103 research outputs found

    Landslide distribution and size in response to Quaternary fault activity: the Peloritani Range, NE Sicily, Italy

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    Landslides contribute to dismantle active mountain ranges and faults control the location of landslides. Yet, evidence of the long-term, regional dependency of landslides on active faults is limited. Previous studies focused on the transient effects of earthquakes on slope stability in compressive and transcurrent regimes. Here we show that in the Peloritani range, NE Sicily, Italy, one of the fastest uplifting areas in the Mediterranean, a clear geographical association exists between large bedrock landslides and active normal faults of the Messina Straits graben. By interpreting aerial photographs, we mapped 1590 landslides and sackungs and 626 fault elements and their facets in a 300 km2 area in the eastern part of the range. We used the new landslide and fault information, in combination with prior geological and seismic information, to investigate the association between bedrock landslides and faults. We find that the distribution and abundance of landslides is related to the presence of large active normal faults, and matches the pattern of the local historical seismicity. Landslide material is more abundant along the East Peloritani Fault System where the long-term activity of the faults, measured by the average yearly geological moment rate, is larger than in the West Peloritani Fault System where landslides are less abundant. Along the fault systems landslide material concentrates where the cumulated fault throws are largest. We conclude that large landslides and their cumulated volume are sensitive to local rates of tectonic deformation, and discriminate the deformation of the single fault segments that dissect the Peloritani range. Our findings are a direct test of landscape evolution models that predict higher rates of landslide activity near active faults. Our work opens up the possibility of exploiting accurate landslide and fault maps, in combination with geological and seismic information, to characterize the long-term seismic history of poorly instrumented active regions. Copyright © 2015 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Lt

    photo geology of the montefalco quaternary basin umbria central italy

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    ABSTRACTWe present a photo-geological map for the 185 km2 fault-bounded, Montefalco Basin, Umbria, Central Italy. The basin formed in the Quaternary in response to extensional tectonics dissecting folds and thrusts of the northern Apennines range. To prepare the 1:25,000 geological map, we integrated geological and morphological information obtained through the visual analysis of three sets of aerial photographs of different age, the collection of new field data, and the review of pre-existing surface and sub-surface geological data. We show that systematic interpretation of aerial photographs contributed to improving the geological mapping, providing information not readily available through traditional field mapping. We expect that the new map will be used for different types of geological and geomorphological investigations, including studies of active tectonic, Quaternary morpho-tectonics, sedimentological and stratigraphic analyses, mining and exploration investigations, and the analysis of landslide..

    Acquiring vulnerability indicators to geo-hydrological hazards: An example of mobile phone-based data collection

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    Abstract Geo-hydrological risk reduction is a key issue for local governments in Italy. In this context, a collaboration was undertaken between multiple actors in the La Spezia municipality aimed at: (i) monitoring building characteristics, using specific and valuable indicators, and (ii) increasing the knowledge of geo-hydrological hazards across residents and local land planners (iii) implementing local emergency civil protection plan. An extensive mobile data collection was carried out through apps specifically developed for Android and IOS mobile devices. The digital forms were differentiated on the basis of the potential hazard: one of 46 fields and one of 125 fields designed for buildings respectively located in flood prone areas and in medium to very high landslide susceptibility areas. The digital version of the forms was designed using the Open Data Kit (ODK) and GISCloud client-server approach. All the collected data, including geospatial locations and images, were automatically sent to a central server, stored and organized in a database. Geospatial data-analysis and maps resulted useful in evaluating possible impacts to exposed buildings to potential geo-hydrological processes. The proposed public participation method for data-gathering increased the knowledge across residents providing a better understanding of the urban systems, of the buildings condition and their relation respect to the geo-hydrological risk. The method can be considered as part of the decision support systems for civil protection purposes to better planning geo-hydrological mitigation measures. The application of mobile technology for data collection can be effectively used when local government resources are limited

    MRE11 inhibition highlights a replication stress-dependent vulnerability of MYCN-driven tumors

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    MRE11 is a component of the MRE11/RAD50/NBS1 (MRN) complex, whose activity is essential to control faithful DNA replication and to prevent accumulation of deleterious DNA double-strand breaks. In humans, hypomorphic mutations in these genes lead to DNA damage response (DDR)-defective and cancer-prone syndromes. Moreover, MRN complex dysfunction dramatically affects the nervous system, where MRE11 is required to restrain MYCN-dependent replication stress, during the rapid expansion of progenitor cells. MYCN activation, often due to genetic amplification, represents the driving oncogenic event for a number of human tumors, conferring bad prognosis and predicting very poor responses even to the most aggressive therapeutic protocols. This is prototypically exemplified by neuroblastoma, where MYCN amplification occurs in about 25% of the cases. Intriguingly, MRE11 is highly expressed and predicts bad prognosis in MYCN-amplified neuroblastoma. Due to the lack of direct means to target MYCN, we explored the possibility to trigger intolerable levels of replication stress-dependent DNA damage, by inhibiting MRE11 in MYCN-amplified preclinical models. Indeed, either MRE11 knockdown or its pharmacological inhibitor mirin induce accumulation of replication stress and DNA damage biomarkers in MYCN-amplified cells. The consequent DDR recruits p53 and promotes a p53-dependent cell death, as indicated by p53 loss- and gain-of-function experiments. Encapsulation of mirin in nanoparticles allowed its use on MYCN-amplified neuroblastoma xenografts in vivo, which resulted in a sharp impairment of tumor growth, associated with DDR activation, p53 accumulation, and cell death. Therefore, we propose that MRE11 inhibition might be an effective strategy to treat MYCN-amplified and p53 wild-type neuroblastoma, and suggest that targeting replication stress with appropriate tools should be further exploited to tackle MYCN-driven tumors

