• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 917
  • 192
  • 31
  • 20
  • 18
  • 13
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 1279
  • 547
  • 237
  • 157
  • 154
  • 149
  • 134
  • 129
  • 118
  • 118
  • 105
  • 99
  • 77
  • 76
  • 69
  • 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.
71

Seleção e avaliação de genes de referência para estudos de expressão gênica em Eucalyptus

Bastolla, Fernanda Macedo January 2007 (has links)
Um dos principais avanços da era pós-genômica consiste na possibilidade da análise da expressão global de genes pela tecnologia de microarranjos de DNA, a qual permite a investigação simultânea do perfil de transcrição de milhares de genes. Com os microarranjos, tornou-se possível comparar os padrões de expressão entre indivíduos de diferentes espécies, de diferentes órgãos/tecidos dentro de uma mesma espécie ou diferentes tecidos submetidos a várias situações e tratamentos e, ainda, analisar os genes de proteínas potencialmente reguladoras da transcrição, os fatores de transcrição. Uma etapa fundamental após a análise dos resultados dos microarranjos consiste na validação experimental dos dados de expressão gênica. Esta validação é realizada pela utilização da técnica de qRT-PCR (“Real Time Quantitative RT-PCR”) um método que, atualmente, apresenta maior sensibilidade e especificidade na análise de transcritos. A qRT-PCR necessita, entretanto, de normalização para uma leitura adequada dos dados. Essa normalização tornou-se bastante específica já que depende da disponibilidade de genes que apresentem transcritos com expressão uniforme em todas as células do organismo ou entre as espécies que estão sendo analisadas, bem como durante várias fases do desenvolvimento e sob diferentes condições ambientais. São os chamados genes-referência ou housekeeping. Entretanto, alguns trabalhos vêm constatando que os genes-referência utilizados na era prégenômica não apresentam expressão estável entre tecidos e genótipos e, por este motivo, não são adequados como controles em qRT-PCR. O objetivo desse trabalho foi investigar a estabilidade de expressão de genes constitutivos freqüentemente utilizados como controles internos em estudos de expressão gênica e selecionar novos genes-referência para Eucalyptus por meio de experimentos de qRT-PCR para a sua utilização na validação de experimentos de microarranjos do Projeto Genolyptus. Como resultados das análises de qRT-PCR, foi possível observar que para xilemas de E. globulus e xilemas e folhas maduras de E. grandis, os genes EuC12, At2g28390, EuC10, Histona H2B, Gliceraldeído- 3-fosfato-desidrogenase (GAPDH), EuC06 e EuC09 foram os que demonstraram, respectivamente, menor variação em suas expressões, caracterizando-se como constitutivos para estes tecidos. De acordo com os resultados encontrados nas análises com cDNAs derivados de folhas e xilemas de E. grandis, somente EuC12 e At2g28390 demonstraram invariabilidade de expressões entre os tecidos. Dois tradicionais genes constitutivos, Histona H2B e GAPDH, apresentaram uma variação considerável nas suas expressões entre os tecidos. Os genes selecionados, servirão como controles internos em todas as qRTPCRs subseqüentes nas avaliações de dados gerados pelos microarranjos de DNA para todos os demais genes sob análise no Projeto Genolyptus, e demais linhas de investigação de Eucalyptus. Paralelamente realizou-se, ainda, a seleção e análise de treze genes com expressão diferencial significativa entre tecidos vasculares das espécies de E. grandis e E. globulus. Estes foram selecionados com base nos resultados de microarranjos do Genolyptus e terão seus padrões de expressão analisados por qRT-PCR. / One of the most important advances of post-genomic era is the possibility of global gene expression analysis by DNA microarray technology, which allow verifying transcription profile for thousand genes simultaneously. Microarray allows comparing expression patterns among individuals from distinct species, from distinct organs/tissues within of the same specie or distinct tissues submitted across a wide range of developmental and environmental conditions, beyond genes of proteins mighty involved in transcriptional regulation, the transcription factors. A basic stage of microarray analysis is the experimental validation from gene expression data. This validation is carried out by the use of qRT-PCR (“Real Time Quantitative RT-PCR”) technique witch is the method that currently presents greater sensitivity and specificity in transcript analysis. However, qRTPCR needs normalization for an accurate data interpretation. This data normalization is specific since it depends on the availability of a gene which displays highly uniform expression in all organism cells, between species under analysis, during various phases of development and under different environmental conditions. They are known as reference or housekeeping genes. However, some studies come evidencing that reference genes normally used in pre-genomic era doesn’t show steady expression between tissues and genotypes and, for this reason, are not suitable as controls in qRT-PCR. The objective of this work was to investigate the expression stability of housekeeping genes often used as internal controls in genetic expression studies and select novel genes for Eucalyptus by qRT-PCR for its use in the validation of Genolyptus Project microarray experiments. As results it was possible to identified histone, EuC06, EuC09, EuC10, EuC12, At2g28390 and GAPDH as the most stably expressed genes between E. globulus xylems and E. grandis xylems and mature leafs, as well pointing them out as control genes for these tissues. In accordance with the results found in the analysis with cDNAs derived from E. grandis leaves and xylems, only EuC12 and At2g28390 had demonstrated expression invariability between tissues. We found out that two traditional housekeeping genes, Histone and GAPDH, shown a considerable expression variation between those tissues. According to our analysis the selected genes will serve as internal controls in all subsequent qRT-PCRs, in microarray data evaluation to other genes under investigation in Genolyptus Project as well as another research lines in Eucalyptus. At the same time, we selected and analyzed thirteen genes with significant differential expression between E. grandis and E. globulus vascular tissues. These had been selected on the basis of the results of Genolyptus microarrays. Their expression patterns will be analyzed by qRTPCR.
72

