identifier: Reza, Mohammad Selim <https://research.library.mun.ca/view/creator_az/Reza=3AMohammad_Selim=3A=3A.html>   (2019) Impact of climate change on agricultural production and food security of Newfoundland and Labrador, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract:
Newfoundland and Labrador (NL) has a food security issue due to lack of suitable
agricultural land, short growing seasons, and unsustainable agricultural policies promoting
conventional industrial farming practices, with a limited range of agricultural produce (milk,
eggs and poultry) and no facilities for secondary processing of these. The food security issue
has been exacerbated in the last decades by climate change events (extreme temperatures,
heavy rains and more frequent droughts) which have negatively impacted the province’s
agricultural industry. The conventional industrial agricultural practices and the profit focus of
maximization agricultural policies have contributed to and have intensified several
environmental, social and economic problems. They have as well provided an inadequate
guarantee for food security, as the NL agriculture industry does not secure enough healthy,
fresh, nutritious, and affordable food alternatives for people to live and be healthy. This
research is based on quantitative and qualitative data, collected through surveying both crop
and dairy farmers located in western, central and eastern regions of the Newfoundland and
Labrador province, and through a literature review of peer-reviewed articles, published
government reports and documents and news articles. The research results show that any
attempt to solve the multi-faceted problems of the NL agriculture impacted by climate change
increases the significance of pursuing an agro-ecological approach to farming in the province.
Integrated and small, highly diversified farms are one sustainable alternative to modern
industrial farming, as they can make the current agricultural practices more resilient to global
climate change (GCC), can enhance food security in the province, as well as reduce the
impact of agricultural practices on GCC. This study has found that 100 percent of the crop
and dairy farms production has been affected by two or more natural hazards, such as long
winters/short growing seasons, late spring frost and heavy rains/rain storms, which are the
results of climate change. More interestingly, 56 percent of the farm owners in the study area believe that industrial or conventional farm practices have little or no impact on
environmental degradation or climate change, since they follow the agriculture rules and
guiding principles imposed by the provincial and the federal government of Canada and
apply efficient farm management strategies. In some cases, the soils, chemical fertilizers and
fossil fuels are poorly managed by the farmers surveyed in the study area, but a good
percentage of the farmers are trying to reduce dependency on chemical fertilizers and
pesticides and fossil fuels and at the same time, are trying to increase the use of organic
fertilizers, pesticides and renewable energy. Moreover, the current research has shown that
there are incipient agro-ecological practices in the province, and that farmers are aware about
climate change and the need to adopt more environment friendly farming practices. New
policy frameworks and work plans are needed to speed up the transition from the current
unsustainable farming practices to small-scale, organic, energy efficient and high yielding
agro-ecological practices. Provincial as well as federal government support, and collaboration
among educational and research institutions, agricultural farms, non-government
organizations and the general public will promote agricultural diversification and integration
and more environmentally-friendly farm practices within the province. These will ameliorate
province’s food security issue, by increasing the supply of local fresh and healthy food, will
provide additional financial benefits to the farm holders, as well as protect the local and the
global environment.


identifier: Nieto-Blázquez, María Esther <https://research.library.mun.ca/view/creator_az/Nieto-Bl=E1zquez=3AMar=EDa_Esther=3A=3A.html>   (2019) Historical biogeography of endemic plants in the Caribbean and Podocarpus as a case study.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract:
Despite numerous floristic studies of the Caribbean region, the large-scale evolutionary origins of its diversity remain relatively under-explored. Here, I add to the empirical knowledge of the origin and assembly of the Caribbean flora by large-scale molecular analysis of the biogeography and phylogenetics of its constituent genera, with special emphasis on the conifer genus Podocarpus L’Hér. ex Pers. and its endemic species in the Antillean island chains. Connection of the Greater Antilles to northern South America by a late Eocene / early Oligocene land bridge, GAARlandia, has been hypothesized to facilitate colonization of the Caribbean islands. Well-calibrated estimates from molecular data of the ages of extant Caribbean endemic plant genera show a combination of relatively recent (late Oligocene / early Miocene) and older (late Paleocene / early Eocene) lineages, such that the GAARlandia hypothesis is not necessary to explain floral colonization of the Caribbean. Ancestors of most endemic genera included in my study were of Antillean origin. I show that diversity in Caribbean Podocarpus is paraphyletic, the result of a single colonization of the Greater Antilles from South America in the late Oligocene, species diversification leading to endemism beginning in the early Miocene, and dispersal to the Lesser Antilles from a Greater Antillean ancestor later in the early Miocene. Detailed examination of the phylogeography of the two endemic species on Hispaniola, P. buchii and P. hispaniolensis, shows an initial colonization to the southern palaeo-island of Hispaniola by a P. buchii ancestor. Subsequent northward stepping-stone migration is evident in the localization of genetic clusters across the main cordillera systems. P. hispaniolensis arose by progenitor-derivative speciation in the Central Cordillera. The assembly of Caribbean flora has been complex, and geology, vicariance, dispersal, and in situ speciation, together shaped the biotic assembly of the islands.
"Abunda la tierra del Cibao (de Ciba, piedra de pinos mui altos que no llevan piñas, por tal orden compuestos por naturaleza, que parecen azeytunos del Axarafe de Sevilla" C. Columbus


identifier: Thistle, Rebecca <https://research.library.mun.ca/view/creator_az/Thistle=3ARebecca=3A=3A.html>   (2019) An evaluation of the effects of simulator training on ice management performance.  Masters thesis, Memorial University of Newfoundland.

abstract:
This research offers practical insights into the relationship between amount of
training and ice management performance. In a previous experiment, it was
found that, on average, experienced seafarers performed better in an ice
management simulator than inexperienced cadets (Veitch, 2018). In a current
experiment, two additional groups of inexperienced cadets were trained for ice
management in either one or two sessions. The training included viewing
examples of expert performance and completing practice scenarios in a
simulator. After training, the cadets completed two ice management simulator
scenarios, one of which was the same as that used in the previous experiment.
Training was found to have a positive effect on ice management performance in
most scenarios. In the scenario used in both experiments, ice management
performance improved with increasing amounts of training and the results
demonstrate a proposed method for estimating the amount of training required to
reach a performance target.


identifier: Oloruntobi, Olalere Sunday <https://research.library.mun.ca/view/creator_az/Oloruntobi=3AOlalere_Sunday=3A=3A.html>   (2019) The pore pressure, bulk density and lithology prediction.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The pore and fracture pressures are the two most important parameters required for the effective well design. In general, the difference between the two parameters at any given depth dictates the drilling window with no consideration for wellbore stability. While pore pressure prediction from the drilling parameters started in the mid-nineties, very few improvements have been made in these areas when compared to other pore pressure prediction techniques such as seismic and well logs. Pore pressure prediction using the d-exponent method does not consider the effect of bit hydraulic energy on the rate of penetration (ROP). This limits the application of the d-exponent to mostly hard rock environments. Under downhole conditions where the bit hydraulic energy has a significant influence on the ROP (soft rock environments), the d-exponent method may produce inaccurate results. Hence, the primary goal of this research is to develop new pore pressure prediction models from the drilling parameters that incorporate the bit hydraulic energy, making them suitable for any subsurface drilling conditions. The new pore pressure prediction models use the concept of specific energy to predict the onset of overpressure. The concept of specific energy is then extended to the real-time identification of subsurface lithology.
Furthermore, overburden pressure is an important input parameter in pore pressure prediction. Inaccurate prediction of overburden pressure may result in the erroneous prediction of pore pressure which can lead to well control and process safety incidents. In areas where density logs are not available, synthetically derived density logs are used for overburden pressure computations. In this research, an attempt is also made to improve the accuracy of pore pressure prediction by improving the accuracy of overburden pressure computation via improvement in density logs prediction. Finally, since pore and fracture pressures are closely related, an attempt is made to develop a new fracture pressure prediction model for the Niger Delta basin.


identifier: Esene, Cleverson Ebeagbor <https://research.library.mun.ca/view/creator_az/Esene=3ACleverson_Ebeagbor=3A=3A.html>   (2019) New insights into transport phenomena involved in carbonated water injection: effective mathematical modeling strategies.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Carbonated water injection (CWI) is a promising enhanced oil recovery (EOR) method that provides an efficient and a more environmentally friendly alternative to meet the ever-increasing demand for energy. An additional benefit from the implementation of CWI is the storage of anthropogenic CO₂ and this has made it even more attractive. Over the years, several attempts have been made to model CWI as an EOR process but have been of very little success due to the underlying assumptions used or the modelling strategy. There are several multi-physics involved during CWI and to have an accurate model to investigate CWI, these physics need to be adequately captured. In this thesis, we have attempted to model CWI adequately by using more realistic and practical assumptions to present a novel modeling strategy. This thesis shows our research in a manuscript-based format which is presented in each chapter as major contributions. Firstly, a comprehensive review of CWI where the behavior of fluids, fluid-rock interactions and challenges associated with CWI technique have been thoroughly discussed. Secondly, the modelling investigation to capture the critical salinity which plays an important role in EOR techniques for sandstones and carbonate as well as the solubility of CO₂ during CWI is presented. Thirdly, a 3-D modeling method to investigate CWI which considers important terms such as gravity, non-instantaneous equilibrium, heterogeneity, anisotropy and well orientation is presented. Fourthly, a 1-D core modelling approach which considers the reaction term and rock dissolution in an improved attempt to capture CWI is presented. Finally, a deterministic approach is presented to effectively predict oil recovery factor based on pattern recognition and artificial intelligence. To facilitate this, the use of artificial neural network (ANN), least square support vector machine (LSSVM) modelling and gene expression programming (GEP) are adopted.


identifier: Turner, Abigail <https://research.library.mun.ca/view/creator_az/Turner=3AAbigail=3A=3A.html>   (2019) Attitudes and perceptions of Newfoundland and Labrador pharmacists toward participating in medical assistance in dying.  Masters thesis, Memorial University of Newfoundland.

