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Efficient Separation And Sensitive Detection Of Listeria Monocytogenes Using Magnetic Nanoparticles, Microfluidics And Interdigitated Microelectrode Based Impedance Immunosensor, Damira Ashimkhanovna Kanayeva

Graduate Theses and Dissertations

Listeria monocytogenes continues to be a major foodborne pathogen that causes food poisoning and sometimes death in immunosuppressed people and abortion in pregnant women. Nanoparticles have recently drawn attentions for use in immunomagnetic separation techniques due to their greater surface area/volume ratio and better stability against sedimentation in the absence of a magnetic field. Interdigitated microelectrodes and microfluidics make material transfer more efficient and biological/chemical interaction between the surface and solution phase much quicker. Magnetic nanoparticles (Fe3O4) with a 30 nm diameter were functionalized with rabbit anti-L. monocytogenes antibodies via biotin-streptavidin bonds and then amalgamated with target bacterial cells …

Tryptophan Anchored Peptides In Lipid Bilayer Membranes: Control Of Peptide Orientation And The Phase Behavior Of Cholesterol-Containing Ternary Lipid Mixtures, Johanna Maria Rankenberg

Graduate Theses and Dissertations

Model WALP peptides and "next generation" WALP-derived hydrophobic model peptides were employed to discover principles that govern protein-lipid interactions in biological membranes.

Ternary cholesterol-containing lipid mixtures were examined in the presence of WALP peptides of different lengths (acetyl-GWW(LA)_nLWWA-ethanolamide, with n between 3 and 8). Deuterium NMR spectra from labeled lipids reveal that WALP peptides may stabilize lipid ordered "raft" domains and therefore promote lipid phase separation, albeit to a minor extent. The results depend upon whether dioleolyl- or diphytanoyl-phosphatidylcholine is present as the fluid lipid component.

Several WALP peptides were modified to remove anchoring Trp residues from one …

Applications Of Site-Specific Recombination Systems In Transgene Expression And Marker Gene Removal, Mehmet Aydin Akbudak

Graduate Theses and Dissertations

Site Specific Recombination systems, such as FLP-FRT and Cre-lox, have been successfully used for site-specific gene integration and marker-gene deletion in plant systems. They are very useful tools in the integration of single-copy full-length transgene cassettes into the genome because the transgene integration via conventional methods often generate multi-copy locus. Such complex locus containing direct and inverted repeats of full-length and truncated copies of the transgene cassette generate aberrant RNA resulting in gene silencing. Therefore, for stable gene expression, a single copy transgene locus is preferred. However, even single copy locus sometimes succumbs to gene silencing. Although the mechanism is …

Intraspecific Variation In Two Cosmopolitan Myxomycetes, Didymium Squamulosum And Didymium Difforme (Physarales: Didymiaceae), Katherine Elizabeth Winsett

Graduate Theses and Dissertations

The myxomycetes (plasmodial slime molds or myxogastrids) are one of three groups considered to be true slime molds (class Eumycetozoa sensu Olive 1975). Two vegetative states--amoebae and plasmodia--along with a spore-producing fruiting body characterize the life cycle of the myxomycetes. These organisms are associated with decaying plant material and are found in all terrestrial habitats worldwide. A number of species are considered cosmopolitan, being found worldwide, where they are associated with a diversity of microhabitats and substrates. A review of the literature, including molecular investigations in all three groups of slime molds, is presented, and this is followed by four …

Analysis Of The Response Of Medicago Truncatula Calcium Oxalate Mutants To Abiotic Stress, Wayra Gabriela Navia-Gine

Graduate Theses and Dissertations

Calcium oxalate crystals are found in most plant species. In Medicago truncatula wild-type A17, crystals accumulate in leaves along the secondary veins and the only role attributed to them so far is defense against chewing insects. Calcium oxalate deficient (cod) mutants were isolated in M. truncatula; the cod mutants include cod5, which completely lack crystals in the leaves and cod6 that accumulates fewer and smaller crystals compared to A17. We analyzed gene expression in the cod mutants and A17 using GeneChip® Medicago Genome Arrays and found important differences in transcriptome between the three genotypes. In particular, we found a gene …

