Comprendere e far comprendere

En este documento, la cuestión básica es cómo aquello que parte de la comprensión contribuye a construir el aprendizaje de una forma diferente a la que se inicia a partir de una actividad sencilla, tiene una medida de comprensión que desea desarrollarse y vivir en el mismo espacio dentro de un proceso de interacción lingüística, de la constante negociación de significados, para poder realizar un aprendizaje significativo.In this paper the basic question is how who stars from the comprehension contributes to build the learning in a different way than who starts from an easy activity, have a light measurement of comprehension that you want to develop and live the same space inside of linguistic interaction process, constant negotiation of meanings, to realize a significant learning.In questo saggio la questione principale è come chi parte dalla comprensione concorra a costruire apprendimento in modo diverso da chi parte da una semplice attività, avere chiara la dimensione di comprensione che si vuole sviluppare e abitare la stessa dimensione all’interno dell’interazione linguistica, costante negoziazione di significati, aiuta ad attivare il processo di progettazione per la realizzazione di un apprendimento significativo.peerReviewe

Spin-down in a rapidly rotating cylinder container with mixed rigid and stress-free boundary conditions

A comprehensive study of the classical linear spin-down of a constant density viscous fluid (kinematic viscosity \nu) rotating rapidly (angular velocity \Omega) inside an axisymmetric cylindrical container (radius L, height H) with rigid boundaries, that follows the instantaneous small change in the boundary angular velocity at small Ekman number $E=\nu/H^2\Omega \ll 1$, was provided by Greenspan & Howard (1963). $E^{1/2}$-Ekman layers form quickly triggering inertial waves together with the dominant spin-down of the quasi-geostrophic (QG) interior flow on the $O(E^{-1/2}\Omega^{-1})$ time-scale. On the longer lateral viscous diffusion time-scale $O(L^2/\nu)$, the QG-flow responds to the $E^{1/3}$-side-wall shear-layers. In our variant the side-wall and top boundaries are stress-free; a setup motivated by the study of isolated atmospheric structures, such as tropical cyclones, or tornadoes. Relative to the unbounded plane layer case, spin-down is reduced (enhanced) by the presence of a slippery (rigid) side-wall. This is evinced by the QG-angular velocity, \omega*, evolution on the O(L^2/\nu) time-scale: Spatially, \omega* increases (decreases) outwards from the axis for a slippery (rigid) side-wall; temporally, the long-time ($\gg L^2/\nu)$ behaviour is dominated by an eigensolution with a decay rate slightly slower (faster) than that for an unbounded layer. In our slippery side-wall case, the $E^{1/2} \times E^{1/2}$ corner region that forms at the side-wall intersection with the rigid base is responsible for a $\ln E$ singularity within the $E^{1/3}$-layer causing our asymptotics to apply only at values of E far smaller than can be reached by our Direct Numerical Simulation (DNS) of the entire spin-down process. Instead, we solve the $E^{1/3}$-boundary-layer equations for given E numerically. Our hybrid asymptotic-numerical approach yields results in excellent agreement with our DNS.Comment: 33 pages, 10 figure

Terapie combinate plurime per prolungare la sopravvivenza delle fistole arterovenose native

La Fistola Arterovenosa Nativa rappresenta a tutt'oggi il gold standard degli accessi vascolari in emodialisi. Tuttavia essa non è applicabile a tutti i pazienti. Le protesi rappresentano una seconda scelta percorribile in alternativa al Catetere Venoso centrale a permanenza, ma sono gravate da maggiori complicanze, hanno una durata inferiore e richiedono un'adeguata sorveglianza e manutenzione. I due casi clinici qui presentati, illustrano come strategie combinate plurime, chirurgiche ed endovascolari, perfettamente complementari e sinergiche, possano garantirne la pervietà a lungo termine e ridurre il ricorso all'uso dei CVC

Alfvén wave far field from steady-current tethers

We analyzed he Alfvén waves ignaturele ft behindi n the ionospherbe y orbiting insulatedt etherso peratinga s thrusterso r generatorws ith steadyc urrentsU. sing a recentd escription of tetherr adiationt o determineth e far field, we showt hat, at their leadinge dges,t heA lfv6n wingsh avea n Airy functionc rosswises tructureT. he field amplitudef alls off weakly as the inversec uber oot of the distancea longt he wavef ront.T he fronti tself, whichc arriesa negligible fractiono f the powerr adiateda sA lfven waves,b roadensp roportionallyto the cuber oot of that distanceW. e showt hatc ollisionadl ecayb ecomesim portanat t about1 03k m alongt he front.F or tethersl ongert han about2 km, the top andb ottoms tructures("wings")a re fully disjoint

Physics-based basis functions for low-dimensional representation of the refractive index in the high energy limit

