Brooks, Kate-Investigating the Bulk Composition and Interior Structure of Terrestrial Exoplanets (Dr. Ralph Pudritz)
An exoplanet’s mass-radius relation is a direct manifestation of the materials it accretes during formation. We present an investigation of the structural properties of solid exoplanets at the end of their formation in protoplanetary disks. Exoplanet populations comprised of thousands of pre-computed planet models were obtained from Alessi and Pudritz (2018) for analysis in this work. We sampled terrestrial planets from these populations, each with its own final mass, orbital radius and chemical composition. The approach includes an investigation of the impact of varied initial disk radii at 33AU, 66AU and 50AU and the influence of planets having formed in the following planet traps: Dead Zone, H2O Ice Line, and Heat Transition Line. The radii of the sampled planets under analysis are computed using a publicly accessible 3-layer grid model produced by Zeng and Sasselov (2013). The results indicate a strong relationship between initial disk radii, planet trap and planet composition. The Mass-Radius distribution of the simulated populations presented here, validates the planet formation model through comparison with the observational exoplanet data. This analysis benefits the development of planet formation theory, successfully contributing to an end-to-end theory of planet formation.
Butt, Mehreen-Investigating the effectiveness of behavioural activation therapy on the quality of life of depressed individuals (Dr. Zena Samaan)
Depression is a common disorder with a lifetime prevalence rate of 16%. Despite the multitude of treatments options available to patients, many do not respond well to treatment. Behavioural Activation (BA) Therapy, is focused on targeting avoidance and ruminative behaviours, where patients are refocused on their goals, values, and directions of their lives rather than changing their core values like in cognitive therapy. This therapy has the potential to improve the symptoms and quality of life (QoL) of individuals with depression. Research conducted on BA therapy and its effects on the QoL of depression patients has not been extensively investigated in a group format; investigation into this is trivial for advancements in treatments for depressive disorders. The treatment was implemented over 28 weeks. QoL will be investigated through 3 surveys: Q-LES-QSF, SF-12 patient questionnaire and WSAS. These surveys will be completed at the initial screening session, session 10 and session 28. The data from the screening session will be compared to that of their final session of treatment, to determine whether or not an overall change in QoL is seen through the treatment. We are expecting to find a significant increase in QoL standards through the treatment process. Through our findings we aim to provide evidence for the use of a more efficacious therapy for this chronic disease. We will also be providing scientific support with more focus on the QoL of affected individuals rather than a focus on just symptomatic relief.
Cappelletto, Nicole-Measuring the Vertical Profile of Electron Fields for Total Skin Electron Irradiation using Radiochromic Film (Dr. Martin Shim)
Total skin electron irradiation (TSEI) is a radiotherapeutic technique used in the treatment of mycosis fungoides. The treatment involves the delivery of a uniform radiation dose at an extended source to surface distance by using 80×200 cm2 uniform electron fields. To ensure the accurate delivery of radiation to the patient, it is necessary to conduct regular quality assurance of the TSEI technique through the measurement of relevant dosimetric data. One of the most time consuming measurements is quantifying the vertical profile of the electron field using ion chambers. Radiochromic film presents a new method of measuring vertical profiles and has the potential to replace the use of ion chambers. Recent advancements in dose calibration in the software FilmQA Pro have finally allowed for reliable film dosimetry. The vertical profile of the electron field described above was measured using both ion chambers and film for two linear accelerators. Several profiles measured over multiple days were compared to each other, as well as to the original data from commissioning, in order to test the accuracy and stability of the film. The results demonstrate the stability of the film measurements and increased accuracy of dose measurements when compared to ion chamber data. As such, a procedure for measuring the vertical profile of the large electron fields used during TSEI with GafChromic EBT-XD radiochromic film was developed. Overall, using radiochromic film to measure vertical profiles saves time, improves the accuracy of dose measurements, and ultimately ensures the reliable delivery of radiation to patients.
Chan, Michael-Applications of Phage Display for Staphylococcus Aureus (Dr. Zeinab Hosseini-Doust)
The Gram-positive bacterium, Staphylococcus aureus, is a harmful pathogen that is often associated with a wide range of human diseases and food contamination. Virulence factors, such as toxins and adhesions, alongside its propensity to develop resistance to antibiotics make Staphylococcus aureus difficult to control and treat. This bacterium has become a substantial public health problem within a clinical setting. Thus, it is of paramount importance to develop detection methods capable of diagnosing Staphylococcus aureus infections and designing subsequent vaccines as a prophylactic treatment.
Phage display, a technique that develops molecular probes capable of selecting for specific targets, has recently gained prominence in many scientific fields. More specifically, phage display has been used to study infectious diseases and continues to hold promising potential for detecting and treating bacterial infections. This technique has enabled the discovery of conserved antigenic epitopes of Staphylococcus aureus, which identifies potential protein candidates for future vaccines. Currently, there are no recent review papers summarizing the applications of phage display on Staphylococcus aureus. As such, a comprehensive search of Web of Science, ScienceDirect, and PubMed was performed. This review paper hopes to provide insight into the specific detection methods that have been developed with the use of phage display technology. Overall, we want to understand the research being conducted to generate a holistic view of the applications of phage display technology on treating Staphylococcus aureus.
Chen, Chen-Evaluating the quality of pilot RCT studies in pediatric urology with CONSORT (2019)
Dr. Forough Farrokhyar, The aim of this systematic review is to assess the quality of pilot randomized controlled trials (RCTs) in pediatric urology based on their adherence to the Consolidated Stands of Reporting Trials (CONSORT) checklist extension to pilot studies. All pilot studies published between 2005 and 2018 in pediatric urology were searched from MEDLINE and EMBASE. Studies included were reported in English, conducted on humans, relevant to at least one clinical intervention in pediatric urology, and framed as pilot RCTs. Of the 1347 titles from the initial search, 70 remained after screening titles, abstracts, and full-texts of the studies. Studies were scored on each of the 13 criteria in the CONSORT statement extension to assess their quality, which included evaluation of the pilot RCT randomization protocol, appropriateness of outcomes, and reported adverse effects. Screening of studies from the initial search and scoring of each screened pilot RCT were completed by two researchers independently, and agreement statistics were performed to ensure consistency. From the lack of stringency in journal criteria for pilot RCTs and the misconceptions surrounding the purpose of a study framed to be pilot, the quality of pilot RCTs in pediatric urology are often suboptimal. Due to the vast cost, sample size, and risk associated with RCTs, researchers are recommended to first complete a pilot study assessing the feasibility of their RCT study design. Unfortunately, suboptimal pilot RCT quality may therefore affect the implementation of future RCTs.
