46 research outputs found

    Ambient-noise tomography of the wider Vienna Basin region

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    We present a new 3-D shear-velocity model for the top 30 km of the crust in the wider Vienna Basin region based on surface waves extracted from ambient-noise cross-correlations. We use continuous seismic records of 63 broad-band stations of the AlpArray project to retrieve interstation Green’s functions from ambient-noise cross-correlations in the period range from 5 to 25 s. From these Green’s functions, we measure Rayleigh group traveltimes, utilizing all four components of the cross-correlation tensor, which are associated with Rayleigh waves (ZZ, RR, RZ and ZR), to exploit multiple measurements per station pair. A set of selection criteria is applied to ensure that we use high-quality recordings of fundamental Rayleigh modes. We regionalize the interstation group velocities in a 5 km × 5 km grid with an average path density of ∼20 paths per cell. From the resulting group-velocity maps, we extract local 1-D dispersion curves for each cell and invert all cells independently to retrieve the crustal shear-velocity structure of the study area. The resulting model provides a previously unachieved lateral resolution of seismic velocities in the region of ∼15 km. As major features, we image the Vienna Basin and Little Hungarian Plain as low-velocity anomalies, and the Bohemian Massif with high velocities. The edges of these features are marked with prominent velocity contrasts correlated with faults, such as the Alpine Front and Vienna Basin transfer fault system. The observed structures correlate well with surface geology, gravitational anomalies and the few known crystalline basement depths from boreholes. For depths larger than those reached by boreholes, the new model allows new insight into the complex structure of the Vienna Basin and surrounding areas, including deep low-velocity zones, which we image with previously unachieved detail. This model may be used in the future to interpret the deeper structures and tectonic evolution of the wider Vienna Basin region, evaluate natural resources, model wave propagation and improve earthquake locations, among others

    Arrival angles of teleseismic fundamental mode Rayleigh waves across the AlpArray

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    The dense AlpArray network allows studying seismic wave propagation with high spatial resolution. Here we introduce an array approach to measure arrival angles of teleseismic Rayleigh waves. The approach combines the advantages of phase correlation as in the two-station method with array beamforming to obtain the phase-velocity vector. 20 earthquakes from the first two years of the AlpArray project are selected, and spatial patterns of arrival-angle deviations across the AlpArray are shown in maps, depending on period and earthquake location. The cause of these intriguing spatial patterns is discussed. A simple wave-propagation modelling example using an isolated anomaly and a Gaussian beam solution suggests that much of the complexity can be explained as a result of wave interference after passing a structural anomaly along the wave paths. This indicates that arrival-angle information constitutes useful additional information on the Earth structure, beyond what is currently used in inversions

    Shear-wave velocity structure beneath the Dinarides from the inversion of Rayleigh-wave dispersion

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    Highlights • Rayleigh-wave phase velocity in the wider Dinarides region using the two-station method. • Uppermost mantle shear-wave velocity model of the Dinarides-Adriatic Sea region. • Velocity model reveals a robust high-velocity anomaly present under the whole Dinarides. • High-velocity anomaly reaches depth of 160 km in the northern Dinarides to more than 200 km under southern Dinarides. • New structural model incorporating delamination as one of the processes controlling the continental collision in the Dinarides. The interaction between the Adriatic microplate (Adria) and Eurasia is the main driving factor in the central Mediterranean tectonics. Their interplay has shaped the geodynamics of the whole region and formed several mountain belts including Alps, Dinarides and Apennines. Among these, Dinarides are the least investigated and little is known about the underlying geodynamic processes. There are numerous open questions about the current state of interaction between Adria and Eurasia under the Dinaric domain. One of the most interesting is the nature of lithospheric underthrusting of Adriatic plate, e.g. length of the slab or varying slab disposition along the orogen. Previous investigations have found a low-velocity zone in the uppermost mantle under the northern-central Dinarides which was interpreted as a slab gap. Conversely, several newer studies have indicated the presence of the continuous slab under the Dinarides with no trace of the low velocity zone. Thus, to investigate the Dinaric mantle structure further, we use regional-to-teleseismic surface-wave records from 98 seismic stations in the wider Dinarides region to create a 3D shear-wave velocity model. More precisely, a two-station method is used to extract Rayleigh-wave phase velocity while tomography and 1D inversion of the phase velocity are employed to map the depth dependent shear-wave velocity. Resulting velocity model reveals a robust high-velocity anomaly present under the whole Dinarides, reaching the depths of 160 km in the north to more than 200 km under southern Dinarides. These results do not agree with most of the previous investigations and show continuous underthrusting of the Adriatic lithosphere under Europe along the whole Dinaric region. The geometry of the down-going slab varies from the deeper slab in the north and south to the shallower underthrusting in the center. On-top of both north and south slabs there is a low-velocity wedge indicating lithospheric delamination which could explain the 200 km deep high-velocity body existing under the southern Dinarides

    Crustal Thinning From Orogen to Back-Arc Basin: The Structure of the Pannonian Basin Region Revealed by P-to-S Converted Seismic Waves

