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Dissertations / Theses on the topic 'Ferns Ferns Epiphytes. Ferns'
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Schuettpelz, Eric. "Evolution and diversification of epiphytic ferns." Diss., View online, 2007. http://hdl.handle.net/10161/181.
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Gay, Honor. "The ant association and structural rhizome modifications of the Far-Eastern epiphytic fern genus Lecanopteris (Polypodiaceae)." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670308.
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Tanaka, Hiroshi. "Effects of an ant symbiont (Crematogaster difformis) of epiphytic ferns on herbivores and lianas on emergent trees in a tropical rainforest." Kyoto University, 2010. http://hdl.handle.net/2433/120432.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第15466号
人博第496号
新制||人||121(附属図書館)
21||人博||496(吉田南総合図書館)
27944
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)准教授 市岡 孝朗, 教授 松井 正文, 教授 加藤 眞, 教授 市野 隆雄
学位規則第4条第1項該当
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Muhammad, Mazhani. "Molecular systemic studies of extant ferns (Monilophytes) with emphasis on medical uses of ferns." Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/78460/.
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Ethnobotanical knowledge of plants’ medicinal use could make a contribution to bioprospecting by identifying plants to target for drug discovery. In recent years, methods to investigate the medicinal uses of flowering plants using a phylogenetic framework have been developed. Drugs derived from higher plants are prevalent, and ferns are relatively neglected. Thus, this thesis investigates the evolutionary patterns amongst fern species that are used medicinally using phylogenetic tools at a range of taxonomic and spatial scales, from global to regional scales, for the first time. Dense sampling at species levels may be critical for comparative studies, thus an updated fern megaphylogeny focusing on four gene regions, rbcL, rps4, atpA and atpB was reconstructed. This large-scale phylogeny comprises more than 3500 fern species in 273 genera and 47 families, covering over a quarter of extant global fern species. To evaluate the medicinal importance of ferns, a database based on a comprehensive review of records published in books, journals or in online sources including databases was assembled. The use database comprised 3220 use-reports for 442 species, and showed that approximately 5% of total estimated extant fern species have a documented therapeutic use, but only 189 species have become the focus of screening concerning their bioactivity properties. Using a comprehensive phylogenetic tree and medicinal data from the database, species used in traditional medicine were shown to be significantly dispersed across the fern phylogeny, contrary to previous findings in many similar studies of flowering plants. Whatever the hierarchical level or spatial scale investigated, the results consistently found evidence of phylogenetic overdispersion of medicinal use, suggesting more exploration of medicinal uses in a phylogenetic context is required before the generality of this approach is globally accepted. Finally, safety and toxicity of ferns that are used as medicine and food were also explored, since fern consumption can pose a serious health risk. The distributions of toxic compounds and arsenic hyperaccumulation in ferns were investigated using taxonomic and phylogenetic approaches in order to access the risk to consumers. Overall, assessment of toxicity in ferns is still limited and awareness needs to be raised about the health risks associated with the use of ferns.
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MAFFRA, FABIOLA ALVARES RODRIGUES DE SOUZA. "FACIAL FEATURES DETECTION BASED ON FERNS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14995@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICONas últimas décadas, a área de detecção da face e suas características tem recebido bastante atenção da comunidade científica dada sua importância em diversas aplicações, tais como, reconhecimento de faces, interação humanocomputador, reconhecimento de expressões faciais, segurança, etc. Esta dissertação propõe a utilização de um classificador baseado em FERNS no treinamento e reconhecimento de pontos característicos a fim de possibilitar a detecção das características da face. São revistas, brevemente, as principais abordagens utilizadas na detecção de características faciais e a teoria de reconhecimento de pontos característicos utilizando os FERNS. Também é apresentada uma implementação de um detector de características da face baseado nos FERNS e os resultados obtidos. O método proposto conta com uma fase de treinamento offline durante a qual diversas vistas dos pontos característicos extraídos de uma imagem de treinamento são sintetizadas e utilizadas no treinamento dos FERNS. A detecção das características da face é realizada nas imagens obtidas, em tempo real, de diversos pontos de vista e sob diferentes condições de iluminação.
Over the last decades, face detection and facial features detection have received a great deal of attention from the scientific community, since these tasks are essential for a number of important applications, such as face recognition, face tracking, human-computer interaction, face expression recognition, security, etc. This work proposes the use of a classifier based on FERNS to recognize interest points across images and then detect and track the facial features. We begin with a brief review of the most common approaches used in facial features detection and also the theory around the FERNS. In addition, an implementation of the facial features detection based on FERNS is present to provide results and conclusions. The method proposed here relies on an offline training phase during which multiple views of the keypoints to be matched are synthesized and used to train the FERNS. The facial features detection is performed on images acquired in real-time from many different viewpoints and under different lighting conditions.
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Larsson, Anders. "Systematics of Woodsia : Ferns, bioinformatics and more." Doctoral thesis, Uppsala universitet, Systematisk biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-232233.
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Ferns are one of the three main clades of vascular plants. They have few easily studied morphological characters, reflected in a historically unstable classification. The fern genus Woodsia is known to have a complex evolutionary history including numerous polyploid taxa and hybrids. It is a cosmopolitan group of small rock loving ferns mainly found in montane areas. This thesis aims at analyzing the patterns of diploid and polyploid evolution in Woodsia and to resolve and classify the relationships of Woodsiaceae and the other families in the large fern clade Eupolypods II. The Eupolypods II family relationships were inferred with DNA sequences from 81 specimens representing all major lineages. This resulted in the first well supported phylogeny of this clade and revealed Woodsiaceae to be non-monophyletic. The genera previously placed in this family were reclassified into five new or resurrected families. Swedish fern genera that have changed family classification are Woodsia (hällebräknar), now in the monogeneric family Woodsiaceae, Athyrium (majbräknar), now in Athyriaceeae and Cystopteris (stenbräknar) and Gymnocarpium (ekbräknar) now in Cystopteridaceae. To analyze the evolution of Woodsia, phylogenies were produced from five plastid and two nuclear regions sequenced from 188 specimens. The results show that most taxa in Woodsia are polyploid. Polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young and many of the polyploid taxa seem to have formed multiple times. The results also address several taxonomic and biogeographic questions. In the process of the work we made methodological advancements and developed 20 new low copy nuclear marker regions as well as a software pipeline for finding primers in transcriptome datasets. The alignment editor software AliView was developed for handling the increasing size datasets in a user friendly way. In conclusion this thesis provides new insights into the complexities of the evolution of a fern genus in which much of the diversity is accommodated in young species formed through polyploidization. It provides a framework of phylogenetic relationships at different levels that both answers long standing questions and generates new ones.
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Bystriakova, Nadia. "The ecology and biogeography of tree ferns." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612141.
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Cibura, Klaus. "Synthese und Reaktionen von Cobalt-Olefin-Komplexen /." Online version, 1985. http://bibpurl.oclc.org/web/24833.
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Kraiman, Claire T. "Ferns and fern allies of Berks County, Pennsylvania." Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 1997. http://www.kutztown.edu/library/services/remote_access.asp.
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Thesis (M. Ed.)--Kutztown University of Pennsylvania, 1997.Source: Masters Abstracts International, Volume: 45-06, page: 3033. Abstract precedes thesis as 1 preliminary leaf. Typescript. Includes bibliographical references (leaves 57-60).
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Winther, Jennifer. "Arbuscular mycorrhizal associations in mycoheterotrophic ferns and lycopods." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3303816.
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Thesis (Ph.D.)--University of Colorado at Boulder, 2007.Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1407. Adviser: William E. Friedman. Includes supplementary digital materials.
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Nagarajan, Vinay K. "Transport and metabolism of arsenicals in arsenic hyperaccumulating ferns /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1083543941&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Vogel, Johannes Christian. "Multiple origins of polyploids in European Asplenium (Pteridophyta)." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388534.
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McCarthy, Mirabai Rachel. "Bryophyte Influence on terrestrial and Epiphytic Fern Gametophytes." Oxford, Ohio : Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1193256414.
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Watkins, James Edward. "Functional ecology of the gametophytes and sporophytes of tropical ferns." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0013484.
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Kluthe, John D. "Ferns as a forest farming crop effects of light levels on growth and frond quality of selected speicies with potential in Missouri /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4587.
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Thesis (M.S.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 8, 2007) Includes bibliographical references.
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Wanninayake, Seetha Podimenike. "Response of a New Zealand tree fern." Thesis, University of Canterbury. Biological Sciences, 2007. http://hdl.handle.net/10092/3274.
