Biochemical alterations in juvenile carp (Cyprinus carpio) exposed to zinc: glutathione reductase as a target     

Franco JL  Posser T  Mattos JJ  Sánchez-Chardi A  Trevisan R  Oliveira CS  Carvalho PS  Leal RB  Marques MR  Bainy AC  Dafre AL 《Marine environmental research》2008,66(1):88-89

The aim of this study was to investigate biochemical changes in juvenile carp (Cyprinus carpio) exposed to zinc chloride (10, 30 and 100 microM) for a period of 48 h. Zinc exposure caused a concentration-dependent reduction in glutathione reductase (GR) activity in gills, liver and brain. Gill glutathione S-transferase (GST) was reduced when animals were exposed to the highest concentration of 100 microM zinc. The phosphorylation of p38(MAPK) increased in the brain of fish exposed to zinc 100 microM, while phosphorylation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and c-Jun N-terminal protein kinase 1/2 (JNK1/2) remained unchanged. Expression of proteins HSP60 and HSP70 were not affected by zinc exposure. Considering the significant concentration-dependent inhibition of GR in all tissues analyzed, this enzyme could be a potential biomarker of exposure to zinc, which has to be confirmed.  相似文献   

Biogeographical drivers of ragweed pollen concentrations in Europe     

Matyasovszky  István  Makra  László  Tusnády  Gábor  Csépe  Zoltán  Nyúl  László G.  Chapman  Daniel S.  Sümeghy  Zoltán  Szűcs  Gábor  Páldy  Anna  Magyar  Donát  Mányoki  Gergely  Erostyák  János  Bodnár  Károly  Bergmann  Karl-Christian  Deák  Áron József  Thibaudon  Michel  Albertini  Roberto  Bonini  Maira  Šikoparija  Branko  Radišić  Predrag  Gehrig  Regula  Rybníček  Ondřej  Severova  Elena  Rodinkova  Victoria  Prikhodko  Alexander  Maleeva  Anna  Stjepanović  Barbara  Ianovici  Nicoleta  Berger  Uwe  Seliger  Andreja Kofol  Weryszko-Chmielewska  Elżbieta  Šaulienė  Ingrida  Shalaboda  Valentina  Yankova  Raina  Peternel  Renata  Ščevková  Jana  Bullock  James M. 《Theoretical and Applied Climatology》2018,133(1-2):277-295

Theoretical and Applied Climatology - The drivers of spatial variation in ragweed pollen concentrations, contributing to severe allergic rhinitis and asthma, are poorly quantified. We analysed the...  相似文献   

Zooplankton distribution and abundance in saline lakes of British Columbia,Canada   总被引：2，自引：0，他引：2  

U. Theodore Hammer  László Forró 《International Journal of Salt Lake Research》1992,1(1):65-80

Zooplankton in saline lakes of the Southern Interior Plateau of British Columbia were collected on three occasions: mid-May and early August, 1990, and in late July, 1991. Salinities ranged from 2.6 to 45.8 g L⁻¹. Of the 17 lakes examined, 13 were hyposaline (∼-20g L⁻¹), four, mesosaline (20–50 g L⁻¹) and none, hypersaline (>50 g L⁻¹). pH ranged from 8.7 (Three Mile) to 10.7 (Goodenough), with values <9.6 in 10, and <9.0 in only three lakes. Lakes with high pHs had high bicarbonate-carbonate alkalinities. Thirty one species of zooplankton occurred: Protista (1), Rotifera (13), Anostraca (2), Cladocera (7), Ostracoda (1) and Copepoda (7). Sixteen species were restricted to hyposaline waters, with seven found only in salinities of ≤5 gL⁻¹. Two species (Diaptomus connexus, Artemia franciscana) were restricted to mesosaline waters of salinity >35 g L⁻¹. Eurysaline species includedBrachionus plicatilis, Hexarthra fennica, Limnocythere staplini, Artemia franciscana andDiaptomus connexus. Most species were abundant in 1+ lakes, but six species always had low populations.B. plicatilis, Hexarthra polyodonta, A. franciscana, Limnocythere staplini, Daphnia similis andD. connexus had densest populations in one or more of the three most saline lakes, viz. Long, Goodenough and Three Mile. Cladocerans other thanD. similis (Alona sp., Ceriodaphnia quadrangula, Daphnia pulex) were usually abundant in lakes of low salinity (<5 g L⁻¹).Diatomus sicilis, present in all except the three most saline lakes, also occurred in abundance in ten of these lakes.Moina hutchinsoni andH. polyodonta were present in both hyposaline and mesosaline lakes, but, more importantly, tended to occur only at higher pH values (>pH 9.4) but not in all such lakes. These can be regarded as alkaline-saline species. Sorensen’s Coefficient of Community Similarity was used to compare communities in Alberta-Saskatchewan and British Columbia. It was low (0.37). A comparison restricted to just Cladocera gave a slightly higher value, 0.44, but a comparison of Copepoda gave a value of 71 per cent similarity between the regions. Multiple regression analyses using pH, TDS and K regressed on species richness for all samples accounted for only 41 per cent of the variance. However, when the analysis was seasonally restricted (May), and thus to a limited chemical range, 47 to 77.5 per cent of the variance was accounted for by these three variables.  相似文献   

