Redox polymer/protein biophotoelectrochemistry was used to analyse forward electron transfer of isolated PSII complexes with natural PsbA-variants. PsbA1- or PsbA3-PSII was embedded in a redox hydrogel that allows diffusion-free electron transfer to the electrode surface and thus measurement of an immediate photocurrent response. The initial photocurrent density of the electrode is up to ~2-fold higher with PsbA1-PSII under all tested light conditions, the most prominent under high-light [2,300 μmol(photon) m-2 s-1] illumination with 5 μA cm-2 for PsbA3-PSII and 9.5 μA cm-2 for PsbA1-PSII. This indicates more efficient electron transfer in low-light-adapted PsbA1-PSII. In contrast, the photocurrent decays faster in PsbA1-PSII under all tested light conditions, which suggests increased stability of high-light-adapted PsbA3-PSII. These results confirm and extend previous observations that PsbA3-PSII has increased P680+/QA- charge recombination and thus less efficient photon-to-charge conversion, whereas PsbA1-PSII is optimised for efficient electron transfer with limited stability., V. Hartmann, A. Ruff, W. Schuhmann, M. Rögner, M. M. Nowaczyk., and Obsahuje bibliografické odkazy
The study concentrates on analysis of heterogeneous rock mass deformations in the final years of underground coal extraction and during the revitalisation period after the end of mining. The research has been carried out in the Walbrzych Coal Basin where underground mining ceased at the end of the 20th Century. In the paper results of initial stages of ground deformation studies on a fragment of the Walbrzych mining grounds concerning analysis of benchmark height changes in a selected levelling line has been described. The results indicate ground subsidence in the period immediately after end of coal extraction and change to a steady uplift of the ground a few years later (2000-2008). Abnormal changes of heights in tectonic fault zones have also been observed. These could be related to heterogeneous rock mass reaction during the revitalisation period., Jan Blachowski, Stefan Cacoń and Wojciech Milczarek., and Obsahuje bibliografii
The study focuses on ceramic production from Žďár nad Sázavou – Staré město, an agglomeration that formed in the third quarter of 13th century and was abandoned after the founding of the ‘new’ town in the early 14th century. The large pottery collection is well dated and captures changes in pottery production during the medieval transformation, tightly connected with the colonisation of the Bohemian-Moravian Highlands. The pottery assemblage from the 2004 excavation season was processed in this study. Material from the pottery kiln discovered in 2006 and found during the review of the research documentation was supplemented afterwards. The main part of study evaluates ceramic production technology, which was rapidly changing during this period. Pottery fragments were divided into ceramic classes according to the properties of the ceramic mass and firing. The descriptive system of technological marks is a part of the study, but it could be used for other medieval pottery collections. Detailed attention was paid to pottery-forming technique marks: coiling, wheel forming and wheel throwing. The analysis of pottery technology is based on the chaîne opératoire of medieval ceramic production. The macroscopic analysis of pottery-making technology is connected with the conclusions of natural science analyses. Their aim was to validate and specify the macroscopic description of ceramic classes and also detailed information about pottery provenance and technology. The analysis of the pottery provides information for the future productiondistribution model of pottery production in the area.
The adaptation of barley (Hordeum vulgare L. cv. Akcent) plants to low (LI, 50 µmol m-2 s-1) and high (HI, 1000 µmol m-2 s-1) growth irradiances was studied using the simultaneous measurements of the photosynthetic oxygen evolution and chlorophyll a (Chl a) fluorescence at room temperature. If measured under ambient CO2 concentration, neither increase of the oxygen evolution rate (P) nor enhancement of non-radiative dissipation of the absorbed excitation energy within photosystem 2 (PS2) (determined as non-photochemical quenching of Chl a fluorescence, NPQ) were observed for HI plants compared with LI plants. Nevertheless, the HI plants exhibited a significantly higher proportion of QA in oxidised state (estimated from photochemical quenching of Chl a fluorescence, qP), by 49-102 % at irradiances above 200 µmol m-2 s-1 and an about 1.5 fold increase of irradiance-saturated PS2 electron transport rate (ETR) as compared to LI plants. At high CO2 concentration the degree of P stimulation was approximately three times higher for HI than for LI plants, and the irradiance-saturated P values at irradiances of 2 440 and 2 900 µmol m-2 s-1 were by 130 and 150 % higher for HI plants than for LI plants. We suggest that non-assimilatory electron transport dominates in the adaptation of the photosynthetic apparatus of barley grown at high irradiances under ambient CO2 rather than an increased NPQ or an enhancement of irradiance-saturated photosynthesis. and I. Kurasová ... [et al.].
