The compositional and mineralogical analysis of fired pigments in Nasca pottery from Cahuachi (Peru) by the combined use of the portable PIXE-alpha and portable XRD techniques

Abstract An analytical protocol based on the combined use of the portable PIXE-alpha (Particle Induced X-ray Emission) and XRD (X-ray Diffraction) non destructive techniques developed at the LANDIS laboratory (Laboratorio di Analisi Non Distruttive) of the INFN–CNR (Istituto Nazionale di Fisica Nucleare–Consiglio Nazionale delle Ricerche) in Catania (Italy), was applied for the characterisation of the surface paints of some archaeological fragments of Nasca pottery from the Ceremonial Centre of Cahuachi in Southern Peru. Measurements were carried out on the black, white, red, orange and grey pigments; quantitative information on the chemical composition as well as on the mineralogical phases present on the paints were obtained. Results allowed to make some considerations about the materials and the manufacturing technique used to realise such fired pigments. It should be noted that during firing the precursor minerals composing the pigments undergo a phase transformation and their identification presents some difficulties

Introducing The Radiation-Hardened Voltage Regulators Rhfl4913 and the Rhfl6000

With the progressive scaling of the modern CMOS processes arising during the recent years, for the devices operating in space the susceptivity to the over-voltage events has increased. They have become more stringent the requirements in terms of accuracy of the supply voltage worth their reliability. For the case of CMOS memories operating at 1.5V it is essential to guarantee a variation of the nominal VOUT to within 5% including those arising on the supply voltage during the transients. Finally, for a voltage regulator operating in space one of the most salient effects are the voltage transients induced on the output by the single events (SET) that may exceed the aforementioned 5% threshold. This can be cause of damage into the circuitry fed downstream. Among the devices in ST portfolio designed to cope with the mentioned effects there are two voltage regulators, the RHFL4913 and the RHFL6000. The first one was initially developed for the harsh environment of the Large Hadron Collider. It was tested by the CERN and it was proven that it is able to operate without problems at up to 100Mrad TID at High Dose Rate without problems 1. Subsequent tests performed at low dose rates (expected in space environment), showed that this device is also ELDRS free up to 1Mrad 2. Further tests performed by NASA highlighted also a certain susceptivity to the SET (3) but this issue can be circumvented by the adoption of a properly sized up RC low pass filter put between the regulator output and the load as shown in fig.1 (4). With the above provision, this regulator is suitable for operating in space. Currently, the RHFL4913 is QMLV qualified

Vertex finding in ALICE by the use of silicon pixel layers in the Inner Tracking System

The performance of the Inner Tracking System of the ALICE detector for primary vertex estimation is discussed. A simulation study of the vertex reconstruction in ALICE through the information given by the two pixel layers is reported. Vertex resolution was studied as a function of the nominal vertex location and of the particle multiplicity

One year of tropospheri clidar measurements of aerosol extinction and backscatter

The aerosol lidar system operational at IMAA-CNR in Tito Scalo (PZ) (Southern Italy, 40°36'N, 15°44'E, 820 m above sea level) is part of the EARLINET project. Systematic lidar measurements of aerosol backscatter and extinction in the troposphere have been performed since May 2000. Aerosol backscatter measurements were performed at both 355 nm and 532 nm, while aerosol extinction coeffi cient were retrieved from simultaneous N2 Raman backscatter signals at 386.6 nm. The observations were performed on a regular schedule of two night time measurements per week (around sunset) and one daytime measurement per week (around 13:00 UTC). Furthermore, special observations concerning Saharan dust outbreaks have been carried out. Starting in May 2000 the lidar measurements performed in Tito Scalo have been collected and analysed. Preliminary results regarding the fi rst year of measurements are reported. In particular, the evolution of the aerosol integrated backscatter and extinction as well as of the mean value of the lidar ratio in the whole aerosol layer is reported. Results show clear evidence of seasonal variation of the observed parameters, with higher values and greater variability during summertime

The identification of dust heating mechanisms in nearby galaxies using Herschel 160/250 and 250/350 micron surface brightness ratios

