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 246 for “"Diatoms"”.
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Barium uptake by marine diatoms.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences; and, (B.S.)--Massachusetts Institute of Technology, Dept. of Biology, 1978.
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Lipoxygenase Activity in Diatoms : A New Tool to Study the Antiproliferative Effects of Diatoms on Copepod Reproduction
… knowledge of the oxylipin metabolism in diatoms has been continuously increasing. Not only have new oxylipin compounds been identified, but it is becoming apparent thatoxylipin metabolism is highly complex and specific.<br></br><br></br>This thesis contributes to the understanding of …
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Characterization of biofuel from diatoms via hydrothermal liquefaction
… low lipid microalgae to produce bio-crude oil. Diatoms are a major group of microalgae in water bodies with a high growth rate and that contribute about 20% of global primary production. Their unique frustule (silica cell wall) results in a high ash content (39% dry weight). This character makes …
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Architectures of Microbiality: From Diatoms to Diatom Houses
… unveiled the microbial world, during which diatoms, owing to their astonishing biological properties, forms, and material possibilities, became the subject of wonderment by a diverse group of naturalists, artists, and architects. I contend that microbial ubiquity constitutes a crucial but …
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The role of diatoms in the global carbon cycle
… climate change. Here we present our work on diatoms, a phytoplankton group of major importance. We reviewed published data on the temperature dependence of diatom growth rate. By applying a quantile regression we calculate the upper-edge of the maximum growth rate. Exponential and optimal …
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Transcriptomic Insights into the Diplontic Life History of Diatoms
… be challenging, if not impossible in some cases. Diatoms (Bacillariophyceae) are no exception to this challenge, and their diversity of life stages and reproductive strategies add further challenges. A central focus of diatom research has been to unravel the evolutionary events that led to their …
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Physio-morphological effects of abrupt thermal stress on diatoms
Introduction: Increased temperature as a stress factor in aquatic environments has recently received much attention. Human population growth accompanied by expanded demands for electrical energy has resulted in increased construction of power generating facilities. Conventional fossil fuel power …
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Holocene environmental change at Groenvlei, Knysna, South Africa : evidence from diatoms
This study demonstrates that diatom analysis of lake sediment can provide very detailed information on long and short term climate change, hampered only by inconsistent sediment accumulation at Groenvlei. Further work may provide insight to periods which were not covered in this study.
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Enhancement of Carotenoid Biosynthesis and Antioxidant Responses in Diatoms by Light Modulation
The ecological success of diatoms is mostly attributed to their ability to adjust biological performances to the variable environmental conditions they experience in the water column. While the efficient photoacclimative and photoprotective mechanisms in diatoms are already reported, the …
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Enhancing the production of Omega-3 polyunsaturated fatty acids in marine diatoms
… Unfortunately, these microalgae, of which diatoms are the dominant class, only accumulate oil during specific stages of their life-cycle and/or under nutritional states which are incompatible with the required high density of growth and target fatty acid profile. Additionally, the …
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The utility of sedimentary diatoms as a measure of historical lake ph
… District Algoma, Ontario. The surface sediment diatoms (0-1 cm) from each of these lakes were carefully identified, enumerated, and classified in terms of their pH indicator status. The surface sediment diatom analysis indicated that lake pH is one of the most important factors affecting the …
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Barium uptake by diatoms and the 226Ra-Ba-Si system in the oceans.
Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
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Algal bioproducts : investigating the effect of light quality on metabolite production by photosynthetic diatoms
… Oysters are fed with live microalgae (including diatoms) during the larval, juvenile and adult stages of growth, as are other shellfish, some crustaceans, shrimps/prawns and fish. The rearing of oysters and other aquaculture products rely on the constant production of live diatoms as feed. Diatom …
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Diatoms of the genus thalassiosira from the tidal San Joaquin River, Stockton CA, USA
<p>Several species of the diatom genus Thalassiosira Cleve, were observed in freshwater phytoplankton samples collected from a fifty-two kilometer reach of the San Joaquin River in the vicinity of Stockton, California, USA. The study was conducted between the South Airport Way bridge near Vernalis …
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Eukaryotic Parasites of Toxic and Bloom-forming Diatoms: Molecular insights in their diversity and physiology
… in both aquatic and terrestrial ecosystems. Diatoms, on the other hand, have long being recognised as one of the most successful group of phytoplankters and their role as main primary producers at the base of the food web in aquatic ecosystems is well-established. This thesis aims at …
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Growth, photophysiology and photosynthesis of two marine diatoms grown under predictable intra-diel light fluctuations
… impact growth and photophysiology of diatoms is poorly understood. To address this, several aspects of photophysiology were measured in the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum when grown under square-wave (SQ), sinusoidal (SI), and low (LF) and high (HF) …
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The Use of Diatoms to Infer Environmental Change of the Lower White River, Southeastern Arkansas
… less disturbed system abundant in benthic diatoms prior to 1996 (estimated age) later converting into an open, nutrient rich system abundant in planktonic, eutrophic indicator diatoms. This shift in lake conditions towards the nutrient rich system also coincided with the lowering of …
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Physiological and metabolic characteristics of polar diatoms: insights into cold adaptation and potential for biotechnology
… and complete darkness in the winter. Marine diatoms are prevalent in the polar oceans, significantly contributing to primary productivity and ecosystem functioning. They are characterized by having optimal growth at low temperatures (<10°C) and have developed various genetic adaptations to …
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