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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

MAŽALAPĖ LIEPA (Tilia cordata Mill.) LIETUVOJE: FENOTIPINĖ ĮVAIROVĖ IR MODALINIŲ MEDYNŲ NAŠUMAS / SMALL-LEAVED LIME (Tilia cordata Mill.) IN LITHUANIA: PHENOTYPICAL DIVERSITY AND PRODUCTIVITY OF MODAL STANDS

Semaškienė, Loreta 07 June 2006 (has links)
This doctoral dissertation has been accomplished during the period of 1995-2006 in the Department of Forestry at the Lithuanian University of Agriculture. In Lithuanian forests only one species of genus - small-leaved lime (Tilia cordata Mill.) – is natural. Study aim was to determine the distribution of lime stands in Lithuania, estimate their productivity and phenotypic variation. For the first time distribution of lime stands in different natural forest regions of Lithuania has been analysed. For the first time studies of the phenotypical diversity were conducted, phenotypical diversity in natural stands has been analysed. Phenological forms of small-leaved lime were singled out, their development differences were justified. Yield models for all lime stand sites and site productivity scale for lime stands were designed.For the first time data on the diversity of phenotypical traits and on the influence of environmental factors on phenotypical indices of lime trees were analysed in Lithuanian stands of natural origin. The data may be applied to estimate the possibilities of lime growth in different conditions, forecasting stand productivity. The data on phenotypic diversity may be important to preserve genetic diversity of naturally growing lime stands. For the first time the distribution of lime stands, their species composition in natural forest regions of Lithuania and in different sites were analysed. Yield models of modal stands and site productivity scales for lime... [to full text]
2

Variabilidade e correlações entre caracteres relacionados às fases vegetativa e reprodutiva em cultivares de coqueiro nos tabuleiros costeiros do norte de Sergipe

CARVALHO, Eric Xavier de 07 February 2006 (has links)
Submitted by (ana.araujo@ufrpe.br) on 2017-02-07T17:52:37Z No. of bitstreams: 1 Eric Xavier de Carvalho.pdf: 648807 bytes, checksum: 66df22d6c50815aa9aeee4122f493050 (MD5) / Made available in DSpace on 2017-02-07T17:52:37Z (GMT). No. of bitstreams: 1 Eric Xavier de Carvalho.pdf: 648807 bytes, checksum: 66df22d6c50815aa9aeee4122f493050 (MD5) Previous issue date: 2006-02-07 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The objective of this work was to evaluate the variability among cultivars of dwarf coconut palms and among hybrids, besides identifying and quantifying associations among morphologic characters in dwarves in Tabuleiros Costeiros of the North of Sergipe State. The coconut palm exploration is an agricultural activity of elevate partner-economic importance, for its multiple uses and purposes, generation of jobs and income. It is economically important for about 86 countries. The Brazilian of coconut palm productivity is low due the poor genectic cultivars is the main problem for this activity in the country. Knowledging variability, through genetic parameters, genetic and phenotypical correlation, and the implications of the effect of the cultivar x environment to know the control of the characters, the potential of the population for selection besides facilitating and speeding up the indication to cultivate to use in programs of genetic improvement. Two experiments had been installed since 1997, in the Farm Agreste in Neópolis (SE). The used experimental desing was randomized block, with six cultivars of dwarf coconut palm and eight hybrids, respectively, with four blocks, 16 usefull plants/plot. The measurements of the characteristics were carried out quarterly from 2001 at 2004 of the analyses of variance and estimate of the components of phenotypical variation, genetic and ambient and 1999 and 2004 considering the characteristics of the juvenile and adult phase of the plants for determination of the correlations. To cultivars of dwarf coconut palm had presented potential variability to the genetic improvement with possibility of gain for selection and indication to the producer to cultivars more suitable to the diverse producing regions. The intervarietais hybrids had presented variability and little specificities in the behavior for the enviromental conditions of the four evaluated years. There are genetic associations among characters of the vegetative and reproductive phases of the dwarf coconut palms. / O objetivo deste trabalho foi avaliar a variabilidade entre cultivares de coqueiro anão e híbridos, além de identificar e quantificar associações entre caracteres morfológicos em anões nos tabuleiros costeiros do norte de Sergipe. O cultivo do coqueiro é uma atividade agrícola de elevada importância socioeconômica, por seus múltiplos usos e finalidades,geração de empregos e renda, além da fixação do homem ao campo sendo importante economicamente para cerca de 86 países. A baixa produtividade brasileira de coco é um dos principais problemas da cultura do coqueiro no país. O conhecimento da variabilidade devida às diferenças genéticas, através de parâmetros genéticos e correlações genética e fenotípica, e as implicações dos efeitos da interação cultivar x ambiente, permitem conhecer o controle genético dos caracteres, o potencial da população para seleção, além de facilitar e acelerar a indicação de cultivares para uso em programas de melhoramento genético. Dois experimentos foram conduzidos desde 1997, na Fazenda Agreste em Neópolis (SE), em delineamento experimental de blocos casualizados, com seis cultivares de coqueiro anão e oito híbridos, respectivamente,com quatro blocos e 16 plantas úteis/parcela. As mensurações dos caracteres foram realizadas trimestralmente de 2001 a 2004 para as realizações das análises de variância e estimativa dos componentes de variação fenotípica, genética e ambiental e nos anos de 1999 e 2003 para determinação das correlações considerando as características das fases juvenil e adulta das plantas. As cultivares de coqueiro anão apresentam variabilidade potencial ao melhoramento genético com possibilidade de ganhos por seleção. Os híbridos intervarietais apresentam variabilidade e pouca espeficidade no comportamento para as condições ambientais dos quatro anos avaliados. Existem associações genéticas entre caracteres das fases vegetativa e reprodutiva do coqueiro anão.
3

