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Description
Transit ridership is declining in most cities throughout America. Public transportation needs to be improved in order for cities to handle urban growth, reduce carbon footprint, and increase mobility across income groups. In order to determine what causes changes in transit ridership, I performed a descriptive analysis of five metro areas in the United States. I studied changes in transit ridership in Dallas, Denver, Minneapolis, Phoenix, and Seattle from 2013 through 2017 to determine where public transportation works and where it does not work. I used employment, commute, and demographic data to determine what affects transit ridership. Each metro area was studied as a separate case because the selected cities are difficult to compare directly. The Seattle metro area was the only metro to increase transit ridership throughout the period of the study. The Minneapolis metro area experienced a slight decline in transit ridership, while Phoenix and Denver declined significantly. The Dallas metro area declined most of the five cities studied. The denser metro areas fared much better than the less dense areas. In order to increase transit ridership cities should increase the density of their city and avoid sprawl. Certain factors led to declines in ridership in certain metro areas but not all. For example, gentrification contributed to ridership decline in Denver and Minneapolis, but Seattle gentrified and increased ridership. Dallas and Phoenix experienced low-levels of gentrification but experienced declining ridership. Therefore, organizations such as the American Public Transportation Association (APTA) who attempt to find the single factor causing the decline in transit ridership, or the one factor that will increase ridership are misguided. Above all, this thesis shows that there is no single factor causing the ridership decline in each metro area, and it is wise to study each metro area as a separate case.
ContributorsBarro, Joshua Andrew (Co-author) / Barro, Joshua (Co-author) / King, David (Thesis director) / Salon, Deborah (Committee member) / School of Politics and Global Studies (Contributor) / Walter Cronkite School of Journalism & Mass Comm (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Alzheimer’s disease (AD) is a progressive cognitive and behavior disorder that is characterized by the deposition of extracellular Aβ plaques, intracellular neurofibrillary tangles, and neuroinflammation. Aβ is generated by cleavage of the amyloid precursor protein (APP) by β-secretase (BACE1) and, subsequently, y- secretase. In recent years, there has been an increasing interest in studying and understanding inflammation as a therapeutic target for AD. Inflammation manifests in the brain in the form of activated microglia and astrocytes. These cells are able to release high levels of inflammatory cytokines such as Tumor Necrosis Factor-α (TNF-α). TNF-α is a major cytokine, which is involved in early inflammatory events and plays a role in the progression of AD pathology. There are currently no treatments that target chronic neuroinflammation. However, previous work in our laboratory with transgenic mice modeling AD suggested that the anti-cancer drug lenalidomide could lower neuroinflammation and slow AD progression, though the cellular and molecular mechanisms are yet to be elucidated. Here we hypothesized that lenalidomide can modulate TNF-α production in microglia and decrease amyloidogenesis. Using immortal cell lines mimicking several brain cell types, we discovered that lenalidomide is likely to decrease inflammation by modulating microglia cells rather than neurons or astrocytes. In addition, the drug may prevent the overexpression of BACE1 upon inflammation, thus blocking the overproduction of Aβ. If confirmed, these results could lead to a better understanding of how inflammation regulates Aβ synthesis and provide novel cellular and molecular therapeutic targets to control the progression AD.
ContributorsGujju, Manasa (Author) / DeCourt, Boris (Thesis director) / Olive, M. Foster (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Nicotine addiction remains a prevalent public health issue, and the FDA has released a statement outlining the systematic reduction of nicotine to non-zero levels in the coming years. Current research has not yet established the effects of abrupt nicotine dose reduction on vulnerability to relapse, nor has abrupt nicotine dose reduction been evaluated in terms of behavioral economic characteristics of demand and elasticity been evaluated for reduced doses of nicotine. Using a rat model, we first evaluated the comparability of between- and within-session protocols for establishing characteristics of demand and elasticity for nicotine to shorten experimental timelines for this study and future studies. We then tested environmental enrichment and sex as factors of elasticity of demand for nicotine. Using a rat model of relapse to cues, we also examined the effects of nicotine dose-reduction on vulnerability to relapse. We found differences in maximum consumption and demand between the between- and within-session protocols, as well as sex differences in elasticity of demand on the within-session protocol where male demand was more elastic than female demand. Additionally, we found that enrichment significantly increased elasticity of demand for nicotine for both males and females. Finally, preliminary analyses revealed that nicotine dose reduction yields more inelastic demand and higher maximum consumption, and these outcomes predict increased time to extinction of the association between nicotine and contingent cues, and increased rates of relapse. These studies highlight the usefulness and validity of within-session protocols, and also illustrate the necessity for rigorous testing of forced dose reduction on nicotine vulnerability.
