Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-04T17:56:43Z No. of bitstreams: 1 camilafariacarrada.pdf: 1705454 bytes, checksum: dbf21cbcbbd9768b8a87c74182b60328 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-07T03:23:56Z (GMT) No. of bitstreams: 1 camilafariacarrada.pdf: 1705454 bytes, checksum: dbf21cbcbbd9768b8a87c74182b60328 (MD5) / Made available in DSpace on 2015-12-07T03:23:56Z (GMT). No. of bitstreams: 1 camilafariacarrada.pdf: 1705454 bytes, checksum: dbf21cbcbbd9768b8a87c74182b60328 (MD5) Previous issue date: 2015-04-24 / É de fundamental importância investigar a colonização de periodontopatógenos e seu papel na etiologia da doença periodontal de crianças e adolescentes com síndrome de Down, os quais apresentam alta prevalência da doença. O objetivo deste estudo foi avaliar qualitativa e quantitativamente a presença na saliva de bactérias periodontopatogênicas em crianças e adolescentes com e sem síndrome de Down. Este estudo transversal incluiu uma amostra de trinta crianças e adolescentes com síndrome de Down (grupo SD), com idade entre 3-12 anos, e trinta controles sem a síndrome (grupo ND), com idades entre 4-12 anos. Exame clínico foi realizado para determinar o índice de sangramento à sondagem e o índice de placa em dentes índice. Amostras de saliva não estimuladas foram coletadas de todos os participantes. A técnica de hibridização in situ fluorescente (FISH) identificou a presença e as densidades de oito bactérias periodontopatogênicas na saliva. O teste qui-quadrado foi utilizado para analisar as variáveis categóricas e o teste U de Mann-Whitney foi utilizado para as variáveis numéricas. Adotou-se um nível de significância de 5%. Os registros clínicos mostraram frequência mais alta de crianças e adolescentes com sangramento à sondagem no grupo SD (P = 0,037); nenhuma diferença foi encontrada em relação ao índice de placa entre os grupos (P = 0,516). Crianças e adolescentes com síndrome de Down apresentaram densidades maiores de Campylobacter rectus (P = 0,013), Porphyromonas gingivalis (P = 0,025), Treponema denticola (P = 0,026), Fusobacterium nucleatum (P = 0,013), Prevotella intermedia (P = 0,001) e Prevotella nigrescens (P = 0,008). Nenhuma diferença significativa foi encontrada nas densidades de Aggregatibacter actinomycetemcomitans (P = 0,057) e Tanerella forsythia (P = 0,584). No grupo SD, as densidades das bactérias do complexo laranja foram significativamente maiores nas faixas etárias de 3 a 7 anos para F. nucleatum, P. intermedia e P. nigrescens, e de 8 a 12 anos para C. rectus. Os resultados confirmam que crianças e adolescentes com síndrome de Down apresentam maior suscetibilidade à doença periodontal e maior prevalência e densidade de patógenos periodontais importantes para o estabelecimento e agravamento da doença periodontal. / It is of particular importance to investigate the colonization of periodontal pathogens and their role in the etiology of periodontal disease in children and adolescents with Down syndrome, who have a high prevalence of periodontal disease. The aim of this study was to assess qualitative and quantitatively the presence of periodontopathogenic bacteria in saliva in a group of Down and non-Down syndrome children and adolescents. This cross-sectional study included a sample of 30 Down syndrome children and adolescents (group DS), aged 3-12 years, and 30 non-Down syndrome children and adolescents (group ND) aged 4-12 years. Dental examinations were performed to determine the bleeding on probing index and plaque index in index teeth. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization (FISH) technique identified the presence and density of eight periodontopathogenic bacteria in saliva. The chisquare test was used to analyze the categorical variables and the Mann-Whitney U test was used for the continuous variables. The significance level was set at 5%. Clinical records showed a higher frequency of children and adolescents with bleeding on probing in DS group (P = 0.037); no significant difference was found in relation to plaque index between the groups (P = 0.516). Down syndrome children showed higher salivary density of Campylobacter rectus (P = 0.013), Porphyromonas gingivalis (P = 0.025), Treponema denticola (P = 0.026), Fusobacterium nucleatum (P = 0.013), Prevotella intermedia (P = 0.001) and Prevotella nigrescens (P = 0.008). No significant difference was found in salivary density of Aggregatibacter actinomycetemcomitans (P = 0.057) and Tanerella forsythia (P = 0.584). In DS group, the densities of bacteria of orange complex were higher in the age groups 3-7 years for F. nucleatum, P. intermedia and P. nigrescens, as well as in age groups 8-12 years for C. rectus. The results confirm that Down syndrome children and adolescents have an increased susceptibility to periodontal disease and higher prevalence and density of important periodontal pathogens for the onset and worsening of the periodontal disease.

