No description available.

No description available.

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Tracy DeLiberty, Dept. of Geography. Includes bibliographical references.

Various strains of Bacillus thuringiensis Mt.) produce crystalline endotoxins specific for larvae of different insect classes. Two strains, B.t. subspp. israelensis and kurstaki produce similar 130 kDa toxins encoded by the CryIVB gene (toxic to Diptera) and the CryIA gene (toxic to Lepidoptera), respectively. The N-terminal region of the CryIVB gene was cloned into the Escherichia coli expression vector pKX223-3. A mosquitocidal transformant was obtained as determined by mosquito bioassays. The gene fragment, if stable, can be cloned into cyanobacteria to achieve biological control of mosquito-borne diseases. A second goal was to identify the binding specificity domain of the CryIVB gene which encodes the portion of the protein toxin that binds the insect midgut causing cell lysis and death. Two potential insect binding specificity domains identified by computer analyses were switched with a known binding specificity region of the CryIA gene. The polymerase chain reaction was utilized to obtain gene fragments of the CryIVB gene which replaced the CryIA gene binding specificity domain. The resulting recombinant clones carrying the CryIA gene containing the .000nd proposed insect binding specificity domain of the CryIVB gene were fotsd to be mosquitocidal. / Department of Biology

The ultimate goal of this research was to perform a domain exchange between a computer identified insect specificity region of the mosquito larvicidal protein Cry IVB and a previously identified domain in a related protein toxin which targets lepidopteran insect larvae. If the insect specificity domain has been correctly identified, an exchange of DNA in this manner transfers the toxicity of one peptide to another by an exchange of the insect specificity domains. New, chimeric peptides may be designed which will target a larger spectrum of insect larvae.In previous research a domain exchange was performed between the two genes carried on plasmid vectors in E. coli and low levels of toxicity to mosquito larvae were observed. Initial efforts of this research attempted to identify these recombinants. However, stability was not achieved by sequential colony screens. Furthermore, a recently published three-dimensional structural model for all the B. thuringiensis crystalline toxins became available and it was quickly determined that the first exchanges excluded most of the f3-sheet domain that is responsible for insect cell receptor binding, the feature that gives the toxins their specificity. Therefore, it was decided that a larger, more inclusive region of Cry IVB DNA must be exchanged between the two toxins.Extensive computer analyses of the Cry IVB sequence and retroactive comparison of these sequences to the three-dimensional model yielded a fragment of DNA that encoded more than 60% of the putative insect specificity domain. Oligonucleotide primers were subsequently designed to flank this region so that the polymerase chain reaction could be employed to amplify the region. Additionally, the primers were engineered to contain terminal restriction endonuclease sites to ease in the exchange of the domain encoding region into Cry IA(c). The region of Cry IVB DNA flanked by the oligonucleotide primers was successfully amplified by the PCR and cloned into the plasmid vector pUC 19 as a reservoir for a future domain exchange. / Department of Biology

Thesis (Ph. D.)--Illinois State University, 2007. / Title from title page screen, viewed on February 11, 2008. Dissertation Committee: Steven A. Juliano (chair), Diane L. Byers, L. Philip Lounibos, Charles F. Thompson, William L. Perry. Includes bibliographical references (leaves 152-163) and abstract. Also available in print.

Thesis (M.S.)--Humboldt State University, 2008. / Includes bibliographical references (leaves 63-68). Also available via Humboldt Digital Scholar.

Thesis (Ph. D. in Neuroscience)--Vanderbilt University, May 2008. / Title from title screen. Includes bibliographical references.

Thesis (ph.D.) - University of Queensland, 2004. / Includes bibliography.

Twenty-six of the 49 mosquito species reported from Virginia were collected in James City County, Virginia during 1985 and 1986. The most abundant species were Psorophora columbiae, Anopheles quadrimaculatus, and Culex species. P. columbiae accounted for 50% and 16% of the light trap collections in 1985 and 1986, respectively. The most predominant mosquitoes collected during 1986 were Culex species. Mosquitoes had an impact on the amount of time residents and campers spent outdoors. Forty-seven percent of the residents and 28% of the campers surveyed had their time outdoors limited by mosquitoes. There was no significant association between the area where the respondent was brought up as a child and their perception of the mosquito problem. No economic impact could be attributed to mosquitoes but the benefits the county's residents received from the mosquito control program annually was estimated to exceed the programs costs by two times. The human tolerance level for mosquito bites was determined to be 5 per night. James City County could adopt and benefit from an integrated mosquito management program. The components of the program are seasonal monitoring of mosquito populations, periodic public attitude surveys, public education programs, physical, chemical, and biological control tactics, and periodic program evaluation. / Master of Science