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The assets of immigrant parentage for first-generation college students: A qualitative study of their lived experiences.
Get PDFThis dissertation builds on literature centering first-generation college students (FGCS) with immigrant parentage in order to develop an understanding of how many of their unique and intersectional experiences may function as assets that could promote retention and degree completion. The sample is comprised of 30 FGCS who are also first- or second-generation immigrants attending a large public research university. A post-intentional phenomenological framework, coupled with an intersectional lens, guided the analysis. My findings elevate the voices and higher education experiences of FGCS with immigrant parentage by detailing how their experiences coming from an immigrant family (a) motivated them to obtain a college degree as an effort to repay their family for the sacrifices made in immigrating to the U.S., (b) influenced them to not include their parents in their decision-making about college, (c) spurred an independent nature that they described as an important aspect of maturity, (d) developed a hierarchy of needs that required addressing before (or simultaneously with) pursuing academic achievements, (e) modeled help-seeking behaviors that included using a variety of social networks and question-asking of those discerned to be experts, (f) provided a discourse of hard work as FGCS narrated their path toward success in college, and (g) established a basis to use resiliency as a means of being hopeful for their futures and the futures of their families. These findings inform recommendations for higher education administrators and practitioners
Creation of Mesa, An Agent-Based Modeling Framework: Simulating the World in Python
Get PDFAgent-based models enable researchers to create digital twins of real-world phenomena and test alternative policies computationally. This dissertation describes the creation of Mesa, an agent-based modeling framework in Python, one of the most popular programming languages in the world. Since 2014, I led the open-source software development effort called Mesa, articulating the basic design philosophy for agent-based models in Python and developing an efficient software architecture. Driven by volunteers, Mesa has facilitated research in the following domains: healthcare and medicine, energy markets and climate change, technology security and operations, biological systems and epidemiology, belief and value systems, supply chains, economies, autonomous systems, and more. Mesa has been cited in more than 350 published papers by more than 790 authors, and the number of projects using the framework runs in the thousands. The core package has had more than 133 contributors. Lastly, I discuss the opportunity to take Mesa from a general tool to an integrated ecosystem to increase research efficiency and standardize the approach to data and building models. Mesa could accelerate research further through community engagement via coding sprints, user research, and a digital community hub
Paleo-oxygenation and Uranium Isotope Behavior in Lower Mississippian Black Shales of North America
Get PDFUranium isotopes in ancient sedimentary rocks have emerged as a powerful proxy for the oxygenation history of Earth surface environments. Proper quantitative interpretation of uranium isotope data hinges, however, on an understanding of isotope fractionation associated with uranium removal to sediments under different redox conditions. Whereas oxygenated environments are plentiful in the modern ocean, studying contemporaneous uranium isotope behavior under a range of low-oxygen conditions is difficult given the paucity modern anoxic basins. For example, it is not possible to simultaneously test uranium isotope fractionation under oxic, euxinic, and ferruginous marine conditions using modern analogues. Here, we present uranium isotope data from coeval Lower Mississippian shales of the Appalachian Basin (North America) that represent a range of redox conditions. Iron speciation and trace metal data indicate that the Tournaisian Sunbury Shale was deposited across a strong redox gradient, from oxic to equivocal conditions proximal to the Catskill Delta in the northeast, to ferruginous conditions in the basin trough, to euxinic conditions towards the basin-bounding Cumberland Sill in the southwest. Overall, we find that both euxinic and ferruginous environments are capable of imparting high degrees of U isotope fractionation, and that U isotope values correlate more strongly with total organic carbon (TOC) and trace metal proxies for productivity than they do with euxinic vs. ferruginous conditions. We also compared our data to coeval carbonates from Nevada, which can be used to estimate Early Mississippian seawater U isotopes values. We find that cores deposited under more stably anoxic conditions below the redoxcline and under consistently brackish salinities away from direct freshwater sources record an increasing U isotope value through time, which loosely mirrors global seawater values. By contrast, cores deposited close to the Catskill Delta and in a shallow mixing zone near the Cumberland Sill show a decreasing U isotope trend through time which is the opposite of global seawater, indicating entirely local controls on U isotope fractionation. Ultimately, these results suggest that highly productive environments with high organic carbon loading can exert a strong control on the global U isotope mass balance regardless of whether euxinic or ferruginous conditions are present. These results necessitate a partial reassessment of the processes controlling seawater U isotope variability through Earth history
