Sfogliando per Autore ""-""
  • Pubblicazione
    Alkaline extracted humic substances: artifacts of the extraction procedure?
    (Nikolla Qafoku, 2019)
    Carlo Bravo
    ;
    Ali Khakbaz
    ;
    Marco Contin
    ;
    Maria De Nobili
      6
  • Pubblicazione
    Automatic pickers performances in the case of the Emilia sequence of May-June 2012
    ("-", 2013)
    TIBERI, LARA
    ;
    Spallarossa D.
    ;
    COSTA, GIOVANNI
    ;
    Bohm G.
    The automatic processing of seismic data, whether for real-time seismic warning system or to reprocessing large amount of seismic recordings, is increasingly being demanded by seismologists especially in case of emergency as for the Emilia sequence in may-june 2012. In this study is presented a comparison between the AutoPicker (DipTeRiS, University of Genova) a new method used for automatic accurate onset phase picking for both P and S wave arrival based on the Akaike's information criterion (AIC), a solid and tested picker as the STA/LTA in Antelope software and the manual pickings. In order to construct the database used for the relocation of Emilia sequence, the RAN strong motion database has been merged with the available velocity and acceleration data extracted from the EIDA database (European Integrated Data Archive) and velocity data recorded by the Southeastern Alps Integrated Network (DMG, OGS, ARSO and ZAMG). The fault system of the Emilia earthquake area is complex and it is not easy to assess which fault has moved. A precise localization of the sequence is essential. The manual pickings, the equivalent locations and the choice of the most appropriate velocity model (“Iside”) used in this study are the results of a work done in collaboration with Università di Chieti and DPC, not described here. The main problem of the AutoPicker and Antelope software is to discriminate events that occur very close to each other in time. The best way to solve that issue is choosing the best setup of both techniques to minimize the problem. Then we are implementing the AutoPicker technique on the Antelope system routinely used by DMG for the real-time data analysis. In addition we use automatic locations and manual locations to produce a travel time tomography of the field near the generating fault of Emilia sequence 2012 and compare the different results in order to study how much the location's errors influence the tomography's results.
  • Pubblicazione
    Development, optimization and applications of an analytical method for Hg isotope ratios determination.
    ("-", 2013)
    C. Baschieri
    ;
    A. Marchetti
    ;
    COVELLI, STEFANO
    ;
    EMILI, ANDREA
    ;
    D. Manzini
    ;
    M. C. Rossi
    ;
    A. Berni
    ;
    C. Durante
    Mercury is one of the most harmful pollutant present on Earth and shows some peculiar characteristics which make this element relevant to study. Hg undergoes to complex biogeochemical transformations in the environment and shows different isotopic fractionation phenomena of both mass dependant (MDF) and mass independent (MIF) nature. The study of the isotopic mass fractionation, seems to be a powerful tool to trace and identify the sources of pollution and the behavior of this element in natural systems and organisms. In order to determine the isotope ratios of mercury an analytical procedure was set up by using a multicollector ICP/MS coupled with an on-line reduction apparatus as sample introduction system. Instrumental mass bias was corrected by using the 205Tl/203Tl isotopic reference coupled to a standard-sample bracketing approach to compensate any instrumental drift. Due to the high mass of the element, the fractionation phenomena are very small thus, the measure precision must be good enough to be able to significantly detect the differences in the isotopic composition. Because of the high number of instrumental parameters which must be set and which may influence the measurements, the instrumental conditions were optimized in order to obtain the suitable internal precision even for sample with low amount of mercury. The optimization step of the instrumental determination was conducted by means of the most advanced and innovative chemometric techniques of Design of Experiments (DoE). The multivariate approach is suitable for optimization purposes and in particular when many parameters must be varied at the same time such in this case. In facts, this method allows obtaining at the same time the maximum useful information with the minor number of experiments. Moreover, the multilinear regression models built on DoE data allow not only to determine the influence of the parameters on the finale responses but also the interactions among the parameters themselves. For the determination of the mercury isotope ratios five parameters were chosen for the optimization: the number of integration cycles, the integration time per cycle, the concentration of mercury in the samples, the concentration of thallium, the internal standard, and the flux of the solutions of mercury and the reduction agents through the reduction system. The responses to be optimized were the internal precisions for each measurement, expressed as RSE%. By means of the models built on the DoE data it was possible to study the influence of the parameters on the measurement precisions and to predict the optimum parameters in different instrumental conditions. The method was applied to sediment samples collected along an ideal transect ranging from the Idrija Hg mine district, Slovenia, to the Aussa-Corno river. Results showed that the isotopic approach can be used as an useful tracing tool in natural environment.
