• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 69
  • 53
  • 11
  • 5
  • 4
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 190
  • 18
  • 18
  • 15
  • 12
  • 12
  • 12
  • 11
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 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.
171

Diel Mediated Populus balsamifera Transcriptome Components Test the Impacts of Artificial Nighttime Lighting

Skaf, Joseph 27 November 2012 (has links)
Artificial nighttime lighting (ANL) is known to adversely affect animals, but little is known what the consequences are to plants. Two genotypes of Populus balsamifera, a common urban tree, were used to investigate how ANL impacts plants. While the two genotypes varied in their physiological sensitivity to ANL, poorer levels of net leaf carbon assimilation compared to control samples suggested that ANL perturbed the perception of time of day for these plants. Gene set analysis on a subset of PopGenExpress microarray samples identified time of day specific processes in P. balsamifera, and a set of candidate ANL-sensitive genes were identified from these. Transcript measurements from the two genotypes revealed that ANL affects plants at the molecular level, for the diel cycling of the putative ANL-sensitive genes was perturbed. Together, these results suggest that ANL affects plants at the physiological and molecular level by perturbing their perception of time of day.
172

Diel Mediated Populus balsamifera Transcriptome Components Test the Impacts of Artificial Nighttime Lighting

Skaf, Joseph 27 November 2012 (has links)
Artificial nighttime lighting (ANL) is known to adversely affect animals, but little is known what the consequences are to plants. Two genotypes of Populus balsamifera, a common urban tree, were used to investigate how ANL impacts plants. While the two genotypes varied in their physiological sensitivity to ANL, poorer levels of net leaf carbon assimilation compared to control samples suggested that ANL perturbed the perception of time of day for these plants. Gene set analysis on a subset of PopGenExpress microarray samples identified time of day specific processes in P. balsamifera, and a set of candidate ANL-sensitive genes were identified from these. Transcript measurements from the two genotypes revealed that ANL affects plants at the molecular level, for the diel cycling of the putative ANL-sensitive genes was perturbed. Together, these results suggest that ANL affects plants at the physiological and molecular level by perturbing their perception of time of day.
173

Enhancing gain from long-term forest tree breeding while conserving genetic diversity /

Rosvall, Ola, January 1900 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
174

Diversidade bacteriana do gene 16S rRNA em carvão pirogênico de Terra Preta Antropogênica da Amazônia Central e Oriental / Bacterial diversity of the 16S rRNA gene in pyrogenic black carbon of Anthropogenic Dark Earth from the Central and Oriental Amazon

