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The Unconventional Amino Acid Starvation Response Of The Malaria Parasite, Plasmodium Falciparum, Shalon Ledbetter

All Theses and Dissertations (ETDs)

The apicomplexan parasite, Plasmodium falciparum, is the causative agent of the most severe form of malaria, resulting in nearly 1 million deaths each year. The parasite establishes its replicative niche within human erythrocytes, where it degrades massive amounts of host cell hemoglobin, salvaging the released amino acids for its own use. However, human hemoglobin does not contain the amino acid isoleucine, which is one of the most prevalent amino acids in the parasite's proteome. Since P. falciparum cannot synthesize isoleucine, it must acquire this amino acid from human serum. Optimal growth and, ultimately, the survival of P. falciparum depend on …

Trace Element Cycling During Iron(Ii)-Activated Recrystallization Of Iron(Iii) Oxide Minerals, Andrew Frierdich

All Theses and Dissertations (ETDs)

Biogeochemical iron cycling initiates secondary abiotic reactions between aqueous Fe(II) and Fe(III) oxide minerals, which results in dynamic recrystallization via simultaneous Fe(II) oxidative adsorption and Fe(III) reductive dissolution. Fe(III) oxide minerals are abundant in soils, sediments, and groundwater systems, and often control the fate and transport of trace elements. A robust understanding of their reactivity with Fe(II) and how associated trace elements are affected during Fe(II)-activated recrystallization is required to predict the effect of biogeochemical processes on contaminant fate and micronutrient availability. The main objective of the research presented in this dissertation is to characterize how Fe(II)-activated recrystallization of iron …

Evaluating Environmental Cues That Affect Schwann Cell Gene Expression To Enhance Peripheral Nerve Regeneration, Nithya Jesuraj

All Theses and Dissertations (ETDs)

The goal of this thesis was to evaluate the effects of different environmental cues on Schwann cell: SC) differentiation and phenotype maintenance to design better SC transplantation therapies for peripheral nerve repair. First, a set of markers, specific for motor or sensory-derived SCs were identified from the literature and gene chips. After 30 days, gene expression patterns of SCs, after expansion in culture, were dysregulated. Cues that have been hypothesized to re-differentiate the SCs in vitro are extracellular matrix: ECM) molecules, growth factors: GFs), and acetylcholine: Ach). To test the effects of ECM, SCs were transplanted into acellular nerve grafts: …

Bioinformatics For High-Throughput Virus Detection And Discovery, Adam Allred

All Theses and Dissertations (ETDs)

Pathogen detection is a challenging problem given that any given specimen may contain one or more of many different microbes. Additionally, a specimen may contain microbes that have yet to be discovered. Traditional diagnostics are ill-equipped to address these challenges because they are focused on the detection of a single agent or panel of agents. I have developed three innovative computational approaches for analyzing high-throughput genomic assays capable of detecting many microbes in a parallel and unbiased fashion. The first is a metagenomic sequence analysis pipeline that was initially applied to 12 pediatric diarrhea specimens in order to give the …

Isoform-Specific Roles Of Extracellular Signal-Regulated Kinases In Pain, Benedict Alter

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Isoform-specific roles of Extracellular Signal-Regulated Kinases in pain by Benedict Joseph Alter Doctor of Philosophy in Biology and Biomedical Sciences Neurosciences Washington University in St. Louis, 2012 Professor Robert Gereau, Chairperson The extracellular signal-regulated kinase: ERK) isoforms, ERK1 and ERK2, are believed to be key signaling molecules in nociception and nociceptive sensitization. Studies utilizing inhibitors targeting the shared ERK1/2 upstream activator, mitogen-activated protein kinase kinase: MEK), and transgenic mice expressing a dominant negative form of MEK have established the importance of ERK1/2 signaling. However, these techniques do not discriminate between ERK1 and ERK2. To dissect the …

Information Processing In A Midbrain Visual Pathway, Dihui Lai

All Theses and Dissertations (ETDs)