The paper presents review of occurrence frequency of extreme hydrological events in a small agricultural basin in the flysh region over the period of 40 years (1964/65 - 2003/04). No human alterations were carried out in the basin over the period studied and hence influence of climatic changes on intensification of water cycle could be evaluated. Peaks over threshold (POT) method was applied separately to winter and summer hydrological events. In comparison with annual maximum series, all mean daily discharge values over a certain thresholds were taken into account for POT frequency analysis. The frequency of POT events has decreased in the past two decades (1984/85 - 1993/94 and 1994/95 - 2003/04). The results reveal that the most extreme values occurred in the 1964/65 - 1973/74 decade, mostly caused by summer rainfall. High event frequency also emerges in the 1974/75 - 1983/84 decade, especially in winter seasons as the consequence of snow melting. It is most likely that influence of climatic changes has not resulted yet in increase of occurrence frequency of POT events in the basin studied over the 40 years period. and Príspevok sa zaoberá frekvenciou výskytu extrémnych hydrologických udalostí na malom poľnohospodárskom povodí vo flyšovom pásme počas 40-ročnej periódy (1964/65-2003/04). Počas tohto obdobia nebolo povodie ovplyvnené významnými zmenami ľudskej činnosti a preto mohol byť zhodnotený vplyv klimatických zmien na intenzifikáciu hydrologického cyklu. POT metóda bola aplikovaná zvlášť pre zimné a letné hydrologické udalosti. V porovnaní so sériami ročných maxím, všetky priemerné denné prietoky nad určitou prahovou hodnotou boli zahrnuté do POT frekvenčných analýz. Frekvencia POT udalostí (nad zvolenou prahovou hodnotou) klesla v posledných dvoch dekádach (1984/85-1993/94 a 1994/95- 2003/04). Výsledky ukazujú, že najextrémnejšie hodnoty priemerných denných prietokov, spôsobené prevažne letnými prívalovými zrážkami sa objavili v dekáde 1964/65-1973/74. Vysoké hodnoty prietokov, spôsobené prevažne topením snehovej pokrývky sa vyskytli tiež v dekáde 1974/75-1983/84. Je nanajvýš pravdepodobné, že v študovanom povodí za obdobie 40-tich rokov klimatické zmeny nemali zatiaľ vplyv na zvyšovanie frekvencie extrémnych udalostí.
Six barley chlorophyll (Chl) mutants, viridis, flavoviridis, chlorina, xanhta, lutea, and albina, differed in the contents of Chl (a+b) and carotenoids (Cars). In accordance with their Chl-deficient phenotype, the Chl a and b and Car contents of mutants decreased from viridis to albina, only xantha had the same or even higher concentration of Cars as the wild type plant. The albina mutant completely lacked and xantha had a significantly reduced photosynthetic activity. We found quantitative differences in protein contents between wild type and mutant plants, with the lowest concentration per fresh mass in the albina mutant. Chl fluorescence analysis revealed that heat-treated barley leaves of both the wild type and Chl mutants had a lower photosystem 2 efficiency than the untreated ones. With 35S-methionine labelling and SDS-PAGE we found that six to nine de novo synthetized proteins appeared after heat shock (2 h, 42 °C) in the wild type and Chl mutants. In albina the expression of heat shock proteins (HSPs) was reduced to 50 % of that in the wild type. Hence mainly albina mutants, with a completely destroyed proteosynthetic apparatus of the chloroplasts, are able to synthesize a small set of HSPs. The albina mutant is a very useful tool for the study of different gene expression of chloroplast and nuclear DNA. and E. Gálová, B. Böhmová, A. Ševčovičová.
