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Climatic Controls on Soil Production, Transport and Chemical Erosion: Insights from Modelling Topography, Soils and Cosmogenic Nuclides at Little Lake, Oregon
No full textPredicting physical and chemical erosion rate responses to climate change are an ongoing challenge in geomorphology. A promising approach for investigating this is by measuring transient variations in physical and chemical erosion rates during climatically variable time periods, which can be accomplished by measuring cosmogenic nuclide concentrations and chemical depletion in sedimentary deposits. Interpreting such measurements warrants applying landscape evolution models that track variations in topography, cosmogenic nuclide concentrations and chemical depletion in soils. We applied a recently developed model that tracks these quantities at Little Lake, Oregon. Previous studies documented variations in cosmogenic nuclide concentrations and chemical depletion in paleo-lake sediments from 50 ka BP to the present, a time interval that includes cooling before the Last Glacial Maximum and warming after it. We extended the model by adding climate-sensitive parameterizations for mineral dissolution, soil transport by frost heave and soil production by frost cracking. We conducted simulations driven by a paleo-temperature time series applicable to Little Lake. Simulations showed that a shift to frost heave, frost cracking and temperature-controlled mineral weathering and alteration elevated 10Be-inferred denudation rates and lowered chemical depletion fraction (CDF) values comparable to those observed in cores from paleo-Little Lake. In contrast, introducing a lake with no changes to process operation led to a decline in denudation rates. No single climate-sensitive process could reproduce both high inferred denudation rates and low CDF, indicating that all of the climate-sensitive processes modelled in our simulations are needed to explain observed values. Modelled denudation rates increased when the connection between frost cracking intensity and maximum soil production rate was strengthened. The integration of climate-sensitive processes showed tha
Philosophy in Action: Ni Una Menos and Liberation Theory
No full textThis thesis explores the intersection of philosophy and social movements, Enrique Dussel\u27s Liberation Philosophy and the Ni Una Menos movement. It argues that Ni Una Menos not only enacts a philosophy of liberation through its mobilization against gender-based violence in Latin America but also critically expands Liberation Philosophy by foregrounding intersectionality and gendered forms of exclusion--often underexamined in traditional liberation theory. Using Dussel\u27s concepts--Exteriority, Praxis, Critique of the Totality, Ethics of Life, and Transmodernity--the study analyzes how Ni Una Menos elevates the lived experiences of marginalized women and gender-diverse individuals into the public and political sphere. Through strategies such as mass protests, digital campaigns, and artivism, the movement advances an inclusive, life-affirming ethic grounded in the realities of structural violence. This case study demonstrates how feminist praxis can exemplify, challenge, and enrich philosophical theories. In linking theory and action, this thesis reveals philosophy as a vital, lived practice reciprocally shaped by contemporary pursuits of justice
Characterization of the Quaternary Active Twin Lakes Fault, Mount Hood, Oregon
No full textThe High Cascades chain of volcanoes results from Cascade Arc volcanism and is responsible for the generation of the highest topography in the state of Oregon. Surrounding Mt. Hood at the crest of the Cascade chain in northern Oregon is the Mt. Hood Fault Zone, an extensional fault zone of generally north-south trending normal faults that down-drop this high volcanic topography. The Twin Lakes Fault is located just south of Mt. Hood and is one of the southernmost faults in the Mt. Hood Fault Zone, previously mapped as approximately 12-13 km in length. This study provides the first in-depth characterization of the Twin Lakes Fault in Oregon\u27s Mt. Hood Fault Zone. The extent of previous work includes only a lidar-derived trace map of the fault and limited field reconnaissance of selected sites. With new lidar data, I utilize GIS to evaluate fault scarps, measure vertical separation across the fault, and revise the existing fault trace mapping. I use a Matlab GUI to analyze 35 topographic profiles taken perpendicular to fault strike to measure vertical separation of correlative surfaces across the fault. Geologic mapping is improved along the length of the Twin Lakes Fault and is paired with fault offsets derived from lidar to investigate whether older units had experienced more offset than younger units. Finally, with empirical fault-scaling relationships, I estimate the potential magnitudes of surface rupturing earthquakes able to be generated by the Twin Lakes Fault. I find that the Twin Lakes Fault is approximately 16 km long, an addition of 3 km compared to the original trace. The updated surficial geology map adds fluvial and lacustrine features and changes glacial-bedrock contacts. I have enhanced its resolution to 1:70k scale from the original 1:100k scale. Offsets between correlative surfaces at scarps are inconsistent within the same units, indicating that the fault may not always rupture along its entire length. An empirical fault-scaling relationship between fault length and earthquake magnitudes suggests a 16 km long normal fault is capable of producing a Mw 6.4 earthquake. Given the fault\u27s proximity to major infrastructure in places such as the city of Portland or the Columbia River Gorge, I propose that the fault is a seismogenic hazard for the region
