The degradation of monumental stones resulting from the mutual interaction between mechanical actions and environment/pollution conditions is investigated here. In particular, the stone degradation is estimated as a function of the environmental conditions and the prediction of damaging phenomena, which can compromise permanently the fruition of monuments. This is done through a macroscopic phenomenological model which accounts for the main aspects of the problem: the chemical reaction and the mechanical behavior of stones. The sulphation reaction and the diffusion of the pollutant agents are described by suitable differential equations coupled with a variational formulation of fracture mechanics. The proposed model permits to evaluate how much aggressive atmospheric agents contribute to the decay of the mechanical properties of the stones as well as to establish the impact of the synergic chemical aggression and stress state. The latter is also influenced by the chemical reaction and by the evolving mechanical properties of the material. The main features of this approach are illustrated by specific numerical simulations.

Innovative approach: it is one of the first real scientific contacts between the mathematical community and the experts in cultural heritage Effective multidisciplinary interaction: the results of concrete collaboration projects between research groups dealing with the degradation of the historical and artistic heritage are presented Development potential: the possibility of finding suitable mathematical models to provide an effective and non-invasive predictive analysis tool can be a fundamental task in the cultural heritage conservation field

The present work is motivated by the development of a mathematical model mimicking the mechanisms observed in lab-on-chip experiments, made to reproduce on microfluidic chips the in vivo reality. Here we consider the Cancer-on-Chip experiment where tumor cells are treated with chemotherapy drug and secrete chemical signals in the environment attracting multiple immune cell species. The in silico model here proposed goes towards the construction of a "digital twin" of the experimental immune cells in the chip environment to better understand the complex mechanisms of immunosurveillance. To this aim, we develop a tumor-immune microfluidic hybrid PDE-ODE model to describe the concentration of chemicals in the Cancer-on-Chip environment and immune cells migration. The development of a trustable simulation algorithm, able to reproduce the immunocompetent dynamics observed in the chip, requires an efficient tool for the calibration of the model parameters. In this respect, the present paper represents a first methodological work to test the feasibility and the soundness of the calibration technique here proposed, based on a multidimensional spline interpolation technique for the time-varying velocity field surfaces obtained from cell trajectories.

The present paper represents a first methodological work for the construction of a robust and accurate algorithm for the solution of an inverse problem given by the identification of the parameters of a lumped mathematical model of fetal circulation introduced by G. Pennati et al. (1997). The underlying estimation techniques here applied are two global search meth- ods, respectively a Parameter Space Investigation (PSI) and the Ensemble Kalman Filter (EnKF), with a refinement performed with a local search method, i.e. Levenberg- Marquardt method (LM). The results here presented show the soundness of our methodology and opens the possibility to apply these techniques for the parameter identification of waveforms obtained from Doppler clinical measurements in the next future. Our final goal is to build a non-invasive simulation tool for the description of the circulation of fetuses in the context of a patient-specific model in order to help clinicians in early diagnosis of pathologies like cardiac distress or growth retardation.

Il documento offre un resoconto dettagliato dell'evento denominato 'Giornate CNR-IAC, di formazione alla comunicazione della scienza', tenutosi a Roma presso la Sede CNR-IAC di Via dei Taurini il 12-13 febbraio 2020, dalle fasi di preparazione e co-definizione del programma, allo svolgimento, all'analisi del questionario di gradimento. L'obiettivo delle giornate CNR-IAC di formazione alla comunicazione della scienza, co-organizzate da CNR-IAC, CNR-DSSTTA e CNR-Ufficio Comunicazione, è squello di migliorare le capacità di comunicazione scientifica dei ricercatori relativamente alle aree tematiche proprie dell'Istituto e verso differenti target, valorizzando lo scambio interdisciplinare e la pratica di esperienze di comunicazione interpersonale (verbale e non verbale), anche attraverso lo svolgimento di attività pratiche. Il lavoro svolto e i risultati raggiunti proiettano l'esperienza verso la definizione di un format da replicare e mettere a sistema a livello di singolo Istituto e di Ente.

