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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Status
  • Public
Subject
Date Range
2010 2019


Single cell analysis has become increasingly important in understanding disease onset, progression, treatment and prognosis, especially when applied to cancer where cellular responses are highly heterogeneous. Through the advent of single cell computerized tomography (Cell-CT), researchers and clinicians now have the ability to obtain high resolution three-dimensional (3D) reconstructions of single cells. Yet to date, no live-cell compatible version of the technology exists. In this thesis, a microfluidic chip with the ability to rotate live single cells in hydrodynamic microvortices about an axis parallel to the optical focal plane has been demonstrated. The chip utilizes a novel 3D microchamber design …

Contributors
Myers, Jakrey, Meldrum, Deirdre, Johnson, Roger, et al.
Created Date
2012

Calcitonin Gene-Related Peptide (CGRP) is an intrinsically disordered protein that has no regular secondary structure, but plays an important role in vasodilation and pain transmission in migraine. Little is known about the structure and dynamics of the monomeric state of CGRP or how CGRP is able to function in the cell, despite the lack of regular secondary structure. This work focuses characterizing the non-local structural and dynamical properties of the CGRP monomer in solution, and understanding how these are affected by the sequence and the solution environment. The unbound, free state of CGRP is measured using a nanosecond laser-pump spectrophotometer, …

Contributors
Sizemore, Sara, Vaiana, Sara, Ghirlanda, Giovanna, et al.
Created Date
2015

CpG methylation is an essential requirement for the normal development of mammals, but aberrant changes in the methylation can lead to tumor progression and cancer. An in-depth understanding of this phenomenon can provide insights into the mechanism of gene repression. We present a study comparing methylated DNA and normal DNA wrt its persistence length and contour length. Although, previous experiments and studies show no difference between the physical properties of the two, the data collected and interpreted here gives a different picture to the methylation phenomena and its effect on gene silencing. The study was extended to the artificially reconstituted …

Contributors
Kaur, Parminder, Lindsay, Stuart, Ros, Robert, et al.
Created Date
2012

Cell morphology and the distribution of voltage gated ion channels play a major role in determining a neuron's firing behavior, resulting in the specific processing of spatiotemporal synaptic input patterns. Although many studies have provided insight into the computational properties arising from neuronal structure as well as from channel kinetics, no comprehensive theory exists which explains how the interaction of these features shapes neuronal excitability. In this study computational models based on the identified Drosophila motoneuron (MN) 5 are developed to investigate the role of voltage gated ion channels, the impact of their densities and the effects of structural features. …

Contributors
Berger, Sandra Daniela, Crook, Sharon, Baer, Steven, et al.
Created Date
2014

Dielectrophoresis (DEP) is a technique that influences the motion of polarizable particles in an electric field gradient. DEP can be combined with other effects that influence the motion of a particle in a microchannel, such as electrophoresis and electroosmosis. Together, these three can be used to probe properties of an analyte, including charge, conductivity, and zeta potential. DEP shows promise as a high-resolution differentiation and separation method, with the ability to distinguish between subtly-different populations. This, combined with the fast (on the order of minutes) analysis times offered by the technique, lend it many of the features necessary to be …

Contributors
Hilton, Shannon, Hayes, Mark A, Borges, Chad, et al.
Created Date
2019

Single molecule identification is one essential application area of nanotechnology. The application areas including DNA sequencing, peptide sequencing, early disease detection and other industrial applications such as quantitative and quantitative analysis of impurities, etc. The recognition tunneling technique we have developed shows that after functionalization of the probe and substrate of a conventional Scanning Tunneling Microscope with recognition molecules ("tethered molecule-pair" configuration), analyte molecules trapped in the gap that is formed by probe and substrate will bond with the reagent molecules. The stochastic bond formation/breakage fluctuations give insight into the nature of the intermolecular bonding at a single molecule-pair level. …

Contributors
Zhao, Yanan, Lindsay, Stuart, Nemanich, Robert, et al.
Created Date
2014

Conformational changes in biomolecules often take place on longer timescales than are easily accessible with unbiased molecular dynamics simulations, necessitating the use of enhanced sampling techniques, such as adaptive umbrella sampling. In this technique, the conformational free energy is calculated in terms of a designated set of reaction coordinates. At the same time, estimates of this free energy are subtracted from the potential energy in order to remove free energy barriers and cause conformational changes to take place more rapidly. This dissertation presents applications of adaptive umbrella sampling to a variety of biomolecular systems. The first study investigated the effects …

