Le misure restrittive a seguito dell’emergenza sanitaria hanno messo in evidenza la necessità di sperimentare nuovi strumenti e ambienti di apprendimento, in particolare per quelle discipline che ...prevedono attività laboratoriali. Per rispondere a questa esigenza è nata una collaborazione tra il Dipartimento di Fisica dell’Università di Torino e l’Équipe Formativa Territoriale del Piemonte che ha focalizzato la sua azione sulla formazione dei docenti. È stato svolto un tirocinio formativo per la progettazione, la realizzazione e la documentazione di attività di Didattica Digitale Integrata con le schede programmabili. Sono stati organizzati incontri di formazione, a cui è seguita un’attività di accompagnamento per seguirne la ricaduta all’interno delle scuole. La proposta è replicabile in altri contesti e con altre tecnologie.
We present our study on the reconstruction of photoelectron tracks in gas pixel detectors used for astrophysical X-ray polarimetry. Our work aims to maximize the performance of convolutional neural ...networks (CNNs) to predict the impact point of incoming X-rays from the image of the photoelectron track. A very high precision in the reconstruction of the impact point position is achieved thanks to the introduction of an artificial sharpening process of the images. We find that providing the CNN-predicted impact point as input to the state-of-the-art analytic analysis improves the modulation factor (\(\sim 1 \%\) at 3 keV and \(\sim 6 \%\) at 6 keV) and naturally mitigates a subtle effect appearing in polarization measurements of bright extended sources known as "polarization leakage".
The flux of positrons and electrons ($e^+ + e^-$) has been measured by the
$Fermi$ Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV.
We discuss a number of interpretations of ...Pass 8 $Fermi$-LAT $e^+ + e^-$
spectrum, combining electron and positron emission from supernova remnants
(SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic
rays with the interstellar medium. We find that the $Fermi$-LAT spectrum is
compatible with the sum of electrons from a smooth SNR population, positrons
from cataloged PWNe, and a secondary component. If we include in our analysis
constraints from AMS-02 positron spectrum, we obtain a slightly worse fit to
the $e^+ + e^-$ $Fermi$-LAT spectrum, depending on the propagation model. As an
additional scenario, we replace the smooth SNR component within 0.7 kpc with
the { individual sources} found in Green's catalog of Galactic SNRs. We find
that separate consideration of far and near sources helps to reproduce the $e^+
+ e^-$ $Fermi$-LAT spectrum. However, we show that the fit degrades when the
radio constraints on the positron emission from Vela SNR (which is the main
contributor at high energies) are taken into account. We find that a break in
the power-law injection spectrum at about 100 GeV can also reproduce the
measured $e^+ + e^-$ spectrum} and, among the cosmic-ray propagation models
that we consider, no reasonable break of the power-law dependence of the
diffusion coefficient can modify the electron flux enough to reproduce the
observed shape.
The flux of positrons and electrons (\(e^+ + e^-\)) has been measured by the \(Fermi\) Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. We discuss a number of interpretations ...of Pass 8 \(Fermi\)-LAT \(e^+ + e^-\) spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays with the interstellar medium. We find that the \(Fermi\)-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and a secondary component. If we include in our analysis constraints from AMS-02 positron spectrum, we obtain a slightly worse fit to the \(e^+ + e^-\) \(Fermi\)-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the { individual sources} found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the \(e^+ + e^-\) \(Fermi\)-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured \(e^+ + e^-\) spectrum} and, among the cosmic-ray propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.
Experiments were designed to demonstrate the actual contribution of yeast in the formation of the primary aroma during the vinification of neutral grapes. Ruché was chosen as the model wine to study ...because of its unique fragrance. A yeast strain specific for Ruché was selected using a new and rapid isolation method for red wines. The results of this study can be summarized as follows: Skins from nonaromatic white or red grapes apparently contain most of the primary aroma compounds that are revealed in the must only after contact with yeast cells under defined conditions. Similar results were obtained with the pulp and seeds fractions; however, the olfactory notes, although well characterized, differed from those obtained with skins alone. Clarification, filtration, and centrifugation of the pulp and seed fractions or sonification of the skins produce different and well-characterized olfaction notes during the contact with yeast. The primary aroma of nonaromatic white and red grapes contained in the skins can be revealed within 24−48 h of yeast contact in a synthetic nutrient medium (SNM). The primary aroma precursors extracted from the skins with methanol, water-saturated butanol, or aqueous buffer at pH 3.2, concentrated and eluted from a C18 resin column, can be transformed to the free form wine aroma markers within 6 h of contact with yeast cells in SNM. By contrast, prolonged maceration of the skins in aqueous alcoholic buffer at pH 3.2 or 1.1, at 50 or 70 °C did not release primary odors typical of wine. The individual primary aroma compounds, identified by GC-MS analysis in Ruché wine samples or in Ruché skin-yeast-SNM samples, could not explain the complexity of the typical Ruché wine odor. Only odors common to many wine varieties were identified by GC−olfactometry analysis. Keywords: Selected yeast; primary aroma; wine variety
Antiproteases are known to be present in amyloid deposits. We evaluated the possibility of using an anti-serine protease (aprotinin) labelled with technetium-99m (TcA), usually employed as a cortical ...renal tracer, for the imaging of amyloid deposits. Because of the known high uptake of TcA by the kidneys, we limited our analysis to extra-abdominal amyloid localizations. We report the scintigraphic findings observed in 24 patients with light chain amyloidosis (AL) and one with a hereditary form who were known or suspected to have extra-abdominal involvement. Planar scans obtained 100min after i.v. TcA administration showed myocardial accumulation in 11 patients, pleuropulmonary accumulation in nine, pericardial accumulation in two and localization in the neck region (thyroid, salivary glands and tongue) in eight. TcA scintigraphy was negative in five patients without clinical or laboratory evidence of extra-abdominal involvement, as well as in 12 control group patients with cardiac and renal diseases. These preliminary results indicate TcA to be a low-cost, readily available radiopharmaceutical for imaging of extra-abdominal involvement in AL type amyloidosis.
