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On the radiobiology of anhydrobiotic saccharomyces cerevisiae : unraveling the role of intracellular water in the radiation response
No full textAnhydrobiosis, denoting “Life without water” in Greek, is an adaptative characteristic held by
few eukaryotic organisms. Given the integral role that intracellular water plays in the
mechanisms of low linear energy transfer (LET) radiation-induced DNA damage, the question is
raised as to what effect the absence of water may have on the radiation resistance of
anhydrobiotic organisms. This project utilized anhydrobiotic Saccharomyces cerevisiae, which is
a budding yeast and the same organism used in the fermentation of beer, wine, and bread. This
yeast is extremely well studied. It has a radiation response on the genetic level, which is very
similar to human cells. With its eukaryotic cell structure, numerous human gene homologs and
paralleled molecular processes in the repair of ionizing radiation-induced DNA damage, it is
regarded as an excellent biological model to study the foundational biological effects of radiation
exposure. Furthermore, its anhydrobiotic capabilities make it an extremely low-maintenance
model, excellent for running long-term experiments where laboratory access is acutely
challenging. As such, its utility in the study of sub-natural background radiation (NBR) exposure
has been investigated. Overall, the goal of this work was to decipher how anhydrobiosis
influences radiation resistance, with a particular focus on the implications for sub-natural
background radiation exposure. This work has shown that the radiation tolerance induced by
desiccation is remarkably consistent through a wide range of radiation doses. Significant
metabolic perturbations relating to sub-NBR exposure and potassium-isotope availability were
observed. Anhydrobiosis perturbed the radiation response of S. cerevisiae in a predictable
manner with low-LET radiation, and further investigation into the metabolic effects of sub-NBR
radiation exposure is prudent to better understand the role of NBR in normal biological function
and homeostasis.Doctor of Philosophy (Ph.D.) in Biomolecular Science
The rise of precarious employment and the loss of union power in the Sudbury Mining Industry, 1969–2020
No full textThis dissertation explores the rise of precarious employment and its relationship to union power
within the Sudbury, Ontario, Canada mining industry between 1969 and 2020. Utilizing a case
study of United Steelworkers (USW) Local 6500, this research maps periods of negotiations,
labour strife, and the 2006 sale of the International Nickel Company (Inco) to Vale S. A. (formerly
Companhia Vale do Rio Doce) as catalysts for shifts in power for the union. These events are
interpreted through the theoretical lens of political economy informed by the work of Leah F.
Vosko’s theorization of precarious employment. I argue that a decline in union power is correlated
to the rise of precarious employment within the industry and the union’s shift away from a mandate
of embeddedness in the local community. The union’s ability to control contracting out has been
limited by neoliberal management strategies focused on cost-cutting and labour flexibility through
the divestment of non-core mining activities and staff; change in ownership, which globalized the
industry; and legislative and policy changes that have increasingly shifted bargaining power away
from workers and unions, towards corporate control. The union also missed opportunities to
engage in a more holistic or socially aware view of union power. The change within the Sudbury
mining industry from a high level of standard employment to precarious employment and the
union’s movement away from community embeddedness has paralleled a significant change in
workers’ subject position, degrading the richness of the narrative resources of unions, which have
in turn contributed to a weakening of union power. The case is built on the analysis of: (1) 35 semi-
structured, individual interviews with union officials, current and retired mine workers, and
industry key informants; (2) an examination of contracting out language from 13 of USW Local
6500’s collective agreements from 1969 to 2020; and (3) archival documents from USW Local
6500, union leaders, and Sudbury politicians. The multi-method approach is pursuant of an
integrative, interdisciplinary analysis of precarious employment within the Sudbury mining
