Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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Description
The elaborate signals of animals are often costly to produce and maintain, thus communicating reliable information about the quality of an individual to potential mates or competitors. The properties of the sensory systems that receive signals can drive the evolution of these signals and shape their form and function. However, relatively little is known about the ecological and physiological constraints that may influence the development and maintenance of sensory systems. In the house finch (Carpodacus mexicanus) and many other bird species, carotenoid pigments are used to create colorful sexually selected displays, and their expression is limited by health and dietary access to carotenoids. Carotenoids also accumulate in the avian retina, protecting it from photodamage and tuning color vision. Analogous to plumage carotenoid accumulation, I hypothesized that avian vision is subject to environmental and physiological constraints imposed by the acquisition and allocation of carotenoids. To test this hypothesis, I carried out a series of field and captive studies of the house finch to assess natural variation in and correlates of retinal carotenoid accumulation and to experimentally investigate the effects of dietary carotenoid availability, immune activation, and light exposure on retinal carotenoid accumulation. Moreover, through dietary manipulations of retinal carotenoid accumulation, I tested the impacts of carotenoid accumulation on visually mediated foraging and mate choice behaviors. My results indicate that avian retinal carotenoid accumulation is variable and significantly influenced by dietary carotenoid availability and immune system activity. Behavioral studies suggest that retinal carotenoid accumulation influences visual foraging performance and mediates a trade-off between color discrimination and photoreceptor sensitivity under dim-light conditions. Retinal accumulation did not influence female choice for male carotenoid-based coloration, indicating that a direct link between retinal accumulation and sexual selection for coloration is unlikely. However, retinal carotenoid accumulation in males was positively correlated with their plumage coloration. Thus, carotenoid-mediated visual health and performance or may be part of the information encoded in sexually selected coloration.
ContributorsToomey, Matthew (Author) / McGraw, Kevin J. (Thesis advisor) / Deviche, Pierre (Committee member) / Smith, Brian (Committee member) / Rutowski, Ronald (Committee member) / Verrelli, Brian (Committee member) / Arizona State University (Publisher)
Created2011
Description
Molecular dynamics (MD) simulations provide a particularly useful approach to understanding conformational change in biomolecular systems. MD simulations provide an atomistic, physics-based description of the motions accessible to biomolecular systems on the pico- to micro-second timescale, yielding important insight into the free energy of the system, the dynamical stability of contacts and the role of correlated motions in directing the motions of the system. In this thesis, I use molecular dynamics simulations to provide molecular mechanisms that rationalize structural, thermodynamic, and mutation data on the interactions between the lac repressor headpiece and its O1 operator DNA as well as the ERK2 protein kinase. I performed molecular dynamics simulations of the lac repressor headpiece - O1 operator complex at the natural angle as well as at under- and overbent angles to assess the factors that determine the natural DNA bending angle. I find both energetic and entropic factors contribute to recognition of the natural angle. At the natural angle the energy of the system is minimized by optimization of protein-DNA contacts and the entropy of the system is maximized by release of water from the protein-DNA interface and decorrelation of protein motions. To identify the mechanism by which mutations lead to auto-activation of ERK2, I performed a series of molecular dynamics simulations of ERK1/2 in various stages of activation as well as the constitutively active Q103A, I84A, L73P and R65S ERK2 mutants. My simulations indicate the importance of domain closure for auto-activation and activity regulation. My results enable me to predict two loss-of-function mutants of ERK2, G83A and Q64C, that have been confirmed in experiments by collaborators. One of the powerful capabilities of MD simulations in biochemistry is the ability to find low free energy pathways that connect and explain disparate structural data on biomolecular systems. An extention of the targeted molecular dynamics technique using constraints on internal coordinates will be presented and evaluated. The method gives good results for the alanine dipeptide, but breaks down when applied to study conformational changes in GroEL and adenylate kinase.
