Digital Commons Network^™

A Study Of Fragmentation And Spontaneous Covalent Self-Assembly Of The Azaorcus Ribozyme From Multiple Small Inactive Rna Fragments, Tharuka Sewwandi Jayathilaka

Dissertations and Theses

The question about the origins of life often appears as a difficult question to answer. A more reliable candidate molecule for the chemical origins of life would be a molecule that is capable of making copies of itself from simple precursors. With the finding of the catalytic activities of RNA molecules by Thomas Cech and Sid Altman in late 1980s, the term ribozyme was introduced to define an RNA molecule with catalytic activity. The RNA World is a conceptual period in the early stages in the development of life because RNA simultaneously possesses evolvability and catalytic function. An RNA molecule …

The Dispute Over The Commons: Seed And Food Sovereignty As Decommodification In Chiapas, Mexico, Carol Frances HernáNdez RodríGuez

Dissertations and Theses

Seeds have become one of the most contested resources in our society. Control over seeds has intensified under neoliberalism, and today four large multinational corporations control approximately 70 percent of the global seed market. In response to this concentration of corporate power, an international social movement has emerged around the concept of seed sovereignty, which reclaims seeds and biodiversity as commons and public goods. This study examines the relationship between the global dynamics of commodification and enclosure of seeds, and the seed sovereignty countermovement for decommodification. I approach this analysis through an ethnographic case study of one local seed sovereignty …

Does Avid Higher Education (Avid He) Increase Student Term-To-Term Progression, Persistence Toward Credited Classes And Social Capital For First-Generation College Students Placing Into Developmental Education: A Mixed Methods Study, Christie M. Plinski

Dissertations and Theses

Often considered the gateway to the middle class in the United States, community colleges are struggling to find ways to support all students in career planning and preparation. Unfortunately, increasing numbers of first generation students who enter community colleges through the door of open access, place into developmental education (remedial) courses and must satisfactorily complete this often-rigid sequence before beginning college level classes. For many first-generation, under-prepared, underresourced students, this is a frustrating and often insurmountable barrier, causing many students to abort their postsecondary training.

Creating intentional conditions and instructional strategies that support student learning is essential in increasing the …

New Approaches For Memristive Logic Computations, Muayad Jaafar Aljafar

Dissertations and Theses

Over the past five decades, exponential advances in device integration in microelectronics for memory and computation applications have been observed. These advances are closely related to miniaturization in integrated circuit technologies. However, this miniaturization is reaching the physical limit (i.e., the end of Moore's Law). This miniaturization is also causing a dramatic problem of heat dissipation in integrated circuits. Additionally, approaching the physical limit of semiconductor devices in fabrication process increases the delay of moving data between computing and memory units hence decreasing the performance. The market requirements for faster computers with lower power consumption can be addressed by new …

The Impact Of Online Professional Development On The Assessment Efficacy Of Novice Itinerant Teachers Of Students With Multiple Disabilities Including Visual Impairments, Jacqulyn Anne Donnenwirth Daniels

Dissertations and Theses

The primary question for this dissertation was: Does online professional development increase novice itinerant Teachers of Students with Visual impairments' (TVI) efficacy for assessing learning and literacy media for students with multiple disabilities including visual impairments? The literature suggested novice TVIs might experience low efficacy when implementing strategies unique to their job after leaving teacher-training programs. Working in an itinerant position can intensify perceptions of low efficacy. One area of low efficacy was conducting and reporting on the assessment of learning and literacy media (ALLM).

Using a quasi-experimental pre/post-design, data were collected from pre/postintervention knowledge questionnaires about the assessment process …

Wind Energy And Wind-Energy-Inspired Turbulent Wakes: Modulation Of Structures, Mechanisms And Flow Regimes, Elizabeth H. Camp

Dissertations and Theses

The interaction of turbulent wakes with one another and with the adjacent fluid directly impacts the generation of electricity in wind turbine arrays. Computational modeling is well suited to the repeated iterations of data generation that may be required to inform understanding of the function of wind farms as well as to develop control schemes for plant function. In order to perform such computational studies, a simplified model of the turbine must be implemented. One of the most computationally efficient parametrizations of the blade utilizes a stationary disk which has a prescribed drag and produces a wake. However, since accurate …

Faculty Senate Monthly Packet June 2018, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The June 2018 Monthly packet includes the May agenda and appendices and the Faculty Senate minutes and attachments from the meeting held May 2018.

