Honors Projects
Showing 81 - 90 of 564 Items
Exploiting Context in Linear Influence Games: Improved Algorithms for Model Selection and Performance Evaluation
Date: 2022-01-01
Creator: Daniel Little
Access: Open access
- In the recent past, extensive experimental works have been performed to predict joint voting outcomes in Congress based on a game-theoretic model of voting behavior known as Linear Influence Games. In this thesis, we improve the model selection and evaluation procedure of these past experiments. First, we implement two methods, Nested Cross-Validation with Tuning (Nested CVT) and Bootstrap Bias Corrected Cross-Validation (BBC-CV), to perform model selection and evaluation with less bias than previous methods. While Nested CVT is a commonly used method, it requires learning a large number of models; BBC-CV is a more recent method boasting less computational cost. Using Nested CVT and BBC-CV we perform not only model selection but also model evaluation, whereas the past work was focused on model selection alone. Second, previously models were hand picked based on performance measures gathered from CVT, but both Nested CVT and BBC-CV necessitate an automated model selection procedure. We implement such a procedure and compare its selections to what we otherwise would have hand picked. Additionally, we use sponsorship and cosponsorship data to improve the method for estimating unknown polarity values of bills. Previously, only subject code data was used. This estimation must be done when making voting outcome predictions for a new bill as well as measuring validation or testing errors. We compare and contrast several new methods for estimating unknown bill polarities.
Investigating the role of eyes absent in photoreceptor axon targeting in Drosophila melanogaster
Date: 2021-01-01
Creator: Bethany J. Thach
Access: Open access
- The eya gene is essential to development of the Drosophila visual system and eye-specific loss of function mutations in the gene commonly result in the missing eye phenotype. The eya2m35g mutation carries a deletion of exon 1B and adjacent regulatory sequences. Flies carrying the eya2m35g allele exhibit a photoreceptor axon phenotype that has not previously been associated with the eya gene. To determine a potential role for eya in photoreceptor axon targeting, I characterized various phenotypes of eya2m35g mutants and generated additional eya alleles consisting of smaller deletions within the eya2m35g mutation to locate the genetic source of axonal disruption. Using immunofluorescence staining to visualize Eya protein, I found a loss of eya expression in the optic lobe region of eya2m35g stage 9 embryos and third instar larvae. I also observed a loss of retinal basal glial (RBG) cells in the larval eye disc. Finally, I demonstrated that the disconnected axon phenotype is generated when a region of the intron immediately downstream of exon 1B is deleted. These findings suggest that a possible regulatory element for eya that is essential for photoreceptor axon targeting exists in this intronic region.
Characterizing the influence of Atlantic water intrusion on water mass formation and primary production in Kongsfjorden, Svalbard
Date: 2015-05-01
Creator: Courtney Michelle Payne
Access: Open access
- With warming global temperatures and changes to large-scale ocean circulation patterns, warm water intrusion into Arctic fjords is increasingly affecting fragile polar ecosystems. This study investigated how warm Atlantic water intrusion and the tidewater glacial melting it causes impacted water mass formation and primary productivity in Kongsfjorden, Svalbard. Data were collected over a 2-week period during the height of the melt season in August near the Kronebreen/Kongsvegen glacier complex, the most rapidly retreating glacier in Spitsbergen. Since 1998, intruding waters have warmed between 4 and 5.5˚C, which has prevented sea ice formation and changed the characteristics of fjord bottom waters. Increased glacial melting in the last decade has changed the characteristics of surface waters in the fjord. Modeled light fields suggest that suspended sediment in this glacial meltwater has reduced the euphotic zone close to the ice face, preventing high primary production in both the consistent and intermittent sediment-laden meltwater plumes. However, measurements collected close to terrestrially terminating glaciers indicate that extremely high primary production can occur in conditions of low turbidity. The results of this study support a three-part model of the effects of warm-water intrusion on water mass formation and primary production, where changes in sea ice coverage and tidewater glacial dynamics affect the optical light field. This model allows for spatial predictions for the most likely impacts of warm water intrusion on primary production in Spitsbergen, and could be extrapolated out to explore potential phytoplankton response in other regions susceptible to warm-water intrusion.
Making Human Beings and Citizens: The Educational Philosophies of Jean-Jacques Rousseau and Mary Wollstonecraft Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Mollie Claire Eisner
Access: Access restricted to the Bowdoin Community
The Jewish “Other” in Argentina: Antisemitism, Exclusion, and the Formation of Argentine Nationalism and Identity in the 20th Century and during Military Rule (1976-1983)
Date: 2021-01-01
Creator: Marcus Helble
Access: Open access
- Throughout the 20th century, Argentine leaders and social actors attempted to shape distinct national identities and a sense of nationalism that corresponded to their respective political ideologies. Beginning in the first couple decades of the 20th century, the formation of a Jewish “other” would be central to the construction of both Argentine national identity and nationalism. This thesis argues that the military dictatorship that led the country from 1976 to 1983 built on this othering of the Jewish community as military leaders sought to forge a national identity linked to Catholicism. It focuses first on three separate periods of the early and mid-20th centuries and how governments in that period built, maintained, and altered the view of the Jewish community as a not fully Argentine “other” living in the country. Using several editions of a far-right antisemitic periodical, declassified State Department documents, and testimonies of Jewish political prisoners and soldiers, the thesis transitions to focus on the military dictatorship of the 1970s and 1980s. It examines two separate periods of the dictatorship, highlighting first the role antisemitic beliefs, and opposing such views, had in an internal power struggle within the military government. In the second period of the dictatorship, during the Malvinas (Falklands) War, the thesis examines how antisemitism became a central part of the military’s efforts to consolidate a sense of national unity during the conflict, even as Jews participated largely for the first time within Argentine nationalism and the military.
