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Full-Text Articles in Physical Sciences and Mathematics

The Use Of Mayflies, Stoneflies And Caddisflies As Indicators Of Fine Sediment Pollution In Salmon-Bearing Streams Of The Pacific Northwest, Cory Michael Mccaffrey Apr 2021

The Use Of Mayflies, Stoneflies And Caddisflies As Indicators Of Fine Sediment Pollution In Salmon-Bearing Streams Of The Pacific Northwest, Cory Michael Mccaffrey

Dissertations and Theses

Fine sediment (particles < 2 mm in diameter) deposition is a natural component of streams but in excess amounts it is harmful to aquatic biota. Fine sediment is the main cause of impairment in streams and rivers of the Pacific Northwest and it can lead to unsuitable spawning and rearing habitat for Endangered Species Act (ESA) listed Salmon and steelhead. From a regulatory perspective, fine sediment presents a challenge because it is difficult to measure in situ and to establish criteria that would indicate stream impairment. Consequently, there is considerable effort to develop biocriteria using stream macroinvertebrates that would help regulators determine if a stream is impaired by excessive fine sediment. Stream macroinvertebrates are widely used to monitor and assess stream degradation because they are affected by the physical, chemical and biological conditions in a stream. In particular, the stream insects known as mayflies (Ephemeroptera, E), stoneflies (Plecoptera, P) and caddisflies (Trichoptera, T) are commonly used as a metric referred to as EPT richness. EPT taxa are well known as pollutant intolerant insects and EPT richness in known to respond negatively to stream degradation. While the sensitivity of EPT to changing water chemistry, increased land use, and hydrologic alteration has been well established, the use of EPT as biocriteria to monitor fine sediment conditions in streams has not been fully evaluated. Studies on the relationship between EPT and fine sediment have shown mixed results, which is likely due to the challenges of quantifying fine sediment in streams. For example, many studies use reach-scale pebble-counts to quantify sediments and reach-scale macroinvertebrate samples to characterize their condition, but the processes that drive macroinvertebrate-sediment relationships primarily operate at the patch-scale. Another issue is the incomplete sediment gradient often observed in the randomized, reach-scale study designs frequently used to collect stream data for regulatory purposes. The purpose of my thesis is to address the use of stream macroinvertebrates as indicators of excessive fine sediment in the regulatory setting. Specifically, I evaluated which aspect of the macroinvertebrate community should be used as an indicator for fine sediment, explored methods for better characterizing benthic fine sediment at the patch-scale and conducted a spatially oriented study that contained a fine sediment gradient. I accomplished this by: 1) using Random Forest and generalized linear models (GLM) to explore relationships between environmental variables, macroinvertebrate metrics and fine sediment in the Pacific Northwest (PNW), 2) developing and validating a novel methodology that quantifies macroinvertebrates and fine sediment at the patch-scale, and 3) designing and conducting a field study in the John Day Basin that included a relatively complete gradient of fine sediment conditions. The results of the exploratory analysis of the PNW data showed that EPT richness and percent EPT richness had the strongest association with fine sediment (model percent variance explained = 42.6% -- 44.5%). Important environmental predictors of EPT richness included percent fine sediment cover, conductivity, chloride, canopy cover and fast-water habitat. Generalized linear models with EPT richness as the response variable and the same environmental predictor variables showed similar results (Pseudo R2 = 0.43 -- 0.50). Using the novel patch-scale sediment sampling methodology, I found that mass of fines and percent of fines was significantly and negatively correlated with velocity (rho = - 0.78, p < 0.001 and rho = -0.52, p < 0.05, respectively). Percent EPT richness exhibited significant and positive correlations with velocity (rho = 0.87, p < 0.001) and a significant and negative correlation with mass of fines (rho = - 0.70, p < 0.01). Non-erosional samples exhibited stronger relationships between velocity and mass of fines (rho = -0.85, p < 0.01) than erosional sampling locations (rho = 0.20, p > 0.05). Results of the John Day study showed that EPT richness was strongly related to fine sediment mass and also positively related to orthophosphate (Pseudo R2 = 0.82). EPT richness decreased 12% between zero and seven percent fine sediment cover but increased between 8% and 10% fine sediment cover. When compared to data collected using a traditional reach-scale approach, the John Day study ...


