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Plato and Descartes: From Informed Reason to Deformed Logic
No full textPlato and Descartes are often paired together as the two great dualists of the Western philosophical tradition. In this essay, I challenge this narrative and show how Plato’s Republic and Descartes’ Meditations present fundamentally irreconcilable epistemological systems. For Plato, knowledge is an encounter with the natural intelligibility inherent in all true being. For Descartes, in contrast, knowledge is reduced to the correspondence of our ideas to the external state of the world
Yukon Dust from Source to Sink: Characterizing the St. Elias Mountains as a High-Latitude Dust Source
No full textHigh-latitude dust is an important, yet poorly understood, component of Earth’s climate system. It impacts weather and albedo by acting as cloud condensation nuclei, directly affects Earth’s radiative balance, and can enhance productivity by supplying nutrients to ecosystems. In order to better understand high-latitude dust dynamics and impacts, we sampled glacial meltwater, surface sediment, and Holocene loess in the Łhù’ààn Mân (Kluane Lake) region of the Yukon Territory, Canada. We found that suspended sediment concentration is correlated with average slope and glaciation within a catchment, and is influenced by river morphology. We present new εNd and 87Sr/86Sr values that define a broader isotopic field than previously measured in the Yukon Territory, and demonstrate a strong relationship between average bedrock age and εNd on a catchment-by-catchment basis throughout the St. Elias Mountains. Our 206Pb/207Pb and 208Pb/207Pb data further define the provenance fingerprint and provide evidence of Asian pollution aerosols in the Yukon Territory. Altogether, these data add to a growing catalog of high-latitude dust-producing regions, offering insights into dust dynamics and transport patterns in the region
The Imperial Origins of Genocide: Colonial Discourses and the Genocides in Timor-Leste and Rwanda
No full textThis project aims to compare the ideological and structural colonial legacies that created the tensions for genocide to occur in Timor-Leste and Rwanda. It also aims to understand how these colonial legacies inhibited the international community\u27s response and exacerbated the genocides. The genocide in Timor-Leste occurred from 1975 to 2002 and was perpetrated by the Indonesian government against the native Timorese population. The genocide in Rwanda occurred from April to July of 1994 and was perpetrated by the Hutu majority against the Tutsi minority. Throughout this thesis, I argue that colonial legacies like nationalism, racial hierarchies, and the maintenance of colonial structures created the ethnic tensions for both of these genocides. I also argue that legacies of the civilizing mission discourse inhibited the international community\u27s response to both genocides. This thesis focuses on the colonial legacies of these genocides rather than the genocides as they occurred to illuminate a larger pattern of post-colonial genocides as a legacy of colonialism
The Impacts of Bir1 Sumoylation on the Spindle Assembly Checkpoint under Replication Stress Conditions
No full textDNA replication errors threaten genome integrity and can result in mutations and oncogenic transformation. To prevent such outcomes, eukaryotic cells employ multiple surveillance mechanisms, including the S-phase checkpoint and the spindle assembly checkpoint (SAC), to coordinate DNA replication with mitotic progression. The Chromosomal Passenger Complex (CPC), particularly the conserved subunit Bir1 (Survivin in humans), plays a critical role in SAC function by ensuring proper kinetochore-microtubule attachments. Recent evidence suggests that post-translational modifications such as sumoylation regulate CPC localization and activity. However, the precise role of Bir1 sumoylation during replication stress remains unclear. We hypothesized that Bir1 sumoylation is essential for maintaining SAC-dependent G2/M arrest in the presence of DNA damage. To test this, we used a Saccharomyces cerevisiae strain expressing a BIR1-SuOff mutant, in which SUMO isopeptidase activity (Ulp1) is fused to Bir1 to prevent its sumoylation, alongside a catalytically inactive control (BIR1-SuC). Upon treatment with methyl methanesulfonate (MMS) to induce replication stress, preliminary data using flow cytometry revealed that BIR1-SuOff cells accumulated less in G2/M, unlike control cells, indicating premature mitotic entry. These findings support the conclusion that Bir1 sumoylation is required for proper SAC activation and mitotic arrest under replication stress, highlighting a critical regulatory mechanism that coordinates DNA replication with chromosome segregation
