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71.
Maria Gabriella Marin Stefano Rigato Francesco Ricciardi Valerio Matozzo 《Marine pollution bulletin》2008,57(6-12):552
The lethal and sublethal effects of the xenoestrogen 4-nonylphenol (NP) were evaluated in the cockle Cerastoderma glaucum. In a 96-h lethality test, bivalves were exposed to 0, 0+ acetone, 0.19, 0.38, 0.75, 1.5 and 3.0 mg NP/l. The 96-h LC50 value was 0.3 mg NP/l. No mortality was observed at 0.1 mg NP/l. The potential estrogenicity of NP was studied in both sexually undifferentiated (resting phase) and differentiated (pre-spawning phase) cockles, exposed for 7 and 14 days to 0, 0+ acetone, 0.0125, 0.025, 0.05, and 0.1 mg NP/l. Vitellogenin (Vg)-like protein levels were determined in both haemolymph and digestive gland by the alkali-labile phosphate (ALP) assay. In the resting phase, exposure for 7 days to 0.1 mg NP/l resulted in significant increases in ALP in both haemolymph and digestive gland, compared with controls. A significant increase was also observed in digestive gland of animals exposed to 0.0125 mg NP/l-exposed animals. After 14 days of exposure, haemolymph ALP levels were significantly increased in exposed animals at all NP concentrations tested, whereas no difference was recorded in digestive gland. In the pre-spawning phase, exposure for 7 days to NP significantly increased ALP levels in haemolymph from males exposed at all NP concentrations tested, whereas no significant variations were found in haemolymph from females. NP (0.05 and 0.1 mg/l) was also shown to increase ALP concentrations significantly in digestive gland of males, but not in those of females. Likewise, after 14 days’ exposure, ALP levels significantly increased in haemolymph from males only at 0.1 mg NP/l. Conversely, NP caused significant increases in ALP levels in digestive gland from both males (at all NP concentrations tested) and females (at 0.025 and 0.1 mg NP/l). These results demonstrate that NP induces Vg synthesis in C. glaucum. Interestingly, males were more responsive to NP than females. 相似文献
72.
New geomorphological and chronological constraints for glacial deposits in the Rivoli‐Avigliana end‐moraine system and the lower Susa Valley (Western Alps,NW Italy) 下载免费PDF全文
73.
Roderik A. Overzier Qi Guo Guinevere Kauffmann Gabriella De Lucia Rychard Bouwens Gerard Lemson 《Monthly notices of the Royal Astronomical Society》2009,394(2):577-594
Motivated by recent observational studies of the environment of z ∼ 6 QSOs, we have used the Millennium Run (MR) simulations to construct a very large (∼4°× 4°) mock redshift survey of star-forming galaxies at z ∼ 6 . We use this simulated survey to study the relation between density enhancements in the distribution of i 775 -dropouts and Lyα emitters, and their relation to the most massive haloes and protocluster regions at z ∼ 6 . Our simulation predicts significant variations in surface density across the sky with some voids and filaments extending over scales of 1°, much larger than probed by current surveys. Approximately one-third of all z ∼ 6 haloes hosting i -dropouts brighter than z = 26.5 mag (≈ M *UV, z =6 ) become part of z = 0 galaxy clusters. i -dropouts associated with protocluster regions are found in regions where the surface density is enhanced on scales ranging from a few to several tens of arcminutes on the sky. We analyse two structures of i -dropouts and Lyα emitters observed with the Subaru Telescope and show that these structures must be the seeds of massive clusters in formation. In striking contrast, six z ∼ 6 QSO fields observed with Hubble Space Telescope show no significant enhancements in their i 775 -dropout number counts. With the present data, we cannot rule out the QSOs being hosted by the most massive haloes. However, neither can we confirm this widely used assumption. We conclude by giving detailed recommendations for the interpretation and planning of observations by current and future ground- and space-based instruments that will shed new light on questions related to the large-scale structure at z ∼ 6 . 相似文献
74.
Maria E. De Rossi Patricia B. Tissera Gabriella De Lucia † Guinevere Kauffmann 《Monthly notices of the Royal Astronomical Society》2009,395(1):210-217
We analyse a sample of 52 000 Milky Way (MW) type galaxies drawn from the publicly available galaxy catalogue of the Millennium Simulation with the aim of studying statistically the differences and similarities of their properties in comparison to our Galaxy. Model galaxies are chosen to lie in haloes with maximum circular velocities in the range 200–250 km s−1 and to have bulge-to-disc ratios similar to that of the MW. We find that model MW galaxies formed 'quietly' through the accretion of cold gas and small satellite systems. Only ≈12 per cent of our model galaxies experienced a major merger during their lifetime. Most of the stars formed ' in situ ', with only about 15 per cent of the final mass gathered through accretion. Supernovae (SNe) and active galactic nuclei (AGN) feedback play an important role in the evolution of these systems. At high redshifts, when the potential wells of the MW progenitors are shallower, winds driven by SNe explosions blow out a large fraction of the gas and metals. As the systems grow in mass, SNe feedback effects decrease and AGN feedback takes over, playing a more important role in the regulation of the star formation activity at lower redshifts. Although model MW galaxies have been selected to lie in a narrow range of maximum circular velocities, they nevertheless exhibit a significant dispersion in the final stellar masses and metallicities. Our analysis suggests that this dispersion results from the different accretion histories of the parent dark matter haloes. Statistically, we also find evidences to support the MW as a typical Sb/Sc galaxy in the same mass range, providing a suitable benchmark to constrain numerical models of galaxy formation. 相似文献
75.
