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An Assessment Of The Diverse Freshwater Turtle Fauna Of Mississippi, Lucas Haralson Dec 2021

An Assessment Of The Diverse Freshwater Turtle Fauna Of Mississippi, Lucas Haralson

Master's Theses

Nestled within the Southeastern United States Turtle Priority Area, Mississippi boasts impressive freshwater turtle diversity and is home to 8.6% of extant turtle species. Despite this impressive richness, few studies have assessed freshwater turtle assemblages in this hotspot of aquatic diversity. This research aimed to elucidate the distributions and abundances of freshwater turtle species through a statewide investigation of all major river drainages of the state. Using baited hoop nets (90 cm and 120 cm diameter), turtles were collected, identified to species and sex, and measured, before being released. Turtle assemblages were assessed in both lotic and lentic environments from …


Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson Dec 2021

Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson

Dissertations

The southeastern United States is a freshwater turtle biodiversity hotspot, second only to southeastern Asia, and this region is inhabited by one of the largest freshwater turtles in the world: the alligator snapping turtle (Macrochelys temminckii). This species was heavily harvested from the 1960’s to the 1980’s for the turtle soup industry, apparently contributing to substantial, range-wide population declines. These declines, coupled with anthropogenic impacts on riverine and floodplain habitats, have led to M. temminckii being petitioned for federal listing under the U.S. Endangered Species Act; it is currently under review by the U.S. Fish and Wildlife Service …


Granulins In Norm And Neurodegenerative Pathologies, Anukool Bhopatkar Dec 2021

Granulins In Norm And Neurodegenerative Pathologies, Anukool Bhopatkar

Dissertations

Granulins (GRNs) are small, cysteine-rich modules produced from the proteolytic cleavage of the precursor protein called progranulin (PGRN). GRNs are present in the form of seven tandem repeats within the precursor and are known to be produced in the extracellular and in lysosomal environments. In physiology, PGRN and GRNs plays pleiotropic roles such as neuronal growth and differentiation, immunomodulation, wound healing. Recent studies have implicated pathological role for PGRN in Alzheimer disease (AD) and frontotemporal dementia (FTD) but specific mechanism(s) remains unclear. However, potential interactions between GRNs and Ab42 and TDP-43 seem like a plausible underlying mechanism. Studies presented here …


Dicer Represses Antiviral Innate Immunity Pathways In Mouse Embryonic Stem Cells, Chandan Gurung Dec 2021

Dicer Represses Antiviral Innate Immunity Pathways In Mouse Embryonic Stem Cells, Chandan Gurung

Dissertations

Recent studies have demonstrated that embryonic stem cells (ESCs) are deficient in expressing type I interferons (IFN), the cytokines that play key roles in antiviral responses. However, the underlying molecular mechanisms and biological implications of this finding are poorly understood. In this study, I used a synthetic RNA-based assay that can simultaneously assess multiple forms of antiviral responses in ESCs. Dicer is an enzyme essential for RNA interference (RNAi), which is used as a major antiviral mechanism in invertebrates but not clear in vertebrates. RNAi activity is detected in wild-type ESCs but is abolished in Dicer knockout ESCs (D−/−ESCs) as …


Comparative Genome Analysis Of Fungal Antagonists Marinomonas Ostreistagni 398 And M. Spartinae 468., Jessie L. Fields Dec 2021

Comparative Genome Analysis Of Fungal Antagonists Marinomonas Ostreistagni 398 And M. Spartinae 468., Jessie L. Fields

Honors Theses

Under certain conditions, the Spartina alterniflora and Juncus roemerianus grasses in marshes undergo progressive decline in an event known as Saltwater Marsh Dieback, which may be attributed to the presence of the plant pathogenic fungi Fusarium. The microbiomes of S. alterniflora and J. roemerianus from Deer Island, MS were characterized and Fusarium suppressing bacteria were identified. Among isolates capable of antagonizing Fusarium were Marinomonas ostreistagni 398 and M. spartinae 468. Despite the progress in understanding the diversity of Marinomonas, our ability to explain ecological, metabolic, and biochemical traits of marinomonads at the genomic sequence level remains limited. Analysis …


