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Is the Metaverse a new world? Interpreting the Metaverse from the perspective of Heidegger’s philosophy
No full textThis thesis examines the phenomenon of the Metaverse from Martin Heidegger’s
perspective, focusing on the concepts of Dasein, reality, truth, and the world. The main focus
of the thesis is the reality and the worldhood in the Metaverse.
The first two chapters will explain the main relevant concepts in Heidegger’s philosophy for
this topic. This starts with Dasein, which refers to the human existence, and world, which
involves the overall network of the significance of meaningful relationships and context. The
understanding of truth and reality is also highlighted and emphasized to clarify the existential
nature of the network that all these concepts form.
In Chapter 3, based on Heidegger’s theories, the relationship between technology and the
world is inquired. Heidegger argues that technology is not only a tool, rather, it has the capacity
to reveal the world as a standing-reserve, reducing the entities to mere means for certain aims,
by way of instrumentalization of the resources that are supposed to be ready for human beings
when they need them.
Through this preparation, the thesis provides a foundation to explore the ontological concept
of the Metaverse. Based on Heidegger’s philosophical framework, chapter 3 of the thesis then
concludes that the Metaverse is indeed a new world. The Metaverse, by providing an immersive
experience and a variety of new experiential and interactive possibilities provides environments
in which people can interact and get involved with visual and digital entities. Dasein through
this involvement allows the entities to refer, and in Heidegger, this means for them to be real.
The entities in the Metaverse are real, although not in the same way as the entities in the
physical world are.
The thesis then suggests that the difference between the reality of entities in the Metaverse
and the ones in the physical world can be explained by the fact that the kind of references they
make in the Metaverse are different from those of the physical world. This means that the
virtual representations and experiences within the Metaverse lack some ontological aspects of
the physical realm.February 202
Crude protein content and probiotic supplementation in sows: effects on sow and piglet performance and indices of gut health
No full textSince the use of in-feed antibiotics has been banned in many jurisdictions, alternative methods that maintain animal performance and health are being investigated. The objective of this study was to investigate the effects of crude protein (CP) content and supplementation of Bacillus-based probiotics (PRO) in late-gestation and lactation sow diets on performance of sows and gut health of suckling pigs. A total of 120 pregnant sows (60 gilts and 60 2+ parity) were assigned to one of four dietary treatments in a 2 x 2 factorial arrangement (2 CP levels, with or without PRO supplementation) from d 85 of gestation to d 21 of lactation. The experiment was conducted in 4 consecutive periods (half gilts and half sows per period). The diets consisted of 1) a corn-soybean meal (SBM)-based low CP (LCP; 12% CP) diet; 2) LCP + 0.05% probiotic (LCP-PRO); 3) a corn-SBM-based high CP (HCP; 15% CP) diet; and 4) HCP + 0.05% probiotic (HCP-PRO) and were formulated in 2 phases: gestation (d 85 – 115) and lactation (d 0 – 21). Commercially swine diets often contain approximately15% CP, therefore the HCP diet in this study reflects the industry standard. Lactation diets contained 14% and 17% CP for LCP and HCP respectively. Sow body weight (BW) and backfat (BF) thickness were recorded on d 85 and 111 of gestation and on d 1 and 21 of lactation. Sow blood and milk were sampled on d 1 and 17 of lactation to analyze plasma urea nitrogen (PUN) concentration, and milk fat, protein, and lactose, respectively. Reproductive performance data were recorded on d 0 of lactation and sow feces were collected d 12 of lactation for digestibility and microbial analysis. One piglet per sow close to average BW for each litter was selected for blood collection to analyze PUN and fecal collection for microbial analysis. Data were analyzed using the PROC MIXED of SAS. The statistical model included CP, PRO and their interaction as fixed effects, and period and replication as random effects. There was an interaction (P < 0.05) between CP and PRO on the number of stillbirths, where the number of stillbirths did not differ between LCP and LCP-PRO groups, while the number decreased in sows fed the HCP-PRO diet compared with the HCP diet. Sows fed LCP diets had reduced (P < 0.05) PUN concentrations on d 1 and d 17 of lactation compared with those fed HCP diets. No difference was found in fat, protein, or lactose content in both colostrum (d 1) and milk (d 17). Piglets from the sows fed LCP diets showed heavier (P < 0.05) birth weights (1.58, 1.57, 1.53, and 1.52 kg for diets 1 to 4) than those in HCP groups, however, the average daily gain (ADG) of week 1 (188, 166, 187, and 187 g for diets 1 to 4) was lower (P < 0.05) for piglets in LCP groups than HCP groups. There was an interaction (P < 0.05) between CP and PRO on piglet fecal DM, where HCP-PRO had higher fecal DM percentage than HCP, however, LCP and LCP-PRO groups did not