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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

Re-descriptions of some Southern african Scyphozoa :out with the old and in with the new

Simone Neethling January 2009 (has links)
<p>Two species of Chrysaora are described from the northern Benguela ecosystem: C. fulgida and C. africana. These species can be diagnosed by a combination of morphological features including lappet and tentacle number, shape of lappets, colouration patterns (alive), shape of the proximal portion of radial septa, gastrovascular pouch shape, point of attachment of gonads and the presence or absence of small raised nematocyst warts on the exumbrellar surface. Objective, quantitative statistical analyses coupled with molecular sequence data support the qualitative morphological dissimilarity observed, as these analyses unambiguously diagnose C. fulgida and C. africana as two distinct species. There is a strong superficial resemblance between the C. fulgida material described here and the preserved specimens of C. hysoscella examined at the Natural History Museum, London. Thorough investigation does however allow the separation of these two species. Morphological features found to be dissimilar were the proximal portion of the manubrium, gastrovascular pouch shape and the presence or absence of sperm sacs. Objective, quantitative statistical analyses support these findings. Nuclear sequence variation suggests considerable divergence between the two species but additional molecular work is needed.</p>
2

Re-descriptions of some Southern african Scyphozoa :out with the old and in with the new

Simone Neethling January 2009 (has links)
<p>Two species of Chrysaora are described from the northern Benguela ecosystem: C. fulgida and C. africana. These species can be diagnosed by a combination of morphological features including lappet and tentacle number, shape of lappets, colouration patterns (alive), shape of the proximal portion of radial septa, gastrovascular pouch shape, point of attachment of gonads and the presence or absence of small raised nematocyst warts on the exumbrellar surface. Objective, quantitative statistical analyses coupled with molecular sequence data support the qualitative morphological dissimilarity observed, as these analyses unambiguously diagnose C. fulgida and C. africana as two distinct species. There is a strong superficial resemblance between the C. fulgida material described here and the preserved specimens of C. hysoscella examined at the Natural History Museum, London. Thorough investigation does however allow the separation of these two species. Morphological features found to be dissimilar were the proximal portion of the manubrium, gastrovascular pouch shape and the presence or absence of sperm sacs. Objective, quantitative statistical analyses support these findings. Nuclear sequence variation suggests considerable divergence between the two species but additional molecular work is needed.</p>
3

Re-descriptions of some Southern african Scyphozoa: out with the old and in with the new

Neethling, Simone January 2009 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) / Two species of Chrysaora are described from the northern Benguela ecosystem: C. fulgida and C. africana. These species can be diagnosed by a combination of morphological features including lappet and tentacle number, shape of lappets, colouration patterns (alive), shape of the proximal portion of radial septa, gastrovascular pouch shape, point of attachment of gonads and the presence or absence of small raised nematocyst warts on the exumbrellar surface. Objective, quantitative statistical analyses coupled with molecular sequence data support the qualitative morphological dissimilarity observed, as these analyses unambiguously diagnose C. fulgida and C. africana as two distinct species. There is a strong superficial resemblance between the C. fulgida material described here and the preserved specimens of C. hysoscella examined at the Natural History Museum, London. Thorough investigation does however allow the separation of these two species. Morphological features found to be dissimilar were the proximal portion of the manubrium, gastrovascular pouch shape and the presence or absence of sperm sacs. Objective, quantitative statistical analyses support these findings. Nuclear sequence variation suggests considerable divergence between the two species but additional molecular work is needed. / South Africa
4

Re-descriptions of some southern African Scyphozoa: out with the old and in with the new

Neethling, Simone January 2009 (has links)
>Magister Scientiae - MSc / Two species of Chrysaora are described from the northern Benguela ecosystem: C. fulgida and C. africana. These species can be diagnosed by a combination of morphological features including lappet and tentacle number, shape oflappets, colouration patterns (alive), shape of the proximal portion of radial septa, gastrovascular pouch shape, point of attachment of gonads and the presence or absence of small raised nematocyst warts on the exumbrellar surface. Objective, quantitative statistical analyses coupled with molecular sequence data support the qualitative morphological dissimilarity observed, as these analyses unambiguously diagnose C. fulgida and C. africana as two distinct species. There is a strong superficial resemblance between the C. fulgida material described here and the preserved specimens of C. hysoscella examined at the Natural History Museum, London. Thorough investigation does however allow the separation of these two species. morphological features found to be dissimilar were the proximal portion of the manubrium, gastrovascular pouch shape and the presence or absence of sperm sacs. Objective, quantitative statistical analyses support these findings. Nuclear sequence variation suggests considerable divergence between the two species but additional molecular work is needed.
5

