Theses & Dissertations - Harvested by LAC

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Development of Inhibitors for Human Deubiquitinases
(University of Guelph) Liu, Qi; Zhang, Wei
Ubiquitination is an important protein post-translational modification that is essential for almost all cellular processes in human cells. The reverse process, deubiquitination is catalyzed by deubiquitinases (DUBs), malfunction of which has been implicated in numerous diseases. Consequently, extensive efforts have been put into developing DUB inhibitors in the past two decades. However, most chemical compounds with DUB inhibitory activities only confer mild potency and low selectivity. This is presumably due to the diversity, complexity, and dynamic regulation of DUB catalysis. To tackle this problem, a protein engineering-based strategy of developing ubiquitin variant (UbV) inhibitors for systematic targeted inhibition of human DUBs was devised. This technology was further expanded to develop inhibitors of E2 conjugating enzymes and E3 ligases. In this thesis, the UbV technology is employed to develop inhibitors for STAMBP and OTUD1, in DUB families of JAMM and OTU, respectively. Unique UbV sequences are identified from phage display-based selection of the UbV library. Following biochemical and cellular characterizations indicate UbVs are potent and specific inhibitors. In addition, the crystal structure of STAMBPL1 in complex with a UbV reveals its inhibitory mechanism. Finally, UbVs for OTUD1 are explored for targeted protein stabilization, which mediate the deubiquitination and stabilization of EGFR in a UbV-induced proximity (UbVIP) approach as a proof-of-concept. The UbV inhibitors developed in this work are the first potent and specific inhibitors targeting the selected DUBs, thus providing new tools for the research community to probe the DUB biochemical mechanisms and facilitate the development of small-molecule inhibitors and the investigation of targeted protein stabilization.
The Impact of Nano Zerovalent Iron on Remediating Mining Soils and Related Toxicity on Barley (Hordeum vulgare L.) and Tomato (Solanum lycopersicum L.)
(University of Guelph) Bowyer, Emily; Hale, Beverley
This study added Nano zero-valent iron (nZVI) to 17 soils collected from a decommissioned gold mine with differing physicochemical properties and elevated concentrations of a metal mixture (As, Co, Cr, Cu, Ni and Pb). Addition of nZVI (5% w/w) reduced the plant available concentrations of As and Co but not of Cr, Cu, Ni or Pb. In nZVI amended soils, pH decreased, barley and tomato root lengths increased, and accumulation of As, Co, Cu and Ni in plant roots relative to total soil metal concentration (bioavailability) decreased. Thus nZVI is a possible remediation agent for field soils contaminated with a metal mixture, so that plant communities can be established. However, the nZVI used in the present study had impurities that made measurable contributions to the concentrations of Cu, Ni and Pb in soils, in some cases causing soil quality guidelines requiring remediation, to be exceeded.
Sexually Differentiated Effects of Bisphenols on Sex Steroid- and Stress-Sensitive Mechanisms, Hippocampal Plasticity, Memory, and Anxiety in Mice
(University of Guelph) Nicholson, Kate; MacLusky, Neil; Choleris, Elena
Bisphenol A (BPA) is an endocrine disrupting chemical known to interfere with cellular and functional effects of sex steroids in the brain. Incongruent reports of BPA’s endocrine disrupting properties have led to widely inconsistent regulations of tolerable daily intake (TDI) limits around the world. Therefore, many products now contain BPA substitutes like bisphenol S (BPS). However, it is unclear if BPS is a truly safer and less-disruptive alternative to BPA. Using mHippoE-14 cell lines, our findings show one hour treatment with either BPA or BPS induced extracellular regulated kinase (ERK) phosphorylation and mitogen activated protein kinase phosphatase 3 (MKP3) expression, an effect that was attenuated by estradiol (E2) pretreatment. E2 pretreatment also prevented BPA’s inhibition of c-Jun N terminal kinase (JNK) phosphorylation. Although BPS alone had no effect on JNK phosphorylation, it significantly increased JNK activation following E2 pretreatment. In our second study, oral treatment with 50 µg/kg/day BPA or BPS reduced hippocampal MKP3 expression and truncated CA1 astrocyte processes in females, while BPS increased CA1 astrocyte process intersections in males. Our final study compared oral administration of 4, 25, or 50 ug/kg/day BPA or BPS on hippocampal structure and function in male and female mice. Our findings revealed impaired spatial memory in BPA and BPS treated males, as well as BPA treated females. We detected increased anxiety-like behaviour in females treated with BPA or BPS and males treated with BPS. In females, BPA and BPS reduced CA1 dendritic branching, length, and apical spine density. In males, BPA and BPS increased CA1 dendritic branching and length, but had no effect on spine density. Biochemically, we observed increased expression of ionized calcium binding adaptor molecule 1 (Iba1) in BPA treated males. Together, these results demonstrate BPA and BPS may have similar effects on rapid estrogen- and stress-sensitive intracellular kinases. Through oral administration at doses relevant for human exposure, our findings demonstrate sexually differentiated and dose-dependent effects of BPA and BPS on hippocampal plasticity, microglial expression, astrocyte structure, spatial memory, and anxiety-like behaviour in mice. Collectively, these results highlight the need to establish and refine current TDI limits for BPA and BPS.