The Stochastic Occupation Kernel (SOCK) Method for Learning Stochastic Differential Equations
No full textWe present a novel kernel-based method for learning multivariate stochastic differential equations (SDEs). The method follows a two-step procedure: we first estimate the drift term function, then the (matrix-valued) diffusion function given the drift. Occupation kernels are integral functionals on a reproducing kernel Hilbert space (RKHS) that aggregate information over a trajectory. Our approach leverages vector-valued occupation kernels for estimating the drift component of the stochastic process. For diffusion estimation, we extend this framework by introducing operator-valued occupation kernels, enabling the estimation of an auxiliary matrix-valued function as a positive semi-definite operator, from which we readily derive the diffusion estimate. This enables us to avoid common challenges in SDE learning, such as intractable likelihoods, by optimizing a reconstruction-error-based objective. We propose a simple learning procedure that retains strong predictive accuracy while using Fenchel duality to promote efficiency. We validate the method on simulated benchmarks and a real-world dataset of Amyloid imaging in healthy and Alzheimer’s disease (AD) subjects
CLEA Labs for Stellar and Cosmological Astronomy Bottled for Silicon Macintosh
No full textProject CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.
These Labs were developed for Windows, but the authors have bottled them for Silicon Macintosh computers
The Rainbow War: Ballot Measure 9 and the Fight Over Gay Rights in Oregon
No full textOn November 3, 1992, Oregonians were asked to vote on Ballot Measure 9, an amendment to Oregon\u27s constitution that would prohibit anti-discrimination protections for homosexuals, prohibit the use of public funds and facilities to promote homosexuality, and require schools to actively discourage homosexuality as abnormal, wrong, unnatural, and perverse. In this narrative history, I will explore Measure 9 and the ways in which it divided the state, beginning with its introduction in May 1991. I examine the history and reasoning of the Oregon Citizens Alliance, the Christian Right organization behind the measure, as well as the gay and lesbian community’s reaction and their efforts to oppose the measure. Important to this story are the cities of Portland, Corvallis, and Springfield, all three of which were threatened with similar local measures that drew them into the larger statewide fight. And there is the religious element, and the disagreements between various denominations that highlight the plurality of views on a highly controversial topic. My goal is to create a foundational history that provides much needed context upon which past and future scholarship can rest
Mechanistic Rationale for Toxic Aerosol Formation from Vaping and Dabbing with a Focus on Ketene Formation from Semi-Synthetic Cannabinoids
No full textCannabis vaping is a relatively new route of administration that is increasingly common among youth and young adults. Cannabis vaping has been associated with cases of acute lung injury, especially among youth, and most often involves the heating and aerosolization of high-potency products having cannabinoid concentrations of ~ 50 % - 98 % w/w. Proponents argue that vaping is safer than smoking due to the characteristically lower temperatures and fewer plant materials. However, the extreme cannabinoid concentrations, along with non-natural formulations having undisclosed additives, require studies of the health effects of these products. Despite the popularity of cannabis concentrate vaping, especially among young people, research and research-informed regulatory oversight are currently lacking.
The work described herein focuses on the production of toxicant emissions upon vaping semi-synthetic cannabinoids. Semi-synthetic cannabinoids are typically synthesized from hemp-derived CBD, and most are currently federally legal. They exert psychoactive and intoxicating effects that are comparable to or greater than those of Δ⁹-THC.
Chapter 2 focuses on semi-synthetic acetylated cannabinoids such as delta 8 tetrahydrocannabinol (∆8-THC-OAc). Acetylated cannabinoids share a common phenyl acetate substructure with vitamin E acetate (VEA), which has been associated with E-Cigarette and Vaping Use Associated Lung Injury (EVALI). The phenyl acetate moiety of VEA releases toxic ketene upon heating and aerosolization. I provide evidence that ketene was generated from vaping and dabbing (flash vaporization on a hot surface) ∆8-THC-OAc at commonly used vape temperatures. Quantitative analysis performed via QNMR, HPLC-MS, and GC-MS led to the determination that the ketene levels generated via one dab or vape were above the exposure limits for ketene.
