Digital Commons Network^™

Nir Dyes For Bioimaging Applications, Jorge O. Escobedo, Oleksandr Rusin, Soojin Lim, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Fluorescent dyes based on small organic molecules that function in the near infra red (NIR) region are of great current interest in chemical biology. They allow for imaging with minimal autofluorescence from biological samples, reduced light scattering and high tissue penetration. Herein, examples of ongoing NIR fluorophore design strategies as well as their properties and anticipated applications relevant to the bioimaging are presented.

Characterization And Correction Of Dark Current In Compact Consumer Cameras, Justin Charles Dunlap, Erik Bodegom, Ralf Widenhorn

Physics Faculty Publications and Presentations

A study of dark current in digital imagers within consumer grade digital cameras is presented. Dark current is shown to vary with temperature, exposure time, and ISO setting. Further, dark current is shown to increase in successive images during a series of images. Consumer cameras are often designed to be as compact as possible and therefore the digital imagers within the camera frame are prone to heat generated by nearby elements within the camera body. It is the scope of this work to characterize the dark current in such cameras and to show that the dark current, in part due …

Study Of The Numerical Modeling Of The Temperature Dependence Of The Dark Current In Charge Coupled Devices, Ralf Widenhorn, Ionel Tunaru, Erik Bodegom, Dan A. Iordache

Physics Faculty Publications and Presentations

As it is well known, the classical works of the Dark Current Spectroscopy method allow - using some not too accurate theoretical relations, but huge numbers of dark current values for thousands of pixels - the evaluation of a reduced number of basic impurities parameters. Unlike these works, this paper tries to obtain--by means of some better approximations of the Shockley-Read-Hall (SRH) model--more information about the studied impurities, as well as the study of the compatibility of the used theoretical model SRH relative to the experimental data. In this manner, both the compatibility SRH model with the studied experimental data …

Hybridization And Postprocessing Techniques For Mixed Eigenfunctions, Bernardo Cockburn, Jay Gopalakrishnan, F. Li, Ngoc Cuong Nguyen, Jaume Peraire

Mathematics and Statistics Faculty Publications and Presentations

We introduce hybridization and postprocessing techniques for the Raviart–Thomas approximation of second-order elliptic eigenvalue problems. Hybridization reduces the Raviart–Thomas approximation to a condensed eigenproblem. The condensed eigenproblem is nonlinear, but smaller than the original mixed approximation. We derive multiple iterative algorithms for solving the condensed eigenproblem and examine their interrelationships and convergence rates. An element-by-element postprocessing technique to improve accuracy of computed eigenfunctions is also presented. We prove that a projection of the error in the eigenspace approximation by the mixed method (of any order) superconverges and that the postprocessed eigenfunction approximations converge faster for smooth eigenfunctions. Numerical experiments using …

Multigrid In A Weighted Space Arising From Axisymmetric Electromagnetics, Dylan M. Copeland, Jay Gopalakrishnan, Minah Oh

Mathematics and Statistics Faculty Publications and Presentations

Consider the space of two-dimensional vector functions whose components and curl are square integrable with respect to the degenerate weight given by the radial variable. This space arises naturally when modeling electromagnetic problems under axial symmetry and performing a dimension reduction via cylindrical coordinates. We prove that if the original three-dimensional domain is convex then the multigrid Vcycle applied to the inner product in this space converges, provided certain modern smoothers are used. For the convergence analysis, we first prove several intermediate results, e.g., the approximation properties of a commuting projector in weighted norms, and a superconvergence estimate for a …

Symmetry And Stability Of Homogeneous Flocks, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

The study of the movement of flocks, whether biological or technological, is motivated by the desire to understand the capability of coherent motion of a large number of agents that only receive very limited information. In a biological flock a large group of animals seek their course while moving in a more or less fixed formation. It seems reasonable that the immediate course is determined by leaders at the boundary of the flock. The others follow: what is their algorithm? The most popular technological application consists of cars on a one-lane road. The light turns green and the lead car …

Phase-Linking And The Perceived Motion During Off-Vertical Axis Rotation, Jan Holly, Scott Wood, Gin Mccollum

Mathematics and Statistics Faculty Publications and Presentations

Human off-vertical axis rotation (OVAR) in the dark typically produces perceived motion about a cone, the amplitude of which changes as a function of frequency. This perception is commonly attributed to the fact that both the OVAR and the conical motion have a gravity vector that rotates about the subject. Little-known, however, is that this rotating-gravity explanation for perceived conical motion is inconsistent with basic observations about self-motion perception: (a) that the perceived vertical moves toward alignment with the gravito-inertial acceleration (GIA) and (b) that perceived translation arises from perceived linear acceleration, as derived from the portion of the GIA …

