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Detection And Enumeration Of Bacterial Pathogens In The American Oyster (Crassostrea Virginica), Mohammad Maruf Billah

Theses and Dissertations

American oyster (Crassostrea virginica) is a popular seafood for its delicacy and high nutritional value. Based on increasing concern about contamination of bacterial pathogens in raw oyster, my research objectives have been focused on detection and enumeration of two important bacterial pathogens, Escherichia coli and Salmonella spp. in the American oyster in south Texas waters, local markets and controlled laboratory studies. Immunohistochemical and RT-PCR analyses showed substantial bacterial pathogen’s presence in gills and digestive glands of oysters collected from San Martin Lake and South Padre Island as well as local markets. Laboratory studies showed increasing trend of both …

Storm Sampling To Assess Inclement Weather Impacts On Water Quality In A Karst Watershed: Sinking Creek, Watauga Watershed, East Tennessee, Porcha Mccurdy

Electronic Theses and Dissertations

Escherichia coli changes in Sinking Creek, an impaired water body in the Watauga watershed of northeast Tennessee, were assessed during storm events using water samples collected with ISCO automated samplers during eight storms at two locations. Turbidity and electrical conductivity (EC) data loggers were deployed in the creek, and dissolved oxygen (DO) was measured in situ to test the stream’s water quality and reaction to inclement weather. Cotton fabric was deployed at both locations and sent to an external lab to test for the presence of Optical Brighteners (OB), which are indicators of residential wastewater. E. coli and turbidity at …

Adjusting The Lens Of Invasion Biology To Focus On The Impacts Of Climate-Driven Range Shifts, Piper D. Wallingford, Toni Lyn Morelli, Jenica M. Allen, Evelyn M. Beaury, Dana M. Blumenthal, Bethany A. Bradley, Jeffrey S. Dukes, Regan Early, Emily J. Fusco, Deborah E. Goldberg, Inés Ibáñez, Brittany B. Laginhas, Montserrat Vilà, Cascade J.B. Sorte

United States Geological Survey: Staff Publications

As Earth’s climate rapidly changes, species range shifts are considered key to species persistence. However, some range-shifting species will alter community structure and ecosystem processes. By adapting existing invasion risk assessment frameworks, we can identify characteristics shared with high-impact introductions and thus predict potential impacts. There are fundamental differences between introduced and range-shifting species, primarily shared evolutionary histories between range shifters and their new community. Nevertheless, impacts can occur via analogous mechanisms, such as wide dispersal, community disturbance and low biotic resistance. As ranges shift in response to climate change, we have an opportunity to develop plans to facilitate advantageous …

Survival Of Off-Host Rhipicephalus (Boophilus) Annulatus (Acari: Ixodidae) Larvae In Study Arenas In Relation To Climatic Factors And Habitats In South Texas, Usa, Emily Jesselle Zamora

Theses and Dissertations

The cattle fever tick, Rhipicephalus (Boophilus) annulatus (Say), is an economically destructive arthropod because of its ability to vector bovine babesiosis. Cattle fever ticks can spend more than 90% of their life cycle as questing larvae, but the effect of climatic factors on their off-host behavior and survival is unclear. The goal of this study was to measure the effects of specific ecological factors on off-host larvae in nature. The study was conducted in a south Texas pasture over a 20-mo period, during which time larval populations were surveyed and ambient weather variables - relative humidity and temperatures – were …

A Tale Of Two Species: Black-Tailed And White-Tailed Prairie Dog Biogeography From The Last Interglacial To 2070, April Dawn Bledsoe

Electronic Theses and Dissertations

Ecological niche models (ENMs) were created for White-tailed and Black-tailed prairie dogs and projected into the Last Interglacial (LI), the Last Glacial Maximum (LGM), and mid-Holocene (mid-H) to discern possible past suitable habitat for both species. Additionally, ENMs were projected into the future year 2070 representative concentration pathways (RCPs) 2.6 and 8.5 to discern how climate change may affect future habitat suitability. Kernel density estimations, minimum convex polygons, and median distribution centers of White-tailed and Black-tailed occurrence records were examined between time-periods to discern the effects of anthropogenic westward expansion on both species’ distributions. Current ENMs were constructed from commonly …

Downstream Survival Of Total Bacteria, Escherichia Coli And Salmonella Spp. In Sinking Creek And Evaluation Of The Effectiveness Of The Implemented Constructed Wetland, Blaire Brooks

