Digital Commons Network^™

An Introduction To Field Excursions For The 2026 Geological Society Of America Cordilleran Section Meeting In Loreto, Baja California Sur, México, Scott E.K. Bennett, Michael H. Darin, Genaro Martínez Gutiérrez

Geology Faculty Publications and Presentations

The 122nd annual meeting of the Geological Society of America (GSA) Cordilleran Section will be held in Loreto, Baja California Sur, México, an idyllic and historic Sonoran Desert city nestled on the eastern shore of the Baja California peninsula. The 2026 Loreto meeting marks a milestone for GSA as it is the first time in the Section’s century-plus history that the meeting has been held on the Baja California peninsula and only the third time that the meeting has been held in México. Thus, the 2026 Loreto meeting and related field trips represent a meaningful expansion of the Section’s engagement …

Does The Internet Equalize Youth’S Civic Engagement? Examining Online And Offline Civic Engagement Among Adolescents And Young Adults, Yue Ni

Psychology Faculty Publications and Presentations

In this study, I examined disparities in online and offline civic engagement among 400 youth aged 15-25 years (Mage = 20.9; SD = 3.1) by subjective socioeconomic status (SES), race/ethnicity, and immigrant status. Results indicated that patterns of disparities in online civic engagement largely mirrored those observed offline. SES was the most consistent predictor: Youth who perceived their families as more well-off reported higher participation across both online and offline civic activities. In contrast, no significant differences were found between white youth and youth of color. Foreign-born youth reported higher levels of civic engagement in online and several …

Personhood Amidst Process, Bennett B. Gilbert

History Faculty Publications and Presentations

Both process philosophy and key forms of philosophical personalism aim to harmonize the flux of reality, especially of organisms, with cosmic values and human meaningfulness. This is because both must face our mortality. This paper makes four suggestions for considering further the connection between these two approaches. First, that process philosophy can supply for personalism a thoroughly reasoned ground for nonreducible complexity. Second, that process thought borrows from personhood its model for cosmic creativity. Third, that both approaches share strong notions of the interdependence of all parts of a relational universe. And fourth, that they differ in respect of moral …

Erasing The Artist, Policing The City: Michael Stewart And New York’S War On Graffiti, Vladislav Kirilov

Anthós

The 1983 death of Michael Stewart, a young Black graffiti artist, exposes the violent logic at the center of New York City’s War on Graffiti. Under Mayor Ed Koch and the rise of broken windows policing, graffiti was framed as a racialized symbol of disorder used to justify intensified control of public space. Rather than becoming political in this moment, graffiti is understood here as an already politicized form of expression shaped by racial and spatial inequality. The article examines how Stewart’s killing made police violence visible, provoking responses from artists, activists, and graffiti writers while revealing the human costs …

Aquatic Invasive Species Survey And Treatment On Lake Umatilla And Lake Celilo 2024-2025 Report, Jacob Rose, Gabriel E. Campbell

Center for Lakes and Reservoirs Publications and Presentations

Flowering Rush (Butomus umbellatus) is an invasive aquatic plant in the Pacific Northwest that threatens salmon habitat. The Center for Lakes and Reservoirs staff surveyed for this and other aquatic species from 2024 and 2025 in the Columbia River in Lake Umatilla and Lake Celilo. This document summarizes their survey efforts including their protocols, data, and small-scale removal efforts.

The Distribution Of A-Numbers Of Hyperelliptic Curves In Characteristic Three, Derek Garton, Jeffrey Lin Thunder, Colin Weir

Mathematics and Statistics Faculty Publications and Presentations

In this paper we present a new approach to counting the proportion of hyperelliptic curves of genus g defined over a finite field Fq with a given a-number. In characteristic three this method gives exact probabilities for curves of the form Y 2 = f(X) with f(X) ∈ Fq[X] monic and cubefree, probabilities that match the data presented by Cais et al. in previous work. These results are sufficient to derive precise estimates (in terms of q) for these probabilities when restricting to squarefree f. As a consequence, for positive integers a and g we show that the nonempty strata …

Congruences For Hecke Eigenvalues Via Period Polynomials, Liobomir Chiriac

Mathematics and Statistics Faculty Publications and Presentations

We study a conjecture motivated by Coleman and Stein’s work on approximating eigenforms of infinite slope by those of finite slopes, which was recast by Rustom [‘Congruences modulo prime powers of Hecke eigenvalues in level 1’, Res. Number Theory 5(1) (2019), Article no. 10, 27 pages] as a congruence for the second Fourier coefficient. We establish the weight condition required for this coefficient to be divisible by nine and obtain the full conjecture under a natural ramification hypothesis. The proof uses period polynomials, especially Zagier’s description of the Hecke action on them.

