Digital Commons Network^™

Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos

Dissertations and Theses

The tunneling fold (T-Fold) superfamily is a small superfamily of enzymes found in organisms encompassing all kingdoms of life. Seven members have been identified thus far. Despite sharing a common three-dimensional structure these enzymes perform very diverse chemistries.

QueF is a bacterial NADPH-dependent oxidoreductase that catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ₀) to a primary amine (preQ₁) in the queuosine biosynthetic pathway. Previous work on this enzyme has revealed the mechanism of reaction but the cofactor binding residues remain unknown. The experiments discussed herein aim to elucidate the role of residues lysine 80, …

Practical Wired Digital Communications Link Analysis, Raymond Matthew Schmelzer

Dissertations and Theses

This thesis deals with the analysis of a Wired High Speed Serial Data Link (PAM2) which is commonly used throughout the data-communications and tele-communications industry. The goal of this study is to build a scalable simulation tool using Matlab that ultimately uses Receiver Bit Error Ratio (BER) as the metric for data link health. This study is also designed to aid in link specification development.

The Matlab and theoretical development is broken up into three sections being Transmitter (TX), Channel (Hs) and Receiver (RX). Realistic noise impairments can be added to each section along the signal path creating signal stresses …

Dietary And Physical Activity Acculturation And Weight Status In Chinese College Students, Yanni Zhang

Dissertations and Theses

This cross-sectional study examined the relationships between length of residence in the United States (U.S.) and dietary and physical activity acculturation, and the relationships between dietary and physical activity acculturation and weight status in 55 Chinese college students. Length of residence in the U.S. was positively associated with larger portion size, greater amount of physical activity, and change in BMI in male participants. Adoption of a Western diet was associated with weight gain. Portion size change was positively associated with BMI change. Lunch size change was positively correlated with BMI change in males while negatively correlated with BMI change in …

The Making Of Modern Egypt: The Egyptian Ulama As Custodians Of Change And Guardians Of Muslim Culture, Marai Boauod

Dissertations and Theses

Scholarship on the modern history of the Middle East has undergone profound revision in the previous three decades or so. Many earlier perceptions, largely based on modernization theory, have been either contested or modified. However, the perception of the Egyptian ulama (the traditionally-educated, religious Muslim scholars) in academic scholarship remains largely affected by the legacy of hypotheses of the modernization theory. Old assumptions that the Egyptian ulama were submissive to political power and passive players incapable of accommodating, let alone of fathoming, conditions of the modern world, and who chose or were forced to retreat from this world, losing much, …

Conventionalizing And Axiomatizing In A Community College Mathematics Bridge Course, Mark Alan Yannotta

Dissertations and Theses

This dissertation consists of three related papers. The first paper, Rethinking mathematics bridge courses--An inquiry model for community colleges, introduces the activities of conventionalizing and axiomatizing from a practitioner perspective. In the paper, I offer a curricular model that includes both inquiry and traditional instruction for two-year college students interested in mathematics. In particular, I provide both examples and rationales of tasks from the research-based Teaching Abstract Algebra for Understanding (TAAFU) curriculum, which anchors the inquiry-oriented version of the mathematics bridge course.

The second paper, the role of past experience in creating a shared representation system for a mathematical operation: …

Thermal Decomposition Of Electronic Cigarette Liquids, Robert Paul Jensen

Dissertations and Theses

Electronic cigarette liquid (e-liquid) is a solution of propylene glycol and/or glycerol with varying concentrations of nicotine and flavorants. Inhalation of vaporized e-liquid is a method of nicotine delivery that is growing in popularity and is commonly regarded as safe relative to smoking traditional tobacco products. The thermal decomposition of glycerol and propylene glycol is typical of alcohols and has been investigated, although not exhaustively. In this work, samples of propylene glycol and glycerol were vaporized using an electronic cigarette (e-cigarette) and were analyzed for evidence of decomposition using nuclear magnetic resonance (NMR) spectroscopy. E-cigarettes are shown to degrade glycerol …

Architectures And Algorithms For Intrinsic Computation With Memristive Devices, Jens Bürger

Dissertations and Theses

Neuromorphic engineering is the research field dedicated to the study and design of brain-inspired hardware and software tools. Recent advances in emerging nanoelectronics promote the implementation of synaptic connections based on memristive devices. Their non-volatile modifiable conductance was shown to exhibit the synaptic properties often used in connecting and training neural layers. With their nanoscale size and non-volatile memory property, they promise a next step in designing more area and energy efficient neuromorphic hardware.