Experimental and Theoretical Investigations in Transition Metal Catalysed Reactions of Heterobicyclic Alkenes
(University of Guelph) Pounder, Austin; Tam, William; Chen, Leanne D.
Over the past fifty years, transition metal catalysis has been pivotal in shaping economical, sustainable, and efficient strategies for the synthesis of pharmaceutically relevant small molecules. Despite substantial progress, the dynamic landscape of drug production demands continual innovation. This thesis addresses this imperative need through a multifaceted exploration of novel synthetic approaches, augmented by the insights provided by computational chemistry. The first endeavor involves the development of palladium- and nickel-catalysed intramolecular ring-opening reactions of aryl halide-tethered oxabicyclic alkenes. This work provides a selective pathway to synthesize tetracyclic compounds featuring the 1,2-dihydronaphthalen-1-ol core. Through strategic substrate design, the hydroxy intermediates are further directed towards functionalization, yielding bicyclo-[3.2.1]-lactone scaffolds (Chapter 2). Continuing the journey, the mechanism and origins of selectivity in the rhodium-catalysed ring-opening reactions of oxabicyclic alkenes with organoboronic acids is explored through a comprehensive computational study (Chapter 3). Next, the attention shifts to iridium/zinc co-catalysis for the ring-opening reactions of heterobicyclic alkenes with indole nucleophiles. This approach highlights a 100% atom-economic C–C bond formation. Computational insights into the mechanism and origins of selectivity enrich our understanding of this transformative methodology (Chapter 4). The final frontier explores cobalt-catalysed hydrogenation and deuteration reactions of heterobicyclic alkenes, utilizing H2O and D2O as the sole hydrogen and deuterium sources. Notably, Lewis-acid co-catalysts are harnessed to promote the reactions while catalyzing concurrent transesterification processes (Chapter 5). Throughout this Thesis, the symbiotic interplay between experimental investigations and computational insights paves the way for the development of novel synthetic methodologies and a deeper understanding of reaction mechanisms. The culmination of these endeavors contributes significantly to the ongoing evolution of drug discovery and production strategies.
