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A Model Study Of Adlayer Pattern Formation Of A Linear Molecule On Square And Triangular Lattices, Gennadiy N. Berezutskiy

Master's Theses and Capstones

We have determined patterning and geometric properties of rigid-diatomic-molecular rotors, fixed on (square and triangular) the lattice site modeled by the Morse potential. Zero-K adlayer patterns were enhanced through the implementation of unconstrained multivariable function using derivative-free method (also known as simplex algorithm). Results have been obtained over wide geometry range for adlayer patterns composed of periodically repeated primary cell.

A primary focus of this work was the calculation of adlayer free energies and geometry at the ground state. Those were obtained from conformational search of the primary (2x2) cell to locate geometric configuration, which minimizes the total energy. The …

Discovering Signaling Events In The Actinorhizal Symbiosis, Nicholas J. Beauchemin

Master's Theses and Capstones

Although the symbiosis between Frankia and actinorhizal host plants has been widely studied, very little is known about the initial molecular interactions. To address this issue, Casuarina cunninghamiana root exudates were collected and tested on Frankia Ccl3. Frankia growth yield was enhanced by root exudates but Frankia could not utilize them as a sole carbon and energy source. Exposure to root exudates caused Frankia hyphal curling and surface property changes in fatty acids and carbohydrates. Pre-exposure to root exudates also decreased the time required for nodule initiation. The results show that root exudates and Frankia physiological changes for symbiosis are …

Identification And Characterization Of Photorhabdus Temperata Mutants Altered In Cell Surface And Symbiosis, Cintia R. Felix

Master's Theses and Capstones

Photorhabdus temperata forms a mutualistic association with the entomopathogenic nematode Heterorhabditis bacteriophora. Nematode growth and development has an obligate requirement for the bacterial symbiont. The objective of this study was to identify and understand cell surface properties that are required for symbiosis. A previously generated library of 10,000 P. temperata transposon mutants was screened for altered surface properties via a calcofluor dye-binding assay. Seventeen mutants were identified and tested in vitro for symbiosis. Key mutants were tested for symbiosis and insect pathogenesis in vivo with Galleria mellonella larvae. Five mutants showed at least a 10-fold decrease of IJ yield. Four …

Analysis Of Arabidopsis Thaliana Protein Phosphatase 2a C Subunit Expression, Megan M. Thompson

Master's Theses and Capstones

Reversible protein phosphorylation is required for presumably most biological pathways. One of the major enzymes involved in eukaryotic dephosphorylation is Protein Phosphatase 2A (PP2A). PP2A is composed of three subunits: A (scaffolding), B (regulatory), and C (catalytic). Our lab is interested in determining the function of the five C subunits (C1, C2, C3, C4 and C5) in Arabidopsis thaliana. We have identified a Na+-induced altered root growth phenotype in c4 mutant plants. The goal of this project was to determine expression of the five C subunit genes throughout the life cycle of Arabidopsis with emphasis on correlating the location of …

Identification And Characterization Of Photorhabdus Temperata Mutants Altered In Hemolysis And Virulence, Christine A. Chapman

Master's Theses and Capstones

Photorhabdus temperata is an invertebrate pathogen and nematode symbiont that is commonly used as a biological control agent in the management of commercial crop pests. The focus of this study was to investigate the poorly understood molecular elements involved in the expression of hemolysis and virulence in this bacterium. A 10,000 transposant library was screened using a blood agar plate assay to identify mutants altered in hemolytic activity. A total of 74 mutants displaying defective, delayed, or early hemolysis were identified and subsequently tested for altered virulence in the Greater Waxmoth, Galleria mellonella, using an in vitro mortality assay. Ten …