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Lead (Pb) pollution is a serious environmental problem. Phytoremediation is emerging as a promising technology for removal of Pb and other heavy metals from soils and waterways. In this study, the phytoremediation potential of a popular landscape plant, in New Zealand, Cyathea medullaris (the black tree fern), was investigated. Pb uptake by the gametophytes and different parts (roots, shoots and leaves) of 3-month-old black tree fern plants in hydroponic experiments were studied using flame atomic absorption spectrometry. Morphological and ultrastructural changes in the Pb-treated materials were also investigated. Generally, the levels of Pb in the various black tree fern tissues increased with the external Pb concentration and exposure time. Transmission electron microscopy observation showed that the cell wall was the major subcellular site for Pb accumulation. Evidence obtained here suggests that the black tree fern gametophytes and the sporophyte can accumulate levels of Pb exceeding 1% of their dry weights. This resembles the capacity of a hyperaccumulating plant.
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Patel, Nikisha. "Apomixis, Hybridization, And Biodiversity In Ferns: Insights From Genera Phegopteris And Polystichum." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/833.
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Apomixis is an evolutionarily important phenomenon across plant lineages. The interaction of apomixis with hybridization and polyploidy can lead to complex patterns of reticulation, complicating efforts to reconstruct evolutionary history in groups where apomixis is common. Ferns, in particular, are rich in apomictic species, notably in centers of species diversity like East Asia. Eastern North America too is home to a number of apomictic species. We investigated the East Asian ferns in Polystichum sections Xiphopolystichum and Duropolystichum (Dryopteridaceae) in order to elucidate the evolutionary and biogeraphic history of seven apomictic species in the group: Polystichum tsus-simense, P. xiphophyllum, P. sinotsus-simense, P. pseudoxiphophyllum, P. mayebarae. P. rigens, and P. neolobatum. In addition, we examined the evolutionary origin of an undescribed apomictic cytotype of North American genus Phegopteris (Thelypteridaceae). The datasets comprised phylogenetic inference based on three nuclear and three plastid markers, analysis of mixed nucleotide signals from chromatograms generated from Sanger sequencing of nuclear markers, ploidy estimates based on flow cytometry data and spore length measurements, morphometric analysis of representative specimens collected in southwest China and nearby regions, and climatic niche models. By interpreting these multiple lines of evidence synthetically, we have discerned multiple highly reticulate complexes of polyploid lineages derived largely from diploid sexual progenitors. Our findings highlight the importance of understanding the role of apomictic reproduction in the context of species diversity, an understanding central to similar future inquiry into the diversity of East Asian and North American ferns.
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Yusuf, U. "Chemosystematic and anatomical studies in the Malaysian aspleniaceae and athyriaceae." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378021.
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Del, Olmo Ruiz Mariana. "Diversity, Distributions, and Host Affiliations of Fungal Endophytes Associated with Seedless Vascular Plants." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/243097.
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In this dissertation, I explore the diversity of endophytic fungi associated with above-ground tissues of neotropical ferns, assess factors shaping their community structure in three forests, and explore the contributions of endophytes and related strains to our understanding of the diversity and ecology of a representative genus of Ascomycota. In Appendix A, I report a survey of endophytic fungi from seven species of ferns at La Selva, Costa Rica. Using both species-level and phylogenetic analyses, I compare culturable endophytes as a function of fern taxonomy, frond tissues (blades vs. stalks), habits (terrestrial vs. epiphytic), and vegetation types (arboretum vs. primary and secondary forest) during two consecutive years. Analysis of>500 strains provides a first taxonomic overview of fern endophytes at a community scale and reveals high diversity, host preference, and interannual variation in fungal assemblages. However, when variation due to host species is taken into account, community structure is similar among fern tissue types, habits, and sampling sites over a small spatial scale. In Appendix B, I expand my work to evaluate the abundance, species-level and phylogenetic diversity, and distributions of fern-affiliated endophytes in three neotropical forests (La Selva, Costa Rica; Barro Colorado Island, Panama; Los Tuxtlas, Mexico). My analysis of > 2000 isolates reveals that communities differ significantly among fern species within sites, and among ferns in different sites. Intersite differences in communities are correlated with geographic distance and environmental dissimilarity. My work suggests that extrapolative estimates of fungal diversity should take into account not just host species, but locality and environmental variation as well. In Appendix C I focus on a representative genus of Ascomycota (Lecythophora) to evaluate how multi-locus phylogenetic analyses of endophytes can detect new species. Lecythophora is a geographically widespread genus that includes opportunistic human pathogens, produces novel secondary metabolites, and consists presently of six described species. Multi-locus analysis of 33 newly collected strains suggested seven phylogenetic species that are new to science and highlighted their capacity to inhibit growth of two plant pathogenic fungi. This work shows how recognition of cryptic species even in well-characterized genera has major implications for estimating fungal biodiversity.
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Mortara, Sara Ribeiro. "Abundância de samambaias em metacomunidades: relacionando padrões e processos com modelos estatísticos." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-17082016-141523/.
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Entender como comunidades são estruturadas a partir de um pool de espécies é uma questão central em Ecologia de Comunidades. Diversas abordagens foram propostas para estabelecer a ligação entre os padrões de estrutura de comunidades e os processos que os geram. As regras de assembleia e a abordagem filogenética em ecologia de comunidades são alguns exemplos. Entretanto, o que estas abordagens não levam em conta é o efeito de processos neutros na estruturação de comunidades. Há um consenso de que tanto nicho como neutralidade afetam a estrutura de comunidades e que se deve avaliar a importância relativa de cada um destes processos. A ideia desta tese foi usar modelos estatísticos para representar como processos neutros e de nicho geram padrões em comunidades. No Capítulo 2 propus uma abordagem baseada em modelos hierárquicos através da qual é possível expressar processos neutros e de nicho. A partir disso, foi possível representar hipóteses em que apenas processos neutros afetam a estrutura da comunidade, apenas processos de nicho ou diferentes combinações entre ambos. Usando seleção de modelos, identifiquei qual a combinação de processos melhor explica as abundâncias observadas das espécies. Com isso, mostrei que as comunidades de samambaias em gradientes altitudinais na Serra do Mar no Paraná, Brasil são estruturadas por uma mistura de filtro ambiental, deriva ecológica e limitação de dispersão. O filtro ambiental define as abundâncias das espécies selecionando as melhores estratégias ecológicas das espécies dependendo da altitude. A variação de abundância entre as espécies que compartilham as mesmas estratégias ecológicas é explicada em parte por deriva ecológica e limitação de dispersão e, em parte, por filtro de habitat independente dos atributos das espécies incorporados no modelo. Com isso, delimitei como processos baseados em nicho e neutralidade afetam a abundância das espécies de samambaias ao longo de gradientes altitudinais. No Capítulo 3 usei um estudo de caso para explorar a ideia central da abordagem filogenética em ecologia de comunidades de que é possível inferir os processos que afetam as comunidades com base em padrões locais de estrutura filogenética. Usei a abordagem de modelos proposta no Capítulo 2 para simular comunidades geradas por processos puramente neutros, puramente de nicho e uma combinação hierárquica entre os dois. Encontrei que comunidades geradas apenas por processos de nicho geram estruturas filogenéticas aleatórias na maioria dos casos. A detecção de estruturas filogenéticas aleatórias foi ainda mais frequente nas comunidades geradas por processos puramente neutros e pela combinação de processos neutros e de nicho, não sendo possível a distinção entre estes dois cenários. Desse modo, o estudo de caso mostrou que estruturas filogenéticas não aleatórias são muito pouco plausíveis e que os processos neutros geram uma forte assinatura nos padrões de estrutura filogenética. Com a abordagem proposta nesta tese foi possível delimitar a influência de processos de nicho e neutralidade em comunidades e entender suas consequências em termos dos padrões por eles gerados. A tradução dos diferentes processos em modelos mistos mostrou-se uma ferramenta poderosa para quantificar padrões e construir explicações de como os processos operam juntosUnderstanding how communities are assembled from a species pool is a central question in community ecology. Different approaches to link pattern and processes in community ecology were proposed. Some examples are assembly rules and the community phylogenetic approach. However, one aspect not accounted in those approaches is how neutral processes affect community patterns. There is a consensus that both niche and neutral processes affect community assembly and that the goal should be assess the relative importance of each process. The general idea if this thesis was to use statistical models to represent how niche and neutral generate community patterns. In Chapter 3, I proposed a framework based on hierarchical models to express niche and neutral processes. I used this approach to represent hypothesis in which only niche processes affect community structure, only neutral processes or a hierarchical combination of both explains species abundance. By using model selection, I identifyied which combination of processes better predicts observed abundances on local communities. I showed that fern communities across altitudinal gradients at Serra do Mar in Paraná, Brazil are structured by a mixture of environmental filtering, ecological drift and limited dispersal. Environmental filtering defines species abundance, selecting the best ecological strategies of species depending on altitude. Variation on species abundance sharing the same ecological strategies is explained in part by drift and limited dispersal, and in part by habitat filtering independent of species traits considered in the models. Hence, I refined how niche and neutral processes affect fern abundance on altitudinal gradients. In Chapter 3, I used a case study to explore the idea from community phylogenetics of inferring processes affecting communities based on patterns of phylogenetic structure. I used the modeling framework from Chapter 3 to simulate communities built by niche, neutral and combination of both processes. I found that communities based on niche processes are likely to generate a random phylogenetic structure. The detection of random phylogenetic strucure was even more common on communities built solely by neutral processes and combination of both niche and neutral processes. Therefore, the case study showed that a non random phylogenetic strucure is unlikely and that neutral processes strongly affect the outcome of phylogenetic patterns. Based on the framework proposed on this thesis it is possible to delimit the influence of niche and neutral processes on community assembly and to understand what are the consequences in terms of community patterns. Translating different processes into mixed models can be a powerful tool to quantify patterns and built explanations on how the processes operate together
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Becker, Katherine R. "A wetland species, Thelypteris noveboracensis, (L.) Nieuwl: the New York fern." Thesis, Boston University, 1994. https://hdl.handle.net/2144/37120.
