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.
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- All Subjects: Biology
- Creators: Ellison, Karin
- Creators: Liebig, Juergen
Description
The coordination of group behavior in the social insects is representative of a broader phenomenon in nature, emergent biological complexity. In such systems, it is believed that large-scale patterns result from the interaction of relatively simple subunits. This dissertation involved the study of one such system: the social foraging of the ant Temnothorax rugatulus. Physically tiny with small population sizes, these cavity-dwelling ants provide a good model system to explore the mechanisms and ultimate origins of collective behavior in insect societies. My studies showed that colonies robustly exploit sugar water. Given a choice between feeders unequal in quality, colonies allocate more foragers to the better feeder. If the feeders change in quality, colonies are able to reallocate their foragers to the new location of the better feeder. These qualities of flexibility and allocation could be explained by the nature of positive feedback (tandem run recruitment) that these ants use. By observing foraging colonies with paint-marked ants, I was able to determine the `rules' that individuals follow: foragers recruit more and give up less when they find a better food source. By altering the nutritional condition of colonies, I found that these rules are flexible - attuned to the colony state. In starved colonies, individual ants are more likely to explore and recruit to food sources than in well-fed colonies. Similar to honeybees, Temmnothorax foragers appear to modulate their exploitation and recruitment behavior in response to environmental and social cues. Finally, I explored the influence of ecology (resource distribution) on the foraging success of colonies. Larger colonies showed increased consistency and a greater rate of harvest than smaller colonies, but this advantage was mediated by the distribution of resources. While patchy or rare food sources exaggerated the relative success of large colonies, regularly (or easily found) distributions leveled the playing field for smaller colonies. Social foraging in ant societies can best be understood when we view the colony as a single organism and the phenotype - group size, communication, and individual behavior - as integrated components of a homeostatic unit.
ContributorsShaffer, Zachary (Author) / Pratt, Stephen C (Thesis advisor) / Hölldobler, Bert (Committee member) / Janssen, Marco (Committee member) / Fewell, Jennifer (Committee member) / Liebig, Juergen (Committee member) / Arizona State University (Publisher)
Created2014
Description
Teaching evolution has been shown to be a challenge for faculty, in both K-12 and postsecondary education. Many of these challenges stem from perceived conflicts not only between religion and evolution, but also faculty beliefs about religion, it's compatibility with evolutionary theory, and it's proper role in classroom curriculum. Studies suggest that if educators engage with students' religious beliefs and identity, this may help students have positive attitudes towards evolution. The aim of this study was to reveal attitudes and beliefs professors have about addressing religion and providing religious scientist role models to students when teaching evolution. 15 semi-structured interviews of tenured biology professors were conducted at a large Midwestern universiy regarding their beliefs, experiences, and strategies teaching evolution and particularly, their willingness to address religion in a class section on evolution. Following a qualitative analysis of transcripts, professors did not agree on whether or not it is their job to help students accept evolution (although the majority said it is not), nor did they agree on a definition of "acceptance of evolution". Professors are willing to engage in students' religious beliefs, if this would help their students accept evolution. Finally, professors perceived many challenges to engaging students' religious beliefs in a science classroom such as the appropriateness of the material for a science class, large class sizes, and time constraints. Given the results of this study, the author concludes that instructors must come to a consensus about their goals as biology educators as well as what "acceptance of evolution" means, before they can realistically apply the engagement of student's religious beliefs and identity as an educational strategy.
