588 research outputs found

    A geomatic approach for emergency mapping of shallow landslides

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    Nel presente contributo viene proposto un approccio geomatico per mappare e caratterizzare dal punto di vista geomorfologico i fenomeni franosi superficiali in situazioni di emergenza. Il metodo è stato applicato durante il rilevamento di una frana che il 27/10/2013 ha interessato la falesia costiera della località "Baia dei Porci", nel Comune di Monte di Procida, in provincia di Napoli. Durante il rilevamento, eseguito parzialmente da barca, sono state scattate 95 foto successivamente elaborate con il software Agisoft PhotoScanTM. Il prodotto ottenuto dall'elaborazione è stato un modello digitale 3D della frana (DEM), georeferenziato nel sistema UTM 33N-WGS84. Dall'elaborazione del DEM eseguita in ESRI ArcGisTM è stato possibile ottenere la carta topografica della frana in scala 1:500, la carta delle pendenze, l'area delle zone di distacco e di deposito ed il volume del materiale franato. Visti i risultati ottenuti si ritiene che l'approccio proposto sia idoneo per essere applicato in situazioni di emergenza provocate da frane superficiali, a supporto delle autorità di Protezione Civile

    Pressure-induced unconventional superconductivity near a quantum critical point in CaFe2As2

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    75As-zero-field nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements are performed on CaFe2As2 under pressure. At P = 4.7 and 10.8 kbar, the temperature dependences of nuclear-spin-lattice relaxation rate (1/T1) measured in the tetragonal phase show no coherence peak just below Tc(P) and decrease with decreasing temperature. The superconductivity is gapless at P = 4.7 kbar but evolves to that with multiple gaps at P = 10.8 kbar. We find that the superconductivity appears near a quantum critical point under pressures in the range 4.7 kbar < P < 10.8 kbar. Both electron correlation and superconductivity disappear in the collapsed tetragonal phase. A systematic study under pressure indicates that electron correlations play a vital role in forming Cooper pairs in this compound.Comment: 5pages, 5figure

    Clues of wildfire-induced geotechnical changes in volcanic soils affected by post-fire slope instabilities

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    Wildfires can significantly affect mountain hillslopes through the combustion of trees and shrubs and changes in soil properties. The type and magnitude of the associated post-fire effects depend on several factors, including fire severity and soil physical-mechanical-hydraulic features that, coupled with climate and topographic conditions, may cause increased runoff, erosion, and slope instability as consequence of intense rainfall. The post-fire response of slopes is highly site-specific. Therefore, in situ surveys and laboratory tests are needed to quantify changes in key soil parameters. The present study documents the post-fire physical and hydromechanical properties of pyroclastic topsoil collected from three test sites that suffered wildfires and rainfall-induced post-fire events in 2019 and 2020 in the Sarno Mountains (Campania Region, southern Italy). The tested pyroclastic soils in burned conditions show (i) no significant changes in grain size distribution, soil organic matter, and specific gravity; (ii) a deterioration in shear strength in terms of decreased soil cohesion caused by the fire-induced weakening of root systems; and (iii) a decrease in hydraulic conductivity. Accordingly, it can be argued that the documented post-fire erosion responses were mainly caused by the reduced cohesion and hydraulic conductivity of the burned topsoil layer, as well as by the loss of vegetation cover and the deposition of fire residues. Although deserving further deepening, this study can represent the necessary background for understanding the initiation mechanism of post-fire erosion processes in the analyzed area and on several natural slopes under similar conditions

    High number of circulating CD34+ cells in patients with myelophthisis.

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    Hematopoietic Stem Cells High number of circulating CD34+ cells in patients with myelophthisis Six patients with bone marrow micrometastases from solid cancers presented with increased numbers of circulating CD34+ cells; the CD34+ cell counts were very high in some cases. By contrast, no patient with metastatic cancer without bone marrow involvement showed raised numbers of circulating hemopoietic progenitors. haematologica 2005; 90:976-977 (http:/

    Sea-level rise impact and future scenarios of inundation risk along the coastal plains in Campania (Italy)

