Embed Size (px)
Citation preview
0
Wednesday, August 6th, 2014
10:00 am – 2:00 pm
Science Complex Atrium
CPES Undergraduate Poster Session
1
Table of Contents
Welcome Message………………………………………………………………………………2
Acknowledgments……………………………………………………………………………….2
CUP Schedule………………………………………………………………………..…………….3
Poster Abstracts
Chemistry…………………………………………………………………………………….4
Engineering…………….……………………………………………………………………9
Physics……..………..………………….……………………………..…..…..………….13
Computer Science………………………………….………………..………………..18
Mathematics and Statistics…..……………………………………………………20
2
Welcome Message We are honored and delighted to welcome you to
the 2014 College of Physical and Engineering Sciences
(CPES) Undergraduate Poster Session. This poster session
is a culmination of each student’s summer work term. It
is an opportunity for students to showcase their research
and for us to celebrate their accomplishments. Judges
will be on hand to provide constructive feedback on the
poster presentations and determine the winners of the
poster competition.
Each student's poster presentation will be evaluated on three occasions by a volunteer graduate
student judge. Based on the scores issued by the judges, the following awards will be presented: three
grand prizes for the best overall poster presentations; a prize for the most visually appealing poster; a prize
for the best poster presentation from a 2nd- or 3rd-year student; a prize for the best poster presentation in
Chemistry, Engineering and Physics/Mathematics & Statistics; respectively; as well as a prize for the best
group poster presentation among the departments.
We hope that the poster session is a positive learning experience and continues to create a sense of
community amongst interdisciplinary faculties.
Yours truly,
Melissa Braschel, Eugene Enriquez, Monika Kulak, Boris Pavlovic
2014 CUPS Organizing Committee
Acknowledgements We would like to thank the Chemistry, Physics, Engineering and Computer Sciences departments at
the University of Guelph for their generous funding. Without their support none of this would have been
possible. A special thanks also goes to the CPES Deans office for their support, funding, and interest in
promoting student engagement. We would also like to thank our panel of volunteer judges for their time
and willingness to impart knowledge.
3
9:40 Poster set-up
10:00 Opening remarks and welcome
10:05 Poster viewing
10:15 Poster judging begins
12:30 Pizza lunch
1:00 Poster viewing continues
1:30 Awards ceremony
2:00 Poster session concludes
CPES Undergraduate Poster Session
4
P01: Quantum Chemical Computational Study of Small Atoms trapped inside Si8O12 Octasilsesquioxanes Aalaa Osman and Glenn Penner. Department of Chemistry, University of Guelph, Guelph, N1G2 W1. [email protected]
We report the results of a quantum chemical study of the trapping of small atoms (H (radical), He and Li
(cation) in the silicate cage of Si8O12H8, the simplest known octasilsesquioxane. The optimized structures are
reported, together with the energy profile for the removal of the atoms from the cages. In the case of the H atom the
ESR spectrum is predicted and in the case of the Li cation the NMR spectrum is predicted.
P02: Comparative Study between 8-Indole and 8-Benzofuran,-2′-Deoxyguanosine as Fluorescent Probes in Thrombin Binding Aptamer
Adam Gabara, Mike Wickens, Kaila Fadock, Mike Sproveiro and Richard Manderville. Department of Chemistry, University of Guelph, Canada N1G 2W1. [email protected]
Aptamers are single-stranded oligonucleotides that can bind to a target molecule with high affinity and
specificity. Indole and benzofuran moieties were attached to the C-8 position of the deoxyguanosine nucleoside,
protected as phosphoramidites, and incorporated into the 15-mer thrombin binding aptamer (TBA), where thrombin
is a protein responsible for coagulation in the blood. Fluorescent properties were analyzed and compared between
the two modifications in duplex and quadruplex form to find the more useful probe.The modified deoxyguanosine
phosphoramidites were incorporated into positions 5, 6 and 8 using solid-phase oligonucleotide synthesis. Thermal
melting, fluorescence and circular dichroism studies were utilized in K+ and Na+ buffers. It was shown benzofuran
exhibited greater change in fluorescence from duplex to quadruplex, and was generally slightly more stable than the
indole. Further studies need to be accomplished with both probes in double incorporations with other modifications
currently being synthesized.
Poster Abstracts Department of Chemistry
5
P03: Ring Opening of Tri-aryl-substituted 5,6-dihydro-1,4-oxathiin S,S-dioxides Erwin Remigio and Adrian Schwan. Department of Chemistry, University of Guelph, Guelph, N1G2 W1. [email protected]
The Schwan group has recently reported a new synthesis leading to aryl-substituted 5,6-dihydro-1,4-xathiin
S,S-dioxides. Previous work with this synthesis has achieved thorough optimization leading to ideal yields of various
oxathiins. However, this reaction is accompanied with the formation of a β-keto sulfone by-product, predicted to arise
from decomposition of the oxathiin. Previous work has achieved efficient separation yielding pure oxathiin, however
by-product identification was not achieved. This work aims to identify and characterize the by-product, through its
isolation upon formation during reaction conditions and base induced decomposition. We hope to gain additional
insight to the mechanism of synthesis for this family of oxathiins, as well as its de- composition and stability
information. In addition, we wish to examine the synthetic value of the ring open by-product and explore possibility of
conversion into an azathiin heterocycle.
