Digital Commons Network^™

Apparent Interactions In Community Models: A Challenge For Theoretical Ecology, Peter J. Taylor

Working Papers on Science in a Changing World

The primary aim of this working paper is to challenge theoretical ecologists to clarify the intended status of any simple model that they use. If we restrict our attention to a subcommunity and treat it as if it were the full community, we need to invoke apparent interactions that incorporate the effects of unspecified or hidden variables as well as direct interactions. This position resembles that of previous discussions of apparent competition (Holt 1977), indirect effects (Lawlor 1979), and ecological abstraction (Schaffer 1981), but my definition of apparent interactions differs from those stated or implied by these authors. I advance …

The Relationship Between Mathematical Expression And Biological Insight: Some Issues In Community Ecology Modeling, Exemplified By The Logistic Equation, Peter J. Taylor

Working Papers on Science in a Changing World

The relationship between mathematical expression and biological insight is a central problem for modelers in community ecology. In this paper I distinguish three interpretations of this relationship: models as redescriptions as observations; models as capturing fundamental or generative biological relations; and models as an aid in exploring how to formulate the inquiries we put to nature. I aim to show that we can reduce ambiguities and confusion and ecological theory if we hold the different interpretations clearly in mind. I conclude by advancing an overall strategy of model building—de/composition—in which each of the interpretations plays a role. The logistic equation, …

Uptake Of Zn65 And Mn54 Into Body Tissues And Renal Granules By The Southern Quahog, Mercenaria Campechiensis, William Lynn Miller Jr.

USF Tampa Graduate Theses and Dissertations

A study was conducted to examine the influence of elevated inorganic phosphate and trace metal concentrations on the uptake and distribution of Zn⁶⁵ and Mn⁵⁴ into the body tissue and phosphoritic renal concretions of a subtropical estuarine bivalve, Mercenaria campechiensis. Chronological sampling of gills, mantle, adductor muscle, viscera, kidneys, and renal granules using gamma ray spectrometry allowed examination of both tissue distribution and accumulation patterns over time. The kidney was the principal site of Mn⁵⁴ accumulation whereas Zn⁶⁵ was concentrated in both the gill and the kidney. The gill initially accumulated zn65 three times faster …

Liquid Metal Sources In Ion Microscopy And Secondary Ion Mass Spectrometry, G. L. R. Mair, T. Mulvey

Scanning Electron Microscopy

This paper reports on state-of-the-art developments in liquid metal sources and some of the finer points of their operating characteristics that are especially relevant to the satisfactory functioning of analytical ion scanning microscopes equipped with secondary ion mass spectrometers. Such effects include unwanted emissions from the source and their exclusion by means of filters and mass separators in the ion-optical column. The design of the ion-optical column is also discussed and some applications of this rapidly advancing form of analytical microscopy are described.

The Cathodoluminescence Mode Of The Scanning Electron Microscope: A Powerful Microcharacterization Technique, D. B. Holt, F. M. Saba

Scanning Electron Microscopy

By detecting cathodoluminescence (CL) in a scanning electron microscope (SEM), pan and monochromatic micrographs and CL spectral analyses analogous to x-ray mode point analyses can be obtained. Complete microcharacterization requires alternate examination of both micrographs and spectra. New techniques for near infra-red CL and low-temperatures to produce sharp spectra are of increasing importance. CL emission is due to electron transitions between quantum mechanical states so the radiative defects present can be unambiguously identified at liquid helium temperatures. Strongly luminescent impurities can be detected to below one part in 10⁸. This is 10⁴ times as sensitive as the …

An Electrophoretic Analysis Of The Genetic Relationship Between Etheostoma Nigrum And Etheostoma Olmstedi (Percidae: Etheostomatini) In The James River Drainage Of Virginia, John Stuart Prince Jr.