Mateus de Souza Terceti 28 August 2009 (has links)
A Terra Preta Antropogênica (TPA) tem essa denominação porque é encontrada em sítios arqueológicos, onde viveram grupos pré-históricos e é considerada um dos solos mais férteis do mundo. Nela é encontrada grande quantidade de material deixado por grupos indígenas como fragmentos cerâmicos, artefatos líticos, e especialmente carvão pirogênico. Estudos realizados com o carvão pirogênico verificaram que ele aumenta a capacidade de trocas catiônicas nesses solos. Por meio de microscopia de fluorencência, foi observada a presença de microrganismos habitando esse carvão, no entanto, não se sabe quais seriam. Devido à falta de informações sobre a diversidade bacteriana nessas estruturas, este trabalho estudou a diversidade bacteriana em amostras de carvão pirogênico de solos TPA coletadas nos sítios Lagoa Balbina (Amazônia Central- Amazonas) e Mina I (Amazônia Oriental - Pará), através de técnicas moleculares independentes de cultivo. O estudo visou também comparar essa diversidade com a encontrada no solo de onde carvão foi isolado. As estruturas de carvão foram separadas fisicamente dos solos e seu DNA genômico total extraído e usado como molde em reação de PCR utilizando oligonucleotídeos do gene 16S rRNA para o Domínio Bacteria. O produto da PCR foi clonado em vetor e os clones foram sequenciados e comparados com o banco de dados de 16S rRNA do RDPX. Com a construção das bibliotecas de clones do gene 16S rRNA a partir das amostras de carvão pirogênico observou-se que existe maior número de bactérias desconhecidas no carvão pirogênico do que no solo onde ele foi isolado. Acidobacteria foi o filo predominante nas bibliotecas de carvão pirogênico das duas localidades de estudo, assim como na biblioteca do solo do sítio Mina I. Já na biblioteca do solo do sítio Lagoa Balbina houve predominância do filo Firmicutes. Por meio do método de rarefação foi possível constatar uma menor riqueza de UTOs nas comunidades bacterianas presentes nas estruturas de carvão pirogênico quando comparado à riqueza de UTOs das comunidades bacterianas cujo habitat é o solo. Mas quando se compara a riqueza de UTOs entre as estruturas de carvão isoladas das duas localidades, observa-se que a riqueza é maior no sítio Mina I. Os valores obtidos com os índices de diversidade revelaram menor diversidade de UTOs nas bibliotecas obtidas para o carvão pirogênico das duas regiões estudadas se comparado dos valores para as bibliotecas obtidas do solo da mesma região. Os valores obtidos com os métodos não paramétricos revelaram maior riqueza de UTOs para as bibliotecas do carvão do sítio Mina I e solo TPA do sítio Balbina. A análise da PCA revelou que as bibliotecas do sítio Balbina mostraram-se altamente similares. Em adição, a análise com S-Libshuff, verificou que todas as bibliotecas comparadas são significativamente diferentes quanto à composição das comunidades bacterianas. O carvão pirogênico não é uma estrutura inerte, pois é capaz de ser habitado por diferentes bactérias e a sua estrutura da comunidade bacteriana é diferente daquela de onde ele foi segregado / Anthropogenic Dark Earth (ADE) has this denomination because it is found at archeological sites, where prehistoric groups lived, and it is considered one of the most fertile soils of the world. In this soil a great amount of material left by indigenous groups was found as ceramic fragments, lithic workmanships, and especially pyrogenic black carbon. Studies accomplished with the pyrogenic black carbon verified that it increases the capacity of cationic changes in soils. Through fluorescence microscopy, the presence of microorganisms was observed inhabiting that black carbon, however, this community is still unknown,due to the lack of information about the bacterial diversity in those structures.This work studied the bacterial diversity in samples of pyrogenic black carbon of ADE soils, collected at the sites Lagoa Balbina (Central Amazon) and Mina I (Oriental Amazon), through molecular techniques independent of cultivation. The study also sought to compare that diversity with the one of the soil where black carbon was isolated. The structures of black carbon were separate physically from the soils and total genomic DNA was extracted and used as template in a PCR reaction, using primers of the 16S rRNA gene for the Bacteria Domain. The PCR product was used for construction of clone libraries and the clones were sequenced and compared with the 16S rRNA of RDPX database. The 16S rRNA gene clone libraries from the samples of pyrogenic black carbon, it shown that is a larger number of unknown bacteria in the black carbon than in the soil where it was isolated. Acidobacteria was the predominant phylum in the pyrogenic black carbon libraries from the both studied places, as well as in the soil library from Mina I site. However in the library Lagoa Balbina site there was predominance of the phylum Firmicutes. Through the rarefaction method it was possible to verify a smaller richness of OTUs in the bacterial communities presents in the pyrogenic black carbon structures when compared to the OTUs richness of the bacterial soil communities.But, when the OTUs richness is compared among the isolated structures of pyrogenic black carbon of the two places, it is observed that the richness is higher in the Mina I site. The values from diversity indexes revealed smaller diversity of OTUs in the pyrogenic black carbon libraries when compared with the soil libraries for the two studied areas. The obtained values with the nonparametric methods revealed larger OTUs richness in the black carbon library of Mina I site and in the ADE soil library of the Balbina site. The PCA analysis showed that the libraries of the site Balbina site were highly similar. In addition, the analysis with S-Libshuff verified that all of the compared libraries were significantly different in bacterial communities composition. The pyrogenic black carbon is not an inert structure, once it is capable of being inhabited by different bacteria, and its bacterial community structure is different from that one where is was segregated
175