abstract:
Introduction: This thesis aimed to describe pharmacists’ willingness to participate in medical assistance in dying (MAiD) and potential barriers to their participation.
Methods: A systematic review on the existing literature and a survey of Newfoundland and Labrador (NL) pharmacists were conducted.
Results: The systematic review found the majority of studies were conducted before 2002 and before MAiD was legal or where MAiD is still not legal. Pharmacists’ willingness to participate varied, and there was a gap in the literature on barriers and facilitators to the pharmacist’s role in MAiD. The survey of NL pharmacists found the majority were willing to participate, however NL pharmacists felt they lacked knowledge regarding MAiD (e.g. MAiD process, MAiD medications, information to provide patients on MAiD) and had concerns about the consequences of participating in MAiD.
Conclusion: The majority of NL pharmacists are willing to participate in MAiD however, more supports (i.e. educational, emotional) are needed to better prepare and assist pharmacists in this new practice area. Furthermore, research is needed to evaluate pharmacists’ experiences with actual participation in MAiD.


identifier: Dávila, Manuel A. Soto <https://research.library.mun.ca/view/creator_az/D=E1vila=3AManuel_A=2E_Soto=3A=3A.html>   (2019) Atlantic cod (Gadus morhua) and Atlantic salmon (Salmo salar) immune responses against Aeromonas salmonicida subsp. salmonicida infection.  Masters thesis, Memorial University of Newfoundland.

abstract:
Atlantic cod and Atlantic salmon are among the main species of the Canadian fisheries and aquaculture industries. Populations of both fish species are exposed to different pathogens such as bacteria that cause infectious diseases. Vibrio anguillarum, Francisella noatunensis, Renibacterium salmoninarum, and Aeromonas salmonicida subsp. salmonicida are the most frequent bacteria that infect Atlantic cod and Atlantic salmon.
Aeromonas salmonicida subsp. salmonicida, is one of the oldest known fish pathogens and the causative agent of furunculosis in marine and freshwater fish. This Gram-negative pathogen is having a negative impact on fish health, especially in emergent marine aquaculture in Canada. A. salmonicida is also an excellent bacterial model to study fish host-pathogen interactions and assist with analyzing compounds that can be useful to stimulate the immunity of the fish.
Here, I evaluate the effect of A. salmonicida on the innate immune response of Atlantic cod and Atlantic salmon primary macrophages utilizing microbiological and molecular biology tools. Additionally, I determine the effect of vitamin D₂ and D₃ as potential immunostimulants against the bacterial infection caused by A. salmonicida in Atlantic salmon.


identifier: Yang, Ruochen <https://research.library.mun.ca/view/creator_az/Yang=3ARuochen=3A=3A.html>   (2019) Risk assessment of fire accidents in chemical and hydrocarbon processing industry.  Masters thesis, Memorial University of Newfoundland.

abstract:
Fire disasters are among the most dangerous accidents in the chemical and hydrocarbon processing industry. Fires have been the source of major accidents such as the Piper Alpha disaster (1976), the BP Texas City disaster (2005), the Buncefield oil depot fire (2005), Puerto Rico’s fire accident (2009), and the Jaipur fire accident (2009). The catastrophic impact of fire accidents necessitates a detailed understanding of the mechanisms of their occurrence and evolution in a complex engineering system. Detailed understanding will help develop fire prevention and control strategies.
This thesis aims to provide a detailed understanding of fire risk in the hydrocarbon production and processing industry. In order to realize this objective, the work presented in the thesis includes three parts: i) Developing a procedure to study potential fire accident scenarios in an offshore facility with different ignition source locations. This procedure helps to design safety measures. The effectiveness of safety measures is verified using a computational fluid dynamics (CFD) code. This work emphasizes that an FLNG layout must be considered with the utmost care since it is the most effective measure in limiting a potential LNG release and subsequent dispersion effect, and directly influences the fire dynamics and thus limits the potential damage. ii) An integrated probabilistic model for fire accident analysis considering the time-dependent nature of the fire is developed. The developed model captures the dynamics of fire evolution using three distinct techniques Bayesian networks, Petri Nets, and a CFD model. The Bayesian network captures the logical dependence of fire causation factors. The Petri Net captures the time-dependent evolution of a fire scenario. The CFD model captures the dimension and impact of the fire accident scenario. The results in this work show that a time-dependent probability analysis model is necessary for fire accidents. iii) Whether fire alone can cause a domino effect is demystified in the last work. A solid-flame model is used in a CFD framework to calculate the escalation vector for a domino effect; escalation probability is assessed using a probit model. The results demonstrate that a pool fire alone sometimes may not cause a domino effect in the current industry. It is other factors, such as explosion and hydrocarbon leakage, work together with a pool fire to escalate into a domino event, for example, the results shown in the case study of the Jaipur fire accident.


identifier: Himi, Umma Hafsa <https://research.library.mun.ca/view/creator_az/Himi=3AUmma_Hafsa=3A=3A.html>   (2019) Statistical comparison of SAR backscatter from icebergs embedded in sea ice and in open water using RADARSAT-2 images of in Newfoundland waters and the Davis Strait.  Masters thesis, Memorial University of Newfoundland.

abstract:
Icebergs are considered a threat to marine operations. Satellite monitoring of icebergs is one option to aid in the development of iceberg hazard maps. Satellite synthetic aperture radar (SAR) is an obvious choice because of its relative weather independence, day and night operation. Nonetheless, the detection of icebergs in SAR can be a challenge, particularly with high iceberg areal density, heterogeneous background clutter and the presence of sea ice.
This thesis investigates and compares polarimetric signatures of icebergs embedded in sea ice and icebergs in open water. In this thesis, RADARSAT-2 images have been used for analysis, which was acquired over locations near the coastline (approximately 3-35 km) of the islands of Newfoundland and Greenland. All icebergs considered here are in the lower incident angle range (below 30 degrees) of the SAR acquisition geometry. For analysis, polarimetry parameters such as co- (HH) and cross- (HV) polarization and several decomposition techniques, specifically Pauli, Freeman-Durden, Yamaguchi, Cloud-Pottier and van Zyl classification, have been used to determine the polarimetric signatures of icebergs and sea ice. Statistical hypothesis tests were used to determine the differences among backscatters from different icebergs. Statistical results tend to show a dominant surface scattering mechanism for icebergs. Moreover, icebergs in open water produce larger volume scatter than icebergs in sea ice, while icebergs in sea ice produce larger surface scatter than icebergs in open water. In addition, there appear to be minor observable differences between icebergs in Greenland and icebergs in Newfoundland.


identifier: Zabihi-Seissan, Sanaollah <https://research.library.mun.ca/view/creator_az/Zabihi-Seissan=3ASanaollah=3A=3A.html>   (2019) Gray wolves adjust their spatial and social environments according to prey distributions in a multi-prey system.  Masters thesis, Memorial University of Newfoundland.

abstract: Animals modify their environment through movement to increase their success in acquiring energy. This may be done by selecting spaces to increase encounter rates with prey through different space use tactics, or in the case of social carnivores, adjusting social environments to balance the tensions associated with capturing prey and sharing the acquired energy with conspecifics. I tested hypotheses on how social predators select space based on three prey distribution metrics, and how they subsequently adjust their level of cohesion with conspecifics based on prey distribution. I tested these hypotheses in Riding Mountain National Park, Manitoba, a multi-prey system where gray wolves (Canis lupus) prey on moose (Alces alces), elk (Cervus canadensis), white-tailed deer (Odocoileus virginianus) and beaver (Castor canadensis). I found evidence that wolves used the predicted space use tactic for their primary prey species and adjust their level of cohesion based on the distribution of moose and beaver.


identifier: Ghosh, Arko <https://research.library.mun.ca/view/creator_az/Ghosh=3AArko=3A=3A.html>   (2019) Modeling and testing of temporal and non-linear dependence in a multivariate process system.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis presents the modeling and testing of temporal and spatial non-linear dependence among the process components in a process system. Due to interconnectivity among process units, the variables are highly correlated and dynamic. Accident models should capture these complex and dynamic behaviours of the components to predict accidents early. Fault tree, Dynamic fault tree, Bayesian network, Dynamic Bayesian network and Copula-based Bayesian network models have been selected to model these characteristics of the variables and develop the early prediction of accidents. At first, temporal dependency has been modeled and experimentally validated. The performances of dependence models are illustrated for accident analysis using Fault tree, Dynamic fault tree and Bayesian network models. Process datasets from a lab-scale pilot plant introducing faults into the system have been used for this purpose. The analysis shows that the inherent properties to capture different spatial (indirect dependencies) and temporal dependencies among process variables make the Bayesian network superior to Dynamic fault tree and the traditional fault tree models. Secondly, non-linear spatial dependence (modeled as covariate direct dependence) along with temporal dependence have been modeled to investigate accidents. A copula-based Bayesian network and traditional Bayesian network have been used to model direct dependence and the performances of the models are validated experimentally. A pilot plant has been used to perform experiments and collect process data sets. The results illustrate that, the copula function can capture the non-linear dependence among process variables. The integration of the copula function and Bayesian network can predict accident probability more efficiently than the traditional Bayesian network. The successful validation of the accident models confirms the evolving nature of the models capturing spatial and temporal dependence to address operational safety challenges in the process industries.


