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.
Displaying 1 - 10 of 319
Filtering by
- All Subjects: Neurosciences
- All Subjects: Rhetoric
Description
Intermittent social defeat stress induces cross-sensitization to psychostimulants and escalation of drug self-administration. These behaviors could result from the stress-induced neuroadaptation in the mesocorticolimbic dopamine circuit. Brain-derived neurotrophic factor (BDNF) in the ventral tegmental area (VTA) is persistently elevated after social defeat stress, and may contribute to the stress-induced neuroadaptation in the mesocorticolimbic dopamine circuit. BDNF modulates synaptic plasticity, and facilitates stress- and drug-induced neuroadaptations in the mesocorticolimbic system. The present research examined the role of mesolimbic BDNF signaling in social defeat stress-induced cross-sensitization to psychostimulants and the escalation of cocaine self-administration in rats. We measured drug taking behavior with the acquisition, progressive ratio, and binge paradigms during self-administration. With BDNF overexpression in the ventral tegmental area (VTA), single social defeat stress-induced cross-sensitization to amphetamine (AMPH) was significantly potentiated. VTA-BDNF overexpression also facilitates acquisition of cocaine self-administration, and a positive correlation between the level of VTA BDNF and drug intake during 12 hour binge was observed. We also found significant increase of DeltaFosB expression in the nucleus accumbens (NAc), the projection area of the VTA, in rats received intra-VTA BDNF overexpression. We therefore examined whether BDNF signaling in the NAc is important for social defeat stress-induced cross-sensitization by knockdown of the receptor of BDNF (neurotrophin tyrosine kinase receptor type 2, TrkB) there. NAc TrkB knockdown prevented social defeat stress-induced cross-sensitization to psychostimulant. Also social defeat stress-induced increase of DeltaFosB in the NAc was prevented by TrkB knockdown. Several other factors up-regulated by stress, such as the GluA1 subunit of Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor and BDNF in the VTA were also prevented. We conclude that BDNF signaling in the VTA increases social defeat stress-induced vulnerability to psychostimulants, manifested as potentiated cross-sensitization/sensitization to AMPH and escalation of cocaine self-administration. Also BDNF signaling in the NAc is necessary for the stress-induced neuroadaptation and behavioral sensitization to psychostimulants. Therefore, TrkB in the NAc could be a therapeutic target to prevent stress-induced vulnerability to drugs of abuse in the future. DeltaFosB in the NAc shell could be a neural substrate underlying persistent cross-sensitization and augmented cocaine self-administration induced by social defeat stress.
ContributorsWang, Junshi (Author) / Hammer, Ronald (Thesis advisor) / Feuerstein, Burt (Committee member) / Nikulina, Ella (Committee member) / Neisewander, Janet (Committee member) / Arizona State University (Publisher)
Created2013
Description
Induced pluripotent stem cells (iPSCs) are an intriguing approach for neurological disease modeling, because neural lineage-specific cell types that retain the donors' complex genetics can be established in vitro. The statistical power of these iPSC-based models, however, is dependent on accurate diagnoses of the somatic cell donors; unfortunately, many neurodegenerative diseases are commonly misdiagnosed in live human subjects. Postmortem histopathological examination of a donor's brain, combined with premortem clinical criteria, is often the most robust approach to correctly classify an individual as a disease-specific case or unaffected control. We describe the establishment of primary dermal fibroblasts cells lines from 28 autopsy donors. These fibroblasts were used to examine the proliferative effects of establishment protocol, tissue amount, biopsy site, and donor age. As proof-of-principle, iPSCs were generated from fibroblasts from a 75-year-old male, whole body donor, defined as an unaffected neurological control by both clinical and histopathological criteria. To our knowledge, this is the first study describing autopsy donor-derived somatic cells being used for iPSC generation and subsequent neural differentiation. This unique approach also enables us to compare iPSC-derived cell cultures to endogenous tissues from the same donor. We utilized RNA sequencing (RNA-Seq) to evaluate the transcriptional progression of in vitro-differentiated neural cells (over a timecourse of 0, 35, 70, 105 and 140 days), and compared this with donor-identical temporal lobe tissue. We observed in vitro progression towards the reference brain tissue, supported by (i) a significant increasing monotonic correlation between the days of our timecourse and the number of actively transcribed protein-coding genes and long intergenic non-coding RNAs (lincRNAs) (P < 0.05), consistent with the transcriptional complexity of the brain, (ii) an increase in CpG methylation after neural differentiation that resembled the epigenomic signature of the endogenous tissue, and (iii) a significant decreasing monotonic correlation between the days of our timecourse and the percent of in vitro to brain-tissue differences (P < 0.05) for tissue-specific protein-coding genes and all putative lincRNAs. These studies support the utility of autopsy donors' somatic cells for iPSC-based neurological disease models, and provide evidence that in vitro neural differentiation can result in physiologically progression.