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Thesis (M.A.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
2031-01-01
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Jamaludin, Azi Azeyanty. "Systematics of Peninsular Malaysian scaly tree ferns (Cyatheaceae) : phylogenetics, computer-aided identification and conservation." Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/78262/.
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The work presented in this thesis evaluates the status of Peninsular Malaysian Cyatheaceae and used molecular and morphological identification tools for the local species. 419 Cyatheaceae frond sample were collected from the widest possible range of Peninsular Malaysia to obtain material for morphology and molecular study. 15 Cyathea species were identified and the species information for Peninsular Malaysia was updated. The species was incorporated into the existing Cyatheaceae phylogeny by using four plastid regions: matK, rbcL, trnG-trnR and trnL-trnF. Bayesian MCMC analysis of the concatenated sequence data resulted in a 50% majority rule consensus tree confirm the placement of the four groups: Cyathea, Alsophila, Gymnosphaera and Sphaeropteris in the family. However, the resulting tree representing nested monophyletic groups, proposing Cyatheaceae to be monogeneric, i.e., Cyathea with two large groups: Cyathea and Sphaeropteris. The same plastid regions were then evaluated to develop DNA barcodes. trnL-trnF was proposed as a barcode for this family as it almost satisfied the three most important criteria: primer universality, sequence quality and species discrimination. This research also developed a multiaccess key for Cyatheaceae field identification based on fifteen taxa identified, by extensive field sampling of the currently recognised species. All of the Cyatheaceae species recognises in this study had also been assessed for the conservation status based on the IUCN Red List criteria. Nine species fall under Least Concern (LC), four species are Near Threatened (NT) and two species are Vulnerable (VU). The thorough knowledge regarding Cyatheaceae in Peninsular Malaysia gained through the work done in this research will benefit in making appropriate conservation strategies for the survival of this family. Overall, the most important outcome of this research was the combination of morphology and molecular data for the purpose of updating taxonomy, identification and conservation of the Cyatheaceae family in Peninsular Malaysia.
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Lindsey, Rebekah Helen. "Lygodium ×fayae abrindo o caminho para uma maior compreensão sobre híbridos de samambaias brasileiras: um estudo morfológico e anatômico sobre as espécies brasileiras de Lygodium (Lygodieaceae), focado em morfologia de estômatos e esporos, e germinação de esporos /." Botucatu, 2020. http://hdl.handle.net/11449/192654.
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Orientador: Ana Paula Fortuna PerezResumo: A família Lygodiaceae sempre teve uma taxonomia contraditória, o número de espécies aceitas no Brasil variando de duas a doze ao longo das décadas. Sendo Lygodiaceae uma família antiga, acredita-se que essas contradições possam ser causadas por híbridos. Os híbridos surgem pelo cruzamento de duas ou mais espécies e, geralmente, são primeiro identificados por suas características morfológicas intermediárias entre as espécies parentais. Normalmente, os híbridos recentes de samambaia são detectados ocorrendo junto com suas espécies parentais. Os esporos de indivíduos híbridos geralmente são mal formados e / ou abortados, portanto, inviáveis, mas os poucos esporos viáveis poderiam iniciar o processo de especiação de uma nova espécie. Considerando a sobreposição de características morfológicas, a hibridação poderia ter ocorrido entre duas espécies de Lygodium no Brasil, L. venustum e L. volubile gerando o hipotético híbrido L. × fayae. Devido à difícil identificação desses táxons, nossos estudos analisaram dois caracteres diferentes (tamanho e morfologia dos esporos e estômatos) por microscopia eletrônica de varredura, estudamos a germinação dos esporos e criamos novas descrições e uma chave de identificação às espécies aceitas para ajudar na delimitação taxonômica dos dois táxons de Lygodium e seu híbrido putativo. De acordo com nossos resultados, as espécies classificadas como L. × fayae na região sudeste do Brasil não são híbridas, mas uma variação morfológica de Lygodium venus... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The family Lygodiaceae has always had a contradictory taxonomy, the number of accepted species in Brazil varying from two to twelve through the decades. Lygodiaceae being an old family, this contradictions are believed to be caused by hybrids. Hybrids arise by the crossing of two or more species, and, usually, they are first identified by its intermediate morphological characteristics among the parental species. Normally, early fern hybrids are detected occurring along with its parental species. The spores of hybrid individuals generally are badly formed and/or aborted, thus, not viable, but the few balanced spores could starts the speciation process of a new species. Considering the overlapping of morphological characteristics, it could have occurred in two species of Lygodium in Brazil, L. venustum and L. volubile and the hypothetical hybrid L. ×fayae. Due to the difficult in identification of these taxa, our studies herein analysed two different characters (spore and stomata size and morphology) through scanning electronic microscopy, we studies the spore germination and new descriptions and an identification key were done to the accepted species to help clearing the taxonomic delimitation of the two taxa of Lygodium and their putative hybrid. According to our results, the species herein classified as L. ×fayae on the Brazilian south-east region is not a hybrid, but a morphological variation of Lygodium venustum. Additional studies on morphometric analysis with the measure... (Complete abstract click electronic access below)
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Bauret, Lucie Anaïs. "How to settle in Madagascar? Towards a better understanding of the biogeographical history of the Malagasy ferns." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066464/document.
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Madagascar est une île continentale de l’Océan Indien, au large de l’Afrique. C’est également un point chaud de biodiversité, hébergeant plus de 12 000 espèces de plantes vasculaires, dont plus de 600 espèces de fougères caractérisées par un endémisme dépassant les 45%. L’Afrique continentale n’héberge en comparaison que 800 espèces. Comment peut-on expliquer une telle concentration de biodiversité à Madagascar ? Quelles sont les origines biogéographiques des fougères malgaches ? L’apport de nouvelles données et la littérature préexistante permettent de proposer ici des hypothèses sur l’histoire biogéographique des fougères de Madagascar. Quatre groupes de fougères ont fait l’objet d’une étude biogéographique : les sous-familles de fougères grammitides et blechnoides, les genres Rumohra et Lindsaea-Odontosoria, ainsi qu’un genre de lycophytes, Phlegmariurus, représentant un réplica dans une autre lignée de plantes vasculaires à spores. L’histoire biogéographique des lignées malgaches au sein de ces groupes a été reconstruite, à partir de phylogénies moléculaires mondiales complétées par les espèces malgaches, de datations moléculaires, ainsi que de l’estimation des aires ancestrales.Bien que Madagascar soit d’origine ancienne, gondwanienne, les résultats des analyses biogéographiques montrent que les fougères et les lycophytes auraient colonisé Madagascar après son isolement, durant le Cénozoïque (< 66 Ma), depuis les néotropiques (Amérique du Sud) l’Afrique et l’Asie tropicale (au sens large, incluant l’Asie continentale et le sud-est asiatique jusqu’en Australasie). En particulier, de nombreuses dispersions ont été observées à partir du Miocène (< 23 Ma). Ces résultats seraient expliqués par une combinaison d’événements au Cénozoïque (formation des forêts tropicales humides Malgaches, formation de courants éoliens permettant la dispersion par spores) et des préférences écologiques des fougères et des lycophytes pour les forêts tropicales humides d’altitude, s’étant formées à partir du Miocène dans les régions sourcesMadagascar is a continental island in the Indian Ocean, near African coasts. It is also a biodiversity hotspot, comprising more than 12,000 species of vascular plants and including more than 600 fern species with an endemism reaching the 45%. Comparatively, continental Africa comprises only 800 species. How can such a diversity be explained in Madagascar? What are the biogeographical origins of the Malagasy ferns? Thanks to new data combined to the literature, hypotheses on the biogeographical history of Malagasy ferns are here proposed.Four fern taxa were newly investigated: grammitid and blechnoid subfamilies, Rumohra and Lindsaea-Odontosoria, as well as Phlegmariurus, a genus of lycophytes considered as a phylogenetic replicate in another vascular spore-bearing plant lineage. The biogeographical history of the Malagasy lineages was inferred, based on worldwide molecular phylogenies completed by Malagasy species, molecular dating and ancestral area estimates.Despite its Gondwanian origin, ferns and lycophytes would have colonized Madagascar after its isolation, during the Cenozoic (< 66 Ma), from the Neotropics (South America), Africa and tropical Asia s.l. (meaning from continental Asia to Southeast Asia and Australasia). Dispersal events were especially inferred from the Miocene (< 23 Ma). These results could be explained by the combination of events during the Cenozoic (establishment of the Malagasy rainforests, onset of wind currents allowing spore dispersal) and ecological preferences of ferns and lycophytes for elevated tropical rainforests that have established from the Miocene in the source regions
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Kachenko, Anthony. "Ecophysiology and phytoremediation potential of heavy metal(Loid) accumulating plants." University of Sydney, 2008. http://hdl.handle.net/2123/6348.