Mathematical Modelling of the Gut Microbiota During Dysbiosis in a Gut Reactor Setting
(University of Guelph) Jegatheesan, Thulasi; Eberl, Hermann
We formulate and study a series of mathematical models of the gut, focusing on the gut microbiota responsible for the degradation of complex carbohydrates, or glycans, and their role in dysbiosis. We first investigate the perturbation and recovery of the gut microbiota from antibiotic treatment. The colon is represented as a bioreactor, with distinct lumen and mucus microhabitats. Glycans are assumed to be the main substrate available to the community, in the form of dietary fiber and host-derived mucins. The microbial community are categorised into four functional groups based on their metabolic role in the fermentation of carbohydrates into short-chain fatty acids (SCFAs) and metabolites. The primary degraders are one of the four functional groups represented in this model, responsible for extracellular enzymatic hydrolysis of glycans into soluble sugars that can then be consumed for growth. We find that survival and recovery of the gut microbiota post-antibiotic treat- ment was dependent on the survival and recovery of the primary degrader group. We further investigate the primary degrader group independently, in both a single compartment and two-compartment setting. Through a mathematical analysis and a computational study, we find that the first step of enzymatic hydrolysis was responsible for the susceptibility of the primary degrader group to washout from antibiotics exposure. We also find that the addition of the mucus compartment provides protection from washout. We extend this model to distinguish between a glycan generalist that can degrade both dietary fiber and mucin, and a mucin specialist species. We study competition between the generalist and specialist in the two-compartment bioreactor setting. Using Sobol sensitivity analysis and a random forest classifier model, we investigate the influence of the input parameters on the gut microbiota’s composition and function. We then conduct a series of simulation experiments to assess the impact of competition between these two species and the integrity of the colonic mucus barrier. The final component of this study examines the interplay between the glycan generalist and the mucin specialist in response to antibiotic treatment. We find that relative species abundance, antibiotic specificity and competition shape the gut microbiota’s response to antibiotics, emphasizing the need to consider these factors in predictive gut reactor models of dysbiosis.
Predicting Pellet Quality at the Mill Level Using Machine Learning and Statistical Models
(University of Guelph) You, Jihao; Ellis, Jennifer; Tulpan, Dan
Feed mills face an ongoing challenge of controlling pellet quality of manufactured feeds, as many factors during formulation and manufacturing influence the physical properties and quality of the output. Many previous studies have been conducted to examine how single (or a few) isolated factors impact pellet quality under controlled research and experimental settings, but these studies have limitations when it comes to extrapolation to the commercial feed mill where a multitude of factors are changing simultaneously. Therefore, the objective of the current thesis was to develop predictive models for pellet quality from data collected (formulation, manufacturing conditions, environment) in the commercial mill setting. To achieve this goal, machine learning (ML) and statistical modelling approaches were applied to build models for predicting the pellet quality. Specifically, there were three objectives: (1) Twelve ML models were developed on a preliminary mill dataset with a small number of factors (N = 16); (2) After applying dimensional reduction methods on a mill dataset with a large number of factors (N = 75), four statistical models were developed; and (3) Feature engineering approaches including feature creation and feature selection were applied to a full dataset with a large number of factors (N = 75), and then the selected feature were used for constructing twelve ML models. The results showed that both ML models and statistical models developed in the current study could be used to predict the pellet quality, and ML models had potential to perform the task of prediction better than statistical models. Some factors, including expanding temperature, target species, starch content, wheat, soybean meal, etc., played an influential role in prediction of the pellet quality in both ML and statistical models. The models developed in this thesis, considering various dynamically changing factors across formulation, manufacturing conditions and the environment, can help commercial feed mills improve the manufacturing process as well as gain a better understanding of how various factors impact the pellet quality. The models developed can also be applied to optimize targeted parameters in the pelleted feed manufacturing process, leading to improvements in the efficiency and sustainability of the feed industry.
A Survey of the Insect Complex Associated with Cannabis sativa Grown Outdoors in Ontario, and the Potential of Companion Plants as an IPM Tactic
(University of Guelph) Auty, Lillian; Cynthia, Scott-Dupree
Following the 2018 legalization of drug-type Cannabis sativa L. in Canada, the licensed area for outdoor cultivation has rapidly increased to meet growing demand. However, cannabis grown outdoors is threatened by damaging insect pests that we know very little about. This project was the first Canadian survey of insect pests and natural enemies associated with outdoor cannabis production. Insect activity associated with outdoor cannabis and effects of companion plants were evaluated at two licensed producers from June through September in 2021 and 2022. Cannabis aphid (Phorodon cannabis), tarnished plant bug (Lygus lineolaris) and thrips (Thrips tabaci and Frankliniella occidentalis) were the most common insect pests. Minute pirate bugs (Orius insidiosus), lady beetles, and green lacewings (Chrysoperla carnea) were the most common natural enemies. The study also found that companion plants: cosmos (Cosmos bipinnatus), Teddy bear sunflower (Helianthus annuus) and Sunspot sunflower (Helianthus annuus) were most effective at attracting natural enemies.
