Toward An Integrated History To Guide The Future,
2011
Arizona State University
Toward An Integrated History To Guide The Future, Sander Van Der Leeuw, Robert Costanza, Steve Aulenbach, Simon Brewer, Michael Burek, Sarah Cornell, Carole L. Crumley, J. A. Dearing, Catherine Downy, Lisa J. Graumlich, Scott Heckbert, Michelle Hegmon, Kathy A. Hibbard, Stephen T. Jackson, Ida Kubiszewski, Paul Sinclair, Sverker Sörlin, W. L. Steffen
Institute for Sustainable Solutions Publications and Presentations
Many contemporary societal challenges manifest themselves in the domain of human?environment interactions. There is a growing recognition that responses to these challenges formulated within current disciplinary boundaries, in isolation from their wider contexts, cannot adequately address them. Here, we outline the need for an integrated, transdisciplinary synthesis that allows for a holistic approach, and, above all, a much longer time perspective. We outline both the need for and the fundamental characteristics of what we call ?integrated history.? This approach promises to yield new understandings of the relationship between the past, present, and possible futures of our integrated human?environment system. We …
Making Ecodistricts: City-Scale Climate Action One Neighborhood At A Time,
2011
Portland State University
Making Ecodistricts: City-Scale Climate Action One Neighborhood At A Time, Ethan Seltzer, Ellen M. Bassett, Joseph Cortright, Vivek Shandas, Timothy W. Smith
Institute for Sustainable Solutions Publications and Presentations
As part of its approach to meeting Climate Action Plan goals, the City of Portland has joined with the Portland Sustainability Institute to create "EcoDistricts" in Portland neighborhoods to seek neighborhood engagement on behalf of city climate action goals. EcoDistricts, like neighborhoods, offer a scale at which individuals can be affective and empowered to make climate-positive choices, but in a manner that can scale up to make citywide climate action real.
Urban Water Demand Modeling: Review Of Concepts, Methods, And Organizing Principles,
2011
Portland State University
Urban Water Demand Modeling: Review Of Concepts, Methods, And Organizing Principles, Heejun Chang, Lily House-Peters
Institute for Sustainable Solutions Publications and Presentations
In this paper, we use a theoretical framework of coupled human and natural systems to review the methodological advances in urban water demand modeling over the past 3 decades. The goal of this review is to quantify the capacity of increasingly complex modeling techniques to account for complex human and natural processes, uncertainty, and resilience across spatial and temporal scales. This review begins with coupled human and natural systems theory and situates urban water demand within this framework. The second section reviews urban water demand literature and summarizes methodological advances in relation to four central themes: (1) interactions within and …
Analysis Of The Dpg Method For The Poisson Equation,
2011
University of Texas at Austin
Analysis Of The Dpg Method For The Poisson Equation, Leszek Demkowicz, Jay Gopalakrishnan
Mathematics and Statistics Faculty Publications and Presentations
We give an error analysis of the recently developed DPG method applied to solve the Poisson equation and a convection-dffusion problem. We prove that the method is quasioptimal. Error estimates in terms of both the mesh size h and the polynomial degree p (for various element shapes) can be derived from our results. Results of extensive numerical experiments are also presented.
Symmetric Nonconforming Mixed Finite Elements For Linear Elasticity,
2011
Portland State University
Symmetric Nonconforming Mixed Finite Elements For Linear Elasticity, Jay Gopalakrishnan, Johnny Guzmán
Mathematics and Statistics Faculty Publications and Presentations
We present a family of mixed methods for linear elasticity that yield exactly symmetric, but only weakly conforming, stress approximations. The method is presented in both two and three dimensions (on triangular and tetrahedral meshes). The method is efficiently implementable by hybridization. The degrees of freedom of the Lagrange multipliers, which approximate the displacements at the faces, solve a symmetric positive-definite system. The design and analysis of this method is motivated by a new set of unisolvent degrees of freedom for symmetric polynomial matrices. These new degrees of freedom are also used to give a new simple calculation of the …
Detecting Specific Saccharides Via A Single Indicator,
2011
Portland State University
Detecting Specific Saccharides Via A Single Indicator, Soojin Lim, Jorge O. Escobedo, Mark Lowry, Robert M. Strongin
Chemistry Faculty Publications and Presentations
An improved synthesis of a rhodamine boronic acid indicator is reported. This compound is used in an optimized data collection protocol for wavelength- and time-dependent selectivity of sugars such as fructose and ribose derivatives. One indicator is thus used to selectively distinguish structurally related sugar analytes.
