Open Theses & Dissertations

Permanent URI for this collection

https://unbscholar.lib.unb.ca/handle/1882/12778

Browse

Now showing 1 - 20 of 2069

Identification and characterization of cytochrome P450 monooxygenases for monoterpenoid indole alkaloid diversification
(University of New Brunswick, 2025-03) Mai, Zhan; Qu, Yang
Cytochrome P450 monooxygenases (CYPs) play a crucial role in monoterpenoid indole alkaloid (MIA) biosynthesis, mediating oxidation reactions like hydroxylation, epoxidation, and ring modifications that drive structural diversity. Despite advances in MIA pharmaceutical biosynthesis, many tailoring reactions remain poorly understood. By integrating transcriptomic and metabolomic data from Tabernaemontana litoralis and Vinca minor, I identified a novel MIA, 11-hydroxypseudovincadifformine, and characterized five CYPs involved in MIA oxidation. TliTbE from T. litoralis catalyzes pachysiphine formation, a lochnericine stereoisomer. TliPs18H is the first CYP modifying a pseudoaspidosperma skeleton. TliC10H hydroxylates voaphylline, while VmPs10H in V. minor completes akuammine biosynthesis and hydroxylates related MIAs. VmV10H further oxidizes structurally diverse MIAs. This study expands our understanding of MIA biosynthesis and enzyme function, unlocking new biocatalysts for MIA production and demonstrating the untapped potential of these plants in alkaloid diversification.
A comparison of the class E and class Φ2 inverter topologies for resonant capacitive power transfer
(University of New Brunswick, 2025-03) MacMillan, Matthew James; Rouse, Chris D.
The class E and Φ2 inverter topologies are compared in the context of a load-independent 13.56 MHz resonant capacitive power transfer (RCPT) system intended for electric vehicle charging. In addition to efficiency and power capacity, radiofrequency emissions are evaluated based on the harmonic content of the voltages presented to the transmit resonator. Both inverters deliver over 1 kW to the transmit resonator while maintaining system-level load independence. While the class E implementation is more efficient, the class Φ2 inverter offers solid performance and a significantly reduced second harmonic, making it desirable from an electromagnetic compatibility standpoint.
An improved MicroJIT for templated compilation in OpenJ9
(University of New Brunswick, 2025-03) Kaur, Harpreet; Kent, Kenneth B.
Programs that run on a Java virtual machine (JVM) are initially interpreted. To improve performance, Just-in-Time (JIT) compilers may be employed at run time to translate the program to native code that can be executed directly. In certain environments, the overhead of an optimizing compiler may be too high to be useful, and a non-optimizing compiler could improve performance over interpreted-only mode with limited overhead, memory footprint and compile times. Furthermore, adding a non-optimizing compiler between the interpreter and an optimizing compiler may reduce warm-up times. This is achieved by performing lightweight, template-based compilations to generate native code that runs faster than interpreting the source code, but slower than the optimized code generated by a full JIT compilation. This work proposes an improved compiler for template-based compilations and evaluates its effectiveness. The aim is to reduce the overhead associated with compiling methods and improving the overall runtime performance. The specific improvements include improving bytecode coverage, supporting static and special methods, handling polymorphism in a template-based compiler and incorporating exception handling. The Eclipse OpenJ9 implementation of the JVM is used as a proof-of-concept to illustrate the solution, coined as MicroJIT. Improving bytecode coverage will allow compiling more methods with MicroJIT, leading to early switching from interpreted to compiled code. The static, special and polymorphic methods are executed using method invocation bytecodes in Java. The method invocation bytecodes provide powerful capabilities for the Java platform and JVM languages. With support missing for these vital reference bytecodes, the initial MicroJIT implementation signals compilation failure when it encounters an unsupported bytecode. Exception handling helps maintain the normal desired flow in case of unexpected events. A thorough performance testing of MicroJIT was carried out to understand its effectiveness, limitations, performance discrepancies and necessary improvements to combat those. The evaluation reveals promising results, showcasing notable performance gains in terms of reduced compilation times and memory footprint, faster warm-up and improved overall execution efficiency. In terms of average execution times, MicroJIT achieves 35%, 3% and 13% gains over the no-optimizing compiler, default compiler run at MicroJIT invocation threshold and quickstart configuration respectively.
Understanding the factors affecting travel demand for persons with a mobility disability in New Brunswick
(University of New Brunswick, 2025-03) Whitehouse, Madeline; Hanson, Trevor R.
