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1452. Ultrafialový svět bezobratlých
- Creator:
- Pavel Pecháček, Stella, David, and Karel Kleisner
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, bezobratlí, ultrafialové záření, 2, and 59
- Language:
- Czech
- Description:
- Nowadays, increasing attention is being paid to the biological significance of UV- -reflecting patterns exposed on the outer surfaces of various organisms. UV radiation plays an important role in the communication of many species of organisms. Here we give a brief overview of the biological functions of UV reflectance in some groups of invertebrates. Special attention is paid to the role of UV reflectance in sexual selection, foraging strategies, and the evolution and ecology of a species in general. and Pavel Pecháček, David Stella, Karel Kleisner.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1453. Ultrafialový svět rostlin. I. Jak vzniká zbarvení - od nositele k interpretovi
- Creator:
- Pavel Pecháček
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, ultrafialové záření, opylovači, rostliny, zrak, ultraviolet radiation, pollinators, plants, vision, ultrafialové světlo, ultrafialové spektrum, 2, and 57/59
- Language:
- Czech
- Description:
- Mnoho skupin živočichů disponuje zrakem citlivým na tzv. ultrafialové světlo. Jednou z takových skupin jsou i různí opylovači, kteří nám dobře známé květy mohou vidět v trochu odlišných barvách, než my. Na květech rostlin totiž často existují vzory patrné pouze v ultrafialové části spektra, které jsou pro člověka neviditelné. V první části seriálu o výskytu a významu těchto vzorů u rostlin se zabývá historií odhalování citlivosti živočichů na ultrafialové světlo, přibližuje otázky, jak funguje zrak a jakým způsobem ultrafialové zbarvení na povrchu organismů vzniká., The vision of many animal groups is sensitive to the so-called ultraviolet (UV) light. These groups include various pollinators, which may see flowers that are quite familiar to us in a different coloration. That is because flowers often feature patterns visible only in the UV part of the spectrum, and thus invisible to humans. This series deals with the occurrence of such patterns and their significance for plants. The first part recounts the history of discovering the sensibility of animals to UV light, expounds on the way how vision works, explains the origin of UV coloration on organismal surfaces., and Pavel Pecháček.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1454. Ultrafialový svět rostlin. II. Jak zachytit neviditelné a když červená není (jen) červená
- Creator:
- Pavel Pecháček
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, rostliny, ultrafialové záření, plants, ultraviolet radiation, 2, and 57/59
- Language:
- Czech
- Description:
- Význam ultrafialových znaků v životě různých organismů byl dlouho opomíjen především z toho důvodu, že UV paprsky jsou pro lidský zrak za normálních okolností neviditelné. Jedna z možností, jak si můžeme ultrafialovou podobu živočichů či rostlin zviditelnit, je použití speciálně upraveného klasického či digitálního fotoaparátu. Druhý díl seriálu o ultrafialových vzorech na květech rostlin se zabývá vývojem techniky záznamu UV podoby různých organismů a popisem získávání fotografií, které doprovázejí tento text. Druhá část článku je věnována vybraným druhům našich nejběžnějších rostlin a charakterizaci jejich ultrafialových znaků., The significance of UV characteristics for the life of various organisms has been neglected for a long time. It stems mainly from the fact, that under normal circumstances, UV rays are invisible to the human eye. One of the ways to make the UV appearance of animals or plants visible is to use a specially adjusted classic or digital camera. This second paper deals with the UV patterns on flowers. It focuses on the development of techniques which allow us to capture the UV appearance of various organisms, and provides a methodology with which the accompanying photos were taken. The article also presents selected species of common native plants, with a description of their UV characteristics., and Pavel Pecháček.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1455. Ultrafialový svět rostlin. III. Neviditelná pestrost květů - evoluce a význam UV znaků
- Creator:
- Pavel Pecháček
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, rostliny, květy, evoluce (biologie), plants, flowers, evolution (biology), 2, and 57/59
- Language:
- Czech
- Description:
- The last part of this series about UV characters on plant flowers presents UV images of several other common plant species native to the Czech flora. Attention is also paid to the possibility of using herbarium material for research into the UV characters of plants. The article summarizes recently discovered knowledge along with the evolutionary and ecological factors behind the emergence and significance of UV characters on plant flowers, particularly their role in the communication of pollinators. and Pavel Pecháček.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1456. Ultraviolet-B radiation or heat cause changes in photosynthesis, antioxidant enzyme activities and pollen performance in olive tree
- Creator:
- Koubouris, G. C., Kavroulakis, N., Metzidakis, I. T., Vasilakakis, M. D., and Sofo, A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, klimatické změny, ozon, olivovník evropský, photosynthesis, climate changes, ozone, Olea europaea, Kréta (Řecko : ostrov), Crete (Greece), abiotic stress, lipid peroxidation, pollen germination, 2, and 581
- Language:
- Multiple languages
- Description:
- The present study attempts to determine how some physiological and reproductive functions of olive tree (Olea europaea L., cv. Koroneiki) respond to enhanced UV-B radiation or heat. Enhanced UV-B radiation was applied to (1) three-year-old potted plants in an open nursery (corresponded to ca. 16% ozone depletion), and (2) in vitro cultured pollen samples (220 μmol m-2 s-1, PAR = 400-700 nm + UV-B at 7.5, 15.0, or 22.5 kJ m-2 d-1). Potted olive plants were also subjected to high temperature (38 +- 4°C) for 28 h to mimic heat levels regularly measured in olive growing areas. A significant effect of UV-B on photosynthetic rate was observed. However, enhanced UV-B radiation did affect neither chlorophyll nor carotenoid content, supporting previous reports on hardiness of the photosynthetic apparatus in olive. Increased superoxide dismutase activity was observed in UV-B-treated olive plants (+ 225%), whereas no effect was found in the plants under heat stress. Neither UV-B and nor heat did affect H2O2 accumulation in the plant tissues. However, the same treatments resulted in enhanced lipid peroxidation (+ 18% for UV-B and + 15% for heat), which is likely linked to other reactive oxygen species. The increased guaiacol peroxidase activity observed in both treatments (+ 32% for UV-B and + 49% for heat) is related to the defense against oxidative membrane damage. The observed reduction in pollen germination (20-39%) and tube length (11-44%) could have serious implications on olive yields, especially for low fruit-setting cultivars or in years and environments with additional unfavorable conditions. UV-B and heat effects described here support the hypothesis that plant response to a given stressor is affected by the overall context and that a holistic approach is necessary to determine plant strategies for climate change adaptation., G. C. Koubouris, N. Kavroulakis, I. T. Metzidakis, M. D. Vasilakakis, A. Sofo., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1457. Umělá inteligence a taxonomie: jsou entomologové ohroženým druhem?
- Creator:
- Jaromír Vaňhara, Fedor, Peter, and Havel, Josef
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Obecná biologie, biologie, entomologové, umělá inteligence, biology, entomologists, artificial intelligence, 2, and 57
- Language:
- Czech
- Description:
- Jaromír Vaňhara, Peter Fedor, Josef Havel.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1458. Umělá mraveniště - okna do mravenčího světa
- Creator:
- Amcha, Pavel
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, mravencovití, formikárium, pozorování mravenců, 2, and 59
- Language:
- Czech
- Description:
- Various types of artificial ant nests (formicaries) are described. These include simple laboratory types to more complex formicaries whose esthetic design is suitable for flat interiors. Formicaries facilitate not only the observation of natural ant behaviour inside a nest, but also of the remarkable practices used by young queens to appropriate the nest of a host ant species. In such equipment it is even possible to arrange a predatory raid by slave-making ants and observe their behaviour inside the attacked nest. Such observations would not have been possible in natural conditions. and Pavel Amcha.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1459. Umí krtek plavat?
- Creator:
- Jan Robovský
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, krtek obecný, 2, and 59
- Language:
- Czech
- Description:
- The article describes two independent observations of swimming in the European Mole (Talpa europaea) and provides a review of previously published records. Moles are primary terrestrial mammals but different phylogenetic lineages show different attitudes to water/moist habitats. and Jan Robovský a kol.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1460. Underestimated chlorophyll a fluorescence measurements on Buxus microphylla red winter leaves
- Creator:
- Peng, J. G., Jiang, X. R., Xu, J., Guo, L., Gao, R. F., and Liu, Y.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- obecná botanika, general botany, boxwood, evergreen species, palisade tissue, red carotenoids, spongy tissue, 2, and 581
- Language:
- Multiple languages
- Description:
- Leaves under stressful conditions usually show downregulated maximum quantum efficiency of photosystem II [inferred from variable to maximum chlorophyll (Chl) a fluorescence (Fv/Fm), usually lower than 0.8], indicating photoinhibition. The usual method to evaluate the degree of photoinhibition in winter red leaves is generally by measuring the Fv/Fm on the red adaxial surface. Two phenotypes of overwintering Buxus microphylla ‘Wintergreen’ red leaves, with different measuring site and leaf thickness, were investigated in order to elucidate how red pigments in the outer leaf layer affected the Chl a fluorescence (Fv/Fm) and photochemical reflectance index. Our results showed that the Fv/Fm measured on leaves with the same red surface, but different leaf thickness, exhibited a slightly lower value in half leaf (separated upper and lower layers of leaves by removing the leaf edge similarly as affected by winter freezing and thawing) than that in the intact leaf (without removing the leaf edge), and the Fv/Fm measured on the red surface was significantly lower than that on the inner or backlighted green surface of the same thickness. Our results suggest that the usual measurement of Fv/Fm on red adaxial surface overestimates the actual degree of photoinhibition compared with that of the whole leaf in the winter., J. G. Peng, X. R. Jiang, J. Xu, L. Guo, R. F. Gao, Y. Liu., and Obsahuje použitou literaturu
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public