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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.
31

Study and exploitation of varietal diversity for agroclimatic adaptation and nutritional content improvement in Capsicum spp

Pereira Dias, Leandro 19 November 2021 (has links)
Tesis por compendio / [ES] Hemos utilizado descriptores convencionales y digitales para caracterizar germoplasma español, con el fin de evaluar la variabilidad y probar la eficiencia de esos métodos para diferenciar los materiales. Los resultados muestran gran diversidad dentro de la colección. Además, el fenotipado digital fue capaz de proporcionar una separación más potente. Finalmente, se seleccionó un subconjunto 17 descriptores capaz de distinguir entre accesiones, explicando el 81.81% de la varianza total. Los rasgos del fruto son los más relevantes para la separación entre variedades. Estos hallazgos serán útiles para la recuperación de las variedades tradicionales y el manejo del germoplasma. Las variedades tradicionales más apreciadas de México poseen una aptitud extraordinaria para ser usados como materiales de pre-mejora. Por lo tanto, nos propusimos estudiar la diversidad fenotípica y genotípica de estos materiales, así como el efecto de la polinización abierta en la fijación de las características. La caracterización morfológica y genética de la progenie mostró niveles similares de uniformidad y heterocigocidad a aquellos mostrados por las líneas parentales, sugiriendo que el sistema de reproducción por polinización abierta es eficiente en términos de alcanzar uniformidad agronómica, preservando un cierto grado de diversidad genética. Los estudios genéticos del germoplasma aportan información de gran utilidad. Se utilizó el GBS para estudiar una colección de Capsicum spp. española con el fin de arrojar luz sobre las relaciones filogenéticas de las variedades locales y evaluar su diversidad. Las accesiones europeas mostraron estar estrechamente relacionadas. Además, el origen y tipo de fruto fueron los principales factores que determinaron estructura genética. Los estudios de filogenia también mostraron una estrecha relación entre las accesiones española y mexicana. Los valores Tajima D fueron consistentes con selección positiva en los grupos de C. annuum relacionados con la domesticación. C. baccatum surge como una importante fuente de variabilidad genética y proporcionando a los investigadores la oportunidad de seleccionar individuos para ser introducidos en programas de mejora para el contenido en compuestos bioactivos y resilientes a las condiciones del cambio climático. Por ello, decidimos caracterizar una colección de C. baccatum y C. annuum. Se observó una gran influencia del sistema de cultivo sobre el contenido nutricional donde las concentraciones vieron favorecidas bajo cultivo al aire libre. Asimismo, las accesiones control de C. annuum mostraron concentraciones superiores para la mayoría de compuestos para los dos ambientes. Por otro lado, la buena respuesta C. baccatum demuestra que existe la posibilidad de mejorar estos materiales bajo las condiciones mediterráneas y un alto contenido en compuestos bioactivos. Por último, bajo nuestras condiciones, una ración de pimiento puede aportar entre un 70% y un 120% de la dosis diaria recomendada de ácido ascórbico y entre un 10% y un 60% de la dosis recomendada de minerales. La mejora de las variedades de pimiento para la absorción y uso del fósforo es de suma importancia en la tarea actual de reducir significativamente la necesidad de fertilizantes. El objetivo de este trabajo fue caracterizar una colección de pimiento frente a bajos insumos de fósforo. En general, las condiciones de estrés condujeron a una reducción significativa de la biomasa. Además, el tratamiento de bajo fósforo estimuló el desarrollo de la raíz lateral y pelos radiculares. Además, la concentración de fósforo en los tejidos vegetales disminuyó significativamente. Esta respuesta fue notoriamente superior en las raíces, mostrando la capacidad de movilizar el fósforo hacia otros órganos. Esto proporciona evidencias de la existencia de variabilidad dentro de Capsicum para la eficiencia del uso del fósforo susceptible de ser utilizada en lo / [CA] Hem utilitzat descriptors convencionals i digitals per a caracteritzar una col·lecció de varietats espanyoles, amb la finalitat d'avaluar la variabilitat i provar l'eficiència d'aqueixos mètodes per a diferenciar els materials. Els resultats mostren una gran diversitat dins de la col·lecció. A més, el fenotipat digital va permetre una separació més potent. Finalment, es va seleccionar un subconjunt de 17 descriptors digitals per a distingir entre accessions, explicant el 81.81% de la variància total. Els trets del fruit són els més rellevants per a la separació entre varietats. Aquestes troballes seran útils per a la recuperació de les varietats tradicionals i el maneig del germoplasma. Moltes de les varietats tradicionals més benvolgudes es poden trobar a Mèxic y posseeixen una aptitud extraordinària per a ser usats com a materials de pre-millora. Per tant, ens vam proposar estudiar la diversitat fenotípica i genotípica d'aquests materials, així com l'efecte de la pol·linització oberta en la fixació de les característiques morfològiques i en la fixació genètica. La caracterització morfològica y genètica va mostrar nivells similars d'uniformitat de la progènie a aquells mostrats per les línies parentals, sugerint que la reproducció de pol·linització oberta és eficient en termes d'aconseguir uniformitat agronòmica i alhora preservant un cert grau de diversitat genètica, un fet d'enorme rellevància per a l'adaptació a les condicions de canvi climàtic. Els estudis genètics del germoplasma existent aporten informació de gran utilitat. En la present tesi es va utilitzar el GBS per a estudiar una col·lecció de Capsicum spp. amb la finalitat de llançar llum sobre les relacions filogenètiques de les varietats locals i avaluar la seua diversitat i estructura. Les