VictorJuiz/thesis huggingface dataset:
Effects of Landscape Spatial Heterogeneity on Host-Parasite Ecology
Keywords: bipartite networks
disease ecology
landscape connectivity
Lyme disease
spatial epidemiology
urban ecology

Landscape spatial heterogeneity interacts with ecological processes that influence pathogen emergence and infectious disease spread. Modification of landscape composition and configuration is hypothesized to alter host densities, frequency of host-parasite interactions, host community assembly processes, and dispersal processes of host, vector, and parasite populations. Understanding the spatial and environmental dependence on host-parasite interactions is, therefore, critical in predicting the response of disease dynamics to widespread habitat modification. I combine wildlife disease ecology with landscape ecological concepts and varied modeling techniques (i.e., multivariate redundancy analyses, network connectivity models, bipartite mutualistic networks, beta diversity analyses) to test the mediating role of landscape spatial heterogeneity on the spread of a vector-borne disease system (chapter 2), and the effect of urban landscape spatial heterogeneity on host exposure to parasitism (chapter 3), host-parasite interaction structure (chapter 4), and host-parasite beta diversity (chapter 5). My results demonstrate that landscape spatial heterogeneity has a differential influence on tick dispersal than pathogen dispersal by the movement of a host community, most critically mediated by stepping-stone habitat. I also provide evidence that urban landscape spatial heterogeneity affects the exposure likelihood of a single host population, the structure of host-parasite interactions in multiple host populations, and the spatial contributions of host and parasite beta diversity. My work demonstrates that landscape spatial heterogeneity has a mediating role in multiple disease systems whereby spatial and environmental factors play a critical role in the likelihood of short- and long-distance pathogen invasion, the persistence of environmentally-mediated parasites, and the selection of generalist host and parasite species in urbanized habitat. Overall my research contributes to our theoretical understanding of the multi-scalar ecological interactions between landscape change and disease dynamics and our applied understanding of the role of landscape in the emergence of infectious diseases.
K-12 Education as a Hermeneutic Adventurous Endeavor: Theorizing the Instrumental Approach, Education as a Sovereign Agent for Humanity, and the Relationships with Philosophy
Keywords: adventurous education
humanity
instrumentalism
philosophy of education
public education
sovereign education

This work introduces and discusses my vision for education as a response to a dominant instrumental approach to education. Situated within a broader discussion of the place and role of public education and education research in our lives and in society, I touch upon several key components of foundations of education in order to point at what I consider a problematic and dangerous approach to education as a social and political instrument. This approach, which has become prevalent and taken for granted, divorces education from its deep human capacities and as a result damages students’ humanity and humanity as a whole. From theorizing the instrumental approach I argue for the need for stronger statements about public K-12 education and to the necessity to protect it, and propose a shift in perceiving its role from a social servant to an agent for humanity based on the guideline that we are all human beings. This characterization is meant to make schooling an adventurous endeavor, both for teachers and students, that enables and encourages imagining alternative ways of life and alternative social arrangements. To support this kind of education, I propose to incorporate basic human features alongside the curriculum, namely experiences, understandings, and meanings. As a step towards restoring education’s agency I propose to establish a sovereign education that will depoliticize schooling and will reconsider its associations with other spheres. Particularly, I examine education’s ties with philosophy and argue for non-committal relationships between them in the form of distilling educative ideas from philosophical discussions. Practical measures and policy implications, as well as several expected objections, are discussed and comparisons are made to other views and educational programs, especially to Dewey’s. By way of conclusion, this work offers several ideas about school as a social organization and about public education as human enterprise.
Integrated Microfluidics for Targeted Applications Including Polymerization, Carbon Dioxide Sequestration and Gas Separation
Keywords: microfabrication
microfluidics
polymerization

