Life Sciences Commons^™

Dsrna Sensing In Fish Cells: Using Chse-214 As A Model For The Study Of Class A Scavenger Receptors, Andrea Monjo

Theses and Dissertations (Comprehensive)

When infecting cells, most viruses produce dsRNA molecules at some point in their replicative cycle. When an infection results in cell lysis, these molecules are released into the extracellular space. Class A scavenger receptors (SR-As) on the surface of animal cells bind extracellular dsRNA and bring it into the cell where dsRNA triggers an innate immune response, enabling the cell to protect itself from an impending virus infection. Very few cells are unable to bind and respond to extracellular dsRNA, thus cell-based assays for studying extracellular dsRNA sensing via SR-As have been limited. CHSE-214 cells are a promising model for …

Disease Models With Immigration, Reem Almarashi

Theses and Dissertations (Comprehensive)

In this thesis we focus first on studying the susceptible, exposed, and infected ($SEI$) disease model without immigration. We determine the basic reproduction number $\mathcal{R}_0$, which can be interpreted as the expected number of new cases that can be produced by a single infection in a completely susceptible population. Further, by using the Jacobian matrix, we determine the local stability of the disease model. Then we have the result that when $\mathcal{R}_0<1$ the DFE point is locally asymptotically stable(L.A.S). In contrast, when $\mathcal{R}_0>1$ we find that the endemic equilibrium is L.A.S. After that, we analyze the $SEI$ model with immigration of infected individuals.

Furthermore, we investigate the direction that the …

Quantifying Relationships Between Phosphorus Availability And Mycorrhizal Associations In Wetland Plants, Daniel Marshall

Theses and Dissertations (Comprehensive)

Increasing evidence indicates that plant community structure and therefore ecosystem function are mediated by below-ground fungal communities that form intracellular associations with plant roots called mycorrhizal associations. Arbuscular mycorrhizal fungi (AMF) are a type of mycorrhiza that colonize the plant host intracellularly but maintain hyphae outside the root cell for resource acquisition. The importance and function of AMF associations are well-documented in terrestrial ecosystems, but are less understood in aquatic or semi-aquatic systems. Phosphorus availability is the primary factor influencing mycorrhizal colonization and growth in terrestrial soils, with phosphorus-abundant soils leading to a decrease in mycorrhizal growth. However, the relationship …

The Complexity Of Electron Transport: A Study Of Variegation Through Chemical Inhibition Of Plastoquinol Terminal Oxidase (Ptox) In Tobacco (Nicotiana Tabacaum), Hillary Peon

Theses and Dissertations (Comprehensive)

The photosynthetic electron transport (PET) chain relies on the chlorophyll and carotenoid biosynthetic pathways for pigments that harness light, and protect the photosynthetic apparatus from damage by light. The pigment pathways also connect to the PET chain through electron transfer where the plastoquinol (PQ) pool accepts electrons from phytoene desaturase (PDS) of the carotenoid pathway and the aerobic cyclase (ACS) of the chlorophyll biosynthetic pathway. Genetic studies have shown a plastoquinol terminal oxidase (PTOX) protein functions to regulate the redox state of the PQ pool. Without PTOX to maintain balance between the two redox states of the PQ pool it …

An Assessment Of How Plant And Mycorrhizal Communities Have Been Affected Along A Mine-Impacted Watershed In The Northwest Territories, Kevin Maccoll

Theses and Dissertations (Comprehensive)

Giant Mine is an inactive gold mine located nine kilometers north of Yellowknife, Northwest Territories. Giant Mine has been the source of arsenic trioxide for the Baker Creek watershed since it opened over 60 years ago. Although arsenic levels in the creek are above the limits considered to be biologically relevant, there is no concrete evidence that plants and mycorrhizae have actually been affected. This study provides an initial assessment of the impacts mining activity at Giant Mine has had on plants and mycorrhizae in the Baker Creek watershed. Nine sites were sampled around Giant Mine: five sites downstream from …

An Examination Of Imagined Contexts: The Unreliability Of Context-Dependent Memory Effects In Recall, Caitlin J. I. Tozios

Theses and Dissertations (Comprehensive)