Contributors
Spiriti, Justin Matthew, Van Der Vaart, Arjan, Chizmeshya, Andrew, et al.
Created Date
2011

In eukaryotes, DNA is packed in a highly condensed and hierarchically organized structure called chromatin, in which DNA tightly wraps around the histone octamer consisting of one histone 3-histone 4 (H3-H4) tetramer and two histone 2A- histone 2B (H2A-H2B) dimers with 147 base pairs in an almost two left handed turns. Almost all DNA dependent cellular processes, such as DNA duplication, transcription, DNA repair and recombination, take place in the chromatin form. Based on the critical importance of appropriate chromatin condensation, this thesis focused on the folding behavior of the nucleosome array reconstituted using different templates with various controllable factors …

Contributors
Fu, Qiang, Lindsay, Stuart M, Yan, Hao, et al.
Created Date
2010

In this work, I present a Bayesian inference computational framework for the analysis of widefield microscopy data that addresses three challenges: (1) counting and localizing stationary fluorescent molecules; (2) inferring a spatially-dependent effective fluorescence profile that describes the spatially-varying rate at which fluorescent molecules emit subsequently-detected photons (due to different illumination intensities or different local environments); and (3) inferring the camera gain. My general theoretical framework utilizes the Bayesian nonparametric Gaussian and beta-Bernoulli processes with a Markov chain Monte Carlo sampling scheme, which I further specify and implement for Total Internal Reflection Fluorescence (TIRF) microscopy data, benchmarking the method on …

Contributors
Wallgren, Ross Tod, Presse, Steve, Armbruster, Hans, et al.
Created Date
2019

Cancer is a serious health concern. Current treatments are limited due to certain subpopulations of cancer cells being resistant to chemotherapy and radiation. These subpopulations have been qualitatively identified but much work remains to quantify the abnormalities they exhibit such as irregular nuclear shape. This dissertation seeks to determine physical science methods which can identify and quantify the biological characteristics of cancer and non-cancer cells. For the first project, the deoxyribonucleic acid (DNA) and chromatin of cancer and non-cancer esophageal cells were quantified using spectrophotometry and atomic force microscopy. Then the cellular nucleus shape, chromocenters, nucleoli, and nuclear speckles were …

Contributors
ARIYASINGHE, NETHMI KANCHANA, Ros, Robert, Arizona State University
Created Date
2019

Mechanical properties, in particular elasticity, of cancer cells and their microenvironment are important in governing cancer cell fate, for example function, mobility, adhesion, and invasion. Among all tools to measure the mechanical properties, the precision and ease of atomic force microscopy (AFM) to directly apply force—in the range of Pico to micronewtons—onto samples—with length scales from nanometers to tens of micrometers—has made it a powerful tool to investigate the mechanics of materials. AFM is widely used to measure deformability and stiffness of soft biological samples. Principally, these samples are indented by the AFM probe and the forces and indentation depths …

Contributors
Rahmani Eliato, Kiarash, Ros, Robert, Nikkhah, Mehdi, et al.
Created Date
2019

This study takes biophysics--a relatively new field with complex origins and contested definitions--as the research focus and investigates the history of disciplinary formation in twentieth-century China. The story of building a scientific discipline in modern China illustrates how a science specialty evolved from an ambiguous and amorphous field into a full-fledged academic discipline in specific socio-institutional contexts. It focuses on archival sources and historical writings concerning the constitution and definition of biophysics in order to examine the relationship between particular scientific styles, national priorities, and institutional opportunities in the People's Republic of China. It argues that Chinese biophysicists exhibited a …

Contributors
Luk, Christine Yi Lai, Koblitz, Ann Hibner, Maienschein, Jane A, et al.
Created Date
2014

The goal of this theoretical study of infrared spectra was to ascertain to what degree molecules may be identified from their IR spectra and which spectral regions are best suited for this purpose. The frequencies considered range from the lowest frequency molecular vibrations in the far-IR, terahertz region (below ~3 THz or 100 cm-1) up to the highest frequency vibrations (~120 THz or 4000 cm-1). An emphasis was placed on the IR spectra of chemical and biological threat molecules in the interest of detection and prevention. To calculate IR spectra, the technique of normal mode analysis was applied to organic …

Contributors
Mott, Adam J., Rez, Peter, Ozkan, Banu, et al.
Created Date
2012

Nanofluidic devices in which one single-walled carbon nanotube (SWCNT) spans a barrier between two fluid reservoirs were constructed, enabling direct electrical measurement of the transport of ions and molecules. Ion current through these devices is about 2 orders of magnitude larger than that predicted from the bulk resistivity of the electrolyte. Electroosmosis drives excess current, carried by cations, and is found to be the origin of giant ionic current through SWCNT as shown by building an ionic field-effect transistor with a gate electrode embedded in the fluid barrier. Wetting of inside of the semi-conducting SWCNT by water showed the change …

