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We investigate the turbulent energy cascade in the near-Sun solar wind by means of a high-resolution fully kinetic simulation initialised with average plasma conditions measured by Parker Solar Probe during its first solar encounter. Our simulation models the electron-scale electric field fluctuations with unprecedented accuracy. This allows us to perform the first detailed analysis of the different terms of the electric field in the generalised Ohm's law (MHD, Hall, and electron pressure terms) at ion and electron scales, both in physical space and in Fourier space. Such analysis suggests rewriting the Ohm’s law in a different form, which disentangles the contribution of different underlying plasma mechanisms in each range of scales. This provides a new insight on how energy in the turbulent electromagnetic fields is transferred through ion and electron scales and seems to favour the role of pressure-balanced structures versus waves. We finally test our assumptions and numerical results by analysing measurements of the magnetic field, electric field, and ion and electron velocity distributions and their moments performed by Solar Orbiter and Parker Solar Probe. Preliminary results show a remarkable agreement with our theoretical expectations inspired by our simulations., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

We present results from a multiscale spatiotemporal study of 3D Hall-MHD and hybrid kinetic numerical simulations of decaying plasma turbulence employing the same numerical setup and reproducing typical solar-wind conditions. The aim is to understand whether the turbulent energy cascade below ion characteristic scales is driven by nonlinear wave-like interactions or is dominated by plasma instabilities taking place in coherent structures, such as current sheets. Moreover, we are interested to assess the role of ion-kinetic physics. By combining Fourier analysis with Fast Iterative Filtering, we compute the 3D k-ω power spectrum of magnetic, velocity, and density fluctuations at the time when turbulence has fully developed. We find that such fluctuations at characteristic ion-kinetic scales consist of anisotropic perturbations with temporal frequencies smaller than the ion-cyclotron frequency. Further analysis reveals that the polarization properties of such perturbations are not compatible with those of wave-like fluctuations.Furthermore, the comparison of the Hall-MHD model with the hybrid kinetic one allows to assess the role of ion-kinetic processes in the turbulent dissipation at sub-ion scales. These results confirm our previous findings obtained with 2D simulations and favor a scenario in which turbulence at ion-kinetic scales is driven by localized intermittent structures rather than by nonlinear interactions of wave-like fluctuations.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Accepted: 2020-02-24, 資料番号: SA1190212000

Since inter-particle collisions are to a large extent negligible, the solar wind plasma is typically observed in a state far from thermodynamic equilibrium, meaning that the velocity distributions of particles of different species display significant deviations from a single Maxwellian. These deviations retain the whole history of the interaction of particles with the turbulent electromagnetic fields. Simultaneous measurements of fields and particle velocity distributions at kinetic scales made at different radial distances can help in tracking this history backwards allowing one to identify the physical mechanisms at play to heat and accelerate particles in the interplanetary medium close to the Sun and all along solar wind expansion. In this scenario, data from the Solar Wind Analyzer instrument onboard the ESA Solar Orbiter mission are very promising in addressing the kinetic physics of protons, ions and electrons in the solar wind close to the Sun. The Italian SWA-Solar Orbiter Working Group entitled "Kinetic Processes" has been formed in May 2020 and gathers scientists from several Italian and international institutions and with different expertises (theoretical modeling, observational data analysis and numerical simulations), who convene periodically to discuss these scientific subjects. The main scientific goals of this working group are (i) to maximize the scientific return of Solar Orbiter data within the Heliospheric communities and (ii) to identify open scientific questions and relevant physical problems for which Solar Orbiter data could play a key role and help scientists to find answers and explanations. Exploitation of combined measurements from the in-situ instruments (SWA, MAG, EPD and RPW) onboard Solar Orbiter will provide the unique opportunity of attacking fundamental plasma physics processes responsible for energy exchanges between fluctuations and particles. In this Abstract, we will present some of the activities carried on within the Italian SWA-Solar Orbiter WG "Kinetic Processes" in the last few months, with the aim of engaging the broader scientific community into the discussion and in preparation of the release of the first Orbiter data.

