Digital Commons Network^™

Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda

Biology Faculty Publications and Presentations

Despite a critical need to evaluate effectiveness of forest treatments in improving stand health, practitioners lack quantitative, repeatable metrics to assess tree vigor and stand health. We evaluated canopy and whole tree attributes of ponderosa pine (Pinus ponderosa Dougl. Ex Laws) related to carbon balance, water balance, and susceptibility to insects and pathogens in dry, pine-dominated forest stands during a multi-year drought, an environmental challenge to stand resilience. Metrics of trees in two unmanaged, and seven treated forested stands, in both uplands and lowlands to develop the quantitative approach. Whole tree and crown attributes including needle length and color, branchlet …

Sea Surface Microplastics: An Inshore-Offshore Gradient Off The Olympic Peninsula, Rosemary Wood

University Honors Theses

The lack of baseline data regarding plastic debris moving through and accumulating in various environmental compartments creates a vast gap in the literature for a number of reasons. These include a current lack of codified methodology to characterize microplastics both in morphology and polymer type, as well as gaps regarding contamination control & validation techniques. In September of 2019, sea surface sampling took place off the Olympic Peninsula, WA with the goal of addressing the following three research questions. First, is variability in microplastic abundance driven by transect location, distance from shore, or both? Second, how does microplastic type, in …

Dim: Adaptively Combining User Interests Mined At Different Stages Based On Deformable Interest Model, Xiaoru Wang, Yueli Li, Zhihong Yu, Fu Li, Heng Zhang, Yali Cai, Lixian Li

Electrical and Computer Engineering Faculty Publications and Presentations

User interest mining is widely used in the fields of personalized search and personalized recommendation. Traditional methods ignore the formation of user interest which is a process that evolves over time. This leads to the inability to accurately describe the distribution of user interest. In this paper, we propose the interest tracking model (ITM). To add the timing, ITM uses Dirichlet distribution and multinomial distribution to describe the evolutional process of interest topics and frequent patterns, which well adapts to the evolution of user interest hidden in short texts between different time slices. In addition, it is well known that …

Collaboration And Evaluation In Urban Sustainability And Resilience Transformations: The Keys To A Just Transition?, Liliana Elizabeth Caughman

Dissertations and Theses

Climate has changed and will continue changing; city populations are swelling as urbanization continues to accelerate; extreme environmental events like heat waves and floods are becoming more severe and more common; and the climate justice movement is rapidly gaining momentum. It in this context that municipal governments find themselves urgently seeking solutions to transition cities from extractive, vulnerable, and unjust to sustainable, resilient, and equitable. The task is complex and will require systemic transformations across interconnected social, environmental, and economic infrastructures. Emerging theories regarding how to govern such massive changes suggest Transition Management strategies and the values of a just …

Identifying A Starting Point For The Guided Reinvention Of The Classification Of Chemically Important Symmetry Groups, Anna Marie Bergman

Dissertations and Theses

The study of abstract algebra is both required for most mathematics majors and notoriously difficult. Much of the mathematics education literature on investigating student thinking in abstract algebra highlights student struggles with understanding even the most fundamental concepts. The abstract nature of the content of the course has been credited as one of the contributors to student difficulties. While there have been various instructional innovations designed to support students in better understanding abstract algebra, and group theory in particular, they have not specifically focused on the issue of the abstract nature of the content. My dissertation study aimed to develop …

An Inquiry Into Developing College Student Socially-Responsible Leadership: Ethics Of Justice And Care In The Midst Of Conflict And Controversy, Jill Frances Childress

Dissertations and Theses

Colleges not only educate students in academic discipline knowledge, but also help them develop skills to meaningfully lead and participate in our complex democracy as socially responsible citizens. All campuses have formal and informal opportunities to engage students in roles that challenge and develop students' socially responsible leadership skills including commitment, common purpose, and collaboration. However, individual and organizational elements such as differences in perspectives and hostile climates can quell leadership and educational participation, inhibit critical student development skills, and result in disempowerment, especially for those students from underserved communities. Given this, a critical question is how can colleges foster …

Inhibition Of Cancer Causing Genes Through The Delivery Of Omomyc In Anti-Myc Therapy: A Systematic Review, Angie Mcgraw

University Honors Theses

A systematic review of the available studies on the interference of OmoMyc with Myc's function in cancerous cells is presented. Myc is a transcription factor that regulates cellular processes such as apoptosis, proliferation, and differentiation. However, Myc is often overexpressed in a variety of cancers, resulting in abnormal growth of cancer cells. Although the inhibition of Myc has been highly desired, it remained a challenge due to its undruggable characteristics. Attempts to inhibit Myc have involved the usage of small-molecules, but these attempts have failed, causing adverse effects and incomplete inhibition of Myc. Despite promising preclinical studies of OmoMyc, it …

