Below is a list of abstracts by third-year students in the Integrated Science Program:
ORAL PRESENTATIONS – MARCH 29, 2017
BRYNLEY HANSON-WRIGHT – COGNITIVE MECHANISMS OF MINDFUL MEDITATION
Mindful meditation is a practice of growing interest in the Western world. As its popularity has expanded, there has been a surge of empirical investigations into its clinical benefits. Mindfulness originates from ancient Buddhist meditation and is now understood as the psychological process of purposefully bringing one’s complete attention nonjudgmentally to the internal and external experiences of the present moment. Mindfulness has been implicated in changes from cellular adaptations to the functioning of the mind as a whole. A multitude of cognitive studies indicate that mindfulness training increases cognitive function in memory, attention, executive control, task switching, signal discrimination, and stimulus detection. This paper seeks to evaluate the proposed underlying cognitive mechanisms leading to these measurable changes in ability. Discussed mechanisms include enhanced self regulation, increased motivation and task engagement, lowered arousal, improved attentional resource deployment, and decreased elaboration and judgment. There also exist fundamental incompatibilities between current mindfulness studies. The considerable variability in defining, measuring, and eliciting mindfulness is explored in this review. Discrepancies arise from considering mindfulness both a trait and a state, and from grouping of practices that develop concentration on a single object with practices that involve open monitoring of all sensations and thoughts. Furthermore, the duration of mindfulness training varies across studies from three-minute videos to three-month retreats, and scores on different mindfulness inventories have poor correlations within subjects. A better understanding of the underlying cognitive mechanism of mindfulness could facilitate improvements to mindfulness interventions in medicine, psychology, and education.
ALEX WILSON – AN ANALYTIC REVIEW OF ASYNCHRONOUS ONLINE LEARNING IN POST-SECONDARY LEARNING
Online learning is quickly increasing its presence in the post-secondary landscape, and with Ontario looking to introduce a fully transferable online first year it is becoming of increasing focus of study. Asynchronous online learning is one of the most popular methods for conducting a wholly online course. While online learning is of budding importance, much of the research surrounding it has yet to be integrated into course design and implementation. This literature review investigated how asynchronous, specifically online learning compared to other online learning, and generally to traditional learning approaches. This review was conducted through online databases, focusing on research in pedagogy and higher education. The majority of this literature was taken from 2012-2017. Many of these publications were either authored by higher education research groups, or by educators studying their own courses. This review examined the benefits on asynchronous online learning in distance education, compressive access to higher education, metacognition, experiential learning retention, and continued enrolment compared to both the traditional classroom and other methods of online learning. Although some trends can be ascertained, the limitations of research conducted in this field, notably lack of controls and confirmation bias, limit the conclusions that can be drawn. The areas where online learning falls short compared to traditional learning, namely experiential education, were further examined and solutions were theorized for future study.
MATT ANDERSON – BEYOND THE WORMLIKE CHAIN MODEL OF DNA
The physical properties and dynamics of DNA are crucial to understanding how important cellular processes such as DNA supercoiling, replication, and transcription work at a fundamental level. The development of the experimental techniques utilizing magnetic tweezers has allowed for experiments to probe some of these physical properties, thus providing data for which models can be tested against. The current model for DNA is known as the wormlike chain (WC) model and provides a proper description of the bending of the DNA. On the other hand, the most general model for a polymer is the Helical Wormlike Chain (HWC) model, which contains energy contributions from bending and twisting. It can be qualitatively imagined as a bendable, twistable, elastic rod, thus providing a more accurate model for DNA.
The goal of this project is to develop a discretized model for DNA based on HWC and use Monte-Carlo simulations to study the force-extension curve of a DNA under a tension force ranging from a few pico-Newtons (pN) through the overstretching transition around 65 pN and into the S-DNA regime. Specifically, I will consider two spatially linked chains subject to bending, torsion, and base pair stacking interactions while under an external torque and applied force. The force-extension curves will be generated from Monte-Carlo simulations on equilibrium states (and thus end-to-end distances of the polymer) for each applied force.
With this model, I expect to find a force-extension curve that reflects the cooperativity of the abrupt overstretching transition while not sacrificing the accuracy of the HWC pre-overstretching transition. If successful it would contribute to understanding of the dynamics of critical DNA processes.
DAVID MARTIN – PELVIC FLOOR STRENGTHENING REGIMENS AS TREATMENT FOR INCONTINENCE IN CANCER PATIENTS
Stress incontinence is common in men and women who have undergone physical treatment for urological or gynecological cancers. Although this symptom has no impact on survival, it can significantly affect a patient’s quality of life. In recent years, studies have explored the viability of pelvic floor exercise regimens as a treatment for stress incontinence. Furthermore, advances in mobile health technology present new opportunities for incorporating personal electronic devices in incontinence treatment regimens.
We will be conducting a comprehensive review of pelvic floor strengthening exercises in male and female cancer patients. Its main objective is to provide background and rationale for a new study on the use of mobile health devices in conjunction with pelvic floor exercises as a treatment for incontinence in males who have undergone pelvic radiotherapy. The review focuses on radiotherapy patients, but will also include studies of males who have undergone radical prostatectomy. As the body of literature is relatively small, the review will be narrative in format rather than systematic.
Research conducted thus far indicates that pelvic floor strengthening is an effective therapy for incontinence in male and female cancer patients. If further research supports this position, the review will be incorporated into a grant proposal for the mobile health technology study discussed above. Pelvic floor exercises may be an effective treatment for incontinence in cancer patient. Further research should explore the impact of mobile health devices of the treatment’s effectiveness.
ORAL PRESENTATIONS – APRIL 3, 2017
ANJALI NARAYANAN – EXPLORING THE MATHEMATICS OF FLUID DYNAMICS
Fluid mechanics has been of incredible interest to both physicists and mathematicians alike. The intricate properties of fluids can be difficult to describe using equations, however, in their simplest forms, fluids can be modelled using Euler equations and associated partial differential equations. This project aims to uncover the basics of fluid dynamics in a mathematical context, focusing on one-dimensional flow, shocks, and the application of fluid equations to traffic flow.
Investigating the basic concepts of fluid dynamics allows one to explore the connection between vector calculus, mathematical analysis, and physics. Conservation laws, fluid dynamics, and applications were modelled using simple partial differential equations derived from concepts of vector calculus and fluid mechanics and then solved via the method of characteristics to help analyze and model the formation and evolution of shock waves. These equations were then taken and numerically modelled as discrete functions in MATLAB.
This project takes physical phenomena common in fluid dynamics and attempts to display a model of them using their governing mathematics. Through this, the project reveals how rather simple mathematical laws can describe the motion and shock formation within different physical contexts – even those seen in daily life such as traffic. The modelling of these applications can help lead to further, more complex modelling of all types of fluids. Overall, this project aims to provide an introduction to fluid dynamics, with a focus on shock formation and description, in a thorough, yet simple mathematical context.
AIDAN BULLEN – EVOLUTIONARY EXPLANATIONS OF SAME-SEX ATTRACTIONS
Non-normative sexuality is one of the ultimate puzzles of evolutionary psychology. The reduction of or outright absence of sexual desire to the opposite sex would significantly lower, if not remove, an individual’s chances of reproducing successfully. This still unsolved puzzle has led to numerous theories being put forth regarding the evolutionary mechanism that has allowed this trait to survive in modern populations. Despite this, there does not exist a literature review that has sought to organize and evaluate the existing theory on the topic. This article will review the existing theories to assess the leading evolutionary explanations of non-normative sexuality in humans.
