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The Java programing language was implemented in such a way as to limit the amount of possible ways that a program written in Java could be exploited. Unfortunately, all of the protections and safeguards put in place for Java can be circumvented if a program created in Java utilizes

The Java programing language was implemented in such a way as to limit the amount of possible ways that a program written in Java could be exploited. Unfortunately, all of the protections and safeguards put in place for Java can be circumvented if a program created in Java utilizes internal or external libraries that were created in a separate, insecure language such as C or C++. A secure Java program can then be made insecure and susceptible to even classic vulnerabilities such as stack overflows, string format attacks, and heap overflows and corruption. Through the internal or external libraries included in the Java program, an attacker could potentially hijack the execution flow of the program. Once the Attacker has control of where and how the program executes, the attacker can spread their influence to the rest of the system.

However, since these classic vulnerabilities are known weaknesses, special types of protections have been added to the compilers which create the executable code and the systems that run them. The most common forms of protection include Address SpaceLayout Randomization (ASLR), Non-eXecutable stack (NX Stack), and stack cookies or canaries. Of course, these protections and their implementations vary depending on the system. I intend to look specifically at the Android operating system which is used in the daily lives of a significant portion of the planet. Most Android applications execute in a Java context and leave little room for exploitability, however, there are also many applications which utilize external libraries to handle more computationally intensive tasks.

The goal of this thesis is to take a closer look at such applications and the protections surrounding them, especially how the default system protections as mentioned above are implemented and applied to the vulnerable external libraries. However, this is only half of the problem. The attacker must get their payload inside of the application in the first place. Since it is necessary to understand how this is occurring, I will also be exploring how the Android operating system gives outside information to applications and how developers have chosen to use that information.
ContributorsGibbs, William (Author) / Doupe, Adam (Thesis advisor) / Wang, Ruoyu (Committee member) / Shoshitaishvilli, Yan (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Special education identification processes related to English language learners (ELs) in the United States have puzzled the field for decades. The phenomenon of referrals, the first step toward identification, is complex since it requires deciphering the root cause of students’ learning struggles—e.g., second language (L2) factors, the possibility of a

Special education identification processes related to English language learners (ELs) in the United States have puzzled the field for decades. The phenomenon of referrals, the first step toward identification, is complex since it requires deciphering the root cause of students’ learning struggles—e.g., second language (L2) factors, the possibility of a learning disability (LD), or the combination of multiple other influences. To investigate the various influences contributing to learning difficulties, I centered this study on three potential sources, individual, institutional, and interpersonal. I aimed to answer, how did sociocultural influences mediate a teacher’s understanding of ELs’ competence? How did sociocultural influences mediate whether a teacher referred ELs to special education services? Using a cultural-historical theoretical approach, I sought deeper theoretical and empirical understandings into how institutional factors (e.g., tiered intervention contexts, policies), combined with other influences, mediated ELs’ referral decisions. I used a multiple parallel case study design following two fifth-grade ELs who faced the possibility of a referral. Interested in the interpersonal domain (e.g., interactions and communication among people), I zoomed in to a local process, student-teacher conferences to examine how classroom processes shaped teachers’ thoughts of students’ competence, and ultimately, referral decisions. I video-recorded teacher-student conference sessions over 14 weeks, and audio-recorded viewing sessions of the recorded conferences to understand teacher and student interpretations of learning competence. To understand how other dimensions (individual and institutional) contributed to teachers’ overall views about the student competence, I interviewed parents and school personnel, wrote observational field notes, and examined archival documents related to student learning over the entire fifth-grade year. I used inductive and iterative qualitative analytical approaches to craft the findings. My findings reaffirmed the complexity involved in finalizing ELs’ referral decisions. I found cultural factors intertwined with structural forces, driving students’ special education candidacies in divergent directions: one evaluated (LD); the other, retained. I also found the referral decisions were based on narrow understandings of learning and behaviors, lack of attention to students’ L2 needs, and faulty and overpowering structural forces which undermined teacher’s professional opinions about the referrals. These findings have implications for research, practice, and policy.
ContributorsAlvarado, Sarah Lopez (Author) / Artiles, Alfredo J. (Thesis advisor) / Graham, Steve (Committee member) / Martinez, Danny C. (Committee member) / Arizona State University (Publisher)
Created2020
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Description
The small mitogenic cytokine Pleiotrophin (PTN) is well-known for its roles in

tissue growth, development, and repair. First isolated from neuronal tissues, much interest in this protein resides in development of the central nervous system and neuronal regeneration. Owning to its role in growth, development and its ability to promote angiogenesis