  • Pubblicazione
    Evaluating mercury contamination in the context of sustainable sediment management of a coastal lagoon: evidence from the Marano and Grado Lagoon saltmarshes (Northern Adriatic Sea)
    (11th International Conference on Mercury as a Global Pollutant (ICMGP 2013), 2013)
    EMILI, ANDREA
    ;
    PETRANICH, ELISA
    ;
    PELLEGRINI, ELISA
    ;
    ACQUAVITA, Alessandro
    ;
    COVELLI, STEFANO
    ;
    Canário, J.
    Saltmarshes are among the most valuable coastal environments, providing several ecosystem services, as well as a fundamental habitat for waterbirds and halophytes. They are also vulnerable to the effects of anthropogenic and natural pressures. Erosive processes, as well as removal by the periodical dredging of navigation channels cause the loss of sediments from the overall lagoon sedimentary budget, with negative effects including the disappearance of saltmarshes. A sustainable management of coastal lagoon sediments should provide for a positive balance between erosion and accretion processes, promoting the construction of peculiar and valuable morphologies such as saltmarshes. On the other hand, several coastal environments suffer the impacts of contamination both from organic and inorganic pollutants. The level of contamination determines the allowed sediment end use and its final destination, such as its disposal into coastal landfills, on the basis of risk assessment and cost-benefit analysis. As such, the geochemical characteristics of sediments are an important parameter informing the management and decision processes. The Marano and Grado Lagoon (Northern Adriatic Sea) has been affected by severe mercury (Hg) contamination from both industrial (a chlor-alkali plant) and long-term mining activities (the Idrija Hg mine in Slovenia), with total sedimentary contents up to 12 μg g-1. There has been evidence of a significant decline in the total saltmarsh area of the lagoon, with direct human impact playing a primary role through dredging and land reclamation. In order to provide evidence for the reuse of dredged sediments for saltmarsh re-construction as a possible alternative in the management of the Marano and Grado Lagoon sediments, we carried out a preliminary evaluation on the content and biogeochemical cycling of Hg in saltmarshes. Mercury content was determined in sediments and in plants from selected saltmarshes located in the Marano and Grado Lagoon. In sediments, Hg content exceeded the estimated background value for the area (0.13 μg g-1), showing the highest concentrations in the eastern sector (Grado Lagoon), the most affected by cinnabar ore extraction. Mercury was also detected in roots, shoots and leaves of the halophytes Sarcocornia fruticosa, Limonium vulgare and Halimione portulacoides, with various degrees of contamination depending on the location, species and depth. Data showed Hg enrichment in the roots, compared to the saltmarsh sediment, as well as hints of translocation of the metal to the aboveground biomass. The results enabled us to estimate the role of saltmarshes as sources and/or sinks of Hg to the lagoon environment and to examine the hydrologic and biogeochemical controls on Hg fate and transport in these environments.
