860 research outputs found
Consapevolmente intelligenti: un\u2019indagine esplorativa sull\u2019uso dei social network nella scuola primaria
I Social Network sono una preziosa occasione per costruire una societ\ue0 pi\uf9 attenta e responsabile, una pra-tica che si assimila imparando a utilizzare il Web in maniera consapevole. La competenza digitale si configu-ra come competenza alla partecipazione attiva alla Rete e alla societ\ue0. L\u2019attenzione \ue8 posta sulla necessit\ue0 di acquisire un know-how per sfruttare i media, con particolare riferimento ai Social Network, in modo intelli-gente cos\uec da farli diventare strumenti intelligenti. Dal punto di vista educativo i Social Network offrono diver-se potenzialit\ue0 in quanto: sono in grado di supportare le funzioni di socializzazione, condivisione e coordi-namento; di incoraggiare il dialogo, promuovere la condivisione di risorse e migliorare lo sviluppo di capacit\ue0 comunicative; di sostenere l\u2019apprendimento facilitando il supporto tra pari nello svolgimento dei compiti. Le criticit\ue0 maggiori derivano dal contrasto tra i modelli d\u2019impiego dei Social Network aperti nei contesti educati-vi formali e le pratiche d\u2019uso degli alunni in ambito informale. Sul tema del rapporto tra i Social Network e i processi di insegnamento/apprendimento, se da una parte si rileva l\u2019urgenza di utilizzarli per potenziare l\u2019intelligenza, per trovare le risposte pi\uf9 efficaci a problemi complessi, dall\u2019altra parte \ue8 necessario che si im-pari a farlo con consapevolezza, con senso critico, con rispetto e responsabilit\ue0. Il lavoro documenta un\u2019indagine esplorativa sull\u2019utilizzo critico e consapevole dei Social Network nella scuola primaria. L\u2019indagine, che si \ue8 svolta nel corrente anno scolastico, ha coinvolto 2399 alunni, 100 insegnanti e 50 diri-genti di 50 scuole primarie della Sicilia occidentale. La ricerca ha inteso esplorare, da una parte, se e in che modo gli alunni di classe quarta e quinta primaria utilizzano i Social Network; dall\u2019altra parte, in che modo insegnanti e dirigenti possono orientare i bambini all\u2019uso consapevole e critico dei social. Gli strumenti utiliz-zati per lo studio sono: il questionario ICRTDIG (Digital Critical Thinking and Intelligence), appositamente costruito e validato per gli alunni, e un\u2019intervista semi-strutturata per gli insegnanti e i dirigenti. I risultati la-sciano intravvedere piste di ricerca e ambiti applicativi interessanti.Social Networks are a noteworthy opportunity to build a more caring and responsible society, a practice that is assimilated by learning to use the Web in a conscious way. The media competence takes the form of ex-pertise both to active participation to the Web and to society. The focus is on the need to acquire the know-how to exploit the media, with particular reference to social networks, in a clever way so as to make them in-telligent instruments. From an educational point of view, Social Networks offer a different potential because they are able to support the functions of socialization, of sharing and of coordination; to encourage dialogue, promote resources sharing and improve the development of communication skills; to support learning by fa-cilitating peer support in the performance of tasks. The main critical issues arise from the contrast between the patterns of use of social networks in formal educational settings and their use within the informal educa-tional settings. As to the relationship between social networks and the teaching/learning processes, on the one hand, there is an urgent need to use them to increase intelligence as well as to find the most effective solutions to complex problems; on the other hand, it is necessary to learn how to do so consciously, critical-ly, with respect and responsibility. The present work documents an exploratory survey on the critical and conscious use of Social Networks at school. The survey carried out during the scholastic year 2016-2017, involved 2239 pupils, 100 teachers and 50 Head Teachers of 50 Sicily Primary schools. The research aimed to explore whether and how students actually use social networks; it explored on how future teachers and educators can guide the young towards a conscious and critical use of Social Networks. The tools used for the study are a questionnaire specially constructed and a semi-structured interview. The results reveal new avenues of research and interesting application areas
Teachers and inclusion: an empirical survey on specialist training for support teachers
This paper illustrates the results of an empirical-experimental research conducted as part of the Specialization Course for support activities, held at the University of Palermo in the academic year 2016/17. The survey, concerning the effectiveness of training courses for teachers for the development of active learning, involved 450 teachers and had the main objective of investigating whether there was an actual increase in specific professional skills functional to school inclusion among those who attended the course. Despite leading to different kinds of meaningfulness, the pre/post-test data are evidence of a general positive improvement, highlighting how a student-centred approach has allowed us to achieve appreciable results in relation to the didactic, communicative-relational, evaluative dimensions and to perceived self-efficacy, which are fundamental skills for the inclusion process of each student
Resource-Aware Multimedia Content Delivery: A Gambling Approach
