Form and Function: X-Ray Scattering and Spectroscopy of Transition Metal-Based Nanoparticles

In recent decades, nanoparticles have been found to possess unique, tunable properties with an enormous variety of applications. The atomic and nanoscale structures govern these functional properties, and structural deviations from the bulk, in part, are responsible for the vast technological uses of nanoparticles. This dissertation tackles the understanding of structure in a number of metal, metal phosphide, and metal oxide nanoparticle systems. Additionally, the syntheses of monodispersed nanoparticle systems allow for correlating their structure with functional properties. Real space analysis using pair distribution functions of monometallic (Ni, Pd) nanoparticles of less than 5 nm in diameter revealed a deviation from the bulk face-centered cubic structure. Their local atomic packing disorder and lack of long-range order resemble that of bulk metallic glasses, which often consist of complex mixtures of a multitude of elements. Bulk metallic glasses have high mechanical strength and can sustain elastic deformations. The significant connection between these two seemingly disparate systems lie in the short-range ordering of their atomic packing motifs, which consist of icosahedral symmetry as seen in their pair distribution functions. Cobalt phosphide (Co2P) nanorods are promising as inexpensive, earth abundant catalysts for the oxygen reduction reaction in fuel cells. Additionally, their 1-D structures demonstrated greater stability as compared to conventional Pt catalysts. Their structure was investigated using high-resolution electron microscopy and a suite of X-ray scattering and absorption techniques. The dynamic structural nature of the solid-solid phase transition in vanadium dioxide (VO2) thin films was investigated using X-ray absorption fine structure spectroscopy. Substitution of transition metal dopants into lattice sites revealed the structurally-driven depression of the metal-to-insulator transition temperature. Bridging form and function, this dissertation reports the colloidal synthesis of monodispersed nanoparticles alongside structural investigations and functional testing

A Behavioral Approach to Understanding the Git Experience

The Investigating and Archiving the Scholarly Git Experience (IASGE) project is multi-track study focused on understanding the uses of Git by students, faculty, and staff working in academic research institutions as well as the ways source code repositories and their associated contextual ephemera can be better preserved. This research, in turn, has implications regarding how to support Git in the scholarly process, how version control systems contribute to reproducibility, and how Library and Information Science (LIS) professionals can support Git through instruction and sustainability efforts. In this paper, we focus on a subset of our larger project and take a deep look at what code hosting platforms offer researchers in terms of productivity and collaboration. For this portion, a survey, focus groups, and user experience interviews were conducted to gain an understanding of how and why scholarly researchers use Version Control Systems (VCS) as well as some of the pain points in learning and using VCS for daily work

Isotope dilution liquid chromatography - tandem mass spectrometry for simultaneous identification and quantification of beta-casomorphin 5 and beta-casomorphin 7 in yoghurt

A highly selective and sensitive liquid chromatography–tandem mass spectrometry method was developed and validated for the simultaneous identification and quantification of beta-casomorphin 5 (BCM5) and beta-casomorphin 7 (BCM7) in yoghurt. The method used deuterium labelled BCM5-d10 and BCM7-d10 as surrogate standards for confident identification and accurate and quantification of these analytes in yoghurt. Linear responses for BCM5 and BCM7 (R2 = 0.9985 and 0.9986, respectively) was observed in the range 0.01–10 ng/μL. The method limits of detection (MLDs) in yoghurt extracts were found to be 0.5 and 0.25 ng/g for BCM5 and BCM7, respectively. Analyses of spiked samples were used to provide confirmation of accuracy and precision of the analytical method. Recoveries relative to the surrogate standards of these spikes were in the range of 95–106% for BCM5 and 103–109% for BCM7. Precision from analysis of spiked samples was expressed as relative standard deviation (%RSD) and values were in the range 1–16% for BCM5 and 1–6% for BCM7. Inter-day reproducibility was between 2.0–6.4% for BCM5 and between 3.2–6.1% for BCM7. The validated isotope dilution LC–MS/MS method was used to measure BCM5 and BCM7 in ten commercial and laboratory prepared samples of yoghurt and milk. Neither BCM5 nor BCM7 was detected in commercial yoghurts. However, they were observed in milk and laboratory prepared yoghurts and interestingly their levels decreased during processing. BCM5 decreased from 1.3 ng/g in milk to 1.1 ng/g in yoghurt made from that milk at 0 day storage and <MLQ at 1 and 7 days storage. BCM7 decreased from 1.9 ng/g in milk to <MLQ in yoghurts immediately after processing. These preliminary results indicate that fermentation and storage reduced BCM5 and BCM7 concentration in yoghurt

