crystallization from the melt and glassy state was examined by differential scanning calorimetry (DSC), density and wide angle x-ray diffraction analysis (WAXD). The measurements confirmed low density of syndiotactic polystyrene crystalline forms, which in the case of α and δe was smaller and in the case of β and γ crystalline forms was slightly larger than the density of the glassy amorphous sPS. Positron annihilation lifetime spectroscopy (PALS) …

Folate Receptor-Targeted Delivery Of Small Interfering Rna To Cancer Cells, Yilin Zhang

Dissertations

The vitamin folic acid (folate, FA) has been extensively explored as a targeting ligand to deliver a variety of diagnostic/prognostic/therapeutic agents into various tumors through the assistance of its receptor – the folate receptor (FR). FR is over-expressed in many types of human cancer and can mediate internalization of FA-conjugates through an endocytic pathway. The discovery of small interfering RNA (siRNA), which is cable of inducing potent gene silencing in a sequence-specific manner, provides an excellent molecular tool to suppress aberrant gene expression in malignancies, and therefore siRNA has the potential to revolutionize cancer therapeutics. Towards the goal of developing …

Inner-Shell Photodetachment Of Transition Metal Negative Ions, Ileana Dumitriu

Dissertations

This thesis focuses on the study of inner-shell photodetachment of transition metal negative ions, specifically Fe¯ and Ru¯. Experimental investigations have been performed with the aim of gaining new insights into the physics of negative atomic ions and providing valuable absolute cross section data for astrophysics. The experiments were performed using the X-ray radiation from the Advanced Light Source, Lawrence Berkeley National Laboratory, and the merged-beam technique for photoion spectroscopy.

Negative ions are a special class of atomic systems very different from neutral atoms and positive ions. The fundamental physics of the interaction of transition metal negative ions with photons …

Robust Interval Estimation Of A Treatment Effect In Observational Studies Using Propensity Score Matching, Scott F. Kosten

Dissertations

Estimating the treatment effect between a treatment group and a control group in an observational study is a challenging problem in statistics. Without random assignment of subjects, there are likely to be differences between the treatment group and control group on a set of baseline covariates. If one of these baseline covariates is correlated to the response variable, then the difference in sample means between the groups is likely to be a biased estimate of the true treatment effect.

Propensity score matching has become an increasingly popular strategy for reducing bias in estimates of the treatment effect. This reduction in …

Active Bundles For Protecting Confidentiality Of Sensitive Data Throughout Their Lifecycle, Lotfi Ben Othmane

Dissertations

Protecting confidentiality of shared sensitive data requires satisfying conflicting needs for disseminating data and preventing unauthorized data disclosures. We propose a solution named the active bundles scheme for protecting sensitive data from their disclosures to unauthorized parties during their dissemination. The scheme protects data throughout their entire lifecycle, from data creation through their dissemination to their evaporation or apoptosis (a partial or complete self-destruction, respectively).

An active bundle packages together sensitive data, metadata, and a virtual machine (VM) specific to the bundle. Metadata contain information related to the use of data, including data access control and dissemination policies. A VM …

Confidence Intervals And Tests On The Difference Of Means Of Two Delta Distributions, Karen Grace Villarente Rosales

Dissertations

Various research fields produce data that are lognormally distributed and inflated with zero values. This type of data follows a delta distribution. In this study, we want to extensively investigate different interval and hypothesis testing methods for comparing the means of two delta populations to see which methods are optimal under different conditions of the populations.