ContributorsBarr, Daniel Alan (Author) / van der Vaart, Arjan (Thesis advisor) / Matyushov, Dmitry (Committee member) / Wolf, George (Committee member) / Shumway, John (Committee member) / Arizona State University (Publisher)
Created2011
Description
Federal education policies call for school district leaders to promote classroom technology integration to prepare students with 21st century skills. However, schools are struggling to integrate technology effectively, with students often reporting that they feel like they need to power down and step back in time technologically when they enter classrooms. The lack of meaningful technology use in classrooms indicates a need for increased teacher preparation. The purpose of this study was to investigate the impact a coaching model of professional development had on school administrators` abilities to increase middle school teachers` technology integration in their classrooms. This study attempted to coach administrators to develop and articulate a vision, cultivate a culture, and model instruction relative to the meaningful use of instructional technology. The study occurred in a middle school. Data for this case study were collected via administrator interviews, the Principal`s Computer Technology Survey, structured observations using the Higher Order Thinking, Engaged Learning, Authentic Learning, Technology Use protocol, field notes, the Technology Integration Matrix, teacher interviews, and a research log. Findings concluded that cultivating change in an organization is a complex process that requires commitment over an extended period of time. The meaningful use of instructional technology remained minimal at the school during fall 2010. My actions as a change agent informed the school`s administrators about the role meaningful use of technology can play in instruction. Limited professional development, administrative vision, and expectations minimized the teachers` meaningful use of instructional technology; competing priorities and limited time minimized the administrators` efforts to improve the meaningful use of instructional technology. Realizing that technology proficient teachers contribute to student success with technology, it may be wise for administrators to incorporate technology-enriched professional development and exercise their leadership abilities to promote meaningful technology use in classrooms.
ContributorsRobertson, Kristen (Author) / Moore, David (Thesis advisor) / Cheatham, Greg (Committee member) / Catalano, Ruth (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study utilized symbolic interaction as a framework to examine the impact of mobility on four veteran elementary general music teachers' identities, roles, and perceptions of role support. Previous research has focused on teacher identity formation among preservice and novice teachers; veteran teachers are less frequently represented in the literature. Teacher mobility research has focused on student achievement, teachers' reasons for moving, and teacher attrition. The impact of mobility on veteran teachers' identities, roles, and perceptions of role support has yet to be considered. A multiple case design was employed for this study. The criteria for purposeful selection of the participants were elementary general music teachers who had taught for at least ten years, who had changed teaching contracts and taught in at least two different schools, and who were viewed as effective music educators by fine arts coordinators. Data were collected over a period of eight months through semi-structured interviews, email correspondence, observations, review of videotapes of the participants' teaching in previous schools, and collection of artifacts. Data were analyzed within and across cases. The cross-case analysis revealed themes within the categories of identity, role, and role support for the participants. The findings suggest that the participants perceived their music teacher roles as multi-dimensional. They claimed their core identities remained stable over time; however, shifts in teacher identity occurred throughout their years as teachers. The participants asserted that mobility at the start of their careers had a positive impact because they each were challenged to solidify their own teacher identities and music teacher roles in varied school contexts. Mobility negatively impacted role and teacher practices during times when the participants adjusted to new school climates and role expectations. Role support varied depending upon school context, and the participants discovered active involvement in the school community was an effective means of seeking and acquiring role support. Reflection experiences in music teacher preparation programs, as well as mentoring and professional development geared toward teacher identity formation and role maturation, may assist teachers in matching their desired school context with their teacher identities and perceptions of the music teacher role.