D’Ercole, Joseph-Oxidative Stress in Fuchs’ Dystrophy: Changes in Metabolism, Transcriptional Activity, and the Extracellular Matrix (Dr. Michelle MacDonald)
Fuchs Endothelial Corneal Dystrophy (FECD) is among the most common corneal diseases affecting the endothelial cell layer of the human cornea. FECD manifests as progressive cell death as well as depositions of the extracellular matrix (ECM) known as guttae. As endothelial cells continue to die, the tissue’s function may be compromised and lead to corneal edema. Furthermore, guttae cause light to scatter, creating visual disturbances. Both corneal edema and guttae lead to a decrease in vision and, in severe cases, an effective total loss of vision. Currently, treatments may only temporarily alleviate corneal edema, and transplantation is the only effective solution. As such, there is an apparent need to better understand and treat FECD. Though the cause of FECD currently remains unknown, previous research has characterized numerous aspects of this disease. This review article will summarize and analyze the current state of the literature by focusing on three components of FECD: 1) metabolic changes, 2) transcriptional and proteomic alterations and, 3) excessive ECM synthesis. The pathogenesis will also be considered, as oxidative stress, likely from mitochondrial metabolism, has been documented and implicated as a risk factor for developing FECD and may explain some observed biochemical changes. As the current body of knowledge on FECD is incomplete, various experimental protocols are also proposed in relation to the aforementioned components. These protocols will serve to better investigate previously characterized aspects of FECD, while also probing into unstudied facets to drive further research and lead to a more holistic understanding of FECD.
Dittrich, Angela-Investigating the differential encoding of rhythm and meter in adults and six-month old infants (Dr. Laurel Trainor)
From early development, rhythm perception plays a major role in the comprehension and production of spoken language, music, and dance. One process involved in rhythm perception is neural entrainment, where brain oscillations increase and decrease in energy periodically with an external rhythm. When instructed to hear an ambiguous six-beat stimulus in either groups of two (duple meter) or three (triple meter), adults neurally entrain to frequencies at the beat and primed meter levels. However, seven-month-olds who listened to the same stimulus while distracted neurally entrained to the beat, duple, and triple frequencies regardless of priming. This study investigates whether infants can be similarly primed to perceive one metrical interpretation versus another. Infants are presented with a six-beat rhythmic pattern accompanied by a simple video of a circle expanding and shrinking in synchrony with the first beat to capture attention. For repetitions, participants listen to either a ‘duple’ or ‘triple’ accented stimulus. This is followed by 16 repetitions of the unaccented, ambiguous stimulus. To further investigate whether participants maintain perception of a particular metrical structure, pitch-deviant tones on beats four (consistent with triple) and five (consistent with duple) are presented to elicit a mismatch negativity (MMN) response, which is an EEG component associated with violations against expectations. Pilot adult EEG data are being analyzed with the prediction that MMN amplitude will be higher for deviants associated with the primed meter condition. This would demonstrate the use of top-down processing in rhythm perception in infants as early as six-months old.
Eshafi, Sarah-Using Virtual Spatialized Auditory Displays to Restore Proprioceptive Function in Individuals with Prosthetic Limbs (Dr. Sue Becker)
One of the main contributors to motor control deficits in individuals with prosthetic limbs is their lack of proprioceptive feedback. Proprioceptive feedback provides individuals with a sense of relative body position and is critical for accurate motor control. A common method used to restore proprioceptive function in individuals with prosthetic limbs is sensory substitution, which involves circumventing the loss of proprioceptive function by replacing it with another sense. One promising form of sensory substitution that has not yet been explored in the context of prosthetics is spatialized auditory-proprioceptive substitution, in which spatialized audio displays simulate a sound coming from a specific point in space. In this context, using audio to identify limb position could circumvent the loss of proprioceptive function. Specifically, head-related transfer functions (HRTFs), which identify the characteristics of a sound entering an ear from a specific point in space, could be used to deliver spatialized auditory cues through headphones to participants to substitute proprioception. This review explores past studies on overall localization performance, the extent to which HRTFs tailored to the individual provide improve localization performance, and the merits of using headtracking technology to alter auditory output in real time. It is expected that using generalized HRTFs will lead to good localization performance, and that individualized HRTFs with headtracking will lead to even better performance. This review will provide a basis for developing easily-perceived spatialized auditory displays, which will eventually be used to test the auditory-proprioceptive substitution hypothesis in the context of proprioceptive loss in individuals with prosthetics.
Gandhi , Aanshi-Applications of Medical Imaging for Cardiovascular Modelling (Dr. Zahra K. Motamed)
Medical imaging is currently the most effective, non-invasive technique for diagnosing and studying many clinical diseases. This study will look particularly at the use of medical imaging for diagnosing or studying the progression of those diseases. Currently, there are multiple imaging modality options that can be used; each with their own advantages and disadvantages. Therefore, it is important to determine the most effective technique to capture details relating to the anatomical structures. A report outlining the advantages and limitations of computed tomography (CT) to determine whether it was an effective medical imaging modality was made. Based on the findings of my work, I expect to conclude which scenarios favour the use of CT and what advancements still need to be made. The report will allow for the use of medical imaging to be completed with a higher quality and undergo constructive improvements. One potential avenue for the future of medical imaging is cardiovascular modelling, which uses these diagnostic modalities to create comprehensive reconstructions of the anatomical structures. To better understand this avenue, I used an open-source program to reconstruct anatomical structures such as the aorta and left ventricle using CT images. These reconstructions will be used in future studies involving hemodynamic properties for predictive and other clinical testing.