Master's Theses

Etheostoma nigrum Rafinesque 1820, the Johnny darter ranges from Alabama to the Hudson Bay and from Colorado east to the Atlantic slope in the James, Roanoke, Tar and Neuse Rivers. Etheostoma olmstedi Storer 1842, the tesselated darter, is restricted to the east coast in the Atlantic and Lake Ontario drainage. In the James and Roanoke River systems in Virginia E. nigrum occupies the piedmont and montane regions whereas E. olmstedi primarily inhabits the coastal plain. The relationship between the morphologically similar species of darters (subgenus Boleosoma) is controversial and has been investigated by several authors. Stone (1947), using multiple character …

The Trend In Canopy Composition In A Young Mesic Forest, Zhenchang Li

Masters Theses

Brewer Woods, a young disturbed mesic sugar maple-beech (Acer saccharum-Fagus grandifolia) forest in Kalamazoo Co., Michigan, was investigated by point-quarter and transition matrix methods. The results indicate that this forest is dominated by sugar maple in both canopy and understory composition. Beech is the second most important species. Fourteen species were found as canopy trees or replacements. The hypothesis that a young forest is more diverse than comparable climax forests such as Warren Woods and Hueston Woods was supported. Its successional trend is that sugar maple will become more abundant at the expense of the other species. Beech is a …

Physical Properties Of Tar Sand Tailings That Influence Their Ability To Sustain Plant Growth, Timothy Cole

Masters Theses & Specialist Projects

The mining of bituminous sandstone rock for the purpose of extracting bitumen has created a need for reclamation. One such mine is located in northern Logan County. Their mining operation involves removing large sections of sandstone, which is impregnated with bitumen, and crushing it to sand-sized material. The sand-sized material is then mixed with organic solvents which extract the bitumen. Once separated, the bitumen is stored for future refinement and the spent sand is stockpiled for later disposal.

The spent sands or waste material are referred to as tar sand tailings. These tailings have particular properties which make reclamation efforts …

Quantification Of Indian Rights: Problems Of Proof, Harry R. Sachse

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

32 pages.

The Endangered Species Act And Western Water Projects, Lawrence J. Macdonnell

Western Water Law in Transition (Summer Conference, June 3-5)

20 pages.

Contains references.

Water Project Financing Needs In Colorado, J. William Mcdonald

Western Water Law in Transition (Summer Conference, June 3-5)

12 pages.

Federal/State Relations In Theory And Practice: A Sovereignty Mismatch, Charles T. Dumars

Western Water Law in Transition (Summer Conference, June 3-5)

12 pages.

Contains footnotes.

Unresolved Issues In Federal Reserved Rights, Michael D. White

Western Water Law in Transition (Summer Conference, June 3-5)

12 pages.

Putting Indian Reservation Water Rights To Use, Richard B. Collins

Western Water Law in Transition (Summer Conference, June 3-5)

10 pages.

Financing Water Projects: Where Do We Go From Here?, Henry P. Caulfield, Jr.

Western Water Law in Transition (Summer Conference, June 3-5)

16 pages.

Financing Water Projects: Where Do We Go From Here?: A Panel Discussion [Colorado House Bill No. 1088, As Amended 4/15/85], Chris Paulson

Western Water Law in Transition (Summer Conference, June 3-5)

4 pages.

Contains text of Colorado House Bill No.1088, as amended 4/15/85.

Interstate Transfers Of Water: Opportunities And Obstables [Sic], A. Dan Tarlock

Western Water Law in Transition (Summer Conference, June 3-5)

34 pages.

Western Ground Water Law: Overview And Recent Developments, J. David Aiken

Western Water Law in Transition (Summer Conference, June 3-5)

27 pages.

Representing The Water Client [Outline], David W. Robbins

Western Water Law in Transition (Summer Conference, June 3-5)

3 pages.

Federal And State Regulation Of Activities Affecting Water Quality, Julia B. Epley

Western Water Law in Transition (Summer Conference, June 3-5)

54 pages.

Legal Implications Of Instream Flows And Other Nonconsumptive Uses, Steven J. Shupe

Western Water Law in Transition (Summer Conference, June 3-5)

14 pages.

