61 research outputs found

    Unregulated Custody Transfers: Why the Practice of Rehoming Should Be Considered a Form of Illegal Adoption and Human Trafficking

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    In this work, the authors prepared and characterized two different graphene oxides: one chemically synthesized (GO sample) and the other one electrochemically synthesized (GO(LiCl)). Both samples were fully characterized with atomic force microscopy (AFM), Raman and Fourier transform infrared (FTIR) spectroscopies, X-ray photo electron spectroscopy (XPS), thermal analysis (TG/DTA), and Z-potential. The antibacterial properties of both graphene oxides were studied using Gram-negative Escherichia coli ATCC 25922 and Gram-positive Staphylococcus aureus ATCC 25923 by spectrophotometer and viable cell count as indirect and direct methods, respectively. Results demonstrated that the GO(LiCl) exhibited a significant antibacterial activity compared to GO that showed a bacteriostatic effect on both pathogens. Electron microscopy analysis confirmed the antibacterial effects of both graphene oxides toward the pathogens, especially working at 80 ÎĽg/mL, for 24 h. Additional studies were also performed and both GO samples were not cytotoxic at 2 ÎĽg/mL toward neuroblastoma cells. Moreover, 2 ÎĽg of GO was suitable to carry the minimum effective dose (5.74 ng/mL) of kinase inhibitor S29 (1-(2-chloro-2-(4-chlorophenyl)ethyl)-N-(4-fluorobenzyl)-1H-pyrazolo[3,4-d] pyrimidin-4-amine), providing negligible side effects related to the S29 treatment (this latter being specifically active on the neuroblastoma cell lines (SK-N-BE(2)))

    The Online Observation Quality System for the ASTRI Mini-Array

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    The ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF), aiming to construct and operate an array of nine Imaging Atmospheric Cherenkov Telescopes (IACTs) to study gamma-ray sources at very high energy (TeV) and to perform stellar intensity interferometry observations. This contribution describes the design and the technologies used by the ASTRI team to implement the Online Observation Quality System (OOQS). The main objective of the OOQS is to perform data quality analyses in real-time during Cherenkov and intensity interferometry observations to provide feedback to both the Central Control System and the Operator. The OOQS performs the analysis of key data quality parameters and can generate alarms to other sub-systems for a fast reaction to solve critical conditions. The results from the data quality analyses are saved into the Quality Archive for further investigations. The Operator can visualise the OOQS results through the Operator Human Machine Interface as soon as they are produced. The main challenge addressed by the OOQS design is to perform online data quality checks on the data streams produced by nine telescopes, acquired by the Array Data Acquisition System and forwarded to the OOQS. In the current OOQS design, the Redis in-memory database manages the data throughput generated by the telescopes, and the Slurm workload scheduler executes in parallel the high number of data quality analyses.Comment: 8 pages, 3 figures, Proceedings of the 37th International Cosmic Ray Conference (ICRC 2021), Berlin, German

    Mirror production for the Cherenkov telescopes of the ASTRI Mini-Array and of the MST project for the Cherenkov Telescope Array

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    The Cherenkov Telescope Array (CTA) is the next ground-based Îł\gamma-ray observatory in the TeV Îł\gamma-ray spectral region operating with the Imaging Atmospheric Cherenkov Technique. It is based on almost 70 telescopes of different class diameters - LST, MST and SST of 23, 12, and 4 m, respectively - to be installed in two sites in the two hemispheres (at La Palma, Canary Islands, and near Paranal, Chile). Several thousands of reflecting mirror tiles larger than 1 m2^2 will be produced for realizing the segmented primary mirrors of a so large number of telescopes. Almost in parallel, the ASTRI Mini-Array (MA) is being implemented in Tenerife (Canary Islands), composed of nine 4 m diameter dual-mirror Cherenkov telescopes (very similar to the SSTs). We completed the mirror production for all nine telescopes of the ASTRI MA and two MST telescopes (400 segments in total) using the cold glass slumping replication technology. The results related to the quality achieved with a so large-scale production are presented, also discussing the adopted testing methods and approaches. They will be very useful for the adoption and optimization of the quality assurance process for the huge production (almost 3000 m2^2 of reflecting surface) of the MST and SST CTA telescopes