ContributorsHjelm, Brooke E (Author) / Craig, David W. (Thesis advisor) / Wilson-Rawls, Norma J. (Thesis advisor) / Huentelman, Matthew J. (Committee member) / Mason, Hugh S. (Committee member) / Kusumi, Kenro (Committee member) / Arizona State University (Publisher)
Created2013
Description
Alzheimer's Disease (AD) is a progressive neurodegenerative disease accounting for 50-80% of dementia cases in the country. This disease is characterized by the deposition of extracellular plaques occurring in regions of the brain important for cognitive function. A primary component of these plaques is the amyloid-beta protein. While a natively unfolded protein, amyloid-beta can misfold and aggregate generating a variety of different species including numerous different soluble oligomeric species some of which are precursors to the neurofibrillary plaques. Various of the soluble amyloid-beta oligomeric species have been shown to be toxic to cells and their presence may correlate with progression of AD. Current treatment options target the dementia symptoms, but there is no effective cure or alternative to delay the progression of the disease once it occurs. Amyloid-beta aggregates show up many years before symptoms develop, so detection of various amyloid-beta aggregate species has great promise as an early biomarker for AD. Therefore reagents that can selectively identify key early oligomeric amyloid-beta species have value both as potential diagnostics for early detection of AD and as well as therapeutics that selectively target only the toxic amyloid-beta aggregate species. Earlier work in the lab includes development of several different single chain antibody fragments (scFvs) against different oligomeric amyloid-beta species. This includes isolation of C6 scFv against human AD brain derived oligomeric amyloid-beta (Kasturirangan et al., 2013). This thesis furthers research in this direction by improving the yields and investigating the specificity of modified C6 scFv as a diagnostic for AD. It is motivated by experiments reporting low yields of the C6 scFv. We also used the C6T scFv to characterize the variation in concentration of this particular oligomeric amyloid-beta species with age in a triple transgenic AD mouse model. We also show that C6T can be used to differentiate between post-mortem human AD, Parkinson's disease (PD) and healthy human brain samples. These results indicate that C6T has potential value as a diagnostic tool for early detection of AD.