      1
  • Pubblicazione
    Fanconi anemia patients are more susceptible to SV40 infection
    (Springer, 2013)
    COMAR, Manola
    ;
    SAVOIA, ANNA
    ;
    DE ROCCO, DANIELA
    ;
    Nunzia Zanotta
    ;
    BOTTEGA, ROBERTA
    ;
    Johanna Svahn
    ;
    Piero Farruggia
    ;
    Aldo Misuraca
    ;
    Fabio Corsolin
    ;
    Carlo Dufour
      1
  • Pubblicazione
    Fast automatic strong motion data analysis for Civil Protection purposes: the 2012 Ferrara earthquake example (Northern Italy)
    ("-", 2013)
    COSTA, GIOVANNI
    ;
    A. Ammirati
    ;
    L. Filippi
    ;
    GALLO, ANTONELLA
    ;
    G. Lavecchia
    ;
    R. de Nardis
    ;
    M. Nicoletti
    ;
    SUHADOLC, PETER
    ;
    TIBERI, LARA
    ;
    E. Zambonelli
    ;
    ZOPPÈ, GIULIANA
    A fast seismic data analysis is essential to provide useful information to Authorities which make decisions immediately after a strong earthquake occurrence. During a strong earthquake, the modern accelerometers are the only instruments which can provide near source high-quality data that are important both for scientific and for civil protection purposes. Automatic and fast techniques have been developed by the University of Trieste for the automatic real-time strong motion data analysis. These techniques have been installed and optimized in the data acquisition centre of the Department of Civil Protection of Italy (DPC) to process the quasi real-time data of the National Accelerometric Network (RAN). RAN counts more than 450 stations covering all the Italian territory. Two local networks, the Friuli Venezia Giulia Accelerometric Network (RAF), located in NE Italy, and the Irpinia Seismic Network (ISNet), contribute their data into the RAN data acquisition system. 148 stations of the integrated RAN triggered the main shock of the Ferrara arc 2012 sequence. The RAN stations recorded the strong motions of the ML 5.9 mainshock, as well as of the major ML 4.1 foreshock and of nearly 35 aftershocks of magnitude ML ¡Ý 4.0. Soon after the mainshock, the DPC installed 15 temporary stations to increase the network coverage in the epicentral area. The performance of the network and of the fast automatic strong motion data analysis during the 2012 Ferrara sequence is analysed. The value of the strong motion parameters calculated by means of the automatic procedure immediately after the events show small differences with respect to the visual inspection procedure. Other aspects related to the seismic source, attenuation of seismic waves, directivity effects and to the comparison between distribution and attenuation of earthquake engineering parameters and observed damage are discussed, highlighting the robustness of the proposed automatic procedure.
  • Pubblicazione
  • Pubblicazione
    Geophysic data interperetation of Passo della Morte landslide: Eastern Italian Alps.
    ("-", 2012)
    ZOPPÈ, GIULIANA
    ;
    COSTA, GIOVANNI
    ;
    G. Marcato
    ;
    FORTE, Emanuele
    The Passo della Morte block-slide covers a relative large area in the Carnic Alps, along the left side of the Taglia- mento River, between Forni di Sotto and Ampezzo (N-E of Italy). The high seismicity and the presence of the landslide increase the risk associated to the interest area. Moreover the large volume of material involved in the landslide (a few million of cubic meters), the presence of important infrastructure such as the road and two tunnels which cross the landslide, as well as the presence of the Tagliamento River that flow at the foot of the landslide, make the area very vulnerable. This study concerns with the western part of the Deep Seated Gravitational Slope Deformation (DSGSD). It fo- cuses on the potential instability of a rock slope (crossed by road tunnels) and its connection with the DSGSD activity. The main objectives of this study are: monitoring the rock mass movement, studying the seismic site ef- fect and defining the stratigraphic and geological characteristics of involved materials. Two vibration sensors have been installed inside the potential landslide: a short-period seismometer and a piezo- electric transducer. The microseismic activity recorded by the sensors has been analyzed, with particular regard to periods characterized by rapid changes in recorded seismic signals, and then correlated with the precipitation trend to evaluate the existence of a possible correlation between these phenomena. The microseismic activity study has highlighted the existence of a close link between microseisms and acoustic emissions recorded respectively by the seismometer and by the piezoelectric transducer. In addition, the comparison with the rainfall pattern has shown a direct relationship between different rainfall events and the sharp increase of microseismic activity detected by the two instruments. The correlation is good, even if acoustic emissions appear to be more sensitive than microseisms to short duration and low intensity rainfall events. The seismic site effects and the directivity in seismic site response of the rock mass have been investigated through the use of Nakamura (1989) method. In particular have been estimated the resonance frequencies and the polariza- tion directions of seismic energy in three selected sites. All sites have shown a clear evidence of polarization in the direction of N/NW-S/SE and E/NE-W/SW, compatible with the maximum slope inclination and with the limestone stratification direction outcropping in this area. In order to define the stratigraphic and geological characteristics of the materials involved, have been performed a GPR investigation and an active seismic survey. The first has been useful to identify vertical and horizontal variations of the lithotypes present, most associated with different degrees of rock fracturing and fluid content. The seismic investigation has permitted to identify a reflective layer and to determine the propagation velocity of compression and shear waves of the two layers found.
