40 research outputs found

    Seismic response of the geologically complex alluvial valley at the "Europarco Business Park" (Rome - Italy) through instrumental records and numerical modelling

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    The analysis of the local seismic response in the “Europarco Business Park”, a recently urbanized district of Rome (Italy) developed over the alluvial valley of the “Fosso di Vallerano” stream, is here presented. A high-resolution geological model, reconstructed over 250 borehole log-stratigraphies, shows a complex and heterogeneous setting of both the local Plio- Pleistocene substratum and the Holocene alluvia. The local seismo-stratigraphy is derived by a calibration process performed through 1D numerical modelling, accounting for: i) 55 noise measurements, ii) 10 weak motion records obtained through a temporary velocimetric array during the August 2009 L’Aquila- Gran Sasso seismic sequence and iii) one cross-hole test available from technical report. Based on the reconstructed seismo- stratigraphy, the local seismic bedrock is placed at the top of a gravel layer that is part of the Pleistocene deposits and it does not correspond to the local geological bedrock represented by Plio-Pleistocene marine deposits. 1D amplification functions were derived via numerical modelling along three representative sections that show how in the Fosso di Vallerano area two valleys converge into a single one moving from SE toward NW. The obtained results reveal a main resonance at low frequency (about 0.8 Hz) and several higher resonance modes, related to the local geological setting. Nonlinear effects are also modelled by using strong motion inputs from the official regional dataset and pointed out a general down-shift (up to 0.5 Hz) of the principal modes of resonance as well as an amplitude reduction of the amplification function at frequencies higher than 7 Hz

    Multidisciplinary Study of Seismic Wave Amplification in the Historical Center of Rome, Italy

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    Assessment of potential strong ground motion within the city of Rome is crucial to preserve its millenary monumental heritage and protect its large urban settlements. Rome is located at a distance of some tens of kilometers from the central Apennines seismogenic zone, where earthquakes of tectonic origin and of a magnitude of up to 7.0 are expected. The geological bedrock is mainly represented by high - consistency fine grained marine sedimentary deposits Pliocene to lower Pleistocene aged and named Monte Vaticano Unit. An upper Pleistocene – Holocene succession of fluvial deposits partially fill the paleo-valley of the Tiber river and of its tributaries formed during the last glacial period (22-18 kyr) carving the seismic bedrock. This alluvial body is composed by an heterogeneous fining-upward succession up to 60m thick. To better quantify the expected ground shaking within the city of Rome, a multidisciplinary research activity has being carried out and: i) a detailed 3D engineering-geology model of the Tiber River alluvia was obtained based on new data from the metro lines under construction; ii) 1D and 2D numerical modeling were performed; iii) effects due to the nonlinear behavior of soil have also been taken into account. The preliminary results show that the heterogeneity of the alluvial fill mainly controls the local seismic response. In addition, an interesting result is the fact that 1D amplification estimates are pervasively higher than the 2D ones

    Multidisciplinary Study of Seismic Wave Amplification in the Historical Center of Rome, Italy

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    Assessment of potential strong ground motion within the city of Rome is crucial to preserve its millenary monumental heritage and protect its large urban settlements. Rome is located at a distance of some tens of kilometers from the central Apennines seismogenic zone, where earthquakes of tectonic origin and of a magnitude of up to 7.0 are expected. The geological bedrock is mainly represented by high - consistency fine grained marine sedimentary deposits Pliocene to lower Pleistocene aged and named Monte Vaticano Unit. An upper Pleistocene – Holocene succession of fluvial deposits partially fill the paleo-valley of the Tiber river and of its tributaries formed during the last glacial period (22-18 kyr) carving the seismic bedrock. This alluvial body is composed by an heterogeneous fining-upward succession up to 60m thick. To better quantify the expected ground shaking within the city of Rome, a multidisciplinary research activity has being carried out and: i) a detailed 3D engineering-geology model of the Tiber River alluvia was obtained based on new data from the metro lines under construction; ii) 1D and 2D numerical modeling were performed; iii) effects due to the nonlinear behavior of soil have also been taken into account. The preliminary results show that the heterogeneity of the alluvial fill mainly controls the local seismic response. In addition, an interesting result is the fact that 1D amplification estimates are pervasively higher than the 2D ones

    Validation and improvement of Risk-UE LM2 capacity curves for URM buildings with stiff floors and RC shear walls buildings

