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Articles 271 - 300 of 3797
Full-Text Articles in Physical Sciences and Mathematics
Physical Controls On The Hydrology Of Perennially Ice-Covered Lakes, Taylor Valley, Antarctica (1996-2013), J. M. Cross, Andrew G. Fountain, M. J. Hoffman, M. K. Obryk
Physical Controls On The Hydrology Of Perennially Ice-Covered Lakes, Taylor Valley, Antarctica (1996-2013), J. M. Cross, Andrew G. Fountain, M. J. Hoffman, M. K. Obryk
Geology Faculty Publications and Presentations
The McMurdo Dry Valleys, Antarctica, are a polar desert populated with numerous closed-watershed, perennially ice-covered lakes primarily fed by glacial melt. Lake levels have varied by as much as 8 m since 1972 and are currently rising after a decade of decreasing. Precipitation falls as snow, so lake hydrology is dominated by energy available to melt glacier ice and to sublimate lake ice. To understand the energy and hydrologic controls on lake level changes and to explain the variability between neighboring lakes, only a few kilometers apart, we model the hydrology for the three largest lakes in Taylor Valley. We …
A First-Tier Framework For Assessing Toxicological Risk From Vaporized Cannabis Concentrates, Shawna Vreeke, David M. Faulkner, Robert Strongin, Echoleah Rufer
A First-Tier Framework For Assessing Toxicological Risk From Vaporized Cannabis Concentrates, Shawna Vreeke, David M. Faulkner, Robert Strongin, Echoleah Rufer
Chemistry Faculty Publications and Presentations
Vaporization is an increasingly prevalent means to consume cannabis, but there is little guidance for manufacturers or regulators to evaluate additive safety. This paper presents a first-tier framework for regulators and cannabis manufacturers without significant toxicological expertise to conduct risk assessments and prioritize additives in cannabis concentrates for acceptance, elimination, or further evaluation. Cannabinoids and contaminants (e.g., solvents, pesticides, etc.) are excluded from this framework because of the complexity involved in their assessment; theirs would not be a first-tier toxicological assessment. Further, several U.S. state regulators have provided guidance for major cannabinoids and contaminants. Toxicological risk assessment of cannabis concentrate …
Enlarging The Stokes Shift By Weakening The Π-Conjugation Of Cyanines For High Signal-To-Noise Ratiometric Imaging, Yongkang Yue, Tingting Zhao, Zhou Xu, Weijie Chi, Xiaojun Chai, Jiahong Ai, Jiawei Zhang, Fangjun Huo, Robert M. Strongin, Caixia Yin
Enlarging The Stokes Shift By Weakening The Π-Conjugation Of Cyanines For High Signal-To-Noise Ratiometric Imaging, Yongkang Yue, Tingting Zhao, Zhou Xu, Weijie Chi, Xiaojun Chai, Jiahong Ai, Jiawei Zhang, Fangjun Huo, Robert M. Strongin, Caixia Yin
Chemistry Faculty Publications and Presentations
The signal-to-noise ratio (SNR) is one of the key features of a fluorescent probe and one that often defines its potential utility for in vivo labeling and analyte detection applications. Here, it is reported that introducing a pyridine group into traditional cyanine-7 dyes in an asymmetric manner provides a series of tunable NIR fluorescent dyes (Cy-Mu-7) characterized by enhanced Stokes shifts (≈230 nm) compared to the parent cyanine 7 dye (nm). The observed Stokes shift increase is ascribed to symmetry breaking of the Cy-Mu-7 core and a reduction in the extent of conjugation. The fluorescence signals of the Cy-Mu-7 dyes …
Reviving Knowledges Through Play And Resistance: The Case Of Navajo Conceptions Of Space, Daniel Ness, Richard D. Sawyer
Reviving Knowledges Through Play And Resistance: The Case Of Navajo Conceptions Of Space, Daniel Ness, Richard D. Sawyer
Northwest Journal of Teacher Education
The authors explore a possible cause of epistemicidal predispositions of the dominant Eurocentric curricula. They posit that one way to determine a plausible contributing factor of this increasing devastation is to consider epistemicide through the lens of intellectual development. To do this, the authors examine parallel patterns of behavior in the domains of developmental and cognitive psychology. The authors then discuss an alternative framework to the Western conception of space within formal K-12 education by presenting the Navajo conception of space and play. Throughout the paper, the authors argue that all students—and especially those living in poverty in commercially constructed, …
Climate Change Curricula In Alberta, Canada: An Intersectional Framing Analysis, Greg Lowan-Trudeau
Climate Change Curricula In Alberta, Canada: An Intersectional Framing Analysis, Greg Lowan-Trudeau
Northwest Journal of Teacher Education
This article is comprised of a climate change-focused framing analysis of proposed revisions to Alberta, Canada’s K-6 curriculum as an ideologically motivated manifestation of curricular epistemicide. Eisner’s three curricula—the explicit, implicit, and null—and scholarship related to intersectional climate and environmental justice, education, and communication provide the theoretical framework. This inquiry concludes with a critical discussion of and possible alternatives to the revised curriculum with further consideration of the implications for those involved with similar endeavours in other jurisdictions across Canada and around the world.
