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L. Marini G. Ottonello M. Canepa F. Cipolli M. Vetuschi Zuccolini 《Environmental Geology》2000,40(1-2):234-242
Systematic stream sediment investigation in a periurban area surrounding Genoa (Italy) revealed the existence of a significant
mercury anomaly localized on the main (3rd rank) bed of the Bisagno river. Statistical multivariate analysis of elemental
abundances points out the anthropic nature of this contamination. Because of the well-known bioaccumulation of Hg in contaminated
media, attention must be focused on the risks associated with the discovered pollution.
Received: 30 November 1999 · Accepted: 22 March 2000 相似文献
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Donatella Fantoni Gianpiero Brozzo Marco Canepa Francesco Cipolli Luigi Marini Giulio Ottonello Marino Zuccolini 《Environmental Geology》2002,42(8):871-882
Thirty of the 58 groundwaters sampled in September-October 2000 in the study area (La Spezia Province, Italy) have Mg-HCO3 to Ca-HCO3 composition, undetectable Cr(III) contents, and virtually equal concentrations of total dissolved Cr and Cr(VI). Therefore, dissolved Cr is present in toto as Cr(VI), with concentrations of 5-73 ppb. These values are above the maximum permissible level for drinking waters (5 ppb). Local ophiolites, especially serpentinites and ultramafites, are Cr-rich and represent a Cr source for groundwaters. However, since Cr is present as Cr(III) in rock-forming minerals, its release to the aqueous solution requires oxidation of Cr(III) to Cr(VI). This can be performed by different electron acceptors, including Mn oxides, H2O2, gaseous O2, and perhaps Fe(III) oxyhydroxides. Based on this evidence and due to the absence of anthropogenic Cr sources, the comparatively high Cr(VI) concentrations measured in the waters of the study area are attributed to natural pollution. 相似文献
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A new algorithm for automatic processing of bathymetric data 总被引：3，自引：0，他引：3
A sea-floor map can be obtained from sonar data using the supplied sonar system software or one of several public domain or proprietary systems. With any of these solutions, the process of production of a sea-floor map is unnecessarily time consuming in the absence of a systematic and efficient solution to the problem of identification of erroneous data (outliers). We present an algorithm to fit bathymetric data and to automatically deal with outliers. The most important characteristics of the algorithm are: production of a triangulated map in which the local spatial resolution and the local known accuracy are dependent both on the sea-floor topography and the data noise amplitude, automatic identification of outliers, intrinsic modularity of the program suitable for a multiprocessor environment, low computing cost, and minimal operator intervention. The algorithm is described and its parameters are defined on the basis of their effect on the results. The results of the application of the algorithm to synthetic data with and without outliers demonstrate its behavior on a known "sea floor". The results of the algorithm on real data and its performances (in term of speed and fitting error) are also tested. 相似文献
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Temperature effects on asexual reproduction of the scyphozoan Aurelia aurita s.l.: differences between exotic (Baltic and Red seas) and native (Mediterranean Sea) populations 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Maria Pascual Verónica Fuentes Antonio Canepa Dacha Atienza Josep‐Maria Gili Jennifer E. Purcell 《Marine Ecology》2015,36(4):994-1002
Massive occurrences of jellyfish can cause direct impacts on the economy, especially on tourism and commercial fisheries. Translocation of jellyfish species by humans has caused damaging blooms in new habitats. Aurelia aurita s.l. has been introduced in many locations around the world. To test the potential success of Au. aurita s.l. in various habitats, scyphistomae from different climatic locations (Mediterranean, Red and Baltic Seas) were cultured individually for 201 days at three temperatures (14, 21 and 28 °C) with the same salinity, food and light. We tested the null hypotheses that there were no differences in survival or asexual reproduction (budding and strobilation) amongst populations [native (Mediterranean) and exotic (Red and Baltic)]. Survival of the three scyphistoma populations did not differ significantly across temperatures; however, the Red Sea group had lower survival at all temperatures than did the other populations. Most individuals strobilated at 14 °C. Red Sea scyphistomae strobilated more quickly than Baltic and Mediterranean Sea scyphistomae and produced the fewest ephyrae, whereas Baltic Sea scyphistomae produced the most. Our results indicate that Au. aurita from the Baltic or Red Seas introduced into the Northwest Mediterranean Sea would potentially persist and successfully asexually reproduce there. A new invader could even have greater asexual production than the local Au. aurita s.l. Establishment of the invaders could increase genetic variation of subsequent generations and increase their adaptability to environmental changes. Our results suggest that introduction of exotic Au. aurita s.l. populations could increase jellyfish blooms in the Mediterranean Sea. 相似文献
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