101 research outputs found

    Editors' Introduction

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    The thought of P.A. Florensky is a peculiar expression of Russian philosophy and, more generally, of Russian cultural identity. At the same time, it can nevertheless be regarded as a legitimate heir to the cultural tradition which from its powerful Ionian roots unfolds through the peaks and abysses of Western philosophy stricto sensu, up to the ultimate crises of contemporary thought..

    Innovative application of NIR-AOTF and MRI to study water behaviour in cut flower

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    In order to study the water status of cut flowers, a comparison study was made between flowers stored in water and flowers stored «dry pack», by using a portable NIR (near infrared)-AOTF(acousto-optical tunable filter) instrument and MRI (magnetic resonance imaging). As model flower, Zantedeschia aethiopica (commercially known as Calla lily) was used. To predict the weight loss and water content by NIR-AOTF, cut flowers were dried in a cold room at 10°C (±1°C) and 85% (±5%) relative humidity (RH), and measured for weight loss. For MRI application, 4 and 20°C storage temperatures were used for flowers kept in water or dry; two stem sections, basal and middle, were measured. Significant correlation results for weight loss and water content ( R2 in calibration = 0.98 for estimated % of water loss and 0.96 for % of water content; R2 cv = 0.95 and 0.90) were obtained by NIR-AOTF spectra acquisitions. MRI detected vessel degradation in the stem of the water-stored flowers at 4°C but at 20°C in dry storage no vessel degradation appeared and images were correlated with dry matter values. The use of image software allowed the transformation of images in normalized population and pixel intensity, which gave hints about the potential use of these data to combine with NIR-AOTF data. NIR-AOTF, an easy-to-use and non destructive instrument, can be used to predict the vase life of cut flowers by measuring water content or weight loss. MRI is a powerful tool to identify the plugging of vessels but it is destructive; the image software used represents a useful tool to correlate MRI with NIR-AOTF to predict vessel plugging

    Antibacterial and antioxidant properties of humic substances from composted agricultural biomasses

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    Background: Bioactive components isolated from composted agricultural biomasses have been receiving progressive attention, because they may improve the antibiotic susceptibility of drug resistant bacterial strains. Here, three different humic substances (HS) were isolated from composted artichoke (HS-CYN) and pepper (HS-PEP) wastes, and from coffee grounds (HS-COF), and characterized by infrared spectrometry, NMR spectroscopy, thermochemolysis–GC/MS, and high-performance size-exclusion chromatography. The antibacterial activity of HS was evaluated against some pathogenic bacterial strains, while their bioactivity was determined by a germination assay on basil (Red–Violet variety) seeds. Results: HS-CYN and HS-PEP exhibited the largest antioxidant activity and most significant antimicrobial capacity against some gram-positive bacterial strains, such as Staphylococcus aureus and Enterococcus faecalis. The same HS determined a significant increase of both root and epicotyls in seed germination experiments. The bioactivity of HS was related not only to their specific molecular composition but also to the conformational stability of their suprastructures. Specifically, the greatest bioactive and antimicrobial properties were related to the largest abundance of hydrophobic aromatic and phenolic components and to a more rigid conformational arrangement, that, in turn, appeared to be related to a small fragmentation degree of lignin structures. Conclusions: Our results showed that extraction of bioactive HS from green composts may be a sustainable and eco-compatible way to valorise agricultural byproducts. HS may be indeed exploited as substrates to produce novel materials not only to improve plant productivity but also for medical applications. Graphical Abstract: [Figure not available: see fulltext.

    Development of second order Theory of Mind: assessment of environmental influences using a dynamic system approach

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    Theory of Mind (ToM) refers to the ability to attribute beliefs to oneself and others. The present study used a dynamic systems approach to assess how environment may affect the development of second-order ToM (e.g., John knows that Mary knows that he went out yesterday). ToM is divided into two major dimensions: comprehension (i.e., to understand a mental state) and prediction (i.e., to predict someone else’s future behaviour or mental state). Two age groups were assessed: 5-6 and 10-11 years old children. In both age groups, participants were assigned to a condition of “Support” (help provided) or “Non-Support” (help not provided). Results show that second-order ToM follows a dynamic growth law that depends on support. Support facilitates performance in ToM production (i.e., to predict one’s future behaviour) for both the 5-6 and 10-11 year old children. Interestingly, the 5-6 year olds who received support presented an increase in the second-order prediction performance at the expense of the second-order comprehension, suggesting that a temporary dip in comprehension performance may facilitate the development of mental rules to predict one’s future behaviour

    Dust evolution with MUPPI in cosmological volumes

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    We study the evolution of dust in a cosmological volume using a hydrodynamical simulation in which the dust production is coupled with the MUPPI (MUlti Phase Particle Integrator) sub-resolution model of star formation and feedback. As for the latter, we keep as reference the model setup calibrated previously to match the general properties of Milky Way-like galaxies in zoom-in simulations. However, we suggest that an increase of the star formation efficiency with the local dust-to-gas ratio would better reproduce the observed evolution of the cosmic star formation density. Moreover, the paucity of quenched galaxies at low redshift demands a stronger role of active galactic nucleus feedback. We tune the parameters ruling direct dust production from evolved stars and accretion in the interstellar medium to get scaling relations involving dust, stellar mass and metallicity in good agreement with observations. In low-mass galaxies, the accretion process is inefficient. As a consequence, they remain poorer in silicate and small grains than higher mass ones. We reproduce reasonably well the few available data on the radial distribution of dust outside the galactic region, supporting the assumption that the dust and gas dynamics are well coupled at galactic scales