Mathematics In The Woods: Exploring Low-Income Parents’ Perceptions Of And Involvement In Their Children’S Mathematical Learning, Lulu Sun
Northwest Journal of Teacher Education
This article features data from a three-day mathematics camping trip that offered parents and their children time and space to enjoy non-digital activities and mathematics-building tasks. Drawing upon data from a larger qualitative study of children and their parents, this article specifically focuses on 10 parents’ perceptions of their children’s mathematics learning, problem-solving, and wellbeing. Findings suggest that, although parents are interested in their children’s mathematics learning, they are most concerned with their children’s development of problem-solving abilities and social skills. Moreover, students’ own learning experience is important for their mathematics learning.
Investigating Small-Group Cognitive Engagement In General Chemistry Learning Activities Using Qualitative Content Analysis And The Icap Framework, Safaa Y. El-Mansy, Jack Barbera, Alissa J. Hartig
Investigating Small-Group Cognitive Engagement In General Chemistry Learning Activities Using Qualitative Content Analysis And The Icap Framework, Safaa Y. El-Mansy, Jack Barbera, Alissa J. Hartig
Chemistry Faculty Publications and Presentations
The level of students’ engagement during active learning activities conducted in small groups is important to understanding the effectiveness of these activities. The Interactive–Constructive–Active–Passive (ICAP) framework is a way to determine the cognitive engagement of these groups by analyzing the conversations that occur while student groups work on an activity. This study used qualitative content analysis and ICAP to investigate cognitive engagement during group activities in a General Chemistry course at the question level, a finer grain size than previously studied. The analysis determined the expected engagement based on question design and the observed engagement based on group conversations. Comparisons …
Response Of Soil Respiration To Changes In Soil Temperature And Water Table Level In Drained And Restored Peatlands Of The Southeastern United States, E. E. Swails, K. Krauss, Marcelo Ardón, A. L. Peralta, A. M. Helton, Jennifer L. Morse, Multiple Additional Authors
Response Of Soil Respiration To Changes In Soil Temperature And Water Table Level In Drained And Restored Peatlands Of The Southeastern United States, E. E. Swails, K. Krauss, Marcelo Ardón, A. L. Peralta, A. M. Helton, Jennifer L. Morse, Multiple Additional Authors
Environmental Science and Management Faculty Publications and Presentations
Background
Extensive drainage of peatlands in the southeastern United States coastal plain for the purposes of agriculture and timber harvesting has led to large releases of soil carbon as carbon dioxide (CO2) due to enhanced peat decomposition. Growth in mechanisms that provide financial incentives for reducing emissions from land use and land-use change could increase funding for hydrological restoration that reduces peat CO2 emissions from these ecosystems. Measuring soil respiration and physical drivers across a range of site characteristics and land use histories is valuable for understanding how CO2 emissions from peat decomposition may respond to raising water table levels. …
Most Recent Rupture On The Boulder Creek Fault Triggered Bedrock Landsliding In The Nooksack Watershed, Whatcom County, Washington, Abigail Catherine Underwood
Most Recent Rupture On The Boulder Creek Fault Triggered Bedrock Landsliding In The Nooksack Watershed, Whatcom County, Washington, Abigail Catherine Underwood
Dissertations and Theses
Catastrophic bedrock landslides with volumes ranging from 106 to 108 m3 contribute to rapid landscape evolution, often resulting in erosion rates that exceed the long-term average rates caused by tectonic uplift. Understanding the spatiotemporal trends of large bedrock landslides helps us understand previous drivers of landscape evolution as well as predict how the landscape will respond in the future. The Nooksack Watershed, Whatcom County, Washington, is particularly susceptible to large slope failures because of its high relief, seismic activity, local geology, and relatively abundant precipitation. Specifically, folded and faulted bedrock structures conducive to landsliding in addition to …
Quantum Key-Length Extension, Joseph Jaeger, Fang Song, Stefano Tessaro
Quantum Key-Length Extension, Joseph Jaeger, Fang Song, Stefano Tessaro
Computer Science Faculty Publications and Presentations
Should quantum computers become available, they will reduce the effective key length of basic secret-key primitives, such as blockciphers. To address this we will either need to use blockciphers with inherently longer keys or develop key-length extension techniques to amplify the security of a blockcipher to use longer keys.
