173 research outputs found

    Point source estimation via finite element multiple-model Kalman filtering

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    Distributed finite element Kalman filter

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    Holocene climate variability of the Western Mediterranean: surface water dynamics inferred from calcareous plankton assemblages

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    A high-resolution study (centennial scale) has been performed on the calcareous plankton assemblage of the Holocene portion of the Ocean Drilling Program Site 976 (Alboran Sea) with the aim to identify the main changes in the surface water dynamic. The dataset also provided a seasonal foraminiferal sea surface water temperatures (SSTs), estimated using the modern analog technique SIMMAX 28, and it was compared with available geochemical and pollen data at the site. Three main climate shifts were identified as (1) the increase in abundance of Syracosphaera spp. and Turborotalita quinqueloba marks the early Holocene humid phase, during maximum summer insolation and enhanced river runoff. It is concomitant with the expansion of Quercus, supporting high humidity on land. It ends at 8.2 ka, registering a sudden temperature and humidity reduction; (2) the rise in the abundances of Florisphaera profunda and Globorotalia inflata, at ca. 8 ka, indicates the development of the modern geostrophic front, gyre circulation, and of a deep nutricline following the sea-level rise; and (3) the increase of small Gephyrocapsa and Globigerina bulloides at 5.3 ka suggests enhanced nutrient availability in surface waters, related to more persistent wind-induced upwelling conditions. Relatively higher winter SST in the last 3.5 ka favored the increase of Trilobatus sacculifer, likely connected to more stable surface water conditions. Over the main trends, a short-term cyclicity is registered in coccolithophore productivity during the last 8 ka. Short periods of increased productivity are in phase with Atlantic waters inflow, and more arid intervals on land. This cyclicity has been related with periods of positive North Atlantic Oscillation (NAO) circulations. Spectral analysis on coccolithophore productivity confirms the occurrence of millennial-scale cyclicity, suggesting an external (i.e. solar) and an internal (i.e. atmospheric/oceanic) forcing.Geoscience PhD scholarship, Universita degli Studi di BariPotenziamento Strutturale dell'Universita degli Studi di Bari, Laboratorio per lo Sviluppo Integrato delle Scienze e delle Tecnologie dei Materiali Avanzati e per dispositivi innovativi (SISTEMA) [PONa3_00369]Fundacao para a Ciencia e a Tecnologia (FCT)Portuguese Foundation for Science and TechnologyEuropean Commission [SFRH/BPD/111433/2015]info:eu-repo/semantics/submittedVersio

    MASW Terra-Mare, applicazione a Taranto per il Progetto Beleolico

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    Per una caratterizzazione sismica del sottosuolo presso la spiaggia dell’insediamento residenziale di "Lido Azzurro” (TA), area interessata alla realizzazione di un parco eolico “near-shore”, l'IAMC ha effettuato uno stendimento sismico del tipo terra-mare con metodologia MASW per la determinazione del profilo verticale delle onde di taglio e del valore Vs30, in riferimento tra l’altro alla classificazione dei terreni di fondazione degli interventi in progetto nelle categorie di suolo, come da paragrafo 3.2.2 delle N.T.C. 2008 “D.M. 14/01/2008”

    Buried volcanic structures in the Gulf of Naples (Southern Tyrrhenian Sea, Italy) resulting from high resolution magnetic survey and seismic profiling

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    In this paper we present a correlation between volcanic structures and magnetic anomalies in the Gulf of Naples (Southern Tyrrhenian Sea) based on high resolution magnetic profiling. A densely spaced grid of magnetic profiles coupled with multichannel seismics (seismic source Watergun 15 cubic inch) was recorded in the Gulf of Naples, representing an active volcanic area during the Late Quaternary (volcanic centers of Somma-Vesuvius, Phlegraean Fields and Ischia and Procida islands). The dataset was collected during the oceanographic cruise GMS00-05 which took place during October-November 2000 in the South Tyrrhenian Sea onboard of the R/V Urania (National Research Council, Italy). Shallow volcanic structures in the subsurface of the gulf were recognized by seismo-stratigraphic analysis of high resolution profiles; the volcanic nature of some of these structures was inferred identifying the magnetic anomalies on a high resolution magnetic anomaly map of the gulf. Even if qualitative, the correlations between seismic and magnetic profiles allow us to better assess the geological structure of the Gulf of Naples

    Stopping Smoking Reduces Mortality in Low-Dose Computed Tomography Screening Participants

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    Abstract Introduction The National Lung Screening Trial has achieved a 7% reduction in total mortality with low-dose computed tomography (LDCT) screening as compared with in the chest radiography arm. Other randomized trials are under way, comparing LDCT screening with no intervention. None of these studies was designed to investigate the impact of smoking habits on screening outcome. In the present study, we tested the effect of stopping smoking on the overall mortality of participants undergoing repeated LDCT screening for many years. Methods Between 2000 and 2010, 3381 smokers aged 50 years or older were enrolled in two LDCT screening programs. On the basis of the last follow-up information, subjects were divided into two groups: current smokers throughout the screening period and former smokers. Results With a median follow-up time of 9.7 years and a total of 32,857 person-years (PYs) of follow-up, a total of 151 deaths were observed in the group of 1797 current smokers (17,846 PYs) versus 109 among 1584 former smokers (15,011 PYs), corresponding to mortality rates of 8.46 and 7.26 for every 1000 PYs, respectively. Compared with current smokers, former smokers had an adjusted mortality hazard ratio of 0.61 (95% confidence interval: 0.44–0.83), with a 39% reduction in mortality. A similar reduction in mortality was observed in the subset of 712 late quitters, with a hazard ratio of 0.65 (95% confidence interval: 0.44–0.96). Conclusions Stopping smoking significantly reduces the overall mortality of smokers enrolled in LDCT screening programs. The beneficial effect of stopping smoking on total mortality appears to be threefold to fivefold greater than the one achieved by earlier detection in the National Lung Screening Trial
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