ContributorsGray, Lori F (Author) / Stauffer, Sandra (Committee member) / Schmidt, Margaret (Committee member) / Sullivan, Jill (Committee member) / Bush, Jeffrey (Committee member) / Tobias, Evan (Committee member) / Arizona State University (Publisher)
Created2011
Description
In this study, I examined how African American students in a church youth group constructed ethnic and spiritual identities as they engaged with community literacy practices. Arizona's small, scattered population of African Americans is reflected within participants' multi-ethnic schools where they describe feelings of being almost invisible to school agents and peers. Listening to students, I came to deeply understand how they struggled with cultural isolation and racial discrimination. The growing tensions with state immigration reform only magnified those feelings as participants perceived the ban on ethnic studies to be another attempt to exclude them from school curriculums. By using utilizing four identity types, I gained greater insights into participants' negotiation of ethnicity and spirituality. Drawing from critical race theory, I utilized counter-storytelling to not only recapture participants' experiences with social injustice, but also to illustrate how the youth group empowers the students to become activists. Resisting the paralyzing effects of racial stereotypes, participants emerged as essayists, artists, orators, and spoken word poets.
ContributorsNicholson, Cynthia Salley (Author) / Paris, Django (Thesis advisor) / Nilsen, Alleen (Committee member) / Stanfield, John H. (Committee member) / Arizona State University (Publisher)
Created2011
Description
A synbody is a newly developed protein binding peptide which can be rapidly produced by chemical methods. The advantages of the synbody producing process make it a potential human proteome binding reagent. Most of the synbodies are designed to bind to specific proteins. The peptides incorporated in a synbody are discovered with peptide microarray technology. Nevertheless, the targets for unknown synbodies can also be discovered by searching through a protein mixture. The first part of this thesis mainly focuses on the process of target searching, which was performed with immunoprecipitation assays and mass spectrometry analysis. Proteins are pulled down from the cell lysate by certain synbodies, and then these proteins are identified using mass spectrometry. After excluding non-specific bindings, the interaction between a synbody and its real target(s) can be verified with affinity measurements. As a specific example, the binding between 1-4-KCap synbody and actin was discovered. This result proved the feasibility of the mass spectrometry based method and also suggested that a high throughput synbody discovery platform for the human proteome could be developed. Besides the application of synbody development, the peptide microarray technology can also be used for immunosignatures. The composition of all types of antibodies existing in one's blood is related to an individual's health condition. A method, called immunosignaturing, has been developed for early disease diagnosis based on this principle. CIM10K microarray slides work as a platform for blood antibody detection in immunosignaturing. During the analysis of an immunosignature, the data from these slides needs to be validated by using landing light peptides. The second part of this thesis focuses on the validation of the data. A biotinylated peptide was used as a landing light on the new CIM10K slides. The data was collected in several rounds of tests and indicated that the variation among landing lights was significantly reduced by using the newly prepared biotinylated peptide compared with old peptide mixture. Several suggestions for further landing light improvement are proposed based on the results.
ContributorsSun, Minyao (Author) / Johnston, Stephen Albert (Thesis advisor) / Diehnelt, Chris Wayne (Committee member) / Stafford, Phillip (Committee member) / Arizona State University (Publisher)
Created2011
Description
In the 1970s James Watson recognized the inability of conventional DNA replication machinery to replicate the extreme termini of chromosomes known as telomeres. This inability is due to the requirement of a building block primer and was termed the end replication problem. Telomerase is nature's answer to the end replication problem. Telomerase is a ribonucleoprotein which extends telomeres through reverse transcriptase activity by reiteratively copying a short intrinsic RNA sequence to generate 3' telomeric extensions. Telomeres protect chromosomes from erosion of coding genes during replication, as well as differentiate native chromosome ends from double stranded breaks. However, controlled erosion of telomeres functions as a naturally occurring molecular clock limiting the replicative capacity of cells. Telomerase is over activated in many cancers, while inactivation leads to multiple lifespan limiting human diseases. In order to further study the interaction between telomerase RNA (TR) and telomerase reverse transcriptase protein (TERT), vertebrate TERT fragments were screened for solubility and purity following bacterial expression. Soluble fragments of medaka TERT including the RNA binding domain (TRBD) were identified. Recombinant medaka TRBD binds specifically to telomerase RNA CR4/CR5 region. Ribonucleotide and amino acid pairs in close proximity within the medaka telomerase RNA-protein complex were identified using photo-activated cross-linking in conjunction with mass spectrometry. The identified cross-linking amino acids were mapped on known crystal structures of TERTs to reveal the RNA interaction interface of TRBD. The identification of this RNA TERT interaction interface furthers the understanding of the telomerase complex at a molecular level and could be used for the targeted interruption of the telomerase complex as a potential cancer treatment.