identifier: Santisteban Vela, Nury Paula <https://research.library.mun.ca/view/creator_az/Santisteban_Vela=3ANury_Paula=3A=3A.html>   (2019) Interaction of antimicrobial peptides with bacterial cell envelopes.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Antimicrobial peptides (AMPs) are small chains of amino acids with the ability
to cause bacterial death. AMPs are usually amphiphilic but diverse in charge and
structure. The mechanism or mechanisms that AMPs implement to kill bacteria
are still under discussion. Studies in model membranes have widely demonstrated
the capacity of AMPs to interact with and disrupt the bacterial cell membrane.
There are however, good reasons to suspect that AMP interactions with nonmembrane
components of bacteria are important. For instance, there is an enormous
discrepancy between the peptide to lipid molar ratio (P:L) necessary to
generate membrane disruption in model systems (~ 1:100), and the P:L necessary
to stop bacterial growth, i.e. the minimal inhibitory concentration (MIC) (~ 10-
100:1). One potential explanation for this discrepancy is that AMPs may interact
with non-membrane components of the bacterial cell envelope. The peptidoglycan
(PGN) layer is one of the primary non-membrane components of Gram-positive
bacterial cell envelopes and is responsible for cell shape and stability. Currently,
there is an open discussion about whether PGN can entrap AMPs and prevent
them from reaching the cell membrane or, instead promote the accumulation of
AMPs on the cell membrane. The primary experimental approach employed in
this thesis was ²H NMR spectroscopy of intact bacteria with 2H-labeled membranes.
Specifically, since the quadrupolar splittings obtained from the spectra
are proportional to the order parameter of the lipid acyl chains, the spectra reflect
the structure and dynamics of the membrane. In particular, ²H NMR spectroscopy
allows us to characterize the disruption of lipid bilayers caused by AMPs. In this
study, different methods to grow ²H-membrane-enriched bacteria were optimized
to obtain ²H NMR spectra of E. coli LA8, E. coli JM109 and B. subtilis. Additionally,
²H NMR was used to observe the level of disruption of the cell membrane
of B. subtilis caused by the presence of different AMPs, MSI-78 and BP100. Both
MSI-78 and BP100 caused the same level of membrane disruption at similar concentrations.
Separately, comparison of the ²H NMR spectra of B. subtilis with
intact and compromised PGN layers showed no differences. The lack of change in
the spectra of PGN-compromised and PGN intact bacteria indicates that there is
no change in the dynamics or structure of the lipid bilayer even with a weakened
PGN layer. Finally, the disruption caused by MSI-78 and BP100 was measured in B. subtilis with a compromised PGN layer. The results indicate that there is no
change in the level of membrane disruption caused by MSI-78 and BP100 when
the PGN layer is partially removed.


identifier: Harvey, Victoria C. <https://research.library.mun.ca/view/creator_az/Harvey=3AVictoria_C=2E=3A=3A.html>   (2019) The behavioural effects of lesions to the head direction cell circuit on spatial learning in rats.  Masters thesis, Memorial University of Newfoundland.

abstract: The head direction (HD) cell circuit acts as a neurological compass, providing information on directional heading to the hippocampus. The HD signal originates in reciprocal connections between the lateral mammillary nuclei (LMN) and the dorsal tegmental nuclei (DTN); the signal is then relayed to the anterodorsal thalamic nuclei (ADN) and cortical areas. The functional role of these regions in spatial learning problems is not well understood. Rats underwent neurotoxic lesions of either the LMN or ADN and were tested using three tasks thought to depend on directional heading. Impairments were seen in both lesioned groups in the water T-maze tasks that required discrimination of headings that were 90° (rotation task) or 180° (direction task) apart. Lesioned rats were also impaired on a 12-arm maze if they were required to discriminate between adjacent arms that were 30° apart, but not when arms were separated by at least 90°. Performance on a response reversal task, where the maze was rotated by 90° each time the response-reinforcer contingency changed, was unaffected by lesions to the LMN or ADN, indicating that this task may not be critically dependent on the HD cell signal. Our results suggest that the difficulty of spatial problems relates to the angular specificity of direction discrimination required.


identifier: Ashourloo, Mahdiyeh <https://research.library.mun.ca/view/creator_az/Ashourloo=3AMahdiyeh=3A=3A.html>   (2019) Adsorption modeling of thin-film molecularly imprinted polymers to measure pyrene in marine environments.  Masters thesis, Memorial University of Newfoundland.

abstract:
This thesis characterizes the adsorption properties of molecularly imprinted polymers (MIPs) for pyrene. MIPs are applied for monitoring organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and can be deployed in freshwater and marine (saline) water for detection of anthropogenic impacts. Exploiting a simple, low-tech method is of high priority as the fast detection of oil spill sources has become a challenge to analytical chemists and environmental scientists. Kinetic tests were conducted employing the developed MIPs in our group using an Ultra Performance Liquid Chromatography (UPLC) for the measurement of pyrene, PAHs, in both small and large volume studies.
Discussed will be the results obtained from kinetic and equilibrium adsorption experiments conducted using these films for measuring pyrene in distilled, tap water, and saline water. To gain an insight into the effects of temperature, pH, and salinity, the same experiments were conducted at varying temperature, pH, and salinity employing the standard batch equilibrium method. This research evaluates the adsorption capacity of the obtained polymers as a means to use MIPs for onsite detection without elaborate calibration making them suitable for use in early warning systems for oil spills.


identifier: Abugharara, Abdelsalam N. A. <https://research.library.mun.ca/view/creator_az/Abugharara=3AAbdelsalam_N=2E_A=2E=3A=3A.html>   (2019) Influence of formation anisotropy and axial compliances on drilling performance.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Drilling provides the path to reach and exploit underground oil and gas reserves. Drilling oil and gas wells can be vertical, inclined, or horizontal. However, as non-vertical drilling has become dominant, success in increasing oil and gas production has been led by horizontal drilling.
Trajectories of horizontal wells have three main curvature segments: vertical, inclined (diagonal or oblique), and horizontal, where the properties of the encountered formation during drilling may vary with inclination.
Rocks, classified as anisotropic (i.e. shale), whose properties are directional dependent or classified as isotropic (i.e. fine-grained and sandstone), whose properties are not directional dependent, have high influence on drilling performance, especially in nonvertical drilling.
The significant shift towards horizontal drilling has increased the interest in laboratory studies and research on directional drilling, particularly in shale, to evaluate the influence of anisotropy orientation on drilling performance (i.e. ROP), and therefore, choose optimal trajectory, enhance performance, and reduce costs.
This dissertation focuses on: (i) developing an experimental procedure for classifying rock anisotropy through oriented physical, mechanical, and drilling measurements, (ii) evaluating the influence of shale (as VTI rocks) anisotropy orientation on drilling parameters, and (iii) investigating the enhancement of the drilling rate of penetration (ROP) by implementing the novel drilling technique of passive Vibration Assisted Rotary Drilling (pVARD).
First, a laboratory baseline procedure was developed for a rock anisotropy characterization involving oriented physical, mechanical, and drilling tests on rock like materials (RLM). This research objective was to develop the procedure on synthetic rocks (RLM) as well as natural rocks, including shale, granite, and sandstone.
Second, detailed oriented physical, mechanical, and drilling measurements were taken for the determined isotropic and non-isotropic rocks in stage I, then aimed to interlink all results of all measurements, through which isotropic rock classifications can be enriched, and confirmed.
Third, compliant (i.e. pVARD) versus non-compliant (without pVARD) drilling was performed in various rocks for the purpose of evaluating the influence of axial oscillations on drilling performance. Also, the parameters behind enhancing ROP with compliant versus non-compliant were investigated in this research.
Last, a relationship between oriented strength and oriented drilling parameters for isotropic and anisotropic rocks was developed. This research aims to establish relationships between strength variation, drilling performance, and the main drilling parameters that influence ROP in different rock types for the purpose of rock isotropy / anisotropy evaluation.


identifier: Rastghalam, Zahra Sadat <https://research.library.mun.ca/view/creator_az/Rastghalam=3AZahra_Sadat=3A=3A.html>   (2019) Aggregation, attachment, and transport of nanoscale titanium dioxide (nTiO₂) in subsurface environments: effects of complex water chemistry and medium.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The transport of contaminants in subsurface environments is influenced by water chemistry and properties of the transport media. Due to the development and application of nanotechnology, engineered nanoparticles, such as nanoscale titanium dioxide (nTiO₂), are being released into the aquatic environment, which may pose serious hazards to the ecosystem. Extensive research has been performed to understand engineered nanoparticle’s fate and transport in groundwater. Many of the studies focus on the influence of simple water chemistry (e.g., pH, ionic strength, dissolved ions) and well-defined porous media (e.g., quartz sand or glass beads). The results obtained from some other studies emphasize the need to consider the effect of heterogeneous media, along with complex water chemistry, when evaluating engineered nanoparticle contamination risks. The objective of this thesis is to elucidate the effect of complex water chemistry and geochemically heterogeneous media on nTiO₂ transport and deposition, and the related mechanisms (e.g., ripening, precipitation, deposition, aggregation, blocking, straining) were explained. Batch experiments illustrated that nTiO₂ aggregation and attachment were strongly influenced by pH and Ca²⁺, both of which modified nTiO₂ surface charges. The effect of phosphate on nTiO₂ and illite attachment to sand was influenced by pH and cation valency. Moreover, illite attachment to sand was much lower than that of nTiO2 under all the conditions tested in this study. Results from column experiments showed that under complex physicochemical conditions, nTiO₂ transport is not only controlled by the interactions between nTiO₂ and common groundwater/aquifer components (e.g., suspended illite clay, phosphate, Fe oxyhydroxide coating) but also the interactions between these components. Finally, column experiments illustrated the importance of soil and sediment mineralogical and organic components, including Fe oxyhydroxides, clay (e.g., illite), and solid organic matter (e.g., peat moss) on nTiO₂ transport. Results from this thesis research contributed to the knowledge of the individual and synergistic effects of complex water chemistry and geochemically heterogeneous media on the fate and transport of engineered nanoparticles in natural environments.