industry and of its relationship to union power. The findings conclude that since the late 1960s,
Inco and the company’s successor, Vale, adopted a staffing strategy to limit the size of the directly
employed, unionized workforce through contracting out. The prevalence of precarious
employment within the Sudbury mining industry demonstrates this form of employment is a risk
to even longstanding, powerful unions such as USW Local 6500
Thermal transport in simulated nanostructures
No full textNanostructures are a critical topic for the research of heat transport as they are frequently used in devices where either temperature control or dissipation are critical. At such small scales, the behaviour of heat transport can be quite distinct from classically familiar modes. In this work, the effects of geometry and scale on nanostructures is investigated through various simulation methods. A particular focus is non-diffusive heat transport and angled geometries, and their interplay. It is seen that complex and angled geometries result in increased thermal resistance, but that this general result can be dependent on the particularities of geometry. Effects such as lattice orientation can cause a reduction of thermal resistance when the alignment is properly chosen. An emphasis is placed on the complexity of heat transport at the nanoscale and its similarities to other models of physical transport, such as radiative and geometrical optics. The variety of these models are reflected in the variety of simulation methods used: molecular dynamics, phonon Monte Carlo, Lattice Boltzmann Methods, classical heat equation solutions and, briefly, reflective ray optics. Discussion is carried out on the implications of a more ballistic and radiative transport scenario than is typically expected in nanoscale situations, and future prospects and consequences are suggested in turn
Factors contributing to metal endowment in the western Wabigoon and southern Abitibi subprovinces: a machine learning approach to Precambrian greenstone belts
No full textMineral exploration workflows are including more quantitative techniques and probabilistic
targeting to capture subtle or convoluted relationships to gain insight about geological processes.
However, related methodological improvements often focus on efficiency and sensitivity, leaving
geologically representative feature engineering underdeveloped. Improving modeling capabilities
alone is insufficient, and both geological plausibility and representation of complex processes or
features are critical to generate robust predictive models. Geological features involved in Magmatic
Ni-Cu-PGE, Volcanogenic Massive Sulfide (VMS) Cu-Zn-Pb-Ag(-Au), and Orogenic Au mineral system
prospectivity from two Archean greenstone belts from the southern Superior Province near Timmins
and Dryden, Ontario are examined and compared using a variety of statistical techniques.
Specifically, this PhD research explores 1) current knowledge and characteristic geological features
for both greenstone belts, 2) methods to enhance geological knowledge using whole rock
geochemistry, 3) methods to reduce bias and improve repeatability when mapping structural
complexity, 4) how data science and geological understanding of mineral systems can be integrated
for enhanced feature engineering 5) which factors control, or are most strongly associated with
mineralization, and 6) why the greenstone belts near Timmins and Dryden, Ontario have contrasting
orogenic Au endowment. Data-related outcomes of this research include multi-disciplinary
geoscientific databases (e.g., structural, field observations, geochemistry), new bedrock geology
maps for each area, and reprocessed aeromagnetic grids. Methodological outcomes of this research
include new geochemical classification diagrams for ultramafic to felsic (including tonalite-
trondhjemite -granodiorite and lamprophyre) Archean igneous rocks, Igneous Rock Favorability
indices, automatic mapping of structural complexity from bedding measurements and aeromagnetic
lineaments, mapping pre-deformation fluid path distances, mapping rheological and chemical
contrast, semi-discrete interpolation of characteristic element ratios, as well as mapping mobile
element gain/loss. Geological knowledge outcomes include the importance ranking of factors
controlling magmatic, volcanogenic, and orogenic prospectivity from random forests as well as
geological insight about contrasting orogenic Au endowment in the Timmins and Dryden areas.
