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Synthesis and characterization of (alpha-amidobenzenedithiolato)indium complexes as green redox active catalysts
No full textGreen Chemistry is an area of interest currently receiving significant attention from both industrial and academic communities. This area aims to develop chemical products and processes that reduce or eliminate the use and generation of substances hazardous to human health and the environment. Designing environmentally benign catalysts capable of performing redox reactions has been at the centre of Green Chemistry initiatives. Traditional catalysis is dominated by precious metals, such as palladium and platinum, due to their ability to achieve variable oxidation states and perform redox chemistry. however, significant environmental concerns exist with their use and disposal. Indium could offer an appealing alternative to traditional precious metals due to its environmentally benign nature and tolerance
towards various functional groups. By incorporating a redox active ligand, the possibility to create a benign, base-metal-centered redox active catalyst exists. To this end, the objectives of this research project are to synthesize and characterize a series of molecular indium complexes incorporating a redox active amidobenzenethiolate (abt) ligand and test their redox capabilities through use of cyclic voltammetry. The target compound MeIn(abt) (1) has been successfully synthesized via a hydrocarbon elimination reaction of Me3In and H2(abt) and spectroscopically characterized. Synthesis of organoindium reactants Ph3In and Mes3In has required modification of literature procedures, with the latter being successfully isolated in a yield of 47%. Significant progress has been made on the synthesis of MesIn(abt) (3). Further work is required in order to isolate crystals of target compounds for X-ray crystallography and
subsequently test their redox properties
The 'links' between literacy growth: Do some students benefit more from intervention than others?
Get PDFThe purpose of the present study was to administer a program review of the LINKS afterschool tutoring initiative at Salem Elementary School in Sackville, New Brunswick. The research aimed to address the effectiveness of the intervention strategy and highlight any measures that might serve as predictive factors with respect to success in the LINKS program. Eleven students were recruited for the LINKS after-school tutoring program (mean age = 92.36 months; 81.80% male). At the beginning of the LINKS program,
participants were assessed by a research assistant on a series of literacy-related measures concerning phonological awareness, oral vocabulary, and spelling dictation items. At the end of the term, the tutor repeated the spelling dictation task performed prior to intervention. Each tutor performed a pre- and a post-assessment with their student on measures of sight word reading, nonsense word decoding, and spelling ability. The results revealed all literacy areas demonstrated significant improvement over the
intervention period. Moreover, phonological awareness prior to intervention was a significant predictor of relative success in the LINKS program. The present study illustrates the overall benefit of including a tier-two intervention program within the general curriculum of the school system
Synthesis and characterization of a novel thiopyridinone ligand for the formation of biologically active bismuth complexes
Get PDFMaltol and its derivatives such as hydroxypyridinones and thiomaltol have been shown to be able to complex to metals and have been determined to have anti-bacterial as well as other medicinal qualities. However, there has yet to be thiol-maltol or thiol derivatives of hydroxypyridinones that have been able to be synthesized. Bismuth complexes have also been shown to have anti-bacterial and anti-fungal properties. Therefore there is an opportunity to be able to form bismuth complexes using maltol or its derivatives that contain synergistic antibacterial qualities between the bismuth metal center and the maltol or maltol derived ligand. The objective of this research is to synthesize, characterize, and optimize the formation of a maltol derived thiopyridinone ligand that has the possibility of binding to a bismuth metal center. Much progress has been made towards the synthesis of the thiopyridinone ligand as the first proposed intermediate has been isolated, and the direct synthesis of the third proposed intermediate from the first has been performed and optimized resulting in high yields. The attempted synthesis of the target thiopyridinone ligand from this intermediate resulted in an impure product that requires further characterization. More work is required to obtain a high yield efficient method for the final step of the target thiopyridinone ligand
Siteseeing: Using machine learning to classify segmented web pages
Get PDFThe aim of this thesis is to extend the SiteSeer system—previously developed by Dr. Cormier—by incorporating machine learning into its classification component. The
SiteSeer system segments web pages into regions, which are then assigned a label from a set of labels called the ontology. It is this second component, the assignment of a label
based on the appearance of a region of the web page, that we used machine learning for in this project. Multiple machine learning architectures were attempted for this,
including a Convolutional Neural Network (CNN), and a Random Forest Ensemble—two architectures we focus on. The Random Forest showed the best performance, while the
CNN's performance fell approximately in the middle. In the best case, we improved accuracy by 40% over weighted random predictions (weighted according to the imbalance in class membership), from 35% to 75%. We also roughly tripled performance compared to the earlier system, going from 20% to 59% accuracy. These results constitute a significant advancement in the performance of the SiteSeer system, and demonstrate that machine learning is an effective technique for classifying the present dataset, despite numerous challenges. The findings could be extended by combining the machine learning with the Hidden Markov Tree from earlier iterations of the system, by collecting more data, and by improving the initial segmentation algorithm that generated the dataset
Everything is edible at least once: An ethics of eating
Get PDF(in lieu of the Abstract, the introduction is presented)
If I could choose where my passion and talents lie, I would choose to be a storyteller—one that can write prose and tell stories that have the power to change lives. But stories have their limits in what they can do, especially if there is no one to hear them. I am not a good storyteller, nor do I know how many people will read my writing. Nevertheless, I choose to write something to make sense of the situation I find myself in. My hope is to use philosophy to navigate my complicated relation with food, and to show readers who share similar concerns a possible ethical eating relation with food.
