Life Sciences Commons^™

Ecophysiology Of Lionfish Metabolic And Visual Systems: Are There Physiological Limits To Inshore Invasion?, Aaron Hasenei

HCNSO Student Theses and Dissertations

Lionfish (Pterois spp.), an invasive species native to the Indo-Pacific, have permanently established themselves throughout the greater Caribbean, Gulf of Mexico, and regions of the Western Atlantic ranging from as far north as North Carolina to central Brazil. As their fundamental range expands, lionfish threaten to migrate into estuarine environments as they have been found to tolerate low salinities and an eclectic range of temperatures. The physiological capacity of invasion was assessed by quantifying the visual ecology of lionfish utilizing corneal electroretinography (ERG) as well as their metabolic scope and hypoxia tolerances under various temperature-oxygen-regimes utilizing intermittent-flow respirometry. Seasonal …

Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern

Biological Sciences Undergraduate Honors Theses

Methanogens, some of Earth’s most primitive prokaryotic organisms, are candidates for possible life forms capable of inhabiting Mars. Specifically, four different species (Methanobacterium formicicum, Methanococcus maripaludis, Methanosarcina barkeri, Methanothermobacter wolfeii) were analyzed for their tolerance to the presence of illite clay. Illite is a crystalline mineral that has been identified from regions of Mars’s surface. Results indicated that all four species grew with some success in the illite at different concentrations. This experimentation with methanogens’ abilities to survive and reproduce in the presence of illite allows for a more accurate understanding of the potential capability of microbial …

Comparisons Between Movement Onset Identification Methods Used In Isometric Mid-Thigh Pull Test, Junshi Liu

Electronic Theses and Dissertations

This dissertation aimed to explore the usefulness of using force derivatives for onset detection in the isometric mid-thigh pull test. First, we examined applications of three differential calculus principles, first and second derivative, and curvature using visual detection as a reference under different baseline conditions. Second, we compared the best derivative method to a threshold-based method using visual detection as a reference. Results of our first investigation showed trivial differences between many differential calculus methods and visual detection. However, statistical differences exceeding a trivial effect was observed when instantaneous force and rate of force develop were examined. Through the first …

Impacts Of Ammonia And Temperature On Freshwater Snail Behavior And Physiology., Megan Christine Dewhatley

Electronic Theses and Dissertations

Gastropods are one of the most imperiled groups of animals in North America, yet there are major gaps in the literature pertaining to pollutants and climate change, and especially sublethal impacts. This dissertation assesses the effects of climate warming and unionized ammonia (NH₃), one of the most abundant water pollutants, on the behavior and physiology of two caenogastropod snails: fine-ridged elimia (Elimia semicarinata) and Shawnee rocksnails (Lithasia obovata) (Gastropoda: Neotaenioglossa: Pleuroceridae). Righting behavior, or the movement used by snails to turn themselves right-side-up, was used as the main endpoint; delays in this behavior compromise …

Investigating The Single Cell Heterogeneity And Physiological Impact Of Mistranslation, Christopher Evans

Dissertations & Theses (Open Access)

Bacterial populations grow clonal populations; however, individual cells have a variety of phenotypes. The physiological heterogeneity observed in populations has been attributed to variations in the processes of gene expression. For example, promoter expression has been shown to be heterogeneous within a population and contribute to increased stress tolerance in a subpopulation of cells. In comparison to transcription, the influence of translation on single cells is unclear. In this study, my collaborators and I have developed a dual-fluorescence reporter that allows us to measure the mistranslation rate in single cells in vivo. Using this reporter, we found that mistranslation …

Behavioral Insights Into Nociceptor Function: A Systematic Approach To Understanding Postsurgical And Neuropathic Pain Mechanisms In Rats, Max Odem

Dissertations & Theses (Open Access)

Postsurgical and neuropathic pain are each clinically common, and often associated with ongoing pain. Ongoing pain has been linked to ongoing activity (OA) in human C-fiber nociceptors. Preclinical studies using rodent neuropathic models have concentrated on allodynia driven by OA generated in non-nociceptive Aβ fibers, but little attention has been paid to postsurgical pain in sham controls or to C-fiber nociceptor OA promoting ongoing pain.