Ge, Yichang-The Use of Narrative Justice to Facilitate Moral Knowledge Acquisition of the Human Right to Clean Drinking Water (Dr. Nancy Doubleday)
This paper examines Indigenous water rights in Canada and investigates narrative justice, a novel approach towards understanding empathetic policy and allyship. Prior to reviewing the concept of narrative justice, the paper highlights key points in Indigenous history pertinent to the silencing and mistreatment of the people. Along with narrative justice, the paper highlights examples from environmental justice to support the literature review. The purpose of this literature review is to connect the emergence of narrative justice as an investigative modality to understanding Indigenous water rights. This paper communicates the need for proper representation of Indigenous peoples in storytelling and research. In addition to narrative justice, the paper highlights the growing gap between Indigenous peoples and the surrounding urban areas. This gap is described using the context of post-truth and how advancements in technology have contributed to a prevailing barrier between Western society and Indigenous communities. In this process, the paper also draws on cases like the Nestle/Kinder Morgan controversy, and other water-taking enterprises to show how Western/non-Indigenous needs are often prioritized. The framework of the paper is written from an ally perspective, in hopes of helping to establish another form of methodology in this field of social justice. This paper aims to contribute towards the growing investigative modalities for narrative water and Indigenous justice. In exploring narrative justice in relation to Indigenous water rights in Canada, this paper offers a fresh approach to social justice and hopes to help facilitate understanding of empathetic policy formation.
Grewal, Sonya-The Effects of Stress on Eating Habits in the McMaster University Undergraduate Population (Dr. Niko Yiannakoulias)
Most university students have experienced academic stress at some point in the school year, and many studies have reported an association between stress and changes in dietary behaviour. Stress has been found to affect eating habits in one of two ways: (1) Individuals seek comfort in food and their food intake during times of high stress increases or (2) Students lose their appetite during times of stress causing their food intake to decrease. This is an important topic among the student population as eating habits affect overall health and well-being, and, consequently, academic performance. This project aims to gain a better understanding of how the diet of McMaster University undergraduate students changes following the onset of academic stress in terms of the amount and types of food consumed. A survey was distributed among the student population via the McMaster Class of 2020 Facebook page. The questions in this survey ask about the eating habits of participants on an average day compared to the time of greatest academic stress. A descriptive statistical analysis was performed and the results of this study offer insights into the effects of stress on dietary behaviour. This knowledge could be useful for implementing strategies that promote healthy eating among the student population during periods of academic stress.
Hosein, Hannah-Negative Regulators of Vulval Development in Caenorhabditis briggsae (Dr. Bhagwati Gupta)
Cancerous cells are able to evade the influence of negative growth signals, allowing for tumorigenesis. This is often caused by a mutation in a proto-oncogene. Many genes linked to human cancer are conserved in Caenorhabditis briggsae, causing the nematode to be a valuable cancer model system. Mutations in Cbr-htz-1 and Cbr-spr-4 of C. briggsae lead to the development of the Multivulva (Muv) phenotype, which can be likened to cancerous growth. Study of the Muv phenotype in C. briggsae can further our understanding of human cancer.
It is unknown whether the Muv phenotype causes the production of less viable offspring and whether the Muv phenotype is temperature-sensitive in Cbr-htz-1 and Cbr-spr-4 mutants. The number of eggs lain and the number of eggs hatched were compared in an embryonic lethality assay to measure the number of viable offspring produced by Cbr-htz-1 and Cbr-spr-4 mutants in comparison to wildtype AF16 C. briggsae. To measure the temperature-dependence of the Muv phenotype, AF16, Cbr-htz-1 and Cbr-spr-4 nematodes were grown at 15˚C and 20˚C. Worms were then scored to compare the penetrance of the Muv phenotype at the different temperatures amongst the three strains. The results of these experiments are currently ongoing. Current experimental observations suggest that Cbr-htz-1 produces fewer viable offspring and that worms grown at 15˚C exhibit a greater Muv penetrance.
By studying the effect of Cbr-htz-1 and Cbr-spr-4 mutations on vulval development, greater insight into the role these genes play in cell proliferation will be achieved, therefore improving our understanding of proto-oncogenes.
Iyengar, Yajur-Analysis of environmental stress metrics on capsular polysaccharide concentration and melanin production in the Cryptococcus neoformans species complex (Dr. Jianping Xu)
The Cryptococcus neoformans species complex (CNSC) is an opportunistic fungal pathogen that can disseminate through the human central nervous system upon infection, leading to meningitis. Under appropriate conditions, cells of CNSC produce melanin pigments and a protective polysaccharide capsule, as two important virulence factors. Previous studies have analyzed melanin production in response to stressors that mimic those used in host defence in one lineage of CNSC. Though quantitative estimates of capsular polysaccharide production have been published, how capsule size might change in response to stressors remains largely unknown. This study analyzed both melanin and capsular polysaccharide production in response to oxidative and nitrosative stressors for a genetically diverse group of strains from the CNSC: Serotype A, Serotype D, Serotype AD, and Serotype B. These results were further used to determine how defensive pathway commitment effected the viability of CNSC cells after exposure to the same stressors. Environmental stress was created by adding reactive oxygen and nitrogen species to growth media at four concentrations. Melanin production was measured using transilluminator-based spot densitometry, while polysaccharide production was measured using phenol-sulfuric acid colorimetry. We found significant differences in melanin production after intermediate oxidative and nitrosative stress, and significant differences in polysaccharide production after intermediate oxidative and high nitrosative stress. The number of colonies increased after capsule commitment under nitrosative stress and melanin commitment under oxidative stress. These results will enable a more complete understanding of the pathogenicity of the CNSC and by extension can reveal otherwise unknown intricacies in its virulence upon infection.
Jivani, Sabrina-A Hydrogeological Investigation of the Niagara Escarpment in Hamilton (Dr. Carolyn Eyles)
The Niagara Escarpment is a prominent landscape feature in the City of Hamilton- and it is crumbling. Erosion processes, involving mass wasting in the form of rock slides and falls are both a financial and safety concern for the City of Hamilton when they damage city infrastructure. This project investigates the hydrogeological processes which can be eroding the escarpment with the goal of providing a better understanding of how water is changing this geological feature over time. This information can aid in the identification of areas of the escarpment that are more susceptible to faster rates of erosion. To interpret how the escarpment may be eroding, research on hydrogeological process that affect escarpment and cliff erosion in general has been conducted. This was combined with an analysis of the lithological properties of the Niagara Escarpment, potential water infiltration and exit areas, and the location of any potential anthropogenic sources of water. Field documentation and photo-analysis of exposed rock faces provided information regarding the nature of seepage zones. ArcGIS was used to conduct a hydrological analysis of regional and local watershed data along with City infrastructure data. These GIS maps were then used to identify areas which may be particularly susceptible to hydrological erosion. By analysing how hydrogeological erosion is changing the Niagara Escarpment, we can make informed predictions on which areas are at high risk of rock falls and mitigate further city damage.