Estudo Morfométrico de Ovinos da Raça Crioula Lanada no Sul do Brasil: Um Subsídio para a Conservação In Situ / Morphometric Traits in Crioula Lanada Sheep in Southern Brazil: A Contribution for In Situ Conservation

SILVA, Marcelo Corrêa da 23 February 2011 (has links)
Made available in DSpace on 2014-07-29T15:07:33Z (GMT). No. of bitstreams: 1 Dissertacao Marcelo Correa da Silva.pdf: 2475185 bytes, checksum: 5145b979ea0db333c12b56b2ecd50859 (MD5) Previous issue date: 2011-02-23 / Intense selection pressure is associated with global economy and market conjectures, which has great influence and threatens the sustainability of genetic varieties used in traditional crop and livestock production. Abrupt change of such breeds for exotic ones is decreasing genetic diversity and has extinguished many domestic varieties worldwide. The Crioula Lanada sheep breed is a Brazilian cultural, ecological and genetic patrimony which was almost extinct in the mid twentieth century. Conservation activities were established in Southern Brazil with collaboration of a farmer´s association and the foundation of an institutional flock. Currently, breed population is still small and little information about these animals is available. It is necessary that characterization studies subsidize the conservation of this important genetic resource so that farmers can make the best of its use in different production systems. A phenotypical study was undertaken to help handling activities and in situ conservation. 15 morphometric variables (cm) and body weight (kg) were evaluated in 67 male and 812 female sheep, distributed in five age categories and raised in four municipalities of Rio Grande do Sul and two of Santa Catarina, Southern Brazil. The influence of age, sex, wool type and geographic location (fixed effects) on morphometric measures was tested, in addition to correlation, factor analysis and the discrimination of the Crioula Lanada sample in Serrana or Fronteira ecotype. Variance, means test, descriptive, correlation analysis and multivariate statistics were carried out using the Statistical Analysis System Program (SAS, 2002). Age, sex and geographic location revealed significant effect (p<0,001) on morphometric measures. Different averages between age categories depend on which variable is being analyzed, being all means equivalent when considering animals older than 3 years. Most correlations where significant (p<0,05), being thoracic perimeter with body weight the strongest (0,72). Correlation between head and body measures were medium or weak, being strong between body weight. Head and body variables are more related among themselves. Leg, arm and tail measurements revealed weak correlations with body weight, besides not being different (p>0,05) among age categories. Using multivariate statistics, it was possible to explain 81% of variance with only two factors, whereat three groups of variables were identified: one with body measures, the second with head measures and the third with thoracic measures and body weight. 95% of Fronteira sheep were correctly classified in its geographic location being possible to correctly classify animals of each herd of the Serrana ecotype and the ecotypes themselves. The results found in this study can be used as a dialectic instrument to study farmers perceptions and develop an in situ conservation program for the Crioula Lanada breed / A intensa pressão de seleção genética exercida nas espécies domésticas é resultado de conjunturas de mercado e economia global e tem representado ameaças às variedades tradicionalmente utilizadas na agricultura e pecuária. A substituição abrupta de grupos genéticos crioulos por raças exóticas tem diminuído a diversidade genética mundial e levado inúmeras raças à extinção. A ovelha Crioula Lanada é um patrimônio genético, cultural e ecológico brasileiro que quase foi extinto em meados do século