Undergraduate Honors Theses

Access to good quality, pathogen-free water is a necessity for human life. Pathogencontaminated water poses a threat to human health, and steps must be taken to minimize that risk using remediation techniques, such as constructed wetlands. Sinking Creek is a tributary of the Watauga River that was placed on the 2016 303(d) list published by the Tennessee Department of Environment and Conservation due to the presence of Escherichia coli. Because of this impairment, a constructed wetland was placed in Sinking Creek to decrease the downstream transport of pathogens. Knowing this, three primary goals were made for this experiment. The first …

The Importance Of River Influx And Pump Storage Operation On Water Quality In A Storage Reservoir, Ethan Batchelor

Undergraduate Theses and Capstone Projects

Pump storage hydroelectricity is a system built by power companies where a dam separating an upper and lower reservoir is used in power generation by passing water between both reservoirs. Environmental regulations require a minimum of 5mg/L of dissolved oxygen be maintained at all times passing through each dam. In central Virginia, American Electric Power operates a hydroelectric Pump Storage Project that includes an upper reservoir, Smith Mountain Lake (SML), and a lower reservoir, Leesville Lake (LL). Unique to this system is the influx of high concentrations of nutrients and other pollutants into the upper reaches of Leesville Lake from …

The Relationship Between Urbanization In The Blackwater Creek Watershed And Potentially Toxic Elements In Sediment, Hannah Chapman

Undergraduate Theses and Capstone Projects

The sediment layers of previously identified, impaired sites in the Blackwater Creek watershed in Central Virginia were examined for potentially toxic elements (PTEs). These impaired sites are located in areas with high levels of urbanization or impervious surface cover. Higher urbanization levels should coincide with more environmental degradation, resulting in higher levels of PTEs, such Cu, Zn, and Pb in the sediment cores. The sediment cores were collected, prepared by microwave digestion, and analyzed by MP-AES (microwave-induced plasma atomic emission spectroscopy) for PTE content. A one-way analysis of variance (ANOVA) determined a statistically strong relationship between increased impervious surface cover …

Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations of groundwater in a former industrial perchlorate manufacturing site have shown high contamination with perchlorate, chlorate, nitrate, hexavalent chromium (Cr (VI)), and chloroform (CF) with levels greater than 3,000, 30,000, 300, 100, and 4 mg/L, respectively. Remediation efforts using biological reduction to desired contaminant levels at this site has been challenging due to high contaminant concentrations, and high total dissolved solids (TDS). Furthermore, removal of Cr(VI) and CF in the presence of nitrate, chlorate, and perchlorate has not been examined at the contaminated site. Nano-scale Zero-Valent-Iron (NZVI) has been effective at reducing groundwater contamination both with and without bacterial …

The Research And Analysis Of Potential Gray Wolf (Canis Lupus) Habitats And Gray Wolf Management In The U.S., Youhan Mei

Department of Environmental Studies: Undergraduate Student Theses

The Gray Wolf (Canis lupus) is a keystone species that have significant impacts on the ecosystem where they belong. They used to have a wide range of habitat across the whole of North America. In 1960, the wolves were treated as threats to the safety of humans and livestock. They were wiped out by the government of the day and only had few populations left in Minnesota and Michigan. Today, there are identified in the “Red List) of International Union for Conservation of Nature as endangered species all around the U.S. This shows the urgent need for conservation, …

Habitat Suitability And Distribution Potential Of Liberibacter Species (“Candidatus Liberibacter Asiaticus” And “Candidatus Liberibacter Africanus”) Associated With Citrus Greening Disease, Inusa Jacob Ajene, Fathiya Khamis, Barbara Van Asch, Gerhard Pietersen, Brenda Amondi Rasowo, Sunday Ekesi, Samira Mohammed

All Peer-Reviewed Publications

Aim: To quantify current and predict future distribution of the citrus greening pathogens “Candidatus Liberibacter asiaticus” (Las) in Africa and “Candidatus Liberibacter africanus” (Laf) globally. Location: Africa. Methods: Three species distribution models (MaxEnt, BIOCLIM and Boosted Regression Trees) were used to predict the current and future potential distribution of Las in Africa, and the potential global distribution of Laf, using long-term bioclimatic variables. Two climate change scenarios (moderate and extreme) were employed to determine how future climate alterations may affect the potential distribution of Las in Africa. Presence data from global reports of Las, as well as the new positional …

