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Effect Of Rearing Conditions On The Allocation Of Larval And Adult Acquired Essential And Nonessential Fatty Acids To Flight In Two Adult Lepidoptera: Danaus Plexippus And Mythimna Unipuncta, Libesha Anparasan

Electronic Thesis and Dissertation Repository

Insects which are nectivorous as adults acquire essential fatty acids, which are important for many biological processes, almost exclusively from the larval diet. Thus, adult allocation of this limited resource may result in trade-offs in migrant insects that delay reproduction. I used the true armyworm, Mythimna unipuncta, and monarch butterfly, Danaus plexippus, to test the hypothesis that environmental cues (fall migratory or summer reproductive) would influence the use of fatty acids during flight (0-6h). I used larval and adult diets manipulated isotopically (δ¹³C) and chromatographic analyses to determine fatty acid composition and source in the fat …

The Effect Of Central Chemoreceptors On The Peripheral Respiratory Chemoreflex Response To Hypoxia In Humans, Nasimi A. Guluzade

Electronic Thesis and Dissertation Repository

We measured the peripheral chemoreflex sensitivity to hypoxia (PChS) at various isocapnic carbon dioxide tensions (PCO₂) to determine the form of the relationship between PChS and central PCO₂. Twenty participants completed three repetitions of modified rebreathing tests with end-tidal PO₂ (P_ETO₂) clamped at 150, 70, 60, and 45 mmHg. PChS was computed at 1-mmHg intervals of P_ETCO₂ as follows: the differences in V̇_E between the three hypoxic profiles and the hyperoxic profile (∆V̇_E) were calculated; three ∆V̇_E values were plotted against corresponding calculated oxyhemoglobin …

21°C Is The Emerging Ideal Temperature For Kidney Preservation In The Presence Of Hydrogen Sulfide, Smriti Juriasingani

Electronic Thesis and Dissertation Repository

Kidney transplantation is the treatment of choice for patients with end-stage kidney disease. However, the shortage of transplantable kidneys has led to ever-increasing waiting lists. As a result, kidneys obtained via donation after cardiac death (DCD) are being used more frequently for transplantation. However, they exhibit poorer outcomes due to ischemia-reperfusion injury (IRI) and cold preservation methods, such as static cold storage (SCS). Supplementing cold preservation solutions with hydrogen sulfide donors, such as AP39, has been shown to improve renal IRI and graft outcomes, but the injury associated with cold preservation remains. This thesis evaluates the effect of subnormothermic kidney …

The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson

Electronic Thesis and Dissertation Repository

Up to 22.6% of pregnant women consume cannabis during pregnancy despite the uncertainty of teratogenicity of the main ingredients in cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This study tested the hypothesis that gestational THC and CBD exposure leads to heart abnormalities. Daily, oral THC exposure induced heart abnormalities in 68% of offspring with three main phenotypes including thickened semilunar valves, ventricular myocardial hypertrophy and hypoplastic coronary arteries in fetuses, and postnatal cardiac dysfunction. Altered gene expression of key cardiogenic regulators, increased proliferation, and reduced epicardial epithelial-to-mesenchymal-transition were demonstrated implicating potential mechanisms responsible for these abnormalities. Also, maternal CBD exposure resulted …

Tracing Nutrient Sources To Lipid Production In Birds And Insects Using Stable Isotope (Δ13c, Δ2h) Tracers: Implications For Nutritional Physiology Of Migratory Species, Libesha Anparasan

Electronic Thesis and Dissertation Repository

Using stable isotope measurements of inert tissues to determine origins and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been attempted. I explored isotopic links between diet and stored lipids in captive White-throated Sparrows (Zonotrichia albicollis) and true armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Isotopic discrimination between body lipids and diet was established as linear calibration functions. Isotopic uptake following a diet switch in moths was used to trace lipid accumulation over time. Isotopic correlations between breath metabolic …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

Thermal Biology Of Temperate And High-Latitude Arachnids, Susan E. Anthony

Electronic Thesis and Dissertation Repository

Temperate and high latitude terrestrial ecosystems have high thermal variability, and the ectotherms that inhabit these regions must have thermal tolerances that mirror these temperatures. However, the thermal limits of many high-latitude arachnids are unknown, as well as any underlying mechanisms of seasonal plasticity for any arachnid. The objective of my thesis is to measure the thermal tolerances of temperate, Arctic, and sub-Arctic arachnids, and identify if they have thermal plasticity, either seasonally or following acclimation. I collected the high-latitude pseudoscorpion Wyochernes asiaticus streamside from the Yukon Territory, where besides large thermal variability, they are also inundated with spring flooding. …