O gene codificador da "proteína-cinase ativada por mitógenos" 5 (MPK5) de Eucalyptus grandis

Borges, Juliana Dametto Krás January 2014 (has links)
As proteínas-cinases ativadas por mitógenos (MAPKs) participam de rotas de transdução de sinais universais em eucariotos e compõem cascatas de fosforilação que levam as células a responder a estímulos extracelulares. Em plantas, MAPKs estão associadas a processos de desenvolvimento e na reposta a hormônios e a estresses bióticos e abióticos. Em trabalhos anteriores de nosso grupo, o gene Egmpk5 de Eucalyptus grandis foi clonado e seu padrão de expressão foi caracterizado em plantas submetidas a diferentes tratamentos. Ainda, plantas de Nicotiana tabacum SR1 foram transformadas com Egmpk5 sob regulação do promotor CaMV 35S para futuro estudo de função do gene. No presente trabalho, foi avaliada mais amplamente a estrutura, a expressão e o produto deste gene. Análises in silico revelaram que Egmpk5 apresenta-se como cópia única no genoma, está organizado em seis éxons e seus cinco íntrons possuem sítios canônicos de splicing de RNA. O produto deduzido deste gene apresenta em sua sequência a assinatura do domínio proteína-cinase e os motivos de ligação a ATP e de ativação/dupla fosforilação, indicando a possibilidade de ser uma proteína funcional. Árvore filogenética foi construída pelo método de Máxima Verossimilhança utilizando o algoritmo MUSCLE para alinhamento das sequências e um valor de bootstrap de 500 repetições com sequências peptídicas similares à proteína deduzida EgMPK5 e permitiu a identificação de MAPKs de outras plantas com função já comprovada na sinalização da divisão celular e na resposta a estresses abióticos, ferimento e patógenos. Análise de RT-qPCR mostrou a expressão de Egmpk5 em níveis comparáveis em raízes, caules e folhas de plantas de E. grandis tratadas com água, e foi detectado um aumento de sua expressão em folhas tratadas com ácido abscísico (ABA) e em todos os órgãos tratados com solução de cloreto de sódio a 200 mM. O estudo da região promotora de Egmpk5 revelou um grupo de possíveis elementos de ação cis relacionados a respostas a estresses. Seis linhagens transformadas de tabaco que tiveram seu estado transgênico confirmado por PCR foram desafiadas com tratamentos de seca e cloreto de sódio, e linhagens mais tolerantes foram identificadas. Ao final destas diversas análises, os resultados obtidos sugerem a participação de Egmpk5 em respostas a estresses abióticos. / Mitogen-activated protein kinases (MAPKs) are part of phosphorylation cascades found in all eukaryotes and are responsible for transducing extracellular stimuli into intracellular responses. In plants, MAPK cascades are involved in growth and development processes and have roles in the response to hormones and biotic and abiotic stresses. In our previous studies, the Egmpk5 gene from Eucalyptus grandis was cloned and its expression profile was characterized in plants subjected to different treatments. Also, Nicotiana tabacum SR1 plants were transformed with Egmpk5 under the control of the CaMV 35S promoter for further function studies. In the present study the structure, expression profiles and product of this gene were further characterized. In silico analyses revealed that the Egmpk5 gene is present as a single copy in the E. grandis genome, and that its structure comprises six exons and five introns with conserved sites for transcript splicing. The deduced product of this gene presents the protein kinase domain signature, ATP-binding site and activation/dual phosphorylation motifs in its structure. A phylogenetic tree was built with sequences similar to the deduced EgMPK5 peptide and lead to the identification of plant MAPKs that have had proven activity in cell division signaling and in the response to abiotic stresses, wounding and pathogens. RT-qPCR analysis showed equal expression of Egmpk5 in roots, stems and leaves of plants treated with water and we detected an increase of expression in leaves treated with abscisic acid (ABA) and also increase in expression in all three organs upon treatment with 200 mM sodium chloride. Analysis of the promoter region of Egmpk5 revealed a group of putative cis-acting elements related to stress responses. Six transformed tobacco lines were confirmed by PCR and were assayed with drought and sodium chloride treatments for the identification of more tolerant individuals. After all analyses performed, results allowed us to suggest that Egmpk5 is involved in abiotic stresses responses.