The effects of nutrient deposition and ecological restoration on the structure and functioning of arbuscular mycorrhizal fungal communities
(University of Guelph) MacColl, Kevin; Maherali, Hafiz
The composition and ecological functions of the soil microbiome are sensitive to human-driven environmental change and land use. Protecting the soil microbiome through conservation will require understanding how microbial functional groups respond to environmental change and ecological restoration. Arbuscular mycorrhizal (AM) fungi are a highly abundant microbial functional group that promote numerous ecological processes, including nutrient cycling and primary productivity, by forming nutrient-exchange mutualisms with most plant species. In this thesis, I investigated how AM fungal community composition and functions are altered by human-driven environmental change and land use, and how AM fungal communities can be protected through restoration. In my first chapter, I conducted a meta-analysis of studies that quantified nutrient deposition effects on AM fungal community composition. Nutrient deposition had a relatively small but statistically significant negative effect on AM fungal species richness, but the magnitude of this effect increased with higher nutrient dosages. In contrast, nutrient deposition had a large and highly significant effect on AM fungal community composition at the species level. In my second chapter, I described patterns in AM fungal response to restoration of intensively managed agricultural fields across Southern Ontario. Restoration stimulated significant increases in AM fungal abundance and species richness as species from disturbance-sensitive families replaced species from one disturbance-tolerant family. In my third chapter, I investigated if restoration returns AM fungal communities to a pre-disturbance condition by contrasting restored sites with a variety of different grasslands. AM fungal communities at restored sites were similar in abundance and species richness to less disturbed grasslands, but were compositionally distinct from all grasslands apart from a selection of low-intensity managed grasslands. In my fourth chapter, I determined if restoration can improve the mutualistic services that AM fungi provide to plants. Restored and agriculturally-degraded AM fungi had similar effects on plant productivity, but differed in their ability to deliver phosphorus to plant functional groups. Together, my thesis highlights the sensitivity of soil microbial composition to environmental change and land use, that restoration can be effective in restoring microbial abundance and diversity, but may not fully restore composition and functions to levels that resemble pre-disturbance conditions.
Optimus Peak: Automatic Extraction of Peak Information of Multi-Dimensional Solution and Solid-State NMR Spectra
(University of Guelph) Brown, Rachel Ellen; Willms, Allan; Graether, Steffen; Ashlock, Daniel
This thesis develops Optimus Peak, an automatic Peak-Picking Algorithm designed for use with protein NMR Spectra. The experiments examined here include testing various thresholding and fitting algorithms for use with NMR spectra, as well as an overall test to compare Optimus Peak to peak-picking algorithms currently in use. The thresholding experiments compared various image processing algorithms (five previously established algorithms and two algorithms developed in this thesis) and their use with protein NMR spectra. The resulting thresholds from these algorithms were compared to manually calculated 5xSigma thresholds using 100 protein NMR spectra (46 2D, 54 3D). Gaussian Thresholding was found to be able to recreate the 5xSigma threshold most accurately (mean: 0.003 percent difference, median: 0.002 percent difference) and most consistently (standard deviation: 0.14, IQR: 0.12). Experiments for peak-fitting involved comparing the use of four evolutionary algorithms to fit noise-less synthetic 2D (two independent dimensions) Gaussian and Lorentzian hills. The algorithms explored in the thesis include a Basic Evolutionary Algorithm, Differential Evolution, Particle Swarm, and MCNon-Walk. Of the algorithms tested, Differential Evolution showed the most promise of finding the true optima (mean: 0.306 euclidean distance from true optima, median: 0.0188 euclidean distance from true optima, standard deviation: 0.6198, IQR: 0.441). The algorithm used for deconvolution in Optimus Peak is called MultiDim-Portion Partitioning. The algorithm was tested using 67 spectra (32 2D, 35 3D), and was evaluated against CCPN and NMRFAM-SPARKY by comparing the number of correct identifications to the total number of Ground Truth peaks, to the total number of models, and using a combined score that penalized false positives. Optimus Peak was not able to find as many Ground Truth peaks as its competitors (Optimus Peak median 29% of ground truth, NMRFAM- SPARKY median 68%, CCPN median 78%). Optimus Peak showed a lower false positive rate, where Optimus Peak was the only program able to produce positive scores that penalized for extra models (Optimus Peak median score: 0.21, NMRFAM-SPARKY median score: -0.36, CCPN median score: -0.70).