Science et BD, comme sauvagarder la rigueur en situations extrêmes

L'Intelligenza Artificiale nasce come disciplina negli anni Cinquanta e negli ultimi anni ha avuto una vera e propria esplosione: nei cellulari, nei computer, nell'analisi delle immagini biomediche e nel riconoscimento del linguaggio naturale, tra le tantissime applicazioni. Ma come si è arrivati a questo? Cosa ci si aspetta? Questa storia di Diego Cajelli disegnata da Andrea Scoppetta è nata grazie alla collaborazione con l'AIxIA (Associazione Italiana per l'Intelligenza Artificiale) e ci parla di N3well. Che è anche una macchina.

Impossibile sopravvalutare l'importanza di Leonardo Pisano, detto "il Fibonacci". Agli inizi del XIII secolo il suo Liber Abbaci porta in Occidente i numeri indo-arabi e la notazione posizionale che usiamo ancora oggi. Descrive inoltre numerosi problemi pratici di grande importanza per i mercanti dell'epoca, spiegando come risolverli con "i nuovi numeri" e i raffinati metodi di calcolo (oggi diremmo "algoritmi") da lui importati. Negli 850 anni dalla nascita, Comics&Science lo ricorda in collaborazione con il Museo degli Strumenti per il Calcolo, l'Università di Pisa, e naturalmente con Il libro di Leonardo, la storia a fumetti che Claudia Flandoli ambienta nella Pisa dell'epoca che accoglie il suo Figliol Prodigo, carico di entusiamo e nuove conoscenze.

Background and Objective: The paper focuses on the numerical strategies to optimize a plasmid DNA delivery protocol, which combines hyaluronidase and electroporation. Methods: A well-defined continuum mechanics model of muscle porosity and advanced numerical optimization strategies have been used, to propose a substantial improvement of a pre-existing experimental protocol of DNA transfer in mice. Our work suggests that a computational model might help in the definition of innovative therapeutic procedures, thanks to the fine tuning of all the involved experimental steps. This approach is particularly interesting in optimizing complex and costly protocols, to make in vivo DNA therapeutic protocols more effective. Results: Our preliminary work suggests that computational model might help in the definition of innovative therapeutic protocol, thanks to the fine tuning of all the involved operations. Conclusions: This approach is particularly interesting in optimizing complex and costly protocols for which the number of degrees of freedom prevents a experimental test of the possible configuration.

The aim of this preliminary study is to understand and simulate the hydric behaviour of a porous material in the presence of protective treatments. In particular, here the limestone Lumaquela deAjarte is considered before and after the application of the silane-based product ANC. A recently developed mathematical model was applied in order to describe the capillary rise of water in stone specimens. The model was calibrated by using experimental data concerning the water absorption by capillarity in both treated and untreated stone specimens. With a suitable calibration of the main parameters of the model and of the boundary conditions, it was possible to reproduce the main features of the experimentally observed phenomenon.

The migration of endothelial cells (ECs) is critical for various processes including vascular wound healing, tumor angiogenesis, and the development of viable endovascular implants. Recent observations (time-lapse imaging over 12hr periods) in our laboratory of ECs cultured on line patterns - surfaces where cellular adhesion is limited to 15 ?m wide lines - have demonstrated the presence of three distinct migration phenotypes: a) running - cells are polarized and migrate continuously and persistently on the adhesive lines with possible directional changes, b) undecided - cells are elongated and exhibit periodic changes in the direction of their polarization and minimal net migration, and c) tumbling-like - cells migrate persistently for a certain amount of time but then stop and round up for a few hours before spreading again and resuming migration. Because EC migration is regulated by intracellular ATP levels and cellular elongation induced ATP release, we hypothesize that the three migration phenotypes on line patterns, which translate into different cell length variations in time, are related to different intracellular ATP profiles. Thus, we have developed a mathematical model to provide a description of the complex interactions between cell length, cytoskeletal (F-actin) organization, and intracellular ATP concentration. To identify the parameters that reproduce the experimental observations, we have implemented an optimization procedure that yields the parameter values that best fit the experimental data on cell lengths. The results show that depending on the parameter values adopted for the simulations, the different ATP profiles can indeed be obtained. Future work will focus on providing experimental evidence for the involvement of intracellular ATP in determining the three types of migration behavior.