73

Taxonomy and population genetics of Teratosphaeria causing stem cankers on Eucalyptus trees

Cortinas Irazabal, Maria Noel 25 May 2011 (has links)
At the time of commencing this study, there were only five papers published on Coniothyrium canker disease of Eucalyptus. These studies included the formal description of the fungus causing the disease and some aspects of its biology and physiology were characterized. The fungus was described, at that time, as Coniothyrium zuluense, which had a very simple morphology, lacked sexual reproductive structures, had small nondescript conidia and it was slow growing in culture. Nevertheless, the taxonomic status of the Coniothyrium canker pathogens changed in several occasions during this study including placement in genera such as Colletogloeopsis, Kirramyces and Teratosphaeria. After the first appearance of Coniothyrium canker in South Africa, the disease was found in many other parts of the world. DNA sequences from cultures of C.zuluense became easier to obtain and this made it possible to undertake phylogenetic comparisons of isolates from various areas. Such studies also showed that C.zuluense was closely related to Mycosphaerella species. The common appearance of Coniothyrium canker in new areas motivated further studies of this disease and it causal agent, particularly applying newly available rDNA-based techniques. This also provided the motivation for studies presented in this thesis. The thesis is introduced by means of a literature review that treats Coniothyrium canker on Eucalyptus. Briefly, the general characteristics of the host species, Eucalyptus, are described. Furthermore, trends relating to emerging diseases in plantations of Eucalyptus during the past two decades are treated with particular focus being placed on Mycosphaerella diseases. The phylogenetic relationships between Coniothyrium, Mycosphaerella and its anamorphs are considered together with the population biology of related pathogens. In chapter two of this thesis, DNA sequence comparisons were used to determine the phylogenetic position of C.zuluense related to other fungi. In particular, the question as to whether C.zuluense was correctly placed in the genus Coniothyrium and its relatedness to Mycosphaerella was considered. Comparisons with the type species of Coniothyrium, C.palmarum and a collection of sequences of Mycosphaerella species were also conducted. In addition, the identity of isolates obtained from China with similarities in colony morphology to C.zuluense was considered. The objective of the study presented in chapter three was to investigate whether all the available isolates in the FABI collection from different countries and associated with Coniothyrium canker represented a single phylogenetic species. An additional methodological objective of this chapter was to select the best DNA regions for phylogenetic studies on this fungus and its relatives. Four DNA regions were selected based on the informative content as well as ease and reproducibility for Polymerase Chain Reaction (PCR) amplification. The studies presented in Chapter 3 of this thesis showed that two species cause Coniothyrium canker and these are now known as Teratosphaeria zuluensis and Teratosphaeria gauchensis. Therefore, the objectives of the studies presented in chapters four and five were to develop highly variable markers to study the genetic variability and population parameters of populations of both species. This included the development of a robust protocol to isolate microsatellites on both fungi and that would also be informative for related genera. The protocol finally developed and used is presented in Appendix 2 of this thesis. In chapters six and seven, the microsatellite markers developed in the previous chapters were applied. The genetic structure of populations of T.zuluensis and T.gauchensis was thus studied. Analyses of the amplified alleles and their frequencies were used to determine the levels of genetic diversity, clonality and to draw preliminary conclusions regarding the origin and global movement of the pathogens. / Thesis (PhD)--University of Pretoria, 2011. / Microbiology and Plant Pathology / Unrestricted
74