Interactions between individual physiology and social information in the North American red squirrel (Tamiasciurus hudsonicus)
(University of Guelph) Hare, Alexander; Newman, Amy; McAdam, Andrew
As the manner in which individuals respond to, and produce social information is intimately connected to their physiological state, it is not surprising that individual physiological responses to stress as mediated through endocrine axes, such as the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes may have impacts not just on the responding individual, but on the surrounding community through social information. Despite the important role that these interactions play in shaping individual responses to stimuli, interactions between conspecifics, and resource utilization, our understanding of how these physiological axes and social information interact remains relatively uninvestigated. My thesis aims to examine the role that the HPA axis and closely associated HPG axis play in directing how social information is produced and incorporated into both the physiology and ecology of free-living mammals. In order to do this, I have conducted field experiments and examined multi-year datasets from a natural population of North American red squirrels (Tamiasciurus hudsonicus) that have been studied continuously for the last 34 years. Conducting a playback experiment in which I manipulated the motivational state and relatedness of senders, I found that receiving red squirrels did not alter territorial behaviour, indicating that the physiological state of senders is less important than other factors, such as changes in resources for kin discrimination. Second, I examined a multi-year dataset of acoustic recordings in order to examine whether there were reliable vocal cues relating to estrus in female red squirrels. Despite finding no distinct cues relating to estrus, I did find that female vocal characteristics changed significantly during pregnancy, providing potential cues to conspecifics within an acoustic neighbourhood. Finally, in examining whether social information regarding circulating glucocorticoids influenced social partners, I found that red squirrel glucocorticoids were influenced by the glucocorticoids of neighbours. I also found novel sex differences in the glucocorticoid levels of males and females. This thesis expands our understanding of how individual physiology and social information influence each other, showing strong association between both the HPA and HPG axes and the social interactions of a natural population of mammals.
Investigating Representations and Students’ Challenges, Experiences and Perceptions of Equity, Diversity and Inclusion at Veterinary Colleges in Canada and the USA
(University of Guelph) Dusome, Kassandra; Khosa , Deep
Though important, equity, diversity and inclusion (EDI) is understudied and reported in veterinary medicine. Using two studies, this research aimed to investigate the representations, and students’ challenges, experiences and perceptions of EDI at veterinary colleges. First, the websites of all veterinary colleges in Canada and the USA were assessed using content and statistical analysis. Male or BIPOC people were more likely to be depicted without animals. BIPOC individuals were under-depicted on some USA websites and over-depicted on others. Website reading level, and access to supports for underrepresented students and mental health resources were inconsistently represented. Second, the survey responses of students at five Canadian and five American colleges were statistically analyzed. Students who were not white, with a disability or part of the LGBTQ2S+ community were more likely to agree or strongly agree that discrimination occurs at college. Overall, fewer students reported experiencing discrimination in colleges compared to workplaces.
Plant response to severing access to arbuscular mycorrhizal networks differs between controlled and field environments
(University of Guelph) Herlin, Olivier; Maherali, Hafiz
Arbuscular mycorrhizal (AM) fungi associate with 70% of plant species and increase the availability of nutrients in exchange for plant sugars. Research determining whether plants benefit from AM fungi is derived predominantly from controlled environments that may not represent the undisturbed field environment. To determine whether plant responses are equivalent between controlled greenhouse and field environments, we quantified 9 plant species responses to severing access to the AM network in both environments using a mesh barrier (48μm) preventing root entry but enabling ingrowth of AM hyphae. We found that in the greenhouse severing access to AM networks reduced plant biomass, but in the field severing increased plant biomass. The lack of correlation in plant mycorrhizal responsiveness between environments suggests that controlled environments may need to account for the surrounding plant density, plant community, and the larger carbon cost from AM networks in the field to observe field relevant plant responses.
