Digital Commons Network^™

Developing A Precision Agriculture Framework To Assess Financial Viability Of Decisions In Farming And Conservation, Jennifer Sublett

Theses and Dissertations

Agricultural producers are invested in managing the impacts of crop damage on their yields and profit. When damage occurs early enough in an agricultural growing season, farmers have the option to replant their corn stand in an effort to recoup some of the lost profits. In this thesis two different types of naturally occurring damage, wildlife depredation and persistent weed or insect patches, were simulated on two representative regions of Mississippi. These data were then used to assess the financial viability of a range of damage mitigation methods, including partial replanting, enrollment into a government conservation buffer, and no action. …

Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner

Theses and Dissertations

Estuarine habitats are considered nursery habitats for fishes and invertebrates, but oligohaline environments are critically understudied. Using a seine net and fyke nets, we sampled Back Bay, Mississippi (USA), a low salinity estuary, once a month for a year to explore the temporal use of the marsh and adjacent submerged landscape by nekton species. We also looked at whether there is evidence of habitat preference in the most numerous nekton species. We used a novel habitat usage index (HUI) to compare seine and fyke net catches of our top 10 species, and evaluated catch size in relation to maturation size. …

Assessing The Relationship Between Soil Health/Quality And Water Quality In The Mississippi Delta, Laura Andrea Sarmiento Rodriguez

Theses and Dissertations

Several studies have reported agronomic benefits by improving soil health/quality, but uncertain knowledge remains when determining specific impacts on water quality off-field. This study investigated the links between runoff water quality and soil health/quality in agricultural fields of the Mississippi delta under three land management scenarios: Conservation Reserve Program (CRP), vegetative buffer (VB), and row crops (RC). Using the Soil Management Assessment Framework (SMAF), a Soil Quality Index (SQI) was obtained based on ten soil health/quality indicators from 2008 and 2012 datasets. The SMAF identified significant differences in soil health/quality improvements among scenarios over a four-year period. Varied relationships between …

Current And Future Perceived Needs And Concerns For Older Adults Aging In Place In Mississippi: Intergenerational Perspectives, Muhammad Riaz

Theses and Dissertations

The study's purpose was to identify the perceived needs and concerns of three generations in a family with an older adult aging in place in Mississippi. This mixed-methods study used snowball sampling in addition to recruitment by community leaders such as Extension agents to collect data through semi-structured interviews and structured questionnaires that asked about current and future problems among aging adults in rural communities in Mississippi. Three generations of Mississippians participated in the study, including older adults (G1; n = 22), adult children (G2; n = 23), and young adult grandchildren (G3; n = 19). Quantitative data were analyzed …

Evaluating Teachers’ Perceptions Of The Social Validity Of Psychological Report Writing Styles, Adam Weseloh

Theses and Dissertations

Psychologists spend a significant portion of their time writing psychological reports. Oftentimes these reports are highly technical and written at a level which the literature has suggested is often difficult for teachers to utilize in their classrooms. Several previous research studies have examined psychological report writing practices and offered suggestions for improvement. One of these suggestions (theme or referral-based report writing) has not been as thoroughly examined in the literature. The purpose of this study was to examine this report writing style compared to more traditional report writing practices. This study utilized a novel approach to assessing teachers’ perceptions of …

Morphological And Structural Characterization Of Shortening Landforms On Mars, Leta Mccullough

Theses and Dissertations

The lithosphere of Mars accommodates shortening through folding and faulting, producing landforms qualitatively categorized as wrinkle ridges or lobate scarps. However, we lack a deep understanding of the morphological differences between these landforms. This study aimed to develop a quantitative model for shortening landform classification based on surface morphology and subsurface architecture. We developed this model by mapping 100 landforms in a GIS, recording parameters for each landform. We conducted a Discriminant Function Analysis (DFA) using these morphometrics. This DFA produced a predictive linear function for categorizing wrinkle ridges and lobate scarps. We then modeled the subsurface structural geology of …