Whole-tree and tension wood-associated expression profiles of micrornas in Eucalyptus trees

McNair, Grant Robert 08 October 2010 (has links)
Trees are large, biologically complex multi-cellular organisms that have adapted to terrestrial growth. This places specific demands on their physiology such as the ability to transport water over long distances and the ability to withstand extreme mechanical forces. Wood formation (xylogenesis) is the development of the secondary vascular system within trees, which mainly addresses these two physiological needs. Xylogenesis is a highly ordered developmental process, consisting of a number of overlapping yet distinct developmental phases. These phases are strictly regulated through a combination of biochemical signalling networks and gene expression regulation.<ul> <li>microRNAs (miRNAs) are endogenous non-coding, small (~22 nt) RNAs that function predominantly as negative regulators of gene expression at the post-transcriptional level. They have been implicated in the regulation of plant developmental processes, including determining cell fate in the apical meristem and timing of developmental events such as flowering and leaf morphogenesis. miRNAs have recently been found to have regulatory roles in plants placed under various conditions of abiotic stress such as drought, mechanical stress, cold and high levels of salinity.</li></ul> Trees placed under mechanical stress produce a specialised form of wood called reaction wood. Reaction wood is referred to as tension wood in angiosperms, as it forms on the outside of a bent trunk or branch in order to correct for the non-vertical growth. The formation of tension wood requires extensive reprogramming of wood development processes. This makes tension wood induction an ideal tool to study and refine our understanding of wood development. Recently, miRNA regulation has been implicated in the control of normal and tension wood formation in trees, but the full extent to which miRNAs are involved in tension wood induction is not known. To identify miRNAs potentially involved in the regulation of normal and tension wood development in fast-growing Eucalyptus plantation trees, real-time quantitative polymerase chain reaction (RT-qPCR) and Northern blot analyses were performed for a number of conserved and putatively novel Eucalyptus miRNAs. A total of 12 miRNAs representing 12 distinct miRNA families were profiled, including three novel miRNAs that are putatively specific to Eucalyptus trees. To more fully understand miRNA function in terms of tree development, the abundance profiles of the selected miRNAs were first determined at the whole-tree level. Of the conserved miRNAs profiled, five (miR160, miR166, miR167, miR172, miR408) were found to have abundance profiles consistent with their predicted roles in plant development. At the whole-tree level, miR90, putatively novel to Eucalyptus, was predominately expressed in the mature leaves and flowers. miR90 may target a MADS-box transcription factor which is not required for mature leaf and flower growth. miR408, a regulator of the expression of a plastocyanin gene involved in lignin polymerisation, was expressed at low levels in the immature and mature xylem, where cell lignification is most prominent. In the tension wood, miR166, a known regulator of wood development and miR408 displayed similar increasing abundance over time in tension wood xylem. These profiles support their potential role in wood development. miR160 and miR167, which target auxin response factors responded early to bending stress, with their abundance reaching maximum levels six hrs post-induction before decreasing again. This is consistent with the observed role of auxin response factors as a mechanism to rapidly respond to stimuli, such as bending. The miRNAs abundance profiles generated in this study suggest that some miRNAs do indeed play a role in normal and tension wood development, though not necessarily directly. These results provide further insights into the complex nature of miRNA regulation and their hypothesised roles in wood development. The miRNAs highlighted herein are strong candidates for further functional studies as their abundance profiles and predicted targets are consistent with roles in wood development. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Genetics / unrestricted
75

