Digital Commons Network^™

Habitat Effects On Scorpion Densities And Microhabitat Use By Centruroides Vittatus And Vaejovis Waueri In South Texas, Jonathan Beltran

Theses and Dissertations

Co-existence between Centruroides vittatus and Vaejovis waueri is influenced by environmental factors that shape their habitats. Differences in surface activity frequency between the two species suggest differential microhabitat use. The observed frequency of scorpions using microhabitats in the Martinez Ranch and La Union Ranch were not significantly different from the expected frequencies. Frequency of scorpions observed using microhabitats in La Union South was significantly different from the expected frequency (P<0.001). Microhabitat use of catclaw was lower than expected and higher than expected for other vegetation. Conditional comparisons of microhabitats were significantly different among habitats (P<0.001), size classes were significantly different among microhabitats (P<0.001), and size classes were significantly different among habitats (P<0.01). Microhabitat use by scorpions on the ground was higher among all habitats. Scorpion use of ground and grass were different among size classes. Size class I-II scorpions had a higher frequency than size class III. Scorpion density for C. vittatus was significantly different among habitats (P<0.0001) and scorpion density for V. waueri was significantly different among habitats (P<0.0001). Centruroides vittatus was significantly higher in the Martinez Ranch and in La Union South. Vaejovis waueri was significantly higher in La iv Union South. Associations between plant densities and scorpion size classes were tested. Plant densities had a significant association with C. vittatus size classes I and II in the Martinez Ranch. Association between plants had a significant correlation with C. vittatus size classes I and IV in La Union Ranch. Association between plants had a significant correlation with V. waueri’s total density. These associations may suggest plant densities may have a synergistic effect on scorpion densities. Soil type composition for the different habitats was hypothesized to influence scorpion densities. Maps for each site were created to show soil type compositions. Soil type findings suggest that La Union South had the soil types with the lowest soil strength. Vaejovis waueri was shown to have a higher density in La Union South where soils are sandier. Results indicate that co-existence between C. vittatus and V. waueri is possible because competition is low through minimal overlap in microhabitat use and intraguild predation avoidance.

A Comparative Analysis Of Viral Aerosol Biological Sampling Efficiency Of A Small Unmanned Aircraft System (Suas)-Mounted Aerosol Sampler And A Reference Static Biosampler®, Jonathan D. Moroz

Theses and Dissertations

Bioaerosol sampling using small unmanned aerial systems (sUAS) is a rapidly developing field that may result in a paradigm shift in emergency response and industrial hygiene sampling conventions. These technologies offer decreased sample acquisition times, larger sampling area coverage, and reduced health and safety risks to traditional human sampling teams. This potential requires a comprehensive investigation of sUAS capabilities and limitations. This study is a continuation of the characterization of an AFIT-developed sUAS-mounted aerosol sampler, proven capable of collecting viable vegetative and spore-forming bacteria through previous AFIT research. Within this study, viral biological sampling efficiency (BSE) of the sUAS-mounted aerosol …

Factors Affecting Consumers’ Purchase Intentions Towards Recycled Products, Sherine Esmat

Theses and Dissertations

The work executed addresses the status of recycling industry in Egypt and its relation to the current sustainability trends as well as climate change issues. It also identifies the main concerns of consumers when purchasing recycled products. Consequently, identifies the key pillars that need to be applied or communicated with the target consumers to enhance the concept of selling recycled products and increase its market share. Since this industry is significantly broad, the focus of the study was only on recycled PET plastic bottles (rPET), this is to ensure attaining accurate and reliable results.