An Environment-Based Education Approach To Professional Development: A Mixed Methods Analysis Of The Creeks And Kids Watershed Workshop And Its Impact On K-12 Teachers, Tiffany Bridgette Austin

Dissertations and Theses

This research is an in-depth study of an environment-based education (EBE) professional development program titled "Creeks and Kids" that models how to employ thematic instruction about watersheds using the environment of a school and its community as a context to integrate teaching and learning about water across core subject areas. This case study investigates the EBE characteristics of the Creeks and Kids Workshop and explores how they adhere to the National Research Council's Standards for Professional Development for Teachers of Science. A mixed-methods analysis gathered qualitative data about the overall experience of teacher-participants during the Creeks and Kids Workshop and …

Removing Textured Artifacts From Digital Photos Using Spatial Frequency Filtering, Ben Huang

Dissertations and Theses

An abstract of the thesis of Ben Huang for the Master of Science in Electric and Computer Science presented [August 12nd, 2010]. Title: Removing textured artifacts from digital photos by using spatial frequency filtering Virtually all image processing is now done with digital images. These images, captured with digital cameras, can be readily processed with various types of editing software to serve a multitude of personal and commercial purposes. But not all images are directly captured and even of those that are directly captured many are not of sufficiently high quality. Digital images are also acquired by scanning old paper …

Local And Traditional Knowledge And The Historical Ecology Of Pacific Herring In Alaska, Thomas F. Thornton, Madonna L. Moss, Virginia L. Butler, Jamie Hebert, Fritz Funk

Anthropology Faculty Publications and Presentations

The article focuses on the historical ecology of the Pacific herring, a marine food web resource, in the Gulf of Alaska. It states the hearing conducted by the Alaska Legislature's House special committee on fisheries on the status and management of herring in Southeast Alaska during which Tlingit fisherman Clarence Jackson of Kake notes the disappearance of herring in his lifetime. Information on herring ecology based from Native and non-Native individuals from Southeast communities and archaeological site reports reveal that non-Natives in Southeast Alaska have exploited herring with the development of a herring reduction plant. It underscores the need for …

Archaeological Evidence For Resilience Of Pacific Northwest Salmon Populations And The Socioecological System Over The Last ~7,500 Years, Sarah K. Campbell, Virginia L. Butler

Anthropology Faculty Publications and Presentations

Archaeological data on the long history of interaction between indigenous people and salmon have rarely been applied to conservation management. When joined with ethnohistoric records, archaeology provides an alternative conceptual view of the potential for sustainable harvests and can suggest possible social mechanisms for managing human behavior. Review of the ~7,500-year-long fish bone record from two subregions of the Pacific Northwest shows remarkable stability in salmon use. As major changes in the ecological and social system occurred over this lengthy period, persistence in the fishery is not due simply to a lack of perturbation, but rather indicates resilience in the …

Portland State University Climate Action Plan, 2010, Fletcher Beaudoin, Noelle Studer-Spevak

Campus Sustainability Office Publications, Reports and Presentations

In June 2007, Portland State University (PSU) joined this effort by signing the American College and University Presidents Climate Commitment (ACUPCC). The commitment challenged PSU to form a committee to oversee climate efforts, track carbon emissions, and develop a Climate Action Plan (CAP) to move toward carbon neutrality. This document fulfills the final requirement for ACUPCC and supports regional climate goals of partner agencies, such as those described in the 2009 City of Portland and Multnomah County Climate Action Plan.

Desegregation And Multiculturalism In The Portland Public Schools, Ethan Johnson, Felicia Williams

Black Studies Faculty Publications and Presentations

Helen Marie Casey’s booklet Portland’s Compromise: the Colored School, 1867–1872 recounts the story of William Brown, an African-American resident of Portland, Oregon, and his role in the first and only case of official segregation of African-American children in Portland Public Schools (PPS) in 1867. After unsuccessfully trying to enroll his children in one of Portland’s only two public elementary schools, Brown appealed to the school board, including directors Josiah Failing, W.S. Ladd, and E.D. Shattuck. Again, his children were denied access. The board of directors explained their resistance to integrated schools by saying: “If we admit them [African-American children], then …

A Class Of Discontinuous Petrov–Galerkin Methods. Ii. Optimal Test Functions, Leszek Demkowicz, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

We lay out a program for constructing discontinuous Petrov–Galerkin (DPG) schemes having test function spaces that are automatically computable to guarantee stability. Given a trial space, a DPG discretization using its optimal test space counterpart inherits stability from the well posedness of the undiscretized problem. Although the question of stable test space choice had attracted the attention of many previous authors, the novelty in our approach lies in the fact we identify a discontinuous Galerkin (DG) framework wherein test functions, arbitrarily close to the optimal ones, can be locally computed. The idea is presented abstractly and its feasibility illustrated through …