A riqueza e a diversidade de espécies forrageiras dos Campos Sulinos, pode propiciar a inserção de espécies nativas em programas de melhoramento. As gramíneas nativas do gênero Paspalum possuem grande variabilidade, que pode contribuir para seleção de genótipos adaptáveis às várias condições ecológicas de regiões tropicais e subtropicais. Dentre as espécies deste gênero destaca-se o Paspalum notatum com ecótipos que possuem superioridade produtiva quando comparados à cultivares comerciais, o que contribui para que esta espécie seja candidata ao lançamento de novas cultivares. Avaliações de plantas melhoradas submetidas a diferentes práticas de manejo, como fertilização ou consorciação, são fundamentais para gerar conhecimento acerca das características produtivas. O objetivo deste trabalho foi avaliar o potencial produtivo de uma progênie híbrida intraespecífica de P. notatum submetida a diferentes níveis de fertilização nitrogenada ou consorciação com leguminosas para serem empregados em sistemas de produção a pasto ou na recuperação de pastagens naturais degradadas. A produção de matéria seca e a densidade populacional de perfilhos dos genótipos de P. notatum respondem de forma positiva aos níveis de fertilização nitrogenada. O nível de fertilização 120 kg N ha-1ano-1 promove a maior eficiência de uso de nitrogênio nos genótipos de P. notatum. Os genótipos B26, C22, C9 e Bagual são indicados para serem utilizados em sistemas de consórcio com leguminosas de clima temperado. A produção de matéria seca de sistemas com genótipos de P. notatum consorciados com trevo branco mais cornichão é semelhante à produção de sistemas fertilizados com até 240 kg N ha-1ano-1, evidenciando a viabilidade do consórcio entre essas espécies. / The richness and diversity of forage species in the Campos Sulinos region may facilitate the inclusion of native species in breeding programs. Native grasses of the Paspalum genus show great variability which may contribute to the selection of adaptable genotypes to the various ecological conditions of tropical and subtropical regions. Within the genus, Paspalum notatum is a species with superiorly productive ecotypes compared to commercial cultivars, rendering this species a candidate for the release of new cultivars. The evaluation of bred plants submitted to different management practices, such as fertilization or consortium with legumes is fundamental to acquire knowledge about the productive features. The objective of the present work was to evaluate the productive potential of an intraspecific hybrid progeny of Paspalum notatum submitted to different nitrogen fertilization levels or intercropped with legumes, with the objective of being used in grazing systems or in the recovery of degraded natural pastures. The dry matter yield and tiller population density of Paspalum notatum genotypes respond positively to nitrogen fertilization levels. The 120 kg N ha-1year-1 fertilization level promotes the highest nitrogen utilization efficiency in Paspalum notatum. Genotypes B26, C22, C9 and Bagual are indicated for legume intercropped systems with temperate legumes. The dry matter production of intercropped systems between Paspalum notatum genotypes with white clover plus birdsfoot trefoil is similar to the production of systems fertilized with up to 240 kg N ha-1year-1, demonstrating the viability of the intercropped between these species.

