Physical Sciences and Mathematics Commons^™

Spatial Symmetry Groups As Sensorimotor Guidelines, Gin Mccollum

Gin McCollum

While some aspects of neuroanatomical organization are related to packing and access rather than to function, other aspects of anatomical/physiological organization are directly related to function. The mathematics of symmetry groups can be used to determine logical structure in projections and to relate it to function. This paper reviews two studies of the symmetry groups of vestibular projections that are related to the spatial functions of the vestibular complex, including gaze, posture, and movement. These logical structures have been determined by finding symmetry groups of two vestibular projections directly from physiological and anatomical data. Logical structures in vestibular projections are …

Valuing New Jersey's Natural Capital: An Assessment Of The Economic Value Of The State's Natural Resources, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

This report is divided into three main parts. Part I presents essential background information, summarizes the detailed findings of Parts II and III and their limitations, and explores in a preliminary way the policy implications of the natural capital project and the future research needs in this area. Part II focuses on ecosystem services and Part III deals with ecosystem goods.

Feral Swine Action Plan For Oregon, Mark Sytsma, Arick Christopher Rouhe

Center for Lakes and Reservoirs Publications and Presentations

Feral swine are defined as free roaming animals of the genus Sus that are not being held under domestic management or confinement. Swine have spread from Europe and Russia to habitats around the world via human introduction. Currently, feral swine populations are established on every continent except Antarctica. Unlike other large mammal invaders, swine have a high reproductive capacity and are omnivorous, which allows for a quick assimilation into most habitats. Once a breeding population is established in an area, the population can quickly increase and negatively impact the ecosystem. A successful invasion of feral swine is difficult, and sometimes …

Observation Of Microslip Dynamics At High-Speed Microcontacts, Brian Borovsky, Adam M. Booth, Erin Manlove

Geology Faculty Publications and Presentations

The high-speed tribological properties of microscale contacts are studied using an indenter probe and quartz crystal microbalance. Elastic and dissipative shear forces are monitored as a function of contact radius for sapphire/gold interfaces with an adsorbed octadecanethiol monolayer. We observe shear force transitions understood as taking the interface from slipping to stuck conditions. We relate this behavior to the presence of interfacial microslip. Dynamic modeling shows that our observations are consistent with an interface that, when sliding, experiences full slip during half of each cycle. We discuss the implications for this technique as a sensitive probe of sliding friction.

North America. Climate Change 2007: Impacts, Adaptation And Vulnerability, Christopher B. Fields, Linda D. Mortsch, Michael Brklacich, Donald L. Forbes, Paul Kovacs, Jonathan A. Patz, Steven W. Running, Michael J. Scott, Jean Andrey, Dan Cayan, Mike Demuth, Alan Hamlet, Gregory Jones, Evan Mills, Scott Mills, Charles K. Minns, David J. Sailor, Mark Saunders, Daniel Scott, William Solecki

Mechanical and Materials Engineering Faculty Publications and Presentations

The United States (U.S.) and Canada will experience climate changes through direct effects of local changes (e.g., temperature, precipitation and extreme weather events), as well as through indirect effects, transmitted among regions by interconnected economies and migrations of humans and other species. Variations in wealth and geography, however, lead to an uneven distribution of likely impacts, vulnerabilities and capacities to adapt. This chapter reviews and synthesises the state of knowledge on direct and indirect impacts, vulnerability and adaptations for North America (comprising Canada and the U.S). Hawaii and other U.S. protectorates are discussed in Chapter 16 on Small Islands, and …

Stochastic Comparisons Of Parallel Systems When Component Have Proportional Hazard Rates, Subhash C. Kochar, Maochao Xu

Mathematics and Statistics Faculty Publications and Presentations

Let Χ₁, … Χ_n be independent random variables with Χᵢ having survival function Fλᵢ, i=1, … , n, and let Y₁, … , Yn be a random sample with common population survival distribution Fλ, where λ = Σᵢ=₁nλᵢl n. Let Χn:n and Yn:n denote the lifetimes of the parallel systems consisting of these components, respectively. It is shown that Xn:n is greater than Yn:n in terms of likelihood ratio order. It is also proved that the sample range Χn:n - Χ₁:n is larger than Yn n:n - Y₁:n according to reverse hazard rate ordering. These two results …

Locally Conservative Fluxes For The Continuous Galerkin Method, Bernardo Cockburn, Jay Gopalakrishnan, Haiying Wang

