Physical Sciences and Mathematics Commons^™

The Rock And Ice Problem In National Parks: An Opportunity For Monitoring Climate Change Impacts, Andrew Godard Bunn

Environmental Sciences Faculty and Staff Publications

The fundamental physics of an enhanced greenhouse effect due to fossil fuel combustion is well understood, and Earth is warming (IPCC 2007). Considerable uncertainty exists regarding the impacts of climate change, but high latitudes and high elevations are thought to be leading indicators of future trends. The suite of high-elevation lands protected by the National Park Service is ideal in terms of documenting and monitoring the physical, floral, and faunal impacts of climate change. Indeed, the network of alpine lands managed by the Park Service in the mountainous western United States spans maritime-to-arid ecosystems over a dozen degrees of latitude …

Riesz Bases Of Root Vectors Of Indefinite Sturm-Liouville Problems With Eigenparameter Dependent Boundary Conditions. Ii, Paul Binding, Branko Ćurgus

Mathematics Faculty Publications

We consider a regular indefinite Sturm-Liouville problem with two self-adjoint boundary conditions affinely dependent on the eigenparameter. We give sufficient conditions under which the root vectors of this Sturm-Liouville problem can be selected to form a Riesz basis of a corresponding weighted Hilbert space.

The Planet, 2009, Spring, Emily A. Linroth, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Environmental Citizenship And Carbon Intensity; Evaluating The Carbon Masters Educational Program, Andrea Jean Thomas

WWU Honors College Senior Projects

This honors senior project is composed of two separate, but integrated documents which, taken together, act as the foundation for a formal, systematic program evaluation model for the climate change education group Carbon Masters. The first section is comprised of a “policy analysis" proposal which outlines a policy problem, two solutions by which to address it, and a method by which to analyze the solutions for their effectiveness, efficacy, and community-building. The policy problem is defined as the fact that there are too little educational programs available to the public that offer valid, proactive, constructive and informational tools to empower …

Lake Whatcom Monitoring Project 2007/2008 Report, Robin A. Matthews, Michael Hilles, Joan Vandersypen, Robert J. Mitchell, Geoffrey B. Matthews

Lake Whatcom Annual Reports

This report is part of an on-going series of annual reports and special project reports that document the Lake Whatcom monitoring program. This work is conducted by the Institute for Watershed Studies and other departments at Western Washington University.

The major objective of this program is to provide long-term baseline water quality monitoring in Lake Whatcom and selected tributaries. Each section contains brief explanations about the water quality data, along with discussions of patterns observed in Lake Whatcom.

Highly Connected Random Geometric Graphs, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Let P be a Poisson process of intensity 1 in a square S_n of area n. We construct a random geometric graph G_n,k by joining each point of P to its k nearest neighbours. For many applications it is desirable that G_n,k is highly connected, that is, it remains connected even after the removal of a small number of its vertices. In this paper we relate the study of the s-connectivity of G_n,k to our previous work on the connectivity of G_n,k. Roughly speaking, we show that for s=o(logn), the threshold (in k) for …

Retention Of Salmon-Derived N And P By Bryophytes And Microbiota In Mesocosm Streams, Michael G. (Michael George) Peterson, Robin A. Matthews

Environmental Sciences Faculty and Staff Publications

Annual migrations of anadromous salmon are an important source of nutrients for many coastal streams. Much of the current research on salmon-derived nutrients has focused on nutrient retention via carcass consumption by mammals, birds, and macroinvertebrates, whereas retention and transfer of nutrients by microbiota has received less attention. Our research objective was to investigate nutrient movement from decomposing salmon tissue into periphyton, bryophytes, leaf-pack microbiota, and amphipods in laboratory mesocosm streams. We measured δ¹⁵N of microbiota growing on unglazed tiles (periphyton), microbiota growing on leaf packs, bryophytes on partially submerged stones, and amphipods; C:N and C:P ratios of …

Pompeiu's Theorem Revisited, Árpád Bényi

Árpád Bényi

Pompeiu's theorem states that if ABC is an equilateral triangle and M a point in its plane, then MA, MB, and MC form a new triangle. In this article, we have a new look at this theorem in the realm of arbitrary triangles. We discover what we call Pompeiu's Area Formula, a neat equality relating areas of triangles determined by the points A, B, C, and M.

