Global Climate Change And The Southern Ocean: How Antarctic Fishes Physiologically Respond To A Changing Environment From The Cellular To The Organismal Level, Laura A. Enzor

Theses and Dissertations

Studies have projected that future changes in sea surface temperature and pCO2 levels will impact higher latitudes to a greater extent than in temperate regions. For notothenioid fishes of the Southern Ocean, evolution in extremely stable, cold waters has resulted in several adaptations which have left these fishes poorly prepared for global climate change. I have analyzed the metabolic and cellular response of Trematomus bernacchii, Pagothenia borchgrevinki and Trematomus newnesi to a long-term, multi-stressor scenario relevant to the predicted changes in the Southern Ocean. By combining whole animal respirometry with cellular level analysis of energy allocation, osmoregulatory mechanisms and cellular …

Methods For Identifying Regions Of Brain Activation Using Fmri Meta-Data, Meredith A. Ray

Theses and Dissertations

Functional neuroimaging is a relatively young discipline within the neurosciences that has led to significant advances in our understanding of the human brain and progress in neuroscientific research related to public health. Accurately identifying activated regions in the brain showing a strong association with an outcome of interest is crucial in terms of disease prediction and prevention. Functional magnetic resonance imaging (fMRI) is the most widely used method for this type of study as it has the ability to measure and identify the location of changes in tissue perfusion, blood oxygenation, and blood volume. In practice, the three-dimensional brain locations …

The Role Of Lis1 In Adult Mammalian System, Xu Gao

Theses and Dissertations

Lis1 haploinsufficiency in humans results in a “smooth brain” phenotype called lissencephaly, and also causes severe cognitive and motor impairments and epilepsy. Seizure severity and frequency typically worsens with time; patients often die within the first decade due to seizure-induced aspiration and pneumonia. Various mouse models have been used to examine the role of Lis1 during brain development, and it is clear that Lis1 regulates a microtubule motor, cytoplasmic dynein. Intriguingly, Lis1 expression remains high in adult brains indicating that it plays a role in mature systems. Indeed, our group found that Lis1 and several related proteins regulate dynein-dependent axon …

Understanding The Evolutionary History Of Biochemical Innovation, Madeline Opal St. Julien

Theses and Dissertations

The serine protease (SP) gene family is an ecologically important gene family because of observed involvement in innate immunity, digestive processes, and embryological development of arthropods. In the past decade, all genes of the serine protease family have been classified in a number of arthropods, with the exception of crustacean. Possible evolutionary mechanisms have been observed based off of varying selectional pressures acting on recent SP expansions in respect to varying diets. Daphnia is the first crustacean to have its genome sequenced, and their genomes were analyzed in this study to elucidate the expansion and divergence of the SP gene …

Regulation Of Dkk1, An Inhibitor Of The Wnt Signaling Pathway, By Dax-1 In Mouse Embryonic Stem Cells, Victor D. Gavallos

Undergraduate Honors Theses

DAX-1 is known to play a key role in the maintenance of pluripotency in mouse embryonic stem cells (mESC), such that elimination of DAX-1 (through methods such as RNAi) leads to the differentiation of ESC (Khalfallah et al. 2009). Earlier research by the Tzagarakis-Foster lab identified target genes of DAX-1 in mESC through PCR array methodology (Torres 2013). The Dickkopf 1 gene (Dkk1) was identified as a potential target of DAX-1 by these studies and has since been confirmed to be a DAX-1 target in mESC. However, to date very little is understood of the mechanism of DAX-1 repression of …

Characterization Of Vibrio Vulnificus Strains Using Phenotypic And Genotypic Assays, James Conrad

Masters Theses, 2010-2019

In this study 143 V. vulnificus isolates of clinical and environmental origin, were examined for growth on differential media, identified to species and tested for antibiotic resistance. A multiplex PCR was created and optimized, and phylogenetic analysis was conducted. The first objective was to compare phenotypic methods to identify V. vulnificus. Colony colors of confirmed V. vulnificus isolates on selective media (Vibrio vulnificus agar, thiosulfate citrate bilesalts sucrose agar, CHROMAgar Vibrio (CAV), and colistin polymyxin B cellobiose agar), mostly matched those characteristic of V. vulnificus. To test the ability of these media to select for V. vulnificus, new presumptive V. …

Development Of An Immunodiagnostic Assay For Canine Tear Lacritin, Alison Mae Enghauser

