RESPONSES OF THE CANOLA (BRASSICA NAPUS L.) ROOTASSOCIATED MICROBIOME AND PLANT GROWTH TO SOIL PHOSPHORUS APPLICATIONS

The abstract of this item is unavailable due to an embargo

Infrared Chemical Imaging of Custom-Made Microfluidic Devices

Microfluidic devices are designed to streamline and improve the operation of chemical processes in a wide variety of industries. Miniaturization has a vast number of advantages; most notably, the large surface area to volume ratio which allow for enhanced control over the physical properties within devices. Such precision leads to more efficient reactions and higher quality products making on-chip chemical synthesis desirable. Optimization of device performance requires an in-depth analysis of the flow profiles, requiring in-situ characterization techniques. Infrared (IR) imaging integrated within microfluidic devices is a label-free, non-invasive detection strategy which provides an in-situ probe to visualize flow patterns and can be utilized to identify and quantify molecules on-chip. IR light is quickly attenuated by optically dense matter such as solvents and device materials when samples are probed in transmission or reflectance modes. In attenuated total reflection (ATR) mode, IR light is directed through a high refractive index material such as a Si internal reflective element (IRE) interrogating the sample-IRE interface with an evanescent wave, limited to within one micron of the surface in the wavelengths of interest. Such a localized probe depth allows for design freedom in both the channel depth and materials. Within a microfluidic device, this imaging technique probes the solution near the no-slip boundary; fluid near channel extremes is flowing at a much slower rate than the bulk due to resistance of the solution with the walls of the channels. As a comparison of the experimental results with the physical phenomena within the devices is crucial to justify the technique, flow profiles must be modelled with both commercial software and mathematical predictions. This thesis aims to develop and demonstrate the focal plane array (FPA) imaging capabilities of the horizontal ATR microscope at the Mid-IR beamline of the Canadian Light Source by imaging fluid flow in custom-made microfluidic devices. Resulting images are compared to expected flow profiles generated by simulations. This work is highly motivated by a desire to implement synchrotron IR imaging using this endstation and offers a prerequisite study for larger field-of-view optimization with a globar source before the extension to synchrotron light, with lower noise and smaller spatial resolution, may be realized

Extendable micro-service architecture for consensus protocol in applications based on Distributed Ledger Technology (DLT)

The abstract of this item is unavailable due to an embargo

Developing and Applying a Yeast Model of Hutchinson-Gilford Progeria Syndrome

The human premature aging disorder Hutchinson-Gilford progeria syndrome can, by virtue of its single molecular cause, be introduced to other living systems which allows for a more controlled and nuanced study of the disease. We have applied this philosophy to the study of aging in yeast (Saccharomyces cerevisiae) and generated a model system of premature aging which captures several of the major molecular phenotypes of Hutchinson-Gilford progeria syndrome. Our system is based on a galactose inducible pYES plasmid vector system that is readily maintained in yeast under selection and that expresses the disease-causing progerin protein N terminally tagged with EGFP. We successfully applied the yeast model of progeria towards exploring interactions and influences between core cellular processes and the severity of the Hutchinson-Gilford rapid aging phenotype. This initially involved inducing Hutchinson-Gilford progeria syndrome in mutant yeast strains with single non-essential gene deletions and screening for phenotype severity. This screening further reinforced confidence in our yeast model of progeria by implicating several processes, including those of genomic stability and mitochondrial function and organization, which were previously known to be influenced by Hutchinson-Gilford type premature aging. As such, we proceeded to apply the yeast model of progeria towards the study of the syndrome. Deletions of individual subunits of the Chromatin Assembly Factor 1 replication-dependent histone assembly complex were found to apparently reduce the fitness-impairment effect of progerin expression in yeast and so represented promising ground for in-depth assessment. Our work suggests that activity of Chromatin Assembly Factor 1 influences the severity of the Hutchinson-Gilford rapid aging phenotype and represents a promising target for future studies

Exploring Cultural Healing and Mental Wellness in a Northern Saskatchewan First Nations Community