The small mitogenic cytokine Pleiotrophin (PTN) is well-known for its roles in

tissue growth, development, and repair. First isolated from neuronal tissues, much interest in this protein resides in development of the central nervous system and neuronal regeneration. Owning to its role in growth, development and its ability to promote angiogenesis and metastasis, PTN’s overexpression in cancers such as glioblastoma, has become the focal point of much research. Many of the receptors through which PTN acts contain glycosaminoglycans (GAGs), through which PTN binds. Thus, understanding the atomistic detail of PTN’s architecture and interaction with GAG chains is of significant importance in elucidating its functional role in growth and malignancy of biological tissues, as well as in neural development and progression of other diseases. Herein the first solution state structure of PTN was solved via nuclear magnetic resonance (NMR), with extensive characterization of its ability to bind GAG. Structurally, PTN consists of two -sheet domains connected by a short flexible linker, and flanked by long flexible termini. Broad distribution of positively charged amino acids in the protein’s sequence yields highly basic surfaces on the -sheet domains as well as highly cationic termini. With GAG chains themselves being linear anionic polymers, all interactions between these sugars and PTN are most exclusively driven through the electrostatic interactions between them, with no discernable specificity for GAG types. Moreover, this binding event is coordinated mostly through basic patches located in the C-Terminal domain (CTD). Although the flexible C- terminus has been shown to play a significant role in receptor binding, data here also reveal an adaptability of PTN to maintain high affinity interactions through its structured domains

when termini are removed. Additionally, analysis of binding information revealed for the first time the presence of a secondary GAG binding site within PTN. It is shown that PTN’s CTD constitutes the major binding site, while the N-terminal domain (NTD) contains the much weaker secondary site. Finally, compilation of high-resolution data containing the atomistic detail of PTN’s interaction with GAG provided the information necessary to produce the highest accuracy model to date of the PTN-GAG complex. Taken together, these findings provide means for specific targeting of this mitogenic cytokine in a wide array of biological applications.
ContributorsRyan, Eathen (Author) / Wang, Xu (Thesis advisor) / Yarger, Jeffery (Committee member) / Liu, Wei (Committee member) / Arizona State University (Publisher)
Created2020
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Description
In this dissertation, I examine how social perceptions of physical disability shape interactions in healthcare. Drawing upon the lived experience and insights of Diné (Navajo) individuals with physical disabilities, family members, and Diné
on-indigenous healthcare workers and service providers, I explore the interrelationship of social perceptions of physical disability with understandings

In this dissertation, I examine how social perceptions of physical disability shape interactions in healthcare. Drawing upon the lived experience and insights of Diné (Navajo) individuals with physical disabilities, family members, and Diné
on-indigenous healthcare workers and service providers, I explore the interrelationship of social perceptions of physical disability with understandings of identity and performance of personhood. Embedded within discourses and critiques of ableism/disablism, narratives highlight the interconnection of constructs of personhood and productivity.

Findings show that social perceptions of physical disability are closely linked to broader cultural norms surrounding concepts of health/illness. I offer a critical analysis of contemporary impacts of colonization and historical trauma on the physical, emotional, sociocultural and economic wellbeing of Diné people and those who fill service provision roles for this diverse population. Situated within broader contexts of defining constructs of ‘Whiteness’ and ‘Indigeneity’, the role of culture and discourses regarding stereotypes are particularly prominent factors in shaping relationships.

This interdisciplinary ethnography brings together contributions from Anthropology, Disability Studies, and Indigenous paradigms. Placing a particular emphasis on the social dynamics in two urban centers in the state of Arizona, this ethnography centers on analyzing areas of medical practice that work well, as well as gaps in the provision of healthcare services, with a particular focus on systemic and infrastructural barriers. These concerns are shared not only by Diné individuals with

physical disabilities and family members, but also by non-indigenous service providers and healthcare professionals.
ContributorsVarvarezou, Dimitra (Author) / Maupin, Jonathan N (Thesis advisor) / Gaughan, Monica (Committee member) / Williams, Deborah (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Extended crystal defects often play a critical role in determining semiconductor device performance. This dissertation describes the application of transmission electron microscopy (TEM) and aberration-corrected scanning TEM (AC-STEM) to study defect clusters and the atomic-scale structure of defects in compound semiconductors.

