Life Sciences Commons^™

Biological And Physiological Condition Of Juvenile California Halibut (Paralichthys Californicus) Exposed To A Contamination Gradient In Mission Bay, Ca, Kevin Stolzenbach

Theses

Contaminated sediments in marine environments have been shown to be good indicators of ecological risk and a means to assess anthropogenic impacts on marine habitats and the animals that inhabit them (Long et al. 1995, Rattner 2009). Estuarine sediments are especially complex media with regard to physical, chemical, and biological characteristics that trap, store, modify and sometimes release contaminants to the biota (Long et al. 1995). Especially vulnerable are animals that are in constant contact with the sediments, such as flatfishes that partially bury themselves for camouflage (Costa et al. 2011). Impacts can be assessed in a number of ways, …

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 …

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 …

Effects Of Step Training On The Kidneys Following Spinal Cord Injury In Rats., Pradeepa Poudyal

Electronic Theses and Dissertations

Detrusor-sphincter dyssynergia after chronic spinal cord injury (SCI) leads to over-distention, high bladder pressures and vesico-ureteric reflux into the kidney, resulting in repeated infections and pyelonephritis. Given the importance/limited knowledge of SCI effects on the upper urinary tract, this study assessed expression of two proteins in the kidneys of contused (T9) male rats relative to controls that are indicative of tissue stress/damage (TGFβ, CD11b). The impact of two therapeutic rehabilitation strategies, 60 minutes of step training and general exercise, was then assessed on these protein levels relative to non-trained SCI controls, plus the effectiveness of a shorter training duration (30 …

Hif-1Α In The Heart: Provision Of Ischemic Cardioprotection And Remodeling Of Nucleotide Metabolism, Joe Wu

Electronic Theses and Dissertations

In our studies we found that stabilized expression of HIF-1α in heart led to better recovery of function and less tissue death after 30 minutes of global ischemia, via mechanisms that preserve the mitochondrial polarization. Our group previously showed that HIF-1α conferred ischemic tolerance by allowing cardiomyocytes to use fumarate as an alternative terminal electron acceptor to sustain anaerobic mitochondrial polarization. The source of fumarate was identified as the purine nucleotide cycle (PNC). Here we discovered that HIF-1α upregulates AMP deaminase 2 (AMPD2), the entry point to the PNC. The combination of glycolysis and the PNC may protect the heart's …

Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman

Graduate Theses and Dissertations

Past studies have shown that the avian vasotocin 4 receptor (VT4R), homologous to the mammalian arginine vasopressin receptor 1a (V1aR/AVPR1A) is involved in immobilization stress. It was not known, however, whether the receptor is also associated with osmotic stress, and if so, what brain regions may be involved. Four treatment groups of chicks were used for the study. One group was subjected to 1h immobilization stress and two groups were administered intraperitoneal injection of 3 M NaCl or 0.15 M NaCl. One additional group served as controls. After 1 h, blood samples were taken for the determination of plasma levels …

Regulation Of Functional Expression Of Mechanosensitive Trpv4 Channel In The Distal Nephron By Dietary Potassium And Sodium Intake, Nabila Boukelmoune

Dissertations & Theses (Open Access)

The Ca²⁺-permeable TRPV4 channel is predominantly expressed in the distal nephron (DN) and its activity is essential for [Ca²⁺]_i elevations in response to increased tubular flow. Here, I probed the physiological mechanisms controlling TRPV4 function and expression in the DN. I found that renal TRPV4 expression and mRNA levels were significantly increased by high K⁺ diet (5%) and decreased by dietary K⁺ restriction (0.003%). In contrast, variations in Na⁺ regimen had no apparent effect on TRPV4 expression and mRNA levels. Regulation of TRPV4 protein expression by K⁺ diet was independent of …

Central Administration Of Neuropeptide Y (Npy) And Vasotocin 4 Receptor (Vt4r/V1ar) Antagonists On Food Intake And A Stress Response In Chicks, Megan Ann Hancock

Graduate Theses and Dissertations

The objective of this study was to determine the central effect of the VT4R antagonists (SR-49059 and H-5350 (Manning compound)) on corticosterone (CORT) levels during stress and food intake. A 22-gauge stainless steel guide cannula was surgically implanted into the lateral ventricle of the birds. A preliminary study was done to test the antagonists and their role on food intake. Birds were injected with saline, NPY (4µg), NPY (4µg)+SR-49059 (250ng), or NPY (4µg)+Manning compound (250ng). Birds injected with saline had the lowest 1h food intake (17.7g1.6). Birds injected with NPY+saline had a significantly higher intake (27.1g 1.0), which was enhanced …

