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 49 for “"Photosynthetic Activity"”.
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Influence of Loss of Function of the Fatty Acid Desaturase 7 Gene on Photosynthetic Activity and Foliar Redox Status
… This study reports that the spr2 mutant enhances photosynthetic efficiency constitutively compared to wild-type (WT) plants. While no constitutive differences in intermediates and products of photosynthesis were detected, the spr2 mutants showed increased growth, suggesting increased …
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Effects of road salt on photosynthetic and enzyme activity of stream biofilms
… on periphyton. I measured extracelluar enzyme activity and photosynthetic activity of natural winter stream periphyton communities under various short-term laboratory salt exposures. The results of this study suggest that short-term exposure to increased concentrations of salt did not affect …
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Rapid measurements of periphytic responses to nutrients using PAM fluorimetry
… fluorometric methods of estimating biomass and photosynthetic activity have been used in saline environments, but generally not over different nutrient treatments and not for a substantial duration. This study evaluated the use of a pulse amplitude modulated (PAM) fluorometer for measuring …
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Multi-scale Remote Assessment of Phenology of Photosynthesis and Productivity of Northern Forests
Northern trees undergo seasonal regulation of photosynthetic activity in response to environmental conditions. Remote sensing provides a powerful tool to assess photosynthetic phenology at the global scale. However, traditional “greenness” based vegetation indices, like the normalized difference …
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Interacting effects of soil nitrogen supply and light availability on understory sapling growth and foliar attributes
… (N) availability, and the link to foliar photosynthetic capacity, typically receive less consideration in describing stand dynamics. My primary hypothesis is that light and soil N availability have species-specific effects on photosynthetic activity and growth, and that together these …
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Why do wasp induced galls of Acacia longifolia photosynthesise?
… galling herbivore. This study investigated the photosynthetic capacity of bud galls induced by the wasp, Trichilogaster acaciae longifoliae (Pteromalidae) in the invasive Acacia longifolia. The role of this photosynthetic activity was examined in terms of its ability to subsidise carbon budgets, …
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Comparisons of the resurrection grass, Eragrostis nindensis, with the related desiccation-sensitive species, E. curvula
… water content (RWC) ofless than 5% in two weeks. Photosynthetic activity in E. curvula is maintained down to 40% RWC, after which further drying results in a sudden irreversible breakdown of the photosynthetic system and its pigments.
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Comparisons of the resurrection grass, Eragrostis nindensis, with the related desiccation-sensitive species, E. curvula
… water content (RWC) ofless than 5% in two weeks. Photosynthetic activity in E. curvula is maintained down to 40% RWC, after which further drying results in a sudden irreversible breakdown of the photosynthetic system and its pigments.
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Modeling Sex-Specific Seasonal Habitat Selection for Elk (Cervus Elaphus) in Central Washington
… and roads. They selected vegetation with high photosynthetic activity modeled using a normalized difference vegetation index (NDVI) in forested and semi desert land cover types. During summer, females selected gentler slopes than males, and with primarily southwest aspects, also at high …
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Photosynthetic rates of Ilex crenata thunb. 'helleri' during propagation
… levels, mineral nutrients and rooting on the net photosynthetic (Pn) rate of unrooted Ilex crenata Thunb. 'Helleri' cuttings. Optimal photosynthetic activity occurred at PAR levels of about 600 micro-Einsteins m⁻² sec⁻¹. The emergence of roots increased the Pn rate. High plant carbohydrate levels …
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Fluorescence Studies of Photosystem II Fluorescence Quenching During Desiccation
… have developed mechanisms to protect their photosynthetic machinery during times of desiccation. In hydrated conditions nonphotochemical quenching (NPQ) mechanisms are able to safely dissipate excess excitation energy as heat, but mechanisms of NPQ associated with desiccation tolerance are …
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Removal of organic compounds from aquatic environments by advanced oxidation processes.
… for seven days to UV-A (365 nm) irradiation. Photosynthetic activity significantly decreased after 24 hours of irradiation with samples showing no photosynthetic activity by the end of the experiment. Intra- and extracellular microcystin (MC) concentrations were markedly decreased in UV-A …
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Observational analysis of twentieth century summer climate over North America
… in space and time with rapid increases in photosynthetic activity through increased crop production and yield. The study thus lays the ground for future research in attributing the causes of regional climate change, especially through the interactions of climate and land use.
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The physiology of dormancy and germination in cysts of the marine dinoflagellate Scrippsiella trochoidea
… of the two forms was comparable. The respiratory activity of quiescent cysts was estimated to be approximately 1.5% of that in vegetative cells. Although chlorophyll-a persisted in quiescent cysts, no photosynthetic activity could be detected therein. The germination of S. trochoidea cysts was …
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Processes and community structure in microbial biofilms of the River Elbe: relation to nutrient dynamics and particulate organic matter
… the upper sediment layers, as highest microbial activity could be expected due to increased import of nutrients. Dissolved oxygen is suggested to control the nitrogen dynamics in the hyporheic zone, as dissolved oxygen in the flowing water varied seasonally and diurnally due to the photosynthetic …
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Eastern Deciduous Forest Phenology and Vegetative Vigor Trends From 2000 to 2013, Mammoth Cave National Park, KY
… Spectroradiometer (MODIS) instrument data, the photosynthetic activity of vegetation at Mammoth Cave National Park (MACA) is tracked from 2000 to 2013. Three methods were employed to examine the changes and climate influences in vegetation over the study period: 1) aggregating the NDVI of the …
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Relationships between tree rings and Landsat EVI in the Northeast United States
… spatially extensive measures of vegetation activity, and the Enhanced Vegetation Index (EVI) has been widely linked to photosynthetic activity of vegetation. Networks of tree ring width (TRW) chronologies provide ground-based estimates of annual net carbon (C) uptake in forests, and time …
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Physiology and Biochemistry of Lead Accumulation in Sesbania Drummondii
… Pb(N03)2 for 0-4 weeks, and were assessed for photosynthetic activity, growth, and Pb accumulation at each harvest. It was observed that S. drummondii seedlings were able to tolerate up to 10 g/kg Pb in soil with the only visible symptom of Pb toxicity being stunted growth. Photosynthetic …
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Sustainable Approaches to Enhance Water Productivity in Cucumis melo
… production by reducing plant growth, photosynthetic efficiency, and yield. Sustainable strategies such as grafting, deficit irrigation, and an improved understanding of plant-water relations offer potential solutions to enhance crop water productivity (CWP). This study conducted at the …
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Trace Greenhouse Gas Fluxes in Upland Forests
… with solar radiation, suggesting a link to photosynthetic activity mediated by tree water transport. Collectively, these results show that trees on free-draining soils could act as net sinks for CH₄ and N₂O. These findings will improve GHG budgets because tree stem uptake is currently …
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