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Effects Of Reduced Predator Abundance On The Predator-Prey Community Of A Tropical Reservoir, Cynthia Holt

Theses and Dissertations

In most Puerto Rico reservoirs, Largemouth Bass Micropterus salmoides are typically fast-growing with distributions composed of distinct year-classes. Cerrillos Reservoir, however, displays the classic characteristics of a crowded bass population common in temperate lakes and ponds with fish stockpiling into a single modal distribution of slow-growing fish. This developed shortly after stocking in 1997, with the population quickly expanding to carrying capacity. Consequently, relative weight declined from above 100 to about 80 and the population was mostly composed of fish <=350 mm. A protected slot limit (356-508 mm) was implemented; however, limited effort and angler attitudes towards harvest of small bass prevented the success of this regulation, which was subsequently removed. In this dissertation, I examined the efficacy of using targeted management harvests for improving growth, size structure, and condition of Largemouth Bass in Cerrillos Reservoir. I used bioenergetics modeling to simulate the effects of targeted harvests. I predicted annual consumption of stock and quality-sized Largemouth Bass and used these estimates to model the effects of population reduction on consumption and growth of remaining bass. To validate the model, experimental removals of Largemouth Bass from the crowded size classes (200-380 mm) were conducted in 2012 and 2013. In these two years, I removed 20% and 22% of the total biomass, respectively. Following the experimental removals, mean condition of Largemouth Bass increased from 83 to 90, and increases were observed in all Largemouth Bass size categories. The reduction in predator abundance resulted in increased prey availability and smaller size structure of sunfish (Lepomis spp.) and tilapia (Coptodon and Oreochromis spp.) populations. I concluded that reducing Largemouth Bass abundance in Cerrillos Reservoir can move population dynamics toward desired management outcomes, but these actions must continue indefinitely to achieve success and sustainability. Annual management harvests are feasible but impractical, so I recommend increasing angler harvest and implementing management efforts designed to limit recruitment (e.g., shoreline rotenone application) to achieve management goals.

Consequences Of External Factors On Placental And Offspring Development And Using Melatonin As A Potential Therapeutic, Dana S. Reid

Theses and Dissertations

Early life is critical for the development of an organism. External factors alter placental efficiency which can lead to consequential effects. The objective of the current study was to (1) examine placental characteristics and molecular factors affected by nutrient restriction (2) evaluate the mitigating properties of melatonin in a nutrient restricted pregnancy in regard to circadian, myogenic and adipogenic factors in fetal muscle and (3) evaluate the effects of prenatal and postnatal melatonin supplementation on offspring performance. In study 1, cows were fed a control (CON) or a 60% restricted (RES) diet from day 140 to 240 of gestation. Animals …

Phenotypic And Genotypic Characterization And Comparison Of Edwardsiella Ictaluri Isolates Derived From Catfish And Ornamental Fish Species, Divya Divya

Theses and Dissertations

The gram-negative bacteria Edwardsiella ictaluri causes significant economic losses in aquacultured fish. Generally considered host-specific to catfish, there are reports of E. ictaluri outbreaks from other aquacultured species, including ornamental fish raised in the southeastern U.S. Thus, a comprehensive phenotypic and genotypic characterization of E. ictaluri isolates from catfish and ornamental aquaculture was warranted. Morphological, biochemical, and protein profiles of catfish and ornamental derived isolates were mostly similar. Plasmid profiles of wild-type isolates were consistent within groups. Analysis of putative anti-microbial resistant isolates from catfish revealed the presence of multi-drug resistant plasmids. Genomic comparisons indicated marked differences among host groups, …

Odor In The Global Environmental Context: The Effect Of Odor Context Reinstatement On Memory, Dustin D. Finch