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    Sea-level rise as a consequence of global warming increases the need to analyze coastal risks to conceive adaptation strategies aimed at coping with marine impacts at both short- and long-term scales. In this context, this study presents future scenarios of inundation risk evaluated along the main alluvial coastal plains of the Campania region (Italy). Due to their geomorphological and stratigraphical setting, the investigated areas are characterized by low topography and relevant but variable subsidence rates. Based on the upgrade of already published data and the new analysis of available datasets derived by multi-temporal interferometric processing of satellite Synthetic Aperture Radar (SAR) images, future scenarios of local sea level for the years 2065 and 2100 have been evaluated coupling global projections with local subsidence trends. Furthermore, aspects related with the distribution of natural and anthropic assets, as well as the local social vulnerability, have been taken into account to calculate the overall risk. The inundation risk maps here proposed can effectively address the request to improve the knowledge of policymakers and local administrators and to raise their awareness about the potential impacts of climate change in coastal areas

    Analisi del campo di deformazione superficiale della Regione Campania da dati SAR (PS-InSAR)

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    Il lavoro presenta un’applicazione della tecnica dei diffusori permanenti (Permanent Scatterers) finalizzata alla caratterizzazione del campo di deformazione superficiale della Regione Campania. Per effettuare l’analisi sono state processate, tramite la tecnica PS-InSARTM, 1078 scene SAR ERS1 ed ERS2 relative al periodo giugno 1992 - gennaio 2001. Sulla base della velocità media annua di spostamento di 1.691.740 PS con coerenza maggiore di 0.65 sono state prodotte mappe di velocità media di deformazione mediante l’utilizzo di una procedura articolata nei seguenti punti: a) filtraggio dei dati effettuato sulla base dei valori di coerenza; b) produzione di mappe di velocità media di deformazione in coordinate SAR; c) generazione di mappe di velocità media di deformazione secondo le componenti verticale ed Est-Ovest; d) validazione di risultati mediante confronto con dati prodotti con differenti metodiche d’indagine. L’analisi dei risultati ottenuti ha consentito di identificare aree caratterizzate da distinti stili deformativi. Aree in subsidenza sono risultate essere, per il periodo di interesse, oltre all’area vulcanica dei Campi Flegrei, le aree costiere dei bacini dei fiumi Volturno e Sele ed il settore centrale dell’isola d’Ischia. Aree con significativi valori di sollevamento sono localizzate nel settore settentrionale del Monte Somma, nel settore centrale della Piana Campana, nel Sannio e nel Cilento. Significativi valori di velocità di spostamento in direzione EW si riscontrano, oltre che nell’area dei Campi Flegrei, nel settore appenninico del bacino del Sele e nell’area interposta tra il Somma-Vesuvio e la catena appenninica. Il quadro deformativo globale risulta essere caratterizzato da un andamento complesso, governato da una molteplicità di processi di differente natura (tettonici, vulcano-tettonici, esogeni ed antropici)

    Continuity of Local Time: An applied perspective

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    Continuity of local time for Brownian motion ranks among the most notable mathematical results in the theory of stochastic processes. This article addresses its implications from the point of view of applications. In particular an extension of previous results on an explicit role of continuity of (natural) local time is obtained for applications to recent classes of problems in physics, biology and finance involving discontinuities in a dispersion coefficient. The main theorem and its corollary provide physical principles that relate macro scale continuity of deterministic quantities to micro scale continuity of the (stochastic) local time.Comment: To appear in: "The fascination of Probability, Statistics and Their Applications. In honour of Ole E. Barndorff-Nielsen on his 80th birthday

    Prognostic role of amenorrhea induced by adjuvant chemotherapy in premenopausal patients with early breast cancer.

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    The prognostic role of drug-induced amenorrhea (DIA) was restrospectively evaluated in 221 out of 254 consecutive premenopausal patients treated with adjuvant CMF or a CMF-containing regimen; 33 patients were eliminated because of lack of menstrual data. All patients had metastatic axillary nodes; drug regimens were: CMF x 9 courses +/- Tamoxifen (TM) and CMF x 6 courses; median age was 43 (range 26-54). Premenopausal status was defined as last normal menses within the 6 weeks preceding initiation of chemotherapy: DIA as cessation of menses for at least 3 months not later than 3 months from the end of chemotherapy. DIA occurred in 166,221 (75.1%) patients and was strictly related to the age of the patients; also, the older the patients the shorter the time required to develop DIA. At median follow up of 69 months, Mantel-Byar analysis showed a longer disease free survival (DFS) for patients who developed DIA as compared with non amenorrheic women (P less than 0.001). DIA prognostic value was independent of age, number of involved nodes, tumour size and number of CMF cycles, as assessed by the Cox model (RH 0.43, 95% C.I. 0.24-0.77), in which DIA was entered as a time dependent covariate
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