    A New Strategy for Glioblastoma Treatment: In Vitro and In Vivo Preclinical Characterization of Si306, a Pyrazolo[3,4-d]Pyrimidine Dual Src/P-Glycoprotein Inhibitor

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    20siopenOverexpression of P-glycoprotein (P-gp) and other ATP-binding cassette (ABC) transporters in multidrug resistant (MDR) cancer cells is responsible for the reduction of intracellular drug accumulation, thus decreasing the efficacy of chemotherapeutics. P-gp is also found at endothelial cells' membrane of the blood-brain barrier, where it limits drug delivery to central nervous system (CNS) tumors. We have previously developed a set of pyrazolo[3,4-d]pyrimidines and their prodrugs as novel Src tyrosine kinase inhibitors (TKIs), showing a significant activity against CNS tumors in in vivo. Here we investigated the interaction of the most promising pair of drug/prodrug with P-gp at the cellular level. The tested compounds were found to increase the intracellular accumulation of Rho 123, and to enhance the efficacy of paclitaxel in P-gp overexpressing cells. Encouraging pharmacokinetics properties and tolerability in vivo were also observed. Our findings revealed a novel role of pyrazolo[3,4-d]pyrimidines which may be useful for developing a new effective therapy in MDR cancer treatment, particularly against glioblastoma.openFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Pešić, Milica; Schenone, SilviaFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Pešić, Milica; Schenone, Silvi

    The Software Architecture and development approach for the ASTRI Mini-Array gamma-ray air-Cherenkov experiment at the Observatorio del Teide

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    The ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF) and devoted to the imaging of atmospheric Cherenkov light for very-high gamma-ray astronomy. The project is deploying an array of 9 telescopes sensitive above 1 TeV. In this contribution, we present the architecture of the software that covers the entire life cycle of the observatory, from scheduling to remote operations and data dissemination. The high-speed networking connection available between the observatory site, at the Canary Islands, and the Data Center in Rome allows for ready data availability for stereo triggering and data processing