I write in response to the growing concern and awareness around the ethical issues in food production and consumption. Ethical eating practices like veganism and vegetarianism are often presented as the ethical alternative to meat-based diets if we are concerned for the wellbeing of animals. But being vegetarian or vegan in North America still requires us to consider the ecological impact of monocrop agriculture and the wellbeing of laborers. The conundrum in choosing between eating animals or supporting agricultural practices that pollute waterways and threaten biodiversity mean no matter what food choices we make we are still implicated in damage of some sort. Attempting to juggle between environmental considerations and consideration of animals often leads to vegans, vegetarians, and other ethical food eaters being criticized for hypocrisy. Furthermore, ethical food diets are often expensive and inaccessible for poor people and effectively reserves ethical eating for those who are wealthy. With the multiple dimensions of consideration, it is tempting to only focus on one aspect as controlling one thing in response to chaos and build up an ethical response to other dimensions from there. But if all eating involves some kind of suffering or damage to the environment, the workers, or the organisms, this approach can be paralyzing. I think it is possible to do better, and to theorize about ethical eating practices that are not overwhelming and are sensitive to oppression and its legacy along the lines of race, gender, and class.
In my thesis, I argue for an ethical eating practice based on a relational ontology of food with the hopes that it provides a good method of thinking through ethical eating practices. I do this by grounding my argument in a theoretical framework that recognizes knowledge and interpretations as situated in social contexts and acquired/developed for social goals. The theoretical framework I engage with and my starting position will be explained in detail in chapter one and exemplified in chapters two and three. Using the idea of generating interpretations of the world for the purpose of change and the goals influencing the aspects of reality to emphasize in interpretation, in chapter two I articulate a relational understanding of food. Understanding food relationally emphasizes ethical issues often disregarded as unimportant or only tangential to food ethics. In this conception of food, these issues are central and inseparable from our ethical relations with food. In chapter three, I respond to more dominant views in food ethics that argue for strict vegan or vegetarian diets. I argue their lack of nuanced understanding of food affects their ability to respond to our differentiated access to foods due to our socio-economic positions and our varied responsibilities associated with them. Recognizing that we are not equally responsible in the ills of our current food consumption practices, I propose a method of developing ethical eating relations that prescribe dimensions of consideration for how we and what we ought to eat. As one possible way of navigating the relations embedded in foods, I suggest treating the food we eat as the body of a friend. Through that interpretation of our eating relations, I aim to show how our individual relations with food can be more ethical, and how managing our eating relations can incite responses to change the social structures that gave rise to the ethical issues in food production.