A study concerning the mechanism of ketene formation was performed (as presented in chapter 3) utilizing cannabinol acetate (CBN-OAc). CBN-OAc-D3 was synthesized to enable tracking of deuterium loss from the acetate methyl to provide evidence for a mechanism involving ketene generation. Additional experimentation in an anerobic environment showed that O2 has a marked oxidative effect on the formation of ketene. Ultimately, a mechanism was proposed that features a β-scission reaction on the acetate moiety, resulting in ketene gas production.
Another semi-synthetic cannabinoid being marketed is THC-JD or ∆8-THC-C8. The structure is ∆8-THC (a ∆9-THC isomer has also been reported) with its carbon tail extended to eight (from five) carbons. To test for the presence of THC-JD (Chapter 4), five commercial samples were acquired, and their neat e-liquids were extracted. GC-MS analysis determined that none of the commercial samples contained detectable amounts of THC-JD. No peaks displayed similar fragmentation patterns or elution times when compared to a reference standard of ∆8-THC-C8. The identified toxicants included mainly ∆8-THC, as well as ∆9-THC, cannabidiol (CBD), cannabigerol (CBG), and ∆8-THC-OAc. Terpenoids such as caryophyllene were also identified
“‘What is one takeaway you\u27ve gotten from this learning experience?’ Analyzing Student Reflections on Introductory Information Literacy Instruction”
No full textReflection is a useful pedagogical tool for both learners in instructional settings and educators seeking to offer meaningful experiences; in this article, a group of academic librarians use the former to engage with the latter. We analyzed more than 830 first-year students’ responses to a reflection question posed at the conclusion of library instruction over the course of the 2023–2024 academic year with a specific eye to the concepts that were and were not resonant, as well as whether there were common areas of confusion. We used a grounded theory approach to make sense of the data and allow ideas to emerge. Based on our analysis, students seemed to find concrete applications of the information literacy frame “Searching as Strategic Exploration” to be their most immediate takeaways, while other frames—such as “Authority Is Constructed and Contextual” and “Information Has Value”—seemed to be less important. We were able to use this large-scale qualitative data set to more comprehensively understand students’ engagement with and meaning derived from these interactions. Better understanding what did—and did not—matter to our students can help us to be more effective instructors and to create more authentic learning experiences
The Librarian Teaching Self-Efficacy Scale
No full textTeaching self-efficacy is a critical factor in instructional success. Little research has been conducted on how academic librarians perceive their own teaching abilities. This study introduces and validates the Librarian Teaching Self-Efficacy Scale, a tool designed to measure self-efficacy beliefs among academic librarians engaged in information literacy instruction. By adapting established self-efficacy scales to the library instruction context, this study examines key factors influencing librarian teaching self-efficacy, including instructional strategies, lesson planning, and collaboration with faculty. Collective self-efficacy, which is perceptions of colleagues’ teaching confidence, is also examined. Statistical analysis indicates a reliable and valid scale which may benefit from further testing. The study highlights implications for librarian professional development, emphasizing the need for continued research on how teaching self-efficacy develops and its potential role in preventing burnout. Ultimately, the Librarian Teaching Self-Efficacy Scale provides a reflective tool for academic librarians to assess and enhance their instructional confidence
Cinematic Empathy: Autistic Interpretation of Social Cues in Narrative Film
No full textFrom research and lived experience we can see a pattern of Autistic people engaging and forming connection with emotional narratives in media, despite stereotypes suggesting they lack empathy or theory of mind. This mixed-methods study sought to lay the groundwork and start preliminary investigation into how film’s structured formal elements may facilitate autistic viewers’ interpretation of social cues that typically challenge autistic-allistic (nonautistic) communication in real life. A sample of 22 participants (13 autistic, 9 allistic) viewed five film scenes depicting lying, flirting, sarcasm, exposition, and flat affect and completed a survey. Both quantitative and qualitative data were analyzed. While the small sample size influenced the statistically nonsignificant results, qualitative analysis of responses suggested parity between groups in recognizing nonverbal social dynamics like lying and flirting. If this holds at scale, it could indicate that the deliberate execution of formal elements in film may aid cross-neurotype understanding. Though underpowered, this study offers a starting point for future research on how film might bridge real-world communication gaps between autistic and allistic individuals