ContributorsCabrera-Brown, Gabriella Paula (Author) / Gipson-Reichardt, Cassandra (Thesis director) / Olive, M. Foster (Committee member) / Davis, Mary (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Cases of heroin use and overdose are on the rise in the United States which has created what some call a public health crisis. Previous studies have investigated the beneficial effect of social interaction recovering addicts, and in animal models of addiction, social interaction can prevent or reverse the conditioned rewarding effects of cocaine. This study sought to determine if social interaction would prevent or diminish a conditioned preference for a heroin-paired context. Following establishment of baseline place preference, adult male Sprague-Dawley rats underwent once daily conditioning with either saline, heroin (1 mg/kg), or the animal's cage-mate for a total of 8 conditioning sessions. Assessment of post-conditioning place preference revealed that both the heroin injections and the presence of the cage-mate produced a place preference . In contrast to the findings of previous studies using cocaine as the conditioning drug, it was determined that rats preferred the heroin-paired context over that paired with the cage-mate.. These findings suggest that the protective effects of social interaction found in prior studies using cocaine as the conditioning drug may not extend to opiates, perhaps a result of stronger contextual conditioning and/or rewarding effects of this class of abused drugs.
ContributorsMarble, Krista Lillian (Author) / Olive, M. Foster (Thesis director) / Tomek, Seven (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The RAS/MAPK (RAS/Mitogen Activated Protein Kinase) pathway is a highly conserved, canonical signaling cascade that is highly involved in cellular growth and proliferation as well as cell migration. As such, it plays an important role in development, specifically in development of the nervous system. Activation of ERK is indispensable for the differentiation of Embryonic Stem Cells (ESC) into neuronal precursors (Li z et al, 2006). ERK signaling has also shown to mediate Schwann cell myelination of the peripheral nervous system (PNS) as well as oligodendrocyte proliferation (Newbern et al, 2011). The class of developmental disorders that result in the dysregulation of RAS signaling are known as RASopathies. The molecular and cell-specific consequences of these various pathway mutations remain to be elucidated. While there is evidence for altered DNA transcription in RASopathies, there is little work examining the effects of the RASopathy-linked mutations on protein translation and post-translational modifications in vivo. RASopathies have phenotypic and molecular similarities to other disorders such as Fragile X Syndrome (FXS) and Tuberous Sclerosis (TSC) that show evidence of aberrant protein synthesis and affect related pathways. There are also well-defined downstream RAS pathway elements involved in translation. Additionally, aberrant corticospinal axon outgrowth has been observed in disease models of RASopathies (Xing et al, 2016). For these reasons, this present study examines a subset of proteins involved in translation and translational regulation in the context of RASopathy disease states. Results indicate that in both of the tested RASopathy model systems, there is altered mTOR expression. Additionally the loss of function model showed a decrease in rps6 activation. This data supports a role for the selective dysregulation of translational control elements in RASopathy models. This data also indicates that the primary candidate mechanism for control of altered translation in these modes is through the altered expression of mTOR.