I cannot un-witness the impacts of climate change, institutional racism, the fact that we live on stolen lands, that my friends continue to fight against misogyny and sexism because they have no choice, and the racist undertones that sometimes appear in moral vegetarianism, veganism, and climate change activism. There is a need for food ethics for reasons from the connection between food production and climate change to issues of who can access food and what foods we should and should not eat. But trying to eat ethically while knowing there are other issues like poverty and water pollution is troubling because deciding which ethical issues to emphasize is and will remain a dilemma. We are in a pickle when it comes to eating ethically. Vegans and vegetarians are often criticized by non-vegans and non-vegetarians as being hypocritical because vegan diets sometimes are complicit in cultural appropriation—I used to be one among vegan denouncers. What I failed to recognize is that those who are vegans and vegetarians for moral (especially environmental) reasons are at least trying to make change for the better. If being ethically pure is not an ideal we strive toward, as I discuss more in chapter one, then recognizing the contradictions of our eating habits might not be as bad since it provides avenues for change. Living in a pickle may be good if we recognize the goal is not to separate ourselves from the vegetable and spice mix, but to put the pickles to good use. So, I start my theorizing from the problems in eating
The effect of mixing bulky oils with alkanethiol-capped gold nanoparticles on nanoparticle self-assembly
Get PDFThe mechanism by which alkanethiol-capped gold nanoparticles (AuNPs) interact with their surrounding environment and self-assemble is a subject of great interest because of the potential applications of AuNP films in electronics, optics, and as chemical sensors. Previous work on AuNP films at the air-water interface has shown that the addition of linear hydrocarbon oils to typically rigid and irreversible pure AuNP films has a modest effect in increasing NP-NP spacing to form more fluid and reversible films. These studies also suggested that the oils were able to effect these changes by interdigitating with the AuNP ligand shells. The present study aimed to improve upon these observed properties through the introduction of longer and bulkier oils to prevent AuNP aggregation using steric repulsion. AuNP-oil film compression isotherms and analysis by transmission electron microscopy, atomic force microscopy, and ultraviolet-visible (UV-vis) spectroscopy revealed that the addition of 1-phenyltridecane and hexadecane increased film fluidity and reduced AuNP aggregation during compression. Additionally, across all AuNP-oil combinations, no compression isotherm characteristic (i.e. earlier onset rise pressure or low hysteresis) was found to be a definite indication of AuNP-oil mixing and of being a good candidate for additional in situ analysis. The effect of increasing oil steric bulk was convoluted by concomitant changes in the stability and wettability of the oils, severely limiting the possible design parameters for oil structure. Finally, UV-vis spectroscopy measurements revealed large shifts in the λmax, which are promising indicators of AuNP-oil mixing. Therefore, in situ UV-vis spectroscopy is likely an ideal technique for assessing the mechanism by which oils mix with AuNP ligands. The shifts observed in the λmax themselves may be explained by the oil interdigitating with the AuNP ligand shell as well as changes in AuNP ligand tilt
Silver nanoparticles have protein-specific negative impacts on cardiac function in brook trout (Salvelinus fontinalis)
Get PDFSilver nanoparticles (nAg) have been increasingly prevalent in societal use due to their antimicrobial nature, highly diversifiable structure, and small size. Non-exhaustively, they are being used in textiles, toys, cleaning products, and other technologies before being released into the environment at various stages of production. With the increasing use of nAg in consumer products, potential long-term effects on humans and the aquatic environment are a serious concern. This study looked to characterize the cardiac effects of nAg in brook trout. The nAg exposure through intravascular (I.V.) injection, 700μg/kg, resulted in a significant increase in both heart rate and blood pressure. There was also a decrease in Na+/K+ ATPase function seen in heart tissue. Inhibition of Na+/K+ ATPase could have indirectly led to the decrease in Na+/Ca2+ exchange, increasing localized Ca2+ and thereby increasing contractility. The total
membrane ATPase was not affected, therefore the mechanism of this inhibition of Na+/K+ ATPase is likely enzyme specific. in the nAg treatment groups, propranolol and atropine were not able to induce an effect on heart rate. This could be due to nAg binding to β-adrenergic, or cholinergic receptor sites prior to harmacological intervention. These results indicate that nAg have a negative impact on cardiac function in brook trout, however further research is required to characterize the mechanism of toxicity
The endocannabinoid, anandamide, modulates anxiety-like behaviours in young, male rats