Novel Roles of Cardiac-derived Erythropoietin in Disease
(University of Guelph) Marrow, Jade P.; Simpson, Jeremy
Myocardial infarction (MI) is a leading cause of death globally. Over 3 million individuals experience ST-segment elevation MI (STEMI) each year. Despite considerable research into cytoprotective mechanisms, no clinically available therapy has been developed that directly reduces ischemic cardiac injury. Understanding the pathophysiological mechanisms underlying MI should reveal novel strategies for treatment and diagnostic purposes (i.e., biomarkers). Emerging preclinical data shows erythropoietin (EPO), a canonically renal-derived erythropoietic cytokine, is also produced by the heart under hypoxic conditions in vitro and in vivo. However, whether these findings translate to functionally relevant outcomes post-MI is currently unknown. Therefore, the overarching purpose of this thesis was to define the contributions to cardioprotection by endogenously produced EPO in the heart and fundamentally improve our understanding of non-canonical EPO biology. My objective was to characterize the systemic (i.e., endocrine) and local (i.e., autocrine/paracrine) effects of cardiac EPO using two in vivo pre-clinical models (i.e., murine permanent occlusion MI and a cardiomyocyte-specific EPO knockout mouse). We hypothesized: 1) cardiac ischemia localized to the heart would induce cardiac Epo expression and contribute to erythropoiesis, and 2) loss of endogenous cardiomyocyte-derived Epo would increase myocardial susceptibility to ischemia-reperfusion injury and impair cardiac functional recovery. Here we show MI upregulates cardiac Epo, stimulating erythropoiesis, alongside the expression of a novel exon 4-deleted Epo splice variant (termed mV-Epo). Administration of recombinant human EPO (rhEPO) or a human orthologue to the mV-EPO variant (hV-EPO) was cardioprotective compared to vehicle-treated MI mice. Therefore, as a non-erythropoietic EPO isoform, hV-EPO represents a promising strategy for amplifying endogenous cardiac EPO signaling in post-MI patients without the rheological side effects posed by traditional rhEPOs. In our second model, cardiomyocyte-specific Epo deletion induced a compensatory increase in Epo expression by neighboring endothelial cells that enabled cellular hypertrophy and superior cardiac function, and reduced ischemia-reperfusion injury. Collectively, cardiac EPO has powerful physiological relevance as a cardioprotectant and erythropoietic cytokine. These findings fundamentally shift our understanding of EPO biology – confirming it as both an endocrine and autocrine/paracrine cardiac hormone – and reinvigorate its therapeutic potential for ameliorating MI-induced dysfunction.
Growing tomato in controlled environments under continuous light requires dynamic LEDs to entrain the circadian rhythm, adjust canopy architecture, and balance photostasis
(University of Guelph) Marie, Telesphore; Grodzinski, Bernard
Controlled environment agriculture (CEA), including greenhouses and indoor production, offers tremendous opportunities to meet food security across the world. The success of CEA depends on electricity, with artificial lighting consuming a large fraction. Previous work has introduced a novel alternating LED strategy that extends the photoperiod in greenhouse production, taking advantage of off-peak electrical pricing while maintaining a healthy crop. Tomato (Solanum lycopersicum L.) is a model species in terms of its sensitivity to extended photoperiods, experiencing photoperiodic injury under continuous light. The alternating LED strategy alleviated photoperiodic injury and it was hypothesized that circadian rhythm entrainment was responsible, as the injury itself has been associated with circadian asynchrony previously. The presented thesis continues to explore and optimize the strategy in different chapters. First, the principles of circadian entrainment are detailed. A perspective centers on the “latitudinal rule”, where predictable chronotypes have evolved to the longer photoperiods in northern latitudes that can guide selectable traits for breeders and tailor ideal entraining cues for any genotype. Second, diurnal transpiration patterns revealed a great way to assess and measure circadian entrainment on a whole-plant level as they integrate cellular-stomata responses with whole-plant hydraulic status. Practically, transpiration, and associated thermal indices, can be sensed remotely to bring circadian data into smart-agriculture. Finally, a modified dynamic LED strategy (dynamic 1) significantly outperformed control (16hr photoperiod with unchanging spectrum), and by-far surpassed constant light (24hr), in total biomass accumulation via morphological and photosynthetic adjustments. A second modification (dynamic 2) attempted to extend the daytime photoperiod by 4hrs and resulted in a subtle photosynthetic stress response. A deep phenotyping gas exchange plus chlorophyll fluorescence multi-curve dataset revealed photorespiration as both beneficial and hazardous in photoperiodic injury. Also, a simple high throughput protocol distinguished dynamic 2 as engaging a nonphotochemical quenching dissipative type response, whereas dynamic 1 engaged an ATP:NADPH balancing response that upregulated ATP synthase activity. Cyclic electron flow at nighttime was also found to likely contribute much needed ATP. Overall, a philosophy is proposed that optimizing plant growth should start with entraining circadian rhythms, and then fine-tune timing/ dosage to choreograph morphology and balance photostasis.