Examining Structural Disparities in Domestic and International Counterterrorism Policy in the US and Their Consequences
Get PDFPrior to the January 6, 2021 storming of the US Capitol, most of the literature and public discourse surrounding the terrorist threat within the United States was almost exclusively focused on Salafi jihadist extremism, while largely ignoring the resurgence of other forms of domestic extremism perpetrated by violent antigovernment and hate-oriented individuals and groups. This dissertation research takes a historical institutionalist approach to understand this disparity using process tracing and qualitative interviews with former US government personnel to examine how key counterterrorism policy decisions were made from World War I to the September 11, 2001 attacks and how these policies were subsequently implemented through investigations and prosecutions of terrorist groups and individuals across the ideological spectrum. While there are legal and structural limitations to investigating and prosecuting domestic terrorism primarily due to fears of government overreach against US citizens similar to what occurred during the J. Edgar Hoover era of FBI leadership, qualitative interview findings also suggest that the US government essentially “dropped the ball” on the domestic terrorism threat after the September 11, 2001, terrorist attacks. Due to the gravity and concern of the threat posed by international terrorism in the wake of the September 11, 2001 attacks this strategy made sense in the short term, but eventually, the emphasis should have shifted back to combating the domestic terrorism threat, however, it did not. Reasons for this are largely due to legal and structural limitations, but also because personnel working against the Salafi jihadist threat found it easier to be taken seriously and advance in their careers when investigating and prosecuting the “other;” which culminated in the Trump Administration’s outright refusal to respond to missed opportunities to counter the rising domestic terror threat. Opportunities exist to better counter the domestic terrorism threat legally and at the agency level but are unlikely to be implemented because of the current political climate and Congress’s inability to take meaningful action
Sovereignty, Legitimacy, and the Bomb: A Framework for Explaining North Korea’s Nuclear Decisions and Strategies
Get PDFNorth Korea has come to be a de facto nuclear weapons state. Kim Jong Un continues to build and add to an increasingly formidable triad of air, land, and sea-based nuclear weaponry, the use of which is governed by a new doctrine of preemption and backed by Kim’s open declaration to never denuclearize. The attainment of Kim’s “treasured sword” caps a many-decades journey through which North Korea weathered mostly U.S.-led efforts initially meant to prevent, and then later, to dismantle its atomic weapons program. The limits to U.S. coercion vis-à-vis North Korea are generally well understood. Wanting to avoid the calamitous destruction of war on the Korean Peninsula, the U.S. has been unable to fully back coercive diplomacy with military force and no combination of carrots or sticks has been capable of inducing North Korean denuclearization. There is much less consensus, however, regarding the Kim dynasty’s nuclear motivations and the factors that have shaped them. While there is widespread scholarly agreement on defensive rationale, namely “regime survival” and “deterrence,” to explain North Korea’s nuclear motivations, many are reluctant to push beyond this. This dissertation posits that the defensive explanation is incomplete at best, and perilous at worst for South Korea. While the co-existence of two separate, sovereign Koreas has settled into normative acceptance within the current international system, the question over Korean legitimacy remains caught in a state-on-state rivalry where questions over survival and security remain trapped in a powder keg—the “Korea question” remains unresolved. Thus, to capture the full range of motivations, this dissertation looks through a Realist lens to address the particularities of North Korea’s pursuit of nuclear weapons. A novel conceptual framework is employed in a single case study to longitudinally trace major nuclear decisions and identify strategies used to advance North Korea’s nuclear program. Several hypotheses derived from the theoretical assumptions of Offensive Realism are tested against the causal chains developed in the case study. Results suggest that nuclear weapons do help to ensure the survival of the Kim regime through the security provided in the form of deterrence. However, North Korea’s layered deterrence—directed at the U.S. mainland, the region, and South Korea—not only shields it from attacks, but also provides the freedom to escalate or de-escalate and probe below the threshold of armed conflict. Nuclear weapons also give North Korea—a country that has struggled with legitimacy as a “rogue” in the current international system—de facto “nuclear state” status, optimizing its power within the region and arming it with the potential, should regional political, military, and economic conditions within the changing international system turn in its favor, to compel South Korea and allow it to gain total sovereign control as the hegemon of the Korean Peninsula—a very real possibility should the U.S. lose its footing in Northeast Asia. This would practically guarantee survival of the Kim regime. Based on the findings in this dissertation, the following recommendations are offered for policymakers, strategists, and other practitioners in the fields of foreign policy, defense policy, and nuclear proliferation to consider for incorporation or further study: (1) Recognize and appreciate the limitations of U.S. coercive policy; (2) avoid U.S.-DPRK “arms control talks”; (3) understand and appreciate North Korea’s true negotiating objectives; (4) thoroughly grasp North Korea’s increasingly offensive motives; and (5) study the possibility of supporting South Korean nuclear parity
