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Active Site Chemistry Of The Nadph-Dependent:7-Cyano-7-Deazaguanine (Preq0) Nitrile Oxidoreductase, An Enzyme Involved In Queuosine Biosynthesis, Bobby Wai Keung Lee

Dissertations and Theses

Queuosine (Q) is a modified nucleoside found at the wobble position of bacterial and eukaryotic transfer RNAs (tRNAs) that are specific for the amino acids tyrosine, histidine, aspartate and asparagine. A recently discovered enzyme in the biosynthetic pathway of Q, the NADPH-dependent 7-cyano-7-deazaguanine oxidoreductase (QueF), carries out the two-fold, four-electron reduction of Q precursor preQ0 to preQ1 and represents the first example of the enzymatic conversion of the nitrile functional group to an amine. Presented herein are kinetic, spectroscopic, mutational, biophysical, and isotope labeling studies directed at the elucidation of the chemical and kinetic mechanisms of this new class of …

Shrinking The Janzen-Connell Doughnut: Consequences Of An Invasive Multiplier (Microstegium Vimineum) On The Mid-Canopy In A Mixed Pine-Oak Forest, Rebekha Shaw

Theses and Dissertations

Introduction of invasive species can alter seed fate predictions made by the Janzen-Connell Escape Hypothesis (JCEH). The JCEH states that there is a suitable region around a plant that is ideal for seed germination, growth, and recruitment. Seeds dispersed too close to the maternal plant are subject to competition from the maternal individual and perhaps density-dependent predation, whereas seeds dispersed further away may end up in suboptimal habitats. Invasive species may change the amount of these suitable habitats for native plants by creating unsuitable light environments and as a result, may influence the size of the ideal recruitment zone surrounding …

Seedlings’ Substrate Preferences In A Minnesota Old Growth Thuja-Betula Forest, Stephen C. Rossiter

Environmental Studies Honors Papers

Northeastern Minnesota’s logging history has altered the forests enough to cause concern about the reproduction of Thuja occidentalis and Betula alleghaniensis. I studied a rare old growth example of an already rare mesic Thuja-Betula forest and asked how well those species were regenerating in that mostly unaltered ecosystem. In managed forests, a lack of suitable substrate is thought to be limiting their seedling establishment so I asked which substrates the seedlings preferred in the old forest. To answer both questions, I measured the seedling densities of all canopy tree species across height classes and substrate types within twenty 100m2 plots. …

Avian Foraging Patterns In Crop Field Edges Adjacent To Woody Habitat, Heidi L. Puckett, James R. Brandle, Ron J. Johnson, Erin E. Blankenship

School of Natural Resources: Faculty Publications

As natural predators of pest insects, woodland birds provide biological pest suppression in crop fields adjacent to woody edges. Although many birds using these habitats forage widely, earlier studies have found that most foraging activity occurs within 50 m of the woody edge. The goals of this study were to determine the primary area of use, or functional edge, for birds foraging in crop fields adjacent to woody edges, and to evaluate their foraging distance patterns. During the summers of 2005 and 2006, avian foraging behavior was observed at 12 research sites in east central Nebraska that contained either a …

Fisheries Research Report No. 184 - Macroscopic And Microscopic Description Of Snapper (Pagrus Auratus) Gonads From Shark Bay, Western Australia, Michael C. Mackie, Gary Jackson, Nadia E. Tapp, Jeffrey V. Norriss, Adrian Thomson

Fisheries Research Reports

Since 1997, research on snapper (Pagrus auratus, Sparidae) in the inner gulfs of Shark Bay has focussed on providing biological information required for the management of the regionally important recreational fishery. A major component of this research has been a comprehensive investigation of snapper reproductive biology to determine size and age at maturity, the timing of the spawning season and to estimate batch fecundity. This research has necessitated a review of the macroscopic staging system used for P. auratus in Western Australian waters and the development of a more detailed microscopic system to allow accurate analyses of histological material. Based …

Fisheries Research Report No. 192 - Determination Of A Cost Effective Methodology For Ongoing Age Monitoring Needed For The Management Of Scalefish Fisheries In Western Australia, Montgomery Craine, Ben Rome, Peter Stephenson, Brent S. Wise, D J. Gaughan, R Lenanton, Richard A. Steckis

Fisheries Research Reports

Final FRDC Report – Project 2004/042

Objectives

1. Determine for the 20 major WA scalefish species (4 - 5 in each bioregion) the relative accuracy of structures used to estimate age (e.g. Sectioned/whole otoliths, lengths, otolith weight, other otolith dimensions or some combination of these).

