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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Genetic variation in the eastern subterranean termite Reticulitermes flavipes (Isoptera: Rhinotermitidae)

Benavides, Lucille H 2004 (has links)
The eastern subterranean termite, Reticulitermes flavipes, is the most widely dispersed termite in North America. The genus Reticulitermes spp. is responsible for 80% of total termite damage caused to urban structures each year. Little is known about the genetic structure of termites, particularly at the colony level. Evidence for what genetically defines a termite colony is a hotly debated topic in current literature due to the implications such findings would have regarding current lawsuits against pest control operations. Information on termite genetic structure is sparse. In this study, the genetic variation and gene flow among Texas populations of R. flavipes at the statewide level and city level was examined. A 324-337 base pairs segment of the mtDNA, AT-rich region was a polymerase chain reaction amplified from 104 different termite specimens from 12 Texas cities. The DNA extracts were then subjected to PCR amplification using specific primers and it was then sequenced. Using the sequence data and appropriate statistical measures it was found that, at the statewide level, nucleotide and haplotypic diversity is low. Gene flow was found to be low on a statewide basis. At the city level nucleotide and haplotypic diversity was high. The findings of this study provide insights into termite genetic structure.

Genetics of song and female preference in the grasshopper Chorthippus brunneus (Orthoptera: acridae) : sexual selection and the mate recognition system

Charalambous, Magda 1990 (has links)
No description available.

Variability in sexual and apomictic Taraxacum Weber

Hughes, J. 1987 (has links)
No description available.

The genetical and past social structure of human populations on the Plain of Holderness

Hicks, C. J. 1985 (has links)
No description available.

Molecular evolution in a hybrid zone

Dallas, J. F. 1985 (has links)
No description available.

Molecular biology of the human G 6-PD gene

Foulkes, Nicholas F. 1989 (has links)
No description available.

Population genetic variation of cultured oyster Crassostrea spp. in Taiwan and neighborhood

Yu, Cheng-Pin 10 September 2002 (has links)
Population genetic variation of cultured oyster Crassostrea spp. in Taiwan and neighborhood Cheng-Pin Yu ¡]Advisor¡GDr. Jin-Hua Cheng¡^ Institute of Marine Biology, National Sun Yat-sen University, Kaohsuang 804 Taiwan R.O.C. Thesis Abstract The genetic variations among oyster populations of Taiwan, Ginmen and Fu-kein coast are analyzed using molecular method. Firstly, DNA sequences of mitochondrial 16S rRNA and COI genes are analyzed according to nucleotide differences and restriction enzyme recognition site. Then, population variations were analyzed by the lane pattern of restriction enzyme fragment¡]RFLP¡^. The sequences of 530 bp DNA fragment of 16S rRNA gene showed little difference¡]0-1 bp¡^between Portuguese oyster and oyster cultured in Taiwan, both have larger differences¡]3-4 bp¡^compared with C. gigas. The sequences of 700 bp DNA fragment of COI gene showed similar results. C. angulata is found in Ginmen and Fu-kein coast for the first time which is identified by the PCR-RFLP of COI gene fragment. PCR-RFLP analysis of COI gene fragment showed C. angulata from Portugal are genetically closest to the oysters collected from Ginmen and Fu-kein.

Breeding maize for stress tolerance

Khan, Asif Ali 1999 (has links)
No description available.

Variation in Thamnocortus insignis - genetically and environmentally plastic?

Mgidi, Theresa Nobuhle 1999 (has links)
Environmental variation of Thamnocortus insignis Mast. (Restionaceae) is presented, by using average dry weight measurements of six populations of this species found along the coast of the Cape Province. The dry weight measurements were used to detect variation in the growth rates of the six populations, which in tum indicates the environmental variation among the populations. The results were showed no significant difference between all six populations and this was due to the relatively very small sizes of the seedlings when the measurements were taken. Genetic variation was investigated by using isozyme electrophoresis of the EST locus. One population (Puntjie) showed significant deviation from the Hardy-Weinberg equilibrium, whilst all the others agreed with the assumptions of the model except for the Superthatch-extra tall population, which was homologous. Estimation of allelic diversity among the populations produced a Fst of 0.098 that implies that there is a high level of gene flow among the six populations of the species. The allelic diversity estimate within populations was also very low (Fis = 0.079) implying that the genetic neighbourhoods are relatively large and there is a high incidence of gene flow within the populations. Both estimation results support the predicted results for dioecious wind-pollinated species such as T. insignis.

A regression modeling approach for describing patterns of HIV genetic variation

Hamblett, Nicole Mayer. 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. Vita. Includes bibliographical references (p. 121-128).

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