Advancements In Time Resolved Spectroscopy And Nonlinear Microscopy, Bryan Semon

Theses and Dissertations

Non-linear optical processes such as coherent anti-Stokes Raman scattering and sum frequency generation offer a view into the chemical and biological interactions of molecules that is distinctly different from linear techniques like near infra-red and fluorescence. This insight comes at a cost: non-linear techniques are more sensitive to external perturbations of the system, increasing the noise and decreasing the repeatability of the data. We work here on both aspects of these non-linear techniques, taking advantage of their power to offer new imaging techniques as well as working to quantify and reduce the non-resonant noise inherent to the system. In pursuit …

Probing The Biophysical Interactions Between Autolysin Proteins And Polystyrene Surfaces, Radha Paramee Wadduwage

Theses and Dissertations

Biofilms formed on medical devices pose significant challenges, compromising device efficiency and serving as sources of infection. Staphylococcus epidermidis, an opportunistic pathogen, relies on the autolysin protein, notably its R2ab and amidase domains, to attach to polystyrene surfaces and initiate biofilm formation. Despite their pivotal role, the structural intricacies of these proteins’ interactions with surfaces remain elusive. In this dissertation, the multifaceted aspects of protein interactions with polystyrene surfaces and the implications of these interactions for biofilm control are studied. Over the course of this study, it is found how the R2ab and amidase domains influence biofilm formation on polystyrene …

The Impact Of Institutional Culture On Technological Pedagogical Content Knowledge In Higher Education, Kenna Spiller Vowell

Theses and Dissertations

Teaching and learning online is an increasingly important aspect of higher education, especially post-Covid-19. Previous studies have shown a relationship between Technological Pedagogical Content Knowledge (TPACK) and teaching efficacy and teaching efficacy and student success. However, the contextual factors impacting TPACK have not been adequately explored. The purpose of this quantitative study was to determine if the contextual factor of institutional culture impacts TPACK among online higher education faculty at institutions in the Southeastern United States as well as to what extent specific dimensions of institutional culture effect TPACK levels. Data were collected using an anonymous online survey that was …

Biochar And Gypsum Effects On Soil Properties And Water Quality In Cotton And Soybean Production Systems In The Mississippi Delta, Amrinder Jakhar

Theses and Dissertations

Intensive tillage practices in the Mississippi Delta degrade soil health, impacting downstream water quality. To address this, two experiments were conducted from 2019 to 2021 and 2020 to 2022 to evaluate the impact of sugarcane biochar and flue gas desulfurization (FGD) gypsum on nutrient leaching losses and soil properties in cotton and soybean cropping systems. Study I applied four biochar rates (0, 10, 20, and 40 Mg ha^-1) to cotton and found improvements in soil properties and subsurface quality, with reduced nutrient leaching losses, except for sulfate and sodium ions. Study II evaluated biochar (10 and 25 Mg …

Green Wood Composites With Natural Preservatives, Thomas Frank Norman

Theses and Dissertations

The purpose of this study is to test the mechanical, dimensional stability, and weathering durability of OSB (oriented strand board) panels that have been treated with varying natural wood preservatives that were chosen from an array of natural antimicrobial compounds. Wood is increasing in popularity for new construction projects but has been limited by its vulnerability to biological degradation. The addition of natural antimicrobial compounds will increase the use life of wood-based strand board allowing its use to expand with the growing construction demand but has little data on how natural antimicrobial compounds impact different properties of the OSB. The …

An Assessment Of Loblolly Pine (Pinus Taeda L.) Mortality And The Impact Of Habitat Fragmentation On Southern Pine Beetle (Dendroctonus Frontalis Zimmerman) Infestation In Mississippi, Usa, Damilola M. Taiwo

Theses and Dissertations

This thesis has two data chapters that consider factors affecting loblolly pine health in localized regions of Mississippi. The first data chapter investigated the abiotic and biotic factors contributing to loblolly pine (Pinus taeda) mortality on private timberland in Mississippi. This assessment considered temperature and precipitation variations, bark beetle populations, foliar and root pathogen tests, and drone survey. The results revealed that the loblolly pine mortality resulted from combination of factors. The second data chapter examined the impact of habitat fragmentation on southern pine beetle (SPB; Dendroctonus frontalis) infestation in Homochitto National Forest (HNF). This was assessed through remote sensing …