Operant assays that reveal negative motivational and cognitive aspects of voluntary pain-related behavior may be particularly sensitive to pain-related alterations. In the mechanical conflict (MC) test, rodents can freely choose to escape from a brightly …

The Thermal Ecology Of Sceloporus Occidentalis, Luis Patricio Burgos

Master's Theses

With temperatures rising globally, assessing the possible impacts of the changing climate becomes more and more urgent. Ectotherms are excellent indicators of potential climatic ramifications on biodiversity because of their heavy reliance on the environment for their thermoregulation. Studies have historically looked at thermal tolerance values to establish predictive models for population and species extinctions.

In chapter 1, we looked at recent studies that suggest that thermal tolerance may be a plastic trait and test the effects empirically. Most studies are based on captive lizards acclimated to laboratory conditions that do not necessarily reflect natural environments, and if thermal tolerance …

The Use Of Current Steering During Subthalamic Deep Brain Stimulation To Alleviate Upper Limb Symptoms Of Parkinson's Disease, Shabna Iftikar Mohideen

Electronic Thesis and Dissertation Repository

Subthalamic (STN) deep brain stimulation (DBS) is an established treatment to alleviate the appendicular motor symptoms of Parkinson's Disease (PD). Current steering during DBS allows the unequal fractionation of current between two electrodes on the lead, resulting in a non-spherical electrical field. It is hypothesized that the way the electrical field is shaped will affect a patient’s upper limb symptom alleviation. Seven PD patients who underwent bilateral STN-DBS were tested over four weeks post-operation. 16 current fractionation settings were tested each week at an amplitude that increased weekly. Optimal setting was defined as the setting that provided the best …

Magnetic Field Frequency-Response For Human Magnetophosphene Perception And Associated Eeg Modulations, Cadence M. Baker

Electronic Thesis and Dissertation Repository

Background: Magnetophosphenes are among the most reliably reported effects resulting from magnetic induction. The frequency dependence of the perception threshold is crucial, as guideline agencies use this information to set exposure limits whose purpose is to protect public and workers.

Objective:Establish the magnetophosphene perception thresholds throughout the extremely low frequency range (0-300 Hz) and evaluate the use of EEG as a biomarker.

Hypothesis:Perception thresholds will be lowest at ~30 Hz. EEG occipital alpha power will decrease upon perception.

Methods:60 participants were exposed to homogenous magnetic fields up to 300 Hz, and 70 mT. EEG alpha power …

Cardiovascular Disease Risk And Menopause: Effects Of Cardiorespiratory Fitness, Exercise, And Follicle Stimulating Hormone, Corinna Serviente

Doctoral Dissertations

Menopause is associated with adverse changes in cardiovascular disease risk factors. A reduction in estrogens is most commonly associated with changing cardiovascular disease risk; however, recent observations suggest that the increase in follicle stimulating hormone that accompanies menopause may also influence risk, potentially through its influence on lipid levels. The changes in cardiovascular disease risk factors may adversely affect endothelial cell function, a pre-clinical marker for cardiovascular disease. Whether cardiorespiratory fitness is protective of endothelial health in this population, thereby mitigating the changes in risk that accompany menopause, is unclear. This dissertation evaluated differences in endothelial health and endothelial responses …

Physiological Response Of The Giant Acorn Barnacle, Balanus Nubilus, To Air Exposure, Emily Jane Resner

Master's Theses

The giant acorn barnacle, Balanus nubilus, is a resident of the subtidal and low intertidal rocky shoreline on the Pacific Coast of North America (Alaska to Baja California). B. nubilusis notable for having the largest muscle fibers in the animal kingdom; fiber diameters that can exceed 3mm in adults! At such extreme sizes these muscle cells may be at risk for insufficient oxygen delivery to mitochondria owing to low SA:V ratios and long intracellular diffusion distances. Oxygen limitation to these muscles may be further exacerbated during low tide air exposure (emersion) or environmental hypoxia events, which are increasing …

Neutrophil Extracellular Traps And Vascular Barrier Injury, Jamie E. Meegan

USF Tampa Graduate Theses and Dissertations

Sepsis is a life-threatening inflammatory condition with high morbidity and mortality rates. Though improvements to diagnosis and management of sepsis have been made, the complexity of the disease process and an incomplete understanding of its endpoint mechanisms have prevented major breakthroughs for early diagnosis and treatment. Representing a common endpoint in a number of inflammatory injuries including sepsis, endothelial barrier dysfunction causes fluid leakage and leukocyte infiltration that leads to tissue damage and multiple organ failure. Therefore, elucidating mechanisms of endothelial barrier regulation is needed to further develop targeted therapies in inflammatory disease.