ContributorsBarnes, Maryann Elizabeth (Author) / Brownell, Sara E (Thesis advisor) / Brem, Sarah K. (Thesis advisor) / Lynch, John M. (Committee member) / Ellison, Karin (Committee member) / Arizona State University (Publisher)
Created2014
Description
A notable feature of advanced eusocial insect groups is a division of labor within the sterile worker caste. However, the physiological aspects underlying the differentiation of behavioral phenotypes are poorly understood in one of the most successful social taxa, the ants. By starting to understand the foundations on which social behaviors are built, it also becomes possible to better evaluate hypothetical explanations regarding the mechanisms behind the evolution of insect eusociality, such as the argument that the reproductive regulatory infrastructure of solitary ancestors was co-opted and modified to produce distinct castes. This dissertation provides new information regarding the internal factors that could underlie the division of labor observed in both founding queens and workers of Pogonomyrmex californicus ants, and shows that changes in task performance are correlated with differences in reproductive physiology in both castes. In queens and workers, foraging behavior is linked to elevated levels of the reproductively-associated juvenile hormone (JH), and, in workers, this behavioral change is accompanied by depressed levels of ecdysteroid hormones. In both castes, the transition to foraging is also associated with reduced ovarian activity. Further investigation shows that queens remain behaviorally plastic, even after worker emergence, but the association between JH and behavioral bias remains the same, suggesting that this hormone is an important component of behavioral development in these ants. In addition to these reproductive factors, treatment with an inhibitor of the nutrient-sensing pathway Target of Rapamycin (TOR) also causes queens to become biased towards foraging, suggesting an additional sensory component that could play an important role in division of labor. Overall, this work provides novel identification of the possible regulators behind ant division of labor, and suggests how reproductive physiology could play an important role in the evolution and regulation of non-reproductive social behaviors.
ContributorsDolezal, Adam G (Author) / Amdam, Gro V (Thesis advisor) / Brent, Colin S. (Committee member) / Gadau, Juergen (Committee member) / Hoelldobler, Bert (Committee member) / Liebig, Juergen (Committee member) / Arizona State University (Publisher)
Created2012
Description
The advent of advanced reproductive technologies has sparked a number of ethical concerns regarding the practices of reproductive tourism and commercial gestational surrogacy. In the past few decades, reproductive tourism has become a global industry in which individuals or couples travel, usually across borders, to gain access to reproductive services. This marketable field has expanded commercial gestational surrogacy--defined by a contractual relationship between an intending couple and gestational surrogate in which the surrogate has no genetic tie to fetus--to take on transnational complexities. India has experienced extreme growth due to a preferable combination of western educated doctors and extremely low medical costs. However, a slew of ethical issues have been brought to the forefront: the big ones manifesting as concern for reduction of a woman's worth to her reproductive capabilities along with concern for exploitation of third world women. This project will be based exclusively on literature review and serves primarily as a call for cultural competency and understanding the circumstances that gestational surrogates are faced with before implementing policy regulating commercial gestational surrogacy. The paper argues that issues of exploitation and commodification hinge on constructions of motherhood. It is critical to define and understand definitions of motherhood and how these definitions affect a woman's approach to reproduction within the cultural context of a gestational surrogate. This paper follows the case study of the Akanksha Infertility Clinic in northern India, a surrogacy clinic housing around 50 Indian surrogates. The findings of the project invokes the critical significance of narrative ethics, which help Indian surrogates construct the practice of surrogacy so that it fits into cultural comprehensions of Indian motherhood--in which motherhood is selfless, significant, and shared.
ContributorsMoorthy, Anjali (Author) / Robert, Jason S (Thesis advisor) / Hurlbut, Benjamin (Committee member) / Ellison, Karin (Committee member) / Arizona State University (Publisher)
Created2011
Description
The repression of reproductive competition and the enforcement of altruism are key components to the success of animal societies. Eusocial insects are defined by having a reproductive division of labor, in which reproduction is relegated to one or few individuals while the rest of the group members maintain the colony and help raise offspring. However, workers have retained the ability to reproduce in most insect societies. In the social Hymenoptera, due to haplodiploidy, workers can lay unfertilized male destined eggs without mating. Potential conflict between workers and queens can arise over male production, and policing behaviors performed by nestmate workers and queens are a means of repressing worker reproduction. This work describes the means and results of the regulation of worker reproduction in the ant species Aphaenogaster cockerelli. Through manipulative laboratory studies on mature colonies, the lack of egg policing and the presence of physical policing by both workers and queens of this species are described. Through chemical analysis and artificial chemical treatments, the role of cuticular hydrocarbons as indicators of fertility status and the informational basis of policing in this species is demonstrated. An additional queen-specific chemical signal in the Dufour's gland is discovered to be used to direct nestmate aggression towards reproductive competitors. Finally, the level of actual worker-derived males in field colonies is measured. Together, these studies demonstrate the effectiveness of policing behaviors on the suppression of worker reproduction in a social insect species, and provide an example of how punishment and the threat of punishment is a powerful force in maintaining cooperative societies.