An interview and a site visit …

The Impact Of Midterm College Mathematics Performance On Retention And Graduation Of Stem Students, Kandy Yu-Juan Ng Rich

Theses and Dissertations

The purpose of this study sought to examine how midterm math performance can impact a student’s final math performance, STEM performance, overall performance, as well as retention and graduation with a STEM major. The sample consisted of 283 first-time full-time undergraduate students who were admitted in Fall 2014 as STEM majors within a liberal arts and sciences college at a private, not-for-profit, urban, highly diverse university located in the northeast. Academic record data from between September 2014 – May 2020 was obtained. Multiple and logistic regression analyses were performed, as well as independent samples t-tests. Results of the study revealed …

Quantifying Insect Emergence In Tidal Freshwaters And The Importance Of Aquatic Prey In Wetland-Dependent Songbird Diet, Samantha L. Rogers

Theses and Dissertations

Insectivorous birds and their arthropod prey are experiencing widespread population declines, driven largely by anthropogenic disturbance and climate change. For wetland-dependent insectivores that consume a mixture of terrestrial and aquatic insects, understanding the availability, consumption, and nutritional qualities of aquatic diet subsidies is important for conservation. I use prothonotary warblers (Protonotaria citrea) as a model species throughout this work, because their breeding season aligns with aquatic insect emergence and they include aquatic insects when provisioning nestlings. In the first chapter, I estimate aquatic insect emergence from tidal freshwaters, which are understudied compared to nontidal systems. Using continuous field …

Building A Macrosystems Ecology Framework To Identify Links Between Environmental And Human Health, Felisha N. Walls

Theses and Dissertations

The structure and functions of natural systems continue to be degraded by human activities such as land-use change. One potential consequence that has received relatively little attention is a corresponding decline in human health. Altered ecosystems can present a host of risks to human health. Yet the consequences of environmental degradation are rarely considered in national-scale research on human well-being. The guiding objective of this work is to compare stream health and socioeconomic metrics with spatially congruent human health metrics throughout the conterminous United States, then to identify potential links between environmental health, socioeconomic factors and human health. Environmental health …

The Living Legends Of Sholoukh – شلوخ الأساطير Facial Scarification In Sudan, Ayah S. Elnour

Theses and Dissertations

Sholoukh — ritual face scarring—is a dying art form in Sudan.

Used to distinguish members of one tribe from another,

Sholoukh reflects the tribal pride of an individual. In the past,

sholoukh was seen as important as having a passport for a tribe

member, however, it was not always applied by choice. Using

just a razor blade, the wisest, most senior tribal elder would scar

the face of a child, initiating them into the tribe for life.

As this tribal art form fades away, the dwindling Sholoukh-bearers

have become living legends in Sudan. To honor them, I create

a collage …

Stage-Structured Predator-Prey Interactions In A Warming World: A Case Study In Riverine Rock Pools, Andrew T. Davidson

Theses and Dissertations

Warming can impact predator-prey interactions through a variety of mechanisms. For example, warming can both alter the rate at which predators consume prey and the rate prey develop through vulnerable life stages. Thus, the overall effect of warming on consumer-resource interactions will depend upon the strength and asymmetry of warming effects on predator and prey performance. Here, we describe the consequences of these asymmetrical responses to temperature by first developing a simple stage-structured modeling framework, then applying that framework to predation of American rock pool mosquito larvae, Aedes atropalpus, by several common predators in riverine rock pools. We then …

Climate, Physiology, And Distributions: The Role Of Thermal Physiology In Biological Invasions, Sean D. Powers

Theses and Dissertations

Climate is a primary factor influencing species range dynamics, particularly for ectotherms whose body temperature is closely tied to the surrounding conditions. While range shifts of ectotherms are attributed to climate warming, the mechanism driving these shifts are not well understood. Studies in macrophysiology demonstrate that the interaction of climate with thermal physiology plays a key role in determining large-scale spatial and temporal patterns for many temperature-sensitive physiological traits. This work has revealed a clear relationship between thermal tolerance breadth and range size. However, more recent analyses of this relationship demonstrate that thermal tolerance breadth only provides a partial explanation …

Application Of High-Performance Liquid Chromatography-Mass Spectrometry In Lignin Model Compound Degradation And Forensic Determination Of Clonazepam And Flunitrazepam In Necrophagous Insect And Liver, Zeinab Rabiei Taemeh

