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The hidden costs: a qualitative study of financial toxicity in hereditary cancer syndromes across Canada
No full textIdentifying financial toxicity (FT) following a cancer diagnosis is critical for providing interventions and support to patients. There is virtually no research on FT in patients with hereditary cancer syndromes (HCS), which account for approximately 10% of all cancers. This thesis examines FT related to two common types of HCS: hereditary breast and ovarian cancer syndrome (HBOC) and Lynch syndrome (LS). A qualitative interpretative description study was employed. Patients across three provinces in Canada with a confirmed molecular diagnosis of HBOC or LS were invited to participate in semi-structured interviews. Data saturation was achieved after interviewing 73 participants diagnosed with HBOC (n= 39) or LS (n= 34). Thematic analysis employing constant comparison was used to analyze the transcripts. Participants described several aspects of FT categorized under three primary themes: 1) objective financial burden (direct out-of-pocket (OOP) medical costs, direct OOP non-medical costs, indirect costs); 2) evaluation of financial resources; 3) subjective financial distress (distress due to financial resource management, basic needs insecurity, future financial insecurity). Findings revealed many interrelated objective and subjective aspects of FT. Evaluation of one’s financial resources emerged as a key factor in the experience of financial distress. Developing policies that facilitate solutions to mitigate FT experienced by patients with HCS is urgently needed.Includes bibliographical references (pages 80-112
“In our own way”: tradition and transmission among later-generation Transylvanian Saxons in Canada
No full textThis thesis examines the motivations and directions of Transylvanian Saxon folklore
transmission among later-generation immigrant members of the Transylvanian Saxon community
in Aylmer, Ontario. Interviews, participant observation, and attendance at cultural performances
and events inform this ethnographic study that applies performance theory to explore the
concepts of nostalgia, authenticity, and tradition and their roles within a small diasporic
organization. Additionally, the author investigates her own position as a third-generation
Transylvanian Saxon and leader within the community. The thesis begins with background
information leading to the author’s participation and research in the community, followed by
introductions to the study’s participants. Transylvanian Saxon heritage and migration narratives
are applied as a framework for presenting the group’s history and participants’ expression of
nostalgia for an unknown Heimat or homeland. Next, a case study of a homecoming event in
Germany illustrates the varying degrees of engagement with costume authenticity between
different Saxon groups. Then, recorded folklore is presented as a key component to transmission
in small immigrant communities where cultural practices are passed down, passed on, and passed
back between members. Finally, contemporary material culture is presented in a case study
demonstrating how nostalgia, authenticity and tradition are being creatively interpreted among
later-generation Saxons and non-Saxons.Includes bibliographical references (pages 145-159
Investigating the roles of B vitamins and one-carbon metabolism in gut homeostasis
No full textVitamins are the organic compounds essential for normal growth and metabolic processes in all living organisms. B vitamins, such as vitamin B9 and B12, act as cofactors in various metabolic reactions, including one-carbon (1C) metabolism, and typically are required in trace amounts. The gut harbors a diverse population of bacteria, some of which are capable of producing certain vitamins. These bacteria also require vitamins for their growth and proliferation, with requirements varying between vitamin-producing and non-producing strains. However, bacterially synthesized vitamins are limited, and dietary intake is vital for meeting the host’s daily requirements. Despite the well-understood functional role of B vitamins, their precise impacts on gut ecology remains poorly understood. The current study aimed to investigate the impacts of vitamin B9 and B12 deficiencies on gut morphology, microbial composition, and their metabolites using a rodent model of vitamin deficiency. Our findings revealed that a deficiency in vitamin B9 or B12 altered mucosal height and decreased acidic mucin production in the colon. Of particular interest, we observed sex-dependent differences in the effects of vitamin deficiency on the gut microbial profile. The analysis of fecal metabolites showed notable alterations in metabolites associated with gut health in the vitamin-deficient groups compared to the control. This study provides evidence that deficiencies in B vitamins, particularly those involved in 1C metabolism, can disturb gut homeostasis in a sex-dependent manner.Includes bibliographical references (pages 73-89
Inelastic light scattering studies of biological macromolecular solutions and virus crystals
No full textIn this study, Brillouin light scattering is used as a tool to explore the elastic and
viscoelastic properties of different macromolecular systems. Specifically, we explore
two common macromolecular systems: aqueous solutions and crystals. By performing
experiments on these different systems, we are able to explore the evolution of the
properties of interest in three distinct regimes. By performing experiments on aqueous
solutions, we are able to explore the dilute regime, wherein solute molecules may be
treated as non-interacting particles, and the semi-dilute regime, where intermolecular
interactions cannot be neglected. Finally, performing experiments on macromolecular
crystals allows us to observe the elastic properties of macromolecules in the solid state.
