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Bacteria with antibiotic resistance are becoming a growing concern as the number of infections they are causing continue to increase. Many potential solutions are being researched in order to combat these pathogens. One such microbe is Pseudomonas aeruginosa, which causes acute and chronic human infections. It frequently colonizes the lungs of cystic fibrosis patients and is deadly. For these reasons, P. aeruginosa has been heavily studied in order to determine a solution to antibiotic resistance. One possible solution is the development of synbodies, which have been developed at the Biodesign Institute at Arizona State University. Synbodies are constructed from peptides that have antibacterial activity and were determined to have specificity for a target bacterium. These synbodies were tested in this study to determine whether or not some of them are able to inhibit P. aeruginosa growth. P. aeruginosa can also form multicellular communities called biofilms and these are known to cause approximately 65% of all human infections. After conducting minimum inhibitory assays, the efficacy of certain peptides and synbodies against biofilm inhibition was assessed. A recent study has shown that low concentrations of a specific peptide can cause biofilm disruption, where the biofilm structure breaks apart and the cells within it disperse into the supernatant. Taking into account this study and peptide data regarding biofilm inhibition from Dr. Aurélie Crabbé’s lab, screened peptides were tested against biofilm to see if dispersion would occur.
ContributorsPatel, Justin Hemant (Author) / Diehnelt, Chris (Thesis director) / Stafford, Phillip (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
Description
This paper examines the development of United States drone policy outside of traditional battle zones. It poses the question of why do states use drones as a projection of force? In particular, the paper examines the expansion of the drone program within a system of democratic checks and balances. It looks at the effect that political and legal influences have had on the expansion of the drone program and hypothesizes that the presence of these constraints should increase drone use outside of traditional battle zones. In order to investigate this hypothesis, the paper looks at data on drone strikes from Yemen and Somalia. The data partially supports the hypothesis as there has not been a clear linear increase in the number of drone strikes in each of these countries. Nevertheless, an examination of the surrounding literature regarding political and legal influences within these countries seems to favorably point to the increase of drone operations. Future research, however, needs to be cognizant of the limitations in gathering specific statistics on drone operations as these operations are covert. It's also important to understand how the covert nature of the drone operations impacts issues regarding political oversight and legality. Lastly, it's important to constantly examine the broader implications drone policy has for US policy.
ContributorsRajan, Rohit Subramaniam (Author) / Wright, Thorin (Thesis director) / Rothenberg, Daniel (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Politics and Global Studies (Contributor)
Created2015-05
Description
The scarcity of fresh water worldwide has necessitated improved technology for desalinating sea water. Reverse osmosis membranes are currently limited by their inclination for fouling, in which a layer forms on the surface of the membrane and impedes water flux. This yields shortened membrane lifespan and increased energy costs. Current technology uses interfacially polymerized polyamide thin film composite membranes, which form nodules, leaves, and other structures that lead to rough film surfaces and may contribute to fouling propensity. In this study, polyamide latex was designed in order to cast a smoother membrane with comparable performance. Polyamide latex particles were formed using a modified procedure based on Lind et. al [10] and characterized for sphericity using scanning electromagnetic microscopy (SEM).
ContributorsMccloskey, Cailen Marie (Author) / Lind, Mary Laura (Thesis director) / Jamieson, Heather (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
The first numerical predictions of the dynamical diquark model of multiquark exotic hadrons are presented. Using Born-Oppenheimer potentials calculated from lattice QCD and phenomenological diquark(triquark) masses, mass eigenvalues that are degenerate in spin and isospin are computed from numerical solutions to both coupled and uncoupled Schroedinger equations. Assuming reasonable estimates of the fine-structure splittings, we find that the band structure of our mass spectra agrees well with the experimentally observed spectrum of charmonium-like states. Using our best fits, we predict a number of unobserved states, such as pentaquark states that lie below the charmonium-plus-nucleon threshold.
ContributorsPeterson, Curtis Taylor Taylor (Author) / Lebed, Richard (Thesis director) / Belitsky, Andrei (Committee member) / Department of Physics (Contributor, Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This thesis focuses on how domain formation and local disorder mediate non-equilibrium order in the context of condensed matter physics. More specifically, the data supports c-axis CDW ordering in the context of the rare-earth Tritellurides. Experimental studies were performed on Pd:ErTe3 by ultra-fast pump-probe and x-ray free electron laser (XFEL). Ginzburg Landau models were used to simulate domain formation. Universal scaling analysis on the data reveals that topological defects govern the relaxation of domain walls in Pd:ErTe3. This thesis presents information on progress towards using light to control material domains.