ContributorsVenkataraman, Lalitha (Author) / Sierks, Michael (Thesis advisor) / Rege, Kaushal (Committee member) / Pauken, Christine (Committee member) / Arizona State University (Publisher)
Created2013
Description
It is commonly known that the left hemisphere of the brain is more efficient in the processing of verbal information, compared to the right hemisphere. One proposal suggests that hemispheric asymmetries in verbal processing are due in part to the efficient use of top-down mechanisms by the left hemisphere. Most evidence for this comes from hemispheric semantic priming, though fewer studies have investigated verbal memory in the cerebral hemispheres. The goal of the current investigations is to examine how top-down mechanisms influence hemispheric asymmetries in verbal memory, and determine the specific nature of hypothesized top-down mechanisms. Five experiments were conducted to explore the influence of top-down mechanisms on hemispheric asymmetries in verbal memory. Experiments 1 and 2 used item-method directed forgetting to examine maintenance and inhibition mechanisms. In Experiment 1, participants were cued to remember or forget certain words, and cues were presented simultaneously or after the presentation of target words. In Experiment 2, participants were cued again to remember or forget words, but each word was repeated once or four times. Experiments 3 and 4 examined the influence of cognitive load on hemispheric asymmetries in true and false memory. In Experiment 3, cognitive load was imposed during memory encoding, while in Experiment 4, cognitive load was imposed during memory retrieval. Finally, Experiment 5 investigated the association between controlled processing in hemispheric semantic priming, and top-down mechanisms used for hemispheric verbal memory. Across all experiments, divided visual field presentation was used to probe verbal memory in the cerebral hemispheres. Results from all experiments revealed several important findings. First, top-down mechanisms used by the LH primarily used to facilitate verbal processing, but also operate in a domain general manner in the face of increasing processing demands. Second, evidence indicates that the RH uses top-down mechanisms minimally, and processes verbal information in a more bottom-up manner. These data help clarify the nature of top-down mechanisms used in hemispheric memory and language processing, and build upon current theories that attempt to explain hemispheric asymmetries in language processing.
ContributorsTat, Michael J (Author) / Azuma, Tamiko (Thesis advisor) / Goldinger, Stephen D (Committee member) / Liss, Julie M (Committee member) / Arizona State University (Publisher)
Created2013
Description
The connection between Hollywood costume design and the films of the 007/James Bond franchise, especially in regards to the changing perspective of the “Bond Girl”, is an intricate relationship that has previously been little researched. In the most recent Bond films, in particular, the female characters have become more powerful than the early characters and their roles within the narratives have changed with their characters taking on stronger and more integral roles. This thesis seeks to examine the films of the 007/James Bond franchise and how the rhetoric of the franchise’s costume design affects the representation of femininity and power in regards to the Bond Girls. After an overview of Bond history and costume theory, two films are analyzed as case studies: Dr. No (1962) which marks the beginning of the film franchise and Casino Royale (2006), which marks the more recent turn the films have taken. This thesis examines how the representations of Bond Girls and the use of costume design for their characters have changed over the course of the franchise from the days of Sean Connery to the recent reboot of the franchise with Daniel Craig as 007 James Bond. In addition to an examination of Bond Girl costume design, this thesis considers the role and influence of the costume designers. A designer’s vision of a character is derived from both the writing and the physical features of the actresses before them. Here this thesis considers how the rhetorical choices made by designers have contributed to an understanding of the relationship between femininity and power. Finally it shows how the costumes effect the power of the female characters and how the Bond Girls of today (Casino Royale) compare and/or contrast to Bond Girls of the past (Dr. No). This thesis combines the areas of feminist film theory and costume theory to provide an original rhetorical analysis of the Bond series in relation to costume design and examines the rhetorical statements made by the costume designers in their designs for the characters and how those statements influence the representations of the characters.
ContributorsSeverson, Andrea (Author) / Goggin, Maureen (Thesis advisor) / Ore, Ersula (Committee member) / Lamp, Kathleen (Committee member) / Arizona State University (Publisher)
Created2013
Description
Perceptual learning by means of coherent motion training paradigms has been shown to produce plasticity in lower and higher-level visual systems within the human occipital lobe both supra- and subliminally. However, efficiency of training methods that produce consolidation in the visual system via coherent motion has yet to be experimentally determined. Furthermore, the effects of coherent motion training on reading comprehension, in clinical and normal populations, are still nascent. In the present study, 20 participants were randomly assigned to one of four experimental conditions. Two conditions had a participation requirement of four days while two conditions required eight days of participation. These conditions were further divided into 500 or 1000 trials per day (4 x 500, 4 x 1000, 8 x 500, 8 x 1000). Additional pre-test and post-test days were used to attain timed pre- and post-tests on the Wide Range Achievement Test IV (WRAT IV) reading comprehension battery. Furthermore, a critical flicker fusion threshold (CFFT) score was taken on a macular pigment densitometer on the pre-test and post-test day. Participants showed significant improvement in CFFT levels, WRAT IV reading comprehension, and speed of completion between pre-test and post-test; however, degree of improvement did not vary as a function of training condition. An interaction between training condition and degree of improvement was evident in coherent dot motion contrast scores, with significant training plasticity occurring in the 4 x 1000 and 8 x 500 conditions.