differ. There was an interaction of CP and PRO on d 21 relative abundance of E. coli, where the abundance of was lower (P < 0.05) in piglets from sows fed HCP-PRO diets compared to piglets from sows fed HCP diets, however, piglets from sows fed LCP diet had a lower abundance (P < 0.05) of E.coli than piglets from sows receiving LCP-PRO diets. There was an interaction effect of CP and PRO on the relative abundance of Lactobacillus in piglets at age 21. Piglets from sows receiving HCP diets had a lower (P < 0.05) relative abundance compared to piglets from sows receiving HCP-PRO diets. Conversely, piglets from sows fed LCP-PRO diets had a lower (P < 0.05) relative abundance of Lactobacillus compared to piglets from sows fed LCP diets. On d 28, piglets from sows fed LCP diets had a decreased (P < 0.05) relative abundance of E.coli compared to pigs from sows fed HCP diets. There was an interaction effect of CP and PRO on d 28 where piglets from sows fed HCP diets had a decreased (P < 0.05) relative abundance of Clostridium perfringens compared to those from sows fed HCP-PRO diets. In conclusion, feeding LCP diets supplemented with PRO to sows has the potential to improve both the reproductive performance of sows and the gut health of suckling pigs.October 202
Applying signal processing techniques to characterize rail corrugation, noise, and vibration
No full textThis thesis presents the application of signal processing techniques to rail transit data for the purposes of rail corrugation maintenance. There are three primary forms of data in this work to which signal processing techniques were applied: (1) the analysis of rail corrugation as a spatial signal, (2) the analysis of wayside noise and noise spectra, and (3) balancing time and frequency resolution for inspection of on-board vibration signals. Grinding maintenance is common for addressing deteriorating rail surface condition, as surface defects like corrugation are removed. However, measuring the rail surface condition and then making the actionable decision to grind can be complex. This work develops a summary of corrugation roughness RCIx(λ), an extension of RCI2018 which uses a representative block root-mean square (RMS) measurement to summarize corrugation across a segment. The act of measuring surface roughness is a time-consuming task for property maintainers, and the act of measuring rail that does not require maintenance is wasteful. The measurement and analysis of wayside noise can give insight into the state of the rail to help property maintainers determine whether rail in a particular location is believed to require direct measurement and intervention, thus minimizing wasted effort. Lveq(λ, v) is developed in this thesis as a noise weighting scheme meant to isolate corrugation-related noise from a wayside noise sample spectrum. The usage of vehicle-mounted accelerometers can provide massive amounts of up-to-date information on rail condition through regular revenue service. This scale of data collection can streamline measurement and maintenance decisions throughout a property, however, the information encoded in this data requires post-processing to identify the characteristics of interest. This work utilizes the wavelet transform as a time-frequency analysis tool to spatially locate a particular frequency attribute in an acceleration sample. The results presented herein showcase the effectiveness of the signal processing techniques applied to these data streams. The growth of corrugation and its response to grinding were demonstrated in both corrugation and wayside noise datasets, while the wavelet transform has demonstrated a sensitivity to characteristics of interest in on-board vibration data.Advanced Rail Management co-funded MitacsFebruary 202
Genetic study of pre-harvest sprouting in spring wheat
No full textPre-harvest sprouting (PHS), which is defined as the germination of seeds prior to harvest under moist conditions, occurs in wheat and is closely related to seed dormancy. Low levels of seed dormancy result in pre-harvest sprouting, which adversely impacts wheat grain yield and end-use quality; for example, sprouted seeds have poor quality that is unsuitable for baking. On the other hand, high levels of seed dormancy cause a delay in germination and seedling establishment. Therefore, prevention of PHS or minimizing its negative effects in wheat requires the development of wheat cultivars with moderate level of dormancy in the seeds. However, the development of such cultivars requires the need to identify genomic regions and genes that are responsible for PHS resistance. Therefore, this research was focused on genome wide association study of a collection of spring wheat lines, which show a wide range of variation in seed dormancy, over six trial environments. Analysis of the association between the phenotypic and genotypic data of wheat lines studied led to the detection of the genomic regions and candidate genes that might have the potential to introduce PHS resistance in spring wheat.February 202
Assessment of mechanical properties and microstructure of Co-Cr dental alloys manufactured by casting, milling, and 3D printing
No full textPurpose
The aim of the present study is to investigate the effect of the three different Co-Cr manufacturing
processes on the mechanical properties and microstructure of Co-Cr dental alloys.