ContributorsHilbert, Alexander Robert (Author) / Newbern, Jason (Thesis director) / Olive, M. Foster (Committee member) / Bjorklund, Reed (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The dissertation focuses on several Romanian avant-garde magazines, such as Contimporanul, Integral, and 75HP, that Romanian artists and writers created in Romania in the 1920s, after Romanian Dadaists Tristan Tzara and Marcel Iancu disbanded from Zurich Dada in the 1910s. The Romanian avant-garde magazines launched the Romanian avant-garde movement—the most intense period of artistic production in the country. The Romanian avant-gardists established Integralism in an attempt to differentiate themselves from other European avant-garde groups and to capture the intense and innovative creative spirit of their modern era by uniting and condensing avant-garde and modern styles on the pages of their magazines. However, I argue that instead of Integralism, what the Romanian avant-garde magazines put forth were Romanian avant-garde versions of Constructivism and Cubism conveyed in the magazines’ constructivist prints and reproductions of cubist paintings. The originality of the Romanian avant-garde magazines, thus, is concentrated in their appropriation and reinterpretation of Constructivism and Cubism rather than in their Integralism. Moreover, in their rebellion and resistance to Romania’s social, political, and artistic status quo, the Romanian avant-garde magazines functioned as an instrument with which the Romanian avant-gardists expressed their complex relationship with their Jewish identity. The magazines were not on the periphery of artistic production, as art history discourse on modern and avant-garde art has situated them, but were an important player in the global network of avant-garde magazines that traversed across eastern and western Europe, South America, the United States, and Japan.
ContributorsMiholca, Amelia (Author) / Mesch, Claudia (Thesis advisor) / Orlich, Ileana (Committee member) / Holian, Anna (Committee member) / Navarro, Rudy (Committee member) / Arizona State University (Publisher)
Created2021
Description
Traditional Reinforcement Learning (RL) assumes to learn policies with respect to reward available from the environment but sometimes learning in a complex domain requires wisdom which comes from a wide range of experience. In behavior based robotics, it is observed that a complex behavior can be described by a combination of simpler behaviors. It is tempting to apply similar idea such that simpler behaviors can be combined in a meaningful way to tailor the complex combination. Such an approach would enable faster learning and modular design of behaviors. Complex behaviors can be combined with other behaviors to create even more advanced behaviors resulting in a rich set of possibilities. Similar to RL, combined behavior can keep evolving by interacting with the environment. The requirement of this method is to specify a reasonable set of simple behaviors. In this research, I present an algorithm that aims at combining behavior such that the resulting behavior has characteristics of each individual behavior. This approach has been inspired by behavior based robotics, such as the subsumption architecture and motor schema-based design. The combination algorithm outputs n weights to combine behaviors linearly. The weights are state dependent and change dynamically at every step in an episode. This idea is tested on discrete and continuous environments like OpenAI’s “Lunar Lander” and “Biped Walker”. Results are compared with related domains like Multi-objective RL, Hierarchical RL, Transfer learning, and basic RL. It is observed that the combination of behaviors is a novel way of learning which helps the agent achieve required characteristics. A combination is learned for a given state and so the agent is able to learn faster in an efficient manner compared to other similar approaches. Agent beautifully demonstrates characteristics of multiple behaviors which helps the agent to learn and adapt to the environment. Future directions are also suggested as possible extensions to this research.
ContributorsVora, Kevin Jatin (Author) / Zhang, Yu (Thesis advisor) / Yang, Yezhou (Committee member) / Praharaj, Sarbeswar (Committee member) / Arizona State University (Publisher)
Created2021
Description
The Hong Kong-born Canadian photographer and performance artist Tseng Kwong Chi mostly worked in the United States until the year he died in 1990. Upon arriving in New York in 1979, he started his career with a new name. By dropping his anglicized name Joseph and replacing it with his Chinese given name Kwong Chi, Tseng made a clear statement: this is my staged persona who refuses to assimilate to Western culture. This thesis deconstructs Tseng’s key works, including his party-crashing Met series, the decade-long East Meets West series, and the extended Expeditionary series. With his persona disguised by wearing a Mao suit and a pair of sunglasses, I argue that Tseng was a pioneer in the genre of Asian American performance photography and that his work foreshadowed the cultural jamming movement in his innovative use of détournement while it also critically comments on orientalism, cultural fetish, and Asian identity politics. Additionally, Tseng’s work served as a bridge, connecting art history with issues of Asian American identity. As a gay artist who worked mostly in the United States, his work was an early example of what Jachinson Chan has suggested as an alternative model of masculinity for Asian American men: that Asian American men can be free, independent, expressive, and willing to embrace femininity with their masculinity. As David Eng has argued, Tseng also bridged the fields of Asian American queer studies and diaspora studies. Moreover, Tseng carried the legacy of the first-generation Chinese American artists in the medium of photography and inspired the next generation of diasporic artists to explore Asian identity, and to contest the image of Mao and the power dynamics between East and West.