For confidence intervals, existing MVUE methods are extended to two sample cases and compared to classical and two proposed robust methods. We investigated the performance of the classical Student's t, Welch t, and Wilcoxon-based interval to see if these methods really perform badly on …

Biochemical Characterization Of Theromin, A Novel Leech Inhibitor, And The Interaction Between The Fourth Metalbinding Domain Of Wilson Disease Protein And Its Copper(I) Chaperone Hah1, Brian A. Zeider

Dissertations

Theromin, a novel thrombin inhibitor from the leech Theromyzon tessulatum, has been shown to be the strongest inhibitor to date. There has been a lot of attention on direct thrombin inhibitors as a much more efficient drug for anticoagulation therapy. One main reason for the need of strong direct thrombin inhibitors is that the current therapy, heparin, causes alternative clotting events in some patients where antibodies are made to the heparin/thrombin complex and causes clots to occur by different methods. Recently there has been a strong inhibitor from a leech used, hirudin, that can inhibit with a K_{i …}

Integrated Approach For The Assessment And Development Of Groundwater Resources In Arid Lands: Applications In The Quetta Valley, Pakistan, Zhanay Sagintayev

Dissertations

The lack of adequate field measurements (e.g., precipitation and stream flow) and difficulty in obtaining them often hampers the construction and calibration of rainfall-runoff models over many of the world's watersheds, leaving key· elements of the hydrologic cycle unconstrained. I adopted methodologies that rely heavily on readily available remote sensing datasets as viable alternatives and useful tools for assessing, managing, and modeling the water resources of such remote and inadequately gauged regions.

The Soil and Water Assessment Tool was selected for continuous (1998-2005) rainfall-runoff modeling of the northeast part of the Pishin Lora basin (NEPL), a politically unstable area that …

The K-Cores Of A Graph, Allan Bickle

Dissertations

Full abstract attached as supplemental file.

Dielectronic Recombination For Aluminum-Like Ions And Photoabsorption Cross Sections For Magnesium Ions At The K-Edge, Shahin Ahmed Abdel-Azim Abdel Naby

Dissertations

Accurate and reliable recombination data are needed for modeling the ions in the finitedensity plasmas that may take place in solar flares and in divertors of magnetically confined fusion devices such as the International Thermonuclear Experimental Reactor (ITER). Dielectronic recombination (DR) is the dominant recombination mechanism in photoionized and collisionally-ionized plasmas. DR rate coefficients for M-shell argon ions have been calculated using a configuration-average approach. DR rate coefficients for the aluminumlike isoelectronic sequence are instead calculated using the state-of-the-art multiconfiguration Breit-Pauli (MCBP) atomic structure and collision code AUTOSTRUCTURE. Good agreement is obtained with the measurements from the Heidelberg heavy-ion Test …

Proton Capture Reactions And Network Calculations On 46Ti, 64Zn, 114Sn And 116Sn Relevant To The Rp-Process, Ravin S. T. Kodikara

Dissertations

The rp-process makes an important contribution to the stellar nucleosynthesis by producing many of the light proton rich nuclei. Successive proton captures on seed nuclei followed by occasional β-decays and electron captures are the key features of this mechanism. For a detailed rp-process analysis, proton capture cross sections and reaction rates are essential. However, the lack of experimental data forces the researcher to largely depend on statistical model predictions.

This dissertation research is an attempt to investigate the proton captures of four particular nuclides; ⁴⁶Ti, ⁶⁴Zn, ¹¹⁴Sn and ¹¹⁶Sn. At Western Michigan University Van de Graaff …

The Molecular Transport And Intercalation Of Guest Molecules Into Hydrogen–Bonded Metal-Organic Frameworks (Hmofs), Greg Anthony Hogan

Dissertations

The process of molecular transport and intercalation has been widely studied for many years, resulting in the discovery of molecular frameworks that are capable of hosting guest molecules or ions. Layered and porous metal-organic frameworks (MOFs) have been found to have applications in the field of catalysis, storage, separations, and ion-exchange. While MOFs are perhaps stronger materials, HMOFs have the advantage of being easily modifiable and more flexible. Because HMOFs have not been extensively studied for their ability to host molecules, and because their ability to withstand guest loss and guest exchange is essentially unknown, here we report the synthesis …

Activation Of The Innate Immune Response By The Alzheimer's Amyloid Beta Protein Via Toll-Like Receptors, Udan Lourdes Maria