The articles were collected through the PsycInfo database using three search queries: homosexuality AND male AND evolution, homosexuality AND female AND evolution and sexual fluidity AND female AND evolution. The abstracts of all articles were reviewed to determine whether they were relevant to the topic. After the abstract review 33 articles were selected, of which 16 were original theories and 17 were evidence for these theories.
Through this review of the literature, the different theories will be assessed according to their predictions and evidence. The results of the review will aim to determine the leading evolutionary theories of non-normative sexuality. While this review will not offer a definitive evolutionary mechanism behind homosexuality, it will fill a hole that exists in the current literature by organizing and assessing the current theory.
JULIA PANTALEO – INVESTIGATING THE EFFECTIVENESS OF THE HONOURS CHEMICAL BIOLOGY AND INTEGRATED SCIENCE PROGRAMS AT MCMASTER UNIVERSITY IN PREPARATION FOR CHEMICAL BIOLOGY GRADUATE SCHOOL
There are large amounts of pedagogical research highlighting the benefits of inquiry-based learning (IBL) and problem-based learning (PBL) on student success in science and, as such, many institutions have started offering IBL and PBL undergraduate programs. Despite studies performed at the undergraduate level, no research has been done on the benefits to graduate school preparation. This study aims to address this gap by performing a pedagogical study involving students in IBL and PBL-based undergraduate programs, specifically the Integrated Science (iSci) and Chemical Biology (CB) programs at McMaster University. Online surveys were administered to students in both programs to gain information about student skill development and the parts of the programs responsible for this development. Interested students participated in a follow-up interview where more detail regarding skill development and thoughts about graduate school preparation were obtained. This information was compared with the skills cited by the literature as necessary for success in graduate school to assess the preparedness of students from both programs. It is expected that skill development between the programs will be similar as both contain components of IBL and PBL. It is suspected that CB students will have a deeper understanding of chemical biology concepts due to the larger number of required courses compared to iSci students. As graduate school places a large emphasis on research experience, it is likely that iSci students will be better prepared due to the abundance of research projects conducted throughout the program. Overall, the results of this study can be used to identify deficits in knowledge and skill development in undergraduate programs and suggest improvements to better prepare students for their futures in science.
VIVIAN MARTIN – PICEA MARIANA GROWTH PATTERNS IN ALBERTAN PEATLANDS FOLLOWING WILDFIRE
Western Boreal Plains Albertan peatlands are essential resources as they are massive carbon stores and have excellent water retention properties which sustain ecosystems throughout varying conditions. Forests in these regions experience wildfires following an approximately 120 year periodic cycle, after which the system must recover and the forest must regrow. In a changing climate, understanding the relationship between growth and climate is essential in ensuring the stability of the ecosystem. Growth patterns of picea mariana (black spruce) in the middle of small peatlands were measured based on tree ring cookies and cores to investigate this recovery in relation to the climate at the time. Precipitation data since 1959 from the Red Earth weather station, central to the 26 sites from which data was collected, was used to create three year precipitation departure graphs. Where data was missing, average values triangulated from three other nearby weather stations, Peace River, Manning and Slave Lake, were supplemented. Patterns of moisture deficit troughs match major recorded forest fires from the region, indicating these troughs significantly increase fire vulnerability. Information sets collected over the past six decades regarding black spruce tree growth and precipitation will be compared for patterns and similarities. Based on previous studies, it is expected that a time lag in system response will be seen. Understanding tree recovery, particularly black spruce due to their abundance, is especially relevant in a changing climate and will be helpful in ensuring the appropriate actions are taken to preserve these essential ecosystems.
JENNIFER HANUSCHAK – EFFECTS OF BIFIDOBACTERIUM LONGUM ON BRAIN CHEMISTRY AND BEHAVIOUR: INVESTIGATING THE UNDERLYING MECHANISMS
The intestinal microbiota is a highly diverse microbial population, consisting of almost 100 trillion microorganisms living in symbiosis with the host. The microbiota-gut-brain axis is the proposed model for bidirectional communication between the intestinal microbiota, the gastrointestinal tract, and the brain. Bottom-up effects along this axis highlight the importance of microbiota stability. Perturbations to the microbial community, which can result from functional gastrointestinal disorders among other causes, are implicated in psychiatric disorders, such as anxiety and depression. Probiotics are transient members of the microbiota that benefit host health. They influence the microbiota-gut-brain axis in a strain specific manner. Bifidobacterium longum is a probiotic strain that has been shown to alter brain chemistry and behaviour in both animals and humans. In particular, administration of this strain to both animals and humans has been shown to have anxiolytic effects, demonstrating its promise as a treatment for patients suffering from psychiatric disorders. This review describes possible underlying mechanisms for the effects of B. longum on brain chemistry and behaviour in order to assist in the identification of areas for future research. Neural, immunological, hormonal, and metabolic pathways for which B. longum can exert its effects are identified. A greater understanding of the underlying mechanisms of action of B. longum will help assess its role as a treatment and lead to a greater overall understanding of the microbiota-gut-brain axis.
BRIDGET MCGLYNN – THE RE-EMERGENCE OF EUTROPHICATION IN LAKE ERIE
Decades of dumping industrial, agricultural, and household wastes into the Great Lakes resulted in sever eutrophication and hypoxic conditions in Lake Erie by the 1960’s. The Great Lakes Water Quality Agreement, signed in 1972 by both the United States and Canada, was influential in limiting the phosphorous load and overall water quality of the lakes such that, by the 1990s, the magnitude and severity of algal blooms in Lake Erie had decreased. Harmful algal blooms re-emerged in the mid 2000s, and have since caused ecological, environmental, and health consequences. This increase in cyanobacteria blooms occurred despite successful efforts to decrease the total phosphorous load entering the lake since the 1970’s. Consequently, novel factors are responsible for this rise in cyanobacteria populations, and the identification of such factors is essential for proper mitigation efforts. A literature review of relevant ecological, environmental, and engineering sources sought to identify such factors. From an overview of primary research, review articles, and governmental reports, it appears this increase in cyanobacteria blooms in Lake Erie is a consequence of two primary factors: the increasing relative magnitude of dissolved reactive phosphorous and the changing nitrogen cycling from the presence of the invasive Dreissena polymorpha (zebra mussels). The increased ammonium concertation from zebra mussel excretions prevents nitrogen from limiting cyanobacteria growth, thereby challenging the long-held assumption that eutrophication is limited primarily by phosphorous. This report outlines the historic sources and mitigation efforts of traditional eutrophication of Lake Erie and investigates the cause of the most recent blooms.
VERONICA VAN DER VLIET – THE HUNGER AIMS: EFFECTIVELY COMBATING FOOD INSECURITY IN HAMILTON, CANADA
The purpose of this project is to identify the specific risk factors driving food insecurity in Hamilton, and the best methods to combat them. Food insecurity is an ever-growing problem in Canada, and currently there are few methods beyond food banks being used to mitigate this crisis. Research indicates that less than one-quarter of food insecure households make use of food banks and over 4 million people in Canada are living in households with some experience of food insecurity. To progress towards a food secure state, other policy and community options must be explored. This paper identifies chief risk factors for food insecurity by evaluating consensus in relevant literature. These factors were found to be income, family dynamic, race, citizenship, gender, living accommodations, and health. These are discussed together and in isolation, particularly in the context of the city of Hamilton, Ontario. Specific policy recommendations in response to each factor is outlined throughout the paper. These results are a precise indication of where work needs to begin if food security for the city of Hamilton is to be achieved.
