Physical Sciences and Mathematics Commons^™

An Ethnographic Study Exploring Factors That Minimize Lunch Waste In Tokyo Elementary Schools, Betty T. Izumi, Rie Akamatsu, Carmen Byker Shanks, Kahori Fujisaki

OHSU-PSU School of Public Health Faculty Publications and Presentations

Objective: To explore factors that minimize lunch waste in Tokyo elementary schools and to consider how such factors can be modified and applied in US schools.

Design: Focused ethnographic study using interviews, observation, participant observation and document review. Data were analysed using thematic analysis.

Setting: Tokyo, Japan.

Participants: Five school dietitians participated in the study. Data collection methods included in-depth interviews, observation of nutrition education lessons, participant observation of school lunchtime and review of relevant school documents (e.g. lunch menus, food waste records).

Results: Five themes emerged from the analysis: (i) reinforcement of social norms …

Polarization In The Production Of The Antihydrogen Ion, Casey A. Yazejian, Jack C. Straton

Physics Faculty Publications and Presentations

We provide estimates of both the cross section and rate coefficient for the radiative attachment of a second positron to create the H̅+ ion, H̅(1s)+e+→H̅+(1s2 1Se)+ℏω, for which the polarization of the initial state H̅(1s) is taken into account. We show how to analytically integrate the resulting six-dimensional, three-body integrals for wave functions composed of explicitly correlated exponentials, a result that may be extended to Hylleraas wave functions. We extend Bhatia’s polarization results for the equivalent matter problem down to the low temperatures required for the Gravitational Behaviour of Antihydrogen …

Effectiveness Of Focused Water Conservation Messaging In The Clackamas River, Or, Rikki Carroll Oden

Environmental Science and Management Professional Master's Project Reports

The Clackamas River in Oregon is a drinking water source for upwards of 300,000 people living in the Portland metro region. This river experiences seasonal low flow during the annual dry season throughout summer and early fall when endangered salmon species return to the river to spawn. This dry season also coincides with the highest period of urban water use. Since precipitation is minimal at this time, water users choose to water their lawns to make up for the lack of rain which contributes to water use tripling during the driest part of the year. To promote local water conservation, …

Size-Dependent Interactions Of Lipid-Coated Gold Nanoparticles: Developing A Better Mechanistic Understanding Through Model Cell Membranes And In Vivo Toxicity, Arek M. Engstrom, Ryan A. Faase, Joe E. Baio, Marilyn R. Mackiewicz, Stacey L. Harper

Chemistry Faculty Publications and Presentations

Introduction: Humans are intentionally exposed to gold nanoparticles (AuNPs) where they are used in variety of biomedical applications as imaging and drug delivery agents as well as diagnostic and therapeutic agents currently in clinic and in a variety of upcoming clinical trials. Consequently, it is critical that we gain a better understanding of how physiochemical properties such as size, shape, and surface chemistry drive cellular uptake and AuNP toxicity in vivo. Understanding and being able to manipulate these physiochemical properties will allow for the production of safer and more efficacious use of AuNPs in biomedical applications.
Methods and Materials: Here, …

Synthesis Of Radioluminescent Caf2:Ln Core, Mesoporous Silica Shell Nanoparticles For Use In X-Ray Based Theranostics, Hayden Winter, Megan J. Neufeld, Lydia Makotamo, Conroy Sun, Andrea M. Goforth

Chemistry Faculty Publications and Presentations

X-ray radiotherapy is a common method of treating cancerous tumors or other malignant lesions. The side effects of this treatment, however, can be deleterious to patient quality of life if critical tissues are affected. To potentially lower the effective doses of radiation and negative side-effects, new classes of nanoparticles are being developed to enhance reactive oxygen species production during irradiation. This report presents the synthesis and radiotherapeutic efficacy evaluation of a new nanoparticle formulation designed for this purpose, composed of a CaF₂ core, mesoporous silica shell, and polyethylene glycol coating. The construct was additionally doped with Tb and Eu …

A Statistical Analysis Of Trans-Resveratrol In Grape Cane From Ten Varieties Of Cultivated Wine Grapes (Vitus Spp.), Harold Rathburn, Peter Bell, Scott Cook, Darrell D. Mayberry, Emryse Geye, Ryann Goodrich