Toxicogenomics Analysis Of Non-Model Transcriptomes Using Next-Generation Sequencing And Microarray, Arun Rawat

Dissertations

With the advent of next generation technologies like Roche/454 Life Sciences that require low cost and less time for sequencing will help in providing a workable draft of non-model species genomes. Availability of high throughput microarray technologies for gene expression profiling provides low-cost tools for investigation of highly-integrated responses to various stimuli. These advancements along with bioinformatics processing have led to an increasing number of non-model species having well-annotated transcriptomes. The project focuses on the life cycle of development, functional annotation, and utilization of genomic tools for the avian wildlife species to determine the molecular impacts of exposure to munitions …

Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle

Dissertations

The Alabama shad, Alosa alabamae, is an anadromous species that is in decline and has seen extirpations from impoundments as well as decreased water quality. Alabama shad live in the Gulf of Mexico and ascend Northern Gulf of Mexico Drainages to reproduce early in the year (January-May). The juveniles spend the majority of the year in these freshwater systems before emigrating out to the Gulf of Mexico as late as December.

This dissertation focuses on the juvenile life stages that occur within the Northern Gulf of Mexico drainages. Spawning conditions of the river, as well as the habitat and diet, …

Folate Receptor-Targeted Delivery Of Small Interfering Rna To Cancer Cells, Yilin Zhang

Dissertations

The vitamin folic acid (folate, FA) has been extensively explored as a targeting ligand to deliver a variety of diagnostic/prognostic/therapeutic agents into various tumors through the assistance of its receptor – the folate receptor (FR). FR is over-expressed in many types of human cancer and can mediate internalization of FA-conjugates through an endocytic pathway. The discovery of small interfering RNA (siRNA), which is cable of inducing potent gene silencing in a sequence-specific manner, provides an excellent molecular tool to suppress aberrant gene expression in malignancies, and therefore siRNA has the potential to revolutionize cancer therapeutics. Towards the goal of developing …

Investigating Heavy Metal Accumulation And Oxidative Stress Tolerance Of Non-Accumulators And Hyperaccumulators In The Brassicaceae Plant Family, Fritzie Joy Into

Theses and Dissertations - UTB/UTPA

Physiological and enzymatic analysis indicated that the non-accumulator A. thaliana showed an oxidative stress response in all assays except for protein carbonylation. Other non-accumulator plant species showed a significant difference in oxidative stress response in the TBARS assay; however, for some assays no stress response was evident. The hyperaccumulator plant species showed no significant difference in oxidative stress as indicated by the all of the assays with the exception of T. montanum var. montanum which showed an oxidative stress response in the SOD assay. Basal catalase enzyme activity was notably higher in the hyperaccumulators T. montanum var. montanum and T. …

Surface Morphology Of Platelet Adhesion Influenced By Activators, Inhibitors And Shear Stress, Melanie Groan Watson

Doctoral Dissertations

Platelet activation involves multiple events, one of which is the generation and release of nitric oxide (NO), a platelet aggregation inhibitor. Platelets simultaneously send and receive various agents that promote a positive and negative feedback control system during hemostasis. Although the purpose of platelet-derived NO is not fully understood, NO is known to inhibit platelet recruitment. NO's relatively large diffusion coefficient allows it to diffuse more rapidly than platelet agonists. It may thus be able to inhibit recruitment of platelets near the periphery of a growing thrombus before agonists have substantially accumulated in those regions.

Results from two studies in …

New Algorithms For Protein Structure Comparison And Protein Structure Prediction, Zaixin Lu

Theses and Dissertations - UTB/UTPA

Proteins show a great variety of 3D conformations, which can be used to infer their evolutionary relationship and to classify them into more general groups; therefore algorithms of protein structure alignment, protein similarity search and protein structure prediction are very helpful for protein biologists. We developed new algorithms for the problems in this field. The algorithms are tested with structures from the Protein Data Bank (PDB) and SCOP, a Structure Classification of Protein Database. The experimental results show that our tools are more efficient than some well known systems for finding similar protein structures and predicting protein structures.

