Physical Sciences and Mathematics Commons^™

The Simple Random Walk On A Random Voronoi Tiling, Amites Sarkar, Louigi Addario-Berry

Amites Sarkar

Let P be a Poisson point process in ℝ^d with intensity 1. We show that the simple random walk on the cells of the Voronoi diagram of P is almost surely recurrent in dimensions d = 1 and d = 2 and is almost surely transient in dimension d ≥ 3.

Austin Creek And Beaver Creek Sampling Project, Robin A. Matthews, Michael Hilles, Joan Vandersypen

Lake Whatcom Other Reports

Beaver Creek and Austin Creek were sampled intensively on November 20, 2004 to measure temperature, dissolved oxygen, turbidity, total nitrogen, total phosphorus, total suspended solids, and fecal coliforms. The objective was to assess the amount of variability that can be expected for water quality measurements collected from these creeks at different times during the day and in different locations within the Austin Creek and Beaver Creek watersheds.

The Planet, 2005, Fall, Sarah M. Kuck, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Satellite-Observed Photosynthetic Trends Across Boreal North America Associated With Climate And Fire Disturbance, Scott J. Goetz, Andrew Godard Bunn, Gregory J. Fiske, Richard A. Houghton

Environmental Sciences Faculty and Staff Publications

We analyzed trends in a time series of photosynthetic activity across boreal North America over 22 years (1981 through 2003). Nearly 15% of the region displayed significant trends, of which just over half involved temperature-related increases in growing season length and photosynthetic intensity, mostly in tundra. In contrast, forest areas unaffected by fire during the study period declined in photosynthetic activity and showed no systematic change in growing season length. Stochastic changes across the time series were predominantly associated with a frequent and increasing fire disturbance regime. These trends have implications for the direction of feedbacks to the climate system …

Observed And Predicted Responses Of Plant Growth To Climate Across Canada, Andrew Godard Bunn, Scott J. Goetz, Gergory J. Fiske

Environmental Sciences Faculty and Staff Publications

Using satellite observations from 1981–2000, and data interpolated from surface weather stations, we examined the association between gross photosynthetic activity (Pg) and climate across the boreal forest and tundra of Canada. The response of annual and interannual Pg was tightly coupled to climate, and seasonal associations between Pg and climate varied with plant functional types. The most important variable for modeling summer growth of conifer forests was the previous spring minimum temperature, whereas tundra responded primarily to summer maximum temperature. Using general circulation model predictors to 2050, we project that tundra will continue to grow vigorously in the coming decades …

Paleomagnetism And Tectonic Significance Of Albian And Cenomanian Turbidites, Ochoco Basin, Mitchell Inlier, Central Oregon, Bernard A. Housen, Rebecca J. Dorsey

Geology Faculty Publications

Understanding continental growth and convergent margin dynamics associated with terrane accretion and modification of the Cordilleran margin of North America is prevented by conflicts in paleogeographic models for major terranes, oceanic plates, and the North American margin. We present new paleomagnetic data suggesting that the Blue Mountains superterrane, located at an inboard portion of the Cordilleran margin, has undergone substantial northward translation and clockwise rotation relative to North America since mid-Cretaceous time. Positive baked-contact, conglomerate, and fold tests, provide evidence that the magnetization of these rocks dates from their deposition. These results yield a mean direction of D = 10.8°, …

On Multiscale Approaches To 3-Dimensional Modeling Of Morphogenesis, Rajiv Chaturvedi, Chengbang Huang, Bogdan Kazmierczak, T. Schneider, Jesus A. Izaguirre, Tilmann Glimm, H. George E. Hentschel, Stuart (Stuart A.) Newman, Mark Alber, James A. Glazier

Mathematics Faculty Publications

In this paper we present the foundation of a unified, object-oriented, three-dimensional (3D) biomodeling environment, which allows us to integrate multiple submodels at scales from subcellular to tissues and organs. Our current implementation combines a modified discrete model from statistical mechanics, the Cellular Potts Model (CPM), with a continuum reaction-diffusion (RD) model and a state automaton with well-defined conditions for cell differentiation transitions to model genetic regulation. This environment allows us to rapidly and compactly create computational models of a class of complex developmental phenomena. To illustrate model development, we simulate a simplified version of the formation of the skeletal …

Reddening And The Extinction Law At High Galactic Latitude, Kristen A. Larson, D. C. B. Whittet

Physics & Astronomy

We present near-infrared (JHKL) photometry of 103 southern stars located behind translucent interstellar clouds at high Galactic latitude. Our data are combined with visual photometry and spectral type information from the literature in a detailed analysis of the wavelength dependence of interstellar extinction by dust in these high-latitude clouds. We investigate the shape of the near-infrared extinction curve and evaluate the total line-of-sight extinction ( A_V) and ratio of total-to-selective extinction ( R_V) in each line of sight. Sources of uncertainty in R_V arising from photometric errors and spectral classification errors are carefully assessed …

The Planet, 2005, Spring, Lucas Henning, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Lake Whatcom Monitoring Project 2003/2004 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.

Comment On "Paleomagnetism And Geochronology Of The Ecstall Pluton In The Coast Mountains Of British Columbia: Evidence For Local, Myrl E. Beck Jr., Bernard A. Housen

Geology Faculty Publications

No abstract provided.

On The Supersymmetry Group Of The Classical Bose-Fermi Oscillator,", Tilmann Glimm, Rudolf Schmid

Mathematics Faculty Publications

Applying the concept of a momentum map for supersymplectic supervectorspaces to the one-dimensional Bose-Fermi oscillator, we show that the largest symmetry group that admits a momentum map is the identity component of the intersection of the orthosymplectic group OSp(2|2) and the group of supersymplectic transformations. This gives a systematic characterization of a certain class of odd supersymmetry transformations that were originally introduced in an ad hoc way.