Bromeliaceae é uma família importante entre as monocotiledôneas devido ao seu elevado número de espécies distribuídas no Neotrópico, e por uma riqueza de caracteres adaptativos a diferentes habitats. Flores de bromélias possuem uma grande variação morfológica, frequentemente negligenciada em estudos de morfoanatomia e de filogenia. Para uma melhor compreensão dos mecanismos de desenvolvimento que levam a essas variações, foram analisados aspectos moleculares e evolutivos do fator de transcrição MADS-box PISTILLATA (PI), a partir de sequências de transcritos isolados de inflorescências de bromélias nativas brasileiras. Sequências PI de Bromeliaceae foram comparadas com outras monocotiledôneas, com verificação de expressão em inflorescências de Tillandsia aeranthos (Loisel.) LB Sm. com o uso de hibridação in situ. Sequências de PI mostraram alta conservação, inclusive em um sítio de deleção encontrado para todos os membros analisados da família. Todos os membros da família se agruparam em um único clado em reconstruções filogenéticas. Entretanto, devido a características de taxas de mutações rápidas e divergência antiga do gene, não foi possível obter uma relação precisa entre diferentes famílias ou ordens. Todavia, PI mostrou ter potencial como ferramenta de análise filogenética para espécies proximamente relacionadas. Os transcritos de PI foram localizados principalmente em tecidos meristemáticos de regiões menos desenvolvidas de inflorescências de Tillandsia aeranthos. Flores mais desenvolvidas presentes nas inflorescências mostraram um padrão de acúmulo preferencial de transcritos PI em pétalas e sépalas, assim como esperado para flores com perianto diferenciado em sépalas e pétalas. De qualquer forma, Tillandsia aeranthos se mostrou eficiente para estudos morfoanatômicos com enfoque em desenvolvimento evolutivo. / Bromeliaceae is an important monocotyledon family due to its high number of species in the Neotropic, and a wealth of adaptive characters to different habitats. Bromeliad flowers have large morphological variations, often neglected in morpho-anatomy, floral development and phylogeny studies. For a better understanding of its floral developmental mechanisms that lead to morphological variations, molecular and evolutionary aspects of the transcription factor MADS-box PISTILLATA (PI) encoding gene isolated had been investigated in native bromeliad inflorescences. Bromeliaceae PI sequences were compared with other monocots, and the expression of these transcripts was detected in Tillandsia aeranthos (Loisel.) LB Sm. inflorescences using in situ hybridization. The PI sequences display high conservation, including a specific deletion site found in all family members. Likewise, all Bromeliaceae members grouped into a single clade in phylogeny reconstruction. However, due to rapid mutation rate and ancient divergence in PI, it was not possible to obtain a precise relationship between different monocot families and orders. Nevertheless, PI showed potential as a phylogenetic tool for analysis between closely related species. PI transcripts were located mainly in meristematic tissues from less developed regions of the inflorescences. More developed flowers showed a preferential PI transcripts accumulation in petals and stamens as expected for differentiated perianth, found in Bromeliaceae flowers. Anyway, Tillandsia aeranthos showed good potential skills for morpho-anatomy focused in evolutionary development.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-09-15T22:23:03Z No. of bitstreams: 1 Tese-Maria do Socorro.pdf: 2248544 bytes, checksum: 195ed518eb9bcdd7d8346e1af11ce2bc (MD5) / Made available in DSpace on 2016-09-15T22:23:03Z (GMT). No. of bitstreams: 1 Tese-Maria do Socorro.pdf: 2248544 bytes, checksum: 195ed518eb9bcdd7d8346e1af11ce2bc (MD5) Previous issue date: 2015-10-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Brazil is one of the main centers of genetic diversity and dispersion of the genus Passiflora. In the present work, several species and interspecific hybrids of Passiflora were characterized through cytogenetic techniques and ISSR markers, as well as these genotypes were evaluated for in vitro multiplication and establishment. Chromosomal preparations were submitted to conventional staining, CMA3/DAPI banding, FISH using 45S/5S rDNA probes and GISH. Genomic DNA of P. edulis and P. cincinnata were used as genomic probes in the GISH. Twenty ISSR primers were used for the characterization by molecular markers. Nodal segments of P. cincinnata, P. laurifolia, P. setacea and P. luetzelburgii were collected and evaluated in the WPM, DKM and MS culture media to establishment of in vitro culture; for in vitro multiplication, explants were inoculated in DKW culture media under different concentrations of BAP, KIN and 2iP cytokinins. The results showed 