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Direct And Indirect Effects Of Invasive Cirsium Arvense On Pollination In Southern Appalachian Floral Communities, Jesse Daniels

Electronic Theses and Dissertations

Invasive plants can alter pollination dynamics in invaded communities by disrupting patterns of pollinator visitation, pollen transfer dynamics (conspecific [CP] and heterospecific [HP]), and reproductive success. The direction of invasive effects (competitive, neutral, and facilitative) may be partially determined by spatial scale and species’ floral traits. Here, we investigated pollinator visitation, CP and HP receipt, and pollen tube growth for species in a C. arvense present community and non-present community at two scales. At the community-level, the effect of C. arvense on pollinator visitation varied among species. Floral symmetry seemed to explain this variation. At the floral neighborhood-level, we found …

Localization Of Sip470, A Plant Lipid Transfer Protein In Nicotiana Tabacum, Shantaya Andrews

Electronic Theses and Dissertations

SABP2-interacting protein 470 (SIP470), a non-specific lipid transfer protein (nsLTP), was discovered in a yeast two-hybrid screening using SABP2 as bait and tobacco leaf proteins as prey. SABP2 is an important enzyme in systemic acquired resistance that converts salicylic acid to methyl salicylate. Localization studies are an important aspect to understanding the biological function of proteins. nsLTPs are generally considered apoplastic proteins and has been localized intracellularly and extracellularly. Transient expression shows highest expression of SIP470-eGFP at 2 days post infiltration into Nicotiana benthamiana. Confocal microscopy showed localization near the periphery of the cell. Subcellular localization using differential centrifugation showed …

Sip-428, A Sir2 Deacetylase Enzyme And Its Role In Biotic Stress Signaling Pathway, Bal Krishna Chand Thakuri

Electronic Theses and Dissertations

SABP2 (Salicylic Acid Binding Protein 2) plays a vital role in the salicylic acid signaling pathway of plants both regarding basal resistance and systemic acquired resistance against pathogen infection. SIP-428 (SABP2 Interacting Protein-428) is a Silent information regulator 2 (SIR2) like deacetylase enzyme that physically interacts with SABP2 in a yeast two-hybrid interaction and confirmed independently by a GST pull-down assay. We demonstrated that SIP- 428 is an NAD+ dependent SIR2 deacetylase enzyme. Transgenic tobacco plants silenced in SIP- 428 expression via RNAi showed enhanced basal resistance to microbial pathogens. Moreover, these SIP-428-silenced lines also exhibited a robust induction of …

The Study Of Alcoholic Liver Diseases, Seun Emmanuel Owoseni

Electronic Theses and Dissertations

Excessive alcohol consumption is the primary contributing factor in the development of alcoholic liver diseases (ALD). Nicotine contained in tobacco is a major addictive alkaloid, which enhances the effects of ALDs. The major enzyme involved in nicotine metabolism is cytochrome P450 2A5 (CYP2A5) which is produced in the liver. Alcohol can stimulate the CYP2A5 enzyme. We utilized cyp2a5-/- knockout mice in this research to examine the effects of CYP2A5.

The cyp2a5-/- mice and wild-type (WT) mice were fed liquid ethanol diet with or without nicotine to induce ALD. Nicotine enhancing effects on ALD were observed in WT mice but not …

Bryophyte Assemblages On American Hornbeam (Carpinus Caroliniana) And The Surrounding Arboreal Communities Within The Forest Of East Texas, Cassey Edwards

Electronic Theses and Dissertations

The bryophytes, the non-vascular plants, include the mosses (Bryophyta with approximately 13,000 species), the liverworts (Marchantiophyta with approximately 5,000 species), and the hornworts (Anthocerotophyta with approximately 150 species). Initial observations indicated that the midstory tree Carpinus caroliniana Walter (American hornbeam) has a bryophyte composition with an unusually high diversity of leafy liverworts. Voucher samples were taken from the four intercardinal directions (Northeast, Northwest, Southwest, and Southeast) from six Carpinus trees and their nearest neighbor that was neither Pinus nor another Carpinus at each of six sites across East Texas. Percent coverage, species richness, Shannon’s diversity and Pielou’s evenness were computed. …

Lead Poisoning In Maine's Common Loons: Examining Biological And Social Dimensions, Brooke S. Macdonald