Theses and Dissertations

Previous research has demonstrated that memory is dependent on the environmental context; memory is better when the same environmental context cues present at study are reinstated at test as compared to when they are not. This finding is called context reinstatement effects (Godden & Baddeley, 1975; Smith, Glenberg, and Bjork, 1978; Smith & Vela, 2001). What is unclear is whether study items are associated with the global context or with unique features within the study environment. We tested whether reinstating a singular feature of a global environment, the odor present during study, was sufficient to produce context reinstatement effects. These …

Oxidative Stress Biomarkers In Blood Plasma Of Moderately Exercised Horses, Elizabeth Catesby Ott

Theses and Dissertations

Equine athletes are subjected to environmental and physical stressors resulting in oxidative stress that can negatively impact performance. Oxidative stress can result in lipid peroxidation, cell damage, and DNA degradation leading to physiological dysfunction and increased instance of disease. It has been established that humans are able to adapt to oxidative stress when exposed to extended periods of high-intensity exercise, however, this has yet to be established in the equine model. In the present study, we sought to establish patterns of oxidative stress expression immediately following exercise and adaption to prolonged exposure to exercise training in the equine model. Results …

Pain And Inflammation Due To Whole-Body Vibration In A Rat Model, Folly Martha Dzan Patterson

Theses and Dissertations

Low back pain is a leading cause of disability and is associated with whole-body vibration exposure in industrial workers and military personnel. The pathophysiological mechanisms by which whole-body vibration causes low back pain have been studied in vivo, but there is little data that improve diagnosis of low back pain. The overall objective of this research was to elucidate diagnostic biomarkers associated with whole-body vibration. Hence, a rat model for vibration-induced inflammatory responses was developed. Von Frey filaments were used to determine the withdrawal threshold of the hind paw as a surrogate behavioral marker for pain. The concentration of nerve …

Perceived Close Friend And Parent Disapproval/Approval Of Illicit Use Of Prescription Stimulants, Kara L. Nayfa

Theses and Dissertations

Illicit use of prescription stimulants (IUPS) has become more common in the late adolescent and emerging adulthood populations. This study examined the impact of close friend and parent disapproval/approval on IUPS in college students.

A sample of 903 college students (M_Age = 19.23) completed a questionnaire assessing variables including lifetime IUPS (14.59% of sample), and perceived close friend/parent disapproval/approval of either academic or recreational IUPS. A 2 X 2 chi-square test of independence was used to analyze data regarding perceived close friend/parent disapproval/approval and IUPS. There were four primary findings.

First, students were significantly less likely to report having …

Bridging The Divide: Revisiting The Conceptualization Of Impulsivity And Its Relation To Alcohol Use And Alcohol Problems., Karen Kelley

Theses and Dissertations

The development of multiple theoretical models and measures of impulsivity has led to inconsistent use of this term and disagreement regarding the most salient predictors of alcohol-related outcomes. The present study examined whether self-report and behavioral measures of impulsivity measure the same construct and how eight conceptually distinct facets of impulsivity relate to alcohol-related outcomes. Participants completed measures and tasks to assess alcohol use, alcohol problems, trait impulsivity, and behavioral impulsivity. The UPPS-P and behavioral measures of impulsivity were largely uncorrelated with each other. Negative urgency and alcohol use emerged as direct predictors of alcohol-related problems. Lack of premeditation demonstrated …

Optimal Control Of Adaptive Wild Hogs, Katherine Barkley

Theses and Dissertations

Wild hogs (sus scrofa) have caused major damage to agricultural crops in the US due to their lack of natural predators and fast reproduction rates. Wild hogs change their behavior to evade capture. Thus, control methods are thwarted and may not result in sufficient mortality to keep pace with the reproduction of wild hogs. This study extends previous invasive species literature to include increasing costs due to adaptability in two settings: the presence of hogs is deterministic or stochastic. The analysis is limited to one farmer's objective function with varying degrees of adaptability for "smartness". The findings concluded the population …

Phytochemical And Biological Strategies To Improve Essential Oils Content In Lavender, Keefah Al-Garallaa