2n = 18 chromosomes for the species and hybrids, regular meiosis, one pair of 5S rDNA sites and two or three pairs of 45S rDNA sites co-localized with the CMA3+/DAPI- bands. It is the first chromosomal counting recorded for P. luetzelburgii. Three groups distinct of chromosomes were revealed by GISH. The hybrid origin and the relationship with the parental species were also confirmed by using of the ISSR markers. DKW culture medium provided the better development of the explants, P. cincinnata CPE16 showed the better in vitro morphogenetic response, and KIN showed to be more efficient in obtaining increased shoots length. / O Brasil ? um dos principais centros de dispers?o da variabilidade gen?tica do g?nero Passiflora. O presente trabalho objetivou caracterizar esp?cies e h?bridos interespec?ficos de Passiflora, atrav?s de t?cnicas citogen?ticas e por marcadores ISSR, al?m de avaliar o estabelecimento e multiplica??o in vitro de gen?tipos de maracujazeiro. Prepara??es citol?gicas foram submetidas ? an?lise convencional, dupla colora??o com os fluorocromos CMA3/DAPI, FISH utilizando como sonda DNAr 5S/45S e GISH. O DNA gen?mico de P. edulis e P. cincinnata foram utilizados como sondas gen?micas na GISH. Foram utilizados 20 primers ISSR na caracteriza??o por marcadores moleculares. Para o estabelecimento do cultivo in vitro, segmentos nodais de P. cincinnata, P. laurifolia, P. setacea e P. luetzelburgii foram coletados e avaliados em meio de cultura WPM, DKW e MS, para a multiplica??o in vitro, os explantes foram inoculados em meio DKW sob diferentes concentra??es de citocininas BAP, KIN e 2iP. Os resultados mostraram 2n = 18 cromossomos para as esp?cies e h?bridos, al?m de meiose regular, um par de s?tios de DNAr 5S e dois a tr?s pares de s?tios de DNAr 45S que co-localizaram as bandas CMA3+/DAPI-, sendo o primeiro registro de contagem para P. luetzelburgii. Na GISH foi observada a forma??o de tr?s grupos cromoss?micos distintos. A origem h?brida e a rela??o com as esp?cies parentais foram tamb?m confirmadas pelo uso dos marcadores ISSR. No cultivo in vitro, o meio DKW proporcionou melhor desenvolvimento dos explantes, em rela??o aos gen?tipos, P. cincinnata CPE16 mostrou melhor resposta morfog?nica in vitro e KIN mostrou-se mais eficiente para obten??o de brota??es com maiores comprimentos.

Direct studies of speciation are possible in the superspecies complex of Drosophila paulistorum, which consists of six different semispecies undergoing incipient speciation. Strict maternal inheritance of mitochondria is the most common pattern of mitochondrial inheritance in animals. Here I show that paternal transmission of mitochondrial DNA occurs in the heteroplasmic Orinocan semispecies and is not limited to hybrid offspring. Inheritance of one mitotype is mainly maternal while the other is mainly paternal; a highly unusual pattern of mitochondrial inheritance. I used absolute quantification real-time PCR on DNA extracted from eggs and imagoes from the Amazonian and Orinocan semispecies, as well as hybrids between these two semispecies. In crosses performed between F1 hybrids with a combination of mitotypes not found in any of the parents, no F2 hybrids were acquired. One possible explanation for this is that differences in mitotypes and inheritance patterns of mitochondrial DNA may cause incompatibilities between the genomes of D. paulistorum. This may be one cause of hybrid inviability and genetic isolation between semispecies, a necessary part of the speciation process. This further complicates the story of the ongoing speciation process in the D. paulistorum superspecies complex, which offers much to learn about speciation, mitochondrial inheritance and interactions between multiple genomes in the same organism.

In order to empower adolescents, this thesis examines how the adult conception of the human in humanism disempowers adolescents. This thesis examines this process in Amie Kaufman and Jay Kristoff's Illuminae, a work of young adult science fiction with non-traditional text structures. In consequence of their disempowerment, the adolescent Kady and artificially intelligent AIDAN impersonate human authorities in order to gain control over their lives. When these attempts fail, Kady and AIDAN transition from a humanist conception of the human, as an isolated self that balances rationality and emotionality, to a posthuman conception of the human, a distributed self that accepts the hybridization of adolescent and machine. The development of a posthuman self enables adolescents and AI control over their own lives, an alternative form of maturation that suggests a means for empowering adolescents through the use of technology. This alternative maturation counters traditional maturation in young adult science fiction and anti-technology trends in young adult science fiction.