Joshi, Dhvanil-A Lithological Analysis of Niagara Escarpment Erosion in Hamilton (Dr. Carolyn Eyles)
Currently, the natural erosion of the Niagara Escarpment in the Hamilton region is an issue because of mass wasting events that result in access road and trail closures. Large rock falls also pose a threat to human safety, especially with many residents living in close proximity to the receding edge of the escarpment. The concern for safety and high-cost consequences make the erosion of the Niagara Escarpment in Hamilton a serious and relevant problem.
This project focuses on examination of the physical properties of the lithological units that make up escarpment across Hamilton and how the vertical and lateral variations in these properties may play a role in controlling erosional rates and mass wasting events.
A literature review was conducted to compile information on how lithological properties can influence erosional rates, details of the rock formations that make up the escarpment in Hamilton, and the relationship between the spacing of bedding planes, joints, and fractures, and erosion processes. The analysis of high-resolution photographs, obtained using unmanned aerial vehicles (UAV) and terrestrial-based photography, allowed the determination of joint and fracture incidence and density at multiple study sites. Quantitative analyses were conducted using MATLAB software. This information was coupled with in-person observations made in the field to assess if any patterns were identifiable.
By understanding the physical factors that influence erosion, it may become clearer what actions are necessary to be better prepared for further erosion in the future.
Kates, Meghan-Optimization of the PRESTO-Tango Reporter Assay for Determining the Effects of Antagonist SB on Receptor G (Dr. John Hassell)
As of 2017, breast cancer is the second most fatal cancer for Canadian women with approximately 40% of treated individuals experiencing relapse. Particularly, tumor initiating cells (TICs) – which promote angiogenesis, tumorigenesis, and metastasis – are refractory to treatment and a major target for drug development. The Hassell lab previously reported that the serotonergic pathway is vital for breast TIC survival and propagation, with particular importance placed on receptor G as a target. The antagonist SB, specific to receptor G, has been found to affect G protein signaling. However, alteration of β-arrestin signaling must be validated. Here, the PRESTO-Tango reporter assay is optimized for this confirmation. This assay creates a novel signaling pathway in HEK293 cells stably expressing a luciferase reporter gene with a tTA-dependent promoter and a protease-β-arrestin fusion protein. A plasmid containing receptor G fused with a cleavable 3′-tTA transcription factor is transfected into these cells. Agonist activation of receptor G causes β-arrestin recruitment and cleavage of tTA from the receptor, allowing its translocation to the nucleus to stimulate luciferase transcription.
This study’s objective was to optimize experimental conditions to study SB’s effect on agonist-induced luciferase activity without cell viability reduction. No experimental protocol tested resolved the difference between these two variables to a significant extent. Further experiments are required to determine if this result truly suggests that SB does not affect signaling in the β-arrestin pathway. If optimized, this system could also be used to study SB analogues for potential discovery of more potent antagonists of the receptor.
Kowal, Sloane-Repeatability, reliability, and reproducibility of measuring human natural killer cells using flow cytometry: Preliminary results (Dr. Joyce Obeid)
Natural killer (NK) cells are a subset of lymphocytes best characterized by their ability to detect and destroy aberrant or infected cells without prior sensitization. Interestingly, NK cells are also the most responsive immune cell to exercise. In order to accurately quantify the magnitude of change in NK cells with exercise, it is important that we identify the degree of error in NK cell measurement. Therefore, the objectives of this project are to assess repeatability, reliability, and reproducibility of NK cell assessment. A total of 10 healthy individuals were asked to provide a blood sample on two separate occasions. Density gradient centrifugation with Histopaque 1077 was used to isolate peripheral blood mononuclear cells (PBMCs) from whole blood. PBMCs were stained with fluorochrome-conjugated monoclonal antibodies for CD3 and CD56. NK cells, defined as CD3-CD56+, were quantified on a MACSQuant flow cytometer. Repeatability was assessed by quantifying NK cells from a single sample on two occasions, separated by ~1 hour. Reliability was established by staining two separate samples collected on the same day. Reproducibility was examined from samples collected on two separate days from the same participant. Intraclass correlation coefficients were used to quantify agreement between paired measurements. In the Child Health & Exercise Medicine Program, we examine the effects of exercise on various health-related markers, including NK cells. The findings of this quality assurance project will allow us to understand the degree to which changes in NK cells are due to an exercise stimulus or related to protocol variability/error.
Lalonde, Emily -A Vignette-Based Field Experiment to Assess Mining Site Managers’ Perception of Threat (Dr. Brent McKnight)
Extreme weather events such as wildfires and floods are predicted to increase due to climate change, particularly at higher latitudes. As such, the natural resource extraction sector in Canada’s boreal forest will become more vulnerable to these events. In order to gain a better understanding of how mining site managers perceive the threat of climate-mediated natural disasters, a pilot study was conducted using undergraduate students from the Integrated Business and Humanities program within the DeGroote School of Business at McMaster University. Using a vignette-based field experiment, four questionnaires were administered to participants, each containing different versions of vignettes. The vignettes evaluated the participants’ perception of the threat of climate-mediated natural disasters by varying seven distinct aspects of how these events are described in reports. The vignettes tested the influence of (1) the locality of the source; (2) the nature of the source; (3) the relationship of the source to the company; (4) the terminology used; (5) the climatic timeframe included, (6) the type of entity impacted by the disaster; and (7) the way the information is presented. The results of this pilot study will help resolve fundamental errors within the experimental design as well as gain a better understanding of what aspects of a climate report influence the participants’ perception of risk. Eventually, these findings will contribute to the primary study to determine what aspects mining managers view as threatening. This knowledge can be used in reports by researchers and governments to target this audience more effectively.