P04: Thiazyl Radicals Used as Bridging and Terminal Ligands of Iron (II) Spin-Crossover Compounds Jessica Kunsminskas da Silva, Scott MacKenzie and Kathryn Preuss, Department of Chemistry, University of Guelph, Guelph ON N1G 2W1. [email protected]
The phenomenon of spin-crossover transition in complexes of d4-d7metals has been studied for the past 50
years in coordination chemistry. Complexes such as bpm[FeII(bpy)(NCS)2]2 and [FeII(bpy)2(NCS)2] have already been
synthesized and have demonstrated their potential application as a molecular material. In this project, we have been
developing a method for the synthesis of magnetically coupled spin-crossover complexes, using paramagnetic
compounds such as4-(2’-pyrimidyl)-1,2,3,5-dithiadiazolyl(PymDTDA) and4-(2’-pyridyl)-1,2,3,5-dithiadiazolyl (PyDTDA).
To coordinate the thiazyl ligands to an iron centre, Fe(py)4(NCS)2 was utilized, as it has readily displaced pyridine
coordination sites. By using this starting material, PymDTDA[FeII(bpy)(NCS)2]2and [FeII(pyDTDA)2(NCS)2] have already
been potentially synthesized - IR spectroscopy has been conducted as an initial form of characterization, however by
recrystallizing the compounds, we expect to isolate the crystals and obtain an X-ray structure.
6
P05: Development of a New Method for Analysis of Phthalate Esters in Bottled Water Using Differential Ion Mobility Mass Spectrometry Hilary Boucher, and Wojciech Gabryelski. Department of Chemistry, University of Guelph, Guelph ON N1G [email protected]
Phthalate esters (phthalates) are ubiquitous plasticizer materials that are added to impart flexibility and
durability to a wide range of personal care and consumer products. They are implicated endocrine disruptors, as
evidence suggests that they are associated with negative reproductive outcomes in males, such as inhibition of
steroidogenesis, sperm DNA damage, and a decrease in anogenital distance—a marker for masculinization. These
anti-androgenic effects may negatively impact reproductive capabilities later in life. Because of a high risk of exposure
to these compounds, numerous analytical methods have been implemented to detect phthalates in food, water,
biological fluids, and consumer products. The most commonly used methods include gas chromatography-mass
spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Unfortunately, because of the
ubiquitous nature of phthalates, solvents, lab equipment, and glassware used in GCMS and LC-MS are often highly
contaminated with phthalates, which results in inaccurate detection and quantification with these methods. In this
work, a new method for the analysis of phthalates in bottled water, electrospray ionization differential ion mobility
mass spectrometry (ESI-FAIMS-MS), has been developed to detect phthalates without the use of preconcentration,
which introduces phthalate contaminants into the sample. FAIMS is a separation device that increases analytical
sensitivity of a technique by eliminating the background noise often observed with traditional LC-MS methods. Future
work will exploit the separation capabilities of FAIMS to identify the most abundant contaminants previously
undetected in bottled water.
P06: Synthesis of a Branched Glycolipid Conjugate for the Production of Biomimetic Lipid Bilayers
Matthew Deen, France- Isabelle Auzanneau, Josh Kuikman and Ali Nejatie Department of Chemistry, University of Guelph, Guelph ON N1G 2W1. [email protected]
Over the past decade the production of a viable biomimetic lipid bilayer system has been sought extensively.
The applications of such a model would have large impact in therapeutic drug discovery as well as extremely selective
sensor systems. The most applicable biomimetic systems currently are tethered bilayer membrane (tBLM) where by
an amphiphilic molecule is used to anchor a bilayer away from a gold surface. At the time of this research tethers with
a wide variety of hydrophilic spacers have been explored (PEGs, peptides, etc.). However they have struggled to form
high quality bilayers. Synthetic work in Dr. Auzanneau’s group has been undertaken towards a novel glycolipid tether.
The synthetic target glycolipid will hopefully be used to form a bilayer that has mechanical and electrochemical
properties that mimic closely those of biological lipid bilayers.
7
P07: Pd and Pt-Catalyzed Ring-Opening Reactions of Cyclopropanated Oxabenzonorbornadienes Oday Alrifai, Emily Carlson and William Tam. Department of Chemistry, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected]
Heterobicycloalkenes, such as oxabenzonorbornadiene, are valuable precursors to a variety of useful organic
compounds, including the preparation of the antidepressant sertraline, which can be obtained through ring-opening
reactions. Depending on the metal catalyst and the nucleophile used, it is known that the mode of ring-opening will
differ, and this helps to control the synthesis of a desired product. We have been examining novel ring-opening
reactions of the cyclopropanated version of oxabenzonorbornadiene, due to its high ring-strain in both the oxabicyclic
framework and the cyclopropane ring. There are three types of ring-openings, which could take place for this
compound upon treatment with a nucleophile. Using various palladium and platinum catalysts, the outcome of ring-
opening of an alcohol nucleophile with cyclopropanated oxabenzonorbornadiene was investigated. The ring-openings
provided a novel and more efficient route to the synthesis of 2-alkoxymethylnaphthalenes, compared to known
literature methods.