    ASTROMETRY TECHNIQUES FOR THE CALIBRATION OF THE ASTRI TELESCOPE WITH THE VARIANCE METHOD

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    In the study of Very High-Energy (VHE) astrophysical phenomena the next generation of Imaging Atmospheric Cherenkov Telescopes (IACT) will play a key role thanks to specific ground-based astronomical observations. In this context, the ASTRI project developed a novel instrument endowed with a Schwarzschild-Couder dual-mirror optical configuration (that has never been adopted before in gamma-ray astronomy) and a dedicated Cherenkov camera entirely designed by the Istituto Nazionale di Astrofisica (INAF) based on SiPM sensors. The prototype telescope ASTRI\u2013 Horn is located in Italy and carried out successfully in 2019 the techno- logy validation phase, paving the way for the realization of the MiniAr- ray: 9 identical telescopes working in stereoscopic mode to be installed in Tenerife (Canary Islands) within the next three years. However, several issues related to the pointing performances emerged during operations with ASTRI\u2013Horn. Actually, the pointing calibration is generally a critical aspect for Cherenkov telescopes, as their cameras are designed for the detection of nanosecond atmospheric flashes rather than for imaging the starfield and, consequently, it is impossible to use the standard astrometry of the focal plane. Furthermore, in the case of ASTRI, the compactness of the mechanical structure prevents from installing an auxiliary monitoring camera sharing the same optical system of the telescope. Despite these difficulties, the optimization of the pointing performances is crucial for ensuring the scientific accuracy of the whole system. The present PhD thesis aims at the development and validation of new astrometric techniques for the pointing calibration of the ASTRI telescope exploiting the so-called Variance method, a statistical algorithm implemented in the Cherenkov camera electronic board. Thanks to the Variance, the AS- TRI telescope is endowed with an ancillary output owning the potentiality to image the stellar component of the night sky background in the Field of View (FoV), with a quite coarse angular resolution (~11\ub0, corresponding to the pixel size of the Cherenkov camera), but a relatively good sensitivity for an IACT (visual magnitude limit ~7). As we discuss in this document the Variance constitutes a unique opportunity for enhancing the pointing performances of the telescope, and we demonstrate that our procedures offer a chance to reach the critical accuracy level required for achieving the scientific objectives of the ASTRI project. Unfortunately, in this period the COVID-19 pandemic and other accidental events, heavily delayed the maintenance operations on the ASTRI\u2013 Horn telescope, and up to now it is still impossible to make new observations dedicated to the validation of our procedures, hence only data taken in previous months were used. As in any other experimental activity, new data taken on purpose would have considerably facilitated our work, but due to the present situation, we focused our attention on Variance data available in the ASTRI archive that has never been explored before. The resulting work represents the first complete and detailed analysis of the Variance method together with its numerous unexplored applications. Our custom astrometry techniques allowed us to reveal that ASTRI\u2013Horn was affected by two kinds of systematic errors, that we characterized and measured for the first time. The experience gained with archive data allowed us to understand how to apply our routines for calibrating the incoming ASTRI MiniArray, indicating an effective strategy to match the crucial requirement for the pointing accuracy. The resulting procedure has already been inserted into the calibration plan of the MiniArray and its Online Observation Quality System (OOQS). The structure of the present document is articulated in eight chapters and three appendices, whose content can be summarized as follows. Chapter 1 presents the status of the art in VHE astrophysics, focusing on the observational features of cosmic rays and gamma rays, together with a description of the main open questions in this research field. Chapter 2 is dedicated to IACTs, presenting their history and operating principles, and introducing the major examples of instruments currently in activity worldwide. Chapter 3 focuses on the ASTRI project, presenting both the prototype telescope ASTRI\u2013Horn and the incoming observatory of the MiniArray. In particular, it is reported a detailed description of the most relevant sub-systems for this thesis: the camera, the optical scheme, and the pointing strategy. Chapter 4 goes into the details of the Variance method. A technical description of its functioning at the electronic level is provided at first, while the core of the chapter is dedicated to our routines for the production of sky images and their calibration. Chapter 5 reports specific tools and procedures that we developed for the analysis of Variance images: the astrometric calibration, the de-convolution of the star signal, and the transformation function to correct the artifacts introduced by the geometric arrangement of the pixels. Chapter 6 describes the algorithm to assess the alignment of the Cherenkov camera to the optical axis of the telescope exploiting the apparent rotation of the FoV during long observing runs in tracking mode. Chapter 7 shows a custom procedure for the star identification developed on purpose for Variance images (as it is impossible to adopt the standard astrometry software for their analysis) allowing to monitor in real-time the actual pointing direction of the telescope. Chapter 8 contains the concluding remarks. It summarizes the main results achieved in this thesis, highlighting their importance but also some limitations and suggesting further improvements. Future perspectives of this work are briefly presented at last, with particular attention to its implementation on the incoming ASTRI MiniArray. At the end of this document, three appendices report additional/complementary material concerning respectively metrological techniques for the inspection of shape and reflectivity of primary mirror segments (A), more details about the software developed for this thesis and the access to it (B), and the massive activity of outreach and education carried out during the doctoral period in the field of Cherenkov astronomy (C)

    Cosmos-lovers' symphonic guide to the galaxy

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    In the past, several authors highlighted analogies between classical music and astronomy fundamentals, comparing acoustic and melody features with the characteristics of cosmic objects. However, we believe that a more profound con- nection between the two disciplines can be explored, considering the harmonic struc- ture and the formal arrangement of symphonic compositions. This new approach can provide a more insightful understanding of both music theory and astrophysics, inspiring both music and physics lovers. In this contribution, we present the format and content of the event “Cosmos-lovers’ symphonic guide to the galaxy”, a show imagined and conceived on the basis of this new perspective on the valuable bino- mial of music and astronomy. During this event, astrophysicist Simone Iovenitti and orchestra conductor Ruben Jais present the analogies between the universe’s evolution and symphonies by Rebel, Rameau, and Ives, played by the Symphonic Orchestra of Milan. Images, animations, and videos are projected in the concert hall both during explanations and the live performance, ensuring a very immersive experience to the audience
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