In this paper, we propose a resource-aware solution to achieving reliable and scalable stream diffusion in a probabilistic model, i.e. where communication links and processes are subject to message losses and crashes, respectively. Our solution is resource-aware in the sense that it limits the memory consumption, by strictly scoping the knowledge each process has about the system, and the bandwidth available to each process, by assigning a fixed quota of messages to each process. We describe our approach as gambling in the sense that it consists in accepting to give up on a few processes sometimes, in the hope of better serving all processes most of the time. That is, our solution deliberately takes the risk not to reach some processes in some executions, in order to reach every process in most executions. The underlying stream diffusion algorithm is based on a tree-construction technique that dynamically distributes the load of forwarding stream packets among processes, based on their respective available bandwidths. Simulations show that this approach pays off when compared to traditional gossiping, when the latter faces identical bandwidth constraints
Multiscale Molecular Dynamics Simulation of Multiple Protein Adsorption on Gold Nanoparticles
A multiscale molecular dynamics simulation study has been carried out in order to provide in-depth information on the adsorption of hemoglobin, myoglobin, and trypsin over citrate-capped AuNPs of 15 nm diameter. In particular, determinants for single proteins adsorption and simultaneous adsorption of the three types of proteins considered have been studied by Coarse-Grained and Meso-Scale molecular simulations, respectively. The results, discussed in the light of the controversial experimental data reported in the current experimental literature, have provided a detailed description of the (i) recognition process, (ii) number of proteins involved in the early stages of corona formation, (iii) protein competition for AuNP adsorption, (iv) interaction modalities between AuNP and protein binding sites, and (v) protein structural preservation and alteration
Energy refurbishment planning of Italian school buildings using data-driven predictive models
In the current practice, the design of energy refurbishment interventions for existing buildings is typically addressed by performing time-consuming software-based numerical simulations. However, this approach may be not suitable for preliminary assessment studies, especially when large building portfolios are involved. Therefore, this research work aims at developing simplified data-driven predictive models to estimate the energy consumption of existing school buildings in Italy and support the decision-making process in energy refurbishment intervention planning at a large scale. To accomplish this, an extensive database is assembled through comprehensive on-site surveys of school buildings in Southern Italy. For each school, a Building Information Modelling (BIM) model is developed and validated considering real energy consumption data. These BIM models serve in the design of suitable energy refurbishment interventions. Moreover, a comprehensive parametric investigation based on refined energy analyses is carried out to significantly improve and integrate the dataset. To derive the predictive models, firstly the most relevant parameters for energy consumption are identified by performing sensitivity analyses. Based on these findings, predictive models are generated through a multiple linear regression method. The suggested models provide an estimation of the energy consumption of the “as-built” configuration, as well as the costs and benefits of alternative energy refurbishment scenarios. The reliability of the proposed simplified relationships is substantiated through a statistical analysis of the main error indices. Results highlight that the building's shape factor (i.e., the ratio between the building's envelope area and its volume) and the area-weighted average of the thermal properties of the building envelope significantly affect both the energy consumption of school buildings and the achievable savings through retrofitting interventions. Finally, a framework for the preliminary design of energy refurbishment of buildings, based on the implementation of the herein developed predictive model, is proposed and illustrated through a worked example application. Worth noting that, while the proposed approach is currently limited to school buildings, the methodology can conceptually be extended to any building typology, provided that suitable data on energy consumption are available
The antioxidant properties of Ce-containing bioactive glass nanoparticles explained by Molecular Dynamics simulations
Molecular dynamics simulations of two glass nanoparticles with composition 25Na2O·25CaO 50SiO2 mol% (Ce-K NP) and 46.1SiO2·24.4Na2O·26.9CaO· 2.6P2O5 mol.% (Ce-BG NP) doped with 3.6 mol% of CeO2 have been carried out in order to explain the enhanced antioxidant properties of the former glass with respect to the latter.
The present models show that the different catalase mimetic activity of the two NPs is related to the Ce3+/Ce4+ ratio exposed at their surface. In fact, this ratio is about 3.5 and 13 in the bulk and at the surface of the Ce-BG NP, and 1.0 and 2.1 in the bulk and at the surface of the Ce-K NPs, respectively. Since both oxidation states are necessary for the catalysis of the dismutation reaction of hydrogen peroxides, NPs with a very high Ce3+/Ce4+ ratio possess poorer antioxidant properties.