Theses and Dissertations

High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) is a versatile technique that has vast applications in analytical chemistry, specifically for the identification, quantitation, and mass analysis of components. This study outlines an exploration of HPLC-MS applications, focusing on its utilization in two distinct areas: lignin degradation studies and forensic investigations.Lignin degradation: Most of the previous studies on lignin degradation, employed gas chromatography-mass spectrometry (GC-MS) for product characterization. Most lignin model compounds, which are widely used in lignin valorization studies, are either not GC-elutable or have low thermal stability. In this work we investigated HPLC-MS as an alternative method, which offers a simultaneous …

Trust And Psychological Empowerment In Global Virtual Teams: Quantitative Ethnography Research, Yujung Seol

Theses and Dissertations

Although global virtual teams are becoming more commonplace because of their many benefits, they are also challenged by a lack of interpersonal and emotional trust between team members. Based on this problem, this study adopted a quantitative ethnographic methodology to explore team members' perceptions of the relationship between trust and psychological empowerment components, such as the meaning of work, competence, self-determination, and impact, in global virtual teams. In addition, this study examined how the team members' perceptions of trust and psychological empowerment differ based on their attributes. To achieve this research purpose, the researcher collected data via semi-structured interviews with …

Land Acquistion For Flood Adaptation Under Changing Climate, Jiyang Zhang

Theses and Dissertations

Flood has caused tremendous life and economic losses over the past few decades and is expected to cause more in the future under the effects of climate change and socioeconomic development. With limited resources, cost-effective adaptation policies are urgently needed to minimize the economic and social impacts of future floods. The increasing flood losses and recent catastrophic flood events around the world expose two major issues of current flood adaptation schemes: 1) Flood risks are not well captured and predicted under climate change, leaving many communities unprepared for potential extreme flood events; 2) Current flood adaptation measures focus on the …

Applications Of Urban Land Evaluation And Site Assessment (Ulesa) In Chesterfield County, Virginia, Emily Hastings

Theses and Dissertations

Urban and suburban agriculture is increasing in popularity across the United States. However, many of these farms are short-lived due to a combination of human factors (e.g., managerial, economic, cultural) and environmental or spatial factors (e.g., zoning, soil quality, distance to markets). Geospatial analysis, in the form of suitability modeling, could aid in locating suitable sites for these activities. Land Evaluation and Site Assessment (LESA) is a suitability modeling technique that generates a score for agricultural land use in traditionally rural spaces. This research explores adapting this method to encompass the complexities of placing diverse, in-ground agriculture in urban and …

The Effect Of Climate Change On Firm Level Costs With Focus On Mena Region, Farah Osama Saieed

Theses and Dissertations

This paper has a main objective of identifying the relationship between environmental factors and climate change on operating costs incurred by firms. This paper also attempts to compare the direction and intensity of the effect on different sectors in order to analyze whether climate change effect differs based on the nature of the business operations. Several papers have previously addressed the relationship between climate change factors ad profits. This literature will add to previous studies by observing the effect on the cost rather than the profits. In addition to providing results that minimize endogeneity, which is found in a large …

The Impact Of Covid-19 On Employment Characteristics, Eliana Shatkin

Theses and Dissertations

The following study examines ways in which COVID-19 has disrupted the United States labor market. My findings present disproportionately negative effects of COVID-19 on employment, labor force participation, worker absence, and weekly working hours for the female population in my sample, as well as veterans, disabled persons, and racial minorities.

Mapping The Distribution Of The Scarlet-Banded Barbet ( Capito Wallacei ) Using Geographic Information Systems ( Gis ) And Species Distribution Modeling ( Sdm ), Stephanie Marie Scherer

Theses and Dissertations

The Scarlet-banded Barbet (Capito wallacei) is a Neotropical barbet discovered in 1996 in the eastern Andean foothills of Peru. Despite being fairly common at the site of discovery, its known distribution is limited to two sites, and searching for other suitable sites is difficult in the wilderness of the eastern Andes. Through the use of geographic information sysems (GIS), remote sensing methods, and Maxent, we constructed a species distribution model (SDM) to determine the likelihood of occupancy of the Scarlet-banded Barbet outside of its current known distribution. The model predicted the occupancy with an area under the curve (AUC) of …

Assessing Virtual Free-Choice Agricultural Learning: A Mixed Methods Approach, Richard John Kennedy

