Redetermination of the Quantum Yield of Photoisomerization and Energy Content in the K-Intermediate of Bacteriorhodopsin Photocycle and Its Mutants by the Photoacoustic Technique

1997 ◽  
Vol 101 (33) ◽  
pp. 6629-6633 ◽  
Author(s):  
Stephan L. Logunov ◽  
Mostafa A. El-Sayed
Keyword(s):  
Quantum Yield ◽  
Energy Content ◽  
Photoacoustic Technique ◽  
Bacteriorhodopsin Photocycle

Effect of salt on the tyrosine and protonated Schiff base deprotonation kinetics in bacteriorhodopsin

1985 ◽  
Vol 63 (7) ◽  
pp. 1699-1704 ◽  
Author(s):  
Paul Dupuis ◽  
M. A. El-Sayed
Keyword(s):  
Schiff Base ◽  
Quantum Yield ◽  
Salt Concentration ◽  
Slow Component ◽  
High Salt ◽  
Proton Release ◽  
High Ph ◽  
Bacteriorhodopsin Photocycle

It is observed that the number of protons pumped per M412 formed in the bacteriorhodopsin photocycle almost doubles at high salt concentrations. In this paper, we studied the rates of deprotonation of tyrosine and of the two components of the protonated Schiff base at high salt concentrations, and at different pHs and temperatures. It is found that at pH = 7, increasing the salt concentration decreases the rates of deprotonation of the protonated Schiff base and tyrosine. This strongly suggests that the observed gain in the quantum yield of proton release per M412 formed when the salt concentration is increased is not a result of an increase in these rates. However, at high pH, e.g. 9.6, increasing the salt concentration increases the rate of deprotonation of the Schiff base by about 50%. Under all conditions, the slow component of the Schiff base is found to lose its proton prior to tyrosine.

Fluorescence quantum yield of rhodamine 6G using pulsed photoacoustic technique

Pramana ◽  
1990 ◽  
Vol 34 (6) ◽  
pp. 585-590 ◽  
Author(s):  
P Sathy ◽  
Reji Philip ◽  
V P N Nampoori ◽  
C P G Vallabhan
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Rhodamine 6G ◽  
Photoacoustic Technique

Demonstrating Nutrient Cost Gradients: A Brooklyn Case Study

2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi
Keyword(s):  
Low Income ◽  
Energy Content ◽  
Food Selection ◽  
The United States ◽  
United States Department ◽  
Micronutrient Deficiencies ◽  
Caloric Density ◽  
Low Income Families ◽  
The Cost ◽  
The Impact

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.

Fine-scale taxonomic and temporal variability in the energy density of invertebrate prey of juvenile Chinook salmon Oncorhynchus tshawytscha

2020 ◽  
Vol 655 ◽  
pp. 185-198
Author(s):  
J Weil ◽  
WDP Duguid ◽  
F Juanes
Keyword(s):  
Energy Density ◽  
Chinook Salmon ◽  
Temporal Variability ◽  
Energy Content ◽  
Single Point ◽  
Single Species ◽  
Fine Scale ◽  
Temporal Differences ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.

Perceived Tension, Movement, and Pleasantness in Harmonic Musical Intervals and Noises

2020 ◽  
Vol 37 (4) ◽  
pp. 298-322 ◽  
Author(s):  
Marco Costa ◽  
Mattia Nese
Keyword(s):  
Visual Analog Scale ◽  
Energy Content ◽  
High Pitch ◽  
Analog Scale ◽  
Psychophysical Procedure ◽  
Preliminary Study

Perceived valence, tension, and movement of harmonic musical intervals (from the unison to the octave presented in a low- and high-register) and standard noises (brown, pink, white, blue, purple) were assessed in two studies that differed in the crossmodal procedure by which tension and movement were rated: proprioceptive device or visual analog scale. Valence was evaluated in both studies with the visual analog scale. In a preliminary study, the proprioceptive device was calibrated with a psychophysical procedure. Roughness of the stimuli was included as covariate. Tension was perceived higher in dissonant intervals and in intervals presented in the high register. The higher the high-pitch energy content in the standard noise, the higher the perceived tension. The visual analog scale resulted in higher tension ratings than the proprioceptive device. Perception of movement was higher in dissonant intervals, in intervals in the high register, and in standard noises than in musical intervals. High-pitch spectrum noises were associated with more sense of movement than low-pitch spectrum noises. Consonant intervals and low-register intervals were evaluated as more pleasant than dissonant and high-register intervals. High-pitch spectrum purple and blue noises were evaluated as more unpleasant than low-pitch spectrum noises.

Size-dependent emission of a dipole coupled to a metal nanoparticle

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3315-3325
Author(s):  
Viktoriia Savchuk ◽  
Arthur R. Knize ◽  
Pavlo Pinchuk ◽  
Anatoliy O. Pinchuk
Keyword(s):  
Numerical Analysis ◽  
Quantum Yield ◽  
Electric Dipole ◽  
Incident Radiation ◽  
Metal Nanoparticle ◽  
Plasmonic Nanoparticle ◽  
Size Dependent ◽  
Emission Enhancement ◽  
Electric Dipoles

AbstractWe present a systematic numerical analysis of the quantum yield of an electric dipole coupled to a plasmonic nanoparticle. We observe that the yield is highly dependent on the distance between the electric dipole and the nanoparticle, the size and permittivity of the nanoparticle, and the wavelength of the incident radiation. Our results indicate that enhancement of the quantum yield is only possible for electric dipoles coupled to a nanoparticle with a radius of 20 nm or larger. As the size of the nanoparticle is increased, emission enhancement occurs at wavelengths dependent on the coupling distance.

Analysis of Pyrolysis Kinetics and Energy Content of Agricultural and Forest Waste

2014 ◽  
Vol 2014 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Mahir Said ◽  
◽  
Geofrey John ◽  
Cuthbert Mhilu ◽  
Samwel Manyele ◽  
...  
Keyword(s):  
Energy Content ◽  
Pyrolysis Kinetics ◽  
Forest Waste

POTENTIAL PRODUCTIVITY ADAPTIVE AGROPHUTOCENOZIS ON SLOPING LANDS OF THE STEPPE TRANS-URALS

2020 ◽  
Author(s):  
R.А. Idrisov ◽  
Keyword(s):  
Protein C ◽  
Nutritional Value ◽  
Energy Content ◽  
Single Species ◽  
Exchange Energy ◽  
Metabolic Energy ◽  
Potential Productivity ◽  
Maximum Productivity ◽  
Sloping Lands ◽  
Natural Herb

The correct construction of agrophytocenoses on the slopes of the steppe trans-Urals helped to create maximum productivity. In the arid climate, the most productive were the double mixtures of alfalfa with brittle sitnik, wheatgrass is syd, providing an average of 41.6 and 40.2 quintals per hectare (c/ha) of hay, 32.1 and 31.0 GJ/ha OE (exchange energy per hectare), 4.5 and 4.3 quintals per hectare of boiled protein (c/ha) over 5 years. Single-species steppe ecotypes, brittle sieve and wheatgrass sieve in productivity slightly gave way to double components, providing respectively hay- 32.2 and 37.2 cents per hectare, exchange energy 22.2 and 25.7 GJ/ha, digested protein 1.93 and 2.53 c/ha. The enrichment of agrophytocense by the legume component allowed to increase the metabolic energy content to the level of 32.1 and 31.0-GJ/ha, digested protein to 4.5 and 4.3 quintals per hectare, which is 14 times the nutritional value of the metabolic energy, the digested protein is 10 times higher than the natural herb.

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