It is generally accepted that the environmental context present during memory encoding serves as an effective cue for recall if reinstated during retrieval. Participants who perform a free recall test in the same context as that during which they learned a set of words, often remember more words than participants who experience a context mismatch from encoding to retrieval. This is referred to as the context-dependent memory effect and forgetting due to a change in context is referred to as context-dependent forgetting. Recent evidence suggests that contexts need not always be physical but can be mentally generated or imagined and …

The Experiences Of Athletes, Parents, And Coaches With The Long-Term Athlete Development Model (Ltad) In Youth Soccer Academies, Kody Watson

Theses and Dissertations (Comprehensive)

The Long-Term Athlete Development Model (LTAD) has been developed to allow children the best chance of engaging in lifelong sport and physical activity. The LTAD focuses on long-term development, not short-term success, which allows for the best opportunity of sport participation and optimal sport potential throughout life (Balyi, Way, & Higgs, 2013). Research surrounding the LTAD model has stated that there is a lack of empirical evidence of the model being utilized within sport, as some researchers believe that it is more theoretical than practical (Lloyd & Oliver, 2012). However, even with this criticism of the LTAD model, Canadian sport …

An Evaluation Of Older Adults’ Perceptions Of Psychological Well-Being When Participating In Community Centre Programs, Kayla Rellinger

Theses and Dissertations (Comprehensive)

Multi-purpose organizations, such as community centres, provide opportunities for individuals to participate in various physical and social activities. Although, it has been well established that community centres provide the opportunity and environment to promote health behaviour changes among older adults (Jones et al., 2013; Stewart, 1997; Wallace et al., 1998), there is a dearth of research differentiating between physically active and non-active community centre programming. The purpose of the current study was to evaluate whether participating in community centre programming influenced four key measures of perceived psychological well-being, as well as, to evaluate whether the perceived psychological well-being of community …

Sedentary Behaviour, Physical Activity, And Mobile Apps Among University Students, Emily E. Dunn

Theses and Dissertations (Comprehensive)

Prolonged sedentary behaviour (SB) poses health risks independent of physical activity (PA) levels (Owen et al., 2010). University students in particular are at risk of engaging in prolonged SB due to the demands of school. Due to the pervasiveness of smartphones, and ability of mobile applications (apps) to target SB (Bond et al., 2014), apps may be used to encourage less SB in this population. Apps for PA have been coded for behaviour change techniques (BCTs) (Conroy et al., 2014; Middelweerd et al., 2014; Yang et al., 2015), however, apps for SB have yet to be assessed for BCTs.

The …

An Investigation Of The Relationship Between Intervertebral Disc Puncture, Inflammation, And Tissue Mechanics Using A Rat-Tail Model., Brigitte Laird

Theses and Dissertations (Comprehensive)

Introduction: The intervertebral disc (IVD) is composed of the annulus fibrosus (AF), which surrounds and contains the nucleus pulposus (NP). It is hypothesized that when the IVD becomes injured, in the case of IVD herniation, a localized innate immune response is initiated. Although the presence of pro-inflammatory cytokines in injured IVDs has been well documented, the extent to which inflammation affects the mechanical properties of the IVD remains poorly understood. The purpose of this study was to determine the effect of IVD damage (via puncture) and inflammation (via lipopolysaccharide (LPS) exposure) on the mechanical and structural properties of the IVD. …

The Effects Of Orthotics And Increased Plantar Sole Mechanoreceptor Activation On Turning Performance In Individuals With Parkinson’S Disease, Kelly A. Robb

Theses and Dissertations (Comprehensive)

Locomotion and turning are complex movement patterns essential to activities of daily living. Individuals with Parkinson’s disease (PD) report difficulties turning, often coupled with impaired balance and increased fear of falling. The purpose of this within-subject study was to determine if orthotics, with and without a textured top cover, can improve gait stability and turning performance within Parkinson’s participants. Seven participants with a diagnosis of idiopathic Parkinson’s disease, aged 55-80 years old, participated in the study. Participants completed three testing sessions; baseline, 4 weeks post-baseline, and 5 weeks post-baseline. The ‘footwear only’ and ‘footwear + non-textured orthotic’ conditions were tested …

