title: Demolishing the Competition: The Association between Competitive Video Game Play and Aggression among Adolescents and Young Adults

subject:
Competition
Video game play
Aggression
Longitudinal

abstract:
The link between video game play and aggression is an important issue as video games
The link between video game play and aggression is an important issue as video games
are the fastest growing form of entertainment in the world. Past research on this
association has been focused primarily on the link between video game violence and
aggression; however, this research has confounded the effect of video game violence
versus competition on aggression. The main goal of the current dissertation, therefore,
was to examine the short- and long-term associations between competitive video game
play and aggression. In addition, the longitudinal work on this association to date has
been limited to adolescent samples, but not young adults. Thus, the second goal of the
dissertation research was to investigate whether video game play predicts aggression in
the long-term among young adults in addition to adolescents. To address these goals,
three studies were conducted. Study 1 consisted of a series of experiments examining the
short-term effect of video game violence versus competition on aggression. Study 2
examined the long-term association between competitive video game play and aggression
among adolescents, and Study 3 examined this long-term link among young adults, in
addition to adolescents. Taken together, the results of the three dissertation studies
converged to suggest that video game competition, rather than violence, may be a
stronger predictor of aggression in both the short- and long-term. Overall, the current
research represents an important advance in our understanding of the association between
video game play and aggression, and leads to a new direction in the video game and
aggression literature.

are the fastest growing form of entertainment in the world. Past research on this

association has been focused primarily on the link between video game violence and

aggression; however, this research has confounded the effect of video game violence

versus competition on aggression. The main goal of the current dissertation, therefore,

was to examine the short- and long-term associations between competitive video game

play and aggression. In addition, the longitudinal work on this association to date has

been limited to adolescent samples, but not young adults. Thus, the second goal of the

dissertation research was to investigate whether video game play predicts aggression in

the long-term among young adults in addition to adolescents. To address these goals,

three studies were conducted. Study 1 consisted of a series of experiments examining the

short-term effect of video game violence versus competition on aggression. Study 2

examined the long-term association between competitive video game play and aggression

among adolescents, and Study 3 examined this long-term link among young adults, in

addition to adolescents. Taken together, the results of the three dissertation studies

converged to suggest that video game competition, rather than violence, may be a

stronger predictor of aggression in both the short- and long-term. Overall, the current

research represents an important advance in our understanding of the association between

video game play and aggression, and leads to a new direction in the video game and

aggression literature.


title: Effect of executive compensation on firm performance

subject:
CEO compensation
pay-for-performance
Fama-French 3-factor model
risk taking
pay-volatility sensitivity

abstract: The paper finds evidence that the equity-based CEO pay is positively related to firm performance and risk-taking. Both stock price and operating performance as well as firm's riskiness increase in the pay-performance sensitivities (PPS) provided by CEO stock options and stock holdings. PPS can explain stock returns better as an additional factor to the Fama-French 3-factor model. When CEOs are compensated with higher PPS, firms experience higher return on asset (ROA). The higher PPS also leads to the higher risk-taking. While CEO incentive compensation has been perceived mixed on its effectiveness, this study provides support to the equity-based CEO compensation in reducing agency conflicts between CEOs and shareholders.


title: DONATION DECISIONS: THE ROLES OF FINANCIAL AND EMOTIONAL INFORMATION

subject:
financial information of non-profits
affective responses to charities
donations
emotional intelligence
group agency

abstract: This paper investigates the impact of personal affinity toward a charity and information regarding financial management of potential recipient charitable organizations on decisions to donate. Using an experiment, the study examines how personal donation decisions differ from corporate donation decisions made by managers and how the emotional intelligence of donors affects donation decisions. The results indicate that threshold and financial information on charities assembled by the Better Business Bureau, a charity rating agency, made a significant impact on corporate donation decisions. The study also shows that emotional intelligence plays an important role that aids both individual donors and managers to regulate their donation decisions.


title: Motivation among reluctant readers: Capturing the goal setting experience in the 'Reading Rocks' program

subject:
Motivation
Goal setting
Learning disabilities
Dyslexia
Children

abstract: This study explored goal setting among children with reading disabilities. Of particular focus was the goal setting experience of participants in a literacy-based program, titled “Reading Rocks”. Reading Rocks, offered by the Learning Disabilities Association of Niagara Region (LDANR), supports children with reading disabilities to become more confident readers. The program aims to strengthen literacy skills among vulnerable readers. Another essential component of the program targets children’s reading motivation through goal setting, a recognized strategy for increasing motivation. I outline the importance of reading, followed by exploring children’s reluctance to read. Goal setting is examined as an opportunity to increase motivation among reluctant readers. My research included a qualitative case study of one child-tutor pair in the program. I utilized a think-aloud protocol, a photo elicitation interview, and researcher observations to collect my data. Lastly, I triangulated the data to analyze how children in Reading Rocks experience goal setting.


title: Anticipated Guilt and Ethical Consumption: The Moderating Role of Consumers’ Socially Responsible Consumption Behaviour

subject: Anticipated Guilt

subject: Ethical Consumption

subject: Socially Responsible Consumption Behaviour (SRCB)

subject: Socially Conscious Self-identity

abstract:
Recent research in the marketing literature has indicated that, while consumers’ interests in ethical products are growing, demand for such products still remains weak.  Previous research has indicated that anticipated guilt can have a positive effect on ethical consumption.  Thus, the objective of the current study is to investigate the moderating role of consumers’ socially responsible consumption behaviour (SRCB) on the relationship between anticipated guilt and ethical consumption. Specifically, the current study hypothesizes that, when viewing a guilt ad, high (vs. low) SRCB individuals will generate higher, ethical purchase intentions, willingness to pay an ethical premium, and attitudes toward an ethical brand.

The findings from the two experimental studies indicate that, when viewing a guilt ad for an ethical product, high SRCB individuals are willing to pay a higher ethical premium and generate more favourable brand attitudes than low SRCB individuals.  However, when viewing a non-guilt ad, high SRCB individuals did not differ from low SRCB individuals in their willingness to pay an ethical premium or brand attitudes. Further, consumers’ socially conscious self-identity was explored as a mediator of these effects.  By understanding the moderating role that SRCB plays in the relationship between anticipated guilt and ethical consumption, this paper intends to assist marketers in understanding for which consumers a guilt appeal is an appropriate strategy in marketing ethical products.


title: Autonomic Cardiovascular Control in Children and Adolescents

subject:
Baroreflex
Maturation
Children
Arterial Stiffness
Orthostatic Stress

abstract:
This thesis investigated the impact of pubertal maturation and sex on cardiovagal baroreflex sensitivity (BRS) and arterial properties of the common carotid artery (CCA), and the relationship between CCA arterial properties and BRS. This thesis also investigated the effect of orthostatic stress on arterial properties of the CCA and carotid sinus (CS), as well as their impact on BRS in response to orthostatic stress.
Children and adolescents between the ages of 8-18 years were examined. To assess pubertal maturation participants were organized into five pubertal groups based on the criteria of Tanner. BRS was assessed by transfer function analysis in the low frequency range (0.05 – 0.15Hz). Pulse pressure (PP) was measured at the CCA (PPCCA) and CS (PPCS) using applanation tonometry, and at the finger (PPFinger) using photoplethysmography. Ultrasound sonography and applanation tonometry were used to determine the distensibility coefficient (DC) at the CCA (DCCCA) and CS (DCCS). A moderate posture stimulus was implemented by passively moving participants into a 50° seated-recumbent (SR) position.
The results demonstrated a sex-by-maturation interaction on BRS (p= 0.019). BRS decreased from early- to post-puberty in males (p<0.01), and remained unchanged in females. Females demonstrated greater BRS compared to males post-puberty (p<0.05). CCA distensibility was not affected by sex or maturation and was not related to BRS. PPCS was greater than PPCCA (p<0.001), while PPFinger was greater than both PPCCA (p<0.001) and PPCS (p<0.001). In response to SR, the relative change in PPFinger was significantly different than the relative change in PPCCA (p<0.001) and PPCS (p<0.001), while the relative change between PPCCA and PPCS were not different. Finally, in response to SR there was a significant decrease in DCCS (p=0.001), but not DCCCA. The relative change in BRS in response to SR was significantly correlated to the relative change in DCCS (p=0.004), but not DCCCA.
The findings demonstrated an important sex-dependent maturation effect on BRS in children and adolescents that was not explained by CCA distensibility. Also, the CS and CCA responded differently to orthostatic stress. The CS was more suitable to evaluate the effect of arterial distensibility on BRS in response to posture change.


title: Acute endocrine responses to plyometrics versus resistance exercise in children

subject: Children, Exercise, Testosterone, Cortisol

abstract: The purpose of this study was to examine the acute hormonal responses to a bout of resistance versus plyometric exercise in young male athletes. Specifically, changes in salivary cortisol, testosterone and testosterone-to-cortisol ratio from pre- to post-exercise between the two different exercise protocols were examined. Twenty-six peri-pubertal active boys participated in this cross-over study, completing two exercise sessions. During each session, participants first completed a 30 min control period, which did not include any exercise, and then was randomly assigned to perform a 45 min of either a resistance exercise or a plyometric exercise protocol. All participants crossed over to perform the other exercise protocol during their second exercise session, a week later. Four saliva samples during each protocol were taken at: baseline, pre-exercise, 5 min post-exercise and 30 min post-exercise. Significant increases in testosterone values were reported 5 min post-exercise following the resistance protocol, but not the plyometric protocol. Both exercise protocols resulted in significant cortisol decreases overtime, as well as significant testosterone-to-cortisol ratio increases. The post-exercise increases in salivary testosterone and testosterone-to-cortisol ratio followed the typical exercise induced anabolic response seen in adults. However, the post-exercise decrease in salivary cortisol was different than the typical adult response indicating an insufficient stimulus for this age group maybe due to their stage of the biological development. Thus, in the adolescent boys, exercise appears to change the anabolic to catabolic balance in favor of anabolism.