Biogeography And Microhabitat Distribution Of Myxomycetes In High-Elevation Areas Of The Neotropics, Carlos Alonso Rojas-Alvarado

Graduate Theses and Dissertations

Myxomycetes are a group of amoeboid organisms with the capacity of forming fruiting bodies that resemble some macrofungi. The ecology and global distribution of species within the group have been studied only during the last half century. For this reason, a number of questions regarding the nature of the interactions that exist between myxomycetes and their environment still lack the empirical evidence required to obtain complete answers. In the Neotropical region, species assemblages have been moderately well studied, but their biogeography and macroecology have received little attention. In high-elevation areas of this region, the situation is especially precarious, due the …

Bronzed Cowbird (Molothrus Aeneus) Habitat Use And Differential Response To Playback Of Host Song, Mary Jennifer Gorton

Theses and Dissertations - UTB/UTPA

During the breeding seasons of 2008 - 2009, 180 fixed-radius point-count surveys and broadcasts of host song were conducted in Santa Ana (SANWR) and Laguna Atascosa (LANWR, 2009 only) National Wildlife Refuges to identify Bronzed Cowbird (Molothrus aeneus) habitat use and test the predictions of the host activity hypothesis. Surveys demonstrated that Bronzed Cowbirds were distributed across all habitat types in both refuges, although there were differences in abundance between the sexes for interior and edge habitats and between habitat types. Bronzed Cowbirds responded differentially to host species playbacks based on suitability and abundance of the host species. The results …

Identification Of Phosphatases Involved In E2f-Associated Apoptosis, Liza D. Morales Smith

Theses and Dissertations - UTB/UTPA

Retinoblastoma (Rb) is a tumor suppressor protein that controls a critical checkpoint between the G1 phase and the S phase of the cell cycle. Rb is able to suppress cell proliferation by binding to the E2F family of transcription factors, inhibiting its ability to activate transcription of genes necessary for cell cycle progression. Mutations in proteins involved with the Rb/E2F pathway can result in hyper-proliferative cells that overtime can acquire and accumulate additional mutations, which could lead to tumorigenesis. To prevent hyper-proliferation, aberrant cells can be eliminated through apoptosis. E2F can induce apoptosis through two pathways: through transactivation of the …

Ethnobotanical History And Seed Oil Chemistry Of The Physic Nut, Jatropha Curcas, Nathan M. Leclear

Theses and Dissertations - UTB/UTPA

Jatropha curcas L., Euphorbiaceae, is a small tree native to the neotropics. Despite renewed economic interests in Physic Nut, mainly for biodiesel production, a comprehensive analysis of the ethnobotanical history of J. curcas is lacking. An account of the pre-Columbian neotropical distribution of this species and its historical uses are presented. Using capillary gas chromatography, studies were conducted to quantify the natural variation in seed oil content and fatty acid composition of the seed oil from several species of Jatropha, including assessment of how these parameters change during seed maturation. Natural variation in seed oil content was detected (F7,93 = …

Genotyping Of Tgif Polymorphisms Associated With Schizophrenia And Psychosis, George Vera Jr.

Theses and Dissertations - UTB/UTPA

Polymorphisms in Transforming Growth β-Induced Factor (TGIF) have been found to contribute to the risk of development of psychosis and related disorders. Identifying the genes responsible for causing schizophrenia and psychosis will allow for treatment at an earlier stage of development, saving the patient problems, time, and money. The purpose of this experiment is to determine the haplotype of DNA samples obtained from earlier experiments. The DNA samples were collected from people with schizophrenia in Costa Rica, Southern Texas, and Northern Mexico. The samples were tested using 5 single nucleotide polymorphisms (SNPs) and amplified using polymerase chain reaction (PCR). Haplotypes …

Adult Distribution And The Effects Of Dispersal And Genetic Drift On Population Genetic Structure Of Resident Rainbow Trout (Oncorhynchus Mykiss) In Babine Lake, British Columbia., Rachel Anne Koehler

Electronic Theses and Dissertations

Resident rainbow trout in Babine Lake, British Columbia are the focus of regionally important recreational and First Nations food fisheries. This study investigates the roles of dispersal and random genetic drift on lake-wide population genetic structure and non-random distribution of adults. Using thirteen microsatellite loci, I found strong divergence between tributary populations and parr and fry life-stages within tributaries. I found that juvenile dispersal did not greatly affect the divergence between parr and fry groups, but that random genetic drift due to low effective population size was the likely cause of divergence between parr and fry. Adult distribution in the …