JOANNA KRYNSKI – FREE ENERGIES OF CELLULAR RESPIRATORY METABOLISM AND RELATIONSHIP TO RADIATION BYSTANDER EFFECT
Photon emissions from cells have been observed and not fully understood thus far in low-dose radiation research; conversely, it is well known that cellular respiratory metabolism is governed by the physical and chemical laws of thermodynamics. Cells that are subject to ionizing radiation release a signal, chemical or electromagnetic in nature, known as the bystander effect, which can induce clonogenic defects in nearby non-irradiated cells. It is hypothesized that emission of photons from cells is correlated to the free energies required for the metabolic reactions to proceed. A literature review was conducted on current knowledge of cellular metabolism including the role of electron transfers. Based on classical thermodynamic equations, published experimental and theoretical data, the free energies of each step of the metabolic process will be estimated. Once these estimated energies have been compiled, spectral data from cells exemplifying the bystander effect will be analyzed. It is hypothesized that the ionizing radiation excites the electrons being transferred in the metabolic reactions, and that energy is discrete and closely described by the estimated free energies. The correlation between the free energies of metabolism and the photon signals released by irradiated cells would shed light on the developing field of low-dose radiation research and would support the idea that radiation affects the cell at the most minute level without a threshold dose.
ORAL PRESENTATIONS – APRIL 5, 2017
ARYAN POUR-BAHREINI – A STUDY OF NEGLECTED TROPICAL DISEASES IN THE CONTEXT OF GLOBAL HEALTH INITIATIVES
One of the most pressing concerns for global health is one that is rarely discussed. Neglected Tropical Diseases (NTDs) are a group of diseases which affect 1 in 7 people worldwide. In addition to devastating health effects, the diseases also cost tens of billions in lost economic productivity and have debilitating social effects. While providing a seemingly insurmountable challenge, global response to the fight against NTDs has proven to be an incredible demonstration of international cooperation.
In matters of global disease management, surveillance and treatment, there is an established connection between worlds of science, industry, and politics. While research, development, and scientific work comprise half the battle, it is then at the hands of politicians and activists to mobilise these efforts into the right hands. The research within this project serves to demonstrate that the fight against NTDs is an exemplary demonstration of effective international cooperation in matters of global health and as well as an outstanding demonstration of effective cooperation between workers in fields of science and politics.
Through an examination of existing literature and a comparison of analogous global health initiatives, this paper analyzes various facets of the NTDs initiative that have made it so effective. The fight against NTDs has shown a strong and continued response from dozens of nations across the world in addition to an unprecedented level of scientific cooperation. Scientific communities have displayed an extraordinary level of open source cooperation and as a result, millions of lives have been saved.
CHIMIRA ANDRES – MULTITEMPORAL MAPPING OF GLACIOLACUSTRINE SYSTEMS IN THE CORDILLERA BLANCA, PERU
The Cordillera Blanca glaciers represent the largest freshwater “reservoir” in the Peruvian Andes stored in glacial lake sources. These high mountain glaciers are extremely sensitive to temporal changes in climate with their differential advances and consequent retreats occurring at rapid rates. Enhanced glacial melt is allowing the creation of numerous proglacial lakes, many of which are impounded by unstable sediment accumulations that are at risk of failure. The threat of glacial lake outburst floods (GLOFs) is extremely serious for communities lying within the Santa River basin; they are also threatened by diminishing water supply as the glaciers recede and meltwater no longer nourishes glacial lakes. Relatively little is known about the number of lakes in the region, their impounding mechanisms, or their long-term sustainability. This project documents the inventory, size and location of glacial lakes in a portion of the Cordillera Blanca using multitemporal satellite image analysis, specifically via a supervised image classification approach, within a GIS framework. This gives rise to a classification system for the identified lakes, recognizing their size, damming systems, and potential longevity. This information is important, not only to evaluate the risk of GLOFs but also the lakes’ potential to sustain water supply for the region. The results of this work have a significant application to the understanding of tropical glaciolacustrine systems along the Cordillera Blanca and to the management of freshwater resources in the Ancash area of Peru.
DAVID BOWMAN – GLACIAL LAKE FLOODING RISK PARAMETERS IN THE CORDILLERA BLANCA, PERU
Recent temperature increases have had major consequences for glaciers worldwide, pressuring a near-global retreat. Increased retreat poses the threat of glacial lake outburst floods (GLOFs), wherein glacier-fed meltwater lakes swell, breach their dams and eject debris flows capable of inflicting significant damage to infrastructure and human life. Given the sensitivity of the tropical latitudes to climatic fluctuations related to temperature, humidity, and precipitation, tropical glaciers are highly susceptible to GLOF-type events. Peru’s Cordillera Blanca has the densest population of tropical glaciers worldwide, and regional settlements and cities have contended with catastrophic GLOFs since the 1700s. Due to the rising severity and frequency of GLOFs over the past several decades, mitigation strategies have been implemented to reduce the impact of GLOFs in the Cordillera Blanca, but Peru’s financial constraints require that resources be directed to the most immediate hazards. This literature review will explore case studies of GLOF events both in the Cordillera Blanca and in other parts of the world, and will identify environmental parameters shown to increase the likelihood of a GLOF. Using these parameters, a framework to determine the likelihood of GLOF occurrence will be outlined. An increased understanding of predisposing risk factors for GLOF occurrence helps to promote more accurate GLOF prediction, and provides more information for efficient resource allocation when employing mitigation and preventative measures at potential hazard zones.
ROSS EDWARDS – MODELLING EXPLORATIONS FOR A SIMPLE PLANKTONIC ECOSYSTEM
Phytoplankton plays an essential role within many types of marine ecosystems globally, constantly regulating the flow of energy and nutrients. Its abundance and interactions make it an ideal bioindicator for measuring conservation efforts that involve water basins. However, the complexity of interactions within planktonic food webs make it extremely difficult to model. Simplified designer ecosystems overcome this problem by providing a controlled environment to analyze the behaviour of phytoplankton. Several deterministic models of a system consisting of nutrients, phytoplankton, and zooplankton were calibrated using data from a designer ecosystem in the lab of Dr. Jurek Kolasa. This designer ecosystem separates different ecological players within the food web into several tanks, which can be monitored. Literature research was used to make calculated assumptions about certain relationships in the model. The models also provide a comparative analysis of several modelling methodologies with historical significance. Specifically, Lotka-Volterra predator-prey relationships and various NPZ models (nitrogen-phytoplankton-zooplankton) from 1930-present were investigated. The models were created using a free-access software called Netlogo as well as Matlab. Results from the simulations of the models support previous relationships found within planktonic ecosystems. Specifically, there was a noticeable dependence on nutrient influx for algae population growth in the designer ecosystem, and a predator-prey relationship between zooplankton and phytoplankton. However, the low light conditions of the designer ecosystem, from which the model was calibrated, limited the accuracy of the results. Future modelling explorations of the designer ecosystem should incorporate higher light conditions and consider more players in the grazer food web.
