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Performance evaluation of BioPET detector for plant-imaging
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Physics, University of Regina. xvi, 98 p.Positron Emission Tomography (PET) imaging for plants has the potential to advance
our understanding of plant physiology and metabolism, leading to the more efficient and
sustainable agricultural practices. However, conventional clinical and preclinical PET
systems are not fully suitable to plant studies due to requirement of a very good spatial
resolution in order to distinguish plant tissues of small size. Additionally, a proper axial
and transaxial Field of View (FOV) is needed to adapt plants of different sizes in a vertical
alignment before imaging. In order to overcome these technical constraints, BioPET, a
plant-imaging instrument was designed and developed. The construction of PET block
detectors and the BioPET system overall are described in this thesis. BioPET, assembled
from its predecessor [1, 2], which was originally a four-module setup known as PhytoPET,
is designed to adapt plant systems. BioPET detectors are equipped with 37 × 37 pixelated
GAGG scintillator with dimensions 50.44 × 50.44 × 13 mm3. Each GAGG scintillator is
coupled to a 8 × 8 SensL SiPM J-60035-64P-PCB photosensor array with a board size
of 50.44 × 50.44 mm2. To increase the data collection efficiency and have enlarged FOV,
12 new detector modules were assembled to form a sixteen-module BioPET system. For
improved light transmission from scintillator to photodetector, a two-component epoxy
resin Ultra-Transparent AB Crystal Glue was tested and used to couple the scintillators
to the photodetector surface with a 5 mm thick borosilicate light guide in between them.
Epoxy-resins from different manufacturers were tested to evaluate their light transmission
efficiencies. In these new modules, Silicon Photomultipliers were used as photodetectors
instead of conventional Photomultiplier Tubes due to their compact size, small bias voltage
requirement and insensitivity to magnetic field. Signals obtained from photosensor array
are read out with an amplifier board AiT ArrayJ-60035-64P-PCB and it outputs 16 outputs
from the rows and columns sum of 8 × 8 SiPM array. Struck Data Acquisition System has
13 modules of SIS3316 16 Channel VME Digitizers. MPOD multi-channel high voltage (HV)
and low voltage (LV) power supply modules kept in a WIENER VME system are used for
the low voltage required for amplifier (±5V) and high voltage required for the SiPM bias
(0-60 V adjustable). An ImageJ macro was developed and validated using phantom images
as prescribed by NEMA NU-4 2008 Standards. BioPET’s geometry enables plant studies
to be performed in a vertical alignment without imposing any physiological constraints on
plants unlike small animal PET scanners with horizontal bed alignment. The optical glue
selected among the others was found to have a transmission efficiency of 95 ± 3%. BioPET’s
performance evaluation tools are developed and it will be fully operational at Saskatchewan
Centre for Cyclotron Sciences (SCCS) operated by Sylvia Fedoruk Canadian Centre for
Nuclear Innovation in Saskatoon. The preliminary performance checks will be done as soon
as the data becomes available.Studentye
Is Cane Sugar “Canadian”? The Disavowal of Global Lives and Lands within Canadian Sugar Marketing
No full textThis article considers the history of global supply chains in relation to Canadian sugar marketing. Now a dietary staple, refined sugar in Canada today is plentiful and affordable. Ninety percent of this sugar is made from imported cane. Yet within Canada little public awareness exists regarding cane sugars’ countries of origin. Inquiring into how Canadian refiners have portrayed their cane sugars’ provenance, this article sketches out the histories of land and labor disavowal within Canadian cane sugar marketing. Looking at advertising produced by the company Rogers Sugar between 1890 and 1931, it finds that during this time a tension existed between portraying Rogers’ sugars as sourced from within the British Empire and as emanating from Canada. As well, in most of its advertising, Rogers’ white Canadian refinery workers are high-lighted. Due to these workers’ ubiquity, the omission of interna-tional contributors to Rogers’ sugars is especially noticeable
An exploratory consideration of cognition and physiology in athletes following concussion
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Kinesiology and Health Studies, University of Regina. v, 122 p.A mild traumatic brain injury (mTBI), colloquially known as a concussion, is an injury of the brain that often results in significant functional impairment for days, weeks, or even months. While the most common symptoms of concussion have been well documented and studies frequently note a deficit in either higher-level cognitive functioning and autonomic physiological control, there is a lack of research describing the effect of concussion on executive functioning and heart rate variability (HRV). The aim of this study was to address gaps in literature by describing changes in an individual’s executive functioning and physiology simultaneously following a concussion using two investigative approaches, using the theory of neurovisceral integration as a guiding framework. Secondary data from University of Regina athletes was used to examine baseline executive functioning (measured by Neurotracker®) and athlete HRV transformed from ECG. These results were subsequently compared to the same measures postinjury. Prior to review of data from the 2019-2020 academic year, there was an expectation that occurrence of a concussion would be associated with a decrease in Neurotracker® performance, Mean R-R intervals (Mean R-R), and Root-Mean-Square-Difference of successive R-R intervals (RMSSD) while also being associated with increases in Low-Frequency/High-Frequency (LF/HF) ratio and Standard Deviation 2/Standard Deviation 1 (SD2/SD1) ratios. Across a sample of eight participants, only one participant experienced the expected change in variable while the two participants that experienced symptoms the longest, featured smaller deviations from their baselines. My study was exploratory in nature and suggests directions for future research.Studentye
Impact of race on police officer's use of force decision-making
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Experimental and Applied Psychology, University of Regina. xvi, 188 p.The current study investigated the potential impact of a subject of complaint’s
(SOC’s) race on officer decision-making, in addition to the potential impact of several
other factors (i.e., dispatch priming, policing experience, fatigue, and chronic stress).