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    We present the results of P-to-S receiver function analysis to improve the 3D image of the sedimentary layer, the upper crust, and lower crust in the Pannonian Basin area. The Pannonian Basin hosts deep sedimentary depocentres superimposed on a complex basement structure and it is surrounded by mountain belts. We processed waveforms from 221 three-component broadband seismological stations. As a result of the dense station coverage, we were able to achieve so far unprecedented spatial resolution in determining the velocity structure of the crust. We applied a three-fold quality control process; the first two being applied to the observed waveforms and the third to the calculated radial receiver functions. This work is the first comprehensive receiver function study of the entire region. To prepare the inversions, we performed station-wise H-Vp/Vs grid search, as well as Common Conversion Point migration. Our main focus was then the S-wave velocity structure of the area, which we determined by the Neighborhood Algorithm inversion method at each station, where data were sub-divided into back-azimuthal bundles based on similar Ps delay times. The 1D, nonlinear inversions provided the depth of the discontinuities, shear-wave velocities and Vp/Vs ratios of each layer per bundle, and we calculated uncertainty values for each of these parameters. We then developed a 3D interpolation method based on natural neighbor interpolation to obtain the 3D crustal structure from the local inversion results. We present the sedimentary thickness map, the first Conrad depth map and an improved, detailed Moho map, as well as the first upper and lower crustal thickness maps obtained from receiver function analysis. The velocity jump across the Conrad discontinuity is estimated at less than 0.2 km/s over most of the investigated area. We also compare the new Moho map from our approach to simple grid search results and prior knowledge from other techniques. Our Moho depth map presents local variations in the investigated area: the crust-mantle boundary is at 20–26 km beneath the sedimentary basins, while it is situated deeper below the Apuseni Mountains, Transdanubian and North Hungarian Ranges (28–33 km), and it is the deepest beneath the Eastern Alps and the Southern Carpathians (40–45 km). These values reflect well the Neogene evolution of the region, such as crustal thinning of the Pannonian Basin and orogenic thickening in the neighboring mountain belts

    Bioequivalence of recombinant factor VIII products: a position paper from the Italian Association of Hemophilia Centers

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    : Over the last three decades, the continuous evolution of recombinant factor VIII (rFVIII) concentrates for replacement treatment of hemophilia A, including recent extended half-life products, implies that patients may switch from one product to another, technologically more advanced, with the aim of improving treatment efficacy, safety, management and, ultimately, quality of life. In this scenario, the issues of bioequivalence of rFVIII products and the clinical implications of their interchangeability are keenly debated, in particular when economic reasons or purchasing systems influence product availability and choices. Although sharing the same Anatomical Therapeutic Chemical (ATC) level, rFVIII concentrates, as other biological products, show relevant differences in terms of molecular structure, source and manufacturing process, which make them unique products, recognized as new active substances by regulatory agencies. Moreover, data from clinical trials with both standard and extended half-life products clearly document the large inter-patient variability of pharmacokinetic profiles after administering the same dose of the same product; in cross-over evaluations, even when mean values are comparable, some patients show better patterns with one product or with the comparator one. Pharmacokinetic assessment thus reflects the response to a specific product in the individual patient, with his genetic determinants, only partially identified, affecting the behavior of exogenous FVIII. These concepts, consistent with the currently recommended approach of personalization of prophylaxis, are discussed in this position paper endorsed by the Italian Association of Hemophilia Centers (AICE), highlighting that ATC or other available classifications do not completely consider differences between drugs and innovations and that substitutions of rFVIII products will not invariably ensure the previously achieved clinical outcomes or generate benefits for all patients

    Vpliv marikulture na okolje

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    The Italian Registry of Thrombosis in Children (RITI) was established by a multidisciplinary team with the aims of improving knowledge about neonatal and paediatric thrombotic events in Italy and providing a preliminary source of data for the future development of specific clinical trials and diagnostic-therapeutic protocols

    A multicenter, real-world experience with recombinant FXIII for the treatment of patients with FXIII deficiency: from pharmacokinetics to clinical practice. The Italian FXIII Study

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    Background: Congenital factor XIII (FXIII) deficiency is a rare coagulation disorder characterized by muscular or mucocutaneous bleeding with life-threatening intracranial hemorrhages (ICHs), especially in cases with severe disease. The best treatment is the use of prophylactic plasma-derived or recombinant FXIII (rFXIII). Few data on the use of rFXIII in the real-world scenario are available. The main goal of this study was to assess the efficacy and safety of catridecacog (NovoThirteen®) in a population of patients with FXIII deficiency. Other objectives were to compare the different pharmacokinetic (PK) profiles of each patient and to use them to create a tailored prophylaxis regimen. Materials and methods: We collected and analyzed all pharmacokinetic and clinical data in our registry of the patients with congenital FXIII deficiency treated with rFXIII at eleven Italian hemophilia centers. Data were collected from January 2019 to December 2020. Results: Overall, data on 20 patients with FXIII deficiency were collected, 16 of whom presented with severe disease. Pharmacokinetics was assessed in 18 cases before starting prophylaxis. Prophylaxis was subsequently started in these patients using a wide range of dosages (25.0-80.0 IU/kg; mean 33.8 IU/kg) and infusion intervals (3.0-8.0 weeks). During a mean follow up of 47 months, two minor bleeds and one ICH in a severe patient who had remained under on-demand treatment were reported. Discussion: Efficacy and safety of rFXIII were proven in all patients. The dosage and infusion timing for the treated patients sometimes differed to those reported in the MENTOR pivotal studies, thus underlying the importance of tailored management in a real-world scenario
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