Digital Commons Network^™

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

Western Research Forum

Using stable isotope measurements of insect tissues to determine origin and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been as thoroughly researched. We explored isotopic links between diet and stored lipids in laboratory raised True armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Pupae were randomly separated into four groups (n=20) and fed isotopically distinct nectar, each consisting of a combination of high δ¹³C (C4 sugar), or low δ¹³C (C3 sugar) carbohydrate, with high δ²H (deuterium spiked), …

Regulation Of Endoplasmic Reticulum Stress Sensitivity By Torc1 Signalling In Yeast, Khadija Ahmed, Patrick Lajoie

Western Research Forum

Incorrect folding of secretory proteins in the endoplasmic reticulum (ER) results in an aberrant accumulation of misfolded proteins (ER stress) and activates a coping mechanism known as the unfolded protein response (UPR). While the mechanisms of UPR activation have been well established, how it integrates with other stress responses remains unclear.

Given that TORC1 is an important regulator of cell growth during protein misfolding stress, we sought to investigate how TORC1 signalling acts in parallel with the UPR to regulate ER stress sensitivity. Our studies employ the budding yeast, Saccharomyces cerevisiae, a biochemically traceable model organism that allows for …

Uncovering The Role Of Ovol1 In Placental Stem Cell Differentiation Using Saccharomyces Cerevisiae, Maram Albakri, Patrick Lajoie, Stephen Renaud, Gargi Jaju, Hazel Dhaliwal

Western Research Forum

OVOL1 is a conserved transcription factor involved in regulating cytrophoblast differentiation in the placenta. Our objective for this study is to use Saccharomyces cerevisiae to uncover the role of OVOL1 in placental stem cell differentiation and proliferation. Previous research suggests that OVOL1 regulates cytotrophoblast progenitor state by regulating genome acetylation. Therefore, our study aims to determine how OVOL1 effect yeast growth and the yeast acetylome, and to use the yeast model to determine downstream targets of OVOL1. In order to understand the role of OVOL1, we will develop a yeast model and employ growth assays to assess growth defects and …

Role Of Gp120 Glycosylation In Sexual Transmission Of Hiv, Yingxue Sun, Adam Meadows, Najwa Zebian, Eric Arts, Carole Creuzenet

Western Research Forum

Background:

In chronic HIV patients, the viral populations are genetically diverse due to mutations introduced by the viral reverse transcriptase during HIV replication. However, more than 80% new infections result from single transmission founder (TF) viruses; therefore, targeting the TFs is key to control AIDS worldwide.

Gp120 is a glycosylated envelope protein required for HIV infection, propagation, and transmission. Glycans on gp120 influence HIV infectivity through their interactions with lectins, the carbohydrate-binding immune proteins in the host mucosa. To transmit sexually, viruses must overcome the lectin traps to access more target T cells.

Hypothesis:

TF viruses are less likely to …

Knocking Out A Negative Regulator Of Hedgehog Signaling Blocks Differentiation Of Cells Into Neurons, Danielle Margaret Spice, Gregory M. Kelly Ph.D.

Western Research Forum

Hedgehog (Hh) signaling, one of many different protein signaling pathways found in mammals, is vital in many stage of neural development. A major negative regulator of Hh signaling is a protein known as Suppressor of Fused (SUFU), which acts to sequester the full length Gli transcription factors, proteins that can turn genes on and off, in the cytoplasm or facilitates its conversion to a repressive form. The P19 embryonal carcinoma cell line is a model of hind-brain neuronal differentiation and the involvement of Hh signaling, in particular the role of SUFU in this process has yet to be explored. We …

The Dissociable Impact Of Auditory Vs. Visual Emotional Cues On Visual Processing, Emma K. Stewart Bsc, Derek Gv Mitchell Phd

Western Research Forum

Background: Emotional information has privileged access to processing resources, which can cause it to have a distracting or facilitating effect on task performance for reasons that are poorly understood. The sensory modality through which it is presented may be one determining factor. Some findings suggest that auditory stimuli facilitate visual task performance while visual stimuli interfere with it, but there are conflicting findings.