title: Are Idiosyncratic Skewness and Idiosyncratic Kurtosis Priced?

subject:
asset pricing
idiosyncratic moments
Fama-MacBeth test

abstract: This thesis investigates the pricing effects of idiosyncratic moments. We document that idiosyncratic moments, namely idiosyncratic skewness and idiosyncratic kurtosis vary over time. If a factor/characteristic is priced, it must show minimum variation to be correlated with stock returns. Moreover, we can identify two structural breaks in the time series of idiosyncratic kurtosis. Using a sample of US stocks traded on NYSE, AMEX and NASDAQ markets from January 1970 to December 2013, we run Fama-MacBeth test at the individual stock level. We document a negative and significant pricing effect of idiosyncratic skewness, consistent with the finding of Boyer et al. (2010). We also report that neither idiosyncratic volatility nor idiosyncratic kurtosis are consistently priced. We run robustness tests using different model specifications and period sub-samples. Our results are robust to the different factors and characteristics usually included in the Fama-MacBeth pricing tests. We also split first our sample using endogenously determined structural breaks. Second, we divide our sample into three equal sub-periods. The results are consistent with our main findings suggesting that expected returns of individual stocks are explained by idiosyncratic skewness. Both idiosyncratic volatility and idiosyncratic kurtosis are irrelevant to asset prices at the individual stock level. As an alternative method, we run Fama-MacBeth tests at the portfolio level. We find that idiosyncratic skewness is not significantly related to returns on idiosyncratic skewness-sorted portfolios. However, it is significant when tested against idiosyncratic kurtosis sorted portfolios.


title: Synthesis of 3', 5'-cyclic diguanylic acid (c-di-GMP) analogues

subject: c-di-GMP

abstract: In the past few years, interest in signaling networks involving 3ʹ, 5ʹ -cyclic diguanylic acid (c-di-GMP) has increased dramatically. Evidence started to emerge that connects c-di-GMP to the regulation of a range of biological processes in bacteria, such as bacterial biofilm formation, virulence, extracellular polysaccharide synthesis, however, much remains to be explored in the signaling pathways that involve this secondary messenger. This molecule has also been shown to be a very powerful immunostimulating agent and potent mucosal vaccine adjuvant.


subject:
Asset pricing
Idiosyncratic skewness
Idiosyncratic kurtosis
Fama-MacBeth regressions


title: Volume-Synchronized Probability of Informed Trading (VPIN), Market Volatility, and High-Frequency Liquidity

subject:
VPIN
market volatility
high-frequency liquidity

abstract: We assess the predictive ability of three VPIN metrics on the basis of two highly volatile market events of China, and examine the association between VPIN and toxic-induced volatility through conditional probability analysis and multiple regression. We examine the dynamic relationship on VPIN and high-frequency liquidity using Vector Auto-Regression models, Granger Causality tests, and impulse response analysis. Our results suggest that Bulk Volume VPIN has the best risk-warning effect among major VPIN metrics. VPIN has a positive association with market volatility induced by toxic information flow. Most importantly, we document a positive feedback effect between VPIN and high-frequency liquidity, where a negative liquidity shock boosts up VPIN, which, in turn, leads to further liquidity drain. Our study provides empirical evidence that reflects an intrinsic game between informed traders and market makers when facing toxic information in the high-frequency trading world.


title: Interactions of onion (Allium cepa) and yellow wax bean (Phaseolus vulgaris) in monoculture and intercropping with weeds, Chenopodium album and Amaranthus hybridus

subject:
Intercropping
Onion
Bean
Chenopodium album
Amaranthus hybridus
Weed

abstract: Intercropping systems are seen as advantageous as they can provide higher crop yield and diversity along with fewer issues related to pests and weeds than monocultures. However, plant interactions in intercropped crop species and between crops and weeds in these systems are still not well understood. The main objective of this study was to investigate interactions between onion (Allium cepa) and yellow wax bean (Phaseolus vulgaris) in monocultures and intercropping with and without the presence of a weed species, either Chenopodium album or Amaranthus hybridus. Another objective of this study was to compare morphological traits of C. album from two different populations (conventional vs. organic farms). Using a factorial randomized block design, both crop species were planted either in monoculture or intercropped with or without the presence of one of the two weeds. The results showed that intercropping onion with yellow wax bean increased the growth of onion but decreased the growth of yellow wax bean when compared to monocultures. The relative yield total (RYT) value was 1.3. Individual aboveground dry weight of both weed species under intercropping was reduced about 5 times when compared to the control. The poor growth of weeds in intercropping might suggest that crop diversification can help resist weed infestations. A common garden experiment indicated that C. album plants from the conventional farm had larger leaf area and were taller than those from the organic farm. This might be associated with specific evolutionary adaptation of weeds to different farming practices. These findings contribute to the fundamental knowledge of crop-crop interactions, crop-weed competition and adaptation of weeds to various conditions. They provide insights for the management of diversified cropping systems and integrated weed management as practices in sustainable agriculture.


title: Macroeconomic News Effects and Foreign Exchange Jumps

subject:
exchange rates
jumps and cojumps
macroeconomic news
smooth transition regression model
crisis

abstract: This thesis investigates how macroeconomic news announcements affect jumps and cojumps in foreign exchange markets, especially under different business cycles. We use 5-min interval from high frequency data on Euro/Dollar, Pound/Dollar and Yen/Dollar from Nov. 1, 2004 to Feb. 28, 2015. The jump detection method was proposed by Andersen et al. (2007c), Lee & Mykland (2008) and then modified by Boudt et al. (2011a) for robustness. Then we apply the two-regime smooth transition regression model of Teräsvirta (1994) to explore news effects under different business cycles. We find that scheduled news related to employment, real activity, forward expectations, monetary policy, current account, price and consumption influences forex jumps, but only FOMC Rate Decisions has consistent effects on cojumps. Speeches given by major central bank officials near a crisis also significantly affect jumps and cojumps. However, the impacts of some macroeconomic news are not the same under different economic states.


title: Macroeconomic News and LOB in Foreign Exchange ECN Market

subject:
limit order book
depth
spread
slope
macroeconomic news

abstract: We investigate the macroeconomic news effect on the dynamics of the limit order books (LOB) for euro-dollar ECN market in different economic states between Jan. 2006 to Dec. 2009. Using a VAR-STR model on the news surprise, pure news, aggregated good and bad news, we show that news effects on the LOB dynamics vary in different states of economy. The LOB dynamics are measured by depth, spread, slope and volatility. In contract to slope and volatility, depth and spread strongly respond to news surprise and pure news during recession and expansion. These characteristics are more affected by aggregated good and bad news during expansion. News effects are robust to alternative characteristic measures, the different sides of the LOB and the different levels in the LOB.


title: Postsecondary Teaching and Learning Development Needs: Motivators and Barriers Associated With Participation in Educational Development

contributor: Department of Graduate and Undergraduate Studies in Education

subject:
educational development
participation
motivation
barriers
postsecondary

abstract: This study investigated instructor perceptions of motivators and barriers that exist with respect to participation in educational development in the postsecondary context. Eight instructors from a mid-size, research intensive university in south-western Ontario participated in semistructured interviews to explore this particular issue. Data were analyzed using a qualitative approach. Motivation theory was used as a conceptual framework in this study, referring primarily to the work of Ryan and Deci (2000), Deci and Ryan (1985), and Pink (2009). The identified motivators and barriers spanned all 3 levels of postsecondary institutions: the micro (i.e., the individual), the meso (i.e., the department or Faculty), and the macro (i.e., the institution). Significant motivators to participation in educational development included desire to improve one’s teaching (micro), feedback from students (meso), and tenure and promotion (macro). Significant barriers to participation included lack of time (micro), the perception that an investment towards one’s research was more important than an investment to enhancing teaching (meso), and the impression that quality teaching was not valued by the institution (macro). The study identifies connections between the micro, meso, macro framework and motivation theory, and offers recommendations for practice.


title: Is Brand Equity an Asset or a Liability in Brand Harm Crisis? Buffering and Amplifying Effects and Contingent Conditions

subject:
brand crisis
brand equity
buffering and amplifying effects
crisis severity
crisis type

abstract: Brand harm crisis often result in negative consumer responses. This thesis addresses the buffering and amplifying theoretical perspectives of brand equity effects. We theorize that brand equity may interplay with the nature of brand-harm crisis in shaping consumer reactions. Results from focus group studies provide interesting insights into the amplifying and buffering effects. Moreover, research findings from two experiment studies show that brand equity amplifies consumer negative responses in a performance-related crisis but only when the crisis is extremely severe. When the crisis becomes less severe, the amplifying effect diminishes from outset. However, in a value-related crisis, the amplifying effect of brand equity is pervasive regardless of the level of crisis severity. The current thesis adds to the extant literature by demonstrating that brand equity can have very complex effects on consumer responses, which are contingent on the severity and domain of a crisis. Theoretical and managerial implications are discussed.


title: The Canada Not For Profit Corporations Act: Perceived impact on the governance of federal sport organizations

subject: Not-for-profit NSO legislation governance sport

abstract: This thesis examined the impact of the Canada Not-for-Profit Corporations Act (2009) on the governance of national sport organizations (NSO). The impact of the legislation was explored through the perceptions of NSO executive leaders and by analyzing the by-laws in effect before the legislation. The legislation was perceived to have the greatest impact on enhancing accountability, specifically affecting membership categories and director selection. The interview data showed that the legislation was necessary to enhance accountability in many NSOs. The Respondents also demonstrated that they understood the goals sought through the legislation. The data also showed that the boards of NSOs were already in alignment with the goals of the legislation. With respect to governance, the data indicated that NSOs rely almost exclusively on their regional sport associations as voting stakeholders. An emerging issue that came out of the results was the role of athletes in the governance of sport organizations.