ContributorsMiller, Alex (Author) / Teitelbaum, Samuel (Thesis director) / Belitsky, Andrei (Committee member) / Kaindl, Robert (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2023-05
Description
Joseph Rotblat (1908-2005) was the only physicist to leave the Manhattan Project for moral reasons before its completion. He would spend the rest of his life advocating for nuclear disarmament. His activities for disarmament resulted in the formation, in 1957, of the Pugwash conferences, which emerged as the leading global forum to advance limits on nuclear weapons during the Cold War. Rotblat's efforts, and the activities of Pugwash, resulted in both being awarded the Nobel Peace Prize in 1995. Rotblat is a central figure in the global history of resistance to the spread of nuclear weapons. He also was an important figure in the emergence, after World War II, of a counter-movement to introduce new social justifications for scientific research and new models for ethics and professionalism among scientists. Rotblat embodies the power of the individual scientist to say "no" and thus, at least individually, put limits of conscience on his or her scientific activity. This paper explores the political and ethical choices scientists make as part of their effort to behave responsibly and to influence the outcomes of their work. By analyzing three phases of Rotblat's life, I demonstrate how he pursued his ideal of beneficial science, or science that appears to benefit humanity. The three phases are: (1) his decision to leave the Manhattan Project in 1944, (2) his role in the creation of Pugwash in 1957 and his role in the rise of the organization into international prominence and (3) his winning the Nobel Peace Prize in 1995. These three phases of Rotblat's life provide a singular window of the history of nuclear weapons and the international movement for scientific responsibility in the 50 years since the bombing of Hiroshima in 1945. While this paper does not provide a complete picture of Rotblat's life and times, I argue that his experiences shed important light on the difficult question of the individual responsibility of scientists.
ContributorsEvans, Alison Dawn (Author) / Zachary, Gregg (Thesis director) / Hurlbut, Ben (Committee member) / Francis, Sybil (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
Description
The purpose of this study was to determine the ratio of vegetable to fruit incorporated during a fresh vegetable and/or fruit juice diet. Juicing is the process of extracting the liquid part of a plant, fruit, or vegetable. Food can be ground, pressed, and spun to separate the liquid from the pulp. A juice diet involves juicing and consuming a variety of vegetables and fruits. The primary objective of this study was to gather information about the ratio of vegetable to fruit incorporated in freshly made juices during a juice diet. Therefore, the study survey inquired about various topics related to ingredient ratio during a juice diet. The survey data allowed for examination of the relationships between ingredient ratio and certain variables (e.g. gender, age, length of time juicing, juice fast participation, health effects, etc.). The study participants were recruited using online social media. Facebook was the primary method for reaching the online juicing community. A written invitation was distributed in several health related Facebook groups encouraging any person with experience juicing to complete an anonymous survey. This post was also shared via Twitter and various health related websites. The study survey data was used to examine the relationships between ingredient ratio and specific variables. The survey data showed participants had varying levels of experience with juicing. The responses indicated many participants were familiar with juice fasting and many participants completed more than one juice fast. Based on the survey response data, the most common ratio of vegetable to fruit incorporated by the participants during a juice diet was 80% vegetable to 20% fruit. The majority of participants indicated daily consumption of freshly made juice containing 70% -100% vegetables. Based on the survey response data, beginner juicers may be less inclined to incorporate organic produce into their juice diet compared to advanced juicers. The majority of participants reported positive health benefits during a juice diet. Some of the positive health benefits indicated by participants include weight loss, increased energy, and a positive impact on disease symptoms. Some of the negative side effects experienced by participants during a juice diet include frequent urination, headache, and cravings. Cross tabulation calculations between the ratio of ingredients and several variables covered by the study survey demonstrated statistical significance (i.e. length of time juicing, frequency of drinking juice, juice fast participation, number of juice fasts completed, servings of vegetables/fruit in a juice, percent of organic vegetables/fruit used in a juice, perceived positive side effects, and perceived negative side effects). This study provided insight about the average ratio of vegetable to fruit incorporated by participants during a juice diet. When analyzing the data it is important to consider the survey data was self-reported. Therefore, every result and conclusion is based on the individual perceptions of the study participants. In future experimentation, the use of medical tests and blood work would be useful to determine the biological and biochemical effects of drinking raw vegetable and/or fruit juice on the human body.
ContributorsMata, Sara Ann (Author) / Mayol-Kreiser, Sandra (Thesis director) / Shepard, Christina (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05