Becoming A Shape, Becoming Yourself: Geometry, Identity, And Belonging In An Early Childhood Classroom, Eva Thanheiser, Molly Robinson, Simon Byeonguk Han, Amanda T. Sugimoto, Courtney Koestler, Mathew D. Felton-Koestler

Mathematics and Statistics Faculty Publications and Presentations

This paper examines how a first-grade geometry lesson became a site for exploring shape, selfhood, and belonging in an early childhood classroom. Drawing on interaction analysis of a lesson built around the picture book The Greedy Triangle , we show how children named personal strengths, identified shapes, followed a triangle through changing categories, reflected on why they liked being themselves, and used their bodies to form polygons. We ask what counts as mathematical activity in this lesson and argue that mathematics is not limited to naming shapes. It also involves noticing attributes, negotiating criteria, tracking transformation, coordinating bodies, and reasoning …

The Hope Industrial Complex: Resisting Manufactured And False Hope With Critical Hope In Peace Education, Thailand's Refugee Context, Staci B. Martin, Hayso Thako, Rey Ty, Sudarat Tuntivivat, Rattanak Ly

School of Social Work Faculty Publications and Presentations

Our Point of Departure (POD) argues that the type of hope fostered within the Karen refugee community in Thailand – manufactured, false, or critical – shapes the impact of peace-building and higher education efforts. Through a dialogue among a Karen scholar, his supervisor, and a migration researcher, we demonstrate that manufactured hope, often driven by external aid, sustains dependency and overlooks core conflicts. In contrast, false hope arises from the gap between student desires and institutional barriers, leading to unmet expectations. We aim to show that by applying critical hope, the pedagogical approach enables the Karen community to enhance its …

Applications Of Artificial Intelligence In Dental Malocclusion: A Scoping Review Of Recent Advances (2020-2025), Man Hung, Owen Cohen, Nicholas Beasley, Cairo Ziebarth, Connor Schwartz, Alicia Parry, Martin S. Lipsky

Institute on Aging Publications

Introduction:

Dental malocclusion affects more than half of the global population, causing significant functional and esthetic consequences. The integration of artificial intelligence (AI) into orthodontic care for malocclusion has the potential to enhance diagnostic accuracy, treatment planning, and clinical efficiency. However, existing research remains fragmented, and recent advances have not been comprehensively synthesized. This scoping review aimed to map the current landscape of AI applications in dental malocclusion from 2020 to 2025. Methods: The review followed the Joanna Briggs Institute methodology and the PRISMA-ScR guidelines. The authors conducted a systematic search across four databases (PubMed, Scopus, Web of Science, and …

Women's Social Roles And Alcohol Use Among Military-Connected Spouses, Sheila Kathleen Mccabe Nickerson

Dissertations and Theses

Increases in women's alcohol use are an intensifying public health problem in the United States, contributing to a hidden epidemic of alcohol-related mortality. Women's alcohol consumption is often not openly discussed or recognized due to social stigma, the perception that women drink less than men, and the fact that women can experience negative health consequences from lower levels of alcohol consumption (relative to men), making the issue less visible than it actually is. A range of factors potentially influence women's drinking, including social roles (i.e., mother); yet, the literature is varied as to whether the combination of multiple-role demands/expectations fosters …

Mechanical Improvements And Control Implementation On A Biomimetic Quadruped Model, Matthew Jack Lutz

Dissertations and Theses

Robotic development started billions of years after earth first began biological prototyping. While the evolutionary process in animals is quite different from robotic prototyping, it still remains no surprise that animals remain more agile, more efficient, and more adaptable than even the most advanced engineered robots to date, simply due to the sheer length of their improvement process. While bridging this improvement gap between deficits in robots and the abilities of animals is difficult, a specific subfield of robotics engineering has attempted to do so using biomimetic robotics. At Portland State, the Agile and Adaptive Robotics Lab (AARL) studies these …