Using Stable Isotopes To Assess The Trophic Ecology Of A Native And Invasive Fish Species In The Western Basin Of Lake Erie, Matthew M. Guzzo

Electronic Theses and Dissertations

Using stable isotopes of carbon (δ13C) and nitrogen (δ15N), I investigate the trophic ecology and niche overlap of Yellow Perch (Perca flavescens) and White Perch (Morone americana) across the western basin of Lake Erie. Stable isotopes varied spatially and temporally in lower trophic level organisms, which are used to estimate carbon sources and trophic position of consumers. These variations inhibit our ability to assess trophic relationships, particularly in large lakes. Yellow Perch relied on benthic food sources, while White Perch occupied higher trophic positions and had larger niche widths. Trophic positions of yellow and white perch were related …

The Influence Of Sperm Competition And Life-History Traits On Brain Size Evolution In Male And Female Birds, Melissa Leila Abdellah

Electronic Theses and Dissertations

Interspecific variation in brain size is described as being an adaptive consequence of development and behaviour. Despite growing interest in sex-specific influences on the development of conspicuous traits, little research has focused on investigating sex-specific determinants of brain size. The overall goal of my thesis was to investigate the sex-specific influences on brain size evolution in birds. By measuring endocranial volume from museum specimens, I collected a large sex-specific dataset spanning 106 avian species. In Chapter 2, I found that male brain size was negatively associated with testis size, suggesting that sperm competition may be critical in determining brain size …

The Influence Of Visual Environment And Sympatry On Plumage Coloration In New World Warblers, Allison Flora Mistakidis

Electronic Theses and Dissertations

Several factors may drive interspecific divergence, and investigating possible mechanisms from multiple angles may be most efficient for understanding the evolutionary history of diverse groups. The main objective of my thesis was to examine mechanisms that may promote plumage divergence in Parulidae warblers. In my first study, I investigated the signalling environments of 17 sympatric species of warblers to test predictions of sensory drive. I determined sexual selection has likely influenced plumage evolution in warblers, plumage and visual environment coloration were correlated, and warblers were not most conspicuous in chosen display environments. In my second study, I tested the relationship …

Dispersal And Invasion Dynamics Of The Round Goby, Neogobius Melanostomus, Facilitating Colonization Of Great Lakes Tributaries, Jennifer Ellen Bronnenhuber

Electronic Theses and Dissertations

The recent upstream colonization of Great Lakes tributaries by round goby, Neogobius melanostomus, provides an opportunity to identify dispersal mechanisms and examine invasion dynamics associated with successful colonization of a novel aquatic environment. Genetic analyses identified a stratified dispersal strategy associated with upstream colonization. Genetic diversity was maintained during colonization by natural dispersal suggesting founder effects may be mitigated and adaptation may facilitate river colonization. Swimming performance analyses indicates that the uni-directional and high flow of rivers does not limit range expansion. However, morphological differences between lake and river populations suggest that dispersal is not a random diffusion of …

Er Stress Mediated Effects On Plasma Membrane Cholesterol And Nitric Oxide Bioavailability, Ruchi Chaube

Electronic Theses and Dissertations

Endothelial dysfunction is due in part to the decrease in the biosynthesis and the bioavailability of nitric oxide (NO) in the endothelial cell layer. The chronic exposure of blood vessels to cardiovascular risk factors such as LDL-cholesterol, free fatty acids, homocysteine and conditions of hyperglycemia can give rise to endothelial dysfunction. Many of these same risk factors have also been shown to induce endoplasmic reticulum (ER) stress, in endothelial cells. However, the potential links between endothelial dysfunction and ER-stress have not been clearly established.

The present study was undertaken with two objectives. Objective 1 was to determine how increased plasma …

Microarray Time-Series Data Clustering Via Gene Expression Profile Alignment, K M Numanul Hoque Subhani

Electronic Theses and Dissertations

Clustering gene expression data given In terms of time-series is a challenging problem that imposes its own particular constraints, namely, exchanging two or more time points is not possible as it would deliver quite different results and would lead to erroneous biological conclusions.