identifier: Munro, Hannah Jarvis <https://research.library.mun.ca/view/creator_az/Munro=3AHannah_Jarvis=3A=3A.html>   (2018) Circulation of pathogenic spirochetes in the genus Borrelia within ticks and seabirds in breeding colonies of Newfoundland and Labrador.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Birds are the reservoir hosts of Borrelia garinii, the primary causative agent of neurological Lyme disease. In 1991 it was also discovered in the seabird tick, Ixodes uriae, in a seabird colony in Sweden, and subsequently has been found in seabird ticks globally. In 2005, the bacterium was found in seabird colonies in Newfoundland and Labrador (NL); representing its first documentation in the western Atlantic and North America. In this thesis, aspects of enzootic B. garinii transmission cycles were studied at five seabird colonies in NL. First, seasonality of I. uriae ticks in seabird colonies observed from 2011 to 2015 was elucidated using qualitative model-based statistics. All instars were found throughout the June-August study period, although larvae had one peak in June, and adults had two peaks (in June and August). Tick numbers varied across sites, year, and with climate. Second, Borrelia transmission cycles were explored by polymerase chain reaction (PCR) to assess Borrelia spp. infection prevalence in the ticks and by serological methods to assess evidence of infection in seabirds. Of the ticks, 7.5% were PCR-positive for B. garinii, and 78.8% of seabirds were sero-positive, indicating that B. garinii transmission cycles are occurring in the colonies studied. Five I. uriae from two seabird colonies were positive for the Asian strain of the Lyme disease-causing species, B. bavariensis, which has previously only been described from the terrestrial realm associated with rodent reservoirs. The complete microbiome of ticks from two seabird colonies was also explored, which was consistent with PCR-based estimates of Borrelia spp. prevalence and identified infections with Coxiella and Ehrlichia spp., which may also be tick-borne. Third, the phylogenetic relationships of B. garinii found in the study samples, with B. garinii from elsewhere in the world, were explored using concatenated multi-locus sequence typing (MLST) gene sequences. This revealed close relationships between B. garinii in Eurasia and seabird colonies in NL. These results add to our knowledge of all levels of this complex, under-studied system, and help to inform us on how seabirds facilitate the global dispersion of B. garinii and other Borrelia species.


identifier: Ignatz, Eric <https://research.library.mun.ca/view/creator_az/Ignatz=3AEric=3A=3A.html>   (2019) Rearing temperature’s effect on the growth performance, nutrient utilization and immune response of growth hormone transgenic female triploid Atlantic salmon (Salmo salar).  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis examined the effect of rearing temperature on AquAdvantage Salmon (AAS; growth hormone transgenic female triploid Atlantic salmon) reared at 10.5°C, 13.5°C, 16.5°C from first feed to 1500 g. Fish reared at 16.5°C reached 1500 g in the shortest amount of time, however, thermal-unit growth coefficient (TGC) results showed that salmon reared at 10.5°C exhibited higher growth rates for most of the trial. Through analysis of whole-body and fillet samples at various growth stages, it was determined that rearing temperature significantly influenced composition, deposition rates and retention efficiencies of numerous nutrients. For example, AAS reared at 16.5°C diverted lipid storage away from muscle tissue into their viscera and were less efficient at retaining important nutrients, such as omega-3 fatty acids. By assessing the antiviral immune gene expression response of fish injected with polyriboinosinic polyribocytidylic acid (pIC), it was concluded that temperature significantly influenced immune responses of AAS. Based on transcript expression responses, as measured by real-time quantitative polymerase chain reaction (qPCR) analysis, it appeared that a more robust immune response was mounted by fish reared at 10.5°C compared to 16.5°C. Collectively, these results help establish foundational knowledge that can guide future research to optimize commercial rearing of AquAdvantage Salmon.


identifier: Rose, Andrew M. <https://research.library.mun.ca/view/creator_az/Rose=3AAndrew_M=2E=3A=3A.html>   (2019) Constructing static black hole-soliton spacetimes.  Masters thesis, Memorial University of Newfoundland.

abstract:
The purpose of this work is to construct new static solutions of five-dimensional
vacuum general relativity describing asymptotically
at black hole-soliton spacetimes.
An asymptotically
at soliton is a globally stationary, everywhere regular positiveenergy
solution. They are characterized by non-trivial spacetime topology. It can be
proved that in the vacuum everywhere-regular solitons cannot exist and we explicitly
show this in specific examples by studying conical singularities in the spacetime.
However, the existence of spacetimes containing both black holes and solitons has
not been ruled out. To investigate this problem in a simplified setting, this thesis
will focus on static solutions with two rotational symmetries. These solutions are
known as Weyl solutions. We construct explicit solutions of this type and study
their properties. We then generalize our solutions to the case with non-vanishing
Maxwell fields and obtain static, electrically charged, black hole-soliton spacetimes.
Throughout the work we take a general approach that should be valuable in a wider
setting.


identifier: Way, Andrew R. <https://research.library.mun.ca/view/creator_az/Way=3AAndrew_R=2E=3A=3A.html>   (2019) Automated image-based quality control of molecularly imprinted polymer films.  Masters thesis, Memorial University of Newfoundland.

abstract:
We present results of applying a feature extraction process to images of coatings of
molecularly imprinted polymers (MIPs) coatings on glass substrates for defect detec-
tion. Geometric features such as MIP side lengths, aspect ratio, internal angles, edge
regularity, and edge strength are obtained by using Hough transforms, and Canny
edge detection. A Self Organizing Map (SOM) is used for classification of texture of
MIP surfaces. The SOM is trained on a data set comprised of images of manufactured
MIPs. The raw images are first processed using Hough transforms and Canny edge
detection to extract just the MIP-coated portion of the surface, allowing for surface
area estimation and reduction of training set size. The training data set is comprised
of 20-dimensional feature vectors, each of which is calculated from a single section of a
gray scale image of a MIP. Haralick textures are among the quantifiers used as feature
vector components. The training data is then processed using principal component
analysis to reduce the number of dimensions of the data set. After training, the SOM
is capable of classifying texture, including defects.


identifier: Riener, Jacqueline <https://research.library.mun.ca/view/creator_az/Riener=3AJacqueline=3A=3A.html>   (2019) Understanding Romanian hunters' cognitive components toward large carnivores in the Făgăraș Mountains, Romania.  Masters thesis, Memorial University of Newfoundland.

abstract: In 2016, the Romanian government introduced a trophy hunting ban on large carnivores throughout Romania causing an uproar in the hunting community. Romanian hunters have been responsible for managing large carnivores and feel this responsibility has been taken from their hands. The overarching goal of this thesis is to understand the hunters’ cognitive components (attitudes, beliefs, and emotions) and acceptable management approaches regarding large carnivores in Romania. A mixed method approach was utilized where quantitative questionnaires (n=512) were distributed to Romanian hunters , and qualitative interviews (n=11) occurred with presidents of hunting associations and directors of wildlife management in the Făgăraș Mountains area. Hunters’ cognitive components and acceptability toward management approaches fluctuate depending on species and context. Human Dimensions of Wildlife research helped in understanding the relationship between human and large carnivores and has acted as a voice for Romanian hunters in the debate toward these species.


identifier: Zhang, Yu <https://research.library.mun.ca/view/creator_az/Zhang=3AYu=3A=3A.html>   (2019) PANDA: prioritization of autism-genes using network-based deep-learning approach.  Masters thesis, Memorial University of Newfoundland.

abstract:
Autism is a neuropsychiatric disorder characterized by impairments in reciprocal
social interaction and communication, and the presence of restricted and repetitive
behaviours. Autism is predominantly heritable, but the underlying genetic associations
are still largely unknown. Understanding the genetic background of complex
diseases, such as autism, plays an essential role in the promising precision medicine.
The evaluation of candidate genes, however, requires time-consuming and expensive
experiments given the large number of possibilities. Thus, computational methods
have seen increasing applications in predicting gene-disease associations. In this thesis,
we proposed a bioinformatics framework, Prioritization of Autism-genes using
Network-based Deep-learning Approach (PANDA). Our approach aims to identify
autism-genes across the human genome based on patterns of gene-gene interactions
and topological similarity of genes in the interaction network. PANDA trains a graph
deep learning classifier using the input of the human molecular interaction network
(HMIN) and predicts and ranks the probability of autism association of every node
(gene) in the network. PANDA was able to achieve a high classification accuracy of
89%, outperforming three other commonly used machine learning algorithms. Moreover,
the gene prioritization ranking list produced by PANDA was evaluated and
validated using a large-scale independent exome-sequencing study. The top decile
(top 10%) of PANDA ranked genes were found significantly enriched for autism association.


identifier: Bouakir, Hassan <https://research.library.mun.ca/view/creator_az/Bouakir=3AHassan=3A=3A.html>   (2019) School leadership strategies for the implementation of universal design for learning (UDL) in international schools.  Masters thesis, Memorial University of Newfoundland.

abstract:
The purpose of this research is to examine the relationships among principals’ support
and leadership style, teacher self-efficacy, and teacher professional development with respect
to the implementation of a universal design for learning (UDL)approach in an international
school context (Qatar). Five teachers and five principals working in international schools in
Qatar were interviewed for the study. The identification of participants took place with the
support of several international schools based in Qatar. The research revealed that even after
implementation a substantial number of educators in international schools in Qatar fail to use
UDL. Several reasons were cited for teachers’ resistance to adopting the UDL framework,
including lack of knowledge about UDL principles and processes; insufficient training and
professional development opportunities, and; perceptions of limited time and resources.
The study also examined leadership strategies for UDL implementation. It is apparent
that the successful implementation of UDL starts at the top. Thus, school leaders are
responsible for modeling UDL instruction, as indicated by the majority of participants in the
study. Participants conceptualized the role of school leadership uncovering the most relevant
strategies to facilitate the UDL implementation. Even though some participants demonstrated
their openness and flexibility in utilizing the UDL framework, there was consensus that all
teachers should be further supported in practice. Both teachers and school leaders in
international schools in Qatar are expected to act in synchrony, under the paradigm of a
common vision to improve the country’s educational system.
The following implications for practice are identified: considering the fact that some
teachers exhibit resistance to change, they need to be fully supported during the
implementation of UDL practices; educators should be provided with sufficient practical
examples of how to utilize the UDL framework in order to achieve optimal results in the long
term, and; given that some teachers still lack basic knowledge about the components and principles of UDL, opportunities should be provided to assist faculty members to build their
knowledge and practice of UDL. This suggests a renewed focus on the available strategic
capacities, teachers’ competencies, and resources to build a solid educational system that
could benefit all stakeholders in the region. Furthermore, there is a need to build a critical
mass of school leaders and educators who can serve as advocates for the consistent use of
UDL.


