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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.
211

Expression and function of cucumoviral genomes / by Bu-Jun Shi.

Shi, Bu-Jun January 1997 (has links)
Bibliography: leaves 104-130. / vi, 130, [25] leaves, [13] 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. / The aim of this thesis is to characterise subgenomic RNAs of cucumoviruses and the functions of their encoding genes. Strains of cucumber mosaic virus (CMV) are classified into two major subgroups (I and II) on the basis of nucleotide sequence homology. The V strain of tomato aspermy virus (V-TAV) and a subgroup I CMV strain (WAII) are chosen to determine whether the 2b genes encoded by these viruses are expressed 'in vivo'. For further investigation of the 2b gene function, cDNA clones of three genomic RNAs of V-TAV are constructed. Using the infectious cDNA clones of V-TAV, a mutant virus containing only one of the two repeats is constructed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997
212

Molecular characterisation of Mycoplasma mycoides subsp. mycoides SC /

Persson, Anja M., January 2002 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.
213

A complex of begomoviruses affecting tomato crops in Nicaragua /

Rojas, Aldo, January 2004 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.
214

Expression and function of cucumoviral genomes /

Shi, Bu-Jun. January 1997 (has links) (PDF)
Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997. / Bibliography: leaves 104-130.
215

Discovery and complete genome sequence of a novel group of coronavirus

Lam, Suk-fun, January 2008 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 83-101) Also available in print.
216

Discovery and complete genome sequence of a novel group of coronavirus /

Lam, Suk-fun, January 2008 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 83-101) Also available online.
217

The mechanism of action of cidofovir and (S)-9-(3-hydroxy-2-phosphonomethoxypropyl) adenine against viral polymerases

Magee, Wendy Colleen. January 2009 (has links)
Thesis (Ph.D.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Sept. 18, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Virology, Medical Microbiology and Immunology, University of Alberta." Includes bibliographical references.
218

Targeted organelle genome assembly and heteroplamsy detection

Dierckxsens, Nicolas 16 October 2018 (has links)
Thanks to the development of next-generation sequencing (NGS) technology, whole genome data can be readily obtained from a variety of samples. Since the massive increase in available sequencing data, the development of efficient assembly algorithms has become the new bottleneck. Almost every new released tool is based on the De Brujin graph method, which focuses on assembling complete datasets with mathematical models. Although the decreasing sequencing costs made whole genome sequencing (WGS) the most straightforward and least laborious approach of gathering sequencing data, many research projects are only interested in the extranuclear genomes. Unfortunately, few of the available tools are specifically designed to efficiently retrieve these extranuclear genomes from WGS datasets. We developed a seed-and-extend algorithm that assembles organelle circular genomes from WGS data, starting from a single short seed sequence. The algorithm has been tested on several new (Gonioctena intermedia and Avicennia marina) and public (Arabidopsis thaliana and Oryza sativa) whole genome Illumina datasets and always outperformed other assemblers in assembly accuracy and contiguity. In our benchmark, NOVOPlasty assembled all genomes in less than 30 minutes with a maximum RAM memory requirement of 16 GB. NOVOPlasty is the only de novo assembler that provides a fast and straightforward manner to extract the extranuclear sequences from WGS data and generates one circular high quality contig.Heteroplasmy, the existence of multiple mitochondrial haplotypes within an individual, has been researched across different fields. Mitochondrial genome polymorphisms have been linked to multiple severe disorders and are of interest to evolutionary studies and forensic science. By utilizing ultra-deep sequencing, it is now possible to uncover previously undiscovered patterns of intra-individual polymorphism. However, it remains challenging to determine its source. Current available software can detect polymorphic sites but are not capable of determining the link between them. We therefore developed a new method to not only detect intra-individual polymorphisms within mitochondrial and chloroplast genomes, but also to look for linkage among polymorphic sites by assembling the sequence around each detected polymorphic site. Our benchmark study shows that this method can detect heteroplasmy more accurately than any method previously available and is the first tool that is able to completely or partially reconstruct the origin sequences for each intra-individual polymorphism. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
219

Análise ampla do genoma para detecção de erros de montagem no genoma de referência bovino e para detecção de locos relacionados a características de produção e reprodução da raça GIR