Chemistry Faculty Publications and Presentations

trans-Resveratrol (resveratrol) has been shown to have various health benefits. As a consequence, there is an effort to determine plentiful sources of this molecule. Certain plants, such as grapes, synthesize resveratrol and therefore appear to be an excellent source of this chemical. Annual pruning of grapevine yields significant amounts of cane material that is normally mulched or simply burned. Previous studies have shown this grape cane to contain economically useful resveratrol. Texas is the seventh largest producer of grapes in the USA with over 162 ha currently under cultivation. As a result it is estimated that more than $3.2 …

Fire And Land Cover Change In The Palouse Prairie–Forest Ecotone, Washington And Idaho, Usa, Penelope Morgan, Emily K. Heyerdahl, Eva K. Strand, Stephen C. Bunting, James P. Riser Ii, John T. Abatzoglou, Max Nielsen-Pincus, Mara Johnson

Environmental Science and Management Faculty Publications and Presentations

Background: Prairie–forest ecotones are ecologically important for biodiversity and ecological processes. While these ecotones cover small areas, their sharp gradients in land cover promote rich ecological interaction and high conservation value. Our objective was to understand how historical and current fire occurrences and human development influenced the Palouse Prairie–forest ecotone. We used General Land Office survey field notes about the occurrence of bearing trees to locate historical (1870s to 1880s) prairie, pine savanna, and forest at the eastern edge of the bioregion. We combined LANDFIRE Existing Vegetation classes to contrast historical land cover with current land cover. We reconstructed …

Dropsonde Observations Of The Ageostrophy Within The Pre-Cold-Frontal Low-Level Jet Associated With Atmospheric Rivers, Rueben Demirdgian, Joel R. Norris, Andrew Martin, F. Martin Ralph

Geography Faculty Publications and Presentations

The pre-cold-frontal low-level jet (LLJ) is an important contributor for water vapor transport within atmospheric rivers, though its dynamics are not completely understood. The present study investigates the LLJ using dropsonde observations from 24 cross-atmospheric river transects taken during the CalWater-2014, 2015 and the AR-Recon 2016, 2018 field campaigns. It is found that the LLJ, located at ;1-km elevation ahead of the cold front, has an average maximum wind speed of 30ms21 and is strongly supergeostrophic with an average ageostrophic component of 6ms21. The alongfront ageostrophy occurs within the atmospheric layer (750–1250 m) known to strongly control orographic precipitation associated …

A Quantum Algorithm For Automata Encoding, Edison Tsai, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Encoding of finite automata or state machines is critical to modern digital logic design methods for sequential circuits. Encoding is the process of assigning to every state, input value, and output value of a state machine a binary string, which is used to represent that state, input value, or output value in digital logic. Usually, one wishes to choose an encoding that, when the state machine is implemented as a digital logic circuit, will optimize some aspect of that circuit. For instance, one might wish to encode in such a way as to minimize power dissipation or silicon area. For …

Examining The Complex Relationship Between Innovation And Regulation Through A Survey Of Wastewater Utility Managers, Luke Sherman, Alida Cantor, Anita Milman, Michael Kiparsky

Geography Faculty Publications and Presentations

Despite pressures to increase performance and decrease costs, innovation has been slow to emerge in the municipal wastewater sector. The relationship between regulation and innovation in this sector is a particularly interesting aspect of this conundrum, given the degree to which public utility decision-making is influenced by regulation. Using a national survey, this paper examines US wastewater utility managers’ perceptions of how regulation influences the adoption of new technologies. Recognizing that the relationship between innovation and regulation is complex, we develop the concept of regulation as multifaceted and examine three interrelated aspects of regulation: (1) regulatory requirements, (2) regulators and …

A Mass Conserving Mixed Stress Formulation For Stokes Flow With Weakly Imposed Stress Symmetry, Jay Gopalakrishnan, Philip L. Lederer, Joachim Schoeberl

Mathematics and Statistics Faculty Publications and Presentations

We introduce a new discretization of a mixed formulation of the incompressible Stokes equations that includes symmetric viscous stresses. The method is built upon a mass conserving mixed formulation that we recently studied. The improvement in this work is a new method that directly approximates the viscous fluid stress $\sigma$, enforcing its symmetry weakly. The finite element space in which the stress is approximated consists of matrix-valued functions having continuous “normal-tangential” components across element interfaces. Stability is achieved by adding certain matrix bubbles that were introduced earlier in the literature on finite elements for linear elasticity. Like the earlier work, …