AURORA BASINSKI-FERRIS – ANALYZING WAVELET TRANSFORMS ON AN ADAPTIVE GRID USING BURGERS’ EQUATION
Partial differential equations (PDEs) are common in simulations of physical phenomena; for example, turbulence can be modelled using the Navier-Stokes equations while magnetic fields are described by Maxwell’s equations. Unfortunately, nonlinear PDEs tend to lack analytic solutions, and numerical analysis must be performed. Efficient numerical solutions of PDEs often utilize an adaptive method because the required resolution over the solution space varies depending on the gradient of the solution function. To avoid a computationally costly uniform high resolution, wavelet transforms are applied on a grid adaptive in both time and space. This project develops MATLAB code to solve Burgers’ equation in one dimension over time, and subsequently implements adaptive grid wavelet transforms on the solution (spatial) functions. This PDE is a good candidate for the method because its solution steepens over time as a shock wave, and the required resolutions vary with the significant gradient changes. Initially, code will be constructed to solve Burgers’ equation by discretizing spatial derivatives using finite differences. The resultant time-dependent ODEs will be solved using Runge Kutta while considering both CFL and viscous stability. Utilizing multiresolution analysis for wavelet transforms, the resolution changes will be examined; then, acting on the solution at a single time step, wavelet transforms will be implemented upon an identified adaptive grid. This model sets up a framework which can be developed to fully solve PDEs using the adaptive wavelet method; if extended to higher dimensions, this could help make simulations of complex physical systems – such as climate modelling – more efficient.
MICHAEL CHONG – EXPLORING THE LORENZ STRANGE ATTRACTOR TO ENCODE AND DECODE SECRET MESSAGES
Systems of ordinary differential equations describe the change in systems over time, and are indispensable tools in modelling dynamical systems in nature. If solutions to a system are aperiodic and sensitive to initial conditions, then we describe them as chaotic. The first part of this project uses both analytical and numerical tools to understand properties of the chaotic Lorenz system. In particular, we use the Lyapunov exponent to quantify the exponential divergence of nearby trajectories, and we use a Lyapunov function and Lorenz map to discuss the limit sets of the system. Solutions for various parameter choices for the system and initial conditions are numerically integrated in MATLAB.
The second part concerns the application of chaos to private communications. Despite sensitivity to initial conditions, two chaotic systems can be made to synchronize via a continuous ‘drive signal’ from a transmitter system to a receiver system, consisting of information on the dynamics of the transmitter system. This approach has been applied to sending and receiving secure messages between Lorenz-based chaotic circuits by adding a useful message component to the drive signal, which is masked by the chaotic noise and then recovered at the receiver circuit by “subtracting” the chaotic dynamics. While anecdotally robust, the original signal is always recovered with some degree of error due to perturbation of the drive signal. In this project, we prepare a numerical simulation of this setup in MATLAB, and investigate the robustness of this process by testing signals of varying magnitude and frequency.
MATTHEW NUGENT – YMGGAO4: THE CRYSTAL THAT NEVER RESTS
YbMgGaO4 has a rhombohedral crystal structure where the effective spin-1/2 Ytterbium moments are arranged in a stacked triangular geometry with antiferromagnetic interactions. The triangular motif provides a source of geometrical frustration, making it a strong candidate for quantum spin liquid (QSL) behaviour. YbMgGaO4 and many other antiferromagnetic crystals are known as QSLs because their individual atoms become magnetically frustrated by their inability to settle into one minimal energy ground state. From this, quantum theory suggests that even near absolute zero where materials enter their lowest energy state, no semi-permanent ordering of spins, known as spin freezing, occurs in YbMgGaO4. This “fluid” state of spins even at low temperatures is what gives QSL its name. A single crystal of YbMgGaO4 was synthesized using the Optical Float Zone Image Furnace and prepared ceramic rods made from 99.99% purity Yb2O3, MgO, and Ga2O3 powders in hopes of verifying it as a QSL. To determine this, the synthesized crystal was oriented with the flat rhombohedral lattice facing a known direction. This was done using the Laue x-ray diffraction machine, which diffracts x-rays off the crystal to give an idea of its present orientation. Following this, magnetic susceptibility tests were performed using a magnetometer, which measured the aligned crystal through the Superconducting Quantum Interference Device, giving data on the magnetization of a crystal as it cools down to 0.5K. These results are analyzed to experimentally determine how strong of a candidate YbMgGaO4 is as a quantum spin liquid.
LAURA GREEN – REVIEW: THE INFLUENCE OF CLIMBING FIBRES ON CEREBELLAR PURKINJE CELLS
The cerebellum is a region of the brain responsible for refining motor control. An important circuit leads from the motor cortex of the brain, responsible for overall motor control, to the cerebellum in a path which includes climbing fibres that synapse onto Purkinje cells. The Purkinje cells then output back to the motor cortex. Several scientists have proposed theories by which the cerebellum might refine motor control. While there are variations, overall, these theories present the synapse between climbing fibres and Purkinje cells as a key processing unit, due to plasticity at the synapse as well as consequences in signal output (Marr, 1969; Linás, 2011). This review will focus on the changes in action potential output of Purkinje cells as a result of climbing fibre input. In particular, climbing fibre input results in complex spikes in the Purkinje cell, which function to cause a delay in the intrinsic simple spike rate. Ultimately, this may decrease the inhibitory output of Purkinje cells onto the cerebellar nuclei, effectively increasing the excitatory output of the cerebellar nuclei to the motor cortex overall. Modulation of this circuit may occur due to variation in the location of climbing fibre output onto the dendrites of Purkinje cells, since synapses onto proximal dendrites branches are likely to degrade less than synapses onto distal dendrite branches. Overall, study of the cerebellum may lead to a better understanding of motor control and development.
Linás, R.R., 2011. Cerebellar motor learning versus cerebellar motor timing: the climbing fibre story. Journal of Physiology, 589(14), 3423-3423.
Marr, D., 1969. A theory of cerebellar cortex. Journal of Physiology 202, 437-470.
DALTON BUDHRAM – SYSTEMATIC REVIEW AND META-ANALYSIS OF THE ASSOCIATION BETWEEN THE OBESITY PREDISPOSING FTO RS9939609 POLYMORPHISM, SUICIDE IDEATION, ATTEMPTED AND COMPLETED SUICIDE IN A LARGE-SCALE MULTIETHNIC POPULATION.
An inverse association between obesity predisposing FTO rs9939609 A allele and completed suicide has been recently suggested in a small case control study from Poland (Chojnicka et al., 2014). The aim of the present study is to investigate the association of FTO rs9939609 polymorphism with suicide ideation, attempted and completed suicide using a large-scale meta-analytic approach in multiethnic populations.
This process involves a systematic review of the literature in Medline, Embase, Web of Science, and PsychInfo and the NIH dbGAP consortium and Genome-wide association study (GWAS) catalog. This will be complemented by data extraction from pre-existing GWAS or custom-arrays in consortia and single studies, and de novo genotyping of FTO in a local suicide case control study. We will employ recently developed global meta-analytic random-effects methods to calculate summary odds ratios (OR) and 95% confidence intervals (CIs) or beta estimates and standard errors (SE) for suicide status and suicide ideation score analyses, respectively.
We have extracted genetic and clinical information for about 20,000 participants so far. We expect to double this number once the study is completed.
Overall, this study will help identify the shared genetic bases for obesity and suicide predispositions and will contribute to innovative prevention strategies for these disorders.