Several health inequities exist between the Indigenous and non-Indigenous populations in Canada. These disparities are a result of colonization, which aimed to disconnect Indigenous Peoples from their land, language, and connection to community. This forced assimilation severed connection between Indigenous Peoples and traditional methods of promoting wellness. Connecting to culture appears to play an important role in enhancing mental wellness among Indigenous individuals and communities. The aims of this project were to: a) explore the role that culture has in promoting mental wellness for First Nations individuals from the Lac La Ronge Indian Band (LLRIB), b) empower young adults from the LLRIB to share their stories of connecting to culture and the impact that this has on their lives. This community-based project was conducted in collaboration a Community Advisory Committee. Using purposive and subsequent snowball sampling, 5 participants between ages 18 and 25 from the LLRIB were recruited to partake in a two-part photovoice project. First, participants captured photographs representing their experiences with connecting to culture and the role that this has in improving their mental wellness. Following this, the participants attended a one-on-one discussion with the student researcher where they shared the stories behind the photographs they presented. Data were analyzed using narrative analysis. Narratives were arranged into one of four overarching categories based on the First Nation Mental Wellness Continuum Framework: hope, belonging, purpose, and meaning. Taking a strengths-based approach, the positive influence of culture and community on individual wellbeing is evident and we gain an understanding of how connecting to culture acts as a protective mechanism when addressing suicide prevention. Implications of findings contribute to a greater understanding of the role that connecting to culture has in improving the wellness of Indigenous Peoples. The results of this project could guide future research endeavours with Indigenous communities to explore wellness of other communities. Overall, the project improves understanding of the idea that Indigenous Peoples find strength and wellness within their culture from connection to community, land, and language

EXPLORING TEACHER RECRUITMENT AND RETENTION POLICIES, PRACTICES, AND PERSPECTIVES IN SASKATCHEWAN AND WEST VIRGINIA A DESCRIPTIVE STUDY

This descriptive study explored and compared what recruitment and retention policies and practices school divisions in Saskatchewan, Canada and West Virginia, United States used to staff their schools and whether or not, and to what degree, institutional isomorphic forces influenced those policies and practices. Survey data from 21 Saskatchewan and 19 West Virginia school divisions and semi-structured interview data from five self-identified survey respondents was collected. Descriptive and inferential statistical techniques and simple qualitative descriptive techniques were used to analyze the data. This study corroborated the suggestion in the literature that school divisions have similar staffing administrative functions, regardless of their location in Saskatchewan or West Virginia; and further that the policies and practices used to recruit and retain teachers are comparable. By extension, school divisions generally have administrative functions, such as staffing, that may be described and compared aculturally. The data supports this assertion. Further, the study also found that institutional isomorphic (coercive, mimetic, and normative) forces affected policies and practices related to recruitment and retention of teachers. All respondents indicated at least some effect on policies and practices by each isomorphic force. The data showed the effect of coercive influencing forces indicates that the Saskatchewan school divisions have a greater degree of autonomy and self-governance than their counterparts in West Virginia. Further, significant findings from the survey data in this study indicated recruiting and retention in rural/remote school divisions was more difficult than non-rural/remote school divisions; recruiting and retention were more difficult for school divisions in West Virginia than school divisions in Saskatchewan. Additionally, the data indicated recruiting and retention challenges and issues in West Virginia were more often related to financial factors compared to Saskatchewan school divisions where non-financial factors were more of an issue. Analysis indicated statistically significant differences between West Virginia and Saskatchewan school divisions around challenges they face when recruiting teachers. These challenges included low/uncompetitive salaries (p=.000), certification requirements (p=.000), degree requirements (p=.002), and uncompetitive benefits (p=.002). Likewise, statistically significant differences between West Virginia and Saskatchewan were also revealed regarding the challenges school divisions face when retaining teachers. The challenges that affected teacher retention were low/uncompetitive salaries, certification requirements, degree requirements, closer proximity to higher paying divisions, and uncompetitive benefits. West Virginia had much more difficulty and faced greater barriers in recruiting and retaining teachers than Saskatchewan. When looking at specific recruitment and retention strategies, West Virginia schools were more likely to rely on assisting teachers in obtaining full license/certification as a strategy than divisions in Saskatchewan, which is likely related to the use of alternative certification practices and provisionally licensed staff in West Virginia. This study illustrated recruitment and retention policies and practices overall are similar among school divisions in Saskatchewan and West Virginia. However, although both school divisions face similar challenges, the West Virginia school divisions were affected more by financial factors, while the Saskatchewan school divisions were affected more by non-financial factors

