16 resultados para Accademia di belle arti (Florence, Italy)

em Université de Lausanne, Switzerland


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Debris flow hazard modelling at medium (regional) scale has been subject of various studies in recent years. In this study, hazard zonation was carried out, incorporating information about debris flow initiation probability (spatial and temporal), and the delimitation of the potential runout areas. Debris flow hazard zonation was carried out in the area of the Consortium of Mountain Municipalities of Valtellina di Tirano (Central Alps, Italy). The complexity of the phenomenon, the scale of the study, the variability of local conditioning factors, and the lacking data limited the use of process-based models for the runout zone delimitation. Firstly, a map of hazard initiation probabilities was prepared for the study area, based on the available susceptibility zoning information, and the analysis of two sets of aerial photographs for the temporal probability estimation. Afterwards, the hazard initiation map was used as one of the inputs for an empirical GIS-based model (Flow-R), developed at the University of Lausanne (Switzerland). An estimation of the debris flow magnitude was neglected as the main aim of the analysis was to prepare a debris flow hazard map at medium scale. A digital elevation model, with a 10 m resolution, was used together with landuse, geology and debris flow hazard initiation maps as inputs of the Flow-R model to restrict potential areas within each hazard initiation probability class to locations where debris flows are most likely to initiate. Afterwards, runout areas were calculated using multiple flow direction and energy based algorithms. Maximum probable runout zones were calibrated using documented past events and aerial photographs. Finally, two debris flow hazard maps were prepared. The first simply delimits five hazard zones, while the second incorporates the information about debris flow spreading direction probabilities, showing areas more likely to be affected by future debris flows. Limitations of the modelling arise mainly from the models applied and analysis scale, which are neglecting local controlling factors of debris flow hazard. The presented approach of debris flow hazard analysis, associating automatic detection of the source areas and a simple assessment of the debris flow spreading, provided results for consequent hazard and risk studies. However, for the validation and transferability of the parameters and results to other study areas, more testing is needed.

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In this paper, we propose a new paradigm to carry outthe registration task with a dense deformation fieldderived from the optical flow model and the activecontour method. The proposed framework merges differenttasks such as segmentation, regularization, incorporationof prior knowledge and registration into a singleframework. The active contour model is at the core of ourframework even if it is used in a different way than thestandard approaches. Indeed, active contours are awell-known technique for image segmentation. Thistechnique consists in finding the curve which minimizesan energy functional designed to be minimal when thecurve has reached the object contours. That way, we getaccurate and smooth segmentation results. So far, theactive contour model has been used to segment objectslying in images from boundary-based, region-based orshape-based information. Our registration technique willprofit of all these families of active contours todetermine a dense deformation field defined on the wholeimage. A well-suited application of our model is theatlas registration in medical imaging which consists inautomatically delineating anatomical structures. Wepresent results on 2D synthetic images to show theperformances of our non rigid deformation field based ona natural registration term. We also present registrationresults on real 3D medical data with a large spaceoccupying tumor substantially deforming surroundingstructures, which constitutes a high challenging problem.

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The distinct core-to-rim zonation of different REEs in garnet in metamorphic rocks, specifically Sm relative to Lu, suggests that Sm-Nd and Lu-Hf isochron ages will record different times along a prograde garnet growth history. Therefore, REE zonations in garnet must be measured in order to correctly interpret the isochron ages in terms of the garnet growth interval, which could span several m.y. New REE profiles, garnet crystal size distributions, and garnet growth modeling, combined with previously published Sm-Nd and Lu-Hf geochronology on a UHP eclogite of the Zermatt-Saas Fee (ZSF) ophiolite, Lago di Cignana (Italy), demonstrate that prograde garnet growth of this sample occurred over a similar to 30 to 40 m.y. interval. Relative to peak metamorphism at 38 to 40 Ma, garnet growth is estimated to have begun at similar to 11 to 14 kbar pressure at similar to 70 to 80 Ma. Although such a protracted garnet growth interval is surprising, this is supported by plate tectonic reconstructions which suggest that subduction of the Liguro-Piemont ocean occurred through slow and oblique convergence. These results demonstrate that REE zonations in garnet, coupled to crystal size distributions, provide a powerful means for understanding prograde metamorphic paths when combined with Sm-Nd and Lu-Hf geochronology. (C) 2009 Elsevier B.V. All rights reserved.

