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Showing 1 to 20 of 22 for “"PHOTOSYNTHETIC PIGMENTS"”.
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Low temperature sequestration of photosynthetic pigments: Model studies and natural aquatic environments
A series of synthetic C-3^1 alkylthioether chlorophyll derivatives, analogous to those found to occur naturally in sediment from Pup Lagoon, Antarctica, have been formed in laboratory reactions that simulate conditions that occur in many natural anoxic aquatic environments (low temperature, …
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The analysis of marine algae photosynthetic pigments by high performance liquid chromatography
A method of analysis of the photosynthetic pigments of in vitro algal cultures, using reverse-phase high performance liquid chromatography (HPLC) is described. This technique was extended to analysis of photosynthetic pigments in samples from the SIBEX-I Expedition; a preconcentration technique was …
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Application of surface-enhanced resonance Raman spectroscopy to chlorophyll and chlorophyll derivatives
… electrodes are preferable for SERRS studies of photosynthetic pigments because the electrogenerated species can be created and monitored with minimal sample manipulation and chemical interference. Although the roughened silver electrode provides intense Raman spectra for the neutral …
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Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis
… fluorescence parameters and levels of photosynthetic pigments (chlorophylls and carotenoids) and of anthocyanins were measured. Electrolyte leakage of drying and rehydrating leaves was monitored to determine the extent of damage to membranes. Quantum efficiency and photosynthetic …
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Desiccation-driven senescence in the resurrection plant Xerophyta schlechteri (Baker) N.L. Menezes
… the degradation of cellular metabolites and photosynthetic pigments and uncontrolled dismantling of cellular membranes and organelles. Angiosperm resurrection plants display vegetative desiccation tolerance and avoid drought-induced senescence in most of their tissues. Developmentally older …
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Investigation of chiral porphyrin aggregates with heterodyne-detected vibrational sum frequency generation spectroscopy
In nature, photosynthetic organisms harvest and transport solar energy through the finely-tuned interplay between vibrational, electronic, and excitonic characteristics within photosynthetic reaction centers. These characteristics depend intimately on the precise arrangement of the reaction …
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Effect of Increased Temperature and Nitrogen on the Non-N-fixing vs. N-fixing Cyanobacteria in Western Lake Erie: Implications for Competition and Climate Change
… N (as NO3), and then analyzed for content of photosynthetic pigments. Both temperature and N affected algae, there were temperature x N interactions, and the effect of N and temperature depended on sampling date and the presence/absence of herbivores. In general, increases in N or temperature …
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Monthly variability in upper ocean biogeochemistry due to mesoscale eddy activity in the Saragasso Sea
… thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-series Study (BATS) site were used. During the three years of this study, four out of six high thorium- 234 flux events over 1000 dpm/m2/d occurred during the passage of an eddy. …
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Monthly variability in upper ocean biogeochemistry due to mesoscale eddy activity in the Saragasso Sea
… thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-series Study (BATS) site were used. During the three years of this study, four out of six high thorium- 234 flux events over 1000 dpm/m 2/d occurred during the passage of an eddy. …
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Characterizing uptake, distribution and fate of CdSe/ZnS quantum dots in Synnechococcus elongatus PCC7942
… destabilization, viability and the activity of photosynthetic pigments were characterized. For characterization of uptake and distribution, flow cytometry, laser scanning confocal microscopy and transmission electron microscopy were used. When quantum dots are dispersed into the environment, …
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Using Leaf Spectra to Elucidate the Taxonomy and Ecology of Living and Dried Plants
… the prediction of PROSPECT leaf traits such as photosynthetic pigments increased while in phenolics and structural leaf traits decreased, and that PROSPECT traits predicted from dried leaves are better at inferring relationships with the nutritional composition of the rhizosphere. Finally, in …
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A study of photoperiodic inhibition of flower development in Lemna Persusilla 6746
… inhibited by an increase in light intensity. Photosynthetic inhibitors, including 3,(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU), partially reverse the inhibition of continuous white light. DCMU also partially reverses the inhibition of red-interrupted long nights, suggesting that …
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Effects of light and nutrient gradients on the taxonomic composition, size structure and physiological status of the phytoplankton community within a temperate eutrophic estuary
… fractionated (<2, 2-5, 5-20, >20µm) chlorophyll, photosynthetic pigments by HPLC, cell counts by inverted microscopy, and in year 2003 flow cytometry counts and primary productivity (by oxygen) and Fast Repetition Rate Fluorometer (FRRF). Analyses of the major nanophytoplankton taxa involved …
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A METE mutant of Chlamydomonas reinhardtii provides new perspectives on the evolution of vitamin B12 auxotrophy
… lipids and free fatty acids, and a decrease in photosynthetic pigments, proteins and free amino acids. This is reminiscent of nitrogen deprivation, but closer investigation revealed that B12 deprivation caused a substantial increase in reactive oxygen species, which preceded a rapid decline in …
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Seasonal variability of phytoplankton photophysiology in the Southern Ocean: an analysis of uncertainties and the impact of assumptions
… Repetition Rate fluorometry (FRRf), which infer photosynthetic capacity by measuring the transport of electrons during photosynthesis. While promising, this technique requires the derivation of several photophysiological parameters, and uncertainties in how these are calculated can affect the …
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Characterizing ancient chemoclines through the use of pigment biomarkers and sedimentary stable isotope signatures
… aquatic systems through the use of sedimentary pigments and the stable carbon and nitrogen isotopes of organic matter. The central aim of the research comprising this volume is to identify how chemocline fluctuations are expressed in the pigment and stable isotope signatures of aquatic …
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Development of Multifunctional Electrical Impedance Spectroscopy System for Characterization in Plant Phenotyping
… to determine the algae species in water. The photosynthetic pigments like Chlorophyll-a concentrations were estimated by measuring impedances of the algae species and the corresponding EIS characteristics were obtained to detect the species. New EIS models were developed and validated with …
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Physiological responses of soybean seeds (Glycine Max L. Merr.) to metal pollutants
… Uptake of metal pollutant, concentration of photosynthetic pigments and photosynthetic functioning were examined in metal-germinated, recovery and control seedlings. In the final section of the study, chemical speciation in the nutrient solution used for cultivation of metal-treatment plants …
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INNOVATIVE APPROACHES TO PLANT PROTECTION AND PRODUCE SAFETY THROUGH HIGH-PRECISION PLANT MANAGEMENT SYSTEMS
… stress, though no significant alterations in photosynthetic pigments were observed. Microbiota profiling showed that disease presence had a stronger effect on bacterial community composition than UV-C treatment, though moderate shifts occurred in UV-C-treated healthy leaves. Gene expression …
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Particulate fluxes in the subtropical convergence region and other marine environments of New Zealand
… to operate across the Rise. The presence of photosynthetic pigments in trap samples from 100 to 550 m depths suggests that sinking material must be transported rapidly out of well lit surface waters, probably as intact marine aggregates or mesozooplankton faecal pellets. The low …
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