The Johnson-Křížek-Mercier Elasticity Element In Higher Dimensions, Jay Gopalakrishnan, Johnny Guzman, Jeonghun J. Lee

Mathematics and Statistics Faculty Publications and Presentations

Mixed methods for linear elasticity with strongly symmetric stresses of lowest order are studied in this paper. On each simplex, the stress space has piecewise linear components with respect to its Alfeld split (which connects the vertices to barycenter), generalizing the Johnson–Mercier two-dimensional element to higher dimensions. Further reductions in the stress space in the three-dimensional case (to 24 degrees of freedom per tetrahedron) are possible when the displacement space is reduced to local rigid displacements. Proofs of optimal error estimates of numerical solutions and improved error estimates via postprocessing and the duality argument are presented.

Microbial Communities Of Selected Regions Of The Deep Springs Lake Aquifer System, Rania Zaki, Emma Bourne, Andrew Storino, Jay Nadeau

Physics Faculty Publications and Presentations

Deep Springs Lake is a small, isolated, highly alkaline soda lake in Inyo County of Eastern California, USA. It is a seasonally filled salt lake or playa, and is part of a closed aquifer system. Such closed systems are globally rare, occurring only in arid zones where annual evaporation is greater than annual rainfall. Deep Springs Lake’s hydrology and geology have been well studied, and it is home to a unique toad species, but its microbiome remains unexplored. Here we perform 16S, 18S, and ITS amplicon sequencing of the lake water, dried salt crust at the edges the lake, and …

"I Like The Idea In Theory": Experiencing The Imperial Matrix Through Legal Gender Marker Changes And Nonbinary Disidentifications, Wynn Strange

Dissertations and Theses

Since 2018 twenty-two states and the District of Columbia have implemented administrative changes that provide a third gender option on at least one state identification document allowing nonbinary and intersex people the opportunity to select a gender marker that reflects their gender identity. This study draws from 28 interviews with agender or otherwise nonbinary people living in Maryland and California. I use queer of color and critical trans theory to consider the implications of legal gender marker changes. This research explores how social, historical, and geographical location can influence ones' awareness of, experiences with, and relation to real and imagined …

Mitigating Risk Of Premature Ovarian Insufficiency Using Adjunct Chinese Herbal Medicines: A Nested Patient-Control Study In Female Cancer Patients With Chemotherapy, Tzu-Ning Tseng, Hou-Hsun Liao, Hanoch Livneh, Ming-Chi Lu, Szu-Chin Li, Tzung-Yi Tsai

Leadership, Learning and Counseling Faculty Publications and Presentations

Premature ovarian insufficiency (POI) is a common late effect of chemotherapy among survivors of adolescent and young-adult cancer (AYAC). Given on the widespread use of Chinese herbal medicine (CHM) in restoring individual health, we performed a cohort-based nested patient-control study with the aim of exploring the effect of blending CHM into routine care on the reduction of chemotherapy-induced POIrisk among females with AYAC.

Leveraging High-Performance Cloud Computing To Model Underwater Acoustic Propagation And Scattering From Time-Evolving Rough Sea-Surfaces Using The Finite-Difference Time-Domain Method, James Alexander Higgins

Dissertations and Theses

This dissertation presents a two-dimensional (2D) Finite-difference Time-domain (FDTD) model for simulating underwater acoustic propagation and scattering from a one-dimensional (1D) time-evolving rough sea-surface. The techniques discussed are extendable to three spatial dimensions. Traditional acoustic modeling techniques often rely on a "frozen" sea-surface assumption, which proves inadequate for long-duration signals interacting with the time-evolving boundary at many different wave height displacements during its transit. To address this, a new FDTD update equation incorporating a variable subgrid is developed, significantly enhancing spatial accuracy at the boundary without increasing computational cost or compromising stability.

