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Synthesis and characterization of lipophilic 3,4-hydroxypyridinone iron(III) complexes
Get PDFFour N-substituted 3,4-hydroxypyridinone compounds were functionalized with four different aryl substituents with hydrocarbon tails of varying lengths. 3,4-hydroxypyridinone ligands were synthesized, isolated and characterized utilizing 1H-NMR, FT-IR spectroscopy and melting point analysis. These ligands were then used to form Fe(III) complexes. Complexes were characterized using FT-IR spectroscopy, UV-Vis spectroscopy, and decomposition point analysis. In addition to Fe(III) complex characterization, a preliminary X-ray structure of complex Fe(1A)2Cl was collected
Investigation and signal enhancement of vertically and horizontally aligned gold nanorod substrates using surface-enhance Raman spectroscopy
Get PDFDue to its anisotropic properties, gold nanorods can absorb and scatter light across a long range of wavelengths. Furthermore, surface plasmon resonances of gold nanorods can result in the
enhancement of the local electromagnetic field around the nanorods, which in turn amplify the intensities of the Raman signals of molecules absorbed on the gold nanorod surfaces. This
property of gold nanorods allows them to be used in surface-enhanced Raman spectroscopy (SERS) for potential use in single-molecule detection. Assembling gold nanorods into an ordered
array has been of great interest to many researchers due to the formation of hot spots, or highly localized intense electric fields that can enhance the Raman signal 100 above the 1010–1011 signal enhancement by SERS alone when two gold nanorods are in close proximity to each other. The present work aims to investigate the difference in the Raman signal enhancement when gold nanorods are aligned vertically and horizontally and relate that difference to hot spots generated in tip-to-tip and side-by-side configurations. The Raman signals of rhodamine 6G were enhanced larger when gold nanorods were aligned vertically, which may be caused by differences in the densities of the hot spot and the qualities of enhancement by AuNRV/H substrates. Additionally, computational modeling was used to predict the absorption and scattering properties of a single gold nanorod, as well as to model the hot spots generated by the two configurations
The effects of cholecystokinin and leptin on glutamate synaptic transmission in the dorsomedial nucleus of the hypothalamus in rats
Get PDFObesity is an epidemic in many developed countries caused by an imbalance in food intake and energy expenditure that presents a multitude of other health risks. In the brain, the dorsomedial nucleus of the hypothalamus (DMH) plays an important role in the regulation of appetite. Cholecystokinin (CCK), an important neuropeptide and satiety hormone acts in the DMH to suppress food intake. Although the exact mechanisms by which CCK inhibits food intake are not entirely understood, there is evidence that CCK alters neurotransmitter release onto DMH neurons. Specifically, CCK increases the release of the major inhibitory transmitter, GABA, onto putative appetite-stimulating DMH neurons. It is unknown, however, whether CCK affects the transmission of glutamate, a major excitatory transmitter, despite reports of CCK modulating glutamate release elsewhere in the brain. We hypothesized that CCK decreases neuronal activity and glutamate transmission in DMH neurons in rats. To test this hypothesis. we used young male Sprague Dawley rats and performed patch clamp electrophysiology to record action potentials and glutamate-mediated currents in living DMH neurons. Surprisingly, CCK had no effect on evoked excitatory postsynaptic currents, even following a high-frequency stimulation (HFS) into the extracellular space, causing increased neurotransmitter release. There was, however, a decrease in the frequency of spontaneous events following HFS in the presence of CCK, suggesting that CCK is involved in facilitating glutamate transmission. Another satiety hormone, leptin, has been reported to act in combination with CCK to reduce appetite when co-injected into other regions of the brain. We therefore co-administered CCK and leptin onto DMH brain slices. Interestingly, there was a significant decrease in glutamate transmission following bath application, however, following HFS, there were no significant effects. There were also no significant changes in the spontaneous activity of these DMH neurons. We then administered leptin alone to determine whether the decrease in glutamate transmission was a direct result of leptin, or if CCK and leptin act together to modulate transmission. No effect was observed following bath application of leptin alone. There was also no significant change following high-frequency stimulation, but there was a decrease in the frequency of spontaneous currents in the presence of leptin. These results suggest that CCK and leptin act synergistically in the DMH to modulate food intake via decreased glutamate transmission at DMH neurons. This research could provide important information regarding the mechanisms by which CCK and leptin suppress appetite in rats, with implications for humans living with obesity