Visual information is processed in brain via the intricate interactions between neurons. We investigated a midbrain visual pathway: optic tectum and its isthmic nucleus) that is motion sensitive and is thought as part of attentional system. We determined the physiological properties of individual neurons as well as their synaptic connections with intracellular recordings. We reproduced the center-surround receptive field structure of tectal neurons in a dynamical recurrent feedback loop. We reveal in a computational model that the anti-topographic inhibitory feedback could mediate competitive stimulus selection in a complex visual scene. We also investigated the dynamics of the competitive selection in …

Identification Of Novel Fluid Biomarkers For Alzheimer's Disease, Rebecca Craig-Schapiro

All Theses and Dissertations (ETDs)

Clinicopathological studies suggest that Alzheimer's disease: AD) pathology begins to appear ~10-20 years before the resulting cognitive impairment draws medical attention. Biomarkers that can detect AD pathology in its early stages and predict dementia onset and progression would, therefore, be invaluable for patient care and efficient clinical trial design. To discover such biomarkers, we measured AD-associated changes in the cerebrospinal fluid: CSF) using an unbiased proteomics approach: two-dimensional difference gel electrophoresis with liquid chromatography tandem mass spectrometry). From this, we identified 47 proteins that differed in abundance between cognitively normal: Clinical Dementia Rating [CDR] 0) and mildly demented: CDR 1) …

The Importance Of Glucose Transport In Reproductive Events, Katie Adastra

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION The Importance of Glucose Transport in Reproductive Events by Katie Lynn Adastra Doctor of Philosophy in Biology and Biomedical Sciences Developmental, Regenerative and Stem Cell Biology Washington University in St. Louis, 2012 Professor Kelle H. Moley, Chairperson Successful pregnancy outcome is contingent on a number of factors, the earliest of which include the events occurring during early pregnancy. This time period from fertilization to implantation requires drastic changes in both the embryo and the uterus, including cell proliferation and differentiation. Alterations in environment may lead to adverse effects during any of these stages. This emphasizes the …

Characterization Of Normal Development And Injury In The Premature Baboon Brain, Jennifer Griffith

All Theses and Dissertations (ETDs)

Nearly 13% of infants born in the United States each year are preterm - that is, born before 37 weeks gestation. Although improvements in clinical care have contributed to survival rates that now exceed 85%, premature infants are at high risk for motor, sensory, cognitive and behavioral disabilities. In order to develop therapeutic interventions to prevent these adverse neurodevelopmental outcomes, we must first understand the nature of cerebral injury associated with premature birth and the mechanisms by which it leads to altered brain development. A baboon: Papio papio) model of preterm birth was used to evaluate cerebral development from 90 …

Serum Response Factor Regulates Multiple Aspects Of Central Nervous System Development, Puo Yuan Lu

All Theses and Dissertations (ETDs)

SRF is a highly evolutionary conserved activity-dependent transcription factor. Previous studies have shown that neuron-specific deletion of SRF results in deficits in tangential cell migration, guidance-dependent circuit assembly, activity-dependent gene expression, and synaptic plasticity in the hippocampus. However, very little is known in terms of whether SRF participates in earlier aspects of central nervous system development such as neuronal projection establishment, cell-fate specifications, and neural stem cell homeostasis and survival. We report that SRF is critical for development of major axonal tracts in the forebrain. Conditional mutant mice lacking SRF in neural progenitor cells: Srf-Nestin-cKO) exhibit striking deficits in cortical …

A Role Of T Cell Receptor Specificity In The Thymic Regulatory T Cell Development, Hyang-Mi Lee

All Theses and Dissertations (ETDs)

The development of regulatory T: Treg) cells is essential for the maintenance of immune tolerance and homeostasis. In the thymus, TCR-specificity to self-antigen appears to be a primary determinant for Treg cell lineage commitment, imprinting both self and foreign antigens in the peripheral Treg cell population to provide dominant tolerance. The degree of T cell self-reactivity considered dangerous by the immune system, thereby requiring thymic education to prevent autoimmunity, is unknown. Here, I analyzed a panel of TCRs with a broad range of reactivity to ovalbumin: OVA323-339) in the RIP-mOVA self-antigen model for their ability to induce mechanisms of thymic …

