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排序方式: 共有161条查询结果,搜索用时 15 毫秒
1.
Hayes RA Regondi S Winter MJ Butler PJ Agradi E Taylor EW Kevin Chipman J 《Marine environmental research》2004,58(2-5):665-669
Metallothionein has been assayed in a range of aquatic animal tissues as an indicator of metal exposure. We sequenced chub (Leuciscus cephalus) metallothionein cDNA which showed over 90% homology to common carp, goldfish and stone loach and 77% homology to rainbow trout sequences for metallothionein. We then used the extended primer method to develop an accurate quantitative competitive RT-PCR assay for metallothionein mRNA. RT-PCR was used to measure metallothionein mRNA in feral chub from a range of field sites, with different levels of heavy metal pollution, in the West Midlands, UK. Measurements were complemented by analysis of liver and gill metallothionein protein by capillary electrophoresis. There was no significant difference in the metallothionein protein levels between fish of different rivers and there was no evidence of elevation of mRNA at the sites of highest metal exposure. The level of metal exposure (e.g. zinc, nickel and cadmium each ranging between 15 and 28 microg/l ) at the pH (7.5-8.5) of these rivers appears insufficient to elevate hepatic or gill metallothionein in chub. A lack of elevation of hepatic metallothionein mRNA in chub exposed to zinc, copper and manganese for 24 h and 10 days in the laboratory also suggests a non-responsiveness of this species. 相似文献
2.
Polycyclic aromatic hydrocarbons in water, seston and copepods in a harbour area in the Western Mediterranean (Ligurian Sea) 总被引:2,自引:0,他引:2
Luigi Pane Simona Boccardo Fabio Bonfiglioli Gian Luigi Mariottini Francesca Priano & Osvaldo Conio 《Marine Ecology》2005,26(2):89-99
Polycyclic aromatic hydrocarbons (PAHs) are widespread carcinogenic, mutagenic and teratogenic pollutants that can significantly affect ecosystems and exert an influence on marine planktonic and benthic communities as well as on higher organisms such as fish and mammals, including humans. In this paper the concentrations of six PAHs in water, seston and copepods were examined in a harbour zone of the Genova Gulf (Ligurian Sea) from November 1997 to June 1998. The importance of freshwater inputs coming from a polluted stream and the influence of seasonal and atmospheric factors were also considered. Highest PAH values were recorded during spring. Fluoranthene, Benzo[b]fluoranthene and Benzo[k]fluoranthene were the most abundant PAHs either in water, seston or copepods. The concentration of total PAHs in seawater was often lower than the detection limit: recorded values ranged between 0.001 and 0.06 ppb. In seston, total PAHs ranged between 0.033 and 6.26 ng·g?1 and in copepods between 0.01 and 2.34 ng·g?1. With this study, PAH contamination in the harbour zone of Genova Sestri‐Ponente and the importance of inputs of organic pollutants coming from land and freshwaters have been emphasized. 相似文献
3.
New geologic mapping of the area near Castellamonte (Torino Province) describes a wide Plio-Quaternary continental succession, up to about 100-m thick. This sequence is distinguished according to allostratigraphic criteria. Altitude, degree of pedogenesis and sediment supply from different basins are also used. Within a single alloformation, several lithofacies are described.Fine-grained fan-delta sediments (Vespia Alloformation) are described in the lower part of the continental succession. The fossil plant remains indicate an Early–Middle Pliocene age. These sediments show an evident deformation and fill ancient lacustrine basins, likely associated with the Canavese Line trend. Their wide distribution and considerable thickness suggest subsidence.Coarse-grained glacial, outwash and fluvial sediments (Colleretto Castelnuovo, S. Defendente, Case Musso, Pagliero, Serra and Piverone Alloformations) are described in the upper part of the continental succession. They consist of undeformed sediments deposited during Middle to Late Pleistocene. These sediments indicate the presence of small local glaciers along the current valley trends. The terracing ratios among the different units and their small thicknesses indicate subsequent differential uplift. 相似文献
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5.
Marbles from the Pohorje area in Slovenia are investigated by mineralogical-petrographical analyses of thin sections as well as by cathodoluminescence in order to detect their local variability in texture and mineral assemblages. The CL colours observed in a cold cathode device are related to the manganese contents. An attempt is made to relate the textures seen under CL to mineral reactions during the process of metamorphism. The predominantly calcite marbles from Pohorje exhibit orange luminescence with some dolomite lenses with red luminescence. The typical mineral assemblages are calcite+tremolite+phlogopite or calcite+dolomite+tremolite+phlogopite. Therefore, the estimated temperature from the stability of mineral assemblage is assumed at approximately 500 °C. 相似文献
6.
Lijing CHENG John ABRAHAM Kevin ETRENBERTH John FASULLO Tim BOYER Ricardo LOCARNINI Bin ZHANG Fujiang YU Liying WAN Xingrong CHEN Xiangzhou SONG Yulong LIU Michael EMANN Franco RESEGHETTI Simona SIMONCELLI Viktor GOURETSKI Gengxin CHEN Alexey MISHONOV Jim REAGAN Jiang ZHU 《大气科学进展》2021,38(4):523-530
The long-term warming of the ocean is a critical indicator of both the past and present state of the climate system. It also provides insights about the changes to come, owing to the persistence of both decadal variations and secular trends,which the ocean records extremely well(Hansen et al., 2011;IPCC, 2013;Rhein et al., 2013;Trenberth et al., 2016;Abram et al., 2019). 相似文献
7.