Human 5’-Tailed Mirtrons Are Processed By Rnasep, Mohammad Farid Zia Oct 2021

Human 5’-Tailed Mirtrons Are Processed By Rnasep, Mohammad Farid Zia

Dissertations

Approximately a thousand microRNAs (miRNAs) are documented from human cells. A third appear to transit non-canonical pathways that typically bypass processing by Drosha, the dedicated nuclear miRNA producing enzyme. The largest class of non-canonical miRNAs are mirtrons which eschew Drosha to mature through spliceosome activity. While mirtrons are found in several configurations, the vast majority of human mirtron species are 5’-tailed. For these mirtrons, a 3’ splice site defines the 3’ end of their hairpin precursor while a “tail” of variable length separates the 5’ base of the hairpin from the nearest splice site. How this tail is removed is …


Environmental Dna (Edna) Surveys For The Smalltooth Sawfish, Pristis Pectinata, In The Chandeleur Islands, Louisiana, Emma M. Humphreys Aug 2021

Environmental Dna (Edna) Surveys For The Smalltooth Sawfish, Pristis Pectinata, In The Chandeleur Islands, Louisiana, Emma M. Humphreys

Honors Theses

The Critically Endangered smalltooth sawfish, Pristis pectinata, was historically found throughout tropical and subtropical coastal waters of the Atlantic Ocean. As a result of mortalities in fisheries and habitat degradation, they became largely restricted to southwest Florida in the U.S. and the Bahamas by the 1980s. However, recent public encounter reports of sawfish in the Florida panhandle, Mississippi, and Louisiana suggest this species is occasionally present in northern Gulf of Mexico waters. Targeted species surveys are needed to improve our understanding of the occurrence and status of this species in these waters. This research used environmental DNA (eDNA) methods …


Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations Aug 2021

Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations

Honors Theses

Character displacement is a pattern that can be used to explain differences between similar species in sympatric and allopatric situations. Gause’s Principle explains that a niche can only be occupied by one species at a time, so character displacement may be a way for similar species in the same habitat to shift resource use and compensate in order for the species to coexist. The Southeastern United States offers a unique opportunity to study this pattern because the diversity of freshwater fauna is quite high. However, the question of “How did this region become so diverse?” remains unanswered. One way for …


Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells Aug 2021

Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells

Master's Theses

The presence of oil has been shown to affect the microbiomes of the water column, sediments, and organisms, both by altering the diversity and the composition of those microbial communities. If the microbiome is altered it may no longer provide benefits to its host organism, impacting its ability to survive. Thus, it is important to understand the effects of large-scale contamination events including the Deepwater Horizon oil spill. This study set out to examine the effects of oil exposure on the microbiome of two benthic species, southern flounder (Paralichthys lethostigma) and eastern oysters (Crassostrea virginica) to further understand the effects …


Characterization Of The Bacterial Microbiome Of Exotic Tick Species Collected From Migratory Birds, Raima Sen Aug 2021

Characterization Of The Bacterial Microbiome Of Exotic Tick Species Collected From Migratory Birds, Raima Sen

Master's Theses

Migratory birds often serve as natural/accidental hosts to ectoparasites like ticks (predominantly immature stages) and are known reservoirs of several pathogens transmitted by ticks. Parasitizing these birds, exotic tick species often hitch rides to non-native ecological niches, bringing along tick-borne pathogens. This study aims to profile the bacteriome of exotic tick species flying in and out of the US from the Neo-tropical South. A total of 421 tick samples comprised of several different tick species were collected off migratory songbirds at sites north of the Gulf of Mexico (Louisiana State). A 16S rRNA metagenomic multiplexed sequencing approach was used to …


Population Parameter Estimation And Stable Isotope Analysis Of Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) In The Pascagoula River, Alfonso Cohuo Aug 2021

Population Parameter Estimation And Stable Isotope Analysis Of Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) In The Pascagoula River, Alfonso Cohuo

Master's Theses

Gulf Sturgeon (GS), Acipenser oxyrinchus desotoi, are a threatened, anadromous fish species in the northern Gulf of Mexico. Their range is from the Pearl River, LA, in the west to the Suwannee River, FL, in the east with a longitudinal divide at Mobile Bay, AL, creating a western population unit (WPU) and an eastern population unit (EPU). Sturgeon belonging to the WPU exhibit lower abundances, higher mortality rates, and are overall less studied than their EPU counterparts. Notable data gaps for the WPU includes the absence of recent population parameter estimations and confirmed feeding habitat. My thesis aims to …