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Doctor of Philosophy(PhD)Soil contamination with heavy metal(loid)s is a major environmental problem that requires effective and affordable remediation technologies. The utilisation of plants to remediate heavy metal(loid)s contaminated soils has attracted considerable interest as a low cost green remediation technology. The process is referred to as phytoremediation, and this versatile technology utilises plants to phytostabilise and/or phytoextract heavy metal(loid)s from contaminated soils, thereby effectively minimising their threat to ecosystem, human and animal health. Plants that can accumulate exceptionally high concentrations of heavy metal(loid)s into above-ground biomass are referred to as hyperaccumulators, and may be exploited in phytoremediation, geobotanical prospecting and/or phytomining of low-grade ore bodies. Despite the apparent tangible benefits of utilising phytoremediation techniques, a greater understanding is required to comprehend the ecophysiological aspects of species suitable for phytoremediation purposes. A screening study was instigated to assess phytoremediation potential of several fern species for soils contaminated with cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn). Hyperaccumulation was not observed in any of the studied species, and in general, species excluded heavy metal uptake by restricting their translocation into aboveground biomass. Nephrolepis cordifolia and Hypolepis muelleri were identified as possible candidates in phytostabilisation of Cu-, Pb-, Ni- or Zn-contaminated soils and Dennstaedtia davallioides appeared favourable for use in phytostabilisation of Cu- and Zn-contaminated soils. Conversely, Blechnum nudum, B. cartilagineum, Doodia aspera and Calochlaena dubia were least tolerant to most heavy metals and were classified as being least suitable for phytoremediation purposes Ensuing studies addressed the physiology of arsenic (As) hyperaccumulation in a lesser known hyperaccumulator, Pityrogramma calomelanos var. austroamericana. The phytoremediation potential of this species was compared with that of the well known As hyperaccumulator Pteris vittata. Arsenic concentration of 3,008 mg kg–1 dry weight (DW) occurred in P. calomelanos var. austroamericana fronds when exposed to 50 mg kg–1 As without visual symptoms of phytotoxicities. Conversely, P. vittata was able to hyperaccumulate 10,753 mg As kg–1 DW when exposed to 100 mg kg–1 As without the onset of phytotoxicities. In P. calomelanos var. austroamericana, As was readily translocated to fronds with concentrations 75 times greater in fronds than in roots. This species has the potential for use in phytoremediation of soils with As levels up to 50 mg kg–1. Localisation and spatial distribution of As in P. calomelanos var. austroamericana pinnule and stipe tissues was investigated using micro-proton induced X-ray emission spectrometry (µ-PIXE). Freeze-drying and freeze-substitution protocols (using tetrahydrofuran [THF] as a freeze-substitution medium) were compared to ascertain their usefulness in tissue preservation. Micro-PIXE results indicated that pinnule sections prepared by freeze-drying adequately preserved the spatial elemental distribution and tissue structure of pinnule samples. In pinnules, µ-PIXE results indicated higher As concentration than in stipe tissues, with concentrations of 3,700 and 1,600 mg As kg–1 DW, respectively. In pinnules, a clear pattern of cellular localisation was not resolved whereas vascular bundles in stipe tissues contained the highest As concentration (2,000 mg As kg–1 DW). Building on these µ-PIXE results, the chemical speciation of As in P. calomelanos var. austroamericana was determined using micro-focused X-ray fluorescence (µ-XRF) spectroscopy in conjunction with micro-focused X-ray absorption near edge structure (µ-XANES) spectroscopy. The results suggested that arsenate (AsV) absorbed by roots was reduced to arsenite (AsIII) in roots prior to transport through vascular tissues as AsV and AsIII. In pinnules, AsIII was the predominant species, presumably as aqueous-oxygen coordinated compounds. Linear least-squares combination fits of µ-XANES spectra showed AsIII as the predominant component in all tissues sampled. The results also revealed that sulphur containing thiolates may, in part sequester accumulated As. The final aspect of this thesis examined several ecophysiological strategies of Ni hyperaccumulation in Hybanthus floribundus subsp. floribundus, a native Australian perennial shrub species and promising candidate in phytoremediation of Ni-contaminated soils. Micro-PIXE analysis revealed that cellular structure in leaf tissues prepared by freeze-drying was adequately preserved as compared to THF freeze-substituted tissues. Elemental distribution maps of leaves showed that Ni was preferentially localised in the adaxial epidermal tissues and leaf margin, with concentration of 10,000 kg–1 DW in both regions. Nickel concentrations in stem tissues obtained by µ-PIXE analysis were lower than in the leaf tissues (1,800 mg kg–1 vs. 7,800 mg kg–1 DW, respectively), and there was no clear pattern of compartmentalisation across different anatomical regions. It is possible that storage of accumulated Ni in epidermal tissues may provide Ni tolerance to this species, and may further act as a deterrent against herbivory and pathogenic attack. In H. floribundus subsp. floribundus seeds, µ-PIXE analysis did not resolve a clear pattern of Ni compartmentalisation and suggests that Ni was able to move apoplastically within the seed tissues. The role of organic acids and free amino acids (low molecular weight ligands [LMW]) in Ni detoxification in H. floribundus subsp. floribundus were quantified using high performance liquid chromatography (HPLC) and ultra performance liquid chromatography (UPLC). Nickel accumulation stimulated a significant increase in citric acid concentration in leaf extracts, and based on the molar ratios of Ni to citric acid (1.3:1–1.7:1), citric acid was sufficient to account for approximately 50% of the accumulated Ni. Glutamine, alanine and aspartic acid concentrations were also stimulated in response to Ni hyperaccumulation and accounted for up to 75% of the total free amino acid concentration in leaf extracts. Together, these LMW ligands may complex with accumulated Ni and contribute to its detoxification and storage in this hyperaccumulator species. Lastly, the hypothesis that hyperaccumulation of Ni in certain plants may act as an osmoticum under water stress (drought) was tested in context of H. floribundus subsp. floribundus. A 38% decline in water potential and a 68% decline in osmotic potential occurred between water stressed and unstressed plants, however, this was not matched by an increase in accumulated Ni. The results suggested that Ni was unlikely to play a role in osmotic adjustment in this species. Drought stressed plants exhibited a low water use efficiency which might be a conservative ecophysiological strategy enabling survival of this species in competitive water-limited environments.
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Rashbrook, Vanessa Karin. "Interactions between ants, herbivorous insects and bracken (Pteridium aquilinum), a fern with extrafloral nectaries." Thesis, Rhodes University, 1989. http://hdl.handle.net/10962/d1002042.