Sepsis is characterized by a hyperinflammatory response …

Cardiodynamic Associations With Resilience In Undergraduate Students And The Effect Of A Mentorship Intervention, Rachel J. Knetsch

Electronic Thesis and Dissertation Repository

The National College Health Assessment (NCHA) indicates that a majority of Canadian university students report feeling overwhelmed, stressed, and anxious during their undergraduate studies. Resilience refers to positive adaptation, or the ability to maintain or regain mental health, despite experiencing adversity (Herrman et al., 2011). While autonomic indices have been used to describe chronic physiological stress, the role of heart rate variability (HRV) as an index of resilience remains unclear. This research tested the hypotheses that (1) there is a relationship between HRV and resilience scoresand (2) a mentorship intervention will improve HRV and resilience outcomes. Fifty-seven first year students …

Synergistic Effects Of Temperature And Salinity On The Gene Expression And Physiology Of Crassostrea Virginica, Hollis Jones

LSU Master's Theses

Crassostrea virginica, the eastern oyster, forms reefs that provide critical services and benefits to the resiliency of the surrounding ecosystem. Changes in environmental conditions, including salinity and temperature, can dramatically alter the services oysters provide by affecting their population dynamics. Climate warming may further exacerbate the effects of salinity changes as precipitation events increase in frequency, intensity, and duration. Temperature and salinity independently and synergistically influence gene expression and physiology in marine organisms. We used comparative transcriptomics, physiology, and a field assessment experiment to investigate whether Louisianan oyster are changing their phenotypes to cope with increased temperature and salinity …

Effects Of Maternal Protein Restriction On The Pulmonary Surfactant System During The Early Life And Adulthood, Reza Khazaee

Electronic Thesis and Dissertation Repository

Fetal growth restriction (FGR) is defined by low birth weight and contributes to a variety of adult-onset diseases with different severities between males and females. However, the effects of FGR on the pulmonary surfactant are not fully elucidated. In this thesis, first, we investigated the FGR effects on the lung function and the surfactant system at the early postnatal life. It was hypothesized that FGR contributes to alterations of lung mechanics and the surfactant system during the neonatal period. Second, we assessed the FGR effects on the surfactant system in response to sepsis in adulthood. It was hypothesized that FGR …

The Effect Of Anoxia On Mitochondrial Function In A Hibernator (Ictidomys Tridecemlineatus), Leah Hayward

Electronic Thesis and Dissertation Repository

Hibernation protects mammalian tissues against ischemia-reperfusion injury, but the underlying biochemical mechanisms are unknown. I hypothesized that the mechanisms allowing for mitochondrial metabolic flexibility during hibernation permit anoxia tolerance and contribute to tissue ischemia-reperfusion tolerance. I assessed mitochondrial performance before and after five minutes of anoxia in liver mitochondria isolated from thirteen-lined ground squirrels. I compared this anoxia effect among animals that were summer active (SA), or during hibernation (in torpor or interbout euthermia; IBE). Anoxia decreased state 3 respiration in all groups, but mitochondria isolated from torpid squirrels were least affected; these decreases paralleled decreased activity of electron transport …

Endothelial Glycocalyx Shedding In Pediatric Diabetic Ketoacidosis, Rufina Ning

Electronic Thesis and Dissertation Repository

Diabetic ketoacidosis (DKA) is a state of severe insulin deficiency resulting in hyperglycemia, ketoacidosis, and inflammation. Children with DKA have an increased risk of microvascular complications (e.g. stroke). The glycocalyx maintains the anti-thrombotic properties of endothelial cells (ECs), however the glycocalyx status is unknown in DKA. We quantified major glycocalyx components: hyaluronic acid (HA), heparan sulfate (HS), chondroitin sulfate (CS), and syndecan-1 in DKA plasma and correlated them with DKA severity. HA/HS were significantly increased in the plasma of DKA patients in comparison to insulin-controlled type-1 diabetics, but only HA correlated to DKA severity. Exogenous addition or removal of HA …