Fluorogenic Probes For Thioredoxin Reductase Activity, Tendai J. Mafireyi, Jorge O. Escobedo, Robert Strongin Apr 2021

Fluorogenic Probes For Thioredoxin Reductase Activity, Tendai J. Mafireyi, Jorge O. Escobedo, Robert Strongin

Chemistry Faculty Publications and Presentations

The thioredoxin system is vital in maintaining the cellular redox state and is implicated in various cancers and other diseases. It comprises of thioredoxin reductase, thioredoxin and NADPH. Various methods have been developed for the detection and quantification of the thioredoxin reductase enzyme. Most of these methods suffer the shortfall of poor specificity, hence there is need to develop more robust and specific techniques. Recently, there has been an increased interest in fluorescent probes that can target thioredoxin reductase. This review highlights the progress in the synthesis and application of the different fluorescent probes that have been employed for this ...


The Amungme And The Environment: Environmental Justice History And Consumerism, Kole A. Dawson Apr 2021

The Amungme And The Environment: Environmental Justice History And Consumerism, Kole A. Dawson

Phi Alpha Theta Pacific Northwest Regional Conference

The Amungme are one of hundreds of Papuan people groups who lived in the Indonesian province in New Guinea for thousands of years. This group subsisted in their environment by hunting, cultivation of small crops, and practicing pig husbandry. In the late 1960s, seeking foreign capital to boost the nation’s economy, the president of Indonesia signed a contract with Freeport McMoRan Copper and Gold. Freeport began mining in the early 1970s, eventually opening one of the world’s largest gold mines. Excavating sacred Amungme sites, Freeport’s massive pollution to the land and water destroyed the indigenous people’s ...


Glaciers Of The Olympic Mountains, Washington - The Past And Future 100 Years, Andrew G. Fountain, Christina Gray, Bryce Allen Glenn, Brian Menounos, Justin Pflug, Jon L. Riedel Apr 2021

Glaciers Of The Olympic Mountains, Washington - The Past And Future 100 Years, Andrew G. Fountain, Christina Gray, Bryce Allen Glenn, Brian Menounos, Justin Pflug, Jon L. Riedel

Geology Faculty Publications and Presentations

In 2015, the Olympic Mountains contain 255 glaciers and perennial snowfields totaling 25.34 ± 39 0.27 km2, half of the area in 1900, and about 0.75 ± 0.19 km3 of ice. Since 1980, glaciers shrank 40 at a rate of -0.59 km2 yr-1 during which 35 glaciers and 16 perennial snowfields disappeared. Area changes of Blue Glacier, the largest glacier in the study region, was a good proxy for glacier change of the entire region. A simple mass balance model of the glacier, based on monthly air temperature and precipitation, correlates with glacier area change. The mass ...


Networking Frameworks: A Method For Analyzing The Complexities Of Classroom Cultures Focusing On Justifying, Eva Thanheiser, Kathleen Melhuish, Amanda Sugimoto, Brenda Rosencrans, Ruth Heaton Apr 2021

Networking Frameworks: A Method For Analyzing The Complexities Of Classroom Cultures Focusing On Justifying, Eva Thanheiser, Kathleen Melhuish, Amanda Sugimoto, Brenda Rosencrans, Ruth Heaton

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we network five frameworks (cognitive demand, lesson cohesion, cognitive engagement, collective argumentation, and student contribution) for an analytic approach that allows us to present a more holistic picture of classrooms which engage students in justifying. We network these frameworks around the edges of the instructional triangle as a means to coordinate them to illustrate the observable relationships among teacher, students(s), and content. We illustrate the potential of integrating these frameworks via analysis of two lessons that, while sharing surface level similarities, are profoundly different when considering the complexities of a classroom focused on justifying. We found ...


Dipole Emission Characteristics Near A Topological Insulator Sphere Coated With A Metallic Nanoshell, Huai-Yi Xie, Railing Chang, P. T. Leung Apr 2021

Dipole Emission Characteristics Near A Topological Insulator Sphere Coated With A Metallic Nanoshell, Huai-Yi Xie, Railing Chang, P. T. Leung

Physics Faculty Publications and Presentations

Topological insulators (TI) are quantum states of (2D/3D) matter with an insulating interior but conducting edge/surface states, with these boundary conducting states being protected topologically by time-reversal symmetry. Composite materials of heavy atoms such as Bi2Te3 can be fabricated to show TI properties due to the strong intrinsic spin-orbit coupling of the electrons in these materials. Among the so many intriguing physical properties of these materials, their topological magneto-electric (TME) response is unique and has been studied intensively in the literature, leading to intriguing optical effects such as Faraday and Kerr rotations of incident polarized ...