Predicting Densities And Elastic Moduli Of Sio2-Based Glasses By Machine Learning, Yong-Jie Hu, Ge Zhao, Mingfei Zhang, Bin Bin, Tyler Del Rose, Qian Zhao, Qan Zu, Yang Chen, Xuekun Sun, Maarten De Jong, Multiple Additional Authors

Mathematics and Statistics Faculty Publications and Presentations

Chemical design of SiO2-based glasses with high elastic moduli and low weight is of great interest. However, it is difficult to find a universal expression to predict the elastic moduli according to the glass composition before synthesis since the elastic moduli are a complex function of interatomic bonds and their ordering at different length scales. Here we show that the densities and elastic moduli of SiO2-based glasses can be efficiently predicted by machine learning (ML) techniques across a complex compositional space with multiple (>10) types of additive oxides besides SiO2. Our machine learning approach relies on a training set …

Experimenting With A Biologically Plausible Neural Network, Dmitri Murphy

University Honors Theses

We present research on an implementation of a biologically inspired Bayesian Confidence Propagation Neural Network (BCPNN). Based on previous work by Christopher Johansson and Anders Lansner, our implementation seeks to test and understand the various properties of this model. The floating-point implementation we built uses discrete time and bit-vectors as input/output. We found that the column based BCPNN model is able to memorize a decent number of input vectors and is able to restore noisy versions of these vectors with relatively high accuracy. We examine the model’s capacity, noise recovery ability and cross-column connection influence, among other attributes. The clearest …

Food Waste Knowledge, Attitudes, And Behavioral Intentions Among University Students, Manar Arica Alattar, James Delaney, Jennifer L. Morse, Max Nielsen-Pincus

Environmental Science and Management Faculty Publications and Presentations

After policy change, educational programming has been cited as one of the most powerful tools for improving food systems and decreasing food waste. University students represent a population in which emerging habits, skills, and identity may be targeted easily and changed through on-campus educational programming. To understand how to best implement programming on impacts of food, food waste, and related issues, the factors that underlie students’ behaviors related to food waste must be understood. We analyzed factors that influence food waste–related behaviors within a university student population to understand the potential for improving targeted, school-based food waste diversion programming. Four …

The Fire And Tree Mortality Database, For Empirical Modeling Of Individual Tree Mortality After Fire, C. Alina Cansler, Sharon M. Hood, J. Morgan Varner, Phillip J. Van Mantgem, Michelle C. Agne, Matthew Ayres, Robert A. Andrus, Jonathon D. Bakker, Michael A. Battaglia, Shelby A. Weiss, Multiple Additional Authors

Geography Faculty Publications and Presentations

Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring …

A Digital Archive Of Human Activity In The Mcmurdo Dry Valleys, Antarctica, Adrian Howkins, Stephen M. Chignell, Poppie Gullett, Andrew G. Fountain, Melissa Carrie Brett, Evelin Preciado

Geography Faculty Publications and Presentations

Over the last half century, the McMurdo Dry Valleys (MDV) of East Antarctica have become a globally important site for scientific research and environmental monitoring. Historical data can make important contributions to current research activities and environmental management in Antarctica but tend to be widely scattered and difficult to access. We address this need in the MDV by compiling over 5000 historical photographs, sketches, maps, oral interviews, publications, and other archival resources into an online digital archive. The data have been digitized and georeferenced using a standardized metadata structure, which enables intuitive searches and data discovery via an online interface. …

Evaluating Cmip6 Model Fidelity At Simulating Non-Gaussian Temperature Distribution Tails, Arielle J. Catalano, Paul Loikith, J. David Neelin

Geography Faculty Publications and Presentations

Under global warming, changes in extreme temperatures will manifest in more complex ways in locations where temperature distribution tails deviate from Gaussian. Confidence in global climate model (GCM) projections of temperature extremes and associated impacts therefore relies on the realism of simulated temperature distribution tail behavior under current climate conditions. This study evaluates the ability of the latest state-of-the-art ensemble of GCMs from the Coupled Model Intercomparison Project phase six (CMIP6), to capture historical global surface temperature distribution tail shape in hemispheric winter and summer seasons. Comparisons with a global reanalysis product reveal strong agreement on coherent spatial patterns of …

On Basing One-Way Permutations On Np-Hard Problems Under Quantum Reductions, Nai-Hui Chia, Sean Hallgren, Fang Song