Paleoecology Of Columbian And Pygmy Mammoths In Southern Nevada And California: How Terminal Pleistocene Ecosystems Shaped Mammoths At The Individual, Population, And Community Level, Lauren Elizabeth Parry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation research is to examine the paleoecology of the Columbian mammoth (Mammuthus columbi) and the pygmy mammoth (M. exilis) on the individual, population, and community level, emphasizing factors internal to their ecosystem that may have contributed to their extinction. I focus specifically on mammoths from Southern Nevada and Southern California to add regional data to the complex and evolving study of North American mammoth paleoecology.

Chapter 2 documents the permitted excavation of a partial mammoth (Mammuthus sp.) between 2016-2018 from late Pleistocene groundwater-discharge deposits near Fairbanks Spring in the Amargosa Valley, Nevada. A preliminary radiocarbon date …

The Impact Of Extreme Heat On Environmental Justice Communities In California: Assessing Equity In Climate Action Plans, Karishma S. Becha

Master's Projects and Capstones

Climate change projections suggest extreme heat events will be more frequent over the next few decades. Extreme heat has both negative environmental and social impacts as it affects energy security, public health by increasing the risk of heat-related illnesses and stresses food and crop supply through prolonged droughts. The impacts of extreme heat will also disproportionately affect communities of low economic status. Because of this, there is a need for better climate action plans that can adapt to and mitigate the impacts brought upon by extreme heat that does not disproportionately impact vulnerable communities. This research analyzed local government Climate …

Tipping Points Of Mississippi Delta Marshes Due To Accelerated Sea-Level Rise, Torbjörn E. Törnqvist, Krista L. Jankowski, Yong-Xiang Li, Juan L. Gonzalez

School of Earth, Environmental, & Marine Sciences Faculty Publications

Coastal marshes are threatened by relative sea-level (RSL) rise, yet recent studies predict marsh survival even under the high rates of RSL rise expected later in this century. However, because these studies are mostly based on short-term records, uncertainty persists about the longer-term vulnerability of coastal marshes. We present an 8500-year-long marsh record from the Mississippi Delta, showing that at rates of RSL rise exceeding 6 to 9 mm year−1, marsh conversion into open water occurs in about 50 years. At rates of RSL rise exceeding ~3 mm year−1, marsh drowning occurs within a few centuries. Because present-day rates of …

Quantifying Greenhouse Gas Emissions And Ammonia Volatilization From Soil Amended With Excreta From Ruminants Fed Alternative Forage-Based Diets, Samuel Park

Graduate Theses and Dissertations

Forage-based ruminant diets supplemented with condensed tannins or polyphenolic-containing legumes may alter nitrogen (N) metabolism in the animal and reduce gas emissions from soil receiving excreta. The objective of the study was to determine if soil receiving urine or manure from sheep fed forage diets supplemented with condensed tannin or polyphenolic-containing legumes would decrease N gas emissions. Two field trials were conducted: in the first trial, sheep were fed alfalfa (Medicago sativa L.) silage diets supplemented with 0, 9, 18, or 27% sericea lespedeza (Lespedeza cuneate [Dumont de Courset] G. Don) (n = 4). In the second trial sheep were …

The Release, Transport, And Utilization Of Phosphorus From Bed-Sediments: A Study Of A Eutrophic Littoral Cove On Beaver Lake In Northwest Arkansas, James A. Mccarty

Graduate Theses and Dissertations

Eutrophication of surface waters not only impacts the environment but also water treatment processes, the most significant of which is from the effects of algae. During peak algal growth in many southern U.S. reservoirs, inflows that bring nutrients are at an annual minimum, and phosphorus released from bed-sediments is trapped in the hypolimnion. Littoral areas, described as the most productive zone of the lake, may be a possible source of phosphorus that fuels algal growth in the reservoir. I studied an isolated shallow cove in the War Eagle Creek arm of Beaver Lake in Northwest Arkansas to measure, quantify, and …

Characterizing The Impacts Of The Invasive Hemlock Woolly Adelgid On The Forest Structure Of New England, Peter Brehm Boucher