2. For each stock, examine the relative impact on the calculated age-compositions and their effect on model outputs and conclusions from varying (i) the method of ageing used (only where this is possible from available data) (ii) the number of individuals used in the samples (iii) the spatial distribution of the samples used (iv) if …

Biogeochemical Behavior Of Dissolved Arsenic And Uranium Concentrations In Public Water Supply Wells, Kevin J. Mcvey

School of Natural Resources: Dissertations, Theses, and Student Research

Public water supply (PWS) wells currently contain dissolved uranium concentrations above the federally mandated maximum contaminant level (MCL) of 30 ppb (parts per billion) and dissolved arsenic concentrations above the 10 ppb MCL. Both uranium and arsenic are known to cause various forms of cancer in humans. Variations in total uranium concentrations in PWS wells in Nebraska indicate a relationship to the duration and rate of pumping in specific wells. Although total arsenic concentrations show some variability over time in specific wells, the relationship to pumping is not as clear. Previous studies show that iron and sulfur bacteria present in …

Refuge Update – May/June 2009, Volume 6, Number 3

RefugeUpdate (USFWS-NWRS)

Table of Contents:
Recovering the New England Cottontail
FOCUS..Ready for Tomorrow
Build It and They Will Come
CARE: Restoring America’s Wildlife Refuges

Stratigraphy And Geochemistry Of Squantum Tillite, Boston Bay Group : Using Field Log And Icp Analysis, Efe Junior Erukanure

Theses, Dissertations and Culminating Projects

The Squantum Tillite has been studied in order to ascertain its depositional history. The Squantum Tillite is part of the Neoproterozoic Boston Bay Group, located in the Boston Basin. Researchers have proposed contradicting hypotheses about the origin of the rocks in the area for over a century. While some believe that the rocks were deposited by glaciers along a prograding submarine margin, others believe the rocks are of volcanic or tectonic origin. Many scientists are inclined to believe the rocks are of tectonic origin because the Squantum Tillite is located in a tectonic Basin (the Boston Basin).

Field logging was …

Indiana Wildlife Disease News, Volume 4, Issue 2 – May 2009

Indiana Wildlife Disease News

Inside this issue:
• Bovine TB
• &#; Wabash River Sturgeon
• &#; 2009-2010 AI surveillance season changes
• &#; Rabies prophylaxis
• 2008-2009 AI surveillance summary
• Wabash River Sturgeon research
• Changes to AI Surveillance
• No TB in wild deer in Indiana
• Pre-exposure rabies prophylaxis available
• Indiana 2008-2009 AI surveillance summary
• Midwest Wildlife Disease Update

Management Of Grassy Balds Communities In The Roan Highlands, James T. Donaldson, Nora Schubert, L. C. Huff

ETSU Faculty Works

The Highlands of Roan Mountain best exemplify that which is rare and unique within high elevation communities of the Southern Appalachian Mountains. The Roan Highlands are protected through a landscape-level conservation initiative originally established by the Southern Appalachian Highlands Conservancy (SAHC) and the U. S. Forest Service (USFS) in 1974. The Roan massif rises more than 6,000 feet above mean sea level and straddles the border of North Carolina and Tennessee in the Pisgah and Cherokee National Forests, respectively. Among its unique aspects, the Roan supports at least 800 known plant species, 27 rare plant communities, and 33 federally or …

A Sedimentary Investigation Of Lineation Patterns Found In The Pinelands Of New Jersey, Jennifer Lynn Lapoma

Theses, Dissertations and Culminating Projects

Late Pleistocene (-15,000 years ago) geomorphic processes in the Pinelands of southern New Jersey were investigated after odd lineations were found on an Electromagnetic Induction (EMI) survey during the construction of a runway expansion at Lakehurst Naval Air Engineering Station. These lineations roughly matched up with alternating high and low albedo lineations identified on a 1931 aerial photomosaic approximately 17 kilometer (km) south of Lakehurst Navy Base in Davensport Branch, New Jersey. These lineations were initially hypothesized to be relicts from strong katabic winds flowing off the Laurentide Ice Sheet that would have been capable of winnowing magnetic sands from …

