Long-range interacting classical systems: universality in mixing weakening

Through molecular dynamics, we study the $d=2,3$ classical model of $N$ coupled rotators (inertial XY model) assuming a coupling constant which decays with distance as $r_{ij}^{-\alpha}$ ($\alpha \ge 0$). The total energy $$ is asymptotically $\propto N {\tilde N}$ with ${\tilde N} \equiv [N^{1-\alpha/d}-(\alpha/d)]/[1-\alpha/d]$, hence the model is thermodynamically extensive if $\alpha/d>1$ and nonextensive otherwise. We numerically show that, for energies above some threshold, the (appropriately scaled) maximum Lyapunov exponent is $\propto N^{-\kappa}$ where $\kappa$ is an {\it universal} (one and the same for $d=1,2$ and 3, and all energies) function of $\alpha/d$, which monotonically decreases from 1/3 to zero when $\alpha/d$ increases from 0 to 1, and identically vanishes above 1. These features are consistent with the nonextensive statistical mechanics scenario, where thermodynamic extensivity is associated with {\it exponential} mixing in phase space, whereas {\it weaker} (possibly {\it power-law} in the present case) mixing emerges at the $N \to \infty$ limit whenever nonextensivity is observed.Comment: 4 pages, 3 figures; Submitted to Physical Review Letter

Canonical solution of a system of long-range interacting rotators on a lattice

The canonical partition function of a system of rotators (classical X-Y spins) on a lattice, coupled by terms decaying as the inverse of their distance to the power alpha, is analytically computed. It is also shown how to compute a rescaling function that allows to reduce the model, for any d-dimensional lattice and for any alpha<d, to the mean field (alpha=0) model.Comment: Initially submitted to Physical Review Letters: following referees' Comments it has been transferred to Phys. Rev. E, because of supposed no general interest. Divided into sections, corrections in (5) and (20), reference 5 updated. 8 pages 1 figur

The mobile-born and the COVID-19 pandemic: opportunities, problems and the role of the telemedicine and e-health

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Metastable states in a class of long-range Hamiltonian systems

We numerically show that metastable states, similar to the Quasi Stationary States found in the so called Hamiltonian Mean Field Model, are also present in a generalized model in which $N$ classical spins (rotators) interact through ferromagnetic couplings decaying as $r^{-\alpha}$, where $r$ is their distance over a regular lattice. Scaling laws with $N$ are briefly discussed.Comment: Latex 2e, 11 pages, 3 eps figures, contributed paper to the conf. "NEXT 2001", 23-30 May 2001, Cagliari (Italy), submitted to Physica

A web-based health technology assessment in tele-echocardiography: the experience within an Italian project

Due to major advances in the information technology, telemedicine applications are ready for a widespread use. Nonetheless, to allow their diffusion in National Health Care Systems (NHCSs) specific methodologies of health technology assessment (HTA ) should be used to assess the standardization, the overall quality, the interoperability, the addressing to legal, economic and cost benefit aspects. One of the limits to the diffusion of the digital tele-echocardiography (T-E) applications in the NHCS lacking of a specific methodology for the HTA . In the present study, a solution offering a structured HTA of T-E products was designed. The methodology assured also the definition of standardized quality levels for the application. The first level represents the minimum level of acceptance; the other levels are accessory levels useful for a more accurate assessment of the product. The methodology showed to be useful to rationalize the process of standardization and has received a high degree of acceptance by the subjects involved in the study.Grazie ai grandi progressi nell\u27information technology le applicazioni di telemedicina sono mature per un uso diffuso. Tuttavia per permettere la loro introduzione nel sistema sanitario nazionale devono essere utilizzate specifiche metodologie di health technology assessment (HTA ) per valutare il grado di standardizzazione, la qualit? totale, l\u27interoperabilit?, il rispetto dei requisiti legali ed economici e il rapporto costo-beneficio. Con riferimento alla tele-ecocardiografia digitale uno dei limiti ? la mancanza di una specifica metodologia di HTA . Nel presente studio, ? stata proposta una soluzione che offre un HTA strutturato di prodotti di tele-ecocardiografia (T-E) digitale. La metodologia ha assicurato anche la definizione di livelli standardizzati di qualit? per l\u27applicazione. Il primo livello rappresenta il livello minimo di accettazione; gli altri livelli riguardano aspetti accessori e sono utili per una pi? accurata valutazione del prodotto. La metodologia si ? mostrata di utilit? per razionalizzare il processo di standardizzazione ed ha ricevuto un elevato grado di accettazione dei soggetti coinvolti

Canonical Solution of Classical Magnetic Models with Long-Range Couplings

We study the canonical solution of a family of classical $n-vector$ spin models on a generic $d$-dimensional lattice; the couplings between two spins decay as the inverse of their distance raised to the power $\alpha$, with $\alpha<d$. The control of the thermodynamic limit requires the introduction of a rescaling factor in the potential energy, which makes the model extensive but not additive. A detailed analysis of the asymptotic spectral properties of the matrix of couplings was necessary to justify the saddle point method applied to the integration of functions depending on a diverging number of variables. The properties of a class of functions related to the modified Bessel functions had to be investigated. For given $n$, and for any $\alpha$, $d$ and lattice geometry, the solution is equivalent to that of the $\alpha=0$ model, where the dimensionality $d$ and the geometry of the lattice are irrelevant.Comment: Submitted for publication in Journal of Statistical Physic