CASSANDRA MASSCHELEIN – SYNTHESIS OF A PILLARARENE DERIVATIVE TO CREATE A CHEMICAL SENSOR
From disease diagnostics to roadside measurement of impairment, there is a need for portable, affordable, and robust chemical sensors. The semi-conducting nature of single-walled carbon nanotubes (SWNTs) has recently gained much attention for applications in sensors. Any signal generated from the chemical sensor can be recorded between two gold electrodes. The use of “click chemistry” allows us to produce receptor-functionalized SWNTs that can be made selective. This is achieved through strain-promoted alkyne-azide cycloaddition (SPAAC) of a pillararene conjugate. Conjugated polymers interact strongly with SWNTs to readily install chemiresistive sensors that respond to binding events with electron deficient guest molecules such as 1,6-dicyanohexane via host-guest chemistry with the pillararene. The pillararene is synthesized through a condensation reaction of 1,4-diethoxybenzene with paraformaldehyde, catalyzed by the Lewis acid boron trifluoride diethyl etherate. This is followed by removal of a single ethyl group using boron tribromide, liberating a hydroxyl-functionalized pillararene. This structure is then alkylated with 1,6-dibromohexane, and the remaining terminal bromide is substituted with sodium azide. This azide containing pillararene conjugate will then be introduced to a dibenzocyclooctyne (DIBO) containing polyinime polymer in order to harness the reactive cyclooctyne functionality. In addition, this polymer undergoes efficient assembly onto the surface of SWNTs. Together the reactants will undergo strain-promoted alkyne-azide cycloaddition (SPAAC). If the binding affinity of the host-guest chemistry is not degraded by structural modifications to the pillararene, proof-of-concept studies will be undertaken to show that interactions of SWNT-bound pillararenes with 1,6-dicyanohexane will lead to changes in thin-film conductivity of this material.
JONATHAN PANUELOS – CENTRAL UPWIND SCHEMES IN SMOOTHED PARTICLE HYDRODYNAMICS
Smoothed particle hydrodynamics (SPH) is a numerical method for solving Euler’s fluid equations. Originally developed for simulating gases in astrophysics, it has found uses in other fields including fluid flows and rigid body physics. SPH defines physical properties – density, velocity, and pressure – at points that follow the fluid field. These physical properties are used to interpolate values for the entire space. This interpolation, however, is inexact and leads to numerical errors in the calculation of momentum and energy fluxes between the particles. Methods for improving this error based off literature was assessed, and planned to be implemented into the SPH code, Gasoline.
A common, accurate class of methods for calculating fluxes are Riemann solvers. Due to their computational expense, however, they render simulations prohibitively slow in some cases – a faster, and possibly sufficiently accurate, alternative is the Kurganov-Tadmor (KT) central scheme. The KT scheme was initially used for grid simulations, thus making the upcoming implementation novel among SPH codes. It has been implemented into the hydrodynamics code, GIZMO, which currently uses a Riemann solver; and its viability will be analyzed via the use of standard test cases, where the KT scheme will be compared against that of a Riemann solver. Initial results are promising, but changes will be made due to the differences between grid codes and SPH. The implementation of the Kurganov-Tadmor central scheme into SPH is expected to yield improved results – accuracy close to exact Riemann solvers at significantly faster speeds.
VARSHA JAYASANKAR – IMPACT OF SCHOOL SCIENCE FAIR PARTICIPATION ON RESEARCH AND INQUIRY SKILLS OF UNDERGRADUATE STUDENTS
Since the inception of competitions at the regional and Canada-wide level in the early 1960s, science fairs have become a common extra and co-curricular activity in Canada. Completion of science fair projects emphasizes the use of the scientific method to investigate a topic of choice, study an area of interest, or develop a novel innovation. This process allows students to utilize many research and inquiry skills. University education is now shifting towards project-based learning, as courses commonly include projects that utilize research and inquiry skills. Additionally, many students embark on independent research projects and theses during their final years of their undergraduate education, where the scientific or similar method, as well as research and inquiry skills, are paramount. The purpose of this study is to determine whether science fair participation in middle and/or high school gives students an advantage during their undergraduate education. Undergraduate students who completed their secondary education in Canada will be surveyed on when they perceived they acquired a set of research and inquiry skills, as well as their confidence in these skills when starting their undergraduate studies. The list of skills was developed using a combination of two systems: the Advanced Placement Capstone™ program, a two-year high school research program and the Test of Scientific Literacy Skills, a measure of undergraduate inquiry proficiency. Comparisons, such as across various levels of science fair (school, regional, national/international) and participation in research-for-credit programs, will be made to determine whether early exposure in the science fair system provides a benefit for university and/or later scientific activities
POSTER PRESENTATIONS – MARCH 30, 2017
ADAM MARR – APPLICATIONS OF THE PELTIER EFFECT IN THE FIELD OF MOLECULAR ELECTRONICS
Molecular diodes are an emerging area of research in which individual molecules can replace conventional materials used to transmit current in a single direction. Given the small nature of these devices, molecules diodes have the potential to revolutionize the computing industry by replacing silicon chips. In particles, the proposed setup consists of a single molecule situated between two leads. Over time, one of the lead’s Fermi levels can be lowered in a series of fixed iterations, producing a voltage and corresponding generated current. An ongoing application of this research involves the Peltier effect, a phenomenon in which flowing electrons can deposit heat on reservoirs where the leads are situated. If electrons move from an n-semiconductor towards a p-semiconductor, heat is removed from a “cold reservoir” (Peltier cooling) and deposited at a “heat sink” (Peltier heating). This application is modeled using a three-lead system as an extension of an existing Python program. In the first half of the setup, heat from a cold reservoir is transmitted to a hot surface as an electron travels through the molecule’s lowest unoccupied molecular orbital (LUMO). To complete the circuit and prevent accumulation of charge, the electron flows back towards the cold reservoir from the lead at the hot reservoir through the highest occupied molecular orbital (HOMO). Ongoing research suggest that more heat is transferred to the hot reservoir than is returned to the cold reservoir, effectively allowing the system to act as a refrigerant. This idea confirms the myriad of future applications for molecular diodes.
DHANYASRI MADDIBOINA – SEX-BASED DIFFERENCES IN THE EXPRESSION OF SEVERAL ANTIMICROBIAL PEPTIDES AND IMMUNOMODULATING CYTOKINES IN YOUNG MURINE LUNG TISSUE
Epidemiological and experimental evidence indicate there are sex differences present in the incidence and severity of most lung infections. The innate immune response to infections is often more robust in females, evident by the lower susceptibility to the development of infections and sepsis. While the precise mechanisms of action remain to be determined, it is apparent that sex steroid hormones can directly affect the function and expression of key innate immune cells involved with the production of inflammatory mediators. During respiratory infection, levels of cytokines such as IL17 and IL22 increase and stimulate lung epithelial cells to produce antimicrobial peptides. AMPs may kill bacteria directly but also increase leukocyte recruitment, which decreases bacterial load. Here, we compare[d] the expression of innate antimicrobial peptides CRAMP, β-defensin 1, 2, and 3 in the lungs of male and female mice. In addition, we have quantitated the levels of IL-22, IL-17, and their receptors IL-22R and IL-17R, because these have been shown to regulate AMP production. RNA was isolated from young female and male specific-pathogen-free (SPF) mice. Primers were optimized using semi-quantitative PCR and differences in expression were measured using real-time qPCR. The housekeeping genes used to normalize gene expression in qPCR were GAPDH and β-actin. We will elucidate whether the AMP and cytokine expression levels show any sex-based differences.
ORIANA KOSHYK – DNA ANALYSIS IN FORENSIC INVESTIGATION: THE PAST, PRESENT, AND FUTURE
What is DNA? What can it reveal about a person? How is it relevant to forensic investigation? These questions can be readily addressed by modern scientists, but remained largely unanswered until the 1980s. DNA (deoxyribonucleic acid) is the basic genetic building block of human life, dictating our appearance, development, behaviour, and reproduction. Since the discovery of its double-helical structure in the 1950s, DNA has become one of the most critical tools in forensic science, having the ability to exonerate the innocent, convict the guilty, and re-open cold cases previously believed to be unsolvable. With the advent of DNA analysis came a more direct route to discovering the missing puzzle pieces of a crime.