Interleukin-17a Facilitates Chikungunya Virus Infection By Inhibiting Ifn-Α2 Expression, Biswas Neupane Aug 2021

Interleukin-17a Facilitates Chikungunya Virus Infection By Inhibiting Ifn-Α2 Expression, Biswas Neupane

Dissertations

Interferons (IFNs) are the key components of innate immunity and are crucial for host defense against viral infections. Here, we report a novel role of interleukin-17A (IL-17A) in inhibiting IFN-α2 expression, thus promoting chikungunya virus (CHIKV) infection. CHIKV infected IL-17A deficient (Il17a-/-) mice expressed a higher level of IFN-α2 and developed diminished viremia and milder footpad swelling in comparison to wild-type (WT) control mice, this was also recapitulated in IL-17A receptor-deficient (Il17ra-/-) mice. Interestingly, IL-17A selectively blocked IFN-α2 production during CHIKV, but not West Nile virus (WNV) or Zika virus (ZIKV), infections. Recombinant IL-17A …


Patterns Of Habitat Use And Trophic Structure In Turtle Grass (Thalassia Testudinum)-Dominated Systems Across The Northern Gulf Of Mexico, Christian Hayes Aug 2021

Patterns Of Habitat Use And Trophic Structure In Turtle Grass (Thalassia Testudinum)-Dominated Systems Across The Northern Gulf Of Mexico, Christian Hayes

Dissertations

Seagrass structural complexity is a primary driver of nekton recruitment and faunal community structure. Few studies, however, have quantified the role of seagrass complexity on habitat use and trophic structures over large spatial scales. A large-scale simultaneous survey was conducted to assess relationships of multiple seagrass morphological complexity metrics to nekton habitat use, trophic dynamics, and blue crab (Callinectes sapidus) growth and mortality across the Northern Gulf of Mexico. Seagrass morphological and nekton community characteristics depended on site and season, and regional variation in seagrass morphology was an important driver of juvenile nekton abundance, species richness, beta diversity, …


The Role Of The Msaabcr Operon In Cell Wall Integrity And Programmed Cell Death During Biofilm Development, Bibek G C Aug 2021

The Role Of The Msaabcr Operon In Cell Wall Integrity And Programmed Cell Death During Biofilm Development, Bibek G C

Dissertations

Staphylococcus aureus is an important human pathogen in both community and health care settings. Biggest challenges with S. aureus as a pathogen is its ability to acquire antibiotic resistance and produce robust biofilms. In this work, we investigated the nature of the cell wall defect in the msaABCR operon mutant in the Mu50 (VISA) and USA300 LAC methicillin-resistant Staphylococcus aureus (MRSA) strains. Results showed that msaABCR-mutant cells had decreased cell wall thickness and cell wall crosslinking in both strains. These defects are most likely due to increased murein hydrolase activity and/or nonspecific processing of murein hydrolases mediated by increased …


Spatial And Seasonal Patterns Of Above- And Belowground Vegetation Biomass And Potential Drivers In The Pascagoula River Delta, Ms, Evan Grimes Aug 2021

Spatial And Seasonal Patterns Of Above- And Belowground Vegetation Biomass And Potential Drivers In The Pascagoula River Delta, Ms, Evan Grimes

Master's Theses

Coastal wetlands provide a valuable wealth of services to the greater coastal ecosystem and human communities. However, threats such as sea level rise and conservation projects, such as freshwater diversions, have the potential to alter coastal wetlands in different ways. In this thesis, I describe the effects of inundation and nitrogen on vegetation productivity using a field-sampling approach and an in situ controlled mesocosm experiment, called a marsh organ. The West Channel of the Pascagoula River contained significantly higher belowground biomass than the East Channel, which is more anthropogenically modified. Vertical distribution of belowground biomass did not strongly vary between …


Mitochondrial Replacement And Mitonuclear Interactions In The Broadstripe Topminnow (Fundulus Euryzonus), Auburn Ansley May 2021

Mitochondrial Replacement And Mitonuclear Interactions In The Broadstripe Topminnow (Fundulus Euryzonus), Auburn Ansley