Despite more than a half-century of study, the basic physical processes responsible for heating and accelerating the solar wind are still not fully understood. These phenomena are at the center of a hot debate that is of great interest for the Solar Orbiter mission (as discussed in details in the Science Activity Plan, SAP) and are strictly linked to the turbulent nature of solar wind fluctuations which cover an extended range of spatial and temporal scales. So the identification of these physical processes is of primary importance for understanding the origins and evolution of the solar wind and its impact on the different bodies of the solar system. Moreover, in a broader context, it would allow also to achieve significant progress in our understanding of stellar astrophysics. Within this context, the Italian Solar Orbiter-SWA Working Group (WGs) on `Multiscale Physics' was created in response to the interest manifested by scientists from several Italian and international institutions on some important topics such as radial evolution of turbulence and Alfvénicity and link between fluid and kinetic scales; solar wind origin; reconnection, intermittency and particle acceleration in the turbulent solar wind (just to cite some of them), with a particular attention to the synergies with other in-situ and remote sensing instruments on board Solar Orbiter and also with other ESA and NASA missions (e.g. L1 observatories and Parker Solar Probe). The `Multiscale Physics' WG involves scientists with an extensive experience in solar wind turbulence and reconnection processes including expertise in data analysis, simulations and modeling. In this contribution, we present the activity developed so far with a particular focus on the scientific cases identified.

International audience; The exponential growth of data volume experienced by astronomy and astrophysics causes new disciplines like machine learning (ML) and data mining (DM) to gain more and more ground in these fields. Applications like clustering, feature selection, automatic classification of events are proving to be a valuable aid in exploiting space data in the era of the synergy between "pure" science and "data-driven" science. The Italian Solar Orbiter-SWA Working Group on Machine Learning and Artificial Intelligence1 together with the European Commission Horizon 2020 project AIDA2, has the scope of applying ML and DM analysis techniques to the Solar Orbiter data. The implementations are numerous. First of all these new techniques can be used to discover unexpected relations between data, can automate tasks so that they can be carried out without human intervention, and can help to forecast physical properties and events. A non-exhaustive list of these activities includes automatic detection of coronal holes in images, automatic recognition of plasma regions, prediction of solar wind properties at 1 AU, classification of solar wind type based on new indicators, analysis of particle velocity distribution functions. In addition, this Working Group will integrate the existing software developed in the context of the various heliospheric missions with the parts regarding Solar Orbiter. These packages are able to handle complex data set with ease and provide statistical analysis and visualization tools. Catalogs of scientific data are also produced, which report, among others, magnetic reconnection and particle acceleration events, detected by routines trained to browse data and select physical processes and features of interest. Here we present the project overview along with the ML and DM tools which will be used to handle and analyse Solar Orbiter data. 1.https://sites.google.com/view/italian-solar-orbiter-swa/ 2.http://www.aida-space.eu/

International audience

International audience

Resumen Este articulo presenta el diseno y puesta en marcha del primer prototipo de Campus Virtual Innova-T3D en la Corporacion Universitaria Minuto de Dios en Bogota, Colombia. La implementacion de herramientas que permiten la interconexion de plataformas E-Learning con Mundos Virtuales 3D, configuran un espacio innovador de aprendizaje que potencia de manera significativa el trabajo colaborativo y la construccion del conocimiento colectivo. La propuesta no solo busca crear un espacio inmersivo de aprendizaje, sino que ademas establece las mejores practicas de implementacion de estos mundos a la educacion universitaria. Palabras clave: mundos virtuales 3D, ambientes inmersivos, gestion del conocimiento, aprendizaje colaborativo 3D Virtual Environments, Educational Alternative for Promoting Collaborative Learning and Knowledge Management in Uniminuto Abstract This paper presents the design and implementation of the first prototype of the Virtual Campus Innova-T3D at the Corporacion Universitaria Minuto de Dios in Bogota, Colombia. The implementation of tools that allow the interconnection of E-Learning Platforms with 3D Virtual Worlds, form an innovative space for learning that significantly enhances the collaborative and collective knowledge construction. The proposal not only seeks to create an immersive space for learning, but also establishes the best practices for implementing these worlds at university education.

