Theses and Dissertations at Montana State University (MSU)
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Item Aerosol stability of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2)(Montana State University - Bozeman, College of Agriculture, 2022) Bushmaker, Trenton John; Chairperson, Graduate Committee: Raina K. Plowright and Vincent J. Munster (co-chair); Neeltje van Doremalen and Dylan H. Morris were authors and Myndi G. Holbrook, Amandine Gamble, Brandi N. Williamson, Azaibi Tamin, Jennifer L. Harcourt, Natalie J. Thornburg, Susan I. Gerber, James O. Lloyd-Smith, Emmie de Wit and Vincent J. Munster were co-authors of the article, 'Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1' in the journal 'New England journal of medicine' which is contained within this thesis.; Claude Kwe Yinda and Dylan H. Morris were authors and Myndi G. Holbrook, Amandine Gamble, Danielle Adney, Cara Bushmaker, Neeltje van Doremalen, Raina K. Plowright, James O. Lloyd-Smith and Vincent J. Munster were co-authors of the article, 'Comparative aerosol stability of SARS-CoV-2 variants of concern' submitted to the journal 'Emerging infectious diseases - CDC' which is contained within this thesis.The routes of transmission of the zoonotic pathogen severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have been extensively studied to understand the spread at individual and population levels. Aerosol particles produced by infected individuals and the deposition patterns inhaled are known to affect the virulence of bioaerosol pathogens. Droplet nuclei particles (< 5 microns) aerosols typically deposit within the alveolar spaces of the lungs, whereas droplet (>5 microns) aerosols typically deposit within the nasopharyngeal and tracheobronchial regions of the respiratory tract. A few studies have evaluated pulmonary disease following droplet nuclei size particles of SARS-CoV-2 aerosol inhalation in African green monkeys and golden hamsters, concluding that both models have mild respiratory disease representative of human disease. More importantly, human participants with SARS-CoV-2 infections have been studied to look at the generation of particles during breathing, talking, and singing; the study concluded droplet nuclei particles accounted for 85% of the copies of virus produced and play a significant role in transmission. However, the environmental persistence of the aerosolized droplet nuclei particles, and the likely role of environmental persistence in driving transmission, is unknown for SARS-CoV-2. In these studies, we show the changing aerosol stability of SARS-CoV-2 during the supplanting waves of Variants of Concern (VOC). With the determination of viable viral particles characterized over time, we can make inferences about the role VOC and aerosol transmission have in driving population-level pathogen transmission. A secondary objective of these studies was to characterize the role those evolving mutations have had on viral entry and aerosol durability. Our work suggests that aerosol stability may be important in driving some population-level phenomena (e.g., indoor transmission, including superspreader events) but given the short infected-to-naive transmission transit time, the variation in the duration of aerosol stability among VOCs may not explain the difference in transmission rates of VOCs. This data will be useful for assessing the future evolution of aerosol transmission of SARS-CoV-2.Item Designing pattern formation through anisotropy(Montana State University - Bozeman, College of Letters & Science, 2019) Gaussoin, Anthony Danwayne; Chairperson, Graduate Committee: Scott McCallaWhen governed by appropriate potentials, systems of particles interacting pairwise in three dimensions self assemble into diverse patterns near the surface of a sphere. The resulting structure of these minimal energy states can be altered through anisotropic effects. This leads to the inverse problem of finding anisotropic potentials that produce specific targeted equilibrium structures. To study this problem, continuous versions of the discrete particle interaction equations are employed so that a leading order approximation can be obtained. Linear stability is then determined through a Fourier type analysis in terms of spherical harmonics. This allows us to solve the linearized inverse problem: for a targeted equilibrium structure, where the particles congregate along a finite set of spherical harmonics, construct an anisotropic potential that induces the same finite set of linear instabilities. Several examples of anisotropic potentials that cause known linear instabilities are presented. The resulting minimal energy configurations are approximated through a gradient descent of the discrete particle energy. These numerical experiments corroborate that the linear instabilities can be used to predict the minimal energy structure in the full nonlinear dynamics. Solving the linearized inverse problem yields a clear path to designing pattern formation through anisotropic effects.Item Interactions of 1 um latex microbeads with biofilms(Montana State University - Bozeman, College of Engineering, 1992) Drury, William JosephItem Modeling the deformation of colliding objects(Montana State University - Bozeman, College of Engineering, 1991) Younkin, Chance ReedItem On the electromagnetic interaction of spin-1/2 particles(Montana State University - Bozeman, College of Letters & Science, 1959) Calvert, James B.Item Heat transfer from vertical, bare and longitudinally finned tubes to a fluidized bed of large particles(Montana State University - Bozeman, College of Engineering, 1982) Todd, Terry Allen