I "decostituiti" de "La Sapienza": Santi Romano, Maurizio Maraviglia e Carlo Costamagna

Il contributo analizza le figure dei tre giuspubblicisti dell'Università di Roma "La Sapienza" (Costamagna, Maraviglia e Romano) sottoposti a procedimento di epurazione dopo la cadutra del fascismo

La giurisdizione durante il regime costituzionale provvisorio e la sua valutazione nella giurisprudenza successiva

L'articolo analizza il ruolo della giurisidizione durante il regime costituzionale provvisorio, evidenziando i profili di continuità tra la giurisprudenza della R.S.I. e quella dello Stato italiano, in ragione della evidente continuità del ceto giudiziario tra Fascismo e Repubblica

A proposito delle questioni di legittimità costituzionale sulla legge n. 18/2015 e della responsabilità dei magistrati in generale

L’articolo analizza le problematiche di natura costituzionale connesse alla nuova legge sulla responsabilità civile dei magistrati. Dopo avere illustrato le novità introdotte dalla l. n. 18/2015, l’autore passa a prendere in esame la giurisprudenza costituzionale in materia di responsabilità dei magistrati, per poi affrontare la fondatezza delle questioni di legittimità costituzionale sulla nuova legge. La conclusione è nel senso che la nuova legge sia legittima sul piano costituzionale

Giurisdizione costituzionale, Corti sovranazionali e giudici comuni. Considerazioni a proposito del dialogo tra corti

L’articolo analizza i rapporti tra Corte costituzionale, Corti sovranazionali e giudici comuni, nella prospettiva del dialogo giudiziale. La tesi esposta è che il dialogo tra corti è la logica conseguenza della espansione del potere giudiziario, e del superamento della idea del giudice come bouche de la loi. L’autore prende in esame anche i casi in cui il dialogo tra corti si è rivelato mancante, insufficiente o contraddittorio. La conclusione, tuttavia, è che, anche quando sembrano divergere o dissentire, i giudici comunque dialogano sempre tra loro.The article analyzes the relationship between the Constitutional Court, supranational courts and ordinary courts, in the judicial dialogue perspective. The thesis is that the dialogue between the courts is the logical consequence of the expansion of judicial power, and the overcoming of the idea of the judge as bouche de la loi. The author also examines the cases in which the dialogue between courts is missing, insufficient or contradictory. The conclusion, however, is that even when they seem to diverge or disagree, the judges always talk to each other

Impact of atrial fibrillation on the cardiovascular system through a lumped-parameter approach

Atrial fibrillation (AF) is the most common arrhythmia affecting millions of people in the Western countries and, due to the widespread impact on the population and its medical relevance, is largely investigated in both clinical and bioengineering sciences. However, some important feedback mechanisms are still not clearly established. The present study aims at understanding the global response of the cardiovascular system during paroxysmal AF through a lumped-parameter approach, which is here performed paying particular attention to the stochastic modeling of the irregular heartbeats and the reduced contractility of the heart. AF can be here analyzed by means of a wide number of hemodynamic parameters and avoiding the presence of other pathologies, which usually accompany AF. Reduced cardiac output with correlated drop of ejection fraction and decreased amount of energy converted to work by the heart during blood pumping, as well as higher left atrial volumes and pressures are some of the most representative results aligned with the existing clinical literature and here emerging during acute AF. The present modeling, providing new insights on cardiovascular variables which are difficult to measure and rarely reported in literature, turns out to be an efficient and powerful tool for a deeper comprehension and prediction of the arrythmia impact on the whole cardiovascular system.Comment: 16 pages, 8 figures, 2 tables, Medical & Biological Engineering & Computing, 2014, Print ISSN: 0140-0118, Online ISSN: 1741-044

Impaired coronary blood flow at higher heart rates during atrial fibrillation: investigation via multiscale modelling

Background. Different mechanisms have been proposed to relate atrial fibrillation (AF) and coronary flow impairment, even in absence of relevant coronary artery disease (CAD). However, the underlying hemodynamics remains unclear. Aim of the present work is to computationally explore whether and to what extent ventricular rate during AF affects the coronary perfusion. Methods. AF is simulated at different ventricular rates (50, 70, 90, 110, 130 bpm) through a 0D-1D multiscale validated model, which combines the left heart-arterial tree together with the coronary circulation. Artificially-built RR stochastic extraction mimics the \emph{in vivo} beating features. All the hemodynamic parameters computed are based on the left anterior descending (LAD) artery and account for the waveform, amplitude and perfusion of the coronary blood flow. Results. Alterations of the coronary hemodynamics are found to be associated either to the heart rate increase, which strongly modifies waveform and amplitude of the LAD flow rate, and to the beat-to-beat variability. The latter is overall amplified in the coronary circulation as HR grows, even though the input RR variability is kept constant at all HRs. Conclusions. Higher ventricular rate during AF exerts an overall coronary blood flow impairment and imbalance of the myocardial oxygen supply-demand ratio. The combined increase of heart rate and higher AF-induced hemodynamic variability lead to a coronary perfusion impairment exceeding 90-110 bpm in AF. Moreover, it is found that coronary perfusion pressure (CPP) is no longer a good measure of the myocardial perfusion for HR higher than 90 bpm.Comment: 8 pages, 5 figures, 3 table