Phylogeny And Evolution Of Phemeranthus (Montiaceae) In North American Xeric Habitats, Taina Price

All Theses and Dissertations (ETDs)

The genus Phemeranthus: Montiaceae; fameflowers, rockpinks, sunbrights) comprises ca. 25 species of succulent, terete-leaved herbaceous perennials, mostly found in xeric rock outcrops and sand barrens. Phemeranthus' center of diversity is in northern Mexico and the southwestern United States, but several species occur in glade and flat-rock ecosystems in the midwestern and southeastern United States. DNA sequences of chloroplast and low-copy nuclear regions were used to infer the phylogenetic relationships of Phemeranthus species. Phemeranthus: excluding P. aurantiacus) is monophyletic and likely sister to the remainder of Montiaceae. The genus contains two geographically structured and morphologically distinguishable clades: a southern clade centered …

High Resolution Spectroscopy: The Study Of Isobutylene, Tabetha Lynn Osborn

Student Theses and Dissertations

The explosive bouquet theory suggests that canines trigger on volatile organic species within an explosive and not the pure explosive. Modeling an explosive detection scheme after this theory, an experimental design using mid infrared sources was established at the ArCLAS facility. A calibration program, documented within this thesis, was created in a Visual Basic platform as an Excel Add-In. The calibration program converts time based spectra collected with a germanium etalon into frequency spaced scans and then to known frequencies to allow spectral assignments to rovibrational transitions of molecules of interest. Additionally, the analysis of isobutylene, a volatile organic bouquet …

Patent: Methods Of Treating Fgf21-Associated Disorders, Brian R. Boettcher, Shari L. Caplan, Douglas S. Daniels, Bernhard Hubert Geierstanger, Norio Hamamatsu, Stuart Licht, Andreas Loew, Stephen Craig Weldon

Chemistry Faculty Publications

The invention relates to the identification of new polypeptide and protein variants of fibroblast growth factor 21 (FGF21) that have improved pharmaceutical properties. Also disclosed are methods for treating FGF21-associated disorders, includ ing metabolic conditions.

Practical Approaches To Biological Network Discovery, Brian Haynes

All Theses and Dissertations (ETDs)

This dissertation addresses a current outstanding problem in the field of systems biology, which is to identify the structure of a transcriptional network from high-throughput experimental data. Understanding of the connectivity of a transcriptional network is an important piece of the puzzle, which relates the genotype of an organism to its phenotypes. An overwhelming number of computational approaches have been proposed to perform integrative analyses on large collections of high-throughput gene expression datasets to infer the structure of transcriptional networks. I put forth a methodology by which these tools can be evaluated and compared against one another to better understand …

Interactions Of Cardiomyocytes And Myofibroblasts: An Experimental And Theoretical Model Study, Teresa Abney

All Theses and Dissertations (ETDs)

Cardiomyocytes and fibroblasts make up the majority of cells in natural myocardium. While cardiomyocytes are primarily responsible for the mechanical contraction, fibroblasts are responsible for maintaining the extracellular matrix and tissue compliance. In response to pathologies such as hypertension or infarction, fibroblasts in the heart can convert to myofibroblasts, a larger and more contractile phenotype between a fibroblast and a smooth muscle cell. Myofibroblasts are essential to wound healing, but can change the compliance and functioning of heart tissue and can produce pathological fibrosis, formation of excess fibrous connective tissue. In developing therapeutic approaches it is essential to understand how …

Information Theoretic Methods For Biometrics, Clustering, And Stemmatology, Po-Hsiang Lai

All Theses and Dissertations (ETDs)

This thesis consists of four parts, three of which study issues related to theories and applications of biometric systems, and one which focuses on clustering. We establish an information theoretic framework and the fundamental trade-off between utility of biometric systems and security of biometric systems. The utility includes person identification and secret binding, while template protection, privacy, and secrecy leakage are security issues addressed. A general model of biometric systems is proposed, in which secret binding and the use of passwords are incorporated. The system model captures major biometric system designs including biometric cryptosystems, cancelable biometrics, secret binding and secret …