Paternal Programming: The Role Of Seminal Plasma In Pregnancy Hemodynamics And Offspring Growth, Rebecca Michele Swanson

Theses and Dissertations

Seminal plasma is commonly known to serve as a transport medium for sperm as it moves through the female reproductive tract for fertilization, however, more recent evidence demonstrates seminal plasma induces an expansive inflammatory response in the uterus. Murine models have found this inflammatory response is important for clearing pathogens and poor-quality sperm, eliciting the secretion of cytokines, chemokines, and embryokines that aid in embryo attachment and growth, placental angiogenesis, and blunting maternal immunity to the embryo. However, there is minimal research on the impacts of seminal plasma uterine priming in bovine, and more specifically embryo growth, uterine blood flow, …

Mechanical Characterization Of Functionally Graded M300 Maraging Steel Cellular Structures, Bradley Jay Sampson

Theses and Dissertations

Traditional methods for increasing the energy absorption of a structure involve using a stronger material or increasing the volume of the structure, resulting in a higher cost or additional weight. Additive manufacturing (AM) can be used to maximize the energy absorption of materials with the ability to create complex geometries such as cellular structures. Previous work has shown that the energy absorption of additively manufactured parts can be improved through functionally graded cellular structures; however, this strategy has not been applied to ultra-high strength steel materials. This work characterizes the effect of multiple functional-grading strategies (e.g. uniform, rod-graded, size-graded) on …

Study Of Augmentations On Historical Manuscripts Using Trocr, Erez Meoded

Theses and Dissertations

Historical manuscripts are an essential source of original content. For many reasons, it is hard to recognize these manuscripts as text. This thesis used a state-of-the-art Handwritten Text Recognizer, TrOCR, to recognize a 16^th-century manuscript. TrOCR uses a vision transformer to encode the input images and a language transformer to decode them back to text. We showed that carefully preprocessed images and designed augmentations can improve the performance of TrOCR. We suggest an ensemble of augmented models to achieve an even better performance.

Phenotyping Cotton Compactness Using Machine Learning And Uas Multispectral Imagery, Joshua Carl Waldbieser

Theses and Dissertations

Breeding compact cotton plants is desirable for many reasons, but current research for this is restricted by manual data collection. Using unmanned aircraft system imagery shows potential for high-throughput automation of this process. Using multispectral orthomosaics and ground truth measurements, I developed supervised models with a wide range of hyperparameters to predict three compactness traits. Extreme gradient boosting using a feature matrix as input was able to predict the height-related metric with R2=0.829 and RMSE=0.331. The breadth metrics require higher-detailed data and more complex models to predict accurately.

Taking Care Of What Matters: How Student Involvement And Characteristics Relate To Senior Student Sense Of Belonging, Kayla Pineda

Theses and Dissertations

Student sense of belonging has been a topic of discussion for decades; however, senior student sense of belonging has not been looked at as closely as other groups of students. As seniors transition out of college, institutions must consider that these students become the alumni who contribute through alumni donations and share their experiences with future generations of students.

Looking at data from a single very high research college campus in a rural state, the study explored variables that relate to senior student sense of belonging. Using Ahn and Davis’s (2020a) 4 domains of student sense of belonging, variables were …

Increasing Graduate School Enrollment In A Shrinking Applicant Pool: A Look At Factors Influencing College Choice, Lindsey Erin Storey Shelton

Theses and Dissertations

For years, the impending enrollment cliff has been a regular topic amongst higher education officials. With this event slated to hit undergraduate programs by 2025, it is anticipated that graduate schools will begin feeling the impact by 2029. By examining factors influencing graduate student college choice, enrollment managers can identify ways to offset the decline in eligible graduate students.