Bacterial endophytes associated with Eucalyptus nitens clones

Stewart, Annie Cecilia 07 November 2012 (has links)
Plants are colonised by a vast amount of bacteria which are found in parts such as seeds, roots, leaves and fruits while fewer are found on blossoms, stems and vascular tissue. These different parts of plants make up distinct micro ecosystems which may result in different bacterial species (endophytes) colonizing these ecosystems. Such interactions could be for life or only a short period of time and may cause no significant damage or they could be latent pathogens. Isolations of both Gram negative and Gram positive bacteria have been made from an extensive range of plant species and include bacterial genera from the following groups: Firmicutes, Actinobacteria, á Proteobacteria, â Proteobacteria, and ã Proteobacteria. The focus of this study was the endophytic bacterial community of resistant, healthy and diseased Eucalyptus nitens clones, the latter of which showed symptoms of bacterial blight and die back previously described as caused by Pantoea ananatis. The endophytic bacteria of these sampled clones were studied using culturing dependent and independent methods. The focus was on the Enterobacteriaceae in order to determine whether P.ananatis is present as an endophyte of these clones. To obtain the isolates, standard culturing techniques were used, followed by sequence identification of the 16S rRNA as well as two housekeeping genes, rpoB and gyrB. Results obtained from the culturing study were compared to results obtained from a PCR-DGGE study of the same samples. Although no conclusion could be drawn as to which organism present caused the disease symptoms on the susceptible clones, it was seen that Enterobacter and Pantoea, were the most frequently isolated in both of the studies from all clones sampled. This implies that they are present as endophytes in the E.nitens clones, together with Pseudomonas and Bacillus as suggested by the DGGE study. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Microbiology and Plant Pathology / unrestricted
76