The effects of macromolecular crowding have been extensively studied by various
experimental techniques. Such works have demonstrated a significant amount of
binding of solvent to the hydration shells of such crowders, drastically reducing the
available free volume. In this work, Brillouin light scattering experiments were performed
on aqueous solutions of Ficoll 70 and Ficoll 400 with concentrations ranging
from 1 wt% to 35 wt% and Bovine Serum Albumin with concentrations of 1 wt%
to 27 wt%. By examining the evolution of longitudinal Brillouin peak parameters
with solute concentration, we calculated viscoelastic properties, including hypersound
velocity, adiabatic bulk modulus and compressibility, apparent viscosity, and hypersound
attenuation. Existing theory could only capture trends in this evolution up
to a threshold concentration due to the neglect of intermolecular interactions. As
such, the addition of a quadratic term was incorporated to account for intermolecular
interactions between solute molecules. In Ficoll solutions, evidence of a central mode,
which is due to relaxation of solvent in the polymer hydration shell, was observed.
In recent years, there has been a growing amount of interest in exploration of the
elastic properties of crystalline macromolecular structures. Such properties of virus
crystals, however, are still hardly known. In the present work, crystals of satellite
tobacco mosaic virus were grown using hang drop vapour diffusion techniques. Crystal
clusters grown were subsequently used in Brillouin light scattering experiments.
Peaks in Brillouin spectra were determined to be due to longitudinal bulk modes,
and the parameters of these peaks were used to approximate hypersound velocity and
attenuation within the crystals.Includes bibliographical reference
A palynological view of selected Norse-era cultural landscapes and subsistence strategies in Greenland
No full textThis thesis is a palynological examination of Norse-era landscape change and subsistence strategies at the Norse Western Settlement of southern Greenland. A central focus is an attempt to understand Norse settlers' actions to maximize the agricultural potential of what many have characterized as a marginal landscape. This thesis accomplishes that task by reporting sheep and goat (caprine) foddering/husbandry strategies at several sites in the Western Settlement and a single Eastern Settlement site. A second chapter explores environmental data from the high-status Western Settlement farm of Sandnes. Landscape management and modification practices of Norse farmers have been a topic of study through several generations of researchers, and I add to this discussion by focusing on the less investigated Western Settlement and ancillary sites of the Eastern settlement using palynological techniques on a probable anthrosol and midden recovered caprine coprolites. These are two potentially significant sources of data that have rarely been utilized. The first chapter reveals caprine foddering strategies in a Western Settlement farm, Eastern Settlement farm, and a potential shieling. The results reinforce previous assumptions regarding the Norse usage of seasonally available resources in foddering strategies. The second chapter led to new interpretations of chronology and land use at Sandnes, a chiefly farm. Notably, the curation of this Norse cultural landscape was a slowly occurring process and may have ended before previously thought. The data presented here offers an example of the Greenlanders' subsistence strategies that allowed them to persist on the western arctic edge of the Norse cultural sphere for at least 425 years.Includes bibliographical references (pages 99-110
Biomechanical investigation of the colonoscopy procedure: is practitioner injury risk greater with patients in the right or left lateral decubitus position?
No full textBackground: A colonoscopy is a medical procedure that uses an endoscope to assess the colon for abnormalities. It has been established in the literature that performing this procedure frequently is associated with operator musculoskeletal injury of the distal upper extremity. However, it is less understood whether this procedure contributes to pain and injury of the low back, an exceedingly common workplace injury that often results in time off.