CELL MORPHOLOGY-BASED CHARACTERIZATION OF THE IRREVERSIBLE ELECTROPORATION FOR TUMOR ABLATION

Irreversible Electroporation (IRE) stands at the forefront of contemporary tumor ablation research. An in-depth understanding of how cells with different morphologies respond to various IRE protocols is crucial for assessing their vulnerability to such ever-changing cancer treatment. In short, this relationship is called throughout this thesis. This thesis study was motivated to explore this relationship based on an in vitro IRE experiment of single cells. The results of the study affirmed the influence of cell morphological features on its susceptibility to IRE treatment. The simulations in the study spotlighted how distinct morphological features impact the distribution of transmembrane potential (TMP) over a threshold value on the plasma membrane. The experimental data in the study, shifting from in silico to in vitro, highlighted disparities in lethal areas for different tumor cells under identical IRE protocols. The study also correlated the membrane occupancy of where TMP over a specific threshold value with the lethal area from in vitro IRE experiments, to improve our understanding of the vulnerability of cells in the context of IRE as well as the pivotal role of their morphology. This study developed a quantitative expression of this relationship, which was also called single cell electroporation (SCE) model, because the relationship also contains the information of cell lethal to IRE. Therefore, the SCE model is useful to guide the IRE operation in the clinical setting, especially promoting the current thinking in medicine, i.e., personalised medicine. This thesis has made a few scientific contributions: (1) Provision of a method along with its tool to automate the extraction of cell morphology along with features, enabling to process thousands of cells per image efficiently; (2) Confirmation of the influence of cell morphology on the distribution of TMP exceeding a critical threshold on the cell membrane; (3) Confirmation of the view that cell morphological features affect the vulnerability of the cell to IRE; (4) Finding of a statistical correlation between the membrane occupancy of where local TMP above the threshold value and the lethal area of cells under the influence of IRE stimulus

Pairing Synchrotron Radiation with an ATR-Integrated Microreactor for In-Situ Spatiotemporal Characterization of Chemical Reactions

Microfluidic devices consist of microfabricated structures designed to control minuscule volumes of fluid with exceptional precision. The growth of this field has allowed researchers to miniaturize lab-based processes, providing an alternative experimental approach which is more efficient, safer, eco-friendly, and cost-effective. In-situ monitoring of chemical reactions is greatly important to the field of chemistry. Real-time characterization allows for a better understanding of the system by investigating the underlying mechanisms and reaction kinetics. Fourier-transformed infrared (FTIR) spectroscopy is a suitable technique to be coupled with microfluidics as it is non-invasive, straightforward, reliable, and sensitive to molecular changes which occur during a reaction. With the use of attenuated total reflection (ATR) FTIR spectroscopy, significant attenuation of radiation by the fluidic environment is overcome. The quantitative capabilities of IR spectroscopy coupled with a microfluidic device provide researchers with the ability to monitor reaction variables such as reagent concentrations in-situ. In this thesis, I evaluate the abilities of a unique microfluidic device equipped with a single-bounce ATR element by monitoring a proof-of-concept chemical reaction using synchrotron sourced IR radiation. The unique capabilities of the Mid-IR beamlines’ horizontal ATR (hATR) endstation at the Canadian Light Source (CLS) allow the beam spot to be positioned at any point along the length of the channel to assess the chemical environment at many different reaction times. Coupling the endstation capabilities with the single-bounce ATR accessory and synchrotron radiation allows different sensing areas to be individually addressed, thereby providing the ability to obtain spatially and temporally resolved information. This microreactor provided in-situ characterization, which was used to spatially and temporally track the concentration changes throughout an SN2 reaction. The collected measurements were then used to determine the kinetic rate constant of the monitored reaction. Therefore, this thesis successfully demonstrates the microreactors’ impressive capabilities to monitor a reaction and extract kinetic parameters