Despite having the second highest rate of disability in Canada, there is little known about how persons with a disability in New Brunswick travel. The purpose of this research was to better understand the barriers to travel persons with a mobility disability experience in New Brunswick. A mail-out stated travel behaviour survey was administered to clients of Ability New Brunswick in Fredericton and Moncton (n = 672, response rate = 15%). Results showed respondents have transportation “all of the time” to make shopping (47%), social (36%), and health trips (56%) and there was strong agreement (62%) that private vehicles are important for travel. There were 13 participants recruited to participate in a semi-automated travel diary to better understand daily travel patterns. Participants made 155 trips, with most (89%) being made using a private vehicle. Stated adaptation interviews revealed participants are reliant on their primary mode of transportation to make trips.
Improving regression-based myoelectric control: User compliance, simultaneity, and incremental learning
(University of New Brunswick, 2025-03) Morrell, Christian; Scheme, Erik
Regression-based myoelectric control offers the potential for simultaneous, independent, proportional control, but current implementations are limited by inconsistent training protocols and robustness issues. This thesis aims to address these limitations by providing a novel training protocol that overcomes key robustness issues that have hindered regression-based myoelectric controllers for decades. Two studies are performed, one demonstrating the volatility of current training protocols and the other proposing an alternative paradigm leveraging context-informed incremental learning. Results first show that models trained using existing protocols are affected by simply changing the visual prompting style. In response, the novel training paradigm is shown to significantly improve performance compared to traditional approaches. Furthermore, multiple co-adaptive approaches are contrasted to demonstrate the importance of building tolerance to user behaviours into myoelectric controllers. The results presented in this work provide important considerations for training myoelectric controllers and emphasize the value of designing with the user in mind.
Prey selection for fatty acid signature analysis using the Akaike information criterion
(University of New Brunswick, 2025-03) Rideout, Tyler; Stephenson, Matthew; Stewart, Connie
The estimation of marine predator diet compositions through fatty acid signature analysis allows valuable insights into the trophic structures of marine ecosystems by comparing the fatty acid signatures of predators with a library of their potential prey. These prey libraries consist of individual fatty acid signatures grouped by species, and in order to obtain unique diet estimates the number of groups in the library must be less than the number of dietary fatty acids in the analysis. We propose a novel application of the Akaike information criterion to identify the correct subset of species from a wider set of potential prey. The estimation of true zeroes through the removal of species from the prey library may result in reduced variability and greater accuracy in the estimation of non-zero proportions. Outcomes from simulation studies as well as the analysis of real-life grey seal data are used to explore the performance of this method.
Agricultural nitrate load attenuation in a small groundwater-influenced wetland system
(University of New Brunswick, 2025-03) Crossley, Leah; MacQuarrie, Kerry T.B.
Nitrate contamination of fresh water in agricultural watersheds, such as those in Prince Edward Island (PEI), is a significant human and environmental health concern. This field study (August 2023 – July 2024) investigated the nitrate loads delivered to and exported from a small (1.2 ha), groundwater-influenced, stream-wetland system in PEI. High frequency monitoring revealed that the annual nitrate load delivered to the wetland was 30,000 kg NO3 N/year. Groundwater discharge contributed about 67% of the nitrate load, while a small stream contributed the remainder. Variations in discharge rates were determined to be the dominant factor affecting the variation in nitrate loads. The wetland acted as a nitrate sink for 49 of 52 weeks, attenuating 39% of the imported nitrate load. The results of this study suggest that small, constructed wetlands can effectively reduce nitrate levels in agriculturally dominated watersheds; however, high-frequency data are required to obtain accurate estimates of nitrate load reductions.
Interpolating between splittings over cyclic subgroups
(University of New Brunswick, 2025-03) Cook, Benjamin R; Touikan, Nicholas
Given a finitely generated and torsion-free group Γ, it may be possible to express Γ as a product of smaller groups. In particular, we consider graph of groups decompositions of Γ — henceforth called splittings — wherein Γ is expressed as a collection of groups that are amalgamated over shared subgroups, and the underlying structure presented as a graph. In this thesis, we present a universal process for interpolating between two distinct splittings X1 and X2 of a group Γ to obtain a third splitting X3, also of the group Γ. While we present our results in the general case, we end the thesis by specifically considering cyclic one-edge cases — where the graph of groups has only one edge, representing a cyclic subgroup — and the three possible combinations of such one-edge splittings. Each of these three combinations yields a unique structure for the resulting interpolated splitting X3.