accessions europees estaven estretament relacionades. A més, les característiques dels fruits i l'origen van ser els principals factors que van determinar la l'estructura genètica. Els estudis de filogènia també van mostrar una estreta relació entre les accessions espanyola i mexicana. Els valors del mètode estadístic Tajima D van ser consistents amb la selecció positiva en els grups de C. annuum relacionats amb la domesticació. C. baccatum sorgeix com una important font de variabilitat i proporcionant l'oportunitat de seleccionar individus per a programes de millora per al contingut en compostos bioactius i condicions del canvi climàtic. Ací es va caracteritzar una col·lecció de C. baccatum i C. annuum. Es va observar una gran influència del sistema de cultiu, on les compostos es van veure afavorides baix cultiu a l'aire lliure. C. annuum van mostrar concentracions superiors per a la majoria de compostos. La bona resposta de C. baccatum demostra que existeix la possibilitat de millorar aquests materials de cara a obtindre individus adaptats a les condicions mediterrànies i un alt contingut en compostos bioactius. Per ultime, sota les nostres condicions, una ració de pimentó pot aportar entre un 70% i un 120% de la dosi diària recomanada d'acidifique ascòrbic i entre un 10% i un 60% de la dosi recomanada de minerals. La millora de les varietats de pimentó per a l'absorció i ús del fòsfor és de suma importància en la tasca actual de reduir la necessitat de fertilitzants. L'objectiu va ser caracteritzar una col·lecció de pimentó enfront de baixos inputs de fòsfor. En general, les condicions d'estrés van conduir a una reducció de la biomassa. A més, va estimular el desenvolupament de l'arrel lateral i de pèls radiculars. A més, la concentració de fòsfor en els teixits vegetals va disminuir significativament. Aquesta resposta va ser notòriament superior en les arrels, mostrant la capacitat de mobilitzar el fòsfor acumulat cap a altres òrgans. Això proporciona evidències de l'existència de variabilitat dins de Capsicum per a l'eficiència de l'ús del fòsfor susceptible de ser utilitzada en / [EN] Herein we used conventional and digital descriptors to characterize a collection Spanish landraces in order to assess the diversity and to test the discriminating ability of said methods. A considerable variation was found for the collection. Digital phenotyping enabled a more powerful separation. We conclude by selecting a subset of 17 descriptors which enable to distinguish among closely related C. annuum accessions. Finally, fruit traits explained the highest percentage of variance for our collection. These findings will be useful to the recovery of heirloom peppers and will boost germplasm characterization and management in seed banks. Some of the most known landraces from Mexico encompass a remarkable aptitude to be used as pre-breeding materials. Hence, we studied the phenotypic and genotypic diversity within these materials and the open-pollination effect on the fixation of morphological characteristics and on the genetic fixation. Morphological and genetic analysis of the progeny showed similar or lower levels of genetic and morphological uniformity than those from progenitors, suggesting that open-pollinated program is efficient in terms of reaching enough agronomic uniformity, while preserving a certain degree of genetic diversity, of paramount importance for the adaptation to climate change. Germplasm genetic studies provide vital information. Herein we used GBS to study a Spanish collection of Capsicum spp. to shed light into phylogenetic relationships and to evaluate their diversity and structure. European accessions showed a close relationship. Furthermore, fruit traits and region of origin were the main factors defining population structure. Spanish and Mexican accessions showed a close phylogenetic relationship; Finally, Tajima's D statistic values were consistent with positive selection in the C. annuum clusters related to domestication. These findings provide relevant information on the origin and relationships of Spanish landraces and for future association mapping studies in pepper. C. baccatum represents a remarkable genetic pool that provides opportunity to select superior individuals to be used in breeding programs for improved bioactive compounds content and resilience to climate change materials. Hence, we characterized a collection of C. baccatum and C. annuum materials. Cultivation system had a major effect controlling fruit's nutrient profile. C. annuum controls presented higher concentrations for most compounds under both conditions. The good performance of C. baccatum accessions shows that there are opportunities to breed materials adapted to the Mediterranean conditions and with interesting properties, especially under open-field conditions. Finally, under our conditions, a serving of pepper cultivated could provide between 70% and 120% of the recommended dietary allowance for ascorbic acid and between 10% and 60% for minerals. Improving pepper varieties for their uptake and use of phosphorus would significantly reduce the need for fertilizer applications. Hence, we characterized the main adaptations, of a Capsicum spp. collection, to low phosphorus inputs. Overall, stress conditions lead to significant reduction of biomass. Stress treatment stimulated lateral root length and root hairs growth. Furthermore, concentration of this mineral in plant tissues decreased significantly. This response was notoriously higher in the roots, demonstrating a high ability to mobilise accumulated phosphorus to other plant organs, providing evidence that within the Capsicum genus there is usable variability for phosphorus use efficiency for breeding programs for low input adaptation. / Pereira Dias, L. (2019). Study and exploitation of varietal diversity for agroclimatic adaptation and nutritional content improvement in Capsicum spp [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/134055 / Compendio
32