In this thesis, clustering methods introducing the concept of multiple alignment of natural cubic spline representations of gene expression profiles are presented. The multiple alignment is achieved by minimizing the sum of integrated squared errors over a time-interval, defined on a set of profiles. The proposed approach with flat clustering algorithms like k-means and EM are …

Mutual Ornamentation, Sex-Specific Behaviour, And Multifunctional Traits In Neotropical Royal Flycatchers (Onychorhynchus Coronatus ), Kathryn Diane Rieveley

Electronic Theses and Dissertations

Sexual selection theory focuses largely on showy male traits and choosy females, with most studies drawing conclusions from sexually dimorphic species. Until recently, female ornamentation was relatively unexplored. I investigated sex-specific behaviour in the mutually ornamented Neotropical royal flycatcher (Onychorhynchus coronatus), where both males and females possess an elaborate concealable crest. From observations in the wild, I characterized vocal and visual displays and found that the crest is a multifunctional trait used in intersexual, intrasexual, and heterospecific contexts. Using a model presentation experiment, I discovered that females exhibited a stronger response than males to territory intrusion, that females …

The Nucleolar Organizer Of The Salivary Gland Polytene Chromosomes As A Measure Of Recent Growth In Laboratory-Reared And Field-Collected Chironomus Spp. (Diptera: Chironomidae) Larvae, Joshua P. Martin

Electronic Theses and Dissertations

Midge larvae possess giant polytene chromosomes. Genes on these chromosomes undergoing transcription are visible as puffs. The nucleolar organizer (NOR), an especially large puff, shrinks when a larva is stressed. Two feeding experiments were conducted to examine how NOR size changes as a function of Chironomus riparius growth. NOR size was linearly related to an individual's recent growth rate, independent of its body size.

Chironomids were collected from wetlands constructed with oil sands mine water and tailings (OSPM), and reference wetlands to evaluate the utility of the NOR as a field-based measure of larval growth and condition. Small larvae (

Study Of Thickly And Thinly Sectioned Melanoma Skin Tissues With Mechanical Scanning Acoustic Reflection Microscopy, Yihan Tian

Electronic Theses and Dissertations

The contents of the present study are organized into two parts: the first is focused on characterizing a thickly sectioned skin tissue with a mechanical scanning acoustic reflection microscopy (hereinafter simply called “SAM”) of pulse-wave mode. The second part is focused on characterizing a thinly sectioned skin tissue with tone-burst-wave mode of SAM. We showed analyses of optical and acoustical images, as well as developed mathematical models using an angular spectrum approach for predicting contrast and characterizing acoustic properties of both sections of tissue. Also, for thin specimens a reflectance function for the tissue located on a substrate was theoretically …

Physiological And Behavioural Response Of The Soybean Aphid (Aphis Glycines Matsumura) To Susceptible And Resistant Soybean, Nicole M. Lamont

Electronic Theses and Dissertations

The soybean aphid, Aphis glycines Matsumura, is an invasive pest which causes damage and yield loss to soybean plants in North America. One method of soybean aphid control involves the use of soybean varieties that negatively impact aphid physiology and behaviour. Mean aphid fecundity measured at different stages of soybean growth showed differences between resistant and susceptible plant varieties as well as differences between the growth stages. Mean aphid longevity on susceptible and resistant plants at different growth stages showed a similar trend. Movement from resistant plants was higher than movement from susceptible plants amongst 1st -2nd instars, apterous adults, …

The Vocal Behaviour Of Common Loons (Gavia Immer): Signalling Strategies & Landscape Scale Communication, Van Thuc La

Electronic Theses and Dissertations

Communication plays a crucial role in the social behaviour of many animals. In this thesis, I examine both signalling strategies and landscape-scale communication in free-living Common Loons (Gavia immer). Using over 6700 hours of passive, single-channel recordings, I demonstrate that Common Loons modify their vocal behaviour in response to time of day, time of year, and changing weather conditions. Using custom software, CALLSPACE, in combination with a ten-microphone acoustic monitoring system that spans three lakes, I examine the dynamics of over 5000 natural vocal interactions among Common Loons. I demonstrate that Common Loons from different territories participate in dyadic and …