Lindzon, Abby-Analyzing Methods for Releasing Secondary Dormancy Response in Eutrema salsugineum Seeds (Dr. Elizabeth Weretilnyk)
The proper germination of a seed is an essential step during a plant’s development. However, when exposed to unfavourable conditions, seeds may restrict their germination and enter a state of secondary dormancy. Although recent research has been conducted on this topic, seed dormancy remains one of the least understood plant phenomena. This project sought to discover what triggers secondary dormancy in Eutrema salsugineum seeds and examine possible treatments that could release it. Dormant wild-type (wt) seeds were plated on varying concentrations of gibberellic acid (GA), a hormone known to stimulate germination. Further tests, using GA, were also conducted with mutagenized seeds also previously found to be dormant. Seeds known to germinate were used as a control for all experiments. Embryo rescue, a method of separating the embryo from the seed coat, was also done in both dormant and non-dormant seeds in hopes that a physical barrier was preventing germination. Results from the GA assay for both mutagenized and wt seeds were inconclusive with dormant wt seeds imbibing and showing irregular testa rupture without later radicle formation. As well, embryo rescue in non-dormant seeds proved successful, in contrast to dormant seeds that failed to germinate. Understanding how to release seed dormancy is necessary for ensuring effective experiments and reducing waste due to seemingly dead seeds. Although inconclusive thus far, results illustrate a connection to the seed coat, making this an interesting avenue to pursue in the future.
Luu, Taylor-Impacts of Forest Management on the Distribution of Mercury in Slimy Sculpin (Cottus cognatus) (Dr. Karen Kidd)
Forests play an integral role in Canada’s natural resource economy and also provide key ecological services to nearby aquatic environments, such as flood control and water quality regulation. Disturbances like forestry can threaten stream integrity by altering a forest’s ability to provide such services. In areas like the Black Brook (BB) District of New Brunswick, one of the most intensively managed sites in Canada, increased mercury levels in stream waters and biota have been observed. However, distributions of mercury contamination in downstream areas remain largely unknown. Thus, this project evaluated the impacts of forestry upon the spatial distribution of total mercury (THg) in the fish species slimy sculpin (Cottus cognatus), as well as discerned sex-dependent variations. Slimy sculpin was an ideal species to use for studying mercury contamination, as individuals exhibit high site fidelity and are a sensitive indicator of mercury as a benthic species. THg concentrations (μg/kg wet weight (ww)) were measured in fish sampled in 2017 from five upstream to downstream sites located within the BB District. Six to ten fish of each sex and of similar length were sampled from each site. THg was measured from homogenized tissue using the DMA-80 Direct Mercury Analyzer. A significant positive interaction between THg μg/kg ww and fish length (mm) was found in females, F(1, 37) = 14.59, p < 0.001, but not males, providing evidence for sex-dependent variations. Overall, this project provided insights into necessary future steps that must be taken to address spatial and sex-dependent variations in mercury contamination.
Mahetaji, Kaushar-Investigating the Consequences of the Jordan Framework for Unreasonable Time Delay in the Canadian Criminal Judicial System (Dr. Greg Flynn)
In 2016, the Supreme Court’s decision in R v. Jordan explicitly addressed time delay in Canada’s criminal judicial system. Jordan addressed section 11(b) of the Charter of Rights and Freedoms, which provides individuals with the right to a trial in a reasonable amount of time. To uphold section 11(b), Jordan formed an analytical framework that established presumptive numerical ceilings (quantitative time constraints), which outlined the 30 and 18 month limits required respectively for trial completion at the superior and provincial court levels. The consequences of Jordan are not fully known.
This article examines Jordan‘s effects using precedent tracing, a methodology that reveals interpretation of Jordan at the trial court level. A stratified random sample of trial court decisions from CanLII post-Jordan is used to extrapolate case-specific information including: net length of delay, delay waived by defence, delay attributable to defence, application of exceptional and/or transitional circumstances, type of crime, reasonability, and the presence of forensic limitations. Each case is plotted on a spatial database, providing a geographical visualization of trial court cases across Canada. Correlations between (1) delay and type of crime, (2) delay and forensic limitations, and (3) delay and geographical region are discussed. Findings relay quantitative evidence that suggests Jordan has increased stay-of-proceedings in specific geographical regions. This corroborates literature that challenges Jordan as a feasible mechanism to countering time delay. Visual outputs present a method for tracking progress on changes to time delay due to Jordan, permitting an understanding of the long-term consequences of a precedent-setting decision.
Mar, Sara-Preliminary study of a novel nucleoid associated protein in Streptomyces venezuelae. (Dr. Marie Elliot)
While eukaryotes use histones to organize their genomes, bacteria rely on nucleoid associated proteins (NAPs) to maintain chromosome integrity and regulate gene expression. Characterization of NAPs contributes to understanding of the molecular mechanisms of bacterium to better produce specific products. Streptomyces bacteria are of interest due their industrially important secondary metabolite production. YlqC, a protein found in Streptomyces venezuelae, has been hypothesized to be a NAP due its high abundance in Streptomyces coelicolor, a related species. However, its function has yet to be confirmed. The goal of this study was to investigate the role of the gene, sven_5287, which encodes the protein YlqC in S. venezuelae. Experiments were done to compare the phenotypes and growth of wildtype S. venezuelae and a sven_5287 deletion strain. PCR targeting was used to create a sven_5287 deletion strain. Growth curves for the deletion and wildtype strain were constructed using OD600 measurements and compared. Light microscopy was also used to determine the stage of growth at each time point. The phenotypes of the strains were also compared throughout growth on of solid media. The deletion strain demonstrated reduced growth and delayed growth stage progression in comparison to the wildtype. The final optical density of the deletion strain was significantly less than the wildtype. These results indicate that YlqC has a role in the overall growth of S. venezuelae. Further studies are needed to confirm its role as a NAP and antibiotic production.