The model's accuracy is rigorously validated against established …

Working Paper No. 104, An Gorta Mór: The ‘Great Hunger’ And Irish Immigrant Labor In 19th Century America, Amanda Bergeson

Working Papers in Economics

This inquiry seeks to establish that portions of the population of Ireland -- responding to what has been referred to in their Celtic language as An Gorta Mór, or in the English language as the ‘Great Hunger -- took to emigrating en masse and therewith contributed bigly to the expansion of America’s labor supply. Bolsterd by Irish immigrants, this expanding mid-nineteenth century labor force provided for an abundance of workers needed for a broadly based industrialization, that would also lead to large-scale urbanization as well as a host of changes in this nation’s social fabric. Of note is that …

Working Paper No. 105, John Locke And The American Experiment, Riley Sharps

Working Papers in Economics

This inquiry seeks to establish that ideas advanced by the Englishman John Locke, regarding private property, natural rights, as well as a social contract for relations between authorities and governed, influenced the American experiment at its founding. Locke’s novel understanding regarding private property greatly influenced leaders railing against British dominance. His ideas were picked up by founding figures such as John Adams, Thomas Jefferson, as well as James Madison, and Thomas Paine. Through their leadership, in particular, Locke’s ideas were carried forward and served as the inspiration behind key concepts appearing in this new nation’s founding documents. First appearing in …

Leveraging Social Capital For Value Creation In Public Procurement: The Role Of Strategic Purchasing Integration, Iryna Malacina, Jad El Bizri, Frederik G. S. Vos, Elina Karttunen, Aki Jaaskelainen

Business Faculty Publications and Presentations

Purpose Although the integration of the purchasing function within strategic decision-making has been extensively studied in the context of the private sector, its significance for the effective functioning of public procurement (PP) remains underexplored. Effective PP is critical for suppliers, users of public services and society at large. This study investigates how the strategic integration of PP influences operational, environmental and innovative value creation by developing social capital in buyer–supplier relationships. Design/methodology/approach This study empirically examined how strategic purchasing integration contributes to the development of social capital in buyer–supplier relationships, which in turn affects value creation. It utilizes survey data …

Lattice Thermal Transport Beyond The Quasiparticle Approximation: Nontrivial Spectral Competition Between Three- And Four-Phonon Interactions, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

The breakdown of the quasiparticle approximation (QPA) for phonons in strongly anharmonic materials necessitates advanced first-principles frameworks for accurate lattice dynamics and thermal transport predictions. We develop a comprehensive beyond-quasiparticle approximation (BQPA) approach incorporating both three- (3ph) and four-phonon (4ph) interactions and apply it to investigate lattice thermal conductivity (κL) in MgO, PbTe, and AgCl – materials that span a broad spectrum of anharmonicity, from weak to severe anharmonic regimes with overdamped phonons. We reveal that while BQPA consistently increases κL relative to QPA due to phonon softening when considering only 3ph interactions, the inclusion of additional 4ph interactions hardens …

More Than Just A Criminal: Talking Back As A Critical Autoethnographic Journey, Anakin Rivera Ramirez

Psychology Faculty Publications and Presentations

This article explores the experiences of doctoral students with criminal records navigating higher education, using a critical theoretical framework to highlight the unique challenges and triumphs I faced. Drawing upon decoloniality and critical race theory perspectives and activism, I define my critical scholarship as challenging the dominant oppression through thoughts and actions. Through autoethnographic and self-reflective narratives, I reflect on how my lived experiences as a Latino who has experienced criminalization. I have shaped my academic pursuits and critical consciousness. The autoethnography discusses systemic barriers such as stigma, discrimination, and institutional biases, showing how these obstacles have informed the author’s …

Concerted Rattling-Induced Strong Anharmonicity And Phonon Coherence Lead To Ultralow Glasslike Thermal Conductivity In Tlagte, Shantanu Semwal, Yi Xia, Chris Wolverton, Koushik Pal

Mechanical and Materials Engineering Faculty Publications and Presentations

Ordered crystalline compounds exhibiting ultralow and glass-like thermal conductivity are both fundamentally and technologically important, where phonon quasi-particles dominate their heat transport. Understanding the microscopic mechanisms that govern such unusual transport behavior is necessary to unravel the complex interplay of crystal structure, phonons, and collective excitations of these quasi-particles. Here, we use state-of-the-art first-principles calculations based on quantum density functional theory to investigate the origin of experimentally measured unusually low and glassy thermal conductivity in semiconducting TlAgTe that possesses disconnected chains of Tl atoms within its three-dimensional crystalline framework made up of distorted AgTe4 tetrahedra. Utilizing a unifying framework of …

Exploring The Experiences Of White Passing And White-Assumed Latine College Students, Emanuel Magaña