We consider the latter approach and revisit the FX and double encryption constructions. Classically, FX was proven to be a secure key-length extension technique, while double encryption fails to be more secure than single encryption due to a meet-in-the-middle attack. In this work we provide positive results, with concrete and tight …
Filling Critical Gaps In The Space-Time Record Of High Lava Plains And Co-Columbia River Basalt Group Rhyolite Volcanism, Vanessa Marie Swenton, Martin J. Streck, Daniel P. Miggins, William C. Mcintosh
Filling Critical Gaps In The Space-Time Record Of High Lava Plains And Co-Columbia River Basalt Group Rhyolite Volcanism, Vanessa Marie Swenton, Martin J. Streck, Daniel P. Miggins, William C. Mcintosh
Geology Faculty Publications and Presentations
Miocene rhyolitic volcanism of eastern Oregon, USA, can be divided into two main episodes. Mantle plume upwelling is thought to have generated Columbia River Basalt Group (CRBG) lavas and coeval >16.5−15 Ma silicic volcanism trending north−south from northeast Oregon to northern Nevada. Rhyolite volcanism of the 12−0 Ma High Lava Plains province has been ascribed to either buoyancy-driven westward plume spreading or to slab rollback and mantle convection spanning from southeast Oregon to Newberry Volcano to the west. The apparent ca. 15−12 Ma eruptive hiatus suggests that rhyolites of these provinces were a product of separate processes, yet this gap …
A Multi-Modal Volumetric Microscope With Automated Sample Handling For Surveying Microbial Life In Liquid Samples, Nathan Oborny, Eugene Serabyn, J. Kent Wallace, Kurt Liewer, Manuel Bedrossian, Stephanie Rider, Chris Lindensmith, Jay Nadeau, Multiple Additional Authors
A Multi-Modal Volumetric Microscope With Automated Sample Handling For Surveying Microbial Life In Liquid Samples, Nathan Oborny, Eugene Serabyn, J. Kent Wallace, Kurt Liewer, Manuel Bedrossian, Stephanie Rider, Chris Lindensmith, Jay Nadeau, Multiple Additional Authors
Physics Faculty Publications and Presentations
In the study of microbial life, microscopy plays a unique role due to its ability to detect ordered structure, motility, and fluorescence signals. As such it has also recently gained attention in the context of searching for extant life on distant Solar System bodies bearing liquid water. In this paper we introduce a multimodal volumetric microscopy system for potential future spaceflight missions that combines digital holographic microscopy (DHM) and volume fluorescence imager (VFI), which are volumetric imaging methods that provide highresolution, high-throughput examination of liquid samples. DHM provides information on the absorption, morphology, and motility of imaged objects without requiring …
The Consequential Role Of Aesthetics In Forest Fuels Reduction Propensities: Diverse Landowners’ Attitudes And Responses To Project Types, Risks, Costs, And Habitat Benefits, Robert G. Ribe, Max Nielsen-Pincus, Chris Enright, Bart R. Johnson, David Hulse
The Consequential Role Of Aesthetics In Forest Fuels Reduction Propensities: Diverse Landowners’ Attitudes And Responses To Project Types, Risks, Costs, And Habitat Benefits, Robert G. Ribe, Max Nielsen-Pincus, Chris Enright, Bart R. Johnson, David Hulse
Environmental Science and Management Faculty Publications and Presentations
Private landowners in the southern Willamette Valley of Oregon, USA were surveyed. The survey queried probabilities of implementing specific fuels reduction projects in extensive areas of specific forest types on their property. The projects were described in relation to the beginning and target forest types, the actions required, costs, and long-term maintenance. Forest types were first rated for scenic beauty and informed levels of wildfire risk reduction, scarce habitat production, and associated property rights risks. Propensities to perform each fuels reduction project were then obtained. These were adversely affected by disbelief in heightened wildfire risks or climate change, higher project …
Canonical Quantile Regression, Stephen Portnoy
Canonical Quantile Regression, Stephen Portnoy
Mathematics and Statistics Faculty Publications and Presentations