Fabrizio Murgia Riccardo Biddau Alessandro Concas Roberto Demontis Luca Fanfani Zeno Heilmann Cristian Lai Giuditta Lecca Eva Lorrai Marino Marrocu Vittorio Alessandro Marrone Laura Muscas Elisaveta Peneva Andrea Piras Massimo Pisu Gabriella Pusceddu Guido Satta Daniela Theis Andrea Vacca Paolo Valera Ana Melina Vallenilla Ferrara Ernesto Bonomi 《Earth Science Informatics》2009,2(1-2):5-21
GRIDA3 (Shared Resources Manager for Environmental Data Analysis and Applications) is a multidisciplinary project designed to deliver an integrated system to forge solutions to some environmental challenges such as the constant increase of polluted sites, the sustainability of natural resources usage and the forecast of extreme meteorological events. The GRIDA3 portal is mainly based on Web 2.0 technologies and EnginFrame framework. The portal, now at an advanced stage of development, provides end-users with intuitive Web-interfaces and tools that simplify job submission to the underneath computing resources. The framework manages the user authentication and authorization, then controls the action and job execution into the grid computing environment, collects the results and transforms them into an useful format on the client side. The GRIDA3 Portal framework will provide a problem-solving platform allowing, through appropriate access policies, the integration and the sharing of skills, resources and tools located at multiple sites across federated domains. 相似文献
76.
Possible xenoestrogenic effects were investigated, for the first time, in two bivalve species from the Lagoon of Venice (Italy): the clam Tapes philippinarum and the cockle Cerastoderma glaucum. Bivalves were collected far from their reproductive phase at the very early stage of gametogenesis (January), and in the pre-spawning period (June) in six sites. Vitellogenin (Vg)-like proteins (a biomarker of exposure to estrogenic compounds) were measured by the alkali-labile phosphate method (ALP), in both haemolymph and digestive gland from males and females (when it was possible to distinguish sex by microscopic observation of gonadal tissue). Haemolymph calcium concentrations (a parameter considered closely related to the presence of Vg-like proteins) and the bivalve condition index (CI) were also measured. In both seasons, bivalves collected at Campalto (near a sewage treatment plant) and Marghera (a highly contaminated area) had higher Vg-like protein levels, particularly in haemolymph, than animals from the other sampling sites. Interestingly, CI had high values in these polluted sites. In June only, Vg-like proteins and Ca(2+) levels in haemolymph exhibited similar trends in both bivalve species at most sampling sites. The responsiveness of bivalves to environmental xenoestrogens was higher in June, allowing better discrimination among sites. The present study demonstrates that animals from highly polluted areas have increased Vg-like protein levels. As endocrine disruption due to exposure to estrogenic compounds may cause fertility reduction, alterations in the sex ratio, and a decrease in reproductive rate, a condition of potential risk for bivalve populations in estuarine areas is highlighted. 相似文献
77.
Disconnected policies and actors and the missing role of spatial planning throughout the risk management cycle 总被引:2,自引:2,他引:0
Kalliopi Sapountzaki Sylvia Wanczura Gabriella Casertano Stefan Greiving Gavriil Xanthopoulos Floriana F. Ferrara 《Natural Hazards》2011,59(3):1445-1474
The present work addresses the problem of lack of coordination between policies and actors with joint competence for risk
management, i.e., civil protection, spatial planning, and sectoral planning (e.g., forest policy in the case of forest fire
risk). Spatial planning in particular is assigned a minor or no role at all though it might perfectly operate as the coordinating
policy platform; the reason is that spatially relevant analysis and policy guidance is an omnipresent component of the risk
management cycle. However, disconnected risk relevant policies turning a blind eye to spatial planning might cause several
adverse repercussions: Breaks in the response-preparedness-prevention-remediation chain (which should function as a continuum),
minimal attention to prevention, risk expansion and growth instead of mitigation, lack of synergies between involved actors
as well as duplicated or even diverging measures and funding. The authors bear witness to the above suggestions by examining
three cases of European (regional and local) risk management systems faced with failures when confronting natural hazards
(floods and forest fires). These three systems are embedded in different types of political-administrative structures, namely
those of the city of Dortmund (Germany) facing floods, Eastern Attica region (Greece), and Lazio Region (Italy) facing forest
fires. 相似文献
78.
79.
80.
Marek PÓŁROLNICZAK Leszek KOLENDOWICZ Bartosz CZERNECKI Mateusz TASZAREK Gabriella TÓTH 《大气科学进展》2021,38(3):387-399
Hazardous events related to atmospheric precipitation depend not only on the intensity of surface precipitation,but also on its type.Uncertainty related to determination of the precipitation type(PT)leads to financial losses in many areas of human activity,such as the power industry,agriculture,transportation,and many more.In this study,we use machine learning(ML)algorithms with the data fusion approach to more accurately determine surface PT.Based on surface synoptic observations,ERA5 reanalysis,and radar data,we distinguish between liquid,mixed,and solid precipitation types.The study domain considers the entire area of Poland and a period from 2015 to 2017.The purpose of this work is to address the question:“How can ML techniques applied in observational and NWP data help to improve the recognition of the surface PT?”Despite testing 33 parameters,it was found that a combination of the near-surface air temperature and the depth of the warm layer in the 0-1000 m above ground level(AGL)layer contains most of the signal needed to determine surface PT.The accrued probability of detection for liquid,solid,and mixed PTs according to the developed Random Forest model is 98.0%,98.8%,and 67.3%,respectively.The application of the ML technique and data fusion approach allows to significantly improve the robustness of PT prediction compared to commonly used baseline models and provides promising results for operational forecasters. 相似文献