Space-Time Discretizations Using Constrained First-Order System Least Squares (Cfosls), Kirill Voronin, Chak Shing Lee, Martin Neumüller, Paulina Sepulveda, Panayot S. Vassilevski

Portland Institute for Computational Science Publications

This paper studies finite element discretizations for three types of time-dependent PDEs, namely heat equation, scalar conservation law and wave equation, which we reformulate as first order systems in a least-squares setting subject to a space-time conservation constraint (coming from the original PDE). Available piece- wise polynomial finite element spaces in (n + 1)-dimensions for functional spaces from the (n + 1)-dimensional de Rham sequence for n = 3, 4 are used for the implementation of the method. Computational results illustrating the error behavior, iteration counts and performance of block-diagonal and monolithic geometric multi- grid preconditioners are …

Investigating Environmental Migration And Other Rural Drought Adaptation Strategies In Baja California Sur, Mexico, Melissa Haeffner, Jacopo A. Baggio, Kathleen Galvin

Environmental Science and Management Faculty Publications and Presentations

This paper explores the relationship between specific household traits (region of residence, head of household occupation, financial diversity, female level of education, land and animal ownership, social capital, and climate perception) and choice of specific adaptation strategies used by households in two sites in Baja California Sur, Mexico, during a severe drought from 2006 to 2012 using survey data and key informant interviews. We analyzed the co-occurrence of household traits adopting different drought adaptation strategies, then applied Qualitative Comparative Analysis (QCA) to examine the relationship between traits and strategies and integrated interview data to understand how rancheros perceive associations. We …

Sediment Chemistry Of Urban Stormwater Ponds And Controls On Denitrification, Joanna R. Blaszczak, Meredith Steele, Brian D. Badgley, James B. Heffernan, Sarah E. Hobbie, Jennifer L. Morse, Erin N. Rivers, Sharon J. Hall, Christopher Neill, Diane E. Pataki, Peter M. Groffman, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

Stormwater ponds and retention basins are ubiquitous features throughout urban landscapes. These ponds are potentially important control points for nitrogen (N) removal from surface water bodies via denitrification. However, there are possible trade-offs to this water quality benefit if high N and contaminant concentrations in stormwater pond sediments decrease the complete reduction of nitrous oxide (N₂O), a potent greenhouse gas, to dinitrogen (N₂) during denitrification. This may occur through decreasing the abundance or efficiency of denitrifiers capable of producing the N₂O reductase enzyme. We predicted that ponds draining increasingly urbanized landscapes would have higher …

Gaussian Processes With Context-Supported Priors For Active Object Localization, Bruno Jedynak

Portland Institute for Computational Science Publications

We devise an algorithm using a Bayesian optimization framework in conjunction with contextual visual data for the efficient localization of objects in still images. Recent research has demonstrated substantial progress in object localization and related tasks for computer vision. However, many current state-of-the-art object localization procedures still suffer from inaccuracy and inefficiency, in addition to failing to provide a principled and interpretable system amenable to high-level vision tasks. We address these issues with the current research.

Our method encompasses an active search procedure that uses contextual data to generate initial bounding-box proposals for a target object. We train a convolutional …

Cox Processes For Counting By Detection, Purnima Rajan, Yongming Ma, Bruno Jedynak

Portland Institute for Computational Science Publications

In this work, doubly stochastic Poisson (Cox) processes and convolutional neural net (CNN) classifiers are used to estimate the number of instances of an object in an image. Poisson processes are well suited to model events that occur randomly in space, such as the location of objects in an image or the enumeration of objects in a scene. The proposed algorithm selects a subset of bounding boxes in the image domain, then queries them for the presence of the object of interest by running a pre-trained CNN classifier. The resulting observations are then aggregated, and a posterior distribution over the …

Baroclinic Tidal Sea Level From Exact-Repeat Mission Altimetry, Edward Zaron

Portland Institute for Computational Science Publications

A near-global model for the sea-surface expression of the baroclinic tide has been developed using exact-repeat mission altimetry. The methodology used differs in detail from other altimetry-based estimates of the open ocean baroclinic tide, but it leads to estimates which are broadly similar to previous results. It may be used for prediction of the baroclinic sea level anomaly at the frequencies of the main diurnal and semidiurnal tides, K₁, O₁, M₂, S₂, as well as the annual modulates of M₂, denoted MA₂ and MB₂. Based on a …

Pedestrian Observation And Data Collection Curriculum Guide, Jennifer Dill, Tara Beth Goddard

TREC Final Reports

This guidebook provides a comprehensive set of class exercises suitable for students in courses related to travel behavior, traffic safety, urban planning and design, community health, or civil engineering. Exercises include activities developed through this project as well as an extensive set of educational materials drawn from online resources. The exercises developed as part of this project focus on pedestrians. They include elements of both traditional traffic counts and behavioral components, the latter of which are often lacking from current data collections efforts. By encouraging students to consider behavioral interactions of roadway users, these exercises can provide students with field …

Garden Pollinators And The Potential For Ecosystem Service Flow To Urban And Peri-Urban Agriculture, Gail A. Langellotto, Andony Melathopoulos, Isabella Messer, Aaron Anderson, Nathan Mcclintock, Lucas Costner