Transferable skills: A student perspective
(University of Guelph) Boivin, Simone; Jacobs, Shoshanah
University graduates do not have the necessary skills to succeed in the workplace. To address this skills gap there have been calls for universities to improve transferable skill education. To accomplish this, it is important to understand students’ attitudes and motivations. To better understand Canadian undergraduate students’ attitudes about and motivation to develop transferable skills in their education I created and distributed a survey to students at the University of Guelph in all disciplines and year levels. I also developed and delivered a scientific inquiry workshop, delivered in two different contexts (biology-specific, and general). I found that students in all year levels have a positive attitude about and are motivated to develop transferable skills, with students mostly focused on the value of transferable skills for employment. Students are also frustrated with current transferable skill education. There is also indication that students feel differently about developing transferable skills in different contexts.
How to Market Your Curator Team: The Role of Entitativity in Curation Subscriptions
(University of Guelph) Wang, Huiquan; Wang, Juan
Curation subscription is an emerging e-commerce business model which provides recurring deliveries of products selected by curators from companies but tailored to subscribers’ individual preferences. Focusing on the essential role of curators in curation subscriptions, the current research explores how subscription companies promote their curation services by managing the entitativity of their curator teams. Results from one study indicate that increasing the entitativity of a curator team can increase the perceived competence of the team, which in turn promotes consumers’ subscription intention. The positive effect of entitativity on subscription intention only presents for consumers with utilitarian purchase motivations. As consumers’ purchase motivations shift from utilitarian to hedonic, the effect attenuates to disappears. Findings of the study provide theoretical implications for future marketing research as well as managerial inspirations for subscription service providers.
Analysis of the Immunomodulatory Properties of Mycobacterium Cell Wall Fraction on the Cytokine Production of Peripheral Blood Mononuclear Cells of Healthy Dogs
(University of Guelph) Ward, Robert; Sharif, Shayan; Geoffrey, Wood; Khalil, Karimi; Charlotte, Pye; Anthony, Yu
Mycobacterium cell wall fraction (MCWF) is a Toll-like receptor agonist that is derived from non-pathogenic Mycobacterium phlei. The objective of this research was to evaluate host responses induced by MCWF in canine peripheral blood mononuclear cells (PBMCs), using enzyme-linked immunosorbent assays (ELISA) and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) for quantifying cytokine protein and mRNA transcripts, respectively. PBMCs were isolated from eight healthy dogs and cells were cultured with MCWF. A significant increase of interleukin (IL)-10 mRNA was detected at all time points for all concentrations of MCWF (p<0.05). mRNA relative abundance reflected this finding. A post-stimulation elevation of interferon (IFN)-γ mRNA was noted at 24-hours with all concentrations of MCWF (p<0.01) and tumor necrosis factor (TNF)-α mRNA was increased for 0.5ng/dL MCWF only at 72-hours (p<0.05) compared to the negative control. Further research into the role of MCWF as a systemically administered immunomodulator or adjuvant to immunotherapy is warranted.