The intersection of thermal hysteresis and river-specific thermal regimes: Effects on thermal aggregation thresholds in juvenile Atlantic Salmon (Salmo salar) and brook trout (Salvelinus fontinalis)
(University of New Brunswick, 2025-03) Collet, Elise; O’Sullivan, Antóin; Linnansaari, Tommi
In summer of 2021, 2022, and 2023, underwater cameras were used to observe the onset of behavioural thermoregulation by juvenile Atlantic salmon (Salmo salar) in the relatively cool Restigouche River, NB, and by juvenile salmon and brook trout (Salvelinus fontinalis) in the warmer Little Southwest Miramichi River, NB. This thesis aimed to determine if juvenile salmon and brook trout aggregated at various temperatures throughout the summer. If so, could the variation be explained by a thermal hysteresis model? Furthermore, whether the aggregation onset thresholds differ for juvenile salmon in each river was investigated. It was determined that brook trout aggregated at a range of temperatures throughout both summers; however, the thermal hysteresis model could not explain the variation. Aggregations of juvenile salmon were not observed in the Miramichi, but aggregations in the Restigouche occurred in both years at various temperatures, and aggregations in 2022 strongly supported the thermal hysteresis model.
The optimization of urban-rural demand responsive transportation services in New Brunswick
(University of New Brunswick, 2025-03) Cartwright, Abigail; Hanson, Trevor R.; Christie, James S.
With over one-third of New Brunswick's population living with a disability, accessible Demand-Response Transit (DRT) services are crucial for those that need it. There is a need for data on the operation and travel patterns associated with DRT services in New Brunswick as new regional agencies are assuming transportation planning responsibilities and looking to expand services. This research used geographically aggregated passenger data from 6 months of trips by a paratransit provider to estimate trip rates and to pilot an exact solution method of Mixed Integer Linear Programming (Christie Method) for vehicle deployment. The Christie Method was able to reasonably replicate the conditions of the existing service provider subject to their level of service requirements and was then applied to a community use-case based on extrapolated trip rates. While effective, the exact solution approach increases processing time exponentially for any additional constraints, therefore other heuristic approaches may warrant future considerations.
Non-invasive non-normal relative permittivity measurements of buried earth layers
(University of New Brunswick, 2025-03) Brown, Brandon C.; Petersen, Brent R.
This dissertation presents a method for determining the relative permittivity of surface and sub-surface layers, such as a layer of snow on the ground and the hidden ground layers. In summer, the traditional two-ray model is expanded to three rays, where the new ray penetrates the top layer of ground until it is reflected by a change in the earth medium. In the winter, a five-ray model is used where snow covers the same ground. Measurements were taken in a field area measuring approximately 6800 m2 with the transmitter and receiver in close proximity to the area of interrogation, and where the ground exhibited lateral homogeneity. A genetic algorithm is used to determine the electrical characteristics of the ground and snow layers based on results from measurements taken from four positions and nine heights at each position, in summer and winter. At a frequency of 2.35 GHz, the snow covering the ground during the winter campaign was found to have a relative permittivity of 11.3.
Complexity, adherence, and nimbleness: Language ideology in a Canadian college
(University of New Brunswick, 2025-03) Beres, Kyle; White, Melissa; Rose, Sherry Lynn
Current Canadian language ideology, rooted in settler colonial and linguistic practices, imposes an English standard that discriminates against multilingual international students. This study sought to examine the pervasiveness and reproduction of standard language ideology in a Canadian college. A critical discourse analysis case study was conducted and included interviews with leaders responsible for language and diversity policies, practices, and procedures and analysis of relevant documents. Using inductive, open coding, four themes emerged: 1. complexity of language beliefs, 2. lack of official language policy, 3. adhering to language standards is crucial for student success, and 4. support is an institutional priority, which were triangulated with power, linguicism, and theory of ideology. These findings highlight how language ideology is complex and challenges and reinforces hegemonic norms. Further research is needed to deepen understanding of language ideology and how the institution can embrace global Englishes and reduce unconscious language oppression.