This is a serious gap in research of officer decision-making within a Canadian context,
with little existing investigation.
The study sample was comprised of 298 Royal Canadian Mounted Police
(RCMP) employees; 149 recruits from Depot Division, and 149 active duty officers from
Divisions across Canada. An intimate partner violence (IPV) vignette was presented in
an online format in five stages (i.e., dispatch, arrival, three escalating scenes with the
SOC: sitting, standing, and with a knife). At each point of the vignette participants
responded to a risk assessment questionnaire that asked them to rate their perceptions of
the scenario and what intervention option they would choose at that assessment point.
The factorial study design was a 2 (Experience: recruits vs member) x 2 (Race of SOC:
White or Indigenous) x 2 (Dispatch Priming: + prior knowledge of SOC race) x 5
(Vignette Risk Assessment Points) with all but the last factor tested betweenparticipants.
The race of the SOC was observed to impact risk assessment rating only at the
most ambiguous assessment point. Specifically, when SOC behaviour was ambiguous,
risk assessment ratings increased more for Indigenous SOCs than for White SOCs. This
result could indicate that there was an increased reliance on racial biases and stereotypes
when rating perceived level of risk during an ambiguous situation. However, despite this
increased perception of risk, race did not influence intervention option choice, even in
the most ambiguous situation. This suggests that either biases did not impact behaviour
choices, or individuals were able to manage initial biases before choosing an intervention
option. Dispatch priming of SOC race was also found to impact situational awareness
ratings when the vignette was most ambiguous, indicating that the information that is
provided by dispatch has the potential to impact officer decision-making, especially if
the scene is ambiguous. The current study indicates the possible but limited impact of
race on officers’ perceptions of risk but not on their behaviour regarding intervention
options.
Experience was found to impact risk assessment ratings such that active duty
officers were likely to have more stable and realistic risk assessments throughout the
vignette. Officers were also likely to indicate they would use less force in their
intervention option choices. This highlights the importance of real work experience in
developing an individual’s decision-making skills.Studentye
Potentially Psychologically Traumatic Event Exposure Histories of new Royal Canadian Mounted Police Cadets
No full textObjective Royal Canadian Mounted Police (RCMP) report extremely frequent and varied exposures to potentially psychologically traumatic events (PPTEs). While occupational exposures to PPTEs may be one explanation for the symptoms of mental disorders prevalent among serving RCMP, exposures occurring prior to service may also play a role. The objective of the current study was to provide estimates of lifetime PPTE exposures among RCMP cadets in training and assess for associations with mental disorders or sociodemographic variables. Methods RCMP cadets (n = 772; 72.0% male) beginning the Cadet Training Program (CTP) completed a survey assessing self-reported PPTE exposures as measured by the Life Events Checklist for the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition-Extended. Binomial tests were conducted to compare the current results to previously collected data from the general population, a diverse sample of public safety personnel (PSP) and serving RCMP. Results Cadets reported statistically significantly fewer PPTE exposures for all PPTE types than serving RCMP (all p’s < 0.001) and PSP (all p’s < 0.001) but more PPTE exposures for all PPTE types than the general population (all p’s < 0.001). Cadets also endorsed fewer PPTE types (6.00 ± 4.47) than serving RCMP (11.64 ± 3.40; p < 0.001) and other PSP (11.08 ± 3.23) but more types than the general population (2.31 ± 2.33; p < 0.001). Participants who reported being exposed to any PPTE type reported the exposures occurred 1–5 times (29.1% of participants), 6–10 times (18.3%) or 10 + times (43.1%) before starting the CTP. Several PPTE types were associated with positive screens for one or more mental disorders. There were associations between PPTE types and increased odds of screening positive for post-traumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD) and social anxiety disorder (SAD) (all p’s < 0.05). Serious transport accident (11.1%), physical assault (9.5%) and sudden accidental death (8.4%) were the PPTEs most identified as the worst event, and all were associated with positive screens for one or more mental disorders. Conclusion The current results provide the first information describing PPTE histories of cadets, evidencing exposure frequencies and types much higher than the general population. PPTE exposures may have contributed to the cadet's vocational choices. The current results support the growing evidence that PPTEs can be associated with diverse mental disorders; however, the results also suggest cadets may be uncommonly resilient, based on how few screened positive for mental disorders, despite reporting higher frequencies of PPTE exposures prior to CTP than the general population.