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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Transcending Microbial Source Tracking Techniques Across Geographic Borders: An Examination Of Human And Animal Microbiomes And The Integration Of Molecular Approaches In Pathogen Surveillance In Brazil And The United States, Amber Mae Koskey Dec 2013

Transcending Microbial Source Tracking Techniques Across Geographic Borders: An Examination Of Human And Animal Microbiomes And The Integration Of Molecular Approaches In Pathogen Surveillance In Brazil And The United States, Amber Mae Koskey

Theses and Dissertations

Waterborne illnesses, attributed to the ingestion or contact with contaminated water, present a significant global health concern. Surface water sources can be impacted by wide array of pollution inputs, but fecal pollution generates the most significant and acute threat to human health. Therefore, the detection of fecal bacteria in surface water sources remains an important public health objective. Current surface water monitoring employs the use of fecal indicator bacteria (FIB) including E. coli and enterococci as proxies for pathogenic organisms carried in fecal pollution. These traditional indicators, detected by culture-based microbiological methods, do not discriminate fecal sources from another. New ...


Evaluating The Influence Of Environmental Factors On The Rate Of Extra-Pair Matings In Tropical And Temperate Populations Of The House Wren (Troglodytes Aedon), Kaitlin Claire Mckenney Dec 2013

Evaluating The Influence Of Environmental Factors On The Rate Of Extra-Pair Matings In Tropical And Temperate Populations Of The House Wren (Troglodytes Aedon), Kaitlin Claire Mckenney

Theses and Dissertations

Considerable variation exists in the rate of extra-pair matings (EPMs) in birds. Environmental variability likely influences EPM rates within species, but the effects of local environmental factors on EPM rates are largely unpredictable. To determine whether broad-scale environmental factors might be better predictors of EPM rates within species, we quantified levels of extra-pair paternity in the house wren (Troglodytes aedon) in four populations spanning a range of latitude, elevation, and primary productivity (measured by actual evapotranspiration rates). Our results indicated an intermediate and variable level of EPM among populations (6 -31% extra-pair young) that was not significantly affected by 3 ...


The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki Dec 2013

The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki

Theses and Dissertations

Developing neurons extend processes to specific targets and establish connections that are essential for future function of the nervous system. One of these processes, the axon, has a motile tip called a growth cone that rearranges its membrane-associated actin cytoskeleton to turn toward or away from environmental guidance cues. Growth associated protein 43 (GAP-43) is one of the most abundant proteins associated with axonal growth cone membranes and is known to modulate the formation and stability of the actin cytoskeleton during axon guidance. Protein kinase C (PKC)-mediated phosphorylation of GAP-43 on serine 42 regulates its interactions with actin. Phosphorylated ...


Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang Dec 2013

Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang

Theses and Dissertations

Influenza is a common infectious disease resulting from a frequently mutated RNA virus. Vaccination is currently the most effective method to prevent people from seasonal or pandemic influenza. The production of traditional egg-based influenza vaccine is time-consuming and provides limited effect against new strains. Therefore, it is necessary to develop a rapid method to produce influenza vaccines. We proposed a novel influenza vaccine based on the E.coli expression system. Hemagglutinin (HA) is the major target surface protein of influenza virus for vaccine development. In this study, we sub-cloned the HAs encoding gene into an E. coli expression vector; the ...


The Role Of Histone H3 And H4 In Centromere Function And Genome Integrity, Payel Chaudhuri Dec 2013

The Role Of Histone H3 And H4 In Centromere Function And Genome Integrity, Payel Chaudhuri

Theses and Dissertations

Histone H2A plays an important role in chromosomal segregation among parent and daughter cells during mitosis. While it is established that this histone is important in maintaining chromosome number in cell, further work is carried out to explore the role of other histones like H3 and H4 for similar effects. A systematic study is initiated by screening a library based on mutation of different amino acid residues in these histones. This detailed screening identified specific regions within H3 and H4, which are critically important for centromeric function. These histones residing near the DNA entry/exit region of nucleosome effects the ...


Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku Dec 2013

Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku

Theses and Dissertations

GLS is a serious foliar disease of maize, a major staple crop grown commercially in the USA for both human and animal feed production, and increasingly, for ethanol production. The disease is caused by two Cercospora species, C. zeae-maydis and C. zeina, both of which infect maize in the USA and in other parts of the world, with yield losses potentially greater than 50%, depending on local conditions. In culture, C. zeae-maydis produces a phytotoxic, host non-specific perylenequinone, cercosporin, and abscisic acid (ABA), for which there is no known pathological or physiological function in the fungus. Experimental evidence indicates that ...


The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh Dec 2013

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an ...