Diversity And Evolution Of Fruits In Cuscuta (Dodders; Convolvulaceae), Anna Ho

Theses and Dissertations (Comprehensive)

Cuscuta (dodder) is a genus of roughly 200 species of obligate stem parasites with sub-cosmopolitan distribution. The fruit, generally regarded as a capsule, has a thin pericarp containing one to four seeds and opening at the base (circumscissile dehiscence; DE), or remaining closed (indehiscent; IN). IN has evolved multiple times in Cuscuta from DE, and is most common in the North American clades of subgenus Grammica. In addition, some species produce fruits that open irregularly. Characteristics pertaining to the fruits of Cuscuta are important as their seeds contribute most to their distribution and prevalence across the globe, and their reduced …

Behavioral Ecology Of An Invasive Species: Habitat And Mate Preference(S) In Drosophila Suzukii, Yvonne Young, Natasha Buckiewicz, Tristan Af Long Dr.

Theses and Dissertations (Comprehensive)

The invasive Spotted-Wing fruit fly, Drosophila suzukii, has inflicted substantial economic losses to the soft-fruit agriculture industry worldwide due to the ability of females in this species to use a large, serrated ovipositor to cut the fruit’s skin and lay eggs directly into the mesocarp of ripening fruit. Once the eggs hatch, larvae consume the fruit flesh, ultimately leaving the fruit unmarketable. This species parasitizes numerous commercial fruit types (including blueberries, blackberries, strawberries, raspberries and occasionally grapes) as well as fruits from a variety of wild plant species. Since fruit types vary in their nutritional composition, as well as their …

Task-Dependent Modulation Of Cortical Excitability And Balance Control In Individuals With Post-Concussion Syndrome, Kristen Kaster, Jayne M. Kalmar Ms., Michael E. Cinelli Mr

Theses and Dissertations (Comprehensive)

In most cases, symptoms resolve between 7-10 days post-concussion. However, in 10-15% of the concussed population, symptoms can remain unresolved for months to years following the head injury. The purpose of this thesis was two-fold, and was broken up into two studies, where the same individuals participated in both studies. The purpose of the first study was to quantify the differences in balance control between individuals with PCS (i.e., had been experiencing symptoms for <30 days) and non-concussed individuals during a lower-limb reaching task. Participants completed a static balance assessment before and after a lower-limb reaching task, which incorporated a Go/No-Go paradigm. Results from this study revealed no differences in the static stability assessments, however, individuals with PCS demonstrated increased medial-lateral COP displacement as well as greater trunk pitch during the reaching task. Overall, the findings reveal persistent balance impairments in individuals with PCS, which may put this population at an increased risk of further injury. The purpose of the second study was to assess task-dependent modulation of cortical excitability prior to planned index finger abduction contractions comparing a non-concussed population to a population with PCS. The protocol in this study consisted of both single and paired-pulse transcranial magnetic stimulation (TMS) which was applied prior to the beginning of 3 different tasks (i.e., a rest condition with no plan to contract, a precision contraction, and a powerful contraction). In addition to the three tasks, participants also had to respond to a Go/No-Go cue. The results of this study revealed an increase in excitability prior to a precision contraction in both non-concussed and PCS groups. No differences in task-dependent modulation were found between the two groups with respect to intracortical facilitation and inhibition, however a negative correlation between number of symptoms reported (SCAT3 symptom evaluation) and intracortical facilitation was revealed. The increase in corticospinal excitability prior to a precision contraction was not explained by the two cortical mechanisms we assessed and may therefore be due to spinal modulation or a different cortical mechanism. Overall, based on the results from this thesis, it appears that individuals with PCS have balance impairments, which may be a result of an inability to maximally activate their postural muscles. Furthermore, it appears that those individuals who reported a higher number of symptoms had greater reductions in intracortical facilitation, likely reflecting the heterogeneity of this clinical group.