Magnitude And Composition Of Sinking Particulate Phosphorus Fluxes In Santa Barbara Basin, California, Emily Sekula‐Wood, Claudia R. Benitez-Nelson, Melissa A. Bennett, Robert Thunell

Faculty Publications

[1] The composition and bioavailability of particulate P influence marine biological community production on both modern and geologic time‐scales, and continental margins play a critical role in the supply, modification, and storage of particulate P. This study examined particulate P cycling in the Santa Barbara Basin (SBB) off the coast of southern California using a ∼520 m deep‐moored sediment trap deployed from 1993–2006 and a sediment core collected in 2005 directly beneath the sediment trap at 590 m. Total particulate P (TPP), particulate inorganic P (PIP), and particulate organic P (POP) were quantified using a 5‐step sequential extraction method (SEDEX) …

Program Effectiveness Of A Parent-Child Group Social Skills Program, Heather Picciott

Theses

The purpose of this study was to evaluate the effectiveness of a social skills group program using pre-post testing and focus groups. Program effectiveness measurement was illustrated using data collected from a pilot parent-child social skills building group program, "Raising Positive Thinkers". The group involved four parent-child dyads and ran for three consecutive weeks, meeting once a week for 90 minutes to introduce, practice and review social skills learned. Quantitative data was collected via pre and post questionnaire using the Social Skills Improvement System rating scale (SSIS). Qualitative data was collected from a focus group at the end of the …

I Just Can't Do It! The Effects Of Social Withdrawal On Prosocial Behavior, Ashley Michelle Fraser

Theses and Dissertations

While there has been research published on social withdrawal during childhood, little work has been done on the effects of social withdrawal during emerging adulthood. Since emerging adulthood is a time of transition and initiation to new environments and social contexts, it would be expected to be a time of great anxiety for individuals predisposed to social withdrawal (shyness). Shyer emerging adults are at risk for internalizing behaviors, lowered self-concept, and delayed entry into romantic relationships, therefore, they may also be more challenged when it comes to enacting prosocial behaviors. In addition, the inability to self-regulate emotions may mediate this …

Magnetic Resonance Elastography Of The Brain: From Phantom To Mouse To Man, Erik Clayton

All Theses and Dissertations (ETDs)

The overall objective of this study is to develop magnetic resonance elastography: MRE) imaging to better understand brain deformation, brain tissue mechanical properties, and brain-skull interaction in vivo. The findings of this study provide parameters for numerical models of human head biomechanics, as well as data for validation of these models. Numerical simulations offer enormous potential to the study of traumatic brain injury: TBI) and may also contribute to the development of prophylactic devices for high-risk subjects: e.g., military personnel, first-responders, and athletes). Current numerical models have not been adequately parameterized or validated and their predictions remain controversial. This dissertation …

From Myth To Meth: Viewing The American Small Town Through The Lens Of Psychoanalytica Fantasy, Christopher Boehm

All Theses and Dissertations (ETDs)

Simultaneously a symbol for benevolent hospitality and hostile insularity, the American small town and its surrounding rural areas have assumed many faces and forms in both filmic and literary representations over the last hundred years. Whereas the metropolis carries with it a specific history and culture that is known, at least in part, by an audience, the small-town, with all its stereotypical associations, lacks an analogous geographical and historical specificity. As a result of this relative anonymity, the small town often becomes a blank canvas onto which a number of conflicting representations can be painted. Despite significant differences in historical, …

Mediating War In Early Modern German Prose, Patrick Brugh

All Theses and Dissertations (ETDs)

Gunpowder technology had been in Europe since the fourteenth century, but it took two hundred years before German authors were aware of its social and aesthetic implications. When early modern people discussed gunpowder warfare in texts of the sixteenth and seventeenth centuries they were astonished by its ability to destroy people, places, and things, as well as an aesthetic of warfare upon which war stories had long been based: heroics. While modern historians still debate the quantitative impact of gunpowder technology on society, early modern authors and eyewitnesses were in unanimous agreement: Gunpowder changed the way they thought about war. …

