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2. Quality of supplementary LED lighting effects on growth and photosynthesis of two different Lactuca recombinant inbred lines (RILs) grown in a tropical greenhouse

Creator:
Choong, T. W., He, J., Qin, L., and Lee, S. K.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
pigmenty, světelné diody, fotosyntéza, pigments, light emitting diodes, photosynthesis, electron transport rate, leaf expansion, light- and CO2-saturated net photosynthetic rate, photochemical and nonphotochemical quenching, stomatal density, 2, and 581
Language:
Multiple languages
Description:
LED lamps with various combinations of red (R) and blue (B) wavelengths were used to supplement sunlight for the growth of a heat-resistant (HR) and heat-sensitive (HS) recombinant inbred lines (RIL) of lettuce. The RB-LED ratios were 100R:0B (0B), 92R:8B (8B), 84R:16B (16B), and 76R:24B (24B) with an equal PPFD of 100 μmol m-2 s-1. The greatest leaf expansion rates were observed at 8B for both genotypes. All HR-RILs had similar values of growth parameters and specific leaf area (SLA). However, higher values of growth parameters were observed in HS-RIL with 0B, 8B, and 16B than that under 24B and sunlight. Furthermore, HS-RIL had higher SLA under 0B compared to other conditions. Photosynthetic light-use efficiency and maximal oxygen evolution rate were the lowest under 8B for both genotypes. The quality of LED lighting, if provided, seemed to implicate genotype dependence, probably as a result of their different sensitivities to heat stress., T. W. Choong, J. He, L. Qin, S. K. Lee., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. What is the optimal light source for optical mapping using voltage- and calcium-sensitive dyes?

Creator:
Olejníčková, Veronika and Sedmera, David
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
světelné diody, light emitting diodes, xenon lamp, chick, mouse, optical mapping, mercury lamp, di-4-ANEPPS, 14, and 612
Language:
English
Description:
Optical mapping is a fluorescence-based physiological method to image spreading of action potential in excitable tissues, such as the heart and central nervous system. Because of the requirements for high speed imaging in low light conditions, highly sensitive high-speed cameras together with an optical system with maximum photon efficiency are required. While the optimization of these two components is relatively straightforward, the choice of the perfect light source is less simple; depending on the other (usually fixed) components, various parameters may acquire different weight in decisionmaking process. Here we describe the rationale for building an optical mapping setup and consider the relative advantages and disadvantages of three different commonly available light sources: mercury vapor lamp (HBO), xenon lamp (XBO), and light emitting diode (LED). Using the same optical system (fluorescence macroscope) and high-speed camera (Ultima L), we have tested each of the sources for its ability to provide bright and even illumination of the field of view and measured its temporal fluctuations in intensity. Then we used each in the actual optical mapping experiment using isolated, perfused adult mouse heart or chick embryonic heart to determine the actual signal to noise ratio at various acquisition rates. While the LED sources have undergone significant improvements in the recent past, the other alternatives may still surpass them in some parameters, so LEDs may not be the automatic number one choice for every application., Veronika Olejnickova, David Sedmera., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public