My research deals with the challenges of harnessing memristive device properties that go beyond the behaviors utilized for synaptic weight storage. Based on devices that exhibit …

Democratization, Political Performance, And Income Distribution In Argentina And Brazil, Nicholas Paul Stowell

Dissertations and Theses

This research examines the effects of democratization and political performance on the functional distribution of income in Argentina and Brazil from the end of their authoritarian periods to the present. The existing literature tends to focus on the impacts of democratization and political performance on the economic growth of the country as a whole or on changes to per capita income. This analysis focuses on the equality of economic development in less developed countries because growth is not necessarily distributed equally and poverty and inequality are both endemic to many less developed countries and also negatively impact development as a …

Understanding Neighborhood Satisfaction For Individuals With Psychiatric Disabilities: A Mixed Methods Study, Amy Leigh Shearer

Dissertations and Theses

Physical and social characteristics of neighborhoods are important to resident satisfaction for clinical and nonclinical populations. This study draws upon data collected from a sample of 172 individuals with psychiatric disabilities living in 16 supportive housing sites in the Portland, Oregon metropolitan area. Research questions explore the extent to which subjective and objective measures of neighborhood physical and social environments contribute to neighborhood satisfaction for this population. Mixed methods were employed to construct a detailed understanding of the factors that influence satisfaction with one's neighborhood of residence. Predictor variables were neighborhood social climate, neighborhood physical quality, perceptions of safety, crime …

Improving The Roadside Environment Through Integrating Air Quality And Traffic-Related Data, Christine M. Kendrick

Dissertations and Theses

Urban arterial corridors are landscapes that give rise to short and long-term exposures to transportation-related pollution. With high traffic volumes, congestion, and a wide mix of road users and land uses at the road edge, urban arterial environments are important targets for improved exposure assessment to traffic-related pollution. Applying transportation management strategies to reduce emissions along arterial corridors could be enhanced if the ability to quantify and evaluate such actions was improved. However, arterial roadsides are under-sampled in terms of air pollution measurements in the United States and using observational data to assess such effects has many challenges such as …

Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones

Dissertations and Theses

The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that …

Information Literacy In The First Year Of Higher Education: Faculty Expectations And Student Practices, Meredith Esther Michaud

Dissertations and Theses

Information literacy is widely acknowledged as important for student success in higher education. Information literacy is the ability to sort through a large amount of available information, decide what is useful and believable, and apply it in an effective and ethical way. Faculty members have expectations regarding information literacy for students in the first year of college, while students have information literacy practices that may or may not match those expectations. In my study, I examined the alignment of faculty member information literacy expectations and student information literacy practices, focusing on freshman students and faculty members who teach freshman students …

Molecular Probes For Pancreatic Cancer Imaging, Lei Wang

Dissertations and Theses

Pancreatic ductal adenocarcinoma (PDAC) has the poorest five-year survival rate of any cancer. Currently, there are no effective diagnostics or chemotherapeutics. Surgical resection is the only curative therapy. However, most patients experience recurrence due largely to challenges in assessing tumor margin status in the operating room. Molecular probes that selectively highlight pancreatic cancer tissue, having the potential to improve PDAC margin assessment intraoperatively, are urgently needed. In this work, a series of red and near-infrared fluorescent probes is reported. Two were found to distribute to normal pancreas following systemic administration. One selectively accumulates in genetically modified mouse models of PDAC, …

Torsional Strengthening Of Reinforced Concrete Beams Using Cfrp Composites, Ranj Rafeeq

Dissertations and Theses

Few decades ago, there were no guidelines for torsion design of reinforced concrete (RC) beams. Hence, many existing beams in older buildings have a lack of adequate torsional strength since they were not properly designed for torsion. One way to regain/rehabilitate adequate torsional strength is through application of externally bonded carbon fiber reinforced polymers (CFRP). To date, American Concrete Institute (ACI) code, as well as other building codes, do not have recommendations or provisions for strengthening RC beams for torsion using fiber-reinforced polymer (FRP) composites due to the inexistence of conclusive experimental and analytical data. Of the very limited works …

The Mediating Effects Of Lmx On The Relationship Between Supervisor And Employee Age Differences, Satisfaction, And Retirement Intentions, Amy Christine Pytlovany

Dissertations and Theses

Increasing age heterogeneity within organizations is pressing researchers to better understand the effects of a multigenerational workforce, teams, and dyads. In response to this, the present research aimed to investigate the effect of employee and supervisor age (in)congruence in relation to job and life satisfaction, as well as retirement intentions, all mediated by leader-member exchange (LMX), using a time-lagged design. Two different theoretical foundations were investigated. Based on the relational demography literature, better outcomes were expected to be associated with age similarity. Theories about implicit expectations relating age and social role guided hypotheses suggesting that beyond just similarity or difference, …

Perceptions Of Hmong Parents In A Hmong American Charter School: A Qualitative Descriptive Case Study On Hmong Parent Involvement, Kirk T. Lee

Dissertations and Theses

Parental involvement plays an essential role in the United States (U.S.) educational system. However, parental involvement poses many challenges for Hmong parents in American schools. Many assumptions are made on the parts of teachers, staff, and Hmong parents about parents' roles pertaining to their involvement in their children's education. Hmong parents struggle to reconcile beliefs, attitudes, and values that they bring with them from Laos with the expectations found in the U.S. due to their unfamiliarity with the U.S. educational system.