The Role Of Cholinergic Signaling In Cardiac Function, Rachel Reingold

Electronic Thesis and Dissertation Repository

Cardiovascular disease is one of the leading causes of death in Canada. Treatment currently focuses on preventing the increase of sympathetic signaling seen in heart failure. However, it has recently been noted that cardiac function is dependent on parasympathetic tone. Previous studies have demonstrated the development of heart failure when cholinergic targets are knocked out in cardiomyocytes. Transgenic mouse models that have increased cholinergic transmission show protection against cardiovascular insults. We have shown that transgenic mice overexpressing vesicular acetylcholine transporter in cholinergic cells show cardiovascular protection in response to ex vivo insults. As well, this protection is seen when cholinergic …

Mechanisms Underlying Freeze Tolerance In The Spring Field Cricket, Gryllus Veletis, Jantina Toxopeus

Electronic Thesis and Dissertation Repository

Freeze tolerance has evolved repeatedly across insects, facilitating survival in low temperature environments. Internal ice formation poses several challenges, but the mechanisms that mitigate these challenges in freeze-tolerant insects are not well understood. To better understand how insects survive freezing, I describe a novel laboratory model, the spring field cricket Gryllus veletis (Orthoptera: Gryllidae). Following acclimation to six weeks of decreasing temperature and photoperiod (mimicking autumn), G. veletis juveniles becomes moderately freeze-tolerant, surviving freezing at -8 °C for up to one week, and surviving temperatures as low as -12 °C. Acclimation is associated with increased control of the temperature and …

Pilot Study: Heart Rate Variability Analysis And Mental Health Outcomes In University Female Hockey Players, Kaitlyn Jacobs

Electronic Thesis and Dissertation Repository

Exercise improves anxiety and depression, both of which are associated with impaired autonomic regulation of heart rate (HR). In turn, HR variability (HRV) is a reliable physiological indicator of external stressors. The following research tested the hypothesis that HRV is indicative of chronic resilience towards mental stress in female varsity hockey players. Seventeen varsity hockey players (HOCK, age 21 ± 1.5) and fifteen healthy controls (CTRL, age 21 ± 2.2) at Western University participated three times throughout a 7-month season. Participants completed questionnaires (brief resilience scale, BRS; generalized anxiety scale, GAD-7; mental health inventory, MHI; visual analog scale, VAS; short …

Effects Of Resistance Exercise On Postprandial Metabolism In Obese Men With Prediabetes, Adam Bittel

Arts & Sciences Electronic Theses and Dissertations

Prediabetes is a metabolic condition defined by elevated fasting (impaired fasting glucose (IFG)) and/or postprandial (impaired glucose tolerance (IGT)) glucose. Prediabetes affects nearly 86 million adults in the United States, with most (up to 70%) progressing to type 2 diabetes within as little as one year. Recent studies have indicated that elevated post-prandial glycemia and hypertriglyceridemia are early indicators of prediabetes, and are major risk factors for complications of prediabetes, including cardiovascular disease (CVD), stroke, elevated blood pressure, and obesity. Resistance exercise is a central component of exercise recommendations for individuals with type 2 diabetes and prediabetes, but the effect …

The Role Of Membrane Excitability In Insulin Regulation, Christopher Howard Emfinger

Arts & Sciences Electronic Theses and Dissertations

In mammals, ATP-sensitive K+ (KATP) channels are essential regulators of insulin secretion from pancreatic islet [beta]-cells, illustrated by the finding that gain-of-function mutations in KATP channels (KATP-GOF) cause neonatal diabetes mellitus (NDM). However, variability in symptom severity and effectiveness of treatment is seen in NDM, even for those with the same mutation and in the same family. Short-term treatment of mice expressing KATP-GOF mutations in [beta]-cells (KATP-GOF mice) with the KATP blocker glibenclamide during disease onset results in two outcomes: one subset becomes severely diabetic (non-remitters), whereas the other subset remains below the glucose levels at which significant side effects …

Functional And Skeletal Muscle Impairments In Progressive Diabetic Ckd, Daniel Bittel

Arts & Sciences Electronic Theses and Dissertations

1-in-3 persons with type 2 diabetes (T2DM) develop chronic kidney disease (CKD), which is characterized by progressive renal dysfunction leading to end-stage renal disease. In response to elevated blood glucose and systemic inflammation of diabetes, a process of active thickening of the renal glomerular basement membrane ensues with concomitant damage to the structural supports (podocytes) of the kidneyճ filtration barrier. This results in impaired renal filtration. The metabolic sequelea of T2DM and CKD also, synergistically, alter skeletal muscleճ degradative pathways, satellite cell function (muscle reparative cells), and mitochondrial health (muscle energetic machinery) -- resulting in muscle breakdown, poor muscle quality, …