P08: Screening Leucyl-leucyl-leucine Against Reactive Molecules Sarah Hollywood, Aaron Smith and Dmitriy Soldatov. Department of Chemistry, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected]
Inclusion compounds and co-crystals are extremely useful in the area of pharmaceuticals due to their
desirable properties such as bioavailability and solubility. We investigated whether solvent assisted grinding of Leucyl-
leucyl-leucine (LLL) and various other molecules would form inclusion compounds and co crystals. We used powder X
ray diffraction to determine whether the products of solvent assisted grinding formed these new compounds. We
then set these successful cases for crystallization. Screening results showed that several solvents and other
compounds were successful in creating inclusion compounds and co crystals. Several of the solvents that successfully
formed inclusion compounds also successfully crystallized, and their crystal structures were solved.
8
P09: Mechanochemical synthesis of metal-radical complexes Taylr Cawte, Michelle Mills, and Kathryn E. Preuss. Department of Chemistry, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected] The design of molecular materials with controllable magnetic properties is a major objective of our research
group. Our approach is to create paramagnetic ligands using thiazyl radicals as building blocks. We have developed an
entirely new family of radical ligand that offers extensive possibilities for coordination studies and investigation of
diverse properties. Coordination of these radicals to transition metals and lanthanides is generally achieved in
solution, however in many cases insolubility issues necessitate excessive amounts of solvent and/or long reaction
times. A more efficient and solvent-free route to coordination complexes of thiazyl radicals is attractive to our group.
Here the preliminary results of coordination reactions by grinding of 1,2,3,5-dithiadiazolyl (DTDA) radical
ligands with M(hfac)n(solv), where M = Mn(II), Dy(III), are described. The reactions were monitored by PXRD and IR
and compared to the analogous complexes generated by traditional solution chemistry and crystallized by
sublimation.
9
P10: Development of a model for demonstrating insertion of intra-venous catheters into the canine leg Claudia Smith, Carolyn Kerr, John Runciman. School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected] Department of Clinical Studies, University of Guelph, Guelph, ON, Canada N1G 2W1.
Live animals are often used for veterinary students to learn basic clinical procedures such as inserting intra-
venous (IV) catheters into dogs. The possibility of designing a realistic dog leg model for instructional purposes as
opposed to using these live animals was investigated. Bones from a canine foreleg were scanned using a CT scanner
and printed using a 3D printer. After the bones were articulated and supported with self-adhering elastic wrap, a
rubber latex tube was attached to represent the cephalic vein and a skin layer was sewn around the entire structure. A
model was successfully created at a cost which was approximately 90% less than products currently commercially
available. Economies were achieved using various design features that enabled easy replacement of materials with
repeated use. Using various engineering tools, a model of the canine foreleg was successfully created for instruction of
veterinary students at the University of Guelph to learn basic techniques for inserting catheters into the canine
cephalic vein.
Figure 1 - Final prototype of canine foreleg model
Poster Abstracts School of Engineering
10
P11: Increasing the Machinability of Titanium Through MQL and Extreme Cooling Techniques
Eric Chadwick and Ibrahim Deiab. School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected] Machinability in short is the ability of the material in question to be cut. When cutting anything with machines
the heat generated from friction decreases the hardness of the material making it easier to cut. It is possible however
that the tool could become softer more quickly and easily than the material. This is the case for titanium alloys and
thus the inspiration for this research topic. Titanium alloys are very desirable in many important applications of
engineering including biomedical and aerospace. The reason for this is that they are extremely resistant to corrosion
(i.e. rust), they retain their hardness at high temperatures and they are less dense than steel but much harder than
aluminum. These properties are all heavily desired in the applications named and it is predicted that the demand for
titanium is only going to increase as aerospace and biomedical engineering will likely always be a part of human
technology.
MQL or Minimum Quantity Lubrication is a lubrication strategy that involves spraying small amounts of
synthetic or (in this case) vegetable oil as well as compressed air at the work piece. By using a mist rather than simply
flooding the tool and work piece, a lot of energy and materials are saved. This increases the environmental and
economical sustainability of machining titanium, which is the primary goal of this research.
Extreme cooling is a strategy that involves using a much colder alternative to compressed air. In this case we
will be looking at super-critical carbon dioxide or “CO2 Snow”. Small amounts of CO2 are used at a time and thus it has
very little impact on the environment and human health when used. Not much research has been done on this
strategy, so we hope to combine this technique with MQL (replacing compressed air with CO2) to achieve optimal
results.
P12: Shaker and column testing of amendments for chemical treatment of highway runoff Joel Gretton, Bill Trenouth and Bahram Gharabaghi. School of Engineering, University of Guelph, Guelph, ON N1G 2W1. [email protected]
Runoff from highways can be a source of chloride and heavy metal contamination. The authors investigated
the ability of abundant and unutilized by-product materials to chemically treat highway washoff. Residuals from mines,
steel mills and water treatment plants were assessed. A synthetic highway runoff solution was prepared using sodium
chloride and six different heavy metals. Using this solution, shaker and column tests were performed to determine
what removal efficiency - if any - each material possessed. Average reductions in concentration of the six heavy metals
assessed ranged between 50.6 and 93.4%.