Optical Tomography For Media With Variable Index Of Refraction, Stephen R. Mcdowall

Mathematics Faculty Publications

Optical tomography is the use of near-infrared light to determine the optical absorption and scattering properties of a medium M ⊂ Rⁿ. If the refractive index is constant throughout the medium, the steady-state case is modeled by the stationary linear transport equation in terms of the Euclidean metric and photons which do not get absorbed or scatter travel along straight lines. In this expository article we consider the case of variable refractive index where the dynamics are modeled by writing the transport equation in terms of a Riemannian metric; in the absence of interaction, photons follow the geodesics …

Modulation Invariant Bilinear T(1) Theorem, Árpád Bényi, Ciprian Demeter, Andrea R. Nahmod, Christoph M. Thiele, Rodolfo H. (Rudolfo Humberto) Torres, Paco Villarroya

Mathematics Faculty Publications

We prove a T(1) theorem for bilinear singular integral operators (trilinear forms) with a one-dimensional modulation symmetry.

Local Well-Posedness Of Nonlinear Dispersive Equations On Modulation Spaces, Árpád Bényi, Kasso A. Okoudjou

Mathematics Faculty Publications

By using tools of time-frequency analysis, we obtain some improved local well-posedness results for the nonlinear Schrödinger, nonlinear wave and nonlinear Klein–Gordon equations with Cauchy data in modulation spaces ℳ_0,s^p,1.

A Critical Constant For The K Nearest-Neighbour Model, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Let P be a Poisson process of intensity 1 in a square S_n of area n. For a fixed integer k, join every point of P to its k nearest neighbours, creating an undirected random geometric graph G_n,k. We prove that there exists a critical constant c_crit such that, for c‹c_crit, G_{n,⌊clogn⌋} is disconnected with probability tending to 1 as n →∞ and, for c‹c_crit, G_{n,⌊clogn⌋} is connected with probability tending to 1 as n →∞. This answers a question …

Numerical Bifurcation Of Separable Parameterized Equations, Yun-Qiu Shen, Tjalling Ypma

Mathematics Faculty Publications

Many applications give rise to separable parameterized equations, which have the form A(y, µ)z + b(y, µ) = 0, where z ∈ R^N , y ∈ Rⁿ, µ ∈ R^s, and the (N + n) × N matrix A(y, µ) and (N + n) vector b(y, µ) are C² -Lipschitzian in (y, µ) ∈ Ω ⊂ Rⁿ × R^s. We present a technique which reduces the original equation to the form …

The Planet, 2009, Winter, Emily A. Linroth, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Every Equation Tells A Story: Using “Equation Dictionaries” In Introductory Geophysics, Jacqueline Caplan-Auerbach

Geology Faculty Publications

Many students view equations as a series of variables and operators into which numbers should be plugged rather than as representative of a physical process. To solve a problem they may simply look for an equation with the correct variables and assume it meets their needs, rather than selecting an equation that represents the appropriate physical process. These issues can be addressed by encouraging students to think of equations as stories, and to describe them in prose. This is the goal of the Equation Dictionary project, used in Western Washington University's introductory geophysics course. Throughout the course, students create personal …

Illuminating Whole Effluent Toxicity Testing: Ultraviolet Radiation, Phototoxicity, And Pah-Contaminated Groundwater, Jason C. Fortner

WWU Graduate School Collection

In this study, the acute toxicity of polycyclic aromatic hydrocarbon (PAH) - contaminated groundwater to Daphnia magna and Pimephales promelas were characterized under both ambient laboratory lighting and ambient laboratory lighting supplemented with ultraviolet radiation (UVR) using USEPA Whole Effluent Toxicity (WET) test methods. Research has shown the toxicity of some PAHs to aquatic organisms increases significantly in the presence of sunlight or artificial UVR, a phenomenon known as photoactivated toxicity or phototoxicity. Based on these findings, the discharge of PAH-contaminated groundwater to surface waters may be a phototoxic hazard to aquatic organisms. Since WET tests are frequently employed to …

A Comparison Of Benthic Macroinvertebrate Assemblages Among Kryal And Rhithral Lake Outlets In The North Cascade Mountains, Kelley L. Turner