Theses and Dissertations

Lavender is an important medicinal plant that is sensitive to various environmental factors. Lavender essential oils have been shown to improve human health in response to many diseases. Lavender is grown all over the world, which indicates its ability to adapt to different climates. There are no reports of its commercial cultivation in Mississippi. It has been proven that there are many factors that directly affect the plant growth and concentration of essential oils in lavender. Studying these factors that affect plant growth and essential oils will be beneficial for lavender producers. The aim of this study is to increase …

Mississippi Teachers' Perceptions Of Environmental Education And Outdoor Instruction During A Covid-19 Pandemic, Kelisha Stamps

Theses and Dissertations

Environmental education (EE) and outdoor instruction are essential to understanding and addressing different environmental issues in school communities. This study investigated Mississippi teachers' perceptions on environmental education and outdoor instruction during 2020-2021. A state-wide survey and follow-up interview were conducted to examine their thoughts about environmental education and outdoor instruction and COVID-19 limitations in their classrooms and how that may affect their perceptions. Analysis was conducted using SPSS contingency and frequency tables, Chi-square Test of Independence, and content analysis of qualitative data. The results showed that Mississippi teacher participants believe that environmental education in Mississippi K-12 schools is very important …

The Application Of Photogrammetry For The Recording And Analysis Of Antemortem Cranial Depression Fractures, Keri Porter

Theses and Dissertations

Compared to other methods for digital modeling, photogrammetry is portable, user-friendly, and cost-effective. Despite the potential benefits to the subfield of bioarchaeology, few investigations into this technology have occurred. This research attempts to fill the gap by investigating the accuracy of photogrammetry for recording antemortem cranial depression fractures (CDFs). Using the Mississippi State Asylum skeletal collection, dry bone measurements of CDFs were compared to those on photogrammetric models. Additionally, three volunteers of various skill levels attempted to identify these fractures using the digital models. Results showed that despite accuracy in recording maximum length and width measurements, maximum depth could be …

Assessing Capabilities Of Thermal Imaging Technologies Equipped To Small Unmanned Aerial Systems (Suas) To Detect Grassland Bird Nests, Lori Hearon

Theses and Dissertations

North American grassland bird populations are declining more rapidly than other groups of birds. A well-established method of quantifying and monitoring grassland bird populations is by locating active nests. Active nests are often difficult to locate in grassland swards due to the varying heights within the canopy that nests are established. Studies quantifying grassland bird populations have low statistical power due to low sample sizes and high disturbance. Advances in small, unmanned aerial systems and thermographic imaging technologies have potential to improve efficiency of locating nests throughout canopies. This study explored detection accuracy of using thermal imagery to identify simulated …

Using Precision Agriculture To Identify Overlap In Conservation And Economic Opportunities In Agricultural Landscapes, Makayla Brister

Theses and Dissertations

Intense agriculture is detrimental to the environment and leads to nutrient runoff, decreased water quality, soil erosion, greenhouse gas emissions, and decreased wildlife habitat. In addition to negative environmental impacts, intense agriculture increases the financial strain on farmers. Farmers also face inconsistent yields from environmentally vulnerable lands. Due to these financial constraints and inconsistent yields, conservation goals are not always economically attractive to farmers and agricultural producers. One possible solution to this issue is the use of precision agriculture (PA) to inform strategic conservation efforts. We used PA technology to identify low-revenue field areas in the Mississippi Delta and Black …

Pact Of Impaired Polyamine Synthesis And Transport On Pneumococcal Transcriptome, Proteome, Metabolome, And Stress Responses, Mary Frances Nakamya