La polyploïdie est un processus important et un moteur de la diversification et de l'évolution des plantes. Peu de polyploïdes naturels ont été décrits chez Juniperus, un genre de conifère représenté par 75 espèces d'arbres ou arbustes à feuilles persistantes, largement réparties dans l'hémisphère nord. Dans ce travail de recherche, l’implication de la polyploïdie dans l'évolution de Juniperus et l’élucidation des mécanismes sous-jacents à ces événements de polyploïdisation sont explorées. La taille du génome (TG) et le niveau de ploïdie ont été évalués chez 111/115 taxons en utilisant la cytométrie en flux et les comptages chromosomiques. Le taux de polyploïdie chez les genévriers s’est avéré être exceptionnellement élevé : 15 taxons sont des tétraploïdes et un seul taxon (J. foetidissima) est hexaploïde. Juniperus foetidissima représente le seul conifère hexaploïde découvert à ce jour à part Sequoia sempervirens. Nous avons également utilisé des approches de modélisation phylogénétique pour déterminer la TG ancestrale dans les trois clades de Juniperus et pour reconstruire le processus évolutif de la polyploïdisation chez ce genre. Au moins 10 événements de polyploïdisation ont eu lieu au cours de l'évolution et de la diversification de Juniperus. Nous avons ensuite exploré l’origine de la polyploïdie chez certaines espèces méditerranéennes. La variation de la TG et le niveau de ploïdie de deux variétés de J. sabina ont été estimés : Les populations échantillonnées de J. sabina var. sabina se sont avérées être diploïdes, tandis que les populations de J. sabina var. balkanensis étaient toutes tétraploïdes. Ces derniers auraient été issus d'une ancienne hybridation entre le tétraploïde J. thurifera et le diploïde J. sabina. Dans les Alpes françaises, où J. sabina var. sabina et J. thurifera sont en sympatrie, des individus présentant des morphologies intermédiaires entre ces deux espèces sont observés. Suite à des estimations des TG, de séquençage des ITS et de régions chloroplastiques, ces individus sont considérés comme des hybrides triploïdes. Enfin, l’utilisation des marqueurs AFLP pour déchiffrer les relations phylogénétiques entre des espèces méditerranéenne a montré que plusieurs pools génétiques contribuent à la diversité de Juniperus. Aussi ces marqueurs ont contribué à la découverte des contributions de ces pools génétiques aux taxons polyploïdes. Alors que les populations libanaises de l'hexaploïde J. foetidissima sont issues d'une lignée ancestrale unique, la population grecque semble résulter d'un mélange inégal de deux lignées anciennes. Ces deux lignées contribuent également au tétraploïde J. thurifera. Cette analyse a également montré que l’espèce méditerranéenne J. excelsa et l’espèce africaine J. procera partagent la même lignée ancestrale. Cependant, des analyses supplémentaires sont nécessaires pour une interprétation plus complète des données. L'importance de l'hybridation interspécifique et de la polyploïdie dans l'évolution des espèces de Juniperus nécessite d’amples recherches visant à comprendre le lien entre ces mécanismes et l'adaptation de ces espèces à un large spectre d'habitats extrêmes. Ces recherches futures devraient aussi contribuer à découvrir comment les espèces de conifères peuvent s’adapter aux changements climatiques. / Polyploidy is considered as an important phenomenon and a key driving force for plant diversification and evolution. Few natural polyploid species have been described in Juniperus, a coniferous genus represented by 75 species of evergreen trees or shrubs widely distributed in the North Hemisphere. The occurrence of polyploidy in the evolution of this genus as well as a more comprehensive view of pathways that were involved in these polyploidization events are explored in this research work. Genome size (GS) and ploidy level assessments were conducted on 111/115 taxa using flow-cytometry and chromosome counts. Juniperus holds an exceptionally high rate of polyploidy, 15 taxa being tetraploids and just one (J. foetidissima) being hexaploid. It represents the only hexaploid conifer discovered to date after Sequoia sempervirens. We also used phylogenetically-informed trait evolution modelling approaches to determine ancestral GS in the three clades of Juniperus and to reconstruct the evolutionary process of polyploidization in Juniperus. At least 10 polyploidization events have occurred during Juniperus evolution and diversification. We then explored the origin of polyploidy in selected Mediterranean species. The GS variation and the ploidy level of two J. sabina varieties were estimated: J. sabina var. sabina sampled populations were shown to be diploid, while J. sabina var. balkanensis populations were all tetraploid. The latter has been postulated to have arisen from an ancient hybridization between the tetraploid J. thurifera and the diploid J. sabina. In the French Alps, where J. sabina var. sabina and J. thurifera occur in sympatry, individuals with intermediate morphologies between these two species are observed. Evidences based on GS assessments, ITS and chloroplastic sequences demonstrated these individuals as triploid hybrids. Finally, the use of AFLP markers to decipher phylogenetic relationships between Mediterranean and Eastern Mediterranean species showed that multiple lineages contributes to Juniperus diversity and shed light on some polyploid taxa origins. While the Lebanese populations of the hexaploid J. foetidissima are issued from a unique ancestral lineage, the Greek population seems to be the result of an unequal admixture of two ancient lineages. These two lineages contribute also to the tetraploid J. thurifera. This analysis showed also that the Mediteranean J. excelsa and the African taxa J. procera shares the same ancestral lineage. However, further analyses are needed for a more complete interpretation of the data. The importance of interspecific hybridization and of polyploidization in the evolution of Juniperus species argues in favor of the development of researches aiming at understanding the link between these mechanisms and the adaptation of those species to a wide range of extreme habitats. Such future researches should contribute to predict how conifer species may adapt to dramatic changes in the Earth’s climate.