Testing The Individual Effective Dose Hypothesis, Hung Vu

All Theses

The assumption of the individual effective dose is the basis for the probit method used for analyzing dose or concentration – response data. According to this assumption, each individual has a uniquely innate tolerance expressed as the individual effective dose (IED) or the smallest dose that is sufficient to kill it. An alternative to IED, stochasticity suggests that individuals do not have uniquely innate tolerance; deaths result from random processes occurring among similar individuals. While the probit method has been used extensively in toxicology the underlying assumption has not been tested rigorously. The goal of this study was to test …

Whole Foods: Renewable Energy Credits, Green Business, And Capitalist Approaches To Climate Change, Samantha Kanofsky

Pomona Senior Theses

Dedication. Acknowledgements. Preface. Chapter 1: Introduction. Chapter 2: Green Business and Carbon Offsetting. Chapter 3A: Case Study. Chapter 3B: Interview. Chapter 4: Case Study. Chapter 5: Conclusion. Bibliography.

Substrate Monitoring, Contaminant Monitoring, And Educational Outreach On Quagga Mussels (Dreissena Bugensis) In Lake Mead, Nevada, Sara Ann Mueting

UNLV Theses, Dissertations, Professional Papers, and Capstones

The invasive species, the quagga mussel, Dreissena bugensis, was found in Lake Mead, Nevada-Arizona, USA on January 6, 2007. Since then, researchers have been attempting to quantify the amount of damage these mussels will cause to the lower Colorado River basin. Three projects were implemented in this thesis to research the quagga mussel in Lake Mead. First, a study to determine which types of substrates quagga mussels will grow on preferentially was conducted. Six different substrates, Acrylonitrile Butadiene Styrene (ABS) plastic, High Density Polyethylene (HDPE) plastic, Concrete Underlayment Board (CUB), aluminum, stainless steel and fiberglass, were placed in the Boulder …

The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focuses on two issues in enhanced biological phosphorus removal (EBPR). The first issue encompasses the effect of the type of carbon sources (i.e. volatile fatty acids and non volatile fatty acids) on the microbiology of EBPR. The second issue deals with the influence of denitrification on EBPR. Few studies have been performed to investigate these two issues. The recent findings on these areas are summarized below to establish the knowledge gaps this dissertation attempted to address. Details on the specific findings can be found in the literature review portion of this proposal.

Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Springs Preserve near downtown Las Vegas, Nevada contains a seven-acre constructed wetland. Springs Preserve managers are planning to use water from the constructed wetland to irrigate creeks immediately north of the wetland. These creeks will be used by a variety ofaquatic wildlife, including endangered amphibians sensitive to harmful metalloids, such as selenium, lead, and arsenic.

In an attempt to answer toxicological questions about contaminant concentrations in the constructed wetland, three metals and metalloids (selenium, arsenic, and lead), two nutrients (nitrogen and phosphorus), and the major ionic species were analyzed at four sampling locations for aqueous concentrations, in two separate …

Improving Success Of Translocating Southern Idaho Ground Squirrels (Spermophilus Endemicus), Katie Lea Busscher

Boise State University Theses and Dissertations

Populations of the southern Idaho ground squirrel (Spermophilus endemicus; SIDGS), a federally listed candidate species, have declined in the last 30 years mainly because of habitat degredation, loss, and fragmentation. As a management tool, translocation is commonly used to augment, establish, or re-establish wildlife populations, although translocation has historically not been the most successful conservation strategy for species that are threatened or endangered animals as a result of habitat loss. I employed various techniques to improve translocation success of southern Idaho ground squirrels. To establish new populations, I relocated SIDGS to areas within their native range not already occupied by …

Understanding Polycyclic Aromatic Hydrocarbon Degradation By Soil Microbial Communites: The Concentration And Distribution Of Aromatic Dioxygenase Genes, Inigo Walker Howlett

Masters Theses and Doctoral Dissertations

The ability to individually identify and enumerate bacterial genes in the environment is an important development in the field of microbial ecology. Researchers are now able to quantify and map populations and communities, the presence of which could only be inferred until recently. Knowledge of this ecology is critical to understanding microbial responses to environmental pollutants, thereby contributing information useful in devising and monitoring bioremediation strategies. The following thesis therefore compares two aromatic dioxygenase genes, nidA and nahAc, which confer the ability for the bacteria carrying the genes to metabolize polycyclic aromatic hydrocarbons (PAHs), persistent pollutant byproducts of coal coking. …