Dissertations and Theses

Between 2009 and 2019 Latine college enrollment has increased, yet retention and graduation rates lag those of their white peers. While barriers for Latine students are well-documented, the influence of colorism, particularly among lighter-skinned or white passing students, remains understudied. This study utilized a qualitative case-study approach grounded in CRT and LatCrit and based on a Street Race Praxis framework. This study explored the experiences of twelve white passing and/or white-assumed Latine students at an emerging HSI in the Pacific Northwest. Using Testimonio informed approach and Counterstory, I drew from interviews, pláticas, site observations, and document analysis to create four …

Oregon State Rank Assessment For Plumed Clover (Trifolium Plumosum Var. Plumosum), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Plumed Clover (Trifolium plumosum var. plumosum) using NatureServe methodology, 2025.

From Cafes To Competitiveness: The Influence Of Amenities On Office Values And Suburban Economic Development In Portland, Or, Jihye Kang

Dissertations and Theses

This dissertation examines the spatial and economic implications of urban amenities in the formation of suburban office markets in the post-pandemic period. The research applies principles from agglomeration theory, spatial econometrics, and urban planning to analyze the statistical relationships between amenity distribution, rent formation, and location behavior across central and non-central submarkets.

The research consists of three integrated papers focused on the Portland–Vancouver–Hillsboro, OR–WA Metropolitan Statistical Area (MSA). The first paper employs spatial econometric modeling, specifically a Spatial Autoregressive Model with Autoregressive Disturbances (SARAR), to examine the relationship between proximity to cafés and office rent levels in Portland’s central business …

Online Decision Mamba, Trenton W. Ruf

Dissertations and Theses

Online in-context reinforcement learning enhances offline-trained policies through online fine-tuning. We introduce Online Decision Mamba (ODM), an architecture that replaces the attention mechanism in Online Decision Transformers (ODT) with the Mamba module to improve long-context sequence modeling and overall RL performance. We performed in-depth evaluations on MuJoCo (OpenAI Gym) and Atari benchmarks, comparing ODM against state-of-the-art offline and online baselines—including Decision Mamba (DM) and ODT. Our results show that ODM achieves competitive or superior performance, with particularly robust gains when initial datasets lack expert demonstrations. In the Qbert Atari environment, ODM shows context-length sensitivity similar to offline DM; however, we …

Citizen's Rare Plant Watch 2025 Recap, Nora Dunkirk

Rae Selling Berry Seed Bank and Plant Conservation Program

Citizen's Rare Plant Watch (CRPW) is a community science program which takes volunteers out to visit populations of rare and threatened Oregon native plant species. Volunteers assess their health and viability, update the Oregon Biodiversity Information Center (ORBIC) state database for rare species, and help contribute to data driven management decisions throughout the state. Housed at Portland State University, this program is open to the public and attracts plant lovers from diverse backgrounds. Each spring, CRPW trains volunteers on methods of data collection, and this year we implemented new technology using Survey123 to streamline population assessments. We focus on species …

Spike Timing Depended Plasticity Produces Unsupervised Learning Of Synergistic Muscle Feedback In A Synthetical Neural Network, Mark Allen Pupkiewicz

Dissertations and Theses

This study investigates how type Ia feedback from muscle spindles can be organized into groups representing agonistic muscle pairs through Spike Timing Dependent Plasticity (STDP). A single degree of freedom joint is actuated with four biologically modeled muscles forming two agonistic pairs. In order to emulate the sensory dynamics of biological muscle spindles, sensors in the model record the active length and velocity states of each muscle, the two primary factors eliciting type Ia afferent responses. In biological networks, synapses from Ia sensory neurons frequently activate interneurons representing agonistic muscle sources. This research investigates whether this organization can emerge in …

Systematics And Systems Theory: Reconstructability Analysis Of The Tetrad, Martin Zwick

Complex Systems Faculty Publications and Presentations

This talk discusses the relationship between systems theory, specifically Reconstructability Analysis, and Systematics, a systems theory-like framework of number symbolism developed by John G. Bennett, which he presented in his four-volume magnum opus, The Dramatic Universe. The talk, given to a community of people interested in Bennett's ideas, focuses on Martin Zwick's paper "Ideas and Graphs: the Tetrad of Activity" archived at https://archives.pdx.edu/ds/psu/36249.