Effects of direct and indirect predator cue intensity on foraging decisions in a deer mouse, Peromyscus
No full textEcologists developed optimal foraging theory as a framework to understand how an animal may spend minimal time to maximize resource intake. A giving-up density (GUD) is a metric of the density of remaining food in a food patch at which an animal decides foraging is no longer economical. This study aims to test how the intensity of direct and indirect predator cues alter foraging patterns of deer mice. To measure GUD, I used depletable food patches deployed in the “upper woods” on the periphery of Colby College. To simulate direct predator cues, 1 mL of fox urine was applied on four cotton balls at different time lags (0, 1, and 4 hours) and deployed at experimental food patches. Mice foraged in the food patches through each trial night until sunrise, when the remaining seeds were collected and weighed in the lab. I found that Peromyscus spp. use indirect cues more than direct cues when evaluating predation risk. There was no significant change exhibited within all urine intensity levels, but forager tolerance for risk reduced in the presence of fresh urine. I saw a significant relationship between weather and GUD, as there was a 13% reduction in mean proportional GUD in rainy compared to clear weather. Seasonal differences also emerged, as 68% of summer trials exhibited complete seed removal from natural low food availability. These findings highlight the importance of indirect cues in shaping foraging strategies and contribute to a nuanced understanding of the landscape of fear
The Future of Code Style: Learning with Gamified Online Tools
No full textHigh-quality code is universally pursued by software developers, and one of the most effective indicators of code quality is code style. However, code style is difficult to teach, particularly to introductory students and programmers who benefit most. In this project, we aim to investigate how online tools can improve and teach Python code style, as well as identify the role of gamification in the process. We build an online platform called Fishy that combines code style appraisal tools and utilizes gamification concepts. Our platform incorporates educational metrics such as a code analysis score and targeted quizzes to assess user performance. We conduct a human experiment (n=25) with participants who are given a code sample, asked to use both Fishy and the conventional pylint code analyzer to improve the code style of their sample, are assessed on their learning, and provide evaluative feedback on the experience. We measure participant success in improving code style under a short time frame, participant learning and retention, and the effect of gamification elements through participant feedback. We find that Fishy is a significantly more helpful tool at improving participant code style in the moment, but is not more effective than pylint in terms of participant learning, although the gamification elements of Fishy make the experience of using the tool more motivating and rewarding. Our results suggest that gamification is a promising approach to learning code style, but more in-depth interventions are needed for achieving higher retention rates
SPRTN Metalloprotease as a Target to Sensitize Cancer Cells to Crosslinking Chemotherapy
Full text linkBifunctional alkylating agents have demonstrated high clinical utility as a chemotherapeutic strategy against cancer. These compounds have been well-characterized for their capacity to exert cytotoxicity via interstrand DNA crosslinking. However, the same electrophilic chemistry can also form DNA-protein crosslinks (DPCs) whose contributions to these drugs’ antitumor effects have been less well-defined. Recently, the metalloprotease SPRTN has been implicated as a predominant mediator of DPC repair in mammalian cells. Previous work has demonstrated that SPRTN deficiency increases the sensitivity of cancer cells to DPC-inducing agents such as formaldehyde and cisplatin, but these findings have yet to be translated more broadly across chemotherapies capable of inducing these lesions. Herein, we investigated the effects of impairing SPRTN repair on cancer cells’ sensitivity to bifunctional alkylating agents. First, we employed RNA interference to transiently knock down SPRTN expression in HeLa cells by over ten-fold relative to non-targeting controls. Using this SPRTN knockdown model, we then demonstrated a 2.4-fold decrease in the LD50 of mechlorethamine relative to control experiments. However, we observed no difference in DPC burden between SPRTN knockdown and control HeLa cells after treatment with a highly lethal dose of mechlorethamine and recovery over an extended period. Our preliminary data suggest a role for SPRTN in HeLa cells’ response to bifunctional alkylating agents, but more work is necessary to validate these propositions. Nonetheless, this study may support that inhibition of SPRTN in combination with crosslinking chemotherapies could warrant further investigation as a therapeutic strategy for the treatment of certain cancers