Honors Theses

When species hybridize, mitochondrial and nuclear introgression can take place. This is commonly observed in freshwater fish species, such as the Fundulus notatus complex, which is composed of F. notatus, F. olivaceus, and F. euryzonus. The broadstripe topminnow, F. euryzonus, is only found in the Amite and Tangipahoa Rivers in the Lake Pontchartrain drainage, where it overlaps in distribution with F. olivaceus. Previous studies determined that F. euryzonus in the Tangipahoa River system possesses mitochondrial DNA (mtDNA) from F. olivaceus as a result of hybridization between the two species. The goal of this thesis was …


Interregulation Between Msaabcr Operon And Ccpe To Determine Staphylococcal Metabolism And Virulence, Erin R. Cox May 2021

Interregulation Between Msaabcr Operon And Ccpe To Determine Staphylococcal Metabolism And Virulence, Erin R. Cox

Honors Theses

Staphylococcus aureus is a complex human pathogen that causes problems in both healthcare and community settings. Staphylococcus aureus is a gram-positive, sphere shaped bacterium that usually colonizes in the nasal cavity of healthy individuals. Staphylococcus aureus infections are a growing health concern due to its ability to produce virulence factors, such as pigmentation, protease production, and capsule formation. Two regulators in S. aureus virulence factors are msaABCR, which is a newly characterized operon, and ccpE. In order to determine the interaction between these two regulators in regulating virulence and metabolism in S. aureus, ccpE and ccpE/ …


The Diversity And Evolution Of Phenazine Biosynthesis Pathways In Enterobacterales, Christian Leise May 2021

The Diversity And Evolution Of Phenazine Biosynthesis Pathways In Enterobacterales, Christian Leise

Honors Theses

Enterobacterales is an order of Gram-negative bacteria that encompasses plant and animal pathogens and organisms of industrial importance. Some of these bacteria produce secondary metabolites classified as phenazines (Phz). Studies in other groups of microorganisms revealed that phenazines are redox-active and exhibit broad antibacterial, antifungal, and antiparasitic activity. Enterobacterales are known to produce phenazines, but details about the diversity, biochemistry, and function of phenazine metabolites in these organisms are missing. In this work, we screened the National Center for Biotechnology Information (NCBI) GenBank for genome sequences of phenazine-producing (Phz+) Enterobacterales. Additionally, genomes of Phz+ strains Pectobacterium carotovorum cc303 and …


Vertebrates At The University Of Southern Mississippi: A Wildlife Survey Of The Bear Point Bayou And Surrounding Gulf Park Campus, Hannah Mcduffie May 2021

Vertebrates At The University Of Southern Mississippi: A Wildlife Survey Of The Bear Point Bayou And Surrounding Gulf Park Campus, Hannah Mcduffie

Honors Theses

This project originated through interest in pursuing a field-based research project involving vertebrates. After conducting literature reviews, it was found that the Bear Point Bayou running through the University of Southern Mississippi Gulf Park Campus has never been thoroughly surveyed for species richness (Mohrman et al. 2016). Four sites on the Gulf Park Campus were chosen and vertebrate species were documented and identified through observations, camera trapping, and vocalization recordings. These data, along with species previously recorded on campus, were combined, and compared to data from the Gulf Coast Phenology Trail of which the Gulf Park Campus was recently added …


Study Of The Role Of The Msaabcr Operon In Tricarboxylic Acid Cycle Activity And Persister Cell Formation In Staphylococcus Aureus, Karsen Motter May 2021

Study Of The Role Of The Msaabcr Operon In Tricarboxylic Acid Cycle Activity And Persister Cell Formation In Staphylococcus Aureus, Karsen Motter

Honors Theses

Staphylococcus aureus is an important human pathogen that causes wide arrays of infections ranging from minor skin infections to lethal systemic conditions such as infective endocarditis, osteomyelitis, sepsis and pneumonia. These systemic diseases are often difficult to treat due to the presence of persister cells. Persister cells are a phenotypic variant of the bacterial population that exhibit extreme and transient antibiotic tolerance accompanied by a transient halt in growth. Upon cessation of antibiotic treatment, however, persisters resume growth which results in recurrence of infections. This characteristic of persister cells therefore displays high clinical significance. In this study, we show the …


Phosphodiesterase D Is Involved In Bile Resistance In Listeria Monocytogenes, Sophia A. Ali May 2021