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    This paper addresses seismic vulnerability assessment at an urban scale and more specifically the capacity curves involved for building damage prediction. Standard capacity curves are a function of predefined building typology and are proposed in the Risk-UE LM2 method for computation of the corresponding damage grades. However, these capacity curves have been mainly developed for building stock of southern European cities and the accuracy of their application with different building features, such as the ones of cities of northern Europe should be assessed. A recent research project of seismic scenarios for the cities of Sion and Martigny in Switzerland provided the opportunity to check the capacity curves of Risk-UE LM2 method. Within the framework of this project, a detailed analysis was achieved for more than 500 buildings. These buildings were typical Swiss buildings and were composed of both unreinforced masonry buildings with stiff floors and reinforced concrete buildings. The construction drawings of each building were collected in order to have the most accurate information about their main structural characteristics. The typological classification that has been adopted was developed in a recent research project. Based on the individual features of the buildings, individual capacity curves were defined. Results of the seismic assessment applied to the 500 buildings compare very well with those obtained by using Risk-UE LM2 method for unreinforced masonry buildings with stiff floors. A slight improvement may be proposed for buildings with three stories through their introduction to the category of low-rise instead of mid-rise buildings. By contrast, accuracy for reinforced concrete buildings with shear walls is very poor. Damage prediction using related capacity curves of Risk-UE LM2 method does not correspond to reality. Prediction is too pessimistic and moreover damage grades increase with the height category (low-rise, mid-rise and high-rise) of these buildings which is in contradiction with the observed damages for this type of buildings. Improvements are proposed to increase the accuracy of the seismic vulnerability assessment for northern European building stock. For unreinforced masonry buildings, a slight modification of the limits of the height category of buildings using the ones defined for RC buildings improves the damage prediction. For reinforced concrete buildings with shear walls improved capacity curves derived from the typological curves of the specific typology C are proposed

    Persistence of Unintegrated HIV DNA Associates With Ongoing NK Cell Activation and CD34+DNAM-1brightCXCR4+ Precursor Turnover in Vertically Infected Patients Despite Successful Antiretroviral Treatment

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    none11noThe quantification of proviral DNA is raising interest in view of clinical management and functional HIV eradication. Measures of all unintegrated HIV DNA (uDNA) forms in infected reservoir cells provides information on recent replication events that is not found from other proviral DNA assays. To evaluate its actual relevance in a cohort of perinatally-infected adult HIV patients (PHIV), we studied how peripheral blood mononuclear cell uDNA levels correlated with total HIV DNA (tDNA) and with overall replication or innate immune control parameters including NK cell activation/exhaustion and lymphoid turnover. Twenty-two PHIV were included, with successfully controlled HIV (HIV RNA <50 copies/mL) on combined antiretroviral therapy for mean of 8.7 ¹ 3.9 years. uDNA accounted for 16 [5.2-83.5] copies/¾g and was strongly correlated with tDNA (ρ=0.700, p=0.001). Flow cytometric analysis of peripheral NK cells showed that CD69 expression was directly correlated uDNA (p=0.0412), but not with tDNA. Interestingly, CD56-CD16+NK cells which include newly described inflammatory precursors and terminally differentiated cells were directly correlated with uDNA levels (p<0.001), but not with tDNA, and an inverse association was observed between the proportion of NKG2D+ NK cells and uDNA (ρ=-0.548, p=0.015). In addition, CD34+DNAM-1brightCXCR4+ inflammatory precursor frequency correlated directly with uDNA levels (ρ=0.579, p=0.0075). The frequencies of CD56-CD16+ and CD34+DNAM-1brightCXCR4+ cells maintained association with uDNA levels in a multivariable analysis (p=0.045 and p=0.168, respectively). Thus, control of HIV-1 reservoir in aviremic patients on ART is an active process associated with continuous NK cell intervention and turnover, even after many years of treatment. Quantification of linear and circular uDNA provides relevant information on the requirement for ongoing innate immune control in addition to ART, on recent replication history and may help stratify patients for functional HIV eradication protocols with targeted options.openTaramasso, Lucia; Bozzano, Federica; Casabianca, Anna; Orlandi, Chiara; Bovis, Francesca; Mora, Sara; Giacomini, Mauro; Moretta, Lorenzo; Magnani, Mauro; Di Biagio, Antonio; De Maria, AndreaTaramasso, Lucia; Bozzano, Federica; Casabianca, Anna; Orlandi, Chiara; Bovis, Francesca; Mora, Sara; Giacomini, Mauro; Moretta, Lorenzo; Magnani, Mauro; Di Biagio, Antonio; De Maria, Andre

    Approach to leg edema

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    Edema is defined as a palpable swelling caused by an increase in interstitial fluid volume. Leg edema is a common problem with a wide range of possible causes and is the result of an imbalance in the filtration system between the capillary and interstitial spaces. Major causes of edema include venous obstruction, increased capillary permeability and increased plasma volume secondary to sodium and water retention. In both hospital and general practice, the patient with a swollen leg presents a common dilemma in diagnosis and treatment. The cause may be trivial or life-threatening and it is often difficult to determine the clinical pathway. The diagnosis can be narrowed by categorizing the edema according to its duration, distribution (unilateral or bilateral) and accompanying symptoms. This work provides clinically oriented recommendations for the management of leg edema in adults

    The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

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    The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well
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