XX. Ações para a conservação da raça foram estabelecidas no sul do Brasil, com ajuda de uma associação de produtores e a criação de um rebanho institucional. Atualmente a população efetiva ainda é pequena e com o pouco conhecimento acerca destes ovinos tornase fundamental que estudos de caracterização subsidiem a conservação deste importante recurso genético e que, assim, seja possível fazer um melhor uso nos diferentes sistemas de criação. O objetivo foi realizar um estudo fenotípico da raça para subsidiar as práticas de manejo e conservação in situ. Utilizaram-se 15 variáveis morfométricas (cm) e o peso corporal (kg) de 67 machos e 812 fêmeas, distribuídos em cinco categorias de idade e criados em quatro municípios do Rio Grande do Sul e dois de Santa Catarina. Foi testada a influência dos efeitos fixos (idade, sexo, tipo de lã e procedência geográfica) sobre as medidas morfométricas, analisada a estrutura de correlação e a possibilidade de discriminar os animais da raça Crioula Lanada em ecótipos Serrana ou Fronteira. Para isso, foram realizadas análises de variância, teste de médias, estatística descritiva, análise de correlação e estatística multivariada. A idade, o sexo e a procedência geográfica dos rebanhos apresentaram efeito significativo (p<0,001) sobre as medidas estudadas. Dependendo da variável morfométrica analisada pode, ou não, haver diferença (p<0,05) entre as cinco categorias de idade, sendo que nenhum valor médio difere entre as categorias com mais de três anos. A maioria das correlações foi significativa (p<0,05), sendo mais forte entre o perímetro torácico e o peso corporal (0,72). As correlações entre as medidas da cabeça e as do corpo foram médias ou fracas, sendo maiores entre si e com o peso corporal. Medidas de perna, braço e cauda tem correlação fraca com o peso corporal, além de não serem diferentes (p>0,05) entre as categorias de idade. Na análise multivariada dos dados, foi possível explicar 81% da variância com dois fatores, no qual três grupos de variáveis foram identificados: um com medidas do corpo, um com medidas da cabeça e o terceiro com medidas do tórax e o peso corporal. As ovelhas criadas na região atribuída ao ecótipo Fronteira foram corretamente classificadas (95%), sendo possível classificar cada rebanho do ecótipo Serrana e os ecótipos entre si. Os resultados encontrados poderão servir como um instrumento de diálogo junto aos criadores para desenvolver um programa de conservação in situ para a raça Crioula Lanada.
4

Kmenové buňky zubní pulpy / Dental pulp stem cells

Suchánek, Jakub January 2011 (has links)
The aim of this dissertation study was to optimize the isolation and long term cultivation protocols for human dental pulp stem cells. The protocols which showed best results were used for cultivation of dental pulp stem cell isolated from exfoliated teeth (SHED). Additional aims were to characterize DPSC and SHED and prove their ability to proliferate over Hayflick's limit and differentiate into mature cell lines (osteoblasts, chondroblasts and adipocytes). In order to find optimal protocols for isolation of dental pulp from tooth, we tried three different approaches. During optimization of cultivation protocol we focused on decreasing amount of fetal calf serum (FCS) from 10 % FCS in cultivation media (most often used in literature) into 2 % and thus get closer to cultivation conditions suitable for clinical usage. We compared DPSC cultivated in three different media (medium with 10 % FCS, 2 % FCS supplemented with growth factors and media with 2 % FCS supplemented with ITS and growth factors). For characterization of DPSC and SHED we used basic biological properties (proliferation activity, viability, morphology), their phenotype and karyotype. The study demonstrated that the best protocol for isolation of dental pulp from tooth was to break the roots and extract the pulp throw this aperture. We...
5