This study employed the used a qualitative, descriptive case study approach to examine the perceptions of Hmong parents involvement …

Teacher Mindfulness In The Middle School Classroom: Reliability And Validity Of A New Scale, Nicolette Paige Rickert

Dissertations and Theses

Despite significant growth in research examining the effects of mindfulness interventions on teachers (Roeser, 2014), studies have mainly relied on self-reports of teacher mindfulness and have not examined observable behavioral manifestations of teacher mindfulness in the classroom. Due to possible biases in self-report measures (Dotterer & Lowe, 2011), as well as the need for a greater range of assessments of the effects of mindfulness trainings on teachers, the current study sought to create a new measure of teacher mindfulness in the classroom from three sources of information: teacher self-reports of their own behavior in the classroom, student perceptions of their …

South Korean Teachers' Beliefs About Diversity: The Impact On Practice Of Multicultural Education, Marie Yeo

Dissertations and Theses

Teachers in South Korean schools have begun to pay attention to the importance of multicultural education as Korea transforms into a multicultural society from a historically mono culture society. Because of Koreans' pride in the homogeneity of their race, language, and culture, multiculturalism is an idea that is hard for many to accept. Education needs to play a key role in fostering and retaining the value of diversity. Studies suggest that teachers' positive beliefs about diversity play a significant role to develop their multicultural competence and eventually to practice better multicultural education. The problem is little evidence exists in the …

Japanese Dialect Ideology From Meiji To The Present, Nao Okumura

Dissertations and Theses

The intent of this study is to examine the trajectory of ideology regarding standard Japanese and dialects from the historical perspective, and also to discuss the cause of the post-war shift of the ideology. Before the war, the government attempted to disseminate hyojun-go aiming at creating a unified Japan in the time when many countries were developing to be nation states after industrial revolution. After the Pacific war, the less strict-sounding term kyotsu-go was more often used, conveying an ideology of democratization. Yet despite the difference in the terms, speaking a common language continues to play a role of unifying …

Do Forest Commons Contribute To International Environmental Initiatives? A Socio-Ecological Analysis Of Nepalese Forest Commons In View Of Redd+, Harisharan Luintel

Dissertations and Theses

Forests in developing countries have the potential to contribute to global efforts to mitigate climate change, promote biodiversity and support the livelihoods of rural, local people. Approximately one-fourth of such forests are under the control of local communities, which primarily manage forests for subsistence and to meet their livelihood needs. The trend of bottom-up community control is increasing through the adoption of decentralization reforms over the last 40 years. In contrast, the United Nations has introduced the top-down program, Reducing Emissions from Deforestation and Forest Degradation (REDD+) for the conservation and enhancement of forest carbon and the sustainable management of …

Bridging The Worlds Of Home And School: A Study Of The Relational Worlds Of First-Generation Students In A School Of Social Work, Miranda Cunningham

Dissertations and Theses

Much scholarship on first-generation students has focused on their academic and social integration in college (Collier & Morgan, 2008; Lowery-Hart & Pacheco, 2011; Stuber, 2011). Little is known about the experiences of first-generation students in schools of social work. In this research I've expanded the focus beyond students' experiences of academic integration to explore how first-generation students in a school of social work describe their relational worlds and the implications for professional socialization.

Informed by Standpoint Feminism and Postmodern/Post structural Feminism, I conducted focus groups with 19 students in two undergraduate programs and one graduate program in a school of …

Determining The Power And Energy Capacity Of A Battery Energy Storage System Utilizing A Smoothing Feeder Profile To Accommodate High Photovoltaic Penetration On A Distribution Feeder, Osama Mohammed Abbas Aly Mansour

Dissertations and Theses

Electricity is a perishable commodity; once it is generated it needs to be consumed or stored. Electric energy storage provides both power and energy capacity. Power capacity applications reduce the need for generation, while energy capacity allows for energy consumption to be decoupled from generation. Previous research was done to develop an algorithm for determining the power (MW) and energy (MWh) capacities of a battery energy storage system (BESS) to mitigate the adverse impacts of high levels of photovoltaic (PV) generation. The algorithm used a flat feeder profile, and its performance was demonstrated on the equinoxes and solstices.