Evaluating Methods For The Analysis Of Rare Variants In Sequence Data,
2011
Brown University
Evaluating Methods For The Analysis Of Rare Variants In Sequence Data, Alexander Luedtke, Scott Powers, Ashley Petersen, Alexandra Sitarik, Airat Bekmetjev, Nathan L. Tintle
Faculty Work Comprehensive List
A number of rare variant statistical methods have been proposed for analysis of the impending wave of next-generation sequencing data. To date, there are few direct comparisons of these methods on real sequence data. Furthermore, there is a strong need for practical advice on the proper analytic strategies for rare variant analysis. We compare four recently proposed rare variant methods (combined multivariate and collapsing, weighted sum, proportion regression, and cumulative minor allele test) on simulated phenotype and next-generation sequencing data as part of Genetic Analysis Workshop 17. Overall, we find that all analyzed methods have serious practical limitations on identifying …
Evaluating Methods For Combining Rare Variant Data In Pathway-Based Tests Of Genetic Association,
2011
St. Olaf College
Evaluating Methods For Combining Rare Variant Data In Pathway-Based Tests Of Genetic Association, Ashley Petersen, Alexandra Sitarik, Alexander Luedtke, Scott Powers, Airat Bekmetjev, Nathan L. Tintle
Faculty Work Comprehensive List
Analyzing sets of genes in genome-wide association studies is a relatively new approach that aims to capitalize on biological knowledge about the interactions of genes in biological pathways. This approach, called pathway analysis or gene set analysis, has not yet been applied to the analysis of rare variants. Applying pathway analysis to rare variants offers two competing approaches. In the first approach rare variant statistics are used to generate p-values for each gene (e.g., combined multivariate collapsing [CMC] or weighted-sum [WS]) and the gene-level p-values are combined using standard pathway analysis methods (e.g., gene set enrichment analysis or …
Cascading Migrations And Implications For Vertical Fluxes In Pelagic Ecosystems,
2011
Old Dominion University
Cascading Migrations And Implications For Vertical Fluxes In Pelagic Ecosystems, Stephen M. Bollens, Gretchen Rollwagen-Bollens, Joel A. Quenette, Alexander B. Bochdansky
OES Faculty Publications
Diel vertical migration is widespread across diverse taxa in the world's lakes and seas, yet its biogeochemical consequences are still poorly understood. The biologically mediated vertical flux of material in the ocean (also known as the "biological pump") is a matter of major interest and concern, as it is thought to play an important role in regulating ocean carbon storage, and by extension, the global carbon cycle. Recent studies spanning multiple trophic levels from fish to dinoflagellates have led us to a concept of coupled vertical migrations that we refer to as "cascading migrations". That is, migrations that …
Stability, Sustainability, And Catastrophe: Applying Resilience Thinking To U.S. Agriculture,
2011
Western Washington University
Stability, Sustainability, And Catastrophe: Applying Resilience Thinking To U.S. Agriculture, Gigi M. Berardi, Rebekah Paci-Green, Bryant Hammond
Environmental Studies Faculty and Staff Publications
Resilience is closely related to notions of sustainability, but emphasizes unpredictable, dynamic environments. As conceptualized in engineering, hazards management, and ecology literature, part of resilience is adaptive capacity, the ability to react effectively to change over time in order to maintain a desirable system state. Agricultural policy has had the effect of undermining such adaptive capacity with its emphasis on stabilization. Using a resilience framework and Hurricane Katrina as an analogy, we suggest that the emphasis on stability and efficiency degrades agricultural system resilience in two ways: through reduced diversity in size and type of production, as well …
Speculations About The Effects Of Fire And Lava Flows On Human Evolution,
2011
Western Washington University
Speculations About The Effects Of Fire And Lava Flows On Human Evolution, Michael J. Medler
Environmental Studies Faculty and Staff Publications