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Bracken (Pteridium aquilinum) is a cosmopolitan species of fern which possesses extrafloral nectaries. A survey of the arthropod fauna associated with the plant throughout its range in South Africa identified the most widespread and damaging bracken herbivores and those species most likely to be influenced by ants visiting the extrafloral nectaries. Seventeen herbivorous arthropods were found to be definitely feeding on bracken and a further thirteen species with a less certain status were recorded. In addition, several species of ants were observed on the fronds and feeding at the extrafloral nectarie. On the basis of their widespread distribution and abundance, four bracken herbivores emerged as being particularly detrimental to the plant in South Africa. They were an eriophyid gall mite, a leafhopper and two moths. The biology of the two lepidopterans, Appana cinisigna and Panotima sp., suggested that they were potentially vulnerable to ants at various stages of their life histories. Laboratory experiments were undertaken to observe ant-lepidopteran interactions under controlled conditions. The ant Crematogaster peringueyi rapidly removed exposed A. cini igna eggs, but did not appear to regard Panotima eggs as food items. Small instar larvae of both species proved vulnerable, but the larger larvae appeared capable of escaping ant predation. Ant exclusion experiments in the field, using natural and artificially augmented ant densities, were carried out at two sites near Grahamstown. The dominant ant species was C. peringueyi. Neither the numbers of lepidopterans nor levels of herbivory were significantly reduced by the presence of ants . Despite the implications of the laboratory tests, the results of these field experiments did not support the hypothesis that ants which visit bracken extrafloral nectaries benefit the plant. Ant-bracken field studies on other continents also reported no significant ant-related effects, though marginal reductions in the abundance of certain herbivores have been noted at one site in the U.K. Since ant protection does not appear to be an inevitable consequence of having extrafloral nectaries, their value to bracken is in some doubt. The most likely situation where effective protection will occur is when high densities of vulnerable herbivores are preyed upon by large numbers of aggressive ants. However, even under these conditions, enhancement of plant fitness is not inevitable. This raises the question of why extrafloral nectaries have been retained in a plant that is as successful and widespread as bracken.
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Karst, Justine. "Ecological separation among fern species in an old-growth forest." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33790.
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The validity of niche-assembly rules in explaining community structure is revisited by testing for ecological separation among ferns. An intensive, fine-scale survey of fern abundance and environmental variation was done in 1-ha of old-growth forest. Three methods of detecting niche segregation (canonical correspondence analysis, detrended correspondence analysis and GIS mapping) suggested that most fern species at the site are distributed according to distinct environmental preferences. The most important gradients separating fern species are first, the amount of soil moisture and second, soil nitrate concentration. Contrary to other findings, pH had little influence on controlling fern distribution. Spatial autocorrelation, detected by partialled ordinations, obscured the presence of niche partitioning. As well, sampling grain changed the apparent location of some species on environmental gradients and their ecological similarity to other species. Finer-scaled environmental heterogeneity or dispersal-mediated processes may account for the unexplained variation in fern species abundance of this site.
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Younginger, Brett Steven. "Fungal Endophytes in a Seed-Free Host: New Species that Demonstrate Unique Community Dynamics." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4387.
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Fungal endophytes are highly diverse, cryptic plant endosymbionts that form asymptomatic infections within host tissue. They represent a large fraction of the millions of undescribed fungal taxa on our planet with some demonstrating mutualistic benefits to their hosts including herbivore and pathogen defense and abiotic stress tolerance. Other endophytes are latent saprotrophs or pathogens, awaiting host plant senescence to begin alternative stages of their life cycles. Most, however, are likely plant commensals with no observable benefits to their hosts while under study. Yet, when considering the context-dependence that may determine plant resistance to pathogen attack, the consortium of endophytes present in the host could alter these outcomes, thereby affecting plant evolution. Despite the excitement of exploiting endophytes for their potential to produce bioactive compounds that are useful to medicine and agriculture, fungal endophyte community ecology is a lagging field. Much remains unknown regarding their colonization patterns within hosts, their spatial and temporal turnover and their diversity. Further, a severe deficiency exists in work on endophytes in seed-free plants, particularly ferns. Since ferns exist in free-living forms in both the haploid and diploid stages, are the second largest group of vascular plants, occupy important ecological niches and represent an older lineage of land plants, this is a major shortcoming in our understanding of plant-fungal ecology and evolution. For these reasons, I have examined endophyte community ecology in a widespread fern host in the Pacific Northwest, Polystichum munitum, addressing several gaps in the endophyte literature. Since an understanding of the degree of early endophyte colonization, temporal turnover and the relative contribution of priority effects to community composition are unknown, I conducted a temporal survey of fern endophyte communities utilizing culture-independent, next-generation sequencing on a monthly basis for an entire growing season. A high degree of temporal turnover was observed early in the growing season, where a late colonist rapidly took over the fern population and persisted throughout the year. This colonist, which was isolated from several of the same plants, appears to support growth rates of the host plant when in the gametophytic stage, but is not highly competitive against other endophytes in vitro. Additionally, in an effort to examine host and habitat specificity I examined the spatial turnover of endophytes across four distinct habitat types: a coastal site, a coniferous understory site, a montane site near Mount Saint Helens but not impacted by the 1980 eruption, and a secondary succession site at Mount Saint Helens, spanning 150-km at a single point in time. A high degree of host specificity was found when compared to endophyte communities in neighboring plant taxa and a lack of distance decay was also observed contrasting with other work examining endophyte biogeographic patterns. We conclude that a high degree of host filtering, combined with an abundance of senescent fern material around the base of the plant--which potentially serves as a reservoir of endophyte inoculum--is likely responsible for the observed results. In the process of the ecological studies described above, I isolated over 500 strains of endophytes that corresponded to ca. 100 operational taxonomic units (OTUs). Four of these OTUs are previously undescribed and form a new family and genus, Catenosporaceae and Catenospora, respectively. One of these taxa is responsible for the strong spatial and temporal signals found in the ecological studies. We emphasize that future work should examine if the same phenomena are observed in other fern systems and further encourage endophyte researchers to expand the scope of their investigations into non-traditional plant lineages, as exciting ecological interactions that contribute to our understanding endophyte ecology--and community ecology as a whole--are waiting to be discovered.
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Kamau, Peris Wangari [Verfasser]. "Systematic Revision of Pteris L. in Tropical Africa and Ecology of Ferns and Lycophytes in Lowland Tropical Rainforests / Peris Wangari Kamau." Koblenz : Universitätsbibliothek Koblenz, 2012. http://d-nb.info/1029224129/34.
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Dearden, Fiona M. "Decomposition and microbial activity in natural temperate and boreal forests: the influence of microsite, proximity to woody debris and interception by ferns." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486461.
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There is a growing but inconclusive body of work on effects of litter-mixing on ecological processes, but few have considered interactions among foliar and woody litters. Further, most work on litter decomposition assumes that litterfall reaches the ground, and the effects of interception of litter (e.g. by ferns or logs) remains largely unexplored. Three studies were perfonned to investigate these issues. The first study was in a long-tenn chronosequence in the Swedish boreal forest where decomposition' rate declined with ecosystem retrogression. Field measurements showed that the ratio of twig to foliage in litterfall increased with prolonged absence ofdisturbance. In a mesocosm experiment, combining foliar and twig litters in their natural proportions reduced overall decomposition rates, suggesting that the increased twig proportion may contribute to the large increase in humus build-up found with prolonged absence of disturbance. The second study was in a New Zealand temperate rainforest, and showed that logs fonned an important microsite for decomposition, with strongly contrasting microbial activity and organic matter content compared with ~e ground. Microbial activity on logs was variable, probably linked to differences in phenolics and decay stage. The third study, also in a New Zealand temperate rainforest, showed that the fern Blechnum discolor has the potential to intercept and retain 10% of falling litter. A higher twig to foliage ratio was found in the litter accumulated in fern crowns than in the incoming litterfall or on the forest floor. Organic matter content, basal respiration and microbial activity were significantly higher in fein crowns than on the forest floor. Further, foliar litter decomposed significantly faster in fern crowns than away from the crown, but not faster than at the trunk base. Consequently, litter interception by ferns may affect nutrient cycling through concentrating nutrients and organic matter in and under ferns.
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Barker, Michael Shane. "A Revision of Caribbean Adiantopsis." Oxford, Ohio : Miami University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1071253706.
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Thesis (M.S.)--Miami University, Dept. of Botany, 2003.Title from first page of PDF document. Document formatted into pages; contains vii, 83 p. : ill. Includes bibliographical references (p. 79-82).
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Lóriga, Piñero Josmaily [Verfasser], and Susanne [Akademischer Betreuer] Renner. "Evolution and classification of Elaphoglossum and Asplenium ferns on Cuba, and discovery of a Miocene Elaphoglossum in Dominican amber / Josmaily Lóriga Piñero ; Betreuer: Susanne Renner." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1155407660/34.
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Richard, Monique 1972. "Fern species diversity in relation to spatial scale and structure." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20850.
