Bassano – Venedig – Rom: "Il dolce intaglio di Volpato"

L'incisore Giovanni Volpato (1735 ca.-1803), allievo di Francesco Bartolozzi a Venezia e trasferitosi nel 1770 a Roma era un incisore che serviva due campi tra di loro molto diversi – da una parte era un'abile e fertile incisore di un genere di stampe che attingeva al genere popolare e al paesaggio di gusto veneziano ma la sua attività maggiormente notata si riferiva al repertorio classico di tradizione romano – riproducendo le opere di Raffaello, Michelangelo, degli Carracci e della loro scuola. La maggior fama del Volpato deriva soprattutto dalle 46 tavole che trasse dalle Logge di Raffaello pubblicate tra 1776 e 1777 delle quali esistono anche esemplari colorati a mano e che hanno profondamente influenzato il gusto della decorazione degli interni in tutta l'Europa oltre il 1800. Alessandro Verri nel 1776 scrisse a suo fratello Pietro a proposito di questa pubblicazione: "Dopo che si sono stampate in Roma le Loggie del Vaticano tutto ha cambiato di gusto. Le carrozze, i muri, gli intagli, le argenterie hanno preso gli ornamenti di quel fonte perenne di ogni varietà." La collaborazione con Gavin Hamilton per la Scholae Italia Picturae e le riproduzioni della Galleria Farnese e della Cappella Sistina come anche del Museo Pio Clementino e delle statue antiche in un repertorio per artisti rivelano il suo interesse per la formazione artistica. In un certo senso si può dire che Volpato era la contropparte di Piranesi e che ambedue effettuavano una precisa e ben meditata divisione dei compiti e di generi e interessi che comunque era al servizio del pubblico turistico che in numero crescente prendeva Roma come meta di viaggi e d'istruzione culturale e si serviva delle incisioni di facile portata di mano. L'importanza delle incisioni come merce di facile trasporto e diffusione è stata per la prima volta riconosciuta da Luigi Lanzi quando definì il Settecento "secolo di rame".

Climate spectrum estimation in the presence of timescale errors

We introduce an algorithm (called REDFITmc2) for spectrum estimation in the presence of timescale errors. It is based on the Lomb-Scargle periodogram for unevenly spaced time series, in combination with the Welch's Overlapped Segment Averaging procedure, bootstrap bias correction and persistence estimation. The timescale errors are modelled parametrically and included in the simulations for determining (1) the upper levels of the spectrum of the red-noise AR(1) alternative and (2) the uncertainty of the frequency of a spectral peak. Application of REDFITmc2 to ice core and stalagmite records of palaeoclimate allowed a more realistic evaluation of spectral peaks than when ignoring this source of uncertainty. The results support qualitatively the intuition that stronger effects on the spectrum estimate (decreased detectability and increased frequency uncertainty) occur for higher frequencies. The surplus information brought by algorithm REDFITmc2 is that those effects are quantified. Regarding timescale construction, not only the fixpoints, dating errors and the functional form of the age-depth model play a role. Also the joint distribution of all time points (serial correlation, stratigraphic order) determines spectrum estimation.

Spin ladders and quantum simulators for Tomonaga–Luttinger liquids

Magnetic insulators have proven to be usable as quantum simulators for itinerant interacting quantum systems. In particular the compound (C5H12N)2CuBr4 (for short: (Hpip)2CuBr4) was shown to be a remarkable realization of a Tomonaga–Luttinger liquid (TLL) and allowed us to quantitatively test the TLL theory. Substitution weakly disorders this class of compounds and thus allows us to use them to tackle questions pertaining to the effect of disorder in TLL as well, such as that of the formation of the Bose glass. In this paper we present, as a first step in this direction, a study of the properties of the related (Hpip)2CuCl4 compound. We determine the exchange couplings and compute the temperature and magnetic field dependence of the specific heat, using a finite temperature density matrix renormalization group procedure. Comparison with the measured specific heat at zero magnetic field confirms the exchange parameters and Hamiltonian for the (Hpip)2CuCl4 compound, giving the basis needed to begin studying the disorder effects.