Moreover, our simulations reveal that the already low silicate connectivity found in the bulk glasses examined here is further reduced on the nanoparticle surface, whereas the Na+/Ca2+ ratio rapidly increases. Sodium, calcium and cerium sites in proximity of the surface are found to be under-coordinated, prone to quickly react with water present in physiological environments, thus accelerating the glass biodegradatio
Biasing crystallization in fused silica: An assessment of optimal metadynamics parameters
Metadynamics (MetaD) is a useful technique to study rare events such as crystallization. It has been only recently applied to study nucleation and crystallization in glass-forming liquids such as silicates, but the optimal set of parameters to drive crystallization and obtain converged free energy surfaces is still unexplored. In this work, we systematically investigated the effects of the simulation conditions to efficiently study the thermodynamics and mechanism of crystallization in highly viscous systems. As a prototype system, we used fused silica, which easily crystallizes to β-cristobalite through MetaD simulations, owing to its simple microstructure. We investigated the influence of the height, width, and bias factor used to define the biasing Gaussian potential, as well as the effects of the temperature and system size on the results. Among these parameters, the bias factor and temperature seem to be most effective in sampling the free energy landscape of melt to crystal transition and reaching convergence more quickly. We also demonstrate that the temperature rescaling from T > Tm is a reliable approach to recover free energy surfaces below Tm, provided that the temperature gap is below 600 K and the configurational space has been properly sampled. Finally, albeit a complete crystallization is hard to achieve with large simulation boxes, these can be reliably and effectively exploited to study the first stages of nucleation
VOLCANIC CO2 FLUX MEASUREMENTS BY TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY
Introduction
In the last decades, the use of near-infrared room-temperature diode lasers for gas sensing has grown significantly. The use of these devices, for instance in combination with optical fibers, is particularly convenient for volcanic monitoring applications [1,2]. Here, we report on the first results of the application of an open-path infrared tunable laser-based at Campi Flegrei (Southern Italy). Such Diode-laser-based measurements were performed, during two field campaigns (october 2012, and january 2013), in the attempt to obtain novel information on the current degassing unrest of Solfatara and Pisciarelli fumarolic fields.
Results and Discussion
At each site, we used an ad-hoc designed measurement geometry, using a TDLS (a Gas Finder unit) and several differently positioned retroreflectors (mirrors), to scan the fumaroles’ plume from different angles and distances. From post-processing of the data (acquired at 1 hz), we derived tomographic maps of CO2 concentrations in the plume and, by integration and combination with plume transport speed (from video cameras), we inferred the CO2 flux directly. The so-calculated fluxes, the first ever obtained at Campi Flegrei, average of 500 tons/day, and support a significant contribution of fumaroles to the total CO2 budget. The cumulative (fumarole [this study] +soil [3]) CO2 output from Campi Flegrei is finally evaluated at 1600 tons/day.
[1] Gianfrani L. et al. (2000). Appl. Phys. B-Rapid Common. 70, 467-470. [2] Richter D. et al (2002), Optics and Lasers in Engineering, Volume 37, Issues 2–3, Pages 171-186. [3] Chiodini G. et al. (2010), Journal of Geophysical Research, Volume 115, B03205, doi:10.1029/2008JB006258
Computational insights into the binding of monolayer-capped gold nanoparticles onto amyloid-\u3b2 fibrils
Amyloids-\u3b2 (A\u3b2) fibrils are involved in several neurodegenerative diseases. In this study, atomistic molecular dynamics simulations have been used to investigate how monolayer-protected gold nanoparticles interact with A\u3b2(1-40) and A\u3b2(1-42) fibrils. Our results show that small gold nanoparticles bind with the external side of amyloid-\u3b2 fibrils that is involved in the fibrillation process. The binding affinity, studied for both kinds of fibrils as a function of the monolayer composition and the nanoparticle diameter, is modulated by hydrophobic interactions and ligand monolayer conformation. Our findings thus show that monolayer-protected nanoparticles are good candidates to prevent fibril aggregation and secondary nucleation or to deliver drugs to specific fibril regions
SERS, XPS and DFT study of xanthine adsorbed on citrate-stabilized gold nanoparticles
We have studied the adsorption of xanthine, a nucleobase present in human tissue and fluids that is involved in important metabolic processes, on citrate-reduced gold colloidal nanoparticles by means of surface-enhanced Raman scattering (SERS), absorption, and X-ray photoelectron spectroscopy (XPS) measurements, along with density functional theory (DFT) calculations. The citrate anions stabilize the colloidal suspensions by strongly binding the gold nanoparticles. However, these anions do not impair the adsorption of xanthine on positively-charged active sites present on the metal surface. We have obtained the Fourier transform (FT)-SERS spectra of adsorbed xanthine by laser excitation in the near infrared spectral region, where interference due to fluorescence emission does not usually occur. In fact, the addition of chloride ions to the Au/xanthine colloid induces the aggregation of the gold nanoparticles, whose plasmonic band is shifted to the near infrared region where there is the exciting laser line of the FT\u2013Raman instrument. Hence, this analytical approach is potentially suitable for spectroscopic determination of xanthine directly in body fluids, avoiding fluorescence phenomena induced by visible laser irradiation
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