identifier: Bahadory, Taimaz <https://research.library.mun.ca/view/creator_az/Bahadory=3ATaimaz=3A=3A.html>   (2019) The phase space of last glacial inception:characterization and feedbacks via ensemble coupled ice/climate modelling.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The feedbacks between ice sheets and the rest of the climate system are a major
source of uncertainty in constraining future sea level change and perhaps aspects of
future climate change. In the past, there is strong evidence that large and at times
relatively abrupt changes in sea level and climate occurred. The past therefore offers
a testable window that may help build confidence in projecting future changes.
Climate models are used to study the evolution of ice and climate during glacial
intervals. However, these models are either computationally expensive to run for
glacial-scale periods, or are too simplified and miss key feedbacks between ice and the
climate. To confidently model changes in the past, ensembles of transient model run
on order 10 ky or longer are required. Therefore, a fast coupled ice-climate model
with relevant feedbacks is required.
Beyond last glacial maximum and especially beyond the range of accurate ¹⁴C
dating (about 40-50 ka), constraints on past ice sheet evolution become sparse. The
last glacial inception (herein including post inception peak retreat, thus covering the
range of about 120 ka to 105 ka) is a poorly understood interval that includes both
rapid ice sheet growth and subsequent decay. It thereby offers a challenging test for
fully coupled ice and climate models.
This thesis documents 3 specific contributions. 1) The fast fully coupled ice-climate
model LCice 1.0 is documented. 2) Results from an ensemble of coupled
transient simulations of the last glacial inception are presented. The ensemble provides
a potential phase-space of ice and climate evolution during the last glacial
inception. 3) Finally, multiple sensitivity experiments isolate the impacts of the two largest northern hemisphere ice sheets on climate and each other.


identifier: Shwedack, Katrina <https://research.library.mun.ca/view/creator_az/Shwedack=3AKatrina=3A=3A.html>   (2019) Effects of anthropogenic noise on communication in dark-eyed juncos (Junco hyemalis).  Masters thesis, Memorial University of Newfoundland.

abstract: Noise pollution has numerous consequences for wildlife, including the disruption of acoustic communication through its impacts on signal production, signal transmission, and signal perception. In this thesis, I demonstrated, using complementary correlational and experimental approaches, that dark-eyed juncos (Junco hyemalis) increase the frequency of their songs in response to noise. Next, I broadcasted noise-altered and unaltered songs in noisy and quiet environments and re-recorded them along a 40-m transect, with microphones set up at 1, 5, 15, and 40 m. I measured song degradation along the transect and found that songs degraded predictably with increasing distance, but that recording environment (noisy or quiet), playback environment (noisy or quiet), and the interaction between the two had no effect on song degradation. This indicates that, although juncos increase the minimum frequency of their songs in response to noise, the shift does not, by itself, increase the transmission of the song through noise.


identifier: Ahern, Andrew <https://research.library.mun.ca/view/creator_az/Ahern=3AAndrew=3A=3A.html>   (2020) Regrounding the commons: Bruno Latour, ecological democracy, and nonhuman political representation.  Masters thesis, Memorial University of Newfoundland.

abstract:
What is the relationship between science and politics, and especially as it concerns the entities of the sciences and the relevance they have in political processes? In the following thesis, I look to form proper political institutions around nonhuman entities through the work of Bruno Latour and his democratic-ecological ethos by way of his 2004 text the Politics of Nature: How to Bring the Sciences into Democracy. In recognition of mass species extinction, the fragility of our soil, the warming climate, the rise of automation, the importance of carbon sequestration, and the various socio-economic problems attached to the environment—what is called political ecology—the old binary of science and politics as opposed, as one discipline concerned with technology and natural objects (science), and the other concerned with humans (politics), is becoming less and less tenable as we become more sensitive and inundated with the aforementioned issues.
With the guidance of the sociologist of science Bruno Latour, these essays attempt to use Latour's framework of a technoscientific political process, plus an expanded sense of spokespersonship as representative institutions for nonhumans. In establishing these processes and institutions, I hope to help orient how we should understand our past failures in improper recognition of nonhumans, and how it is we can better bring nonhumans into democracy through the aid of Latour. By redefining politics as the issues that bring about a concerned public, Latour also looks to include nonhumans as a part of the public. Nonhumans as a public is one of the significant points through these pages.
I hope to accomplish three things in this thesis. 1. Contribute to Latourian scholarship by providing exegesis around his 2004 text The Politics of Nature. 2. In doing this, I hope to better situate the current political ecology movements, as seen by a premier thinker concerned with climate change and the Anthropocene. In relation to that contribution, I would like to further establish Bruno Latour as a political theorist with a political philosophy that is worth examining. At the end of this work, I provide my own philosophic contribution in shaping policy and existing institutions in a warming and sea-rising technological future by the aid of Latour's institutional vision from the Politics of Nature. The reader will have to reconsider how they view politics, who the constituents are, and whom the "we" are when talking about a common world "we" would like to share. Arguably, the most radical vision for democratic politics in the 21st century is to include those things humans have historically tried to subjugate as mere objects, or the materials of Nature, or the work of social construction. The next step in the democratic project is to include the entities that without human subsistence would be futile: it is time to recognize multi-species living, the collaboration between nonhumans for the sake of human flourishing, and the work that politics can do in organizing a sense of commonality.


identifier: Golbabanezhadazizi, Aliasghar <https://research.library.mun.ca/view/creator_az/Golbabanezhadazizi=3AAliasghar=3A=3A.html>   (2020) Development and optimization of molecularly imprinted polymers for the analysis of organic pollutants in environmental water samples.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Agricultural, industrial, and municipal water releasing organic contaminants into
the environment is of serious ongoing concern. To monitor these waterborne pollutants,
sample preparation steps are required prior to analysis. Consequently, massive efforts have
been directed toward new approaches that are fast, selective, cost-effective, user-friendly
and green. Molecularly imprinted polymers (MIPs) are an elegant solution to add selectivity
into sorptive materials.
In this thesis, MIPs were prepared using different polymerization techniques and in
various formats such as MIP particles, MIP thin film, and MIP-coated mesh. The prepared
sorbents were successfully utilized for extraction of different classes of pollutants such as
polycyclic aromatic hydrocarbons (PAHs) and organophosphorus pesticides (OPPs) from
water samples. To improve the heterogeneity of MIPs, a controllable polymerization
mechanism (reversible addition fragmentation chain transfer (RAFT) polymerization) was
implemented for synthesis MIPs on Fe₃O₄@SiO₂ particles for extraction of PAHs. A
tailormade MIP formulation was also created and optimized for selective extraction of
OPPs from water. The sorbent formulae are versatile for use in different formats such as
thin film and mesh. MIP extraction devices can be readily interfaced with various detection
systems such as gas chromatography flame ionization detector (GC-FID), atmospheric
pressure chemical ionization gas chromatography-tandem mass spectrometry (APCI-GCMS/
MS) and liquid chromatography -tandem mass spectrometry (LC-MS/MS) using liquid
desorption, and thermal desorption. Additionally, these devices can increase the
throughput, reliability, and simplicity of environmental analysis. For example, we developed a new solvent assisted thermal desorption head space (ST-HD) method, which
we demonstrate to be excellent for the introduction of analytes enriched by MIP thin films,
and it is amenable to direct and semi-automated method improving reproducibility and
throughput.
In this thesis, MIP fabrication and performance will be demonstrated and evaluated.
The value MIP techniques in providing precious sensitivity, selectivity to the quality of
analysis of organic pollutants in water is presented.


identifier: Corey, Alexander <https://research.library.mun.ca/view/creator_az/Corey=3AAlexander=3A=3A.html>   (2019) Teacher as facilitator: a case study of enhanced student agency.  Masters thesis, Memorial University of Newfoundland.

abstract: This research investigates an enhanced agency classroom. A small class of 12 grade-six students undertook a two-week unit in which they could exercise their agency by choosing what they wanted to learn, how they wanted to learn it and how they wanted to be assessed. Qualitative data was collected in the form of a journal, written by the teacher-researcher who made detailed observations of his role, the role of the students, and the overall effects of providing such a classroom. Ultimately, the enhanced agency unit acted as a polarizing tool where some students were able to embrace their agency and increase their sense of engagement, motivation and academic outcomes, while others found the lack of structure and routine difficult to cope with. Recommendations for further research and how to more effectively enhance student agency are also made.


identifier: Arzhang, Behnam <https://research.library.mun.ca/view/creator_az/Arzhang=3ABehnam=3A=3A.html>   (2019) Fluctuation diagnostics in the 2D Hubbard model from the dual-fermion method.  Masters thesis, Memorial University of Newfoundland.

abstract:
In this thesis, we use the Dual Fermion approximation (DF) to study the Hubbard
model on the 2D square lattice by using two-particle quantities such as susceptibilities
and full vertex functions.
In the first chapter we give an introduction to the strongly correlated systems including
their definitions and features. Then, in the next chapter, to solve our model we
present some numerical methods. The numerical methods that we used for our study
are the dynamical mean-field theory (DMFT), the continuous-time auxiliary field impurity
solver (CTAUX), Fluctuation diagnostics and Dual Fermion approximation
(DF). The DF method provides high-resolution results for single-particle quantities
such as the density of states (DOS) and Self Energy as well two particles spin susceptibility
and vertex functions. With these results, we can present high-resolution
results of the fluctuation diagnostics method with minimal computational expense.
We examine the full Q-vector dependence of the extended self-energy at the Nodal
and Antinodal k-points and provide interpretation for the claim that spin fluctuations
are responsible for the observed metal-to-insulator behaviour.