Overall, this research demonstrates the importance of integrative studies that leverage multi-
disciplinary data, methods, and knowledge to improve existing geological understanding, maximize
data utility, and generate robust exploration targets. These improvements may enhance exploration
under difficult conditions, such as in data sparse environments, regions affected by clustered/partial
data representation, or targets under cover.(PhD) in Precambrian and Economic Geolog
Recovery of smelter-impacted peatlands (Sudbury, Ontario): botanical and microbial community perspectives
Get PDFOver one century of mineral smelting activities in the Sudbury Basin denuded the
regional landscape of vegetation near Sudbury, Ontario, previously (early 1960s) the once the
world’s largest point source of SO2 and particulate Ni and Cu emissions. In 1986, fourteen years
after the start of major local pollution controls, Gignac and Beckett reported that poor fen
peatlands neighboring a Sudbury smelter contained flat, black, and barren peat, depicting severe
pollutant stresses. I investigated the plant and microbial communities, and interrelated
geochemical controls, in these severely smelter-damaged poor fens. Over the past 35 years
Sphagnum moss, a keystone peatland genus, has re-established in poor fens as close as 4 km to
smelters, whereas in 1986, Sphagnum was not observed until 12 km. Chemical analysis of the
peat showed that total Ni and Cu concentrations in peat samples were lower than in 1986, and
decreased with increasing distance from the smelter. As peatlands are globally important carbon
sinks, with microbial communities mediating peatland C-cycling, I determined how smelter
activity has altered peat moss and soil microbiomes. I showed that microbial community
structure was controlled by plant species and microtopography in endophytic Sphagnum
communities but was primarily influenced by metal contamination and pH in peat. After healthy
Sphagnum and peat plugs were placed into a contaminated peatland. Sphagnum fuscum (a
hummock species) and Sphagnum fallax (a lawn species) showed signs of successful
establishment (expansion and new growth) after two years, suggesting that more efforts should
be made to restore Sudbury’s peatlands. The transplant peat microbiome shifted towards a
community structure mirroring the microbiome of the host peatland illustrating the central role of
this genus as an ecosystem engineer. I conclude my thesis discussion that because Sudbury
peatlands show signs of slow natural recovery and considering the results from the Sphagnum
transplant study, that pollutant legacies are abating to the point that large-scale active restoration
efforts can now begin.Doctor of Philosophy (PhD) in Boreal Ecolog
A braided approach within a mainstream counselling organization
Get PDFIndigenous people in Canada have experienced a complicated history that includes forced
colonization, segregation, and forced assimilation tactics imposed on them by the Canadian
government. As a result, Indigenous people today suffer from complex mental health needs and
require a unique therapeutic approach. This final practicum report focuses on a braided approach
in a therapeutic setting, which involved gaining knowledge around mainstream healing practices
and Indigenous healing practices and learning to delicately braid them together to produce a
unique healing approach that could be applied with Indigenous and non-Indigenous clients.
Through my practicum at Family TLC, I set out to observe how braided approaches could be
implemented into a mainstream therapeutic organization. Furthermore, it was essential for me to
critically reflect on how my understanding of my social location would evolve throughout my
practicum which was a secondary objective. The last objective reflected in this final paper, is
regarding the use of a braided healing approach with non-Indigenous clients and their perception
on their therapeutic healing journey. Finally, I have included reflections on the practicum site, the
support within the organizations, barriers and challenges experienced, and a future within the
organization
Laurentian University Truth and Reconciliation Report Card (2023)
No full textAs a broad community consultation that included members of the Laurentian University Native Education Council (LUNEC) and over sixty institutional leads from across the university, the Truth and Reconciliation Task Force (TRTF) was established in the fall of 2018 in direct response to the 2015 Truth and Reconciliation Commission’s Calls to Action.