Diurnal and circadian regulation of wood formation in Eucalyptus trees

Solomon, Owen Luke 18 November 2008 (has links)
Wood is one of the most important products of world trade, due to its countless uses as a source of timber, fibre, and renewable energy. In addition to its economic importance, the formation of wood represents a global carbon sink which reduces the excess atmospheric CO2 that contributes to global warming. The formation of wood or xylogenesis is a complex example of cell differentiation, controlled by multiple interacting environmental factors and the coordinated expression of hundreds of genes. Genomic studies have proved a valuable tool in identifying the genes associated with xylogenesis. The expression of these genes has been shown to under strict spatial regulation in a developmental-stage specific fashion. Despite recent advances in the understanding of this process, there remains much to learn about the cellular, molecular and developmental processes involved. While the spatial regulation of wood formation has been well described, less attention has been devoted to the temporal regulation of this process. Most organisms are known to match their activities to the daily oscillation of night and day in what is known as a diurnal rhythm. A subset of these diurnal rhythms are termed circadian rhythms, and persist in the absence of environmental time cues, with a period of approximately 24 hours. Circadian rhythms are endogenous in nature, being generated by a small number of central oscillator genes, and illustrate an organism's ability to measure time. Circadian rhythms are found across a wide taxonomic spectrum, and are believed to confer an adaptive benefit, possibly due to the ability to anticipate regular changes in the external environment. As wood formation is a major sink for the products of light driven photosynthesis, it represents a likely target for circadian control in plants. A large proportion of photosynthesis genes themselves are known to be under circadian control, as are several cell wall formation genes. Most studies of temporal rhythms in plants, however, have used the herbaceous model species Arabidopsis, which does not have a woody stem. It is likely, therefore, that the circadian control of many wood formation genes remains to be discovered. We used a spotted cDNA mIcroarray carryIng 2608 elements to quantitatively measure daily changes in transcript abundance in the wood-forming tissues of a fast growing, Eucalyptus hybrid. Eucalyptus is a large genus of tree species, many of which are of great economic importance, and are widely grown in plantations for solid timber and pulp production. We found that almost ten percent of the genes on the microarray showed significant daily changes in expression (-loglOP>3.74). These genes included Eucalyptusorthologues of the Arabidopsis central clock genes CCA1 (CIRCADIAN CLOCK ASSOCIATED 1) and GIGANTEA (GI) which cycled with a period and phase matching that seen in Arabidopsis. The remaining genes were involved in pathways including carbohydrate metabolism, hormone signalling, transcription regulation and wood formation. The types of genes that were seen to be diurnally influenced, suggests a role for circadian control of various important plant metabolic pathways, including aspects of carbon allocation to wood formation. / Dissertation (MSc)--University of Pretoria, 2008. / Genetics / unrestricted
77

Evaluation of eucalyptus citriodora derived p-menthane-3,8-diol-citronellal acetal as a bio-plasticizer for cosmetic application

Burger, Kirstin January 2013 (has links)
Plasticizers are generally added to cosmetic and personal care products to improve the filmforming abilities of the product and increase flexibility of the film formed on the skin or hair surface. For example, plasticizers are present in perfumes to prolong the release of the specific scent, which is the ultimate goal in a good quality perfume. Plasticizers in nail varnishes prevent chipping, improve the aesthetics by adhering to the keratin in the nail which means the coating stays on for much longer, which is the ultimate goal in nail products. Plasticizers improve the gloss, resist chipping and allow quick drying time. Therefore it can be seen that plasticizers play a vital role in personal care products like perfumes and nail varnishes. Certain plasticizers e.g. phthalates, can cause problems associated with human health and can harm the environment. They are easily available and large volumes can be obtained at a low cost. These phthalates, for example, di-butyl phthalate (DBP) have been identified as carcinogenic. Nowadays the occurrence of cancer is rapidly increasing. The plasticizers present in a large number of consumer and personal care products, can possibly be linked to the ever increasing reports of cancer. Therefore a substitute to the traditional phthalate plasticizers must be investigated. The aim of this research is to produce a plasticizer derived from naturally occurring Eucalyptus oil, which can be used to replace the existing plasticizers in cosmetic formulations. Para-menthane-3,8-diol (PMD), occurring naturally in the oil from the tree, Eucalyptus citriodora, forms an acetal with citronellal (PMD, acetal, citronellal all occur naturally in the oil). It has been previously shown that PMD-citronellal acetal will exhibit plasticizing properties similar to conventional plasticizers. The objective was to enhance the formation of the acetal in the Eucalyptus oil by reacting it with excess PMD. An effective synthesis method for the PMD-citronellal acetal enriched oil (~73.8 percent) was determined from optimization experiments. The physical characterisation of the PMD-citronellal acetal enriched oil was done and compared with that of DBP. The acetal-enriched oil had a lower density, slightly higher solubility in water (at 25°C), lower refractive index (Brix percent) and a higher boiling point (350°C) than DBP. The physical characteristics of the Eucalyptus oil source and the acetal-enriched Eucalyptus oil were very similar. This can be expected as the Eucalyptus oil consists of ~84.3 percent Citronellal, ~ 1.3 percent PMD and 2.7 percent PMD-citronellal acetal. In this study the effectiveness of the acetal-enriched Eucalyptus oil (referred to from now on as the bio-plasticizer) was compared to a conventional plasticizer such as di-butyl phthalate (DBP), commonly used in cosmetic products. Two cosmetic formulations were produced: a nail varnish and a perfume formulation. Various tests were performed on these formulations to investigate the plasticizing properties of the bio-plasticizer. The objectives were to determine if the natural plasticizer is as effective as the potentially carcinogenic phthalate plasticizers and can be used as a substitute for the phthalates in personal care products. The results indicate that the bio-plasticizer does behave similarly to di-butyl phthalate, however, the effectiveness of the bio-plasticizer is lower than that of di-butyl phthalate. As the viscosity of the synthesized oil was high, this affected the overall consistency of the products. A more viscous nail varnish and perfume was produced in comparison to the DBP counterpart. The stability of the bio-plasticizer in the cosmetic formulations of nail varnish and perfume was also investigated. The cosmetic products were incubated at 0°C, 25°C and 40°C over a period of two months. Any changes in colour, odour, pH, refractive index, separation and plasticizer peak change in the gas chromatogram trace were recorded. It was determined that the PMD-citronellal acetal-enriched oil was relatively unstable under elevated temperatures and light intensity. Storage under higher temperatures (40°C) tends to increase the acidity. Therefore the bio-plasticizer must be placed in a closed, covered bottle and stored in an environment away from light and elevated temperatures. According to the gas chromatogram peaks, it was clear that both the bio-plasticizer and the DBP were more unstable in the perfume formulation than in the nail polish and were especially sensitive to light when in the perfume. This could possibly be due to the interaction with the fragrance molecule, p-anisaldehyde.
78