Phosphodiesterase D Is Involved In Bile Resistance In Listeria Monocytogenes, Sophia A. Ali

Honors Theses

Listeria monocytogenes is a deadly foodborne bacterium that is responsible for almost 20% of food-related deaths in the United States. Listeria monocytogenes contaminates ready-to-eat products such as cheese, deli meat, and ice cream. Once ingested, it invades the intestinal lining and can enter the bloodstream, causing listeriosis. There is a gap in the knowledge of the pathogenesis of L. monocytogenes in how it is able to survive in the gastrointestinal tract in the presence of bile, which has bactericidal properties. Previous studies have suggested that the second messenger cyclic-dimeric-GMP may be involved in the regulation of virulence factors of Listeria. …


Effects Of Prescribed Fire On Soil Respiration In A Longleaf Pine Forest., Caroline E. Paxton May 2021

Effects Of Prescribed Fire On Soil Respiration In A Longleaf Pine Forest., Caroline E. Paxton

Honors Theses

Prescribed fire is a common tool used to increase the herbaceous diversity in longleaf pine forest understories and to eliminate competition from undesirable mid-canopy species. Little is known about the effects of these fires on the soil respiration rates within these forests. A study of the effects of prescribed fire on soil respiration was conducted within a longleaf pine stand at the Lake Thoreau Environmental Center to examine soil respiration across seasons and before and after a prescribed fire. Soil CO2 efflux rates were measured using a LICOR LI-8100A gas flux system with long-term chambers from October 2020 to …


Investigating Pirna Expression And Function In Regenerating Tissue Of Segmented Annelid Capitella Teleta, Beatriz Schueng Zancanela May 2021

Investigating Pirna Expression And Function In Regenerating Tissue Of Segmented Annelid Capitella Teleta, Beatriz Schueng Zancanela

Honors Theses

Regeneration can be observed virtually in all animals and previous studies have identified numerous genes involved in this process. In some invertebrates, the P-element induced wimpy testis (PIWI) genes appear to have an essential role. One such organism is Capitella teleta, a widely accepted model for annelid development. PIWI proteins are associated with small non-coding RNA called PIWI-interacting RNAs or piRNAs, which are involved in transposon silencing in the germline cells of many animals. It was previously believed that these proteins were only expressed in germline cells, however, recent studies have shown expression in somatic tissues as well. The function …


Assessing The Occurrence Of Trichechus Manatus Latirostris In Mobile Bay, Alabama Using Edna, Elora Pierce May 2021

Assessing The Occurrence Of Trichechus Manatus Latirostris In Mobile Bay, Alabama Using Edna, Elora Pierce

Honors Theses

In the past several decades Florida manatees (Trichechus manatus latirostris) have begun to expand their summer range into the northern Gulf of Mexico. Because this is a recent occurrence, not much is known about their habitat use and distribution in this region. Citizen-sourced sighting data suggests that Florida manatees frequent subembayments of Mobile Bay, Alabama, reaching a sighting peak in August. To assess the occurrence of manatees in this area environmental DNA surveys were used from winter (February 19-20) and summer (August 21-22) of 2018. At each of the 21 sites ranging from the mouth of Mobile Bay, …


Phenotypic Characterizations Of Msaabcr Operon Deletion In Staphylococcus Epidermidis Rp62a, Raelyn Williams May 2021

Phenotypic Characterizations Of Msaabcr Operon Deletion In Staphylococcus Epidermidis Rp62a, Raelyn Williams

Honors Theses

Staphylococcus epidermidis is a human pathogen that is increasingly known for its role in hospital infections associated with implantable medical devices. Antibiotic resistance has become a concerning issue for these infections as this bacteria have various virulence traits that help to evade immune response and antibiotic treatment. Currently, the most effective way to treat S. epidermidis infection is removal of the implant and long-term antibiotic treatment. S. epidermidis causes infection by expressing several protein factors that induce biofilm formation, the bacteria’s primary virulence mechanism. The purpose of this study was to perform the phenotypic characterizations of the msaABCR operon in …


Molecular Characterization Of Galectin From Amblyomma Americanum In Context Of Α-Gal Syndrome, Sumar Beauti May 2021

Molecular Characterization Of Galectin From Amblyomma Americanum In Context Of Α-Gal Syndrome, Sumar Beauti