  • Pubblicazione
    Gray Platelet Syndrome: association of NBEAL2 mutations with thrombocytopenia and absence of alpha-granules in platelets
    ("-", 2012)
    E. De Candia
    ;
    BOTTEGA, ROBERTA
    ;
    A. Pecci
    ;
    N. Pujol Moix
    ;
    P. Heller
    ;
    P. Noris
    ;
    DE ROCCO, DANIELA
    ;
    G.M. Podda
    ;
    C.L. Balduini
    ;
    SAVOIA, ANNA
      1
  • Pubblicazione
    Identification of previously undescribed NBEAL2 gene mutations in a novel case of gray platelet syndrome
    ("-", 2012)
    G.M. Podda
    ;
    E. Femia
    ;
    M. Schiavone
    ;
    A. Pecci
    ;
    BOTTEGA, ROBERTA
    ;
    SAVOIA, ANNA
    ;
    E. De Candia
    ;
    G. Carpani
    ;
    V. Oriana
    ;
    M. Cattaneo
      2
  • Pubblicazione
    Landslide characterization through seismic noise investigation
    ("-", 2013)
    ZOPPÈ, GIULIANA
    ;
    COSTA, GIOVANNI
    ;
    G. Marcato
    The purpose of this study is to evaluate the capabilities of seismic noise data for detection of landslide sliding surfaces using the H/V spectral ratio (Nakamura method). The case study is Passo della Morte landslide, located in the Nord East of Italy (Carnic Alps) along the left side of the Tagliamento River. Its surface is approximately 530 thousand m2 and movements are up to 5 cm/year of on most active zones. The risk associated with this phenomenon is the interference with a National Road (N.R. 52) and two road tunnels. Moreover, Tagliamento River flowing at the landslide toe, a possible damming has to be taken into account. Several studies have been carried out to characterize the landslide behavior, via multiple displacement measuring techniques (laser scanner, GPS, extensimeter, inclinometer, TDR), micro-seismic monitoring systems (seismometer and acoustic emission sensor) and seismic survey (GPR and seismic refraction). The main objectives of this investigation are: determine the depth of landslide sliding surface in various sites and reconstruct its geometry by applying the law [f0=Vs/4H] to the resonance frequencies found with Nakamura method. Measurements sites have been set 200m apart on a regular grid covering all the surface to be monitored. Seismic noise has been recorded using a Lennartz seismometer (LE-3D/5s) connected to a Quanterra Q330 (Kinemetrics) acquisition system. Results have been validated by means of several boreholes performed in the examined area. On the other hand, the H/V spectral ratios in the horizontal plane as a function of the azimuth have been analyzed in order to investigate the directivity in seismic site response on the landslide. The results obtained with this work will be presented.
  • Pubblicazione
    Molecular genetic testing of Fanconi anemia: experience of the Italian Research Group on Fanconi Anemia
    ("-", 2013)
    DE ROCCO, DANIELA
    ;
    FALESCHINI, MICHELA
    ;
    BOTTEGA, ROBERTA
    ;
    E. Cappelli
    ;
    J. Svahn
    ;
    P. Farruggia
    ;
    D. Longoni
    ;
    V. Poggi
    ;
    M. Pillon
    ;
    C. Dufour
    ;
    SAVOIA, ANNA
      1
  • Pubblicazione
    Molecular Genetic Testing of Fanconi Anemia: Experience of the Italian Research Group on Fanconi Anemia.
    ("-", 2010)
    SAVOIA, ANNA
    ;
    M. Criscuolo
    ;
    BOTTEGA, ROBERTA
    ;
    A. Borriello
    ;
    M. Pillon
    ;
    D. Longoni
    ;
    P. Farruggia
    ;
    A. Misuraca
    ;
    C. Dufur
      1
  • Pubblicazione
    The Spinel Peridotite Mantle xenoliths of Waw-En Namus volcano, southern Libia
    (EMC 2012, 2012)
    NARDUZZI, FRANCESCO
    ;
    DE MIN, ANGELO
    ;
    Zanetti A.