Investigating Further Preservice Teachers’ Conceptions Of Multidigit Whole Numbers: Refining A Framework, Eva Thanheiser

Mathematics and Statistics Faculty Publications and Presentations

This study was designed to investigate preservice elementary school teachers’ (PSTs’) responses to written standard place-value-operation tasks (addition and subtraction). Previous research established that PSTs can often perform but not explain algorithms and provided a four-category framework for PSTs’ conceptions, two correct and two incorrect. Previous findings are replicated for PSTs toward the end of their college careers, and two conceptions are further analyzed to yield three categories of incorrect views of regrouped digits: (a) consistently as 1 value (all as 1 or all as 10), (b) consistently within but not across contexts (i.e., all as 10 in addition but …

Designing Exhibits For Gender Equity, Toni Nicole Dancu

Dissertations and Theses

Gender equity has been a national and global aim for over half a century (Ceci & Williams, 2007; National Center for Education Statistics, 2003; National Science Board, 2008). While gains have been made, one area where inequity remains is spatial reasoning ability, where a large gender gap in favor of males has persisted over the years (Else-Quest, Linn, & Shibley Hyde, 2010; National Science Board, 2008; Ruble, Martin, & Berenbaum, 2006). This gender gap in spatial reasoning has had substantial societal impact on the career interests of females in areas of Science, Technology, Engineering, and Math (STEM), contributing to the …

A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic

Geography Faculty Publications and Presentations

We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96-99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal of …

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: Tito Capobianco, internationally renowned state director, returns for the fifth time to direct opera students; Middle East Studies graduate Peter Bechtold '61 brings his expertise back to Portland State; every year senior students work with hundreds of partners to solve—not just to study—community need; and more.

Gaining Ground: Wetlands, Hurricanes, And The Economy: The Value Of Restoring The Mississippi River Delta, David Batker, Isabel De Torre, Robert Costanza, Paula Swedeen, John W. Day, Roelof Boumans, Kenneth Bagstad

Institute for Sustainable Solutions Publications and Presentations

This report shows conclusively that physical sustainability and delta expansion secures vast economic benefits locally and nationally. Within the context of the current financial crisis, investment in restoration secures short-term benefits of employment, income generation, greater ecosystem services and other economic benefits, and the long term goals of increased storm protection, greater oil and gas supply reliability and other economic benefits. A sustainable restoration of the Mississippi River Delta is a good investment with a high rate of return. Gaining ground is the most successful economic strategy for securing hurricane defenses and economic development.

Climate Change And Freshwater Resources In Oregon, Heejun Chang, Julie Jones

Institute for Sustainable Solutions Publications and Presentations

Climate change will affect various sectors of water resources in Oregon in the 21st century. The observed trends in streamflow show significant declines in September flow and, although not significant, increases in March flow in many transient rain-snow basins. These streamflow trends are associated with rising temperature and coincident declines in snowpack in spring in the latter half of the 20th century. While there are no distinct trends in high precipitation events, such events are associated with climate variability such as ENSO and PDO. Effects of ENSO and PDO are more pronounced at the beginning and end of the wet …

Symbolic Structures As Systems: On The Near Isomorphism Of Two Religious Symbols, Martin Zwick

Complex Systems Faculty Publications and Presentations

Many symbolic structures used in religious and philosophical traditions are composed of “elements” and relations between elements. Similarities between such structures can be described using the systems theoretic idea of “isomorphism.” This paper demonstrates the existence of a near isomorphism between two symbolic structures: the Diagram of the Supreme Pole of Song Neo-Confucianism and the Kabbalistic Tree of medieval Jewish mysticism. The similarities of these two symbols in form and meaning are remarkable in the light of the many differences that exist between Chinese and Judaic thought. Intercultural influence might account for these similarities, but there is no historical evidence …

Integrating Education, Evaluation & Partnerships Into Large-Scale Sustainable Stormwater Management Programs, Vivek Shandas, Anne Nelson, Carine Arendes

Urban Studies and Planning Faculty Publications and Presentations

Integrated stormwater management using green infrastructure shows promise in saving money and mitigating environmental impacts caused by urban development. Equally important are the potential community benefits, including better understanding of ecological systems, increased access to urban green spaces, safer and healthier neighborhoods, and informed residents that are equipped to take action to improve watershed health. As a partnership between the City of Portland Environmental Services, Portland State University, and residents of the Tabor to the River (T2R) neighborhood, we conducted a survey to understand the role of civic ecology in green infrastructure projects. The survey results indicate a high interest …

Sticky Points In Modeling Household Energy Consumption, Loren Lutzenhiser, Mithra Moezzi, David Hungerford, Rafael Friedmann