Methods
Dumbbell-shaped specimens (n=6) were fabricated with CAST (lost wax casting technique), CNC
(computer numerical control milling), and DMLS (direct metal laser sintering) techniques. The
mechanical propertied were evaluated following the (ISO) standard 6892. Tensile test was
performed to evaluate 0.2% yield strength, tensile strength, elongation, and elastic modulus, 3-
point-bending test was done for flexural strength, and microhardness test to analyze hardness. The
microstructure was evaluated through scanning electron microscopy (SEM) and energy dispersive
X-ray analysis (EDX), as well as X-ray diffraction analysis (XRD) for alloy phase identification.
Statistical differences for the tensile test, 3-point-bending, and hardness were evaluated by oneway
ANOVA followed by post hoc Tukey tests to determine the interaction among the groups.
Results
The DMLS groups showed the highest values for 0.2% yield strength (908.0±13.1MPa), tensile
strength (1123.7±6.5MPa), flexural strength (2273.0±43.2MPa), and microhardness
(438.2±44.9HV) followed by CAST (462.1±8.0MPa, 632.6±23.7MPa, 1351.2±35.7MPa, and
400.0±33.3HV respectively) and CNC (413.0±10.0MPa, 533.1±17.4MPa, 1155.6±41.7MPa, and
295.0±22.1 HV respectively). No statistical differences found for elongation between CNC
(15.3±3.9%) and DMLS (10.1±0.6%), as well as for DMLS (10.1±0.6%) and CAST (2.3±0.2%)
(P>.05). No statistical differences found for elastic modulus among all groups (P>.05). EDX
2
revealed a slightly different chemical composition among the groups. XRD spectra revealed facecentered
cubic (fcc) as the dominant phase and a small amount of hexagonal close-packed (hcp)
in all three tested groups, as well as a peak of σ phase identified exclusively in the CAST group.
Conclusions
The mechanical properties and microstructures of Co-Cr dental alloys is dependent on the
fabrication method. Overall, DLMS specimens performed better than CAST and CNC.October 202
Localized control of magnetization reversal in square artificial spin ice
No full textThis work investigates the localized control of magnetization reversal in square artificial spin ice (SASI) systems through the introduction of vertical control elements (VCEs). This research focuses on the effects of localized magnetic fields created by VCEs on the magnetization dynamics within SASI. We explore theoretical considerations and implementation strategies for using VCEs to modulate the energy barriers of individual spin flips, thereby influencing the overall magnetization reversal process. Using a single-spin flip Monte Carlo algorithm, we simulate the hysteresis behaviour of a 16-spin SASI system with and without the presence of VCEs. The simulation parameters are chosen to include thermal fluctuations at low temperature and field symmetry breaking. The results demonstrate that VCEs can effectively pin or facilitate the flipping of specific spins, allowing for controlled domain wall nucleation and propagation, mediated by motion of the lattice excitations, known as monopole charges. This control over monopole charge dynamics has potential applications in magnetic storage devices and spintronic technologies. The study provides insights into the impact of the controlled application of localized magnetic fields on the energy landscape of ASI systems.October 202
Safety and Effectiveness of Catheter-directed Thrombolysis Compared to Systemic Thrombolysis in Treating Massive and Submassive Pulmonary Embolism with Hemodynamic Compromise - A literature review
No full textIntroduction: Pulmonary embolism (PE) results from a blood clot that causes a blockage to one
of the pulmonary arteries in the lungs. This blockage can cause symptoms ranging from dyspnea
and chest pain to more severe ones, such as signs of obstructive shock, respiratory failure, and
cardiac arrest. Systemic thrombolysis (ST) has been found to effectively decrease the mortality
risk of patients who are currently hemodynamically unstable due to PE but also comes with an
increased risk for bleeding, such as intracranial hemorrhage. Therefore, catheter-directed
thrombolysis (CDT) is used when ST fails or when contraindicated. CDT helps minimize
exposure to thrombolytics because of having a localized directed infusion of the agent to lysis
the clot. Due to the nature of this procedure, this could be explored if CDT is a more effective
and safer choice than ST.