The influence of physical and biological processes on the ichthyoplankton communities in the Gulf of Sirte (Southern Mediterranean Sea)
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Angela Cuttitta Sergio Bonomo Salem Zgozi Angelo Bonanno Bernardo Patti Enza Maria Quinci Marco Torri Mohamed Hamza Abdul Fatah Daw Haddoud Akram El Turki Abdul Bari Ramadan Simona Genovese Salvatore Mazzola 《Marine Ecology》2016,37(4):831-844
This paper reports on the first study on the ichthyoplankton community structure in the Gulf of Sirte and its spatial distribution in relation to environmental conditions and zooplankton abundance. The results make an important contribution to the future management of fisheries in this unexplored, but much exploited, area. Biological samples were collected in July 2008 using a Bongo40 net. In total, 1914 larvae were found and 1652 of these were identified. In particular, bathypelagic taxa were the most abundant, followed by demersal, mesopelagic, pelagic and epipelagic taxa. The ichthyoplankton community had a patchwork distribution influenced by oligotrophic conditions, the bottom depth and oceanographical features. The results suggest that environmental forcings were able to transport the ichthyoplankton to productive areas. Indeed, maximum fish egg densities were found in coastal stations in correspondence with the Atlantic Tunisian Current inflow, whereas larvae were mainly concentrated in the east side of the Gulf, probably as a result of advection by the anticyclonic circulation. Additionally, the distribution patterns of the total larvae density and the different assemblages were well matched with the abundance of the zooplankton, probably determining final larval survival, growth and recruitment. 相似文献
8.
9.
Simona Regenspurg Mashal Alawi Guido Blöcher Maria Börger Stefan Kranz Ben Norden Ali Saadat Traugott Scheytt Lioba Virchow Andrea Vieth-Hillebrand 《Environmental Earth Sciences》2018,77(13):516
After completion of an exploration well, sandstones of the Exter Formation were hydraulically tested to determine the hydraulic properties and to evaluate chemical and microbial processes caused by drilling and water production. The aim was to determine the suitability of the formation as a reservoir for aquifer thermal energy storage. The tests revealed a hydraulic conductivity of 1–2 E-5 m/s of the reservoir, resulting in a productivity index of 0.6–1 m3/h/bar. A hydraulic connection of the Exter Formation to the overlaying, artesian “Rupelbasissand” cannot be excluded. Water samples were collected for chemical and microbiological analyses. The water was similarly composed as sea water with a maximum salinity of 24.9 g/L, dominated by NaCl (15.6 g/L Cl and 7.8 g/L Na). Until the end of the tests, the water was affected by drilling mud as indicated by the high pH (8.9) and high bicarbonate concentration (359 mg/L) that both resulted from the impact of sodium carbonate (Na2CO3) additives. The high amount of dissolved organic matter (>?58 mg/L) and its molecular-weight distribution pattern indicated that residues of cellulose, an ingredient of the drilling mud, were still present at the end of the tests. Clear evidence of this contamination gave the measured uranine that was added as a tracer into the drilling mud. During fluid production, the microbial community structure and abundance changed and correlated with the content of drilling mud. Eight taxa of sulfate-reducing bacteria, key organisms in processes like bio-corrosion and bio-clogging, were identified. It can be assumed that their activity will be affected during usage of the reservoir. 相似文献
10.
Simona Avnaim‐Katav Ahuva Almogi‐Labin Amir Sandler Dorit Sivan Naomi Porat Ari Matmon 《第四纪科学杂志》2012,27(7):675-686
The current detailed chronostratigraphic framework of the last 1 Ma of an eastern Mediterranean sequence (Haifa Bay, Israel) aims to examine the relative roles of sea‐level changes, climate and tectonics. Seven continuous marine cores, up to ~120 m long, were recovered from shallow water depths. The cores were dated by optically stimulated luminescence, 14C, magnetostratigraphy, 230Th/234U, 26Al/10Be, occurrence of index fossils and correlated to the global sea‐level curve and Marine Isotope Stages (MIS). The sedimentary sequence accumulated during the last ca. 1.0 Ma consists of 21 transgression–regression units with hiatuses between them. Five marine/terrestrial cycles, which occur in the lower part of the sequence, are attributed to the Jaramillo subchron and the Brunhes–Matuyama boundary, and correspond to MIS 29–21. The top ~50 m includes three sedimentary cycles deposited in the last ca. 400 ka. The regressive phases during this interval correspond to Glacial MIS 8, 6 and 2, while the transgressions correspond to Interglacial MIS 11, 7, 5 and 1. Thus, for the first time, this study documents the longest Quaternary succession dated so far in a key area of the Levant, sensitive to global history of sea‐level changes and glacial/interglacial fluctuations. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献