Comportamento de clones de seringueira quanto ao ataque de Tenuipalpus heveae Baker (Acari: Tenuipalpidae) e potencial de Euseius citrifolius Denmark & Muma (Acari: Phytoseiidae) como seu predador

Monteverde, Maria de Souza [UNESP] 15 August 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-15Bitstream added on 2014-06-13T21:00:08Z : No. of bitstreams: 1 monteverde_ms_me_ilha.pdf: 836300 bytes, checksum: 7e7bd78d557e5adfa1ab64afe788595f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O cultivo da seringueira [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.] em sistema de monocultura tem favorecido o desenvolvimento de várias espécies de insetos e ácaros, entre eles, o ácaro-vermelho, Tenuipalpus heveae Baker que pode provocar intenso desfolhamento. Entre os ácaros predadores que têm sido coletados nos seringais paulistas, Euseius citrifolius Denmark & Muma tem sido registrado com freqüência e abundância. Para os produtores, o conhecimento sobre a resistência dos clones ao ataque de insetos e ácaros pode ser muito importante para o estabelecimento de estratégias de controle. O presente trabalho teve por objetivos: 1 - comparar o comportamento de clones de interesse econômico para o Estado de São Paulo, quanto ao desenvolvimento populacional de T. heveae e à reação ao seu ataque; 2 - avaliar a atividade predatória de E. citrifolius sobre as fases de desenvolvimento do ácaro-vermelho. Para o experimento de clones foram utilizadas mudas ensacadas, de RRIM 600, PB 235, PR 255, RRIM 937, RRIM 938 e PB 350, infestadas artificialmente com fêmeas de T. heveae. As avaliações foram feitas no período de dez a sessenta dias após a infestação, a cada dez dias, para contagem do número de ovos, larvas, ninfas e adultos. A intensidade dos sintomas observados nos folíolos e nas mudas foi avaliada através de uma escala de notas. Para a atividade predatória os testes foram realizados em placas de Petri contendo uma camada de algodão umedecido e sobre ela um disco de folha de seringueira de 2,5 cm de diâmetro. Três testes foram conduzidos, um para cada fase de desenvolvimento biológico de E. citrifolius a saber: larvas, ninfas e fêmeas adultas, alimentando-se de cada fase do ciclo biológico de T. heveae. As avaliações foram realizadas após 24 horas da exposição do predador com a presa, para larvas e ninfas e após 24, 48 e 72... / Rubber tree crops [Heveae brasiliensis (Willd. Ex Adr. de Juss.) Müell. Arg.] under monoculture practice has contributed to the development of many insect and mite species, amongst which, the red mite, Tenuipalpus heveae Baker, which can cause intense defoliation. Concerning the predator mites which have been collected in the rubber tree crops in São Paulo state, Euseius citrifolius Denmark & Muma has often been recorded in great numbers. The knowledge of the clones' resistance to the insects and mites attacks can be of great importance to the use of control strategies. This study has the following objectives: 1 - to compare the development of T. heveae on the likely clones for São Paulo state and their response to this mite attack; 2 - to evaluate the predatory activity of E. citrifolius concerning the red mite life stages. For the clones experiment, seedlings of RRIM 600, PB 235, PR 255, RRIM 937, RRIM 938 and PB 350, artificially infested with T. heveae females have been used. The evaluations were done within the period of ten to sixty days after infestation, every ten days, for eggs, larvae, nymphs and adults count. The severity of the observed symptoms on leaflets and seedlings was evaluated according to a rating scale. The predatory activity tests were conducted in Petri dishes with a piece of wet cotton inside on which laid a circular piece of rubber tree leaf with a 2.5-cm diameter. Three tests were carried out, one for each of the E. citrifolius life stages to be studied: larvae, nymphs and adult females, feeding on the different life stages of T. heveae. The evaluations were performed after 24 hours of prey exposure to the predator larvae and nymphs, and after 24, 48 and 72 hours when observing the predator adult females. The PB 235 clone has been proved to be the most susceptible to T. heveae and the PR 255, RRIM...(Complete abstract, click eletronic address below)
176

Assignment of the human homeobox 11-like 2 gene (HOX11L2) to chromosome 5q34→q35 by radiation hybrid mapping