Large-scale brain networks: what the resting brain can tell us about phenotypic differences and pharmacological interventions

Deza Araujo, Yacila Isabela 16 August 2019 (has links)
This doctoral thesis aims to demonstrate the relevance of resting-state functional connectivity (RSFC) for the study of brain function. RSFC refers to the spontaneous brain activity structured in intrinsic connectivity networks. These networks mirror task-based activations and show significant variations across several behavioral domains and phenotypical traits. Furthermore, changes in these networks after, for instance, pharmacological manipulations, may disentangle the specific role of several neurotransmitters systems in normal and pathological functional connectivity. While various neuroimaging techniques enable the detection of intrinsic connectivity networks, data-driven methods, such as independent component analysis, provide a robust spatial representation of brain networks that are distinguishable from physiological signals and scanner noise. Within the above-mentioned framework, this thesis presents data from two studies designed to better understand 1) individual differences in decision making reflected in intrinsic network connectivity and 2) variations in intrinsic network connectivity following serotonergic manipulations. The first part is the general introduction where I present the theoretical background, the methodology used in both experiments and an overview of the current research related to the studies of this thesis. The second chapter presents the first study, which examined the relationship between a set of value-based decision-making parameters with large-scale intrinsic connectivity networks. Findings of this study revealed that individuals who prefer to gamble in order to avoid a sure loss, exhibit stronger connectivity between the default mode and left frontoparietal systems to their adjacent brain regions, especially to those involved in prospective thinking, affective decision making and visual processing. The third chapter presents the second experimental study, which examined changes in default mode network connectivity after two tryptophan interventions to increase and decrease brain serotonin synthesis, and a control condition. Results of this study showed decreased functional connectivity between the default mode network and emotion-related regions associated with higher serotonin brain levels. Finally, the fourth chapter includes a general discussion that integrates the significance of the findings from both studies. In this section, limitations and recommendations for future research are also considered before presenting the conclusion that highlights the contribution of this work for unraveling the continuous activity of the resting brain.:1.CONTENTS 1 LIST OF FIGURES 3 LIST OF TABLES 4 ABBREVIATIONS 5 ABSTRACT 7 GENERAL INTRODUCTION 9 1.1. Resting-state functional connectivity: the silent work of the resting brain 9 1.2. Intrinsic connectivity networks 12 1.3. Independent Component Analysis 17 1.4. Summary: research objectives and study hypotheses 20 STUDY I: Risk seeking for losses modulates the functional connectivity of the default 2.mode and left frontoparietal networks in young males 22 2.1. Abstract 23 2.2. Introduction 24 2.3. Materials and Methods 26 2.4. Results 33 2.5. Discussion 41 2.6. Notes 44 2.7. Supplemental Material Study I 45 3. STUDY II: Acute Tryptophan Loading Decreases Functional Connectivity between the Default Mode Network and Emotion-Related Brain Regions 49 3.1. Abstract 50 3.2. Introduction 51 3.3. Materials and Methods 53 3.4. Results 61 3.5. Discussion 67 3.6. Acknowledgments 71 3.7. Supplemental Material Study II 72 4. GENERAL DISCUSSION 78 4.1. Research objectives and summary of results 78 4.2. Risk seeking for losses is associated with changes in default mode and frontoparietal systems 79 4.3. Higher serotonin brain synthesis decreases DMN connectivity 80 4.4. Integration of findings 81 4.5. Limitations and future directions 83 4.6. General conclusion 85 5. ZUSAMMENFASSUNG 86 Hintergrund 86 Fragestellung 86 Material und Methoden 87 Ergebnisse 88 Schlussfolgerungen 89 6. SUMMARY 90 Background 90 Research question 90 Material and Methods 91 Results 92 Conclusion 92 7.REFERENCES 93 8.ANNEX 113 8.1. Publikationsverzeichnis 113 8.3.Danksagung 115 8.4. Erklärungen zur Eröffnung des Promotionsverfahrens 116 8.5. Erklärung zur Einhaltung gesetzlicher Vorgaben118 8.6. Erklärungen zur Publikation 119
6