Datové sklady a OLAP v prostředí MS SQL Serveru / Data Warehouses and OLAP in MS SQL Server Environment

Madron, Lukáš January 2008 (has links)
This paper deals with data warehouses and OLAP. These technologies are defined and described here. Then an introduction of the architecture of product MS SQL Server and its tools for work with data warehouses and OLAP folow. The knowledge gained is used for creation of sample application.
33

Advanced BaZrO3-BaCeO3 Based Proton Conductors Used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

Bu, Junfu January 2015 (has links)
In this thesis, the focus is on studying BaZrO3-BaCeO3 based proton conductors due to that they represent very promising proton conductors to be used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs). Here, dense BaZr0.5Ce0.3Y0.2O3-δ (BZCY532) ceramics were selected as the major studied materials. These ceramics were prepared by different sintering methods and doping strategies. Based on achieved results, the thesis work can simply be divided into the following parts: 1) An improved synthesis method, which included a water-based milling procedure followed by a freeze-drying post-processing, was presented. A lowered calcination and sintering temperature for a Hf0.7Y0.3O2-δ (YSH) compound was achieved. The value of the relative density in this work was higher than previously reported data. It is also concluded that this improved method can be used for mass-production of ceramics. 2) As the solid-state reactive sintering (SSRS) represent a cost-effective sintering method, the sintering behaviors of proton conductors BaZrxCe0.8-xLn0.2O3-δ (x = 0.8, 0.5, 0.1; Ln = Y, Sm, Gd, Dy) during the SSRS process were investigated. According to the obtained results, it was found that the sintering temperature will decrease, when the Ce content increases from 0 (BZCLn802) to 0.3 (BZCLn532) and 0.7 (BZCLn172). Moreover, the radii of the dopant ions similar to the radii of Zr4+ or Ce4+ ions show a better sinterability. This means that it is possible to obtain dense ceramics at a lower temperature. Moreover, the conductivities of dense BZCLn532 ceramics were determined. The conductivity data indicate that dense BZCY532 ceramics are good candidates as either oxygen ion conductors or proton conductors used for ITSOFCs. 3) The effect of NiO on the sintering behaviors, morphologies and conductivities of BZCY532 based electrolytes were systematically investigated. According to the achieved results, it can be concluded that the dense BZCY532B ceramics (NiO was added during ball-milling before a powder mixture calcination) show an enhanced oxygen and proton conductivity. Also, that BZCY532A (NiO was added after a powder mixture calcination) and BZCY532N (No NiO was added in the whole preparation procedures) showed lower values. In addition, dense BZCY532B and BZCY532N ceramics showed only small electronic conductivities, when the testing temperature was lower than 800 ℃. However, the BZCY532A ceramics revealed an obvious electronic conduction, when they were tested in the range of 600 ℃ to 800 ℃. Therefore, it is preferable to add the NiO powder during the BZCY532 powder preparation, which can lower the sintering temperature and also increase the conductivity. 4) Dense BZCY532 ceramics were successfully prepared by using the Spark Plasma Sintering (SPS) method at a temperature of 1350 ℃ with a holding time of 5 min. It was found that a lower sintering temperature (&lt; 1400 ℃) and a very fast cooling rate (&gt; 200 ℃/min) are two key parameters to prepare dense BZCY532 ceramics. These results confirm that the SPS technique represents a feasible and cost-effective sintering method to prepare dense Ce-containing BaZrO3-BaCeO3 based proton conductors. 5) Finally, a preliminary study for preparation of Ce0.8Sm0.2O2-δ (SDC) and BZCY532 basedcomposite electrolytes was carried out. The novel SDC-BZCY532 based composite electrolytes were prepared by using the powder mixing and co-sintering method. The sintering behaviors, morphologies and ionic conductivities of the composite electrolytes were investigated. The obtained results show that the composite electrolyte with a composition of 60SDC-40BZCY532 has the highest conductivity. In contrast, the composite electrolyte with a composition of 40SDC-60BZCY532 shows the lowest conductivity. In summary, the results show that BaZrO3-BaCeO3 based proton-conducting ceramic materials represent very promising materials for future ITSOFCs electrolyte applications. / <p>QC 20150423</p>
34