Beta-Cell Β1 Integrin Deficiency During Second Transition Stage Of Fetal Pancreas Development On Islet Growth, Phyo Win

Electronic Thesis and Dissertation Repository

β1 integrin has been shown to be important for pancreatic beta-cell growth and functioning. Congenital and postnatal studies have shown beta-cell mass reduction with β1 integrin knockout (β1KO). Using an inducible cre recombinase (CreERT) expressed from the mouse insulin promoter (MIP) crossed to a line in which Itgb1 (β1 integrin encoding gene) was flanked by loxP sites (MIP-CreERT+; β1itg designated as MIPβ1KO), we examined the in vivo temporal role of beta-cell β1 integrin effect on islet growth during the second transition stage of pancreas development.

Prenatal MIPβ1KO mice displayed decreased beta-cell area, mass, density and proliferation. In addition, a decrease …

The Role Of Developmental Timing Regulators In Progenitor Proliferation And Cell Fate Specification During Mammalian Neurogenesis, Jennifer S. Romer-Seibert

Graduate School of Biomedical Sciences Theses and Dissertations

Developmental timing is a key aspect of tissue and organ formation in which distinct cell types are generated through a series of steps from common progenitors. These progenitors undergo specific changes in gene expression that signifies both a distinct progenitor type and developmental time point that thereby specifies a particular cell fate at that stage of development. The nervous system is an important setting for understanding developmental timing because different cell types are produced in a certain order and the switch from stem cells to progenitors requires precise timing and regulation. Notable examples of such regulatory molecules include the RNA-binding …

Insight Into Translational Activation In Yeast Mitochondria, Julia Lynn Jones

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial function depends on over a thousand proteins, of which the majority are nuclear DNA-encoded and approximately one percent are mitochondrial DNA-encoded. The mitochondrial DNA of Saccharomyces cerevisiae contains eight protein-encoding genes, seven of which are required for proper function of the respiratory complexes and one encodes a ribosomal protein. The bigenomic nature of the oxidative phosphorylation complexes requires coordinated expression and regulation from both the nuclear and the mitochondrial genomes. It is currently unclear how this regulatory network operates. However, it is thought that nuclear genome-encoded messengers localized to the mitochondria aid in this coordination.

A family of proteins …

The Role Of Perivascular Fibrosis In Post-Stroke Glymphatic Impairment And Cerebral Amyloid Angiopathy, Matthew D. Howe

Dissertations & Theses (Open Access)

In healthy brain tissue, toxic amyloid-β (Aβ) proteins are transported by the pulsatile flow of cerebrospinal fluid (CSF) along perivascular drainage pathways. Ischemic stroke may disrupt this process, leading to a perivascular build-up of Aβ, termed cerebral amyloid angiopathy (CAA). I hypothesize that an abnormal pattern of extracellular matrix deposition within the vascular basement membrane, termed fibrosis, impairs Aβ drainage from the aged brain after stroke. I further hypothesize that inhibition of astrocytic transforming growth factor-β (TGF-β) signaling can reverse these phenotypes. Finally, I also hypothesize that serum biomarkers of perivascular fibrosis can be used to diagnose CAA following intracerebral …

Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees

Graduate Theses and Dissertations

Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition [TN] at 24°C) …

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) …

An Investigation Into Fatigue Management: Effects Of Two Different Loading Protocols On Markers Of Inflammation And The Endocrine Response, Jake Bernards

Electronic Theses and Dissertations

The purposes of this dissertation were to 1) determine the effectiveness of the neutrophillymphocyte ratio (NLR) as an athlete monitoring tool in resistance training and 2) determine if repetition maximum or relative intensity loading scheme is superior in managing fatigue through the hormonal, inflammatory, and performances response throughout a 10-week periodized resistance training program. Results from the dissertation give merit to continued research regarding the use of NLR as a monitoring tool to help determine the degree of recovery. Furthermore, results from this dissertation lead to questioning the effectiveness of using a repetition maximum (RM) loading scheme within a periodized …