Mathematics and Statistics Faculty Publications and Presentations

The standard continuous Galerkin (CG) finite element method for second order elliptic problems suffers from its inability to provide conservative flux approximations, a much needed quantity in many applications. We show how to overcome this shortcoming by using a two step postprocessing. The first step is the computation of a numerical flux trace defined on element inter- faces and is motivated by the structure of the numerical traces of discontinuous Galerkin methods. This computation is non-local in that it requires the solution of a symmetric positive definite system, but the system is well conditioned independently of mesh size, so it …

Selective Growth Of Single-Crystalline Zno Nanowires On Doped Silicon, Rolf Könenkamp, Robert Campbell Word, M. Dosmailov, J. Meiss, Athavan Nadarajah

Physics Faculty Publications and Presentations

We report the growth of single-crystalline ZnO nanowires on n- and p-type Si wafers by electrodeposition. On strongly doped n-type Si high-quality nanowires can be grown under similar conditions as used for metallic substrates. For low electron concentrations occurring in weakly n-type or in p-type wafers, nanowire growth is inhibited. This difference allows selective growth in strongly n-type areas. The inhibited growth on weakly n-type and p-type wafers can be improved by applying stronger cathodic electrode potentials or by illuminating the growth area. The wires on n-Si show efficient electroluminescence covering the visible and extending into the ultraviolet spectral range.

Quantum Physics And Welfare Policy?, Jack C. Straton

Physics Faculty Publications and Presentations

Welfare policy is examined through the paradoxical logic of Nagarjuna’s tetralema, providing a lens through which wave-particle duality in quantum mechanics is then viewed. Through this process students are challenged to radically expand their critical-thinking horizons beyond conventional dualistic bounds. They learn not only this key property of quantum reality, but have to come to grips with the nature of knowledge itself, and the degree to which they censor their own awarenesses.

Three-Dimensional Structure Of Cdx (X= Se, Te) Nanocrystals By Total X-Ray Diffraction, S. K. Pradhan, Z. T. Deng, F. Tang, Y. Ren, Peter Moeck, V. Petkov

Physics Faculty Publications and Presentations

The three-dimensional structure of oleic acid-capped CdSe and thiol-capped CdTe nanocrystals used as quantum dots has been determined by total synchrotron radiationx-ray diffraction and atomic pair distribution function analysis. Both CdSe and CdTe are found to exhibit the zinc-blende-type atomic ordering. It is only slightly distorted in CdSe implying the presence of nanosize domains and very heavily distorted in CdTe due to the presence of distinct core-shell regions. The results well demonstrate the great potential of the experimental approach and thus encourage its wider application in quantum dot research.

Fabrication Of Carbon Nanotube-Based Nanodevices Using A Combination Technique Of Focused Ion Beam And Plasma-Enhanced Chemical Vapor Deposition, Jianfeng Wu, Micah Eastman, Timothy Gutu, Madeline Wyse, Jun Jiao, S.-M. Kim, M. Mann, Y. Zhang, K. B. Teo

Physics Faculty Publications and Presentations

This study focuses on the fabrication of two nanodevice prototypes which utilized vertical and horizontal carbon nanotubes used the focused ion beam to localize the catalysts, followed by plasma-enhanced chemical vapor deposition. First, metal-gated carbon nanotube field emitter arrays were fabricated on multilayer substrates containing an imbedded catalyst layer. Second, horizontally aligned single-walled carbon nanotubes were grown on a transmission electron microscopy grid. This allows the carbon nanotubes to be directly analyzed in a transmission electron microscope. It is expected that the methodology introduced here will open up opportunities for the direct fabrication of carbon nanotube based nanodevices.

Bridges And Barriers To Developing And Conducting Interdisciplinary Graduate-Student Team Research, Max Nielsen-Pincus, Wayde Cameron Morse, Jo Ellen Force, J. D. Wulfhorst

Environmental Science and Management Faculty Publications and Presentations

Understanding complex socio-environmental problems requires specialists from multiple disciplines to integrate research efforts. Programs such as the National Science Foundation’s Integrative Graduate Education and Research Traineeship facilitate integrated research efforts and change the way academic institutions train future leaders and scientists. The University of Idaho and the Tropical Agricultural Research and Higher Education Center in Costa Rica collaborate on a joint research program focusing on biodiversity conservation and sustainable production in fragmented landscapes. We first present a spectrum of integration ranging from disciplinary to transdisciplinary across seven aspects of the research process. We then describe our experiences and lessons learned …

Estimating Nutrient Uptake By Mature Tree Roots Under Field Conditions: Challenges And Opportunities, Melissa S. Lucash, Dave M. Eissenstat, J. Devereux Joslin, Karis J. Mcfarlane, Ruth D. Yanai

