Theses and Dissertations at Montana State University (MSU)
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Item Adapting archetypal analysis to scientific imaging applications(Montana State University - Bozeman, College of Letters & Science, 2022) Potts, Catherine Gabriel; Chairperson, Graduate Committee: Dominique ZossoScientific imaging applications create large sets of high-dimensional data, which may be difficult to process using traditional supervised machine learning representative models. First, many representative models generate computational elements that are difficult to interpret in terms of the scientific application and second, the high embedding dimension of the images often makes generating the models computationally inefficient. We propose using archetypal analysis (AA) as the representative model for these scientific imaging problems, since the computational elements, so called archetypes, resemble members of the original dataset. Specifically, the archetypes are generated as extreme points to an approximation of the convex hull of the data cloud, which means they maintain the structure of individual data points. To improve the computational task of generating the AA model, we propose a sketch-based AA method which projects the data to a lower embedding dimension before calculating the computational elements, lowering computation time for these high-dimensional problems, while at the same time retaining the geometric structure enough so that the computational elements closely match the results of AA. We also applied a primal-dual hybrid gradient (PDHG) solver to the AA algorithm structure attempting to speed up computation. To verify the significance of the interpretation of AA, we applied AA to transient fluorescent calcium images, recorded in the Kunze Neuroengineering lab as videos, in order to determine whether or not adding different nanoparticles changed the way the neurons in culture communicate. We also applied our sketch-based AA method to other sorts of imaging data sets, exploring the differences between our method and the standard AA method. Our experimentation shows the different ways that AA can be adapted to scientific imaging applications, providing a machine learning representation model that is interpretable in the context of the imaging problem and verifies the benefits of the sketch-based method in terms of computation time.Item Does calcium propionate elicit similar growth and reproductive responses as monensin in developing heifers?(Montana State University - Bozeman, College of Agriculture, 2017) Hubbard, Ashton Rose; Chairperson, Graduate Committee: Rachel L. Endecott; C. C. Reichhardt, A. R. Williams, I. R. McGregor, C. M. Page, D. M. Staudenmeyer and R. L. Endecott were co-authors of the article, 'Does calcium propionate elicit similar feed efficiency and reproductive responses as monensin in developing heifers?' submitted to the journal 'Journal of animal science' which is contained within this thesis.Replacement beef heifer development is critical for the continued production of beef and for ranch success. Objectives of this research were to investigate the growth and reproductive responses of developing heifers fed similar basal diets supplemented with pellets containing different feed additives. Pellet treatments consisted of 2.27 kg x heifer -1 x d -1 of: 1) control with no feed-additive (CON), 2) 200 mg x heifer -1 x d -1 monensin (MON), or 3) 40 g x heifer -1 x d -1 calcium propionate (PRO). Experiment 1 utilized one hundred and ninety-eight heifers (254 + or = 3.8 kg) stratified by BW and randomly assigned to one of six pens (n = 2 pens per treatment). Experiment 2 utilized fifty-eight heifers (304 + or = 3.4 kg) stratified by BW and randomly assigned to one of 12 pens (4 pens per treatment). Heifers were fed a grass hay basal diet in both experiments (Exp. 1: 65% TDN and 11% CP; Exp. 2: 62% TDN and 15% CP, DM basis). Experiment 1 was 129 d and Experiment 2 was 122 d. Body weights were collected at the beginning and end of each experiment, with interim BW collected every 30 d. Serum samples were collected via coccygeal venipuncture and analyzed for progesterone to determine pubertal status. Overall pregnancy rates and pregnancy rate from AI were determined. Experiment 1 observed no differences for initial BW, final BW, overall ADG, pregnancy rate from AI, or overall pregnancy rate (P > or = 0.16). Fewer CON and PRO heifers were pubertal at experiment start than MON heifers (P < or = 0.01) in Experiment 1, which was unexpected. Differences in puberty achievement were diminished at the end of the experiment. Experiment 2 observed no differences for initial BW, final BW, overall ADG, pregnancy rate from AI, or overall pregnancy rate (P > or = 0.19). Treatment had no effect on puberty achievement at beginning or end of experiment (P > or = 0.09). A period effect was observed for ADG in both experiments (P < or = 0.01) which may be related to cold stress. Neither calcium propionate nor monensin resulted in improved performance compared to no feed additive. Further research is warranted to elucidate the impact of calcium propionate on heifer development.Item The effect of excess calcium with borderline and deficient phosphorus in the rations of steer calves(Montana State University - Bozeman, College of Agriculture, 1950) Lewis, James K.Item Self-feeding beef calves mineral mixtures varying in calcium and phosphorus levels(Montana State University - Bozeman, College of Agriculture, 1958) Smyrl, Samuel H.Item The influence of calcium on biofilm processes(Montana State University - Bozeman, College of Engineering, 1986) Turakhia, Mukesh HarilalBacteria exhibit a tendency for adsorbing to and colonizing surfaces which are submerged in aquatic environments. Adsorption is mediated by extracellular polymeric material which is formed by the bacteria and extends from the cell to the attachment surface. The attached cells reproduce and form additional extracellular polymer increasing the mass of the deposit. The cellular-extracellular matrix is termed a bipfilm. The purpose of this study was to investigate the effect of calcium on cellular reproduction and extracellular polymer formation by Pseudomonas aeruginosa in a biofilm. Experiments were conducted with a pure culture of Ps. aeruginosa using fixed film bioreactors with glucose serving as the limiting nutrient. Results indicate calcium increases the rate and extent of cellular carbon accumulation at the surface. However, there was no effect of calcium on the amount of polymer carbon accumulated on the surface. Results also suggest that free calcium (or calcium assisted ligands) is essential to the structural integrity of the biofilm. The energy required for biochemical conversion of glucose into biomass by suspended or immobilized culture of Ps. aeruginosa was constant and was independent of time, biomass concentration, specific cellular growth rate, and calcium concentration in the medium.Item The effect of varying levels of dietary calcium upon lipid excretion and deposition in swine(Montana State University - Bozeman, College of Agriculture, 1968) Hecker, Arthur LeoItem Calcium levels in finishing cattle rations(Montana State University - Bozeman, College of Agriculture, 1981) Dew, Randall Keith