Hypothesis: We hypothesize that emotional content of a different sensory modality from the task improves task-related performance via a general alerting and arousing effect for all stimuli, while emotional content of the same modality disrupts performance when …

An Application Of The Modifiable Areal Unit Problem: Optimizing Cluster Method Parameters To Produce Predictive Data For Hiv Outbreaks, Connor J. Chato, Art Fy Poon

Western Research Forum

Background

A popular approach to study HIV outbreaks is to cluster cases based on genetic similarity. However, there is no widely-used statistical criterion which optimizes the parameters for sequence-based clustering methods. The relationship between a cluster-defining similarity threshold and it’s associated set of clusters can be analogized to the aggregation level in the Modifiable Areal Unit Problem (MAUP).

Hypothesis

Based on the selection of aggregation level for study partitions in MAUP, we present a statistical framework to optimize the similarity threshold for pairwise distance algorithm TN93 (http://github.com/veg/tn93). We hypothesize that defining this threshold includes case connections such that …

The Wet Bridge Transfer System: An Novel In Vitro Tool For Assessing Exogenous Surfactant As A Pulmonary Drug Delivery Vehicle, Brandon J. Baer

Western Research Forum

Background:

Due to its complex branching structure, direct drug delivery to the remote areas of the lung is a major challenge. Consequently, most therapies, such as those treating pulmonary infection and inflammation, must utilize large systemic dosing, with the potential for adverse side effects. A novel alternative strategy is to use exogenous surfactant, a material capable of distributing throughout the lung, as a pulmonary drug delivery vehicle.

Objective:

Utilize an in vitro transferring system to assess exogenous surfactant (BLES) as a pulmonary delivery vehicle for different therapeutics.

Methods:

An in vitro technique was developed to simultaneously study surfactant delivery and …

Dairy Intake And Cognitive Function In Canadian Older Adults, Mariam R. Ismail Miss, Alan Salmoni

Western Research Forum

Background: Dietary intake is one of the modifiable factors that may affect older adults’ cognitive function in their later years. Few research has considered the potential role of dairy foods on cognitive function. Methods: Across-sectional study was undertaken in 2014. Cognitive function was assessed using The Montreal Cognitive Assessment (MoCA), Rey Complex Figure Test and Recognition Trial (RCFT), Trail-Making Test (TMT), Victoria Stroop Test (VST) and the Digit Span Test (DST). Dietary intake was assessed via estimated 5-day food intake records and analyzed for saturated fat, vitamin D and calcium. Results: A total of 32 participants (8 males and 24 …

Optimization Of The Touchscreen-Based Visuomotor Conditional Learning Task In Mice, Oren Princz-Lebel, David I. Wasserman, Miguel Skirzewski, Penny A. Macdonald, Lisa M. Saksida, Tim J. Bussey

Western Research Forum

The translational gap between animal models and clinical trials is a longstanding, yet largely unresolved, limitation in the study of cognition. This discrepancy is largely due to the differences in how cognition is assessed in animal models compared to those in clinical populations. In the stimulus-response (S-R) learning literature, for example, the techniques used to assess the acquisition of habitual behaviour differ greatly across species, leading to poor cross-species translation and often conflicting results. As a result, we set out to optimize a S-R learning task in mice using the touchscreen-based operant technologies. Similar to human studies, this touchscreen technique …

Genomic Analysis Of Mitochondria Of Metschnikowia, Dong Kyung Lee

Western Research Forum

Genomic Analysis of Mitochondria of Metschnikowia

Background

Our current understanding of mitochondrial genomes is biased toward metazoans, which represent the majority of sequenced mitochondrial DNAs (mtDNAs). The high diversity in size, shape, and gene synteny among yeast mitochondrial genomes make them an appealing alternative to those of metazoans for studying genomic diversity and evolution. Recently, more than 60 draft-genome assemblies of large-spored Metschnikowia species have been determined. Complete mitochondrial genomes of these yeasts, however, are yet to be constructed and characterized. Therefore, I propose to construct and analyze the mitochondrial genomes of all 61 strains of large-spored Metschnikowia species.