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake by roots of mature trees is difficult to measure accurately under field conditions using existing methods. In this review, we discuss current techniques for measuring uptake at the root surface including excised roots, isotopic tracers, autoradiography, depletion, and lysimeters. Although these methods have provided many insights, each has drawbacks. Estimates of uptake are affected by the sampling scheme, experimental conditions, whether roots are excised or not, concentrations of ions, and the rate of efflux of ions. Microbes and mycorrhizas can also affect estimates of uptake. A greater focus on methods development is critical to advancing our understanding of …

Antibacterial Targets In Fatty Acid Biosynthesis, H. Tonie Wright, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The fatty acid biosynthesis pathway is an attractive but still largely unexploited target for development of new anti-bacterial agents. The extended use of the anti-tuberculosis drug isoniazid and the antiseptic triclosan, which are inhibitors of fatty acid biosynthesis, validates this pathway as a target for anti-bacterial development. Differences in subcellular organization of the bacterial and eukaryotic multi-enzyme fatty acid synthase systems offer the prospect of inhibitors with host vs. target specificity. Platensimycin, platencin, and phomallenic acids, newly discovered natural product inhibitors of the condensation steps in fatty acid biosynthesis, represent new classes of compounds with antibiotic potential. An almost complete …

Dna Multiplex Hybridization On Microarrays And Thermodynamic Stability In Solution: A Direct Comparison, Daniel J. Fish, M. Todd Horne, Greg P. Brewood, Jim P. Goodarzi, Saba Alemayehu, Ashwini Bhandiwad, Robert P. Searles, Albert S. Benight

Chemistry Faculty Publications and Presentations

Hybridization intensities of 30 distinct short duplex DNAs measured on spotted microarrays, were directly compared with thermodynamic stabilities measured in solution. DNA sequences were designed to promote formation of perfect match, or hybrid duplexes containing tandem mismatches. Thermodynamic parameters DeltaH degrees , DeltaS degrees and DeltaG degrees of melting transitions in solution were evaluated directly using differential scanning calorimetry. Quantitative comparison with results from 63 multiplex microarray hybridization experiments provided a linear relationship for perfect match and most mismatch duplexes. Examination of outliers suggests that both duplex length and relative position of tandem mismatches could be important factors contributing to …

Modular Polyketide Synthases And Cis Double Bond Formation:  Establishment Of Activated Cis-3-Cyclohexylpropenoic Acid As The Diketide Intermediate In Phoslactomycin Biosynthesis, Mamoun M. Alhamadsheh, Nadaraj Palaniappan, Suparna Daschouduri, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The majority of modular polyketide synthase (PKS) systems which generate unsaturated products do so with trans double bonds. Phoslactomycin B (PLM B) presents a class of antitumor and antiviral natural polyketide products that have unique structural features, including a linear unsaturated backbone with one trans and three cis double bonds. There is substantial evidence that trans double bonds are established by ketoreductase-dehydratase (KR-DH) didomains within a PKS module. In cases where modules containing these didomains appear to generate product containing a cis double bond there is no experimental evidence to determine if they do so directly, or if they also …

Probing Reactivity And Substrate Specificity Of Both Subunits Of The Dimeric Mycobacterium Tuberculosis Fabh Using Alkyl-Coa Disulfide Inhibitors And Acyl-Coa Substrates, Sarbjot Sachdeva, Faik Musayev, Mamoun M. Alhamadsheh, J. Neel Scarsdale, H. Tonie Wright, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The dimeric Mycobacterium tuberculosis FabH (mtFabH) catalyses a Claisen-type condensation between an acyl-CoA and malonyl-acyl carrier protein (ACP) to initiate the Type II fatty acid synthase cycle. To analyze the initial covalent acylation of mtFabH with acyl-CoA, we challenged it with mixture of C6-C20 acyl-CoAs and the ESI-MS analysis showed reaction at both subunits and a strict specificity for C12 acyl CoA. Crystallographic and ESI-MS studies of mtFabH with a decyl-CoA disulfide inhibitor revealed a decyl chain bound in acyl-binding channels of both subunits through disulfide linkage to the active site cysteine. These data provide the first unequivocal evidence that …

The Topology Of Surface Mediatrices, James Bernhard, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

Given a pair of distinct points p and q in a metric space with distance d, the mediatrix is the set of points x such that d(x,p)=d(x,q). In this paper, we examine the topological structure of mediatrices in connected, compact, closed 2-manifolds whose distance function is inherited from a Riemannian metric. We determine that such mediatrices are, up to homeomorphism, finite, closed simplicial 1-complexes with an even number of incipient edges emanating from each vertex. Using this and results from [J.J.P. Veerman, J. Bernhard, Minimally separating sets, mediatrices and Brillouin spaces, Topology Appl., in press], we give the classification …

Some Recent Results On Stochastic Comparisons And Dependence Among Order Statistics In The Case Of Phr Model, Subhash C. Kochar, Maochao Xu

Mathematics and Statistics Faculty Publications and Presentations

This paper reviews some recent results on stochastic orders and dependence among order statistics when the observations are independent and follow the proportional hazard rates model.