Contributors
Pang, Pei, Lindsay, Stuart, Ros, Robert, et al.
Created Date
2011

The heliobacterial reaction center (HbRC) is widely considered the simplest and most primitive photosynthetic reaction center (RC) still in existence. Despite the simplicity of the HbRC, many aspects of the electron transfer mechanism remain unknown or under debate. Improving our understanding of the structure and function of the HbRC is important in determining its role in the evolution of photosynthetic RCs. In this work, the function and properties of the iron-sulfur cluster FX and quinones of the HbRC were investigated, as these are the characteristic terminal electron acceptors used by Type-I and Type-II RCs, respectively. In Chapter 3, I develop …

Contributors
Cowgill, John, Redding, Kevin, Jones, Anne, et al.
Created Date
2012

Invasive salmonellosis caused by Salmonella enterica serovar Typhimurium ST313 is a major health crisis in sub-Saharan Africa, with multidrug resistance and atypical clinical presentation challenging current treatment regimens and resulting in high mortality. Moreover, the increased risk of spreading ST313 pathovars worldwide is of major concern, given global public transportation networks and increased populations of immunocompromised individuals (as a result of HIV infection, drug use, cancer therapy, aging, etc). While it is unclear as to how Salmonella ST313 strains cause invasive disease in humans, it is intriguing that the genomic profile of some of these pathovars indicates key differences between …

Contributors
Yang, Jiseon, Nickerson, Cheryl A., Chang, Yung, et al.
Created Date
2015

In a typical living cell, millions to billions of proteins—nanomachines that fluctuate and cycle among many conformational states—convert available free energy into mechanochemical work. A fundamental goal of biophysics is to ascertain how 3D protein structures encode specific functions, such as catalyzing chemical reactions or transporting nutrients into a cell. Protein dynamics span femtosecond timescales (i.e., covalent bond oscillations) to large conformational transition timescales in, and beyond, the millisecond regime (e.g., glucose transport across a phospholipid bilayer). Actual transition events are fast but rare, occurring orders of magnitude faster than typical metastable equilibrium waiting times. Equilibrium molecular dynamics (EqMD) can …

Contributors
Seyler, Sean Lee, Beckstein, Oliver, Chamberlin, Ralph, et al.
Created Date
2017

Peptides offer great promise as targeted affinity ligands, but the space of possible peptide sequences is vast, making experimental identification of lead candidates expensive, difficult, and uncertain. Computational modeling can narrow the search by estimating the affinity and specificity of a given peptide in relation to a predetermined protein target. The predictive performance of computational models of interactions of intermediate-length peptides with proteins can be improved by taking into account the stochastic nature of the encounter and binding dynamics. A theoretical case is made for the hypothesis that, because of the flexibility of the peptide and the structural complexity of …

Contributors
Emery, Jack Scott, Pizziconi, Vincent B, Woodbury, Neal W, et al.
Created Date
2010

Synthetic gene networks have evolved from simple proof-of-concept circuits to complex therapy-oriented networks over the past fifteen years. This advancement has greatly facilitated expansion of the emerging field of synthetic biology. Multistability is a mechanism that cells use to achieve a discrete number of mutually exclusive states in response to environmental inputs. However, complex contextual connections of gene regulatory networks in natural settings often impede the experimental establishment of the function and dynamics of each specific gene network. In this work, diverse synthetic gene networks are rationally designed and constructed using well-characterized biological components to approach the cell fate determination …

Contributors
Wu, Fuqing, Wang, Xiao, Haynes, Karmella, et al.
Created Date
2017

Sensitivity is a fundamental challenge for in vivo molecular magnetic resonance imaging (MRI). Here, I improve the sensitivity of metal nanoparticle contrast agents by strategically incorporating pure and doped metal oxides in the nanoparticle core, forming a soluble, monodisperse, contrast agent with adjustable T2 or T1 relaxivity (r2 or r1). I first developed a simplified technique to incorporate iron oxides in apoferritin to form "magnetoferritin" for nM-level detection with T2- and T2* weighting. I then explored whether the crystal could be chemically modified to form a particle with high r1. I first adsorbed Mn2+ ions to metal binding sites in …

Contributors
Clavijo Jordan, Maria Veronica, Bennett, Kevin M, Kodibagkar, Vikram, et al.
Created Date
2012