This report analyzes the historical background of DNA testing, how it was first introduced into the legal system, as well as how this technique is still evolving to solve criminal cases more efficiently. Information was collected from published articles regarding the history, procedures, and legal applications of DNA profiling. In addition, interviews were conducted with criminal attorneys familiar with DNA in the context of forensic investigation. The aim of this report is to highlight the role that DNA serves as the single most important evidentiary source for the resolution of criminal cases worldwide. It will further establish the significance of DNA profiling in criminal law, and how continued research into more accurate analytical techniques will always be of great benefit to the safety of societies.
Budowle, B. and van Daal, A., 2009. Extracting evidence from forensic DNA analyses: future molecular biology directions. BioTechniques, 46, pp.339-350.
Giannelli, P., 1997. The abuse of scientific evidence in criminal cases: The need for independent crime laboratories. Virginia Journal of Social Policy and the Law, 439, pp.122-139.
Jobling, M. and Gill, P., 2004. Encoded evidence: DNA in forensic analysis. Nature Reviews Genetics, 5, pp.739-751.
Liu, P., Yeung, S., Crenshaw, K., Crouse, C., Scherer, J. et al., 2008. Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer. Forensic Science International: Genetics, 2(4), pp.301-309.
Lynch, M., Cole, S.A., McNally, R. and Jordan, K., 2008. Truth Machine: The Contentious History of DNA Fingerprinting. Chicago: The University of Chicago.
Saks, M. and Koehler, J., 2005. The coming paradigm shift in forensic identification science. Science, 309(5736), pp.892-895.
Wilson, M., DiZinno, J., Polanskey, D., Replogle, J. and Budowle, B., 1995. Validation of mitochondrial DNA sequencing for forensic casework analysis. International Journal of Legal Medicine, 108(2), pp.68-74.
CONNOR NELSON – THE POST-SECONDARY TRANSITION: IS HIGH SCHOOL PREPARING STUDENTS FOR UNIVERSITY EXAMS?
One of the most integral parts of the modern undergraduate experience is writing exams. Studying for exams requires well developed study skills and the use various cognitive skill areas such as organisation, knowledge acquisition, memory, and utilisation. It is often assumed that students have developed these skills by the time they are faced with their first university level examination, despite varied experiences with high school exams. The result is a disconnect between the expectations of universities and of students with regards to the skills that students have developed by the time they reach first year. This study aims to analyze this disconnect, by investigating the preparedness level of students entering the Integrated Science program with respect to writing their first exams. Students in all years of the program were given an in-class survey analyzing aspects of their high school experience such as time spent studying, strategies used, and changes made during different parts of their academic career. One-on-one interviews were also conducted to gain insight into more specific factors that affect study skill development in high school. This data was both statistically and qualitatively analyzed to uncover common themes among positive and negative first year exam writing experiences. The results of this analysis have the potential to shift the way high schools prepare student for university exams, as well as the expectations of the Integrated Science program for its incoming students.
MARY KATHRYN BOHN – INVESTIGATING THE EFFECT OF SEX HORMONES ON PANCREATIC Β CELL FUNCTION IN ATHEROSCLEROTIC MICE
As of 2015, 8.3% of the global population is estimated to be living with diabetes. A large body of epidemiological and pathological data has shown that diabetes is an independent risk factor for cardiovascular disease (CVD) in both men and women. Specifically, diabetic patients are found to have a twofold to fourfold increased risk of CVD. Studying the mechanisms that predispose diabetic patients to accelerated atherosclerosis has proven to be difficult due to the interdependency of many factors such as abnormal amounts of lipids in the blood, hypertension, obesity, and relative insulin and glucose concentrations. The Werstuck lab has recently established a novel atherosclerosis-prone hyperglycemic mouse strain with a C57BL/J6 genetic background, namely the ApoE-/-:Ins2+/Akita model. In this model, testosterone was shown to have an atheroprotective or proatherogenic effect depending on the glycemic status of the mouse. While these results suggest that sex hormones have noticeable effects on pancreatic β cell function and on vasculature, further investigation is required to uncover the mechanism behind these unexpected results. Through the use of immunofluorescence and immunohistochemistry, we were able to quantify endoplasmic reticulum stress in ApoE-/-:Ins2+/Akita male mice to further characterize the effect of sex hormones on pancreatic β cell function and vasculature. Therefore, it takes first step towards developing sex-specific targeted therapies for chronic diseases.
SUNNY TIAN – EXAMINING BIASES IN INFORMAL SCIENCE EDUCATION INSTITUTIONS
Informal science education (ISE) is defined as often voluntary, self-directed, and provides science education opportunities for those not enrolled in an academic institution. ISE establishments such as science centers and museums are an important way of improving public science literacy and informing the public on current, widely debated issues such as sustainability and climate change. However, it cannot be assumed that experiences in ISE spaces provide the same experience for everyone. For my independent project, I will examine if ISE institutions inadvertently create barriers or spaces that exclude certain people, such as visible minorities, and create a “not for us” mentality.
To do this, I will compile a literature review looking within topics of science communication, science education, and linguistic psychology, as well as literature from other relevant fields such as gender and cultural studies. Next, I will visit the ROM, a local ISE institution, to further my experience and research and gain a first-person perspective. Then, I will create a rubric-style criterion to evaluate ISE centers for their bias and accessibility, and lastly use this data to compile a list of suggestions on where I believe improvements could be made in this aspect of science communication. Ultimately, through this project I hope to gain a more complex and holistic understanding of how these biases shape communication and how we interact with information.
JASON SCHNEIDER – MATHEMATICAL MODELLING OF GLACIAL RECESSION IN THE CORDILLERA BLANCA, PERU
It is well-established that, under the effects of climate change, the glaciers in the Cordillera Blanca in Peru are receding. This recession is of concern to the people living in the mountains since the glaciers act as their primary source of water during the dry season. Mathematical models have been employed in the past to establish plausible future glacial conditions in order to study things like subsurface hydrology. However, the methodology used has generally been simplistic since the mathematical models were not the main focus of the aforementioned research. Therefore, past models did not take into account many of the unique properties of tropical glaciers. For this study, an energy-balance model will be constructed using new input parameters like humidity and precipitation to attempt to quantify how ice thickness will change throughout the glacier on Copap mountain in different climate conditions. From there, predicted future climate conditions based upon climate models used in the fifth IPCC report will be input into the glacial recession model to see how the glacier should recede in the future. It is predicted that the glaciers will continue to recede, however the rate and extent of which is not known. To conclude, this paper will attempt to predict the recession of the Copap glacier in the Cordillera Blanca in Peru via mathematical modelling. By doing this, the feasibility of energy-balance models can potentially be established for a tropical glacial environment, and the rate of recession of the Copap glacier may be able to be determined.