Directflow: A Domain-Specific Language For Information-Flow Systems, Andrew P. Black, Chuan-Kai Lin

Computer Science Faculty Publications and Presentations

Programs that process streams of information are commonly built by assembling reusable information-flow components. In some systems the components must be chosen from a pre-defined set of primitives; in others the programmer can create new custom components using a general-purpose programming language. Neither approach is ideal: restricting programmers to a set of primitive components limits the expressivity of the system, while allowing programmers to define new components in a general-purpose language makes it difficult or impossible to reason about the composite system. We advocate defining information-flow components in a domain-specific language (DSL) that enables us to infer the properties of …

Cache Coherence Protocol Verification Using Ωmega, Ki Yung Ahn

Computer Science Faculty Publications and Presentations

We verify some correctness properties of the DASH cache coherence protocol using Ωmega. Ωmega is a language with a rich type system featuring GADTs, type functions, and user-guided type checking rules. Cache coherence protocols have both safety properties and liveness properties. We show how to describe some of the safety properties of DASH cache coherence protocol in mega. Since liveness properties are not easily expressed by types, we investigate invariants sufficient to imply some of the liveness properties of concern, and assert those invariants as well in the type system of Ωmega. Using Ωmega, we can have both a working …

Protecting The Internet With Public Work, Ed Kaiser, Wu-Chang Feng

Computer Science Faculty Publications and Presentations

Distributed denial-of-service attacks represent a growing problem for networked systems. To tackle this problem, this paper explores the addition of a public work function to the service advertisement mechanisms used by such systems. When under attack, services advertise this function along with their location information and clients must attach a solution to the function with subsequent requests. The function, which can be made specific to the source of traffic, is publicly verifiable, allowing arbitrary network devices at the edges of the network to quickly verify that subsequent communication from the source will be accepted by the destination. We describe a …

Why Don’T People Use Refactoring Tools?, Andrew P. Black, Emerson Murphy-Hill

Computer Science Faculty Publications and Presentations

Tools that perform refactoring are currently under-utilized by programmers. As more advanced refactoring tools are designed, a great chasm widens between how the tools must be used and how programmers want to use them. In this position paper, we characterize the dominant process of refactoring, demonstrate that many research tools do not support this process, and initiate a call to action for designers of future refactoring tools.

Using Building Energy Simulation And Geospatial Modeling Techniques In Determine High Resolution Building Sector Energy Consumption Profiles, Shem C. Heiple

Dissertations and Theses

A technique is presented for estimating hourly and seasonal energy consumption profiles in the building sector at spatial scales down to the individual taxlot or parcel. The method combines annual building energy simulations for cityspecific prototypical buildings and commonly available geospatial data in a Geographical Information System (GIS) framework. Hourly results can be extracted for any day and exported as a raster output at spatial scales as fine as an individual parcel (

Interview With Ron Hays, Eagle Creek Natural Building, 2006 (Audio), Ron Hays

All Sustainability History Project Oral Histories

Interview of Ron Hays by Joe Arbow at SE Portland, Oregon on December 8th, 2006.

The interview index is available for download.

Interview With Dan Lajoie, Departure: Architecture Planning, 2006 (Audio), Dan Lajoie

All Sustainability History Project Oral Histories

Interview of Dan Lajoie by Tirsa Firncrook in SE Portland, Oregon on December 4th, 2006.

The interview index is available for download.

Interview With Steven Edward Koch, Koch Landscape Architecture, 2006, Steven Edward Koch

All Sustainability History Project Oral Histories

Interview of Steven Edward Koch by Robyn Russnogle on December 4th, 2006.

The interview index is available for download.

Interview With Carol Mayer-Reed, Mayer/Reed, 2006 (Audio), Carol Mayer-Reed

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Interview of Carol Mayer-Reed by Robyn Russnogle at on December 1st, 2006.

The interview index is available for download.

Interview With Greg Sawyer, Providence Builders, 2006 (Audio), Greg Sawyer

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Interview of Greg Sawyer by Amy Evangelista in NE Portland, Oregon on December 1st, 2006.

The interview index is available for download.

Interview With Yianni Doulis, Yianni Doulis Architecture, 2006 (Audio), Yianni Doulis

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Interview of Yianni Doulis by Daniel Woodward in NW Portland, Oregon on December 1st, 2006.

The interview index is available for download.