Physical Sciences and Mathematics Commons^™

Design And Analysis Of Multispecies Toxicity Tests For Pesticide Registration, Wayne G. Landis, Robin A. Matthews, Geoffrey B. Matthews

Environmental Sciences Faculty and Staff Publications

The community conditioning hypothesis describes ecological structures as historical, nonequilibrial, and by definition complex. Indeed, the historical nature of ecological structures is seen as the primary difference between single-species toxicity tests and multispecies test systems. Given the complex properties of ecological structures, multispecies toxicity tests need to be designed accordingly with appropriate data analysis tools. Care must be taken to ensure that each replicate shares an identical history, or divergence will rapidly occur. Attempting to realize homogeneity by linear cross inoculation or waiting for an equilibrium state to occur assumes properties that ecological structures do not have. Data analysis must …

Preservation Of The Range Under Perturbations Of An Operator, Branko Ćurgus, Branko Najman

Mathematics Faculty Publications

A sufficient condition for the stability of the range of a positive operator in a Hilbert space is given. As a consequence, we get a class of additive perturbations which preserve regularity of the critical point 0 of a positive operator in a Krein space.

Conserving Coastal Wetlands Despite Sea Level Rise, W. K. (William K.) Nuttle, Mark M. Brinson, D. Cajon, J. C. Callaway, R. R. Christian, G. L. Chmura, William H. Conner, Robert H. Day, M. Ford, J. Grace, J. Lynch, Richard A. Orson, R. W. Parkinson, D. Reed, John M. Rybczyk, T. J. Smith Iii, Richard P. Stumpf, K. Williams

Environmental Sciences Faculty and Staff Publications

Coastal wetlands provide valuable services such as flood protection and fisheries production to a global population that is increasingly concentrated near the coast and dependent on its resources. Many of the world's coastal wetlands suffered significant losses during this century, and the creation of new wetland areas is not keeping pace with recent losses. Some destruction of wetland areas can be expected as a consequence of the continual reworking of the coastal zone by dynamic geologic processes. Yet human activities also play a role, both directly by encroaching on coastal wetlands and indirectly by influencing the hydrologic and geologic processes …

Discrete Tomography: Determination Of Finite Sets By X-Rays, Richard J. Gardner, Peter Gritzmann

Mathematics Faculty Publications

We study the determination of finite subsets of the integer lattice Zⁿ, n ≥ 2, by X-rays. In this context, an X-ray of a set in a direction u gives the number of points in the set on each line parallel to u. For practical reasons, only X-rays in lattice directions, that is, directions parallel to a nonzero vector in the lattice, are permitted. By combining methods from algebraic number theory and convexity, we prove that there are Sour prescribed lattice directions such that convex subsets of Zⁿ (i.e., finite subsets F with F = Z …

Channel Restructuring Along Crystal Springs: Creating Salmon Habitat On A Lowland Stream, Lua Olsen

WWU Honors College Senior Projects

Crystal Springs is a small tributary of Tenmile Creek located in the lower drainage basin of the Nooksack River (Figure 1). It is 2.6 km in length and has a total relief of approximately 21 meters. A soil survey of the area suggests that prior to agricultural development, Crystal Springs existed as a swamp and was later trained into the man-made irrigation ditch which it currently occupies. Aerial photographs taken as early as June 30, 1947 reveal that the channel has undergone no significant change in morphology in the last 50 years. Recently a local landowner granted permission for the …

Lake Whatcom Monitoring Project 1995/1996 Report, Robin A. Matthews, Michael Hilles, 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.

Short-Lived Intermediates In Aspartate Aminotransferase Systems, George Czerlinski, Richard Levin, Tjalling Ypma

Mathematics Faculty Publications

The kinetics of the reaction of aspartate aminotransferase with erythro-beta-hydroxy-aspartate, in which rapid mixing is followed (upon reaching a suitable stationary state) by a very fast temperature jump, is numerically simulated. Values for rate constants are used to the extent known, otherwise estimated. It is shown that reaction steps not resolvable by rapid mixing can be resolved by subsequent chemical relaxation. Since several absorption spectra of enzyme complexes overlap, use of a pH-indicator is investigated. When the pH-indicator is coupled to the protonic dissociation of free enzyme, the fast steps are easily detected in the chemical relaxation portion of the …