A qualitative exploration of EMG activity visual feedback for spinal cord injury hand function rehabilitation
(University of New Brunswick, 2025-03) Aikens, Janelle; Englehart, Kevin; Scheme, Erik
Spinal cord injuries (SCI) often lead to impaired hand function, reducing independence and requiring sustained motivation for rehabilitation, particularly when movement feedback is compromised. Augmented feedback, such as electromyography (EMG)-based visual feedback, may support motor learning and motivation, but its impact on SCI rehabilitation remains underexplored. This study investigates how EMG-based visual feedback influences motivation and its’ suitability for hand function rehabilitation. Using a qualitative approach informed by Self-Determination Theory, we conducted semi-structured interviews with five individuals with tetraplegia and a focus group with seven occupational therapists. Findings indicate that EMG feedback serves as an extrinsic motivator by providing tangible progress indicators and may enhance intrinsic motivation fostering enjoyment and aligning with personal interests. Themes highlight its potential across rehabilitation contexts, from pre-functional muscle awareness to improved patient-therapist communication. This research underscores EMG visual feedback’s role in bridging subfunctional and functional movement, offering a promising tool for advancing SCI rehabilitation.
Understanding teachers’ and school leaders’ perceptions of the teacher assessment process: Implications for teaching practices and ongoing professional development and learning
(University of New Brunswick, 2025-03) Adeniyi, Ruth Oluwafunke; Brien, Ken
Since the early 19th century, there has been a significant emphasis on regulating teachers’ practices and improving schools through rigorous teacher assessment. Teachers and school leaders continue to face ongoing criticism for their struggles to adapt to evolving assessment policies, especially given the limited evidence of improved performance resulting from these changes. This qualitative case study investigates the perceptions and practices surrounding the teacher assessment system within three middle schools in the Anglophone West School District (ASD-W) in New Brunswick. The primary objectives are to examine the understanding of the New Brunswick teacher assessment system among teachers and school leaders, assess their perceptions of autonomy in the assessment process, identify the impact of self-assessments and reflection on instructional practices, and determine how reflective feedback influences ongoing professional learning. Situated within an interpretative paradigm and informed by Weick’s (1995) organizational sensemaking theory, this research aims to understand how teachers and school leaders continuously interpret and navigate assessment processes to make decisions that enhance professional practices. Purposeful sampling was employed to select research sites within the Anglophone West school district (ASD-W). Data collection methods included semi-structured interviews and document reviews to gain comprehensive insights into participants’ perspectives on the assessment system. This study’s findings highlight the importance of educational policies that balance holding teachers accountable while supporting their professional development while fostering an environment of trust and collaboration. Additionally, it emphasizes the need for comprehensive self-assessment frameworks, reflective teaching methods, and personalized ongoing professional development and learning (OPDL) opportunities. These elements are crucial for enhancing teacher empowerment and improving instructional outcomes. Overall, these findings contribute to the broader discourse on teacher assessment and OPDL, offering valuable insights for policymakers, teachers, and school leaders aiming to navigate and enhance the complexities of teacher assessment systems.
Estimating the vertical offsets of a crowd-sourced bathymetry system using Kalman Filter solution
(University of New Brunswick, 2025-03) Ibekwute, Samuel Izuchukwu; Church, Ian
Crowd-sourced Bathymetry (CSB), recognized for its potential in mapping uncharted waters, is faced with credibility and useability concerns, which makes Hydrographic Offices (HOs) hesitant to consider them for use in official nautical charts. This research implemented a Kalman Filter (KF) algorithm to estimate the vertical offsets between theGNSS receiver and the sonar and the GNSS receiver and the waterline, two quantities which are often not measured in a CSB system. The algorithm uses Ellipsoid Reference Survey (ERS) principles, estimated uncertainties, and hydrodynamic models for tidal adjustments. The solution was tested with six datasets collected from the Gulf of St. Lawrence where the difference between the previously estimated GNSS to sonar offset and the KF solution results ranged between -1.286m and 1.168m. The results showed the technique's ability to significantly improve CSB data quality by resolving these offsets, paving the way for wider adoption in official charts.
The Falls Island Collection: A report on a collection of late Maritime Archaic through Protohistoric period artifacts from Falls Island in Cobscook Bay, Maine.