Theses and Dissertations

This dissertation is a compilation of published work and a manuscript that seeks to understand the role of polyamine metabolism in the regulation of pneumococcal physiology. Streptococcus pneumoniae (pneumococcus) is the major cause of community-acquired pneumonia, and otitis media worldwide. Genetic diversity and serotype replacement, and antibiotics resistance to confound existing therapeutic strategies and limit the effectiveness of the available capsule polysaccharide (CPS) based vaccines. Polyamines such as putrescine, spermidine and cadaverine are ubiquitous polycationic hydrocarbons that interact with negatively charged molecules and modulate important cellular processes. Intracellular polyamine concentrations are regulated by biosynthesis, degradation, and transport. This work investigated …

Post-Traumatic Stress Disorder Symptoms Impacting Caregivers Of Children With Charge Syndrome, Matthew A. Ferrigno

Theses and Dissertations

The current study aimed to focus on Post-Traumatic Stress Disorder (PTSD) symptoms in parents who have a child diagnosed with a rare genetic syndrome called CHARGE Syndrome. While previous studies have investigated related factors to parental PTSD (Reda & Hartshorne, 2008; Wulffaert et al., 2009), this study was one of the first to focus on parental PTSD symptomology and possible traumatic experiences related to CHARGE (e.g., medical complications). Specific concerns related to PTSD addressed in the current study included trauma histories, the number of surgeries a child underwent, and parent stress levels. One hundred and ninety-seven parents completed surveys that …

Pain Tolerance Feedback And Deliberate Self-Harm In Men And Women, Matthew A. Timmins

Theses and Dissertations

There is a growing literature supporting the idea that those who engage in non-suicidal deliberate self-harm (DSH) have altered pain perception compared to individuals who do not. For example, individuals who report a history of non-suicidal DSH behavior have a decreased sensitivity to transient pain during laboratory-based pain induction (e.g., Glenn et al., 2014). Research suggests that brief manipulations targeting individual beliefs can affect performance on subsequent tasks, including measures of pain sensitivity. To date, however, no study has examined the effects of experimentally manipulated pain perception on DSH behavior. The Self-Aggression Paradigm (SAP: Berman & Walley, 2003; McCloskey & …

Utilization Of Bioinformatic And Next Generation Sequencing Approaches For The Discovery Of Predictive Biomarkers And Molecular Pathways Involved In Bovine Respiratory Disease, Matthew Adam Scott

Theses and Dissertations

Bovine respiratory disease (BRD) is a highly dynamic disease complex that results from host, microbial agent, and environmental interactions. Despite nearly a century of targeted research, BRD remains the most economically damaging disease in beef cattle production and appears to be increasing in global incidence. While modern modalities for BRD detection exist, clinical diagnosis and management decisions largely depend upon clinical observations and their associated risk of disease. Though these approaches lack precision, they remain in use for many reasons, including fiscal and time constraints within beef production systems. Advancements in high-throughput sequencing have demonstrated the ability to provide insight …

Response Effort Attenuates Provoked Aggression In Men And Women, Michaela Patoilo

Theses and Dissertations

Previous efforts to manage aggressive behavior have generally focused on the emotion of anger, as opposed to aggressive behaviors. Several small-N studies have explored the promising approach of contingency-based interventions (e.g., the effort required to respond aggressively; Zhou et al., 2000), but have produced mixed results. Therefore, the present study aimed to determine whether experimentally-manipulated response effort effectively attenuates provoked aggressive responding using a modified version of the Taylor Aggression Paradigm (TAP; Berman et al., 2009). Participants included 123 (40 men; Mean age = 20.9, SD = 4.6) randomly assigned to either a low- or high-effort condition, crossed with a …

Thimet Oligopeptidases Top1 And Top2 Are Essential Regulators Of Defense Priming And Systemic Acquired Resistance In Arabidopsis Thaliana, Najmeh Nejat

