Matching Items (164)
Description
PD-L1 blockade has shown recent success in cancer therapy and cancer vaccine regimens. One approach for anti-PD-L1 antibodies has been their application as adjuvants for cancer vaccines. Given the disadvantages of such antibodies, including long half-life and adverse events related to their use, a novel strategy using synbodies in place of antibodies can be tested. Synbodies offer a variety of advantages, including shorter half-life, smaller size, and cheaper cost. Peptides that could bind PD-L1 were identified via peptide arrays and used to construct synbodies. These synbodies were tested with inhibition ELISA assays, SPR, and pull down assays. Additional flow cytometry analysis was done to determine the binding specificity of the synbodies to PD-L1 and the ability of those synbodies to inhibit the PD-L1/PD-1 interaction. Although analysis of permeabilized cells expressing PD-L1 indicated that the synbodies could successfully bind PD-L1, those results were not replicated in non-permeabilized cells. Further assays suggested that the binding of the synbodies was non-specific. Other tests were done to see if the synbodies could inhibit the PD-1/PD-L1 interaction. This assay did not yield any conclusive results and further experimentation is needed to determine the efficacy of the synbodies in inhibiting this interaction.
ContributorsMujahed, Tala (Author) / Johnston, Stephen (Thesis director) / Blattman, Joseph (Committee member) / Diehnelt, Chris (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The devastating 2014 Ebola virus outbreak in Western Africa demonstrated the lack of therapeutic approaches available for the virus. Although monoclonal antibodies (mAb) and other molecules have been developed that bind the virus, no therapeutic has shown the efficacy needed for FDA approval. Here, a library of 50 peptide based ligands that bind the glycoprotein of the Zaire Ebola virus (GP) were developed. Using whole virus screening of vesicular stomatitis virus pseudotyped with GP, low affinity peptides were identified for ligand construction. In depth analysis showed that two of the peptide based molecules bound the Zaire GP with <100 nM KD. One of these two ligands was blocked by a known neutralizing mAb, 2G4, and showed cross-reactivity to the Sudan GP. This work presents ligands with promise for therapeutic applications across multiple variants of the Ebola virus.
ContributorsRabinowitz, Joshua Avraam (Author) / Diehnelt, Chris (Thesis director) / Johnston, Stephen (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Both technological and scientific fields continue to revolutionize in a similar fashion; however, a major difference is that high-tech corporations have found models to continue progressions while still keeping product costs low. The main objective was to identify which, if any, components of certain technological models could be used with the vaccine and pharmaceutical markets to significantly lower their costs. Smartphones and computers were the two main items investigated while the two main items from the scientific standpoint were vaccines and pharmaceuticals. One concept had the ability to conceivably decrease the costs of vaccines and drugs and that was "market competition". If the United States were able to allow competition within the vaccine and drug companies, it would allow for the product prices to be best affected. It would only take a few small companies to generate generic versions of the drugs and decrease the prices. It would force the larger competition to most likely decrease their prices. Furthermore, the PC companies use a cumulative density function (CDF) to effectively divide their price setting in each product cycle. It was predicted that if this CDF model were applied to the vaccine and drug markets, the prices would no longer have to be extreme. The corporations would be able to set the highest price for the wealthiest consumers and then slowly begin to decrease the costs for the middle and lower class. Unfortunately, the problem within the vaccine and pharmaceutical markets was not the lack of innovation or business models. The problem lied with their liberty to choose product costs due to poor U.S. government regulations.
ContributorsCalderon, Gerardo (Author) / Johnston, Stephen (Thesis director) / Diehnelt, Chris (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The fence between the US and Mexico had been and continues to be a controversial topic in both the U.S., Mexico and around the world. This study will look at the negative externalities related to the environment, society, and economy of the current fence on the border. The central question behind the thesis is whether or not the fence has a direct impact on the ecosystem and people around it.
ContributorsHoyt, Stephanie Alexis (Author) / Schoon, Michael (Thesis director) / Breetz, Hanna (Committee member) / School of Sustainability (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
ABSTRACT Peptide microarrays may prove to be a powerful tool for proteomics research and clinical diagnosis applications. Fodor et al. and Maurer et al. have shown proof-of-concept methods of light- and electrochemically-directed peptide microarray fabrication on glass and semiconductor microchips respectively. In this work, peptide microarray fabrication based on the abovementioned techniques were optimized. In addition, MALDI mass spectrometry based peptide synthesis characterization on semiconductor microchips was developed and novel applications of a CombiMatrix (CBMX) platform for electrochemically controlled synthesis were explored. We have investigated performance of 2-(2-nitrophenyl)propoxycarbonyl (NPPOC) derivatives as photo-labile protecting group. Specifically, influence of substituents on 4 and 5 positions of phenyl ring of NPPOC group on the rate of photolysis and the yield of the amine was investigated. The results indicated that substituents capable of forming a π-network with the nitro group enhanced the rate of photolysis and yield. Once such properly substituted NPPOC groups were used, the rate of photolysis/yield depended on the nature of protected amino group indicating that a different chemical step during the photo-cleavage process became the rate limiting step. We also focused on electrochemically-directed parallel synthesis of high-density peptide microarrays using the CBMX technology referred to above which uses electrochemically generated acids to perform patterned chemistry. Several issues related to peptide synthesis on the CBMX platform were studied and optimized, with emphasis placed on the reactions of electro-generated acids during the deprotection step of peptide synthesis. We have developed a MALDI mass spectrometry based method to determine the chemical composition of microarray synthesis, directly on the feature. This method utilizes non-diffusional chemical cleavage from the surface, thereby making the chemical characterization of high-density microarray features simple, accurate, and amenable to high-throughput. CBMX Corp. has developed a microarray reader which is based on electro-chemical detection of redox chemical species. Several parameters of the instrument were studied and optimized and novel redox applications of peptide microarrays on CBMX platform were also investigated using the instrument. These include (i) a search of metal binding catalytic peptides to reduce overpotential associated with water oxidation reaction and (ii) an immobilization of peptide microarrays using electro-polymerized polypyrrole.