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Species with different requirements can coexist if the environment varies in space; we therefore expect a positive relationship between species diversity and environmental heterogeneity. In this thesis I examine the influence of environmental structure on patterns of fern diversity in one hectare of old-growth forest and compare these patterns to other surveys covering a broad range of scales. The nineteen species recorded in the hectare had non-random spatial distributions and differed in their soil preferences. Diversity was positively related to soil moisture and negatively related to soil fertility, but there was no relationship with environmental variance. The counteracting influence of dispersal may predominate over selection processes at the hectare scale. Both species-area curves and the decreasing correlation of species composition with distance had very similar slopes over quadrat sizes ranging from 1 x 1 m to 50 x 50 km, suggesting that some diversity patterns may be independent of scale.
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Garcia, Juliana Bittencourt. "Desenvolvimento do aerênquima em raízes de Cebatopteris richardii brongn. (PTERIDACEAE) submetidas a estresse hídrico." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/158512.
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O aerênquima é um tecido vegetal com grandes lacunas de ar que podem ter função de circulação de gases e/ou sustentação de órgãos, estando presente nas raízes e órgãos aéreos de plantas aquáticas ou sob alagamento, podendo ainda ser formado em decorrência de algum estresse. Ceratopteris richardii é uma planta aquática, de hábito anfíbio que apresenta aerênquima em seus órgãos vegetativos. Dessa forma, esse trabalho buscou analisar a formação de aerênquima nas raízes e pecíolo desta espécie frente a uma situação de restrição hídrica e verificar sua plasticidade fenotípica. Vinte indivíduos de C. richardii foram cultivados e submetidos a um tratamento com diferentes concentrações de PEG 6000. Em todas as amostras analisadas, foi observada a formação de aerênquima. A análise qualitativa mostrou diferença entre os tratamentos, porém, a análise estatística revelou que as diferenças não são significativas para o número amostral empregado. Variações de crescimento do esporófito revelaram que a espécie de estudo modificou algumas características de desenvolvimento em resposta a restrição hídrica. Tais resultados revelam importantes características para esta espécie, que parece aclimatar-se a situação de estresse a qual foi submetida. Com base nisso, sugere-se ampliar estes estudos para elucidar questões relacionadas a formação de aerênquima e o ambiente, seja para esta espécie ou de outro grupo taxonômico.Aerenchyma is a plant tissue with large air gaps that may have gas circulation function and / or sustain organs. This structure is present in roots and aerial organs of water plants and in plants under flooding it may also be formed during some stress. Ceratopteris richardii is an aquatic plant, with amphibious habit that has aerenchyma in their vegetative organs. Thus, the aim of this study is analyze the aerenchyma formation in roots and stem of this specie under water restriction situation and verify their phenotypic plasticity. Twenty specimen of C. richardii were cultured and subjected to treatment with different concentrations of PEG 6000. In all samples, were observed aerenchyma formation. Qualitative analysis showed differences among treatments, however, the statistical analysis revealed that the differences are not significant for the sample size. Sporophyte growth variations revealed that the specie of study modified some growth characteristics in response to water restriction. These results reveal important characteristics for C. richardii, which seems to acclimatize the stress situation which has submitted. On the base that, it is suggested further studies to become clearer the relation between aerenchyma formation and environment, even to either this species or another taxonomic group.
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Nogueira, Tâmara Magalhães Oliveira. "Caracterização da atividade antinociceptiva do extrato metanólico de Adiantumlatifolium Lam. em modelos experimentais de dor inflamatória." reponame:Repositório Institucional da FIOCRUZ, 2010. https://www.arca.fiocruz.br/handle/icict/4309.
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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil
Adiantum, um dos gêneros mais amplamente distribuídos da família Pteridaceae é empregado na medicina popular mundialmente. Neste trabalho, nós investigamos as propriedades antinociceptivas do extrato metanólico de Adiantum latifolium (EMA) em modelos animais de dor inflamatória. As propriedades farmacológicas de EMA foram avaliadas nos testes de contorção, formalina, retirada de cauda e nos modelos de edema de pata induzido por carragenina e edema de orelha induzido pelo ácido aracdônico. A toxicidade aguda de EMA, assim como seu efeito sobre o desempenho motor dos camundongos no teste de rota rod, foram investigados. Além disso, o perfil químico de EMA foi avaliado por cromatografia. A administração oral (100-400 mg/Kg) ou intraperitoneal (1-100 mg/Kg) de EMA produziu uma inibição dose-dependente do número de contorções abdominais induzidas pelo ácido acético em camundongos. Do mesmo modo, o tratamento com EMA (100 mg/Kg/IP) inibiu a hipernocicepção induzida pela formalina tanto na fase inicial quanto na fase tardia. Em contraste, EMA não alterou o limiar de resposta a estímulo térmico no teste de retirada de cauda, indicando ausência de ação central. Confirmando sua atividade antiinflamatória, EMA (100 e 200 mg/Kg/IP) inibiu eventos importantes relacionados à resposta inflamatória induzida pela carragenina ou ácido aracdônico: edema local e aumento nos níveis de interleucina-1β tecidual. Camundongos tratados com EMA (200 mg/Kg) não mostraram alteração no desempenho motor no teste de rota rod, ou sinais de toxicidade (1000 mg/Kg) durante um período de 14 dias. A análise fitoquímica preliminar indicou a presença de terpenos, esteróides, flavonóides e ácidos fenólicos, os quais podem ser responsáveis pelos efeitos antinociceptivo e/ou antiinflamatório de EMA. Os extratos metanólicos de diferentes partes da planta apresentaram atividade antinociceptiva de igual magnitude, sugerindo que o princípio ativo de EMA se distribui por toda a planta. Quando as frações do extrato foram avaliadas, a butanólica e de acetato de etila apresentaram maior eficácia, sendo consideradas as frações mais ativas. Nossos resultados demonstram que Adiantum latifolium apresenta consistente atividade antinociceptiva e antiinflamatória em diferentes modelos experimentais, possivelmente pela inibição da produção e/ou liberação de IL-1β, constituindo bom candidato para o desenvolvimento farmacológico. Palavras-
Adiantum, one of the most widely distributed genera of the Pteridaceae family, is employed in folk medicine worldwide. In the present study, we investigated the antinociceptive effects of the methanolic extract of Adiantum latifolium (MEA) in animal models of inflammatory pain. The pharmacological properties of MEA were evaluated by using writhing, formalin and tail flick tests, carrageenan-induced paw oedema and arachidonic acid-induced ear oedema models. Mice motor performance was evaluated in the rota-rod test and the acute toxicity evaluated over 14 days. In the next experiments series, the active part of Adiantum latifolium, as well as the active fraction of MEA, was evaluated. A phytochemical screening for classes of constituents of MEA was carried out by thin layer chromatography (TLC). Oral (100-400 mg/kg) or intraperitoneal (1-100 mg/kg) administration of MEA produced a dose-related inhibition of acetic acid-induced writhing in mice. Furthermore, treatment with MEA (100 mg/kg/IP) inhibited both the early and late phases of formalin induced hypernociception. In contrast, MEA (100 mg/kg/IP) did not prevent the thermal nociception in the tail flick test. In addition, MEA (100 and 200 mg/kg/IP) inhibited important events related to the inflammatory response induced by carrageenan or arachidonic acid: namely local oedema and increase in tissue interleukin-1β levels. MEA (200 mg/kg/IP) treated mice did not show any motor performance alterations. Over the study duration of 14 days, there were no deaths or toxic signs recorded in the group of mice given 1000 mg/kg of MEA. Phytochemical analysis indicated the presence of terpenes, steroids, flavonoids and phenolic acids, which may be responsible for the MEA antinociceptive and/or antiinflammatory effects. Methanolic extracts from different parts of Adiantum latifolium showed equivalent antinociceptive activity, suggesting that the active principle of EMA is homogeny distributed through the plant. Buthanolic and ethyl acetate fractions were the more active fractions of MEA. Our results demonstrate that Adiantum latifolium presents significant antinociceptive and antiinflammatory activities in different experimental models, possibly through an inhibition of IL-1β production and constitute good candidate for pharmacologic development.
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Salazar, Cotugno Laura Inés [Verfasser], Jürgen [Akademischer Betreuer] Homeier, Christoph [Akademischer Betreuer] Leuschner, and Michael [Akademischer Betreuer] Kessler. "Unraveling the causal links between ecosystem productivity measures and species richness using terrestrial ferns in Ecuador / Laura Inés Salazar Cotugno. Gutachter: Christoph Leuschner ; Michael Kessler. Betreuer: Jürgen Homeier." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044173548/34.
