Digital Commons Network^™

Comparative Study Of Selenium Requirements Of Three Phytoplankton Species: Gymnodinium Catenatum, Alexandrium Minutum (Dinophyta) And Chaetoceros Cf. Tenuissimus (Bacillariophyta, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff

OES Faculty Publications

This study investigated the selenium (Se) requirements of three phytoplankton species which commonly bloom in southern Australian estuaries. The present study showed that the toxic dinoflagellate Gymnodinium catenatum Graham had an obligate requirement for Se (IV) in culture. After two transfers (~ 4 weeks ≈ 7 generations) in Se-deficient seawater medium, this phytoplankton species exhibited a decline in growth rate (25%) and biomass yield (90%), while complete cessation of cell division occurred under prolonged (8 weeks ≈ 12 generations) Se starvation. Addition of 10^-9-10^-7 M H₂SeO₃ to nutrient-enriched seawater medium resulted in increased G.catenatum …

The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins

OES Theses and Dissertations

The Eastern Shore of Virginia (Greens Creek) as well as a large portion of the North Atlantic coastline is characterized by estuarine systems not dominated by large river systems. Instead, small freshwater creeks influence many coastal systems yet little information has been documented on their ecological significance. The focus of this research is to identify the biogeochemical and physical interactions within an estuarine water-column and understand the importance of freshwater sources in governing phytoplankton production. The hypothesis of this research is that increases in external nutrient loading into Greens Creek will not result in an increase in primary production. The …

Impact Of Agricultural Land Use On Some Hungarian Karst Regions, Ilona Bárány-Kevei

International Journal of Speleology

The karst regions are found in the medium altitude mountains of Hungary. Their land use types are natural and sustainable forestry, grazing and vineyards. In international comparison, Hungary belongs to those countries of Europe where arable land is abundant, therefore, in the future its extension has to be reduced. That means agricultural activity has to be restricted on the sensitive karst surfaces. This paper presents ways of sustainable forestry and other land use types for three karst regions of Hungary.

A Coupled Bio-Optical And Mixed Layer Model For The Equatorial Pacific, James Vincent Koziana

OES Theses and Dissertations

A one dimensional coupled bio-optical and mixed layer model is developed and applied to problems involving the role of phytoplankton-induced turbidity (PIT) on the vertical structure and heating of the upper ocean in the Equatorial Pacific Ocean. The bio-optical and mixed layer model for optically pure sea water was forced with climatological environmental conditions to provide a reference simulation for 140°W in the eastern Equatorial Pacific Ocean. This reference simulation was used for comparison to other simulations which considered the effects of variations in wind stress and solar input for a homogeneous chlorophyll a profile and variations in the magnitude …

Iowa Academy Of Science Membership Directory, 1999-2000, Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Editorial Board, Journal ... 5
Committees ... 6
Sections ... 18
ISTS Regional Directors ... 22
Awards of Merit ... 24
Excellence in Science Teaching Awards ... 25
Past Presidents ... 26
Membership Roster ... 27
Corporate Sponsors ... 70

Evaluating Oral Histories For Restoration Ecology, Margaret Robertson

Theses : Honours

Significant ecological restoration is required in the agricultural regions of south-western Australia. Environmental history, including local knowledge based on long-term observation of the biophysical environment, can help guide this process. Scientists already use local anecdotal information because other information sources are absent or too recent, yet they are often skeptical of its veracity. This study focused on whether environmental oral histories can be evaluated for factual accuracy and their capacity to be useful in the restoration process. Some of the complexities associated with linking environmental histories with restoration ecology, and the role played by oral histories in establishing the link …

Field Methods To Enhance Degradation Of Nitrate In Surficial Soils, Urko Atxotegi Alegria

Dissertations and Theses @ UNI

An environmental field study was conducted from April to October 1998 in the Black Hawk County, Iowa. The main goal of the study was to find an appropriate field method to enhance degradation of nitrates in the surficial soil. Seven different methods were developed in the study to compare between four variables. The variables that were investigated were the source of nitrates, the moisture content of the soil, the uptake by plants and the total carbon content of the soil. The investigation has also been conducted to find out the specific influence of each parameter on landuse. A weather station …