Biosensor Platforms for Molecular Analyses of Circulating Cancer Biomarkers

Shao, Huilin January 2013 (has links)
Solid cancers often shed (sub)cellular materials into the circulation, such as circulating tumor cells and extracellular microvesicles. Mounting evidence supports that these circulating materials could serve as surrogate cancer markers for classifying primary tumors, stratifying patients for targeted therapies, assessing treatment efficacy, and achieving clinical benefits. A sensor platform capable of sensitive and portable detection of circulating cancer markers would thus be an invaluable tool, that will advance our understanding of tumor biology as well as clinical outcomes. This dissertation describes various systems that we have developed for quantitative analyses of circulating cancer biomarkers. Firstly, we have developed a novel magnetic resonance sensing platform for microvesicle analyses. By using a chip-based platform that combines microfiltration and bioorthogonal nanoparticle targeting, we demonstrate for the first time that magnetic biosensing can be applied for clinical evaluation of circulating microvesicles in blood samples to monitor cancer therapy. Secondly, we have advanced a new plasmonic sensor to achieve label-free detection of microvesicles. Based on periodic nanohole arrays, this platform has been applied for high-throughput protein profiling of microvesicles in native ascites. Finally, we have implemented microfluidic devices to effectively enrich circulating tumor cells from peripheral whole blood, and to enable comprehensive molecular analyses of isolated tumor cells at a single cell resolution. By enabling rapid, sensitive and cost-effective detection of circulating cancer markers, these developed platforms could significantly expand the reach of preclinical and clinical cancer research, in informing therapy selection, rationally directing trials, and improving sequential monitoring to achieve better clinical outcomes.
6

Comparisons biological, and molecular serology between isolated from Cowpea aphid-borne mosaic virus, resistance source for identification and virus interactions between species in Vigna unguiculata / ComparaÃÃes biolÃgicas, sorolÃgicas e moleculares entre isolados de Cowpea aphid-borne mosaic virus, identificaÃÃo de fonte de resistÃncia e interaÃÃes entre espÃcies de vÃrus em Vigna unguiculata

Laianny Morais Maia 30 January 2015 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Passion fruit (Passiflora edulis) and cowpea (Vigna unguiculata) are important crops of economical impact for the Northeast of Brazil. Fruit woodiness is an important virus disease of passion fruit, caused by Passionfruit woodiness virus (PWV) and Cowpea aphid-borne mosaic virus (CABMV), both from the genus Potyvirus. CABMV is also responsible for important disease on cowpea. The present research had the objective to study and compare the biological, serological and molecular properties of isolates of CABMV obtained from passion fruit (CABMV-P Pet, CABMV-P Gua, CABMV-P Sb and CABMV-P Uba) and from cowpea (CABMV-C Fort and CABMV-C Bv). CABMV-C Fort and CABMV-C Bv were purified from infected cowpea cv. Pitiuba systemically infected. The obtained purified preparations presented concentrations of 16.4 mg of virus per mL (CABMV-C Bv) and 15.9 mg of virus per mL (CABMV-C Fort). Both purified virus preparations were used