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Hernández, Rojas Adriana Carolina [Verfasser], and Georg [Akademischer Betreuer] Miehe. "Biogeographical patterns of species richness, range size and phylogenetic diversity of ferns along elevational-latitudinal gradients in the tropics and its transition zone / Adriana Carolina Hernández Rojas ; Betreuer: Georg Miehe." Marburg : Philipps-Universität Marburg, 2020. http://d-nb.info/1223130835/34.
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De, Bever Alan. "The effectiveness of different combinations of hoaglands’s solution and azolla filiculoids on hydroponically cultivated beta vulgaris subsp. cycla ’Fordhook Giant'." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/844.
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Thesis (MTech (Horticultural Sciences)--Cape Peninsula University of Technology, 2012This study evaluated the effects of different combinations of Hoagland’s solution and Azolla filiculoides on Beta vulgaris subsp. cycla ‘FORDHOOK GIANT’ grown in different hydroponic nutrient solutions. These solutions were comprised of a full Hoagland’s solution and a Hoagland’s solution minus nitrogen solution and amalgamations of these with Azolla respectively. The objectives were to assess the effects of different combinations of Hoagland’s solution and A. filiculoides on uptake of nitrogen and other nutrients, photosynthesis, chlorophyll content, growth and development in B. vulgaris grown in hydroponic cultures. The treatments were made up of 1) Hoagland’s minus N solution (as the control), 2) A. filiculoides plus Hoagland’s minus N solution, 3) A. filiculoides plus a full Hoagland’s solution and 4) full Hoagland’s solution. Each treatment was replicated 4 times. Nutrient uptake was measured at 4 and 8 weeks into the experiment. Photosynthesis was measured by analysing the photosynthetic rate, stomatal conductance, intercellular CO2 concentration and the evapotranspiration rate of B. vulgaris on a weekly basis. Chlorophyll content was determined by analysing the samples at 4 and 8 weeks. Growth and development was determined by measuring plant height, leaf number, leaf colour, fresh weight and dry weight. Plant height, leaf number and leaf colour on a biweekly intervals, while fresh and dry weight were analysed at 4 and 8 weeks into the experiment. In this study, the most favourable results were attained by the full Hoagland’s solution. This treatment produced plants with the highest nutrient uptake, photosynthesis, chlorophyll content and best growth and development. Preceding this was the Azolla plus full Hoagland’s solution, followed by the Azolla plus Hoagland’s minus nitrogen solution. The poorest results were noted in the control (Hoagland’s minus nitrogen solution) as all the tested parameters in this treatment were the lowest. In this study, Azolla plus Hoagland's minus N solution treatment produced significant growth in B. vulgaris. Although nitrogen was not applied in this treatment, there was improved nitrogen content in B. vulgaris organs. It is postulated that, probably, Azolla released the fixed nitrogen in its surrounding environment making it available to B. vulgaris hence improving N uptake and growth. This implies that there was a synergistic effect from Azolla–Anabaena symbiosis. More studies to understand the mechanisms involved in improving the plant growth are recommended.
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Rajmanickam, Vijayaraj, Hema Achyuthan, Christopher Eastoe, and Anjum Farooqui. "Early-Holocene to present palaeoenvironmental shifts and short climate events from the tropical wetland and lake sediments, Kukkal Lake, Southern India: Geochemistry and palynology." SAGE PUBLICATIONS LTD, 2017. http://hdl.handle.net/10150/624066.
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The Kukkal basin, Tamil Nadu, India, receives most of its rain from the southwest monsoon (SWM). A sediment core from Kukkal Lake preserves a continuous sediment record from the early-Holocene to present (9000 yr BP to present). The present lake is situated at an elevation of similar to 1887m a.s.l., in a small basin that appears to have alternated between a and wetland depositional environment. Climate proxies, including sediment texture, total organic carbon (TOC), total nitrogen (TN), C/N, pollen and geochemical composition indicate a steady progression to wetter conditions, with two stepwise changes at about 8000, and between 3200 and 1800 yr BP. The change at 8000 yr BP appears to correspond to a brief (100-150years) dry spell recorded elsewhere in India. The change at 3200-1800 yr BP consisted in a rapid intensification of the SWM, and may correlate with the initiation of the Roman Warm Period'. There is no clear evidence of changes at the times of the Medieval Warm Period' (MWP') and the Little Ice Age' (LIA'). The C/N ratio of the sediments ranges from 14.02 to 8.31, indicating that the organic matter originated from a mixture of lacustrine algae, vascular and terrestrial plants. Chemical weathering indices (Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA)) are consistent with extreme silicate weathering. Pollen data show a development from savanna vegetation prior to about 8000 yr BP, followed by grassland with palms, the appearance of ferns just prior to 3200 yr BP and the establishment of the tropical humid forest between 3200 and about 1800 yr BP.
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Link-Pérez, Melanie A. "Revision and Molecular Systematics of the Neotropical Fern Genus Adiantopsis (Pteridaceae)." Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1271788914.
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Ozdarici, Ok Asli. "A Segment-based Approach To Classify Agricultural Lands Using Multi-temporal Kompsat-2 And Envisat Asar Data." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614195/index.pdf.
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Agriculture has an important role in Turkeyhence automated approaches are crucial to maintain sustainability of agricultural activities. The objective of this research is to classify eight crop types cultivated in Karacabey Plain located in the north-west of Turkey using multi-temporal Kompsat-2 and Envisat ASAR satellite data. To fulfill this objective, first, the fused Kompsat-2 images were segmented separately to define homogenous agricultural patches. The segmentation results were evaluated using multiple goodness measures to find the optimum segments. Next, multispectral single-date Kompsat-2 images with the Envisat ASAR data were classified by MLC and SVMs algorithms. To combine the thematic information of the multi-temporal data set, probability maps were generated for each classification result and the accuracies of the thematic maps were then evaluated using segment-based manner. The results indicated that the segment-based approach based on the SVMs method using the multispectral Kompsat-2 and Envisat ASAR data provided the best classification accuracies. The combined thematic maps of June-August and June-July-August provided the highest overall accuracy and kappa value around 92% and 0.90, respectively, which was 4% better than the highest result computed with the MLC method. The produced thematic maps were also evaluated based on field-based manner and the analysis revealed that the classification performances are directly proportional to the size of the agricultural fields.
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Sencan, Secil. "Decision Tree Classification Of Multi-temporal Images For Field-based Crop Mapping." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605503/index.pdf.
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ABSTRACT
DECISION TREE CLASSIFICATION OF MULTI-TEMPORAL IMAGES FOR FIELD-BASED CROP MAPPING
Sencan, Seçil M. Sc., Department of Geodetic and Geographic Information Technologies Supervisor: Assist. Prof. Dr. Mustafa Tü
rker August 2004, 125 pages A decision tree (DT) classification approach was used to identify summer (August) crop types in an agricultural area near Karacabey (Bursa), Turkey from multi-temporal images. For the analysis, Landsat 7 ETM+ images acquired in May, July, and August 2000 were used. In addition to the original bands, NDVI, PCA, and Tasselled Cap Transformation bands were also generated and included in the classification procedure. Initially, the images were classified on a per-pixel basis using the multi-temporal masking technique together with the DT approach. Then, the classified outputs were applied a field-based analysis and the class labels of the fields were directly entered into the Geographical Information System (GIS) database. The results were compared with the classified outputs of the three dates of imagery generated using a traditional maximum likelihood (ML) algorithm. It was observed that the proposed approach provided significantly higher overall accuracies for the May and August images, for which the number of classes were low. In May and July, the DT approach produced the classification accuracies of 91.10% and 66.15% while the ML classifier produced 84.38% and 63.55%, respectively. However, in August nearly the similar overall accuracies were obtained for the ML (70.82%) and DT (69.14%) approaches. It was also observed that the use of additional bands for the proposed technique improved the separability of the sugar beet, tomato, pea, pepper, and rice classes.
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Sebesta, Nicole. "The Effects of Fire on Spore Viability of Lygodium microphyllum (Old World Climbing Fern)." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2203.
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Lygodium microphyllum, native to the Old World tropics, has invaded central and southern Florida, destroying native habitats, reducing biodiversity and altering fire regimes. Prescribed fire, one of several methods used to manage L. microphyllum infestations, reduces fern biomass over large areas, but its effects on spore viability are unknown. To provide tools to evaluate whether fire-dispersed spores are viable, this research determined how heat affects spore viability. Spores were exposed to temperatures of 50°C to 300°C for durations of 5 seconds to 1 hour, then allowed to germinate on agar in petri plates. Percent germination was assayed after two weeks. Temperatures of 50°C had little effect; 300°C killed spores for all durations. Results indicate that while viability of unburnt spores decreases with increasing temperature and duration of heat exposure, spores are killed when exposed to relatively low temperatures compared to those in fires.
