The LHAASO PeVatron bright sky: what we learned

The recent detection of 12 gamma-ray Galactic sources well above E > 100 TeV by the LHAASO observatory has been a breakthrough in the context of Cosmic Ray (CR) origin search. Although most of these sources are unidentified, they are often spatially correlated with leptonic accelerators, like pulsar and pulsar wind nebulae (PWNe). This dramatically affects the paradigm for which a gamma-ray detection at E > 100 TeV implies the presence of a hadronic accelerator of PeV particles (PeVatron). Moreover, the LHAASO results support the idea that sources other than the standard candidates, Supernova Remnants, can accelerate Galactic CRs. In this context, the good angular resolution of future Cherenkov telescopes, such as the ASTRI Mini-Array and CTA, and the higher sensitivity of future neutrino detectors, such as KM3NeT and IceCube-Gen2, will be of crucial importance. In this brief review, we want to summarize the efforts done up to now, from both theoretical and experimental points of view, to fully understand the LHAASO results in the context of the CR acceleration issue.Comment: Accepted for the special Issue "High Energy Multi-Messenger Astrophysics: Latest Research and Reviews" of the journal "Applied Science

The Orion Region: Evidence of enhanced cosmic-ray density in a stellar wind forward shock interaction with a high density shell

Context. In recent years, an in-depth gamma-ray analysis of the Orion region has been carried out by the AGILE and Fermi-LAT (Large Area Telescope) teams with the aim of estimating the H2-CO conversion factor, XCO. The comparison of the data from both satellites with models of diffuse gamma-ray Galactic emission unveiled an excess at (l,b)=[213.9, -19.5], in a region at a short angular distance from the OB star k-Ori. Possible explanations of this excess are scattering of the so-called "dark gas", non-linearity in the H2-CO relation, or Cosmic-Ray (CR) energization at the k-Ori wind shock. Aims. Concerning this last hypothesis, we want to verify whether cosmic-ray acceleration or re-acceleration could be triggered at the k-Ori forward shock, which we suppose to be interacting with a star-forming shell detected in several wavebands and probably triggered by high energy particles. Methods. Starting from the AGILE spectrum of the detected gamma-ray excess, showed here for the first time, we developed a valid physical model for cosmic-ray energization, taking into account re-acceleration, acceleration, energy losses, and secondary electron contribution. Results. Despite the characteristic low velocity of an OB star forward shock during its "snowplow" expansion phase, we find that the Orion gamma-ray excess could be explained by re-acceleration of pre-existing cosmic rays in the interaction between the forward shock of k-Ori and the CO-detected, star-forming shell swept-up by the star expansion. According to our calculations, a possible contribution from freshly accelerated particles is sub-dominant with respect the re-acceleration contribution. However, a simple adiabatic compression of the shell could also explain the detected gamma-ray emission. Futher GeV and TeV observations of this region are highly recommended in order to correctly identify the real physical scenario.Comment: 8 pages, 5 figures, accepted by A&

Using Medicinal Plants in Valmalenco (Italian Alps): From Tradition to Scientific Approaches

This ethnobotanical survey was carried out in Caspoggio (Valmalenco, SO, Italy) with the purpose of investigating the traditional uses of medicinal plants. Moreover, a bibliographic research meant to validate or refute the uses, focusing on the potentially responsible compounds, was performed. Fifty-nine species, attributable to 30 families (Asteraceae, Pinaceae, Malvaceae, and Lamiaceae the most cited), were mentioned. Arnica montana, anti-inflammatory for traumas and musculoskeletal pains; Pinus mugo, expectorant; Malva sylvestris, anti-inflammatory and soothing; Achillea moschata, digestive. The compounds, responsible for the therapeutic activities, are often polyphenols and terpenoids: helenanin in A. montana, -pinene, -3-carene, and limonene in P. mugo, gossypin and malvin in M. sylvestris, luteolin and apigenin in A. moschata. Scientific evidence for at least one of the traditional activities described was found for 50 species but only in 26 out of 196 works consulted, it is possible to make a comparison between investigated extracts and traditional preparations. This study is thus a stimulus to new phytochemical investigations, mimicking as much as possible the traditional preparations. This work is part of the European Interreg Italy-Switzerland B-ICE project, aimed at creating a management model for the ongoing climate change and searching for new sources of territory valorization as attractions for tourists

Influence of silsesquioxane addition on polyurethane-based protective coatings for bronze surfaces

Two-component solvent-born polyurethane coatings for the protection of bronze from corrosion were prepared. Trisilanol-heptaisooctyl polyhedral oligomeric silsesquixane (POSS) nanoparticles were exploited to increase the coating protective efficiency. Its improvement was confirmed through a combination of characterisation techniques. In particular, the POSS addition caused an increase of the water contact angle, and an enhancement of the elastic connotation and abrasion resistance of the polyurethane coating. Potentiodynamic polarisation measurements also indicated that the coating containing POSS nanoparticles has an improved protection efficiency. Impedance spectroscopy revealed that the magnitude of low-frequency impedance of polyurethane coatings decreased more for the coating without POSS during exposure in electrolyte for thirty days. Ex situ IR reflection-absorption spectroelectrochemistry was exploited to get insight into the degradation of coatings during chronocoulometric charging at anodic potentials. IR reflection-absorption technique was also used to evaluate any possible effect of different stripper solutions on the bronze substrate

Continuing evidence that COVID-19 has influenced syphilis epidemiology in Rome

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Bioresorbable Nanostructured Chemical Sensor for Monitoring of pH Level In Vivo