Lee-Kirsch, Min-Ae, Engel, Kerstin, Paditz, Ekkehart, Rösen-Wolff, Angela, Lee, Young-Ae, Gahr, Manfred January 2001 (has links)
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
177

Characterization of posttranslational modification of 19 kDa protein expressed by Mycobacterium avium subspecies paratuberculosis

Spinelli, Natalia 01 January 2008 (has links)
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease, a chronic enteritis in ruminants, and has recently been linked to Crohn's disease in humans. To generate an effective vaccine against MAP, it is necessary to identify MAP antigens that trigger protective immunity. Unfortunately, not much is known about MAP proteins despite decades of research. We have previously shown that a 4.8 kb insert from MAP will produce a 16 kDa recombinant protein when expressed in Escherichia coli and 19 kDa recombinant protein when expressed in M smegmatis ( smeg 19K). The difference of 3 kDa in size of these expressed proteins may be related to posttranslational modificatjons that occur in Mycobacterium species. We hypothesized that smeg19K is a lipoglycoprotein since blast analysis revealed approximately 76 % amino acid identity between the MAP 19 kDa protein and a known lipoglycoprotein, the 19 kDa protein of M tuberculosis. This prediction was confirmed following positive staining of smeg19K with Sudan Black 4B, a postelectrophoresis dye used to stain for lipids. Smeg 19K has also stained positively for glycosylation with the lectin concavalin A, a highly specific stain for mannose residues. As expected, treatment with tunicamycin (an antibiotic known to inhibit N-glycosylation) and treatment with deglycosylation assay (non-specific for mannose ), showed no reduction in size of 19 kDa glycolipoproteins. Since covalent modification of proteins with acyl or glycosyl moieties alter immunogenicity and/or pathogenicity, the study here provides foundation for future experiments regarding the antigenicity of MAP 19 kDa lipoglycoprotein and its role in disease pathogenicity.
178

A General Duality Theory for Clones

Kerkhoff, Sebastian 12 October 2011 (has links) (PDF)
In this thesis, we generalize clones (as well as their relational counterparts and the relationship between them) to categories. Based on this framework, we introduce a general duality theory for clones and apply it to obtain new results for clones on finite sets.
179

La rentabilité de la fidélisation du consommateur : 3 essais complémentaires. / Profitability and Sensitivity of Consumer Loyalty : 3 Complementary Essays.

Vallaud, Thierry 19 June 2013 (has links)
Dans cette thèse sur travaux, l’auteur part de deux travaux précédents sur la rentabilité de la fidélisation et la détermination du potentiel client pour faire un constat : une partie de la rentabilité de la fidélisation et du potentiel pour une marque est basée sur la part captable du chiffre d’affaire fait à la concurrence ; le taux de captation.Dans ce nouveau travail il s’agit de montrer que le taux de captation est basé sur l’élasticité du taux de nourriture. A partir d’une analyse de la littérature et de plusieurs modélisations sur des données de panel scannérisées, l’auteur démontre, sur plusieurs marchés, que l’élasticité du taux de nourriture est contrainte et prévisible.C’est donc en tenant compte de cet écart limité qu’une marque peut estimer le taux de captation et donc la rentabilité de la fidélisation ainsi que le potentiel client. / In this thesis based on works the author goes from two previous studies on the profitability of loyalty and customer potential determination to make a statement : part of the profitability of loyalty and of the potential for a brand is based on the reachable share of turnover done by the competition ; the catch rate.In this new work it is shown that the catch rate is based on the elasticity of the share of category requirement. From a review of the literature and several modeling on scanning panel data the author demonstrates on several markets that elasticity of the share of category requirement is limited and predictable.Then it’s in taking into account this small difference that a brand can estimate the “catchable” rate and therefore the profitability of loyalty and potential of a customer.
180

A General Duality Theory for Clones

Kerkhoff, Sebastian 28 June 2011 (has links)
In this thesis, we generalize clones (as well as their relational counterparts and the relationship between them) to categories. Based on this framework, we introduce a general duality theory for clones and apply it to obtain new results for clones on finite sets.

Page generated in 0.0159 seconds