ContributorsKumar, Pallav (Author) / Woodbury, Neal (Thesis advisor) / Allen, James (Committee member) / Johnston, Stephen (Committee member) / Arizona State University (Publisher)
Created2013
Description
ABSTRACT Over the past several decades, the dilemma of free-roaming horses in the U.S. has proven to be one of the most divisive issues in management of public lands. According to federal land management agencies, without population regulation, horses can increase at the rate of 15-20% a year on arid rangelands with inadequate numbers of natural, large predators. Horses compete for valuable forage and water resources alongside cattle and native wildlife in delicate riparian areas highly susceptible to the negative ecological effects of soil compaction and overgrazing. Most U.S. management policies, therefore, call for increased removal of free-roaming horses as they are categorized as “un-authorized livestock” or "non-native" species. Wild horse advocates, however, continue to petition for improvement in animal welfare and expansion of the horses’ territory. With heightened social conflict spurred by animal rights and ecological concerns, not to mention the often-stark differences over what really “belongs” on the landscape, the success of appropriate management strategies hinges on managing agencies’ preparedness and ability to respond in a timely and inclusive manner. A critical element of the management context is the public’s views toward the wild horse and the science used to manage them. Synthesizing the vast literature in the history and philosophy of wildlife management in the American West, and utilizing an ethnographic and case study approach, my research examines the range of stakeholder concerns and analyzes the factors that have led to the disconnect between public values of wild horses and public policy for the management of the federally protected free-roaming horses in Arizona’s Apache-Sitgreaves National Forests.
ContributorsMurphree, Julie Joan (Author) / Minteer, Ben A. (Thesis advisor) / Schoon, Michael (Thesis advisor) / Bradshaw, Karen (Committee member) / Chew, Matthew (Committee member) / Arizona State University (Publisher)
Created2022
Description
Communications around sustainability have been found to be incongruent with eliciting the transformative change required to address global climate change and its' repercussions. Recent research has been exploring storytelling in sustainability, specifically with an emphasis on reflexive and emancipatory methods. These methods encourage embracing and contextualizing complexity and intend to target entire cognitive hierarchies. This study explores the possibility of using emancipatory and reflexive storytelling as a tool to change attitudes pertaining to the Valley Metro Light Rail, an example of a complex sustainability mitigation effort. I explore this in four steps: 1) Conducted a pre-survey to gauge preexisting attitudes and predispositions; 2) Provided a narrative that uses storytelling methodologies of reflexivity and emancipation through a story about the light rail; 3) Conducted a post-survey to gauge attitude shift resulting from the narrative intervention; 4) Facilitated a focus group discussion to examine impact qualitatively. These steps intended to provide an answer to the question: How does emancipatory and reflexive storytelling impact affective, cognitive and conative attitudes regarding local alternative transportation? By using tripartite attitude model, qualitative and quantitative analysis this paper determines that reflexive and emancipatory storytelling impacts attitudinal structures. The impact is marginal in the survey response, though the shift indicated a narrowing of participant responses towards one another, indicative of participants subscribing to emancipation and reflexivity of their held attitudes. From the group discussion, it was evident from qualitative responses that participants engaged in emancipating themselves from their held attitudes and reflected upon them. In doing so they engaged in collaboration to make suggestions and suggest actions to help those with experiences that differed from their own. Though this research doesn’t provide conclusive evidence, it opens the door for future research to assess these methodologies as a tool to elicit shared values, beliefs and norms, which are necessary for collective action leading to transformative change in response to global climate change.
