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31332. Utváření a význam pavoučích osobností v ekologické dynamice
- Creator:
- Michalko, Radek
- Format:
- print, bez média, and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, pavouci, ekologie, evoluce (biologie), ekologická dynamika, evoluční dynamika, personalita, vnitrodruhová variabilita, 2, and 57/59
- Language:
- Czech
- Description:
- Vnitrodruhová variabilita v chování zvířat, tj. personalita, výrazně ovlivňuje ekologické i evoluční procesy. V tomto článku se pojednává o tom, jak může personalita vzniknout u pavouků a její vliv na potravní sítě., Inter-individual behavioural differences, i.e. personalities, play a very important role in eco-evolutionary processes. Here, we describe how spiders’ personalities arise and how they influence the dynamics of food webs., and Radek Michalko.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31333. UV-A irradiation guards the photosynthetic apparatus against UV-B-induced damage
- Creator:
- Gartia, S., Pradhan, M. K., Joshi, P. N., Biswal, U. C., and Biswal, B.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- antheraxanthin, carotenoids, chlorophylls, clusterbean, Cyamopsis tetranoloba, fluorescence induction, violaxanthin, xanthophylls, and zeaxanthin
- Language:
- Multiple languages
- Description:
- In clusterbean leaves UV-B radiation caused a reduction in contents of chlorophylls and carotenoids and in the efficiency of photosystem 2 photochemistry. The degree of damage was reduced when UV-A accompanied the UV-B radiation. This indicates the counteracting effect of UV-A radiation against UV-B-induced impairment. and S. Gartia ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31334. UV-A screening in plants determined using a new portable fluorimeter
- Creator:
- Kolb, C. A., Schreiber, U., Gademann, R., and Pfündel, E. E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- apigenin, berry, comparison of devices, flavonoids, Hordeum, leaf, luteolin, transmittance, and Vitis
- Language:
- Multiple languages
- Description:
- UV screening by plant surfaces can be determined by exposing plant organs to UV radiation and measuring the chlorophyll (Chl) fluorescence elicited. From this fluorescence, the UV transmittance can be derived: the more intense the screening the lower the reporter Chl fluorescence and the lower the UV transmittance. The relationships between UV screening at 375 nm, as determined in the field by a portable UV-A-PAM fluorimeter, and UV screening at 314 and 360 nm, measured in the laboratory with the non-portable XE-PAM fluorimeter, were investigated in leaves of grapevine (Vitis vinifera L. cv. Bacchus) and barley (Hordeum vulgare cv. Ricarda), as well as in white grape berries. With leaves, linear trends were observed between XE-PAM measurements at 314 nm and UV-A-PAM measurements at 375 nm but the relationship between transmittance at 360 and 375 nm in barley was curved: a simple model calculation suggests that this curvi-linearity arises from particularly weak absorbance of barley flavonoids at 375 nm relative to absorbance at 360 nm. Transmittance values at 314 nm plotted against 375 nm yielded a much smaller slope in grapevine leaves than in barley leaves, which was attributed to screening in the short-wavelength UV by hydroxycinnamic acids in the former but not in the latter species. With grape berries, a poor correlation was detected between transmittances at 314 and 375 nm which might arise from high scattering of UV radiation at the berry surface. Such artefacts appear to be confined to the UV-B region, as berry transmittance at 360 nm correlated very well with that at 375 nm. Thus, assessment of UV screening in the field at short UV wavelengths using 375 nm readings from a UV-A-PAM fluorimeter is possible provided that information is available on the relationship between the transmittance at the UV wavelength of interest and at 375 nm for the sample tissue being investigated. and C. A. Kolb ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31335. UV-B induced alterations in composition of thylakoid membrane and amino acids in leaves of Rhizophora apiculata Blume
- Creator:
- Moorthy, P. and Kathiresan, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- lipid peroxidation, mangrove, and saturated and unsaturated fatty acids
- Language:
- Multiple languages
- Description:
- Seedlings of Rhizophora apiculata were exposed to UV-B radiation at four doses equivalent to 10, 20, 30, and 40 % ozone depletion. The seedlings irradiated with high doses of UV-B had characteristic decline in contents of specific proteins with molecular masses of 33, 23, and 17 kDa. On the contrary, proteins of 55, 33, 25, 23, and 17 kDa were accumulated in the seedlings exposed to low doses of UV-B. The UV-B, in general, enhanced formation of saturated fatty acids and reduced unsaturated fatty acids, to a maximum extent of 88 and 26 %, respectively. The low dose of UV-B increased content of oleic acid by 9 %, and the high dose reduced it by 34 %. The high dose of UV-B enhanced the lipid peroxidation by 48 %, whereas the low dose of UV-B did not show any significant effect. The contents of amino acids such as aspartate, glutamate, asparagine, serine, glutamine, threonine, and histidine were increased in low UV-B doses by 53, 86, 142, 72, 3, 119, and 32 %, respectively; while in high doses they were reduced significantly. and P. Moorthy, K. Kathiresan.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31336. UV-B induced production of MMP-2 and MMP-9 in human corneal cells
- Creator:
- Igor Kozák, Klisenbauer, D., and Tomáš Juhás
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, UV-B irradiation, human corneal epithelial cells, human corneal fibroblasts, MMP-2 production, MMP-9 production, acute photokeratitis, 14, and 612
- Language:
- English
- Description:
- The purpose of this study was to determine the production of metalloproteinases (MMP) 2 and 9 following UV-B irradiation in human corneal epithelial cells and fibroblasts. Epithelial cells and fibroblasts were separated from human donor corneas and exposed to UV-B lamp irradiation for 20, 40, 80 and 120 s. Media samples were collected at 8, 24, 48 and 72 h and gelatinase A and B production was assayed by the ELISA test. Statistical significance of production was assessed by the paired t-test. Increased production of MMP-2 was found in human corneal fibroblasts in response to UV-B irradiation. A statistically significant production of MMP-2 was not observed in human corneal epithelial cells following UV-B exposure. We did not detect any increase in MMP-9 after irradiation in either epithelial cells or fibroblasts. MMP-2 is produced by the corneal fibroblasts in the acute phase after UV-B irradiation. MMP-9 is not released in vitro following UV-B irradiation damage and therefore does not directly participate in the pathophysiology of acute photokeratitis., I. Kozák, D. Klisenbauer, T. Juhás., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31337. UV-B radiation mediated alterations in the nitrate assimilation pathway of crop plants. 1.. Kinetic characteristics of nitrate reductase
- Creator:
- Balakumar, T., Selvakumar, V., Sathiameena, K., Murugu Ilanchezhian, C., and Paliwal, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, fresh and dry mass, leaf area, root, shoot, and Vigna unguiculata
- Language:
- Multiple languages
- Description:
- The kinetics and other characteristics of nitrate reductase (NR, EC 1.6.6.1) in cowpea [Vigna unguiculata (L.) Walp.] seedlings irradiated with biologically effective UV-B radiation (280-320 nm, 3.2 W m-2 s-1) were recorded. The in vivo and in vitro NR activities were inhibited by 34 and 41 % under UV-B treatment, respectively. Both Vmax and Km for the substrate were enhanced by UV-B radiation. The Km for nitrate increased from 1.2 to 1.7 mM after the UV-B irradiation. The change in Km for NADH was from 0.12 to 0.17 mM. The increases in Km indicate that UV-B radiation seriously changes the topology of NR, particularly with respect to the nitrate and NADH binding sites. The rate of NR turnover indicates the extent of damage inflicted by UV-B radiation on the nitrate metabolism. The half-life (t1/2) of NR was reduced from 7 to 4 h in the UV-B treated seedlings. UV-B also inhibited the kinetics of nitrate uptake by plants: its Km increased from 0.08 to 0.12 mM. and T. Balakumar ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31338. UV-B radiation mediated alterations in the nitrate assimilation pathway of crop plants. 2.. Kinetic characteristics of nitrite reductase
- Creator:
- Balakumar, T., Sathiameena, K., Selvakumar, V., Murugu Ilanchezhian, C., and Paliwal, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- nitrate reductase, nitrite reductase, enzyme induction and kinetics, and Vigna unguiculata
- Language:
- Multiple languages
- Description:
- Cowpea [Vigna unguiculata (L.) Walp. cv. Co 4] seedlings were subjected to a weighted irradiance of 3.2 W m-2 s-1 of biologically effective ultraviolet-B radiation (UV-B, 280-320 nm) and the changes in the kinetic and other characteristics of nitrite reductase (NiR) were recorded. The activity of NiR was hampered by 19 % under UV-B irradiation compared to the control. The UV-B treated plants required higher concentrations of nitrate for the induction of NiR synthesis than the controls. The NiR activity decay kinetics showed that the UV-B treatment significantly lowers the t1/2 of the enzyme, thereby indicating a reduced rate of enzyme turnover. The comparison of kinetic characteristics of nitrate reductase (NR) and NiR under UV-B treatment showed that NiR was not so sensitive to UV-B radiation as NR. As shown by enzyme turnover rates, NiR extracted from plants irradiated by UV-B in situ was less sensitive to UV-B radiation than the enzyme extract subjected to in vitro UV-B irradiation. Though NiR was less damaged by UV-B treatment than NR, subtle changes occurred in its kinetic characteristics. and T. Balakumar ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31339. UV-stellar spectra - some basic achievements
- Creator:
- Boyarchuk, A. A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- astronomy, stellar spectra, and UV-regions
- Language:
- Czech
- Description:
- Observations of stellar spectra in the UV-region during twenty years are briefly reviewed. Basic achievements have been made in the investigation of interstellar absorption, effective temperatures scale, mass loss, stellar chromospheres and non-stationary stars.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
31340. Úvaha o významu pomocných věd. Příspěvek k metodice etnografického výzkumu
- Creator:
- Langer, Jiří
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- interdisciplinary research, multi-aspect studies, vernacular architecture, and churches
- Language:
- Czech
- Description:
- My experience from interdisciplinary research is based on the exploitation of studies of related branches of science that serve as auxiliary sciences to the major branch of science. In the course of study of more complex phenomena of folk culture one needs to research into their origin (not their typological development). The most limiting factor, from my point of view, is ethnographical regionalisation and the established borderlines of regions and countries. Another limiting factor is a close cohesion with the established understanding of branch-specific sources of information and methods, particularly physical preservation of ethnographic artefacts. The significance of training in auxiliary sciences for multiaspect studies is described via six examples from the author’s own study of wooden multi-aspect in Europe. Having combined aspects from several disciplines, the author managed to come up with new perspectives with respect to various issues of origins of well-known phenomena. The result was an attempt to synthesise a phenomenon the genetics of which can be examined in broad interethnic contexts only. Each and every synthesis does indeed answer the research questions, but it also asks new questions for further researches to answer. It is therefore necessary to prepare accordingly, with respect to these researches. interdisciplinary studies require familiarisation with analytical methods in related branches of science. Education of experts in ethnology could be extended to include the study of auxiliary sciences, as is the case of the auxiliary sciences of history.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public