Dissertations

Alzheimer’s Disease (AD) is the most common form of neurodegenerative disease characterized by the generation and deposition of amyloid beta plaques and the formation of neurofibrillary tangles. A wealth of data now demonstrate that inflammation is a prominent feature in AD pathology and a potential therapeutic target for the treatment and prevention of the disease. The emergence of evidence linking amyloid beta protein (Aβ), the primary component of senile plaques, to inflammation has led to new insights into understanding AD pathology. Aβ, a protein fragment resulting from cleavage of human amyloid precursor protein (APP), primarily exists in two forms: a …

Cloud Computing:Strategies For Cloud Computing Adoption, Faith Shimba

Dissertations

The advent of cloud computing in recent years has sparked an interest from different organisations, institutions and users to take advantage of web applications. This is a result of the new economic model for the Information Technology (IT) department that cloud computing promises. The model promises a shift from an organisation required to invest heavily for limited IT resources that are internally managed, to a model where the organisation can buy or rent resources that are managed by a cloud provider, and pay per use. Cloud computing also promises scalability of resources and on-demand availability of resources.

Although, the adoption …

Computational Methods For Two-Phase Flow With Soluble Surfactant, Kuan Xu

Dissertations

A mathematical model is formulated and solved for the two-phase flow of a viscous drop or inviscid bubble in an immiscible, viscous surrounding fluid in the zero Reynold's number or Stokes flow limit. A surfactant that is present on the interface is also soluble in the exterior fluid, and the drop is deformed by an imposed linear flow. The geometry is two-dimensional and Cartesian.

The dissolved surfactant is considered in the physically realistic limit of large bulk Péclet number. That is, it convects and diffuses as a passive scalar in the bulk flow where the ratio of its convection to …

Natural Selection On Mrna Secondary Structure And Its Correlation With Protein Functional Groups, Suresh Solaimuthu

Dissertations

Natural selection may occur at multiple levels of the biological hierarchy, including at the molecular level. It may occur on any phenotypic trait that evidences variation and that is heritable. This research uses computational methods to investigate whether the stability of the secondary structures of mRNAs has been the subject of natural selection.

The DNA sequence that codes for a particular target protein is only partially determined by that protein, since the redundancy of the genetic code permits multiple possible synonymous codons for each peptide. An RNA transcript of a DNA protein template (gene) folds back on itself through complementary …

Study Of Magnetic Helicity In Solar Active Regions And Its Relationship With Solar Eruptions, Sung-Hong Park

Dissertations

It is generally believed that eruptive phenomena in the solar atmosphere such as solar flares and coronal mass ejections (CMEs) occur in solar active regions with complex magnetic structures. The magnetic complexity is quantified in terms of twists, kinks, and interlinkages of magnetic field lines. Magnetic helicity has been recognized as a useful measure for these properties of a given magnetic field system. Magnetic helicity studies have been naturally directed to the energy buildup and instability leading to solar eruptions. However, in spite of many years of study, detailed aspects of initiation mechanisms of eruptive events are still not well …

A Numerical Study On The Propagation And Interaction Of Strongly Nonlinear Solitary Waves, Qiyi Zhou

Dissertations

We study numerically a strongly nonlinear long wave model for surface gravity waves propagating in both one and two horizontal dimensions. This model often referred to as the Su-Gardner or Green-Naghdi equations can be derived from the Euler equations under the assumption that the ratio between the characteristic wavelength and water depth is small, but no assumption on the wave amplitude is required. We first generalize the model to describe large amplitude one-dimensional solitary waves in the presence of background shear of constant vorticity. After computing the solitary wave solution of the strongly nonlinear model, the interaction between two solitary …

The Public Understanding Of Climate Change : A Case Study Of Taiwanese Youth, Shih-Yun Kuo

Dissertations

Global climate change is likely to be the most challenging environmental dilemma of the 21st century because its impacts on ecosystems and human society are transnational in scale and long term in scope. Due to its high scientific complexity and uncertainty and high political and economic sensitivity, mitigating the problem will require interdisciplinary cooperation and collective and sustained efforts on the part of all nations. Sufficient domestic support from both government and the lay public will not only be significant to the success of an international climate regime, but also crucial to the effectiveness of potential domestic climate policies.