11
P13: Characteristics Influencing the Social Behavior of Pseudomonas aeruginosa in a Wound Infection
Evan Wright, Suresh Neethirajan and Xuan Weng. BioNano Laboratory, School of Engineering, University of Guelph, Guelph, ON N1G 2W1. [email protected]
Chronic non-healing wounds present a major medical problem and can lead to disability, decreased quality of
life, and incredibly high treatment costs exceeding 10 billion dollars annually in the United States alone. While bacterial
biofilms play a major role as a bioburden in the wound, the precise understanding of the influence of bacteria on the
pathogenesis and healing of chronic wounds is unclear. One reason for this lack of understanding is that the current
model for bacterial infection is flawed; it focuses on planktonic cells when in reality bacteria aggregate to form biofilms
and thereby complex structures which then adheres to the tissue surface. Synergistic interactions between bacterial
strains affect the biovolume and the functionality of biofilms. However, the exact mechanisms for co-existence of
microbial biofilms in a wound are unknown. A better understanding of polymicrobial interactions would lead to an
improvement in the treatment of wound infections.
The opportunistic human pathogen Pseudomonas aeruginosa (PA01) is a major cause of infections in chronic
wounds, burns and the lungs of cystic fibrosis patients. Due to the similarity in genomic composition, wild type PA01
and the GFP expressing PA01 strains of Pseudomonas aeruginosa were chosen for this study to understand the
differences in their chemotactic sensitivity, swimming velocity and their biofilm forming ability. The overall goal of this
study was to determine and elucidate the ecological strategies of both the wild type and the GFP expressing PA01
bacteria in their interaction with microscale nutrient sources inside an in-vivo wound environment. The characteristics
studied were rate of biofilm formation in both static and dynamic environments, biofilm thickness, cell size, motility,
and chemotaxis.
A biologically relevant in-vitro model to understand the wound pathogenic bacterial chemotaxis and motility
was designed and fabricated using a novel 3D microfluidic system. The developed microfluidic platform provided a
pathological and a physiological tissue mimicking environment of the wound. The concentrations of the wound bed
nutrients inside the 3D model was manipulated by creating cues caused byL-Arginine and L-Glutamine that influenced
the swimming behaviour of both the wild type and GFP expressing PA01. The difference in the chemotactic migration
index and the velocity and the motility pattern between the GFP Pseudomonas aeruginosa (PA) and the wild type PA
could possibly be attributed to the decreased synthesis or the catabolism of amino acids for coupling nitrogen and
carbon metabolism caused by L-Arginine or Glutamine.
Biofilm experiments conducted using cell culture dishes for 4 and 24 hours showed that the GFP strains formed
aggressive biofilm compared to the wild type strains, establishing rapid growth and a higher surface coverage area. The
preliminary results reveal that there is ecological differentiation between the two populations as evidenced by the
differences in chemotactic sensing, swimming velocity and rate of biofilm formation.
12
P14: Investigation of Durotaxis and Electrotaxis of Single Cell Pseudomonas aeruginosa Using Microfluidics
Lee Preiss and Suresh Neethirajan. BioNano Laboratory, School of Engineering, University of Guelph, Guelph, ON N1G 2W1. [email protected]
Pseudomonas aeruginosa (PA-76) is an opportunistic pathogen that commonly targets the impaired lungs of
persons living with cystic fibrosis; is also pre-dominant in the wound environment, and otherwise acquired in hospital
settings. Inherent spatial heterogeneity of wound matrix and the configuration of the phases with the dynamic
fluctuations in the chemical gradients, mechanical environment, and hydration conditions affect the microhabitats of
pathogenic bacteria. Wound matrix is complex with heterogeneous pore spaces where the chemicals, nutrients and
other enzyme resources essential for the bacterial survival may significantly vary across the micrometric spatial scales.
To better understand the interactions between diffusional heterogeneity of wound matrix that affects bacterial growth
- influence of the surface features on single cell motility should be explored further. Electrical stimulation has the
potential to enhance wound healing through controlling bacterial growth. Microfluidic technology serves as a potential
tool for systematic understanding of the complex biophysical and biochemical processes of bacterial motility at spatial
scales relevant for single cell interactions. The overall goal of this project is to understand the single cell migration
pattern and the swimming dynamics of the pathogenic Pseudomonas aeruginosa through mechano-electro taxis
approach using the developed microfluidic platforms.
By employing a total of 3 novel microfluidic platforms with varying complexity in terms of mechanical micro-
deformations, we directly measured the swimming behaviour and the migration pattern of PA-76. In addition, a
serpentine microfluidic platform was also developed to generate a linear stiffness gradient with type I collagen of
varying concentrations (0, 75 and 150μg/mL) for investigating the durotaxis. A simple Y-device channel was used for
characterizing the electrotaxis of PA-76 using the captured 15 second video segments at 15 fps obtained from the
inverted optical microscope.
The swimming velocity and the run length of single cell PA-76 were influenced by the mechanical cues caused
due to the microscale confinement features of the developed microfluidic platforms. Notably, PA-76 changed
directions rapidly as they encounter the microscale confinements with decreased run-length. All three devices, the
circular, semi-circular and square micro-designs, showed this trend with a directness measurement (comparison of
Euclidean and accumulated distance) of 0.138, 0.100 and 0.091 respectively. The single cell velocity was comparable
between the semi-circular and square designs (20.18 and 19.87μm/s) but a reduced velocity was seen with the circular
pillars (11.02μm/s). The preliminary results of our durotaxis experiments shows that the cell migration is driven by
increasing gradient of stiffness. Detailed electro-tactic analysis of cell paths of PA-76 provide new insight into the
response of single bacterial cells to electric fields that may further provide novel tools for enhancing wound care
management.