ContributorsSwanson, Jake Ryan (Author) / Roseland, Mark (Thesis advisor) / Larson, Kelli (Committee member) / Calhoun, Craig (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
Understanding the dynamic interactions between humans and wildlife is essential to establishing sustainable wildlife-based ecotourism (WBE). Animal behavior exists within a complex feedback loop that affects overall ecosystem function, tourist satisfaction, and socioeconomics of local communities. However, the specific value that animal behavior plays in provisioning ecosystem services has not been thoroughly evaluated. People enjoy activities that facilitate intimate contact with animals, and there are many perceived benefits associated with these experiences, such as encouraging pro-environmental attitudes that can lead to greater motivation for conservation. There is extensive research on the effects that unregulated tourism activity can have on wildlife behavior, which include implications for population health and survival. Prior to COVID-19, WBE was developing rapidly on a global scale, and the pause in activity caused by the pandemic gave natural systems the chance to recover from environmental damage from over-tourism and provided insights into how tourism could be less impactful in the future. Until now it has been undetermined how changes in animal behavior can alter the relationships and socioeconomics of this multidimensional system. This dissertation provides a thorough exploration of the behavioral, ecological, and economic parameters required to model biosocial interactions and feedbacks within the whale watching system in Las Perlas Archipelago, Panama. Through observational data collected in the field, this project assessed how unmanaged whale watching activity is affecting the behavior of Humpback whales in the area as well as the socioeconomic and conservation contributions of the industry. Additionally, it is necessary to consider what a sustainable form of wildlife tourism might be, and whether the incorporation of technology will help enhance visitor experience while reducing negative impacts on wildlife. To better ascertain whether this concept of this integration would be favorably viewed, a sample of individuals was surveyed about their experiences about using technology to enhance their interactions with nature. This research highlights the need for more deliberate identification and incorporation of the perceptions of all stakeholders (wildlife included) to develop a less-impactful WBE industry that provides people with opportunities to establish meaningful relationships with nature that motivate them to help meet the conservation challenges of today.
ContributorsSurrey, Katie (Author) / Gerber, Leah (Thesis advisor) / Guzman, Hector (Committee member) / Minteer, Ben (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
University-level sustainability education in Western academia attempts to focus on eliminating future harm to people and the planet. However, Western academia as an institution upholds systems of oppression and reproduces settler colonialism. This reproduction is antithetical to sustainability goals as it continues patterns of Indigenous erasure and extractive relationships to the Land that perpetuate violence towards people and the planet. Sustainability programs, however, offer several frameworks, including resilience, that facilitate critical interrogations of social-ecological systems. In this thesis, I apply the notion of resilience to the perpetuation of settler colonialism within university-level sustainability education. Specifically, I ask: How is settler colonialism resilient in university-level sustainability education? How are, or could, sustainability programs in Western academic settings address settler colonialism? Through a series of conversational interviews with faculty and leadership from Arizona State University School of Sustainability, I analyzed how university-level sustainability education is both challenging and shaped by settler colonialism. These interviews focused on faculty perspectives on the topic and related issues; the interviews were analyzed using thematic coding in NVivo software. The results of this project highlight that many faculty members are already concerned with and focused on challenging settler colonialism, but that settler colonialism remains resilient in this system due to feedback loops at the personal level and reinforcing mechanisms at the institutional level. This research analyzes these feedback loops and reinforcing mechanisms, among others, and supports the call for anti-colonial and decolonial reconstruction of curriculum, as well as a focus on relationship building, shifting of mindset, and school-wide education on topics of white supremacy, settler colonialism, and systems of oppression in general.
ContributorsBills, Haven (Author) / Klinsky, Sonja (Thesis advisor) / Goebel, Janna (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2022
Description
A remarkable phenomenon in contemporary physics is quantum scarring in classically chaoticsystems, where the wave functions tend to concentrate on classical periodic orbits. Quantum
scarring has been studied for more than four decades, but the problem of efficiently detecting
quantum scars has remained to be challenging, relying mostly on human visualization of
wave function patterns. This paper develops a machine learning approach to detecting
quantum scars in an automated and highly efficient manner. In particular, this paper exploits Meta
learning. The first step is to construct a few-shot classification algorithm, under the
requirement that the one-shot classification accuracy be larger than 90%. Then propose a
scheme based on a combination of neural networks to improve the accuracy. This paper shows that
the machine learning scheme can find the correct quantum scars from thousands images of
wave functions, without any human intervention, regardless of the symmetry of the underlying
classical system. This will be the first application of Meta learning to quantum systems. Interacting spin networks are fundamental to quantum computing. Data-based tomography oftime-independent spin networks has been achieved, but an open challenge is to ascertain the
structures of time-dependent spin networks using time series measurements taken locally
from a small subset of the spins. Physically, the dynamical evolution of a spin network under
time-dependent driving or perturbation is described by the Heisenberg equation of motion.
Motivated by this basic fact, this paper articulates a physics-enhanced machine learning framework
whose core is Heisenberg neural networks. This paper demonstrates that, from local measurements, not only the local Hamiltonian can be recovered but the Hamiltonian reflecting the interacting structure of the whole system can
also be faithfully reconstructed. Using Heisenberg neural machine on spin networks of a
variety of structures. In the extreme case where measurements are taken from only one spin,
the achieved tomography fidelity values can reach about 90%. The developed machine
learning framework is applicable to any time-dependent systems whose quantum dynamical
evolution is governed by the Heisenberg equation of motion.
ContributorsHan, Chendi (Author) / Lai, Ying-Cheng (Thesis advisor) / Yu, Hongbin (Committee member) / Dasarathy, Gautam (Committee member) / Seo, Jae-Sun (Committee member) / Arizona State University (Publisher)
Created2022