Center for Urban Studies Publications and Reports

A variety of approaches have been proposed to explaining individual household energy consumption, its variation, and its potential reduction. Some focus on technology, some on costs, and some on a combination of behaviors, attitudes, intentions, and norms. All try to make sense of a problem that, from a modeling perspective, involves hundreds of potentially important factors, yet is supported by highly inadequate or at best selective data. While there is value in "doing the best one can" with the resources at hand, building a defensible science requires a cold hard look at the quality of theory, research and data. This …

What Drives Academic Bioscientists: Money Or Values?, David E. Ervin, Sharmistha Nag, Hui Yang, Steven T. Buccola

Economics Faculty Publications and Presentations

The article determines the factors that drive academic bioscience to better understand the role of genetically engineered (GE) crops in the sustainability of U.S. agriculture. Some challenges brought about by GE crops in the U.S. farm sustainability include tracking and controlling water pollution, protecting against herbicide resistance and nitrogen fixation. Professional norms are also considered as a great factor driving the academic bioscience.

Optimum Land Allocation For Species Protection And Military Training On Dod Installations, Sahan T.M. Dissanayake, Hayri Önal, James D. Westervelt, Harold E. Balbach

Economics Faculty Publications and Presentations

Poster

Bisped: Filling A Critical Shortage Area, Julie Esparza Brown, Bruce A. Miller

Education Faculty Publications and Presentations

This article is # 18 in a larger 140 page work described here: The monograph showcases professional development projects by school districts and colleges of education that train teachers to work successfully with English learners (ELs) across the nation. The papers presented in this monograph offer real-life examples of successful and innovative practices, including institutionalized mentoring programs, new classroom methodologies, best practices for ELs with disabilities, collaboration between colleges of education and school districts, and the evaluation of PD programs. This monograph contains the following articles: (1) Professional Development in Action: Introduction; (2) The National Professional Development Program (Cynthia Ryan …

Oregon's Fish And Wildlife In A Changing Climate, Mark A. Hixon, Stanley V. Gregory, W. Douglas Robinson, C. Scott Baker, Harold P. Batchelder, Clinton Epps, Tiffany S. Garcia, Susan M. Haig, Ricardo M. Letelier, David A. Lytle, Bruce A. Menge, Jeffery C. Miller, David L.G. Noakes, William T. Peterson, James M. Rice, Steven S. Rumrill, Carl B. Schreck, Robert M. Suryan, Mark D. Sytsma, Angelicque E. White

Center for Lakes and Reservoirs Publications and Presentations

Chapter 7 in: The Oregon Climate Change Assessment Report

Oregon's fish and wildlife include animals on land, fish and other species in rivers and lakes, and various kinds of sea life in estuaries and coastal ocean. Oregon is one of the most ecologically diverse states in the country. The state’s robust biodiversity, some of which is already threatened or endangered -- inhabits complex and dynamic ecosystems that we have only begun to understand, let alone examine in terms of climate change.It is clear that the abundance and distribution of species are shifting already and will shift more rapidly as habitats …

Hydroacoustic Survey And Point Sampling Of Macrophytes In Diamond Lake 2009, Joseph Eilers, Benn Eilers, Mark D. Sytsma, Rich Miller

Center for Lakes and Reservoirs Publications and Presentations

MaxDepth Aquatics, Inc. was contracted to conduct a hydroacoustic survey of macrophyte distribution in Diamond Lake in 2009. The survey essentially repeated surveys conducted in 2002 and 2007, allowing for a detailed assessment of conditions in 2009 and comparisons among previous years. In addition, Portland State University was contracted to conduct a depth stratified random point sample survey of macrophyte species presence and absence. The point sample survey was similar to surveys conducted in 2005 and 2007. The results of the 2009 hydroacoustic survey showed that macrophytes were widely distributed throughout the lake at depths less than 8 meters, although …

Genetically Engineering Crops For A Sustainable Agriculture, David E. Ervin, Rick Welsh

Economics Faculty Publications and Presentations

The article examines the role of genetically engineered (GE) crops in fostering a more sustainable agriculture. An overview of the National Academy of Sciences metal study of the impacts of GE crops on farm sustainability in the U.S. is given. The two types of GE crops are discussed, one which produces its own insecticide called insect resistant (IR) crops and the other is engineered to resist particular herbicides. An explanation for sustainable agriculture is also presented.

A Class Of Discontinuous Petrov–Galerkin Methods. Part I: The Transport Equation, Leszek Demkowicz, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

Considering a simple model transport problem, we present a new finite element method. While the new method fits in the class of discontinuous Galerkin (DG) methods, it differs from standard DG and streamline diffusion methods, in that it uses a space of discontinuous trial functions tailored for stability. The new method, unlike the older approaches, yields optimal estimates for the primal variable in both the element size h and polynomial degree p, and outperforms the standard upwind DG method.