The relationship between the refractive index decrement, $\delta$, and the real part of the atomic form factor, $f^\prime$, is used to derive a simple polynomial functional form for $\delta(E)$ far from the K-edge of the element. The functional form, motivated by the underlying physics, follows an infinite power sum, with most of the energy dependence captured by a single term, $1/E^2$. The derived functional form shows excellent agreement with theoretical and experimentally recorded values. This work helps reduce the dimensionality of the refractive index across the energy range of x-ray radiation for efficient forward modeling and formulation of a well-posed inverse problem in propagation-based polychromatic phase-contrast computed tomography

Integrare le ICT nella didattica universitaria

Negli ultimi anni la sfida per il miglioramento della qualit\ue0 della didattica ha spinto sempre pi\uf9 le universit\ue0 a orientarsi verso modelli learner-centered, nella direzione socio-costruttivista dell\u2019allestimento di ambienti d\u2019apprendimento integrati. Numerose ricerche, infatti, sottolineano come il cambiamento sia favorito dallo sviluppo di processi trasformativi che, unitamente alla considerazione delle concezioni sull\u2019apprendimento e sull\u2019insegnamento, affrontino sistematicamente la progettazione didattica, integrando le diverse conoscenze dei docenti relative ai contenuti, alle metodologie e alle tecnologie. In particolare, le riflessioni sull\u2019uso delle ICT hanno sviluppato studi teorici e analisi metodologiche volti a ripensare il loro impiego, anche nell\u2019ambito della didattica universitaria, considerandole sempre pi\uf9 come strumenti utili sia sul piano cognitivo (per ricercare, produrre, rielaborare e far interagire il sistema dei saperi), sia su quello socio-culturale (per favorire processi di comunicazione, sviluppo, condivisione e scambio)

Experimental test of Non-Commutative Quantum Gravity by VIP-2 Lead

Pauli Exclusion Principle (PEP) violations induced by space-time non-commutativity, a class of universality for several models of Quantum Gravity, are investigated by the VIP-2 Lead experiment at the Gran Sasso underground National Laboratory of INFN. The VIP-2 Lead experimental bound on the non-commutative space-time scale $\Lambda$ excludes $\theta$-Poincar\'e far above the Planck scale for non vanishing ``electric-like" components of $\theta_{\mu \nu}$, and up to $6.9 \cdot 10^{-2}$ Planck scales if they are null. Therefore, this new bound represents the tightest one so far provided by atomic transitions tests. This result strongly motivates high sensitivity underground X-ray measurements as critical tests of Quantum Gravity and of the very microscopic space-time structure.Comment: 13 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:2209.0007

Pensiero computazionale: una quarta competenza dopo scrivere, leggere e far di conto

International audienceThe author explains what computational thinking consist of, its importance and evolution and its main results in education university in contemporary society in which Internet allows a continuous exchange of information between things and objects (Internet of things) of everyday life This is important because allows everyone to increase our knowledge of the environment and our ability to react to events On the other hand –the main risk is a global information, non differentiated on indi- vidual need of people For the author, this means learning the linguistic forms with which we can build models of reality, better suited to being responsible citizens in information societyMuovendo da osservazioni su Internet, l’infrastruttura tecno-comunicativa che consente a un numero di persone ogni anno maggiore di restare sempre connessa, ovunque ci si trovi, a poco prezzo, senza interruzioni dovute alla propria mobilità, Martini spiega che cosa sia il pensiero computazionale, per quale ragione sia impor- tante svilupparlo, e quali conseguenze tutto ciò abbia per la formazione, anche universitaria. Infatti la IoT-Internet of things, poiché permette la raccolta e lo scambio di informazioni fra macchine e oggetti d’uso quotidiano in modo diffuso e pervasivo, consente di accrescere la nostra conoscenza dell’ambiente e la nostra capacità di reagire agli eventi Martini però evidenzia un rischio: la diffusione dell’informazione è uniformata al modo dominante di vedere il mondo; si rischia così di perdere la capac- ità di presentare questa moltitudine di informazioni in maniera differente, a seconda delle necessità delle persone Esporsi al pensiero computazionale, conclude Martini, significa apprendere le forme linguistiche con cui si può costruire modelli della realtà, più adatti ad essere cittadini responsabili nella società dell’informazion

Distributed Detection of Cycles

Distributed property testing in networks has been introduced by Brakerski and Patt-Shamir (2011), with the objective of detecting the presence of large dense sub-networks in a distributed manner. Recently, Censor-Hillel et al. (2016) have shown how to detect 3-cycles in a constant number of rounds by a distributed algorithm. In a follow up work, Fraigniaud et al. (2016) have shown how to detect 4-cycles in a constant number of rounds as well. However, the techniques in these latter works were shown not to generalize to larger cycles $C_k$ with $k\geq 5$. In this paper, we completely settle the problem of cycle detection, by establishing the following result. For every $k\geq 3$, there exists a distributed property testing algorithm for $C_k$-freeness, performing in a constant number of rounds. All these results hold in the classical CONGEST model for distributed network computing. Our algorithm is 1-sided error. Its round-complexity is $O(1/\epsilon)$ where $\epsilon\in(0,1)$ is the property testing parameter measuring the gap between legal and illegal instances