OPUS: Open Ulethbridge Scholarship

Open ULeth Scholarship (OPUS) is the University of Lethbridge's open access research repository. It contains a collection of materials related to research and teaching produced by the academic community.

Self-archiving your research in OPUS is one way to meet Open Access policies of granting agencies. It is important to retain your final, post-peer-reviewed drafts for submission to OPUS, as this is often the only version publishers will allow to be archived. Click here for information on the U of L Open Access Policy.

Check here for more information about OPUS.

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Recent Submissions

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Volunteer retention research report: nonprofit professionals' version
(2024) Wymer, Walter; Najev Cacija, Ljiljana
We developed this study to add to the stream of scholarly research literature on volunteer retention. We asked many Canadian nonprofit organizations to participate in this study. We tried to include a variety of different types of nonprofit organizations, from across the country, to have an inclusive and representative sample. While we were primarily interested in influences on volunteer retention, we understood that committed volunteers also support their organizations in addition to volunteering. Therefore, in additional to investigating influences on volunteer retention, we also examined how these factors might influence other types of support intentions like donations, bequests, positive word-of-mouth referrals, an helping the organization recruit additional volunteers. We developed and tested two models. One model examined organizational influences on volunteer behavioral intentions. The second model examined experiential influences, meaning factors pertaining to the volunteering experience. With respect to organizational influences on volunteer retention and other support intentions, we found that brand strength had an important and broad effect on our outcome variables. Organizational transparency was also influential with respect to donation and bequest intentions. Other influences are presented later in this report. With respect to experiential influences on volunteer retention and other support intentions, we found that feeling valued was particularly important. Feeling valued not only had a direct effect on our outcome variables but also exerted an indirect effect through its influence on volunteer satisfaction. Perceived usefulness had a positive influence on feeling valued. We also found that social connectedness and value congruence were positive influencers. In this report, we present our methods and procedures. We present our variable definitions and how they were measured in our questionnaire. We present our significant findings and discuss managerial implications of our findings.
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Structural and biophysical analysis of a Haemophilus influenzae tripartite ATP-independent periplasmic (TRAP) transporter
(eLife Sciences Publications, 2024) Currie, Michael J.; Davies, James S.; Scalise, Mariafrancesca; Gulati, Ashutosh; Wright, Joshua D.; Newton-Vesty, Michael C.; Abeysekera, Gayan S.; Subramanian, Ramaswamy; Wahlgren, Weixiao Y.; Friemann, Rosmarie; Allison, Jane R.; Mace, Peter D.; Griffin, Michael D. W.; Demeler, Borries; Wakatsuki, Soichi; Drew, David; Indiveri, Cesare; Dobson, Renwick C. J.; North, Rachel A.
Tripartite ATP-independent periplasmic (TRAP) transporters are secondary-active transporters that receive their substrates via a soluble-binding protein to move bioorganic acids across bacterial or archaeal cell membranes. Recent cryo-electron microscopy (cryo-EM) structures of TRAP transporters provide a broad framework to understand how they work, but the mechanistic details of transport are not yet defined. Here we report the cryo-EM structure of the Haemophilus influenzae N-acetylneuraminate TRAP transporter (HiSiaQM) at 2.99 Å resolution (extending to 2.2 Å at the core), revealing new features. The improved resolution (the previous HiSiaQM structure is 4.7 Å resolution) permits accurate assignment of two Na+ sites and the architecture of the substrate-binding site, consistent with mutagenic and functional data. Moreover, rather than a monomer, the HiSiaQM structure is a homodimer. We observe lipids at the dimer interface, as well as a lipid trapped within the fusion that links the SiaQ and SiaM subunits. We show that the affinity (KD) for the complex between the soluble HiSiaP protein and HiSiaQM is in the micromolar range and that a related SiaP can bind HiSiaQM. This work provides key data that enhances our understanding of the ‘elevator-with-an-operator’ mechanism of TRAP transporters.
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Proceedings of the 25th Analytical Ultracentrifugation workshops and symposium
(Springer, 2023) Demeler, Borries; Gilbert, Robert; Patel, Trushar R.