Two Black Utopias Of The United States: Self Determination And Survival, Makaveli Gresham

University Honors Theses

In line with Charles Davis III's assertion in regards to the formation of black space and it’s spectral qualities representing the "material conditions of black survival", two black utopian projects: Soul City, North Carolina and the unrealized work of Architects Renewal Committee in Harlem (ARCH) in New York City are analyzed to explicate to what extent that the United States built environment is compatible with "black survival". These two case studies are used to inform an understanding of the anti-black nature of Modernism and the cultural relationship between the construction of "whiteness" and "blackness" in the United States. This relationship …

Examining The Popularity Concept In The Initial Public Offering (Ipo) Market, Preston Rad

University Honors Theses

Popularity is the act of being liked. In Popularity: A Bridge Between Classical and Behavioral Finance, authors Roger Ibbotson, Thomas Idzorek, Paul Kaplan, and James Xiong (hereafter IIDX) explore the concept of Popularity in capital market theory. IIDX argue that certain companies have Popular characteristics that leads to overpricing caused by a Popularity premium. This paper begins with an overview of the historical methods of asset pricing, starting with the Capital Asset Pricing Model (CAPM). It progresses through the expansion of the model by financial theorists such as Eugene Fama and Kenneth French. Jay Ritter (1991) has documented the …

Facilitating Mixed Self-Timed Circuits, Alexandra R. Hanson

University Honors Theses

Designers constrain the ordering of computation events in self-timed circuits to ensure the correct behavior of the circuits. Different circuit families utilize different constraints that, when families are combined, may be more difficult to guarantee in combination without inserting delay to postpone necessary events. By analyzing established constraints of different circuit families like Click and GasP, we are able to identify the small changes necessary to either 1) avoid constraints entirely; or 2) decrease the likelihood of necessary delay insertion. Because delay insertion can be tricky for novice designers and because the likelihood of its requirement increases when mixing different …

Projections Of Change In Frequency And Persistence In Atmospheric Ridging Over The Pacific Northwest Using Cmip6 Models, Ellen Koukel

University Honors Theses

The hydroclimatology of the Pacific Northwest is characterized by wet winters and dry summers; however, the end of the rainy season is subject to considerable year-to-year variability. Early onset of the dry season can introduce challenges for water resource managers. Historically, anomalously dry springs are the result of persistent atmospheric ridging, with notable examples in May 2015 and 2018. As climate change may affect the persistence and frequency of ridges, it is important to understand potential changes in springtime ridging. Future changes will have implications for the length of the rainy season and consequently freshwater availability throughout the region. Therefore, …

Music Education As A Potential Mediator For Social Decline, Gabriel V. Trees

University Honors Theses

Many cultures around the world are experiencing a decline in social wellness. This may be attributed to the decrease in quality and quantity of social connections people have been experiencing in recent times. Among the activities that seem to help humans feel connected and accountable to each other are the community singing, dancing, and drumming that has been part of our human heritage since before the beginning of written history. Active participation in group music making has been shown to promote prosocial attitudes and behaviors. Music education for preschoolers and primary school students may be an effective method of providing …

Fallen Objects: Collaborating With Artificial Intelligence In The Field Of Graphic Design, Harrison S. Gerard

University Honors Theses

In this paper, I discuss the creation, execution and reception of my digital art series Fallen Objects, in which I collaborate with a neural net to create pseudo-found objects. I explore how artists might collaborate with Artificial Intelligence obliquely, not by having the AI generate the images themselves, but instead generate input for the artists to make the images. While many artists are focused on training neural nets to replicate their own art inputs, I instead focus on working with an AI trained on external, easily-accessible data and creating images from the prompts it delivers. In this way, the AI …

Effect Of Parasitic Orobanche Uniflora On Sedum Plants And The Potential Implications For Urban Green Roofs, Jessica Bigger

University Honors Theses

An increasing presence of the parasitic plant Orobanche uniflora has been observed on green roofs in urban areas such as Portland, Oregon. Although little is known about these plants, they are believed to be detrimental to host plants such as sedums that grow on green roofs. Orobanche uniflora takes over the host plant’s cellular structure and uses this to take in nutrients. This poses a problem for green roof succulents because if the host plants are killed by the parasite then the green roofs will not be able to function as effectively. Green roofs may also be contributing to an …

On Dc And Local Dc Functions, Liam Jemison

University Honors Theses

In this project we investigate the class of functions which can be represented by a difference of convex functions, hereafter referred to simply as 'DC' functions. DC functions are of interest in optimization because they allow the use of convex optimization techniques in certain non-convex problems. We present known results about DC and locally DC functions, including detailed proofs of important theorems by Hartman and Vesely.

We also investigate the DCA algorithm for optimizing DC functions and implement it to solve the support vector machine problem.