Local Effects Of Culverts On Habitat Features And Fish Assemblages In Blue Ridge Streams, Daniel Huser

Masters Theses and Doctoral Dissertations

I studied environmental conditions, fish assemblages, and culvert features in 11 headwater streams (Tennessee and Conasauga river drainages) in Cherokee National Forest (Blue Ridge ecoregion), Tennessee, May-August 2008. Culvert-related effects on instream habitat and fish assemblages were measured at 10 stream sites: five sites contained culverts with artificial bottom substrates and five sites contained culverts with natural bottom substrates. On each stream, paired sampling reaches (reach length ~35 times mean reach width, drainage area <11 km 2) were established 50 m upstream and 50 m downstream of the culvert. Reaches downstream of culverts with artificial substrates (compared to upstream reaches; related-samples t test) exhibited greater water depths, lower gravel/sediment depths, and higher percentages of bedrock and boulder substrates (P < 0.10). Reaches downstream of natural substrate culverts (compared to upstream reaches) exhibited faster current velocities (P < 0.10). Fish abundance (predominantly western blacknose dace Rhinichthys obtusus) was consistently higher downstream than upstream (P < 0.10), regardless of the culvert type. In addition, reaches downstream of artificial substrate culverts exhibited reduced species evenness compared to upstream reaches. Mark-recapture experiments on two streams documented fish movements through a natural substrate culvert (similar to those in reference areas); however, movements through a perched pipe culvert were not detected. Data collected i n the present study suggest that culverts had localized effects on instream habitat and fish assemblages, and that certain types of culverts may impede fish dispersal.

Effects Of Urbanization On Instream Habitat And Fish Assemblages In The Chattanooga Metropolitan Area, Tennessee-Georgia, Joshua Smith

Masters Theses and Doctoral Dissertations

Twenty-one stream sites in the Ridge and Valley ecoregion of Tennessee and Georgia were studied in 2008 to evaluate the effects of watershed urbanization on instream environmental parameters and fish assemblages. I also investigated changes in urbanization and stream conditions at 10 sites over a 10-year period (1998-2008). Electrofishing yielded 12,329 fish, composed of 38 species from eight families. Urbanization in the study watersheds was measured (using ArcGIS 9.3; released June, 2008) by calculating the building density and percent urban land use. Correlation analysis revealed that more urbanized watersheds were characterized by increased proportions of fine sediments and pool areas, …

Spatial Ecology Of Raccoons Related To Cattle And Bovine Tuberculosis In Northeastern Michigan, Todd C. Atwood, Thomas J. Deliberto, Holly J. Smith, Justin S. Stevenson, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

In 1995, Mycobacterium bovis, the causative bacterium of bovine tuberculosis (bTB), was detected in 5 beef cattle operations in Alcona County, Michigan, USA. In accordance with Federal law, the operations were depopulated to prevent the spread of bTB. Subsequent wildlife surveillance programs identified high prevalence of M. bovis in mesocarnivores, including raccoons (Procyon lotor), which suggested that raccoons may be complicit in vectoring the pathogen among livestock operations. Our goal was to develop an empirical basis for generating hypotheses about the likelihood for raccoons to mediate the transmission of bTB to livestock. We found intersexual differences in scale-dependent …

Development Of An Original Laboratory Prototype For A Field Tritium Detector Containing A Pem Electrolyzer Mounted In Series With A Gas Proportional Counter, Aurelie Soreefan

All Dissertations

Tritium is naturally present in very small concentrations in the environment, principally in the form HTO. Thermonuclear detonations, leaks from waste tanks at the Department of Energy (DOE) sites and accidental releases from nuclear power plants have introduced significant quantities of tritium into the environment. Even though tritium is the least toxic of the known beta emitters, its presence in the environment, primarily in the aqueous form, poses a radiological threat because of its easy accessibility. Tritium removal from the environment is technologically impractical. Thus tritium contamination is generally contained, decays in place and is monitored to protect the public …

Recovery Of Fathead Minnows (Pimephales Promelas) Following Episodic Copper Exposure: A Biochemical, Physiological, Individual, And Population Perspective, Holly Zahner

