Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 37 for “"ferns"”.
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Reconeixement de punts clau en imatges mitjançant l'algorisme Random Ferns
… clau en imatges mitjançant l'algorisme Random Ferns.
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A comparative study of the leaf epidermis of forty-two native California ferns
… old famliy Polypodiaceae, as represented by the ferns of California, into five families. The classification of Munz and Keck is the most recent treatment in this paper.</p>Historically, classification of the leptosporangiate ferns has been based on the sorus, but the last half century has seen …
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The Control of Spore Germination in Anemia Phyllitidis (L.) Swartz and Other Ferns
… require light for germination. In one family of ferns, the Schizaeaceae, the gibberellins overcome this light requirement and induce dark-germination. Fern gametophytes produce antheridium-inducing substances. The Anemia substance, antheridogen-B, is demonstrated to induce germination in two …
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The biosystematics of pteridophytes: aspects of morphology and reproductive biology of some epiphytic ferns
… and reproductive biology of several epiphytic ferns, including seven species of Polypodiaceae (Campyloneurum angustifolium, C. phyllitidis, Lepisorus thunbergianus, Microgramma heterophylla, Phlebodium aureum, Phymatosorus scolopendria, Polypodium pellucidum) and six of Elaphoglossum (E. …
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Studies on the evolution of morphological traits in ferns, with an emphasis on the family Dipteridaceae.
Extant ferns form a diverse, monophyletic group that is sister to the seed plants. Although ferns are rarely the dominant feature of any particular flora, they are found in many of the same habitats that seed plants occupy today. Studying the evolution of characters within this separate line of …
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Effects of nutrient limitation on understory communities in a tropical forest
Ferns are the second most diverse group of vascular plants whose diversity and abundance peak in mid-elevation tropical forests. Soil nutrient limitation is an important factor influencing plant communities and yet little is known about the factors influencing fern floristic composition and …
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Ferns as a forest farming crop: effects of light levels on growth and frond quality of selected speicies with potential in Missouri
… managed for high-value timber or veneer logs. Ferns may be an option to forest farmers as a high-value understory crop.The purpose of this research is to quantify the effects of various levels of light intensity on selected fern species believed to have potential use in the floral green and …
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Studi keanekaragaman dan pola distribusi tumbuhan paku di Taman Nasional Bromo Tengger Semeru
… Tumbuhan paku diidentifikasian menggunakan Ferns of Malaysia in Colour (Piggot, 1988), Flora of Thailand, Pteridophyta (Iwatsuki dan Iwatsuki, 1979, 1985, 1988, 1989), Key to The Families Of Ferns And Fern Allies in Australia (McCarthy, 1998) dan Jenis Paku Indonesia (LIPI,1980). Hasil …
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Palynological Correlation of the Kentucky no. 12 Coal
… order of abundance, arborescent lycopods, tree ferns, calamites, small ferns, gymnospermous trees, seed ferns, herbaceous lycopods, and others from unknown origin.</p> <p>The pattern of spore distribution in the columns did not appear to be affected by the presence of several partings, a feature …
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Mid Cretaceous fossil forests of Alexander Island, Antarctica
… forests dominated by araucarian conifers, ferns and shrubs, occupied stable areas of the floodplain characterised by low-energy floods. Disturbance vegetation dominated by Taeniopteris, liverworts, angiosperms and ferns, occupied river channel banks where frequent floods provided fresh …
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Palynology of the Springfield Coal of the Illinois Basin (Middle Pennsylvanian) with quantitative comparison of spore floras and coal-ball peats and implications for paleoecological studies
… are the dominant biomass producers, and tree ferns usually rank second. The disparities in the two records were evaluated using R-values, ratios of the abundance of a taxon in the spore record to its abundance in coal balls. Although R-values are too variable among zones in profiles to …
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Distribution of leaf dissection and sclerophylly along microhabitat gradients in pteridophytes of the Cape peninsula
… have been proposed for the two sets of traits. Ferns are well-suited to the study of leaf structure and its impact in different environments, as they show remarkable variation in leaf dissectedness and sclerophylly, and are able to inhabit a variety of marginal habitats. In this study, …
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Pengaruh pemberian kombinasi tepung keong mas (Pomacea canaliculata) dan tepung paku air (Azolla pinnata) terfermentasi terhadap konsumsi ransum, pertambahan bobot badan dan konversi rasum ayam petelur strain isa brown periode layer
… of golden apple snail flour and aquatic ferns fermentation as a substitute for fish meal and soybean meal is one alternative that is used to overcome the high cost the feed ingredients of aquatic ferns and golden apple snails have a similar protein content of fish meal and soybean meal. …
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A new member of the zygopteridales from the lower Upper Devonian (Frasnian) of Ellesmere, N.W.T., Arctic Canada
… and suggest affinity instead with zygopterid ferns. Within the Zygopteridales, this plant seems to align most closely with the Rhacopytaceae. The Frasnian dating of this plant suggests that laminated foliage had been achieved by some zygopterid ferns long before previously recognized. The …
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The lower cretaceous flora of the gates formation from western Canada
… (Marchantiolites and Thallites), Equisetites, ferns (Gleichenites, Acanthopteris and Coniopteris of Dicksoniaceae, Cladophlebis, Sphenopteris and a new genus), seed-ferns (Sagenopteris and a new genus), conifers (Pityocladus and Pityophyllum of Pinaceae, Athrotaxites and Elatides of …
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Paleoecology and Taphonomy of Middle Pennsylvanian-Age Coal-Swamp Plants: Herrin Coal-Ball Peat and Coal, Peabody Camp 11 Mine, Herrin Coal, Western Kentucky
… abundances of major plant groups (lycopods, ferns, and pteriodosperms) in coal-ball profiles and in coal differ by less than 10% after accounting for differential compaction of plant tissues. Standard deviations in taxonomic and maceral composition among coal columns are generally less than …
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Bryophyte and macrolichen diversity of the Purdiaea nutans forest in southern Ecuador and its relationship to soil, climate and vegetation structure
… pattern for lichens, liverworts, mosses, and ferns. The results indicate that diversity patterns for epiphytic and terrestrial species are distinct and should be treated separately. Among the studied taxonomic groups, ferns and liverworts show most similar patterns of alpha and beta diversity …
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Food habits of the Allegheny woodrat (Neotoma magister )
… ( Vaccinium spp.), acorns (Quercus spp.), ferns ( Dryopteris spp.), and lichens. In the Ridge and Valley woodrats ate primarily blackberry (Rubus spp.) leaves, fungi, greenbrier (Smilax spp.) leaves, acorns, and oak leaves. Additionally, we examined the effects of common timber management …
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Modified System Design and Implementation of an Intelligent Assistive Robotic Manipulator
… local tracking method with the ferns global detector/tracker to create a method that utilizes the strengths of both systems to overcome their inherent weaknesses. The last improvement is a particle-filter based tracking algorithm that robustifies the visual servoing function of …
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