Different Prognostic Value of Functional Right Ventricular Parameters in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

BACKGROUND -The value of standard two-dimensional transthoracic echocardiographic (TTE) parameters for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is controversial. METHODS AND RESULTS -We investigated the impact of right ventricular fractional area change (FAC) and tricuspid annulus plane systolic excursion (TAPSE) for prediction of major adverse cardiovascular events (MACE) defined as the occurrence of cardiac death, heart transplantation, survived sudden cardiac death, ventricular fibrillation, sustained ventricular tachycardia or arrhythmogenic syncope. Among 70 patients who fulfilled the 2010 ARVC/D Task Force Criteria and underwent baseline TTE, 37 (53%) patients experienced a MACE during a median follow-up period of 5.3 (IQR 1.8-9.8) years. Average values for FAC, TAPSE, and TAPSE indexed to body surface area (BSA) decreased over time (p=0.03 for FAC, p=0.03 for TAPSE and p=0.01 for TAPSE/BSA, each vs. baseline). In contrast, median right ventricular end-diastolic area (RVEDA) increased (p=0.001 vs. baseline). Based on the results of Kaplan-Meier estimates, the time between baseline TTE and experiencing MACE was significantly shorter for patients with FAC <23% (p<0.001), TAPSE <17mm (p=0.02) or right atrial (RA) short axis/BSA ≥25mm/m(2) (p=0.04) at baseline. A reduced FAC constituted the strongest predictor of MACE (hazard ratio 1.08 per 1% decrease; 95% confidence interval 1.04-1.12; p<0.001) on bivariable analysis. CONCLUSIONS -This long-term observational study indicates that TAPSE and dilation of right-sided cardiac chambers are associated with an increased risk for MACE in ARVC/D patients with advanced disease and a high risk for adverse events. However, FAC is the strongest echocardiographic predictor of adverse outcome in these patients. Our data advocate a role for TTE in risk stratification in patients with ARVC/D, although our results may not be generalizable to lower risk ARVC/D cohorts.

Usefulness of inducible ventricular tachycardia to predict long-term adverse outcomes in arrhythmogenic right ventricular cardiomyopathy

The role of the electrophysiologic (EP) study for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy is controversial. We investigated the role of inducible sustained monomorphic ventricular tachycardia (SMVT) for the prediction of an adverse outcome (AO), defined as the occurrence of cardiac death, heart transplantation, sudden cardiac death, ventricular fibrillation, ventricular tachycardia with hemodynamic compromise or syncope. Of 62 patients who fulfilled the 2010 Arrhythmogenic Right Ventricular Cardiomyopathy Task Force criteria and underwent an EP study, 30 (48%) experienced an adverse outcome during a median follow-up of 9.8 years. SMVT was inducible in 34 patients (55%), 22 (65%) of whom had an adverse outcome. In contrast, in 28 patients without inducible SMVT, 8 (29%) had an adverse outcome. Kaplan-Meier analysis showed an event-free survival benefit for patients without inducible SMVT (log-rank p = 0.008) with a cumulative survival free of an adverse outcome of 72% (95% confidence interval [CI] 56% to 92%) in the group without inducible SMVT compared to 26% (95% CI 14% to 50%) in the other group after 10 years. The inducibility of SMVT during the EP study (hazard ratio [HR] 2.99, 95% CI 1.23 to 7.27), nonadherence (HR 2.74, 95% CI 1.3 to 5.77), and heart failure New York Heart Association functional class II and III (HR 2.25, 95% CI 1.04 to 4.87) were associated with an adverse outcome on univariate Cox regression analysis. The inducibility of SMVT (HR 2.52, 95% CI 1.03 to 6.16, p = 0.043) and nonadherence (HR 2.34, 95% CI 1.1 to 4.99, p = 0.028) remained as significant predictors on multivariate analysis. This long-term observational data suggest that SMVT inducibility during EP study might predict an adverse outcome in patients with arrhythmogenic right ventricular cardiomyopathy, advocating a role for EP study in risk stratification.

Radiofrequency ablation of multiple accessory pathways

The aim of the study was to review the clinical and electrophysiological characteristics and results of radiofrequency catheter ablation in patients with multiple accessory pathways to compare them with those of patients with single accessory pathways. Electrophysiological study and radiofrequency catheter ablation were performed in 1010 consecutive cases with Wolff Parkinson White Syndrome. Presence of multiple accessory pathways was documented in 31 patients (3.1%); 30 had two, and 1 had three accessory pathways. Of the 63 accessory pathways, 42 were manifest and 21 concealed. Nine patients had Ebstein's anomaly associated with atrioventricular bypass tracts. The most common combination was right posteroseptal with right free wall bypass tracts (15 patients with 30 accessory pathways). Fifty-one of the sixty-three accessory pathways (81%) were ablated successfully without complications. The duration of the procedure was 100 +/- 58 min and the fluoroscopic time 40 +/- 17 min. A follow up of 5 +/- 3 years after ablation, demonstrated recurrences of six accessory pathways (9.5%). In conclusion, patients with multiple accessory pathways can be treated by radiofrequency ablation in only one session with a high success rate although slightly less than that in patients with a single accessory pathway (81% vs 93%, P<0.01).