Graduate Doctoral Dissertations

Climate change is raising winter temperatures in the Northeastern United States, both expanding the range of an invasive pest, the hemlock woolly adelgid (HWA; Adelges tsugae), and threatening the survival of its host species, eastern hemlock (Tsuga canadensis). As a foundation species, hemlock trees underlie a distinct network of ecological, biogeochemical, and structural systems that will likely disappear as the HWA infestation spreads northward. Remote sensing can offer new perspectives on this regional transition, recording the progressive loss of an ecological foundation species and the transition of evergreen hemlock forest to mixed deciduous forest over the course of the infestation. …

Characterization Of Microbial Communities Across Disease States And Environmental Conditions In Kemp’S Ridley (Lepidochelys Kempii) And Green Sea Turtles (Chelonia Mydas), Kerry L. Mcnally

Graduate Doctoral Dissertations

All species of sea turtles are threatened or endangered, with various diseases and conditions affecting populations around the world. Understanding healthy populations as well as populations beset by disease conditions, such as fibropapillomatosis and cold-stunning, could lead to helpful tools in the conservation management and medical treatment needed to protect these species. Microbial communities, or the microbiome, at different body sites of sea turtles likely play important roles in the health of these animals, from aiding in digestion to immune system regulation. Disruption of these communities, either through disease and/or environmental factors, may play a role in disease processes and …

Private Land, Public Trust: Strategic Conservation Planning For Public Wildlife On Private Lands Through The Usfws Partners For Fish And Wildlife Program, Clint Wirick

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Law requires federal agencies to develop long-term strategic plans. Strategic plans define goals, objectives, and performance measures defining how the agencies and programs will reach their stated goals. U.S. Fish and Wildlife Service’s Partners for Fish and Wildlife (PFW) develops strategic plans every five years. Each individual state develops a plan for their respective state. Those state plans are compiled for the region and become part of Regional Comprehensive Strategic Plan. The current strategic plan expires in 2021. States will begin the strategic planning process in 2020. In Utah, PFW staff will also begin developing a strategic plan for the …

Tree Removal Analysis Of The 2018-2019 Gambles Mill Eco-Corridor Restoration, Zach Harrell

Environmental Studies Senior Seminar Projects

Trees have been extensively researched, and it has been concluded that they are useful not only useful tools in enhancing biofiltration, as well as managing stormwater and retaining sediment, but they also benefit the health of the ecosystem as a whole. But as the University of Richmond’s Gambles Mill Eco-corridor was restored between 2018 and 2019 in order limit to the amount of phosphorus, nitrogen, and other sediment flowing into the Little Westham Creek; many of the trees that combat these problems were removed. The following research intends to analyze the number of trees actually removed throughout the restoration, as …

Assessing The Sublethal Impacts Of Sulfoxaflor On The Physiology And Behavior Of Daphnia Magna, Mary M. Hoffman

Departmental Honors & Graduate Capstone Projects

Agricultural pest species are a growing concern due to increasing resistance to neonicotinoids. Sulfoxaflor, a sulfoximine pesticide recently approved by the USEPA, was developed to replace neonicotinoids and has shown to have high efficacy in the field. Environmental introduction is primarily caused by wet spray application or agricultural runoff. Sulfoxaflor binds to insect nicotinic acetylcholine receptors, triggering overactivation that leads to paralysis and death. Preliminary exposure studies have shown neonatal effects and development of liver tumors in rats and mice at 500 and 750 ppm, respectively. Little research into the effects on aquatic nontarget invertebrates has been conducted; as such, …

Stream Restoration As A Method Of Improving Local Water Quality, Emily George

Environmental Studies Senior Seminar Projects

Projects of stream restoration are a known Best Management Practice (BMP) to approach stormwater management, and have been adopted globally as a means of improving local hydrology. Urbanization has led to an increase in impervious surfaces, resulting in deteriorated streams, many of which are subject to stream restoration. Stormwater control measures (SCM), such as stream restoration, are considered to be a subset of green infrastructure as a method to reconnect streams with surrounding riparian areas, revitalize original hydrology, and support the local ecosystems. This paper looks into the viability of stream restoration as a way of improving water quality, focusing …