Senior Honors Projects, 2010-2019

Purpose: Lacritin is a naturally occurring human glycoprotein secreted from the lacrimal gland as a component of tears. Preliminary studies suggest that down-regulation of lacritin is associated with various ocular diseases, such as dry eye syndrome and blepharitis. Thus, lacritin shows potential as a new topical therapeutic for the treatment of ocular diseases. Previous studies have shown that recombinant human lacritin, when topically applied to rabbit eyes, promotes basal tearing. Antibodies produced against the terminal ends of human lacritin were used to develop a clinical immunodiagnostic assay that detect and quantify lacritin in human tear samples. In order to develop …

Examining The Effectiveness Of Ecotourism As A Funding Source For Protected Area Management In Guyana, Jordan S. Flagel

Masters Theses, 2010-2019

Protected areas in tropical rainforests serve many important ecosystem services, including carbon sequestration. These areas are often in need of donor or grant funding to operate as governments in tropical forested countries are not always able to provide adequate funds for protection. This paper focuses on the Iwokrama International Center for Rainforest Conservation and Development in the South American country of Guyana, which has had funding issues since the global economic crisis of 2008 and an accompanying shift in donor country financial priorities. Increasing the amount of sustainable ecotourism in the Iwokrama reserve was identified as a potential source for …

Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino

Masters Theses, 2010-2019

The decline in the development of novel antimicrobials, combined with the misusage and over prescription of antibiotics, has contributed to the increasing prevalence of antimicrobial-resistant infections. Thus development of effective novel disinfectants could reduce the transmission of pathogens and decrease the risk of infection by antibiotic resistant organisms. The antimicrobial activity of amphiphiles, compounds with hydrophobic and hydrophilic regions, was first reported in 1935, and has influenced the synthesis of amphiphiles with variations in structure. In this study, three series of amphiphiles were synthesized by two subsequent Menshutkin reactions. Each amphiphile contains one or two hydrocarbon tails ranging from 8 …

The Relationship Between Riparian Zone Width And Floristic Quality In Shenandoah County, Virginia, Jamie D. Smith

Masters Theses, 2010-2019

Riparian zones harbor an above average plant biodiversity. This biodiversity is threatened by invasive species and increasing human disturbance, the latter of which includes deforestation from agriculture and urban development. In this study, I examine relationship between the width of a forested riparian zone and the vegetation growing there. By using floristic quality assessment as a measure of anthropogenic disturbance, one can determine if wider riparian zones foster exclusion of non-native species while providing higher quality habitats for native plants. A randomized block design was used with three forested riparian treatments: deforested, moderately forested (woody vegetationstream), and extensively forested (woody …

Profile Of The Unfolded Protein Response In C. Elegans Depleted Of The Translational Chaperone, Nac., Caylin S. Murray

Masters Theses, 2010-2019

The function of a protein is a direct consequence of its final structure, which is achieved by protein-folding processes that generate a tertiary state through the juxtaposition of locally formed secondary structures. Because all cells need functional proteins to survive, each contains robust and redundant mechanisms that regulate the folding of newly forming proteins, and the refolding of misfolded proteins that are often generated during stress. Essential to these mechanisms, chaperones are proteins that aid in protein folding of nascent and misfolding protein without being incorporated in the final structure. One chaperone complex, the nascent polypeptide-associated complex (NAC), aids in …

Reproductive Parameters Of Two Coastal Pelagic Fishes Off Southeast Florida: Blackfin Tuna Thunnus Atlanticus And Little Tunny Euthynnus Alletteratus, Sonia Ahrabi-Nejad

HCNSO Student Theses and Dissertations

The ability to manage a fish stock relies on an understanding of life history characteristics and basic biology of the species. Numerous age-growth studies are facilitated by the relative ease of ageing fishes through hard-part analyses. Determining reproductive parameters for fish populations is equally important for stock assessments and management, and histological examination of gonads provides the most accurate determination of fecundity and spawning periods. Coastal pelagic fishes are often targeted commercially and recreationally due to their easy access by private vessels. However, there are few studies researching the biology and reproduction of recreational fishes in the waters of Southeastern …

Potential Effects Of Elevated Co2 On Pitcher Plant Nectar Composition, Prey Capture, And Inquiline Communities, Deirdre Courtney

Honors Theses

Human activities such as fossil fuel burning and deforestation have contributed significantly to the increasing levels of CO₂ in the atmosphere since the industrial revolution. Under the IPCC A1FI emission scenario, we are expected to reach levels as high as 1000 ppm by the end of the century. On average, C₃ plants experience a 27% increase in carbon to nitrogen (C:N) ratio under elevated CO₂. As a result, C₃ plants typically exhibit an increase in carbon-based secondary compounds. Carnivorous plants are a rare type of C₃ plant that has adapted to survive in low …