Theses and Dissertations

The effector-triggered immunity (ETI) is activated at the site of pathogen infection and results in a state of enhanced immunity called systemic acquired resistance (SAR) in distal, uninfected plant organs. SAR relays on mobile signals transported from infected cells to distal organs, and on signal amplification which supports transcriptional re-programming associated with priming and execution of SAR. Previous research in our lab has identified the chloroplastic TOP1 and cytosolic TOP2 as salicylic acid (SA)–binding oligopeptidases, non-competitively inhibited by SA. We demonstrate that SAR triggered with P. syringae DC3000 AvrRpt2 is abolished in top2 whereas top1 top2 exhibits a SAR slightly …

Identification And Analysis Of Genes Associated With Drought Tolerance In Rice, Muteb Daham Q Alrifdi

Theses and Dissertations

Rice (Oryza sativa L.) is an important crop cultivated worldwide, and abiotic stresses limit its productivity. Different approaches were carried out to understand the mechanisms of rice defense responses against abiotic stresses, mainly drought. The NADPH-generating enzymes engaged in response to dehydration and salt stresses during the seedling stage of Nipponbare cultivar were analyzed. Enzyme activities of 6-phosphogluconate dehydrogenase (6PGDH), NADP-dependent aldehyde dehydrogenase, NADP-malic enzyme (NADP-ME) in leaves, and 6PGDH in roots were significantly increased in response to dehydration stress. NADP-ME and NADP-glutamate dehydrogenase activities in roots increased significantly in response to salt stress. These results suggest the involvement of …

Optical Probing Of Spatial Structural Abnormalities In Cells/Tissues Due To Cancer, Drug-Effect, And Brain Abnormalities Using Mesoscopic Physics-Based Spectroscopic Techniques, Prakash Adhikari

Theses and Dissertations

The quantitative measurement of structural alterations at the nanoscale level is important for understanding the physical states of weakly disordered optical mediums such as cells/tissues. Progress in certain diseases, such as cancer or abnormalities in the brain, is associated with the nanoscale structural alterations at basic building blocks of the cells/tissues. Elastic light scattering, especially at visible wavelengths range provides non-invasive ways to probe the cells/tissues up to nanoscale level. Therefore, a mesoscopic physics-based open light scattering technique with added finer focusing, partial wave spectroscopy (PWS), is developed to probe nanoscale changes. Then, molecular-specific light localization technique, a close scattering …

Development And Evaluation Of Ground And Aerial Robotic Systems In Commercial Poultry Houses, Pratik Parajuli

Theses and Dissertations

The live production sector of the poultry industry has a growing interest in robotics. Robotics have the possibility to monitor environmental conditions, assess bird welfare, and reduce labor for farm workers and owners. However, interactions of poultry with robotic systems in commercial poultry house environments is largely unknown. Therefore, the goal of this research was to assess the effect of ground and aerial robots on bird stress using avoidance distance (AD) and fleeing speed (FS) as indirect indicators. A low-cost, autonomous robot was also developed to aid in collecting data on environmental conditions in commercial broiler houses. AD and FS …

A Zoological Spectacular: Conservation In An American Zoo, Rita Bouwens

Theses and Dissertations

Accredited US zoos aim to support wildlife conservation and educate and influence the public and create a conservation-minded community by curating immersive multispecies experiences. In this case study, I examine how zoos may practice conservation through the frameworks of biopolitics, spectacle, affect, and mainstream conservation paradigms. To conduct this research, I interviewed 10 zoo staff from the animal, education, development, and retail departments of a Midwestern zoo. Their rhetoric about zoos and how they practice conservation suggests that zoo staff aim to generate affective responses from guests by displaying animals in managed care. These affective responses that staff hope to …

From Origin To Application: A Study Of Plant Orphan Genes, Seth Jordan O'Conner

Theses and Dissertations

As sequencing technology has taken off since the late 1990's, a unique phenomenon has been observed repeatedly: genes with little to no conservation across species. For a while, the predominant theory that arose to explain these genes was duplication and subsequent evolution of conserved genes. While this theory can explain some, still many genes have now been proven to arrive de novo - from previously non-coding DNA. This work further investigates the origins of these de novo evolved genes and their practical application relevance in crop biotechnology. This work demonstrates the dynamic nature of plant mitochondrial genomes between even closely …

