Adaptive variability of pigments in representatives of the genus Nostoc Vauch. (Cyanophyta) under different light conditions

2001 ◽  
Vol 3 (4) ◽  
pp. 69-76
Author(s):  
Svetlana I. Los' ◽  
R. N. Fomishina
Keyword(s):  
Light Conditions ◽  
Adaptive Variability

Decarboxylation Reactions in a Photocatalytic Microchip

2018 ◽  
Author(s):  
Kenji Katayama ◽  
Momona Seki ◽  
Kayoko Tokumitsu ◽  
Woon Yong Sohn
Keyword(s):  
Reaction Time ◽  
Organic Reactions ◽  
Light Conditions ◽  
High Yields

The photocatalytic microchip was demonstrated as an efficient platform of the photocatalytic organic reactions, which features an easy control of the reaction time and light conditions. We demonstrated the photocatalytic decarboxylation and the following adduct reaction inside the microchip and successfully achieved high yields of the products.

Light Absorption and Partitioning in Response to Nitrogen in Apple Leaves

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541a-541
Author(s):  
Lailiang Cheng ◽  
Leslie H. Fuchigami ◽  
Patrick J. Breen
Keyword(s):  
High Light ◽  
Thermal Dissipation ◽  
Photochemical Quenching ◽  
Light Conditions ◽  
Psii Efficiency ◽  
Fluorescence Measurements ◽  
Free Radical Formation ◽  
Highly Correlated ◽  
Non Photochemical Quenching ◽  
Leaf N

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.

The problem of ballistic design of the space system Earth remote sensing in stable near-circular sun-synchronous orbits with long-term spacecraft lifetime

2018 ◽  
pp. 3-9
Author(s):  
V. M. Artyushenko ◽  
D. Y. Vinogradov
Keyword(s):  
Remote Sensing ◽  
Target Function ◽  
Normal Operation ◽  
Space Systems ◽  
Light Conditions ◽  
Space System ◽  
Earth Remote Sensing ◽  
Synchronous Orbit ◽  
Favorable Conditions

The article deals with the issues related to the problem of ballistic design of the space system of remote sensing of the Earth on stable near-circular solar-synchronous orbits with long-term existence of spacecraft. We propose a rational method of maintaining a solar-synchronous orbit in given light conditions with prolonged active lifetime of space systems. In solving this problem, the total time of normal operation of the system for a given period of operation, during which the most favorable conditions for the use of spacecraft are provided on the main parts of orbits, is taken as a target function.

On the photoreactivity of some hardwood species studied by their leaf characteristics

1970 ◽  
Vol 23 ◽  
Author(s):  
M. Van Miegroet
Keyword(s):  
Morphological Characteristics ◽  
Vegetation Period ◽  
Forest Stand ◽  
Light Environment ◽  
Light Radiation ◽  
Light Conditions ◽  
Site Factors ◽  
Leaf Characteristics ◽  
Single Tree ◽  
Changing Light

A  certain number of measurable characteristics of tree leaves (morphological  characteristics, absorption of light radiation, intensity of respiration and  photosynthesis) are clearly linked with the presence of physiologically  active pigments in the leaves.     Leaf characteristics are highly and inequally influenced by changing  conditions of light environment, especially those related to light intensity,  light quality and duration of the daily illumination period. These  modifications do not only apply to light radiation as created under  laboratory conditions, but also to light conditions ensuing from the place in  the crown of a single tree, the social position of the tree in a forest stand  and the site factors in general.     There are also changes taking place due to the progression of the  vegetation period, at the end of which all species are less tolerant or more  light demanding. The reaction of the leaves towards light radiation out of  different regions of the spectrum is also different. The so-called blue light  radiation (λmax = 440 nm) seems to be of the greatest importance in this  relation, as species react quite different to its action.     The biggest variation in leaf characteristics due to changing light  environment was measured for oak and beech, which both react quickly and are  qualified as 'photolabile species'. No important variations occur in leaves  of ash and maple, which therefore are qualified as 'photostable species'.      As a consequence of variable reactions to changing light conditions, the  relationships between the species are continually modified, even in such a  way that their potential for dominance is not constant.     The classical division into tolerant and intolerant species or  classification of the species based upon the degree of light demand, is  highly inaccurate and it seems preferable to speak of relative light demands  and relative tolerance. All these observations and conclusions bring about a  clear confirmation of the necessity to recognize the individuality of the  single tree, the special character of each growth condition, the own  structure of each forest stand, the specific reaction to one sided  modifications of environmental factors. This is especially important for an  intensive sylvicultural practice.     They also prove the necessity for more physiological and biochemical  research to arrive at a better understanding of growth and its mechanism.      Sylviculture in fact must try to regulate, on an expanded scale, the  phenomens of growth, which is the exchange, absorption and transformation of  energy.     A practical interpretation and regulation of fundamental laws of physiology  and growth will be possible as soon as a clinical form of sylviculture is  created and the adequate instrumentarium developed.