identifier: Akpoguma, Blessing Ivie <https://research.library.mun.ca/view/creator_az/Akpoguma=3ABlessing_Ivie=3A=3A.html>   (2019) Greenhouse gas emission from small bog pools in a boreal peatland in Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: Studies on the greenhouse gases (GHG) potential and emissions from peatlands have been studied extensively in recent years due to the increasing atmospheric concentration of GHG and impact on climate change. However, most research estimating GHG emissions and factors regulating these emissions from peatlands are focused on the terrestrial microforms of peatlands. Thus, less is known about the GHG emission potential from peatland pools, which are the aquatic components. I conducted a study in small bog pools during the 2018 growing season to determine the drivers and concentration of CH4 dissolved in pool surface waters using the headspace method. Also, a five-year growing season (2013, 2014, 2015, 2016 and 2018) static floating chamber was used to quantify the variation in GHG flux from pools across the growing seasons. Results showed that pools are supersaturated with CH4 ranging in concentration from 2.32 to 180.98 µmol L-1 , among the highest concentration reported for small inland waters. The super-saturation observed in these pools may have been influenced by several biological, chemical, and physical factors but were best predicted by a relationship with temperature, vegetation, dissolved organic carbon (DOC), and pool surface area. I also found that CO2 flux was significantly different across the years (p < 0.05) in which pools acted as sources during 2013 and 2018 ( [mean] = 23.91 and 7.79 mmol m-2 d -1 respectively) and as sinks in 2014, 2015 and 2016 ( [mean] = -7.41, -8.98 and -9.04 mmol m-2 d -1 respectively). In contrast, pools acted mostly as sources of CH4 to the atmosphere in 2013, 2016 and 2018 and were negligible sinks during 2014 and 2015 ( [mean] = 0.41, 0.00, -0.01, 0.19 and 0.52 mmol m-2 d -1 for years 2013 to 2018 respectively). However, flux of CH4 was not significantly different across the years (P > iv 0.05). Pools acted mostly as negligible sinks of N2O flux, which is typical of ombrotrophic peatlands. N2O flux did not vary among years (p > 0.05). Pool depth was found to be the best predictor of CO2 fluxes, while dissolved organic carbon was found to be the major predictor of CH4 emission. This study shows that the concentration and emission of GHG from bog pools varies depending on climatic conditions and within pool biogeochemistry, therefore bog pools’ GHG emission potential can be influenced in future climate scenarios.


identifier: Lundrigan, Sarah <https://research.library.mun.ca/view/creator_az/Lundrigan=3ASarah=3A=3A.html>   (2019) Mean and eddy induced transport in the ocean region adjacent to the Greenland-Scotland Ridge.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The circulation and transport in the ocean region adjacent to the Greenland-
Scotland Ridge (GSR) are crucial for maintaining heat, freshwater, and sea-ice exchange
between the Nordic Seas and Subpolar North Atlantic Ocean. The Nordic
Seas receive low-density Atlantic Water and transform it into dense water. The dense
water overflow contributes to the North Atlantic Deep Water mass formation, which
feeds the lower limb of the Atlantic Meridional Overturning Circulation. The thesis
presents results from a study of the temperature and salinity transport in the ocean
region adjacent to the GSR consisting of three sub-projects.
The first sub-project is focused on model simulations of interannual to decadal
variability of the exchange through the GSR and its impact on the variability of the
temperature and salinity in the Nordic Seas. The model results demonstrate that
the increase in the transport of fresh and cold waters through Fram Strait in the
1960s was concurrent with a reduction in the exchange over the GSR. The resulting
imbalance in salinity and heat fluxes through the strait and over the ridge contributed
to the freshening of the water masses of the Nordic Seas and intensified the Great
Salinity Anomaly in the 1960s. In the late 1980s the AW transport over the GSR was
stronger than normal while the exchange through Fram Strait was close to normal.
The related imbalance in the lateral heat fluxes through the strait and over the ridge
warmed the Nordic Seas and caused an increase in the temperature of the AW inflow
to the Arctic Ocean in the late 1980s (i.e., about a decade earlier than the warming
of the subpolar North Atlantic Ocean in the mid-1990s).
The second sub-project is focused on observational estimates of the heat flux convergence of the ocean region adjacent to the GSR. Along-track altimeter and
sea surface temperature satellite observations and ARGO in-situ measurements of
temperature and salinity are used to investigate the heat transport by mean currents
and eddies in the ocean region adjacent to the GSR from 2003 to 2008. The results
from the analysis show that the heat advection by the mean flow in the surface layer
is zonally asymmetric with a higher magnitude in the western part of the region. This
asymmetry is associated with an excessive mean heat advection in an area adjacent
to the Denmark Strait. The advection of heat is high and positive south of the strait
and low and negative north of it. We suggest that this heat advection impacts the
local budgets of heat and potential energy of the mean flow in the surface layer.
The third sub-project studies the vertical structure of the convergence of advective
fluxes of heat (HFC) and salt (SFC) in the ocean region adjacent to the GSR. The
study is based on SODA (Simple Ocean Data Assimilation) ocean reanalysis for the
period between 1965 and 2010. The SODA based estimates show that the high
values found in satellite based estimates of HFC over the Denmark Strait are part
of a pattern of high HFC and SFC in the whole water column. In this region, the
HFC has a maximum at the surface. The highest values of SFC there are found in
the subsurface layer at depths between 500 and 1500 m. A similar structure of high
positive SFC and HFC are observed at intermediate depths over the Iceland-Faroe
Ridge. The EOF analysis of the HFC and SFC shows that the variability of the HFC
and SFC in these two regions are dominated by modes of coherent variations in the
SFC and HFC. During warming period in the late 1980s these modes drove strong
variations of the HFC and SFC over Denmark Strait and Iceland-Faroe Ridge which
correlated well with the variations in the surface wind stress curl.


identifier: Carnevale, Christian <https://research.library.mun.ca/view/creator_az/Carnevale=3AChristian=3A=3A.html>   (2019) The effects of chronic hypoxia and nitric oxide on myocardial contractility in steelhead trout (Onchorhynchus mykiss).  Masters thesis, Memorial University of Newfoundland.

abstract: Environmental hypoxia has been intensifying and spreading in recent years due to climate change, and there is accumulating evidence that the cardiac function of hypoxia-intolerant fish is negatively affected by long-term exposure to low oxygen conditions. However, the cause of this reduced heart performance has not been conclusively identified, and it is unknown whether nitric oxide (NO)-mediated effects are involved. This thesis examined how chronic hypoxia (> 8 weeks at ~8 kPa O₂) influenced the contractility (i.e., work and power) of steelhead trout (Oncorhynchus mykiss) spongy myocardial strips upon exposure to graded hypoxia (21 – 1.5 kPa), and influenced NO-mediated performance. Hypoxic-acclimated strips produced less shortening power (by ~35%) as compared to those from normoxic-acclimated conspecifics, but experienced similar reductions in contractility during acute hypoxia and did not recover as well upon re-oxygenation. The effects of NO on myocardial function were not greatly affected by hypoxic-acclimation, but were found to be highly dependent on contraction frequency and strain.


identifier: Strickland, Caroline <https://research.library.mun.ca/view/creator_az/Strickland=3ACaroline=3A=3A.html>   (2019) A reinforcement learning approach to multi-robot planar construction.  Masters thesis, Memorial University of Newfoundland.

abstract:
We consider the problem of shape formation in a decentralised swarm of robots
trained using a subfield of machine learning called reinforcement learning. Shapes
are formed from ambient objects which are pushed into a desired pattern. The
shape is specified using a projected scalar field that the robots can locally sample.
This scalar field plays a similar role to the pheromone gradients used by social
insects such as ants and termites to guide the construction of their sophisticated
nests. The overall approach is inspired by the previously developed orbital construction
algorithm.
Reinforcement learning allows one or more agents to learn the best action
to take in a given situation by interacting with their environment and learning
a mapping from states to actions. Such systems are well-suited to robotics, as
robots often interact with complex environments through a variety of sensors and
actuators. When reinforcement learning is applied to a multi-agent system, it is
called 'multi-agent reinforcement learning' (MARL). The main feature that MARL
offers is flexibility | a multi-agent decentralised system can have agents added,
removed, or reconstructed without need for rewriting the system. This allows for
more robust solutions due to its ability to cope with failure.
With the use of simulators paired with MARL, we can effectively learn policies
that result in the formation of unique shapes. This is a vast improvement over
hand-coded solutions, as it removes dependence on hard-coded actions. Reinforcement
learning eliminates the need for writing control algorithms in the first place
| which tend to be be extremely task-specific and time-consuming.


identifier: King, Eleanor Rosalind <https://research.library.mun.ca/view/creator_az/King=3AEleanor_Rosalind=3A=3A.html>   (2020) A mixed methods investigation of non-medical prescription stimulant use to promote wakefulness at an Atlantic Canadian university.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
This study is a mixed-methods investigation into the non-medical use of
prescription stimulants for the purpose of staying awake among students at
Memorial University of Newfoundland. The quantitative part of the study involved
a comprehensive online survey, which asked for information regarding
demographic characteristics and substance use, and included standardized measures
of sleep, mental health and attitudes towards non-medical use of prescription drugs.
A total of 3,699 participants were recruited and the clean, complete data for 3,160
participants was used for the analysis. The prevalence of non-medical use of
prescription stimulants for the purpose of staying awake was 3.1%. The factors
associated with such use were alcohol, tobacco and nicotine vapour use, poor sleep
quality, daytime sleepiness, and more liberal attitudes towards the non-medical use
of prescription drugs. The factors associated with these more liberal attitudes
include male gender, non-White ethnicity, international student status, alcohol,
tobacco, and nicotine use, depressive symptoms and clinical level of anxiety
symptoms. Factors associated with less liberal attitudes were part-time study and
borderline level of anxiety symptoms.
In order to provide more insight into why students use prescription
stimulants for staying awake, ten semi-structured interviews were conducted.
Participants reported obtaining the stimulants from friends who had prescriptions
for ADHD, and stated that they were using them to stay awake longer in order to
study, indicating that the underlying motive for misuse was academic stress.Participants recognized that such use could impact sleep and reported using
exercise and meditation as alternatives to stimulant use, but admitted that
stimulants were much more effective in the short-term. Any
prevention/intervention programs should involve promoting sleep hygiene and
academic skills, as well as highlighting the negative effects of non-medical
prescription stimulant use. These programs should be aimed at the aforementioned
groups of students who are at most risk of engaging in such use.