Female Chief Executive Officers and Cross-Border Mergers and Acquisitions

The surge in Cross-Border Mergers & Acquisitions (CBMAs) has paralleled the advancements in global technology, providing opportunities for seamless information exchange. As the landscape of Chief Executive Officers (CEOs) evolves, literature has taken further interest in CEO gender. Drawing upon data from WRDS Compustat, Execucomp, and SDC Thomson Platinum spanning thirty-one years, our study analyzes the relationship between United States CEOs and CBMAs. The objective of our research is to discover the relationship between CEO gender on CBMA interactions. Employing a comprehensive set of CEO, firm, and deal-level controls, we present significant findings. Our analyses indicate female CEOs are less likely to engage in CBMAs, while using more stock as a method of payment, aligning with financial and behavioral literature of female CEOs being inherently more risk averse. Our results display there is no statistically significant relationships between female CEOs, acquisition premium, and deal size. This study provides further analyses on the unique decision-making tendencies of CEOs based on gender and gender behaviors, providing valuable results on the patterns influencing their decisions and consequences

Treatment of Black Liquor Produced From Wheat Straw Pulping Process

With the increasing number of pulp and paper industries, the production of black liquor, which is one of the main by-products of the pulping process, is also being increased simultaneously. The produced black liquor is toxic to human, aquatic life and the environment as a whole because of its high pH and alkalinity, hence, various ways for its treatment and management are being carried out, yet it has been mostly used as energy for fuels only. Furthermore, the black liquor produced, especially, in the wheat straw pulp and paper industry is found to contain high concentrations of lignin, silica, etc., and its poor biodegradability on the other hand hinders the performance of conventional biological degradation methods of wastewater treatment. Hence, this research incorporated the use of an electrocoagulation process as a pretreatment step, where the flocculating agent was generated by electro-oxidation of sacrificial anodes that removed pollutants in black liquor by electrostatic attraction. The study investigated its efficacy for the biological degradation of black liquor under anaerobic conditions with varying concentrations of black liquor. This study included the optimization of the electrocoagulation process of pretreatment of black liquor with the help of the Response Surface Method in which pH (7-11), voltage (10-30 V), and electrolysis time (10-60 min) were used as the operational parameters and Chemical Oxygen Demand (COD), phenol, Total Solid (TS), Total Dissolved Solid (TDS), color, pH, and Specific Energy Consumption (SEC) were used as the analytical parameters. Proximate analysis, Klason lignin analysis, Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Fluorescence were also carried out to understand the characteristics of black liquor samples. Finally, anaerobic digestion was carried out with both untreated and pretreated black liquor for 36 days with varying concentrations from (10% to 30%) to find out the effectiveness of electrocoagulation for biological degradation. The degradation of the black liquor was evaluated by the reduction of COD, pH, TS, and volatile matter (VM). Along with that, biomethane potential was also assessed during the process of anaerobic digestion of black liquor. The overall optimum condition for electrocoagulation treatment of black liquor was initial pH 9, 20 V, and 35 min electrolysis time, which led to a successful removal of 49.40% COD, 43.61% phenol, 53.89% TS, 46.50% TDS, and 29.33% color and a reduction in alkalinity of the black liquor by 0.52 pH. The optimized condition of electrocoagulation resulted in a black liquor with 21,000 mg/L COD, 198 mg/L phenol, 19,690 mg/L TS, 7,000 mg/L TDS, 50.49 whiteness index and 8.48 pH . The operation was conducted with an average current output of 0.87 A and a current density of 33.02 mA/cm2. The specific energy consumption was found to be 1.98 kWh/kg of COD removal. Additionally, it helped reduce lignin by 71.85%, and volatile matter by 12.50% (dry basis) and 58.00% (wet basis). Overall, electrocoagulation treatment of black liquor followed by anaerobic digestion reduced the inhibition time and the retention time for gas production. The biogas yield obtained from 30% EC treated BL in 10 days optimal time was 185.14 mL/g of COD loading, which was double in value than that produced from the raw black liquor. When pretreated, gas yield increased by 40.00% and 99.50% for 10% and 30% black liquor concentration, respectively. 25.14% of COD, 13.43% of TS, and 35.34% of VM was reduced when 30% of pretreated black liquor was digested under anaerobic condition. Hence, this study incorporated the ability to treat black liquor produced in wheat straw pulp and paper industry by an integrated approach of electrocoagulation and biological degradation under anaerobic conditions