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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.
1

Automatic segmentation and classification of multiplex-fluorescence in-situ hybridization chromosome images

Choi, Hyo Hun 28 July 2010 (has links)
Multicolor fluorescence in-situ hybridization (M-FISH) techniques provide color karyotyping that allows simultaneous analysis of numerical and structural abnormalities of whole human chromosomes. Chromosomes are stained combinatorially in M-FISH. By analyzing the intensity combinations of each pixel, all chromosome pixels in an image are classified. Often, the intensity distributions between different images are found to be considerably different and the difference becomes the source of misclassifications of the pixels. Improved pixel classification accuracy is the most important task to ensure the success of the M-FISH technique. Along with a reliable pixel classification method, automation of the karyotyping process is another important goal. The automation requires segmentation of chromosomes, which not only involves object/background separation but also involves separating touching and overlapping chromosomes. While automating the segmentation of partially occluded chromosomes is an extremely challenging problem, a pixel classification method that satisfies both high accuracy and minimum human intervention has not been realized. The main contributions of this dissertation include development of a new feature normalization method for M-FISH images that reduces the difference in the feature distributions among different images, and development of a new decomposition method for clusters of overlapping and touching chromosomes. A significant improvement was achieved in pixel classification accuracy after the new feature normalization. The overall pixel classification accuracy improved by 40% after normalization. Given a cluster, a number of hypotheses was formed utilizing the geometry of a cluster, pixel classification results, and chromosome sizes, and a hypotheis that maximized the likelihood function was chosen as the correct decomposition. Superior decomposition results were obtained using the new method compared to the previous methods. Contributions also include development of a color compensation method for combinatorially stained FISH images (including M-FISH images) based on a new signal model for multicolor/multichannel FISH images. The true signal was recovered based on the signal model after color compensation. The resulting true signal does not have color spreading (channel crosstalk) among different color channels. Two new unsupervised nonparametric classification methods for M-FISH images are also introduced in this dissertation: a fuzzy logic classifier and a template matching method (a minimum distance classifier). While both methods produce an equivalent accuracy compared to a supervised classification method, their computation time is significantly less than a Bayes classifier. Highly sophisticated and practical algorithms have been developed through this research. Using the developed methods, the amount of human intervention required will be significantly reduced: chromosomes are reliably and accurately segmented from the background, pixels are accurately classified, and clusters of overlapping and touching chromosomes are automatically decomposed. / text
2

Automatic segmentation and classification of multiplex-fluorescence in-situ hybridization chromosome images

Choi, Hyo Hun, 1973- 10 August 2011 (has links)
Not available / text
3

Genetic Characterization of Dormancy in Durum Wheat

Dilawari, Mridull January 2012 (has links)
Two populations derived by crossing LDN x LDN Dic-3A (Population I) and LDN x LDN Dic-3B (Population II) were genetically characterized for the seed dormancy present on chromosome 3A and 3B of durum wheat. The genes for seed dormancy in these two populations were contributed by the wild parent T. dicoccoides. Although the populations showed transgressive segregants for both dormant as well as nondormant parent, the populations were similar to the dormant parent at Langdon and Prosper 2006 field locations for Population I and at Langdon 2007 and Autumn greenhouse season for Population II. Genotypic and phenotypic analysis over the combined populations showed an environmental effect on expression of the trait. Different QTL were identified for both field and greenhouse season for the population derived from the cross between LDN x LDN Dic-3A. Five QTL for seed dormancy were identified on chromosome 3A for the QTL analysis performed over combined field locations. One QTL ranging between marker interval Xcfa2193 and Xcfd2a was consistently present for the 30 day period of seed germination and was also found to be linked to red grain color trait. The QTL analysis performed on the population derived from the cross between LDN x LDN Dic-3B identified only one major QTL on the long arm of chromosome 3B between the marker interval Xbarc84 and Xwmc291. This QTL was consistently present for all the field and spring greenhouse season for the seed germination period of 30 days. The QTL x E effect was also observed for this QTL, however it was very small.
4

MAD2 inactivation on chromosomal instability and tumorigenesis in prostate epithelial cells

To, Kit-wa, 杜潔華 January 2007 (has links)
published_or_final_version / abstract / Anatomy / Doctoral / Doctor of Philosophy
5

Molecular studies of homologous chromosome pairing in Triticum aestivum

Thomas, Stephen W. (Stephen William) January 1997 (has links) (PDF)
Errata pasted on front fly-leaf. Bibliography: leaves 139-173. This thesis identifies DNA structures and genes involved in the process of homologous chromosome pairing in allohexaploid bread wheat (Triticum aestivum). In addition to studying late replicating DNA, a speculative model on the action of the pairing genes in allohexaploid wheat and the putative function of the AWWM5 gene is discussed.
6

Molecular studies of homologous chromosome pairing in Triticum aestivum / by Stephen W. Thomas.

Thomas, Stephen W. (Stephen William) January 1997 (has links)
Errata pasted on front fly-leaf. / Bibliography: leaves 139-173. / iv, 173, [88] leaves, [1] leaf of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis identifies DNA structures and genes involved in the process of homologous chromosome pairing in allohexaploid bread wheat (Triticum aestivum). In addition to studying late replicating DNA, a speculative model on the action of the pairing genes in allohexaploid wheat and the putative function of the AWWM5 gene is discussed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997
7

Molecular studies of homologous chromosome pairing in Triticum aestivum / by Stephen W. Thomas.

Thomas, Stephen W. (Stephen William) January 1997 (has links)
Errata pasted on front fly-leaf. / Bibliography: leaves 139-173. / iv, 173, [88] leaves, [1] leaf of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis identifies DNA structures and genes involved in the process of homologous chromosome pairing in allohexaploid bread wheat (Triticum aestivum). In addition to studying late replicating DNA, a speculative model on the action of the pairing genes in allohexaploid wheat and the putative function of the AWWM5 gene is discussed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997
8

Localization of chromosomal regions influencing the phenotypes of the metabolic syndrome

Cai, Guowen 28 August 2008 (has links)
Not available / text
9

Cytogenetic and molecular genetic markers for chromosome 6R of rye linked to CCN resistance / by Christopher Taylor.

Taylor, Christopher, 1966- January 1996 (has links)
Includes bibliographies. / xiv, 175, [96] leaves, [17] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on the generation of molecular tools for the analysis of chromosome 6R of rye and the application of these tools in structural analysis of 6RL. Results presented include physical and genetic maps of chromosome 6RL incorporating RFLP and PCR markers and CreR, the locus conferring resistance to cereal cyst nematode (CCN). The ability to detect small introgessions of rye chromatin in wheat is demonstrated. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

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