Scienceworks: A University-Based Science Outreach Group, Rochelle Payne Ondracek, Diandra Leslie-Pelecky

Diandra Leslie-Pelecky Publications

ScienceWorks is a science and engineering outreach group at the University of Nebraska- Lincoln, comprised of faculty, graduate students, undergraduates and community volunteers. We are brought together by one goal - to make science fun and accessible for everyone. ScienceWorks has developed over 30 modules that emphasize a range of scientific and engineering topics and guide the participants in discovery-based learning. Modules cover a wide variety of topics, including pressure, materials, electromagnetism, archaeology, DNA, optics and fracture. Most ScienceWorks modules involve hands-on activities. In Electromagnetism for example, students are asked to use a length of wire and a nail to …

Affinity Chromatography: A Review Of Clinical Applications, David S. Hage

David Hage Publications

Affinity chromatography is a type of liquid chromatography that makes use of biological-like interactions for the separation and specific analysis of sample components. This review describes the basic principles of affinity chromatography and examines its use in the testing of clinical samples, with an emphasis on HPLCbased methods. Some traditional applications of this approach include the use of boronate, lectin, protein A or protein G, and immunoaffinity supports for the direct quantification of solutes. Newer techniques that use antibody-based columns for on- or off-line sample extraction are examined in detail, as are methods that use affinity chromatography in combination with …

The Carbon Cycle And Biogeochemical Dynamics In Lake Sediments, Walter E. Dean

United States Geological Survey: Staff Publications

The concentrations of organic carbon (OC) and CaCO₃ in lake sediments are often inversely related. This relation occurs in surface sediments from different locations in the same lake, surface sediments from different lakes, and with depth in Holocene sediments. Where data on accumulation rates are available, the relation holds for organic carbon and CaCO₃ accumulation rates as well. An increase of several percent OC is accompanied by a decrease of several tens of percent CaCO₃ indicating that the inverse relation is not due to simple dilution of one component by another. It appears from core data that …

Predation Of Artificial Ground Nests On White-Tailed Prairie Dog Colonies, Bruce W. Baker, Thomas R. Stanley, James A. Sedgwick

United States Geological Survey: Staff Publications

Prairie dog (Cynomys spp.) colonies are unique to prairie and shrub-steppe landscapes. However, widespread eradication, habitat loss, and sylvatic plague (Yersinia pestis) have reduced their numbers by 98% since historical times. Birds associated with prairie dogs also are declining. Potential nest predators, such as coyotes (Canis latrans), swift foxes (Vulpes velox), and badgers (Taxidea taxus), may be attracted to colonies where a high concentration of prairie dogs serve as available prey. Increased abundance of small mammals, including prairie dogs, also may increase the risk of predation for birds nesting on colonies. …

Atrazine Degradation In A Small Stream In Iowa, Dana W. Kolpin, Stephen J. Kalkhoff

United States Geological Survey: Staff Publications

A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment. Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and two of its initial biotic degradation products, desethylatrazine and deisopropylatrazine. Samples were collected on the basis of a Lagrangian model of streamflow in order to sample the same parcel of water as it moved downstream. Atrazine concentrations substantially decreased (roughly 25-60% ) between water entering and exiting the study reach …

Negative Ph, Efflorescent Mineralogy, And Consequences For Environmental Restoration At The Iron Mountain Superfund Site, California, D. Kirk Nordstrom, Charles N. Alpers

United States Geological Survey: Staff Publications

The Richmond Mine of the Iron Mountain copper deposit contains some of the most acid mine waters ever reported. Values of pH have been measured as low as -3.6, combined metal concentrations as high as 200 g/liter, and sulfate concentrations as high as 760 g/liter. Copious quantities of soluble metal sulfate salts such as melanterite, chalcanthite, coquimbite, rhomboclase, voltaite, copiapite, and halotrichite have been identified, and some of these are forming from negative-pH mine waters. Geochemical calculations show that, under a mine-plugging remediation scenario, these salts would dissolve and the resultant 600,000-m³ mine pool would have a pH of …

Trapping Considerations For The Fossorial Pocket Gopher, Gary W. Witmer, Rex Marsh, George Matschke