(University of New Brunswick, 2025-02) Cummings, Joshua A.; Hrynick, M. Gabriel; Anderson, Arthur
Falls Island is located in Cobscook Bay, Maine, in the western Quoddy Region. Between the 1930s and 1950s, local avocational archaeologists John and Douglas Knapton visited the island and collected artifacts from eroding shell middens and intertidal zones. Their collection was donated to the Robert S Peabody Institute, where they are currently curated. I analyzed the artifacts using a culture-historical approach. The collection suggests an extensive period of occupation from the Late Maritime Archaic through Late Maritime Woodland periods (ca. 5500-550 cal BP). In this thesis I place the artifacts chronologically using typology from the Quoddy Region, the Atlantic Northeast, and New England. I also conducted a pedestrian survey of Falls Island, which revealed two remaining archaeological sites, and two eroded sites. This thesis uses collections research and pedestrian survey to analyze coastal archaeological sites in the Quoddy Region.
DGSim: A scalable and configurable framework for simulating energy consumption of household appliances
(University of New Brunswick, 2025-02) Addala, Bhavani Sai Prasad; Kent, Kenneth B.
We introduce DGSim, a flexible and scalable framework for simulating household energy consumption. Traditional energy simulation tools often struggle with configurability across diverse household types and scalability to urban and regional scales. First, we explore DGSim’s ability to adapt to different appliance configurations and household structures, allowing precise modeling of varied consumption patterns. Second, we implement a multi-faceted configurability approach, enabling detailed customization for appliances, usage patterns, and community demographics. Third, we enhance scalability with optimizations that support large-scale simulations involving millions of instances, allowing DGSim to model energy use across residential communities. Our evaluation demonstrates DGSim’s capability to provide insights for demand-side management, highlighting its benefits over existing simulation frameworks for both detailed and large-scale residential energy analysis.
“The Greatest Scoundrels in the Universe:” Haitian migrants, revolutionary contagion, and Jamaican migration law during the Haitian Revolution
(University of New Brunswick, 2025-02) Waters, Colin; Hunt-Kennedy, Stefanie
In 1791, the enslaved people of French Saint-Domingue revolted, leading to a thirteen-year revolutionary war. In the neighbouring British colony of Jamaica, slaveowners feared that revolutionary ideology would spread and inspire Jamaican bondspeople to revolt. Between 1791 and 1799, Jamaican lawmakers, who were themselves slaveowners, responded to the threat of revolutionary contagion through a series of laws known as the Alien and Foreign Slave Acts. The creation and development of these laws was also shaped by a long-standing political dispute between Jamaica and Great Britain over their respective privileges and powers and over the future of slavery. The legislation sought to limit the entry of Saint-Domingue migrants, including white slaveowners, free people of colour, and the enslaved, restrict their movements within Jamaica, and surveil them. These laws, unprecedented in their scope and severity, demonstrate the ways that Jamaican slaveowners drafted legislation to navigate colonial politics and perpetuate slavery.
Developing a hybrid actuated cable-driven parallel manipulator using a compact tape rod actuator
(University of New Brunswick, 2025-02) Sanford, Paul William; Antonio Carretero, Juan
Cable-driven parallel manipulators (CDPMs) are an active area of research due to their efficiency, speed, and range of workspace sizes. In this work, a parallel manipulator with hybrid actuation is developed to expand the capabilities of conventional CDPMs by adding a compact linear actuator. The linear actuator, which unlike cable actuators can push and pull, is created using three tape measures forming a rigid rod that can be spooled. The combined mechanism is controlled using position and force sensors for each of the four actuators. The mechanical design, control system, kinematics, and electronics are discussed. The cable and tape rod actuators were tested individually and as a manipulator with quasi-static loading. The control system and cable actuators were able to reliably apply compressive forces to the tape rod actuator, which experienced early fatigue and excessive wear.
Chasing the dream: Understanding the journey of Canadian high performance athletes, the nature of the challenges and the motivation to persevere
(University of New Brunswick, 2013-01) Allain, Monique; Morrison, William; Peterson, Patricia
The purpose of this study was to develop a better understanding o f the journeys of Canadian high performance athletes, specifically, their experiences of strain and social support in becoming and being a senior national team member, representing Canada at international events. Eleven Canadian high performance athletes shared their journeys while competing at the 2011 Pan American Games, held in October 2011 in Guadalajara. The research design employed a narrative inquiry approach, and included in-depth interviews that were conducted with participating athletes. The goal of this investigation was to give voice to the athletes, allowing them to share their stories. The process of interviewing and analyzing the athletes’ stories yielded a deeper understanding of how they drew upon internal and external resources in meeting core psychological needs associated with relatedness, competence and autonomy support. Based on the completed research, a five-step model for building athletes’ resiliency is proposed.

Browse

Recent Submissions