Integrable Smooth Planar Billiards And Evolutes, Edoh Y. Amiran

Mathematics Faculty Publications

Any elliptic region is an example of an integrable domain: the set of tangents to a confocal ellipse or hyperbola remains invariant under reflection across the normal to the boundary. The main result states that when Ω is a strictly convex bounded planar domain with a smooth boundary and is integrable near the boundary, its boundary is necessarily an ellipse. The proof is based on the fact that ellipses satisfy a certain “transitivity property”, and that this characterizes ellipses among smooth strictly convex closed planar curves. To establish the transitivity property, KAM theory is used with a perturbation of the …

Hessian (Leonardian, Middle Lower Permian) Depositional Sequences And Their Fusulinid Zones, West Texas, Charles A. Ross, June R. P. Ross

Geology Faculty Publications

The lower Leonardian (Lower Permian) Hess Limestone in the eastern part of the Glass Mountains, West Texas, forms a high, well-exposed escarpment of repetitious, shallow-water, platform limestone facies for about 35 km. The strike of the outcrops cuts the strike of depositional facies at relatively low angle so that the actual width of the carbonate platform, from its marginal rim to shore facies, was probably less than 10 km (Figs. 1, 2). At the platform margin, the Hess Limestone passes abruptly into coarse, conglomeratic slope deposits that form the Skinner Ranch Formation. The pebbles, cobbles, boulders, (some the size of …

An Analysis Of Pre-Settlement Biomass And Vegetation In Northwest Whatcom County, Washington, Circa Late 19th Century., Jayme Anne Gordon

WWU Honors College Senior Projects

Much of ecology, especially terrestrial ecology, studies how a given system changes over time. Pressures from preservationists and demands for timber products have focused ecological attention on Pacific Northwest forest ecosystems, and much of the debate has been over how change affects "old-growth” forests. Old-growth forests have a number of distinguishing characteristics including species composition, size of trees and forest structure that make them unique (Waring and Franklin 1979, Franklin et al. 1981). Old-growth forests west of the Cascade mountain range are dominated by Douglas fir (Psuedotsuga menziesii) and western hemlock (Tsuga heterophylla) trees approximately 200-750 …

Magnetic Anisotropy Of Barbados Prism Sediments, Bernard A. Housen

Geology Faculty Publications

Anisotropy of magnetic susceptibility (AMS) results from sediments spanning the basal décollement of the Barbados accretionary prism show a striking progression across this structure that strongly supports the hypothesis that it is strongly overpressured. In the accretionary prism above the décollement, the minimum AMS axes are subhorizontal and nearly east–west trending, whereas the maximum AMS axes are nearly north–south trending, and shallowly inclined. At the top of the décollement, the AMS minimum axes orientations abruptly change to nearly vertical; this orientation is maintained throughout the décollement and in the underthrust sediments below. The AMS orientations in the prism sediments above …

Structural Geology Of The Décollement At The Toe Of The Barbados Accretionary Prism, Alex Maltman, Pierre Labaume, Bernard A. Housen

Geology Faculty Publications

The base of the Barbados accretionary prism is defined by a décollement, which separates material accreting to the Caribbean Plate from underthrusting Atlantic Ocean sediment. A three-dimensional seismic survey has shown the structure to contain intervals of negative polarity, interpreted as representing pockets of overpressured fluid. Consequently, Ocean Drilling Program Leg 156 was designed specifically to investigate the hydrogeological and deformational behavior of the décollement.

Analysis of recovered cores shows the structure to comprise a zone of intensified but heterogeneous deformation, 31 m thick, but 39 m thick if suprajacent breccia and various physico-chemical anomalies are included. The top of …

Nealian And Lenoxian (Wolfcampian, Lower Permian) Depositional Sequences, Fusulinid Facies And Biostratigraphy, Glass Mountains, Texas, Charles A. Ross, June R. P. Ross

Geology Faculty Publications

The Wolfcampian Series crops out along the base of the Glass Mountains escarpment (King, 1930, 1937) and, in the western part of the Marathon Basin, in folded and faulted beds exposed in the Dugout structural fold belt, the westernmost belt in the Marathon Orogen (Ross, 1963). The Wolfcampian is divided into two stages, a lower Nealian Stage and an upper Lenoxian Stage (Ross and Ross, 1987a, 1987b). Strata of these two stages are separated by a major tectonic event in the history of the Marathon orogeny and, as a result, by a major angular unconformity that separates the structurally deformed …