All Dissertations

The US EPA utilizes the Biotic Ligand Model (BLM) when developing site-specific water-quality criteria for copper. The BLM was calibrated using toxicity data from fixed duration continuous exposures (48 or 96h LC50). However, exposures of copper in natural aquatic systems typically vary in concentration, duration, and may occur multiple times over the life-span of an organism. Additionally, organisms will experience periods in copper free water, potentially allowing them to detoxify and recover homeostasis. Yet, the BLM framework does not consider brief exposures (<24h), multiple exposures, latent responses, or organism recovery, potentially resulting in an inaccurate assessment of exposure toxicity. A recently proposed physiologically-based addition to the BLM will extend the applicability of the framework to brief, multiple pulse copper exposures. Thus, the overall goal of this research was to characterize the recovery of larval Pimephales promelas following episodic copper exposure at a biochemical, physiological, individual, and population level.
The response of whole-body sodium, whole-body Na+/K+-ATPase, and whole-body carbonic anhydrase in larval P. promleas was quantified …

Predicting The Growth Potential Of A Shallow, Warm-Water Sport Fishery: A Spatially Explicit Bioenergetics Approach, Samuel Kirk Dahle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Capturing the range of fish consumption and growth potential of large, heterogeneous lentic systems can be challenging due to strong gradients in productivity, the diversity of habits types present, and in some cases, site-specific water quality issues. Cutler Reservoir (Utah, USA) displays a high degree of spatial and temporal variation in physical conditions and potential water quality limitations for fish, including high summertime water temperature and large, diel fluctuations in dissolved oxygen concentrations. The combination of bioenergetics modeling and GIS spatial analysis offers a promising interface for quantifying the fish consumptive and growth potential across a spatially and temporally heterogeneous …

Watershed-Scale Analysis Of Riparian Buffer Function, Molly Van Appledorn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability of riparian buffers to filter undesirable nutrients from upland sources has long been recognized as an important ecosystem service for maintaining or improving water quality, and as a result, many land management strategies have been built around the preservation or restoration of buffer zones. Newly derived flow-path metrics have shown great promise as a way to assess riparian buffer function at the watershed scale but a thorough investigation of metric performance was necessary. The goals of this study were to: 1) test the independence of flow-path metrics from traditional metrics using a spatially extensive, independent sample of watersheds, …

Nitrogen Transport, Transformation And Cycling Through A Mountain Lake, Bull Trout Lake, Idaho, Usa, Ryan Settle Lockwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of a mountain lake on nitrogen dynamics in a sub-alpine watershed were examined via watershed monitoring, mesocosm experiments, microcosm experiments, and enzymatic assays during spring and summer of a single year. Our study addressed the questions: (1) How does hydrologic transport through the lake affect the net fluxes of dissolved nitrogen (N) species? (2) What are the net effects of the littoral zone biota on dissolved N fluxes? (3) What are the seston and benthic uptake rates of nitrate? (4) What is the magnitude of N retention in littoral zone sediments? (5) What role does microbial hydrolysis of …

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …

Exploring The Spawning Dynamics And Identifying Limitations To The Early Life-History Survival Of An Important, Endemic Fish Species, Sara Elizabeth Seidel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For many native, imperiled salmonid species, the prioritization of recovery and conservation efforts hinges upon the identification of a species most limiting life stage. The early life-history stage can be a limiting life stage for fish, and given the importance of the reproductive stage to overall persistence, there is a need to better understand the spawning ecology and early life history of many salmonids. The Logan River, in northern Utah, contains one of the largest metapopulations of imperiled Bonneville cutthroat trout (BCT) throughout the Bonneville Basin. Little research has evaluated the temporal and spatial distribution of BCT spawning nor quantified …

Ecotourism In Dominica: Studying The Potential For Economic Development, Environmental Protection And Cultural Conservation, Vanessa Slinger-Friedman

Faculty Articles

Over the last 20 years, the government of the small Caribbean island nation of Dominica has pursued the development of ecotourism on the island. The hope is that this industry will promote dispersed economic development while providing environmental protection and cultural conservation. However, not enough has been done to determine whether or not the industry is achieving the desired results. To this end, this study explores the growth of the tourism industry on Dominica and shows that, while not perfect, ecotourism is providing some definite benefits to the island in this regard.