12
P15: Discrimination of Bacterial Species Using Surface-enhanced Raman Spectroscopy
Luciana Daikuara, Rekha Dhayakaran, Long-yan Chen and Suresh Neethirajan. BioNano Laboratory, School of Engineering, University of Guelph, Guelph, ON N1G 2W1. [email protected]
Rapid detection of bacteria is essential for food safety and biomedical applications. Current methods to identify
a microorganism in a sample based on either microbiological methods such as polymerase chain reaction (PCR) or
biochemical techniques are time consuming or expensive and requires species-specific probes, and lower sensitivity.
An alternative method of microorganism identification is the Raman spectroscopy, a sensible, rapid, simple and
straightforward method which does not require invasive experimental procedures or other reagents, furthermore can
detect multiples microorganisms at once and has potential to identify a single cell.
This study aims to evaluate whether noble metallic nanoparticle mediated Surface-enhanced Raman
spectroscopy (SERS) is able to rapidly distinguish and differentiate pathogenic bacteria from a single sample utilizing
multivariate statistical analysis methods such as Principal Components Analysis (PCA) and Linear Discriminant Analysis
(LDA). Citrate capped silver nanoparticles (Ag NPs) with average diameter around 20 nm and with a characteristic
ultraviolet-visible (UV-Vis) absorption band at 400 nm were prepared and used in the study. In order to accomplish this
goal, samples of 6 pathogens (Listeria monocytogenes, Listeria innocua, Escherichia coli, Helicobacter pylori,
Pseudomonas aeruginosa, and Staphylococcus aureus) were mixed with the colloidal NPs and measured in Raman
spectroscopy, respectively. The data set in the Raman spectral range from 400 to 1800 cm-1 was dimensionally reduced
using PCA. The presence of fractal colloidal aggregates induced by the bacterial samples was found to enhance the
Raman signal considerably. By using Raman measurements and PCA and LDA function on all pathogen Raman
spectrum, a good discrimination between the bacteria was obtained. It is believed that the nanoparticle mediated SERS
could be a powerful fingerprinting tool for the sensitive and rapid characterization of pathogenic microbes.
P16: Evaluation of a Domestic Greywater Wetland Treatment and Reuse System
Tamarra Lewis, Olathe MacIntyre and Khosrow Farahbakhsh. School of Engineering, University of Guelph, Guelph, ON N1G 2W1. [email protected]
The importance of creating local sustainable environments is growing in necessity every day. Water quality and
flow rates associated with a planted greywater reuse system in a local backyard greenhouse was investigated over a
four month period. The system treated shower water for use in toilet flushing with a planted biofilter and ultraviolet
disinfection. The system was able to meet Health Canada Guidelines (HCG) for toilet flushing water, however
perturbations due to maintenance and reconfigurations to create a more user-friendly design reduced water quality
during the study. A large surface area can produce esthetically excellent water, but this must be balanced with a small
footprint for domestic needs. Achieving passive aeration throughout the system design is a critical design challenge.
Optimization of the HCG for toilet flushing water and feasibility of implementing the system into other consumer’s
homes are discussed.
13
P17: Purification of monodisperse PHYTOSPHERIX™ nanoparticles from corn Perry Mahon1, John Atkinson1, Anton Korenevski2 and John R. Dutcher1,2
1Department of Physics, University of Guelph, Guelph, ON N1G 2W1. [email protected] 2Mirexus Biotechnologies, Guelph, ON N1G 3M5
Phytoglycogen nanoparticles, which are commercialized under the trademark name PHYTOSPHERIX™, are
naturally occurring, monodisperse polysaccharide nanoparticles found in certain types of plants. PHYTOSPHERIX™
nanoparticles have unique properties that make them ideal for applications in cosmetics, nutraceutical and
pharmaceutical industries. One of their unique and useful properties is a high degree of monodispersity in the
nanoparticle diameter. We have investigated the size distribution of PHYTOSPHERIX™ nanoparticles obtained from
corn, using various purification methods to increase their monodispersity. Cross-flow ultra-filtration using 500 and
300 kilodalton filters was performed to isolate and purify the nanoparticle dispersions in water, and dynamic light
scattering was used to determine their hydrodynamic radius and polydispersity index. A Bradford protein assay was
also performed on PHYTOSPHERIX™ dispersions to compare protein content before and after ultra-filtration. We
found that cross-flow ultra-filtration produced very monodisperse PHYTOSPHERIX™ sample dispersions with very little
protein content.
P18: Determination and investigation of 0+ states in 162Er Dylan Kisliuk and Paul Garrett. Department of Physics, University of Guelph, Guelph ON N1G 2W1. [email protected]
Atomic nuclei have properties known as nuclear spin and parity. A 0+ state is one which has 0 net nuclear spin
and even parity. This work was designed to determine previously unobserved 0+ states in 162Er as well as their
relationship to the ground state which is also 0+. It is possible to determine 0+ states in excited nuclei based on the
cross sectional angular distribution for each individual excitation energy. Energies that were suspected of following a
0+ angular distribution pattern were analyzed further using a distorted wave Born approximation.