Multi-Institutional Study Of Self-Efficacy Within Flipped Chemistry Courses, Nicole Naibert, Kerry D. Duck, Michael M. Phillips, Jack Barbera Mar 2021

Multi-Institutional Study Of Self-Efficacy Within Flipped Chemistry Courses, Nicole Naibert, Kerry D. Duck, Michael M. Phillips, Jack Barbera

Chemistry Faculty Publications and Presentations

Active learning environments have been shown to be beneficial for student learning; however, including such activities can be limited by the class time available. One method that can provide more opportunities for active learning during face-to-face class time is the flipped learning approach. However, studies on the impacts of flipped learning environments on student motivation are limited. Therefore, in this multi-institutional study, general chemistry students enrolled in flipped courses at three institutions responded to measures of self-efficacy and self-regulatory strategies. The results from these measures were used to evaluate how students’ academic self-efficacy (ASE) and chemistry self-efficacy (CSE) changed over ...


Tribal Revegetation Project Final Project Report: 92-Acre Area, Area 5 Radioactive Waste Management Complex, Nevada National Security Site, Nevada, Jeremy Spoon, Brittany Kruger, Richard Arnold, Kate Monti Barcalow, Tribal Revegetation Committee, Trc Mar 2021

Tribal Revegetation Project Final Project Report: 92-Acre Area, Area 5 Radioactive Waste Management Complex, Nevada National Security Site, Nevada, Jeremy Spoon, Brittany Kruger, Richard Arnold, Kate Monti Barcalow, Tribal Revegetation Committee, Trc

Anthropology Faculty Publications and Presentations

Nuwu (Southern Paiute), Newe (Western Shoshone), and Nuumu (Owens Valley Paiute) are linguistically related, Numic-speaking peoples who are part of the broader Uto-Aztecan language group. Numic peoples view the land as a holistic, living, sentient being with feelings and purpose. The land is personified with human characteristics and it needs to be experienced to be understood through “learning by doing.” Numic peoples do not support ground disturbing activities within their ancestral lands, including activities tied to the storage of low-level radioactive waste or classified materials on the NNSS, which they view as culturally inappropriate. These deep-rooted ancestral connections are the ...


Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alexander Mclean, John Bershaw Mar 2021

Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alexander Mclean, John Bershaw

Geology Faculty Publications and Presentations

We characterize the topographic evolution of the Pacific Northwest, United States, during the Cenozoic. New paleosol carbonate stable isotope (δ18O) results from central Oregon are presented, along with published proxy data, including fossil teeth, smectites, and carbonate concretions. We interpret a polygenetic history of Cascade Mountain topographic uplift along-strike, characterized by: 1) Steady uplift of the Washington Cascades through the Cenozoic due long-term arc rotation and shortening against a Canadian buttress, and 2) Uplift of the Oregon Cascades to similar-to-modern elevations by the late Oligocene, followed by topographic stagnation as extension developed into the Neogene. Since the Miocene, meteoric water ...


The Perceptions Of Rural Teachers Engaged In Environmental Education Professional Development Workshops: A Case Study Of The Alder Creek Community Forest And The Story Of Your Place, Bryan R. Benz Mar 2021

The Perceptions Of Rural Teachers Engaged In Environmental Education Professional Development Workshops: A Case Study Of The Alder Creek Community Forest And The Story Of Your Place, Bryan R. Benz

Dissertations and Theses

Environmental issues can be difficult for people to understand and for teachers to address in their classrooms. Issues such as climate change and ozone depletion are difficult to comprehend and present a challenge for most people to understand thoroughly the complexity of these environmental challenges. Professional development programs could provide the tools for teachers to improve their environmental literacy and a pathway for learning new methods for engaging their students. However, in rural Oregon, where professional development opportunities are scarce, teachers rely on a lean supply of organizations to provide these experiences. Alder Creek Community Forest, a nonprofit organization, provides ...