    ;
    GRILLO, BARBARA
    alkaline) since Jurassic times (Guiraud et al. 2005). Moreover, paleomagnetic data, suggest that the drifting of the African plate during the last 100 Ma has been very limited, thus allowing for the keeping the contact with the deeper mantle. Starting from these premises, the peridotite xenoliths, hosted in nephelinitic basalts from the Waw En-Namus volcano and investigated in comparison with those from Gharyan area (Beccaluva et al., 2007), could shed a light on the evolution of the Libyan sub-continental lithospheric mantle and on the geodynamic events that affected it over time. The mineral phases of such xenoliths, as well as few glassy veins, were studied in order to determine major and trace elements compositions. Three types of olivines, orthopyroxenes, clinopyroxenes, and spinels were recognized (magmatic, peridotitic and related to melt-peridotite reactions), as well as the presence of Na, K and ultra-potassic (UK) glasses. The investigated glasses, selected among those which apparently have been not (or scarcely) modified in their composition by peridotite-melt reactions, show higher La/Yb and Zr/Hf ratios with respect to Waw En-Namus lavas implying the involvements of slightly different mantle sources. Moreover, the presence of UK glasses (characterized by a strong Pb positive anomaly) suggest the involvement, as source, of a lithospheric or sub-lithospheric component. The mantle phases indicate a moment of basaltic extraction starting from a depleted (DMM-like) condition followed by a recent metasomatism. In the apparently not metasomatized ones, Th/Yb and Ta/Yb ratios suggest that ancient metasomatic events, which probably occurred during the Pan-African cycle, played a role in their history. In comparison, the metasomatized mineral phases, according with the recent geophysical data (Begg et al., 2009), mainly suggest relationships with the continuous asthenospheric upwelling. Beccaluva, L., Bianchini G., Ellam, R.M., Marzola, M., Oun, K.M., Siena, F., Stuart, F.M. (2008). 253– 277 in: Coltorti, M., & Grégoire, M., (eds.). Geol. Soc. Lond. Spec. Publ. 293. Begg, G.C., Griffin,W.L., Natapov, L.M., O’Reilly S.Y., Grand, S.P., Hronsky, J.M.A., Djomani, Y.P., Swain, C.J., Deen, T., Bowden, P. (2009). Geosphere, 5, 23-50. Guiraud, R., Bosworth, W., Thierry, J., Delplanque, A. (2005). Journal of African Earth Sciences, 43, 83-143
      2
  • Pubblicazione
    Understanding Hg biogeochemical cycling in an Italian lagoon environment – A key to the coexistence of fish and clam farming and Hg contaminated sediments
    (11th International Conference on Mercury as a Global Pollutant (ICMGP 2013), 2013)
    COVELLI, STEFANO
    ;
    J. Faganeli
    ;
    M. E. Hines
    ;
    A. Acquavita
    ;
    EMILI, ANDREA
    ;
    M. Horvat
    ;
    M. Giani
    ;
    F. Baldi
    The Marano and Grado Lagoon is the second largest wetland along the northern Adriatic coastline. Fishing, collection of clams and mussels, and fish and clam farming in the lagoon are important economically for the inhabitants. The Lagoon has experienced significant contamination by mercury from effluents from a chlor-alkali plant and during the last centuries, from the Idrija mercury mine. Factors controlling mercury cycling in lagoon environments are normally poorly defined, but critical to understanding the links between sources and higher trophic levels that are ultimately vectors of human exposure. Understanding the fate of the element when dredged sediments are used for saltmarshes reclamation could be, for instance, a future challenge in research. This presentation discusses results of a comprehensive investigation of mercury cycling in the Lagoon aimed at supplying the local and regional Administrators with information useful to minimize the risk of mercury contamination to humans. Mercury was investigated in several matrices (water, sediment, biota) and its mobility was tested along with its speciation in relation to biogeochemical processes occurring in this coastal environment, where bacterial communities have a primary role in converting mercury to its more toxic form, methylmercury. The large amount of mercury buried in the Lagoon sediments and the complexity of the lagoon ecosystem, suggest that in situ reclamation of the sediments may not be feasible. The presence of mercury in the lagoon environment must be then considered a permanent issue and the biogeochemical behaviour of this metal in the sediment-water system must be carefully monitored.