In this work we developed a mathematical model describing the crystallization process of salt dissolved in water flowing within a porous medium (in this case the common brick). Starting from this model a numerical tool was developed that allows to describe the effects of salt penetrating inside porous media and to forecast the effects of the application of crystallization inibitors.

t. The present work was inspired by the recent developments in laboratory experiments made on chip, where culturing of multiple cell species waspossible. The model is based on coupled reaction-diffusion-transport equationswith chemotaxis, and takes into account the interactions among cell populations and the possibility of drug administration for drug testing effects.Our effort was devoted to the development of a simulation tool that is able toreproduce the chemotactic movement and the interactions between differentcell species (immune and cancer cells) living in microfluidic chip environment.The main issues faced in this work are the introduction of mass-preservingand positivity-preserving conditions involving the balancing of incoming andoutgoing fluxes passing through interfaces between 2D and 1D domains of thechip and the development of mass-preserving and positivity preserving numerical conditions at the external boundaries and at the interfaces between 2Dand 1D domains

In this paper we propose and study a hybrid discrete-continuous mathematical model of collective motion under alignment and chemotaxis effect. Starting from paper [23], in which the Cucker-Smale model [22] was coupled with other cell mechanisms, to describe the cell migration and self-organization in the zebrafish lateral line primordium, we introduce a simplified model in which the coupling between an alignment and chemotaxis mechanism acts on a system of interacting particles. In particular we rely on a hybrid description in which the agents are discrete entities, while the chemoattractant is considered as a continuous signal. The proposed model is then studied both from an analytical and a numerical point of view. From the analytic point of view we prove, globally in time, existence and uniqueness of the solution. Then, the asymptotic behaviour of a linearised version of the system is investigated. Through a suitable Lyapunov functional we show that for t -> +infinity, the migrating aggregate exponentially converges to a state in which all the particles have a same position with zero velocity. Finally, we present a comparison between the analytical findings and some numerical results, concerning the behaviour of the full nonlinear system.

We consider a simple example of a partially dissipative hyperbolic system violating the Shizuta-Kawashima condition, ie such that some eigendirections do not exhibit dissipation at all. In the space-time resonances framework introduced by Germain, Masmoudi and Shatah, we prove that, when the source term has a Nonresonant Bilinear Form, as proposed by Pusateri and Shatah CPAM 2013, the formation of singularities is prevented, despite the lack of dissipation. This allows us to show that smooth solutions to this preliminary case-study model exist globally in time.

Report del convegno "MACH2019", svolto a Roma in data 25-29 marzo 2019, co-organizzato da Università degli Studi di Milano, Istituto per le Applicazioni del Calcolo M. Picone, Università degli Studi di Sassari, finanziato da Università degli Studi di Milano, Istituto per le Applicazioni del Calcolo M. Picone e INdAM (Istituto Nazionale di Alta Matematica). Obiettivo: costruire un ponte permanente tra esperti del patrimonio culturale e la comunità matematica. Il report raccoglie info sul convegno (focus, topics, data e location, organizzatori, speaker e partecipanti sponsors e attività extra), dati sui partecipanti, agenda ed abstract e prossimi passi (proceedings). Anno: 2019 (8 aprile)

Pubblicazione divulgativa della collana Comics&Science dedicato all'astrofisica

volume divulgativo dedicato alla tavola periodica della serie Comics&Science

We consider an evolution system describing the phenomenon of marble sulphation of a monument, accounting of the surface rugosity. We first prove a local in time well posedness result. Then, stronger assumptions on the data allow us to establish the existence of a global in time solution. Finally, we perform some numerical simulations that illustrate the main feature of the proposed model.

In this paper, we consider a class of models describing multiphase fluids in the framework of mixture theory. The considered systems, in their more general form, contain both the gradient of a hydrostatic pressure, generated by an incompressibility constraint, and a compressible pressure depending on the volume fractions of some of the different phases. To approach these systems, we propose an approximation based on the Leray projection, which involves the use of a symbolic symmetrizer for quasi-linear hyperbolic systems and related paradifferential techniques. In two space dimensions, we prove the well-posedness of this approximation and its convergence to the unique classical solution to the original system. In the last part, we shortly discuss the three dimensional case.