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The RCMP Study is supported by the RCMP, the Government of Canada, and the Ministry of Public Safety and Emergency Preparedness. L. M. Lix is supported by a Tier I Canada Research Chair in Methods for Electronic Health Data Quality. T. O. Afifi is supported by a Tier I Canada Research Chair in Childhood Adversity and Resilience. Asmundson is supported by a University of Regina President's Research Chair. The development, analyses, and distribution of the current article was supported by a generous grant from the Medavie Foundation.Facultyye
Psychometric evaluation of observational tools in the assessment of pain in older adults with severe dementia
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Clinical Psychology, University of Regina. x , 98 p.Specialized observational tools that assess pain in specific patient populations (e.g., older
adults living with dementia, people with developmental disabilities) or that assess
specific types of pain in populations with limited ability to communicate (e.g., orofacial
pain) are available and routinely used in clinical practice and research settings. This
investigation involved the comparison of various observational pain assessment tools in
the assessment of pain in people with dementia. Despite available psychometric
evaluations, it has not been demonstrated that observational pain assessment tools,
specifically developed for patients with moderate to severe dementia, are better equipped
to assess various types of pain in this population than observational tools developed for
other populations (e.g., adults with intellectual disabilities), or tools developed to assess
a specific type of pain (e.g., orofacial pain). In the first part of this investigation, tools
developed to assess pain in people with dementia were compared to a tool developed for
other populations with limited ability to communicate. The ability of an orofacial painspecific
tool to detect general types of pain was also assessed. Finally, the validity and
reliability of a newly developed ‘meta-tool’, the Pain Assessment in Impaired Cognition
scale (PAIC15), was also compared to that of well-established tools for pain in dementia.
The second part of this investigation focused on whether university students who are not
trained in the health professions could use these tools (developed specifically for use by
healthcare staff) validly and reliably. Results demonstrated that all observational pain
assessment tools could discriminate painful from non-painful situations when applied to
a dementia sample irrespective of whether they were developed specifically for people
with dementia. The general pain tools and the orofacial pain tool performed comparably.
Convergent and discriminant validity analyses indicated that all pain tools correlated
moderately to highly with one another and showed low correlations with a measure of
agitation. The psychometric properties of the relatively less researched PAIC15 were
also comparable to that of the well-established pain measures but were not found to be
superior. Untrained observers were also able to use the tools under investigation in a
valid fashion suggesting that, with professional guidance and under professional
supervision, lay people can gather useful standardized information about pain in a loved
one with dementia and share this information with health care providers. The results of
this investigation do not support the need for specialized pain assessment tools for
different adult populations with cognitive impairments.Studentye
Celebration Of Authorship Program 2022-2023
No full textArcher Library is proud to unveil the 2022-23 University of Regina Celebration of Authorship Program booklet. This downloadable publication highlights University of Regina authors/creators of books, edited proceedings, sound recordings,
musical scores and film or video recordings published over the last year in any format (print or electronic).