title: Players and Avatars: The Connections between Player Personality, Avatar Personality, and Behavior in Video Games

subject:
Personality
Video Games
Avatars
Psychopathy
Aggression

abstract: The increasing variety and complexity of video games allows players to choose how to behave and represent themselves within these virtual environments.  The focus of this dissertation was to examine the connections between the personality traits (specifically, HEXACO traits and psychopathic traits) of video game players and player-created and controlled game-characters (i.e., avatars), and the link between traits and behavior in video games.  In Study 1 (n = 198), the connections between player personality traits and behavior in a Massively Multiplayer Online Roleplaying Game (World of Warcraft) were examined.  Six behavior components were found (i.e., Player-versus-Player, Social Player-versus-Environment, Working, Helping, Immersion, and Core Content), and each was related to relevant personality traits.  For example, Player-versus-Player behaviors were negatively related to Honesty-Humility and positively related to psychopathic traits, and Immersion behaviors (i.e., exploring, role-playing) were positively related to Openness to Experience.  In Study 2 (n = 219), the connections between player personality traits and in-game behavior in video games were examined in university students.  Four behavior components were found (i.e., Aggressing, Winning, Creating, and Helping), and each was related to at least one personality trait.  For example, Aggressing was negatively related to Honesty-Humility and positively related to psychopathic traits.  In Study 3 (n = 90), the connections between player personality traits and avatar personality traits were examined in World of Warcraft.  Positive player-avatar correlations were observed for all personality traits except Extraversion.  Significant mean differences between players and avatars were observed for all traits except Conscientiousness; avatars had higher mean scores on Extraversion and psychopathic traits, but lower mean scores on the remaining traits.  In Study 4, the connections between player personality traits, avatar traits, and observed behaviors in a life-simulation video game (The Sims 3) were examined in university students (n = 93).  Participants created two avatars and used these avatars to play The Sims 3.  Results showed that the selection of certain avatar traits was related to relevant player personality traits (e.g., participants who chose the Friendly avatar trait were higher in Honesty-Humility, Emotionality, and Agreeableness, and lower in psychopathic traits).  Selection of certain character-interaction behaviors was related to relevant player personality traits (e.g., participants with higher levels of psychopathic traits used more Mean and fewer Friendly interactions).  Together, the results of the four studies suggest that individuals generally behave and represent themselves in video games in ways that are consistent with their real-world tendencies.


title: Fit For Action: A Comparative Case Study of the Implementation of an Adaptive Fitness and Conditioning Program for Moderate Functioning Teens and Transition Age Youth with ASD

subject: Fitness, Autism, Adapted, physical, activity

abstract: The purpose of my research was to develop and refine pedagogic approaches, and establish fitness baselines to adapt fitness and conditioning programs for Moderate-functioning ASD individuals. I conducted a seven-week study with two teens and two trainers. The trainers implemented individualized fitness and conditioning programs that I developed. I conducted pre and post fitness baselines for each teen, a pre and post study interview with the trainers, and recorded semi-structured observations during each session. I used multi-level, within-case and across case analyses, working inductively and deductively. My findings indicated that fundamental movement concepts can be used to establish fitness baselines and develop individualized fitness programs. I tracked and evaluated progressions and improvements using conventional measurements applied to unconventional movements. This process contributed to understanding and making relevant modifications to activities as effective pedagogic strategies for my trainers. Further research should investigate fitness and conditioning programs with lower functioning ASD individuals.


title: New Teacher Perceptions of Inclusive Pedagogies: Designing New Future for the Changing Classroom

subject:
Inclusive Education
Learning Science
Teacher Education
Mixed-Methods
Accessibility

abstract:
Our perceptions of knowledge attainment have changed (Bezemer & Kress, 2010). The
type of students our teachers once were is vastly different from the students they
currently teach. We need our next generation to thrive in a dynamically, interactive world
saturated with opportunities for meaning making (Kress & Selander, 2012). Our current
students are responsible for continuing our society, but that does not mean we need them
to become us (Gee, 2009). Rather desperately, we need them to be thinkers and
expressive in a variety of modes. The world will be different when they take their rightful
place as the next generation of leaders, and so too must their thinking be different (Cope
& Kalantzis, 2000). This explanatory mixed-method study (Creswell, 2013; Mertens,
2014) involved an investigation into perceptions of new teachers regarding inclusive
pedagogies like Universal Design for Learning (CAST, 2011). It specifically discusses
the contemporary thinking of 44 new Ontario teachers regarding inclusive pedagogies in
their teacher education as well as their relative intent to utilize them in their practice. This
study reveals a distinct tone of skepticism and provides suggestions for the continued
improvement of teacher education programs in this province.


title: The role of microRNAs and retinoid signaling during spinal cord regeneration in the adult newt.

subject: Retinoic Acid, Regeneration, MicroRNAs, Spinal Cord, Urodele

abstract: The molecular events after spinal cord injury that lead to the establishment of a permissive environment and epimorphic regeneration remain unclear. Two molecular pathway regulators that may converge to create a spinal cord regeneration-permissive environment in the urodele are retinoic acid (RA) and microRNAs (miRNAs). Recent evidence suggests that RARβ-mediated signaling is necessary for tail and caudal spinal cord regeneration in the adult newt. MicroRNAs are attractive candidates as mediators of retinoid signaling during regeneration, as their pleiotropic effects are vital in situations where global changes in gene expression are required. Thus, the overall aim of this thesis was to determine if miRNAs are involved in tail and caudal spinal cord regeneration in the adult newt, and if they act as regulators and/or effectors of retinoid signaling during this process. I have demonstrated here, for the first time, that multiple miRNAs are dysregulated in response to spinal cord injury in the adult newt, as well as in response to inhibition of retinoid signaling. Two of these miRNAs, miR-133a and miR-1, appear to target RARβ2 transcripts both in vivo and in vitro. Inhibition of RA signaling via RARβ with a selective antagonist, LE135, alters the pattern of expression of these miRNAs, which leads to an inhibition of tail regeneration. These data are indicative of a negative feed back loop, albeit potentially an indirect one. I also aimed to examine which miRNAs are affected by inhibiting RA synthesis during regeneration, and provided a long list of miRNAs that are dysregulated. These data provide the foundation for future studies on the putative roles of these miRNAs, as well as their function in retinoid signaling. Overall, these studies provide the first evidence for a role for miRNAs as mediators of retinoid signaling during caudal spinal cord regeneration in any system.


title: Inverse Illumination Design with Genetic Programming

subject:
Evolutionary Design
Genetic Programming
Illumination
Many Objectives
Evolutionary Computation

abstract: Interior illumination is a complex problem involving numerous interacting factors. This research applies genetic programming towards problems in illumination design. The Radiance system is used for performing accurate illumination simulations. Radiance accounts for a number of important environmental factors, which we exploit during fitness evaluation. Illumination requirements include local illumination intensity from natural and artificial sources, colour, and uniformity. Evolved solutions incorporate design elements such as artificial lights, room materials, windows, and glass properties. A number of case studies are examined, including many-objective problems involving up to 7 illumination requirements, the design of a decorative wall of lights, and the creation of a stained-glass window for a large public space. Our results show the technical and creative possibilities of applying genetic programming to illumination design.


title: Predicting the Pose of β-Casomorphin-5 and 7 in the Opioid Receptors

subject:
Opioid Receptors
β-Casomorphins
Computational Docking
Pose

abstract: The opioid receptors consist of three main subtypes; μ, δ, and κ. Previous binding studies have shown that fragments of the milk protein, β-casein, known as β-casomorphins are agonists of these receptors which are selective for the μ receptor subtype. Using the crystal structures of these three receptors, computational molecular docking studies were done using the software GOLD to determine the conformation of β-casomorphin-5 and 7 when they bind to these three opioid receptors. GOLD was able to discriminate among the three receptors when docking the rigid ligands co-crystalized with the receptors. However, GOLD could not discriminate among the three receptors for either of the highly flexible β-casomorphins. A per amino acid scoring method was developed to overcome this problem. This method was used to predict the conformation of both β-casomorphin-5 and 7 in the μ receptor and determine that the two amino acid residues, Lys303 and Trp318 of the μ receptor are responsible for discriminating among the three receptor subtypes for binding of the β-casomorphin-5 and 7.


title: Determining the Effectiveness of the Therapeutic Recreation Specialist - Certified Training at Baycrest Health Sciences

subject:
Therapeutic Recreation
Training
Champion
Leadership

abstract: The purpose of this study was to determine the effectiveness of the “Champion” training of the Therapeutic Recreation Specialist – Certified (TRSC) at Baycrest Health Sciences (BHS).  BHS recently implemented a new model for Therapeutic Recreation Services that employs the model of champion for implementation of both best and next practices within the organization. This mixed methods study used both case study and program evaluation in order to understand whether the training that comprised of five different topics allowed the six participants to develop the skills needed to be champions.   The results supported that learning did occur during the training and that the experience was positive for the participants.  The overall finding from this study is that while the training was useful, the participants did not feel confident about utilizing these skills without further training; hence, this training can only be considered an introduction to the concepts presented.


title: Teachers’ Beliefs and Perceptions of Bullying and Bullying Prevention Initiatives

subject:
Bullying Prevention
Bullying
Self-Efficacy
Teacher Beliefs
School Climate

abstract: While bullying prevention programs appear to be decreasing the number of bullying incidents overseas, bullying prevention programs here in Canada have not been proving as effective. Evaluations of bullying prevention programs often focus on the outcomes and neglect to examine the training regimen for teachers. As teachers are on the front lines of bullying prevention programs, the current study explored teachers’ beliefs about the various types of bullying, their perceptions of their own abilities (e.g., teacher bullying prevention efficacy (TBPE), self-concept, and theory of mind) to implement bullying prevention initiatives, and how the school climate may influence their efficacy beliefs. Participants in the current study were 61 Canadian teachers (n = 51 women), predominantly from Ontario. Participating teachers represented all elementary division levels (primary, junior, and intermediate). Participants’ teaching experience ranged from zero years of teaching (pre-service) to 28 years of experience (M = 10.50, SD = 7.35). It was found that participants reported a relatively high TBPE score, which was related to their likely intervention in cyberbullying situations but not for other forms of bullying situations. It was found that teachers were most likely to intervene in physical bullying than verbal, relational, and cyberbullying, respectively. TBPE was influenced by the school climate. Teachers’ scores on the theory of mind scale was not a significant indicator of any teachers’ bullying beliefs. Analyses exploring the relationship between bullying beliefs and self-concept, morality predicted teachers TBPE scores and the likelihood of intervention. Teachers’ recommendations for bullying prevention training and school bullying prevention programs were explored. Results are discussed in terms of implications for practice and future research.