Post-Fire Changes In Interior Alaska's Vegetation Composition, Jannike E. Allen

University Honors Theses

Global warming is altering the fire regime of interior Alaska, which may have cascading effects on the prevalence of forest types and species dominance across this region. Our objective was to investigate the relationship between vegetation composition and fire in the boreal forest of interior Alaska. We utilized data from over 700 plots sampled across the landscape designated as the Tanana region by the US Forest Service for Forest Inventory Analysis (FIA), as well as fire history records. We compared biomass and stem density of conifer and hardwood forest types, as well as individual tree species, across a gradient of …

Laurent Series Expansion And Its Applications, Anna Sobczyk

University Honors Theses

The Laurent expansion is a well-known topic in complex analysis for its application in obtaining residues of complex functions around their singularities. Computing the Laurent series of a function around its singularities turns out to be an efficient way to determine the residue of the function as well as to compute the integral of the function along any closed curves around its singularities. Based on the theory of the Laurent series, this paper provides several working examples where the Laurent series of a function is determined and then used to calculate the integral of the function along any closed curve …

Perceptions Of Students Of Color About Their Experience In An Alternative High School: A Phenomenological Inquiry, Massene Mboup

Dissertations and Theses

Public schools in Oregon have been struggling to include students of color and teachers of color for so long. Students of color represent more than one third of the school population, yet remain underserved, underrepresented, and over disciplined. Most of their teachers and support staff are White; the teachers of color represent less than 8% of the teaching staff. The students of color attend comprehensive high schools that generally ignore them--or push them out. Some students of color end up in alternative schools.

My problem of practice was the oppression of students of color in urban schools. Specifically, my research …

Leveraging Model Flexibility And Deep Structure: Non-Parametric And Deep Models For Computer Vision Processes With Applications To Deep Model Compression, Anthony D. Rhodes

Dissertations and Theses

My dissertation presents several new algorithms incorporating non-parametric and deep learning approaches for computer vision and related tasks, including object localization, object tracking and model compression. With respect to object localization, I introduce a method to perform active localization by modeling spatial and other relationships between objects in a coherent "visual situation" using a set of probability distributions. I further refine this approach with the Multipole Density Estimation with Importance Clustering (MIC-Situate) algorithm. Next, I formulate active, "situation" object search as a Bayesian optimization problem using Gaussian Processes. Using my Gaussian Process Context Situation Learning (GP-CL) algorithm, I demonstrate improved …

Optimized Xanthene-Based Probes For Pancreatic Cancer Imaging, Ian Ruramai Munhenzva

Dissertations and Theses

Pancreatic Ductal Adenocarcinoma (PDAC) is one of the deadliest human malignancies with an extremely poor 5-year survival rate of below 5%. Surgical resection is the most effective treatment of choice because chemotherapy and radiation therapy do not improve life expectancy. Residual tumor after PDAC surgery is common due to a lack of PDAC targeted intraoperative contrast agents to confirm clear margins.

Fluorescence imaging has the potential to improve surgery outcome and PDAC patients' survival rate via the use of highly PDAC-specific molecular probes to facilitate tumor identification. This thesis describes the application of a focused library of benzoxanthene fluorophores for …

Smart Contract Vulnerabilities On The Ethereum Blockchain: A Current Perspective, Daniel Steven Connelly

Dissertations and Theses

Ethereum is a unique offshoot of blockchain technologies that incorporates the use of what are called smart contracts or DApps -- small-sized programs that orchestrate financial transactions on the Ethereum blockchain. With this fairly new paradigm in blockchain, however, comes a host of security concerns and a track record that reveals a history of losses in the range of millions of dollars. Since Ethereum is a decentralized entity, these concerns are not allayed as they are in typical financial institutions. For example, there is no Federal Deposit Insurance Corporation (FDIC) to back the investors of these contracts from financial loss …

Faculty Senate Monthly Packet May 2020, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The May 2020 Monthly packet includes the May agenda and appendices and the Faculty Senate minutes and attachments from the meeting held April 2020.

PSU faculty, staff, and students may access a recording of the meeting via this link. Log-in is required.