The work presented in this thesis explores the utilization of microfluidic (MF) reactors fabricated in different materials for targeted applications and capitalizes on various fundamental advantages inherent to MFs for studying chemical reactions. In Chapter 3, we describe MF reactor fabrication in polymer materials, including polycarbonate, cyclic olefin polymer, acrylic polymer, polyethylene, poly(vinyl chloride), and polystyrene to address the previous lack of MF reactor materials that are chemically stable in polar and nonpolar solvents, have gas impermeability, are cost-efficient, and biocompatible. We investigated polymer performance under specific conditions and optimized fabrication conditions of MF reactors following well-defined requirements. Chapter 4 explores development and utilization of a MF platform with integrated online attenuated total reflection Fourier infrared spectroscopic characterization for studying kinetics of an exemplary reaction, namely, polymerization of N-isopropyl acrylamide in the presence of accelerator N’,N’,N,N–tetramethylethylenediamine, and initiator ammonium persulfate. The polymerization was studied in flow in a high-throughput manner at various reagent concentrations and pH values. Monitoring the rate of disappearance of the monomer IR band vs. time, we obtained reaction orders with respect to reagents and found good correlation to values reported in the literature. In Chapter 5, we utilized MF reactors by generating segmented flow of CO2 gas and solvent (bromobenzene) to investigate fundamental information, such as thermodynamics and reaction efficiency, of the reaction involving CO2 gas and Frustrated Lewis pairs (FLPs). We developed a method to overcome the challenges inherent in batch processes and successfully obtained ΔG, ΔH, ΔS, and enhancement factors, in the temperature range from 0 °C to 40 °C. This information is vital for future optimization and development of FLPs. Finally, Chapter 6 explores the use of FLPs to effectively separate gases by extracting one gas in a reactive solvent phase. We used MFs to assess the efficiency of the separation of ethylene from its mixture with ethane, due to the chemical reaction of ethylene with FLP. Increasing the FLP concentration and reducing the temperature from 25 to 0 °C, led to significant increase separation of ethylene. The resultant separation factor for ethylene was 7.3 with an ethylene purity of 88%.
Vapours Adsorption on Non-porous or Porous Solids: Zeta Adsorption Isotherm Approach
Keywords: Adsorption
contact angle
Porous
Surface tension
Thermodynamics

The Zeta adsorption isotherm, ZAI, has been extended so it may now be applied to describe the adsorption of molecularly adsorbed gases, of dissociatively adsorbed gases, and of vapours. This isotherm assumes, as a hypothesis to be tested, that the adsorbates consist of differently sized clusters. The ZAI theory is used to derive an expression for predicting the cluster distributions in the adsorbed phase. Cluster distribution predictions are a unique feature of ZAI and they are not available from other adsorption isotherms. For vapours, this isotherm supposes that an adsorbate at pressures less than the saturation-vapour pressure, P_s (T), consists of molecular clusters with 1, 2, 3••• up to a limited maximum value of ζ_m molecules. Since ζ_m is bounded, we show that ZAI has no singularities for any pressure. This allows the adsorption of vapours at pressures greater than P_s to be investigated. The cluster distribution predicts the formation of an adsorbed film at a vapour phase pressure greater than P_s. Further, the ZAI is combined with Gibbsian thermodynamics to obtain an expression for the surface tension at the solid-vapour interface, and a method has been proposed for determining the conditions at which an adsorbed vapour becomes an adsorbed liquid. For molecularly gas adsorption, the same procedure is applied; it is found that ζ_m is unity, meaning there is no clustering. When the same procedure is applied for dissociative gas adsorption, namely for hydrogen adsorbing on metals, ζ_m is found to be two, meaning the adsorbates consist of both adsorbed atoms and molecules and the mole fraction of the adsorbed molecules and atoms are predicted. For porous materials, we present a method by which the values of the pore structure may be determined from the ZAI combined with the necessary conditions for thermodynamic equilibrium. The consistency of the proposed method is evaluated by comparing the values of the material properties obtained by different vapours. These results also agree closely with the TEM images. A total of 27 different fluid-solid systems have been examined successfully with the Zeta adsorption isotherm. ZAI is also used to determine the surface properties of two mesoporous silica templates (MCM-41 and SBA-15) and a highly porous shale.
Personal Projects in Emerging Adulthood: Pathways to Alcohol Use and Alcohol Problems
Keywords: Alcohol
Emerging Adulthood
Expectancies
Motives
Personal Projects
University Students

Emerging adulthood (ages 18-25) is an important developmental stage marked by identity exploration, transitions, and instability. In particular, the first year of university is an important life transition for many emerging adults and is often associated with the development of new personal goals in addition to increased alcohol use and alcohol problems. Recent research has highlighted the value of using personal projects analysis (PPA) to examine links between personal goals and alcohol use and related-problems. However, few studies have examined a comprehensive model of alcohol use and alcohol problems using a PPA framework in conjunction with other well-established correlates of alcohol use (i.e., alcohol expectancies and drinking motives). Alcohol expectancies pertain to beliefs individuals have about how alcohol use will impact them and drinking motives are the reasons individuals choose to use alcohol. This dissertation is comprised of two studies. Study one utilizes a cross-sectional design to examine the relationship between project content (e.g., whether a project is academic, health/body, or interpersonal in nature) in conjunction with project appraisals (e.g., how important or difficult the project is) and alcohol use and alcohol problems. In addition, this study included alcohol expectancies as possible moderators of these relationships. Study two examines changes in appraisals of projects over a period of three months and the relationship between these changes and alcohol problems. In addition, drinking motives are examined as mediators of this relationship. Results indicate that both alcohol expectancies and drinking motives are important variables in considering how personal projects are related to subsequent alcohol use and alcohol problems. In addition, personal projects and their related appraisals, alcohol expectancies, and drinking motives are important targets in considering future prevention and intervention efforts to reduce alcohol use and related-problems among emerging adults in their first year of university.
Improving the Social Skills of Children with High-Functioning Autism Spectrum Disorder: An Intervention Study
Keywords: Community intervention
Friendship training
High-functioning Autism Spectrum Disorder
Social skills
Theory of Mind
Visual supports