Utsunomiya, Adam Taiti Harth [UNESP] 11 March 2015 (has links) (PDF)
Made available in DSpace on 2015-09-17T15:25:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-11. Added 1 bitstream(s) on 2015-09-17T15:46:47Z : No. of bitstreams: 1 000845533.pdf: 2245393 bytes, checksum: 5278ffe65b8b2c74810887e8684ffc07 (MD5) / A base genética que rege os processos fisiológicos para expressão dos fenótipos de produção de leite ainda não está completamente compreendida, pois poucos genes causais ou marcadores associados com a variação na expressão desses fenótipos foram relatados e espera-se que mais genes estejam envolvidos. Com o surgimento da era genômica, os esforços para identificar polimorfismos de sítio único (Single Nucleotide Polymorphisms - SNPs) foram expressivos. Os SNPs permitem estabelecer uma forte relação entre a expressão de características economicamente importantes e regiões específicas do genoma de um indivíduo. Tal relação é confirmada por estudos de associação ampla do genoma (GWAS), gerando conhecimento a cerca dos genes e fragmentos cromossômicos ligados a características importantes, os quais são posteriormente explorados na biologia dos sistemas. Qualquer inferência acerca de segmentos cromossômicos que possam estar associados a fenótipos de interesse utiliza uma montagem de um genoma de referência, onde todos os genes estão ancorados. Porém, o processo de montagem de um genoma é complexo e erros quanto ao posicionamento de sequências são esperados. Desta forma, este trabalho propõe avaliar a montagem de referência do genoma bovino produzido pelo grupo de pesquisa da universidade de Maryland e a aplicação do GWAS na raça Gir (Bos indicus) aos fenótipos de produção de leite, proteína e gordura, porcentagem de proteína e gordura e idade ao primeito parto, com o intuito de identificar regiões cromossômicas que possam estar relacionadas com aspectos importantes da produção de leite e fertilidade, contribuindo para a melhor compreensão dos fenômenos que regem tais aspectos / The genetic basis of physiological processes underlying milk production traits are not completely understood, and few causal genes and markers associated with these traits have been reported to date. The emergence of the genomics era, efforts for the discovery of single nucleotide polymorphisms (SNPs) are numerous. These markers allow for establishing relationships between differences in economically important traits and specific genomic coordinates. These relationships are confirmed in genome-wide association studies (GWAS), which provide knowledge about genes and chromosomal segments affecting traits of interest that can be further explored in systems biology. Inferences about genomic localtions that are potentially implicated in phenotypic differences rely on a reference genome assembly where genes are annotated. However, genome assembly is a complex task that is prone to errors, and cases of wrong positioning of nucleotide sequences are not rare. Therefore, this thesis aimed at assessing candidate misassembled regions in the reference bovine genome assembly and performing a GWAS for milk traits in Gir cattle (Bos indicus), including milk, protein and fat yield, percentage of protein and fat, and age at first calving, targeting the identication of genomic regions that are potentially related to important aspects of fertility and milk production
220

Construção de filogenias baseadas em genomas completos / Phylogenies construction based on whole genomes

Oliveira, Karina Zupo de 03 May 2010 (has links)
Orientador: João Meidanis / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T11:01:22Z (GMT). No. of bitstreams: 1 Oliveira_KarinaZupode_M.pdf: 15064313 bytes, checksum: a46cd0b3c6eebcfc48b81920aa2232db (MD5) Previous issue date: 2010 / Resumo: Contexto: A classificação de espécies começou sendo determinada pelas características fenotípicas dos organismos. Logo que o DNA foi descoberto, o sistema de classificação passou também a utilizar-se das características genotípicas. Ao longo dos últimos anos, avanços científicos permitiram que fossem sequenciados genomas completos. A cada ano, o número de genomas completamente sequenciados aumenta, e, com isso, é cada vez maior o número de trabalhos que tentam utilizar-se do maior número possível de genes para comparar dois ou mais organismos com o objetivo de melhor entender o relacionamento entre as diversas espécies. Experimento: Este trabalho executa comparações de pares de cromossomos de um grupo de 10 genomas completos da família Vibrionaceae e um genoma completo da bactéria Escherichia coli como externo ao grupo. As homologias entre as proteínas são determinadas através da base de famílias Protein Clusters (NCBI). A seguir, arvores ultramétricas e a classificação COG das proteínas são utilizadas para resolver as paralogias correspondentes. Após isto, as proteínas únicas, que representam os eventos de perda e ganho de genes, são eliminadas, de forma a igualar o conteúdo dos cromossomos. Tipicamente, 50% das proteínas originais do pares de organismos de mesma família 'sobrevivem" para serem utilizadas no cálculo da distância de rearranjo. Menos proteínas sobrevivem nas comparações com a bactéria externa ao grupo. A distância total é calculada pela soma do número de proteínas eliminadas e da distância de ordenação, medida através da distância de rearranjo dos cromossomos. Resultados: As comparações produziram matrizes de distâncias utilizadas para inferir árvores filogenéticas através do algoritmo Neighbor-Joining (NJ). As árvores filogenéticas encontradas mostraram-se congruentes em topologia com a árvore produzida pelo gene 16S rRNA. Isto mostra que a comparação de genomas completos é uma proposta sensata. Os desafios agora são aperfeiçoar os detalhes. O material suplementar (Apêndice A) contém uma implementação computacional dos experimentos / Abstract: Context: Species classification was originally determined by phenotypic characteristics. With the advent of DNA sequencing, the classification system started using genotypes as well. Over the last decades, scientific progress allowed complete sequencing of genomes. Each year, the number of genomes completely sequenced increases, and with it, the number of works trying to use as much genes as possible to compare two or more organisms, in order to get a better understand of the relationship between several species. Experiment: This work executes a pairwise chromosome comparison from a set of 10 complete genomes from the Vibrionaceae family and one complete Escherichia coli genome as an outgroup. In our experiment, the homologies between proteins are assessed using the Protein Clusters (NCBI) database. In the next step, paralogies are resolved using ultrametric trees and COG classification. In the sequel, the loss and gain events are treated, thus, proteins present in only one chromosome from the pair are eliminated, in order to equalize the set of families in both chromosomes. Typically, 50% of the original proteins survive in comparisons between organisms of the same family (comparisons with the outgroup yield less survivors). The total distance is calculated by adding the number of eliminated proteins with the order distance, which is measured by the rearrangement distance beetween the chromosomes. Results: Genome comparison produces distance matrices used to infer the phylogenetic trees through the Neighbor-Joining (NJ) algorithm. The phylogenetic trees generated are congruent regarding the topology with the tree inferred using the 16S rRNA gene. Also, in order to run a deeper investigation, the experiment was executed with some variations such as not resolving the paralogies using ultrametric trees or only classifying proteins using COG database. Supplemental material (Appendix A) contains the experiment computational implementation / Mestrado / Biologia Computaçional / Mestre em Ciência da Computação

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