United States Department of Agriculture Wildlife Services: Staff Publications

Fossorial mammals such as the pocket gopher (Thomomys spp.) are well adapted to life in an underground closed burrow system. These animals can have considerable influence on ecosystems and can cause significant damage to agricultural crops, forest resources, and field machinery. The research and management of pocket gopher populations poses many challenges to land managers and research biologists. Both live-trapping for research purposes and kill trapping for control purposes are important tools for working with pocket gophers. Trapping can be an effective and efficient tool if the proper traps are used and trappers are trained to place traps properly …

Two-Photon Excitation Of Rhenium Metal-Ligand Complexes, Joseph R. Lakowicz, Felix N. Castellano, Ignacy Gryczynski, Zygmunt Gryczynski, Jonathan D. Dattelbaum

Chemistry Faculty Publications

We describe the emission spectral properties of two rhenium metal-ligand complexes with one and two-photon excitation, Re(bpy)₂(CO)₃Cl and [Re(bpy)(CO)₃CH₃CN]⁺, where bpy is 2,2’-bipyridyl and CH₃CN is acetonitrile. Similar emission spectra and intensity decay times characteristic of the metal-to-ligand charge transfer state were observed for one- and two-photon excitation. The lifetime and quantum yield of the acetonitrile complex are approximately 14-fold higher than that of the chloride complex. Both complexes display high anisotropies near 0.33 in frozen solution with one-photon excitation. Two-photon excitation results in anisotropies about 40% larger, …

Statistical Physics, Neural Networks, Brain Studies, Gerard Toulouse

Turkish Journal of Physics

An overview of some aspects of a vast domain, located at the crossroads of physics, biology and computer science is presented: 1) During the last fifteen years, physicists advancing along various pathways have come into contact with biology (computational neurosciences) and engineering (formal neural nets). 2) This move may actually be viewed as one component in a larger picture. A prominent trend of recent years, observable over many countries, has been the establishment of interdisciplinary centers devoted to the study of: cognitive sciences; natural and artificial intelligence; brain, mind and behaviour; perception and action; learning and memory; robotics; man-machine communication, …

Agriculture, Landscape And Human Impact In Some Karst Areas Of Italy, Ezio Burri, Benedetta Castiglioni, Ugo Sauro

International Journal of Speleology

Italy is made up for about 1/5 of its surface by soluble rocks, which represent the arena of karst environments. The karst morpho-units, some hundreds, are mainly distributed inside the alpine structure of the Mediterranean mountains. A very large number of rock formations are present, different in facies, lithology, age, etc. Among these, carbonate rocks prevail, followed by gypsum and salt. Most of the carbonate rocks are limestones sedimented in a platform environment and they show a wide range of porosity, frequency of fractures and bedding planes. The climatic processes, the expression of some different sub-types of Mediterranean climate (from …

Karst And Agriculture In Australia, David Gillieson, Mia Thurgate

International Journal of Speleology

Much of the development and degradation of karst lands in Australia has occurred in the last two centuries since European settlement. Recent prolonged El Niño events add further climatic uncertainty and place real constraints on sustainable agriculture. The lower southeast of South Australia is perhaps the one area in Australia where karst, and particularly karst hydrology, impinge on the daily lives of the community in that pollution and overexploitation of the aquifer are readily apparent to the local population. Effluent from intensive dairy farms, piggeries and cheese factories enters the karst and has caused concern over pollution of water supplies. …

Vitamin Effect On The Aerobic Biodegradation Of Phenanthrene, Antracene, Fluoranthene, And Pyrene In A Contaminated Soil From An Industrial Site, Ilkay Cam

Theses

Bioremediation of organic wastes is often a cost-effective technology for the in situ treatment of contaminated soils. In this study, the possibility of increasing the rate and extent of biodegradation for phenathrene, anthracene, fluoranthene, and pyrene in an industrial PAH contaminated soil via vitamin mixture supplementation was explored.

