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The Antibacterial Efficacy of Silver (I) Cyanoximates Against Streptococcus mutans UA159 Biofilm Growth and Infection in Galleria mellonella Larvae
Get PDFStreptococcus mutans is the known etiological agent of dental caries. S. mutans’ virulence factors, namely biofilm formation and lactic acid fermentation, contribute to its pathogenic behavior within the oral cavity. Biofilms are thick, antibiotically resistant communities of bacteria that are much more difficult to treat than planktonic or free-floating bacteria. Continued misuse of antibiotics against dynamic communities, like biofilms, has led to increased research on non-antibiotic alternatives. Amongst these alternatives, there are silver and silver-based compounds. Silver is commonly incorporated into medicine due to its inhibitory and bactericidal effects and antibacterial properties. Silver (I) cyanoximates have demonstrated promising antibacterial activity against various microorganisms that colonize the surfaces of subcutaneous medical devices. To study the antimicrobial properties of silver (I) cyanoximates, specifically Silver(I) Nitrosodicyanomethanide (Ag(ACO)) and Silver(I)α-Oximido-(2-benzoyl)acetonitrile (Ag(BCO)), aerobic and anaerobic growth curves, hydroxyapatite (HA) disc assays, and in vivo treatment assays were performed against S. mutans UA159. Both compounds inhibited planktonic growth aerobically and anaerobically at concentrations between 32 ug/mL and 128 ug/mL. Both compounds also inhibited biofilm formation on HA discs at concentrations between 64 ug/mL and 128 ug/mL. To test whether the compounds showed antibacterial activity in-vivo, Galleria mellonella larvae were used. All concentrations of Ag(BCO) and Ag(ACO) successfully eliminated, limited, or delayed bacterial infection in G. mellonella larvae compared to S. mutans UA159 control. Continued research on antibiotic alternatives that target and disrupt biofilm-forming microorganisms contributes to the general understanding of how to treat S. mutans biofilms. This may lead to the incorporation of silver (I) cyanoximates in the prevention and treatment of dental caries and other biofilm-related infections
Land Back and Justice: Examining Indigenous Land and Water Rights in the United States
Get PDFThis paper evaluates U.S. policies regarding Indigenous land and water rights in the context of changing global climate conditions and a societal shift towards reparative justice models. Theories from the literature on Indigenous sovereignty and environmental protection at large, as well as the literature on reparative justice and post-colonial theory, are combined with case studies of environmental personhood in Ecuador and New Zealand to examine how a policy model could be created for the U.S. that strengthens Indigenous rights. It is argued that this colonial capitalist process has resulted in oppressive policies that harm Indigenous populations and negatively impact the environment. Two overarching research questions are addressed to support this argument. First, how have previous and current U.S. policymaking efforts impacted Indigenous groups and their ancestral environments? Secondly, how can a conception of environmental personhood be used as a possible policy framework for Land Back that addresses environmental protections while preserving Indigenous sovereignty in the U.S.? This paper argues for a new U.S. policy model that expands on rights of nature and environmental personhood frameworks; it combines green legislation, green state constitutions, and reform at the Bureau of Indian Affairs to increase Indigenous sovereignty and environmental protections
Brrr! It’s Cold in the Fridge: The Treatment of Women in the Marvel Cinematic Universe
Get PDFFemale characters depicted within the Marvel Cinematic Universe (MCU) have faced unequal treatment and significant erasure since the origin of the franchise. As the series gained popularity and cultural discussions of representation grew, the MCU has since introduced more female characters. This then prompts concerns regarding the quality of that representation and how those female characters are treated within the franchise, and if that treatment has changed over time. Six films were selected from across the four first phases of the MCU for content analysis and data was compiled into two tables to quantifiably measure the depowerment aspect of fridging, which is excessive violence and disempowerment ascribed solely to female characters. The tools used to quantify and analyze includes the Bechdel Test (Bechdel, 1985, as cited in Selisker, 2015), the Smurfette Principle (Pollitt, 1991), and the Female Affiliation Complex (Gilbert & Gubar, 1988 as cited in Nichols, 2022). The Bechdel Test, Smurfette Principle, and Female Affiliation Complex all serve as theoretical frameworks for quantifiably measuring female representation within a piece of media. These three frameworks were then applied to the six films using the method of content analysis. This study found that female representation across the six films had increased both in quantity and quality, with the most drastic change occurring across the fourth phase of the MCU. These findings are indicative of an overall awareness of diversity that seems projected to increase as the franchise continues
An Evaluation of the Effects of Reinforcer Choice on Nutrient-Dense and Calorie-Dense Edible Reinforcers
Get PDFThis research assessed the effects of manipulating choice of edible items by increasing choice of nutrient-dense items and restricting choice of calorie-dense items on skill acquisition. A preference assessment was utilized to identify the top three preferred nutrient-dense and calorie-dense food items. Participants were then exposed to four different conditions in which their preferred edible items were delivered as reinforcers following skill acquisition targets to compare skill acquisition rates between the following reinforcers: nutrient-dense food items with choice, nutrient-dense food items without choice, and calorie-dense food items without choice. The study also evaluated preference for choice. The results showed two out of the three participants acquired skills at an equal rate comparing nutrient-dense edible reinforcers to calorie-dense edible reinforcers. There was also no clear preference for choice among the participants
Blockchain Adoption and the Volatility of Bitcoin and Ethereum
Get PDFCryptocurrencies and blockchain technology have gained a lot of interest in recent years either as an investment alternative or due to their practical applications. Even though it all started with a humble paper written by Satoshi Nakamoto in 2008, the market value of cryptocurrencies reached $3 trillion during their peak in 2021. As cryptocurrencies and blockchain technology evolve, their adoption and common use may impact how prices of digital currencies like Bitcoin and Ethereum behave in the markets. This dissertation looks for a potential connection between the creation of smart contracts in the Ethereum Virtual Machine and the return and volatility of Ethereum and Bitcoin. Additionally, this dissertation applies different techniques to measure volatility, market efficiency, and the day-of-the-week effect in Ethereum and Bitcoin markets. The results of these analyses show that there is not a clear connection between Bitcoin and smart contracts created in the Ethereum platform, but in the case of Ethereum, a connection does exist. Regarding volatility, the study found some evidence that the erratic behavior of Bitcoin and Ethereum is decreasing, offering periods of less volatility and signs of efficiency in the market. Regarding the day-of-the-week effect, it changes dramatically depending on market conditions like during COVID-19, in which the performance changed patterns compared to previous years, but then returned to some stability after the public health emergency. The results show that the day-of-the-week effect is more consistent in the variance equation than in the return equation for Bitcoin and Ethereum