WWU Graduate School Collection

This study compares the physico-chemical conditions and composition of benthic macroinvertebrates from five rhithral (snowmelt-fed) and five kryal (glacially-fed) lake outlet streams in the North Cascade Mountains, WA. Non-metric, non-parametric cluster and association analysis (NMCAA) clearly separated outlet streams of kryal and rhithral origin based on physico-chemical and taxon variables. Kryal lake outlets were characterized by lower water temperatures, unstable in-stream channels and higher turbidity, discharge and fine substrates than rhithral sites. A total of 24,985 specimens representing 93 macroinvertebrate taxa were collected. Rhithral lake outlets had significantly higher densities and supported more taxa than kryal sites (9,049 ind./m2 and …

Effects Of Salmon-Derived Nutrients On An Artificial Stream System, Danielle M. Love

WWU Graduate School Collection

An artificial stream system was constructed to study responses of autotrophic and heterotrophic stream communities to salmon-derived nutrients. The artificial stream system contained 12 raceways (1.2 m long x 20 cm wide x 13 cm tall) that were provided with a constant flow of well water. The experimental treatment group consisted of clay pots filled with pureed salmon carcasses and agar to simulate decomposing salmon carcasses; a control group was included consisting of pots containing agar without salmon tissue. Unglazed clay tiles were placed downstream from the clay pots for periphyton to colonize. Periphyton samples were collected from these tiles. …

The Generation Of A Diverse Suite Of Late Pleistocene And Holocene Basaltic-Andesite Through Dacite Lavas From The Northern Cascade Arc At Mount Baker, Washington, Troy D. Baggerman

WWU Graduate School Collection

This study highlights geochemical diversity in a spectrum of basaltic andesite through dacite lavas from Mount Baker, WA, and describes processes that are responsible for their generation. Petrographic observations, mineral chemistry, along with whole rock major oxide concentrations, and trace and REE data are provided for three Late Pleistocene and Holocene lava flows: the basaltic andesite of Sulphur Creek (SC) (52.5-55.8 wt.% Si02, Mg# 57-54), the andesite of Glacier Creek (GC) (58.3-58.7 wt.% Si02, Mg # 63-64), and the andesite and dacite of Boulder Glacier (BG) (60.2-64.2 wt.% Si02, Mg # 50-57). Major oxide concentrations for SC and BG display …

A Survey Of Transfer Learning Methods For Reinforcement Learning, Nicholas Bone

Computer Science Graduate and Undergraduate Student Scholarship

Transfer Learning (TL) is the branch of Machine Learning concerned with improving performance on a target task by leveraging knowledge from a related (and usually already learned) source task. TL is potentially applicable to any learning task, but in this survey we consider TL in a Reinforcement Learning (RL) context. TL is inspired by psychology; humans constantly apply previous knowledge to new tasks, but such transfer has traditionally been very difficult for—or ignored by—machine learning applications. The goals of TL are to facilitate faster and better learning of new tasks by applying past experience where appropriate, and to enable autonomous …

Fixing The Leaky Pipe: Increasing Recruitment Of Underrepresented Groups In Ecology, Brian L. Bingham, Lisette E. Torres

Environmental Sciences Faculty and Staff Publications

Many students from underrepresented groups lack adequate opportunities and mentorship as they head through the “pipeline” to graduate school. Despite the need for unique perspectives in collaborative scientific research, ethnic minority students continue to “leak” from the system. Here, I present some points for consideration for academic professionals (including educators, administrators, and program managers), based on the first-hand experiences of successful minority scientists.

Recent Extreme Avalanches: Triggered By Climate Change?, Christian Huggel, Jacqueline Caplan-Auerbach, Rick Wessels

Geology Faculty Publications

On 25 September 2008, seismo meters operated by the Alaska Volcano Observatory (AVO) registered strong ground shaking. On the basis of previous experience with such large seismic signals, AVO personnel were able to rapidly identify the seismic event as an avalanche. Two days later, an AVO overflight of Iliamna volcano, near Alaska's Cook Inlet, confirmed that a massive chunk of glacial ice and rock had broken free from its position on the upper flanks of the volcano, generating a massive avalanche that could have buried an entire town had it occurred in a more populated area.

Rapidly moving rock, ice, …

The Planet, 2008, Fall, Emily A. Linroth, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Lake Samish Water Monitoring Project 2008 Final Report, Robin A. Matthews, Joan Vandersypen

Lake Samish

This report is a revised version of the 2006 and 2007 Final Reports by Matthews, et al., and contains most of the original text, updated figures, and additional discussion of all data collected from June 2005 through July 2008.