Treatment of rotation errors in the final adjustment of GPS baseline components     

László Bányai 《Journal of Geodesy》1991,65(2):102-108

Summary The significant coordinate difference changes of the same baselines, measured in different observing sessions, may be interpreted as the rotation around the station held fixed during the differenced processing, if the length changes of these baselines show random behavior. These rotation errors can significantly bias the final network adjustment based on redundant observing sessions and a relative approach. The Gauss-Helmert model with the estimation of the stochastic properties of the rotation errors is the most effective investigated approach. The standard deviation of the baseline length differences between those derived from a precise geodetic network and derived by Trimvec relative positioning software improved by a factor 2.4 after the final network adjustment using the introduced Gauss-Helmert model.  相似文献   

Computer estimation of intensities: The 1985 Berhida,Hungary, earthquake     

Tibor Zsíros  Péter Mónus  László Tóth 《Pure and Applied Geophysics》1990,132(3):533-543

In this paper a computerized method for the intensity estimation from macroseismic observations is presented. The successive steps of the MSK intensity scale (2° to 10°) receives weights according to the observations marked on the earthquake questionnaires. These weights are summed for the individual scale steps. The distribution of these summed weights and their relation to an experimentally chosen function of the criterion make it possible to estimate the appropriate intensity value and its reliability. By computer evaluation of earthquake reports an objective comparison of estimated intensities given by different seismologists can be made, provided that uniform earthquake questionnaires are used. The application of this method will result in more homogeneous intensity data.  相似文献   

Determination of total carbonate content in some representative loess-paleosol profiles     

László Gerei  János Balogh  Magda Reményi 《GeoJournal》1995,36(2-3):187-188

Samples taken from loess and paleosols were examined for carbonate content. The main results were as follows:

1. The carbonate content measured differed significantly when the samples were analysed jointly with the concretions occurring in them or separately from these constituents.
2. Solubility of different carbonates (calcite, dolomite, aragonite etc.) was found different. This factor also might have influenced the measured total amounts of carbonates.

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Caprock analysis from the Mihályi-Répcelak natural CO<Subscript>2</Subscript> occurrence,Western Hungary     

Csilla Király  Ágnes Szamosfalvi  László Zilahi-Sebess  Péter Kónya  István János Kovács  Eszter Sendula  Csaba Szabó  György Falus 《Environmental Earth Sciences》2016,75(8):635

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Black hole spin and radio loudness in a Λ cold dark matter universe     

Claudia del P. Lagos  Nelson D. Padilla  Sofía A. Cora 《Monthly notices of the Royal Astronomical Society》2009,395(2):625-636