identifier: Roubo, Kelly <https://research.library.mun.ca/view/creator_az/Roubo=3AKelly=3A=3A.html>   (2019) Narrating Waegook identity: building transitory foreign-teacher community through folklore in the Republic of Korea.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
With increasing global mobility, itinerant expatriate groups – whether of teachers, retirees, students, or backpackers – constitute transitory folk groups easily overlooked by folklore studies. This thesis is an ethnographic study of a transient folk group of foreign teachers in Suncheon, Republic of Korea, and of how narratives about their experiences inform their sense of identity within that community. My observations of such groups in the Republic of Korea include working as a foreign English teacher in the 1990s, conducting fieldwork as a participant-observer from 2006-2008, and through additional research in 2017-2018 via the Internet. As a former foreign teacher, this work is auto-ethnographic in nature, as my time in Korea has informed not only my approach to this research, but who I am today.
Alan Dundes famously suggested a folk group may be comprised of as few as two people (1965, 2). Folk groups can also coalesce for brief periods, even the duration of a conversation, wherein the content of narratives facilitates construction of shared identity, as in the “transitory community” of foreign teachers I studied. With little else in common, foreign teachers share narratives – of their work, the challenges they face, and personal experiences of life abroad. This creates bonds and equips them with vernacular knowledge specific to that community. These exchanges develop connective tissue for this transitory community, provide a mechanism for survival in an unfamiliar environment, and help create a sense of belonging in Korea, despite the teachers’ outsider status.
Esoteric knowledge is employed within the transitory community as a status marker, providing evidence of competence as well as channeling information to those who need it. Additionally, the themes of some narratives reflect feelings of marginalization among people who, as white Westerners, sense a loss of standing and power. This change of status is often contradicted by how they position themselves in their narratives, wherein they present themselves as more competent, worldly, or knowledgeable than Korean counterparts.


identifier: Mujica, Francis <https://research.library.mun.ca/view/creator_az/Mujica=3AFrancis=3A=3A.html>   (2019) Developing a fundamental understanding of how oil impacts diagenesis and the effect in transport properties by investigating rock samples from close to the oil-water contact, Ben Nevis formation, Hebron field.  Masters thesis, Memorial University of Newfoundland.

abstract: There is ongoing debate as to whether or not oil emplacement in a reservoir rock impedes or stops diagenetic process. The Ben Nevis reservoir in the Hebron Field, offshore Newfoundland has a short transition zone and a clearly identified oil-water contact (OWC). Rock samples from above and below the OWC were used to analyse the role of oil emplacement in the diagenetic processes, with the main focus on quartz overgrowth and its impact on transport properties. The main contributions of this work is that we challenge the debate on whether or not oil emplacement impacts diagenesis for the Hebron Field, a relatively shallow, low temperature reservoir (< 2 km depth, 50-70 °C) using pore size distribution instead of a singular porosity value, and digital rock analysis for the transport properties. Core analysis includes scanning electron microscopy, mineral liberation analysis, cathode-luminescence, mercury injection capillary pressure (MICP), microcomputed tomography scans, and digital rock analysis and simulations. Our results suggest that quartz cement tends to be more abundant towards the water leg. This observation is in agreement with the “oil emplacement retards diagenesis” theory discussed in the literature. Despite differences in quartz overgrowth, the pore size distributions (MICP results) and digital rock images do not reveal any significant differences in the pore structures above and below the OWC. This could indicate that the differences in quartz overgrowth is not substantial enough to cause a significant reduction of the pore size, and thereby impact transport properties.


identifier: Marvikhorasani, Hanieh <https://research.library.mun.ca/view/creator_az/Marvikhorasani=3AHanieh=3A=3A.html>   (2019) Scalable feature selection methods by augmenting sparse lease squares.  Masters thesis, Memorial University of Newfoundland.

abstract:
Feature selection has been used widely for selecting a subset of genes (features) from
microarray datasets, which help discriminate healthy samples from those with a particular
disease. However, most feature selection methods suffer from high computational
complexity when applied to these datasets due to the large number of genes present.
Usually, a small subset of these genes have a contributing factor to the disease, and the
rest of the genes are irrelevant to the condition. This study proposes a sparse method,
Sparse Least Squares (SLS), based on singular value decomposition and least squares
to filter out irrelevant features. In this thesis, we shall also consider reducing the number
of features by clustering genes and selecting representative genes from each cluster
based on two different metrics. These dataset size-reduction methods are incorporated
into three state-of-the-art feature selection methods, namely, mRMR, SVM-RFE, and
HSIC-Lasso. These methods are applied to three Inflammatory Bowel Disease (IBD)
datasets and combined with support vector machines and random forest classifiers.
Experimental results show that the proposed SLS method significantly reduces the
running time of feature selection algorithms and improves the prediction power of
the machine learning models. SLS is integrated into a novel feature selection method
(DRPT), which, when combined with Support Vector Machine (SVM), is able to
generate models to discriminate between healthy subjects and subjects with Ulcerative
Colitis (UC) based on the expression values of genes in colon samples. The best models were validated on two validation datasets and achieving higher predictive performance
than a model generated by a recently published biomarker discovery tool
(BioDiscML).


identifier: Que, Hua <https://research.library.mun.ca/view/creator_az/Que=3AHua=3A=3A.html>   (2020) Surviving to thriving: post-secondary education for refugee youth in smaller centres in Canada.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
The research investigates refugee youth’s aspirations for and access to post-secondary education in St. John’s, Newfoundland and Labrador, Canada. The theoretical framework that underpins this study consists of segmented assimilation theory and the bioecological model of human development. A basic qualitative research approach was employed. Twenty refugee youths and three staff members from educational service providers participated in this study. Data were collected through one-on-one semi-structured interviews.
Findings revealed that new life in Canada instilled hope into refugee youth as they aspired to get into university after high school. Refugee youth referred to their parents, support teachers and staff in high school, their friends, and university academic advisors as important people who helped them realize their educational goals. In addition, three educational programs were identified by refugee youth as helpful in preparing them for post-secondary education. Nonetheless, refugee youth’s access to post-secondary education was impeded by a number of barriers, including financial difficulties resulting from the repayment of transportation loans and a lack of target scholarships for refugee students pursuing post-secondary education, lack of information about post-secondary admission requirements, scholarships, and on-campus employment opportunities, negative peer influence from refugee students who were less motivated, limited communication with local peers, and fear of the unknown and the academic challenges they would face in post-secondary education. In addition, refugee youth aged 19 or over found it difficult to further their education due to the policy of high school age limits and a lack of appropriate adult educational programs geared to their needs. Recommendations were also offered to reduce these barriers such as eliminating transportation loans and offering targeted scholarships and bursaries to refugee youth; providing refugee youth with information and assistance they need to make informed decisions about their education and career; increasing the number of ESL teachers at the secondary level and continuing to offer ESL support for college and university refugee students; and optimizing language and academic support for refugee young adults with goals of pursuing post-secondary education.


identifier: Gribanov, Igor <https://research.library.mun.ca/view/creator_az/Gribanov=3AIgor=3A=3A.html>   (2020) Numerical investigation of fracture of polycrystalline ice under dynamic loading.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Cohesive zone model is a promising technique for simulating fracture processes in brittle ice.
In this work it is applied to investigate the fracture behavior of polycrystalline cylindrical samples
under uniaxial loading conditions, four-point beam bending, and L-shaped beam bending.
In each case, the simulation results are compared with the corresponding experimental data
that was collected by other researchers. The model is based on the implicit finite element
method combined with Park-Paulino-Roesler formulation for cohesive potential and includes
an adaptive time stepping scheme, which takes into account the rate of damage and failure
of cohesive zones. The benefit of the implicit scheme is that it allows larger time steps than
explicit integration. Material properties and model parameters are calibrated using available
experimental data for freshwater ice and sea ice samples.
For polycrystalline ice, granular geometry is generated and cohesive zones are inserted between
grains. Simulations are performed for samples with different grain sizes, and the resulting
stress–strain and damage accumulation curves are recorded. Investigation of the dependency
between the grain size and fracture strength shows a strengthening effect that is
consistent with experimental results.
The proposed framework is also applied to simulate the dynamic fracture processes in Lshaped
beams of sea ice, in which case the cohesive zones are inserted between the elements
of the mesh. Evolution of the stress distribution on the surface of the beam is modeled for
the duration of the loading process, showing how it changes with progressive accumulation of
damage in the material, as well as the development of cracks. An analytical formula is derived
for estimating the breaking force based on the dimensions of the beam and the ice strength.
Experimental data obtained from the 2014-2016 tests are re-evaluated with the aid of this new
analysis.
The computation is implemented efficiently with GPU acceleration, allowing to handle geometries
with higher resolution than would be possible otherwise. Several technical contributions
are described in detail including GPU-accelerated FEM implementation, an efficient way of
creation of sparse matrix structure, and comparison of different unloading/reloading relations
when using an implicit integration scheme. A mechanism for collision response allows modeling
the interaction of fragmented material. To evaluate the collision forces, an algorithm for
computing first and second point-triangle distance derivatives was developed. The source code
is made available as open-source.


identifier: Schoot, Ignace <https://research.library.mun.ca/view/creator_az/Schoot=3AIgnace=3A=3A.html>   (2019) Opening up containment: making space in Newfoundland salmonid aquaculture.  Masters thesis, Memorial University of Newfoundland.

abstract:
Studies in geography and STS looking at containment-in-practice have shown that
thinking about containment as a hermetic closing off of a definite space is not suitable for
this world, which is characterized by leakages, overflows, excesses, movements, and
borders being crossed, contested and drawn again. However, renderings of containment
still play an important role in the practices that make and break our worlds. This thesis
attempts to open up containment by thinking through how containment is done in two
different cases in sea-based salmonid aquaculture on the south coast of the Canadian
island of Newfoundland. Based on insights from poststructuralist geography, materialsemiotic
STS, and animal geography, containment is approached as an ongoing spatial
practice that needs to be constantly done and done again. This thesis respectively explores
the provincial Code of Containment and the making of the rearing environment for
farmed fish in and around the net-pen, and articulates containment as a (bio)political way
of creating, holding together, and unmaking realities, including industrial salmonid
aquaculture and the way animal lives and deaths are valuated.


identifier: Hawco, Jessica Bernadette <https://research.library.mun.ca/view/creator_az/Hawco=3AJessica_Bernadette=3A=3A.html>   (2020) The palaeontology of Ediacaran Avalonia: new insights using morphometrics and multivariate statistical analyses.  Masters thesis, Memorial University of Newfoundland.