Methods: A systematic literature review using Scopus, PubMed, and Medline is done to search
for the effectiveness and safety of catheter-directed thrombolysis in contrast to systemic
thrombolysis.
Results: 49 articles were found through these three search engines. Seven articles were found to
be relevant and reviewed to compare the safety and effectiveness of CDT to ST.
Conclusion: This study concludes that CDT is more effective and safer than ST in treating
submassive PE with hemodynamic compromise and massive PE. This conclusion was solely
based on retrospective studies. Future randomized controlled trials should be done to support this
study's inference and see if guidelines regarding the standard of care can be changed
Development of novel biomarker drugs for detection and therapeutic monitoring of glioblastoma
No full textIntroduction: Glioblastoma multiforme (GBM) is an aggressive brain tumor, comprising 46% of all malignant primary brain tumors. Despite advancements in surgery, radiation, and chemotherapy, GBM prognosis remains poor, with a median survival of 14–16 months. More effective diagnostic and therapeutic strategies are urgently needed. Previous studies have shown amantadine, a Health Canada-approved drug, is metabolized via Spermidine/spermine acetyl transferase 1 (SAT1). As SAT1 expression is increased in many different cancers, the present studies examined the acetylation of amantadine and related drugs by GBM cells to determine the potential of these agents as biomarker candidates.
Methods: The acetylation of spermidine, amantadine, rimantadine and hydroxyl rimantadine were examined using recombinant acetyltransferase enzymes and human GBM cell lines (U251, LN229, MD59K) cultured under normal conditions and following SAT1 induction with N(1),N(11)-diethylnorspermine (DENSpm) (10uM). The formation of acetylated metabolites was determined either indirectly through fluorometric acetyltransferase assay kit or directly by liquid chromatography mass spectroscopy (LCMS) detection methods. The expression of SAT1 and SAT2 in the GBM cells was determined using immunofluorescence and western blot. The permeability of amantadine, rimantadine and their respective acetylated metabolites were also examined a microfluidic culture model of the blood-brain barrier (BBB).
Results: The study highlights SAT1-driven acetylation of amantadine and rimantadine, with acetyl rimantadine formation showing as much as 10-times greater accumulation in GB tumor cells and in the SAT1 recombinant enzyme assays compared to amantadine. Permeability of both the drugs and their acetylated metabolites in the microfluidic BBB culture model ranged from 1 x 10-6 to 10-4 cm/s and were consistent with solutes that can readily pass the BBB. While the acetylation of amantadine and rimantadine was selective for SAT1, studies suggest potential for direct acetylation by acetyl CoA that requires further investigation in the context of GBM drug metabolism.
Conclusions: Both amantadine and rimantadine may serve as GBM progression biomarkers, with Acetyl rimantadine showing better potential for diagnostic accuracy based on greater acetylated metabolite formation in GBM cells. These findings suggest that rimantadine could be a more effective biomarker candidate for GBM therapy monitoring.February 202
The role of thioredoxin-interacting protein in corticosterone induced damage in astrocytes
No full textBackground: Chronic treatment with corticosterone (CORT) can induce oxidative stress and neuroinflammation. Thioredoxin-interacting protein (Txnip) inhibits antioxidant protein thioredoxin, interrupting protein thiol reduction and inducing oxidative stress. Txnip can also bind to NLRP3, facilitating NLRP3 inflammasome forming, activating caspase-1 and releasing IL-1β. Previously, our laboratory found that chronic CORT treatment increased Txnip levels in cultured mouse neurons and microglia, suggesting that CORT may upregulate Txnip, inhibiting thioredoxin activity and activating NLRP3 inflammasome, which may amplify oxidative stress and neuroinflammation.