Electronic Theses and Dissertations

Lead poisoning from ingested fishing tackle is a well-documented conservation concern for adult common loons in the Northeastern United States. To mitigate this issue, the state of Maine began implementing restrictions on lead tackle use in 2002, with new legislation added in 2016 and 2017. In addition to legislative action there have been various non-regulatory strategies employed in Maine to help raise awareness, such as the Fish Lead Free campaign. Human behavior is the root cause of lead fishing tackle in aquatic environments, and also can determine the success of legislative and educational efforts. Measuring underlying factors that influence behaviors, …

Characterization Of Sip68 For Its Role In Plant Stress Signaling, Saroj Chandra Lohani

Electronic Theses and Dissertations

Glucosyltransferases catalyze the transfer of glucose molecules from an active donor to acceptor molecules and are involved in many plant processes. SIP68, a tobacco glucosyltransferase protein, is a SABP2-interacting protein. It was identified in a yeast two-hybrid screen using SABP2 as bait and tobacco proteins as prey. SABP2, converts methyl salicylate to salicylic acid (SA) as a part of the signal transduction pathways in SA-mediated defense signaling. Subcellular localization is a crucial aspect of protein functional analysis to assess its biological function. The recombinant SIP68 tagged with eGFP was expressed transiently in Nicotiana benthamiana and observed under confocal microscopy. Fluorescent …

The Effect Of Wild Blueberry Bioactives On Endothelial Cell Migration And Angiogenesis: An In Vitro Mechanistic, Genomic And Proteomic Approach, Panagiotis Tsakiroglou

Electronic Theses and Dissertations

The goal of this study is to investigate the effects of wild blueberry fractions (Anthocyanins and Phenolic acids) on vascular function and physiology. More specifically the potential effects of the above fractions and their combination in physiological concentrations on endothelial cell migration, angiogenesis, gene expression and proteins synthesis of markers related to the above processes. The objectives are to study whether anthocyanins, phenolic acids and their combinations (ACNs:PAs) affect: a) cell proliferation, b) speed of endothelial cell migration, c) angiogenesis, d) gene expression of genes critical for cell migration and angiogenesis such as RAC1, RHOA, AKT1, eNOS and VEGF and …

Flower Visitation In Relation To Pollen And Nectar Nutrition: Implications For Pollinator Habitat And Conservation, Megan E. Leach

Electronic Theses and Dissertations

Pollination of both wild and crop plants is at a crossroads; honey bee populations are experiencing losses at a higher rate than ever before, and some native bee species are declining in abundance to the point of being listed as endangered species. A few examples of these threats include pesticide exposure, habitat loss, and climate change. In response to bee population declines, conservation efforts have been initiated to increase habitat quality for bees by planting pollinator reservoirs or gardens. Plants provide nutrition to bees in the form of pollen and nectar. Several studies have shown links between higher nutritional quality …

Spg Directs Arp2/3 Mediated F-Actin Networks To Support Syncytial Furrow Ingression In Drosophila, Shannon M. Henry

Electronic Theses and Dissertations

In the Drosophila embryo, nuclear divisions 10-13 occur in a syncytium with transient membrane furrows separating neighboring nuclei before the occurrence of cellularization. This process is driven by cytoskeletal and membrane trafficking networks, and while RalA and Rab8 have been identified to drive membrane addition to furrows, less is known about the control of dynamic F-actin networks needed for furrow formation. Here, the role of the DOCK protein Sponge (Spg) in furrow formation is explored through shRNA knockdown and live-imaging of syncytial Drosophila embryos. I have found that Spg is required for furrow ingression and that without Spg, furrows can …

Unfolded Protein Response Pathways In Skeletal Muscle Homeostasis., Kyle R. Bohnert

Electronic Theses and Dissertations

Skeletal muscle mass, contractile properties, and metabolic function are regulated through the coordinated activation of multiple intracellular signaling pathways and genetic reprogramming. The endoplasmic reticulum (ER) plays a pivotal role in protein folding and calcium homeostasis in many cell types, including skeletal muscle. Disruption of calcium levels or accumulation of misfolded proteins in the ER lumen leads to stress, which results in the activation of a signaling network called the unfolded protein response (UPR). Further, recent studies have suggested that in certain conditions, UPR pathways can be activated independent of ER stress. However, the role of ER stress and the …

Investigating The Interaction Of Monoamines And Diel Rhythmicity On Anti-Predator Behavior In An Orb-Weaving Spider, Larinioides Cornutus (Araneae: Araneae), Rebecca Wilson