Objectives: To investigate the effects of patient posture (left lateral decubitus [LL, right lateral decubitus [RL], and supine) on biomechanical and psychological outcome measures (muscle activity, perceived pain, exertion, and posture) in endoscopists during a simulated colonoscopy.
Methods: Eighteen practicing endoscopists performed three 10-minute trials of a simulated colonoscopy with varying patient positions: LL, RL, and supine. Surface electromyography (sEMG) sensors recorded muscle activity, and an ergonomic assessment tool assessed posture and injury risk. Perceived exertion and discomfort were measured before and after each trial using the BORG-CR10 and Visual Analog Scales. Descriptive statistics, Shapiro-Wilk tests, and one-way repeated measures ANOVA were used to analyze normally distributed data. Non-parametric data were assessed using the Wilcoxon signed-rank test. Tukey's post hoc tests were used where necessary, and Pearson correlations examined trends in height, weight, and BMI. Significance was accepted at p < 0.05.
Results: This study found that patient position did not result in significant differences in muscle activity, perceived discomfort, or perceived exertion during a short exposure to simulated colonoscopy. Specifically, average muscle activity levels across positions were low and not significantly different (F(2, 32) = 3.415, p = 0.068, η² = 0.176). Perceived discomfort and exertion showed similar patterns with no significant differences observed (discomfort: F(2, 32) = 2.686, p = 0.110, η² = 0.144; exertion: F(2, 34) = 1.045, p = 0.342). However, Rapid Upper Limb Assessment scores indicated a significantly lower ergonomic risk in LL position compared to the RL and supine positions (LL vs. RL: median 4 vs. 6.5, p < 0.03; LL vs. supine: median 4 vs. 6, p < 0.03). While no significant differences were found in muscle activity or perceived discomfort, ergonomic assessment scores suggest that all positions have elevated injury risk, particularly if
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exposures would be prolonged. Future research should examine longer durations and real-world scenarios to better understand the impact of patient positioning on injury risk.
Limitations: This study faced several limitations. The sample size was small, with only 18 participants who were predominantly right-handed, healthy, and of Caucasian ethnicity, limiting generalizability. The study used a high-fidelity simulation with a dummy patient, which may have reduced the procedural challenge and variability. Additionally, participant bias could have influenced subjective reports of strain, as more experienced endoscopists may have perceived the procedure differently. Future research should involve larger, more diverse samples and real-world settings inclusive of full workloads to address these limitations and provide more comprehensive insights into the impact of patient position on musculoskeletal demands.
Conclusion: In conclusion, this study finds that patient position does not significantly affect muscle activity or perceived pain and exertion scores during a short exposure to simulated colonoscopy. As such, endoscopists may not need to adjust patient positioning to mitigate musculoskeletal strain in brief procedures. Future research should investigate the impact of longer procedure durations and real-world settings to further explore factors that may influence injury risk.Includes bibliographical reference
Anti-oppressive science teaching: an investigation of intermediate and secondary science teachers' views and practices
No full textWhether via outright abuse, exploitation, neglect, or exclusion, the oppression of
marginalized identities within science is a long-standing and well-documented
phenomenon. In the absence of intentional and concerted efforts, school science programs
can perpetuate this oppression. Anti-oppressive pedagogy is a set of theories and
practices which seeks to challenge this, to dismantle oppressions within and beyond the
classroom, and to liberate students. The purpose of this research study was to examine
teachers’ views on and use of anti-oppressive teaching in intermediate-secondary science
classrooms in Newfoundland and Labrador. The study employed a mixed methods
design, which incorporated a digital questionnaire and semi-structured interviews with
science teachers. The results demonstrated significant variability among local teachers'
perspectives. Several participants expressed a lack of awareness in relation to oppression
in science, and some expressed resistance to engaging with such topics in their classes.