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Launila, Andreas. "Real-Time Head Pose Estimation in Low-Resolution Football Footage." Thesis, KTH, Computer Vision and Active Perception, CVAP, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12061.
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This report examines the problem of real-time head pose estimation in low-resolution football footage. A method is presented for inferring the head pose using a combination of footage and knowledge of the locations of the football and players. An ensemble of randomized ferns is compared with a support vector machine for processing the footage, while a support vector machine performs pattern recognition on the location data. Combining the two sources of information outperforms either in isolation. The location of the football turns out to be an important piece of information.
QC 20100707
Capturing and Visualizing Large scale Human Action (ACTVIS)
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Harrington, Jesse Patrick. "Vengeance and saintly cursing in the saints' Lives of England and Ireland, c. 1060-1215." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277930.
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This dissertation concerns the narrative and theological role of divine vengeance and saintly cursing in the saints’ Lives of England and Ireland, c. 1060-1215. The dissertation considers four case studies of primary material: the hagiographical and historical writings of the English Benedictines (Goscelin of Saint-Bertin, Eadmer of Canterbury, and William of Malmesbury), the English Cistercians (Aelred and Walter Daniel of Rievaulx, John of Forde), the cross-cultural hagiographer Jocelin of Furness, and the Irish (examining key textual clusters connected with St. Máedóc of Ferns and St. Ruadán of Lorrha, whose authors are anonymous). This material is predominantly in Latin, with the exception of the Irish material, for which some vernacular (Middle Irish) hagiographical and historical/saga material is also considered. The first four chapters (I-IV) focus discretely on these respective source-based case studies. Each is framed by a discussion of those textual clusters in terms of their given authors, provenances, audiences, patrons, agendas and outlooks, to show how the representation of cursing and vengeance operated according to the logic of the texts and their authors. The methods in each case include discerning and explaining the editorial processes at work as a basis for drawing out broader patterns in these clusters with respect to the overall theme. The fifth chapter (V) frames a more thematic and comparative discussion of the foregoing material, dealing with the more general questions of language, sources, and theological convergences compared across the four source bases. This chapter reveals in particular the common influence and creative reuse of key biblical texts, the Dialogues of Gregory the Great, and the Life of Martin of Tours. Similar discussion is made of a range of common ‘paradigms’ according to which hagiographical vengeance episodes were represented. In a normative theology in which punitive miracles, divine vengeance and ritual sanction are chiefly understood as redemptive, episodes in which vengeance episodes are fatal can be considered in terms of specific sociological imperatives placing such theology under pressure. The dissertation additionally considers the question of ‘coercive fasting’ as a subset of cursing which has been hitherto studied chiefly in terms of the Irish material, but which can also be found among the Anglo-Latin writers also. Here it is argued that both bodies of material partake in an essentially shared Christian literary and theological culture, albeit one that comes under pressure from particular local, political and sociological circumstances. Looking at material on both sides of the Irish Sea in an age of reform, the dissertation ultimately considers the commonalities and differences across diverse cultural and regional outlooks with regard to their respective understandings of vengeance and cursing.
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Schwingel, Julio Cesar da Silva. "A matemática da samambaia de Barnsley." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/1833.
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CAPESEste trabalho objetiva apresentar as ideias matemáticas principais da Samambaia de Barnsley, um fractal que recria uma imagem que assemelha-se a uma folha de samambaia da variedade Black Spleenwort e tem como base quatro transformações afins elementares. Algumas mutações da Samambaia de Barnsley são também apresentadas.
This work aims to present the main mathematical ideas of Barnsley’ Fern, a fractal that recreates an image that resembles a fern leaf of the Black Spleenwort variety and is based on four elementary affine transformations. Some mutations of Barnsley’ Fern are also presented.
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Solis, Montero Andres. "Efficient Feature Extraction for Shape Analysis, Object Detection and Tracking." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34830.
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During the course of this thesis, two scenarios are considered. In the first one, we contribute to feature extraction algorithms. In the second one, we use features to improve object detection solutions and localization. The two scenarios give rise to into four thesis sub-goals. First, we present a new shape skeleton pruning algorithm based on contour approximation and the integer medial axis. The algorithm effectively removes unwanted branches, conserves the connectivity of the skeleton and respects the topological properties of the shape. The algorithm is robust to significant boundary noise and to rigid shape transformations. It is fast and easy to implement. While shape-based solutions via boundary and skeleton analysis are viable solutions to object detection, keypoint features are important for textured object detection. Therefore, we present a keypoint featurebased planar object detection framework for vision-based localization. We demonstrate that our framework is robust against illumination changes, perspective distortion, motion
blur, and occlusions. We increase robustness of the localization scheme in cluttered environments and decrease false detection of targets. We present an off-line target evaluation strategy and a scheme to improve pose. Third, we extend planar object detection to a real-time approach for 3D object detection using a mobile and uncalibrated camera. We develop our algorithm based on two novel naive Bayes classifiers for viewpoint and feature matching that improve performance and decrease memory usage. Our algorithm exploits the specific structure of various binary descriptors in order to boost feature matching by conserving descriptor properties. Our novel naive classifiers require a database with a small memory footprint because we only store efficiently encoded features. We improve the feature-indexing scheme to speed up the matching process creating a highly efficient database for objects. Finally, we present a model-free long-term tracking algorithm based on the Kernelized Correlation Filter. The proposed solution improves the correlation tracker based on precision, success, accuracy and robustness while increasing frame rates. We integrate adjustable Gaussian window and sparse features for robust scale estimation creating a better separation of the target and the background. Furthermore, we include fast descriptors and Fourier spectrum packed format to boost performance while decreasing the memory footprint. We compare our algorithm with state-of-the-art techniques to validate the results.
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Buchtela, Radim. "Učení detektorů pomocí sledování objektů." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236342.
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This thesis is devoted to learn detectors by object tracking in video sequence. In this thesis, we discuss methods for object tracking, object detection and online learning and possibilities of their using in sophisticated techniques, which combine object tracking and online learning detectors.
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Langa, Sílvia da Fátima. "The impact and control of waterweeds in the Southern Mozambique Basin rivers." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1001905.
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In Mozambique, establishment of aquatic weeds has been enhanced through the increased enrichment of water bodies by nutrient runoffs from human and agricultural wastes that lead to an increase in nitrate and phosphate in the water. The aquatic weeds, water hyacinth (Eichhornia crassipes), red water fern ( Azolla microphylla), water lettuce (Pistia stratiotes) and salvinia (Salvinia molesta) were found in most watercourses in Mozambique and are becoming aggressive in some watercourses, especially in the Umbeluzi and Incomati rivers. Farmers and people living along the rivers are aware of the negative impact of the water weeds because the large mats of weeds cause loss of shoreline and navigability along the rivers. Other commonly perceived effects of aquatic invasive plants in Mozambique rivers include: reduced navigable surface area; difficulties for fishermen, which reduces income; increased prevalence of insects and insect-borne disease, and decreased aesthetic value. The methods currently used for the control and management of the aquatic weeds are mechanical and manual control. Both methods are costly, time consuming, and only provide a short-term solution to the problem. The study found that the weevils Neochetina eichhorniae and N. bruchi were effective biological control agents in the study area but their impact is too gradual compared to the aggressive proliferation of water hyacinth. The one year lab-experiment clearly demonstrated that the water lettuce weed had a significant impact on the recruitment of macro-invertebrates to the artificial substrates, and water lettuce contributed to the reduction of oxygen in the water and consequent reduction of macro-invertebrate abundance and diversity. The biodiversity recovered at the same time in the pools containing water lettuce controlled by N. affinis and water lettuce controlled by herbicide, but richness and diversity of macro-invertebrates was higher in the water lettuce controlled by N affinis during the first sampling occasion compared to the water lettuce in pools controlled by herbicide, where macro-invertebrates increased only when DO levels recovered after water lettuce mat decay. The number of taxa recorded in this study is an indication of the significance of macro-invertebrates in an aquatic environment. This therefore emphasizes the need for more research efforts into macrophyte and macro-invertebrate associations in the aquatic system to better understand the implications of habitat modification arising from human activities. It will also enable us to be better equipped with a more appropriate ecological understanding for aquatic resources management.
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Gehrig-Downie, Christine. "Epiphyte diversity and microclimate of the tropical lowland cloud forest in French Guiana." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BC27-3.
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