4,014 research outputs found
Segnalazione di un orizzonte carbonatico nella Nurra Paleozoica e suo significato stratigrafico nelle successioni dell'Ercinico Sardo.
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I graniti peralluminosi sin-tettonici nell'area di Aggius-Trinità D'Agultu e loro rapporti con le metamorfiti di alto grado della Bassa Gallura (Sardegna Settentrionale).
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Isotopic ages of two contrasting tectono-metamorphic episodes in the Variscan Chain in Northern Sardinia.
No full textGeochemistry and Rb-Sr age of syn-tectonic peraluminous granites of Western Gallura, Northern Sardinia: constraints on their genesis. Mineral.
No full textImmigrants, schooling and background. Cross-country evidence from PISA 2006
No full textUsing data from PISA 2006, we examine the performance of immigrant students in different international educational environments. Our results show smaller immigrant gaps – differences in scores with respect to natives - where educational systems are more flexible and students’ mobility between courses and school programs is higher. Unlike previous studies, our analysis reveals no direct relation between these gaps and education models, be they comprehensive or tracking, adopted by countriesInternational migration; educational systems; PISA;
Transvenous removal of pacing and defibrillating leads: the pisa experience.
No full textIntroduction: Transvenous extraction of Pacing (PL) and Defibrillating Leads (DL) is today a highly effective technique. Device related complications are currently rising the need of Transvenous Lead Removal (TLR). Aim of this report is to analyse the longstanding experience performed in a single Italian Center.
Methods: since January 1997 to December 2010, we managed 1627 consecutive patients (1238 men, mean age 65.7 years, range 3-95) with 2914 leads (mean pacing period 70.2 months, range 1-420). PL were 2485 (1303 ventricular, 1011 atrial, 171 coronary sinus leads), DL were 429 (409 ventricular, 6 atrial, 14 superior vena cava leads). Indications to TLR were sepsis in in 28%, local infection in 55% and noninfectice indication in 17% of the leads. We performed mechanical dilatation using the Cook Vascular (Leechburg PA, USA) polypropylene sheaths and, if necessary, other intravascular tools (Catchers and Lassos, Osypka, Grentzig-Whylen, G); a Internal Trans-Jugular Approach (JA) through the internal jugular vein was performed in case of free-floating leads or failure of standard approach.
Results: Removal was attempted in 2906 leads because the technique was not applicable in 8 PL. Among these, 2852 leads (2423 PL, all the 429 DL) were completely removed (98.1%), 29 (1%) partially removed, 25 (0.9%) not removed. Among 2825 exposed leads, 434 were removed by manual traction (15.4%), 2117 by mechanical dilatation using the venous entry site (74.9%), 15 by femoral approach (FA) (0.5%) and 205 by JA (7.2%). All the free-floating leads were completely removed, 24.7% by FA and 75.3% by JA. Major complications occurred in 10 cases (0.61%): cardiac tamponade (9 cases, 2 deaths), hemotorax (1 death).
Conclusions: our experience shows that in centers provided with wide experience, TLR using mechanical dilation has a high success rate and a low incidence of serious complications. The use of the JA allows a very high effectiveness and safety in case of free-floating or difficult exposed leads
Deep learning of structural changes in historical buildings: the case study of the Pisa tower
No full textStructural health monitoring of buildings via agnostic approaches is a research challenge. However, due to the recent advent of pervasive multi-sensor systems, historical data samples are still limited. Consequently, datadriven methods are often unfeasible for long-term assessment. Nevertheless, some famous historical buildings have been subject to monitoring for decades, before the development of smart sensors and Deep Learning (DL). This paper presents a DL approach for the agnostic assessment of structural changes. The proposed approach has been experimented to the stabilizing intervention carried out in 2000-2002 on the leaning tower of Pisa (Italy). The data set is made by operational and environmental measures collected from 1993 to 2006. Both conventional and recent approaches are compared: Multiple Linear regression, LSTM and Tansformer. Experimental results are promising, and clearly shows a better change sensitivity of the LSTM, as well as a better modeling accuracy of the Transformer
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