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Description
In an effort to address the lack of literature in on-campus active travel, this study aims to investigate the following primary questions:<br/>• What are the modes that students use to travel on campus?<br/>• What are the motivations that underlie the mode choice of students on campus?<br/>My first stage of research involved a series of qualitative investigations. I held one-on-one virtual interviews with students in which I asked them questions about the mode they use and why they feel that their chosen mode works best for them. These interviews served two functions. First, they provided me with insight into the various motivations underlying student mode choice. Second, they provided me with an indication of what explanatory variables should be included in a model of mode choice on campus.<br/>The first half of the research project informed a quantitative survey that was released via the Honors Digest to attract student respondents. Data was gathered on travel behavior as well as relevant explanatory variables.<br/>My analysis involved developing a logit model to predict student mode choice on campus and presenting the model estimation in conjunction with a discussion of student travel motivations based on the qualitative interviews. I use this information to make a recommendation on how campus infrastructure could be modified to better support the needs of the student population.
ContributorsMirtich, Laura Christine (Author) / Salon, Deborah (Thesis director) / Fang, Kevin (Committee member) / School of Public Affairs (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Laboratory automation systems have seen a lot of technological advances in recent times. As a result, the software that is written for them are becoming increasingly sophisticated. Existing software architectures and standards are targeted to a wider domain of software development and need to be customized in order to use them for developing software for laboratory automation systems. This thesis proposes an architecture that is based on existing software architectural paradigms and is specifically tailored to developing software for a laboratory automation system. The architecture is based on fairly autonomous software components that can be distributed across multiple computers. The components in the architecture make use of asynchronous communication methodologies that are facilitated by passing messages between one another. The architecture can be used to develop software that is distributed, responsive and thread-safe. The thesis also proposes a framework that has been developed to implement the ideas proposed by the architecture. The framework is used to develop software that is scalable, distributed, responsive and thread-safe. The framework currently has components to control very commonly used laboratory automation devices such as mechanical stages, cameras, and also to do common laboratory automation functionalities such as imaging.
ContributorsKuppuswamy, Venkataramanan (Author) / Meldrum, Deirdre (Thesis advisor) / Collofello, James (Thesis advisor) / Sarjoughian, Hessam S. (Committee member) / Johnson, Roger (Committee member) / Arizona State University (Publisher)
Created2012
Description
Single cell analysis has become increasingly important in understanding disease onset, progression, treatment and prognosis, especially when applied to cancer where cellular responses are highly heterogeneous. Through the advent of single cell computerized tomography (Cell-CT), researchers and clinicians now have the ability to obtain high resolution three-dimensional (3D) reconstructions of single cells. Yet to date, no live-cell compatible version of the technology exists. In this thesis, a microfluidic chip with the ability to rotate live single cells in hydrodynamic microvortices about an axis parallel to the optical focal plane has been demonstrated. The chip utilizes a novel 3D microchamber design arranged beneath a main channel creating flow detachment into the chamber, producing recirculating flow conditions. Single cells are flowed through the main channel, held in the center of the microvortex by an optical trap, and rotated by the forces induced by the recirculating fluid flow. Computational fluid dynamics (CFD) was employed to optimize the geometry of the microchamber. Two methods for the fabrication of the 3D microchamber were devised: anisotropic etching of silicon and backside diffuser photolithography (BDPL). First, the optimization of the silicon etching conditions was demonstrated through design of experiment (DOE). In addition, a non-conventional method of soft-lithography was demonstrated which incorporates the use of two positive molds, one of the main channel and the other of the microchambers, compressed together during replication to produce a single ultra-thin (<200 µm) negative used for device assembly. Second, methods for using thick negative photoresists such as SU-8 with BDPL have been developed which include a new simple and effective method for promoting the adhesion of SU-8 to glass. An assembly method that bonds two individual ultra-thin (<100 µm) replications of the channel and the microfeatures has also been demonstrated. Finally, a pressure driven pumping system with nanoliter per minute flow rate regulation, sub-second response times, and < 3% flow variability has been designed and characterized. The fabrication and assembly of this device is inexpensive and utilizes simple variants of conventional microfluidic fabrication techniques, making it easily accessible to the single cell analysis community.