ContributorsSmith, Adrian A. (Author) / Liebig, Juergen (Thesis advisor) / Hoelldobler, Bert (Thesis advisor) / Gadau, Juergen (Committee member) / Johnson, Robert A. (Committee member) / Pratt, Stephen (Committee member) / Arizona State University (Publisher)
Created2011
Description
Within ethics, a number of scholars advocate an interdisciplinary approach of combining the two traditionally different professions of science and philosophy with the confidence that this collaboration will be a mutually beneficial experience. Current ethicist-scientist interactions include embedded-ethicists and research ethics consultation services. Both methods are employed with the hope that they will reduce social and ethical problems that could arise from scientific research, and enhance the reflective capacity of investigative teams. While much effort has been put forth in the endeavor of creating ethicist-scientist interactions, there remains opportunity to refine these new interaction models to make them more robust. There is need for ethicists to understand the context of ethical decision-making in the laboratory. By extension, before interacting with scientists in a research lab, research ethicists ought to have the ability to understand the science and also be familiar with the different factors that influence scientific research, such as funding, productivity requirements, time constraints, politics of laboratories and institutional reward structures. Through literature review and the analysis of qualitative data obtained from the ethnographic study in a neuroscience laboratory, this thesis explores the strengths and weaknesses of ethicist-scientist interactions and aims to understand the culture, traditions and values of this community and their perspectives on their role as scientists and their relationship to ethics. This study shows that the quantity and quality of ethics discussions in the lab are limited and dictated by time constraints and minimal incentives. Other influencing factors are the researchers' perspectives on ethics and how they view their role as a scientist in relation to the public.
ContributorsMin, Gyongeun Catherine (Author) / Ellison, Karin (Thesis advisor) / Robert, Jason S (Thesis advisor) / Minteer, Ben A (Committee member) / Arizona State University (Publisher)
Created2012
Description
Despite the minor differences in the inclusiveness of the word, there is a general assumption among the scientific community that the 'pursuit of knowledge' is the most fundamental element in defining the word 'science'. However, a closer examination of how science is being conducted in modern-day South Korea reveals a value system starkly different from the value of knowledge. By analyzing the political discourse of the South Korean policymakers, mass media, and government documents, this study examines the definition of science in South Korea. The analysis revealed that the Korean science, informed by the cultural, historical, and societal contexts, is largely focused on the values of national economic prosperity, international competitiveness, and international reputation of the country, overshadowing other values like the pursuit of knowledge or even individual rights. The identification of the new value system in South Korean science deviating from the traditional definition of science implies that there must be other definitions of science that also deviates, and that even in the Western world, the definition of science may yield similar deviations upon closer examination. The compatibility of the South Korean brand of science to the international scientific community also implies that a categorical quality is encompassing these different contextual definitions of science.
ContributorsHyun, Byunghun (Author) / Hurlbut, Ben (Thesis advisor) / Maienschein, Jane (Committee member) / Ellison, Karin (Committee member) / Arizona State University (Publisher)
Created2011
Description
Researchers in the twentieth and twenty-first centuries identify the study of the intrinsic and external factors that influence human aging as senescence. A commonly held belief in the year 2015 is that at least some kinds of cells can replicate over long periods or even indefinitely, thereby meaning the cell does not undergo senescence (also known as replicative senescence) and is considered immortal. This study aims to provide information to answer the following question: While some scientists claim they can indefinitely culture a stem cell line in vitro, what are the consequences of those culturing practices? An analysis of a cluster of articles from the Embryo Project Encyclopedia provides information to suggest possible solutions to some potential problems in cell culturing, recognition of benefits for existing or historical culturing practices, and identification of gaps in scientific knowledge that warrant further research. Recent research suggests that hESCs, and immortalized cell lines in general, do not escape the effects of senescence. While there exists a constant change in the practices of cell culturing, a large portion of scientists still rely on practices established before modern senescence research: research that seems to suggest that cultured hESCs, among other immortal cell lines, are not truly immortal.