Marchetti, Sam-The Effect of Necromones on Hippodamia convergens Foraging Behaviour (Dr. Chad Harvey)
Each year, Ontario’s wine industry is negatively impacted by Harmonia axyridis, the multi-coloured Asian lady beetle (MALB), as it ends up in the wine press and can release a chemical that significantly impacts wine quality. Traditionally, pesticides are used to control the MALB in vineyards, but these have negative impacts on workers and surrounding ecosystems. This study presents the use of pheromones released at death, called necromones, as a potential alternative, as necromones have been known to have repellent effects in conspecifics. Due to ease of accessibility, Hippodamia convergens, a related, native coccinellid species, was used in this study. Individuals were placed in groups of 12 in a simple resource-choice experiment, given the option between two sets of food, water, and shelter, where one set was sprayed with necromone, and another set was not. A significantly higher number of individuals were found on the necromone side of the trial container than on the control side, and significantly more individuals were alive than dead or feigning death. Time after the initiation of the trial had no significant impact on the number of individuals on either side, or the number alive, dead, or feigning death. The results attained from this study are preliminary, and counter what would be expected based on previous studies, but lend some insight into the potential for necromones to act as an attractant rather than a repellent. The experiment itself should be repeated with a larger sample size and further controls to eliminate much of the associated uncertainty.
Mills, Sam-Analyzing the Landscape of Fear for Urban Meso-predators – Do North American Coyotes and European Red Foxes perceive the Urban Landscape as a food source or a threat? (Dr. Chad Harvey)
The distribution of a species is strongly influenced by a concept known as the Landscape of Fear, which explores a species’ perception of an environment through analyzing its associated benefits and risks. The purpose of this article was to examine how changes in the landscape of fear can explain the recent colonization of urban habitats by mesopredators, to produce a manuscript examining this concept with two mesopredator species from different geographical locations. Attention was focused onto the North American Coyote (Canis latrans) invading North American cities, and the European Red Fox (Vulpes vulpes) occupying English. Comparisons between these species are vital for identifying the landscape of fear, and whether species continue to populate human-dominated habitats as technologies advance and cities expand. Determining whether these results are reproducible worldwide, allows predictions for the urban migration of other mesopredators. Among other factors, a key contributor towards this urban migration is the removal of perceived disadvantages associated with their natural environments, such as fear of predation and limited resource availability. Whereas, technology is the key perceived risk with human-dominated habitats. Research indicates new adaptational behaviours emerging, recognizing these technologies as high-risk and a subsequent decline in fatalities as a result, due to generational teaching. Additionally, both species conferred a dietary shift from hunting for small animals to scavenging in urban environments. Further research is necessary to explore the possible implications of changes in species distribution towards human-dominated habitats.
Montague, Coulter-Engineering pH-responsive Starch Nanoparticle Clusters with Programmable Size Change to Improve Local Drug Delivery to Tumour Cores (Dr. Todd Hoare)
This abstract has been omitted from our website due to a confidentiality agreement between the student and their supervisor.
Poole, Kristin-Historical Significance of Darwin’s On the Origin of Species (Dr. Sarah Symons)
Though the theory of evolution predates the Darwinian era, 19th century scientists felt that the evidence and proposed mechanism of action were insufficient to support the theory. Therefore, evolution was not popularized until the publishing of Darwin’s book On the Origin of Species. The text provided both experimental evidence and a plausible mechanism for evolution that revolutionized the field of biology. In addition to its importance within the scientific community, the publication of Darwin’s book is also historically significant. This paper investigates the prominent social, political, and religious factors that both influenced and were influenced by Darwin’s book. Furthermore, it uses Darwin’s book as a context in which to explore the relationship between the development of science and society. This literature review explores key historical events surrounding the publication of On the Origin of Species including Darwin’s specimen observations on the Beagle Voyage, the lack of recognition of Wallace’s contribution, and the clash between religion and science in ‰ÛÏThe Great Evolution Debate‰Ûù. This is accomplished through analyzing letters, autobiographies, biographies, newspapers, and obituaries referencing key figures such as Charles Darwin, Thomas Huxley, and Alfred Russel Wallace. Through this research a strong relationship between science and society was identified with important modern implications – including the division of scientific education and religion. Overall, these findings allow for a critical reflection on the factors that influence the development and acceptance of scientific theory, therefore emphasizing the acknowledgement of scientific theory as a process that is often as important as the theory itself.
Porteous, Morgan-Episodic Future Thinking as an intervention Method for Binge Drinking in the Undergraduate Population (Dr. Sue Becker)
Binge drinking is an alcohol disorder characterized by intermittent periods of excessive alcohol consumption, followed by periods of alcohol abstinence, and is marked by steep delayed discounting decision making. Although binge drinkers don’t inherently have an alcohol dependence, they are at risk of developing one. This delayed discounting (DD) refers to an individual’s preference for smaller, immediate rewards over larger, delayed rewards. Performance on DD tasks has been linked to one’s ability to imagine themselves in the future, thereby implicating Episodic Future Thinking (EFT). Studies found that EFT lowered discount decision making in populations of substance abusers. Accordingly, EFT was tested for its potential to be effective in impacting decision making in at-risk populations. We used an Alcohol Expectancy (AEQ), and an Alcohol Use Questionnaire (AUQ), Lifestyle and Habits Questionnaire, Delayed Discounting Task, and an Alcohol Purchase Task (APT) to quantify people’s attitudes towards drinking, both before and after intervention with EFT. We invoked futuristic thinking by presenting participants with an age-morphed image of themselves based on either a “Healthy Aging” or “Alcohol and Aging” experimental condition. They simultaneously completed a writing task that required imagining the future. Pre and post scores for the AEQ and DD task were computed. A mixed model ANOVA was used to examine if there were differences between these scores but yielded no significant results. This intervention should be refined and investigated further for its potential in a clinical setting to help people struggling with substance abuse.
Rivera-Madrinan, Felipe-Bell’s inequalities and the future of quantum mechanics (Dr. Cliff Burgess)
Bell’s inequalities were created as a metric by which to test the outcome of experiments testing for a system of locally hidden variables that could explain quantum mechanical observations. Originally, Bell’s inequalities provided a plausible way to test for the validity of the Einstein-Podolsky-Rosen paradox, which had stood in opposition to the Copenhagen interpretation since its conception. Since then, Bell’s inequalities have been used to further our understanding of the probabilistic nature of Quantum Mechanics and have been recently considered as a standard by which to test the measurement of entangled particles in emerging quantum computational technology. This poster will aim to give an understanding of the ideas motivating Bell’s inequalities, the modern analogues by which they are tested, and its application in quantum computing.