Effects Of Wildfires On Tree Establishment In Conifer-Dominated Boreal Forests In Southern Northwest Territories, Kirsten Reid

Theses and Dissertations (Comprehensive)

Black spruce (Picea mariana) and jack pine (Pinus banksiana) both release a large majority of their seeds after fire and thus experience large pulses of recruitment during these punctuated events. Global warming is driving intensification of the wildfire regime in the boreal forest, which is resulting in shifts from coniferous to deciduous dominated forests in some parts of the boreal forest of North America. This shift can present consequences for forest structure, ecosystem dynamics, carbon cycling, and wildlife habitat.

During 2014, the Northwest Territories experienced a historically unprecedented fire year with 3.4 million hectares of forest …

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the …

The Effects Of A 12-Week Custom Foot Orthotic Intervention On The Intrinsic Muscles Of The Foot, And Dynamic Stability During Unexpected Gait Termination In Healthy Young Adults, Katrina Protopapas

Theses and Dissertations (Comprehensive)

Introduction: Custom-made foot orthotics (CFO’s) are a commonly prescribed intervention to help individuals that are suffering from foot pain and foot disorders. However, the mechanisms of CFO’s are still poorly understood and are not well known. With the plantar intrinsic muscles of the foot being in direct contact with the CFO, it puts these structures at risk for disuse muscle atrophy as a result of being offloaded. Therefore, the purpose of the current study was to determine the effect of a 12-week custom-made foot orthotic intervention on the intrinsic muscles of the foot and dynamic stability during unexpected gait termination. …

Peripheral Visual Motion Sensitivity In Previously Concussed, Asymptomatic Individuals, Alyssa Prangley

Theses and Dissertations (Comprehensive)

Background: Individuals acquire information about self-motion from the environment which specifies actions necessary to be successful (Fajen & Matthis, 2011). However, concussed individuals demonstrate residual disturbance in execution of postural movement at 30 days post injury, depicting an impaired ability to perceive self-motion in a visually conflicting environment (Slobounov et al. 2006). The objective of this thesis was to investigate the extent to which one’s behaviours on a central field of view task are influenced by the amount and type of peripheral visual movement during a collision avoidance task, as well as to determine the additive effects of changes to …

The Function Of Drosophila Larval Class Iv Dendritic Arborization Sensory Neurons In The Larval-Pupal Transition Is Separable From Their Function In Mechanical Nociception Responses, Hannah E. Brown, Trishna Desai, Allison J. Murphy, Harshida Pancholi, Eric C. Liebl

Faculty Publications

No abstract provided.

Special Agent Ricin: The Making Of A Scientific Blockbuster, Joy Udoh

The Synapse: Intercollegiate science magazine

No abstract provided.

Rigorous Innovation: How Neuroscience Shapes Our View Of Creativity, Emma Hahn

The Synapse: Intercollegiate science magazine

No abstract provided.

Venturing Into The Unknown: The First Human Head Transplant, Christine Craddock

The Synapse: Intercollegiate science magazine

No abstract provided.

Diy Genetics: The Ethics Of Crispr, Leah Treidler

The Synapse: Intercollegiate science magazine

No abstract provided.

Gut Check: How Microbiome Research Is Reshaping Our View Of Bacteria In Human Health, Rachel Reardon

The Synapse: Intercollegiate science magazine

No abstract provided.

Dr. Chie Sakakibara: Collaborative Research With The Iñupiaq People In Utqiagvik, Alaska, Lauren Rhodes

The Synapse: Intercollegiate science magazine

No abstract provided.

Revisiting A Forgotten Epidemic: West Africa’S Largest Ebola Outbreak Three Years Later, Jayla Johnson

The Synapse: Intercollegiate science magazine

No abstract provided.

Crossword Corner, Rachel Dan

The Synapse: Intercollegiate science magazine

No abstract provided.

Paul Rich: Building Offshore Windfields, Monica Dix

The Synapse: Intercollegiate science magazine

No abstract provided.

The Curious Case Of The Reindeer In The Tundra, Eleda Fernald

The Synapse: Intercollegiate science magazine

No abstract provided.

Whale You At? The Influence Of Solar Storms On Frequency Of Whale Strandings In The North Sea, Gaby Sarri-Tobar

The Synapse: Intercollegiate science magazine

No abstract provided.