This study is one of the first investigations conducted within the Italian school system to capture teachers’ perspective, experiences and perceptions about the impact of the COVID-19 pandemic on school education. It was performed two months after the beginning of lockdown, when online teaching and learning processes were fully in place and had reached a steady state. The paper reports a descriptive analysis together with a network analysis, and the search for causal relationships among the variables that have been investigated. Generally, respondents reported that the reactions of educational institutions and individual teachers were satisfactory, preventing the collapse of the education system in spite of loss of contact with 6-10% of the student population and a significant teacher workload increase that posed individual time management challenges. Although teachers tended to adopt teaching strategies that reproduced standard classroom dynamics, the possibility of operating in this comfort zone generated a positive feeling about using technologies, a perception of increased digital skills mastery and a change in mindset about educational processes. In turn, this led to an increase in the perceived sustainability of online education, with about a third of the teachers expressing the wish to adopt a blended configuration for future teaching activities. Almost all participants recognized the significance of a digital pedagogy and the need to include it in the training curricula to prepare future teachers.

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In this paper, we report one of the first investigations conducted at the National level with university teachers, with the aim to capture their perceptions about the capability of the learning ecosystems to react to the lockdown imposed by the pandemic and the recourse to on-line learning. The study, conducted about two months after the beginning of the lock-down, shows that: a) learning ecosystems reacted promptly and in a satisfactory manner to assure the didactic continuity at both the systemic and individual level; b) the teaching activities were mainly confined to transmissive ex-cathedra lectures in the attempt to reproduce standard university dynamics; c) the working load increased with respect to face-to-face activities; d) the intention to use on-line learning in the future is driven by preconceptions rather than experiences and by the capability to manage one’s own time. The comparison with the outcomes of a similar study conducted with school teachers shows that the latter adopt a broader spectrum of didactic activities (although they still tend to remain in their comfort zone), experienced a heavier increase of the working load, and were more influenced by the situation they experienced. Although both teachers categories recognized the relevance of digital pedagogy, in the case of school teachers - as shown by the causal structure of the variables considered in our studies - it should be urgently included in teacher education curricula, while in the case of the university teachers it appears to be a possible route to support integration of on-line activities with standard face-to-face ones.

The single-vortex dynamics in ladders of overdamped Josephson junctions is investigated by means of numerical simulations. We derive the velocity (v), the coefficient of viscosity (η) and the height of the dynamical barrier for the cell-to-cell vortex motion (E b ) as functions of the bias current (i dc ), the magnetic field penetration depth (λ ⊥ ) and the vortex position (x). The vortex dynamics can be satisfactorily described in terms of the motion of a particle subjected to a potential U(x, i dc , λ ⊥ ), the form of which is analysed.

We report measurements of torque relaxation in a Cu:Mn (5 at.%) spin-glass sample under a variety of experimental protocols, which can give strikingly different decay patterns. We conclude from the data that relaxation in this type of spin-glass is through local reorganizations of groups of spins rather than by cluster inversions, and that the reorganizations of spins which take place upon the application of a magnetic field to a zero-field-cooled sample are closely linked to the reorganizations which lead to relaxation.PACS numbers: 75.50. Kj, 75.lO.Nr The relaxation of the magnetization in spin-glasses has been intensively studied. Initially results were parametrized in terms of a logarithmic decay 1,2 ; recent very precise low-field SQUID data have been analyzed with use of a combination of algebraic and stretched exponential decay factors. 3 Although a number of models have been proposed, 4 the actual mechanism of the relaxation remains obscure.In magnetization measurements the relaxation of the longitudinal magnetization (mllH) is observed after the strength of H is modified; one can also use torque experiments to observe transverse relaxation after the direction of the applied field is changed. 5 ' 6 This field rotation has the effect of tending to turn the spin system against the frozen-in anisotropy axes, and so is a quite different perturbation from a variation of the strength of the applied field. The motivation of this work was to compare the relaxation resulting from small-angle field rotations with relaxation of the remanent magnetization after the applied field is reduced to zero, so as to obtain a new viewpoint on the relaxation process. In the one published torque-relaxation study, data were taken following a long waiting time at //=0; it was suggested that torque relaxation was governed by a different mechanism from that of magnetization decay. 5 Torque measurements allow the experimenter an almost limitless set of possible alternative procedures to follow, as he has at his disposition the parameters temperature, field strength, and angle. We have carried out torque measurements under a limited set of experimental protocols in order to establish the ground rules for this type of relaxation. A number of systematic rules could be established; we will discuss these and give a simple image of spin-glass relaxation which is compatible with these systematics and which provides new insight concerning the relaxation mechanism. We will postpone the full quantitative presentation to a later publication.Our measurements were made on a Cu:Mn (5 at.%) sample which has a T g value of 28 K. Data were taken with a capacity-cell torquemeter where the sample temperature can be controlled from 1.5 to 30 K in fields up to 9 kG. The torque signal was monitored continuously; before initialization of each procedure, the sample was heated to above T g . Here we will only present some of the results at 4.2 K; extensive data at other temperatures and on other samples will be reported on elsewhere.The figures show resul...