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In the Lower Rio Grande Valley of Texas, dipterous leafminers cause damage to pepper crop by destroying small plants (excessive mining), reduction of yield, and by vectoring plant diseases. The objectives of the present research were to identify leafminers species, which cause damage to peppers in South Texas, their associated parasitoid guilds and to evaluate the efficacy of abamectin, novaluron, spinetoram and lambda-cyhalothrin against leafminers as well as their effects on the parasitoid complex. Field surveys were conducted on various pepper varieties in different cities of South Texas. Insecticide evaluation was carried out on field plots in Weslaco TX using the different insecticide treatments and water. To determine the insecticides? lethal effects on adult leafminer parasitoids, Neochrysocharis formosa and Ganaspidium nigriman...

Cognitive Radio (CR) capitalizes advances in signal processing and radio technology and is capable of reconfiguring RF and switching to desired frequency bands. It is a frequency-agile data communication device that is vastly more powerful than existing multi-channel multi-radio (MC-MR) technology. In this thesis, we investigate the important problem of multi-hop networking with CR nodes. In a CR network, each node has a set of frequency bands (not necessarily of equal size) that may not be the same as those at other nodes. The uneven size of frequency bands prompts the need of further division into sub-bands for optimal spectrum sharing. We characterize behaviors and constraints for such multi-hop CR network from multiple layers, including modeling of spectrum sharing and sub-band division, scheduling and interference constraints, and...

Our studies on the synthesis and biological evaluation of novel anticancer drugs consist of three research areas; namely, synthesis of Mitogen Activated Protein (MAP) kinase inhibitors, Checkpoint (Chk1) inhibitors and nordihydroguaiaretic acid (NDGA) analogues. The first research area involved synthesis of MAP kinase inhibitors. MAP kinases are a family of serine I and threonine II kinases which can act together to generate a process of phosphorylation events within the cell signalling pathway leading eventually to cell division. The compounds made in this project were specifically designed to target the stress related kinases, a MAP kinase pathway which controls the expression of genes involved in cell proliferation. The stress related kinases are known to have serine or threonine joined to a proline III residue. In an atte...

Currently, an automatic system for full-field photoelastic stress analysis still remains susceptible due to the ambiguity problem in phase-shifting digital photoelasticity. The project therefore studies the important problem and some new techniques have been developed with the aim of building up a unified tool for photoelastic stress analysis.

The extracellular crude-proteins of Shewanella baltica OS223 showed about 50-fold higher collagenase activity compared with that of other strains in the screening. The crude-collagenases had maximal activity at 35°C and at pH7, respectively; they were activated by Sr2+ and Ca2+, and strongly inhibited by Chymostatin and EDTA-Na2. The crude-collagenases remained 80% activity after 60min incubation at 30°C and 50% activity after 25min at 40°C. S. baltica OS223, a non-pathogenic strain, grew best at room temperature with the doubling time of 1.6 h. A putative collagenase gene, encoding an extracellular zinc metalloprotease which was classified as peptidase M9A collagenase, was found in its genome. Cloning of the gene into recombinant vector for purification and large-scale production could be done in future and the characters of the colla...

Biofilms on equipment surfaces can be vectors for cross-contaminations in food processing facilities. A particular problem is that biofilms can protect pathogenic bacteria from daily cleaning and disinfection operations. In the present study, microflora were recovered from fresh-cut processing facilities, identified, and tested for biofilm forming potential. Subsequently, dual-species biofilms of selected isolates and Escherichia coli O157:H7 were investigated. Approximately 30% of the isolates were potent biofilm formers, producing large amounts of biomass. A hundred and seventeen tested isolates were identified into 23 genera, including plant related bacteria and coliforms with some opportunistic pathogens. Dual-species biofilms formed by Burkholderia caryophylli or Ralstonia insidiosa