In using multiple regression methods for prediction, one often considers the linear combination of explanatory variables as an index. Seeking a single such index when here are multiple responses is rather more complicated. One classical approach is to use the coefficients from the leading Canonical Correlation. However, methods based on variances are unable to disaggregate responses by quantile effects, lack robustness, and rely on normal assumptions for inference. An alternative canonical regression quantile (CanRQ) approach seeks to find the linear combination of explanatory variables that best predicts the τ" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: …
From Machine Learning To Deep Learning: A Comprehensive Study Of Alcohol And Drug Use Disorder, Banafsheh Rekabdar, David L. Albright, Haelim Jeong, Sameerah Talafha
From Machine Learning To Deep Learning: A Comprehensive Study Of Alcohol And Drug Use Disorder, Banafsheh Rekabdar, David L. Albright, Haelim Jeong, Sameerah Talafha
Computer Science Faculty Publications and Presentations
This study aims to train and validate machine learning and deep learning models to identify patients with risky alcohol and drug misuse in a Screening, Brief Intervention, and Referral to Treatment (SBIRT) program. An observational cohort of 6978 adults was admitted in the western region of Alabama at three medical facilities between January and December of 2019. Data were cleaned and pre-processed using data imputation techniques and an augmented sampling data method. The primary analysis involved the multi-class classification of alcohol and drug misuse. Our study shows that accurate identification of alcohol and drug use screening instrument scores was best …
River Discharge Mediates Extent Of Phytoplankton And Harmful Algal Bloom Habitat In The Columbia River Estuary (Usa) During North Pacific Marine Heat Waves, Taylor N. Dodrill, Yangdong Pan, Tawnya D. Peterson
River Discharge Mediates Extent Of Phytoplankton And Harmful Algal Bloom Habitat In The Columbia River Estuary (Usa) During North Pacific Marine Heat Waves, Taylor N. Dodrill, Yangdong Pan, Tawnya D. Peterson
Environmental Science and Management Faculty Publications and Presentations
Marine heat waves (MHWs) have been associated with extensive harmful algal blooms (HABs) in the northeast Pacifc Ocean, but the degree to which these large-scale oceanographic events are mirrored in nearshore environments has not been well established. We compared phytoplankton assemblages in the Lower Columbia River Estuary (LCRE) during two Pacifc MHWs that took place in 2015 and 2019, with observations from 2017, a year with no MHW. These data were paired with environmental data from the summers of 2015–2019 to characterize differences in estuarine conditions during MHWs that promote phytoplankton assemblage transitions and identify HAB-conducive conditions. Bloom densities of …
Herbicide-Resistance In Turf Systems: Insights And Options For Managing Complexity, Jennifer H. Allen, David Ervin, George Frisvold, James T. Brosnan, James D. Mccurdy, Rebecca G. Bowling, Aaron J. Patton, Matthew T. Elmore, Travis W. Gannon, Lambert B. Mccarty, Multiple Additional Authors
Herbicide-Resistance In Turf Systems: Insights And Options For Managing Complexity, Jennifer H. Allen, David Ervin, George Frisvold, James T. Brosnan, James D. Mccurdy, Rebecca G. Bowling, Aaron J. Patton, Matthew T. Elmore, Travis W. Gannon, Lambert B. Mccarty, Multiple Additional Authors
Public Administration Faculty Publications and Presentations
Due to complex interactions between social and ecological systems, herbicide resistance has classic features of a “wicked problem.” Herbicide-resistant (HR) Poa annua poses a risk to sustainably managing U.S. turfgrass systems, but there is scant knowledge to guide its management. Six focus groups were conducted throughout the United States to gain understanding of socio-economic barriers to adopting herbicide-resistance management practices. Professionals from major turfgrass sectors (golf courses, sports fields, lawn care, and seed/sod production) were recruited as focus-group participants. Discussions emphasized challenges of the weed management of turfgrass systems as compared to agronomic crops. This included greater time constraints for …
Towards More Equitable And Climate Resilient Communities With Jola Ajibade, Jola Ajibade
Towards More Equitable And Climate Resilient Communities With Jola Ajibade, Jola Ajibade
PDXPLORES Podcast
In this episode of PDXPLORES, Professor Jola Ajibade discusses research examining how cascading social and environmental hazards might impact communities in the Portland metro region and what policymakers and community members can do to mitigate the risks and promote a more just, livable, and sustainable urban future.
