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81.
82.
Cristiana Guerranti Stefania Ancora Nicola Bianchi Guido Perra Emiliano Leonida Fanello Simonetta Corsolini Maria Cristina Fossi Silvano Ettore Focardi 《Marine pollution bulletin》2013
Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found. 相似文献
83.
S. Bianchi A. Corral F. Panessa X. Barcons G. Matt L. Bassani F. J. Carrera E. Jiménez-Bailón 《Monthly notices of the Royal Astronomical Society》2008,385(1):195-199
We report on simultaneous optical and X-ray observations of the Seyfert galaxy, NGC 3147. The XMM–Newton spectrum shows that the source is unabsorbed in the X-rays ( N H < 5 × 1020 cm−2 ) . On the other hand, no broad lines are present in the optical spectrum. The origin of this optical/X-rays misclassification (with respect to the Unification Model) cannot be attributed to variability, since the observations in the two bands are simultaneous. Moreover, a Compton-thick nature of the object can be rejected on the basis of the low-equivalent width of the iron Kα line (≃130 eV) and the large ratio between the 2–10 keV and the [O iii ] fluxes. It seems therefore inescapable to conclude that NGC 3147 intrinsically lacks the Broad-Line Region, making it the first 'true' type 2 Seyfert galaxy. 相似文献
84.
Alessio Rovere Stefano Bellati Valeriano Parravicini Marco Firpo Carla Morri Carlo Nike Bianchi 《Estuaries and Coasts》2009,32(2):333-339
The existence of linkages between ecological and geomorphological processes and the influence of human activities both on
the biota and on geomorphology is well known for terrestrial environments, while it has been seldom reported for submerged
ones. A survey in the Noli-Bergeggi area (NW Mediterranean Sea) has been carried out to test the hypothesis that the harvesting
of Lithophaga lithophaga has an impact not only on the hammered rock, but also on the sediments at the cliff foot. Size and roundness of pebbles have
been measured at different stations and statistical analyses have been used to test the differences between impact and control
situations. Results show a dependence of the roundness of pebbles on the date mussel harvesting, indicating a decrease both
of the roundness index and of its variability at the cliff foot in impacted sites. Conclusions stress the biogeomorphological
nature of this activity, not limited to the present location. 相似文献
85.
Can plankton communities be considered as bio-indicators of water quality in the Lagoon of Venice? 总被引:4,自引:0,他引:4
Bianchi F Acri F Aubry FB Berton A Boldrin A Camatti E Cassin D Comaschi A 《Marine pollution bulletin》2003,46(8):964-971
This study examines whether plankton of the Lagoon of Venice could be considered as a bio-indicator of areas subjected to various anthropogenic influences. This study was a two year hydrochemical and biological survey in five areas of the Lagoon of Venice, each with different environmental conditions due to pollution from urban, industrial, thermal and agricultural wastes. Phytoplankton associations did not show any promising species. In the different lagoonal areas, this community was differentiated into its major groups. In contrast, the copepod Acartia tonsa Dana could be considered as a target species in highly eutrophic areas. 相似文献
86.
In April 2000, we collected box cores from five stations along a cross-shelf transect on the Louisiana (LA) continental shelf. Novel esters of carotenols and chlorins (carotenoid chlorin esters, CCEs), which are highly specific grazing markers, were identified in surface and deep sediments (>10 cm) from the LA shelf. Chlorophyll-a inventory indicated that CCEs are one of the major decay products of chlorophyll-a in shelf sediments. Abundances of total CCEs (9-18%) in surface sediments along the cross-shelf transect were comparable to the abundance of pheophytin-a, pyropheophytin-a, and total steryl chlorin esters (SCEs). Prior work has identified four CCEs which have dehydrated fucoxanthin/fucoxanthinol as a substitute alcohol of phytol. We report on four newly identified CCEs associated with nondehydrated fuxocanthin/fucoxanthinol esterified to (pyro)pheophorbide-a. These nondehydrated CCEs were generally present in lower concentrations than their dehydrated counterparts, but were detectable by atmospheric pressure chemical ionization (APCI) mass spectrometry coupled with high-performance liquid chromatography (HPLC). We attributed differences between this study and previous work to the time allowed for predepositional decay and grazing processes to occur. The rapid sedimentation of CCEs in the shallow water column (ca. 10 m) on the LA shelf allowed for effective burial of all CCEs compared to the deeper water column regions sampled by previous work. This speculation is supported by the fact that the concentrations of CCEs with nondehydrated fucoxanthin/fucoxanthinol were extremely low in sediments from the site on the outer LA shelf with a deeper (253 m) water column. We also tentatively identified an additional CCE and its isomer as fucoxanthinol didehydrate pyropheophorbide-a ester. We suggest that the formation and transformation of CCEs are primarily controlled by the following three biologically mediated reactions: demethoxycarbonylation, dehydration, and deacetylation. Our laboratory copepod grazing experiment also confirmed that CCEs can be excellent class-specific biomarkers of zooplankton grazing on phytoplankton. 相似文献
87.