ContributorsWei, Xin (Author) / Mesch, Claudia (Thesis advisor) / Hoy, Meredith (Committee member) / Kuo, Karen (Committee member) / Arizona State University (Publisher)
Created2022
Description
This dissertation consists of three chapters that investigate the rapid adoption and complex implementation of city commitments to transition to 100% renewable energy (100RE). The first paper uses a two-stage, mixed methods approach to examine 100RE commitments across the US, combining a multivariate regression of demographic, institutional, and policy factors in adoption and six interview-based state case studies to discuss implementation. Adoption of this non-binding commitment progressed rapidly for city councils around the US. Results show that many cities passed 100RE commitments with no implementation plan and minimal understanding of implementation challenges. This analysis highlights that many cities will need new institutions and administrative capacities for successful implementation of these ambitious new policies. While many cities abandoned the commitment soon after adoption, collaboration allowed cities in a few states to break through and pursue implementation, examined further in the next two studies. The second paper is a qualitative case study examining policymaking for the Utah Community Renewable Energy Act. Process tracing methods are used to identify causal factors in enacting this legislation at the state level and complementary resolutions at the local level. This Act was passed through the leadership and financial backing of major cities and committed the investor-owned utility to fulfill any city 100RE resolutions passed through 2019. Finally, the third paper is a mixed-methods, descriptive case study of the benefits of Community Choice Aggregation (CCA) in California, which many cities are using to fulfill their 100RE commitments. Cities have adopted CCAs to increase their local voice in the energy process, while fulfilling climate and energy goals. Overall, this research shows that change in the investor-owned utility electricity system is in fact possible from the city scale, though many cities will need institutional innovation to implement these policies and achieve the change they desire. While cities with greater resources are better positioned to make an impact, smaller cities can collaborate to similarly influence the energy system. Communities are interested in lowering energy costs for customers where possible, but the central motivations in these cases were the pursuit of sustainability and increasing local voice in energy decision-making.
ContributorsKunkel, Leah Christine (Author) / Breetz, Hanna L (Thesis advisor) / Parker, Nathan (Committee member) / Salon, Deborah (Committee member) / Arizona State University (Publisher)
Created2022
Description
With rapid advances in technology development and public adoption, it is crucial to understand how these services will shape the future of travel depending on the extent to which people will use these services; impact the transportation and infrastructure systems such as changes in the use of transit and active modes of travel; and influence how technology developers create and update these transportation technologies to better serve people’s mobility needs. This dissertation explores how two major emerging services, namely ridehailing services and autonomous vehicles (AVs), will be used in the future when they are widely available and vastly used, and how they may impact the transportation infrastructure and societal travel patterns. The four proposed chapters use comprehensive quantitative and qualitative methods to explore the status of these technologies from theory, through robust modeling frameworks, to practice, by investigating the recent AV pilot deployments in real-world settings. In the second chapter, it was found that increased frequency of ridehailing use is significantly associated with a decrease in bus usage, suggesting that ridehailing functions more as a substitute for buses than as a complement and implying that transit agencies should explore ways to incorporate ridehailing services in their plans to enhance transit usage. Next, the third chapter showed that interest in using AVs for running errands had a positive and significant effect on AV ownership intent, even after accounting for a host of variables. The fourth chapter depicted how ridehailing experiences have a considerable effect on the willingness to ride AV-based services in both private and shared modes, suggesting that experience is crucial for future adoption of these services. Then, two recent real-world AV experiences are explored in the fifth chapter. Lessons learned from these experiments reinforced the importance of first-hand experiences in promoting AV awareness and trustworthiness, potentially leading to greater degrees of adoption. Finally, the results and discussions presented in this dissertation strengthen the body of literature on key emerging transportation technologies and inform policymakers and stakeholders to properly prepare cities and the public to welcome these technologies into our transportation system in an efficient, equitable, and complementary way.
ContributorsMagassy, Tassio Bezerra (Author) / Pendyala, Ram M (Thesis advisor) / Khoeini, Sara (Committee member) / Polzin, Steven E (Committee member) / Salon, Deborah (Committee member) / Arizona State University (Publisher)
Created2023