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 …

Photosynthetic Acclimation To Warming And Elevated Co2 In Two Antarctic Vascular Plant Species, Vi Nt Bui

Electronic Thesis and Dissertation Repository

Climate change can affect the performance of the only two vascular plant species found in Antarctica, Deschampsia antarctica and Colobanthus quitensis. I investigated the response of these two species to warming and elevated CO₂ in terms of photosynthesis and leaf anatomy. While photosynthesis increased directly with rising temperature and CO₂, it showed no acclimation to changes in growth temperature, and a small degree of acclimation to growth under elevated CO₂. Likewise, leaf anatomy displayed little plasticity in response to changes in the growth environment, although D. antarctica’s stomatal groove structure was modified under …

Cardioprotective Role Of The Cholinergic System, Mouhamed Dakroub

Electronic Thesis and Dissertation Repository

The process of aging is an irreversible continuum experienced by all individuals. A large number of physiological transformations occur to the cardiovascular system as one ages. These changes result in increased risk of developing cardiovascular diseases, many of which are frequently seen in geriatric populations. While the exact mechanisms of age-related cardiac dysfunction have not been established, abnormal cholinergic dysfunction has been implicated in the pathology of other age related diseases; therefore, we have hypothesized that age induced cholinergic dysfunction is detrimental to cardiac function and health. This study seeks to identify whether increased cholinergic signaling, either by transgenic overexpression …

The Ctcf Chromatin Organizer Is Required For Hindlimb Development, Katherine L. Rabicki

Electronic Thesis and Dissertation Repository

Mutations in chromatin organizer CTCF were identified in patients with intellectual disability and skeletal defects. Previous studies demonstrated that depletion of CTCF in murine limb mesenchyme results in apoptosis in the forelimb. The role of CTCF in the hindlimb, however, is unknown. My objective was to investigate effects of CTCF deletion on chondrogenesis and skeletal development in the hindlimb. In vitro wild-type micromass cultures demonstrate that chondrocyte gene expression is delayed in the hindlimb when compared to forelimbs. Embryonic Ctcf^Fl/Fl;Prx1Cre mice were investigated, and qRT-PCR and histology were performed on limb buds and long bones. Results show that …

Reactivity Of The Middle Cerebral Artery To Carbon Dioxide, Nicole Coverdale

Electronic Thesis and Dissertation Repository

Transcranial Doppler ultrasound (TCD) is used for the assessment of cerebral blood flow velocity (CBFV) at the middle cerebral artery (MCA) with the assumption that diameter of the artery does not change. Thus, CBFV is equivalent to cerebral blood flow (CBF). The purpose of this thesis was determine if the MCA dilates during hypercapnia (HC) and/or constricts during hypocapnia (HO) in healthy young and older adults using 3T magnetic resonance imaging (MRI). We also determined how these changes in MCA cross-sectional area (CSA) influence estimates of CBF and cerebrovascular reactivity (CVR) from TCD in young and older adults. Lastly, we …

The Role Of Shroom3 In Kidney Development, Alexandra Sull

Electronic Thesis and Dissertation Repository

Chronic kidney disease (CKD) affects 10% of the population in industrialized nations. Recent genome wide association studies (GWAS) have correlated SHROOM3 with glomerular filtration rate and albuminuria. To elucidate Shroom3’s role in the kidney, I employed a gene trap mouse model (Shroom3^Gt/Gt allele) that produces a non-functional Shroom3 protein. Shroom3 is expressed in the podocytes embryonically and in adulthood as well as other cell types. Shroom3 loss results in glomerular cysts and reduced glomerular number. Some Shroom3^+/Gt and Shroom3^Gt/Gt podocytes showed loss of apical ROCK1, pMLC and actin consistent with the role of Shroom3 in …

Novel Video Imaging To Examine Cardiac Function In Xenopus Embryos, Judith Sull

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) occur in approximately 1% of live births and the etiology has been associated with disturbances in cardiogenesis. However, the majority of research examining CHDs relies on static morphological data, which does not elucidate how defects alter cardiac function. I used Xenopus laevis embryos to examine the association between CHDs and functional alterations using a novel imaging system that can obtain high- resolution images through a non-invasive procedure. A high-speed video camera and software were used to assess cardiac function, permitting functional characterization of late Xenopus cardiogenesis. Verification of the imaging system’s ability to detect changes in …

Prenatal Exposure To Bisphenol A Disrupts Fetal Liver Maturation In A Sex-Specific Manner, Bianca Debenedictis