Pacific Northwest Littoral Data, Curt D. Peterson, Kara E. P. Kingen Mar 2021

Pacific Northwest Littoral Data, Curt D. Peterson, Kara E. P. Kingen

Geology Faculty Datasets

This document contains five data tables in PDF file formats, that are used to characterize littoral subcell (beach, river mouth, and inner-shelf) conditions in the Pacific Northwest (PNW) region (Washington, Oregon, and Northern California). These data have been compiled from pre-existing data sets (see citations in Table notes and References, below) for the purposes of predicting possible beach erosion from potential future sea level rise (SLR), as introduced in Kingen (2018) and Peterson et al. (2019, 2020a,b). The five data tables include Heavy-mineral tracers (Table 1), Heavy-mineral data (normalized) (Table 2), Subcell beach profile settings (Table 3), Subcell beach ...


Evaluating A Commercially Available In-Duct Bipolar Ionization Device For Pollutant Removal And Potential Byproduct Formation, Yicheng Zeng, Prashik Manwatkar, Aurelie Laguerre, Marina Beke, Insung Kang, Akram S. Ali, Delphine K. Farmer, Elliott T. Gall, Mohammad Heidarinejad, Brent Stephens Mar 2021

Evaluating A Commercially Available In-Duct Bipolar Ionization Device For Pollutant Removal And Potential Byproduct Formation, Yicheng Zeng, Prashik Manwatkar, Aurelie Laguerre, Marina Beke, Insung Kang, Akram S. Ali, Delphine K. Farmer, Elliott T. Gall, Mohammad Heidarinejad, Brent Stephens

Mechanical and Materials Engineering Faculty Publications and Presentations

We conducted a series of experiments to evaluate the gas and particle removal effectiveness and potential for byproduct formation resulting from the operation of a commercially available in-duct bipolar ionization device. Laboratory tests were conducted with the ionizer installed in a small air handler serving a large semi-furnished chamber. Chamber experiments were conducted under (i) normal operating conditions to characterize the impact of the ionizer on concentrations of particles (0.01–10 μm), ozone (O3), nitrogen dioxide (NO2), volatile organic compounds (VOCs), and aldehydes, and (ii) particle injection and decay conditions to characterize the impact of the ionizer operation on ...


Group Theory Visualized Through The Rubik's Cube, Ashlyn Okamoto Feb 2021

Group Theory Visualized Through The Rubik's Cube, Ashlyn Okamoto

University Honors Theses

In my thesis, I describe the work done to implement several Group Theory concepts in the context of the Rubik’s cube. A simulation of the cube was constructed using Processing-Java and with help from a YouTube series done by TheCodingTrain. I reflect on the struggles and difficulties that came with creating this program along with the inspiration behind the project. The concepts that are currently implemented at this time are: Identity, Associativity, Order, and Inverses. The functionality of the cube is described as it moves like a regular cube but has extra keypresses that demonstrate the concepts listed. Each ...


Public Perceptions Of Ocean Health And Marine Protection: Drivers Of Support For Oregon’S Marine Reserves, Paul Manson, Max Nielsen-Pincus, Elise F. Granek, Thomas C. Swearingen Feb 2021

Public Perceptions Of Ocean Health And Marine Protection: Drivers Of Support For Oregon’S Marine Reserves, Paul Manson, Max Nielsen-Pincus, Elise F. Granek, Thomas C. Swearingen

Environmental Science and Management Faculty Publications and Presentations

Over the past several decades marine conservation policy has supported the implementation of protected areas in ocean and coastal environments to restrict some elements of human use for ecological benefits. The appropriate extent of protection and the allowable uses are often the subject of public debate about marine protected area policy. Local community dynamics around marine protected area designation and management have been the subject of much ocean and coastal management social science research. However, broader public opinions and attitudes about marine protected areas are not well understood and are critical for managers seeking to maintain their public trust obligations ...


Distribution And Antibiotic Resistance Profiles Of Salmonella Enterica In Rural Areas Of North Carolina After Hurricane Florence In 2018, Yuqing Mao, Mohamed Zeineldin, Moiz Usmani, Sital Uprety, Joanna Shisler, Antarpreet Jutla, Avinash Unnikrishnan, Thanh H. Nguyen Feb 2021

Distribution And Antibiotic Resistance Profiles Of Salmonella Enterica In Rural Areas Of North Carolina After Hurricane Florence In 2018, Yuqing Mao, Mohamed Zeineldin, Moiz Usmani, Sital Uprety, Joanna Shisler, Antarpreet Jutla, Avinash Unnikrishnan, Thanh H. Nguyen

Civil and Environmental Engineering Faculty Publications and Presentations

The frequency and magnitude of extreme events are increasing globally (Arnell & Gosling, 2016). Inundation, as a result of massive flooding, has the potential to change environmental conditions abruptly, and as a result, add pressure to the metabolism and proliferation of microorganisms (Furtak et al., 2020). The resulting overland flows and additional burden from domestic sewer and septic tank systems during an extreme flood event can introduce pathogens into ecologically unstable water bodies. For example, Yu et al. (2018) reported elevated levels of Escherichia coli and antibiotic resistance genes (ARGs) in river water samples 6 months after flooding in Houston, TX ...