Honors Theses

The lone star tick Amblyomma americanum is a vector of various disease-causing pathogens and tick-borne alpha-gal syndrome (AGS) with rapidly expanding populations in the south- and northeast regions of the United States. This study aimed to molecularly characterize galectin and determine its involvement in galactose-α-1,3-galactose (α-gal) synthesis, transport, reproductive fitness, and microbial homeostasis in this tick. The lone star tick galectin possesses two conserved carbohydrate recognition domains and shares homology with other Ixodid tick galectins. Time and tissue-dependent expression data shows that galectin is constantly expressed in salivary glands, midgut, and ovary tissues. An RNA interference approach was used to …


The Role Of Gac/Rsm Signal Transduction Pathway In The Biology Of Antagonistic Marine Bacterium Gynuella Sunshinyii 449, Anhthu Truong May 2021

The Role Of Gac/Rsm Signal Transduction Pathway In The Biology Of Antagonistic Marine Bacterium Gynuella Sunshinyii 449, Anhthu Truong

Honors Theses

Gynuella sunshinyii is a newly characterized bacterium with a remarkable ability to produce multiple secondary metabolites that act as potential antibiotics for medical applications. Currently, little is known about gene regulation in this unusual microorganism. In 2018, studies conducted of rhizosphere microbiomes of tidal marsh grasses on Deer Island, MS, resulted in multiple isolates of halophilic, aerobic, Gram-negative bacteria with antagonistic properties. One of the most active antagonists was identified as Gynuella sunshinyii 449. The genome of strain 449 was sequenced with Illumina MiSeq, assembled with Unicycler and SPAdes, and annotated with RASTtk. The annotation revealed a 6.09 Mb genome …


The Impact Of Oxygen Availability And Oxidative Stress On Regulation Of Cyclic-Dimeric-Gmp In Listeria Monocytogenes Strain F2365, Anna G. Welch May 2021

The Impact Of Oxygen Availability And Oxidative Stress On Regulation Of Cyclic-Dimeric-Gmp In Listeria Monocytogenes Strain F2365, Anna G. Welch

Honors Theses

Listeria monocytogenes is a gram-positive foodborne pathogen that results in the infectious disease listeriosis. The second messenger molecule cyclic-dimeric-GMP has been found to be responsible for the regulation of expression of many of its virulence factors with diguanylate cyclases and phosphodiesterases regulating the intracellular concentration of cyclic-di-GMP through synthesis and degradation, respectively. This study investigated the possibility that the availability of oxygen is the environmental signal crucial to the regulation of these enzymes. Prior research in our laboratory has demonstrated that the intracellular concentration of cyclic-di-GMP is elevated when exposed to anaerobic conditions. Due to this, it was hypothesized that …


Biochemical And Computational Characterization Of Small Regulatory Rnas In The Eastern Oyster, Crassostrea Virginica, Isabelle Townsend May 2021

Biochemical And Computational Characterization Of Small Regulatory Rnas In The Eastern Oyster, Crassostrea Virginica, Isabelle Townsend

Honors Theses

RNA interference (RNAi) is a process by which gene expression is regulated using small non-coding RNAs (ncRNAs). Three classes of ncRNAs, including micro-RNA (miRNA), short-interfering RNA (siRNA), and Piwi-interacting RNA (piRNA), are readily distinguishable in eukaryotic systems based on unique characteristics such as read sizes, overlap signatures, and mode of biogenesis. In this study, a method for purification of small RNAs was explored in the eastern oyster, Crassostrea virginica. This method involved the use of Sepharose beads for anion exchange chromatography to enhance purification of Argonaute associated small RNAs. Following RNA extraction and purification, small RNA libraries were created …


Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang May 2021

Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang

Dissertations

Changes in climate and atmospheric acidic deposition alter biogeochemical cycles in forested ecosystems. I investigated the responses of vegetation, soil, and hydro-related processes to changes in climate and acidic deposition at five high-elevation forests in the southeastern U.S. using a biogeochemical model - PnET-BGC model. I focused on change-points and thresholds concepts that were less studied in forest ecosystems as well as seasonal variability of responses and extreme events. I applied principal component analysis (PCA) to reduce the dimensionality of data. I developed a Bayesian multi-level model to derive key biogeochemical variables response to temperature and precipitation (local) and latitude …