ContributorsGroth, Anthony (Author) / Náñez, José E. (Thesis advisor) / Hall, Deborah (Committee member) / Risko, Evan F. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Simultaneously culture heroes and stumbling buffoons, Tricksters bring cultural tools to the people and make the world more habitable. There are common themes in these figures that remain fruitful for the advancement of culture, theory, and critical praxis. This dissertation develops a method for opening a dialogue with Trickster figures. It draws from established literature to present a newly conceived and more flexible Trickster archetype. This archetype is more than a collection of traits; it builds on itself processually to form a method for analysis. The critical Trickster archetype includes the fundamental act of crossing borders; the twin ontologies of ambiguity and liminality; the particular tactics of humor, duplicity, and shape shifting; and the overarching cultural roles of culture hero and stumbling buffoon. Running parallel to each archetypal element, though, are Trickster's overarching critical spirit of Quixotic utopianism and underlying telos of manipulating human relationships. The character 'Q' from Star Trek: The Next Generation is used to demonstrate the critical Trickster archetype. To be more useful for critical cultural studies, Trickster figures must also be connected to their socio-cultural and historical contexts. Thus, this dissertation offers a second set of analytics, a dialogical method that connects Tricksters to the worlds they make more habitable. This dialogical method, developed from the work of M. M. Bakhtin and others, consists of three analytical tools: utterance, intertextuality, and chronotope. Utterance bounds the text for analysis. Intertextuality connects the utterance, the text, to its context. Chronotope suggests particular spatio-temporal relationships that help reveal the cultural significance of a dialogical performance. Performance artists Andre Stitt, Ann Liv Young, and Steven Leyba are used to demonstrate the method of Trickster dialogics. A concluding discussion of Trickster's unique chronotope reveals its contributions to conceptions of utopia and futurity. This dissertation offers theoretical advancements about the significance and tactics of subversive communication practices. It offers a new and unique method for cultural and performative analyses that can be expanded into different kinds of dialogics. Trickster dialogics can also be used generatively to direct and guide the further development of performative praxis.
ContributorsSalinas, Chema (Author) / de la Garza, Amira (Thesis advisor) / Carlson, Cheree (Committee member) / Olson, Clark (Committee member) / Ellsworth, Angela (Committee member) / Arizona State University (Publisher)
Created2013
Description
Specific dendritic morphologies are a hallmark of neuronal identity, circuit assembly, and behaviorally relevant function. Despite the importance of dendrites in brain health and disease, the functional consequences of dendritic shape remain largely unknown. This dissertation addresses two fundamental and interrelated aspects of dendrite neurobiology. First, by utilizing the genetic power of Drosophila melanogaster, these studies assess the developmental mechanisms underlying single neuron morphology, and subsequently investigate the functional and behavioral consequences resulting from developmental irregularity. Significant insights into the molecular mechanisms that contribute to dendrite development come from studies of Down syndrome cell adhesion molecule (Dscam). While these findings have been garnered primarily from sensory neurons whose arbors innervate a two-dimensional plane, it is likely that the principles apply in three-dimensional central neurons that provide the structural substrate for synaptic input and neural circuit formation. As such, this dissertation supports the hypothesis that neuron type impacts the realization of Dscam function. In fact, in Drosophila motoneurons, Dscam serves a previously unknown cell-autonomous function in dendrite growth. Dscam manipulations produced a range of dendritic phenotypes with alteration in branch number and length. Subsequent experiments exploited the dendritic alterations produced by Dscam manipulations in order to correlate dendritic structure with the suggested function of these neurons. These data indicate that basic motoneuron function and behavior are maintained even in the absence of all adult dendrites within the same neuron. By contrast, dendrites are required for adjusting motoneuron responses to specific challenging behavioral requirements. Here, I establish a direct link between dendritic structure and neuronal function at the level of the single cell, thus defining the structural substrates necessary for conferring various aspects of functional motor output. Taken together, information gathered from these studies can inform the quest in deciphering how complex cell morphologies and networks form and are precisely linked to their function.