GPS permanent stations KRAW, KATO and ZYWI are part of so called Active Geodetic Network which covers entire area of Upper Silesian Coal Basin (USCB) in Poland and forms precise reference frame for geodetic and geodynamic applications. Moreover the above mentioned stations belong to EUREF Permanent Network. The stations, as datum points, play important role in precise positioning and geoid determination in area of USCB. The study of the stability of these points is one of the main components in precise monitoring of ground deformation in mining areas. The analysis of stability of permanent GPS stations KRAW, KATO and ZYWI are based on the coordinate time series obtained from the EUREF weekly solutions. The relative coordinate time series of weekly solutions for the vectors KRAW - KATO, KRAW - ZYWI , KATO - ZYWI are presented. The consistency, linearity, seasonal variations and jumps in the relative coordinate time series are discussed., Władysław Góral and Jacek Kudrys., and Obsahuje bibliografii
Repeated geodetic observations were applied in mining location Louky near Karviná to detect surface changes from undermining in complex geo-mechanical conditions. Analyses of the subsidence magnitude and the length and direction of horizontal displacements showed that the subsidence trough was formed unevenly not only due to the position of the exploited local longwall panels and their different size but also showed a notable effect of the dominant tectonic fault. The significantly uneven development of the subsidence trough negatively affects line constructions. Terrain deformations of the road and stream pipeline were computed and classified into the building site categories according to the Czech standard ČSN 73 0039. The course of individual deformations in the monitored locality is influenced by a complex geo-mechanical situation. While the course of the subsidence curves is continuous at the observed pipeline and the classification of individual sections into building site categories corresponds with that, the road profile points out a more complex development of surface deformations. At the end of the observed period, 5 % of the profiles’ sections fell into category III (medium intensity), 49 % into category IV (moderate intensity) and 32 % stayed in category V (very moderate intensity of mining effects).
Using GNSS method, fixed points of an observation network were repeatedly surveyed on the surface of the undermined area. Below the surface, at the depth of c. 1 km, there were four mining panels exploited subsequently. The main reaction of the surface points to the changes in the rock massif and the movement of the points were different, according to their surface position, local geo-mechanical conditions etc. This paper analyses the time-dependence of the surface points mining subsidence and horizontal movements on the progress of the exploitation., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografické odkazy
The aim of this study was to determine the accuracy and precision of McMaster method with Raynaud's modification in the detection of the eggs of the nematodes Toxocara canis (Werner, 1782) and Trichuris ovis (Abildgaard, 1795) in faeces of dogs. Four variants of McMaster method were used for counting: in one grid, two grids, the whole McMaster chamber and flotation in the tube. One hundred sixty samples were prepared from dog faeces (20 repetitions for each egg quantity) containing 15, 25, 50, 100, 150, 200, 250 and 300 eggs of T. canis and T. ovis in 1 g of faeces. To compare the influence of kind of faeces on the results, samples of dog faeces were enriched at the same levels with the eggs of another nematode, Ascaris suum Goeze, 1782. In addition, 160 samples of pig faeces were prepared and enriched only with A. suum eggs in the same way. The highest limit of detection (the lowest level of eggs that were detected in at least 50% of repetitions) in all McMaster chamber variants were obtained for T. canis eggs (25-250 eggs/g faeces). In the variant with flotation in the tube, the highest limit of detection was obtained for T. ovis eggs (100 eggs/g). The best results of the limit of detection, sensitivity and the lowest coefficients of variation were obtained with the use of the whole McMaster chamber variant. There was no significant impact of properties of faeces on the obtained results. Multiplication factors for the whole chamber were calculated on the basis of the transformed equation of the regression line, illustrating the relationship between the number of detected eggs and that of the eggs added to the sample. Multiplication factors calculated for T. canis and T. ovis eggs were higher than those expected using McMaster method with Raynaud modification.