Electronic Theses and Dissertations

Circadian rhythms are ubiquitous among organisms, influencing a wide array of physiological processes and behaviors including aggression. While many neurophysiological mechanisms are involved in the regulation of aggressive behaviors, relatively few studies have investigated the underlying components involved in the interplay between circadian rhythms and aggression. Spiders are an ideal model system for studying circadian regulation of aggression as they are ecologically both predators and prey. Recent studies have revealed a nocturnal orb- weaving spider Larinioides cornutus exhibits a diel and circadian rhythm in anti-predator behavior (i.e. boldness) that can be manipulated by administration of octopamine (OA) and serotonin (5- …

Role Of Ataxia-Telangiectasia Mutated Kinase In Cardiac Autophagy And Glucose Metabolism Under Ischemic Conditions, Patsy Thrasher

Electronic Theses and Dissertations

Ataxia-telangiectasia mutated kinase (ATM), a serine/threonine kinase primarily located in the nucleus, is typically activated in response to DNA damage. Individuals with mutations in ATM gene develop a disease called Ataxia telangiectasia (AT). These individuals are more susceptible to ischemic heart disease and metabolic disorder. Our lab has previously shown that ATM plays a critical role in β-adrenergic receptor (β-AR) - and myocardial infarction (MI)-stimulated myocyte apoptosis and cardiac remodeling. This study tested the hypothesis that ATM plays a critical role in cardiac autophagy and glucose metabolism following MI and ischemia, respectively. Early during MI (4 hours after its onset) …

Impact Of Reproductive Mode On Skeletal Development In A Reproductively Bimodal Squamate Species, Amanda Tedder

Electronic Theses and Dissertations

Viviparity has evolved multiple times within squamates. Eggshells are reduced in viviparous forms, which reduces calcium available to embryos during development. This study tested the hypothesis that reduced calcium impacts neonates of viviparous forms. Developmental series from oviparous and viviparous populations of Zootoca vivipara (reproductively bimodal) were cleared & stained to reveal bone development. Photographs (high magnification, calibrated to size) were used to obtain measurements of lengths of the body, humerus, femur, skull and lower jaw, and of ossified portions of limb bones. Percent ossification was scored for targeted skull bones. Results were analyzed using general linear models and revealed …

Post-Transcriptional Regulation Of Rsma In Pseudomonas Aeruginosa, Ian Miller

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative bacillus found in numerous environments. Gene regulatory mechanisms such as; Two-Component Systems, transcriptional and post-transcriptional regulators, and small non-coding RNAs control the expression of virulence factors that allow P. aeruginosa to initiate acute infections and persist as a chronic infection. A significant post-transcriptional regulator involved in these regulatory networks is the Regulator of Secondary Metabolites (RsmA). In this study, we investigated the contribution of a putative stem-loop on expression of RsmA. We constructed rsmA leader fusions to measure translation with and without the stem-loop present. Secondly, we introduced point mutations to disrupt the formation …

Unique Osmoregulatory Morphology In Primitive Sharks: An Intermediate State Between Holocephalan And Derived Shark Secretory Morphology, Matthew Eric Larsen

Electronic Theses and Dissertations

Discovery of an unusual rectal gland in the Atlantic sixgill shark, Hexanchus vitulus, led to examination of rectal glands in 29 species of epipelagic and deep-sea sharks. Eight of 14 deep-sea species of sharks had digitiform glands that were previously assumed to be characteristic of elasmobranchs (N=281; mean width-length ratio ± SD = 0.18 ± 0.07). Hematoxylin-and-eosin stained sections from deep-sea sharks were similar to those from shallow water sharks. Glands from the family Somniosidae were kidney bean-shaped (N = 3; mean width-length ratio ± SD = 0.46 ± 0.05); whereas those from the families Echinorhinidae and Hexanchidae appeared lobulate …

Does Spaceflight Increase The Chance Of Female Astronauts Developing Uterine Cancer?, Areej Mosa

Electronic Theses and Dissertations

One of the main questions put forth by NASA and the European Space Agency (ESA) is whether or not an organism, especially mankind, can complete an entire life cycle in space. With this in mind, it is essential to study the effect of spaceflight on reproductive tissues. Using simulated microgravity techniques and whole-body radiation we sought to determine if females subjected to a simulated spaceflight environment have increased incidences of uterine cancer. Uterine tissue from mice subjected to simulated spaceflight was analyzed using immunohistochemical staining and western blot analysis. Two pathways commonly activated in cancer were investigated. Additionally, the uterine …

Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex

Electronic Theses and Dissertations

Lake Baikal is the oldest known lake and a unique ecosystem, home to several species of fresh water sponge. A disease outbreak affecting the dominant species, Lubormirskia baialensis, was recently reported. The cause of the disease has not been determined but one of the current hypothesis is that the increase in methane concentration is correlated to the disease outbreak. This pilot study characterized the microbiomes of sick and healthy sponges through the use of 16S rRNA sequencing. Sick sponge microbiomes shared a conserved group of taxa while the healthy sponge microbiomes had greater diversity. Indicator species analysis identified two significant …

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …

Identification Of “Fhua” Like Genes In Rhizobium Leguminosarum Atcc 14479 And Its Role In Vicibactin Transport And Investigation Of Heme Bound Iron Uptake System, Sushant Khanal

Electronic Theses and Dissertations

Siderophores are low molecular weight, iron chelating compounds produced by many bacteria for uptake of iron in case of iron scarcity. Vicibactin is a trihydroxamate type siderophore produced by Rhizobium leguminosarum bv. trifolii ATCC 14479. This work focuses on identifying an outer membrane receptor involved in the transport of vicibactin. We have confirmed the presence of the putative fhuA gene in R. leguminosarum bv. trifolii ATCC 14479. This bacteria shows mutualistic symbiosis with the red clover plant Trifoliium prantense. Leghemoglobin, with its cofactor heme is present in the plant root nodules that surrounds the infecting organism present in the nodules. …

A Role Of Vitamin B2 In Reducing Amyloid-Beta Toxicity In A Caenorhabditis Elegans Alzheimer’S Disease Model, Muhammad Tukur Ameen

Electronic Theses and Dissertations

Alzheimer’s disease (AD) is associated with amyloid-beta peptide deposition and loss of mitochondrial function. Using a transgenic C. elegans AD worm model expressing amyloid-beta in body wall muscle, we determined that supplementation with either of the forms of vitamin B₂, flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD) protected against amyloid-beta mediated paralysis. FMN and FAD were then assayed to determine effects on ATP, oxygen consumption, and reactive oxygen species (ROS) with these compounds not significantly improving any of these mitochondrial bioenergetic functions. Knockdown of the daf-16/FOXO transcriptional regulator or the FAD synthase enzyme completely abrogated the …

Tidal Creek And Substrate Effects On Oyster Reef Associated Fish And Decapod Condition And Density, Thomas S. Funk

Electronic Theses and Dissertations

Oyster reefs are essential fish habitat and a worldwide loss of reefs has the potential to negatively affect reef-associated nekton populations. Along the 100 km Myrtle Beach, SC shoreline, oyster reefs ostensibly have disappeared within swash tidal creeks, which are anthropogenically altered estuarine systems that drain into the coastal ocean directly over shoreline beaches. To address oyster reef losses, a series of shell bag reefs were constructed within multiple swash tidal creeks. Reefs also were constructed in tidal creeks associated with estuaries directly connected to the ocean by an inlet. The purpose of this study was to compare nekton usage …

Wildlife Use Of Vernal Pools In An Urbanizing Landscape With A Focus On Population Vitality Of Vernal Pool-Breeding Amphibians, Carly Eakin

Electronic Theses and Dissertations

Vernal pools in the northeastern United States provide essential habitat for pool-breeding amphibians and provide resources for other forest-dwelling wildlife. These pools and pool-breeding amphibians in particular are threatened by land conversion associated with urbanization and urban-associated factors. The responses of these amphibians and of birds and mammals using vernal pools to intermediate levels of urban development are largely unknown. I used field observations and lab experiments to study the amphibians, birds, and mammals associated with vernal pools along an urban development gradient in greater Bangor, Maine.