ContributorsMyers, Jakrey R (Author) / Meldrum, Deirdre (Thesis advisor) / Johnson, Roger (Committee member) / Frakes, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Website usage on both smartphone and tablet devices is rapidly increasing. Website success hinges largely upon how well information on the site is recalled and perceived. The purpose of this study is to explore the question of whether or not the differences in display size and resolution of smartphone versus tablet devices affect the recall of website information. I hypothesize that tablets will produce greater website recall than smartphones, due to their larger screen size and higher resolution which may reduce cognitive strain. During the study, participants viewed a sample website for two minutes on either an iPhone or iPad, and then participated in a brief 20 question memory test to evaluate how well they remembered the website information. Although test scores for the iPad users were about one test point higher than test scores for the iPhone users, the difference was not statistically significant. However, the study was limited by the low sample size (n = 94). This indicates that further research may find that tablets indeed allow for increased recall of certain kinds of website content.
ContributorsRaines, David Thomas (Author) / Martin, Judith (Thesis director) / Johnson, Kathryn (Committee member) / Wiedmaier, Benjamin (Committee member) / Barrett, The Honors College (Contributor) / Hugh Downs School of Human Communication (Contributor) / Department of Psychology (Contributor)
Created2013-05
Description
Background
Grading schemes for breast cancer diagnosis are predominantly based on pathologists' qualitative assessment of altered nuclear structure from 2D brightfield microscopy images. However, cells are three-dimensional (3D) objects with features that are inherently 3D and thus poorly characterized in 2D. Our goal is to quantitatively characterize nuclear structure in 3D, assess its variation with malignancy, and investigate whether such variation correlates with standard nuclear grading criteria.
Methodology
We applied micro-optical computed tomographic imaging and automated 3D nuclear morphometry to quantify and compare morphological variations between human cell lines derived from normal, benign fibrocystic or malignant breast epithelium. To reproduce the appearance and contrast in clinical cytopathology images, we stained cells with hematoxylin and eosin and obtained 3D images of 150 individual stained cells of each cell type at sub-micron, isotropic resolution. Applying volumetric image analyses, we computed 42 3D morphological and textural descriptors of cellular and nuclear structure.
Principal Findings
We observed four distinct nuclear shape categories, the predominant being a mushroom cap shape. Cell and nuclear volumes increased from normal to fibrocystic to metastatic type, but there was little difference in the volume ratio of nucleus to cytoplasm (N/C ratio) between the lines. Abnormal cell nuclei had more nucleoli, markedly higher density and clumpier chromatin organization compared to normal. Nuclei of non-tumorigenic, fibrocystic cells exhibited larger textural variations than metastatic cell nuclei. At p<0.0025 by ANOVA and Kruskal-Wallis tests, 90% of our computed descriptors statistically differentiated control from abnormal cell populations, but only 69% of these features statistically differentiated the fibrocystic from the metastatic cell populations.
Conclusions
Our results provide a new perspective on nuclear structure variations associated with malignancy and point to the value of automated quantitative 3D nuclear morphometry as an objective tool to enable development of sensitive and specific nuclear grade classification in breast cancer diagnosis.
Grading schemes for breast cancer diagnosis are predominantly based on pathologists' qualitative assessment of altered nuclear structure from 2D brightfield microscopy images. However, cells are three-dimensional (3D) objects with features that are inherently 3D and thus poorly characterized in 2D. Our goal is to quantitatively characterize nuclear structure in 3D, assess its variation with malignancy, and investigate whether such variation correlates with standard nuclear grading criteria.
Methodology
We applied micro-optical computed tomographic imaging and automated 3D nuclear morphometry to quantify and compare morphological variations between human cell lines derived from normal, benign fibrocystic or malignant breast epithelium. To reproduce the appearance and contrast in clinical cytopathology images, we stained cells with hematoxylin and eosin and obtained 3D images of 150 individual stained cells of each cell type at sub-micron, isotropic resolution. Applying volumetric image analyses, we computed 42 3D morphological and textural descriptors of cellular and nuclear structure.
Principal Findings
We observed four distinct nuclear shape categories, the predominant being a mushroom cap shape. Cell and nuclear volumes increased from normal to fibrocystic to metastatic type, but there was little difference in the volume ratio of nucleus to cytoplasm (N/C ratio) between the lines. Abnormal cell nuclei had more nucleoli, markedly higher density and clumpier chromatin organization compared to normal. Nuclei of non-tumorigenic, fibrocystic cells exhibited larger textural variations than metastatic cell nuclei. At p<0.0025 by ANOVA and Kruskal-Wallis tests, 90% of our computed descriptors statistically differentiated control from abnormal cell populations, but only 69% of these features statistically differentiated the fibrocystic from the metastatic cell populations.
Conclusions
Our results provide a new perspective on nuclear structure variations associated with malignancy and point to the value of automated quantitative 3D nuclear morphometry as an objective tool to enable development of sensitive and specific nuclear grade classification in breast cancer diagnosis.