title: Removing Oneself from the Shadows: A Heuristic Inquiry to Understand the Lived Experience of Epilepsy in Young Adult Women and their Epilepsy Disclosure

subject:
Epilepsy
Epilepsy Disclosure
Heuristic Inquiry
People Living With Epilepsy
Seizures

abstract: Epilepsy is a chronic neurological disorder characterized by recurrent seizures (Stein & Kanner, 2009). The purpose of this study was to understand the essence of being a young woman living with epilepsy using heuristic inquiry (Moustakas, 1990). The research was built upon the assumption that each experience is unique, yet commonalities exist. Five women aged 22 to 28 years living with epilepsy were interviewed. Additionally, the researcher described her life with epilepsy. Participants characterized life with epilepsy as a transformative journey. The act of meeting and interacting with another woman living with epilepsy provided an opportunity to remove themselves from the shadows and discuss epilepsy. Three major themes of seizures, medical treatment, and social relationships were developed revealing a complex view of an illness requiring engaged advocacy in the medical system. Respondents frequently make difficult adjustments to accommodate epilepsy. This study provides a complex in-depth view of life with epilepsy.


title: The effect of different phases of synchrony on the synchrony effect

subject: behavioural synchrony, endorphins, pain threshold, in-phase synchrony

abstract: Synchronization of behaviour between individuals has been found to result in a variety of prosocial outcomes. The role of endorphins in vigorous synchronous activities (Cohen, Ejsmond-Frey, Knight, & Dunbar, 2010) may underlie these effects as endorphins have been implicated in social bonding (Dunbar & Shultz, 2010). Although research on synchronous behaviour has noted that there are two dominant phases of synchrony: in-phase and anti-phase (Marsh, Richardson, Baron, & Schmidt, 2006), research on the effect of synchrony on endorphins has only incorporated in-phase synchrony. The current study examined whether both phases of synchrony would generate the synchrony effect. Twenty-two participants rowed under three counterbalanced conditions - alone, in-phase synchrony and anti-phase synchrony. Endorphin release, as measured via pain threshold, was assessed before and after each session. Change in pain threshold during the in-phase synchrony session was significantly higher than either of the other two conditions. These results suggest that the synchrony effect may be specific to just in-phase synchrony, and that social presence is not a viable explanation for the effect of synchrony on pain threshold


title: Tacitus' Germania and the Jesuit Relations: Intertextuality in the Transatlantic World of the Early Jesuits in New France.

subject:
Jesuits
Tacitus
New France
Jesuit Relations
Germania

abstract:
The first Europeans who wrote about the Indigenous people of the newly discovered Americas, not only used medieval, but also classical literature as a tool of reference to describe 'otherness.'
As true humanists, the French Jesuits who arrived in the New World were deeply influenced by their classical education and, as claimed by Grafton, reverted to ancient ethnographic texts, like Tacitus' Germania, to support their analyse of the Indigenous people they encountered. Books talk to books. Inspired by Germania, the early French Jesuits managed to convey to their readers a subtle critique of their own civilization, enhancing, like Tacitus, the virtuous aspect of the so-called barbarians they described while illustrating the corruption of their respective civilized worlds.
This thesis suggests that the essence of Tacitus' work is definitively present in Pierre Biard's letters and his Relation. His testimonies illustrate the connection the early French Jesuits had with the humanist thought of their time.


title: Exploring the Current State of Grades 4 to 8 Science Education in Ontario

subject:
Science Education
Ontario
Elementary Education
Science Pedagogical Content Knowledge
Science Teachers

abstract: This study sought to explore the current state of Grades 4 to 8 science education in Ontario from the perspective of Junior/Intermediate (J/I) teachers. The study’s methodology was a sequential 2-phased mixed methods explanatory design denoted as QUAN (qual)  qual. Data were collected from an online survey and follow-up interviews. J/I teachers (N = 219) from 48 school boards in Ontario completed a survey that collected both quantitative and qualitative data. Interviewees were selected from the survey participant population (n = 6) to represent a range of teaching strategies, attitudes toward teaching science, and years of experience. Survey and interview questions inquired about teacher attitudes toward teaching science, academic and professional experiences, teaching strategies, support resources, and instructional time allotments. Quantitative data analyses involved the descriptive statistics and chi-square tests. Qualitative data was coded inductively and deductively. Academic background in science was found to significantly influence teachers’ reported level of capability to teach science. The undergraduate degrees held by J/I science teachers were found to significantly influence their reported levels of capability to teach science. Participants identified a lack of time allocated for science instruction and inadequate equipment and facilities as major limitations on science instruction. Science in schools was reported to be of a “second-tiered” value to language and mathematics. Implications of this study include improving undergraduate and preservice experiences of elementary teachers by supporting their science content knowledge and pedagogical content knowledge.


title: Pharmacological analysis of 50 kHz vocalizations in the male rat

subject:
rat
50 kHz
ultrasonic vocalization
dopamine

abstract: The production of 50 kHz ultrasonic vocalizations in rats has been associated with both positive social interactions and appetitive behavioural situations. Furthermore, there is significant evidence showing that these vocalizations are controlled by the meso-limbic dopamine system. The purpose of this study was to perform a pharmacological analysis of 50 kHz calls by using dopamine and two dopamine agonists amphetamine and apomorphine, to induce calls. The acoustic parameters of the different call types were compared across each agonist. All three agonists were able to significantly induce more 50 kHz vocalizations compared to the vehicle control. Furthermore, calls elicited by apomorphine had a significantly higher bandwidth compared to those elicited by dopamine and amphetamine. All three agonists also had significantly different pharmacokinetic properties. These observations suggest that the D2 receptor sub-type is involved in the length of call bandwidths.


title: Parent Prediction of Autism Spectrum Disorder in Infants At Risk: A Follow-up Study

subject:
early identification
at-risk infants
autism spectrum disorder
parent report
lost diagnosis

abstract:
Later-born siblings of children with autism spectrum disorder (ASD) are considered at biological
risk for ASD and the broader autism phenotype. Early screening may detect early signs of ASD and facilitate intervention as soon as possible. This follow-up study revisits and re-examines a second-degree autism screener for children at biological risk of autism, the Parent Observation Early Markers Scale (POEMS, Feldman et al., 2012). Using available follow-up information, 110 children (the original 108 infants plus 2 infants recruited after the completion of the original study) were divided into three groups: diagnosed group (n = 13), lost diagnosis group (n = 5), and undiagnosed group (n = 92). The POEMS continued to show acceptable predictive validity. The POEMS total scores and mean number of elevated items were significantly higher in the diagnosed group than the undiagnosed group. The lost diagnosis group did not differ from the undiagnosed group on POEMS total scores and elevated items at any age, but the lost diagnosis group had significantly lower total scores and number of elevated items than the diagnosed group starting at 18 months. Both ASD core and subsidiary behaviours differentiated the diagnosed and undiagnosed groups from 9−36 months of age. Using 70 as a cut-off score, sensitivity, specificity, and positive predictive value (PPV) were .69, .84, and .38, respectively. The study provides further evidence that the POEMS may serve as a low-cost early screener for ASD in at risk children and pinpoint specific developmental and behavioural problems that may be amenable to very early intervention.


title: Instagram, Social Media, and the "Like": Exploring Virtual Identity's Role in 21st Century Students' New Socialization Experience

subject:
Virtual Identity
Instagram
21st Century Pedagogy
Virtual Social Capital

abstract: Personal technologies and social media use have changed the socialization experience of our 21st century learners. As learners have a new, embodied, virtual identity that is an omnipresent force within their social interactions, this study sought to examine how virtual identity influences student relationships both within and outside of a school context. This study also explored how personal technologies and social media use have influenced learners’ perceptions of their own 21st century learning. Using a qualitative inquiry, purposeful sampling was employed to recruit 6 participants between the ages of 15 to 19 to examine their social networking site use and education experience. Data were collected from single, one-on-one semi-structured interviews in which participants discussed their experiences using social media. Data were also collected from the teens’ personal Instagram accounts, and a personal reflexive researcher’s journal was kept for triangulation of data. Open and axial coding strategies alongside constant comparative methods were used to analyze data. Participants shared how they and their peers use social media, the pressures and expectations from other users, social media’s influence on peer relationships, and how social media influences their choices in the physical realm. All 6 participants explained that their teachers do not talk to them about their social media use, and even offered critiques of the school system itself and its inability to prepare students for the new realities of a digital world. This study concludes that while social media is very influential on students’ socialization, educators should be more concerned about the lack of guidance and support that students receive in school in terms of appropriate social media use and the navigation of virtual identity.