Lake Samish is a valuable aquatic resource, providing public access for boating, fishing, swimming, picnicking, and other water and lakeshore activities. Residents around the lake enjoy outstanding views of both the lake and its surrounding watershed, and the lake serves as a water supply for many of the lakeshore residents. Lake Samish is located in the Washington State Department of Ecology’s …

Molecular Nanoscience And Engineering On Surfaces, Willi Auwarter, Agustin Schiffrin, Alexander Weber-Bargioni, Yan Pennec, Andreas Riemann, Johannes V. Barth

Physics & Astronomy

Molecular engineering of low-dimensional materials exploiting controlled self-assembly and positioning of individual atoms or molecules at surfaces opens up new pathways to control matter at the nanoscale. Our research thus focuses on the study of functional molecules and supramolecular architectures on metal substrates. As principal experimental tools we employ low-temperature scanning tunneling microscopy and spectroscopy. Here we review recent studies in our lab at UBC: Controlled manipulation of single CO molecules, self-assembled biomolecular nanogratings on Ag(111) and their use for electron confinement, as well as the organisation, conformation, metalation and electronic structure of adsorbed porphyrins.

Methane, Manganese, And Helium In Hydrothermal Plumes Following Volcanic Eruptions On The East Pacific Rise Near 9°500n, Brooke Love, Joseph A. (Joseph Anton) Resing, James P. Cowen, John E. Lupton, Daniel J. Fornari, Timothy M. (Timothy Mitchell) Shank, Dondra Biller

Environmental Sciences Faculty and Staff Publications

As part of a rapid response cruise in May 2006, we surveyed water column hydrothermal plumes and bottom conditions on the East Pacific Rise between 9°46.0'N and 9°57.6'N, where recent seafloor volcanic activity was suspected. Real-time measurements included temperature, light transmission, and salinity. Samples of the plume waters were analyzed for methane, manganese, helium concentrations, and the δ¹³C of methane. These data allow us to examine the effects of the 2005–2006 volcanic eruption(s) on plume chemistry. Methane and manganese are sensitive tracers of hydrothermal plumes, and both were present in high concentrations. Methane reached 347 nM in upper …

Lake Whatcom Monitoring Project 2006/2007 Report, Robin A. Matthews, Michael Hilles, Joan Vandersypen, Robert J. Mitchell, Geoffrey B. Matthews

Lake Whatcom Annual Reports

This report is part of an on-going series of annual reports and special project reports that document the Lake Whatcom monitoring program. This work is conducted by the Institute for Watershed Studies and other departments at Western Washington University.

The major objective of this program is to provide long-term baseline water quality monitoring in Lake Whatcom and selected tributaries. Each section contains brief explanations about the water quality data, along with discussions of patterns observed in Lake Whatcom.

The Planet, 2008, Spring, Page A. Buono, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

On Isoconcentration Surfaces Of Three Dimensional Turing Patterns, Tilmann Glimm, H. George E. Hentschel

Mathematics Faculty Publications

We consider three-dimensional Turing patterns and their isoconcentration surfaces corresponding to the equilibrium concentration of the reaction kinetics. We call these surfaces equilibrium concentration surfaces (EC surfaces). They are the interfaces between the regions of "high" and "low" concentrations in Turing patterns. We give alternate characterizations of EC surfaces by means of two variational principles, one of them being that they are optimal for diffusive transport. Several examples of EC surfaces are considered. Remarkably, they are often very well approximated by certain minimal surfaces. We give a dynamical explanation for the emergence of Scherk's surface in certain cases, a structure …

The Morphostatic Limit For A Model Of Skeletal Pattern Formation In The Vertebrate Limb, Mark Alber, Tilmann Glimm, H. George E. Hentschel, Bogdan Kazmierczak, Yong-Tao Zhang, Jianfeng Zhu, Stuart (Stuart A.) Newman

Mathematics Faculty Publications

A recently proposed mathematical model of a “core” set of cellular and molecular interactions present in the developing vertebrate limb was shown to exhibit pattern-forming instabilities and limb skeleton-like patterns under certain restrictive conditions, suggesting that it may authentically represent the underlying embryonic process (Hentschel et al., Proc. R. Soc. B 271, 1713–1722,2004). The model, an eight-equation system of partial differential equations, incorporates the behavior of mesenchymal cells as “reactors,” both participating in the generation of morphogen patterns and changing their state and position in response to them. The full system, which has smooth solutions that exist globally …