The Public Trust Doctrine: Conflict With Traditional Western Water Law?, Harrison C. Dunning

Western Water Law in Transition (Summer Conference, June 3-5)

24 pages.

Contains references.

Inefficiency, Waste, And Loss: Water Supplies Of The Future?, John W. Krautkraemer

Western Water Law in Transition (Summer Conference, June 3-5)

24 pages.

Contains references.

Agenda: Western Water Law In Transition, University Of Colorado Boulder. Natural Resources Law Center

Western Water Law in Transition (Summer Conference, June 3-5)

Conference organizers and/or faculty included University of Colorado School of Law professors James N. Corbridge, Jr., Lawrence J. MacDonnell, Richard B. Collins, David H. Getches and Charles F. Wilkinson.

The prior appropriation doctrine has governed the allocation and use of water in the western United States since the 1850s. The shifting nature of water demand is bringing about changes in the traditional legal system. This conference will consider the fundamental principles of the prior appropriation doctrine together with the important new developments in the law now underway throughout the West.

The Prior Appropriation System In Western Water Law: The Law Viewed Through The Example Of The Rio Grande Basin, James N. Corbridge Jr., Charles F. Wilkinson

Western Water Law in Transition (Summer Conference, June 3-5)

17 pages.

Contains references.

Administering Water Rights: The Permit System, Lawrence J. Wolfe

Western Water Law in Transition (Summer Conference, June 3-5)

69 pages.

Contains references.

Administering Water Rights: The Colorado System, Raymond L. Petros

Western Water Law in Transition (Summer Conference, June 3-5)

140 pages (includes illustrations and maps).

Contains bibliography.

Current Concepts Of Metabolic Functional Imaging With Positron Emitters, John W. Keyes Jr.

Henry Ford Hospital Medical Journal

Positron emitting radionuclides have unique properties that make them nearly ideal as radioactive tracers for in vivo metabolic studies. Using positron emission tomographic (PET) scanning and positron-labeled radiopharmaceuticals, one can study local glucose metabolism in tissues, blood flow, oxygen utilization, protein synthesis, and many other functions noninvasively in normal subjects and patients who have various diseases. A review of some of these techniques and the relative advantages and problems associated with the PET approach is presented.

Santa Clara Magazine, Volume 27 Number 7, Summer 1985, Santa Clara University

Santa Clara Magazine

2 - COMMON COURTESY By Thomas J. Peters. Competitive advantage is boiled down to service, quality, and courtesy. Everyone should provide it. Why else be in business?

9 - THE RISE AND FALL OF OPEC By T John Whalen, Jr. Traces the evolution of OPEC, discusses the dominant factors that led to its loss of power, and analyzes its impact on world oil prices and supplies.

13 - AN AFFLUENT AMERICAN RESPONDS TO GLOBAL POVERTY By William J. Wood, S.J. A Jesuit reflects on global poverty and explains why he is an affluent American, and describes those who are in …

The Prairie Naturalist Volume 17, No. 2. June 1985

The Prairie Naturalist

Paul B. Kannowski, Editor

Nikki R. Seabloom, Assistant Editor

Douglas H. Johnson, Book Review Editor

TABLE OF CONTENTS

A CHECKLIST OF TEXAS ANTS ▪ G. C. Wheeler and J. Wheeler

HABITAT SELECTION BY SMALL MAMMALS OF THE TALL-GRASS PRAIRIE: EXPERIMENTAL PATCH CHOICE ▪ S. K. Peterson, G. A. Kaufman, and D. W. Kaufman

CORN CONSUMPTION BY WINTERING MALLARDS DURING MORNING FIELD-FLIGHTS ▪ R. J. Whyte and E. G. Bolen

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1984 ▪ R. N. Randall

MOUNTAIN PLOVER FOOD ITEMS ON AND ADJACENT TO A PRAIRIE DOG TOWN ▪ S. L. Olson

ECOLOGICAL DISTURBANCE IN …