Here, the authors report on the manufacturing and in vivo assessment of a bioresorbable nanostructured pH sensor. The sensor consists of a micrometer-thick porous silica membrane conformably coated layer-by-layer with a nanometer-thick multilayer stack of two polyelectrolytes labeled with a pH-insensitive fluorophore. The sensor fluorescence changes linearly with the pH value in the range 4 to 7.5 upon swelling/shrinking of the polymer multilayer and enables performing real-time measurements of the pH level with high stability, reproducibility, and accuracy, over 100 h of continuous operation. In vivo studies carried out implanting the sensor in the subcutis on the back of mice confirm real-time monitoring of the local pH level through skin. Full degradation of the pH sensor occurs in one week from implant in the animal model, and its biocompatibility after 2 months is confirmed by histological and fluorescence analyses. The proposed approach can be extended to the detection of other (bio)markers in vivo by engineering the functionality of one (at least) of the polyelectrolytes with suitable receptors, thus paving the way to implantable bioresorbable chemical sensors

A study of the learning conceptions of preservice science teachers

Este trabajo tiene por objetivo realizar un análisis de las concepciones sobre el aprendizaje de estudiantes universitarios a partir de un enfoque descriptivo, con base en el hecho de que estas concepciones presentan elementos tanto implícitos como explícitos. Los participantes fueron 74 estudiantes de segundo año de carreras de profesorados de la Facultad de Ciencias Exactas y Naturales (FCEyN) de la Universidad Nacional de Mar del Plata (UNMdP), Argentina. Las fuentes de datos fueron una definición y un dibujo sobre una situación de aprendizaje realizados por los estudiantes. En las representaciones sobre el aprendizaje los estudiantes incluyeron principalmente aspectos referidos al contenido y al contexto organizacional e interpersonal en el que se aprende. Los resultados mostraron que la definición presentó una concepción más heterogénea en sus componentes, más sofisticada que las concepciones expresadas en el dibujo, pero con elementos de una visión reproductiva del aprendizaje y un procesamiento cognitivo superficial.This work aims to perform an analysis of university student’ learning conceptions, which have both implicit and explicit elements. A descriptive approach was used. The participants were 74 second-year students of teaching programs from the Faculty of Exact and Natural Sciences (FCEyN)) from the National University of Mar del Plata (UNMdP), Argentina. The data sources were a definition and a drawing made by the students, about a learning situation. An analysis of their content was carried out to describe which elements were incorporated in each data source. In the representations about learning the students included mainly aspects related to the content and the organizational and interpersonal context in which they learn. The results showed that the definition was a more heterogeneous conception in its components, more sophisticated than the conceptions expressed in the drawing, but with elements of a reproductive vision of learning and a superficial cognitive processing

Un estudio de las concepciones de aprendizaje de los futuros profesores de ciencias en su etapa inicial de formación

Este trabajo tiene por objetivo realizar un análisis de las concepciones sobre el aprendizaje de estudiantes universitarios a partir de un enfoque descriptivo, con base en el hecho de que estas concepciones presentan elementos tanto implícitos como explícitos. Los participantes fueron 74 estudiantes de segundo año de carreras de profesorados de la Facultad de Ciencias Exactas y Naturales (FCEyN) de la Universidad Nacional de Mar del Plata (UNMdP), Argentina. Las fuentes de datos fueron una definición y un dibujo sobre una situación de aprendizaje realizados por los estudiantes. En las representaciones sobre el aprendizaje los estudiantes incluyeron principalmente aspectos referidos al contenido y al contexto organizacional e interpersonal en el que se aprende. Los resultados mostraron que la definición presentó una concepción más heterogénea en sus componentes, más sofisticada que las concepciones expresadas en el dibujo, pero con elementos de una visión reproductiva del aprendizaje y un procesamiento cognitivo superficial.Fil: Giuliani, María Florencia. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Psicología Básica, Aplicada y Tecnología. Universidad Nacional de Mar del Plata. Facultad de Psicología. Instituto de Psicología Básica, Aplicada y Tecnología; ArgentinaFil: Di Mauro, María Florencia. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; ArgentinaFil: Ferreyro, Jorgelina Anabel. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; ArgentinaFil: Varela, Martina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; ArgentinaFil: García, María Basilisa. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; Argentin

AGILE Study of the Gamma-Ray Emission from the SNR G78.2+2.1 (Gamma Cygni)

We present a study of the γ-ray emission detected by the Astrorivelatore Gamma ad Immagini LEggero-Gamma Ray Imaging Detector (AGILE-GRID) from the region of the SNR G78.2+2.1 (Gamma Cygni). In order to investigate the possible presence of γ rays associated with the SNR below 1 GeV, it is necessary to analyze the γ-ray radiation underlying the strong emission from the pulsar PSR J2021+4026, which totally dominates the field. An “off-pulse” analysis has been carried out, by considering only the emission related to the pulsar off-pulse phase of the AGILE-GRID light curve. We found that the resulting off-pulsed emission in the region of the SNR—detected by the AGILE-GRID above 400 MeV—partially overlaps the radio shell boundary. By analyzing the averaged emission on the whole angular extent of the SNR, we found that a lepton-dominated double-population scenario can account for the radio and γ-ray emission from the source. In particular, the MeV-GeV averaged emission can be explained mostly by Bremsstrahlung processes in a high density medium, whereas the GeV-TeV radiation can be explained by both Bremsstrahlung (E ≲ 250 GeV) and inverse Compton processes (E ≳ 250 GeV) in a lower density medium