Undergoverned Spaces: An Investigation of Underlying Dynamics
Get PDFUndergoverned spaces are regions where hierarchical control structures are contested, with two or more governance groups competing for territory and the allegiance of the local population. These regions are notable for the fierce competition that exists between the various governance groups and potential risks to the international order that they represent. Further, the needs of the local population in these regions often go unaddressed or, even worse, locals become targets for exploitation by the various governance groups, both the centralized state and any unsanctioned, non-centralized arbiters of control within the region's borders. For these reasons, the academic study of undergoverned spaces as competitive arenas are of increasing interest to policy and decision makers, particularly as pertains to stability operations and international aid attempts. Despite this, the study of undergoverned spaces remains complicated due to the lack of readily available data. Due to the lack of infrastructure and accompanying access concerns, such as insufficient population census data or lack of accurate records pertaining to insurgent activities, extracting reliable and meaningful data from these regions is exceedingly difficult, if not impossible. This lack of data is a problem that agent-based modeling (ABM) is particularly well suited to address due to the ability to grow systems from the bottom-up and simulate emergent behavior. This dissertation project develops an agent-based model of an undergoverned space, specifically with two governance groups caught in tight competition for territorial control and local allegiance. One group represents the centralized state authority while the other represents a rival governance group, both competing for access within the region. The key driver of this model is the local population, which has the ability to move to areas with preferable dynamics and who will switch allegiances depending on their needs. This research explores the theory underpinning these unique regions and seeks a better understanding of the applications for international aid attempts by developing an agent-based model based on a foundational theories of undergoverned spaces. The results demonstrate the innate dynamics of ungoverned spaces that keep governance groups in a state of tight competition, while also implicating the conditions under which one group or the other may be able to gain the upper hand. Further, the research proposes four quantifiable measures of undergoverned spaces based on theoretical properties that have previously been largely qualitative, including ungovernability, capacity, legitimacy, and conduciveness
Ground-based light curve follow-up validation observations of TESS object of interest TOI 3779.01
Get PDFThe objective of this study is to determine if TESS object of interest TOI 3779.01 is an exoplanet which is currently classified as a possible candidate in the NASA Exoplanet Archive. The raw telescope data of TOI 3779.01 was collected from the GMU Observatory. These images were reduced, plate solved, and aligned using AstroImageJ to generate a light curve of TOI 3779.01’s transit. There is a dimming of the host star during the transit period, however, since there was notable light pollution during the observational night and nearby reference stars failed the NEB (Nearby Eclipsing Binary) check, the aperture could have been contaminated. To find the planet-to-star radius ratio of TOI 3779.01 we first used the transit depth (6.93 ppt) calculated from our transit model in AstroImageJ to get a ratio value of 0.083246. Using the transit model ratio and transit depth, the radius of TOI 3779.01 is 0.09152 R☉(stellar radius). This value comes close with two other estimates: the first is using the TESS predicted transit depth (8.8) which yielded 0.103189 R☉ and the other is a python probabilistic model which predicted 0.037. These calculations assumes that the stellar radius of the host star is 1.1 R☉. Based on the large radius, we classified TOI 3779.01 as a Hot Jupiter. However, since the aperture was contaminated, the findings of this study can be further used by the TESS team to do more research employing other methods like spectroscopy and chromaticity
Virtue and Vice: Remembering Susan P. Conner and Revolutionary Women