Este artículo presenta el diseño y puesta en marcha del primer prototipo de Campus Virtual lnnova-T3D en la Corporación Universitaria Minuto de Dios en Bogotá, Colombia. La implementación de herramientas que permiten la interconexión de plataformas E-Learning con Mundos Virtuales 3D, configuran un espacio innovador de aprendizaje que potencia de manera significativa el trabajo colaborativo y la construcción del conocimiento colectivo. La propuesta no solo busca crear un espacio inmersivo de aprendizaje, sino que además establece las mejores prácticas de implementación de estos mundos a la educación universitaria. This paper presents the design and implementation of the first prototype of the Virtual Campus lnnova-T3D at the Corporación Universitaria Minuto de Dios in Bogotá, Colombia. The implementation of tools that allow the interconnection of E-Learning Platforms with 3D Virtual Worlds, form an innovative space for learning that significantly enhances the collaborative and collective knowledge construction. The proposal not only seeks to créate an immersive space for learning, but also establishes the best practices for implementing these worlds at university education.

This study aims to verify whether there are any macroeconomic variables that have significant power in predicting the dynamics of financial markets. In particular, we want to identify an econometric model that can guide the strategies of operators in building their investment portfolios. The analysis considers the US market during a period of rapid economic change and high volatility of stock prices.The authors evidence that a number of variables have systematically influenced the evolution of the stock market during the period under review. These variables are the macroeconomic indicators that relate to the sentiment of consumers and companies, the term structure, the premium for the risk of default, the rate of growth of the monetary base, the oil price and sea freight rates.

Simple Summary RAB7A (RAs-related in Brain 7A) is a master regulator of intracellular traffic controlling transport to late endosomes and lysosomes, two organelles of the endocytic pathway important for degradation. Thanks to this function, RAB7A is also involved in cellular processes linked to cancer, such as apoptosis, cytoskeletal reorganization, and cell migration. Therefore, the interest in the role of RAB7A in cancer progression is increasing. Previously, we demonstrated that RAB7A regulates phosphorylation and assembly of vimentin, a cytoskeletal intermediate filament protein, which is also an important mesenchymal marker of cancer cells. The aim of the present study is the identification of the kinases responsible for vimentin phosphorylation whose activity is affected by the modulation of RAB7A expression. We found that RAB7A is able to regulate AKT (also called protein kinase B or PKB) and PAK1 (P21-Activated Kinase 1) and several of their downstream effectors, which control proliferation, apoptosis, survival, migration, and invasion. These data suggest that RAB7A could have a key role in cancer development. Abstract RAB7A is a small GTPase that controls the late endocytic pathway but also cell migration through RAC1 (Ras-related C3 botulinum toxin substrate 1) and vimentin. In fact, RAB7A regulates vimentin phosphorylation at different sites and vimentin assembly, and, in this study, we identified vimentin domains interacting with RAB7A. As several kinases could be responsible for vimentin phosphorylation, we investigated whether modulation of RAB7A expression affects the activity of these kinases. We discovered that RAB7A regulates AKT and PAK1, and we demonstrated that increased vimentin phosphorylation at Ser38 (Serine 38), observed upon RAB7A overexpression, is due to AKT activity. As AKT and PAK1 are key regulators of several cellular events, we investigated if RAB7A could have a role in these processes by modulating AKT and PAK1 activity. We found that RAB7A protein levels affected beta-catenin and caspase 9 expression. We also observed the downregulation of cofilin-1 and decreased matrix metalloproteinase 2 (MMP2) activity upon RAB7A silencing. Altogether these results demonstrate that RAB7A regulates AKT and PAK1 kinases, affecting their downstream effectors and the processes they regulate, suggesting that RAB7A could have a role in a number of cancer hallmarks.

Il saggio si concentra sull'importanza di Dante nelle opere poetiche e teoriche di T.S.Eliot e Ezra Pound. Dante è un punto costante di riferimento - nella grande tradizione occidentale - per i due grandi esponenti dell'avanguardia del Novecento, non solo per la sua concezione della poesia, ma anche per la funzione etica che questa può esercitare in un grave momento di crisi dei valori come quello intorno alla Prima Guerra Mondiale.