Connectivity Of Random K-Nearest-Neighbor Graphs, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Let P be a Poisson process of intensity one in a square S_n of area n. We construct a random geometric graph G_n,k by joining each point of Pto its k ≡ k(n) nearest neighbours. Recently, Xue and Kumar proved that if k ≤ 0.074logn then the probability that G_n,k is connected tends to 0 as n → ∞ while, if k ≥ 5.1774logn, then the probability that G_n,k is connected tends to 1 as n → ∞. They conjectured that the …

Review Of: Newton Methods For Nonlinear Problems: Affine Invariance And Adaptive Algorithms, By P. Deuflhard, Tjalling Ypma

Mathematics Faculty Publications

In the context of solving nonlinear equations, the term "affine invariance" was introduced to describe the fact that when a function F: Rⁿ → Rⁿ is transformed to G = AF ,where A is an invertible matrix, then the equation F(x) = 0 has the same solutions as G(x) = 0, and the Newton iterates X_^k+1 = X_k-F'(X_k)^-1F(X_k) remain unchanged when F is replaced by G. The idea was that this property of Newton's method should …

Mechanisms Of Telomerase Binding To Telomeres, George Czerlinski, Tjalling Ypma

Mathematics Faculty Publications

There are essentially two alternative mechanisms for the binding of telomerase to telomeres, assuming that a protective component is initially bound to the telomerase binding region on the telomeres. Either the protective (or blocking) agent first dissociates and telomerase binds thereafter, or telomerase binds first and the protective agent then dissociates from the ternary complex. In the limit, this second possibility permits the ternary complex to become a transition complex (creating another possible mechanism). Numerical simulation of both rapid mixing and chemical relaxation is used to study these alternatives. We aim to determine how the mechanisms may be distinguished experimentally …

The Planet, 2005, Winter, Laurie Ballew, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Huxley Horizon, 2005, Winter, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.

Getting Organized At The Nanoscale With Thermotropic Liquid Crystal Solvents, David L. Patrick, F. Scott Wilkinson, Tiffany L. Fegurgur

Chemistry Faculty and Staff Publications

This paper summarizes recent progress toward an emerging, unconventional application of thermotropic liquid crystals (LCs) - their use as solvents for controlling the assembly of non-LC nanoscale building blocks. LCs offer a number of potential advantages compared to conventional isotropic solvents, including the ability to influence building block orientation and other structural properties. Strategies are reviewed for the exploitation of LC media to engineer order in a range of systems, including oriented organic monolayers, chiral films, and nanometer-scale particles.

Brittle Deformation In An Ancient Accretionary Prism Setting: Lopez Structural Complex, San Juan Islands, Nw Washington, John R. (John Rhea) Gillaspy

WWU Graduate School Collection

Fault-bounded slices of allochthonous Paleozoic to Mesozoic bedrock of the San Juan Islands in northwest Washington provide a locality in which to study terrane translation and ductile and brittle deformation in an accretionary wedge setting, as well as the factors involved in preservation of blueschist-facies terranes. This study contributes to understanding of the tectonic evolution of the Lopez Structural Complex, a major Late Cretaceous terrane-bounding fault zone in the San Juan Thrust System. Structural study is combined with X-ray diffraction and fluid inclusion analysis to constrain the relative timing, kinematics, and P-T conditions of fabric formation and post-fabric brittle deformation …

The Effect Of Interactive Computer Animations On Introductory Geology Students' Conceptual Understanding Of Mountain Building Processes, Michelle (Michelle Alicia) Malone

WWU Graduate School Collection

The use of computer animations to help students visualize processes they cannot observe directly is becoming more widespread in geoscience classrooms, but few studies have formally assessed the effectiveness of these technological aids as learning tools. This research project evaluated the effect of interactive computer animations on undergraduate introductory geology students' understanding of mountain building processes. The study focused on introductory geology students’ misconceptions about the formation of mountains. With the assistance of Flash programmers, an online interactive web activity was developed. This tool was aimed at reducing misconceptions, and included activities related to plate tectonics, isostasy, erosion and rock …

A Paleomagnetic Paleolatitude Determination From The Upper Cretaceous Units Of The Gold Beach Terrane, Southwest Coastal Oregon, Noel Liner

WWU Graduate School Collection

The paleolatitude for the Gold Beach terrane has been under debate from several sources (Bourgeois, 1980b; Bourgeois, 1985; Jayko and Blake, 1985; Seiders and Blome, 1987; Aalto, 1989) since the 1980 publication of Joanne Bourgeois’ PhD thesis connecting the Upper Cretaceous formations of the Gold Beach terrane to the Nacimiento Block, currently in the vicinity of Southern California; During the Cretaceous, the Nacimiento Block was farther south than its present position by about 200 km (Blake and Jayko, 1985). The opposing hypothesis of Seiders and Blome (1987) connects the Gold Beach terrane to the neighboring Klamath block, implying at most …

The Hydrogeology Of North Lummi Island, Washington, William M. (William Martin) Sullivan

WWU Graduate School Collection

Lummi Island is a 10.8 square mile island in the northern Puget Sound Region, west of Bellingham, Washington. The population of Lummi Island has grown steadily for decades to approximately 900 permanent and 1,500 seasonal residents. The increasing demand for groundwater resources on the island has caused some wells to experience seasonal shortages and seawater intrusion, prompting an assessment of the hydrogeology for growth-management purposes. My study focused on characterizing the hydrogeology of the north half of the island (3.9 square miles) where most residents live and where groundwater is the sole source of potable water.

I examined data collected …