Towards Control of Dutch Elm Disease: dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmi / dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmi

Carneiro, Joyce Silva 01 August 2013 (has links)
Ophiostoma novo-ulmi is the causal agent of Dutch elm disease (DED) which has had a severe impact on the urban landscape in Canada. This research program focused on developing molecular genetic strategies to control this pathogenic fungus. The first strategy involved the development of RNA interference (RNAi) for the down-regulation of genes involved in pathogenicity. An efficient RNAi cassette was developed to suppress the expression of the endopolygalacturonase (epg1) locus which encodes a cell-wall degrading enzyme. This epg1-RNAi cassette significantly reduced the amount of polygalacturonase activity in the fungus and resulted in almost complete degradation of epg1 mRNA. The need for a native promoter to selectively down-regulate specific gene loci was addressed by developing a carbon-catabolite regulated promoter (alcA) to drive the expression of the epg1-RNAi cassette. The expression of an alcA-driven epg1-RNAi cassette resulted in the down-regulation of epg expression under glucose starvation but normal levels of expression in high glucose. The expression could therefore be controlled by culture conditions. The second strategy explored the potential of using dsRNA viruses to vector disruptive RNAi cassettes. An isolate of O. novo-ulmi strain 93-1224 collected in the city of Winnipeg, was infected by two dsRNA mitoviruses which upon sequence characterization were named OnuMV1c and OnuMV7. To assess the transmissibility of this dsRNA virus the infected isolate 93-1224 was paired with three naive isolates of the related fungi O. ulmi and O. himal-ulmi. Through the use of nuclear and mitochondrial markers it was determined that the virus OnuMV1c may not rely on mitochondrial fusion for transmission but may have a cytoplasmic transmission route. This investigation of gene expression and manipulation has provided tools to help understand gene regulation in O. novo-ulmi. It has also added to our knowledge of mitoviruses, their transmission and potential use as a biological control. By enhancing our understanding of transmissible hypovirulence this work contributes to efforts to develop a new approach to target DED as well as a potential model for the control of other fungal diseases. / Graduate / 0307 / 0306 / 0369 / jscarneiro@hotmail.com
35

Ovlivnění genetické diverzity rákosových porostů strukturou říčních systémů / Impact of river system structure on the genetic diversity of reed populations

Fuxová, Gabriela January 2011 (has links)
Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...
36

The autonomous crewmate : A sociotechnical perspective to implementation of autonomous vehicles in sea rescue

Lundblad, Oscar January 2020 (has links)
The usage of autonomous vehicles is starting to appear in several different domains and the domain of public safety is no exception. Wallenberg Artificial Intelligence, Autonomous Systems and Software Program (WASP) has created a research arena for public safety (WARA-PS) to explore experimental features, usages, and implementation of autonomous vehicles within the domain of public safety. Collaborating in the arena are several companies, universities, and researchers. This thesis examines, in collaboration with Combitech, a company partnered in WARA-PS, how the implementation of autonomous vehicles affects the sociotechnical system of a search and rescue operation during a drifting boat with potential castaways. This is done by creating a case together with domain experts, analyzing the sociotechnical system within the case using cognitive work analysis and then complementing the analyses with the unmanned autonomous vehicles of WARA-PS. This thesis has shown how the WARA-PS vehicles can be implemented in the case of a drifting boat with potential castaways and how the implementation affects the sociotechnical system. Based on the analyses and opinions of domain experts’ future guidelines has been derived to further the work with sociotechnical aspects in WARA-PS. / WARA-PS

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