331 research outputs found

    Towards a Geological Information System: the CARGeo System and the Regione Lombardia Geological Database.

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    In the framework of the national mapping program «CARGNew Italian Geological Map at 1:50.000 scale», Regione Lombardia is generating a detailed map (1:10.000 scale) of its territory. Surveying criteria have been carefully defined in order to produce homogeneous geological maps: geological survey has been performed at the 1:10.000 scale, and data have been stored in a GIS-oriented database. The detailed survey scale improved the geological knowledge: the new maps represent an important tool for territorial planning requirements of public administrations and engineering geologists (e.g. in hydrogeological and seismic risk evaluation). Field geologists performed data input in the geological data base by alternating field campaigns and data input throughout the year, taking advantage of periods when field activities are slackened (i.e. according to climate conditions). In this way, data entry is nearly synchronous with data collection, and field data become quickly accessible. Data entry by the field geologists on one side slows down the field activity, however, it guarantees a precise digitalization of geometric data and a correct attribute assignment, allowing to optimize working time. To allow the data entry to non-GIS-specialized users, we developed an ArcView®-VisualBasic®-MSAccess® application, enabling the simultaneous acquisition of geometric and alphanumeric data. Data base management and cartographic production are performed with ArcInfo®, through specific procedures which, after data reorganization and control (both alphanumeric and geometric), lead to the final cartographic output at different scales. The 1:10.000 geological database is migrated in the ArcSDE structure and prepared for data view, query and download (www.cartografia.regione.lombardia.it/cargweb) using ESRI (ArcIMS) tools. From the 1:10.000 geological database we derived the database for the 1:50.000 CARG maps by both automatic and manual generalization according to the CARG-APAT standards. During the different phases of the project, several problems arose, due to both project organization and data storage system (from data collection in the field to elaboration and digitalization, and, in case, to final publication). – Data collection: the survey activity was divided between «bedrock » and «quaternary» specialists. The double survey provided a high-quality geological description of the territory, but slowed the generation of the data-flow. Based on this experience, the last assigned areas are surveyed by a single geologist, under the supervision of quaternary and bedrock experts. – Users feedback: geologists are normally used to draw their maps on paper; learning how to produce electronic maps can be difficult, and the software tools have to be studied very carefully and present user friendly interfaces. Nevertheless, in our experience, a training period has to be planned, and geologists have to be supported by a GIS expert, who can understand their needs and modify the software accordingly. – System architecture: the ArcView®-VisualBasic®-MSAccess® (Windows platform) – ArcInfo® (UNIX platform) environment, revealed problems in the client-server stability of an earlier version; some unsolved troubles remain, mainly related to the network architecture. The presence in the CARG-Regione Lombardia crew of consultant geologists, experienced and trained in collection, analysis and data entry in the final database, accelerated the critical phases of: – Data base derivation from Regione Lombardia dataset to CARG-APAT standard

    Impact of routine videothoracoscopy as the first step of the planned resectiona for lung cancer. Experience of 1306 cases

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    We have analyzed our experience of 1306 patients with NSCLC, submitted from November 1991 to December 2007 to routine videothoracoscopy exploration, as the first step of the planned procedure, in order to evaluate its validity in obtaining precise assessment of tumor extension, verifying thoracoscopic resectability and in decreasing the rate of unnecessary thoracotomies. Thoracoscopy revealed inoperability in 58 patients (4.4%) mostly due to pleural dissemination (2.4%) or mediastinal infiltration (1.7%). Of the remaining 1248 (95.6%), 449 (34.4%) had thoracoscopic resection (230 lobectomies, 6 pneumonectomies, 230 wedge resections), 767 (58.7%) underwent open resection (592 lobectomies, 175 pneumonectomies), and 32 (2.4%) had an exploratory thoracotomy (ET). Among the 32 ETs, thoracoscopy had suspected unresectability in 7 (0.5%), had been incompletely carried out in 4 early cases (0.3%) and had been unfeasible in 21 (1.6%). In our previous series from 1980 to 1991 the E.T. rate had been 11.6%. In the present series, after the introduction of routine thoracoscopy, the E.T. rate is 2.4% and the global rate of patients correctly staged, by thoracoscopy is 73.3%, significantly better than by CT. Video exploration resulted highly reliable in excluding conditions of unresectability with a negative predictive value (NPV) of 0.97. We conclude that preliminary thoracoscopy is useful in obtaining correct staging, reliably evaluates resectability of the lesion and helps in decreasing unnecessary thoracotomies

    Routine surgical videothoracoscopy as the first step of the planned resection for lung cancer

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    Objectives Notwithstanding preoperative staging, a number of procedures still end in an exploratory thoracotomy as a result of unexpected findings. The aim of this work is to evaluate the validity of routine videothoracoscopy, performed as the first step of every planned resection for non–small cell lung cancer, to assess tumor resectability and feasibility of the resection through thoracoscopy. Methods and Results From November 1991 to December 2007, in our department, 1306 patients with non–small cell lung cancer, judged operable at conventional staging, underwent videothoracoscopy before the operation. Thoracoscopy revealed inoperability in 58 (4.4%) patients, mostly owing to pleural dissemination (2.5%) or mediastinal infiltration (1.7%). In the remaining 1248 (95.6%), thoracoscopy did not reveal inoperability. Of these, 449 (34.4%) underwent thoracoscopic resection. The other 799 (61.2%) underwent thoracotomy: 767 underwent resection, but 32 (2.5%) had an exploratory thoracotomy. Thoracoscopy had suggested unresectability in 7 (0.5%) patients, had been incompletely carried out in 4 (0.3%), and was unfeasible in 21 (1.6%) owing to insurmountable technical reasons. In our previous series from 1980 to 1991 the exploratory thoracotomy rate had been 11.6%. In the present series, after the introduction of routine thoracoscopy in the staging process, the exploratory thoracotomy rate was 2.5%. Thoracoscopy was reliable in excluding unresectability (negative predictive value 0.97). The global percentage of correct staging was significantly better (P < .0001) by thoracoscopy (73.3%) than by computed tomography (48.7%). Considering T descriptor, video-assisted thoracic surgery correctly matched with final pathologic staging in 96.2% of patients. Conclusions Routine preliminary videothoracoscopy ensured assessment of tumor resectability and feasibility of the resection through thoracoscopy and limited unnecessary thoracotomies