Role Of Integrin-Linked Kinase In Epidermal Integrity And Barrier Function, Samar Sayedyahossein

Electronic Thesis and Dissertation Repository

Integrin-linked kinase (ILK) is a β integrin adaptor protein that translates extracellular stimuli to intracellular signaling events. ILK plays a role in actin cytoskeleton dynamics and cell adhesion. The structure and function of the epidermis is highly dependent on cell-cell adhesion and cell-basement membrane interactions. The mechanisms whereby ILK contributes to epidermal integrity are poorly understood. Using a mouse model of epidermis-restricted Ilk gene inactivation, I observed that ILK loss causes abnormal morphology and presence of intra-epidermal and epidermal-dermal microblisters in embryos as early as E17.5. ILK-deficient epidermis is also characterized by abnormal localization or/and absence of adherens junctions, tight …

Inheritance Of Virulence In The Root Rot Pathogen Phytophthora Sojae, Sirjana Devi Shrestha

Electronic Thesis and Dissertation Repository

The oomycete Phytophthora sojae causes stem and root rot of soybean plants. The interaction of pathogen avirulence (Avr) and host resistance (R)-genes determine the disease outcome. The Avr3a mRNA transcript level is variable among P. sojae strains and determines virulence towards the R-gene Rps3a. To study the inheritance of virulence, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 and P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F₅ generation. However, test-crosses of F₁ (Avr3a^ACR10/Avr3a …

Changes In Coral Community Composition At Devil's Crown, Galapagos Islands, Ecuador: A 7,700 Year Perspective, Katharine Jane Hendrickson

HCNSO Student Theses and Dissertations

Coral mortality caused by El Niño–Southern Oscillation (ENSO) activity and its related disturbances has been researched throughout the Eastern Pacific. In the past three decades, disturbances related to the El Niño–Southern Oscillation (ENSO) have been shown to influence coral growth in the Eastern Pacific. In the Galápagos Islands, Ecuador, more than 97% of corals experienced mortality after the severe 1982-1983 ENSO episode. However, two of the most dominant coral species found in a coral community adjacent to Devil’s Crown; Psammocora stellata and Diaseris distorta survived this severe ENSO event. By reconstructing sediment cores of the coral community, this study assessed …

A Comparison Of Community Composition Analyses For The Assessment Of Responses To Wood-Ash Soil Amendment By Free-Living Nematodes, Paul B.L. George

Electronic Thesis and Dissertation Repository

Land-use changes can have far-reaching consequences for resident communities and ecosystem functioning. Developing appropriate assessment methods to observe and quantify this change is an important application of community ecology. Here I compare four methods of community assessment for free-living soil nematodes under forest harvesting disturbance and wood ash application. Neither morphological assessment (richness, abundance, diversity) nor molecular assessment (morpho-richness using T-RFLP) was responsive to experimental treatments. Trait-based approaches (Maturity Index (MI) and Body Size Spectra (BSS)) were more sensitive to forest harvest and wood-ash amendment treatments. The efficacy of these methods was also qualitatively compared. Of all methods, the BSS …

Neuromuscular Adaptations To Voluntary Contraction Following Postactivation Potentiation, Cameron B. Smith

Electronic Thesis and Dissertation Repository

Muscle contractile properties are history-dependent, and following a conditioning contraction, muscle tissue may be fatigued (slower, weaker) or potentiated (faster, stronger). Postactivation potentiation of evoked contractions, such as the electrically stimulated twitch, has been thoroughly studied. However, the effects of potentiation on voluntary contraction are not well understood, and prior study is largely equivocal.

The following studies propose to determine the effects of potentiation during 1) submaximal contractions at different muscle lengths 2) ballistic contractions following tetanic and voluntary conditioning, and 3) motor evoked potentials following tetanic and voluntary conditioning contractions. Evoked twitch potentiation was assessed with all of the …

Distribution, Growth, And Impact Of The Coral-Excavating Sponge, Cliona Delitrix, On The Stony Coral Communities Offshore Southeast Florida, Ari Halperin

HCNSO Student Theses and Dissertations

Bioerosion is a major process that affects the carbonate balance on coral reefs, and excavating sponges from the genus Cliona are some of the most important bioeroders on Caribbean reefs. The orange boring sponge, Cliona delitrix, is an abundant excavating sponge offshore southeast Florida that frequently colonizes dead portions of live stony corals, killing live coral tissue as it grows. With the recent decline in coral cover attributed to combined environmental and anthropogenic stressors, the increasing abundance of excavating sponges poses yet another threat to the persistence of Caribbean coral reefs.