ContributorsHutchinson, Katie Marie (Author) / Duch, Carsten (Thesis advisor) / Neisewander, Janet (Thesis advisor) / Newfeld, Stuart (Committee member) / Smith, Brian (Committee member) / Orchinik, Miles (Committee member) / Arizona State University (Publisher)
Created2013
Description
This study analyzes syllabi for first-year college composition courses and interview responses to examine how the choices made by instructors affect online course design. Using the Syllabus Assessment Instrument designed by Madson, Melchert and Whipp (2004), this dissertation looks specifically at attendance and participation policies, course behavior policies, contact information, required material choices, course organization decisions and tool decisions to reveal how instructors do or do not accommodate online class pedagogies. This study finds that the choices instructors make in syllabus design provide significant information about the overall online course design itself. Using Selber's multiliteracies as a frame for understanding the choices made by instructors, this study finds that instructors focus primarily on functional literacies in their discourses and in the way they communicate their choices to students. Instructors vary in how they inform students of the mechanics of how to interact with tools, how often to interact with the online course, and how to use the tools within the online course. While these aspects of online courses are important, focusing on these aspects of the online course overshadows alternative perspectives on tool use that could encourage critical reflection by both instructors and students. To help instructors and departments design more effective syllabi and courses, this study raises questions and offers observations about how instructors communicate policies and how they understand these policies and pedagogies in online courses. In providing general guidelines for syllabus design and course design, this study will help writing instructors and composition programs better understand the significance of the choices they make in online course design.
ContributorsPfannenstiel, Amber Nicole (Author) / Goggin, Peter (Thesis advisor) / Daly Goggin, Maureen (Committee member) / Hayes, Elisabeth (Committee member) / Arizona State University (Publisher)
Created2013
Description
The current research examines the influence of disciplines, advisors, committees, language, culture, and previous experiences in students' search and selection of dissertation topics, as well as whether and how students react to those influences during this process. Invention has been an area of research for rhetoricians for centuries, but most modern research focuses exclusively on the pre-writing process in first composition classrooms (Young, 1976). The current research collected survey and interview data from second- and third-year Ph.D. students in natural sciences, social sciences, and humanities at a large research university in the United States. 80 second- and third-year Ph.D. students completed an online survey; 11 students and four of their advisors participated in a semi-structured interview. The results demonstrate that the majority of students spent over three months in the selection of dissertation topics, and the humanities students tended to spend longer time in this process than social sciences or humanities students. Additionally, students have much in common in their perception of the criteria they would use in the selection of dissertation topics, and those criteria are similar to what previous researchers (Isaac, Koenigsknecht, Malaney, & Karras, 1989; Kozma, 1997; Sessions, 1971) have identified. However, when it comes to the actual selection experiences, the interviews show that students do not necessarily apply those criteria rationally. Moreover, disciplines appear to have an overarching effect on students' topic selection. Natural sciences advisors appeared to have more direct involvement in students' topic choice than advisors in social sciences or humanities. The linguistic and cultural backgrounds of the eleven doctoral participants were not found influential in their selection of dissertation topics. Finally, although Ph.D. advisors generally have a good understanding of students' academic progress, their knowledge of the students' personal and professional concerns may differ, and the latter knowledge is crucial in their advising on students' dissertation topic choice. The current study suggests invention in the scholar and researcher level is significantly different from that of first-year composition classrooms. The successful invention of dissertation topics is indispensable of the influence of disciplines, programs as well as the intellectual and practical support students can receive.
ContributorsXia, Jing (Author) / Matsuda, Paul K (Thesis advisor) / James, Mark (Committee member) / Renaud, Claire (Committee member) / Arizona State University (Publisher)
Created2013