Hypothesis …

Cell-Free Dna Release During Programmed Cell Death In Ischemia Reperfusion Injury, Alexander Dionne, Anthony M. Jevnikar, Zhu-Xu Zhang

Western Research Forum

Transplantation is invariably associated with acute allograft injury caused by ischemia reperfusion injury (IRI). This injury causes cells of the allograft to undergo various forms of programmed cell death including apoptosis and necroptosis. During programmed cell death, immunogenic molecules are released from cells, one of which is cell-free DNA (cfDNA). We hypothesize that cfDNA is released by microvascular endothelial cells (MVECs) during programmed cell death of IRI and that cfDNA acts as both a biomarker for cellular injury as well as a biologically active molecule capable of amplifying inflammation and organ injury.

Our results indicate that cfDNA is released by …

Optimization Of Simultaneous Facial Emg And Fmri, Maggie Prenger

Western Research Forum

The scientific study of emotion began in the 19^th century with Duchenne’s study of the “universal and immutable” language of facial expressions. In The Mechanism of Human Physiognomy, he manipulates human facial expressions by electrically stimulating facial muscles. Facial electromyography (EMG) is a modern technique that is reminiscent of Duchenne’s work; it allows researchers to measure facial muscle activity through surface recording electrodes, providing a real-time measure of natural emotional reactions.

Although facial EMG is a reliable measure of emotional behavior, it fails to provide any information about brain activity responsible for emotional processes. Functional magnetic resonance imaging (fMRI) …

Spontaneous Mimicry Of Emotional Facial Expressions As A Function Of Trait Sadism, Cathleen Fleury, Mary Ritchie, Derek Mitchell

Western Research Forum

Using electromyography (EMG), it has been shown that facial muscles imperceptibly mirror the facial expressions of others, a phenomenon referred to as spontaneous facial mimicry. Facial mimicry may be involved in empathy processing, and is impaired in several empathy deficit disorders. It was previously believed to follow the direct-matching principle, a theory postulating that spontaneous facial mimicry involves the observer mirroring their partner’s expression exactly. However, several recent studies have demonstrated that context and individual differences may be influencing factors of spontaneous facial mimicry. In the present study, we propose to investigate the relationship between facial mimicry and empathy through …

Obstacle Negotiation And Dual-Tasking In People With A Unilateral Transtibial Amputation., Humberto Omana, Michael Payne, Ricardo Viana, Susan Winnifred Hunter

Western Research Forum

Background: Falls in people with a lower limb amputation (PLLAs) are common and most often occur while walking, resulting in physical and psychological consequences that adversely affect quality of life. Walking is a complex motor task requiring cognitive resources. Due to walking with a prosthesis, PLLAs report focussing on every step they take, indicating greater cognitive needs. However, cognitive resources are limited, and most of our everyday activities also involve the simultaneous performance of motor and cognitive tasks, known as dual-tasking. The inter-relationship between mobility, cognition and postural stability in PLLAs using a prosthesis is just starting to be understood. …

Effect Of Stress And Methylmercury Exposure On Song Sparrows (Melospiza Melodia) Energy Balance., Claire Bottini

Western Research Forum

Mercury is an endocrine disruptor well known for its deleterious impacts on wildlife and humans but its effects on songbirds’ populations still require more investigation. In their natural habitat, birds face multiple stressors (e.g. predation, food unpredictability, inclement weather) in addition to pollutants. However the accumulated effects of both stress and pollutants are rarely studied. Such co-occurring pressures may synergistically increase risk for birds as both stress and mercury exposure may disrupt energy acquisition and/or allocation. My project aims to determine the interactive effects of stress and mercury exposure on songbird energy balance. Adults’ song sparrows (Melospiza melodia) …

Modelling Non-Linear Functional Responses In Competitive Biological Systems., Nickolas Goncharenko

Western Research Forum

One of the most versatile and well understood models in mathematical biology is the Competitive Lotka Volterra (CLV) model, which describes the behaviour of any number of exclusively competitive species (that is each species competes directly with every other species). Despite it's success in describing many phenomenon in biology, chemistry and physics the CLV model cannot describe any non-linear environmental effects (including resource limitation and immune response of a host due to infection). The reason for this is the theory monotone dynamical systems, which was codeveloped with the CLV model, does not apply when this non-linear effect is introduced. For …