Electronic Thesis and Dissertation Repository

Developmental exposure to BPA is associated with liver dysfunction and diseases in adulthood. However, the effects of BPA on liver development are unknown. To address this question, pregnant mice were exposed to BPA via diet from embryonic day 7.5 (E7.5) to E18.5. At E18.5, fetal livers were collected, and analyzed for changes in the expression of key hepatic maturation markers. We found the following significant protein alterations in BPA-exposed female but not male fetal livers: (a) mature hepatocyte markers, albumin and glycogen synthase, were decreased; (b) immature hepatocyte marker, alpha-fetoprotein, was increased; (c) master transcription factor of hepatocyte differentiation, C/EBP-α, …

Analysis Of The Vascular Phenotype Of The Ent1-Null Mouse, Keisha A. Best

Electronic Thesis and Dissertation Repository

Adenosine is important in the regulation of vascular tone and the Equilibrative Nucleoside Transporter 1 (ENT1) is a regulator of adenosine concentrations. Thus, changes in ENT1 expression and activity may alter vascular tone regulation. We therefore examined the cardiovascular phenotype of ENT1-null (ENT1^-/-) as compared to wild type mice (ENT1^+/+). Heart rates (HRs) and blood pressures (BPs) of ENT1^-/- and ENT1^+/+ littermate male mice were obtained while conscious and anaesthetized, and metabolic data were collected over a 24 hr period. Vascular reactivity was assessed in aortic ring segments obtained from 3 month old ENT1 …

Cold-Activation Of The Drosophila Melanogaster Immune System, Golnaz Salehipourshirazi

Electronic Thesis and Dissertation Repository

Evidence of immune response enhancement after cold exposure suggests that cold activates the insect immune system. I investigated whether the immune response of Drosophila melanogaster is activated by cold exposure in the absence of pathogens. To explore if different kinds of cold affect the immune response differently, I included acute and chronic cold exposure. I cold-exposed flies, and then examined up-regulation of immune-related genes. In addition, I measured hemocyte concentration, phenoloxidase activity, and woundinduced melanization. Acute cold exposure increased hemocyte concentration and woundinduced melanization. Chronic cold did not change hemocyte concentration, phenoloxidase activity or melanization in flies. Acute and chronic …

Aging And Obesity Models In Osteoarthritis, Sara Ohora

Electronic Thesis and Dissertation Repository

Osteoarthritis (OA) is a degenerative joint disease whose exact mechanisms are not well understood, but aging and obesity are common risk factors. To determine the role of transforming growth factor-alpha (TGFα) in obesity-associated OA, Tgfa null and control mice on control and high fat diets were compared. In addition, spontaneous OA was investigated in aging C57BL/6J mice. Quantitative magnetic resonance was used to assess body composition in the obesity model, while gait analysis, histological staining and OARSI scoring were used to determine OA in both models. Mice on high fat diet developed no OA, but Tgfa null mice weighed significantly …

Decoding Motor Intentions From Human Brain Activity, Jason P. Gallivan

Electronic Thesis and Dissertation Repository

“You read my mind.” Although this simple everyday expression implies ‘knowledge or understanding’ of another’s thinking, true ‘mind-reading’ capabilities implicitly seem constrained to the domains of Hollywood and science-fiction. In the field of sensorimotor neuroscience, however, significant progress in this area has come from mapping characteristic changes in brain activity that occur prior to an action being initiated. For instance, invasive neural recordings in non-human primates have significantly increased our understanding of how highly cognitive and abstract processes like intentions and decisions are represented in the brain by showing that it is possible to decode or ‘predict’ upcoming sensorimotor …

Cardiac Adaptation To Chronic Blockade Of Voltage-Gated, L-Type Calcium Channels In The Sarcolemma, Ji Zhou

Electronic Thesis and Dissertation Repository

L-type Ca²⁺ channels (dihydropyridine receptors, DHPRs) in the sarcolemma are essential to cardiac excitation-contraction (E-C) coupling. Thus, Ca²⁺ influx through DHPRs upon cardiomyocyte excitation triggers Ca²⁺ release from the sarcoplasmic reticulum (SR) through ryanodine receptors (RyRs) to initiate myofilament activation and muscle contraction. Muscle relaxation occurs upon sequestration of Ca²⁺ back into the SR lumen by sarco/endoplasmic reticulum calcium-ATPase (SERCA) in the SR. As a treatment option for hypertension, long-term use of DHPR blockers is associated with increased risk of heart failure; underlying mechanisms are unknown. This research used male Wistar rats treated with verapamil (subcutaneously, …