Established in 2021, the Truth and Reconciliation Task Force Implementation Committee (TRTF-IC) is responsible for overseeing the fulfillment of the Task Force’s recommendations. This institutional report card was collectively determined on Sept 30, 2021 by over forty Laurentian University community members on the inaugural National Truth and Reconciliation Day in Canada
Prediction and survival analysis of head and neck cancer in patients using epigenomics data and advanced machine learning methods
Get PDFEpigenomics is the field of biology dealing with modifications of the phenotype that do
not cause any alteration in the sequence of cell DNA. Epigenomics adds something to the top of
DNA to change the properties, which eventually prohibits certain DNA behavior from being
performed. Such modifications occur in cancer cells and are the sole cause of cancer. The main
objective of this research is to perform prediction and survival analysis of Head and Neck
Squamous Cell Carcinoma (HNSCC) which is one of the biggest reasons of death and accounts
for more than 650,000 cases and 330,000 deaths annually worldwide. Tobacco use, alcohol
consumption, Human Papillomavirus (HPV) infection (for oropharyngeal cancer), and Epstein-
Barr Virus (EBV) infection are the main risk factors associated with head and neck cancer (for
nasopharyngeal cancer). Males, with a proportion ranging from 2:1 to 4:1, are slightly more
affected than females. Four different types of data are used in this research to predict HNSCC in
patients. The data includes methylation, histone, human genome and RNA-Sequences. The data is
accessed through open-source technologies in R and Python programming languages. The data is
processed to create features and with the help of statistical analysis and advanced machine learning
techniques, the prediction of HNSCC is obtained from the fine-tuned model. The optimal model
was determined to be ResNet50 utilizing the Sobel feature selection method for image data and
ReliefF-based feature selection for clinical features, achieving a test accuracy of 97.9%. The
model's precision score was 0.929, its recall score was 0.930, and its F1 score was 0.930.
Additionally, the ResNet101 model demonstrated the best performance using the Histogram of
Gradients feature selection method for image data and mutual information-based feature selection
for clinical features, yielding a test accuracy of 96.1%. Its precision score, recall score, and F1
score were identical to the aforementioned ResNet50 model. The research also utilized Kaplan-
Meier survival analysis to investigate the survival rates of patients based on various factors,
including age, gender, smoking status, tumor size, and location of site. The results obtained from
this analysis yielded the effectiveness of the method in providing valuable insights for risk
assessment.Master of Science (MSc) in Computational Science
La relation en supervision en travail social dans un contexte en distanciel
Get PDFLa supervision en distanciel et la perspective de la superviseure ont été peu explorées.
Pratique innovante, la supervision en distanciel en travail social amène divers
questionnements quant aux impacts et aux influences des outils numériques sur la relation
en supervision. Ce texte aborde le résultat d’une analyse de pratique suite à un stage
spécialisé exécuté à la Société Huntington du Canada. La pratique ciblée analyse le
processus complexe et nuancé du développement et du maintien de la relation en
supervision en distanciel. Partant d'une démarche inductive et réflexive de type
autoethnographique qui englobe un cadre théorique composé de l’approche humaniste,
systémique et le concept du savoir-relier, les apprentissages dégagés identifient la
confiance au cœur des relations dans ce contexte. La confiance joue un rôle pivot où elle
doit croître au-delà de la relation en supervision. Elle doit s’enraciner dans sa propre
pratique pour ensuite se réaliser dans les liens avec l’équipe et finalement envers les divers
systèmes dans lesquels nous pratiquons. La réflexivité permet d’explorer sa pratique et
cette analyse vise à stimuler des discussions et d’autres questions de recherche dans ce
domaine émergent en travail social.Maîtrise en service social (MSS
Plants, people and historic buildings: adapting the TTC Danforth carhouse and garage In Toronto through biophilic design
No full textOver the years, historic buildings are gradually
disappearing within the cities due to poor
management, neglect, abandonment, or lack
of funding. Renovation of these buildings is
rewarding in the end, but it is a delicate, costly,
and time-consuming process. The importance
of building conservation and the issues of
demolition as a conventional solution for old
buildings become controversial and challenging.
Adaptive reuse solution is now a rising
architectural approach in building conservation.
This study will focus on the adaptive reuse of
buildings by integrating plants based on the concept of Biophilia with consideration of
climatic conditions. The emergence of biophilic
architecture is rapidly growing, and its value can
no longer be ignored. The project proposes to
adapt the unused Danforth Garage historic transit
hub in Toronto into a sustainable community hub
by applying the architectural concept of growth
through the densification of both human and
plant inhabitants. The planning and place-making
design aspects nurture the connection between
humans and nature in architectural designs.Master of Architecture (M.Arch