Physical Sciences and Mathematics Commons^™

Studies In Peptide Synthesis Towards The Lanthionine Analog Of Des-N-Tetramethyl Triostin A, Ganesh Devdas Kini

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies have been carried out towards the synthesis of bicyclic octadidepsipeptide lanthionine 4, an analog of des-N-tetramethyl triostin A. Starting with a symmetrical lanthionine unit 5 (R₁, R₃ = Me; R₂, R₄ = t-butyloxycarbonyl), synthesized from the corresponding cystine by contraction with hexaethylphosphorus triamide, linear octadidepsipeptides 29 and 32 were synthesized.

Attempted cyclizations of 29 and 32 to the bicyclic octapeptide were unsuccessful.

The failure of the symmetrical approach to 4 prompted the synthesis of an unsymmetrical lanthionine unit with appropriate compatible protecting groups. Attempts to synthesize unsymmetrical lanthionines by nucleophilic displacement on …

Effects Of A Wildfire On Seed Rain And Soil Seed Reserve Dynamics Of A Good Condition Sagebrush-Grass Rangeland In Central Utah, Mohamed Ali Hassan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this research were to investigate the ecological importance of soil seed reserves and seed rain on regeneration of a good condition sagebrush-grass range vegetation after a wildfire and draw conclusions leading to better understanding and management of such ecosystems. Investigations were conducted for two successive years on a community where major plants were neither rhizomatous nor sprouting. In such cases soil seed reserves and seed rain have to be the main source of regeneration. In addition to monitoring soil seed reserves and seed rain, vegetation changes during the past two years and the historical conditions of the …

Microcomputer Algorithms For Prime Number Testing, Susan Dale Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper gives a survey of different methods of prime number testing. Emphasis has been given to algorithms based upon Fermat's Theorem: if p is an odd prime number, then p divides a^p-a. All of the computer programs described in this paper have been written for use on microcomputers and so the feasibility of using microcomputers is also discussed. Finally, numbers of various forms have been considered for primality with special attention given to Mersenne and Fermat numbers. It is hoped that some of the information contained in this paper may provide worthwhile enrichment ideas for mathematics educators.

Cluster Analysis For Acid Rain Data In Norway, Ali Ghafourian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper gives a description of three well known clustering methods, and discusses the advantages and disadvantages of each. Then, the results of these three clustering methods are compared through examining them on a specific set of data.

Cell-Mediated Immunity Of The Dog Lung And Effects Of Inhaled 239puo2 Or Pulmonary Tumors, Jennifer Baker Galvin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cell-mediated immunity (CMI) in the lung has not been well characterized due to the lack of applicable tests. A major objective was to define pulmonary CMI serially in immunized and control lung lobes using the leukocyte procoagulant (LPCA) assay in young adult dogs. This was compared to a standard, but less reproducible CMI assay, macrophage migration inhibition facet (MIF). The CMI response, as measured by the LPCA assay, peaked in the blood 7 days after lung immunization. The pulmonary CMI response measured with cells obtained by bronchial lavage from the immunized and control lung lobes peaked at 9 to 12 …

Correction Of Bias In Estimating Autocovariance Function, Len-Hong Wu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis was to evaluate a method for reducing the bias of estimation for autocovariance estimators. Two methods are compared, one is the standard method and the other is an adjustment method. The Monte Carlo method is used within comparison.

The bias and the mean squared error of the estimated autocovariance is computed for several time series models and two variations of the adjustment method of estimation. The results indicate some improvement in bias and mean squared error for the new method.

Cow Brain Glutaminase: Purification And Influence Of Phosphate And Borate Ions On Its Activity And Molecular Weight, Mahnaz Badamchian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An efficient and simple purification procedure for cow brain glutaminase (L- glutamine amidohydrolase, EC 3.5.1.2) is described. The main steps consisted of acetone extraction and French press treatment in the presence of phosphate ions, precipitation of nucleic acids and lipids by 0.08 % protamine·S04 and high speed centrifugation (300,000xg), ammonium sulfate fractionation, and gel filtration on Sepharose 4B first as the low molecular weight and then as the aggregated form. The yield was 22% and the final preparation had a specific activity of 142 μmoles/min/mg. The purification was more than 8000-fold over crude brain homogenate. The enzyme showed one strong …

Photochemical Energy Storage (Photosensitized Isomerization Of Norbornadiene To Quadricyclane By Copper(I) Complexes), Dennis J. Fife

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research has focused on the sensitized photoisomerization step of a solar energy storage system based on the interconversion of norbornadiene (NBD) and quadricyclane (Q). Sensitizers studied in the photoisomerization were arylphosphine complexes of copper(I) halides [(Ph₃P)₃CuX, (MePh₂P)₃CuX, (DIPHOS)CuCl; X = Cl, Br, I and DIPHOS = Ph₂P(CH₂)₂PPh₂]. The lowest electronic excited state of the complexes can be an effective triplet energy sensitizer as evidenced by a maximum quantum yield of 1.0 with (MePh₂P)₃CuX. The sensitization mechanism of the L …