The effects of three hydrocarbon dispersant agents (Corexit 9527, Hydrogamosol LT and OSR LT 126) on the bacterial flora of the marine environment are analysed in 20-square-metre basins filled with lagoon seawater.Four months after the first treatment, oil slicks were no longer visible, whereas the appearance of the untreated reference slick had hardly changed. The treatment of 10-litre crude-oil slicks causes an appreciable and long lasting increase in the bacterial population. 相似文献
88.
M. J. Dagg T. S. Bianchi G. A. Breed W. -J. Cai S. Duan H. Liu B. A. McKee R. T. Powell C. M. Stewart 《Estuaries and Coasts》2005,28(5):664-674
During June 2003, a period of mid level discharge (17,400 m−3 s−1), a parcel of water in the lower Mississippi River was sampled every 2 h during its 4-d transit from river km 362 near Baton
Rouge to km 0 at Head of Passes, Louisiana, United States. Properties measured at the surface during each of the 48 stations
were temperature, salinity, dissolved organic carbon (DOC), total dissolved nitrogen, dissolved macronutrients (NO3+NO2, PO4, Si(OH)4), chlorophylla (chla; three size fractions: < 5 μm, 5–20 μm, and > 20 μm) pigment composition by HPLC, total suspended matter (TSM), particulate
organic carbon (POC), and particulate nitrogen (PN). Air-water CO2 flux was calculated from surface water dissolved inorganic carbon and pH. During the 4 d transit, large particles appeared
to be settling out of the surface water. Concentrations of chla containing particles > 20 μm declined 37%, TSM declined 43%, POC declined 42% and PN declined 57%. Concentrations of the
smaller chla containing particles did not change suggesting only large particulate materials were settling. There was no measurable loss
of dissolved NO3, PO4, or Si(OH)4, consistent with the observation that chla did not increase during the 4-d transit. DOC declined slightly (3%). These data indicate there was little autotrophic or
heterotrophic activity in the lower Mississippi River at this time, but the system was slightly net heterotrophic. 相似文献
89.
The experimental multipole electron density, ρ(r), of diopside was derived from high-resolution single-crystal diffraction at room temperature. Its topological analysis revealed
predominantly ionic Si–O bonding, as found in electron density studies of other silicates. In particular, the non-bridging
Si–O bonds are slightly less ionic in character than the bridging Si–O bonds. The Ca–O and Mg–O bonds are classified as pure
closed-shell ionic interactions. An analysis of –∇2ρ(r) showed the presence of maxima around the oxygen atoms, associated to lone pairs domains that are involved in bonds with
the surrounding ions. Calculation of atomic basins gave net charges of –1.56(12), 3.11(17), 1.79(13) and 1.88(18) e for O
(averaged), Si, Ca and Mg atoms, respectively. O···O interactions between the O atoms at the vertices of the SiO4 tetrahedron were also detected from the topological analysis of ρ(r), and indicate a cooperative interaction among the lone pairs of neighbouring oxygen atoms. All these results were also confirmed
by periodic restricted Hartree–Fock (RHF) calculations.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
90.