There was also considerable disparity observed in terms of teachers’ reported
implementation of anti-oppressive teaching practices. Overall, findings indicated that the
integration of these practices within local intermediate and secondary science programs is
severely limited. The study revealed several factors which influence teachers'
engagement with anti-oppressive teaching. Consideration of these factors, together with
existing literature, illuminated some key actions for advancing anti-oppressive science
teaching and promoting equity in science.Includes bibliographical references (pages 109-132
Quantile regression for count data with optimized jittering
No full textQuantile regression (QR) is a natural extension to the classic linear regression. It
models the conditional quantiles of the continuous response variable instead of modeling
the conditional mean. Often times we encounter discrete response variables,
such as counts or other kind of categorical variables. Due to the discontinuity of
counts, traditional QR creates systematic bias when applied to count data and hence
is not directly applicable. Jittering with uniform random perturbations is one of the
options to smooth the discrete response. In this thesis, we propose a new QR model
for count data, which improves the existing uniform jittering method. The proposed
approach involves artificially adding Tweedie or Beta random perturbations to original
count response, generating pseudo-continuous QR response. Through proper
selection of perturbation parameters, jittering can provide better parameter estimation
of the regression parameters as compared with the existing methods. We
employ the Asymmetric Laplace Distribution (ALD) to determine the optimal perturbation
parameters through the Monte-Carlo Expectation Maximization (MCEM)
and Metropolis-Hasting (MH) sampler. Our proposed method for QR model provides
consistent estimators of the QR coefficients. The estimators follow asymptotic
normal distribution as sample size goes to infinity. Simulation studies show much
improved performance when sample sizes are small to moderate. As an illustration,
the proposed method was applied to analyze a fishery data.Includes bibliographical references (pages 160-167
Correlational patterns of neuronal activation and epigenetic marks in the basolateral amygdala and piriform cortex following olfactory threat conditioning and extinction in rats
No full textIntroduction: Cumulative evidence suggests that sensory cortices interact with the basolateral amygdala (BLA) defense circuitry to mediate threat conditioning, memory retrieval, and extinction learning. The olfactory piriform cortex (PC) has been posited as a critical site for olfactory associative memory. Recently, we have shown that N-methyl-D-aspartate receptor (NMDAR)-dependent plasticity in the PC critically underpins olfactory threat extinction. Aging-associated impairment of olfactory threat extinction is related to the hypofunction of NMDARs in the PC.
Methods: In this study, we investigated activation of neuronal cFos and epigenetic marks in the BLA and PC using immunohistochemistry, following olfactory threat conditioning and extinction learning in rats.
Results: We found highly correlated cFos activation between the posterior PC (pPC) and BLA. cFos was correlated with the degree of behavioral freezing in the pPC in both adult and aged rats, and in the BLA only in adult rats. Markers of DNA methylation 5 mC and histone acetylation H3K9/K14ac, H3K27ac, and H4ac exhibited distinct training-, region-, and age-dependent patterns of activation. Strong correlations of epigenetic marks between the BLA and pPC in adult rats were found to be a general feature. Conversely, aged rats only exhibited correlations of H3 acetylations between the two structures. Histone acetylation varied as a function of aging, revealed by a reduction of H3K9/K14ac and an increase of H4ac in aged brains at basal condition and following threat conditioning.
Discussion: These findings underscore the coordinated role of PC and BLA in olfactory associative memory storage and extinction, with implications for understanding aging related cognitive decline.Memorial University Open Access Author's Fun
Managing hazmat emergency logistics with random travel time: a distributionally robust approach
No full textIn the field of emergency logistics involving hazardous materials (hazmat), the
optimization of emergency facility locations and risk mitigation is paramount. Prior
research primarily focused on emergency planning with deterministic travel times.
However, real-world emergency responses encounter diverse factors leading to uncertainties
in travel duration. This study addresses the hazmat emergency facility
location and allocation problem by considering stochastic emergency response times.
The proposed distributionally robust optimization model aims to minimize emergency
facility construction costs while concurrently mitigating potential system risk
under the worst-case distribution of response time within an ambiguity set. Given
limited distribution data derived from historical records, two methodologies are employed
to convert this data into tractable ambiguity sets. Experimental assessments
conducted using a hypothetical and a real-world case study in China showcase the
superior efficacy and efficiency of the proposed approach. Furthermore, sensitivity
analyses of parameters shed light on the various factors influencing the system, illustrating
the interplay between cost minimization and risk mitigation objectives,
and offering optimal solutions for different parameter configurations. These findings
yield invaluable insights for decision-makers involved in hazmat emergency response
operations.Includes bibliographical references (pages 96-111