Alcohol Modulation Of Dopamine Release, Nathan Dan Schilaty

Theses and Dissertations

The mesolimbic dopamine (DA) system projects from the ventral tegmental area (VTA) to structures associated with the limbic system, primarily the nucleus accumbens (NAc). This system has been implicated in the rewarding effects of drugs of abuse. Many drugs of abuse act in the VTA, the NAc, or both. Dopamine neurons in the VTA that project to the NAc, and the GABA neurons that inhibit DA neurons locally in the VTA or project to the NAc, play an important role in mediating addiction to various drugs of abuse, in particular alcohol. There is a growing body of evidence of co-dependence …

The Role Of Ceramides In Mediating Endotoxin-Induced Mitochondrial Disruption, Melissa Ellen Hansen

Theses and Dissertations

Ceramides are sphingolipids that serve as important second messengers in an increasing number of stress-induced pathways. Ceramide has long been known to affect the mitochondria, altering both morphology and physiology. Lipopolysaccharide (LPS) is a prevalent circulating inflammatory agent in obesity, potentially mediating some of the pathologies associated with weight gain. Given previous findings of TLR4-mediated ceramide accrual and ceramide-mediated mitochondrial disruption, we questioned whether ceramide is necessary for LPS-induced mitochondrial disruption. We found that LPS treatment increased gene transcript levels of ceramide synthesis enzymes and mitochondrial fission proteins and increased ceramide content in cultured myotubes and in mouse tissue. Mitochondrial …

Boundary Contour Based Surface Representation., Yong Su

Electronic Theses and Dissertations

We receive most information about our surrounding space and objects through the eyes. To reconstruct the 3D space and objects in the visual system from the 2D retinal images, surface representation must be a critical intermediate stage in the visual processing stream. It is hypothesized in the dissertation that the visual system represents textured surface by a border-to-interior strategy: boundary contours would be encoded first and then border-ownership assignments would be resolved. This process would solve the related problems such as figure-ground segregation, surface depth relationship, occlusion, transparency, etc. As a result, the boundary contours of the surfaces would be …

Post-Transcriptional Regulation Of The Type Iia Sodium-Phosphate Cotransporter By Parathyroid Hormone., Rebecca Dale Murray

Electronic Theses and Dissertations

The type IIa sodium-phosphate cotransporter (Npt2a) is expressed in the apical membrane of the renal proximal tubule and is responsible for the reabsorption of the majority of the filtered load of phosphate. Parathyroid hormone (PTH) is secreted by the parathyroid gland in response to a decrease in serum calcium or an increase in serum phosphorus, and acutely induces phosphaturia through the rapid stimulation of endocytosis of Npt2a and its subsequent lysosomal degradation. Chronic PTH stimulation leads to sustained phosphaturia, but the mechanisms for the chronic regulation of Npt2a by PTH remain unclear. We hypothesize that PTH decreases Npt2a mRNA levels …

The Effect Of A Controlled Frequency Breath Holding Training Program On Running Economy Among Elite College Swimmers., Patrick Sims 1988-

Electronic Theses and Dissertations

Running economy (RE) is the amount of oxygen consumed while running at a submaximal intensity. Along with aerobic capacity (VO2max), RE is an important predictor of running performance. Little research has investigated changes in RE with restricted breathing training [i.e. controlled breath-holding (CFB)] during exercise. RE may improve ~6% amongst a novice swimming cohort through CFB training, but this has not been established in elite swimmers. The purpose was to further establish that CFB training (16 sessions of 12 x 50-m with ~15 seconds rest between each 50-m, using only ~2 breaths per 50-m) can improve RE in 25 elite …

Extent Of Cysteine Modification Of Snap-25 In Vitro, Alex Mcgregor Dabell

Theses and Dissertations

Exocytosis, the fusion of a vesicle to a cellular membrane, involves a protein named SNAP-25. This protein, containing two alpha helices connected with a linker region, is localized to the cell membrane via palmitic acids attached to the cysteine residues of its linker region in a process called palmitoylation. Are cysteine residues of the SNAP-25 linker region palmitoylated in an ordered manner and to a particular extent? The answer to this question may give insight into the regulated nature of exocytosis. While it is generally accepted that SNAP-25 must be palmitoylated in order to perform its exocytotic functions, the details …