Systems Of Meaning In Place Attachment, Emily Routman

Geography and the Environment Capstone Projects

Numerous scholars agree that contact with natural landscapes has benefits for the landscape and the person experiencing them, including increased environmentally-responsible behaviors as well as psychological, cognitive, physiological, and social benefits. People develop a sense of place in outdoor landscapes while experiencing the physical environment, and sense of place is strengthened by place attachment – one’s emotional ties to a place. According to Williams and Patterson (1999), place attachment is perceived through four systems of meaning: 1) aesthetic/inherent, 2) goal-directed/instrumental, 3) cultural/symbolic, and 4) individual/expressive. The present study sought to understand which of these four systems of meaning are the …

Exploring Options For Mussel Restoration, Henry Hurt

Environmental Studies Senior Seminar Projects

This paper seeks to explore the feasibility and possible procedures of restoring freshwater mussels to the Little Westham Creek (LWC) as a way to reduce excess organic pollutants such as nitrogen and phosphorus coming from upstream. To this end, the use of mussels in bioremediation and restoration procedures found in scientific literature were reviewed with the goal of creating a guideline of how such a project would be carried out at the Gambles Mill Eco- Corridor. Based on the results of past literature, water data collected by students in this seminar, and data from RES, it was estimated that a …

Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The vulnerability of soil toward erosion might be reduced by having a good vegetative cover over the soil surface, slope improvement, and improving soil properties so that it is not easily detached and transported. However, the establishment of proper vegetative cover is a long process because it takes time for seeds to germinate and attain maturity. As an alternative approach, if soil resistance was increased by increasing the shear strength of soil against erosive forces offered by eroding agents, the soil system would become capable of withstanding the detachment of its particles on the application of shear stress. To achieve …

Determination Of Distribution Of Microplastics In Rappahannock River, Va, And Toxicity Of Polyethylene Microplastics With Interaction Of Methoxychlor On Daphnia Magna, Thanh-Binh Duong

Departmental Honors & Graduate Capstone Projects

Microplastics have become an emerging contaminant of concern in freshwater systems as a component of wastewater treatment plant (WWTP) effluent, household discharge, and industrial outflows. While microplastics have been detected in aquatic environments throughout the world, our knowledge regarding microplastics in the Chesapeake Bay Basin and their impacts on aquatic invertebrates combined with chemical pollutants is limited. This study consisted of two parts: a field-based assessment examining the spatial distribution of microplastics in the Rappahannock River, VA; and a lab-based analysis examining the effects of polyethylene microplastics and the pesticide methoxychlor on the viability and mobility of Daphnia magna. …

Sea Level Rise Vulnerability Analysis Of Mangrove Ecosystems Using Gis, Kayla Caldwell

HCNSO Student Theses and Dissertations

Climate change is accelerating beyond what is natural due to excessive emissions from human activities. The sea level has been rising for many years and is currently at a rate of 3.6 mm/yr. Mangroves are known to only keep pace with a sea level rate of less than 1.2 mm/yr. Mangroves are particularly vulnerable to rising sea levels if they are not able to keep pace through vertical sediment accretion or inland migration. To test the vulnerability of the south Florida mangrove ecosystems to sea level rise, this study analyzed changes in the mangrove forest coverage of the Oleta River …

Chamaecyparis Obtusa (False Cypress-Hinoki) Id #982, Samuel Johnson

BIO 140 Arboretum Project

Location: By the Misto Gatehouse in front of McAuley Hall

Height: 33.4 ft

Fagus Sylvatica Var. Laciniata (Fernleaf Beech) Id #1048, Andrea Connors

BIO 140 Arboretum Project

Location: Lawrence Avenue behind McKillop Library

Effect Of White Rot Fungi Pretreatment On Methane Production From Anaerobic Fermentation Of Coal, Zhang Huaiwen, Huang Song, Yan Xiatong, Zhao Shufeng, Zhang Minglu, Xia Daping

Coal Geology & Exploration

To investigate the effect of white rot fungi pretreatment on methane production from anaerobic fermentation of coal, fermentation experiments of biogas production were conducted using long flame coal. The coal samples pretreated with white rot fungi were the experimental group(EG), and original untreated coal samples were the control group(CG). The COD(chemical oxygen demand) mass concentration, activity of coenzyme F420, and changes of coal morphology were measured using potassium dichromate method, ultraviolet spectrophotometry, and SEM, respectively. The results showed the following: The total gas production and conversion rate in the EG and CG were 2 322.00 mL and 5.10%, 1 330.20 …