    Recurring flood distribution patterns related to short-term Holocene climatic variability

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    Received: 01 July 2015, Accepted: 08 October 2015, Published online: 09 November 2015Millennial- and multi-centennial scale climate variability during the Holocene has been well documented, but its impact on the distribution and timing of extreme river floods has yet to be established. Here we present a meta-analysis of more than 2000 radiometrically dated flood units to reconstruct centennial-scale Holocene flood episodes in Europe and North Africa. Our data analysis shows a general increase in flood frequency after 5000 cal. yr BP consistent with a weakening in zonal circulation over the second half of the Holocene, and with an increase in winter insolation. Multi-centennial length phases of flooding in UK and central Europe correspond with periods of minimum solar irradiance, with a clear trend of increasing flood frequency over the last 1000 years. Western Mediterranean regions show synchrony of flood episodes associated with negative phases of the North Atlantic Oscillation that are out-of-phase with those evident within the eastern Mediterranean. This long-term flood record reveals complex but geographically highly interconnected climate-flood relationships, and provides a new framework to understand likely future spatial changes of flood frequency.GB was funded by the Spanish Ministry of Economy and Competitiveness through the research projects CLARIES (CGL2011–29176), and PALEOMED (CGL2014–58127-C3-1-R).Peer reviewe

    Large well-relaxed models of vitreous silica, coordination numbers and entropy

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    A Monte Carlo method is presented for the simulation of vitreous silica. Well-relaxed networks of vitreous silica are generated containing up to 300,000 atoms. The resulting networks, quenched under the BKS potential, display smaller bond-angle variations and lower defect concentrations, as compared to networks generated with molecular dynamics. The total correlation functions T(r) of our networks are in excellent agreement with neutron scattering data, provided that thermal effects and the maximum inverse wavelength used in the experiment are included in the comparison. A procedure commonly used in experiments to obtain coordination numbers from scattering data is to fit peaks in rT(r) with a gaussian. We show that this procedure can easily produce incorrect results. Finally, we estimate the configurational entropy of vitreous silica.Comment: 7 pages, 4 figures (two column version to save paper

    Polyhedral units and network connectivity in calcium aluminosilicate glasses from high-energy x-ray diffraction

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    Structure factors for Cax/2AlxSi1-xO2 glasses (x=0,0.25,0.5,0.67) extended to a wave vector of magnitude Q= 40 1/A have been obtained by high-energy x-ray diffraction. For the first time, it is possible to resolve the contributions of Si-O, Al-O and Ca-O coordination polyhedra to the experimental atomic pair distribution functions (PDF). It has been found that both Si and Al are four-fold coordinated and so participate in a continuous tetrahedral network at low values of x. The number of network breaking defects in the form of non-bridging oxygens (NBO's) increases slowly with x until x=0.5 (NBO's ~ 10% at x=0.5). By x=0.67 the network breaking defects become significant as evidenced by the significant drop in the average coordination number of Si. By contrast, Al-O tetrahedra remain free of NBO's and fully integrated in the Al/Si-O network for all values of x. Calcium maintains a rather uniform coordination sphere of approximately 5 oxygen atoms for all values of x. The results suggest that not only Si/Al-O tetrahedra but Ca-O polyhedra, too, play a role in determining the glassy structure

    LEARNING FROM THE PAST TO FACE THE FUTURE: LANDSLIDES IN THE PIAVE VALLEY (EASTERN ALPS, ITALY)

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    Landslides are a critical process in landscape evolution and may pose a serious threat to people and infrastructure. In the last decades, a growing interest in such phenomena has developed in the Alps, where narrow valleys are increasingly in\uachabited, and landslides have caused several casualties. Understanding the driving factors, triggers, evolution, and impact of past and future failures is of the utmost importance when dealing with land use and risk reduction. In this paper, four distinct case stud\uacies are presented, showing how different approaches can interact and produce a comprehensive understanding of a landslide event. All examples lie in the middle sector of the Piave Valley (NE Italy) and deal with failures that occurred in the distant past (i.e., the historic Masiere di Vedana rock avalanche), in the near past (i.e., the 1963 Vajont event), in the present (i.e., the 60-years -lasting Tessina landslide) and in the future (i.e., possible Mt. Peron instabilities). The final goal of the paper is to show how the understanding of past landslides is fundamental to obtain reliable predictions on future failures, and how modelling designed to predict the evolution of potential detachments can be applied to understand the dynamics of ancient events

    Towards a map of the Upper Pleistocene loess of the Po Plain Loess Basin (Northern Italy)

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    Upper Pleistocene (MIS 4-2) loess sequences occur in most of continental Europe and in Northern Italy along the Po Plain Loess Basin. Loess is distributed along the flanks of the Po Plain and was deposited on glacial deposits, fluvial terraces, uplifted isolated hills, karst plateaus, slopes and basins of secondary valleys. Loess bodies are generally tiny and affected by pedogenesis, being locally slightly reworked by slope processes and bioturbation. Notwithstanding, loess in the Po Plain is an important archive of paleoenviron-mental record and its mapping provides new insights in paleoenvironmental and palaeoseismic reconstructions of Northern Italy
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