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Full-Text Articles in Life Sciences

The Secretory Pathway Calcium Atpase 2c Promotes Increased Cytosolic Calcium Levels, Melissa Fenech Dec 2019

The Secretory Pathway Calcium Atpase 2c Promotes Increased Cytosolic Calcium Levels, Melissa Fenech

Electronic Thesis and Dissertation Repository

Pancreatic acinar cell exocytosis requires precise calcium (Ca2+) signals. When cytosolic Ca2+ levels remain high, cellular functions are disrupted, which is associated with initiation of pancreatitis. Ca2+ signals are achieved through regulating endoplasmic reticulum (ER) stores, Ca2+ATPases, and store-operated Ca2+ entry (SOCE). However, how these pathways interact to create precise signals is not well understood. In a pancreatic model of dysregulated Ca2+ homeostasis, secretory pathway Ca2+ATPase 2 (SPCA2) expression is significantly decreased. In the pancreas, only a C-terminally truncated form of SPCA2 (termed SPAC2C) exists. Recent studies indicate a role …


Action Potential Subpopulations In Human Muscle Sympathetic Nerve Activity: Discharge Properties And Governing Mechanisms, Stephen A. Klassen Oct 2019

Action Potential Subpopulations In Human Muscle Sympathetic Nerve Activity: Discharge Properties And Governing Mechanisms, Stephen A. Klassen

Electronic Thesis and Dissertation Repository

What discharge properties are expressed by varying-sized sympathetic action potential (AP) subpopulations active under baseline conditions in humans and what are the governing mechanisms? To address this overall question the microneurographic approach was employed to record multi-unit muscle sympathetic nerve activity (MSNA), after which a continuous wavelet transform exposed APs in the recorded neurogram. Study One examined the role of the paravertebral ganglia on sympathetic neural discharge patterns. Through trimethaphan infusion under baseline conditions, this study revealed ordered de-recruitment of larger to smaller AP clusters, suggesting that the paravertebral ganglia contribute to the distribution of firing probabilities expressed by differently-sized …


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 Oct 2019

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 …


Effects Of Elevated Temperature And Elevated Co2 On Leaf Carbon Fluxes In Boreal Conifers: Lab And Field Studies, Mirindi Eric Dusenge Oct 2019

Effects Of Elevated Temperature And Elevated Co2 On Leaf Carbon Fluxes In Boreal Conifers: Lab And Field Studies, Mirindi Eric Dusenge

Electronic Thesis and Dissertation Repository

Rising CO2 may warm northern latitudes up to 10 °C by the end of the century. However, responses of plant physiological processes (such as photosynthesis and respiration) and growth to climate change remain uncertain. Seedlings and mature trees of tamarack (a deciduous species) and black spruce (an evergreen species), North America dominant conifers, were exposed to combined warming (up to +9 ˚C) and elevated CO2 (up to +300 ppm). In seedlings, stomatal conductance (gs) tended to increase with warming in tamarack seedlings, while gsdeclined with warming in spruce. In both species, CO2 had …


Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello Sep 2019

Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello

Electronic Thesis and Dissertation Repository

Stromal-interaction molecule 2 (STIM2) is an endoplasmic reticulum (ER) membrane-inserted Ca2+-sensing protein which, together with the plasma membrane Ca2+ channel Orai1, regulates basal Ca2+ homeostasis and store-operated Ca2+ entry (SOCE). Recent evidence suggests that S-nitrosylation, which is the covalent attachment of a nitric oxide (NO) moiety to a cysteine thiol, can attenuate the function of the paralog STIM1 protein. Compared to STIM1, STIM2 also functions as a basal Ca2+ homeostatic feedback regulator. Therefore, the objective of my study was to evaluate the susceptibility of STIM2 to S-nitrosylation and the effects that this …


Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli Aug 2019

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …


Mapping And Functional Characterization Of Proteolytic Cleavage Of Murine Kidney Injury Molecule-1, Saranga Sriranganathan Aug 2019

Mapping And Functional Characterization Of Proteolytic Cleavage Of Murine Kidney Injury Molecule-1, Saranga Sriranganathan

