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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.
21

Estudos anatômicos, ultra-estruturais e bioquímicos da síndrome Kranz em folhas de duas espécies de Gomphrena L. (Amaranthaceae) / Anatomical, ultrastructural and biochemical surveys in leaves to two Gomphrena L. species (Amaranthaceae)

Natalia Paganotti Antonucci 10 March 2010 (has links)
A síndrome Kranz é um conjunto de características anatômicas, ultra-estruturais e bioquímicas que culminam na realização da fotossíntese C4. Tal síndrome apresenta grande diversidade dentre as Angiospermas, tornando-se conveniente seu estudo em todos os níveis acima citados para a completa caracterização da mesma. No presente trabalho foi investigada a síndrome Kranz de Gomphrena arborescens e G. scapigera (Amaranthaceae) com ênfase na origem ontogenética da bainha Kranz, na descrição ultra-estrutural e na confirmação bioquímica sobre o tipo de fotossíntese C4. O desenvolvimento foliar dessas espécies indica que a bainha Kranz é originada da camada mais interna do mesofilo, a endoderme foliar. Uma discussão sobre os termos presentes na literatura para a descrição dessa bainha, todos eles focados em sua função na fotossíntese C4, demonstra a importância de se utilizar termos que informem a origem ontogenética dessa bainha, como endoderme e periciclo. Na análise ultra-estrutural, foram identificados possíveis fatores que interferem na fotossíntese de ambas as espécies, como o espessamento e a composição da parede da bainha Kranz, o posicionamento centrípeto dos cloroplastos e a presença de retículo periférico nos mesmos. Embora a análise bioquímica tenha resultado em informações ainda não conclusivas, o dimorfismo dos cloroplastos sugere a realização da fotossíntese C4 do tipo NADP-ME. O presente trabalho, de uma forma geral, contribui ao conhecimento da síndrome Kranz dentre as Amaranthaceae s.s., um grupo em que a ultra-estrutura e a bioquímica ainda são pouco conhecidas, e ressalta a importância dos estudos anatômicos, principalmente com enfoque ontogenético, para o melhor conhecimento da diversidade da síndrome Kranz dentre as Angiospermas. / The Kranz syndrome is a set of anatomical, ultrastructural and biochemical features that culminate in the C4 photosynthesis. This syndrome has a huge diversity among Angiosperms, so it became suitable to survey all the levels above cited for its complete characterization. In the present work the Kranz syndrome of Gomphrena arborescens and G. scapigera (Amaranthaceae) is studied, with emphasis on the ontogenetic origin of the Kranz sheath, on the ultrastructural description, and on the biochemical confirmation about the C4 photosynthesis kind. The foliar development of these species shows that the Kranz sheath is originated from the inner layer of the mesophyll, the foliar endodermis. A discussion about the literature terms used to describe the Kranz sheath, all of them referring to the function of this layer in C4 photosynthesis, demonstrates the importance of using terms that inform the ontogenetic origin of this layer, such as endodermis and perycicle. The ultrastructural analysis identified possible factors that interfere on the C4 photosynthesis of both species, such as wall thickening and composition of Kranz sheath cells, the centripetal position of chloroplasts and the peripheral reticulum in chloroplasts. Although biochemical analysis has resulted in no conclusive information, the chloroplast dimorphism suggests the NADP-ME C4 photosynthesis. This work, in a general way, contributes to the knowledge of the Kranz syndrome among Amaranthaceae s.s., a group that has the ultrastructure and the biochemistry of C4 photosynthesis poorly known. It also draws attention to the importance of anatomical surveys concerning the ontogenetic origin of Kranz sheath for a better understanding on the diversity of Kranz syndrome among Angiosperms.
22

S-phase Synchronization Promotes Chemoradiotherapy-induced Apoptosis in Prostate Cancer Cell Lines

Shyam, Sunitha 31 July 2007 (has links)
No description available.
23

Complement Component C4 in Human Systemic Lupus Erythematosus: from Genetic Deficiencies to Copy-Number Variations