title: The Influence of Burnout Symptoms on the Relationship between Work-Life Balance and Self-Rated Health

subject:
Epidemiology
Occupational Health
Burnout
Work-Life Balance
Stress

abstract: The effects of stress at work are estimated to cost Canadian employers more than 20 billion dollars annually through absenteeism, sick leave and decreased productivity. Over the past two decades, Canadians have reported higher stress levels, increased work hours and more work performed outside of normal business hours. This work-life imbalance has far-reaching repercussions–affecting an employee’s performance as well as their health. Chronic exposure to these high levels of stress can also lead to burnout. The primary purpose of this study was to determine the magnitude in which burnout symptoms influence the relationship between work-life balance and self-rated health. The secondary purpose of this study was to determine if gender and age interactions exist in the relationship between burnout, work-life balance, and self-rated health. This cross-sectional study involved secondary analysis of 220 managers, workers and human service professionals who completed an Occupational Health Clinics for Ontario Workers’ Mental Injury Toolkit (MIT) survey for the launch of the MIT. The MIT survey is a modified form of the short version of the Copenhagen Psychosocial Questionnaire and includes expanded questioning around burnout, stress, sleep troubles, cognitive, and somatic symptoms. There were no significant differences in self-rated health based on a respondent’s gender or age, indicating that no interaction of gender and age would be required. Respondents with low self-rated health reported significantly higher burnout and work-life imbalance compared to those with high self-rated health. The regression analysis demonstrated that the magnitude in which burnout mediates the relationship between work-life balance and self-rated health was 96%. These findings support previous studies that associate high levels of work-life imbalance or burnout with poor self-rated health or health outcomes. In this study, the shared variance between work-life balance and burnout also supports recent efforts to redefine the context and causes of burnout to include non-work factors. Based on our findings, the potential exists for the development of workplace health promotion strategies that address maintaining a balance between work and home as they may improve employee health and reduce burnout.


title: Motivation and Reading Achievement: Understanding the Needs and Motivation Processes of Adult Literacy Learners

subject:
adult literacy
adults with low literacy skill
intrinsic motivation
self-efficacy
reading value

abstract: Adult struggling readers are understudied and most evidence-based remedial approaches target youth. This thesis examined relationships among motivation constructs across typical and struggling adult readers. Age was also investigated as a moderator in these relationships. Participants included 198 adults in adult basic education and 138 undergraduate students. Examining the influence of self-efficacy on reading achievement, moderation analyses indicated there were stronger relationships for typical readers. Furthermore, stronger relationships were found for younger participants when moderated by age. Additional regression analyses identified positive relationships between two measures of intrinsic motivation and reading value. This relationship was replicated for avoidance and value. Though age was not uniformly sampled across ability grouping, age did not account for these effects. Despite difficulties with reading, adults still exhibited motivation to engage with texts with equal to greater levels of reading value. Value and intrinsic motivation may have unique developmental courses associated with longstanding reading challenges.


title: Examining the Influence of the Patient Declaration of Values on Hospital Policies and Practices

subject:
Patient Declaration of Values
Health Services Research
Case Study
Patient-Centred Care
Organizational Culture and Change

abstract: The purpose of this study was to explore how a leading Ontario hospital operationalizes their Patient Declaration of Values (PDoV) in policy and in practice. This was a single case study, which took place in a leading patient-centred Ontario hospital. The study included 18 individual interviews with employees and patient experience advisors, as well as, document analysis of strategic planning reports (n=10). Five themes emerged: (1) setting the stage, (2) inspiring change, (3) organizational structures, (4) organizational and environmental barriers, and (5) reflection and improvement. This study has highlighted the role of the PDoV within a leading Ontario hospital. It lends itself to providing a process with core strategies for creating change in an acute health care organization; to embed a culture of patient and family centred care.


title: Sport Values of Bantam, Midget and Intermediate Female Hockey Players and Their Minor Hockey Associations

subject:
Female
Sport Values
Value Congruence
Ice Hockey
Value Importance

abstract:
The sport values of female hockey players and their minor hockey associations were explored to better inform a values-based approach for adult-managed minor hockey. Data were collected from 294 participatory HL and competitive Rep players (12-22 years of age) using the Youth Sport Values Questionnaire-2 and from 30 hockey association board members using a modified YSVQ-2.
Results indicated player importance (VI) ratings for Moral (M = 4.08) and Competence (M = 4.15) values were not significantly different but were significantly higher than Status (M = 2.11) value. Significant weak relationships between age and competition level versus VI ratings were found. There were medium/ high Moral, medium/ low Competence and high/ high Status value congruence between Rep and HL Player-Board Members, respectively. Based upon the findings, girls’ minor hockey associations need to recognize the values female youth players prioritize, and ensure each is considered within a values-based decision-making approach to governance.


title: The Influence of the Media on Shaping Perceptions of Leadership in Sport: A Within and Between Groups Design

subject: media influence leadership sport

abstract: An experimental design that included both between-group and within-group designs was used to assess media influence on perceptions of sport leadership. Participants were recruited and randomly assigned to three groups, where each group completed two separate survey sessions regarding leader personality traits and behaviours. During the second survey session, experimental Groups 1 and 2 watched a video on a separate, respective sport leader prior to filling out the survey. There were a total of 104 participants (N = 104) for the first session, and 99 (N = 99) participants completed the second session. One-way ANOVA, factorial repeated measures ANOVA, and ANCOVA were used for data analysis. Results indicate a significant change in Group 2’s results after watching the video clip, thus rejecting the null hypotheses. Results and implications are discussed, highlighting their relationships to sport and media related theories and sport management practice.


title: The Mediating Role of Perceived Scholastic Competence in the Relationship Between Motor Coordination and Academic Performance

subject:
Academic Performance
Scholastic Competence
Motor Proficiency
Children

abstract: Children with developmental coordination disorder (DCD) are often referred to as clumsy because of their compromised motor coordination. Clumsiness and slow movement performances while scripting in children with DCD often result in poor academic performance and a diminished sense of scholastic competence. This study purported to examine the mediating role of perceived scholastic competence in the relationship between motor coordination and academic performance in children in grade six. Children receive a great deal of comparative information on their academic performances, which influence a student's sense of scholastic competence and self-efficacy. The amount of perceived academic self-efficacy has significant impact on academic performance, their willingness to complete academic tasks, and their self-motivation to improve where necessary. Independent t-tests reveal a significant difference (p < .001) between DCD and non-DCD groups when compared against their overall grade six average with the DCD group performing significantly lower. Independent t-tests found no significant difference between DCD and non-DCD groups for perceived scholastic competence. However, multiple linear regression analysis revealed a significant mediating role of 15% by perceived scholastic competence when examining the relationship between motor coordination and academic performance. While children with probable DCD may not rate their perceived scholastic competence as less than their healthy peers, there is a significant mediating effect on their academic performance.


title: 3-O-Demethylation of thebaine and the synthesis of a flacourtia aglycone from benzoic acid.

subject:
thebaine
oripavine
flacourtoside
chemoenzymatic dihydroxylation

abstract:
Two synthetic projects were embarked upon, both fraught with protecting group
nuance and reaction selectivity. Transformations of the opiate skeleton remain a
valuable tool for the development of new medicines. Thebaine, a biosynthetic
intermediate in the expression of morphine, was converted in three steps to
oripavine through two parallel modes. Through the use of protecting group
manipulations, two irreversible scaffold rearrangements were avoided during
aryl methyl ether bond cleavage. This chemistry constitutes a new path in
manipulations of the morphinan scaffold through protective groups.
A new compound family, the flacourtosides, contains an unusual cyclohexenone
fragment. The newly described compounds show in preliminary tests antiviral
activity against dengue and chikungunya. This aglycone was approached on
three pathways, all beginning with the chemoenzymatic dihydroxylation of
benzoic acid. A first attempt from a known vinyl epoxide failed to epimerize and
cooperate under deprotective conditions. A second and third attempt made use
of a diastereoselective dihydroxylation reaction, which was critical in reaching
the correct stereochemistry and oxidation state. The methyl ester of the
aglycone was prepared, constituting the first synthesis of the non-trivial natural
product framework.


title: Trading nitrogen for carbon: Nitrogen and carbon translocation in a  plant/fungal (Metarhizium spp.) symbiosis

subject:
Metarhizium
endophyte
nitrogen cycling
plant symbiosis
carbon exchange

abstract: While nitrogen is critical for all plants, they are unable to utilize organically bound nitrogen in soils. Therefore, the majority of plants obtain useable nitrogen through nitrogen fixing bacteria and the microbial decomposition of organic matter. In the majority of cases, symbiotic microorganisms directly furnish plant roots with inorganic forms of nitrogen. More than 80% of all land plants form intimate symbiotic relationships with root colonizing fungi. These common plant/fungal interactions have been defined largely through nutrient exchange, where the plant receives limiting soil nutrients, such as nitrogen, in exchange for plant derived carbon. Fungal endophytes are common plant colonizers. A number of these fungal species have a dual life cycle, meaning that they are not solely plant colonizers, but also saprophytes, insect pathogens, or plant pathogens. By using 15N labeled, Metarhizium infected, wax moth larvae (Galleria mellonella) in soil microcosms, I demonstrated that the common endophytic, insect pathogenic fungi Metarhizium spp. are able to infect living soil borne insects, and subsequently colonize plant roots and furnish ts plant host with useable, insect-derived nitrogen. In addition, I showed that another ecologically important, endophytic, insect pathogenic fungi, Beauveria bassiana, is able to transfer insect-derived nitrogen to its plant host. I demonstrated that these relationships between various plant species and endophytic, insect pathogenic fungi help to improve overall plant health. By using 13C-labeled CO2, added to airtight plant growth chambers, coupled with nuclear magnetic resosnance spectroscopy, I was able to track the movement of carbon from the atmosphere, into the plant, and finally into the root colonized fungal biomass. This indicates that Metarhizium exists in a symbiotic partnership with plants, where insect nitrogen is exchanged for plant carbon. Overall these studies provide the first evidence of nutrient exchange between an insect pathogenic fungus and plants, a relationship that has potentially useful implications on plant primary production, soil health, and overall ecosystem stability.


title: Associations Between Personal Cancer History and Lung Cancer Risk

subject:
lung cancer
subsequent primary cancer
cancer history
risk prediction
epidemiology

abstract:
The study aim was to investigate the relationship between factors related to personal cancer
history and lung cancer risk as well as assess their predictive utility. Characteristics of interest
included the number, anatomical site(s), and age of onset of previous cancer(s). Data from the
Prostate, Lung, Colorectal and Ovarian Screening (PLCO) Cancer Screening Trial (N = 154,901)
and National Lung Screening Trial (N = 53,452) were analysed. Logistic regression models were
used to assess the relationships between each variable of interest and 6-year lung cancer risk.
Predictive utility was assessed through changes in area-under-the-curve (AUC) after substitution
into the PLCOall2014 lung cancer risk prediction model. Previous lung, uterine and oral cancers
were strongly and significantly associated with elevated 6-year lung cancer risk after controlling
for confounders. None of these refined measures of personal cancer history offered more
predictive utility than the simple (yes/no) measure already included in the PLCOall2014 model.