Click on the "Download" button to access the audio transcript.
Cascadia Subduction Zone Earthquake Vertical Ground Acceleration Investigation And Potential Impact On Bridges In The Pacific Northwest, Rachel Caroline Bassil
Cascadia Subduction Zone Earthquake Vertical Ground Acceleration Investigation And Potential Impact On Bridges In The Pacific Northwest, Rachel Caroline Bassil
Civil and Environmental Engineering Master's Project Reports
The effects of vertical ground accelerations during subduction zone earthquakes currently are not sufficiently understood. There are numerous case studies and evidence that effects of vertical ground accelerations can significantly impact the performance of bridges during a seismic event, but most previous research has been focused on shallow crustal earthquakes. Current bridge design codes provide little guidance for accounting for vertical ground accelerations in seismic design, in part because additional information is needed about the characteristics of vertical ground motions during Cascadia Subduction Zone (CSZ) earthquakes in the Pacific Northwest.
For this study, recorded seismic data from recent subduction zone …
Transient Vision Loss Associated With Prefilled Aflibercept Syringes: A Case Series And Analysis Of Injection Force, Daniel J. Lee, Brittni A. Scruggs, Erik J. Sánchez, Merina Thomas, Ambar Faridi
Transient Vision Loss Associated With Prefilled Aflibercept Syringes: A Case Series And Analysis Of Injection Force, Daniel J. Lee, Brittni A. Scruggs, Erik J. Sánchez, Merina Thomas, Ambar Faridi
Physics Faculty Publications and Presentations
Purpose
To describe cases of significant vision loss after intravitreal aflibercept administration using prefilled syringes (PFS) and to study the relationships among syringe design, injection speed, and injection force.
Design
Retrospective case series and experimental study.
Participants
Twelve patients who received intravitreal aflibercept via PFS.
Methods
All retina specialists (n = 13) at Oregon Health & Science University and the Veterans Affairs Portland Medical Center were queried in December 2020 to report episodes of significant vision loss after aflibercept PFS use. Chart review was completed for all affected patients. Using a commercially available force measuring system, injection force was measured …
Computational Investigation Into Heteroleptic Photoredox Catalysts Based On Nickel(Ii) Tris-Pyridinethiolate For Water Splitting Reactions, Avik Bhattacharjee, Dayalis S.V. Brown, Trent E. Ethridge, Kristine M. Halvorsen, Alejandra C. Acevedo Montano, Theresa M. Mccormick
Computational Investigation Into Heteroleptic Photoredox Catalysts Based On Nickel(Ii) Tris-Pyridinethiolate For Water Splitting Reactions, Avik Bhattacharjee, Dayalis S.V. Brown, Trent E. Ethridge, Kristine M. Halvorsen, Alejandra C. Acevedo Montano, Theresa M. Mccormick
Chemistry Faculty Publications and Presentations
This work demonstrates a strategy to fine-tune the efficiency of a photoredox water splitting Ni(II) tris-pyridinethiolate catalyst through heteroleptic ligand design using computational investigation of the catalytic mechanism. Density functional theory (DFT) calculations, supported by topology analyses using quantum theory of atoms in molecules (QTAIM), show that the introduction of electron donating (ED) −CH3 and electron withdrawing (EW) −CF3 groups on the thiopyridyl (PyS–) ligands of the same complex can tune the pKa and E0, simultaneously. Computational modeling of two heteroleptic nickel(II) tris-pyridinethiolate complexes with 2:1 and 1:2 ED and EW −CH3 and −CF3 …
Chemical Interactions And Cytotoxicity Of Terpene And Diluent Vaping Ingredients, Yanira Baldovinos, Alexandra Archer, James C. Salamanca, Robert M. Strongin, Christie Sayes
Chemical Interactions And Cytotoxicity Of Terpene And Diluent Vaping Ingredients, Yanira Baldovinos, Alexandra Archer, James C. Salamanca, Robert M. Strongin, Christie Sayes
Chemistry Faculty Publications and Presentations
Vaping devices have risen in popularity since their inception in 2007. The practice involves using a variety of commercially available devices. Internal heating systems in devices aerosolize e-liquid formulations of complex mixtures including an active ingredient (e.g., THC, CBD, and nicotine), diluents (or cutting agents), solvents, and flavoring agents (e.g., terpenes and aldehydes). The vaping toxicology literature consists of cytotoxicity studies of individual chemicals and commercial formulas. Because of the variation of e-liquid composition, there is a limited understanding of the toxicity of ingredient combinations. This study analyzed the cytotoxic effects after exposure to individual and binary mixtures of a …