Wu, Yee Ling 27 August 2009 (has links)
No description available.
24

Developmental regulators of Kranz anatomy

Sedelnikova, Olga January 2016 (has links)
The C<sub>4</sub> biochemical pathway is the most efficient form of photosynthesis in warm environments and introducing this system into globally significant, but less efficient, C<sub>3</sub> photosynthetic crops could bring major yield increases. The most photosynthetically efficient C<sub>4</sub> grass species have a specialised leaf anatomy characterised by high vein density with two distinct cell types radially arranged around the vascular bundles (Kranz anatomy). Although this anatomy was first described in 1882, the genetic regulators controlling Kranz development are still not known. In recent years, transcriptomic analysis has allowed researchers to identify candidate Kranz regulator genes, and a model for Kranz development has been proposed, however, this model has not been experimentally validated. This study used in situ hybridisation to visualise expression patterns for a set of candidate Kranz regulator genes in maize and the orthologous genes in rice. Further, morphological analysis of rice lines with constitutive expression of the candidate Kranz regulator genes AINTEGUMENTA 1 and DAG-LIKE 1 and 2 were used to characterise protein function during C<sub>3</sub> monocot leaf development. The function of maize AINTEGUMENTA in the C<sub>3</sub> eudicot arabidopsis was also investigated. The results of the in situ hybridisation experiments led to the refinement of the Kranz model and identified potential roles for the candidate regulators during leaf development. The constitutive expression experiments highlighted the regulatory differences between eudicot and monocot leaf development and implicated the regulation of auxin-cytokinin homeostatis as a key factor in Kranz development. Ultimately, this work can be used to guide research into Kranz development and has direct implications for engineering C<sub>4</sub> photosynthesis into rice.
25

Understanding the genetic basis of C4 photosynthesis through breeding

Reeves, Gregory January 2019 (has links)
No description available.
26

An ontology-based system to generate epidemiologic profiles

FERNANDES, P. C. B. 22 August 2012 (has links)
Made available in DSpace on 2016-08-29T15:33:17Z (GMT). No. of bitstreams: 1 tese_5084_.pdf: 1868850 bytes, checksum: 22f46d96f48ef171f653cbcd277c6088 (MD5) Previous issue date: 2012-08-22 / Epidemiology is a field of study in Medicine which seeks to understand the factors that determine the frequency and distribution of diseases in humans. This field allows one to understand the phenomena of health and disease of a particular population by generating this populations epidemiological profile. The knowledge provided in this profile allows a shift in the focus from treating to preventing diseases, which is an important aim of the current Brazilian health care program. This dissertation proposes a system to study the epidemiological profile in a basic health care unit. This system applies an ontology as basis for modeling and querying the epidemiological information. An ontology is a conceptual model which captures an specific view of a domain of discourse. This model may be used to structure the systems information, which later can be queried also with basis on this same ontology. A preliminary validation of this systems prototype has shown that it is able to successfully generate the health care units epidemiological profile, providing new knowledge about the patients and treatments involved in this unit. Such prototype may now be applied in this real setting to guide the actions of health care professionals in dealing with hypertension and other health conditions. In order to develop the system, a goal-oriented methodology based on Tropos is applied. This methodology guides software development since an early stage of organizational modeling until the systems implementation by using current standards for ontology implementation. Many of the available ontology engineering methodologies presuppose the existence of a set of questions which provide the objective and scope of the ontology under development. However, these so-called competency questions are not always clear from start. The highlight of the proposed methodology is applying goal analysis to assist the ontology engineer to reason about and model competency questions. Following this view, such competency questions are comparable to system requirements, elicited and modeled during the requirements engineering stage of a software development process. Both the developed system and the proposed methodology are contributions of this work. However, while the former has proven to be useful in practice, further steps must be carried out in order to properly validate the latter, by applying it to other cases.
27