The Social Implications of Assisted Reproductive Technologies: An Analysis of Feminist Discourse and Popular Media
No full textAssisted reproductive technologies (ARTs) have been a valuable tool in allowing many people to have children who previously struggled with infertility. However, feminists have raised the question: what impact do these new reproductive technologies have on women? This thesis investigates the discourse around the social implications of ARTs from the seventies to the present day. Looking at both feminist literature and portrayals of ARTs in women’s magazines, I performed a discourse analysis to track how the perception of the social implications of ARTs has changed over time. I also use a science, technology, and society (STS) studies lens to look at these arguments and show how this could be a tool in shaping the future of ARTs. I will argue that the feminist discourse around ARTs took a more positive turn in recent decades – shifting away from ideas that portray ARTs as taking power away from women to arguments that see ARTs as a way for women to take back control of their infertility experience
Black Rhino Conservation and Ranger Wellness in Namibia
No full textWildlife rangers play an essential role in conserving biodiversity worldwide. Until recently, little was known about ranger working conditions and welfare. In 2019 the World Wildlife Fund (WWF) released a report that summarized survey results about ranger wellness from 7,110 rangers across multiple continents. However, the WWF study had geographic gaps and did not survey rangers from southern Africa, including the Republic of Namibia. In Namibia, rangers in the Kunene region are central to the conservation of the desert-adapted black rhino. Save the Rhino Trust (SRT) is a Namibian organization that supports rhino rangers and black rhino conservation. The aim of this thesis is to compare the status of Namibian rhino ranger welfare to the welfare of rangers in other African countries surveyed by the WWF using the WWF survey data and survey data from a 2021 SRT survey of 55 rangers. Additionally, this thesis aims to evaluate the impact of a welfare intervention implemented in 2021 by SRT using the 2021 survey and a 2024 SRT survey of 25 rangers. I find that Namibian rangers have improved welfare compared to other rangers in Africa related to exhaustion, access to clean drinking water, and the belief that the basic necessities provided to them are sufficient. However, rangers in Namibia have less access to medical treatment and insurance than rangers in other African countries. The results of this thesis suggest that SRT’s welfare intervention to date has had mixed results. The SRT interventions have helped rangers to address selected ailments, such as headaches, scorpion stings, and diarrhea, but there is remaining need for ongoing programming such as regular doctor’s visits and continual first aid training to continue to support and improve ranger welfare. Understanding the status of ranger welfare as well as what can be done to improve ranger welfare is critical not only for black rhinos in Namibia but for the conservation of many other species around the world
Map or Graph? Investigating the Structure of Spatial Representations
No full textThe present study investigated the structure of spatial representations using a novel computer-based navigation task in concert with computational modeling, specifically with the Successor Representation (SR) model. In particular, we examined whether participant’s knowledge of a virtual environment fit in better with either the cognitive map or labeled graph hypothesis for spatial representation. Twenty-four participants aged 18-22 learned the positions of 25 objects within a 5x5 grid of virtual rooms through disparate routes. Participants then made relative and absolute distance judgments, generated novel shortcuts, and drew a map of the environment to test their knowledge about the spatial locations of each object. Both relative and absolute distance judgments demonstrated systematic biases based on the distance and learned connectivity between the objects, and the SR also generated similar biases when we trained it on our task. The shortcut and map drawing tasks revealed a wide array of individual differences, showing that some participants struggled to integrate spatial knowledge across different routes. Our results from the intersection between computational modeling and the careful study of behavior provide some evidence in favor of the labeled graph hypothesis as well as insights into the large individual variability seen in spatial navigation