The Influence Of Spaceflight And Simulated Microgravity On Bacterial Motility And Chemotaxis, Jacqueline Acres, Myka Jaap Youngapelian, Jay Nadeau Feb 2021

The Influence Of Spaceflight And Simulated Microgravity On Bacterial Motility And Chemotaxis, Jacqueline Acres, Myka Jaap Youngapelian, Jay Nadeau

Physics Faculty Publications and Presentations

As interest in space exploration rises, there is a growing need to quantify the impact of microgravity on the growth, survival, and adaptation of microorganisms, including those responsible for astronaut illness. Motility is a key microbial behavior that plays important roles in nutrient assimilation, tissue localization and invasion, pathogenicity, biofilm formation, and ultimately survival. Very few studies have specifically looked at the effects of microgravity on the phenotypes of microbial motility. However, genomic and transcriptomic studies give a broad general picture of overall gene expression that can be used to predict motility phenotypes based upon selected genes, such as those ...


Using The Gouy Phase Anomaly To Localize And Track Bacteria In Digital Holographic Microscopy 4d Images, True Gibson, Manuel Bedrossian, Eugen Serabyn, Chris Lindensmith, Jay Nadeau Feb 2021

Using The Gouy Phase Anomaly To Localize And Track Bacteria In Digital Holographic Microscopy 4d Images, True Gibson, Manuel Bedrossian, Eugen Serabyn, Chris Lindensmith, Jay Nadeau

Physics Faculty Publications and Presentations

Described over 100 years ago, the Gouy phase anomaly refers to the additional π phase shift that is accumulated as a wave passes through focus. It is potentially useful in analyzing any type of phase-sensitive imaging; in light microscopy, digital holographic microscopy (DHM) provides phase information in the encoded hologram. One limitation of DHM is the weak contrast generated by many biological cells, especially unpigmented bacteria. We demonstrate here that the Gouy phase anomaly may be detected directly in the phase image using the z-derivative of the phase, allowing for precise localization of unlabeled, micrometer-sized bacteria. The use of dyes ...


Niche Partitioning Of Low-Light Adapted Prochlorococcus Subecotypes Across Oceanographic Gradients Of The North Pacific Subtropical Front, Anne W. Thompson, Kathleen Kouba, Nathan A. Ahlgren Jan 2021

Niche Partitioning Of Low-Light Adapted Prochlorococcus Subecotypes Across Oceanographic Gradients Of The North Pacific Subtropical Front, Anne W. Thompson, Kathleen Kouba, Nathan A. Ahlgren

Biology Faculty Publications and Presentations

The cyanobacterium Prochlorococcus is the most abundant photosynthetic cell on Earth and contributes to global ocean carbon cycling and food webs. Prochlorococcus is known for its extensive diversity that falls into two groups of ecotypes, the low‐light (LL) and high‐light (HL) adapted ecotypes. Previous work has shown niche partitioning of the very abundant HL adapted ecotypes and subecotypes across oceanographic gradients including temperature, nutrients, and day length. However, niche partitioning of subecotypes within the LL adapted ecotypes has not been studied as well because they are less abundant and less accessible than surface, HL populations. Through high‐throughput ...


Automated Test Generation For Validating Systemc Designs, Bin Lin Jan 2021

Automated Test Generation For Validating Systemc Designs, Bin Lin

Dissertations and Theses

Modern system design involves integration of all components of a system on a single chip, namely System-on-a-Chip (SoC). The ever-increasing complexity of SoCs and rapidly decreasing time-to-market have pushed the design abstraction to the electronic system level (ESL), in order to increase design productivity. SystemC is a widely used ESL modeling language that plays a central role in modern SoCs design process. ESL SystemC designs usually serve as executable specifications for the subsequent SoCs design flow. Therefore, undetected bugs in ESL SystemC designs may propagate to low-level implementations or even final silicon products. In addition, modern SoCs design often involves ...