Poster Abstracts Department of Physics
14
P19: Development of new methods for protein structure determination by solid state Nuclear Magnetic Resonance Rebecca Frederick and Vladimir Ladizhansky. Department of Physics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
Various forms of nuclear magnetic resonance (NMR) spectroscopy are increasingly being used to examine the
structure and dynamics of membrane proteins due to the challenge of studying them in their natural environment.
NMR requires high quality samples with isotopic enrichment; one preparation method involves deuterating the
sample throughout its purification. For the membrane protein Anabaena sensory rhodopsin (ASR), a protocol was
developed for its purification in minimal media that has produced respectable yields of approximately 4.75mg per litre
of media. To achieve the deuteration necessary for NMR studies while balancing the cost of isotopes and attaining a
high protein yield, optimization of this process is being attempted by replacing water with deuterium oxide (D2O). The
BL21 Escherichia coli (E.coli) cells used to produce ASR were adapted to D2O, as it is toxic to these cells. Other cell
growth factors including the growth time between culture inoculations, the time of induction of protein expression,
and the length of induction are currently being optimized. In future work, the remaining process for ASR sample
preparation for NMR in D2O will be examined, including known problems with the sonication and solubilization steps.
P20: Comparison of Deuterated and Normal Scintillators for Neutron Detection using GEANT4 Monte Carlo Simulations Joseph Turko, Vinzenz Bildstein , Evan Rand and Paul E. Garrett. Department of Physics, University of Guelph, Guelph ON. N1G 2W1. [email protected]
Neutron detection techniques using liquid organic scintillator technology has been used due to the pulse
shape discrimination method of determining the nature of incoming radiation; either gamma rays or neutrons
released in nuclear decays. Two different scintillators will be compared: BC501A and BC537, where the essential
component is the aromatic benzene ring in both, but the latter, BC537, is deuterated (with 1H hydrogen being
substituted with 2H hydrogen isotopes; deuterium). The GEANT4 C++ simulation toolkit developed at CERN, was used
to model the passage of neutrons through the two detectors and examine various aspects of nuclear elastic
scattering; the processes used in the scintillators for neutron detection. Due to the isotropic nature of (n,p) elastic
scattering off of BC501A in the center of mass reference frame, (n,d) scattering from BC537 reveals information
15
regarding incoming neutron energies.
P21: Sample preparation for laser spectroscopy analysis of new Pseudomonas putida rhodopsin to establish proton transfer pathways.
Milena Ljumovic, Andrew Harris and Leonid Brown. Department of Physics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
Rhodopsins are a family of light-activated membrane proteins that can act as ion pumps or sensory receptors.
Many different taxa of bacteria have structurally distinct rhodopsins and recently a new rhodopsin has been found in
the bacterium Pseudomonas putida. We are interested in discovering what function, ion transport or sensory
reception, this P. putida rhodopsin (PSPR) may have. The homology with bacteriorhodopsin (BR) allows us to identify
putative key amino acid residues for proton transport, this being histidine 37 (H37) as a potential proton donor and
aspartate 73 (D73) as a proton acceptor. These residues were mutated into asparagine (N) using two different
plasmids, and both were transformed into Escherichia coli C41 cells using a heat-shock transformation technique.
These cells were grown using shake-flask cultures of enriched media to contain high levels of over-express the protein
with bound retinal. The E. coli cells were broken using sonication and then the protein was solubilized using detergent
and purified with nickel-nitrilotriacetic acid resin that binds to the 6xHistidine-tag on the protein. Typically, 6 mg of
PSPR per liter of cell culture was obtained. The purified protein was reconstituted into artificial liposomes which was
stored for future laser spectroscopic analysis. Laser spectroscopy was used to analyze the photocycle dynamics of
wild-type PSPR and its mutants, H37N, and D73N within the native E. coli membrane environment. PSPR encased
within polyacrylamide gel was subjected to a 7 ns, 532 nm flash and was measured at various wavelengths and pH
conditions. The results thus far show PSPR has a millisecond photocycle turnover rate similar to other rhodopsin ion
pumps like BR, H37 is not the proton donor, and D73 is a counterion but may not be the only proton acceptor. To
further investigate proton transfer pathways, we plan to measure proton transport across spheroplasts embedding
PSPR and also will analyze more mutants.
P22: A Numerical Investigation of Low Temperature Spin Ice Physics Brian Yee and Michel Gingras. Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1. [email protected]
Frustration is a physical property whereby local geometric constraints preclude the ability to satisfy every
pairwise interaction in a system. Pyrochlore oxides are a class of highly frustrated materials with local geometric
constraints on magnetic moments that are the same as the constraints that water ice exhibits – thus the name Spin
Ice. It is of interest to investigate whether or not Spin Ice retains other characteristics of water ice such as the value of
16
it's nonvanishing zero-point entropy. In this poster we outline the method and theory of constructing a computational
approach to investigate low-temperatures spin-ice physics, and present what properties are possible using the
computational approach.