Managing feeder …

Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko

Dissertations and Theses

Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …

Demography And The Evolution Of Logistic Organization On The Northern Northwest Coast Between 11,000 And 5,000 Cal Bp, Thomas Jay Brown

Dissertations and Theses

Focusing on the relationship between demography and sedentary behavior, this thesis explores changes to mobility strategies on the Northern Northwest Coast of North America between 11,000 and 5,000 cal BP. Drawing on a regional database of radiocarbon dates, it uses summed probability distributions (SPDs) of calibrated dates as a proxy for population change, in combination with syntheses of previously published technological, paleo environmental and settlement pattern data to test three hypotheses derived from the literature about the development of logistic mobility among maritime hunter-gatherers on the Northern Coast.

In all, each of the hypotheses proposes that early peoples on the …

Household Water Filter Use Characterization In Rural Rwanda: Signal Interpretation, Development And Validation, Sarita Lucia Tellez Sanchez

Dissertations and Theses

Access to safe drinking water is an important health factor in many developing countries. Studies have shown that unsafe drinking water and poor sanitation practices leads to diarrheal disease, which is one of the leading causes of death of children under five in developing countries. Provision and proper use of household water filters have been shown to effectively improve health.

This thesis is focused on the refinement and validation of algorithms for data collected from pressure transducer sensors that are used in household water filters (the Vestergaard Frandsen LifeStraw Family 2.0) deployed in Rwanda by the social enterprise DelAgua Health. …

Seismic Behavior And Design Of The Linked Column Steel Frame System For Rapid Return To Occupancy, Arlindo Pires Lopes

Dissertations and Theses

The Linked Column Frame (LCF) is a new brace-free lateral structural steel system intended for rapid return to occupancy performance level. LCF is more resilient under a design level earthquake than the conventional approaches. The structural system consists of moment frames for gravity that combines with closely spaced dual columns (LC) interconnected with bolted links for the lateral system. The LC links are sacrificial and intended to be replaced following a design level earthquake. The centerpiece of this work was a unique full-scale experiment using hybrid simulation testing; a combination of physical test of a critical sub-system tied to a …

Discovery And Characterization Of The Proteins Involved In The Synthesis Of N⁶-Threonylcarbamoyl Adenosine, A Nucleoside Modification Of Trna, Christopher Wayne Deutsch

Dissertations and Theses

N6-threonylcarbamoyl adenosine (t⁶A) is a universally conserved tRNA modification found at position 37 of tRNAs which decode ANN codons. Structural studies have implicated its presence as a requirement for the disruption of a U-turn motif in certain tRNAs, leading to the formation of properly structured anticodon stem loop. This structure is proposed to enhance the base pairing between U₃₆ of tRNA and A₁ of the codon which aids in translational frame maintenance.

Despite significant effort since its discovery in the 1970s the enzymes involved in its biosynthesis remained undiscovered. Bioinformatic analysis identified two proteins as likely …

Local Approaches To Regional Problems: Suburban Government Responses To Portland's Regional Housing Crisis, Emma Deppa

Dissertations and Theses

The Portland metropolitan region has seen unprecedented growth in the last three decades, resulting in both economic expansion and considerable gentrification. While lauded for its commitment to sustainability and a "smart development" ethos, many questions remain for the city with respect to the needs of displaced residents and a burgeoning population of young professionals. This study examines how various levels of government implement growth management policies to accommodate these demographic changes, and aims to assess whether and how the consequences of growth, especially gentrification and displacement, are meaningfully addressed. Qualitative interviews were conducted with staff members and elected officials from …

Social Support And Depression Symptomatology Post Injury In Division 1 Athletes, Alyssa Catherine Tiedens

Dissertations and Theses

The way in which an athlete responds to the injury--emotionally, behaviorally, and cognitively--can significantly affect the athlete's mental health in a negative way if not handled appropriately. There are different forms of social support that are known to be helpful with coping during specific stages of injury. The purpose of this study was to examine the relationship between perceived levels of social support and depression symptomatology post injury in Division 1 collegiate athletes at Portland State University (PSU).

Participants were PSU student athletes (n=115). Variables: social support amount (SSQN), social support satisfaction (SSQS), and depression symptomatology (CESD-R) score. Selected injured …

Vision-Based Motion For A Humanoid Robot, Khalid Abdullah Alkhulayfi

Dissertations and Theses

The overall objective of this thesis is to build an integrated, inexpensive, human-sized humanoid robot from scratch that looks and behaves like a human. More specifically, my goal is to build an android robot called Marie Curie robot that can act like a human actor in the Portland Cyber Theater in the play Quantum Debate with a known script of every robot behavior. In order to achieve this goal, the humanoid robot need to has degrees of freedom (DOF) similar to human DOFs. Each part of the Curie robot was built to achieve the goal of building a complete humanoid …