All That Influences the Condition of Women: The Moral Foundations of Female Education in Tocqueville and Rousseau This record is embargoed.
- Embargo End Date: 2026-05-20
Date: 2021-01-01
Creator: Nicole Danielle Tjin A Djie
Access: Embargoed
Caring like a state: The elaboration of a care ideology in Peru and Sri Lanka in the 20th century
Date: 2015-05-01
Creator: Katharine Herman
Access: Open access
- This project compares the interaction between the government and the population in both Peru and Sri Lanka through the 20th century, focusing on the provision of care (services, benefits, and recognition as provided by the governing apparatus) as a locus for their most meaningful interaction. The provision of care can be seen as a form of communication established in certain practices, symbols, and discourses. Moreover, the provision of care works to reorient the subject population into a more beneficial relationship with the state–notably one of increased dependence and trust. Through the elaboration of what care is and how it functions, a care ideology is established creating a terrain through which the politics of the governed and the governing alike can be legitimized. Care ideology can then be considered a further articulation of the state idea, creating a dialogue about how governance can or should be affected within a certain context. These case studies then illustrate the terrain over which both of these governing bodies work. In Sri Lanka, the governing apparatus provides a means for citizens to live a symbolically meaningful life through paddy farming. In Peru, the governing apparatus provides access to the state through civil infrastructure like roads and education. Through care, material goods become invested with meaning and the state idea becomes materialized. Care is a then substantial project undertaken by the state to ensure its own reproduction and further widen the possibilities for the state project to be effected through its own citizens.
Accretion Onto a Black Hole at the Center of a Neutron Star: Nuclear Equations of State
Date: 2022-01-01
Creator: Sophia Christina Schnauck
Access: Open access
- A recent re-examination of Bondi accretion (see Richards, Baumgarte and Shapiro (2021)) revealed that, for stiff equations of state (EOSs), steady-state accretion can only occur for accretion rates exceeding a certain minimum. To date, this result has been explored only for gamma-law equations of state. Instead, we consider accretion onto a small black hole residing at the center of a neutron star governed by a more realistic nuclear EOS. We generalize the relativistic Bondi solution for such EOSs, approximated by piecewise polytropes, and thereby obtain analytical expressions for the accretion rates which were reflected in our numerical simulations. After taking several different piecewise EOSs at different neutron star densities into account, the accretion rates of the different EOSs were only slightly larger than the previously observed minimum. In other words there appears to be evidence for a nearly universal accretion rate that depends only on the black hole mass. However, we also observed that for certain densities the fluid profiles of several EOSs exhibited superluminal sound speeds outside the horizon of the black hole, suggesting that the EOSs are not appropriate at these densities.
Evaluating Dam Relicensing and River Herring Habitat Restoration from a Broad, Multi-Ecosystem Perspective
Date: 2022-01-01
Creator: Matthew L. Thomas
Access: Open access
- This study investigates the potential benefits of using a broad, multi-ecosystem analysis in the licensing and relicensing of hydropower facilities. Specifically, it considers the impact of river herring restoration on coastal food webs and cod and other groundfish populations in the Gulf of Maine. The past two decades of research on fisheries management, ecosystem connectivity, and the connection between river herring and groundfish in the Gulf of Maine have resulted in a better understanding of the ways in which human activities, such as dam building, influence ecological processes. The paper analyzes two case studies of six Maine dams currently engaged in the Federal Energy Regulatory Commission’s (FERC) hydroelectric dam relicensing process. The analysis illustrates the shortcomings of the Federal Power Act’s provisions that address the balancing of ecological and power generation concerns. Following the case studies, a series of policy recommendations are presented to encourage a more transparent and predictable relicensing process that adequately values both ecological and power generation goals. Changes are suggested for both the FERC process itself and the process by which state and federal resource agencies may provide comments regarding how a proposed dam licensing or relicensing affects natural resources under their jurisdiction. The proposed policy recommendations will increase the resilience of natural systems as they adapt to climate impacts.
An Investigation on Data Gaps in Scope 3 Emissions Accounting and Disclosure using 2010-2021 Carbon Disclosure Project (CDP) Questionnaire Responses This record is embargoed.
- Embargo End Date: 2027-05-17
Date: 2022-01-01
Creator: Samara Nassor
Access: Embargoed