The Effect Of Pain Tolerance Feedback On Human Aggression, Suzanne C. Amadi

Theses and Dissertations

Pain is a sensory experience associated with physical discomfort that is influenced by cognition and emotion and has been linked to an increased risk for aggression. The purpose of the current study was to examine the association between pain and aggression under controlled laboratory conditions using both experimental and non-experimental approaches. The aims of the study were two-fold. First, to manipulate perceived pain tolerance via faux feedback and then observe whether aggression differs as a function of this pain perception manipulation using a laboratory analogue of aggression. Second, to examine whether self-ratings of pain sensitivity and behavioral measures of pain …

Evaluation And Mechanisms Of Host-Plant Resistance To The Wireworm-Diabrotica-Systena Complex In Sweetpotatoes (Ipomoea Batatas) And A Commercial Kairomone Lure In Diabroticites, Thomas J. Douglas

Theses and Dissertations

An evaluation of host-plant resistance to the wireworm-Diabrotica-Systena (WDS) complex of root-feeding insects in sweetpotatoes was performed on a total of 15 cultivars and advanced lines over the course of 4 years (2017-2020). It was found that sweetpotatoes varieties can differ significantly in amount of damage incurred. Several mechanisms of resistance were proposed and tested: periderm toughness, dry weight percentage, and volatile organic chemical defenses. No significant difference was found amongst the varieties tested concerning the physical properties. Chemical analysis was limited in scope but did show some differences between a susceptible variety when compared to a resistant variety in …

Identification And Evaluation Of Mycotoxins Produced By Macrophomina Phaseolina, Vivek Hemant Khambhati

Theses and Dissertations

The fungus Macrophomina phaseolina (Tassi) Goidanich (Mp) is the causal agent of charcoal rot in soybean and infects over 500 plant species worldwide. Mp produces various mycotoxins and is suspected of utilizing a toxin-mediated process to penetrate host tissue. Identification and evaluation of secondary metabolites produced by Mp will further elucidate the pathogenesis mechanisms used by the fungus. Mp cultures isolated from soybean were evaluated for phytotoxicity in a hydroponic soybean bioassay and chemically analyzed by LC-MS/MS. All Mp cultures at two dilutions induced phytotoxicity symptoms including chlorosis, necrosis, wilting, stunting, and death. Analysis identified 13 unreported secondary metabolites including …

Kinetic Spectroscopic Quantification Of Biomarkers In Practical Samples, Weiyu Peng

Theses and Dissertations

Kinetic spectroscopic quantification refers to a subset of chromogenic (CG) and fluorogenic (FG) assays that deduce analyte concentration based on the UV-vis or fluorescence signal obtained during the CG/FG reaction processes. Existing kinetic spectroscopic quantification are based predominantly on reactions that can be approximated as a first-order process. Presented in this thesis is the kinetic spectroscopic quantification that uses higher order CG/FG reactions where the overall reaction can be approximated as combination of two sequential first-order processes. Included in chapter one is the theoretical model and several proof-of-concept applications. This model analyte is malondialdehyde (MDA), a lipid peroxidation biomarker of …

Existence And Multiplicity Of Positive Solutions For One-Dimensional P-Laplacian With Nonlinear And Intergral Boundary Conditions, Xiao Wang

Theses and Dissertations

In this dissertation, we study the existence and multiplicity of positive solutions to classes of one-dimensional singular p-Laplacian problems with nonlinear and intergral boundary conditions when the reaction termis p-superlinear or p-sublinear at infinity. In the p-superlinear case, we prove the existence of a large positive solution when a parameter is small and if, in addition, the reaction term satisfies a concavity-like condition at the origin, the existence of two positive solutions for a certain range of the parameter. In the p-sublinear case, we establish the existence of a large positive solution when a parameter is large. We also investigate …