Electronic Thesis and Dissertation Repository

Kidney injury molecule-1 (KIM-1) is a transmembrane glycoprotein expressed apically on proximal tubule epithelia during acute kidney injury (AKI). KIM-1, as a phagocytic receptor, facilitates clearance of apoptotic cells (efferocytosis) from tubular lumen, thereby reducing inflammation and promoting repair. Human KIM-1 undergoes spontaneous and accelerated ectodomain shedding into urine and blood via metalloproteases; tumour necrosis factor-a converting enzyme (TACE/ADAM17) and a disintegrin and metalloprotease 10 (ADAM10). Blood and urine KIM-1 are clinical AKI biomarkers, however, biological significance of KIM-1 shedding is unknown. To study this in vivo in mice, I first aimed to identify murine KIM-1 cleavage site and study …


Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer Jul 2019

Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) arise from perturbations in complex molecular and cellular processes underlying normal embryonic heart development. CHDs are the most common congenital malformation, occurring in 1 to 5% of live births, and are the leading cause of pediatric mortality. Adverse genetic and environmental factors can impede normal cardiogenesis and increase the likelihood of CHDs. Pregestational maternal diabetes increases the risk of CHDs in children by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. The aim of …


Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco Jul 2019

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 …


A Four Week 30 S Weight Training Intervention Improves 2000 M Rowing Ergometer Performance Of Provincial And National Collegiate Female Rowers, Matthew Lee Jun 2019

A Four Week 30 S Weight Training Intervention Improves 2000 M Rowing Ergometer Performance Of Provincial And National Collegiate Female Rowers, Matthew Lee

Electronic Thesis and Dissertation Repository

This study compared the effects of a 4 week, 30 s weight training program (30SEC), to a low-repetition weight training program (LoRep), on rowing performance and aerobic capacity in preconditioned, provincial and national collegiate female rowers. 30SEC (n=5) performed 5 sets of dumbbell deadlifts (DL) and dumbbell bench pulls (BP), executing a maximum of 18 repetitions in 30 s, three times per week. LoRep (n=5) performed 4-5 sets of 2-6 repetitions of weight training exercises twice per week. Both regimes performed an identical high volume of predominantly aerobic rowing ergometer training. 30SEC improved 1 Minute Test (p2max, peak power output …


The Role Of C-Kit And Insulin Receptor Tyrosine Kinases In Beta Cell Function And Insulin Secretion, Amanda Oakie Jun 2019

The Role Of C-Kit And Insulin Receptor Tyrosine Kinases In Beta Cell Function And Insulin Secretion, Amanda Oakie

Electronic Thesis and Dissertation Repository

The receptor tyrosine kinases (RTKs) c-Kit and insulin receptor (IR) initiate similar intracellular signalling pathways in pancreatic beta cells to regulate beta cell proliferation, survival, and insulin secretion. Mice with a c-Kit overexpression specifically in beta cells (c-KitβTg) demonstrated improved beta cell proliferation and insulin secretion compared to control mice, and islets from c-KitβTg mice also demonstrated increased IR expression. The potential interplay between c-Kit and IR and their roles during ageing and metabolic stress are not currently known. This work reports the examination of c-Kit and IR signalling using in vitro and in vivo models to determine their effects …


Is Professional Breath-Hold Diving Associated With Endothelial Dysfunction?, Emilie Woehrle Jun 2019

Is Professional Breath-Hold Diving Associated With Endothelial Dysfunction?, Emilie Woehrle

Electronic Thesis and Dissertation Repository

Professional breath-hold diving has been linked to acute dangers; however, the long-term impacts on vascular health are unknown. The endothelium releases vasodilator substances and its functionality is an indicator of vascular health. We are testing the hypothesis that chronic exposure to severe hypoxia may alter endothelial function in breath hold divers. Divers and controls completed a flow-mediated dilation (FMD) protocol, where brachial blood flow velocity was measured following blood flow occlusion. Percent FMD was calculated as the primary measure of endothelial function. T-tests assessed the statistical significance of between-group differences. The %FMD were similar between groups (p >0.05); however, divers …