title: Profiling young carers' lives: An examination of individual, family, and social contexts

subject:
Young carers
caregiving
population differences
profile

abstract: Young carers (YCs) who provide prolonged care for ill, disabled, or addicted family member(s) face a tremendous risk for negative developmental trajectories when remaining hidden (Charles, Stainton, & Marshall, 2009; Charles, 2011; Cass, 2007). Despite a growing recognition of YCs, understanding how providing care impacts a young person is not fully understood. The present study aimed to investigate circumstantial, family, and individual factors which may be associated with YCs’ caregiving role. By comparing YCs to a normative sample, a comprehensive YC profile was formed. A secondary comparative analysis was conducted on 124 YCs (72 females and 52 males, Mage = 12) and a normative sample (n = 124) matched on YCs’ age, gender, and number of siblings within the family. Unique attributes of the YC population were discussed, thereby creating a YC profile. Future research may be able to use this profile to promote identification and recognition of YCs.


title: Psychopathy and the Ability to Detect Cheaters: An Evolutionary Perspective

subject: Psychopathy, Deception, Evolutionary,  Cheating, Suspicion

abstract: This research examined psychopathy as an evolutionary adaptation that involves cheating and deception. I theorized that this strategy should be associated with certain abilities. This research examined the association between psychopathic traits and the ability to detect cheaters, altruism, deception, and psychopathic traits. Results indicated that psychopathic traits were not significantly associated with the ability to detect cheaters or altruism. Results indicated that high Factor 1 psychopathy scores, and low Factor 2 psychopathy scores, were indicative of higher ratings of deception when viewing deceptive videos. Conversely, when viewing truthful videos, Factor 1 was a significant predictor of higher ratings of deception. Finally, our results indicated that total psychopathy scores were associated the ability to identify psychopathic traits in others. Taken together the results provide mixed support for the evolutionary perspective of psychopathy.


title: Backbone Colouring of Graphs

subject: Graph Theory, Graph Colouring, Planar Graphs, Spanning Tree, Backbone Colouring

abstract:
Consider an undirected graph G and a subgraph of G, H. A q-backbone k-colouring of (G,H) is a mapping f: V(G) {1, 2, ..., k} such that G is properly coloured and for each edge of H, the colours of its endpoints differ by at least q. The minimum number k for which there is a backbone k-colouring of (G,H) is the backbone chromatic number, BBCq(G,H).

It has been proved that backbone k-colouring of (G,T) is at most 4 if G is a connected C4-free planar graph or non-bipartite C5-free planar graph or Cj-free, j∈{6,7,8} planar graph without adjacent triangles.

In this thesis we improve the results mentioned above and prove that 2-backbone k-colouring of any connected planar graphs without adjacent triangles is at most 4 by using a discharging method.

In the second part of this thesis we further improve these results by proving that for any graph G with χ(G) ≥ 4, BBC(G,T) = χ(G). In fact, we prove the stronger result that a backbone tree T in G exists, such that ∀ uv ∈ T, |f(u)-f(v)|=2 or |f(u)-f(v)| ≥ k-2, k = χ(G). For the case that G is a planar graph, according to Four Colour Theorem, χ(G) = 4; so, BBC(G,T) = 4.


title: Cell-selective modulation of the neuromuscular system in Drosophila

subject: Drosophila neuromodulator neuromuscular cell-selective electrophysiology

abstract: The capacity for all living cells to sense and interact with their environment is a necessity for life. In highly evolved, eukaryotic species, like humans, signalling mechanisms are necessary to regulate the function and survival of all cells in the organism. Synchronizing systemic signalling systems at the cellular, organ and whole-organism level is a formidable task, and for most species requires a large number of signalling molecules and their receptors. One of the major types of signalling molecules used throughout the animal kingdom are modulatory substances (e.x. hormones and peptides). Modulators can act as chemical transmitters, facilitating communication at chemical synapses. There are hundreds of circulating modulators within the mammalian system, but the reason for so many remains a mystery. Recent work with the fruit fly, Drosophila melanogaster demonstrated the capacity for peptides to modulate synaptic transmission in a neuron-specific manner, suggesting that peptides are not simply redundant, but rather may have highly specific roles. Thus, the diversity of peptides may reflect cell-specific functions. The main objective of my doctoral thesis was to examine the extent to which neuromodulator substances and their receptors modulate synaptic transmission at a cell-specific level using D. melanogaster. Using three different modulatory substances, i) octopamine - a biogenic amine released from motor neuron terminals, ii) DPKQDFMRFa - a neuropeptide secreted into circulation, and iii) Proctolin - a pentapeptide released both from motor neuron terminals and into circulation, I was able to investigate not only the capacity of these various substances to work in a cell-selective manner, but also examine the different mechanisms of action and how modulatory substances work in concert to execute systemic functionality . The results support the idea that modulatory substances act in a circuit-selective manner in the central nervous system and in the periphery in order to coordinate and synchronize physiologically and behaviourally relevant outputs. The findings contribute as to why the nervous system encodes so many modulatory substances.


title: Using PageRank Algorithm in Analyzing Dictionary Graphs and PageRank in Dynamic Graphs

subject:
PageRank
Dictionary Graphs
Dynamic Graphs

abstract:
In this thesis we are going to analyze the dictionary graphs and some other kinds of graphs using the PagerRank algorithm.
We calculated the correlation between the degree and PageRank of all nodes for a graph obtained from Merriam-Webster dictionary, a French dictionary and WordNet hypernym and  synonym dictionaries.
Our conclusion was that PageRank can be a good tool to compare the quality of dictionaries.
We studied some artificial social and random graphs. We found that when we omitted some random nodes from each of the graphs, we have not noticed any significant changes in the ranking of the nodes according to their PageRank.
We also discovered that some social graphs selected for our study were less resistant to the changes of PageRank.


title: Polynuclear Ni(II) Complexes with Schiff Bases as Bridging Ligands:  A Molecular Approach to Nanoscience

subject: Polynuclear Ni(II) Complexes, Molecular Nanoscience, Single Molecule Magnets, Schiff Bases

abstract: The initial employment of N-salicylidene-2-amino-5-chlorobenzoic acid (sacbH2) as bridging/chelating ligand in metal cluster chemistry has provided access to five new polynuclear NiII complexes with large nuclearities, unprecedented metal core topologies, and interesting magnetic properties. The obtained results are presented in two projects. The first project includes the investigation of the general Ni2+/RCO2-/sacbH2 reaction system (where R- = CH3-, But-, ButCH2-) in which the nature of the carboxylic acid was found to be of crucial importance, affecting enormously the nuclearity of the resulting complexes. The second project deals with the study of the general Ni2+/X-/sacbH2 reaction system (where X- = inorganic anions) under basic conditions, yielding new cluster compounds with molecular chain-like structures and ferromagnetic exchange interactions between the metal centers.


title: Accounting for Human Rights Violations Risk: Conflict Minerals Mandatory Disclosures under the Dodd Frank Act

subject:
Human Rights
Dodd-Frank Act
Corporate Disclosure
Conflict Minerals
Corporate Social Responsibility

abstract: This paper examines the equity market response to firms’ disclosure of human rights violation risk with regard to conflict mineral usage as required by Section 1502 of the Dodd-Frank Act (the Act). This paper assesses the aggregate equity market response to regulatory events leading to the passage of the Act, the equity market reaction to voluntary early disclosures and mandatory disclosures of conflict mineral information in Form SD, as well as the determinants of the equity market response. Using a sample of 4,399 US registrants from January 1, 2008 to September 30, 2014, we document a significant negative stock market reaction to the passage of the Act and to conflict minerals disclosures on Form SD. The equity market reaction is more negative and limited to companies that source their minerals from conflict zones, companies with human rights violations, and companies with ambiguous disclosures. Taken together, the results of this study provide an economic justification for companies with poor conflict minerals practices to improve in order to avoid high costs that will arise if firms are forced to disclose human rights abuses. This paper also provides preliminary evidence that Form SD is successful in reducing the governance gap that exposes investors to unnecessary sanction, litigation and reputation risk from firms’ activities in conflict minerals usage.


title: Examining Bullying Intervention Motivations Through a Cost/Benefit Analysis

subject:
Bullying
bystanders
evolutionary psychology
adolescents
anti-bullying programming

abstract: The purpose of the present study was to examine the role of the bystander in bullying situations. A cost/benefit model was explored in researching factors adolescents consider in deciding whether to intervene when witnessing bullying. Adolescents in the present study (N = 101 (50.5% female), between the ages of 12 to 18, M = 15.37 years; SD = 1.71 years) completed self-report questionnaires, and also responded to bullying scenarios, stating how the bystander would react, while explaining potential personal costs and benefits.  Adolescents were able to articulate various personal costs and benefits when making the decision to intervene. Conclusions of the present study include: 1) the evolutionary approach is quite informative in illuminating the decision process of the bystander, 2) adolescents’ beliefs about bullying and the role of bystanders are different from their teachers’, and 3) the rather explicit cost/benefit model could be used to develop more targeted anti-bullying programs.