Recent research argues that an association with fire, stretching back millions of years, played a central role in human evolution resulting in many modern human adaptations. Others argue that hominin evolution was driven by the roughness of topographic features that resulted from tectonic activity in the African Rift valley. I combine these hypotheses to propose that, for millions of years, active lava flows in the African Rift provided consistent but isolated sources of fire, providing very specific adaptive pressures and opportunities to small isolated groups of hominins. This allowed these groups of early hominins to develop many fire specific adaptations …
Kernel-Based Interior-Point Methods For Cartesian P*(Κ)-Linear Complementarity Problems Over Symmetric Cones,
2011
Georgia Southern University
Kernel-Based Interior-Point Methods For Cartesian P*(Κ)-Linear Complementarity Problems Over Symmetric Cones, Goran Lesaja
Department of Mathematical Sciences Faculty Publications
We present an interior point method for Cartesian P*(k)-Linear Complementarity Problems over Symmetric Cones (SCLCPs). The Cartesian P*(k)-SCLCPs have been recently introduced as the generalization of the more commonly known and more widely used monotone SCLCPs. The IPM is based on the barrier functions that are defined by a large class of univariate functions called eligible kernel function which have recently been successfully used to design new IPMs for various optimization problems. Eligible barrier (kernel) functions are used in calculating the Nesterov-Todd search directions and the default step-size which leads to a very good complexity results for the method. For …
Meander Graphs And Frobenius Seaweed Lie Algebras,
2011
Georgia Southern University
Meander Graphs And Frobenius Seaweed Lie Algebras, Colton Magnant, Vincent E. Coll, Anthony Giaquinto
Department of Mathematical Sciences Faculty Publications
The index of a seaweed Lie algebra can be computed from its associated meander graph. We examine this graph in several ways with a goal of determining families of Frobenius (index zero) seaweed algebras. Our analysis gives two new families of Frobenius seaweed algebras as well as elementary proofs of known families of such Lie algebras.
Predicted Ultrafast Dynamic Metallization Of Dielectric Nanofilms By Strong Single-Cycle Optical Fields,
2011
Georgia Southern University
Predicted Ultrafast Dynamic Metallization Of Dielectric Nanofilms By Strong Single-Cycle Optical Fields, Maxim Durach, Anastasia Rusina, Matthias F. Kling, Mark I. Stockman
Department of Physics and Astronomy Faculty Publications
We predict a dynamic metallization effect where an ultrafast (single-cycle) optical pulse with a ≲1 V/Åfield causes plasmonic metal-like behavior of a dielectric film with a few-nm thickness. This manifests itself in plasmonic oscillations of polarization and a significant population of the conduction band evolving on a ∼1 fs time scale. These phenomena are due to a combination of both adiabatic (reversible) and diabatic (for practical purposes irreversible) pathways.
Color Control And White Light Generation Of Upconversion Luminescence By Operating Dopant Concentrations And Pump Densities In Yb3+, Er3+, And Tm3+ Tri-Doped Lu2O3 Nanocrystals,
2011
Chinese Academy of Sciences
Color Control And White Light Generation Of Upconversion Luminescence By Operating Dopant Concentrations And Pump Densities In Yb3+, Er3+, And Tm3+ Tri-Doped Lu2O3 Nanocrystals, Yanping Li, Jiahua Zhang, Yongshi Luo, Xia Zhang, Zhendong Hao, Xiao-Jun Wang
Department of Physics and Astronomy Faculty Publications
We synthesized a series of Yb3+, Er3+ and Tm3+ tri-doped Lu2O3 nanocrystals with various dopant concentrations by the hydrothermal approach. Due to a unique electronic state at the top of the valence band, Lu2O3 based materials exhibit intense upconversion luminescence involving 1G4 → 3H6 of Tm3+ in blue, (2H11/2, 4S3/2) → 4I15/2 in green and 4F9/2 → 4I15/2 in red of Er3+ upon near infrared excitation …
Generation Of Broadband Emission By Incorporating N3- Into Ca3Sc2Si3O12:Ce3+ Garnet For High Rendering White Leds,
2011
Chinese Academy of Sciences
Generation Of Broadband Emission By Incorporating N3- Into Ca3Sc2Si3O12:Ce3+ Garnet For High Rendering White Leds, Yongfu Liu, Xia Zhang, Zhendong Hao, Xiao-Jun Wang, Jiahua Zhang
Department of Physics and Astronomy Faculty Publications
Adding Si3N4 into green emitting Ca3Sc2Si3O12:Ce3+ garnet phosphor generates an additionally red emission band peaking around 610 nm that are assigned to Ce3+ ions having N3− in their local coordination. The excitation spectrum of the red band consists of not only a distinct band at 510 nm of itself but also an intense blue band at 450 nm that belongs to the typical Ce3+ ions with green emission, indicating a notable energy transfer from the green emitting Ce3+ ions to the red ones. The …