Differential response of lymphatic, venous and arterial endothelial cells to angiopoietin-1 and angiopoietin-2

BACKGROUND: The lymphatic system complements the blood circulatory system in absorption and transport of nutrients, and in the maintenance of homeostasis. Angiopoietins 1 and 2 (Ang1 and Ang2) are regulators of both angiogenesis and lymphangiogenesis through the Tek/Tie-2 receptor tyrosine kinase. The response of endothelial cells to stimulation with either Ang1 or Ang2 is thought to be dependent upon the origin of the endothelial cells. In this study, we examined the effects of the angiopoietins on lymphatic, venous and arterial primary endothelial cells (bmLEC, bmVEC and bmAEC, respectively), which were isolated and cultured from bovine mesenteric vessels. RESULTS: BmLEC, bmVEC and bmAEC cell populations all express Tie-2 and were shown to express the appropriate cellular markers Prox-1, VEGFR3, and Neuropilin-1 that define the particular origin of each preparation. We showed that while bmLECs responded slightly more readily to angiopoietin-2 (Ang2) stimulation, bmVECs and bmAECs were more sensitive to Ang1 stimulation. Furthermore, exposure of bmLECs to Ang2 induced marginally higher levels of proliferation and survival than did exposure to Ang1. However, exposure to Ang1 resulted in higher levels of migration in bmLECs than did to Ang2. CONCLUSION: Our results suggest that although both Ang1 and Ang2 can activate the Tie-2 receptor in bmLECs, Ang1 and Ang2 may have distinct roles in mesenteric lymphatic endothelial cells

Characterizing the Use of Telepsychiatry for Patients with Opioid Use Disorder and Cooccurring Mental Health Disorders in Ontario, Canada

Rural patients with opioid use disorder (OUD) face a variety of barriers when accessing opioid agonist therapy (OAT) and psychiatric services, due to the limited supply of physicians and the vast geographic area. The telemedicine allows for contact between patients and their physician—regardless of physical distance. Objective. We characterize the usage of telemedicine to deliver psychiatric services to patients with OUD in Ontario, as well as traits of treatment-seeking patients with opioid dependence and concurrent psychiatric disorders. Methodology. A retrospective cohort study was conducted using an administrative database for patients who received psychiatric services via telemedicine between 2008 and 2014 and who also had OUD. Results. We identified 9,077 patients with concurrent opioid use and other mental health disorders who had received psychiatric services via telemedicine from 2008 to 2014; 7,109 (78.3%) patients lived in Southern Ontario and 1,968 (21.7%) in Northern Ontario. Telemedicine was used more frequently to provide mental health services to patients residing in Northern Ontario than Southern Ontario. Conclusion. Telemedicine is increasingly being utilized throughout Ontario for delivering mental health treatment. There is an opportunity to increase access to psychiatric services for patients with opioid dependence and concurrent psychiatric disorders through the use of the telemedicine

Embryonic vascular endothelial cells are malleable to reprogramming via Prox1 to a lymphatic gene signature

Peer reviewe

Dancing with power in ‘We are the university: Students co-creating change’

Much of the student-staff partnership literature calls for increased collaboration and power sharing among staff and students. Less common are accounts by student partners themselves that take up the challenge of what partnership and power feel like as universities embrace their neoliberal trajectory - and - purport to do so on behalf of students themselves. Especially acute is the conundrum of how partnership initiatives can, and do, reproduce the very power dynamics they set out to transform. We are a group of students and staff working in curriculum partnership together at Western Sydney University. The context of our work together is the 21C project, a university-wide strategy to transform curriculum, teaching, and learning, drawing on ‘partnership pedagogy’. In this paper, we engage in a process of reflexive inquiry to interrogate a new elective unit that many of us are involved in as advocates, co-creators, as students and staff learning together, and as evaluators, called We are the university: Students co-creating change (WATU). To highlight partnership’s intricate power plays, we offer a fictionalised account to reflect our multi-voiced experiences of being involved in WATU. We have come to understand power’s simultaneity in partnership as forms of power over, as permission-giving, as sharing (or partnership), and as the power to act (agency). The account is our story of partnership’s inevitable contradictions - a collaboration that teaches us about the challenges of working together while being cautious of partnership’s transformatory claims