title: Examining the roles of core and local temperature on forearm skin blood flow

subject:
Cutaneous circulation
Reflexive vasodilation
Local heating
Thermal balance

abstract: The interaction between local and reflexive control of skin blood flow (SkBF) is unclear. This thesis isolated the roles of rectal (Tre) and local (Tloc) temperature on forearm SkBF regulation at normal and elevated body temperatures, and to investigate the interaction between local and reflexive SkBF control. While either normothermic (Tre ~37.0°C) or hyperthermic (∆Tre +1.1°C), SkBF was assessed on the dorsal aspect of each forearm in 10 participants while Tloc was manipulated in an A-B-A-B fashion between neutral (33.0°C) and hot (38.5°C). Finally, local heating to 44°C was performed to elicit maximal SkBF. Data are presented as a percentage of maximal cutaneous vascular conductance (CVC), calculated as laser-Doppler flux divided by mean arterial pressure. Tloc manipulations performed during normothermia had significantly greater effects on CVC than during hyperthermia. The decreased modification to SkBF from the Tloc changes during hyperthermia suggests that strong reflexive vasodilation attenuates local SkBF control mechanisms.


title: Searching for Accommodations within the Ontario Criminal Justice System for Persons with Fetal Alcohol Spectrum Disorder: Views of Social Service Agency and Justice Professionals

subject:
Fetal Alcohol Spectrum Disorder
Criminal Justice System
Equity
Accommodations

abstract:
Although persons with intellectual disabilities have been conceptualized as having rights
to equality in Canada and internationally, there continue to be gaps in the delivery of justice when they are involved within the criminal process. The literature consistently reported that individuals with Fetal Alcohol Spectrum Disorder (FASDs) often experienced challenges within the justice system, such as difficulty understanding abstract legal concepts (Conry & Fast, 2009). In the Canadian legal system, accommodations are available to enable persons with disabilities to receive equal access to justice; however, how these are applied to persons with FASDs had not been fully explored in the literature. In this study, in-depth interviews were conducted with social service agency workers (n=10) and justice professionals (n=10) regarding their views of the challenges persons with FASDs experience in the justice system and their suggestions on the use of accommodations. The findings showed that while supports have been provided for individuals with intellectual disabilities, there has been a lack of specialized accommodations available specifically for individuals with FASDs in accessing their right to justice.


title: Deconstructing Child Youth Care:  an autoethnographic exploration of physical restraints in children’s residential settings

subject: autoethnography discourse children residential restraints

abstract: This thesis is written through the front-line perspective of a child/youth worker who has experienced ‘rupture’ in her personal understanding of the Child Youth Care (CYC) practice.  Using a collection of personal journal entries written about her individual experiences of CYC education, mentorship/training, front-line residential practice and frequently used interventions, this thesis takes the reader (and the writer) on a discovery of prominent discourses that exist within the residential CYC profession.  Focusing on the use of physical restraints on children by residential Child/Youth Workers, this research project utilizes Deconstructive Discourse Analysis and Liberation Psychologies to illustrate a critical examination of power-knowledge and scientific/medical discourses in CYC practice. By focusing on Foucault’s concepts of disciplinary power, binary division and theory of panopticism, the writer seeks to explore a personal reflection and comprehension of how power is used to assert control over children/youth through mental health treatment and physical interventions.


title: Investigation of the Time Dependent Influence of Extracellular Osmotic Stress on Protein Turnover in Skeletal Muscle Cells

subject:
cell-shrinkage
cell-swelling
osmotic stress
protein metabolism
skeletal muscle

abstract: Acute alterations in cell volume can substantively modulate subsequent metabolism of substrates. However, how such alterations in skeletal muscle modulate protein metabolism is limited. The purpose of this study was to determine the time dependent influence of extracellular osmotic stress on protein turnover in skeletal muscle cells. L6 cells were incubated in hyperosmotic (HYPER; 425.3 ± 1.8mmol/kg), hypo-osmotic (HYPO; 235.4 ± 1.0mmol/kg) or control (CON; 333.5 ± 1.4mmol/kg) media for 4, 8, 12, or 24hrs. During the final 4hrs, incorporation of L-[ring-3,5-3H]-tyrosine was measured to estimate protein synthesis. Western blotting measured markers of protein synthesis and degradation. No differences were observed in any outcomes except p70S6K phosphorylation whereby HYPO was lower (p<0.05) than CON and HYPER; which remained similar except for a large increase at 8hrs for HYPER. These findings suggest that regardless of duration, extracellular osmotic stress does not significantly affect protein metabolism in L6 cells.


title: Predicting the Risk of Lung Cancer in Never-smokers

subject:
lung cancer
risk prediction
epidemiology
never-smokers
public health

abstract:
Despite being considered a disease of smokers, approximately 10-15% of lung cancer
cases occur in never-smokers. Lung cancer risk prediction models have demonstrated
excellent ability to discriminate cases from non-cases, and have been shown to be more
efficient at selecting individuals for future screening than current criteria. Existing
models have primarily been developed in populations of smokers, thus there was a need
to develop an accurate model in never-smokers. This study focused on developing and
validating a model using never-smokers from the Prostate, Lung, Colorectal, and Ovarian
Cancer Screening Trial. Cox regression analysis, with six-year follow-up, was used for
model building. Predictors included: age, body mass index, education level, personal
history of cancer, family history of lung cancer, previous chest X-ray, and secondhand
smoke exposure. This model achieved fair discrimination (optimism corrected c-statistic
= 0.6645) and good calibration. This represents an improvement on existing neversmoker
models, but is not suitable for individual-level risk prediction.


title: The National Hockey League (NHL) Entry Draft: An Examination of the Impact of Brand Associations Attached to the Russian Hockey Players

subject: Hockey, Draft

abstract: This research was conducted to investigate whether negative brand associations attached to Russian hockey players impact their draft rankings during the National Hockey League (NHL) Entry Draft. A quantitative analysis based on various regression model specifications was used to test whether Russian players were drafted relatively equally to their counterparts in the NHL Entry Draft. The data consisted of the NHL draft picks between 1993 and 2013 and their performance statistics and physical characteristics. The results suggested that Russian players were drafted relatively equal to their counterparts from other countries. Meanwhile, Russian players who played in the CHL before the draft are actually drafted better than Canadians who played in the same league. Hence, the negative brand associations attached to Russians were unlikely to impact their draft rankings. This study redefined the so-called “Russian Factor” from a notion that allegedly damages Russian players’ rankings to one that enhances their rankings.


title: Responses to Reflection in Two Invertebrate Species

subject: behaviour crayfish Drosophila

abstract: The present thesis investigates the responses to reflection in both the crayfish Procambarus clarkii and the fruit fly Drosophila melanogaster. Responses to reflection in crayfish depend on social status and the current work suggests that learning and memory consolidation are required for these responses to be altered. Crayfish were treated to either massed or spaced training fights prior to reflection testing. The results show that subordinate crayfish treated to spaced training display a response typical of subordinate crayfish but subordinate crayfish treated to massed training exhibit a response typical of dominant crayfish. Fruit flies are shown to be attracted to reflection and responses to reflection are described here for the first time. Responses in fruit flies are shown to be dependent on social status. The frequency of behaviours were altered in isolated flies but not socialized flies. The addition of pheromones cVA and 7,11-HD were used to investigate how the addition of chemical cues altered responses to reflection in fruit flies. Socialized fruit flies treated with cVA exhibited an increase in the frequency of behaviours on both mirrored and clear glass walls, while isolated flies exhibited a decrease. Socialized flies treated with 7,11-HD spent more time on mirrored walls compared to glass walls, whereas the frequency of all behaviours were decreased in isolated flies treated with 7,11-HD.


title: A Life without Gluten: Dietary Adherence, Physical Activity and Motives

subject:
Gluten-free diet
Physical Activity
Dietary Adherence
Motivation
Celiac Disease

abstract:
The purpose of this study was to look at individuals living on a gluten-free diet (GFD), their dietary adherence, PA levels and the reasons why they engage in these lifestyle behaviours consistent with Organismic Integration Theory (Deci & Ryan, 2002). Participants (N = 202; Mage = 42.35 years, SDage = 12.43 years) completed a series of online questionnaires. GFD adherence (74.7%) across the previous week was consistent with existing literature (Dowd et al., 2013), but participant physical activity scores were higher than reported normative values (p = .00; Wilson et al., 2010). Specific motives predicted gluten-free dietary adherence (i.e., integrated and identified regulations) and PA (i.e., intrinsic and identified regulations; p < .05). Findings may be used by health professionals to inform behavioural interventions consistent with OIT (Deci & Ryan,
2002).


title: Novel Magnetic Materials Based on Macrocyclic Ligands: Towards High Relaxivity Contrast Agents  and Mononuclear Single-Molecule Magnets

subject:
Macrocyclic ligands
MRI contrast agents
Lanthanide single-molecule magnets

abstract:
The preparation and characterization of coordination complexes of Schiff-base and crown ether macrocycles is presented, for application as contrast agents for magnetic resonance imaging, Project 1; and single-molecule magnets (SMMs), Projects 2 and 3.
In Project 1, a family of eight Mn(II) and Gd(III) complexes of N3X2 (X = NH, O) and N3O3 Schiff-base macrocycles were synthesized, characterized, and evaluated as potential contrast agents for MRI. In vitro and in vivo (rodent) studies indicate that the studied complexes display efficient contrast behaviour, negligible toxicity, and rapid excretion. In Project 2, DyIII complexes of Schiff-base macrocycles were prepared with a view to developing a new family of mononuclear Ln-SMMs with pseudo-D5h geometries. Each complex displayed slow relaxation of magnetization, with magnetically-derived energy barriers in the range Ueff = 4 – 24 K. In Project 3, coordination complexes of selected later lanthanides with various crown ether ligands were synthesized. Two families of complexes were structurally and magnetically analyzed: ‘axial’ or sandwich-type complexes based on 12-crown-4 and 15-crown-5; and ‘equatorial’ complexes based on 18-crown-6. Magnetic data are supported by ab initio calculations and luminescence measurements. Significantly, the first mononuclear Ln-SMM prepared from a crown ether ligand is described.