This study looked at applicants’ decisions to enroll or not enroll over a 5-year period at a public, research-intensive institution. The results of this study provided insight into the individual and academic factors that influence college choice, while also measuring the …

Condition Assessment Of The Northern Climatic Research House At The Usda Forest Service Forest Products Laboratory, Tanaya Johnson

Theses and Dissertations

In 2001 a Northern Climatic Test House (the House) was constructed to demonstrate appropriate and novel building techniques and materials for the upper Midwest region of the USA. The House is a 2,300-square-foot, two-story structure located on the grounds of the USDA Forest Service Forest Products Laboratory (FPL) in Madison, Wisconsin. It is considered a research structure and not part of the FPL’s building inventory. Following construction, the House was heated and cooled but not occupied. Regular (sometimes daily) tours were conducted from it’s opening until about 2008, when tours had diminished to less than one per week. Since eliminating …

Effects Of Supplementing Sources Of Zinc On Digestibility Parameters Of Beef Steers, Arminda Spikes James

Theses and Dissertations

Zinc (Zn) has numerous functions and life sustaining processes depend on the presence of Zn within the body. Zinc sulfate is a common form of Zn supplemented in the beef industry. Inorganic sulfate based minerals have been associated with negative rumen effects, mainly, decreased rumen fermentation and protozoa numbers. Our studies concluded no difference in digestibility of three different forms of Zn (zinc glycinate, zinc sulfate, and zinc hydroxychloride). Although overall digestibility did not change, there were specific mineral concentration differences after steers consumed concentrate treatment for 10 days. These differences implied that the mineral fed was consumed and absorbed …

Conventional And Strip-Tillage Systems With Fertilizer Placement In Irrigated And Dryland Corn And Soybean In The Mississippi Delta, James Chad Hankins

Theses and Dissertations

Years of intensive tillage operations and heavy winter rainfalls have taken a toll on the soils in the Mississippi Delta causing compaction and nutrient losses due to runoff. The purpose of this research was to determine the effects of tillage systems and P and K fertilizer placement methods on corn and soybean production, as well as soil properties in the Mississippi Delta. The tillage treatments included conventional tillage, conventional tillage with subsoiling, and strip-tillage. The fertilizer placement treatments included a non-treated control, incorporated with tillage, and broadcast after tillage. Strip-tillage treatments reduced soil compaction and maintain nutrient levels while improving …

College Preparedness. Narratives Of Transitions From High School To College., Chelsey Luann Vincent

Theses and Dissertations

Despite many theories on student success as well as many resources to help students make the transition from high school to college, many students do not persist in or graduate from college. The purpose of this dissertation is to provide insight into what takes place when students leave P-12 institutions and enter institutions of higher education by using focused narrative inquiry. This study took place at a large research university in the south. The study included 4 participants at various parts of their transition journey. Participants in the study responded to written prompts. Follow up interviews were conducted, and a …

An Investigation Into Applications Of Canonical Polyadic Decomposition & Ensemble Learning In Forecasting Thermal Data Streams In Direct Laser Deposition Processes, Jonathan Storey

Theses and Dissertations

Additive manufacturing (AM) is a process of creating objects from 3D model data by adding layers of material. AM technologies present several advantages compared to traditional manufacturing technologies, such as producing less material waste and being capable of producing parts with greater geometric complexity. However, deficiencies in the printing process due to high process uncertainty can affect the microstructural properties of a fabricated part leading to defects. In metal AM, previous studies have linked defects in parts with melt pool temperature fluctuations, with the size of the melt pool and the scan pattern being key factors associated with part defects. …

Exploring The Impact Of Extracurricular Activities On Adolescent Development: A Study Of Students Attending Schools In Poverty And Non-Poverty Areas, Clifton B. Thames

Theses and Dissertations

Previous literature has indicated a relationship between poverty, participation in extracurricular activities, and developmental outcomes. The current study aimed to investigate and develop a deeper understanding of extracurricular activities (ECAs) and their impacts on adolescent development using two self-report tools, the YES 2.0 and the Delinquent Attitude Scale (DAS). The researcher surveyed 174 high school seniors from students attending schools in poverty areas and students attending schools not located in poverty areas in Mississippi, examining disparities in ECA opportunities, barriers to participation, and the positive and negative impacts of ECAs on development. Additional data were collected from school administrators, allowing …

