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2D geometric morphometrics of murine mandibular toothrows from Liang Bua (Flores, Indonesia): implications for taxonomic identification
Get PDFThis study uses—and evaluates the efficacy of—two-dimensional geometric
morphometrics (2DGM) to quantitatively characterize the size and shape of murine rodent (i.e.,
rat) mandibular molar rows from the archaeological site of Liang Bua, a limestone cave located
on the Indonesian island of Flores and the type site of Homo floresiensis. Murine remains make
up a significant portion of Liang Bua’s sizable faunal assemblage and contribute significantly to
understanding the paleoecology of western Flores. As such, it is essential to develop robust
methodologies to accurately assess the taxonomy of these remains. Using images of complete
mandibular toothrows, this study aims to test the functionality of 2DGM for taxonomic
assessments based on the size and shape variation present in the Liang Bua murine assemblage.
The results show that 2DGM offers important information about mandibular toothrow size and
shape that can be used in conjunction with qualitative and other quantitative data for murine
species identification at Liang Bua and other archaeological sites on Flores. Additionally, this
study explores the effects of image angle and tooth wear on 2DGM analyses and provides several
recommendations for how to mitigate these potential issues in future work. Since the Liang Bua
murine remains represent multiple species of varying body sizes and habitat preferences,
quantitative variation and descriptions of previously uncharacterized inter- and intra-species
variation described in this study will help to facilitate ongoing paleoecological reconstructions of
the cave’s history
Adipose tissue remodeling in response to corticosterone and β3-adrenergic receptor agonist mirabegron
Get PDFWith the rise of metabolic diseases including obesity and type 2 diabetes, the need to investigate one
of the most dynamic endocrine organs is critical for combating these diseases. Adipose tissue (AT) exists
predominantly in two forms: white AT (WAT) and brown AT (BAT). This study set out to investigate how
chronic levels of glucocorticoids (GC), namely corticosterone, influence AT, and if the negative effects of GCs
can be combated with a β3-adrenergic receptor (β3AR) agonist, mirabegron. Mice were subjected to oral
treatments of either, corticosterone (500µg/day), mirabegron (either 0.024mg/day or 0.24mg/day), a
combination of the two, or naïve or vehicle (<1% ethanol) controls for four weeks. The corticosterone dose
was chosen to match the level of corticosterone circulating in Cushing’s syndrome patients, and the
mirabegron treatments were chosen to be a much lower dose (0.024mg/day) than or to closely resemble
the maximal dosage approved (0.24mg/day) for overactive bladder patients. We hypothesized that
mirabegron would offset the negative impacts of corticosterone-induced metabolic dysfunction and lipid
accumulation within the AT depots. Corticosterone treatment resulted in BAT whitening, significantly
(p≤0.05) increased body and AT weights, whole-body insulin resistance and circulating leptin levels. [...
A case study of moisture regime on Pinus banksiana across Ontario
Get PDFWith climate change affecting the boreal forest there are many
consequences to plant species on different site types that can be detrimental to
their longevity and productivity, affecting ecosystem health. In this study
moisture regime effect on Pinus banksiana Lamb. (jack pine) productivity was
explored. This study shows that mean annual increment on the moisture
regimes 0-2 are the most productive annual with DBH growth and height growth.
The introduced climatic stressors such as raised temperature can negatively
impact these sites and allow for a major amount of drought stress to take place,
which will hinder the productivity of this widely used commercial species. There
will also be a shift in moisture regime for the regimes 3-7 causing these to
become drier. This could allow for the fresh (3) and the moist sites (4-7) to
become more productive as they dry out
An intelligent system for fault diagnosis in gearboxes
Get PDFGearboxes are commonly used in rotating machinery for power transmission. A gearbox consists
of shafts, gears, and bearings, each component having specific mechanical dynamics and fault
properties. Reliable gearbox fault detection and health monitoring techniques are critically
needed in industries for more efficient predictive maintenance applications. The objective of this
work is to develop a new technology for health monitoring of gearboxes. Firstly, a new wavelet
analysis method is technique for analysis of gear faults in a gearbox with demodulation from
other rotating components such as shaft and bearings. Secondly, a mode decomposition
technique is proposed to highlight bearing fault features in a gearbox. Thirdly, a new evolving
neuro-fuzzy (eNF) classifier is developed to integrate the merits of different fault detection
techniques for real-time health condition monitoring of gear systems. The effectiveness of the
proposed techniques is verified by simulation and experimental tests
Application of Walki®Biomass cover as a better alternative to plastic mulching
Get PDFMulch is a material that works as a protective layer over the soil so as to retain water and
prevent excess evaporation. They are either in the form of continuous sheets like plastic
mulch or they come in a shredded form, like wood chips etc. Plastic mulching, though
it’s not good for the soil is one of the most widely used mulch materials. The main
problem with plastic mulching is its disposal after use, since it being non-biodegradable
it cannot be decomposed. So, all that plastic accumulates in the soil, and can cause
environmental hazards. In recent years research has been conducted to find a better
alternative to plastic mulching, including invention of the biodegradable plastic. It was
found that biodegradable plastic had remarkably similar temperature and water retention
properties but was coming at a higher price than regular plastic. This thesis is focused on
achieving the purpose of mulching using Walki Biomass cover, a paper-based laminate
that also has a mesh of biodegradable plastic which is partly water resistant and is a
100% biodegradable
A review of anthropogenic threats and the decline of at-risk lichen populations in Canada
Get PDFLichens are among the most common species in Canada, but their population has
declined in recent years. This review focuses on the key factors associated with the
decline in lichen species in Canada. The study investigated the anthropogenic threats
linked to the deterioration of at-risk lichen species. The study mainly focused on the
effect of human factors since they have been established to have a significant role in the
decline of lichen species in Canada. Existing studies from Lakehead University Library