Soil contained with PAHs was obtainecl from the Bayway refinery site formerly owned by Exxon (Linden, NJ). Experiments were conducted in which the contaminated soil was amended with a mixtures of four vitamins (niacin, biotin, folic acid, and panthothenic acid). Peat moss, a common soil amendment, was also added in some experiments. …

Sub-Lethal Effects Of Hypoxia/Hypercapnia On Callinectes Sapidus In The York River Estuary, Virginia, Sandra R. Hypes

Theses and Dissertations

This research examined effects of hypoxic environments on blue crabs, Callinectes sapidus in an estuarine environment. Hypoxic conditions were treated as a multiple stressor involving low dissolved oxygen (D.O.), increased carbon dioxide (hypercapnia), and low pH concurrently. The objectives were to: 1) identify hypoxiahypercapnia by monitoring D.O. and pH as an indicator of hypercapnia in shallow regions of the York River, 2) measure blue crab abundance, and 3) describe blue crab responses to hypoxiahypercapnia via field work at Taskinas Creek and lab measurements of respiration. Ambient D.O. and pH were positively correlated in the Taskinas Creek and York River sites …

Photodecolorization And Photodegradation Of Crystal Violet Adsorbed On Metal Oxide Surfaces, Reygan Mashay Freeney

Dissertations and Theses @ UNI

The photodecolorization and the photodegradation of the triphenylmethane dye crystal violet (basic violet 3) adsorbed on four metal oxide catalysts was studied. Crystal violet dissolved in methanol was adsorbed onto the surfaces of an anatase and rutile titanium dioxide mixture, rutile titanium dioxide, zinc oxide, and magnesium oxide, and the solvent was allowed to evaporate. The samples were irradiated using a 1000 W mercury-xenon arc lamp with glass optics as a light source. A wide spectrum and narrow regions of the spectrum were studied to determine their impact on the decolorization and degradation of crystal violet. Diffuse reflectance spectroscopy was …

Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

We study the adsorption, including wetting, of a Lennard-Jones gas on a rough surface consisting of rough layer on a smooth substrate with which the gas interacts via a 9-3 potential. The rough layer is two molecular diameters thick and consists of a disordered quenched matrix of hard spheres. As well as interacting with the other matrix spheres by the hard-sphere potential, the matrix molecules interact with the gas molecules by the hard-sphere potential. Hence, on average, the degree to which the gas molecules can approach the substrate depends only on the density of the matrix layer. The density of …

Apex: Cross-Platform Analysis Program For Exafs, Nicholas Dimakis, Grant Bunker

Physics & Astronomy Faculty Publications

We have developed version 1.0 of a freely available (including source code) suite of basic X-Ray Absorption Fine Structure (XAFS) data analysis programs for data reduction and single scattering analysis. This package is based on the University of Washington (UW/NRL) Fortran 77 programs that are available on the International XAFS Society (IXS) database, complemented by a graphical TCL/TK scripting language based user interface which runs virtually unchanged between platforms, using the native look and feel of the corresponding platform. The package has been tested on MacOS 8.1, Linux, IRIX, Windows95 and NT. Particular emphasis is placed on simplicity, reliability, and …

Nitrate Attenuation In A Narrow Non-Forested Riparian Buffer Zone In An Agricultural Watershed In Southern Ontario, Mark David Harris

Theses and Dissertations (Comprehensive)

Riparian buffer zones are defined as strips of natural vegetation separating streams or lakes from surrounding upland landscapes. These zones may effectively reduce the nitrate-N load in shallow ground water draining intensively fertilized agricultural regions. Contemporary research has tended to focus on wide, forested riparian zones situated on poorly drained lowland sites. In addition, research has typically focused on the growing season, when the ecosystem is biologically active, with relatively day hydrological conditions. This field study monitored spatial and temporal patterns of nitrate-N in a comparatively narrow, non-forested buffer zone situated in an upland agricultural watershed in southern Ontario. Results …

Regional Ecology Of The St. Elias Mountain Parks: A Synthesis With Management Implications (British Columbia, Yukon, Alaska), Ryan Kenneth Danby

Theses and Dissertations (Comprehensive)

The St. Elias region of North America occupies portions of British Columbia, Alaska, and the Yukon Territory and comprises a network of public lands and protected areas managed by a variety of agencies. This thesis characterizes and analyzes the broad- scale, or regional, ecology of these lands and provides an assessment of the implications this has for ecosystem-based management—particularly as it relates to intergovernmental cooperation. A multi-stage, map-based, multidisciplinary process is used to synthesize information on the region’s physical, biological, and institutional environments. The fields of conservation biology and landscape ecology provide theoretical foundations for analysis. The ecological synthesis and …