Mechanisms Of Early Brain Morphogenesis, Benjamen Filas

All Theses and Dissertations (ETDs)

In structures with obvious mechanical function, like the heart and bone, the relationship of mechanical forces to growth and development has been well studied. In contrast, other than the problem of neurulation: formation of the neural tube), developmental mechanisms in the nervous system have received relatively little attention. The central aim of this research is to characterize the biophysical mechanisms that shape the early embryonic brain. Experiments were performed primarily in the chicken brain, which is morphologically similar to humans during early stages of development. Proposed mechanisms were tested using computational models to ensure that hypotheses are consistent with physical …

Whispering Gallery Mode Microresonators For Lasing And Single Nanoparticle Detection, Lina He

All Theses and Dissertations (ETDs)

Whispering gallery mode: WGM) microresonators have attracted great interests due to the significantly enhanced light-matter interactions originating from their high quality factors and small mode volumes. They are suitable for a wide range of applications including sensing, lasing, nonlinear optics, and so forth. However, temperature fluctuations as one of the most common environmental noises disturb the cavity resonances and thus degrade the device stability and sensitivity. We introduce a wetting technique to coat the silica resonator with a thin layer of polymer which has the negative thermo-optic coefficient to compensate for the thermal effect in silica, and demonstrate complete thermal …

Vilém Flusser's Media Philosophy: Tracing The Digital In Nature Through Art, Anne Popiel

All Theses and Dissertations (ETDs)

Philosopher Vilém Flusser's theories and metaphorical writing style are considered together in order to explain the connection between digital technology, nature and artistic creativity in his work.

Propulsion By Sinusoidal Locomotion: A Motion Inspired By Caenorhabditis Elegans, Xialing Ulrich

All Theses and Dissertations (ETDs)

Sinusoidal locomotion is commonly seen in snakes, fish, nematodes, or even the wings of some birds and insects. This doctoral thesis presents the study of sinusoidal locomotion of the nematode C. elegansin experiments and the application of the state-space airloads theory to the theoretical forces of sinusoidal motion. An original MATLAB program has been developed to analyze the video records of C. elegans' movement in different fluids, including Newtonian and non-Newtonian fluids. The experimental and numerical studies of swimming C. elegans has revealed three conclusions. First, though the amplitude and wavelength are varying with time, the motion of swimming C. …

Micro-Imaging Of The Mouse Lung Via Mri, Wei Wang

All Theses and Dissertations (ETDs)

Quantitative measurement of lung microstructure is of great significance in assessment of pulmonary disease, particularly in the earliest stages. Conventional stereological assessment of ex-vivo fixed tissue specimens under the microscope has a long and successful tradition and is regarded as a gold standard, but the invasive nature limits its applications and the practicality of use in longitudinal studies. The technique for diffusion MRI-based 3He lung morphometry was previously developed and validated for human lungs, and was recently extended to ex-vivo mouse lungs. The technique yields accurate, quantitative information about the microstructure and geometry of acinar airways. In this dissertation, the …

Fatty Acid Composition In The Mature Milk Of Bolivian Forager-Horticulturalists: Controlled Comparisons With A Us Sample, Melanie A. Martin, William D. Lassek, Steven J. C. Gaulin, Rhobert W. Evans, Sheela S. Geraghty, Barbara S. Davidson, Ardythe L. Morrow, Hillard Kaplan, Michael Gurven

ESI Publications

Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6–82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational …

Citizen Action, Power Relations And Wetland Management In The Tampa Bay Urban Socio-Ecosystem, Cornelius Owusu Adjei

USF Tampa Graduate Theses and Dissertations

Wetlands are vital ecosystems that provide ecological, economic and social benefits to societies. In the Tampa Bay region in West Central Florida, a growing population has put immense pressure on wetlands. The situation has not gone unnoticed in the public domain with concerns raised about the need to formulate policies that would protect them. However, it has been difficult to ascertain the level of citizen involvement in the decision making process.

This study aimed at investigating whether the perceptions and concerns of citizens drove them to influence local water policy. Questionnaires were used to collect data from residents living in …