Singh, Natasha-Geochemical characterization of chert at Stelida, Naxos (Cyclades, Greece) (Dr. Tristan Carter)
Raw material characterization involves determining a unique set of properties to describe the geological material from a specified natural source. This is a necessary step towards identifying the source of an archaeological artifact’s raw material, which can contribute to the interpretation of socioeconomic, cultural, and behavioural aspects of the populations that exploited the raw material source. Chert is a rare raw material in southern Greece, but outcrops abundantly at Stelida (Naxos), where it was exploited for tool-making throughout prehistory by early modern humans and pre-sapiens populations. An initial broad-stroke geochemical analysis of the source has been followed by a detailed intra-source study, with this project examining if perceived visual/haptic distinctions have elemental correlates. The latter involved using energy-dispersive x-ray fluorescence (EDXRF) spectrometry in the McMaster Archaeological XRF Lab to analyze 133 geological chert samples from 22 collection points. Concentrations of eight major oxides and ten trace elements were measured. The control used to assess the spectrometer’s accuracy in each sample run was the RGM-2, certified by the US Geological Service. Preliminary work suggests some potential means of elementally discriminating Stelida raw materials at the sub-source level. Future work aims to then geochemically differentiate Stelida products from those of other regional chert sources. This can then assist in a larger exploration of how temporal and spatial patterns in raw material exploitation may inform us about the cognitive abilities and toolmaking skills of past hominin populations in the Cyclades.
Speedie, Jess-Exploring molecular line intensity distributions in nearby galaxies with the ALMA archive (Dr. Christine Wilson)
The evolution of a galaxy is largely determined by the formation of stars from condensing interstellar gas and the radiation energy that is subsequently released back into the galactic environment by the stars themselves. Star- forming clouds of gas, interspersed throughout the galaxy, are mainly composed of molecular hydrogen – but they also contain species such as CO, CN and HCN. These latter three molecular species produce radio emission which can be used to trace the distribution and density of the gas clouds. Combining these with a fourth ingredient, an estimate of the local star formation rate from radio continuum emission at 93 GHz, we can explore the link between star formation and molecular gas properties within a galaxy.
We conduct a spatial analysis with ALMA observations of CO, CN, HCN and the 93 GHz continuum for a sample of seven nearby galaxies. The galaxy sample represents a diverse selection of galactic environments; some exhibit central starburst regions or active galactic nuclei (AGN), and yet others are star-forming spiral galaxies or galaxy mergers. We find that in some galaxies, star formation efficiency and dense gas fraction are higher towards the galactic centre. In galaxies with central AGN, we see an enhancement in the CN:HCN ratio, consistent with the idea that x- and UV-rays from an AGN can photo- dissociate nearby HCN into CN. A larger sample and higher resolution data would give further insight into how small-scale star formation processes conspire to create the large-scale effects we observe integrated over whole galaxies.
Terpstra, Megan-Inhibitory Effect of Grapefruit Leads to Altered Drug Pharmacokinetics (Dr. Michelle MacDonald)
Grapefruit is known to interact with more than 85 drugs belonging to a diverse range of drug classes. A single glass of grapefruit juice (GFJ) is sufficient to cause a clinically significant drug interaction. Understanding how these interactions occur is vital for predicting and avoiding grapefruit-drug interactions. These interactions result from inhibition of CYP3A4 – a member of the cytochrome P450 enzyme family, P-Glycoprotein (P-gp) – an efflux protein, and Organic Anion-Transporting Polypeptides (OATPs). Therefore, this paper aims to investigate how grapefruit interacts with these pathways to alter drug pharmacokinetics. The results of ten primary papers composed of both clinical and in vitro studies are presented. Repeated consumption of GFJ increases its inhibitory effect on CYP3A4. Additionally, different components of grapefruit (furanocoumarins, naringin/naringenin and bioflavonoids) are responsible for the inhibition of these pathways, causing mechanism-based inhibition of CYP3A4 and competition-based inhibition of P-gp and OATPs. Furthermore, due to their functions, inhibition of CYP3A4 and P-gp increases drug absorption, increasing plasma drug concentrations. Whereas, the reverse results from inhibition of OATPs. The pharmacokinetics of sertraline (anti-depressant), celiprolol (β-inhibitor), atorvastatin (statin), ethinylestradiol (estrogen) and oxycodone (opioid) were found to be altered by grapefruit. These drugs were investigated since they belong to the classes of drugs most commonly prescribed to people over the age 45, the demographic most likely to experience grapefruit-drug interactions. By better understanding grapefruit-sensitive pathways and how they alter drug pharmacokinetics, predictions can be made about other drugs that may interact with grapefruit and whether these pathways are sensitive to other foods.
Tomas, Emma-Music Performance Anxiety Survey Study (Dr. Laurel Trainor)
Music Performance Anxiety (MPA) is a mental disorder commonly affecting musicians, where symptoms of anxiety and a fear of making a mistake in performance settings may occur. MPA falls within the broader category of Social Anxiety Disorder (SAD) in the Diagnostic Statistical Manual-5, yet this categorization lacks consensus within the scientific community. This project aims to design, monitor, and implement data collection and analyze responses to an online survey study to explore the relationship between SAD and MPA, as well as to examine potentially related comorbid disorders and other cognitive factors. Upon eligibility and completion of a set of diagnostic questionnaires, professional musicians are categorized by whether they exhibit symptoms of MPA, SAD, both, or neither. The following set of 13 questionnaires collects information on state and trait cognitive factors like anxiety, neuroticism, stress, and depression. Participants then complete an Emotional Stroop task aimed to examine correlations between attentional bias and symptom category membership; acting as a measure of potential risk for developing MPA. Data collection and survey completion is occurring on an ongoing basis beyond the scope of this project. Predictions include highest group membership for symptoms of both MPA and SAD. In questionnaires analyzing comorbidity, it is predicted that MPA and SAD participants will score highest on negative affect emotional tests and exhibit the most anxiety. The current report outlines research methodology with overall predicted results and future steps.