In the first part of this study, I …

The Role Of Mate Preference And Personality On Reproductive Performance In An Ex-Situ Conservation Breeding Program For The Giant Panda (Ailuropoda Melanoleuca), Meghan S. Martin

Dissertations and Theses

Successful captive-breeding and re-introduction programs must have the ability to breed a surplus of genetically suitable animals for release into the wild. Unfortunately, many individuals in captive breeding programs often do not reproduce even when they are apparently healthy and presented with genetically appropriate mates. Mate choice can affect multiple parameters of reproductive sperformance, including mating success, offspring production, survival, and fecundity. We investigated the role of mate preference and personality on the reproductive performance of male and female giant pandas (Ailuropoda melanoleuca) as measured by intromission success and litter production. We conducted these studies on giant pandas at the …

Effect Of Photoperiod On Redox Regulation Of Phenotypic Plasticity And Cellular Growth In Chlorella Vulgaris, Lauren E. Hollis

Electronic Thesis and Dissertation Repository

Photoautotrophs are predisposed to maintain a balance between light energy absorption with the capacity to consume this energy through metabolism. An imbalance in energy flow may be a consequence of increased light intensity and is sensed as modulation of excitation pressure (EP). Chlorella vulgaris acclimated to continuous high EP exhibits a yellow-green phenotype characterized by reduced chlorophyll content and high chlorophyll a/b ratio with reduced light-harvesting complex abundance relative to the dark green phenotype of low EP-acclimated cultures. Previous studies on acclimation to EP in green algae have been conducted under constant growth light. To determine the role of EP …

Hcpe, A Potential Immuno-Modulatory Protein From Helicobacter Pylori That Is Dependent On The Disulfide Bond Protein Dsbhp, Jeff Lester

Electronic Thesis and Dissertation Repository

H. pylori is a human gastric pathogen that colonizes ~ 50% of the world’s population. It can cause gastritis, gastric or duodenal ulcers and also gastric cancer. H. pylori produces Helicobacter cysteine rich protein HcpE, a secreted protein which may play a role in virulence. In this study we show that HcpE is secreted in the culture supernatant both as a soluble protein and in association with outer membrane vesicles, and may play a role in the modulation of H. pylori inflammatory responses. We identified that Dsb_HP is necessary for HcpE production and secretion in H. pylori, and …

Assessment Of Macroinvertebrate Communities And Heavy Metal Contamination Along The Intracoastal Waterway In Fort Lauderdale, Florida, Robert Bernhard

HCNSO Student Theses and Dissertations

Sediments from four areas adjacent to marinas and a background site in the Intracoastal Waterway were assessed for macroinvertebrate composition and heavy metal contamination. Sediment core samples were collected in 2004 and 2005 for analyses of macroinvertebrate composition and sediment grain size. Additional sediment samples were collected in 2005 for chemical analyses of metals (Al, As, Cd, Cr, Cu, Fe, Pb, Hg, Ni and Zn). MANOVA and dendograms using Bray-Curtis similarity matrices grouped the sites into two clusters: the 3 sites closest to the New River formed one group, and the two end sites formed the other. The sites nearest …

Examining The Role Of Dax-1 In Regulation Of Cell Proliferation In Human Breast Cells, Amy E. Scandurra

Master's Theses

DAX-1 is a member of the Nuclear Hormone Receptor superfamily and acts as a transcriptional repressor. DAX-1 plays an important role in the development of adrenal and gonadal tissues. In addition to its role in normal cell development and differentiation, DAX-1 appears to have some influence on the progression of cancer. This work aims to examine the role of DAX-1 in regulation of proliferation in breast cancer. In our study, we have expressed DAX-1 in a DAX-1 deficient breast cancer cell line as well as knocked down DAX-1 expression in normal DAX-1 positive breast cells. Through these experiments, we were …

Thylakoid Phosphorylation And Cell Morphology In The Antarctic Psychrophile, Chlamydomonas Sp. Uwo241, Beth Szyszka-Mroz

Electronic Thesis and Dissertation Repository

The unicellular green microalga, Chlamydomonas sp. UWO 241, was isolated from Lake Bonney, Antarctica. A unique characteristic of this algal strain is its inability to undergo state transitions combined with an altered thylakoid protein phosphorylation profile, which suggests the absence of LHCII phosphorylation, and preferential phosphorylation of a set of novel proteins. Examination of the unique phosphoproteins revealed that they are associated with a large pigment-protein supercomplex, which contains components of both photosystem I and the cytochrome b₆/f complex and likely functions in cyclic electron flow (CEF).