ContributorsBartlett, Zane (Author) / Maienschein, Jane (Thesis advisor) / Ellison, Karin (Committee member) / Hurlbut, James (Committee member) / Arizona State University (Publisher)
Created2015
Description
Access to testing for the human immunodeficiency virus (HIV), as well as other care services related to HIV/AIDS, have greatly improved in Tanzania over the last decade. Despite the country’s efforts to increase the number of individuals who get tested for HIV annually, it is estimated that only 52.2-70.0% of people living with HIV (PLWH) knew their HIV positive status at the end of 2017. In addition, research in Tanzania has shown that HIV-related stigma and discrimination are widespread and contribute to low uptake of HIV testing and non-adherence to antiretroviral treatment (ART). In order to achieve the goals set forth by the Government of Tanzania and the Joint United Nations Programme on HIV/AIDS (UNAIDS), as well as move towards an AIDS-free generation, a deeper understanding of the stigma-related barriers to seeking an HIV test is necessary. This research aims to better understand the relationship between HIV-related stigma and attitudes towards HIV testing among community members in Northern Tanzania. In addition, it looked at the specific barriers that contribute to low uptake of HIV testing, as well as the impact of social networks on an individual’s motivation and willingness to get tested for HIV. In this research, community members in Meru District (N = 108, male = 69.4%, female = 28.7%) were surveyed using various validated instruments that covered a range of topics, including knowledge of HIV/AIDS, testing attitudes, and perceived risk of HIV infection. The mean overall score for correct answers on the knowledge measure was 69.8% (SD = 16.4). There were no significant group differences between individuals who had ever tested and individuals who had not tested in relation to HIV/AIDS knowledge or HIV testing attitudes. The factors that were significantly associated with getting an HIV test were knowing someone who had previously tested (p = 0.003), as well as openly discussing HIV testing within one’s social group (p = 0.017). Participants also provided qualitative responses for barriers to receiving an HIV test, motivations for getting tested, and suggested interventions for improving HIV testing uptake. The goal of this research is to develop recommendations for interventions that are better informed by attitudes and motivations for testing.
ContributorsAllen, Megan (Author) / Jacobs, Bertram (Thesis advisor) / Neuberg, Steven (Committee member) / Ellison, Karin (Committee member) / Arizona State University (Publisher)
Created2019
Description
Advocacy groups work across many aspects of “death with dignity” practice and treatment, and provide insight across multiple aspects of “death with dignity”. This study argues that key advocacy groups in the American death with dignity movement influenced the broader conceptualization of death with dignity in a way that makes patients more able to achieve it. This influence has been a dynamic process across different periods of practice starting the discussion of “death with dignity” in 1985 through today, although this thesis extends only to 2011. The question in this study is how do the three main historical advocacy groups in the US: the Hemlock Society, Compassion in Dying, and Compassion and Choices, conceptualize death with dignity with regards to patient and doctor relationship, legal and policy factors, and medical technologies and protocols? This study found that the Hemlock Society (1980-2005) characterized death with dignity as a terminally ill patient being able to “self-deliver” from suffering via autoeuthanasia regardless of medical community approval or legality. Compassion in Dying (1993-2007) characterized death with dignity as involved advocacy work with terminal patients and their communities to pursue palliative care and hospice up to the point of assisted death. This organization was also involved in the passing of Oregon Death with Dignity Act. Compassion and Choices (2007-present) characterized death with dignity similarly to Compassion in Dying but also advocated for adequate management of pain and suffering symptoms in palliative care to prevent people from desiring death over the illness. Conceptualizing death with dignity is important for understanding why patients want death with dignity and better accommodating their end of life needs when they are suffering with terminal illness.
ContributorsCohan, Hailey Elizabeth (Author) / Ellison, Karin (Thesis advisor) / O'Neil, Erica (Committee member) / Piemonte, Nicole (Committee member) / Arizona State University (Publisher)
Created2019