Computer Science Faculty Publications and Presentations

A fundamental pursuit in complexity theory concerns reducing worst-case problems to average-case problems. There exist complexity classes such as PSPACE that admit worst-case to average-case reductions. However, for many other classes such as NP, the evidence so far is typically negative, in the sense that the existence of such reductions would cause collapses of the polynomial hierarchy(PH). Basing cryptographic primitives, e.g., the average-case hardness of inverting one-way permutations, on NP-completeness is a particularly intriguing instance. As there is evidence showing that classical reductions from NP-hard problems to breaking these primitives result in PH collapses, it seems unlikely to base cryptographic …

Selectivity And Robustness Of Sparse Coding Networks, Dylan M. Paiton, Charles Frye, Sheng Y. Lundquist, Joel D. Bowen, Ryan Zarcone, Bruno A. Olshausen

Computer Science Faculty Publications and Presentations

We investigate how the population nonlinearities resulting from lateral inhibition and thresholding in sparse coding networks influence neural response selectivity and robustness. We show that when compared to pointwise nonlinear models, such population nonlinearities improve the selectivity to a preferred stimulus and protect against adversarial perturbations of the input. These findings are predicted from the geometry of the single-neuron iso-response surface, which provides new insight into the relationship between selectivity and adversarial robustness. Inhibitory lateral connections curve the iso-response surface outward in the direction of selectivity. Since adversarial perturbations are orthogonal to the iso-response surface, adversarial attacks tend to be …

Computer Science For Equity: Teacher Education, Agency, And Statewide Reform, Joanna Goode, Max Skorodinsky, Jill Hubbard, James Hook

Computer Science Faculty Publications and Presentations

This paper reports on a statewide “Computer Science for All” initiative in Oregon that aims to democratize high school computer science and broaden participation in an academic subject that is one of the most segregated disciplines nationwide, in terms of both race and gender. With no statewide policies to support computing instruction, Oregon's legacy of computer science education has been marked by both low participation and by rates of underrepresented students falling well-below the already dismal national rates. The study outlined in this paper focuses on how teacher education can support educators in developing knowledge and agency, and impacting policies …

An Integrated Feasibility Study Of Reservoir Thermal Energy Storage (Rtes) In Portland, Or, Usa, John Bershaw, Alison E. Horst, Ashley Streig, Darby Patrick Scanlon, Ellen Elizabeth Svadlenak, Jenny Liu, Peter Hulseman, Ray E. Wells, Multiple Additional Authors

Geology Faculty Publications and Presentations

In regions with long cold overcast winters and sunny summers, Deep Direct-Use (DDU) can be coupled with Reservoir Thermal Energy Storage (RTES) technology to take advantage of pre-existing subsurface permeability to save summer heat for later use during cold seasons. Many aquifers worldwide are underlain by permeable regions (reservoirs) containing brackish or saline groundwater that has limited beneficial use due to poor water quality. We investigate the utility of these relatively deep, slow flowing reservoirs for RTES by conducting an integrated feasibility study in the Portland Basin, Oregon, USA, developing methods and obtaining results that can be widely applied to …

Northward Migration Of The Oregon Forearc On The Gales Creek Fault, Ray E. Wells, Richard J. Blakely, Sean Bemis

Geology Faculty Publications and Presentations

The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset of a basement high in Eocene Siletz River Volcanics since ca. 35 Ma and ∼8.8 km of right-lateral separation of Miocene Columbia River Basalt at Newberg, Oregon, since 15 Ma (∼0.62 ± 0.12 mm/yr, average long-term rate). Relative uplift of Eocene Coast Range basalt basement west of the fault zone is at least …

Geologic Map Of The Greater Portland Metropolitan Area And Surrounding Region, Oregon And Washington, Ray E. Wells, Ralph Haugerud, Alan Niem, Wendy A. Niem, Russell Evarts, J. E. O’Connor, Ian Madin, Marvin Beeson, Multiple Additional Authors

Geology Faculty Publications and Presentations

This geologic map encompasses the greater Portland metropolitan area (the metro area), an urbanized region astride the confluence of the Willamette and Columbia Rivers in Oregon and Washington. The metro area includes the Portland-VancouverHillsboro metropolitan area, defined by the U.S. Census as the 23rd largest such area in the U.S., having a population of more than 2.2 million people (https://www.census.gov/dataviz/visualizations/026/508.php). The map area extends beyond the urbanized core to include outlying towns and cities and the bounding fault zones that separate the metro area from the adjacent Coast Range and Cascade Range (or Cascades; figs. 1, 2, and 3). The …