The role of small RNAs in C4 photosynthesis

Gage, Ewan January 2013 (has links)
The C4 cycle represents a series of biochemical and anatomical modifications that are targeted to overcome the effects of photorespiration caused by the oxygenase capability of Ribulose Bisphosphate Carboxylase/Oxygenase (RuBisCO). The cycle has evolved independently in over 60 lineages, which suggests that recruitment of genes into the C4 cycle is a relatively easy process. However, the mechanisms by which the anatomy and cell-specificity of the components of the C4 cycle is achieved is poorly understood. Preliminary work in maize indicated several components of the C4 cycle may be targeted by microRNAs (miRNAs). To explore this, a library of sRNA sequences from mature leaf tissue of the model C4 species Cleome gynandra L. was generated and then searched against a list of expressed sequence tag sequences for candidate genes of the C4 cycle. To complement this, transgenic C. gynandra containing the viral p19 protein, which is capable of suppressing miRNA activity, were produced. A limited subset of the candidate C4 genes showed a high level of sRNA read alignment. In C. gynandra plants expressing p19 photosynthesis was compromised and transcripts of several genes (most notably RbcS and RCA) were upregulated. These data were complemented by examining the effect of illumination on developing C. gynandra cotyledons, and attempts to generate a hybrid between C. gynandra and the C3 C. hassleriana Chodat. RbcS also showed elevated abundance in etiolated cotyledons, although this rapidly declined after illumination. The remainder of the C4 genes profiled accumulated in etiolated tissue, but were upregulated within 6 hours of illumination. Therefore, this study has illustrated that miRNA activity may play a role in maintaining the C4 photosynthetic cycle at optimum efficiency, although it has not been possible to identify at which point(s) this regulation is applied. Secondly, RbcS appears to be subject to multiple regulatory mechanisms in C. gynandra, and it is possible that miRNAs have a role in negatively regulating expression of RbcS.
28

Factors inducing the chloroplast movement in C₄ plants underhigh light-stress conditions and effects of the response on photosynthesis / 強光ストレス環境におけるC₄植物の葉緑体運動の誘導要因および光合成に与える影響

Maai, Eri 25 May 2020 (has links)
京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13360号 / 論農博第2891号 / 新制||農||1080(附属図書館) / 学位論文||R2||N5299(農学部図書室) / (主査)教授 中﨑 鉄也, 教授 白岩 立彦, 教授 土井 元章 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
29

Softwarová knihovna pro robotickou buňku / Software library for robotic cell

Krištof, Martin January 2021 (has links)
This thesis deals with the design of a software library for PLC Siemens S7-1200 usable in programming of robotic cell. The theoretical part explains the principle of PLC programming and the configuration of an industrial robot. The practical part presents the design of the software library and then the individual blocks of the library are described. The library contains blocks for PLC and is also supplemented by blocks for HMI. Using the proposed library reduces the time required for programming. The software library allows the creation of a unified structure of control programs within the company. The result of the diploma thesis is a tested software library usable in the field.
30

Analysis of C4-Dicarboxylic Acid Transport Genes in Rhizobium Meliloti / C4-Dicarboxylic Acid Transport Genes in R. Meliloti

Yarosh, Oksana 01 1900 (has links)
Rhizobium meliloti mutants defective in C₄-dicarboxylic acid transport (Dct⁻) were previously isolated by Tn5 mutagenesis, and divided into two groups based on complementation of Dct- with cosmid clones. In this work further characterization was carried out on the two loci. Group I mutants were found to be defective in dicarboxylate transport (Dct⁻), nitrate utilization, and symbiotic nitrogen fixation. Subcloning and complementation work confined the Group I mutations to a 3.5 kbp BamHI-EcoRI fragment containing the ntrA gene. Group V mutants were defective in dicarboxylate transport and demonstrated varying levels of nitrogen fixation. Complementation and site-directed Tn5 mutagenesis revealed three transcriptional units, corresponding to dctA, dctB, and dctD, localized within a 6 kbp HindIII fragment. The use of dctA::TnphoA fusions determined the expression of dctA to be ntrA, dctB, and dctD dependent. Dct+ revertants of dctB and dctD mutants were selected which carried second-site mutations responsible for restoring the Dct⁺ phenotype. / Thesis / Master of Science (MS)

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