TYLER OR – FABRICATION OF CELLULOSE-BASED AEROGELS WITH TUNABLE THICKNESS, SHAPE, AND MORPHOLOGY FOR DYE-SENSITIZED SOLAR CELL
Aerogels are highly porous and ultralight materials that have a wide range of applications, such as high surface area electrodes, catalysts, and semi-solid electrolytes. An ongoing challenge is to produce patterned thin (i.e., in the micron range) aerogels with controlled thickness and patterns. Aerogels retaining high porosity and flexibility after deposition are particularly promising for incorporation into electronic devices. While the fabrication of thin silica-based aerogels has been extensively explored using methods such as dip coating, spin, spray, and surface tension coating with sol precursors, none of these provide precise control over both thickness and shape. In this work, a simple and versatile procedure for controlling the thickness and shape of aerogels based on cellulose nanocrystals (CNCs) and poly(oligoethylene glycol methacrylate) (POEGMA) was developed. CNCs are rigid rod-shaped nanoparticles, extracted from natural cellulose, and in this case they have been chemically modified to crosslink with the flexible POEGMA polymer. To prepare the thin film aerogels, first a Parylene or tape mold with the desired aerogel shape and thickness (7 – 85 µm) was deposited on a substrate. Next, a mixture of CNCs and POEGMA (both at 1 wt.%) was drop casted into the mold and pressure was applied to the crosslinked CNC-POEGMA gel. The gel was frozen and lyophilized, which creates macropores due to ice crystal growth, and then the mold was removed from the substrate, leaving behind a thin aerogel. The flexible, porous and high surface area CNC-POEGMA aerogels will eventually be used as ‘quasi-solid electrolytes’ in dye-sensitized solar cells (DSSCs), with the goal of improving their long-term stability and simplifying their fabrication. The high porosity of the aerogel is expected to facilitate electron transfer within the device and we have shown that the absorbent and inert nature of the aerogel allows it to hold common DSCC electrolyte solutions. The performance of these aerogel-containing DSSCs will be tested and reported.
JASLEEN PAHWA – ESKAPE PATHOGENS: A NEW EMERGENCE OF MULTI-DRUG RESISTANT BACTERIA
The issue of antimicrobial resistance has become exponentially alarming as new emerging mutant strains of pathogens encode for resistance against specific antibiotic treatments. This not only jeopardizes the health of the infected individual, but also meddles with the health of surrounding individuals due to the potential of hospital- and community-acquired infections formed by these pathogens. Some of the most malignant multi-drug resistant pathogens fall within the acronym of ESKAPE, which includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. By acting as a catalyst to the post-antibiotic era, these six pathogens have become a threat to human health with their continued increase of resistance. Pharmaceutical companies have acknowledged the potential harm of these pathogens, and have responded by decreasing their production of novel drugs due to economical standings. The significance of the threat that these pathogens pose to society is undermined due to the lack of awareness and education promoted to society.
A literature review will be conducted giving an in-depth insight to each of these pathogens, along with their importance, clinical information, resistance mechanisms, antibiotic therapy, and treatments to prevent further resistance. Information will also be collected upon the emergence of novel bactericidal drugs targeted towards eliminating these pathogens; insight will be given into the biochemical pathways involved in the mechanism of action of these drugs. This literature review is aimed to raise awareness of antimicrobial resistance within the scientific community, as education is the first step required to diverge from the post-antibiotic era.
IAN FARE – SEMI-ANALYTIC FITTING FORMULAE FOR STELLAR EVOLUTION OF HELIUM-RICH STARS
Recent observations by the Hubble Space Telescope have shown that globular clusters are not single, simple populations, but contain multiple distinct populations with differing ages and compositions. The newly discovered, smaller populations are likely rich in helium, which impacts their evolution, and the dynamics of the cluster as a whole. Single-star evolution (SSE) formulae used in globular cluster simulations give stellar properties as functions of their age, mass, and metallicity, but not of their helium abundance. We are extending the formulae to evolve helium-rich stars, by fitting new formulae to a new stellar evolution model that does account for abnormal helium abundances. We have found that while these properties are functions of mass, the ratio of their high-helium values to their normal-helium values is often not. On that basis, we are working to fit adjustment formulae for the ratios of high-helium to normal-helium stellar properties as functions of only helium abundance. Thus, we can extend SSE formulae to high-helium stars by first evolving them as though they were normal-helium stars. Then, we can compute the true value of their properties using our new formulae, accounting for their helium abundance. We present formulae for main-sequence lifetime, luminosity, and temperature of helium-rich stars, and discuss their implications in the understanding of high-helium evolution. We have found that helium-rich stars act in many ways like higher-mass normal-helium stars. We will incorporate them into N-body globular cluster simulations, and see how they impact cluster dynamics.
RAISA AHMED – THE EFFECTS OF TEMPERATURE ON THE LOSS OF HETEROZYGOSITY IN AD HYBRIDS OF CRYPTOCOCCUS NEOFORMANS
Cryptococcus neoformans (C. neoformans) is a prominent human fungal pathogen classified as a basidomycete. The pathogen is infectious in immunocompromised individuals, causing moderate to severe infections such as meningitis. A recent rise in immunocompromised individuals has shown an increase in fungal diseases; therefore it is important to understand factors affecting virulence of fungal pathogens. C. neoformans has been identified as an ideal organism for the study of fungal pathogens. The objective of this project was to explore the effects of temperature on the heterozygosity and therefore virulence of AD hybrids of Cryptococcus neoformans. The most heterozygous progeny of the fungal pathogen (JK18) was selected from a cross between CDC15 and JEC20. The single colony was streaked on YEPD agar plates in 10 equal lines. The colonies were incubated at room temperature (23 °C), body temperature (37°C) and 42°C. The lines were maintained using a pick-streak-incubation technique conducted every 72 hours. After 45 days, the data was analyzed through DNA phenotyping, restriction length polymorphism and PCR to determine the changes in heterozygosity present at different temperatures. It was found that an increase in temperature resulted in loss of heterozygosity in the AD hybrid of C. neoformans. Less growth and a decrease in heterozygous genes was observed in colonies incubated at higher temperatures. An increased understanding of fungal pathogens and conditions affecting virulence will aid in the treatment and preventing of associated diseases.
ANGELA GUPTA – SIGNALLING THROUGH PI3K DEPENDENT PATHWAYS IN A MOUSE MODEL OF AUTISM
Half of all autism cases are described as idiopathic: cases with no genetic cause, thus resulting from environmental and epigenetic factors. Aberrant connectivity is an underlying cause of autism, as spine abnormalities are consistently seen. Pathways downstream of PI3K, including Eps8/Rac and mTOR/eIF4E, play a key role in the regulation of spine dynamics, spine protein translation and stability. Eps8 is an actin-capping protein that regulates dendritic spine density and synaptic plasticity through actin-based remodelling. Eps8 knockout mice have immature spines and exhibit autistic-like behaviour. Overexpression of the cap binding protein eIF4E, which regulates translation within the synapse also causes autism-like phenotypes in mice. Here, valproic acid (VPA), a histone deacetylase inhibitor, was used as an environmental agent in a mouse model for the study of idiopathic autism. The purpose of this project is to analyze whether signalling pathways downstream of PI3K are disrupted in VPA-exposed mice compared to controls. Western blotting in post-mortem parietal and temporal cortex tissue from 18 VPA-exposed mice and 22 saline-treated mice were used to assay Eps8, eIF4E, phosphorylated eIF4E and β-actin as a control. Western blotting revealed that male VPA-exposed and control mice have more eIF4E and phospho-eIF4E normalized to eIF4E than female VPA and control mice tissue samples. There were no significant changes found in eIF4E, phospho-eIF4E or Eps8 in VPA-exposed mice versus controls. These results suggest that the deficits seen in PI3K dependent spine protein translation and spine dynamics in VPA-exposed mice may not occur through the eIF4E or Eps8 pathways.
PAIGE DARVILLE-O’QUINN – THE EFFECTS OF T CELL DEFICIENCY ON OBJECT RECOGNITION.