An extensive effort was made to identify specific locations of

Extended crystal defects often play a critical role in determining semiconductor device performance. This dissertation describes the application of transmission electron microscopy (TEM) and aberration-corrected scanning TEM (AC-STEM) to study defect clusters and the atomic-scale structure of defects in compound semiconductors.

An extensive effort was made to identify specific locations of crystal defects in epitaxial CdTe that might contribute to degraded light-conversion efficiency. Electroluminescence (EL) mapping and the creation of surface etch pits through chemical treatment were combined in attempts to identify specific structural defects for subsequent TEM examination. Observations of these specimens revealed only surface etch pits, without any visible indication of extended defects near their base. While chemical etch pits could be helpful for precisely locating extended defects that intersect with the treated surface, this study concluded that surface roughness surrounding etch pits would likely mitigate against their usefulness.

Defect locations in GaAs solar-cell devices were identified using combinations of EL, photoluminescence, and Raman scattering, and then studied more closely using TEM. Observations showed that device degradation was invariably associated with a cluster of extended defects, rather than a single defect, as previously assumed. AC-STEM observations revealed that individual defects within each cluster consisted primarily of intrinsic stacking faults terminated by 30° and 90° partial dislocations, although other defect structures were also identified. Lomer dislocations were identified near locations where two lines of strain contrast intersected in a large cluster, and a comparatively shallow cluster, largely constrained to the GaAs emitter layer, contained 60° perfect dislocations associated with localized strain contrast.

In another study, misfit dislocations at II-VI/III-V heterovalent interfaces were investigated and characterized using AC-STEM. Misfit strain at ZnTe/GaAs interfaces, which have relatively high lattice mismatch (7.38%), was relieved primarily through Lomer dislocations, while ZnTe/InP interfaces, with only 3.85% lattice mismatch, were relaxed by a mixture of 60° perfect dislocations, 30° partial dislocations, and Lomer dislocations. These results were consistent with the previous findings that misfit strain was relaxed primarily through 60° perfect dislocations that had either dissociated into partial dislocations or interacted to form Lomer dislocations as the amount of misfit strain increased.
ContributorsMcKeon, Brandon (Author) / Smith, David J. (Thesis advisor) / McCartney, Martha R. (Thesis advisor) / Liu, Jingyue (Committee member) / Zhang, Yong-Hang (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Adoptive transfer of T cells engineered to express synthetic antigen-specific T cell receptors (TCRs) has provocative therapeutic applications for treating cancer. However, expressing these synthetic TCRs in a CD4+ T cell line is a challenge. The CD4+ Jurkat T cell line expresses endogenous TCRs that compete for space, accessory proteins,

Adoptive transfer of T cells engineered to express synthetic antigen-specific T cell receptors (TCRs) has provocative therapeutic applications for treating cancer. However, expressing these synthetic TCRs in a CD4+ T cell line is a challenge. The CD4+ Jurkat T cell line expresses endogenous TCRs that compete for space, accessory proteins, and proliferative signaling, and there is the potential for mixed dimer formation between the α and β chains of the endogenous receptor and that of the synthetic cancer-specific TCRs. To prevent hybridization between the receptors and to ensure the binding affinity measured with flow cytometry analysis is between the tetramer and the TCR construct, a CRISPR-Cas9 gene editing pipeline was developed. The guide RNAs (gRNAs) within the complex were designed to target the constant region of the α and β chains, as they are conserved between TCR clonotypes. To minimize further interference and confer cytotoxic capabilities, gRNAs were designed to target the CD4 coreceptor, and the CD8 coreceptor was delivered in a mammalian expression vector. Further, Golden Gate cloning methods were validated in integrating the gRNAs into a CRISPR-compatible mammalian expression vector. These constructs were transfected via electroporation into CD4+ Jurkat T cells to create a CD8+ knockout TCR Jurkat cell line for broadly applicable uses in T cell immunotherapies.
ContributorsHirneise, Gabrielle Rachel (Author) / Anderson, Karen (Thesis advisor) / Mason, Hugh (Committee member) / Lake, Douglas (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Satellite cells are adult muscle stem cells that activate, proliferate, and differentiate into myofibers upon muscle damage. Satellite cells can be cultured and manipulated in vitro, and thus represent an accessible model for studying skeletal muscle biology, and a potential source of autologous stem cells for regenerative medicine. This work