Vamos, Lauren-The utility of traditional cultural art forms to communicate scientific advancements (Dr. Sarah Symons)
Failed modern public health campaigns and the phenomenon of climate change denial are two of the many manifestations of an ineffective contemporary science communication model. Clearly, a drastic change in the model must be implemented to better facilitate communication between scientists and the public. In this literature review, I examine instances of art communicating science to study emerging themes. I performed a basic keyword search in three journals: Science Communication, The International Journal of Science Education, and Leonardo, and included all instances of any traditional art form from any culture communicating science in the last 15 years. I found evidence that a culture’s traditional art forms can communicate science in a way that increases both public engagement with science, and public perception of science and scientists. Art provides a better communication model because it is culturally-relevant and personal, it is grounded in the traditional backgrounds of the viewer, and it provides information in a way that allows the individual to take ownership of the information by ‘filling in the gaps’ with imaginative narrative. Fundamentally, art can achieve these goals because new information can be easily assimilated to pre-existing mental models surrounding an individual’s artistic and cultural background as it appeals to the schemata of the viewers. Future collaboration between artists and scientists is necessary to continue to advance the field, in order to bridge the gap between scientists and the public.
Wong, Lindsey-Adapting an ATD shaft for cadaveric foot connection in vehicle collision simulation (Dr. Cheryl Quenneville)
Modern vehicle precautions, including seat belts and air bags, have shifted the concern for injury from the upper body to lower limbs. As cadaveric testing involves several limitations, typical collision testing uses Anthropomorphic Test Devices (ATDs, or ‘crash test dummies’) equipped with impact force sensors. However, this system neglects data collection from the foot. This demonstrates the need for accurate lower limb surrogates in safety testing. Ideally, tests to develop injury tolerance curves for the lower limb would include the standard injury assessment site (human foot) while minimizing the required cadaveric material. In the present work, the Hybrid III ATD was modified to accept a cadaveric foot secured in a boot. The project goal was to refine this method of attachment and develop an Achilles tendon tensioning device to simulate the 2kN force of active muscles on the foot during emergency braking. The Achilles tendon was sutured to a mesh grip, which was tensioned with a hand-winch to apply 2kN of force along the longitudinal axis of the tendon. Four other tendon groups were sutured to a 3D printed distal tibia/fibula portion on the ATD for support during simulated vehicle collision impact. Pilot impact testing confirmed the reliability of the tensioning device for maintaining constant force. The resulting configuration and testing protocol will be used to determine fracture patterns at varying ankle postures to inform the automotive industry on expected foot fractures in specific impact scenarios. Ultimately, this technique will help improve vehicle safety testing for preventing lower limb injuries.
Xiang, Emily-Developmental Priors on Musical Rhythm by Iterated Reproduction (Dr. Laurel Trainor)
Musical enculturation refers to the specialization of processing mechanisms in the brain as a result of exposure to prevalent structures in the musical system of a particular culture. Evidence for musical enculturation to rhythm and meter has recently been demonstrated even in infants. This can lead to the development of priors, whereby the human brain interprets perceived observations in the context of pre-existing internal beliefs about the environment. A 2017 study by Jacoby and McDermott examining priors on musical rhythm in adults showed that US listeners exhibited biases towards rhythms with simple integer ratios that are very prevalent in Western music, whereas adults from other culture show different biases. As an extension of this study, the present research used the same paradigm to examine rhythmic priors in Western children of 6 to 7 years of age, when they are thought to still be undergoing an extended period of experience-driven neural plasticity. The purpose of this study was to investigate potential rhythmic priors in Western children using a rhythmic iterated tapping task. It was hypothesized that 6- to 7-year-old Western participants would exhibit biases towards integer ratios common in Western music as a result of musical enculturation, though not to the same extent as Western adult listeners.
Yee, Ruby-Quantifying vulvar edema during radiation therapy (Dr. Kara Schnarr)
Vulvar cancer is a relatively uncommon disease (comprising ~5% of all gynecological cancers) with a unique set of challenges. The presence of numerous nearby organs at risk, such as bladder, rectum, and small bowel, necessitate treatment planning which minimizes toxicity to healthy tissues. Radiation therapy must therefore be highly conformal and individualized to each patient. However, vulvar edema during radiation treatment can cause swelling beyond the confines of the target volume, resulting in patients receiving inadequate doses.
This study seeks to quantify changes in vulvar volume over the course of radiation therapy. In addition, the direction of movement associated with these changes is addressed. The results can be used to guide further investigation in a currently under-studied area of research.
Cone beam CT images from one patient were taken on each day of treatment and compared with a CT image taken prior to treatment. The vulva was contoured on each cone beam image using Pinnacle3 software. The nature of the edema (magnitude and direction) was then characterized as a function of time through the analysis of the contour volumes. Volumes were observed to decrease approximately linearly at a rate of -1.041cm3/day, with day-to-day fluctuations as high as 33.834cm3. The results indicated that edema occurs primarily in the anterior/posterior direction.
The results of this study may eventually lead to the redefining of appropriate margins during radiation therapy planning for vulvar cancer. Ultimately, the findings presented here contribute to continued efforts in ensuring that patients receive the highest possible quality of treatment.
Zogheib, Ciara-Multivariate Evaluation of Projectile Point Data in the Museum of Ontario Archaeology Online Archive (Dr. Tristan Carter)
Digital scholarship and ensured accessibility of cultural information are increasingly becoming ethical imperatives for archaeologists. The Museum of Ontario Archaeology (MOA) supports these imperatives by maintaining an online, publicly accessible archive containing individually archived stone projectile points from the pre-contact occupation of Ontario. This digital archive is a potentially valuable research and heritage tool, but from an information science perspective, it leaves much to be desired. This project aims to test the internal consistency, completeness, and usability of information in the MOA online archive via a review of 500 projectile point entries, dated from 1979 to 2015. These entries are analyzed using exploratory multivariate statistics and multiple correspondence analysis (MCA) to identify trends and quantitatively evaluate the quality of projectile point data in the MOA online archive.
The results of these analyses reveal that archive vocabulary is non-standardized, and that information is inconsistent and often incomplete, with certain categories (ie. place, date) present and searchable in less than 34% of archive entries. MCA results show that artifacts archived in the same decade are significantly more similar to each other than to entries from other decades, suggesting that inconsistencies in information availability across the archive are due to data entry choices or errors rather than to any intrinsic qualities based on age/typology of the points themselves.
By identifying weaknesses in the archive and hypothesizing potential causes, this project makes recommendations for improvement of the MOA’s archival process with the hope of optimizing a valuable online resource for both researchers and stakeholder communities in Ontario.