Proteomic And Biochemical Studies Of Estrogen-Mediated Signaling And Novel Estrogen Receptor-Interacting Proteins In Breast Cancer Cells, Zhenqi Zhou Aug 2013

Proteomic And Biochemical Studies Of Estrogen-Mediated Signaling And Novel Estrogen Receptor-Interacting Proteins In Breast Cancer Cells, Zhenqi Zhou

Theses and Dissertations

Estrogen plays essential roles in the growth, development, and homeostasis of a number of tissues, and can also be linked to the growth of breast cancer. The biological activities of estrogen are mediated by estrogen receptors (ERs) ERá and ERâ, and also orphan G-protein-coupled receptor 30 (GPR30). In order to identify novel proteins that are involved in ER-mediated actions of estrogen, we used mass spectrometry-based quantitative proteomic methods to systematically profile global protein expression in responses to E2 (17â-estradiol) stimulation in human breast cancer cell, and identify and characterize cellular novel proteins that are associated with ERs in breast cancer ...


Design, Development, And Characterization Of Novel Antimicrobial Peptides For Pharmaceutical Applications, Yazan H. Akkam Aug 2013

Design, Development, And Characterization Of Novel Antimicrobial Peptides For Pharmaceutical Applications, Yazan H. Akkam

Theses and Dissertations

Candida species are the fourth leading cause of nosocomial infection. The increased incidence of drug-resistant Candida species has emphasized the need for new antifungal drugs. Histatin 5 is a naturally occurring human salivary antifungal peptide and the first line of defense against infections of the oral cavity. This research has focused on understanding the activity of histatin 5, and subsequently designing novel peptides that may serve as models for the further development of therapeutics to treat fungal infection.

This objective has been achieved in three steps: studying the structural requirement of histatin 5 involved in antifungal activity, the identification of ...


Bio-Separation Process Improvement Via Genomic Manipulation: Development Of Novel Strains For Use In Immobilized Metal Affinity Chromatography (Imac), Ryan Curtis Haley May 2013

Bio-Separation Process Improvement Via Genomic Manipulation: Development Of Novel Strains For Use In Immobilized Metal Affinity Chromatography (Imac), Ryan Curtis Haley

Theses and Dissertations

The dissertation is comprised of three parts. Part I describes proteomic analysis of native bacterial proteins from Escherichia coli (E.coli) that bind during Immobilized Metal Affinity Chromatography (IMAC). Part II describes the value in exploiting proteome based data as a tool toward the design an E. coli expression strain that is particularly useful when Immobilized Metal Affinity Chromatography is employed as the initial capture step of a homologous protein purification process. Part III describes a methodology of chromosomal mapping of all contaminant gene products.

The objective of Part I was to identify all E. coli proteins that bind to ...


Dynamics And Model Of The Pore-Forming Protein Lysenin, Eric Krueger May 2013

Dynamics And Model Of The Pore-Forming Protein Lysenin, Eric Krueger

Theses and Dissertations

Membrane transporters are a class of membrane proteins that function to provide a pathway across a cell membrane for the movement of ions and biomolecules. Investigations into the regulatory mechanism of these systems are hindered by their extensive preparation requirements compounded by their fragility and instability. However, lysenin, a pore-forming protein extracted from the earthworm Eisenia foetida, provided a unique opportunity to study a protein which is stable in both a soluble and membrane phase. Lysenin channels possess several important properties characteristic of ion channels without the inherent difficulties that plague investigations with biologically vital membrane transporters like voltage-gated ion ...


Cell Surface Adhesins, Exopolysaccharides And The Por (Type Ix) Secretion System Of Flavobacterium Johnsoniae, Abhishek Shrivastava May 2013

Cell Surface Adhesins, Exopolysaccharides And The Por (Type Ix) Secretion System Of Flavobacterium Johnsoniae, Abhishek Shrivastava

Theses and Dissertations

Flavobacterium johnsoniae, a member of the phylum Bacteroidetes, crawls rapidly over surfaces. Cell movement is thought to result from the action of the gliding motor, composed of Gld proteins, on the cell-surface adhesin SprB. Cells lacking SprB are partially defective in motility. Transposon mutagenesis of an sprB mutant resulted in the identification of remA, which encodes a motility adhesin that is partially redundant with SprB. Cells lacking SprB and RemA had more severe motility defects than did cells lacking just SprB. RemA moves on the cell-surface with a speed of 1 to 2 micrometer per sec, similar to SprB. RemA ...


Quorum Sensing In Vibrios And Cross-Species Activation Of Bioluminescence Lux Genes By Vibrio Harveyi Luxr In An Arabinose-Inducible Escherichia Coli Expression System, Anne Marie Wannamaker May 2013

Quorum Sensing In Vibrios And Cross-Species Activation Of Bioluminescence Lux Genes By Vibrio Harveyi Luxr In An Arabinose-Inducible Escherichia Coli Expression System, Anne Marie Wannamaker

Theses and Dissertations

Bacterial bioluminescence is observed in over twenty known species, primarily in the family Vibrionaceae. However, only Vibrio fischeri and Vibrio harveyi bioluminescence expression mechanisms are well studied. In V. harveyi, expression of the lux operon is activated by the transcription factor LuxR (LuxRVH), resulting in bioluminescence. Homologs of LuxRVH in other Vibrio species have been shown to regulate transcription of a variety of genes. Three parallel quorum sensing pathways co-regulate the expression of LuxRVH. The first objective was to assess possible quorum sensing regulation of lux operon expression in V. cholerae, V. chagasii, V. orientalis, and V ...