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Aims and background. In 2002, a survey including 1759 patients treated from 1980 to 1998 established a "benchmark" Italian data source for prostate cancer radiotherapy. This report updates the previous one. Methods. Data on clinical management and outcomes of 3001 patients treated in 15 centers from 1999 through 2003 were analyzed and compared with those of the previous survey. Results. Significant differences in clinical management (-10% had abdominal ma-gnetic resonance imaging; +26% received ≥70 Gy, +48% conformal radiotherapy, -20% pelvic radiotherapy) and in G3-4 toxicity rates (-3.8%) were recorded. Actuarial 5-year overall, disease-specific, clinical relapse-free, and biochemical relapse-free survival rates were 88%, 96%, 96% and 88%, respectively. At multivariate analysis, D'Amico risk categories significantly impacted on all the outcomes; higher radiotherapy doses were significantly related with better overall survival rates, and a similar trend was evident for disease-specific and biochemical relapse-free survival; cumulative probability of 5-year late G1-4 toxicity was 24.8% and was significantly related to higher radiotherapy doses (P <0.001). Conclusions. The changing patterns of practice described seem related to an improvement in efficacy and safety of radiotherapy for prostate cancer. However, the impact of the new radiotherapy techniques should be prospectively evaluated.

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La tesi di Dottorato, condotta in accordo di colutela tra l'Università di Roma Tor Vergata e l'UNIL di Losanna, ha affrontato l'analisi di un gruppo di undici disegni custodia presso la National Gallery of Scotland di Edimburgo, copie di alcuni dei più significativi mosaici medioevali delle chiese di Roma, ricostruendone la genesi, quindi le vicende legate alla committenza, e il percorso collezionistico. I disegni scozzesi, oggetto di un importante articolo di Julian Gardner pubblicato sul Burlington Magatine nel 1973, furono commissionati intorno agli anni Settanta del XVII secolo dall'antiquario romano Giovanni Giustino Ciampini (1633-1698) in connessione alla stesura della sua opera di erudizione più avvertita e famosa: i Vetera Mommenta in' quibus praecipue Musiva Opera, sacrarum, profanan,mque, Aedìum structura, ac nonnulli antiqui ritus dissertationibus iconìbusque illustrantur. La composizione dei Vetera Mommenta - un'opera riccamente illustrata che nasce per rispondere alle esigenze della ideologia della Chiesa di Roma in un momento di rinnovata crisi del sistema - impone a Ciampini di porsi da un lato nella prospettiva della più alta tradizione antiquaria cinque e seicentesca, di cui recupera i metodi di lettura e di analisi applicati allo studio delle monete e dei monumenti antichi interpretati quali prove per la ricostruzione storica, e dall'altra, come è emerso dalle mie ricerche, lo pone immediatamente in contatto con gli avamposti del più moderno metodo di indagine storica e filologica applicato alle fonti e ai documenti della storia ecclesiastica, inaugurato dall'ambiente bollandista e inaurino. I monumenti paleocristiani e medioevali assumono in quest'ottica lo status di 'fatti incontestabili', le fonti primarie attraverso le quali Ciampini ricuce le tappe salienti della storia della Chiesa, da Costantino fino al XV secolo. Nel 1700 le copie di Edimburgo arrivano nelle mani del mercante e connoisseur milanese il padre oratoriano Sebastiano Resta (1635-1714), di stanza a Roma presso la Chiesa Nuova della Vallicella dal 1660, che decide di rilegarle tutte insieme in un volume da donare al suo maggiore acquirente e patrono, il vescovo di Arezzo Giovanni Matteo Marchetti. Come spiega Resta in alcune sue lettere, il presente avrebbe dovuto costituire insieme una curiosità ed offrire un confronto: infatti «le copie delli mosaici di Roma che erano di Monsignor Ciampini» - afferma Resta - avrebbero mostrato al Marchetti «le maniere di que' tempi gottici, barbari e divoti de cristiani e [fatto] spiccare i secoli seguenti». Questa indagine infatti ha fatto riemergere aspetti della precoce attenzione di Sebastiano Resta per l'arte dei "secoli bassi", mai debitamente affrontata dagli studi. E' infatti sulla scorta di una profonda conoscenza dei testi della letteratura artistica, e in connessione alla esplosione vivacissima della controversia Malvasia/Baldinucci sul primato del risorgere delle arti in Toscana, che Sebastiano a partire dagli anni Ottanta del Seicento comincia a meditare sul Medioevo artistico con il fine di spiegare l'evoluzione del linguaggio tecnico e formale che ha condotto alla perfezione dell'atte moderna. In questa prospettiva ι disegni del XIV e XV secolo che egli riuscì ad intercettare sul mercato valgono quali testimonianze delle maniere degli artefici più antichi e sono imbastiti nei molteplici album che Resta compone nel rispetto della successione cronologica dei presunti autori, e ordinati in base alle scuole pittoriche di pertinenza. La tesi permette perciò di descrivere nelle loro diverse specificità: da un lato il modo dei conoscitori come Resta, interessati nell'opera al dato stilistico, con immediate e sensibili ricadute sul mercato, e disposti anche con passione a ricercare i documenti relativi all'opera in quanto pressati dall'urgenza di collocarla nella sequenza cronologica dello sviluppo del linguaggio formale e tecnico; dall'altro gli antiquari come Ciampini e come Bianchini, per i quali le opere del passato valgono come prove irrefutabili della ricostruzione storica, e divengono quindi esse stesse, anche nel loro statuto di copia, documento della stona. Sono due approcci che si manifestano nel Seicento, e talvolta in una medesima persona, come mostra il caso anche per questo cruciale di Giovati Pietro Bellori, ma che hanno radici cinquecentesche, di cui i protagonisti di queste vicende sono ben consapevoli: e se dietro Resta c'è palesemente Vasari, dietro Ciampini e soprattutto Bianchini c'è la più alta tradizione antiquaria del XVI secolo, da Antonio Augustin a Fulvio Orsini.