Urban Studies and Planning Faculty Publications and Presentations

Hedgerows, flowering strips, and natural areas that are adjacent to agricultural land have been shown to benefit crop production, via the provision of insect pollinators that pollinate crops. However, we do not yet know the extent to which bee habitat in the form of urban gardens might contribute to pollination services in surrounding crops. We explored whether gardens might provision pollinators to adjacent agricultural areas by sampling bees from gardens in the Portland, Oregon metropolitan area, and estimating typical foraging distances in the context of commercialand residential-scale pollination-dependent crops up to 1000 m from garden study sites. We estimate that …

How Green Is Our Valley?: Five-Year Study Of Selected Lis Journals From Taylor & Francis For Green Deposit Of Articles, Jill Emery

Library Faculty and Staff Publications and Presentations

This study reviews content from five different library and information science journals: Behavioral & Social Sciences Librarian, Collection Management, College & Undergraduate Libraries, Journal of Electronic Resources Librarianship and Journal of Library Administration over a five-year period from 2012–2016 to investigate the green deposit rate. Starting in 2011, Taylor & Francis, the publisher of these journals, waived the green deposit embargo for library and information science, heritage and archival content, which allows for immediate deposit of articles in these fields. The review looks at research articles and standing columns over the five years from these five journals to see if …

Who Teaches Technical And Professional Communication Service Courses?: Survey Results And Case Studies From A National Study Of Instructors From All Carnegie Institutional Types, Sarah Read, Michael J. Michaud

English Faculty Publications and Presentations

In this article, we offer answers to the question, “Who teaches the technical and professional communication service course and in what institutional situations?” We present data from a national online survey of technical and professional communication instructors from across all Carnegie institutional types (2- and 4-year). In addition, we share four case-studies of survey respondents whose situations present the greatest challenges facing those who seek to improve or reform the technical and professional communication service course. We close the article by putting the case studies into the context of the reported survey data and arguing for how advocates for the …

Mass Accretion And Ozone Reactivity Of Idealized Indoor Surfaces In Mechanically Or Naturally Ventilated Indoor Environments, Elliott T. Gall, Donghyun Rim

Mechanical and Materials Engineering Faculty Publications and Presentations

In indoor environments, accretion of mass to materials may provide sites for surface chemistry that differ from those of the original material. Since indoor surfaces are a major sink of oxidant gases, surface mass accretion may impact indoor O₃ chemistry. In this study, the effect of surface mass accretion on O₃ surface deposition was tested by deploying cleaned borosilicate glass plates in two types of indoor environments: a mechanically ventilated ( MV ) office and a naturally ventilated ( NV ) residence located in Singapore. In each environment, seven replicate glass plates and one field blank were deployed …

Sensing Building Structure Using Uwb Radios For Disaster Recovery, Jeong Eun Lee

Dissertations and Theses

This thesis studies the problem of estimating the interior structure of a collapsed building using embedded Ultra-Wideband (UWB) radios as sensors. The two major sensing problems needed to build the mapping system are determining wall type and wall orientation. We develop sensing algorithms that determine (1) load-bearing wall composition, thickness, and location and (2) wall position within the indoor cavity. We use extensive experimentation and measurement to develop those algorithms.

In order to identify wall types and locations, our research approach uses Received Signal Strength (RSS) measurement between pairs of UWB radios. We create an extensive database of UWB signal …

Pathways To Kindergarten Growth: Synthesizing Theories Of The Kindergarten Transition To Support Children's Development, Rita Yelverton

Dissertations and Theses

The transition into Kindergarten is a critical time for children's development--children's patterns of academic development and engagement with school often start in Kindergarten and persist throughout their academic careers. This is a developmental period that is marked by many changes in children's lives, and therefore it is not a surprise that many children struggle during this transition. These struggles are more common for children who are living in poverty, and although there have been national initiatives to address opportunity gaps in access to early education, investigations into the effectiveness of these programs in promoting children's Kindergarten development have shown mixed …

Analytical And Toxicological Evaluation Of Flavor Chemicals In Electronic Cigarette Refill Fluids, Rachel Z. Behar, Wentai Luo, Kevin J. Mcwhirter, James F. Pankow, Prue Talbot

Chemistry Faculty Publications and Presentations

Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing …

Theory, Operation, And Application Of Neural Networks, John Andersen

University Honors Theses

This paper examines the history and current state of machine learning. It examines neural networks, theory behind neural networks, how they are implemented, and how they are used. The systems and networks examined have up to three modes of learning. Theory behind machine learning is broken up into three approaches; rule-based, Bayesian, and neural networks. Operation of machine learning algorithms has been enabled by several prevalent libraries in the open source community, as well as various hardware technologies. Due to this surge in resources application developers have been able to apply machine learning in novel ways. An application of machine …