P23: Analyzing Bacterial Twitching Motility using Digital Image Processing. William Dawkins, Erin Shelton, Maximiliano Giuliani and John R. Dutcher. Department of Physics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
Bacteria have the ability to colonize many different surfaces, forming communities on the surfaces called
bacterial biofilms. A key aspect to the colonization of a surface is the self-organization of the bacteria that is facilitated
by motion or motility of the bacteria. Some types of bacteria achieve motility on surfaces by extending and retracting
very thin protein filaments called type IV pili (T4P) in a grappling hook mechanism. This leads to “twitching” of the
cells across a surface. We investigate the twitching motility of Pseudomonas aeruginosa PAO1 at a glass-agar interface
under well-controlled environmental conditions. Using optical microscopy, time sequenced images of the bacteria
near the expanding front of the colony were collected. We have used digital image processing techniques to quantify
the local spatial orientation of the cells within the bacterial colony during their movement. In particular, we computed
the Fast Fourier Transform (FFT) of images of the bacterial colony front. This yields an image of the different spatial
frequencies present in each image, and also contains information about the orientations of the bacterial cells. By
applying a filter mask to the FFT image to keep only certain spatial frequencies, and then performing the inverse FFT,
we can more clearly visualize and quantify the local orientations of the cells in the images.
P24: Static response of neutron-rich matter Matthew Buraczynski and Alexandros Gezerlis. Department of Physics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
Neutron stars are the very dense stellar remnants of supernova explosions. Their structure depends on the
relationship between energy and density (equation of state) of matter making up the star. The crust of a neutron star
is composed of degenerate neutrons in a lattice of neutron-rich nuclei. We focus our study on this system and
investigate the effect on the equation of state of adding an external cosine potential to neutron matter in the
presence of strong nucleon-nucleon interactions. Complications include the need to study large systems and the
interactions' dependence on the state of the nucleons. Combinations of qualitative insights with large-scale
simulations allow us to solve these problems. We run quantum Monte Carlo (QMC) simulations, which are both non-
perturbative and accurate, to find the ground-state energy of this many body system at various densities. The results
17
will be relevant to the understanding of neutron-star structure and to the development of phenomenological theories
of neutron-rich nuclei.
P25: Mechanical integrity of Pseudomonas aeruginosa cells after exposure to polymyyxin B nonapeptide and vancomycin as measured by conventional AFM techniques in pure water and by an innovative lateral force-reducing method of AFM imaging in a buffer system. M. Labine, R. Parg and J.R. Dutcher. Department of Physics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
Because bacteria have the ability to continually adapt to changes in their environmental conditions and can
become resistant to conventional antimicrobial compounds, there is an urgent need to develop new antimicrobial
strategies and to better understand their mechanism of action. In our original study, a novel atomic force microscopy
(AFM)-based technique was employed to measure the effect of antimicrobials on the mechanical integrity of bacterial
cells [1]. In the present study, Pseudomonas aeruginosa PA01 cells were exposed to polymyxin B nonapeptide
(PMBN), an effective permeabilizer of bacterial outer membranes, alone and in combination with an effective
antimicrobial, vancomycin, which acts on the peptidoglycan layer of the cell membrane and cannot itself penetrate
the bacterial outer membrane. In both studies thus far, measurements were performed in pure water using poly-L-
lysine as a biological glue to achieve strong adhesion of the bacterial cells to the imaging substrate. The purpose of the
present work is to perform the AFM measurements under more relevant, natural conditions, i.e. in a slightly acidic
buffer solution, and to evaluate the effectiveness of the use of mussel adhesive protein (MAP) as the biological glue.
Preliminary results were obtained using an Asylum MFP-3D AFM system, which necessarily applies a lateral force
during imaging that can dislodge weakly adhered cells from the surface. Current investigations are being conducted
on improvements to this experiment that should be achieved through the use of our new JPK AFM system and a
unique QI mode of imaging that can image objects more gently and without applying a lateral force. This new
technique should dramatically increase success with performing the current AFM creep deformation experiment in
native buffer solution and allow us to apply this technique to a wide variety of bacteria and antimicrobials.
18
P26: ICON: The program the offers a trans-disciplinary learning experience to undergraduate students Brianna Driscoll, Jessica Nelson, Shoshanah Jacobs1 and Daniel Gillis2 . 1Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1. 2School of Computer Science, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected]
For every real-world challenge, the solution often requires some degree of trans-disciplinary thinking. Within
traditional academic frameworks, however, creating opportunities for students to explore their ability to contribute to
trans-disciplinary teams and discover the benefits of such activities can be limited. A review of the literature has
found examples in graduate and research sectors, but very few for undergraduates. In addition, these programs have
been limited in scope, where some programs may only have interactions among a small number of disciplines. Existing
programs have tended to be either research or teaching based, with few finding a balance between the two in order
to reach the full potential of a trans-disciplinary method of problem solving.
What if there was a program that used third and fourth year independent study courses giving undergraduate
students the option: do a traditional research project, with one advisor OR join forces in the brand new program
called ICON (Ideas-Congress) where students from any and all disciplines have the chance to collaborate with other
undergraduates to find answers to a real-world challenge presented by a community partner. ICON proposes to use
the existing academic framework, offering this unique opportunity to any student who is interested, regardless of
their major and area of discipline. Students have the chance to act as experts in their field, bringing fresh perspectives
that fellow students can consider as valuable pieces to the solution puzzle. ICON goes one step further! This is not just
an undergraduate project, but a project between the University, its students, its faculty, and the community. Each
project aims to have a community partner who can aid in enriching the experience and reinforce the experiential
learning experience. ICON hopes that students, faculty, and the community will experience many benefits, including:
Department of Computer Science
Poster Abstracts
19
increased networks, opportunities for post-grad employment with community partners or their associates,
appreciation for the value of other disciplines, and the list goes on…The next question is, WHO WANTS TO SIGN UP?