Les réseaux de collecte de l’IoT soulèvent de nombreux problèmes d'optimisation, à cause des capacités limitées des capteurs en énergie, en traitement et en mémoire. Dans l'optique d’améliorer la performance du réseau, nous nous intéressons à une contribution liée à l'optimisation du déploiement 3D d’intérieur des nœuds sur les réseaux de capteurs sans fil en utilisant des méta-heuristiques hybrides se basant sur des modèles mathématiques multi-objectif. L’objectif principal est donc de proposer des hybridations et modifications des algorithmes d’optimisation dans le but de réaliser le positionnement 3D adéquat des nœuds dans les réseaux de capteurs sans fil avec satisfaction d’un ensemble de contraintes et objectifs qui sont souvent antagonistes. Nous proposons d'axer notre contribution sur les méta-heuristiques hybrides et combinés avec des procédures de réduction de dimentionalité et d’incorporation de préférences des utilisateurs. Ces schémas d’hybridation sont tous validés par des résultats numériques de test. Ensuite, des simulations complétées par; et confrontées à ; des expérimentations sur des testbeds réelles. / IoT collection networks raise many optimization problems; in particular because the sensors have limited capacity in energy, processing and memory. In order to improve the performance of the network, we are interested in a contribution related to the optimization of the 3D indoor deployment of nodes using multi-objective mathematics models relying on hybrid meta-heuristics. Therefore, our main objective is to propose hybridizations and modifications of the optimization algorithms to achieve the appropriate 3D positioning of the nodes in the wireless sensor networks with satisfaction of a set of constraints and objectives that are often antagonistic. We propose to focus our contribution on meta-heuristics hybridized and combined with procedures to reduce dimensionality and to incorporate user preferences. These hybridization schemes are all validated by numerical tests. Then, we proposed simulations that are completed by, and confronted with experiments on real testbeds.

Ce travail vise à étudier le comportement mécanique des composites renforcées par des fibres de lin ainsi que le comportement mécanique et hydrique des composites hybrides. Un taux de porosité élevée observée chez ces matériaux conduit à une dégradation des propriétés mécaniques. Des essais de traction et de flambement avec suivi par émission acoustique ont permis d’identifier les mécanismes d’endommagements qui règnent dans ces matériaux et à mettre en évidence leur chronologie d’apparition. Des observations microscopiques des faciès de rupture ont permis de valider ces résultats. Une optimisation des propriétés mécaniques et notamment en termes de réduire le taux de porosité a été testée et ceci en insérant des fibres de carbone dans la structure. Les résultats ont montré que la position des fibres de carbone est primordiale dans l’amélioration des propriété hydrique et mécaniques. / This work aims to study the mechanical behavior of composites reinforced by flax fibers as well as the mechanical and water behavior of hybrid composites. A high porosity rate observed in these materials leads to a degradation of the mechanical properties. Tensile and buckling tests with acoustic emission monitoring have identified the mechanisms of damage that reign in these materials and highlight their chronology appearance. Microscopic observations of fracture facies validated these results. An optimization of the mechanical properties particularly in terms of reducing the porosity rate has been tested by inserting carbon fibers in the structure. The results showed that the position of carbon fibers is essential in the improvement of water and mechanical properties.

Genus Diphasiastrum Holub is one of the most complicated and biosystematically very little investigated groups within Lycopodiaceae family. There are 6 species recognized in Central European region. Three of them (D. alpinum, D. complanatum, D. tristachyum) are considered basic - parental taxa, and their hybridization probably gave origin to the three adjacent species - intermediates (D. issleri, D. zeilleri, D. oellgaardii). These supposedly hybridogenous taxa often co-ocur with at least one parental species. All the taxa often meet in secondary habitats where they tend to form hybrid swarms (e.g. on ski slopes which represent an ideal biocorridor for meeting the species from alpine zone with the species from lower altitudes). In such places reciprocal crossings between all of the taxa occur, often accompanied by introgression. The degree of hybridization, including the possible introgression, was studied using absolute genome size analyses combined with classical and geometric multivariate morphometrics. Genome size was estimated for 570 plants from 83 localities, mostly from the Czech Republic. Despite the fact that each parental taxa had a specific range of absolute genome sizes, adjacent species formed more or less disconnected continuum. Multivariate statistical methods (PCA, RDA, Loess, PLS)...