The absence of phosphorylation of LHCII proteins, associated with state …

Cascades Island Lamprey Passage Structure: Evaluating Passage And Migration Following Structure Modifications, Siena Marie Lopez-Johnston

Dissertations and Theses

Pacific lamprey (Entosphenus tridentatus), an endemic species to the Columbia River Basin, U.S.A, has experienced staggering decreases in returns to spawning territories in recent decades. As lamprey are threatened severely by a lack of passage at mainstem dams, lamprey specific passage structures have been designed and constructed to address the problem. The Cascades Island Lamprey Passage Structure (LPS) at Bonneville Dam is the longest and steepest structure of its type, following the addition of an exit pipe which allows lampreys to travel from the tailrace of the dam to the forebay. The intent of this study was to …

Validation Of The Multi-Segment Foot Model With Bi-Planar Fluoroscopy, Aïda Valevicius

Electronic Thesis and Dissertation Repository

A multi-segment foot model (MSFM) is a useful tool for measuring foot joint kinematics although soft-tissue artefact is often present. Quantifying this error is needed to evaluate the accuracy of this model. This study validated the MSFM against bi-planar radiostereometric analysis (RSA) fluoroscopy. Heel-strike, mid-stance, and toe-off events during the stance phase were compared between motion capture and fluoroscopy. Rise/drop of the medial longitudinal arch showed a significant difference (p < 0.05) during toe-off, but no significant difference during heel-strike or mid-stance. Hindfoot supination/pronation and internal/external rotation, and forefoot supination/pronation motions showed no significant difference between the two techniques. The lack of significant difference will allow the MSFM to be used as a sufficiently accurate technique for measuring foot joint motions.

Longitudinal Quantitative Analysis Of Gait And Balance In Friedreich's Ataxia, Jeannie B. Stephenson

USF Tampa Graduate Theses and Dissertations

Friedreich's Ataxia (FA) is an autosomal-recessive, neurodegenerative disease characterized by progressive lower extremity muscle weakness and sensory loss, balance deficits, limb and gait ataxia, and dysarthria. FA is considered a sensory ataxia because the dorsal root ganglia and spinal cord dorsal columns are involved early in the disease, whereas the cerebellum is affected later. Balance deficits and gait ataxia are often evaluated clinically and in research using clinical rating scales. Recently, quantitative tools such as the Biodex Balance System SD and the GAITRite Walkway System have become available to objectively assess balance and gait, respectively. However, there are limited studies …

Low Temperature Tolerance Of Adult Drosophila Suzukii (Diptera: Drosophilidae), Ruth Jakobs

Electronic Thesis and Dissertation Repository

The crop pest Drosophila suzukii, native to Southeast Asia, has been found in Ontario since 2010. This raises concern with respect to it establishing permanent populations, however, little is known about its cold tolerance. I investigated the low-temperature tolerance, including phenotypic plasticity, of D. suzukii. While acclimation increased cold tolerance, there was no evidence of short-term cold-hardening. Chill coma occurs at -1.2 °C, which will limit winter activity. Cold shock decreased the reproductive output of females, but this negative effect may be mitigated by re-mating. Drosophila suzukii is chill-susceptible and 80 % of the flies die after exposure …

Novel Mechanisms In The Sorting Of Proglucagon To The Secretory Granules Of The Regulated Secretory Pathway, Leonard M. Guizzetti

Electronic Thesis and Dissertation Repository

The prohormone proglucagon encodes for multiple peptide hormones, including glucagon, glucagon-like peptide-1 (GLP-1), and GLP-2, produced through tissue-specific processing by prohormone convertase (PC) 1/3 and PC2. In alpha cells, PC2 yields glucagon, the major counter-regulatory hormone to insulin, which together, control glucose homeostasis. In contrast, GLP-1 and GLP2 are mainly produced in intestinal L-cells by PC1/3. GLP-1 stimulates insulin secretion following a meal, and therefore has opposing function to glucagon regulating glucose homeostasis; in contrast, GLP-2 enhances gut nutrient absorption. Efficient sorting of proglucagon to secretory granules is required for nutrient-regulated secretion. The aim of this thesis is to discover …