A Simpler Machine Learning Model For Acute Kidney Injury Risk Stratification In Hospitalized Patients, Yirui Hu, Kunpeng Liu, Kevin Ho, David Riviello, Jason Brown, Alex R. Chang, Gurmukteshwar Singh, H. Lester Kirchner
A Simpler Machine Learning Model For Acute Kidney Injury Risk Stratification In Hospitalized Patients, Yirui Hu, Kunpeng Liu, Kevin Ho, David Riviello, Jason Brown, Alex R. Chang, Gurmukteshwar Singh, H. Lester Kirchner
Computer Science Faculty Publications and Presentations
Background: Hospitalization-associated acute kidney injury (AKI), affecting one-in-five inpatients, is associated with increased mortality and major adverse cardiac/kidney endpoints. Early AKI risk stratification may enable closer monitoring and prevention. Given the complexity and resource utilization of existing machine learning models, we aimed to develop a simpler prediction model. Methods: Models were trained and validated to predict risk of AKI using electronic health record (EHR) data available at 24 h of inpatient admission. Input variables included demographics, laboratory values, medications, and comorbidities. Missing values were imputed using multiple imputation by chained equations. Results: 26,410 of 209,300 (12.6%) inpatients developed AKI during …
Biogeochemical Responses To Mixing Of Glacial Meltwater And Hot Spring Discharge In The Mount St. Helens Crater, Ashley Dubnick, Q. Faber, J. R. Hawkings, N. Bramall, B. C. Christner, Peter T. Doran, Jay Nadeau, C. Snyder, Multiple Additional Authors
Biogeochemical Responses To Mixing Of Glacial Meltwater And Hot Spring Discharge In The Mount St. Helens Crater, Ashley Dubnick, Q. Faber, J. R. Hawkings, N. Bramall, B. C. Christner, Peter T. Doran, Jay Nadeau, C. Snyder, Multiple Additional Authors
Physics Faculty Publications and Presentations
Environments where geothermal waters and glacier meltwater mix are common on Earth yet little is known about the biogeochemical processes that occur when hot, reduced geothermal water mixes with cold, oxidized glacial meltwater in natural systems. Mount St. Helens provides an ideal location to study the interaction between geothermal and glacier waters since the water sources, and their mixing environment in Step Creek, are exposed in the volcanic crater. We find that the two water sources contain distinct major ion, trace element, dissolved organic matter (DOM), and biological signatures. The hot spring contains high concentrations of biogeochemically reactive components (e.g., …
Short Warm-Side Wet-Bulb Temperature Distribution Tails Lead To Accelerated Increases In Extreme Threshold Exceedances Under Global Warming, Yianna Sotirios Bekris
Short Warm-Side Wet-Bulb Temperature Distribution Tails Lead To Accelerated Increases In Extreme Threshold Exceedances Under Global Warming, Yianna Sotirios Bekris
Dissertations and Theses
Humid-heat extremes threaten human health and are increasing in frequency with global warming, so elucidating factors affecting their rate of change is critical. This thesis examines the role of historical (1985-2014) wet-bulb temperature distribution tail shape on the probability of wet-bulb temperature extreme threshold exceedances under 2°Celsius global warming. Analysis of global climate models and reanalysis reveals that non-Gaussian wet-bulb temperature distribution tails are common worldwide across extensive, spatially coherent regions. More rapid increases in the number of days exceeding the historical 95th percentile are projected in locations with shorter-than-Gaussian warm-side tails. Of the two primary components of wet-bulb temperature, …
Topological Anomaly Detection In Dynamic Multilayer Blockchain Networks, Dorcas Ofori-Boateng, I. Segovia Dominguez, C. Akcora, M. Kantarcioglu, Y. R. Gel
Topological Anomaly Detection In Dynamic Multilayer Blockchain Networks, Dorcas Ofori-Boateng, I. Segovia Dominguez, C. Akcora, M. Kantarcioglu, Y. R. Gel
Mathematics and Statistics Faculty Publications and Presentations
Motivated by the recent surge of criminal activities with cross-cryptocurrency trades, we introduce a new topological perspective to structural anomaly detection in dynamic multilayer networks. We postulate that anomalies in the underlying blockchain transaction graph that are composed of multiple layers are likely to also be manifested in anomalous patterns of the network shape properties. As such, we invoke the machinery of clique persistent homology on graphs to systematically and efficiently track evolution of the network shape and, as a result, to detect changes in the underlying network topology and geometry. We develop a new persistence summary for multilayer networks, …