Satellite cells are adult muscle stem cells that activate, proliferate, and differentiate into myofibers upon muscle damage. Satellite cells can be cultured and manipulated in vitro, and thus represent an accessible model for studying skeletal muscle biology, and a potential source of autologous stem cells for regenerative medicine. This work summarizes efforts to further understanding of satellite cell biology, using novel model organisms, bioengineering, and molecular and cellular approaches. Lizards are evolutionarily the closest vertebrates to humans that regenerate entire appendages. An analysis of lizard myoprogenitor cell transcriptome determined they were most transcriptionally similar to mammalian satellite cells. Further examination showed that among genes with the highest level of expression in lizard satellite cells were an increased number of regulators of chondrogenesis. In micromass culture, lizard satellite cells formed nodules that expressed chondrogenic regulatory genes, thus demonstrating increased musculoskeletal plasticity. However, to exploit satellite cells for therapeutics, development of an ex vivo culture is necessary. This work investigates whether substrates composed of extracellular matrix (ECM) proteins, as either coatings or hydrogels, can support expansion of this population whilst maintaining their myogenic potency. Stiffer substrates are necessary for in vitro proliferation and differentiation of satellite cells, while the ECM composition was not significantly important. Additionally, satellite cells on hydrogels entered a quiescent state that could be reversed when the cells were subsequently cultured on Matrigel. Proliferation and gene expression data further indicated that C2C12 cells are not a good proxy for satellite cells. To further understand how different signaling pathways control satellite cell behavior, an investigation of the Notch inhibitor protein Numb was carried out. Numb deficient satellite cells fail to activate, proliferate and participate in muscle repair. Examination of Numb isoform expression in satellite cells and embryonic tissues revealed that while developing limb bud, neural tube, and heart express the long and short isoforms of NUMB, satellite cells predominantly express the short isoforms. A preliminary immunoprecipitation- proteomics experiment suggested that the roles of NUMB in satellite cells are related to cell cycle modulation, cytoskeleton dynamics, and regulation of transcription factors necessary for satellite cell function.
ContributorsPalade, Joanna (Author) / Wilson-Rawls, Norma (Thesis advisor) / Rawls, Jeffrey (Committee member) / Kusumi, Kenro (Committee member) / Newbern, Jason (Committee member) / Stabenfeldt, Sarah (Committee member) / Arizona State University (Publisher)
Created2020
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Description
The human ankle is a vital joint in the lower limb of the human body. As the point of interaction between the human neuromuscular system and the physical world, the ankle plays important role in lower extremity functions including postural balance and locomotion . Accurate characterization of ankle mechanics in

The human ankle is a vital joint in the lower limb of the human body. As the point of interaction between the human neuromuscular system and the physical world, the ankle plays important role in lower extremity functions including postural balance and locomotion . Accurate characterization of ankle mechanics in lower extremity function is essential not just to advance the design and control of robots physically interacting with the human lower extremities but also in rehabilitation of humans suffering from neurodegenerative disorders.

In order to characterize the ankle mechanics and understand the underlying mechanisms that influence the neuromuscular properties of the ankle, a novel multi-axial robotic platform was developed. The robotic platform is capable of simulating various haptic environments and transiently perturbing the ankle to analyze the neuromechanics of the ankle, specifically the ankle impedance. Humans modulate ankle impedance to perform various tasks of the lower limb. The robotic platform is used to analyze the modulation of ankle impedance during postural balance and locomotion on various haptic environments. Further, various factors that influence modulation of ankle impedance were identified. Using the factors identified during environment dependent impedance modulation studies, the quantitative relationship between these factors, namely the muscle activation of major ankle muscles, the weight loading on ankle and the torque generation at the ankle was analyzed during postural balance and locomotion. A universal neuromuscular model of the ankle that quantitatively relates ankle stiffness, the major component of ankle impedance, to these factors was developed.