for rabbit immunizations to produce polyclonal antisera with reactive titers of 1:128.000 in PTA-ELISA. Electrophoresis analyses of the virus purified preparations revealed the presence of only one capsidial protein with molecular weight of 34 kDa for both virus isolates. Parts of the genomes, corresponding to the coat protein gene (cp), from the virus isolates obtained from cowpea and from passion fruit were amplified by RT-PCR. The philogenetic analyses of the amplified cDNA fragments grouped with the CABMV isolates sequences deposited in the GenBank, according to their original host. Based on the biological, serological and molecular results, the virus isolates studied were classified into two biotypes: Biotype Cowpea (CABMV-C) including CABMV-C Bv and CABMV-C Fort obtained from cowpea, and biotype Passion fruit (CABMV-P) including CABMV-P Pet, CABMV-P Gua, CABMV-P Sb and CABMV-P Uba obtained from passion fruit. Source of immunity to CABMV-C Bv and CABMV-C Fort was identified in cowpea and the genotype was designate Lab-Poty. Studies of virus interaction in cowpea demonstrated strong synergistic effect among CABMV-C, Cucumber mosaic virus (CMV) and Cowpea severe mosaic virus (CPSMV). / O maracujazeiro (Passiflora edulis) e o feijoeiro caupi (Vigna unguiculata) sÃo culturas de elevada importÃncia econÃmica para o Nordeste brasileiro. Entre as viroses que se manifestam no maracujazeiro, destaca-se o endurecimento dos frutos causado por Passionfruit woodiness virus (PWV) e Cowpea aphid-borne mosaic virus (CABMV), ambos pertencentes ao gÃnero Potyvirus, sendo o CABMV responsÃvel por importante doenÃa do feijoeiro caupi. A presente pesquisa teve como objetivo estudar e comparar as propriedades biolÃgicas, sorolÃgicas e moleculares de isolados de CABMV obtidos de maracujazeiro (CABMV-P Pet, CABMV-P Gua, CABMV-P Sb e CABMV-P Uba) e isolados obtidos de feijoeiro caupi (CABMV-C Fort e CABMV-C Bv). Os isolados CABMV-C Fort e CABMV-C Bv foram purificados a partir de plantas de feijoeiro caupi cv. Pitiuba sistemicamente infetadas. As preparaÃÃes purificadas obtidas apresentaram concentraÃÃes de 16,4 mg de vÃrus por mL (CABMV-C Bv) e 15, 9 mg de vÃrus por mL (CABMV-C Fort), as quais foram usadas na imunizaÃÃo de coelhos, para a produÃÃo de antissoros policlonais, com tÃtulo de 1:128.000 em PTA-ELISA. AnÃlises eletroforÃtica das preparaÃÃes virais revelaram uma Ãnica proteÃna capisidial com peso molecular de 34 kDa. Partes do genoma correspondente ao gene da capa protÃica (cp) dos isolados virais obtidos de feijoeiro caupi e de maracujazeiro foram amplificadas por RT-PCR. AnÃlises filogenÃticas dos fragmentos dos cDNA amplificados se agruparam com sequencias de isolados do CABMV depositadas no GenBank, de acordo com os hospedeiros originais. Com base nos resultados de estudos biolÃgicos, sorolÃgicos e moleculares, os isolados virais estudados foram classificados em dois biÃtipos: BiÃtipo Cowpea (CABMV-C) incluindo CABMV-C Bv and CABMV-C Fort obtidos de feijoeiro caupi e biÃtipo Passion fruit (CABMV-P) incluindo CABMV-P Pet, CABMV-P Gua, CABMV-P Sb e CABMV-P Uba obtidos de maracujazeiro. Fontes de imunidade a CABMV-C Bv e CABMV-C Fort foi identificada em feijoeiro caupi e o genÃtipo foi designado de Lab-Poty. Estudos de interaÃÃo viral em feijoeiro caupi, mostraram forte sinergismo entre CABMV-C, Cucumber mosaic virus (CMV) e Cowpea severe mosaic virus (CPSMV).
7