Get PDFAnxiety disorders are a major psychological health concern in society today and while treatments are available that target neurotransmitters such as GABA and serotonin, they are known to cause adverse effects. Other neurotransmitters, like endocannabinoids (eCBs) and nitric oxide (NO), have been shown to modulate anxiety-like behaviours; however, the mechanisms regarding how eCBs and NO affect anxiety in youth remains unclear. Many studies have highlighted the importance of the eCB anandamide in the modulation of anxiety and the stress response. Thus, the purpose of this study was to further investigate eCBs, specifically anandamide, and NO in young rats. We hypothesized that anandamide will modulate anxious behaviours in a CB1 receptor and NO dependent manner. In order to investigate this hypothesis, young male Sprague-Dawley rats were placed into one of the following treatment groups: 1) vehicle (saline), 2) URB597 (fatty acid amide hydrolase (FAAH) inhibitor), 3) vehicle (30-minute restraint), 4) URB597 (30-minute restraint), 5) L-NAME (blocks NO synthesis, 30-minute restraint), 6) URB597 + L-NAME (30-minute restraint), 7) SR141716 + URB597 (cannabinoid 1 (CB1) receptor antagonist, 30-minute restraint), and their anxiety was tested using the elevated plus-maze. There were no statistically significant differences observed between nonstressed experimental groups (vehicle and URB597). Administration of URB597 prior to acute stress significantly decreased open arm time in the maze, reflecting anxiogenic behaviour. In the presence of the CB1 receptor antagonist or the NO synthesis blocker, URB597 significantly increased anxious behaviours. These findings suggest that anandamide may have anxiogenic-like effects following acute stress in which CB1 receptors and NO does not play a role
Quantitation of Vn96 Peptide using liquid chromatography and mass spectrometry
Get PDFVn96 is a small commercial peptide created by the Atlantic Cancer Research Institute to extract extra cellular vesicles from blood and plasma samples. The peptide is proven to be a successful coagulation reagent, however the viscous characteristics that encompass the peptide present many analytical challenges. Using liquid chromatography coupled with mass spectrometry, (LCMS), Vn96 was analyzed using three different mass spectrometers; a triple quadrupole, a linear quadrupole ion trap, and a quadrupole orbitrap. An extensive understanding of each instrument was done to determine the best settings for the characterization of Vn96. It is shown that the calibration curve for Vn96 produces a non-zero intercept. During the analysis of Vn96 it was determined that adsorption was occurring at concentrations below 5ug/mL resulting in inconsistent data received by the LCMS. It was determined that use of low bind sample vials is required to eliminate Vn96 from adhering to sample vial walls. Additionally, 20% acetonitrile (ACN) and 1.8M sodium chloride (NaCl) is observed to significantly increase signal intensity of Vn96. The lowest concentration of Vn96 detectable using ethyl acetate and sodium chloride is 10ng/mL
A retrospective review of colorectal cancer patient outcomes
Get PDFColorectal cancer (CRC) occupies the second highest spot of the leading cause of cancer
related mortalities in Canada. It is heterogenous in development and presentation, therefore,
treatment strategies must be personalized to best treat the individual conditions of each patient.
Prognostic factors are used by physicians as a guiding tool in creating treatment strategies. For
that reason, it is important to understand the value that each prognostic factor provides in
estimating prognosis. Prognostic molecular biomarkers have recently demonstrated their
importance in predicting response to systemic therapies. In this study, a retrospective chart
review was conducted at a single institution located in New Brunswick, Canada, in order to
evaluate the demographic, clinical, and pathologic prognostic factors and their individual
influence on patient outcome in terms of overall survival and reoccurrence free survival. This
study also determined the simultaneous effect of multiple prognostic factors, lymph node yield
and resection margins, on patient outcome. In addition, adherence to specific CRC guidelines at
this institution were assessed for compliance in regards to lymph node yield and resection
margins. This study showed that for the relatively small sample of patients, the strongest
prognostic factors for overall survival was histologic grade of the tumour, while the strongest
prognostic factors for reoccurrence free survival were age at diagnosis, distal resection margin
and circumferential resection margin. When lymph node yield and resection margins were
assessed simultaneously their influence on patient outcome was not significant in improving
reoccurrence free survival even with adherence to guidelines. There was relatively high
compliance to CRC guidelines for both lymph node yield and circumferential resection margins.
Furthermore, this study also assessed the practicality of molecular investigating for a potential
prognostic biomarker, the RAD18 gene, in formalin fixed paraffin embedded (FFPE) tissue. This
was done by evaluating a method for retrieving high quality DNA from FFPE. Gel
electrophoresis indicated high DNA fragmentation and unsuccessful amplification as a result of
the protocol used for FFPE tissue. Overall, these results allow for recognition of survival and
reoccurrence trends. Because there is no central database of CRC patient outcome after surgery
in the province of New Brunswick, our study may point to areas where further investigation is
needed. In the future, we hope this will provide a foundation for a larger survival analysis that
will increase knowledge on OS and RFS, allowing for more successful CRC patient outcome in
New Brunswick