This neuromuscular model is then used as a basis to study the alterations caused in ankle behavior due to neurodegenerative disorders such as Multiple Sclerosis and Stroke. Pilot studies to validate the analysis of altered ankle behavior and demonstrate the effectiveness of robotic rehabilitation protocols in addressing the altered ankle behavior were performed. The pilot studies demonstrate that the altered ankle mechanics can be quantified in the affected populations and correlate with the observed adverse effects of the disability. Further, robotic rehabilitation protocols improve ankle control in affected populations as seen through functional improvements in postural balance and locomotion, validating the neuromuscular approach for rehabilitation.
ContributorsNalam, Varun (Author) / Lee, Hyunglae (Thesis advisor) / Artemiadis, Panagiotis (Committee member) / Santello, Marco (Committee member) / Sugar, Thomas (Committee member) / Lockhart, Thurmon (Committee member) / Arizona State University (Publisher)
Created2020
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Description

Underground infrastructure is a critical part of the essential utility services provided to society and the backbone of modern civilization. However, now more than ever before, the disastrous events of a striking underground utilities cost billions of dollars each year in societal damages. Advanced technology and sophisticated visualization techniques such

Underground infrastructure is a critical part of the essential utility services provided to society and the backbone of modern civilization. However, now more than ever before, the disastrous events of a striking underground utilities cost billions of dollars each year in societal damages. Advanced technology and sophisticated visualization techniques such as augmented reality (AR) now play a significant role in mitigating such devastating consequences. Therefore, it is vitally important to coordinate resources, share information, and ensure efficient communication between construction personnel and utility owners. Besides, geographic information systems (GIS) provide a solution for interoperability in the construction industry. Applying such technologies in the field of underground construction requires accurate and up-to-date information. However, there is currently limited research that has integrated AR and GIS and evaluated the effectiveness and usability of the combination in this domain. The main objective of this research was to develop an integrated AR-GIS for mapping and capturing underground utilities using a mobile device. To achieve these objectives, a design research approach utilized to develop and evaluate a mobile extended-reality (XR-GIS) application. This research has produced an efficient solution for data collection and sharing among stakeholders in the underground construction industry. The main challenge in creating a reliable and adaptive outdoor AR system is the accurate registration of virtual objects in the real world. Due to the limited accuracy of smartphones, this study used an external Global Positioning System (GPS) devices to reduce positional error. The primary motivation behind this research is to make the construction industry more aware of the benefits of leveraging AR to prevent utility strikes and enhance public safety.

This dissertation fills the gap in the knowledge regarding applying Augmented Reality (AR) in the underground infrastructure mapping. This study’s three research objectives are:

(1) Identify the challenges and barriers facing the underground construction industry when applying AR.

(2) Develop an integrated AR-GIS for mapping and capturing underground utilities using a mobile device.

(3) Evaluate the horizontal accuracy of the captured data used by the AR phone application XR-GIS that has been developed by the author.

ContributorsFenais, Amr (Author) / Ariaratnam, Samuel T (Thesis advisor) / Ayer, Steven K (Committee member) / Kaloush, Kamil (Committee member) / Arizona State University (Publisher)
Created2020
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Description
ABSTRACT



This dissertation examines the role of tribal sovereignty and self-determination in research for Diné participants and elders from 1956-1986. The qualitative historical research study explored the following questions: How has past research been conducted on the Navajo Nation? What is the role of sovereignty and self-determination in

ABSTRACT



This dissertation examines the role of tribal sovereignty and self-determination in research for Diné participants and elders from 1956-1986. The qualitative historical research study explored the following questions: How has past research been conducted on the Navajo Nation? What is the role of sovereignty and self-determination in research and research methodology for Diné peoples? And, how might Diné philosophy inform a research methodology that aligns with cultural protocols and practices? Six elders who participated in research from 1956-1986 participated in in-depth interviews about their experiences. Using Sa’ąh Naaghái Bik’eh Hozhǫ̨̨́ǫ́n and related Diné philosophy models, findings of this study inform an Indigenous elder knowledge protection model (i.e. Nihookáá’ Diné Nidoolkah Bindii’ą’) to support existing Diné tribal IRB protocols and policies and provides additional insight for tribal cultural protection organizations. Lastly, the researcher presents a Diné intersectional methodology for future research.
ContributorsHenderson, Sharon Leann (Author) / Brayboy, Bryan (Thesis advisor) / Solyom, Jessica (Committee member) / Mccarty, Teresa (Committee member) / Arizona State University (Publisher)
Created2020