Riqueza e diversidade de fungos micorrízicos arbusculares em agrossistemas com milho, no Nordeste do Brasil

MELLO, Catarina Maria Aragão de 29 May 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-20T11:44:47Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Catarina Maria Aragao de Mello.pdf: 5575765 bytes, checksum: b3c4ea02e6cc1d75d2d5ecf461a8b707 (MD5) / Made available in DSpace on 2017-07-20T11:44:47Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Catarina Maria Aragao de Mello.pdf: 5575765 bytes, checksum: b3c4ea02e6cc1d75d2d5ecf461a8b707 (MD5) Previous issue date: 2015-05-29 / FACEPE / O conhecimento da diversidade de fungos micorrízicos arbusculares em raízes de plantas cultivadas é um pré-requisito para o manejo efetivo e a sustentabilidade de sistemas agrícolas. O objetivo deste trabalho foi determinar qualitativa e quantitativamente as comunidades de FMA em agrossistemas plantados com milho, em Pernambuco. Na primeira etapa do trabalho foram realizadas coletas em três estações experimentais do Instituto Agronômico de Pernambuco: uma localizada em área úmida (Zona da Mata - Itambé) e duas no semiárido (Agreste – Caruaru; Sertão - Serra Talhada) em 2010 e 2011. A análise morfológica dos esporos permitiu a diferenciação de 57 espécies de FMA, das quais duas novas para a ciência. Maior densidade de esporos ocorreu na área do agreste, que apresentou menor riqueza de espécies de FMA. Na área mais úmida foi registrada maior riqueza. A estrutura das comunidades de FMA diferiu entre os locais, segundo o teste de procedimento de permutação multi-resposta (MRPP), em função de diferenças nos atributos químicos e granulométricos dos solos. Duas novas espécies foram descritas: Fuscutata aurea, registrada em Itambé e Paraglomus pernambucanum, encontrada em amostras coletadas em Caruaru e Serra Talhada. Foi proposta uma nova combinação para Paraglomus (P. bolivianum) e revisada a ocorrência mundial dos representantes de Paraglomus e Pacispora. Na segunda etapa do estudo (2012) foram realizadas coletas em três propriedades privadas irrigadas, localizadas também nas Zonas da Mata, Agreste e Sertão, respectivamente nos municípios de Igarassu, Passira e Serra Talhada, em dois períodos de desenvolvimento do milho (60 – floração e 90 dias – colheita). A análise morfológica dos esporos revelou a presença de 43 espécies de FMA. Também foram realizadas análises moleculares da raiz, sendo sequenciados 433 clones do SSU rDNA, dos quais 93 pertencentes a indivíduos das ordens Diversisporales, Gigasporales, Glomerales e Paraglomerales. Dentre os 259 clones do LSU rDNA, 153 corresponderam a gêneros incluídos em Diversisporales, Gigasporales e Glomerales. Os demais clones foram relacionados a outros grupos de eucariotas. Em todas as áreas predominaram representantes de Acaulospora e Glomus. Houve diferença significativa entre as áreas para a maioria dos atributos químicos e composição granulométrica dos solos. A estrutura das comunidades de FMA foi significativamente diferente entre as áreas, de acordo com a ordenação (NMS) e o método estatístico (PERMANOVA). A maior porcentagem de raiz colonizada ocorreu em plantas coletadas em Igarassu (Mata), enquanto a maior riqueza de espécies foi encontrada em solos de Passira (Agreste). A diversidade de FMA no solo difere daquela encontrada no sistema radicular de plantas colonizadas. Representantes dos gêneros Claroideoglomus, Diversispora, Dominikia, Intraornatospora, Redeckera e Rhizoglomus não foram identificados no solo rizosférico, enquanto Ambispora e Paradentiscutata foram observados apenas a partir da análise morfológica dos esporos presentes no solo, não sendo obtidas sequências desses gêneros. A rizosfera de plantios de milho, mesmo em áreas com diferentes características edafoclimáticas, abriga diversificada comunidade de FMA, com dominância dos gêneros Glomus e Acaulospora. O estádio fenológico do milho pode influenciar a diversidade, e a composição das comunidades de FMA pode ser melhor determinada com o uso conjunto de ferramentas moleculares e morfológicas para identificação dos fungos. / The effective management and sustainability of agricultural systems depends on the knowledge of the diversity of AMF in roots of cultivated plant. The aim of this study was to determine qualitatively and quantitatively the AMF communities in corn agrosystems, in Pernambuco, Northeast Brazil. In the first stage of this work collections were carried out in three experimental stations of the Agronomic Institute of Pernambuco: one located in an Atlantic rain forest area (Forest Zone - Itambé) and two in semiarid areas ("Agreste" - Caruaru and "Sertão" - Serra Talhada), in 2010 and 2011. Fifty seven taxa were found, two of which are new species. In the “agreste” area we found higher number of spores and lower richness of AMF species. The highest species richness was registered in the most humid area. The structure of the AMF communities differed among the sites, according to the multi-response permutation procedure test (MRPP), due to differences in chemical and physical soil attributes. The new species described are: Fuscutata aurea, registered in Itambé (humid area) and Paraglomus pernambucanum found in samples from the semiarid areas. A new combination for Paraglomus (P. bolivianum) was proposed, and a survey of the global occurrence of Paraglomus and Pacispora was performed. In the second stage of this study (2012), samples were taken in three private properties, with irrigated fields of corn also located in the three areas: rain Forest (Igarassu), "Agreste" (Passira) and "Sertão" (Serra Talhada). The collections were performed in two periods of corn development (60 days – flowering, and 90 days - harvest). The morphological analysis revealed the presence of 43 AMF taxa. Molecular root analyses were performed, and 433 clones sequenced (SSU rDNA), of which 93 belonged to individuals of the orders Diversisporales, Gigasporales, Glomerales and Paraglomerales. Among the 259 clones of the LSU rDNA, 153 corresponded to genera included in Diversisporales, Gigasporales and Glomerales. The remaining clones were related to other eukaryotic groups. Species of Acaulospora and Glomus predominated in the areas. Significant differences among the areas for most chemical and physical soil attributes were found. The structure of the AMF communities was significantly different among the areas, according to the ordination (NMS) and the statistical method (PERMANOVA). The highest percentage of root colonization occurred in plants collected in Igarassu (Forest), while the highest species richness was found in Passira soils (Agreste). The diversity of AMF in the soil differs from that found in the root system of colonized plants. The genera Claroideoglomus, Diversispora, Dominikia, Intraornatospora, Redeckera and Rhizoglomus were only detected through molecular analysis, while Ambispora and Paradentiscutata were observed just from morphological analysis. The rhizosphere of corn crops in areas with different soil and climatic characteristics has a diverse community of AMF, with dominance of Glomus and Acaulospora species. The growth stage of corn plants can influence the diversity of AMF fungi, which decreased in the rhizosphere of older plants. The simultaneous use of morphological and molecular approaches can improve the knowledge about the composition of AMF communities.

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