Assessment and development of microarray-based DNA fingerprinting in Eucalyptus grandis and related species

Lezar, Sabine 06 February 2006 (has links)
DNA micro-array technology is a new and powerful technology that could substantially increase the speed of forest tree breeding programmes. This thesis represents a compilation of investigations that focus on the exploitation of DNA micro-array technology for genetic marker analysis of Eucalyptus trees. The major focus of the studies presented in this thesis was on the assessment and development of micro-array-based DNA fingerprinting in Eucalyptus. A DNA chip for Eucalyptus was not available at start of the study. As a result of this study a 384-prototype chip was developed to evaluate the potential of micro-arrays for fingerprinting closely related Eucalyptus clones, species and hybrids. These studies show that micro-arrays are an efficient DNA marker technology for genome-wide fingerprinting of complex organisms for which no sequence data exist. However, cross-hybridisation and the lack of dedicated software products remain a challenge. The 384-probe array developed in this study was subsequently employed for the detection of putative markers associated with tolerance to Chrysoporthe austroafricana in Eucalyptus grandis. Putative tolerance-associated markers were identified by bulk segregant analysis (BSA) and converted to cleaved amplified polymorphic sequence markers for further characterization in segregating Eucalyptus populations. BSA revealed a total of 109 scorable, polymorphic loci, of which nine appeared to be associated with tolerance or susceptibility. Two DArT markers were converted to cleaved amplified polymorphic sequence (CAPS) markers, which discriminate susceptible and tolerant individuals. These PCR markers can be used for the rapid screening for disease tolerance in Eucalyptus planting and breeding stock. The collection of studies included in this thesis demonstrated that DArT is an efficient DNA marker technology for genome-wide genotyping, particularly for application in less-studies plant genomes. Whole-genome profiling using DArT raises significant opportunities for tree breeding programmes and for future genome analysis of Eucalyptus. / Thesis (PhD)--University of Pretoria, 2011. / Genetics / Unrestricted
79

Irrigação de eucalipto com efluente sanitario de lagoa facultativa : eficiencia do sistema solo-planta no pos-tratamento / Irrigation eucalyptus with sanitary sewage pond : efficiency of soil-plant system post-treatment