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The eclogite facies assemblage K-feldspar-jadeite-quartz in metagranites and metapelites from the Sesia-Lanzo Zone (Western Alps, Italy) records the equilibration pressure by dilution of the reaction jadeite + quartz = albite. The metapelites show partial transformation from a pre-Alpine assemblage of garnet (Alm(63)Prp(26)Grs(10))-K-feldspar-plagioclase-biotite +/- sillimanite to the Eo-Alpine high-pressure assemblage garnet (Alm(50)Prp(14)Grs(35))-jadeite (Jd(80-97)Di(0-4)Hd(0-8)Acm(0-7))=zoisite-phengite. Plagioclase is replaced by jadeite-zoisite-kyanite-K-feldspar-quartz and biotite is replaced by garnet-phengite or omphacite-kyanite-phengite. Equilibrium was attained only in local domains in the metapelites and therefore the K-feldspar-jadeite-quartz (KJQ) barometer was applied only to the plagioclase pseudomorphs and K-feldspar domains. The albite content of K-feldspar ranges from 4 to 11 mol% in less equilibrated assemblages from Val Savenca and from 4 to 7 mol% in the partially equilibrated samples from Monte Mucrone and the equilibrated samples from Montestrutto and Tavagnasco. Thermodynamic calculations on the stability of the assemblage K-feldspar-jadeite-quartz using available mixing data for K-feldspar and pyroxene indicate pressures of 15-21 kbar (+/- 1.6-1.9 kbar) at 550 +/- 50 degrees C. This barometer yields direct pressure estimates in high-pressure rocks where pressures are seldom otherwise fixed, although it is sensitive to analytical precision and the choice of thermodynamic mixing model for K-feldspar. Moreover, the KJQ barometer is independent of the ratio P-H2O/P-T. The inferred limiting a(H2O) for the assemblage jadeite-kyanite in the metapelites from Val Savenca is low and varies from 0.2 to 0.6.

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This work presents geochemistry and structural geology data concerning the low enthalpy geothermal circuits of the Argentera crystalline Massif in northwestern Italian Alps. I n this area some thermal springs (50-60 degreesC), located in the small Bagni di Vinadio village, discharge mixtures made up of a Na-Cl end-member and a Na-SO4 component. The latter is also discharged by the thermal springs of Terme di Valdieri located some kilometres apart within the same tectonic complex. Both end-members share the same meteoric origin and the same reservoir temperature, which is close to 150 degreesC. Explanations are thus required to understand how they reach the surface and how waters of the same origin and circulating in similar rocks can attain such different compositions. Sodium-sulphate waters discharged at both sites, likely represent the common interaction product of meteoric waters with the widespread granitic-migmatitic rocks of the Argentera Massif, whereas Na-CI waters originate through leaching of mineralised cataclastic rocks, which are rich in phyllosilicatic minerals and fluid inclusions, both acting as Cl- sources. Due to the relatively low inferred geothermal gradient of the region, -25C/km, meteoric waters have to descend to depths of 5.5-6 km to attain temperatures of similar to 150 degreesC. These relevant depths can be reached by descending meteoric waters, due to the recent extensional stress field, which allows the development of geothermal circulations at greater depths than in other sectors of the Alps by favouring a greater fractures aperture. The ascent of the thermal waters rakes place along brittle shear zones. In both sites, the thermal waters emerge at the bottoms of the valleys, close to either the lateral termination of a brittle shear zone at Terme di Valdieri, or a step-over between two en-echelon brittle shear zones at Bagni di Vinadio. These observations attest to a strong control operated on the location of outlet regions by both brittle tectonics and the minima in hydraulic potential inside the fractured massif.