Brain function is heavily impacted by the adaptive immune system. Specifically, it has been shown that a lack of T cells leads to decreased cognitive abilities, as well as reduced anxiety-like behaviours. Studying these effects of T cells on learning and memory may provide insight into mechanisms underlying neurological disorders involving behaviour and cognition. Through a novel object test, this study aims to determine the impact of T cells on the capacity to discriminate between different objects. The experiment was performed using TCRβ—/—δ—/— mice deficient in T cells, and immune healthy wild type controls. Object recognition and differentiation is observed during the test phase of the experiment, in which mice were presented with two objects – one familiar from the habituation phase, and one novel. The time spent around the novel object is indicative of the mice’s ability to recall the familiar object. Additionally, the mice used must be genotyped to confirm the absence or presence of T cells. DNA was extracted from the tails of the mice, and following PCR amplification, the DNA fragments were separated and visualized through agarose gel electrophoresis. Given that T cell deficiency gives rise to cognitive impairments, we expect the immune compromised mice to display decreased ability to discriminate between objects. This evidence helps us to further understand the role of the adaptive immune system on memory and how the absence of t-cells influences recognition and discrimination.
JAMIE MALONEY – QUANTITATIVE AND COMPARATIVE ANALYSIS OF MCMASTER FOREST COMMUNITY STRUCTURE
Over the past 10 years, evidence has shown an increase in the mortality rate of Fraxinus sp. in urban forests. This raises an issue, as the conservation of these areas is reliant on tree diversity and contributes to the biodiversity of local ecosystems. Evaluating the community structure of the McMaster Forest (MF) provides a valuable opportunity to assess the value and the importance of an urban forest ecosystem. MF is a 48-hectare teaching and research facility located in Hamilton, Ontario. The size of this site, and the inherent diversity of tree species present, makes this an ideal study location. The current state of the forest was assessed by using traditional forest community metrics (e.g frequency, dominance, density, and average size). Data was obtained from an ongoing tree census of the forest, which included variables like tree species, diameter at breast height, and a reference location within a 20m by 20m grid. Calculation of standard forest metrics, and the relative importance value, for important trees species were used to determine their relative significance, and to identify potential changes in the forest community structure. One particular area of interest in this study is how urban forests are going to change as a result of the emerald ash borer (EAB), Agrilus planipennis. A previous study of the MF indicated high incidence of EAB circa 60%. As an example of the utility of this study, re-calculation of forest community structure metrics after the removal of infected ash species from the dataset were made to identify dynamic change in the forest ecosystem. The results of this study will generate insight into community structure of urban forests, as well as the need for conservation as a result of invasive species.
AARANI MATHIALAGAN – THE LIVES AND LIFESTYLES OF PAST HUMAN POPULATIONS
Ancient skeletal remains serve as a physical record or memory of the environment and conditions in which an individual once lived. As a ‘voice’ of the past, each skeleton can offer a distinct narrative of the individual’s life and lifestyle. Skeletal remains present the most direct evidence for the conditions of past populations, including health and well-being, dietary history, violence and trauma, lifestyle, ancestry, and demography. These areas inform our understanding of a range of issues, such as the causes and consequences of adaptive shifts in the past, the biological impact of invasion and colonization, differential access to resources, and conflict and warfare. Central to bioarchaeological inquiry are the interaction between biology and behaviour, and the effect of environment on health and lifestyle. The advancement of scientific techniques such as the development of polymerase chain reaction (PCR), stable isotope analysis, and histological and radiological analysis has facilitated the reconstruction of the lives and lifestyles of past human populations. The dynamic evolution of human populations can be traced and interpreted through scientific data and techniques. Current bioarchaeological literature on ancient populations examines a diverse range of time periods and geographic regions. Ancient skeletal remains from the Italian Iron Age (c. 700 – 500 BCE) will be analysed through data collection on dental health, stable isotope analysis, and the analysis of pathological changes to bone. A multidisciplinary approach is applied to understand and interpret data collected from Italian Iron Age skeletons, contributing to the existing body of research.
JULIA BANDURA – CHANGES IN PSD-95 EXPRESSION IN ENVIRONMENTALLY-ENRICHED RAT SOMATOSENSORY CORTEX
Postsynaptic density protein 95 (PSD-95) is a membrane-associated guanylate kinase (MAGUK) and is the key anchoring protein of the postsynaptic density, the electron-rich region near the membrane of the postsynaptic neuron. PSD-95 binds and regulates trafficking of glutamate receptors, including AMPARs and NMDARs. Redistribution of PSD-95 occurs activity-dependently during development, and synaptic plasticity following long-term potentiation. Less PSD-95 expression occurs in the rat juvenile state than in adults. The current study sought to determine changes in expression of PSD-95 in response to short-term and long-term environmental enrichment in rat somatosensory cortex, to determine if PSD-95 expression decreases and returns to a more juvenile state, or increases in response to activity. Rat somatosensory cortex from control (no environmental enrichment), short-term environmentally-enriched rats, and long-term environmentally-enriched rats were previously Western blotted for expression of PSD-95. The current study analyzed the available PSD-95 expression data previously obtained and preliminary results show a significant increase in PSD-95 expression in long-term environmentally-enriched rats. These results suggested that increased PSD-95 may correlate with changes in synaptic plasticity associated with environmental enrichment, particularly growth of dendritic spines. Environmental enrichment may cause increased trafficking of AMPARs and NMDARs by PSD-95 in dendritic spines of environmentally-enriched rats, suggesting a partial cause for increases in synaptic plasticity associated with environmental enrichment.
RAMA AL-ATOUT – INVESTIGATING THE RELATIONSHIP BETWEEN HIPPOCAMPAL MEMORY FUNCTION AND MOOD AND LIFESTYLE FACTORS
Heavy episodic drinking, or binge drinking (BD), is characterized by the consumption of large amounts of alcohol over a short time, and is particularly prevalent in university students. Studies have demonstrated that this type of alcohol consumption in young people, along with high scores on indices of stress and depression, causes severe neuropathological changes to the brain and results in impaired performance on high interference memory tasks that are hippocampus-dependent. We are interested in investigating the relationships between chronic and acute stress, exercise, anxiety, binge drinking patterns, and cognitive function. To achieve this, approximately 50 participants will partake in a series of mood and lifestyle questionnaires, EEG measurements, and an array of cognitive tasks. The cognitive test battery will assess visual memory and new learning, creates proactive interference, working memory, and spatial memory. The participants will also undergo two EEG measurements to establish a baseline measure of alpha symmetry, an unbiased indicator of stress and anxiety. We also want to determine whether the cognitive deficits associated with early onset BD can be recovered after cessation in adult participants. Multiple regression analysis to find correlations between variables will be done in SPSS. The results will indicate the relationship between alcohol, mood, and cognitive function, and whether cognitive deficits as a result of BD can be recovered in the adult hippocampus.
SIMON ZHANG – HYPERBOLIC REPRESENTATION OF A DRUG-DRUG INTERACTION NETWORK
The modernization of medicine has led to increased quality of life and life expectancy. However, with thousands of drugs on the market and many novel drugs being added each year, the public is often not up-to-date with harmful drug-drug interactions that might occur between the pills they are taking. Many deaths brought on by drug-drug interactions have been recorded. We therefore aim to create a visual database to allow for easy determination of possible adverse effects of prescribed drug.
Beginning with a literature review into drug-drug interactions and hyperbolic spaces, data was taken from existing text-based drug databases to create a simple network of drugs. Then, by using force estimation techniques, we show the possibility of embedding networks into hyperbolic spaces. After mapping the network onto the Poincaré disc, hyperbolic analysis can be used to understand and explain unique, emergent properties of the network and relationships between drugs, such as the identification of outlier drugs and natural clustering of drugs. The end result is a hyperbolic network of drug-drug interactions as well as a legend for detailed visualization.
A simple visual database can be created and easily updated for public use. This both serve as a tool that allows pharmacists to be verify their prescriptions as well as help citizens avoid possible adverse effects when taking non-prescription drugs.