Oleic Acid Attenuates Palmitic Acid-Induced Impairments In Mouse Blastocyst Development, Maisoon Dafalla Yousif Jun 2019

Oleic Acid Attenuates Palmitic Acid-Induced Impairments In Mouse Blastocyst Development, Maisoon Dafalla Yousif

Electronic Thesis and Dissertation Repository

Palmitic acid (PA) and oleic acid (OA) are the most abundant saturated and monounsaturated non-esterified fatty acids, respectively, in serum. The consequences of PA and OA treatment on preimplantation mouse embryo development were investigated. It was hypothesized that OA treatment from the two-cell stage onwards would attenuate PA-induced reductions in mouse blastocyst development. PA significantly reduced development to the blastocyst stage. Transcript analysis revealed that PA increased ER stress pathway markers activating transcription factor 3 and C/EBP homologous protein transcripts, and XBP1 splicing. Co-culture of PA-treated embryos with OA prevented this PA-induced ER stress and rescued blastocyst development. Cytoplasmic lipid …


Menstrual Phase Differences In Muscle Deoxygenation, Respiration And Blood Lactate Concentration Do Not Influence Exercise Performance, Jordyn L. Smith Apr 2019

Menstrual Phase Differences In Muscle Deoxygenation, Respiration And Blood Lactate Concentration Do Not Influence Exercise Performance, Jordyn L. Smith

Electronic Thesis and Dissertation Repository

The purpose was to evaluate muscle deoxygenation (Δ[HHb]), oxygen uptake (VO2), ventilation (VE), and arterialized blood lactate [La-] throughout exhaustive incremental (RAMP) and severe-intensity exercise (SI) during follicular (FOL) and luteal (LUT) menstrual phases. During RAMP, Δ[HHb]/VO2 was 65% lower in LUT below gas exchange threshold (p0.05). During SI,Δ[HHb]/VO2 was 18% lower in LUT during the kinetic phase (p0.05). No FOL/LUT differences in RAMP-performance (FOL: 218 ± 35 W; LUT: 221 ± 29 W) or SI-endurance (FOL: 99 ± 20 s; LUT: 96 ± 15 s) (p>0.05) were found. These data demonstrate that physiological differences between menstrual phases exist, …


Growth Characteristics And Lipid Metabolism Of Cultured Migratory Bird Skeletal Muscle Cells, Kevin G. Young Apr 2019

Growth Characteristics And Lipid Metabolism Of Cultured Migratory Bird Skeletal Muscle Cells, Kevin G. Young

Electronic Thesis and Dissertation Repository

Diets rich in n-3 polyunsaturated fatty acids (PUFA) may alter the muscle metabolism of migratory birds, improving their endurance performance. I established and validated for the first time in vitro muscle models of a migratory songbird (yellow-rumped warbler, Setophaga coronata coronata) and shorebird (sanderling, Calidris alba). To evaluate the role of n-3 PUFA in improving fatty acid metabolism in migratory bird muscle, I measured metabolic outcomes following n-3 PUFA supplementation in these two avian cell types and a murine (Mus musculus, C2C12) cell line. PUFA supplementation in C2C12 cells …


Thermal Biology Of Temperate And High-Latitude Arachnids, Susan E. Anthony Apr 2019

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. …


Quantitative Proteome Analysis Of Alfalfa In Drought Stress Under The Influence Of Mir156, Alpa Puri Mar 2019

Quantitative Proteome Analysis Of Alfalfa In Drought Stress Under The Influence Of Mir156, Alpa Puri

Electronic Thesis and Dissertation Repository

Medicago sativa is one of the most produced perennial forage crops in Canada. Drought stress is a major form of abiotic stress affecting the productivity and annual yield of alfalfa. A small noncoding RNA, miR156 has a role in abiotic stress tolerance, while regulating downstream SPL genes. In this study, whole leaf proteome and amino acid concentrations of miR156OE (A8) genotype of alfalfa under drought stress were quantified. In results, 3,000 proteins groups were identified using MaxQuant when searched against Medicago truncatula protein sequence database. Gene ontology analysis showed enriched proteins were involved in biological and molecular processes such as …