ContributorsBley, Christopher James (Author) / Chen, Julian (Thesis advisor) / Allen, James (Committee member) / Ghirlanda, Giovanna (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study follows three secondary teachers as they facilitate a digital storytelling project with their students for the first time. All three teachers were not specifically trained in digital storytelling in order to investigate what happens when a digital storytelling novice tries to do a project like this with his or her students. The study follows two high school English teachers and one middle school math teacher. Each teacher's experience is shared in a case study, and all three case studies are compared and contrasted in a cross-case analysis. There is a discussion of the types of projects the teachers conducted and any challenges they faced. Strategies to overcome the challenges are also included. A variety of assessment rubrics are included in the appendix. In the review of literature, the history of digital storytelling is illuminated, as are historical concepts of literacy. There is also an exploration of twenty-first century skills including multiliteracies such as media and technology literacy. Both the teachers and their students offer suggestions to future teachers taking on digital storytelling projects. The dissertation ends with a discussion of future scholarship in educational uses of digital storytelling.
ContributorsGordon, Corrine (Author) / Blasingame, James (Thesis advisor) / Nilsen, Alleen P (Committee member) / Early, Jessica (Committee member) / Marsh, Josephine (Committee member) / Arizona State University (Publisher)
Created2011
Description
Research has shown that being a female athlete in a male-dominated sports world is an oppressive burden, yet the experiences of being a black female athlete have been largely ignored. To combat this lack of attention, this paper invokes communication and feminist theorist Bell Hook's concept of moving black women from margin to center to reveal the intersectional oppression of gender and racial narratives that they face in sports. By outlining the difference between white and black femininity and studying media portrayals of popular black female athletes such as Venus and Serena Williams and others, it becomes obvious how black women are typecast into certain social and athletic roles. This research also includes an auto-ethnographic component of my own experience as a black female lacrosse player at the NCAA Division I level. This component functions as a point of comparison and contrast of the ideas and concepts I discuss. Lastly, I offer recommendations and suggestions as to how to empower young black female athletes and retain them in a variety of sports. The goal of my thesis is to place special attention onto black women in an area which there is an extreme lack of representation. My own empirical research has led me to the conclusion that not only is such a discussion important, but it is absolutely necessary. If we are to fight back against hegemonic social structures such as racism and gender roles in the sports world, we must first understand what we are up against. My thesis gives us a glimpse into our imposing opponents, and I hope that future research continues this trend so that black female athletes like myself may one day be considered an athlete in the same sense that our white peers are.
ContributorsWright, Daniela Casselle (Author) / Edson, Belle (Thesis director) / Zanin, Alaina (Committee member) / Hugh Downs School of Human Communication (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Self-efficacy in engineering, engineering identity, and coping in engineering have been shown in previous studies to be highly important in the advancement of one’s development in the field of engineering. Through the creation and deployment of a 17 question survey, undergraduate and first year masters students were asked to provide information on their engagement at their university, their demographic information, and to rank their level of agreement with 22 statements relating to the aforementioned ideas. Using the results from the collected data, exploratory factor analysis was completed to identify the factors that existed and any correlations. No statistically significant correlations between the identified three factors and demographic or engagement information were found. There needs to be a significant increase in the data sample size for statistically significant results to be found. Additionally, there is future work needed in the creation of an engagement measure that successfully reflects the level and impact of participation in engineering activities beyond traditional coursework.
ContributorsJones, Elizabeth Michelle (Author) / Ganesh, Tirupalavanam (Thesis director) / Graham, Kaely (Committee member) / Electrical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05