Exploring The Glucocorticoid Actions Of 1Α-Hydroxycorticosterone (1Α-Oh-B) In The Elasmobranch Fishes, Faith Nichole Lambert

Master's Theses

The corticosteroid 1α-hydroxycorticosterone (1α-OH-B) is unique to the elasmobranch fishes. It is thought that 1α-OH-B acts as both the primary glucocorticoid (GC) and mineralocorticoid (MC) in these fishes, a dual role analogous to that of cortisol in the teleost fishes. The MC characteristics of 1α-OH-B are well supported, but data supporting its GC functions are lacking. In this study, the putative GC actions of 1α-OH-B were examined. The first experiment characterized the physiological stress response of the Atlantic stingray (Dasyatis sabina) to air exposure, with particular regards to the roles of corticosteroids and metabolic fuels. Results demonstrate that …

A Movement Tool Kit For The Divergent And Convergent Cps Guidelines: Instruction Cards And Activity Floor Mats, Adela Vangelisti

Creativity and Change Leadership Graduate Student Master's Projects

A Movement Tool Kit for the Divergent and Convergent CPS Guidelines:

Instruction Cards and Activity Floor Mats

Movement is as natural to humans as breathing is, and, yet, passivity starts early in schools. We are taught to sit still and in silence for long periods of time. By the time we reach adulthood and enter the workforce, we have almost forgotten our sense of embodiment. This lack of movement is counter-productive, not only to learning but to the development of creativity as well. For this project, I designed a tool to recapture the joy and playfulness of movement. Furthermore, the …

Characterization Of Aldh Positive Cells In The Human Fetal Pancreas, Amanda Oakie

Electronic Thesis and Dissertation Repository

Aldehyde dehydrogenase (ALDH) is an enzyme that regulates differentiation during pancreatic development, but determining the role of ALDH during endocrine differentiation is not well defined. The purpose of this study was to characterize transcription factors (TFs) and putative stem cell surface markers in ALDHhi or ALDHlo populations of the human fetal pancreas (18-22 weeks of age), and examine their expansion and differentiation in vitro and in vivo. Cell surface marker analysis demonstrated high co-localization of the stem cell marker CD133 with ALDHhi cells. ALDHhi cells also contained higher expression of islet- associated TFs and insulin. Expansion of sorted ALDHhi cells …

Functional Morphology And Feeding Mechanics Of Billfishes, María Laura Habegger

USF Tampa Graduate Theses and Dissertations

Billfishes (marlins, spearfishes, sailfishes and swordfish) are one of the fastest and largest marine apex predators, and perhaps their most recognizable attribute is their bill or rostrum. The proposed function for this novel structure has ranged from hydrodynamic enhancement to defensive weaponry. However, the most supported hypothesis for its function has been linked to feeding. Billfishes have been observed to subdue their prey with their rostrum, either stunning or cutting them into pieces before ingestion. Due to their large body sizes and pelagic lifestyles a thorough investigation of the function of this structure has been logistically challenging. The goal of …

A Rhog/Ilk/Elmo2/Rac1 Pathways Modulates Microtubule Stability, Bradley C. Jackson

Electronic Thesis and Dissertation Repository

Integrin-linked kinase (ILK) is a widely expressed scaffold protein important for cell adhesion, migration, and phagocytosis. ILK and its interacting partner, engulfment and cell motility protein 2 (ELMO2), may also modulate microtubule dynamics. Here, I show that sustained microtubule growth and acetylated tubulin levels are reduced in the absence of ILK and, conversely, that exogenous ILK exerts a stabilizing effect on microtubules. Further, exogenous ELMO2, ras homology growth related protein (RHOG) and ras-related C3 botulinum toxin substrate 1 (RAC1) stabilize microtubules in an ILK-dependent manner. Potential downstream effectors of the effect of ILK on microtubule stability include glycogen synthase kinase- …

Amyloid Β Peptides, Signalling And Trafficking Of The Α7 Nicotine Receptor, Kirk Young