Design and synthesis of redox active diindanes
Get PDFThe field of Green Chemistry seeks to reduce the risks and environmental impact associated with chemicals and chemical processes. To serve as guidelines for this purposeful design, Anastas and Warner introduced the 12 Principles of Green Chemistry. One of these principles, catalysis, is key as the use of chemical catalysts eliminates waste that would result from the use of stochiometric amounts of reactant. Many of the most successful and widespread redox catalysts in industry today feature precious heavy transition metals, such as palladium and rhodium, though the toxicity and environmental impact of these metals is undesirable. In contrast to these expensive transition metals, the base main group metal indium possesses several characteristics that make it appealing for green catalysis. Indium compounds are relatively non-toxic and have potential use as Lewis acid catalysts in aqueous solution. Indium is typically trivalent and not intrinsically redox active, which necessitates the design of indium compounds in lowered oxidation states to impart redox activity. The current work seeks to synthesis and characterize the novel redox active diindane [(NCN)2In2(naphth)] (1) which will ultimately be tested as a redox active green catalyst. The synthetic routes explored and the structural characterization of the novel compounds (NCN)InBr2 (6) and [(NCN)In]2(naphth)2 (8) are reported
To what extent is the history of Africville, Nova Scotia an example of environmental racism?
Get PDFEnvironmental racism and its effects have serious impacts on minority communities, and it is no stranger to Canada. Indigenous, Black, and other minority communities have all been affected by environmental racism throughout Canada’s history. One local example of this is the case of Africville: a majority Black community once located just outside Halifax, Nova Scotia along the north-eastern corner of the Halifax peninsula, overlooking Bedford Basin. After enduring over a century’s worth of multiple hazardous land uses, Africville was declared a “slum” by the municipality and destroyed by the city of Halifax, displacing its residents, and wiping clean its historic landownership. This thesis argues that the history of Africville is a textbook case of environmental racism
HEAR! HEaR! Voices of Canadian Women
Get PDFWhat difference can women’s voices make? This is the question posed by Shari Graydon, author, speaker, and founder of Informed Opinions, a national initiative aimed at amplifying women’s voices in Canadian public discourse. It is the question explored in HEAR! HEaR! Voices of Canadian Women as well. Contributors to this collection of papers were participants in a pair of conferences, “Discourse and Dynamics: Canadian Women as Public Intellectuals” and “Speaking Her Mind: Canadian Women and Public Presence,” that focussed on the multitudinous but often muffled voices of women in Canada and the intellectual import of their contributions. Speakers included writers, scientists, journalists, social workers, musicians, and academics—both established and emerging scholars. Together on panels and in paper presentations they confronted the under-representation of women’s voices in Canada from a wide variety of perspectives, backgrounds, professions, and pursuits.type of work: book**Please visit the accompanying website at https://speakinghermind.ca/ for more information.**
Introduction: Audibly Laudable: Voices of Canadian Women / Aritha van Herk & Christl Verduyn -- Refiguring the Public Intellectual: Lessons from Life Stories by Feminists in the Faculty Body / Wendy Robbins -- Who Gets to Be a Public Intellectual in Canada? / Iga Mergler & Neil McLaughlin -- Four Contemporary Canadian Women Intellectuals Negotiate the Challenges of Public Sphere Witnessing: Dionne Brand, Samantha Nutt, Sheila Watt-Cloutier, and Janice Williamson / Diana Brydon -- Stranger Sociability: Lisa Robertson as Counterpublic Intellectual / Heather Milne -- Is There a Canadian Uncle Tom’s Cabin? Canadian Women Writers and Social Change / Carole Gerson -- "Speaking Out": Gwethalyn Graham’s Non-Fiction / Galletly -- Idola Saint-Jean and Flora MacDonald Denison: Two Feminist Intellectuals in French and English Canada / Sarah Spear -- Speaking Your Mind, or Not: The Judicial Careers of Police Magistrates Emily Murphy and Alice Jane Jamieson, 1916-1932 / Mélanie Methot -- Speaking from South Africa: E. Maud Graham, Florence Randal, and the South African War / Bridgette Brown -- Margaret Gould (1900-1981): Social Worker, Social Critic, Public Intellectual / Marjorie Johnstone -- Public (Lending) Rights: Women’s Advocacy in The Writers’ Union of Canada / Erin Raml