Theses and Dissertations

Since the mid-19th century, agricultural museums and living history sites, first in Scandinavia and then in the United States and Canada, have provided historical, cultural, and, sometimes, scientific information about farming to visitors. Many of these visitors have been school children on field trips. Assessment of this learning, however, has been scant, particularly within the free-choice style inherent in these types of educational venues. At the same time, assessment of free-choice learning, often analyzed through the Contextual Model of Learning (Falk & Dierking 2000), has taken place at educational sites like zoos, natural history museums, and science centers. This study, …

Novel Applications In Mississippi Cotton And Peanut, Anna Beth Gaudin

Theses and Dissertations

Studies were conducted in the field from 2020-2021 in peanut and cotton to optimize peanut growth and yield through prohexadione calcium application methods as well as weed control through increasing herbicide sites of action. These studies were established on multiple on-farm and small-plot locations in Mississippi. Prohexadione calcium studies concluded that following application of prohexadione calcium effects on yield and peanut growth were inconsistent. Neither varying application timing nor rate resulted in peanut yield that was different than when adhering to the label recommendations. Increasing sites of action studies concluded that broadleaf signalgrass and Amaranthus species control was optimized at …

How Federal Pollution Discharge Permits Affect U.S. Water Quality: A Study On Concentrated Animal Feeding Operations, Cloe C. Mueller

Theses and Dissertations

This paper uses difference-in-difference regression models to examine how state-level pollution discharge permits on concentrated animal feeding operations affect U.S. water quality. I ultimately deem the permitting to be ineffective at improving water quality, calling attention to the need to re-evaluate the ``socially optimal level of pollution."

Understanding The Spatio-Temporal Evolution Of Surface Heat Flux In The Tropics From Observations And Models, Xin Zhou

Theses and Dissertations

An important component of the earth’s surface energy budget is the surface heat flux that allows the exchange of mass and energy between the ocean and the atmosphere and thereby influences oceanic and atmospheric circulations. For better prediction of weather and climate, numerical models must be able to capture the mean and variability of surface heat flux since surface heat flux directly feeds into model simulation of convection and precipitation. In this study, we explore the spatial and temporal variations of different surface heat flux components over the tropical oceans using observations and atmospheric global climate models (AGCMs). We confine …

An Analysis Of The Effects Of Temperature And Other Environmental Factors On Microorganismal Productivity Within Aquatic Ecosystems Using Long-Term Data From Various Lter And Ilter Sites, Andrew Dorbu

Theses and Dissertations

Global climate change is a phenomenon resulting in more extreme weather patterns and species diversity loss. In this study, I explore the impacts of climate change on regional patterns of microbial productivity. Variation in microbial productivity was explained using temperature, salinity, and dissolved oxygen as predictors in regression models with data from the LTER and iLTER network of sites that ranged from the poles to the equator. I found a positive relationship between temperature and productivity. Antarctica and Arctic sites exhibited the strongest positive relationships supporting prior research demonstrating temperature as one of the driving forces of productivity change in …

Mining For Progress: Copper, Conflict, And Corporate Social Responsibility, Fritz Culp

Theses and Dissertations

My dissertation examines how transnational mega-mines efface non-Western ways of knowing and being from the Andes. A growing branch of research is questioning the socio-environmental impacts of mining and the influence of regulatory institutions. Despite remarkable scholarship on the ongoing environmentalism of modern-mining, little critical attention has been given to the industry’s pivot to ‘sustainable’ development and its objectives that remain epistemologically centered on the West. My project addresses these gaps by examining Las Bambas—a large-scale copper mine located in South-Central Peru—and its contrasting objectives that emphasize both environmental ‘conservation’ and the ‘modernization’ of non-Western spaces. Building upon the critical …

Development Of A Methodology For The Quantification Of Reaerosolization Of A Biological Contaminant Surrogate Particle From Military Uniform Fabric, George D. Cooksey