We encourage you to take a moment to view the program booklet and extend your congratulations to all of the University of Regina students, faculty, staff, and alumni who are being celebrated this year
Sexual harassment experiences
No full textA Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts (Honours) in Psychology, University of Regina. iv, 29 p.As individual institutions make efforts to provide better support for those who experience sexual harassment (SH), there remains little research into the gender differences among sexual harassment experiences. In the past, the prevalence rate of SH in the workplace focused on the female experience and it has been well examined in the literature. However, there has not been as much research on the differential experiences of sexual harassment between males and females in the workplace. In this study we utilized data from the Survey of Sexual Misconduct at the Workplace (SSMW) cycle 1, 2020 to explore the relationship between differential gender experiences of SH in the workplace, and factors contributing to decisions of reporting SH. The study addresses two principal research questions. The first is: What types of SH may be differentially experienced by male and female victims? These may include: verbal, unwanted physical, and/or other forms of SH. The second research question is: What other factors may contribute to SH experiences and under-reporting by males or females? Some of these factors may include perpetrator gender, gender norms in the workplace, sexual orientation, mental health or others. The findings of this research could potentially result in suggestions for developing public awareness campaigns. These in turn may actively inform the Canadian perception of SH to one of understanding and support, leading to improved training and reporting policies.Studentn
Constraint propagation and variable ordering heuristics for solving Constrained Partial CP-nets
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Computer Science, University of Regina. x, 58 p.Representing, reasoning and finding Pareto optimal solutions from users' qualitative conditional preferences is one of the interesting research topics in Artificial Intelligence(AI). A conditional Preference Network (CP-net) is one of the extensively used graph models to represent these conditional preferences. Based on user-specific partial order for every value of a set of variables, a CP-net is constructed in ceteris paribus (all else being equal). A Partial CP-net can be used if a user does not specify the order for every variable value. The Search-Partial-CP algorithm can be used for reasoning and producing a set of Pareto optimal solutions from the partial CP-net along with user-defined hard constraints. This thesis contributes towards the improvement of the Search-Partial-CP algorithm along with the addition of functionality to increase usability.
We address the challenges we face, in practice, when searching for a solution from a partial CP-net and a set of hard constraints using the Search-Partial-CP algorithm. The first reason for choosing this backtrack search algorithm is due to its ability to work with an acyclic partial CP-net and hard constraints. Secondly, it reduces the run time complexity by removing infeasible or dominated outcomes early from the search space. Finally, this algorithm can be stopped after finding the first feasible solution in cases where finding one optimal solution is enough. However, when we need to find multiple Pareto optimal solutions, a different approach can be integrated to compare those solutions, such as dominance testing or ordering query.
A new heuristic for variable ordering is introduced to find the Pareto optimal solutions faster without adding complexity to the existing algorithm. The complexity of finding the first solution in Search-Partial-CP is the same as the underlying constraint satisfaction problem (CSP). Existing variable ordering heuristics orders all the variables of the CSP based on their constraints. The proposed heuristic works simultaneously with the algorithm and orders the subset of the variables that are not dependent on any other variable at that particular time.
While producing the Pareto optimal solution set using Search-Partial-CP, dominance testing is performed. A comparative study is provided by running both dominance query and ordering query for the same set of CP-nets and corresponding hard constraints that are randomly generated through the RB model. Unless we apply some assumption, the algorithm for dominance testing is PSPACE-complete. However, it can be reduced to NP or can also be solved in polynomial time.Studentye
Problem recognition and treatment recommendations of somatic and cognitive-affective presentations of depression and generalized anxiety
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Clinical Psychology, University of Regina. ix, * 104.Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are among the
leading causes of disability in the world; yet, rates of treatment seeking are exceptionally
low. Poor mental health literacy is an important barrier to treatment seeking. One
component of mental health literacy that impedes help seeking is poor problem
recognition, or misidentifying a disorder and its symptoms when they are present.
Although a wealth of research has established that accuracy of problem recognition is
associated with help seeking related constructs (e.g., types of treatments recommended,
intentions to seek treatment), no study to date has examined problem recognition of MDD
or GAD across varying symptom presentations. The current study aimed to examine rates
of problem recognition of MDD and GAD across predominantly somatic and cognitiveaffective
presentations. To address the study aims, N = 299 participants were recruited
using TurkPrime. N = 292 participants were randomly assigned to either the cognitive affective
condition in which they were presented with case-study vignettes of MDD and
GAD with predominantly cognitive-affective presentations, or the somatic condition in
which they were presented with case-study vignettes of MDD and GAD with
predominantly somatic presentations. Participants’ problem recognition and treatment
recommendations were assessed following each vignette. We found significant main
effects of disorder (i.e., MDD, GAD) and presentation (i.e., somatic, cognitive-affective)
on problem recognition, such that MDD was associated with higher recognition than
GAD, and cognitive-affective presentations were associated with higher recognition than
somatic presentations. A large effect of disorder, and a small effect of presentation were
observed. The interaction effect of disorder and presentation on problem recognition was
non-significant. Further, problem recognition was associated with treatment
recommendations. However, disorder and presentation were not related to treatment
recommendations. We also found a significant difference in treatment recommendations
made for self and others. Findings from the current study fill a gap in the literature by
providing an initial understanding of mental health literacy across symptom
presentations. This is likely to aid in the further development of mental health literacy
programs. Clinically, these findings also have the potential to help avoid misdiagnoses
and the diagnostic delays associated with somatic presentations of MDD and GAD.Studentye