In Chapter 1, I examined bird and mammal use and assemblage composition at …

An Examination Of Beta Diversity Indices And Their Predictors In Two Large-Scale Systems, Philip Schroeder

Electronic Theses and Dissertations

Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (γ) can be broken down into within-site diversity (α) and between-site diversity (β). In particular, it has been noticed that the β …

Characterizing Biogeochemical Shifts In Two Salix Caroliniana Michx. Encroached Freshwater Subtropical Marshes, Janet Ho

Electronic Theses and Dissertations

Shrub encroachment is a common disturbance in wetlands, but little is known about how shrub encroachment impacts functions such as carbon (C) storage and nitrogen (N) cycling. The objective of this thesis was to identify differences in physiochemical properties (within soil, water and leaf tissue) and biogeochemical processes (soil respiration, enzyme activity, litter decomposition, and N cycling) in two subtropical freshwater marshes encroached by coastal plain willow (Salix caroliniana Michx.). Two study regions (Moccasin Island and Lake Apopka) were selected because of their location in the St. John's River watershed and their unique histories and hydroperiod, allowing for an investigation …

Unearthing The Past And Present Of A Semi-Fossorial Lizard: Conservation Genetics, Phylogeography, And Taxonomy Of Plestiodon Egregius., Kathryn Mercier

Electronic Theses and Dissertations

Characterizing an organism's evolutionary history and population structure as well as understanding the forces shaping that divergence is crucial to conservation biology. A clear understanding of the patterns of diversity and divergence are imperative for the best management of the organism, while an awareness of what drives these patterns can lead to better predictions of how organisms will respond to future climate change. Historical climate changes and associated sea level change are among the main forces driving divergence in many species. To examine how effects of climate changes may have driven patterns of intraspecific divergence, I examined Mole Skinks, Plestiodon …

Microbial Communities And Their Impact On Bioenergy Crops In Dynamic Environments, Brandon Monier

Electronic Theses and Dissertations

Native perennial grasses, such as prairie cordgrass (PCG, Spartina pectinata Link), and switchgrass (SG, Panicum virgatum L.) have a great potential as bioenergy crops, because they require fewer inputs, produce more energy, and reduce greenhouse gas emissions in comparison to annual cropping systems such as corn and soybean. SG has been selected by the U.S. Department of Energy for development as bioenergy crop, but studies have shown that PCG can outcompete switchgrass in terms of biomass production. These crops can also form associations with a wide variety of plant growth promoting microbes including arbuscular mycorrhial (AM) fungi. In CHAPTER 2, …

The Contributions Of Fc Gamma Receptors And Macropinocytosis To The Internalization, Sorting And Clearance Of Antibody Coated Nanovesicles In Macrophages, George Opoku-Kusi Jr.

Electronic Theses and Dissertations

Macrophages are tissue-resident phagocytes that play critical roles in immune response and tissue homeostasis. They have a tremendous capacity to internalize objects of various sizes ranging from nanoscale viral particles to micron sized bacteria and tumor cells. This phenomenon, termed phagocytosis for the uptake of large particles, or endocytosis for the uptake of small particles, is integral to the immune response in multicellular organisms. Macrophages express FcγRs, which are tyrosine kinase receptors that bind IgG on an opsonized target. Binding of IgG Fc domain to the extracellular domain of an FcγR triggers signaling cascades that coordinate internalization of the opsonized …

Black-Tailed Prairie Dog (Cynomys Ludovicianus) State-And-Transition Model For Loamy Ecological Sites In Mlra 62 In Custer State Park, South Dakota, Mark R. Hendrix

Electronic Theses and Dissertations

Black-tailed prairie dogs (Cynomys ludovicianus) are native burrowing rodents that occupy large areas in the shortgrass and mixed-grass prairies of the Northern Great Plains. They are an important component of these prairie systems due to their impacts on plant communities. Currently State-and-Transition models (STMs) for grassland Ecological Site Descriptions (ESDs) address grazing by livestock as a major factor affecting states and phases within states. Impacts from other grazers, such as prairie dogs, are either not addressed directly, or are included only in a transition to a generalized early seral state. There are, however, dramatic differences in plant communities …

Surveillance Of South Dakota Mosquito Abundance, Infection Rate, And Insecticide Susceptibility, Geoffrey P. Vincent

Electronic Theses and Dissertations

The aim of this dissertation was to survey and evaluate the abundance, infection rate, and insecticide susceptibility of mosquito fauna present in South Dakota. Mosquito surveillance has been conducted across South Dakota to record and track potential West Nile virus (WNV) vectors from 2004 to 2017. The nuisance mosquito Aedes vexans was found to be the most abundant species overall in the state and most abundant in many of the regions. The WNV vector, Culex tarsalis, was found to be the second most abundant mosquito and the most abundant vector mosquito across the state. However, geospatial variation did exist between …