Previous research has found that although most children with high-functioning autism spectrum disorder (HFASD) desire friendship, they have fewer and less stable friendships and report more loneliness than their peers. They also tend to be socially naïve, vulnerable to deception and more often bullied. A significant contributor to their challenges is an impaired Theory of Mind (ToM), which is the ability to reason about mental states (e.g. knowledge, emotions, desires, beliefs, intentions). While social difficulties define ASD, research suggests that visual processing may be a relative strength. This bias favoring visual information over verbal mental representations appears to have enabled some children to gain mental state understanding via the use of visual supports. Since peer acceptance is a powerful predictor of mental health and the risks of peer rejection—and benefits of friendship— extend into adulthood, it is important to teach friendship-making skills. This was the broad objective of the study, which drew upon research demonstrating that despite deficits in ToM, children with HFASD have strengths in visual processing which can be utilized to enhance learning. A visually scaffolded, social skills and Theory of Mind intervention (S.S.ToM) for children with HFASD was designed and evaluated and compared to Children’s Friendship Training (CFT), a well-respected social skills intervention and a delayed treatment control group (DTC). Between-group comparisons revealed significant differences between the S.S.ToM and DTC groups on two measures of social responsiveness. Within-group differences for the S.S.ToM group were significant for all social responsiveness and ToM measures. Between- and within-group results were not as strong for the CFT group, however, there were fewer participants in this group and the lack of significance could be attributed to a lack of power. As a preliminary examination this study suggests that the S.S. ToM is an effective intervention but further research is needed.
A Neurofeedback-based Near-infrared Spectroscopy Brain-computer Interface
Keywords: Brain-computer Interface
Near-infrared Spectroscopy
Personalized Mental Tasks
Self-regulation
User-centered

Near-infrared spectroscopy (NIRS) brain-computer interfaces (BCIs) enable individuals to interact with their environment using only cognitive activities. This thesis investigates the development of a more user-friendly, intuitive, and easy to use NIRS-BCI through six research objectives: exploring prescribed and personalized mental task frameworks offline, using researcher-selected tasks to move beyond the binary paradigm, exploring correlations of user characteristics with accuracy, comparing user-selected personalized tasks to prescribed tasks online, weaning off mental tasks to achieve voluntary self-regulation, and applying personalized frameworks to a client case study. Firstly, personalized tasks outperformed prescribed tasks in a five-session offline study conducted on ten able-bodied participants. Specifically, user-selected tasks resulted in significantly higher ease-of-use, while researcher-selected tasks resulted in significantly higher accuracies. The same data were used to show that researcher-selected personalized mental tasks enabled classification in some users beyond a binary BCI paradigm. Accuracy was strongly positively correlated with perceived ease of session, ease of concentration, and enjoyment, but strongly negatively correlated with verbal IQ. In a second study, when comparing two able-bodied groups online (N = 9 and N = 10), the usability of user-selected personalized mental tasks exceeded prescribed mental tasks without a decrease in accuracy. Expanding on this study, the nine able-bodied subjects who used user-selected tasks took part in an additional ten sessions and were weaned off mental tasks to achieve online voluntary self-regulatory control of a BCI using a neurofeedback-based paradigm. Participants indicated that they found self-regulation to be more intuitive and easier to use than mental tasks. Finally, user- and researcher-selected frameworks were applied to a client with undiagnosed motor impairments, unveiling a host of neuropsychological challenges to BCI control. Overall, this thesis advances the field of knowledge of NIRS-BCIs, specifically with respect to usability.
Sociology and the Problems of Problem Gambling Research: Connectin Private Troubles to Public Issues
Keywords: Medicalization
Problem gambling

This study addresses the lack of sociological perspectives in theoretical frameworks commonly used in problem gambling research, and demonstrates the connection of often overlooked aspects of the social environment to variables commonly used to predict and explain problem gambling. Using the often studied correlates of problem gambling, namely,, anxiety disorders; mood disorders; and gender, each paper shows how the relationships between those correlates and problem gambling are significantly modified by features of the social environment. Contributions of sociological research to theoretical frameworks for explaining problem gambling are posited as modifications to the Pathways Model to Problem Gambling. Advanced generalized linear modeling is used to explore the interconnections of these relationships in all three studies. The research findings are discussed in relation to the dangers of reducing complex social issues such as the prevalence of problem gambling to a series of individual characteristics found in problem gamblers. Implications of governmental responsibility in gambling provision, the medicalization of abnormal behaviours, and the role of sociological research in identifying patterns of inequality are also explored.
Safety Communication for Vehicular Networks: Context-aware Congestion Control and Cooperative Multi-hop Forwarding
Keywords: congestion control
multi-hop forwarding
safety aware
VANET
vehicular networks