We use a combination of a cosmological N -body simulation of the concordance Λ cold dark matter paradigm and a semi-analytic model of galaxy formation to investigate the spin development of central supermassive black holes (BHs) and its relation to the BH host galaxy properties. In order to compute BH spins, we use the α model of Shakura & Sunyaev and consider the King et al. warped disc alignment criterion. The orientation of the accretion disc is inferred from the angular momentum of the source of accreted material, which bears a close relationship to the large-scale structure in the simulation. We find that the final BH spin depends almost exclusively on the accretion history and only weakly on the warped disc alignment. The main mechanisms of BH spin-up are found to be gas cooling processes and disc instabilities, a result that is only partially compatible with Monte Carlo models where the main spin-up mechanisms are major mergers and disc instabilities; the latter results are reproduced when implementing randomly oriented accretion discs in our model. Regarding the BH population, we find that more massive BHs, which are hosted by massive ellipticals, have higher spin values than less massive BHs, hosted by spiral galaxies. We analyse whether gas accretion rates and BH spins can be used as tracers of the radio loudness of active galactic nuclei (AGN). We find that the current observational indications of an increasing trend of radio-loud AGN fractions with stellar and BH mass can be easily obtained when placing lower limits on the BH spin, with a minimum influence from limits on the accretion rates; a model with random accretion disc orientations is unable to reproduce this trend. Our results favour a scenario where the BH spin is a key parameter to separate the radio-loud and radio-quiet galaxy populations.  相似文献   

MINVIT: Multi Instrumental Visualization Tool for Solar Physics     

A. Cora  S. Giordano  C. A. Volpicelli  S. Mancuso 《Earth, Moon, and Planets》2009,104(1-4):131-133

In recent years much effort has been devoted to constructing systems for sharing resources within the solar physics community. Several advanced archives and data analysis systems do exist, but there is low availability of data visualization tools for displaying simultaneous multi instruments/wavelengths solar data. Meanwhile map server technology has received great attention by the IT researcher and geophysical community. In this paper we discuss a possible use of an open source environment for building spatially enabled Internet applications for the visualization and analysis of solar physics data sets. We present the preliminary status of the MINVIT (Multi Instrumental Visualization Tool) project, which shall be able to merge images and information produced by different instruments in a single/synoptic image available on-line. Moreover, the tool is designed in order to allow the visualization of the temporal evolution of data. We further discuss the possible integration into the grid framework, focusing on a middleware able to query EGSO resources such us UOC and SEC in order to include data from several space and ground-based solar observatories.  相似文献   

Submicroscopic accessory minerals overprinting clay mineral REE patterns (celadonite–glauconite group examples)     

Erzsébet Tóth  Tamás G. Weiszburg  Teresa Jeffries  C. Terry Williams  András Bartha  Éva Bertalan  Ildikó Cora 《Chemical Geology》2010,269(3-4):312-328

Samples of glauconite, representing different stages of glauconitisation, as well as different formation environments, were analysed for rare earth elements (REE) and other trace elements using a combination of bulk sample and spatially-resolved in situ techniques. The results indicate that the high-sensitivity, spatially-resolved technique of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) produces values up to two orders of magnitude lower than the bulk sample analyses. This suggests that submicroscopic rare earth element-bearing phases are distributed within the glauconite aggregates comprising the bulk samples. Analytical scanning electron microscopy (ASEM) revealed the presence of micrometre-sized grains of apatite and pore filling precipitates of an unidentified (REE, Ca)-phosphate (approximate composition Ca_0.3–0.4(Ce_0.4La_0.1–0.2Nd_0.1)PO₄) in some glauconite grains.The inherent REE concentrations of the glauconite aggregates (i.e., glauconite crystallites without accidental mechanical inclusions or authigenic, not layer silicate mineral precipitates) was found to be relatively low (e.g., typically less than 100 ppm), and this value decreased with increasing glauconitisation (smectite–mica transformation through a series of recrystallisation processes). These results suggest that the REEs substitute for Ca in the interlayer space of the layer silicate structure and, therefore, the REE content decreases as Ca is progressively removed from the interlayer (smectite–mica transition).LA-ICP-MS, when combined with electron probe microanalysis (EPMA) or ASEM, offers an opportunity to exclude submicroscopic accessory minerals from glauconite trace element analyses, and so produces reliable trace element data for the respective minerals which host those elements.These results illustrate that accessory minerals are difficult to eliminate from clay samples, and that care needs to be taken in the interpretation of clay mineral REE distributions, irrespective of the aggregation state of the studied clay (i.e., whether finely dispersed within the sedimentary rock, or forming millimetre-sized aggregates). Model calculations showed that authigenic apatite associated with the studied green marine clays tends to have higher REE content than “bioapatites”, the total REE content being above 10 000 ppm.  相似文献