Probability Axioms And Set Theory Paradoxes, Ari Herman, John Caughman Jan 2021

Probability Axioms And Set Theory Paradoxes, Ari Herman, John Caughman

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we show that Zermelo–Fraenkel set theory with Choice (ZFC) conflicts with basic intuitions about randomness. Our background assumptions are the Zermelo–Fraenekel axioms without Choice (ZF) together with a fragment of Kolmogorov’s probability theory. Using these minimal assumptions, we prove that a weak form of Choice contradicts two common sense assumptions about probability—both based on simple notions of symmetry and independence.


Mit-S1 Constitutive Model Calibration For A Portland-Area Soil, Steven Ryan Young Jan 2021

Mit-S1 Constitutive Model Calibration For A Portland-Area Soil, Steven Ryan Young

Dissertations and Theses

Soils that are intermediate to sands and clays are a challenge for geotechnical engineers since most methods for interpreting soil properties or soil behaviors are based on sands or clays and do not address behaviors of intermediate soils. This is a particular challenge for engineers in the Portland-area where many of the major soil units are composed of intermediate soils. Analysis of intermediate soils is further challenged since many standard constitutive models are based on sandy or clay-like soils. However, the MIT-S1 constitutive model is capable of capturing intermediate soil behavior. A calibration of the MIT-S1 constitutive model for Portland-area ...


Reassessing Hydrothermal Heat Discharge And The Relationship Of Hot Springs In The North Oregon Cascades, Aaron Alexander Orr Jan 2021

Reassessing Hydrothermal Heat Discharge And The Relationship Of Hot Springs In The North Oregon Cascades, Aaron Alexander Orr

Dissertations and Theses

Reservoir temperatures of hydrothermal systems in the Pacific Northwest reflect the feasibility of geothermal energy production and the tectonic framework of the region. Multicomponent geothermometry techniques were applied to new and historic water chemistry data in the north-central Oregon Western Cascades and the lower Wind River Valley in southern Washington in order to recalculate reservoir temperatures. Revised reservoir temperatures, water chemistry, and isotope data were used to determine relationships between hot springs in the north-central Oregon Cascades. Geothermal reservoir temperatures were estimated for the lower Wind River Valley (98.44 ± 0.96°C) and for Austin and Bagby Hot Springs ...


Rock Glaciers And Related Cold Rocky Landforms: Overlooked Climate Refugia For Mountain Biodiversity, Stefano Brighenti, Scott Hotaling, Debra S. Finn, Andrew G. Fountain, Masaki Hayashi, David Herbst, Jasmine E. Saros, Lusha M. Tronstad, Constance I. Millar Jan 2021

Rock Glaciers And Related Cold Rocky Landforms: Overlooked Climate Refugia For Mountain Biodiversity, Stefano Brighenti, Scott Hotaling, Debra S. Finn, Andrew G. Fountain, Masaki Hayashi, David Herbst, Jasmine E. Saros, Lusha M. Tronstad, Constance I. Millar

Geology Faculty Publications and Presentations

Mountains are global biodiversity hotspots where cold environments and their associated ecological communities are predicted to be threatened by climate warming. Considerable research attention has been devoted to understanding the ecological effects of alpine glacier and snowfield recession. However, much less attention has been given to identifying climate refugia in mountain ecosystems where present-day environmental conditions will be maintained, at least in the near-term, as other habitats change. Around the world, montane communities of microbes, animals, and plants live on, adjacent to, and downstream of rock glaciers and related cold rocky landforms (CRL). These geomorphological features have been overlooked in ...


Boolean Network Control With Ideals, Ian H. Dinwoodie Jan 2021

Boolean Network Control With Ideals, Ian H. Dinwoodie

Mathematics and Statistics Faculty Publications and Presentations

A method is given for finding controls to transition an initial state x0 to a target set in deterministic or stochastic Boolean network control models. The algorithms use multivariate polynomial algebra. Examples illustrate the application.


Poised For Change: University Students Are Positively Disposed Toward Food Waste Diversion And Decrease Individual Food Waste After Programming, Manar Arica Alattar, Jennifer L. Morse Jan 2021

Poised For Change: University Students Are Positively Disposed Toward Food Waste Diversion And Decrease Individual Food Waste After Programming, Manar Arica Alattar, Jennifer L. Morse

Environmental Science and Management Faculty Publications and Presentations

Eaters (consumers of food) are responsible for 60% of waste along the food cycle in developed countries. Programs that target individual and household food waste behavior change are essential to addressing such waste. School cafeterias worldwide offer an opportune microcosm in which to educate on food and nutrition skills and change related behavior. No Scrap Left Behind, a cafeteria food waste diversion program, was developed, piloted, and assessed based on measures of both direct and indirect food waste behavior, and attitudes, knowledge, and emotions related to food waste. Participants had positive attitudes towards food waste reduction, engaged in food waste ...