scholarly journals Phytochrome interacting factors 4 and 5 control seedling growth in changing light conditions by directly controlling auxin signaling

2012 ◽  
Vol 71 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Patricia Hornitschek ◽  
Markus V. Kohnen ◽  
Séverine Lorrain ◽  
Jacques Rougemont ◽  
Karin Ljung ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Auxin Signaling ◽  
Light Conditions ◽  
Changing Light

scholarly journals A Method of Fast Segmentation for Banana Stalk Exploited Lightweight Multi-Feature Fusion Deep Neural Network

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 66
Author(s):  
Tianci Chen ◽  
Rihong Zhang ◽  
Lixue Zhu ◽  
Shiang Zhang ◽  
Xiaomin Li
Keyword(s):  
Neural Network ◽  
Execution Time ◽  
Deep Neural Network ◽  
Feature Fusion ◽  
Frame Rate ◽  
Light Conditions ◽  
Segmentation Method ◽  
Segmentation Accuracy ◽  
Automatic Picking ◽  
Changing Light

In an orchard environment with a complex background and changing light conditions, the banana stalk, fruit, branches, and leaves are very similar in color. The fast and accurate detection and segmentation of a banana stalk are crucial to realize the automatic picking using a banana picking robot. In this paper, a banana stalk segmentation method based on a lightweight multi-feature fusion deep neural network (MFN) is proposed. The proposed network is mainly composed of encoding and decoding networks, in which the sandglass bottleneck design is adopted to alleviate the information a loss in high dimension. In the decoding network, a different sized dilated convolution kernel is used for convolution operation to make the extracted banana stalk features denser. The proposed network is verified by experiments. In the experiments, the detection precision, segmentation accuracy, number of parameters, operation efficiency, and average execution time are used as evaluation metrics, and the proposed network is compared with Resnet_Segnet, Mobilenet_Segnet, and a few other networks. The experimental results show that compared to other networks, the number of network parameters of the proposed network is significantly reduced, the running frame rate is improved, and the average execution time is shortened.

scholarly journals Salinity Tolerance of Four Hardy Ferns from the Genus Dryopteris Adans. Grown under Different Light Conditions

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Piotr Salachna ◽  
Rafał Piechocki
Keyword(s):  
Light Stress ◽  
Leaf Damage ◽  
Light Conditions ◽  
Reduced Height ◽  
Individual Taxon ◽  
Necrotic Spots ◽  
Sun And Shade ◽  
Tolerance To Salinity ◽  
Leaf Greenness ◽  
Ground Part

Hardy ferns form a group of attractive garden perennials with an unknown response to abiotic stresses. The aim of this study was to evaluate the tolerance of three species of ferns of Dryopteris genus (D. affinis, D. atrata and D. filix-mas) and one cultivar (D. filix-mas cv. “Linearis-Polydactylon”) to salinity and light stress. The plants were grown in full sun and shade and watered with 50 and 100 mM dm−3 NaCl solution. All taxa treated with 100 mM NaCl responded with reduced height, leaf greenness index and fresh weight of the above-ground part. In D. affinis and D. atrata salinity caused leaf damage manifested by necrotic spots, which was not observed in the other two taxa. The effect of NaCl depended on light treatments and individual taxon. D. affinis and D. atrata were more tolerant to salinity when growing under shade. Contrary to that, D. filix-mas cv. “Linearis-Polydactylon” seemed to show significantly greater tolerance to this stress under full sun. Salt-treated D. filix-mas cv. “Linearis-Polydactylon” plants accumulated enhanced amounts of K+ in the leaves, which might be associated with the taxon’s tolerance to salinity. Among the investigated genotypes, D. filix-mas cv. “Linearis-Polydactylon” seemed the most and D. affinis and D. atrata the least tolerant to salinity and light stress.

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