Argument mining as rapid screening tool of COVID-19 literature quality: Preliminary evidence

BackgroundThe COVID-19 pandemic prompted the scientific community to share timely evidence, also in the form of pre-printed papers, not peer reviewed yet.PurposeTo develop an artificial intelligence system for the analysis of the scientific literature by leveraging on recent developments in the field of Argument Mining.MethodologyScientific quality criteria were borrowed from two selected Cochrane systematic reviews. Four independent reviewers gave a blind evaluation on a 1–5 scale to 40 papers for each review. These scores were matched with the automatic analysis performed by an AM system named MARGOT, which detected claims and supporting evidence for the cited papers. Outcomes were evaluated with inter-rater indices (Cohen's Kappa, Krippendorff's Alpha, s* statistics).ResultsMARGOT performs differently on the two selected Cochrane reviews: the inter-rater indices show a fair-to-moderate agreement of the most relevant MARGOT metrics both with Cochrane and the skilled interval scores, with larger values for one of the two reviews.Discussion and conclusionsThe noted discrepancy could rely on a limitation of the MARGOT system that can be improved; yet, the level of agreement between human reviewers also suggests a different complexity between the two reviews in debating controversial arguments. These preliminary results encourage to expand and deepen the investigation to other topics and a larger number of highly specialized reviewers, to reduce uncertainty in the evaluation process, thus supporting the retraining of AM systems

Robot-assisted upper limb training for patients with multiple sclerosis: an evidence-based review of clinical applications and effectiveness

Upper extremities limitation is a common functional impairment in patients with Multiple Sclerosis (PwMS). Novel technological devices are increasingly used in neurorehabilitation to support motor function improvement and the quantitative assessment of motor performance during training in patients with neurological diseases. In this review, we systematically report the evidence on clinical applications and robotic-assisted arm training (RAT) in functional recovery in PwMS. PubMed/MEDLINE, the Cochrane Library, and the Physiotherapy Evidence Database (PEDro) databases were systematically searched from inception to March 2021. The 10-item PEDro scale assessed the study quality for the RCT, and the AMSTAR-2 was used to assess the quality of the systematic review. The 5-item Oxford CEBM scale was used to rate the level of evidence. A total of 10 studies (161 subjects) were included. The selected studies included one systematic review, four RCTs, one randomized crossover, and four case series. The RCTs were scored as high-quality studies, while the systematic review was determined to be of low quality. Shoulder range of motion, handgrip strength, and proximal arm impairment improved after RAT. Manual dexterity, arm function, and use in daily life also ameliorated arm function. The high clinical heterogeneity of treatment programs and the variety of robot devices affects the generalizability of the study results; therefore, we emphasize the need to standardize the intervention type in future studies that evaluate the role of robotic-assisted training in PwMS. Robot-assisted treatment seems safe and useful to increase manual dexterity and the quality of movement execution in PwMS with moderate to severe disability. Additional studies with an adequate sample size and methodological rigour are warranted to drive definite conclusion

Upper limb robotic rehabilitation for patients with cervical spinal cord injury: a comprehensive review

The upper extremities limitation represents one of the essential functional impairments in patients with cervical spinal cord injury. Electromechanics assisted devices and robots are increasingly used in neurorehabilitation to help functional improvement in patients with neurological diseases. This review aimed to systematically report the evidence-based, state-of-art on clinical applications and robotic-assisted arm training (RAT) in motor and functional recovery in subjects affected by cervical spinal cord injury. The present study has been carried out within the framework of the Italian Consensus Conference on "Rehabilitation assisted by robotic and electromechanical devices for persons with disability of neurological origin" (CICERONE). PubMed/MEDLINE, Cochrane Library, and Physiotherapy Evidence Database (PEDro) databases were systematically searched from inception to September 2021. The 10-item PEDro scale assessed the study quality for the RCT and the AMSTAR-2 for the systematic review. Two different authors rated the studies included in this review. If consensus was not achieved after discussion, a third reviewer was interrogated. The five-item Oxford CEBM scale was used to rate the level of evidence. A total of 11 studies were included. The selected studies were: two systematic reviews, two RCTs, one parallel-group controlled trial, one longitudinal intervention study and five case series. One RCT was scored as a high-quality study, while the systematic review was of low quality. RAT was reported as feasible and safe. Initial positive effects of RAT were found for arm function and quality of movement in addition to conventional therapy. The high clinical heterogeneity of treatment programs and the variety of robot devices could severely affect the generalizability of the study results. Therefore, future studies are warranted to standardize the type of intervention and evaluate the role of robotic-assisted training in subjects affected by cervical spinal cord injury