Get PDFSusan Conner’s work and mentorship have had a profound and enduring impact on French History. In remembering her work, this paper will apply her methodology and findings on prostitutes during French Revolution to the experience of religious women. Two of Conner’s articles will foreground my paper. “Public Virtue and Public Women: Prostitution in Revolutionary Paris, 1793-1794,” which first appeared in the journal Eighteenth-Century Studies, in 1994, and “Politics, Prostitution, and the Pox,” from the 2001 edition of the Journal of Social History contributed enormously to historians’ understanding of the place of women during the revolutionary decade. Susan Connor’s evaluation of the meaning of “virtue” for prostitutes during the French Revolution had resonance for the religious women who also did not fit into the Revolution’s vision for virtuous womanhood. As Conner noted, the “revolutionaries were quick to invoke [Virtue’s] name,” but less quick to grapple with its meaning.1 Virtue became “republican virtue” and the Catholic Church’s monopoly on virtue became anathema to revolutionary France. While Conner’s work studied the women whose “sexual appetite” was allegedly endangering both men and society, the nuns’ complete refusal of their sexual appetite, through celibacy, was an equal and opposite threat
Facilitating NeuroMorpho.Org Curation via Neuronal and Glial Metadata Analysis
Get PDFThis thesis has been embargoed for 2 years. It will not be available until July 2023 at the earliest.NeuroMorpho.Org is a scientific database of digital reconstructions of neurons and glia. It serves as a large-scale repository of a wide range of morphological information that can be accessed all over the world, thus encouraging data sharing and communication amongst the international neuroscience community. The curation of such data is very helpful in mining and understanding the relationships between dendritic and axonal branching, glial processes, brain connectivity, and synaptic signaling. Metadata refers to information about the data. NeuroMorpho.Org specifically provides metadata for each curated cell, including details on the animal subject, brain region, cell type, and experimental protocol. This information is extracted from the corresponding peer reviewed publications that describe the reconstructed neurons or glia. The manual process of metadata extraction and annotation can be labor intensive, time consuming, and error prone. In this regard, machine learning can be employed to overcome such challenges by facilitating and eventually automating the identification of relevant information. To ensure efficacy, machine learning tools must be trained with a corpus of existing annotations. Here we deployed a two-pronged approach for analyzing NeuroMorpho.Org metadata to provide a useful training set to aid the ongoing development of semi-automated annotation. First, we investigated our records of metadata in order to deduce any systematic patterns that may underlie neurobiological rules or statistical trends and could be expressed into artificial intelligence heuristics. Specifically, we used a frequency-based data mining algorithm known as "Apriori", which makes use of association rules to compute frequent itemsets consisting of neuronal and glial metadata. Second, we utilized machine learning tools in extracting key metadata via an approach known as "named entity recognition", or NER, such that metadata acquisition can be automated. In this case, it is necessary to perform several rounds of manual annotations that the algorithm can learn from, thus making automated annotation as precise as possible. Altogether, our investigation can potentially aid technologies in training algorithms for robust metadata annotation, which can lead to the expansion and enhancement of NeuroMorpho.Org.2023-07-2
An Investigation of Multi-sensory Feedback for Prosthetic Control
Get PDFThere have been significant advances in prosthetic control technologies over the last few decades, from the development of advanced controllable multi-articulated hands with multiple degrees of freedom, to the rapid growth in the number of algorithms that enable control over these hands based on the user's biological signals. Sophisticated sensing technologies such as electromyography and ultrasound imaging have been used to derive control signals from the users. Alongside being able to control the prosthetic hand, there is a need to have sensory feedback that relays information regarding the state of the hand (grasp, location, pose) to the user. This feedback is critical since the human abilities to move and interact with objects in the environment depend heavily on being able to accurately predict forward kinematics of the body, as well as the ability to integrate sensory cues from the environment. These forward models, as well as the resulting event-based audio-visual, proprioceptive, and haptic feedback, play an important role in being able to accurately and finely manipulate objects in our environment. When users engage in tasks that are complex, and require fine collaboration between several of these feedforward and feedback mechanisms there is a need to characterize the interactions between them. In this dissertation, I have described a framework to characterize prosthetic control technologies from a multisensory perspective. A similar approach was described by Childress et. al., but I have modified it by also including not just the feedback that users get from the environment but also the characteristics of the human machine interface controller as well. I argue that position-based control scheme offer some benefits with respect to intuitiveness, by using sonomyography as an example. I also describe how user performance is affected by the systematic deprivation of certain kinds of feedback (visual, haptic). Finally, I propose a semi-autonomous control system that uses position-based control while relinquishing some fine control to the prosthetic hand itself. The findings of this thesis suggest that such a holistic framework would be beneficial to analyze future prosthetic control systems, and that the development of feed-forward and feedback systems should go hand in hand for the maximum benefit of the user