Microplastic Prevalence In Four Oregon Rivers Along A Rural To Urban Gradient Applying A Cost-Effective Validation Technique, Amy Valine, Ashley Peterson, Dorothy Horn, Kaegan M. Scully‐Engelmeyer, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Microplastics are ubiquitous in our environment and are found in rivers, streams, oceans, and even tap water. Riverine microplastics are relatively understudied compared to those in marine ecosystems. In Oregon, we sampled eight sites along four freshwater rivers spanning rural to urban areas to quantify microplastics. Plankton tow samples from sites along the Columbia, Willamette, Deschutes, and Rogue Rivers were analyzed using traditional light microscopy for initial microplastic counts. Application of Nile Red dye to validate microplastics improved microplastic identification, particularly for particles (Wilcox Test; p‐value=0.001). Nile Red‐corrected microfiber abundance was correlated with human population within five kilometers of the …

Addressing Diversity And Inclusion Through Group Comparisons: A Primer On Measurement Invariance Testing, Guizella A. Rocabado, Regis Komperda, Jennifer E. Lewis, Jack Barbera

Chemistry Faculty Publications and Presentations

As the field of chemistry education moves toward greater inclusion and increased participation by underrepresented minorities, standards for investigating the differential impacts and outcomes of learning environments have to be considered. While quantitative methods may not be capable of generating the in-depth nuances of qualitative methods, they can provide meaningful insights when applied at the group level. Thus, when we conduct quantitative studies in which we aim to learn about the similarities or differences of groups within the same learning environment, we must raise our standards of measurement and safeguard against threats to the validity of inferences that might favor …

Portland State Magazine, Portland State University. Office Of University Communications

Portland State Magazine

PSU’s alumni magazine, published 2-3 times a year. In this issue: 1970, the year that changed PSU; celebrating 50 years of the Honors College; PSU's new museum opens with a focus on free exhibitions and educational programming; Ph.D. candidate Katie Conlon takes on plastics waste; Professor Darrell Grant’s new opera about gentrification in Northeast Portland; a walk-on player’s long journey to a starting position with Viking football; alum Chris Bartlo wins a Presidential Award for his work at Wilson High; and more

Climate From The Mcmurdo Dry Valleys, Antarctica, 1986–2017: Surface Air Temperature Trends And Redefined Summer Season, Maciej K. Obryk, Peter T. Doran, Andrew G. Fountain, M. Myers, Christopher P. Mckay

Geology Faculty Publications and Presentations

The weather of the McMurdo Dry Valleys, Antarctica, the largest ice‐free region of the Antarctica, has been continuously monitored since 1985 with currently 14 operational meteorological stations distributed throughout the valleys. Because climate is based on a 30‐year record of weather, this is the first study to truly define the contemporary climate of the McMurdo Dry Valleys. Mean air temperature and solar radiation based on all stations were −20°C and 102 Wm⁻², respectively. Depending on the site location, the mean annual air temperatures on the valleys floors ranged between −15°C and −30°C, and mean annual solar radiation varied …

The Creative Philosophies Of Leonardo Da Vinci: Nature As The Perfect Creator, Julia M. Swanson

Young Historians Conference

Leonardo da Vinci is highly regarded for his many contributions to the arts and sciences, though not much is known of his philosophical work. This paper focuses on his creative methodologies and their formation, as influenced by his Italian roots and the presence of Aristotlean philosophy within the Renaissance. The combination of philosophy and his environment produced unique naturalistic creativity.

Religious Motivations Can Only Get You So Far: The Impacts And Limitations Of Lutheran Educational Reforms, Abigail Schipper

Young Historians Conference

Education was once reserved strictly for the few, the rich, the Catholic, and the male. Along with reforming many of the theological and political practices of 16th century Europe, the Protestant Reformation also introduced educational reforms that would enhance the literacy of the Germany States, instituted compulsory education laws, and extended said compulsory education to girls. However, these reforms were hindered by that which motivated the reforms in the first place: The reformers’ primary goal was to spread a religion, not to educate a populace. Because of this, the educational reforms mainly impacted only the upper classes and failed to …

Spectrum Modeling Of Out-Of-Band Intermodulation For Dual-Band Rf Amplifiers In Ofdm Modulation, Xianzhen Yang, Siyuan Yan, Xiao Li, Qiang Wu, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Dual-band RF amplifiers play increasingly important roles in next-generation mobile communication systems including 5G, and the out-of-band intermodulation products are often not negligible since they generate interference to adjacent channels. In this article, following our previous modeling of cross-modulation for amplified dual-band signals, an analytical expression of out-of-band intermodulation for dual-band orthogonal frequency-division multiplexing signals is derived using the third-order intercept points IP₃. The experimental measurement results validate the proposed analytical expression.

Archaeological Feature Identification Through Geochemical Analysis Of Arctic Sediments From The Cape Krusenstern National Monument, Northwest Alaska, Patrick William Reed

Dissertations and Theses

Identification and interpretation of archaeological phenomena is typically based on visual cues and the physical presence of "something archaeological," such as a diagnostic artifact, landscape modification, or structural element. Yet many archaeological features, i.e. the discrete archaeological deposits related to past human behavior, lack clear indicators of human activity that provides clues to the feature's origin. At the Cape Krusenstern beach ridge complex, located in northwest Alaska, ambiguous features, that could be natural or anthropogenic (vegetation anomalies), or are of unknown cultural function (indeterminate), comprise 60% of the identified features at the complex. These ambiguous features represent a large gap …