    Red Horizontal Branch stars: an asteroseismic perspective

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    Robust age estimates of red giant stars are now possible thanks to the precise inference of their mass based on asteroseismic constraints. However, there are cases where such age estimates can be highly precise yet very inaccurate. An example is giants that have undergone mass loss or mass transfer events that have significantly altered their mass. In this context, stars with "apparent" ages significantly higher than the age of the Universe are candidates as stripped stars, or stars that have lost more mass than expected, most likely via interaction with a companion star, or because of the poorly understood mass-loss mechanism along the red-giant branch. In this work we identify examples of such objects among red giants observed by Kepler\textit{Kepler}, both at low ([Fe/H] â‰Č−0.5 \lesssim -0.5) and solar metallicity. By modelling their structure and pulsation spectra, we find a consistent picture confirming that these are indeed low-mass objects consisting of a He core of ≈0.5 M⊙\approx 0.5 \, M_\odot and an envelope of ≈0.1−0.2 M⊙\approx 0.1 - 0.2 \, M_\odot. Moreover, we find that these stars are characterised by a rather extreme coupling (q≳0.4q \gtrsim 0.4) between the pressure-mode and gravity-mode cavities, i.e. much higher than the typical value for red clump stars, providing thus a direct seismic signature of their peculiar structure. The complex pulsation spectra of these objects, if observed with sufficient frequency resolution, hold detailed information about the structural properties of likely products of mass stripping, hence can potentially shed light on their formation mechanism. On the other hand, our tests highlight the difficulties associated with measuring reliably the large frequency separation, especially in shorter datasets, with impact on the reliability of the inferred masses and ages of low-mass Red Clump stars with e.g. K2 or TESS data.Comment: Accepted for publication in A&A Letter

    ViDA: a VlasovDArwin solver for plasma physics at electron scales

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    We present a Vlasov–DArwin numerical code (ViDA) specifically designed to address plasma physics problems, where small-scale high accuracy is requested even during the nonlinear regime to guarantee a clean description of the plasma dynamics at fine spatial scales. The algorithm provides a low-noise description of proton and electron kinetic dynamics, by splitting in time the multi-advection Vlasov equation in phase space. Maxwell equations for the electric and magnetic fields are reorganized according to the Darwin approximation to remove light waves. Several numerical tests show that ViDA successfully reproduces the propagation of linear and nonlinear waves and captures the physics of magnetic reconnection. We also discuss preliminary tests of the parallelization algorithm efficiency, performed at CINECA on the Marconi-KNL cluster. ViDA will allow the running of Eulerian simulations of a non-relativistic fully kinetic collisionless plasma and it is expected to provide relevant insights into important problems of plasma astrophysics such as, for instance, the development of the turbulent cascade at electron scales and the structure and dynamics of electron-scale magnetic reconnection, such as the electron diffusion region

    Methicillin-resistant Staphylococcus aureus nasal colonization in a department of pediatrics: a cross-sectional study

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    BACKGROUND: We describe methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage at admission in patients admitted to a Department of Pediatrics. METHODS: All patients received a nasal swab at admission. A questionnaire was administered and molecular genetics analyses were performed on all identified MRSA isolates. RESULTS: We enrolled 785 patients, affected with both acute and chronic diseases. MRSA nasal colonization prevalence was 1.15% (CI: 0.5607%-2.093%). Methicillin-sensitive Staphylococcus aureus (MSSA) nasal colonization prevalence at admission was 19.75% (CI 17.07%-22.64%). Only one MRSA isolate carried the SCCmec V variant; all other isolates carried the SCCmecIV variant. Five out of 9 MRSA-colonized patients had an underlying condition. Antibiotic therapy in the previous 6 months was a protective factor for both MRSA (OR 0,66; 95% CI: 0,46-0,96) and MSSA (OR 0,65; 95% CI: 0,45-0,97) colonization. A tendency to statistical significance was seen in the association between hospitalization in the 6 months prior to admission and MRSA colonization at admission (OR 4,92; 95% CI: 0,97-24,83). No patient was diagnosed with an S. aureus infection during hospitalization. CONCLUSIONS: The majority of our MRSA colonizing isolates have community origins. Nevertheless, most MRSA-colonized patients had been hospitalized previously, suggesting that strains that circulate in the community also circulate in hospital settings. Further studies should elucidate the role of children with frequent contact with health care institutions in the circulation of antibiotic resistant strains between the hospital and the community

    AI-based Data Preparation and Data Analytics in Healthcare: The Case of Diabetes

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    The Associazione Medici Diabetologi (AMD) collects and manages one of the largest worldwide-available collections of diabetic patient records, also known as the AMD database. This paper presents the initial results of an ongoing project whose focus is the application of Artificial Intelligence and Machine Learning techniques for conceptualizing, cleaning, and analyzing such an important and valuable dataset, with the goal of providing predictive insights to better support diabetologists in their diagnostic and therapeutic choices.Comment: The work has been presented at the conference Ital-IA 2022 (https://www.ital-ia2022.it/
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