    Progress and verification of DTT ICRF antenna simulation using COMSOL

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    In this paper we present the extension of a full-wave FEM model (COMSOL®+MATLAB®) - initially developed to compute the electromagnetic field in presence of the anisotropic inhomogeneous plasma of the Electron Cyclotron Resonance Ion Sources (ECRISs) [1] – to the Ion Cyclotron Range of Frequency (ICRF). The model - based on the full non-uniform dielectric tensor in "cold plasma" approximation - has been employed to study antenna geometries of increasing complexity. Various antenna types have been analyzed, starting from single flat strap up to the two straps of an antenna option considered for the Divertor Tokamak Test facility (DTT) [2]. The results have been compared, cross-checked and validated with a simpler COMSOL-based tool [3] and with the TOPICA code [4]

    The tunable resonant IC antenna concept and its design for DTT experiment

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    The intrinsic poor loading of Ion Cyclotron (IC) plasma-facing antennas makes the use of Tuning and Matching Systems (TMSs) a necessity. The antenna plus TMS is a resonant system; in the TMS and access lines high voltages (tens of kV) must be accounted for in the unavoidable unmatched part of the feeding lines. In this work, we propose and test an innovative type of IC launcher; it is based on achieving resonance of the self-standing antenna, i.e. without the TMS. A mechanical full-metal tuning mechanism is described and demonstrated to allow wide-band operation. A systematic analysis of possible antenna topologies has led to identifying a structure that can allow good impedance matching along with compliance with maximum electric field constraints. Most of the design is carried out using a simplified plasma and a commercial analysis tool and then validated with a realistic plasma using TOPICA code

    Preliminary analysis of the ICRF launcher for DTT

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    The paper reports the preliminary analysis of different typologies of ICRH launchers for chosing the most efficient solution for the ICRH system of the Divertor Tokamak Test facility (DTT), designed by the Italian DTT Limited Liability Consortium (S.C. a r.l.). In its final configuration this system will couple to the DTT plasma a nominal power of 6 MW in the 60 – 90 MHz frequency range by means of four launchers. This very preliminary analysis has been done with the ANSYS HFSS code

    Skin dysbiosis and Cutibacterium acnes biofilm in inflammatory acne lesions of adolescents

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    Acne vulgaris is a common inflammatory disorder affecting more than 80% of young adolescents. Cutibacterium acnes plays a role in the pathogenesis of acne lesions, although the mechanisms are poorly understood. The study aimed to explore the microbiome at different skin sites in adolescent acne and the role of biofilm production in promoting the growth and persistence of C. acnes isolates. Microbiota analysis showed a significantly lower alpha diversity in inflammatory lesions (LA) than in non-inflammatory (NI) lesions of acne patients and healthy subjects (HS). Differences at the species level were driven by the overabundance of C. acnes on LA than NI and HS. The phylotype IA1 was more represented in the skin of acne patients than in HS. Genes involved in lipids transport and metabolism, as well as potential virulence factors associated with host-tissue colonization, were detected in all IA1 strains independently from the site of isolation. Additionally, the IA1 isolates were more efficient in early adhesion and biomass production than other phylotypes showing a significant increase in antibiotic tolerance. Overall, our data indicate that the site-specific dysbiosis in LA and colonization by virulent and highly tolerant C. acnes phylotypes may contribute to acne development in a part of the population, despite the universal carriage of the microorganism. Moreover, new antimicrobial agents, specifically targeting biofilm-forming C. acnes, may represent potential treatments to modulate the skin microbiota in acne

    Isolation of flavonoids and flavonoid glycosides from Myrsine africana and their inhibitory activities against mushroom tyrosinase

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    Bioassay-guided fractionation of the methanol extract of the shoots of Myrsine africana led to the isolation of the new compound myricetin 3-O-(2″,4″-di-O-acetyl)-α-l-rhamnopyranoside (9) and 11 known compounds. The known compounds quercetin 3-O-(3″,4″-di-O-acetyl)-α-l-rhamnopyranoside (8), rutin (10), quercetin 3-O-α-l-rhamnopyranoside (11), and myricetin 3-O-α-l-rhamnopyranoside (12) are reported for the first time from the methanol extract of the shoots of M. africana. Compounds 10 and 12 showed significant inhibition of tyrosinase with 50% inhibition (IC50 values) of the enzyme at 0.13 ± 0.003 and 0.12 ± 0.002 mM, respectively, which was supported by the docking fitness scores obtained through molecular docking analysis. In addition, compounds 1–12 displayed significant antioxidant activity with IC50 values ranging 1.90 to 3.90 μM.The University of Pretoria and the National Research Foundation.https://pubs.acs.org/journal/jnprdfhj2019Plant Production and Soil Scienc
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