title: Peer Victimization and the Need to Belong within the Context of Recess

subject:
peer-victimization
the need to belong
recess
mixed-methods

abstract: Within the school setting, recess is often reported as a frequent context for bullying (Vaillancourt et al. 2010), but is currently understudied. The present study utilized a mixed-methods approach in order to examine the frequency of peer victimization at recess and explore how the current context of recess relates to children’s sense of belonging. Participants included 464 students between grades 4 to 8 from nine Southern Ontario elementary schools. Self-report measures on peer victimization and belongingness were completed, along with open-ended questions regarding the recess context. Results demonstrated the frequencies of peer victimization at recess, the relationship between victimization and belonging, contextual factors that promote and impede belongingness at recess, and solutions to support children who feel left out.These findings provide further insight for educators and administrators in order to better support children who experience victimization within the recess context.


title: Métis or Moniyâw: Explorative stories of decolonizing my Métis identity

subject: Métis Decolonization Identity Autoethnography Métissage

abstract: This thesis explores my emergent processes of identifying as a Métis person through autoethnographic narratives. I provide an overview of Métis history, identification, and decolonization, especially written by and for Aboriginal peoples. Using a decolonizing framework of Indigenous métissage (Donald, 2012) – which brings together complex, and nuanced influences to build knowledge – and an autoethnographic methodology, I explore cultural knowledges through critical self-reflection. I collected autoethnographic data in the form of personal journals and family artifacts; additionally, I shared conversations with other Métis peoples, which I used to further inform my own processes of identification and decolonization. The study results are presented as narrative vignettes, offering conclusions about: a) cultural ambivalence; b) privilege; c) language and music reclamation; and d) building relationships with both people and land. This research builds upon literature by, about, and for the benefit of Aboriginal peoples and settlers and offers considerations relevant to decolonization and identification.


title: Chemical, biochemical, and molecular characterization of a low vindoline Catharanthus roseus mutant.

subject:
monoterpenoid indole alkaloid
EMS mutagenesis
plant secondary metabolism
Catharanthus roseus

abstract:
The Madagascar periwinkle (Catharanthus roseus) is the sole source of the anticancer drug vinblastine, which is formed via the coupling of monoterpenoid indole alkaloids (MIAs) catharanthine and vindoline. A mutant line of C. roseus (M2-1865) with an altered MIA profile was identified in a screen of 4000 M2 lines generated by ethylmethanesulfonate (EMS) chemical mutagenesis. While this line did not accumulate vinblastine due to reduced levels of vindoline within the leaves, significant levels of 2,3-epoxide derivatives of tabersonine accumulated on the leaf surface.
	Detailed nucleotide, amino acid, and enzyme activity analyses of tabersonine 3-reductase in the M2-1865 line showed that a single amino acid substitution (H189Y) diminished the biochemical activity of T3R by 95%. Genetic crosses showed the phenotype to be recessive, exhibiting standard Mendelian single-gene inheritance. The usefulness of EMS mutagenesis in elucidating MIA biosynthesis is highlighted by the results of this study.


title: The Conceptualization and Exploration of Place Allegiance: Towards a Unified Model of Person-Place Relationships within Outdoor Recreation

subject:
Place allegiance
Outdoor recreation
Sense of place
Place attachment
Relationships with place

abstract: The academic study of place has been generally defined by two distinct and highly refined discourses within outdoor recreation research: place attachment and sense of place. Place attachment generally describes the intensity of the place relationship, whereas sense of place approaches place from a more holistic and intimate orientation. This study bridges these two methodological and theoretical separate areas of place research together by re-conceptualizing the way in which place relationships are viewed within outdoor recreation research. The Psychological Continuum Model is used to extend the language of place attachment to incorporate more of the philosophy of sense of place while attending to the empirical strength and utility of place attachment. This extension results in the term place allegiance being coined to depict the strong and profound relationships outdoor recreationists build with their places of outdoor recreation. Using a concurrent mixed methods research design, this study explored place allegiance via an online survey (n = 437) and thirteen in-depth qualitative interviews with outdoor recreationists. Results indicate that place allegiance can be measured through a multi-dimensional model of place allegiance that incorporates behaviours, importance, resistance, knowledge and symbolic value. In addition, place allegiance was found to be related to an individual's influence on life course and his/her willingness to exhibit preservation and protection tendencies. Place allegiance plays an important role in acknowledging the importance of authentic place relationships in an effort to confront placelessness. Wilderness recreation is an important avenue for outdoor recreationists to build strong place relationships.


title: Evaluating Knowledge of a Function-based Cognitive-Behavioural Treatment for Obsessive Compulsive Behaviour in Autism Spectrum Disorder

subject:
Autism
OCD
Cognitive Behavioural Therapy
Parent Training
Strategy Acquisition

abstract: Children with Autism Spectrum Disorder (ASD) have restricted and repetitive behaviours (RRBs) which may be similar to obsessions and compulsions in Obsessive Compulsive Disorder (OCD).   These behaviours can be intrusive and interfere in the lives of the child and their family.  Preliminary studies have shown success in using adapted Cognitive Behavioural Therapy (CBT) to treat these behaviors in children with high functioning ASD.  Using a hypothetical vignette, this thesis attempted to examine procedural knowledge that the children and their parents gained while participating in a CBT treatment that was evaluated in a Randomized Controlled Trial.  For both parents and children, there was a significant increase in number of strategies generated from pre to post-treatment.  Further, children in the experimental group generated significantly more strategies than the treatment as usual (TAU) group post-intervention.  There was no significant correlation between number of strategies generated and the child’s treatment success, age, or IQ.


title: Optimal and Robust Designs of Step-stress Accelerated Life Testing Experiments for Proportional Hazards Models

subject:
Step-stress accelerated life test
Cox's proportional hazards model
Robust design
Maximum likelihood estimation
Reliability estimation

abstract:
Accelerated life testing (ALT) is widely used to obtain reliability information about a product within a
limited time frame. The Cox s proportional hazards (PH) model is often utilized for reliability prediction.
My master thesis research focuses on designing accelerated life testing experiments for reliability estimation.
We consider multiple step-stress ALT plans with censoring. The optimal stress levels and times of changing
the stress levels are investigated. We discuss the optimal designs under three optimality criteria. They are
D-, A- and Q-optimal designs. We note that the classical designs are optimal only if the model assumed is
correct. Due to the nature of prediction made from ALT experimental data, attained under the stress levels
higher than the normal condition, extrapolation is encountered. In such case, the assumed model cannot be
tested. Therefore, for possible imprecision in the assumed PH model, the method of construction for robust
designs is also explored.


title: Investigation of Frustrated Quasi-One-Dimensional Quantum Spin-Chain Materials

subject:
Material Science
Condensed Matter Physics
Magnetic Materials
Quantum spin-chains

abstract:
Copper arsenite CuAs2O4 and Copper antimonite CuSb2O4 are S=1/2 (Cu2+
3d9 electronic configuration) quasi-one-dimensional quantum spin-chain compounds.
Both compounds crystallize with tetragonal structures containing edge sharing CuO6
octahedra chains which experience Jahn-Teller distortions. The basal planes of the
octahedra link together to form CuO2 ribbon-chains which harbor Cu2+ spin-chains. These compounds are magnetically frustrated with competing nearest-neighbour and next-nearest-neighbour intrachain spin-exchange interactions. Despite the similarities between CuAs2O4 and CuSb2O4, they exhibit very different magnetic properties. In this thesis work, the physical properties of CuAs2O4 and CuSb2O4 are investigated using a variety of experimental techniques which include x-ray diffraction, magnetic susceptibility measurements, heat capacity measurements, Raman spectroscopy, electron paramagnetic resonance, neutron diffraction, and dielectric capacitance measurements.

CuAs2O4 exhibits dominant ferromagnetic nearest-neighbour and weaker antiferromagnetic next-nearest-neighbour intrachain spin-exchange interactions. The ratio of the intrachain interactions amounts to Jnn/Jnnn = -4.1. CuAs2O4 was found to order with a ferromagnetic groundstate below TC = 7.4 K. An extensive physical characterization of the magnetic and structural properties of CuAs2O4 was carried out. Under the effect of hydrostatic pressure, CuAs2O4 was found to undergo a structural phase transition at 9 GPa to a new spin-chain structure. The structural phase transition is accompanied by a severe alteration of the magnetic properties. The high-pressure phase exhibits dominant ferromagnetic next-nearest-neighbour spin-exchange interactions and weaker ferromagnetic nearest-neighbour interactions. The ratio of the intrachain interactions in the high-pressure phase was found to be Jnn/Jnnn = 0.3. Structural and magnetic characterizations under hydrostatic pressure are reported and a relationship between the structural and magnetic properties was established. CuSb2O4 orders antiferromagnetically below TN = 1.8 K with an incommensurate helicoidal magnetic structure. CuSb2O4 is characterized by ferromagnetic nearest-neighbour and antiferromagnetic next-nearest-neighbour spin-exchange interactions with Jnn/Jnnn = -1.8. A (H, T) magnetic phase diagram was constructed using low-temperature magnetization and heat capacity measurements. The resulting phase diagram contains multiple phases as a consequence of the strong intrachain magnetic frustration. Indications of ferroelectricity were observed in the incommensurate antiferromagnetic phase.


title: Identification of Network-Based Risk Factors Associated with Gonorrhea

subject: sexually transmitted infections, sexual network analysis, epidemiology

abstract: The evolving antimicrobial resistance coupled with a recent increase in incidence highlights the importance of reducing gonococcal transmission. Establishing novel risk factors associated with gonorrhea facilitates the development of appropriate prevention and disease control strategies. Sexual Network Analysis (NA), a novel research technique used to further understand sexually transmitted infections, was used to identify network-based risk factors in a defined region in Ontario, Canada experiencing an increase in the incidence of gonorrhea. Linear network structures were identified as important reservoirs of gonococcal transmission. Additionally, a significant association between a central network position and gonorrhea was observed. The central participants were more likely to be younger, report a greater number of risk factors, engage in anonymous sex, have multiple sex partners in the past six months and have sex with the same sex. The network-based risk factors identified through sexual NA, serving as a method of analyzing local surveillance data, support the development of strategies aimed at reducing gonococcal spread.