Veronez, Alex Henrique, 1977- 14 August 2018 (has links)
Orientadores: Bruno Coraucci Filho, Ronaldo Stefanutti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-14T15:20:45Z (GMT). No. of bitstreams: 1 Veronez_AlexHenrique_M.pdf: 2620595 bytes, checksum: d6d885f2c501fdcaeb697bcdcccbccf0 (MD5) Previous issue date: 2009 / Resumo: O uso de efluente sanitário tratado na agricultura, como fonte de água e nutrientes, é uma alternativa à eventual necessidade de um pós-tratamento e ao lançamento em corpos d'água. O trabalho experimental foi desenvolvido na UGRHI 08 (Unidade Hidrográfica de Gerenciamento de Recursos Hídricos Sapucaí/Grande), no município de Franca-SP, e teve a finalidade de avaliar a eficiência do sistema soloplanta no pós-tratamento de efluente, por meio da irrigação de cultura de eucalipto, da espécie urograndis, monitorando a qualidade dos lixiviados, nas profundidades de 0,30; 0,60 e 0,90 m, e, o DAP - Diâmetro à Altura do Peito da planta. Foram instaladas parcelas, constituindo 8 tratamentos, com 4 repetições cada. Dos 8 tratamentos, 2 foram irrigados com água, 5 com efluente e 1 não recebeu nenhum tipo de irrigação artificial. Quanto à adubação, 5 tratamentos receberam NPK, B e Zn; sendo 4 deles irrigados com água residuária e 1 com água natural. Os lixiviados coletados na área da pesquisa evidenciaram a presença de nitrato na maioria dos tratamentos irrigados com efluente e uma elevada eficiência na remoção de DBO e DQO. Em relação à planta, o tratamento estatístico mostrou que o desenvolvimento do DAP foi maior nos tratamentos irrigados com efluente quando comparados aos demais tratamentos. Os resultados comprovam que o pós-tratamento de efluente na cultura de eucalipto é efetivo quanto aos aspectos sanitários e agronômicos. / Abstract: The use of treated sanitary effluent in Agriculture as water resource and nutrients is an alternative to the eventual necessity of a post treatment as also as to the launching in water bodies. The experiment was developed at UGRHI 08 (Hydrographic Unity of Hydric Resources in Sapucaí/Grande) in the city of Franca-SP. It aimed to evaluate the efficiency of the plant - ground system at the effluent post treatment, through the process of irrigation of the eucalyptus cultivation, which species is urograndis, monitoring the leachate quality, in the deeps of 0,30; 0,60 e 0,90m, and the DAP (Diameter at the High of the Plant Chest). Parcels were installed, forming 8 treatments, with 4 repetitions each one. From the 8 treatments, 2 were irrigated with water, 5 with effluents and 1 didn't receive any kind of artificial irrigation. Referring to the seasoning 5 treatments received NPK, B and Zn; 4 of them were irrigated with wastewater and 1 with natural water. The leachated collected in the research area showed the presence of nitrate in the most of the treatments irrigated with effluent and a high efficiency in the BOD and COD removing. In relation to the plant, the statistic treatment, showed that the DAP development was bigger in the treatments irrigated with effluents than in the other ones. The results so far prove that the post treatment of effluent in the eucalyptus cultivation is effective concerning the sanitary and agronomic aspects. / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
80

Estudo comparativo das deformações fisicas e mecanicas do Eucalyptus saligna utilizando as normas ABNT e COPANT

Gameiro, Ana Regina Manfredini 15 July 2018 (has links)
Orientador : Jorge E. Quintero / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos e Agricola / Made available in DSpace on 2018-07-15T19:07:51Z (GMT). No. of bitstreams: 1 Gameiro_AnaReginaManfredini_M.pdf: 4590411 bytes, checksum: 14a86a37904b130d39ead7d4ec7db57d (MD5) Previous issue date: 1980 / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola

Page generated in 0.0565 seconds