SWASV speciation of Cd, Pb and Cu for the determination of seawater contamination in the area of the Nicole shipwreck (Ancona coast, Central Adriatic Sea)     

Annibaldi A  Illuminati S  Truzzi C  Scarponi G 《Marine pollution bulletin》2011,62(12):2813-2821

The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ∼9 (Cd), ∼3 (Pb) and ∼5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed.  相似文献   

Zooplankton succession during extraordinary drought–flood cycles: A case study in a South American floodplain lake     

Griselda Chaparro  María Cristina Marinone  Ruben J. Lombardo  María Romina Schiaffino  Alice de Souza Guimarães  Inés O’Farrell 《Limnologica》2011,41(4):371-381

We examined the zooplankton abundance and composition of Laguna Grande, a floodplain wetland of the Lower Paraná Basin (Argentina), during an extraordinary drought–flood cycle that affected both the environment and the biological conditions of the lake. Low waters were characterised by remarkably high conductivities and pH values, and high phytoplankton and bacterioplankton abundances with cyanobacterial blooms, while high waters showed opposite features. In relation to zooplankton, the mean abundances of all the taxonomic groups (rotifers, cladocerans, copepods, ciliates, and heterotrophic nanoflagellates) were slightly higher at low waters. Major changes were observed in the specific composition of metazooplankton: the euryhaline species assemblage that dominated in the dry warm period was replaced by several oligohaline littoral and planktonic species characteristic of the Paraná River Basin, when the water level rose. Mean species richness values at high waters doubled those of low waters and were directly correlated to water depth. Most of the rotifers of the genus Brachionus and the cladoceran Moina micrura switched from parthenogenetic to sexual reproduction during low waters, as a response to a harsh environment and crowding. We suggest that the main changes in the environmental conditions in this eutrophic floodplain lake are driven by the hydrology, which regulates the zooplankton succession. The herein described shifts in the zooplankton structure and dynamics of Laguna Grande over an extraordinary drought–flood cycle contribute to the understanding of the processes that might occur under the scenarios predicted by climate change models.  相似文献   

Corrigendum to ‘Pathogenic fungi: An unacknowledged risk at coastal resorts? New insights on microbiological sand quality in Portugal’ [Mar. Pollut. Bull. 62 (2011) 1506–1511]     

Raquel Sabino  Cristina Veríssimo  Maria Ana Cunha  Bela Wergikoski  Filipa C. Ferreira  Raquel Rodrigues  Helena Parada  Leonor Falcão  Laura Rosado  Catarina Pinheiro  Eleonora Paixão  João Brandão 《Marine pollution bulletin》2011,62(12):2880

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Application of protective products to “Noto” calcarenite (south-eastern Sicily): a case study for the conservation of stone materials     

Mauro F. La Russa  Germana Barone  Cristina M. Belfiore  Paolo Mazzoleni  Antonino Pezzino 《Environmental Earth Sciences》2011,62(6):1263-1272

Noto is an important Baroque urban center in south-eastern Sicily, which was completely reconstructed after the severe earthquake of 1693. Most of its monuments and historic buildings were built in Pietra di Noto stone, a pale cream calcarenite, quarried in outcrops located near the city. This stone, still currently used as building material, is undergoing many forms of alteration and degradation, which cause significant damage to monuments. In this study, three commercial protective products were tested on some Noto calcarenite samples from quarries, with the aim of assessing their protective effectiveness. In particular, petrographic analyses by optical microscopy were carried out for textural characterization of the stone materials. Capillary water absorption, porosimetric and colorimetric procedures, UV radiation and salt crystallization aging tests were performed to better evaluate interactions between protective products and substrate.  相似文献   

Assessing food web dynamics and relative importance of organic matter sources for fish species in two Portuguese estuaries: a stable isotope approach     

França S  Vasconcelos RP  Tanner S  Máguas C  Costa MJ  Cabral HN 《Marine environmental research》2011,72(4):204-215

Stable carbon and nitrogen isotopes (δ13C, δ1?N) were used to analyse food web dynamics of two of the main estuaries of the Portuguese coast: Tejo and Mira. The ultimate sources of organic matter supporting production of some of the most abundant and commercially important fish species were determined; and seasonal, inter- and intra- estuarine differences in the trophic relations among producers and consumers were identified. Stable isotope analysis was performed in different producers, primary consumers (main prey items for fish) and fish species (Solea solea, Solea senegalensis, Pomatoschistus microps, Dicentrarchus labrax, Liza ramada, Diplodus vulgaris and Atherina presbyter) of two areas in each estuary, in July and October 2009. Model calculations showed that the main prey for the fish species in the Tejo estuary used mostly salt marsh-derived organic matter as nutritional sources, with no marked differences between the sampled months. Trophic levels of fish species from the same estuary differed at multiple scales: inter-species, seasonally and spatially (both between and within estuaries). Significant differences in isotopic composition of fish species were more pronounced spatially (between the two sampled areas in the estuary) than seasonally (between sampled months). Trophic relationships in both estuaries demonstrated that organic matter is transferred to higher trophic positions mainly through benthic pathways. This shows the flexibility of these species to share resources and to exploit temporary peaks in prey populations. The present results showed that extensive disturbance in intertidal habitats from both estuaries may potentially change the balance of organic matter in the base of these complex food webs.  相似文献   

On the use of infinite elements in the analysis of two-dimensional layered elastic systems via discretized integral equations     

Cristina Jommi  Giorgio Novati 《Computers and Geotechnics》1989,8(4):269-288

A boundary integral equation approach is presented for the two-dimensional plane strain analysis of horizontally layered elastic systems resting on a rough and rigid base. The validity of Somigliana identity for unbounded layers is discussed and an Infinite Boundary Element is proposed in order to take into account the lateral unboundedness of the physical problem in the discretized equations. This element is implemented in a computer code based on a successive stiffness solution procedure. A series of numerical tests concerning single- and multi-layered problems is illustrated, and the performance of the proposed solution method is compared with that of more traditional boundary element and finite element techniques.  相似文献   

K dwarfs and the chemical evolution of the solar cylinder     

Eira Kotoneva  Chris Flynn  _&#; †  Cristina Chiappini  Francesca Matteucci 《Monthly notices of the Royal Astronomical Society》2002,336(3):879-891

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Mineralogical characterization of some basaltic asteroids in the neighborhood of (4) Vesta: first results     

René Duffard  Daniela Lazzaro  Maria Cristina De Sanctis  Jorge M Carvano 《Icarus》2004,171(1):120-132

We present reflectance spectra of 19 V-type asteroids obtained at the 3.6 m Telescopio Nazionale Galileo covering 0.8 to 2.5 μm. For 8 of these asteroids we obtained also visible spectra in the same observational run. The range from 0.8 to 2.5 μm, encompassing the 1 and 2 μm pyroxene features, allows a precise mineralogical characterization of these asteroids. The obtained data suggests the possible coexistence of distinct mineralogical groups among the V-type asteroids, either probing different layers of (4) Vesta or coming from different bodies. No clear correlation was found between mineralogies and the objects being, or not, member of the Vesta dynamical family.  相似文献   

The percentage of stellar light re-radiated by dust in late-type Virgo Cluster galaxies     

Cristina C. Popescu  Richard J. Tuffs 《Monthly notices of the Royal Astronomical Society》2002,335(2):L41-L44

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Fluxes of solute in two catchments with contrasting deposition loads in Atlantic Forest (Serra do Mar/SP-Brazil)     

M. Cristina Forti  Christine Bourotte  Valdir de Cicco  Francisco C.S. Arcova  Maurício Ranzini 《Applied Geochemistry》2007

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