The 25th International Analytical Ultracentrifugation (AUC) Workshops and Symposium (AUC2022) took place at the University of Lethbridge in Lethbridge, Canada, in July 2022. In total, 104 attendees (Attendance Profile: 104 attendees, 69 in-person, 35 remote. Brazil 1, Canada 24, China 1, Czech Republic 2, Finland 1, France 3, Germany 22, India 3, Italy 1, Japan 4, Spain 1, Switzerland 3, Taiwan 1, United Kingdom 5, United States 32) participated in the event and presented the latest advances in the field. While the primary focus of the conference was to showcase the applications of AUC in chemical, life sciences, and nanoparticle disciplines, several presentations also integrated complementary methods, such as isothermal titration calorimetry, microscale thermophoresis, light scattering (static and dynamic), small-angle X-ray scattering, X-ray crystallography, and cryo-electron microscopy. Additionally, the delegates gained valuable hands-on experience from 20 workshops covering a broad range of applications, experimental designs and systems, and the latest software innovations in solution biophysics. The AUC2022 special volume highlights the sustained innovation, utility and relevance of AUC and related solution biophysical methods across various disciplines, including biochemistry, structural biology, synthetic polymer chemistry, carbohydrate chemistry, protein and nucleic acid characterization, nano-science, and macromolecular interactions.
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Crystal structure of the TreS:Pep2 complex, initiating α-glucan synthesis in the GlgE pathway of mycobacteria
(American Society for Biochemistry and Molecular Biology, 2019) Kermani, Ali A.; Roy, Rana; Gopalasingam, Chai; Kocurek, Klaudia I.; Patel, Trushar R.; Alderwick, Luke J.; Besra, Gurdyal S.; Fütterer, Klaus
A growing body of evidence implicates the mycobacterial capsule, the outermost layer of the mycobacterial cell envelope, in modulation of the host immune response and virulence of mycobacteria. Mycobacteria synthesize the dominant capsule component, α(1→4)-linked glucan, via three interconnected and potentially redundant metabolic pathways. Here, we report the crystal structure of the Mycobacterium smegmatis TreS:Pep2 complex, containing trehalose synthase (TreS) and maltokinase (Pep2), which converts trehalose to maltose 1-phosphate as part of the TreS:Pep2–GlgE pathway. The structure, at 3.6 Å resolution, revealed that a diamond-shaped TreS tetramer forms the core of the complex and that pairs of Pep2 monomers bind to opposite apices of the tetramer in a 4 + 4 configuration. However, for the M. smegmatis orthologues, results from isothermal titration calorimetry and analytical ultracentrifugation experiments indicated that the prevalent stoichiometry in solution is 4 TreS + 2 Pep2 protomers. The observed discrepancy between the crystallized complex and the behavior in the solution state may be explained by the relatively weak affinity of Pep2 for TreS (Kd 3.5 μm at mildly acidic pH) and crystal packing favoring the 4 + 4 complex. Proximity of the ATP-binding site in Pep2 to the complex interface provides a rational basis for rate enhancement of Pep2 upon binding to TreS, but the complex structure appears to rule out substrate channeling between the active sites of TreS and Pep2. Our findings provide a structural model for the trehalose synthase:maltokinase complex in M. smegmatis that offers critical insights into capsule assembly.
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Canadian science meets parliament: building relationships between scientists and policymakers
(Oxford University Press, 2021) Zhao, Jiaying; Azad, Meghan B.; Bertrand, Erin M.; Burton, Cole; Crooks, Valorie A.; Dawson, Jackie; Ford, Adam T.; Kaida, Angela; Krishnaswamy, Arjun; Kuok, Chikin; Mah, Catherine L.; McTaggart, Matt; Moehring, Amanda J.; Robert, Dominique; Schulte-Hostedde, Albrecht; Sparling, Heather; De Vera, Mary A.; Waterman, Stephanie; Patel, Trushar R.
The first Science Meets Parliament event in Canada was held in November 2018 in Ottawa, where twenty-eight Tier II Canada Research Chairs (a specific class of Canadian university professor acknowledged by their peers as having the potential to lead in their field) from diverse disciplines met with forty-three Members of Canadian Parliament and Senators. The main goal of this event was to facilitate communication between these two key pillars of the society, to promote mutual understanding of the nature of their respective work, roles, and responsibilities, and to build long-term relationships. Here, we, representatives of the first cohort of scientists to participate in the program, summarize our experiences and lessons learned from this event, as well as our assessment of the benefits of attending this event for scientists, policy decision-makers, and institutions. Furthermore, we provide suggestions for similar future events in Canada and elsewhere.