Hst Morphologies Of Z~2 Dust Obscured Galaxies Ii. Bump Sources,
2011
University of Arizona
Hst Morphologies Of Z~2 Dust Obscured Galaxies Ii. Bump Sources, R. Shane Bussmann, Arjun Day, Jennifer Lotz, Lee Armus, Michael J. I. Brown, Peter Eisenhardt, James L. Higdon, Sarah J.U. Higdon, Buell T. Januzzi, Emeric Le Floc'h, J. Melbourne, B. T. Soifer, Daniel Weedman
Department of Physics and Astronomy Faculty Publications
We present Hubble Space Telescope imaging of 22 ultra-luminous infrared galaxies (ULIRGs) at z 2 with extremely red R – [24] colors (called dust-obscured galaxies, or DOGs) which have a local maximum in their spectral energy distribution (SED) at rest-frame 1.6 μm associated with stellar emission. These sources, which we call "bump DOGs," have star formation rates (SFRs) of 400-4000 M ☉ yr–1 and have redshifts derived from mid-IR spectra which show strong polycyclic aromatic hydrocarbon emission—a sign of vigorous ongoing star formation. Using a uniform morphological analysis, we look for quantifiable differences between bump DOGs, power-law DOGs (Spitzer …
Wheels Of Fire. Iv: Star Formation And The Neutral Ism In The Ring Galaxy Am0644-741,
2011
Georgia Southern University
Wheels Of Fire. Iv: Star Formation And The Neutral Ism In The Ring Galaxy Am0644-741, James L. Higdon, Sarah J.U. Higdon
Department of Physics and Astronomy Faculty Publications
We combine data from the Australia Telescope National Facility and Swedish ESO Submillimeter Telescope to investigate the neutral interstellar medium (ISM) in AM0644-741, a large and robustly star-forming ring galaxy. The galaxy's ISM is concentrated in the 42 kpc diameter starburst ring, but appears dominated by atomic gas, with a global molecular fraction (f mol) of only 0.062 ± 0.005. Apart from the starburst peak, the gas ring appears stable against the growth of gravitational instabilities (Q gas = 3-11). Including the stellar component lowers Q overall, but not enough to make Q < 1 everywhere. High star formation efficiencies (SFEs) follow from the ring's low H2 content. AM0644-741's star formation law is highly peculiar: H I obeys a Schmidt law while H2 is uncorrelated with star formation rate density. Photodissociation models yield low volume densities in the ring, especially in the starburst quadrant (n 2 cm–3), implying a …
Nonlinear Time Dependence Of Dark Current In Charge-Coupled Devices,
2011
Portland State University
Nonlinear Time Dependence Of Dark Current In Charge-Coupled Devices, Justin Charles Dunlap, Erik Bodegom, Ralf Widenhorn
Physics Faculty Publications and Presentations
It is generally assumed that charge-coupled device (CCD) imagers produce a linear response of dark current versus exposure time except near saturation. We found a large number of pixels with nonlinear dark current response to exposure time to be present in two scientific CCD imagers. These pixels are found to exhibit distinguishable behavior with other analogous pixels and therefore can be characterized in groupings. Data from two Kodak CCD sensors are presented for exposure times from a few seconds up to two hours. Linear behavior is traditionally taken for granted when carrying out dark current correction and as a result, …
Photoelectron Emission Control With Polarized Light In Plasmonic Metal Random Structures,
2011
Portland State University
Photoelectron Emission Control With Polarized Light In Plasmonic Metal Random Structures, Robert Campbell Word, Joseph Fitzgerald, Rolf Kӧnenkamp
Physics Faculty Publications and Presentations
The authors report on the possibility of switching the emission rate of photoelectrons by polarization changes in the plasmon excitation light. Photoelectron emission is strongly enhanced in the near-field of localized surface plasmons and occurs from areas with typical diameters of 20-70 nm. The underlying physical process involves excitation of a localized surface plasmon polariton with a femtosecond laser pulse, and a subsequent multi-photon photoemission process. The non-linearity of this process leads to a sharp polarization dependence that allows efficient switching of the emission. We demonstrate that a 90° polarization change can result in on/off ratios of ∼100 for electron …