Treated with Love: Understanding Dog and Cat Caregivers’ Perceptions, Decisions, and Experiences with Feeding Treats
(University of Guelph) Nielson, Shelby; Khosa, Deep
Treats are commonly fed by most dog and cat caregivers and can constitute a significant proportion of an animal’s diet, potentially contributing to obesity. Previous research has explored the nutritional aspects of the primary diet for companion animals, though factors surrounding treat feeding specifically have received far less attention. While reducing or eliminating treats is commonly recommended as a strategy for weight management, caregivers can struggle to adhere to such dietary recommendations. This research consisted of two sequential phases using a mixed-methods approach. The first phase utilized an online questionnaire to quantitatively explore dog and cat caregivers’ (n=1053) perceptions, decisions, and behaviours for feeding treats. Data were analyzed using descriptive statistics and multivariable modelling, and results were used to inform the development of a question guide for the subsequent qualitative phase. The second phase involved the use of five online focus groups to provide an in-depth exploration of caregivers’ (n=24) perceptions and behaviours surrounding treat feeding, including their motivations and barriers related to reducing treat feeding with dogs and cats. Findings elucidated a diverse spectrum of how caregivers incorporate treats in their pet’s diets, evident through a multitude of treat types, as well as how and why treats are provided. The research identified associations between certain treat feeding habits and obesity, including daily chews (OR=2.99) for dogs and table scraps (OR=4.22) for cats. Findings highlighted the importance of treats in the human-animal bond, which can influence caregivers’ willingness and capability to deny treats. Changing the pet’s routine (OR=1.67) was identified as a significant factor that was positively associated with caregivers’ reported capability to reduce their pet’s current treat intake as difficult. Overall, participating caregivers reported a low reliance on veterinarians for support in decisions and habits related to feeding treats. Outcomes of this research have both clinical and educational implications, offering a foundational framework for the development of targeted interventions. Findings highlight opportunities to enhance the available resources that can empower both veterinary professionals and caregivers to make well-informed decisions and foster sustainable treat feeding practices to support weight management and overall health, while fostering the human-animal bond.
Histological Heterogeneity: Tissue-Level Diversity of Lizard Osteoderms
(University of Guelph) Willan, Gabriella; Vickaryous, Matthew
Osteoderms are bone-rich elements that form within the dermis of various vertebrates including many species of lizard. Lizard osteoderms demonstrate variability in size, shape, and body-wide distribution but a detailed comparative assessment of their microstructure is lacking. Here, I characterized the histological diversity of osteoderms from representative members of the lizard groups Gekkota (geckos), Scincomorpha (scincids, cordylids, Gerrhosaurids), and Anguimorpha (anguids, Shinisaurus, helodermatids, varanids). In virtually all lizards, osteoderms are composed primarily of bone, albeit with a heterogeneous and often laminated fibrillary organization. Histologically, most osteoderms are dominated by lamellar, woven-fibred, and/or Sharpey-fibred bone, although details of the organization and relative contribution of each bone matrix differs between genera. In addition, we found that multiple genera from each major group also develop a highly mineralized, collagen and cell-poor capping tissue – a feature previously restricted to only a handful of species. Singularly, the osteoderm-like elements from the gekkotan Geckolepis entirely lack bone and instead are composed of a plate of collagen topped with mineralized capping tissue.
Glucose-Induced Memory Enhancement Mediated by Opioid Systems in Rats
(University of Guelph) Soodeen, Keith; Leri, Francesco
The mechanism of the memory enhancing effects of peripheral administered glucose is not well understood. This line of research is important because it may offer insight into food addictive seeking behaviours and obesity. The aim of the current study was to investigate the effect of subcutaneous glucose injections on memory consolidation and if the memory enhancement could be blocked by modulating the opioid or catecholamine systems. In this study, male Sprague-Dawley rats were tested on object recognition with post-training administration of glucose as well as with post-training administration of a contrave-like drug combination and glucose. It was found that glucose (100mg/kg) enhancing effect on object recognition tasks could be blocked with the contrave-like combination, naltrexone alone, and naloxone methiodide. This experiment concluded that opioid receptors are involved with the memory enhancement from glucose.

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