20
P27: Improving Commercial Fisheries Management With Online Services And Mobile Applications Bruno Kreutz, Gustavo Pampolini, Marcus Vinicius Silva Magalhaes, Thiago Wittmann, Cem Bakar, and Daniel Gillis. School of Computer Science, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected]
The Saugeen Ojibway First Nations (SON) operate a lake whitefish (Corregonus clupeaformis) commercial
fishery in the traditional waters of Lake Huron. To best manage the population of whitefish, the SON have collected
and analyzed harvest and effort data for over 30 years. To improve data collection and analysis, this project involves
the development of a new database structure, web portal, and mobile application for improved data collection. The
database structure is managed by a web portal that permits different user accounts to manage the system. Mobile
applications allow fishers and biologists to collect data in a more timely manner. The web portal and mobile
applications will be beta-tested this autumn.
P28: Enhancing Education for the Visually Impaired Using Sonification and Gesture Control Devices
Oliver Cook, Rick Knoop, Hugo Possani, Peter (Frazer) Seymour, Daniel Gillis and Denis Nikitenko. School of Computer Science, University of Guelph, Guelph, ON, Canada N1G 2W1. [email protected]
Visually impaired individuals face many difficulties when presented with the task of learning some core
mathematical concepts, in part because of the wide amount of abstraction needed, which leads to the use of a
graphical language. Concepts related to diagrams and graph theory are inherently visual, and become difficult without
the use of sight. In order to assist these individuals, sonification can be used to provide a non-visual representation of
the data equivalent to conventional methods, providing a new tool. Sonification is the process of using non-speech
audio cues to convey information in data, possibly encoded in sonorous signals. By modifying audio properties of a
tone such as pitch, timber, gain, and position, mathematical functions can be expressed sonically. This representation
can further be enhanced with the addition of gesture and touch controls which can provide a more physical and
tactile understanding. Focus for this study is placed on teaching the broad shape and properties of functions typically
taught to grade 11-12 students with applications extending into more complicated graphs and concepts. A series of
tests are planned to be conducted on both visually impaired and non-visually impaired participants, to measure
improvements in learning using this method and comparing results. The experiment will consist of several tests that
will check the user’s understanding of a function by playing representative sounds and asking the user to determine
its physical interpretation. The sonification team is currently developing 1) modules to convert functions to sounds,
and 2) a dynamic and accessible platform to interact with the users. Experiments are expected to take place over the
next several months.
21
P29: New user-friendly scripts for the investigation the colon using the compuGUT Kathleen Songin, Richard Yam and Hermann Eberl. Department of Mathematics & Statistics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
With the development of a new simulation model, the compuGUT, we are able to track quantities of interest
(fibers, sugars, SCFAs and microbes) in the large intestine during digestion. The model at present is in beta testing,
being used to confirm the model computes results as expected for known 'Test Scenarios'. For this reason, the model
itself is highly inaccessible to researchers without significant experience with large C source code. To overcome these
computational inconveniences, we've been able to create R scripts that are more user-accessible than the underlying
compuGUT model, allowing us to use the compuGUT as a simulation platform for experimentation. An example
simulation study is investigating the effect of dietary fiber on the microbial composition along the colon. The results
provided percentage concentration amounts over a fixed amount of days, of different microbes that compose the gut
microflora. The compuGUT continues to be re-worked and tested, thus all simulation results must be considered
preliminary at this stage. However, with our user-accessible scripts, that are able to call the compuGUT model in an
intuitive and convenient manner, we expect to aid the compuGUT evolve from a numerical integration program to a
user-friendly research and learning tool; an in silico platform to study the basics of colon fermentation.
Poster Abstracts Department of Mathematics and Statistics
22
P30: Two-Stage Residual Outcome Genetic Association Analysis Sierra Gillis and Zeny Feng. Department of Mathematics and Statistics, University of Guelph, Guelph, ON. N1G 2W1. [email protected]
In the study of coronary heart disease in association to single nucleotide polymorphisms (SNPs), data for
confounding factors is available for large samples (N) while genetic information is only available for a small sub-
sample of subjects (n). A typical study would use a regression analysis to test the association phenotypic traits of
continuous or binary data types with confounding and genetic risk factors by using the smaller sample size of data. A
two-stage method is proposed to utilize the complete set of data and to avoid a loss in power. In the first stage, the
relationship between cofactors and the trait is modeled by a generalized linear model using data from all N subjects.
This model can involve interaction terms between covariates and genotypes. A subset of size n of Pearson residuals
from this model for subjects whose genotypic data is known is then used in the second stage as the response variable
to test the genetic association with SNPs. Simulation studies are performed to compare the power of analysis and
Type I Error rate of the two-stage sub-sampling method to the more commonly used one stage regression analysis of
smaller sample size. To continue the study, the genotype data for each individual SNP can be regressed on the
residuals of each phenotypic trait from the models in stage one. This allows testing for the SNP having a pleiotropic
effect.
23
CUPS 2014
University of Guelph 50 Stone Rd. W.
Guelph ON. N1G 2W1
Notes