The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Peter T. Doran, Julian M. Cross

Geology Faculty Publications and Presentations

The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 Cel., the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers …

Potential Greenhouse Gas Reductions From Natural Climate Solutions In Oregon, Usa, Rose A. Graves, Ryan D. Haugo, Andres Holz, Max Nielsen-Pincus, Aaron Jones, Bryce Kellogg, Cathy Macdonald, Kenneth Popper, Micheal Schindel

Environmental Science and Management Faculty Publications and Presentations

Increasing concentrations of greenhouse gases (GHGs) are causing global climate change and decreasing the stability of the climate system. Long-term solutions to climate change will require reduction in GHG emissions as well as the removal of large quantities of GHGs from the atmosphere. Natural climate solutions (NCS), i.e., changes in land management, ecosystem restoration, and avoided conversion of habitats, have substantial potential to meet global and national greenhouse gas (GHG) reduction targets and contribute to the global drawdown of GHGs. However, the relative role of NCS to contribute to GHG reduction at subnational scales is not well known. We examined …

Using Diatoms To Assess River Restoration: A Pilot Study In Whychus Creek, Oregon, Usa, Patrick M. Edwards, Yangdong Pan, Lauren Mork, Colin R. Thorne

Environmental Science and Management Faculty Publications and Presentations

A primary goal of river restoration is to reestablish lost ecological functions. Yet the impact of restoration on diatom assemblages and algal biomass in a stream is rarely addressed in the scientific literature reporting the outcomes of restoration projects aimed at improving riverine habitat. To investigate the potential for using benthic diatoms as indicators of the benefits to habitat associated with river restoration, we conducted a pilot diatom study in Whychus Creek, a headwater tributary of the Deschutes River in Oregon, USA. As part of a work study project for college students, we collected periphyton samples in a restored reach, …

Student Sustainability Leadership Development At Portland State University: Developing Holistic Sustainability Leaders, Megan Suzanne Schneider

Dissertations and Theses

In order to address the myriad of social, economic, and environmental challenges the world is facing, we need to be able to engage in leadership that fosters collective action towards sustainable solutions. Higher education is an institution that can equip people with the abilities to engage in sustainability leadership. This master's thesis research explores how students develop sustainability leadership through their college experience. Nine students, who had been identified as sustainability leaders through their participation in the Student Sustainability Center (SSC), a co-curricular sustainability program at Portland State University, were selected to be part of this grounded theory research project. …

Statistical Analysis Of Social Network Change, Teresa Danielle Schmidt

Dissertations and Theses

This project explores two statistical methods that infer social network structures and statistically test those structures for change over time: regression-based differential network analysis (R-DNA) and information theory-based differential analysis (I-DNA). R-DNA is adapted from bioinformatics and I-DNA employs reconstructability analysis.

This project applies both R-DNA and I-DNA to analyze Medicaid claims data from one-year periods before (May 2011- Apr 2012) and after (Jan 2013-Dec 2013) the formation of the Health Share of Oregon Coordinated Care Organization (CCO). The formation of CCOs was legislated by the state of Oregon in 2012 with the triple aim of improving health outcomes, reducing …

Flood Dynamics In The Portland Metropolitan Area, Past, Present, And Future, Lumas Terence Helaire

Dissertations and Theses

The Portland area has an extensive flood history since it was founded in 1845. In the late 19th century, the Portland area was prone to flooding from snowmelt freshets (3-6 months duration) and brief winter rain or rain-on-snow events. Since that time the magnitude of spring freshets has been curtailed by 45% due to climate change, flow diversions, and reservoir management. Along with changes in hydrology, the bathymetry of the Lower Columbia River has been altered by the dredging of the navigation channel, diking, and land reclamation. To understand how these changes in hydrology and bathymetry have affected tidal and …

An Application Of Deep Learning Models To Automate Food Waste Classification, Alejandro Zachary Espinoza

Dissertations and Theses

Food wastage is a problem that affects all demographics and regions of the world. Each year, approximately one-third of food produced for human consumption is thrown away. In an effort to track and reduce food waste in the commercial sector, some companies utilize third party devices which collect data to analyze individual contributions to the global problem. These devices track the type of food wasted (such as vegetables, fruit, boneless chicken, pasta) along with the weight. Some devices also allow the user to leave the food in a kitchen container while it is weighed, so the container weight must also …