Prolonged Glucose Deprivation Sensitizes Snf1 To Negative Regulation By Pka To Delay Entry Into Quiescence, Leah Bernadette Doughty May 2013

Prolonged Glucose Deprivation Sensitizes Snf1 To Negative Regulation By Pka To Delay Entry Into Quiescence, Leah Bernadette Doughty

Theses and Dissertations

AMPK, the fuel gauge of the cell, and its upstream kinase, LKB1, have been implicated in cancer prevention and stress response associated with energy exhaustion. In the yeast Saccharomyces cerevisiae, Snf1 is the ortholog of mammalian AMPK. In S. cerevisiae, Snf1 is activated by phosphorylation of its T–loop at Thr210, primarily by its upstream kinase Sak1, in absence of the preferred carbon source, glucose, or during some other stress responses. Cyclic AMP–dependent protein kinase A, PKA, is involved in nutrient signaling largely antagonistically to Snf1. Using yeast strains of the Sigma 1278b genetic background, which have a high ...


Molecular Diagnosis Of Metabolic Fast Growth Related Diseases In Broiler, Adnan Ali Khalaf Al-Rubaye May 2013

Molecular Diagnosis Of Metabolic Fast Growth Related Diseases In Broiler, Adnan Ali Khalaf Al-Rubaye

Theses and Dissertations

Pulmonary Hypertension Syndrome (PHS) and lameness are important metabolic diseases that affect rapidly growing broilers. The research reported in the first section of this dissertation focused on developing qPCR assays to identify differences in the expression levels of four candidate genes possibly associated with PHS: angiotensin II type 1 receptor (AGTR1): urotensin receptor 2D (UTS2D); serotonin receptor/transporter type 2Bn (HTR2B); and angiotensinogen cleaving enzyme (ACE). Expression levels of these candidate genes were examined in four different tissues. We established ribosomal protein S14 (RPS14) and RNA polymerase subunit 2B (RP2B) as suitable reference genes because they showed the most consistent ...


Characterization Of The Ribosomal Protein L22e Family In Drosophila Melanogaster: Evidence For Functional Diversification Of Duplicated Ribosomal Protein Genes, Michael G. Kearse Jan 2013

Characterization Of The Ribosomal Protein L22e Family In Drosophila Melanogaster: Evidence For Functional Diversification Of Duplicated Ribosomal Protein Genes, Michael G. Kearse

Theses and Dissertations

Gene duplication is a contributing factor to genome evolution in eukaryotes. With an additional copy, selective pressure is relieved, allowing for accumulation of genetic variation and possible development of new or altered functions. Ribosomal protein (Rp) genes are a common class of duplicated genes found throughout eukaryotes. Typically encoding highly similar or identical proteins at separate loci, duplicated Rps were originally thought to be redundant and to relieve the high demand for translation. However, recent reports in yeast have shown phenotypic differences between Rp paralogue knockouts, suggesting functional non-redundancy. Little effort has been devoted toward elucidating the function of Rp ...


The Sperm Equatorial Segment: An Organizing Center For Sperm Protein Relocalization And Facilitation Of Fertilization, Wutigri Nimlamool Jan 2013

The Sperm Equatorial Segment: An Organizing Center For Sperm Protein Relocalization And Facilitation Of Fertilization, Wutigri Nimlamool

Theses and Dissertations

The equatorial segment (the EqS) of mammalian sperm has been reported to be a site for sperm-egg fusion initiation. The subdomain, called the equatorial subsegment (the EqSS), within the EqS has been identified in sperm of many species; however, there is no clear report showing the existence of this subdoman in human sperm. The EqS has been hypothesized to be an organizing center for assembly of molecular complexes required for gamete interaction and fusion. Several sperm proteins have been reported to relocate to the EqS to make this region fusion competent. However, molecular mechanisms that regulate relocalization of sperm proteins ...


Signaling Networks That Induce Melanomagenesis And Metastasis That Can Be Exploited For Therapeutic Benefit, Eden Elizabeth Tanzosh Jan 2013

Signaling Networks That Induce Melanomagenesis And Metastasis That Can Be Exploited For Therapeutic Benefit, Eden Elizabeth Tanzosh

Theses and Dissertations

Melanoma is the most lethal type of skin cancer and originates in melanocytes, cells that produce the pigment melanin. Five year survival rates are particularly high for this type of cancer if the tumor is diagnosed and treated early. However, survival rates decline significantly if the tumor is allowed to metastasize. Frequency of melanoma has risen over recent years, especially in young people. Much progress has been made in treating melanoma; however, tumor recurrence is frequently seen in patients after treatment has concluded. The leading genes that are found to be mutated in melanoma are v-Raf murine sarcoma viral oncogene ...