Database and Google Scholar were used as data sources. The study found that loss of
habitat through deforestation and fire is associated with a decline in the lichen
population. Also, overexploitation through large-scale logging and wood harvesting,
agricultural activities, including clearing forests for land use or farming activities, and
urbanization and air pollution from industrial activities are associated with a decline in
the number of lichen species in Canada. Lichen conservation measures should be
enacted and supported in Canada to reduce human activities and improve the growth and
survival of lichens
From alpinism to activism: outdoor athletes’ perspectives on ecological and climate learning through their sport
Get PDFWhile climate change education has been studied extensively, the process of
environmental and climate learning outside of a structured educational context has seen
little study. Previous research has shown the efficacy of outdoor, experiential, and
place-based education in facilitating ecological literacy, ecological consciousness,
sustainable behaviours, and climate change awareness in school-based and public
education; however, little research has been conducted to understand the development
of this process outside of an educational context, nor in high-level outdoor athletes
whose hobbies and/or careers often demand that they spend considerable time in
nature. This exploratory qualitative study uses semi-structured interviews in a limited
athlete sample (n=7) to explore the perspectives of high-level outdoor athletes on the
influence of their involvement in outdoor sport on the development of their ecological
consciousness, ecological literacy, sustainable or responsible behaviours, and climate
activism. Findings suggest that connection to nature through sport may have a profound
influence, impacting how these athletes conceptualize the environment, climate change,
and their place in human-ecological systems, guiding their learning and actions. This
aligns with goals of environmental and sustainability education, climate change
education, and place-based education by providing insight into ways that outdoor sport
may provide opportunities to engage with nature in a meaningful, authentic, and
environmentally sustainable way while also enabling a deeper understanding of the
potential of outdoor sport to motivate individuals to climate action
Advanced separation and anaerobic digestion technologies for value-added bioproducts and biofuel from pulp and paper mill wastes
Get PDFIn the first research project, the extraction of hemicellulose from the process water and synthetic
hydrolyzate using liquid-liquid extraction (LLE) was examined. Specifically, the effects of the main
experimental variables (the type of solvent, hydrolyzate to solvent volume ratio, and pH) on extraction
performance were explored. The tested solvents showed varying affinity and selectivity to recover
hemicellulose. It was found that the hemicellulose extraction efficiency of n-hexane (71.03%) and tributyl
phosphate (TBP) (72.34%) was higher than that of 1-butanol (62.36%), and toluene (67.03%) at a solvent:
hydrolyzate volume ratio of 1:3. A pH value of 4.3, a phase ratio of 1:3 mL/mL, and an extraction time of
30 min were considered optimal conditions for hemicellulose extraction.
In the second study, the thermophilic submerged anaerobic membrane bioreactor (ThSAnMBR) technology
was used for pulp and paper primary sludge treatment, and both biological and membrane performance
were evaluated. The biological performance was studied in terms of biogas production, solids reduction,
chemical and structural changes of the digestate, and permeate quality under various operating conditions.
While the effect of primary sludge on the membrane performance and fouling was systematically
investigated. Several experimental parameters were investigated including solids retention time (SRT) (32-
55 days), hydraulic retention time (HRT) (3-8 days), organic loading rates (OLRs) (2.5-6.8 kg-COD/m3d),
temperature (50±1°C), membrane fouling and cleaning frequency. Membrane performance was evaluated
by monitoring its flux and corresponding transmembrane pressure as well as changes in its chemical and
physical properties resulting from operating conditions using Fourier transform infrared (FTIR), scanning
electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), contact angle, and pore size
measurement. [...
Amorphous lead oxide (a-PbO) for direct conversion X-ray imaging detectors
Get PDFModern medical imaging revolutionized the way that medical conditions are diagnosed. It became
possible after significant advancements in science and technology related to the medical
visualization field. X-ray imaging is one of the most commonly used modalities; it now relies on
the digital Flat Panel X-ray Imagers (FPXIs) that can provide high-quality radiographs while
benefiting from many advantages inherent to the digital detectors technology, including reduced
radiation exposure and convenience of use. Although some FPXIs have already been
commercialized, their application is very limited, and they do not exploit the full potential of this
technology. Therefore, there is a niche that can only be filled through extensive research and
development. The work carried out and presented in the dissertation contributes to this effort.
In this work, an Amorphous Lead Oxide (a-PbO) photoconductor is investigated as a material of
choice in the direct conversion digital FPXIs for various medical and industrial X-ray imaging
applications, including general radiography, real-time fluoroscopy, digital breast tomosynthesis,
and non-destructive testing. a-PbO is a recently developed material with high X-ray stopping
power in a wide X-ray energy range and high theoretical X-ray–to–charge conversion efficiency. [...
Invasive plant cover and density following emerald ash borer-induced mortality in southern Ontario forests
Get PDFThe emerald ash borer has caused widespread ash mortality in eastern North
American forests, where forest managers are also facing challenges due to invasions of
undesirable exotic plant species. This study aims to explore relationships between the
two phenomena based on existing evidence that disturbance caused by insect pests may
facilitate invasive plant colonization. The presence of invasive species was analyzed in
the context of ash mortality following emerald ash borer infestation in four forests in the
Region of Waterloo in Ontario. Multivariate analysis with generalized linear models
was used to detect relationships between invasive plants and various environmental
variables. Significant relationships with invasive plant cover and density are found for
decline in ash basal area, ash mortality occurrence, change in total basal area, current
basal area, canopy closure, regeneration density, and tree species composition. Potential
effects of competitive exclusion and site richness on invasive plant species are
discussed