Amélioration de la robustesse de souches de levures aux stress technologiques par une stratégie de génie microbiologique : Application à la production industrielle de bio-éthanol à partir de matières premières agricoles / Robustness improvement of yeast strains under technological stresses through a microbiological engineering strategy : Application to industrial production of bio-ethanol from agricultural feedstocks

Amillastre, Emilie 16 July 2012 (has links)
Sous contraintes industrielles, les micro-organismes sont soumis à différents stress technologiques, liés à leur culture en réacteur de grande taille, altérant leur viabilité et les performances des procédés. Les fluctuations des paramètres physico-chimiques (température, pH, …) sont responsables de cette baisse d’efficacité de la fermentation. Afin de contribuer à l’intensification des performances des procédés de production de bio-éthanol, ce projet de thèse propose d’améliorer la robustesse d’une souche industrielle de Saccharomyces cerevisiae productrice d’alcool vis-à-vis d’un stress environnemental : la température. La stratégie générale de ce projet réside dans l’obtention d’un mutant plus tolérant que la souche sauvage au stress appliqué par abaissement de son taux de décès. Un pilote original de culture en continu a été mis en place, couplant mutagénèse aux UV, générant des modifications génétiques et pression de sélection par des variations de température, permettant la sélection des variants les plus robustes. Un modèle phénoménologique a été développé afin de simuler les cinétiques microbiennes selon le mode de conduite du pilote et d’optimiser les conditions de fonctionnement nécessaires à l’obtention des futurs variants. Ce modèle cinétique fait intervenir l’influence de la température sur les cinétiques de croissance, de décès cellulaire et de production d’éthanol chez Saccharomyces cerevisiae. Ces cinétiques ont été quantifiées expérimentalement en fonction de la température et des traitements de mutagénèse par UV. Grâce aux conditions obtenues par simulation, des cultures en mode continu ont été réalisées et des variants obtenus ont été caractérisés, en condition de production intensive d’éthanol, sur la base de leurs performances en termes de croissance, de décès et de capacités fermentaires. Cette stratégie a permis de sélectionner un variant possédant une meilleure robustesse vis-à-vis de la température, caractérisé par un taux de décès plus faible que celui de la souche sauvage. Néanmoins ce variant ne se caractérise pas par de meilleures performances fermentaires / Under industrial constraints, microorganisms are exposed to various stresses, due to their cultivation in large scale bioreactor, altering their viability and the performances of bioprocesses. Fluctuations in physico-chemical parameters (temperature, pH, ...) are responsible for this reduction in fermentation efficiency. This Ph.D project intends to improve the robustness of an industrial ethanol producer Saccharomyces cerevisiae strain under heat stress, in order to improve its industrial production of bio-ethanol under temperature fluctuating environment. The strategy of this project is to obtain a mutant more tolerant than the wild type strain to heat stress, possessing a lower death rate. An original continuous culture reactor has been designed, coupling UV mutagenesis (generating genetic modifications) and selection pressure (temperature) to select the most robust variant. A phenomenological model was proposed to simulate microbial kinetics based on the monitoring strategy of the chemostat and to optimize the operating conditions necessary for the generation of variants. This dynamic model involves the impact of the temperature on the kinetics of growth, cell death and ethanol production in Saccharomyces cerevisiae. These kinetics were experimentally quantified as a function of the temperature and the UV treatment. Continuous cultures were carried out under the simulated conditions and some variants were characterized in very high ethanol performance fermentations in terms of growth, death and production performances. This strategy allowed us to select a variant possessing a better thermal robustness characterized by a lower death rate than the wild type strain under heat stress. However, the reduction of the death rate did not translate into better ethanol production performances

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