Warming Of The Willamette River, 1850–Present: The Effects Of Climate Change And Direct Human Interventions, Stefan Talke, David Jay, Heida Diefenderfer
Warming Of The Willamette River, 1850–Present: The Effects Of Climate Change And Direct Human Interventions, Stefan Talke, David Jay, Heida Diefenderfer
Civil and Environmental Engineering Faculty Publications and Presentations
Using archival research methods, we found and combined data from multiple sources to produce a unique, 140 year record of daily water temperature (Tw) in the lower Willamette River, Oregon (1881–1890, 1941–present). Additional daily weather and river flow records from the 1850s onwards are used to develop and validate a statistical regression model of Tw for 1850–2020. The model simulates the time-lagged response of Tw to air temperature and river flow, and is calibrated for three distinct time periods: the late 19th, mid 20th, and early 21st centuries. Results show that Tw has trended upwards at ~1.1 °C …
Introduction To Mathematical Analysis I - 3rd Edition, Beatriz Lafferriere, Gerardo Lafferriere, Mau Nam Nguyen
Introduction To Mathematical Analysis I - 3rd Edition, Beatriz Lafferriere, Gerardo Lafferriere, Mau Nam Nguyen
PDXOpen: Open Educational Resources
Video lectures explaining problem solving strategies are available
Our goal in this set of lecture notes is to provide students with a strong foundation in mathematical analysis. Such a foundation is crucial for future study of deeper topics of analysis. Students should be familiar with most of the concepts presented here after completing the calculus sequence. However, these concepts will be reinforced through rigorous proofs.
The lecture notes contain topics of real analysis usually covered in a 10-week course: the completeness axiom, sequences and convergence, continuity, and differentiation. In addition, the notes include many carefully selected exercises of various levels …
Ecological Homogenization Of Oil Properties In The American Residential Macrosystem, Christopher D. Ryan, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Sarah E. Hobbie, Dexter H. Locke, Jennifer L. Morse, Rinku Roy Chowdhury, Tara Trammell, Multiple Additional Authors
Ecological Homogenization Of Oil Properties In The American Residential Macrosystem, Christopher D. Ryan, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Sarah E. Hobbie, Dexter H. Locke, Jennifer L. Morse, Rinku Roy Chowdhury, Tara Trammell, Multiple Additional Authors
Environmental Science and Management Faculty Publications and Presentations
The conversion of native ecosystems to residential ecosystems dominated by lawns has been a prevailing land-use change in the United States over the past 70 years. Similar development patterns and management of residential ecosystems cause many characteristics of residential ecosystems to be more similar to each other across broad continental gradients than that of former native ecosystems. For instance, similar lawn management by irrigation and fertilizer applications has the potential to influence soil carbon (C) and nitrogen (N) pools and processes. We evaluated the mean and variability of total soil C and N stocks, potential net N mineralization and nitrification, …
Predicting Springtime Herbicide Exposure Across Multiple Scales In Pacific Coastal Drainages (Oregon, Usa), Kaegan Michael Scully-Engelmeyer, Elise F. Granek
Predicting Springtime Herbicide Exposure Across Multiple Scales In Pacific Coastal Drainages (Oregon, Usa), Kaegan Michael Scully-Engelmeyer, Elise F. Granek
Environmental Science and Management Faculty Publications and Presentations
Identification of non-point sources of watershed pollution such as pesticide runoff is challenging due to spatial and temporal variation in landscape patterns of land use and environmental conditions. Regional case study monitoring investigations can document region-specific conditions and processes to inform managers about pesticide movement through watersheds. Additionally, modeling field-collected data within these contexts can be used to predict pesticide presence in un-sampled areas. During a 45 day period in the spring of 2019, we sampled sixteen coastal watersheds in Oregon, USA for current-use water-borne herbicides commonly used in forestland vegetation management. At 80 % of sampling locations, at least …