Quantitation Of Pyrethrum Residues In Brown Tree Snakes, John J. Johnston, Carol A. Furcolow, Stephanie A. Volz, Richard E. Mauldin, Thomas M. Primus, Peter J. Savarie, Joe E. Brooks

United States Department of Agriculture Wildlife Services: Staff Publications

A reversed-phase solid-phase extraction–gas chromatography (SPE–GC)–electron capture detection method is developed to quantitate individual rethrin residues in pyrethrum-exposed brown tree snakes. Aliquots (6 g) of homogenized snake tissue are extracted with 10 mL acetonitrile. The rethrins are recovered from the acetonitrile extract and concentrated using C₈ SPE. The rethrins are eluted from the SPE column with pentane, evaporated to near dryness, and reconstituted to 1 mL with 1-propanol. Individual rethrins are quantitated using GC analysis of the 1-propanol solution. Method limits of detection for rethrins range from 0.63 to 6.51 ng/g. The mean recovery for all rethrins is 70.8% …

Changes In Early Winter Abundance Of Four Gull (Larus) Species On Western Lake Erie, 1951-1995, Laura A. Tyson, Richard A. Dolbeer, Jerrod L. Belant

United States Department of Agriculture Wildlife Services: Staff Publications

Many gulls (Larus spp.) that nest on and north of the Great Lakes concentrate along the south shore of western Lake Erie in early winter. Monitoring population trends of these gulls is important because of increasing conflicts between gulls and humans. We used data from four Christmas Bird Count locations to examine population trends of four gull species on western Lake Erie during nine 5-year periods, 1951-1995. Overall, ring-billed gulls (Z. delawarensis} were the dominant species (59% of gulls counted) followed by herring (Z. argentatus, 20%), Bonaparte's (Z. Philadelphia, 18%) and great blackbacked (Z. marinus, 0.2%) gulls. Ring-billed gulls displayed …

Impact Of Snowfall On The Utah Preventive Aerial Hunting Program, Kimberly K . Wagner, Michael R. Conover

United States Department of Agriculture Wildlife Services: Staff Publications

Aerial hunting is one of the tools used by wildlife managers to reduce predation by coyotes (Canis latrans) on livestock and wildlife (Guthery and Beasom 1977, Sterner and Schumake 1978, Stout 1982. Smith et al. 1986). In research conducted by Wagner and Conover (1999), areas with preventive aerial hunting had fewer confirmed and estimated lamb losses to coyote predation and required significantly fewer hours of additional corrective predation management than areas without aerial hunting. Aerial hunting is perceived to be especially valuable for large areas and areas with rough terrain and limited access (United States Department of the …

Effective Of Preventive Coyote Hunting On Sheep Losses To Coyote Predation, Kimberly Wagner, Michael Conover

United States Department of Agriculture Wildlife Services: Staff Publications

Aerial hunting is commonly used by agriculture agencies in the Intermountain West to reduce coyote (Canis latrans) predation on domestic sheep. We assessed the effect of aerial hunting of coyotes on sheep losses to coyotes, and the need for corrective predation management (hours of work, device nights) on the same pastures when sheep arrived for the subsequent summer grazing season (3-6 months after aerial hunting). Comparisons were made between paired pastures with (treated) and without (untreated) winter aerial hunting from helicopters. Average (x ± SE) pasture size was 45.2 ± 14.1 km² (n = 21) for treated …

Use Of Netted Cage Traps For Capturing White-Tailed Deer, Kurt C. Vercauteren, Jeff Beringer, Scott E. Hygnstrom

United States Department of Agriculture Wildlife Services: Staff Publications

The safe and humane live capture of deer may be an important component of management and research projects. Growing populations of white-tailed deer (Odocoileus virginianus) in both urban and agricultural settings often conflict with local human interests and present challenges to natural resource managers. Netted cage traps can be an important tool when managing deer populations where traditional control methods may not be appropriate or acceptable. Netted cage traps can also be used by researchers to acquire deer for marking, measurements, or other non-lethal purposes. We discuss the design of netted cage traps, trapping techniques, and the handling …