Electronic Thesis and Dissertation Repository

The α7 nicotinic acetylcholine receptor (nAChR) is an ionotropic receptor for the neurotransmitter acetylcholine and its precursor, choline. Interestingly, α7 nAChR binds amyloid β 42 (Aβ42) peptide, which has a primary role in Alzheimer’s disease pathology. Aβ42 peptide forms aggregates and different structural forms elicit different physiological outcomes. Oligomeric, fibrillar and non-aggregated preparations of Aβ42 were characterized by atomic force microscopy. Immunoblotting of neuronal cells exposed to these preparations determined oligomeric aggregates of Aβ42 mediate ERK1/2 intracellular signalling through α7 nAChR. Cell surface ionotropic receptors are regulated through endocytosis to maintain the integrity of neurotransmission. Cellular pathways for endocytosis of …

Rapid Method Of Processing Sperm For Nucleic Acid Extraction In Clinical Research, Matthew K. De Gannes

Masters Theses

Background: Sperm contain highly compact nuclei, inhibiting DNA extraction using traditional techniques. Current methods extracting sperm DNA involve lengthy lysis and no means of stabilizing DNA, hindering clinical research.

Objective: We sought to optimize an efficient method of extracting high quality human sperm DNA.

Methods: Sperm from three volunteers were isolated using PureCeption. We tested 1) proteinase K with DNA/RNA Shield, 2) DTT and TCEP as reducing agents, 3) QIAshredder homogenization, and 4) stability of sperm DNA fresh (baseline) or after 4 weeks of storage at 4^OC in DNA/RNA Shield using modified Quick-gDNA MiniPrep. DNA was PCR amplified …

Biosteel High Performance Sports Drink Improves Exercise Performance Following A Simulated Hockey Game, Kolten C. Abbott

Electronic Thesis and Dissertation Repository

INTRODUCTION: BioSteel High Performance Sports Drink (BioSteel) is one of the most popular sports supplements consumed by professional and amateur athletes. BioSteel Inc^® claims that consumption of BioSteel before and during exercise will result in “enhanced energy while delaying the onset of muscular and mental fatigue”. PURPOSE: Assess the efficacy of BioSteel supplementation on anaerobic and aerobic exercise performance as well as sport-specific cognition throughout exercise. METHODS: Eleven exercise-trained men completed a simulated hockey game on a cycle ergometer under two experimental conditions: BioSteel and isoenergetic placebo. Measures of exercise performance and cognition were assessed before, throughout and after …

Mutations At The 46th Residue Change Properties Of Cx50 Gap Junction Channels, Xiaoling Tong

Electronic Thesis and Dissertation Repository

The interface of the first transmembrane domain and the first extracellular loop (TM1/E1 border) in several gap junction (GJ) channels is known to line a portion of the pore and plays an important role in determining GJ channel properties. By introduction of a charged residue into this domain of Cx50, the resultant mutant channels showed drastically altered unitary conductance (γ_j) and transjunctional voltage-dependent gating (V_j-gating). Specifically G46D and G46E increased the Cx50 γ_j from 201 to 256 and 293 pS, respectively and G46K channel showed a decreased γ_j of only 20 pS. Moreover, in …

The Implications Of Altered Cholinergic Signaling In Cardiac Health And Disease, Ashbeel Roy

Electronic Thesis and Dissertation Repository

­Cardiac remodeling and dysfunction occur prior to the onset of heart failure. Altered regulation of cardiac function by the autonomic nervous system has been implicated in the progression of heart disease. Both altered sympathetic and parasympathetic tone contribute to cardiac disease; however, the role of the parasympathetic nervous system, and specifically acetylcholine (ACh), in cardiac dysfunction has not been fully elucidated. In these studies, we sought to determine whether changes in neuronal and/or non-neuronal ACh release regulate cardiac activity and alter the progression of cardiac remodeling and dysfunction. A systemic decrease in the expression of the vesicular acetylcholine transporter …

Ilk Modulates Stress-Induced Apoptosis In Epidermal Keratinocytes, Michelle Im

Electronic Thesis and Dissertation Repository

Integrin-linked kinase (ILK) is a ubiquitous scaffold protein that mediates cellular responses to integrin stimulation by extracellular matrix proteins. Mice with inactivation of the Ilk gene in squamous epithelia display defects in skin regeneration after injury, failure to thrive, and perinatal death. ILK-deficient epidermis exhibits reduced adhesion to the basement membrane and impaired hair follicle morphogenesis. In culture, ILK-deficient keratinocytes fail to attach and spread efficiently, and demonstrate decreased survival. We now show that ILK-deficient keratinocytes exhibit lower proliferative capacity and increased apoptosis in the absence or presence of growth factors. This reduced viability appears to be independent of the …

