Aerosolové částice se vyskytují všude okolo nás v mnoha různých formách, například jako prach, mlha, kouř, dým nebo smog. Tyto částice ovlivňují dohlednost, klima, zdraví obyvatel a jejich kvalitu žvota. Atmosférický aerosol je v současné době jedním z největších problémů znečištění ovzduší. Tento článek dokumentuje vznik aerosolu, formy jeho výskytu a depozice. Dále popisujeme nejužívanější metody jeho odběru a monitorování. V závěrečné části jsou ukázány první výsledky získané pomocí nového zařízení na zkoumání resuspenze aerosolu - resuspenzní komory., Martin Civiš, Jan Hovorka, Devraj Thimmaiah., and Obsahuje bibliografii
The effects of the atomic ratio of N to P (N:P) on the response of Alexandrium tamarense to UV radiation (UVR) were investigated in this study. Artificial sea water of 5 different N:P ratios for indoor culture and with 3 different N:P ratios for outdoor culture were used for a period of 14 and 9 d, respectively. The short-term response of cells to UVR was analyzed using a fluorometer. Cells that acclimated to nutrient conditions at the Redfield value (16:1) showed the fastest growth rate and highest pigment concentrations in both indoor and outdoor conditions, compared to those acclimated to the non-Redfield conditions. Moreover, these physiological parameters were functions of the N:P ratio according to a two-order equation (y = a + bx + cx2, R2>0.95). The fluorescence data of indoor cultures showed that A. tamarense grown at 16:1 (N:P) exhibited the greatest ratio of repair rate/damage rate (r/k) and minimum level of UVR-induced inhibition. among those grown at all of the N:P ratios following UVR exposure. Outdoor cultures had the same patterns of fluorescence as indoor cultures, but the less UVR-induced inhibitions were detected compared the former with the latter. The following three parameters, the r/k, level of inhibition caused by the two radiation treatments following 60 min of exposure (PAR and PAB, respectively), and level of UVR-induced inhibition, were also functions of the N:P ratio according to the two-order equation (R2>0.96). Further, there was a negative correlation between
UVR-induced inhibition and the r/k ratio. In summary, the Redfield value (16:1) was the optimal nutrient stoichiometry for the protection of A. tamarense against the deleterious effects of UVR. Results were not impacted by previous light history experienced by cells., W. C. Guan, L. Li., and Obsahuje bibliografii
To investigate the effects of atmospheric CO2 enrichment on physiology and autumnal leaf phenology, we exposed 3-year-old sugar maple (Acer saccharum Marsh.) seedlings to 800 (A8), 600 (A6), and 400 μL(CO2) L-1 (AA) in nine continuous stirred tank reactor (CSTR) chambers during the growing season of 2014. Leaf abscission timing, abscised leaf area percentages, leaf number, light-saturated net photosynthetic rate (PNmax), leaf area, accumulative growth rates, and biomass were determined and assessed. The results suggested the following: (1) no significant differences were found in the timing of leaf abscission in the three CO2-concentration treatments; (2) PNmax was continuously stimulated to the greatest extent in A8 at 319% and 160% in A6 until the end of the growing season, respectively; and (3) leaf number, leaf area, and accumulative height growth all significantly increased by elevated CO2, which led to a 323% increase in A8 biomass and 235% in A6 biomass after 156-d fumigation. In summary, the results suggest, the timing of leaf abscission of sugar maple in fall was not modified by CO2 enrichment, the increased carbon gain by elevated CO2 was mainly due to increased leaf area, more leaves, and the continuously enhanced high photosynthesis throughout the growing season instead of the leaf life span., L. Li, W. J. Manning, X. K. Wang., and Obsahuje bibliografii
Antiparasitic allogrooming in two adults of Red Fox (Vulpes vulpes) was observed in the Javorie Mountains in Slovakia on 18th April 2016. This rare observation was documented by photographs and video. In this context, the occurrence of ticks on Red Foxes and in fox faeces in Europe is briefly reviewed and discussed. and Ivan Literák.
During vertebrate evolution, structural changes in red blood cells (RBC) and hemoglobin (Hb), have probably resulted in the importance of blood carbon dioxide transport. The chloride/bicarbonate exchange across the RBC membrane, which is an integral part of the blood CO2 transport process in vertebrates, has been examined on two different species of teleost fish, Euthynnus alletteratus and Thunnus thynnus, at several oxygenation states of erythrocyte HOS (high-oxygenation state, about 90 % of saturation) and LOS (low-oxygenation state, about 15 % of saturation). The results were compared with those observed in human RBC under the same experimental conditions and with the chicken (Gallus gallus) erythrocytes, which have particular modifications at the N-terminus of the band 3 protein (B3). In fish the kinetic measurements have shown a different anion transport in several oxygenation states of erythrocytes, indicating that also at lower levels of vertebrate evolution there exists a modulation of the anionic flow affected by oxygen. The functional correlation of anion transport to changes of parts of the hemoglobin sequence responsible for alterations in the interactions with the cytoplasmic domain of band 3 protein (cdb3) allowed us to suggest a hypothesis about fish physiology. The highest values of kinetic measurements observed in fish have been attributed to the metabolic need of the RBC in response to the removal of CO2 that in teleosts is also of endogenous origin., A. Russo, E. Tellone, S. Ficarra, B. Giardina, E. Bellocco, G. Lagana, U. Leuzzi, A. Kotyk, A. Galtieri., and Obsahuje bibliografii a bibliografické odkazy
The review is devoted to the outstanding contributions to the path of carbon in photosynthesis by Professor Emeritus Andrew A. Benson, on the occasion of his death at the age of 97, on January 16, 2015. Benson is the legendary co-discoverer of the photosynthetic reductive pentose phosphate cycle, known to every student of photosynthesis as the Benson-Bassham-Calvin cycle. This pathway evolved into the dominant assimilation mechanism for atmospheric carbon into metabolites. The fundamental ecological and biochemical optimization and evolutionary stability of this mechanism unfolded elegantly in Benson’s hands, as he was the first to recognize the building blocks for the synthesis of essential organic compounds that satisfy the energetic needs and demands of most life forms. Photosynthetic carbon metabolism together with other energy and oxidative reactions and secondary biosynthetic processes are critical for the formation of organic matter; and, thereby, the Benson-Bassham-Calvin cycle ensures maintenance of the biosphere., K. Biel, I. Fomina., and Obsahuje bibliografii
Benzoxazolin-2-(3H)-one (BOA) has been tested in many plants species, but not in soybean (Glycine max). Thus, a hydroponic experiment was conducted to assess the effects of BOA on soybean photosynthesis. BOA reduced net photosynthetic rate, stomatal conductance, and effective quantum yield of PSII photochemistry without affecting intercellular CO2 concentration or maximal quantum yield of PSII photochemistry. Results revealed that the reduced stomatal conductance restricted entry of CO2 into substomatal spaces, thus limiting CO2 assimilation. No change found in intercellular CO2 concentration and reduced effective quantum yield of PSII photochemistry revealed that CO2 was not efficiently consumed by the plants. Our data indicated that the effects of BOA on soybean photosynthesis occurred due to the reduced stomatal conductance and decreased efficiency of carbon assimilation. The accumulation of BOA in soybean leaves reinforced these findings. and Obsahuje bibliografii