abstract:
The Avalonian Ediacaran fossil assemblage of Newfoundland, Canada contains abundant
fossils with a wide range of morphologies and preservational styles. Quantitative
morphological and statistical analysis in Ediacaran fossil assemblages has recently been
used to recognize natural morphological groupings, providing evidence for variability
within and between taxa.
This approach is first used herein to test the grouping of the serially arranged, millimeterscale
chambered organism known as Palaeopascichnus. The combined morphometric and
statistical analytical approach was applied to collected specimens from Ferryland, and
demonstrates constrained, discrete growth patterns. The same technique was used to
compare fossil palaeopascichnids with extant Protista, which has supported the protistan
affinity for the hitherto enigmatic palaeopascichnids.
This thesis also statistically investigates an Ediacaran taxonomic dispute known as the
Beothukis/Culmofrons problem. The two taxa (Beothukis mistakensis and Culmofrons
plumosa) were established separately, but were later synonymized. To determine the
validity of this taxonomic reassignment, this thesis investigates the clustering of specimens
based on their morphology and morphometrics and assesses the validity of certain
taxonomic characters within the specimen dataset. These findings validate the original
genus-level differentiation of Beothukis and Culmofrons, while also showing evidence for
previously unrecognized variation within the genus Beothukis. Overall, this technique has
led to the finding that more morphotypes may exist within the Ediacaran biota than
originally thought, and proves the utility of detailed statistical and morphological analysis
in determining morphological diversity and disparity.


identifier: Roberts, Josh <https://research.library.mun.ca/view/creator_az/Roberts=3AJosh=3A=3A.html>   (2019) Covert contrast in the acquisition of English /ɹ/: a case study.  Masters thesis, Memorial University of Newfoundland.

abstract:
In this thesis I examine the potential role of covert contrast (the phenomenon by which a
phonological contrast produced by a language learner falls below the threshold of perception of
adult speakers of this language) in the development of one child learning the contrast between /ɹ/
and /w/ in English. More specifically, using a longitudinal corpus documenting the development
of American English by one child learner, I compare data obtained by impressionistic means of
phonetic transcription against acoustic measurements of the same speech tokens. As we will see,
the results from both the transcription data and the acoustic measurements mirror one another in
ways that undermine the claim that covert contrast represents a necessary stage in acquisition
(Scobbie et al. 1996). Additionally, the current study reveals a disparity in the time of acquisition
for /ɹ/ in coronal stop-initial onsets vs. all other onset environments which highlights the
influence of articulatory factors on the production of /ɹ/ across different phonological contexts.
Finally, the acoustic component of the study uncovers what can be termed a ‘covert allophone’ in
the case of /w/ in that same coronal-initial complex onset environment. I conclude this thesis
with a discussion of both the theoretical and methodological implications for future research on
the development of phonological contrasts by children.


identifier: Jayawardhane, Jayamini <https://research.library.mun.ca/view/creator_az/Jayawardhane=3AJayamini=3A=3A.html>   (2019) Does alternative oxidase play a role in plant adaptation to anoxia and post-anoxia?  Masters thesis, Memorial University of Newfoundland.

abstract: Low oxygen stress and reaeration have detrimental effects on plants. Transgenic tobacco plants differentially expressing alternative oxidase (AOX) were used to investigate its role during anoxia and post-anoxia. Superoxide, hydrogen peroxide and malondialdehyde (MDA) levels increased under anoxia and post-anoxia exhibiting lower level in AOX-overexpressing lines. Nitric oxide (NO) emission increased during anoxia stronger in overexpressing lines while nitrosylation of proteins followed a reverse pattern. ATP/ADP ratio decreased during anoxia and increased with reaeration being higher in overexpressing lines. Alcohol dehydrogenase and aconitase increased during anoxia and decreased during post-anoxia in overexpressing lines. AOX-knockdown lines had higher SOD and lower catalase activity than overexpressors. The activities of enzymes of ascorbate-glutathione cycle decreased during both conditions being higher in overexpressing lines. We conclude that AOX is involved in NO turnover and plays a protective role by reducing the level of reactive oxygen species and sustaining energy requirements during anoxia and post-anoxia.


identifier: Bautista, Joseph J. <https://research.library.mun.ca/view/creator_az/Bautista=3AJoseph_J=2E=3A=3A.html>   (2019) Long range transport of polybrominated diphenyl ethers (PBDEs) and their natural analogues determined through size-resolved aerosols, and levels in Atlantic Ocean fish from Newfoundland coasts.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract:
Conventional flame retardants of polybrominated diphenyl ethers (PBDEs) are harmful endocrine disrupters that may endure in the environment and experience long range transport (LRT) to areas far from their sources. Despite a gradual phasing out of PBDEs as flame retardants by the Stockholm Convention and other legislation, humans and the environment are still exposed. Recently, natural methoxy and hydroxyl analogues of PBDEs, MeO-BDEs and OH-BDEs, have been discovered in marine environments and are seasonally associated with phytoplankton primary production that may determine how they contribute to the general persistent organic pollutant (POP) abundance as environmental toxicants. Aerosol mechanisms may link these marine pools to the atmosphere and to the global biosphere by LRT on aerosols. Consumption of biota contaminated with PBDEs and their natural analogues may act as a pathway for human exposure.
The optimization of PBDE and MeO-BDE extraction and analysis is essential to obtain accurate and precise results and improve method efficiency. Approaches to optimize several aspects of PBDE analysis are described here, along with new techniques for aerosol sampling. The efficacy of several novel internal standards for PBDE and MeO-BDE analysis by gas chromatography coupled to mass spectrometry with electron capture negative ionization (GC-ECNI-MS) is assessed. This is achieved through evaluation of standard reference material household dust and Atlantic cod liver with standard addition, internal calibration, and external calibration. A Micro Orifice Uniform Deposition Impactor (MOUDI) instrument collected aerodynamic aerosol samples in the marine boundary layer. We observe MeO-BDEs in atmospheric aerosols for the first time. We present their atmospheric levels and assessed their sources and potential for LRT based on their aerosol size distribution.
We also examine PBDE and MeO-BDE levels in fish livers from Atlantic cod (Gadus Morhua) and Greenland halibut/turbot (Scophthalmus maximusfish). These are traditional Newfoundland and Labrador (NL) fishery stocks and are also known to harbor POPs. These fish samples were used to monitor PBDE and MeO-BDE distribution coastal regions of NL.


identifier: Borges, Julia <https://research.library.mun.ca/view/creator_az/Borges=3AJulia=3A=3A.html>   (2020) Drawing the line: advance requests for medical assistance in dying: broad considerations with a special focus on dementia.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis considers the issue of whether to expand Medical Assistance in Dying (MAiD) legislation to include advance requests (ARs) broadly, with particular consideration for the dementia condition. The goal is to provide a deeper understanding of the value tensions involved in a decision of if and how ARs for MAiD should be extended to the Canadian population. To date, much of the discussion of the ethics of advance requests for MAiD focuses on those with dementia. This condition poses particular challenges in that it will, at some point, certainly cause a loss of capacity and living with such loss of capacity may be considered unbearable suffering to some individuals. The question of whether to legalize ARs for MAiD hinges on notions of the self and the nature of autonomy, both of which are affected by dementia. This thesis aims to address some of these challenges with a view to understanding whether and under what circumstances an AR for MAiD might be justified. This thesis provides suggestions and arguments aimed specifically at whether ARs for MAiD ought to be legalized and does not suggest whether MAiD ought to be legalized for individuals with mental illness as a sole underlying condition. Further, the scope of this thesis focuses on the moral and ethical considerations and implication that ought to be considered in potential expansion of legislation, not the resulting implications of actually expanding such legislation. Overall, the thesis focuses on the ethics of the potential legalization of ARs for MAiD in general, with a sub-focus on dementia, as the condition poses unique challenges as mentioned above.


identifier: Sun, Jiamin <https://research.library.mun.ca/view/creator_az/Sun=3AJiamin=3A=3A.html>   (2019) A study of dendrochirotid sea cucumbers with a focus on Cucumaria frondosa and its potential use in integrated multi-trophic aquaculture.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Sea cucumbers play fundamental roles in marine ecosystems, and they have long been commercially harvested for seafood. In light of stock declines worldwide, research on cold-water suspension-feeding species is expanding. This thesis explores two species from the North Atlantic. The first chapter validates an aging technique in Psolus fabricii, based on the growth rings found in its large calcareous dermal plates. Imaging of plates obtained from juveniles of known age confirmed the annual addition of a layer that extends the plate both vertically and horizontally, generating a pair of dark and light rings that can be used for aging. Wild individuals from shallow inshore areas were aged to a maximum of 28 years and their main morphometrics compared with age. The three other experimental chapters focus on Cucumaria frondosa, which has been commercially harvested for decades in North America and was identified as a potential candidate for aquaculture, especially as a biofilter in integrated multi-tropic aquaculture (IMTA). The locomotor and feeding behaviours, and microhabitat selection (spatial distribution) of C. frondosa in response to various environmental factors were investigated in the laboratory. Sea cucumbers moved away from static conditions and fled the strongest flows, and their tentacle deployment and insertion rates (i.e. feeding rate) increased with flow. The flow regime favoured by C. frondosa was 21-40 cm s⁻¹. Individuals were overall more mobile during the night, whereas no feeding differences were detected between diurnal and nocturnal phases. Gradients in phytoplankton concentration modulated the deployment of feeding tentacles but did not trigger any displacement toward the food source. C. frondosa exhibited a clear preference for substrates composed of bare rocks and rocks with coralline algae and displayed a slight preference for darker substrate backgrounds. Finally, C. frondosa held in effluent water from salmon culture was determined to assimilate the waste, which modulated its biochemical composition; however, its health condition declined, suggesting that it cannot find appropriate or sufficient nutrients for growth and reproduction in these wastes. The findings presented here aim to improve our understanding of the biology and ecology of cold-water suspension-feeding sea cucumbers to guide and assist fisheries management and aquaculture development.