Theses and Dissertations

During a mass casualty medical evacuation after a bioaerosol attack, a decontamination method is needed that is effective at both decontamination and preventing the secondary hazard of biological particles reaerosolizing from contaminated clothing. However, neither the efficacy of current decontamination methods nor the risk of biological particle reaerosolization is significantly explored in existing literature. The goals of this thesis were to develop a repeatable methodology to quantify the reaerosolization of a biological contaminate off Airman Battle Uniform (ABU) fabric swatches, and to test the efficacy of one decontamination method (high-volume, low-pressure water) using 1 mpolystyrene latex (PSL) spheres as a …

Persistence And Mitigation Of Pfas Within Concrete Stormwater Drainage Infrastructure, Jason R. Mcdonald

Theses and Dissertations

The persistence, fate, and transport of per- and poly-fluoroalkyl substances, which have been shown to have adverse effects on human health, have been previously studied in environmental media such as soils and groundwater. This study investigates concrete, a medium that is rarely studied but frequently present in instances where PFAS originating from AFFF releases and spills have occurred. Used heavily throughout aviation firefighting, AFFF poses environmental hazards due to the length of PFAS degradation and toxicological implications, thus its classification as a forever chemical. From the very limited reports to date, studies have suggested very slow release from concrete, potentially …

Promoting Climate Change Mitigation & Supporting Ngos: Converging The Theory Of Planned Behavior & The Elaboration Likelihood Model, Passant Mostafa Halawa

Theses and Dissertations

In the 21st century, public opinion's attention in developed nations has increasingly been directed to climate change and the urgency for humanity to take action. The main discourse is that climate change would have devastating consequences on a global scale, threatening humanity’s existence. However, in most developing countries climate change is generally not regarded as an important topic and climate change messages suffer from poor public engagement. Most recent research has investigated climate change communication efficiency in developed countries. The novelty of this study lies in understanding the effectiveness of climate change messages in the Egyptian context. More specifically this …

The Effects Of Environmental Corporate Social Responsibility On Financial Returns, Kevin Acevedo

Theses and Dissertations

A major issue concerning companies is global warming and the impact that firms have on the environment. Companies are taking steps towards sustainability, but it is unclear if sustainable business practices are beneficial to companies’ financial performance. This paper examines the effect of environmental corporate social responsibility (CSR) of Fortune 250 companies on financial performance. The analysis reveals significant effects on financial performance, but they are inconsistent and hard to interpret.

Environmental Attitudes Of Community College Students Concerning Age, Gender, And Race, Robert W. Fournier

Theses and Dissertations

Many studies have shown the mental, physical, and academic benefits of environmental education to students. Equally important, environmental education can develop our students into more environmentally minded citizens. However, we are learning that most students are not receiving accurate environmental information while in school, which may impact their attitudes toward the environment and subsequent actions to protect it. Understanding current college-aged students' (Generation Z's) attitudes toward the environment are critical as they are next in line to make political and business decisions that will affect our planet. Using the New Ecological Paradigm Scale (NEP), 1,556 community college students were surveyed …

Posthuman Queer Ecosexuality: Shakespeare And Earthly Consummation, Lisa Robinson

Theses and Dissertations

“Posthuman Queer Ecosexuality” explores the culminating productivity of a queer landscape fertilized by dead bodies. Tragedy as a genre provides a higher queer possibility simply because it does not contend with picture perfect happy endings. By seeing an inherent connection between queerness and death, the paired couples of the specific Shakespearean tragedies explored in this project, King Lear (1605), Othello (1604), and Antony and Cleopatra (1607), fertilize the respective landscapes within their plots. These main six characters are queered by forced connections to nature due to their gender, race, or function as a ruling body. Once they are placed in …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …

Wet, Flowering, Dry, Caroline A. Minchew

Theses and Dissertations

Wet, flowering, dry is a series of photographic works that explore how vernal pools are a macrocosm for holding memory and a site of omnipresent solitude and decay. This installation distills an embodied and ephemeral experience of how we are grounded in a network of invisible connections with our surroundings. This network becomes evident through biological, historical, and field research conducted at the vernal pools for over a year. Through slow observation and consideration of how multiple stories of place can weave together into a larger parable, Wet, flowering, dry reveals how the life cycle of a vernal pool is …