ContributorsNandakumar, Vivek (Author) / Kelbauskas, Laimonas (Author) / Hernandez, Kathryn (Author) / Lintecum, Kelly (Author) / Senechal, Patti (Author) / Bussey, Kimberly (Author) / Davies, Paul (Author) / Johnson, Roger (Author) / Meldrum, Deirdre (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School of Electrical, Computer and Energy Engineering (Contributor) / Biodesign Institute (Contributor) / Center for Biosignatures Discovery Automation (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Department of Physics (Contributor)
Created2012-01-05
Description
In this honors thesis certain religious and moral beliefs were analyzed and used to predict active euthanasia acceptance for Christians in the United States. The factors used to predict euthanasia acceptance for a suffering, terminally ill individual were religiosity, empathy, God representations, and attitudes toward God. Negative correlations were observed between acceptance of euthanasia and religiosity, empathy, positive attitudes toward God, and a benevolent God representation. Positive correlations were observed between acceptance of euthanasia and negative attitudes toward God, whereas there was no significant correlation between support for euthanasia and an authoritarian God representation. When acceptance of euthanasia was regressed on these independent variables, religiosity was the most significant predictor of acceptance. It was concluded that highly religious Christians may tend to prioritize their religious teachings over their instinctual empathy for a suffering person because prematurely ending a patient’s life interferes with God’s will and reduces his role in worldly affairs.
ContributorsAustin, Richard Vincent (Author) / Johnson, Kathryn (Thesis director) / Cohen, Adam (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Gift-giving economies are economic models that freely give resources rather than barter for them or purchase them from market. Need-based transfers fit into this economic model by freely giving resources on the basis of need, provided the giver can spare the resources. The Maasai are an East African pastoral tribe that practices need-based transfers through a tradition they call osotua. If they have a partner with an established osotua relationship, then they will give any amount of cattle that partner request, provided they can spare the cattle. Cheating each other is unheard of in this tradition, but for this simulation I am introducing cheating into this economic model through feigning need. If a cheater is not in need, they will act like they are in need. If they are in need, then the cheater will request more cattle than what they need to survive. I am testing two different responses to cheating: walking-away and punishing. In the walk-away condition, the victim ends their osotua partnership and establishes a new one. In the punishment condition, a portion of the cheater's stolen cattle is destroyed.
ContributorsDunkelberger, Sophia (Author) / Aktipis, Athena (Thesis director) / Presson, Clark (Committee member) / Johnson, Kathryn (Committee member) / School of Social and Behavioral Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Perceptions of the self differ between cultures, generally between those cultures in the West and East. Some of the ways that these individuals from these cultures may differ are in their self-construal, their collectivist and individualist tendencies, and how they perceive control in their lives. The current study proposes that some of these differences are influenced by different concepts individuals hold regarding the "soul", or inner self. These concepts may be promoted by the different religious beliefs prominent in different regions. The Soul Perception Index, being developed through this study, measures belief in multiple souls, a universal soul, a single soul, or no soul. It was predicted that a belief in a single soul will correlate with an individual view of the self (individualism, independent self-construal, internal locus of control), and a universal or multi-soul belief will correlate with an interdependent view of the self (collectivism, interdependent self-construal, and external locus of control). We found that these variables did not significantly differ in their relationships with soul belief. However, Indian Hindu participants and Chinese participants seemed to score highly on all self-view variables and all soul perception types indicating that individuals from these cultures may be more predisposed to hold opposing beliefs simultaneously while US Christians are not.
ContributorsNaidu, Esha Svetha (Author) / Cohen, Adam (Thesis director) / Glenberg, Arthur (Committee member) / Johnson, Kathryn (Committee member) / School of Historical, Philosophical and Religious Studies (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This research examined the influence that Christian and Hindu religious beliefs have on environmentalism; specifically, whether beliefs that one would return to this earth after death (i.e., a belief in reincarnation) and how the world might end may explain more positive attitudes toward the environment. Participants were 533 self-identified Christians and Hindus in the United States and India who completed an online survey assessing religiosity, positive attitudes towards environmentalism, afterlife beliefs, and eschatological beliefs. Christians showed significantly lower ratings of environmentalism compared with Hindus. There were also significant negative differences found based on beliefs about heaven, eschatology beliefs, and increased religiosity in Christians, and significant positive differences found based on reincarnation, eschatology beliefs, and increased religiosity in Hindus. Overall, these results suggest that Christians are less likely to have positive attitudes toward environmentalism compared with Hindus, and that beliefs about the afterlife and the end of the world were significant predictors of environmentalist attitudes.
ContributorsParde, Madeline Morgan (Author) / Cohen, Adam (Thesis director) / Glenberg, Arthur (Committee member) / Johnson, Kathryn (Committee member) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
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