Alteration of cerebrovascular haemodynamic patterns due to atrial fibrillation: an in silico investigation

There has recently been growing evidence that atrial fibrillation (AF), the most common cardiac arrhythmia, is independently associated with the risk of dementia. This represents a very recent frontier with high social impact for the number of individuals involved and for the expected increase in AF incidence in the next 40 years. Although a number of potential haemodynamic processes, such as microembolisms, altered cerebral blood flow, hypoperfusion and microbleeds, arise as connecting links between the two pathologies, the causal mechanisms are far from clear. An in silico approach is proposed that combines in sequence two lumped-parameter schemes, for the cardiovascular system and the cerebral circulation. The systemic arterial pressure is obtained from the cardiovascular system and used as the input for the cerebral circulation, with the aim of studying the role of AF on the cerebral haemodynamics with respect to normal sinus rhythm (NSR), over a 5000 beat recording. In particular, the alteration of the haemodynamic (pressure and flowrate) patterns in the microcirculation during AF is analysed by means of different statistical tools, from correlation coefficients to autocorrelation functions, crossing times, extreme values analysis and multivariate linear regression models. A remarkable signal alteration, such as a reduction in signal correlation (NSR, about 3 s; AF, less than 1 s) and increased probability (up to three to four times higher in AF than in NSR) of extreme value events, emerges for the peripheral brain circulation. The described scenario offers a number of plausible cause-effect mechanisms that might explain the occurrence of critical events and the haemodynamic links relating to AF and dementia.Comment: 13 pages, 9 Figures, 3 Table

Rate Control Management of Atrial Fibrillation: May a Mathematical Model Suggest an Ideal Heart Rate?

Background. Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. Methods. The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Results. Left ventricular pressure increased by 56.7%, from 33.92+-37.56 mmHg to 53.15+-47.56 mmHg, and mean systemic arterial pressure increased by 27.4%, from 82.66+-14.04 mmHg to 105.29+-7.63 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45+-8.5 to 39.09+-8.08 mL), ejection fraction (from 61.1+-4.4 to 39.32+-5.42%) and stroke work (SW, from 0.88+-0.04 to 0.58+-0.09 J) decreased by 49.5, 35.6 and 34.2%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product, RPP, tension time index per minute, TTI/min, and pressure volume area per minute, PVA/min) increased from the 50 to the 130 bpm simulation, respectively, by 185.7% (from 5598+-1939 to 15995+-3219 mmHg/min), 55.5% (from 2094+-265 to 3257+-301 mmHg s/min) and 102.4% (from 57.99+-17.9 to 117.37+-25.96 J/min). In fact, left ventricular efficiency (SW/PVA) decreased from 80.91+-2.91% at 50 bpm to 66.43+-3.72% at the 130 bpm HR simulation. Conclusion. Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.Comment: 9 page

Power spectra of random spikes and related complex signals:with application to communications

"Random spikes" belong to the common language used by engineers, physicists and biologists to describe events associated with time records, locations in space, or more generally, space-time events. Indeed, data and signals consisting of, or structured by, sequences of events are omnipresent in communications, biology, computer science and signal processing. Relevant examples can be found in traffic intensity and neurobiological data, pulse-coded transmission, and sampling. This thesis is concerned by random spike fields and by the complex signals described as the result of various operations on the basic event stream or spike field, such as filtering, jittering, delaying, thinning, clustering, sampling and modulating. More precisely, complex signals are obtained in a modular way by adding specific features to a basic model. This modular approach greatly simplifies the computations and allows to treat highly complex model such as the ones occurring in ultra-wide bandwidth or multipath transmissions. We present a systematic study of the properties of random spikes and related complex signals. More specifically, we focus on second order properties, which are conveniently represented by the spectrum of the signal. These properties are particularly attractive and play an important role in signal analysis. Indeed, they are relatively accessible and yet they provide important informations. Our first contribution is theoretical. As well as presenting a modular approach for the construction of complex signals, we derive formulas for the computation of the spectrum that preserve such modularity: each additional feature added to a basic model appear as a separate and explicit contribution in the corresponding basic spectrum. Moreover, these formula are very general. For instance, the basic point process is not assumed to be a homogeneous Poisson process but it can be any second order stationary process with a given spectrum. In summary, they provide very useful tools for model analysis. We then give applications of the theoretical results: spectral formulas for traffic analysis, pulse based signals used in spread spectrum communications, and randomly sampled signal