Such …

Design, Synthesis, And Polymerization Of Novel Heterocyclic Monomers As Precursors For Functional Polyester, Poly(Ester Amide)S And Polyamides, Eylem Tarkin-Tas

Dissertations

The research presented in this dissertation involves the synthesis and polymerization of heterocyclic monomers which pave the way to biodegradable polyester nanocomposites, functional polyesters or poly(ester amide)s, functional polyamides and supramolecular polymers. The key monomers are ε-caprolactone, γ-acetamido-ε- caprolactone, γ-ethylene ketal-ε-caprolactam and α-amino-ε-caprolactam.

Poly(ε-caprolactone) organo-modified montmorillonite nanocomposites were prepared by in-situ polymerization using dibutyltin dimethoxide as initiator/catalyst. The montmorillonite was first modified with 1-decyl-2-methyl-3-(11-hydroxyundecyl)- imidazolium cation. The hydroxyl functionality was used for not only initiating polymer chains from the surface of the clay platelets but also for grafting polymer chains to the surface by acting as a reversible chain transfer …

Relativistic Studies Of The Charmonium And Bottomonium Systems Using The Sucher Equation, Charles Martin Werneth

Dissertations

In this dissertation, bound states of quarks and anti-quarks (mesons) are studied with a relativistic equation known as the Sucher equation. Prior to the work in this dissertation, the Sucher equation had never been used for meson mass spectra. Furthermore, a full angular momentum analysis of the Sucher equation has never been studied. The Sucher equation is a relativistic equation with positive energy projectors imposed on the interaction. Since spin is inherent to the equation, the Sucher equation is equivalent to a relativistic Schrödinger equation with a spin-dependent effective potential. Through a complete general angular momentum analysis of the equation, …

Structure-Property Correlation In Cyclopolymerization Of New Acrylate-Based Functional Monomers, Huseyin Tas

Dissertations

New ether dimer; (ED-Od) and (ED-Eh) and diester; (ODE) and (EHDE) derivatives of α-(hydroxymethyl)acrylate, each having two octadecyl and 2-ethylhexyl side chains respectively, and an amine-linked di(2-ethylhexyl)acrylate (AL-Eh), having three 2-ethylhexyl side chains, were synthesized and (co)polymerized to evaluate the effects of differences in the structures of the monomers on final (co)polymer properties, particularly glass transition temperature, Tg. The free radical polymerizations of these monomers yielded high molecular weight polymers. Cyclopolymer formation of ED-Od, ED-Eh and AL-Eh was confirmed by 13C NMR analysis and the cyclization efficiencies were found to be very high (~100%). Copolymers of ED-Od, ODE, ED-Eh, EHDE, …

Local Radial Basis Function Methods For Solving Partial Differential Equations, Guangming Yao

Dissertations

Meshless methods are relatively new numerical methods which have gained popularity in computational and engineering sciences during the last two decades. This dissertation develops two new localized meshless methods for solving a variety partial differential equations.

Recently, some localized meshless methods have been introduced in order to handle large-scale problems, or to avoid ill-conditioned problems involving global radial basis function approximations. This dissertation explains two new localized meshelss methods, each derived from the global Method of Approximate Particular Solutions (MAPS). One method, the Localized Method of Approximate Particular Solutions (LMAPS), is used for elliptic and parabolic partial differential equations (PDEs) …

Studies Of Meson Mass Spectra In The Context Of Quark-Antiquark Bound States, Mallika Dhar

Dissertations

This dissertation deals with the computation of meson mass spectra in the context of quarkantiquark (q ¯ q) bound-state. Traditionally the q ¯ q bound-state problem is treated by solving the non-relativistic Schrödinger equation in position representation with a linear confining potential and a Coulomb-like attractive potential. For high energy, relativistic kinematics is necessary. It is well known that relativistic kinematics cannot be treated properly in position representation, but it can easily be handled in momentum representation. On the other hand, the linear potential and Coulomb-like potential have singularities in momentum-space and complicated subtraction procedure is necessary to treat the …