Vehicular safety applications have the potential to make travel on our roads and highways much more safe. These applications require both reliable and up-to-date knowledge of the local neighbourhood, as well as reliable multi-hop propagation of safety alert messages. Under the IEEE Wireless Access in Vehicular Environments (WAVE) standard, the envisioned platform for vehicular communication, the former is attained through an exchange of single-hop broadcast safety beacons in the control channel. However, congestion of these periodic broadcast safety packets remains an obstacle to the large-scale deployment of vehicular ad hoc networks (VANETs). Excessive offered load on the shared control channel results in a deterioration of network performance and a subsequent reduction in the safety level at the application layer. Existing methods focus on providing fairness in the resources allocated, but fail to account for the different network performance requirements of vehicles in different driving situations. First, we address the problem of beaconing rate adaptation in response to network congestion and the driving context. We define a delay constraint profile for each communication link based on the driving context of the vehicles. We formulate the problem as a load minimization problem subject to a probabilistic constraint on the probability of violation of the delay requirements for each link in the network. We also develop an alternate formulation of the problem as a weighted network utility maximization (NUM) problem. We propose distributed algorithms to solve this problem in a decentralized manner and validate their performance through simulations. Some analytical results on their convergence are also provided. Next, we turn to the problem of providing reliable multi-hop forwarding in vehicular networks. Cooperative vehicular multi-hop schemes achieve reliability using broadcast transmissions and multiple forwarding relays at each hop. However, packet duplication must be controlled to circumvent the broadcast storm problem. Existing multi-hop dissemination schemes do not account for the presence of periodic safety beacons on the shared safety channel. We propose a cooperative forwarding protocol for highway vehicular networks, which extends a reliable vehicular broadcast medium access control (MAC) protocol based on positive orthogonal codes (POC). Multiple cooperating relays act as a virtual relay and schedule their transmissions to correspond to a single POC codeword. The proposed method exploits spatial diversity while mitigating the effect of hidden terminals. By allocating separate POC-based schedules for multi-hop packets and the periodic broadcast of safety heartbeat packets, the proposed protocol reduces the interference between the two types of safety transmissions. The performance of the protocol is studied through analysis using a Markov model and validated via simulations.
Soil Nutrient and Greenhouse Gas Cycles in Managed Mixed Deciduous Ontario Forests: The Role of Elevated Atmospheric Nitrogen Deposition and Nutrient and Biochar Amendments
Keywords: biochar
carbon dioxide
denitrification
methane
nitrous oxide
topography

Canada’s temperate forests are experiencing an environmental disturbance in the form of atmospheric nitrogen deposition arising from fossil fuel burning and agricultural practices. Nitrogen, a major nutrient required for plants and soil microorganisms, is normally in short supply in temperate forest ecosystems. However, when soil nitrogen is in excess, various negative impacts can result such as nutrient leaching, increased nitrous oxide emissions and disturbances to carbon cycling, including reduced soil methane uptake. Research has revealed a shift from nitrogen to phosphorus limitation in forests in central Ontario where chronic nitrogen deposition rates are high, and introducing soil amendments might have the potential to mitigate these negative effects. Before management strategies can be devised, it is important to characterize the degree of nitrogen excess, and how soil nutrient cycling and fluxes of greenhouse gases are being influenced, which may offset carbon gains from increased primary productivity. In an assessment of ambient soil characteristics representing natural topographic heterogeneity at Haliburton Forest, high inorganic nitrogen pools did not result in elevated nitrous oxide effluxes in upland soils, though hot spots and hot moments of nitrous oxide efflux occurred in wet depression areas where ammonium concentrations and moisture were high. Rapid methane efflux was also observed including what appear to be the highest rates in forest systems reported to date. A reduction in longer- (>5 year) and shorter-term (0-3 year) inorganic nitrogen pools in upland phosphorous-amended sites does support that the forest is phosphorous limited, however, there was no evidence of increased nitrous oxide emissions, even in nitrogen-amended sites that would be expected under nitrogen saturated conditions. Phosphorous limitation may be ameliorated by amending soils with biochar, which resulted in increased soil phosphorus, pH, and cation retention. The results of this research reveal that soils in temperate forests in Ontario are at a stage of nitrogen excess relative to ecosystem demands, but do not appear to have reached nitrogen saturation. However, with elevated exchangeable nitrogen pools and increasing nitrogen deposition, denitrification and methanogenic potentials, particularly under predicted increasing moisture regimes, may substantially impact and offset the overall carbon sink at this forest.