Basics Of Bessel Functions, Joella Rae Deal

University Honors Theses

This paper is a deep exploration of the project Bessel Functions by Martin Kreh of Pennsylvania State University. We begin with a derivation of the Bessel functions J_a(x) and Y_a(x), which are two solutions to Bessel’s differential equation. Next we find the generating function and use it to prove some useful standard results and recurrence relations. We use these recurrence relations to examine the behavior of the Bessel functions at some special values. Then we use contour integration to derive their integral representations, from which we can produce their asymptotic formulae. We also show an …

Music And Ireland's National Identity: Connecting Folk Music And Cultural Theory Through Emotional Sociology, Alexandra Habecker

University Honors Theses

Music has been a crucial component of every major social movement in history. Though studies have shown that music and other areas of the arts are a product of the surrounding world in response to their own historical context, I propose that music can and has directly impacted society through the effects of music on the human emotional response. By looking at cultural theory through a musicological lens and using Ireland's rich and rooted musical culture as an example, this thesis suggests that with further research into the connection between music and emotions, along with expanding interest in the growing …

Gerrymandering And The Courts: Evaluating Judicially Manageable Standards, Amelia L. Zuidema

University Honors Theses

For years the Supreme Court has struggled to set judicially manageable standards for cases involving partisan gerrymandering. The author argues that partisan gerrymandering is justiciable and that standards do exist.

Internet Of Things Security: Ongoing Threats And Proposed Solutions, Samuel Strba

University Honors Theses

This paper will describe the security vulnerabilities posed by Internet of Things (IoT) devices, and potential solutions to alleviate these vulnerabilities. It will describe how IoT devices work, and how they differ from conventional devices such as personal computers in utilizing the Internet. Then the paper will describe the security threats associated with IoT devices, and how a lack of proper security in IoT devices exacerbates this problem. Finally, it will describe proposed solutions to improve IoT device security. IoT devices are seeing increasing deployment in the field, and the continued growth of the Internet of Things along with the …

Quantitative Assessment Of The Lewis Acidity Of Diaryliodonium Salts, Florian H. Guillot

University Honors Theses

Diaryliodonium salts are promising novel reagents in arylation chemistry as they represent an efficient, inexpensive and non-toxic alternative to the most commonly used heavy-metal-based oxidants and organometallic catalysts. While the electrophilicity of these reagents has been widely accepted, few studies have made use of these new reagents as Lewis acids. In order to further the understanding of diaryliodonium salts, this work aims to quantify the Lewis acidity of a variety of aryl(2,4,6-trimethoxyphenyl)iodonium salts. To this end, the Guttmann-Beckett method was used in which NMR titrations of triethylphosphine oxide (TPO) and diaryliodonium salts were performed in deuterated acetonitrile. Nonlinear regression was …

An Analysis Of Green Infrastructure Implementation Strategies In Portland And Other Global Leaders In Climate Action, Rachel L.R. Lemont

University Honors Theses

Green infrastructure has become increasingly popular as a way to mitigate and adapt to the effects of climate change in urban environments. Cities all over the world, including Portland, have developed their own strategies which inform local organizations on the actions they should take to be climate resilient - and many of these strategies include the implementation of green infrastructure. This thesis compares Portland's green infrastructure implementation strategies to those known around the world, and utilizes themes found in those strategies to create a survey on local green infrastructure initiatives in the Portland area. This information will be important for …

Uncovering Newton's Laws Within A Game Of Tug-Of-War, Roberto C. Perez-Franco

University Honors Theses

Introductory physics students frequently struggle with the application of Newton's laws of motion. Students frequently misinterpret Newton's 3^rd Law, which states that for every action there is an equal and opposite reaction. The confusion arises when allocating the action-reaction force pair to a system; students think that the force pair act on the same object, but the force pair actually act on different objects. One interesting example, where action-reaction force pairs come into play, is the game of Tug-of-War. Therefore, to address some misconceptions about Newton's laws of motion, we implemented an activity where we looked at how the …

The Contrast Of Covariational Reasoning And Other Problem Solving Methods Of A Calculus Student, Micah Kurzer

University Honors Theses

Research has shown that covariational reasoning is indicative of success across a variety of mathematics topics, especially calculus. This paper will build on the prior research by examining one calculus student’s covariational reasoning over a multiple term teaching experiment. The tasks associated with the teaching experiment appear in a variety of mathematical forms, and in varying contexts, so that the student’s techniques for each task provide results that can be interpreted using existing frameworks. Analyzing the covariational reasoning of the student with these frameworks reveals relationships between the methods the student uses to solve tasks involving covariational reasoning and the …