Evaluating Selected Properties Of Underutilized Hardwood Species For Fabrication Of Cross-Laminated Timber Industrial Mats, Mercy Itunu Ogunruku

Theses and Dissertations

Softwood is more in demand than hardwood because it is used primarily in the US's largest wood-consuming industry, construction, resulting in increased importation of softwood annually to meet this demand. Hardwood, used for non-structural purposes like furniture and interior designs, is more abundant in US forests. However, some hardwood species are underutilized and undervalued. Cross-laminated timber (CLT) has increased the demand for softwood.

A study evaluated the mechanical and physical properties of three underutilized hardwood species (321 yellow poplar, 393 sweetgum, and 262 red oak specimens) for CLT industrial mat manufacturing. The results showed that red oak had a higher …

Electroencephalography And Biomechanics Of The Basketball Throw, Phong Ky Phan

Theses and Dissertations

According to various studies, compared with novice athletes, experts exhibit superior integration of perceptual, cognitive, and motor skills. This superior ability has been associated with the focused and efficient organization of task-related neural networks. Specifically, skilled individuals demonstrate a spatially localized or relatively lower response in brain activity, characterized as ‘neural efficiency’, when performing within their domain of expertise. Previous works also suggested that elite basketball players can predict successful free throws more rapidly and accurately based on cues from body kinematics. These traits are the result of a prolonged training of specific motor skills and focused excitability of the …

Of Changing Climate And Habitat: Range-Wide Individual Growth And Local Patterns Of Phenology And Landscape Use In A Threatened Pit-Viper, James Helferich

Theses and Dissertations

Over the 21st century, climate change and wetland habitat loss will pose major threats to the Eastern Massasauga (Sistrurus catenatus), a federally threatened and Great Lakes region endemic rattlesnake. I collected capture-recapture data from sites across the range and modeled the effect of climatic variables on growth rate and asymptotic size. I found that high snow residence time was associated with larger asymptotic sizes but slower growth, while high spring precipitation increased growth rate. I then projected future growth and size under different carbon emission scenarios. Given the threat posed by successional encroachment of woody vegetation, I used spatially explicit …

Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura

Theses and Dissertations

I investigated the effect of climate change in one of the few expanding markets in the world in Brazil. In the last decades the demand for pulpwood increased from zero to 11 million tons, leading to an expansion of 700 thousand hectares of Eucalyptus plantation. In 2024, a new mill will start operating increasing the consumption of wood fiber by 8.2 million tons (+49%). I used mathematical programming to investigate how different scenarios of productivity and land will affect the market. My results showed that around 946,000 hectares (+124%) of additional timberland will be necessary in the upcoming decades. The …

Identifying Malware Similarity Through Token-Based And Semantic Code Clones, Christopher I. G. Lanclos

Theses and Dissertations

Malware is the source or a catalyst for many of the attacks on our cyberspace. Malware analysts and other cybersecurity professionals are responsible for responding to and understanding attacks to mount a defense against the attacks in our cyberspace. The sheer amount of malware alone makes this a difficult task, but malware is also increasing in complexity. This research provides empirical evidence that a hybrid approach using token-based and semantic-based code clones can identify similarities between malware. In addition, the use of different normalization techniques and the use of undirected matrices versus directed matrices were studied. Lastly, the impact of …

Towards Understanding The Interactions Between Ospreys And Human-Made Structures In The Tennessee River Valley, Natasha Karina Murphy

Theses and Dissertations

Raptor nests on human-built structures represent a significant source of conflict as they can result in bird mortality, fires, structure damage, service distribution, or power outages when falling nest materials or animals connect with energized conductors. Power companies, such as the Tennessee Valley Authority (TVA), wish to mitigate these conflicts to avoid service disruptions. In this dissertation, I present my work towards understanding and mitigating the interactions between Ospreys (Pandion haliaetus) and human-made structures. To achieve this, I explored multiple elements of conflict identification, monitoring, and basic ecology of the target species to better inform conflict mitigation. In Chapter I, …