Objective: Since astrocytes can release proinflammatory cytokines and reactive oxygen species, facilitating oxidative stress and neuroinflammatory processes. The objective of this study is to determine if CORT treatment can upregulate Txnip in astrocytes, further promoting oxidative stress and inflammation.
Methods: Primary cultured mouse astrocytes were used in the present study. Thioredoxin and Txnip protein levels were measured by immunoblotting assay. Eosin-labeled insulin was used as a substrate for measuring thioredoxin activity. Total reduced thiol level was measured using Ellman’s assay. Protein sulfenylation and carbonylation were measured by dimedone conjugation and biotin-hydrazide conjugation methods respectively. NLRP3/Txnip binding was measured by co-immunoprecipitation assay. Fluorogenic Z-YVAD-AFC was used as a substrate for measuring caspase-1 activity, while IL-1β release was measured by enzyme-linked immunosorbent assay. Crispr/Cas9/Txnip sgRNA was used to knock out Txnip gene.
Results: We found that CORT treatment for 24 hours had no effect on thioredoxin levels, but increased Txnip levels. CORT-increased Txnip levels were decreased by mineralocorticoid receptor antagonist spironolactone and glucocorticoid receptor antagonist RU486. CORT treatment decreased thioredoxin activity, but had no effects on total reduced thiol levels, sulfenylated protein levels and carbonylated protein levels. However, CORT treatment increased Txnip/NLRP3 binding activity, caspase-1 activity and IL-1β release. Txnip knockout attenuated CORT-increased caspase-1 activity and IL-1β release.
Conclusion: The findings suggest that CORT treatment increases Txnip level, which could promote NLRP3 activity, activate caspase-1 and release IL-1β to facilitate neuroinflammatory process in astrocytes. However, due to enriched antioxidants in astrocytes, CORT-increased Txnip may not be sufficient to exert oxidative stress.October 202
The potential effectiveness of the Strategic Assessment of Climate Change Guidance: application of a learning lens
Get PDFThe purpose of this thesis research was to investigate the potential effectiveness of Canada’s Strategic Assessment of Climate Change (SACC) Guidance in offering a new path for the integration of climate change considerations into federal impact assessment (IA) processes under the Impact Assessment Act (IAA), and, by doing so, helping to ensure that resulting decisions, at a minimum, do not hinder Canada’s ability to meet its climate change commitments. Three “effectiveness” criteria were developed to define “effectiveness” within the context of the research.
Two past federal environmental assessments (EAs) were chosen for review according to selection criteria. SACC Guidance was reviewed, summarized, and counterfactually applied to these EAs. Semi-structured interviews were conducted with IA experts and practitioners. Additional EA/IA documentation regarding more current projects was also reviewed to understand how SACC Guidance was being implemented. Throughout data collection and analysis, attention was paid to how the SACC Guidance’s strengths and gaps may be linked to certain learning outcomes identified by Suškevičs et al. (2018, 2019), and how these learning outcomes link more broadly to the policy’s effectiveness. Data was collected using written notes and audio recordings, which were transcribed, coded, and analysed using NVivo software.
Ten strengths and gaps in the IAA/SACC Guidance’s approach to considering climate change in IA were identified. Four of these represent gaps which weaken the policy’s effectiveness, while five represent strengths which have a potential to enhance its effectiveness. One feature was determined to have the potential to act as either a strength or a gap depending on implementation. Three additional long-standing EA/IA issues were also identified, which more generally relate to how the IA process is structured, and thereby create gaps in IA’s handling of climate change considerations.
For each of the strengths and gaps identified, opportunities to build on strengths and fill gaps were also identified. Application of the learning framework created a nuanced understanding of the strengths and gaps, which served to enhance recommendations for opportunities to improve the IAA/SACC Guidance’s effectiveness. Generally, it was found that there is a relationship between enhancing the IAA/SACC Guidance’s learning approach and enhancing its effectiveness.February 202