Role Of C-Kit Receptor Tyrosine Kinase On Ins-1 Cell Vegf-A Expression In Vitro, Alexei Popell

Electronic Thesis and Dissertation Repository

Interactions between Stem Cell Factor (SCF) and c-Kit are critical in maintaining β-cell survival and function. VEGF-A, essential in facilitating islet vasculature formation, is secreted by β-cells. This work investigates the mechanisms by which c-Kit regulates VEGF-A production in β-cells, using a rat insulinoma (INS-1) cell line as an in vitro model. Cells were treated with recombinant hSCF or cultured with c-Kit (r) siRNA for 72 h. VEGF-A accumulation in the culture medium was measured by ELISA, while qRT-PCR, western blot, and immunofluorescence analyses were also performed. SCF augmented VEGF-A production in a time-dependent (p < 0.05 vs. control at 6 h and 24 h), and dose-dependent manner (p < 0.01 vs. control at 30-100 ng/mL). SCF stimulation increased phosphorylation of proteins along the PI3K/Akt/mTOR pathway (p < 0.05 vs. control groups), and decreased phosphorylation following siRNA treatment. Our results indicate that c-Kit exerts a regulatory effect on VEGF-A production in β-cells.

Niacin And Microvascular Endothelial Cell Response To Fatty Acid Excess And Hypoxia, Dominic Pang

Electronic Thesis and Dissertation Repository

Niacin can reduce vascular disease risk, but its mechanism of action is controversial, and may not be dependent on systemic lipid modifying effects. This thesis tested the hypothesis that niacin directly improves endothelial cell function under lipotoxic and low oxygen conditions, as seen in ischemic conditions during metabolic syndrome, and investigated the potential mechanism involved. Human microvascular endothelial cell (HMVEC) survival was reduced by exposure to excess fatty acids under both normoxic and low oxygen conditions. Angiogenic function, as determined by tube formation on Matrigel, was impaired during fatty acid overload under either normoxic or low oxygen conditions. These effects …

Mirna-21 Has Anti-Inflammatory Effects In The Macrophage Response To Peritonitis., Rebecca Elise Barnett

Electronic Theses and Dissertations

This project investigated the role of miRNA-21 in the macrophage response to peritonitis; with the goal of understanding whether the associated mechanism has potential benefits in the clinical treatment of peritonitis. A novel therapeutic intervention in the treatment of peritonitis could modulate the host immune response to decrease an exaggerated pro-inflammatory innate response and then prevent or ameliorate the development of sepsis and organ failure. We found the following: 1. MiRNA-21 expression increases in peritoneal macrophages after lipopolysaccharide (LPS) stimulation. 2. Over expression of miRNA-21 decreases TNF-a secretion from macrophages after LPS stimulation. Suppression of miRNA-21 expression results in increased …

Osteoblast Oncostatin M Signaling In Modeled Spaceflight, Jacob Goyden

Boise State University Theses and Dissertations

Bone deterioration is a challenge in long-term spaceflight with significant connections to terrestrial disuse bone loss. Prolonged unloading and radiation exposure, defining characteristics of space travel, have both been associated with changes in inflammatory signaling via IL-6 class cytokines in bone. While there is also some evidence for perturbed IL-6 class signaling in spaceflight, there has been scant examination of the connections between free fall, radiation, and inflammatory stimuli in bone. Our lab and others have shown that the IL-6 class cytokine oncostatin M (OSM) is an important regulator of bone remodeling. We hypothesize that spaceflight alters osteoblast OSM signaling, …

Physiological Effects Of A Kettlebell Workout Versus A High-Resistance Circuit Workout, Brett Schreiber

Graduate Theses and Dissertations

Purpose: To compare the physiological effects of a single kettlebell workout to a high-resistance circuit workout in resistance-trained males. Methods: 12 resistance trained healthy males (age: 24 ± 2.97 years; height: 1.75 ± 0.064 m; body mass: 75.99 ± 8.46 kg) participated in this study. Participants had a familiarization visit and two subsequent experimental visits (kettlebell workout; circuit workout). The kettlebell workout consisted of 12-minutes of standardized kettlebell swings. The circuit workout consisted of three sets of 6 repetitions of smith machine squats, bench press, leg curl, and lat pulldown. Heart rate, rectal temperature, skin temperature, blood lactate, rating of …