An Introduction To Number Theory, J. J. P. Veerman Jan 2021

An Introduction To Number Theory, J. J. P. Veerman

PDXOpen: Open Educational Resources

These notes are intended for a graduate course in Number Theory. No prior familiarity with number theory is assumed.

Chapters 1-6 represent approximately 1 trimester of the course. Eventually we intend to publish a full year (3 trimesters) course on number theory. The current content represents a course the author taught in Fall 2020.

It is a work in progress. If you have questions or comments, please contact Peter Veerman (veerman@pdx.edu).


Ecohydrology Of Epiphytes: Modelling Water Balance, Cam Photosynthesis, And Their Climate Impacts, Gretta Miller, Samantha Hartzell, Amilcare Porporato Jan 2021

Ecohydrology Of Epiphytes: Modelling Water Balance, Cam Photosynthesis, And Their Climate Impacts, Gretta Miller, Samantha Hartzell, Amilcare Porporato

Civil and Environmental Engineering Faculty Publications and Presentations

Epiphytes are aerial plants, often characterized by CAM (crassulacean acid metabolism) photosynthesis, which make up a significant portion of the biomass in some rainforests. Their unique characteristics have not yet been included in ecohydrological models, and their potential impact on local hydrometeorology is largely unexplored. This work introduces a water balance model for epiphytes, which adapts the soil‐plant‐atmosphere continuum model to represent a plant system without soil and couples it to the Photo3 photosynthesis model, which includes CAM photosynthesis. The model, which is parameterized with field data of Guzmania monostachia, accurately captures the observed hydraulic and photosynthetic behaviour ...


Inventory Of Rock Glaciers In The American West And Their Topography And Climate, Allison Reese Trcka Dec 2020

Inventory Of Rock Glaciers In The American West And Their Topography And Climate, Allison Reese Trcka

Dissertations and Theses

Rock glaciers are flowing geomorphic landforms composed of an ice/debris mixture. A uniform rock glacier classification scheme was created for the western continental US, based on internationally recognized criteria, to merge the various regional published inventories. A total of 2249 rock glaciers (1564 active, 685 inactive) and 7852 features of interest were identified in 10 states (WA, OR, CA, ID, NV, UT, ID, MT, WY, CO, NM). Sulfur Creek rock glacier in Wyoming is the largest active rock glacier (2.39 km2). The mean area and elevation for active and inactive rock glaciers are 0.18 km2 ...


Estimating Posterior Quantity Of Interest Expectations In A Multilevel Scalable Framework, Hillary R. Fairbanks, Sarah Osborn, Panayot S. Vassilevski Dec 2020

Estimating Posterior Quantity Of Interest Expectations In A Multilevel Scalable Framework, Hillary R. Fairbanks, Sarah Osborn, Panayot S. Vassilevski

Mathematics and Statistics Faculty Publications and Presentations

Scalable approaches for uncertainty quantification are necessary for characterizing prediction confidence in large‐scale subsurface flow simulations with uncertain permeability. To this end we explore a multilevel Monte Carlo approach for estimating posterior moments of a particular quantity of interest, where we employ an element‐agglomerated algebraic multigrid (AMG) technique to generate the hierarchy of coarse spaces with guaranteed approximation properties for both the generation of spatially correlated random fields and the forward simulation of Darcy's law to model subsurface flow. In both these components (sampling and forward solves), we exploit solvers that rely on state‐of‐the‐art ...


Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt Dec 2020

Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt

Dissertations and Theses

Strong earthquake shaking is a natural hazard threat in the Pacific Northwest. Soil failure due to strong earthquake shaking -- known as cyclic soil failure or liquefaction -- is expected to cause large ground deformations and damage to roads, bridges, and other civil infrastructure. Cyclic soil strength (CRR) is often characterized with in-situ geotechnical tests including the cone penetration test (CPT). Relationships between CRR and in-situ test data are not well established for soils in the Pacific Northwest. Portland State University, in partnership with New Albion Geotechnical has compiled a database of cyclic lab tests for Pacific Northwest soils to characterize the ...