Examining the relationship between stress and sexual desire
Get PDFStress affects many aspects of our health, including sexual health. Stress is often cited as a cause of low sexual desire; however, there is little research on the relationship between stress and sexual desire. In the present study, I examined how attention may impact this relationship using the dot probe task. I predicted that higher levels of stress would be associated with lower sexual desire, and this relationship would be mediated by attention to erotic and threat stimuli. Sexual desire was evaluated using newly developed vignettes to measure in-the-moment desire. These vignettes were validated in two pilot studies and the main study. Stress was measured using the self-report measures of perceived stress and daily stress. The dot probe task erotic images, angry faces (threat stimuli), and neutral stimuli were used in the dot probe task. Results showed that there was a positive relationship between perceived stress and sexual desire, but there were no associations between stress and response bias towards either threat or erotic stimuli.
Vignette scores were moderately positively correlated with an established measure of sexual desire. Overall, this study validated a new measure of sexual desire and found a relationship between stress and sexual desire, but it was not mediated by attentional bias
Images of the other in a world of motion: Perceptions of foreigners in late Edo Japan
Get PDFThroughout most of the Edo period (1603-1868), the Pacific Ocean or taiheiyō (“peaceful sea”) was an object of mystery. The Japanese who lived near the coast saw the ocean everyday, but it remained an uncharted body of water. This was largely due to constraints placed by the ruling Tokugawa shogunate that prohibited the construction of sea-faring vessels in order to regulate foreign contact. As a result, the Pacific remained a source of unknown curiosities that were beyond physical reach. However, by the nineteenth century, the possibilities and dangers of this peaceful sea were no longer distant but were coming to Japan’s shore whether it liked it or not
The effects of top-down and bottom-up forces on the nutritional quality at an intertidal mudflat in the Bay of Fundy
No full textMudflats in the upper Bay of Fundy are highly productive ecosystems that support shorebird and invertebrate life. The base of the food web in these mudflats is a biofilm containing microphytobenthos— photosynthetic microorganisms that are the main primary producers in mudflat ecosystems. Major mudflat consumers, like snails and shorebirds, can interact with biofilm in complex ways through predation on biofilm consumers as well as direct consumption and physical disturbance of the biofilm. The goal of this study was to determine the ecological factors that affect the nutritional quality (measured as content of protein, carbohydrate, and total organic matter) of mudflat biofilm. The nutritional content of biofilm was measured during an experimental manipulation of the top-down effects of key predators (mud snails and Calidrid shorebirds) and the bottom-up effects of increased nutrient availability for microphytobenthos from July – Aug, the annual period when mudflat consumers are most active and abundant. We established a repeated measures split-plot experiment at Grande Anse, in the upper Bay of Fundy, in summer of 2020 in which control plots, bird exclosures, and bird and snail (full) exclosures were established at each of twenty sites with ten of these sites randomly selected to be fertilized. We collected biofilm samples from all treatments in all sites as sediment contact cores of the top 2 mm of sediment during three sampling periods: 3-4 July, 30-31 July, and 27-28 August. We found clear temporal trends in biofilm protein and carbohydrate content, with the absolute abundance of both declining after the first sampling period and a corresponding increase in organic matter-normalized protein content. Predator treatments also had a significant effect on the absolute carbohydrate content in late August in unfertilized plots, with more carbohydrate in bird exclosures compared to controls. Fertilizer treatment significantly decreased the organic matter-normalized carbohydrate content in late July. These findings indicate that biofilm protein and carbohydrate content are affected by seasonal factors and that their abundance might not be limited by external nutrient supply (or at least it does not increase with nutrient addition). Additionally, this work shows that predators, such as shorebirds, might alter the nutritional content of mudflat biofilm in addition to being supported by it