We examined variations in the 160/250 and 250/350 micron surface brightness ratios within 24 nearby (<30 Mpc) face-on spiral galaxies observed with the Herschel Space Observatory to identify the heating mechanisms for dust emitting at these wavelengths. The analysis consisted of both qualitative and quantitative comparisons of the 160/250 and 250/350 micron ratios to H alpha and 24 micron surface brightnesses, which trace the light from star forming regions, and 3.6 micron emission, which traces the light from the older stellar populations of the galaxies. We find broad variations in the heating mechanisms for the dust. In one subset of galaxies, we found evidence that emission at <=160 microns (and in rare cases potentially at <=350 microns) originates from dust heated by star forming regions. In another subset, we found that the emission at >=250 microns (and sometimes at >=160 microns) originates from dust heated by the older stellar population. In the rest of the sample, either the results are indeterminate or both of these stellar populations may contribute equally to the global dust heating. The observed variations in dust heating mechanisms does not necessarily match what has been predicted by dust emission and radiative transfer models, which could lead to overestimated dust temperatures, underestimated dust masses, false detections of variability in dust emissivity, and inaccurate star formation rate measurements.Comment: Accepted for publication in MNRA

Tracking inside the ALICE Inner Tracking System

One of the main purposes of the ALICE Inner Tracking System (ITS) is to improve the resolution of the track parameters found in the main ALICE tracker detector, the Time Projector Chamber (TPC). Some results about tracking efficiency and resolution of track parameters obtained with a tracking code, based on the Kalman filter algorithm are presented

The Herschel Virgo Cluster Survey XVI: a cluster inventory

Herschel FIR observations are used to construct Virgo cluster galaxy luminosity functions and to show that the cluster lacks the very bright and the numerous faint sources detected in field galaxy surveys. The far-infrared SEDs are fitted to obtain dust masses and temperatures and the dust mass function. The cluster is over dense in dust by about a factor of 100 compared to the field. The same emissivity (beta) temperature relation applies for different galaxies as that found for different regions of M31. We use optical and HI data to show that Virgo is over dense in stars and atomic gas by about a factor of 100 and 20 respectively. Metallicity values are used to measure the mass of metals in the gas phase. The mean metallicity is about 0.7 solar and 50% of the metals are in the dust. For the cluster as a whole the mass density of stars in galaxies is 8 times that of the gas and the gas mass density is 130 times that of the metals. We use our data to consider the chemical evolution of the individual galaxies, inferring that the measured variations in effective yield are due to galaxies having different ages, being affected to varying degrees by gas loss. Four galaxy scaling relations are considered: mass-metallicity, mass-velocity, mass-star formation rate and mass-radius - we suggest that initial galaxy mass is the prime driver of a galaxy's ultimate destiny. Finally, we use X-ray observations and galaxy dynamics to assess the dark and baryonic matter content compared to the cosmological model

Immune-checkpoint inhibitors from cancer to COVID‑19: A promising avenue for the treatment of patients with COVID‑19

The severe acute respiratory syndrome associated coronavirus‑2 (SARS‑CoV‑2) poses a threat to human life worldwide. Since early March, 2020, coronavirus disease 2019 (COVID‑19), characterized by an acute and often severe form of pneumonia, has been declared a pandemic. This has led to a boom in biomedical research studies at all stages of the pipeline, from the in vitro to the clinical phase. In line with this global effort, known drugs, currently used for the treatment of other pathologies, including antivirals, immunomodulating compounds and antibodies, are currently used off‑label for the treatment of COVID‑19, in association with the supportive standard care. Yet, no effective treatments have been identified. A new hope stems from medical oncology and relies on the use of immune‑checkpoint inhibitors (ICIs). In particular, amongst the ICIs, antibodies able to block the programmed death‑1 (PD‑1)/PD ligand-1 (PD‑L1) pathway have revealed a hidden potential. In fact, patients with severe and critical COVID‑19, even prior to the appearance of acute respiratory distress syndrome, exhibit lymphocytopenia and suffer from T‑cell exhaustion, which may lead to viral sepsis and an increased mortality rate. It has been observed that cancer patients, who usually are immunocompromised, may restore their anti‑tumoral immune response when treated with ICIs. Moreover, viral-infected mice and humans, exhibit a T‑cell exhaustion, which is also observed following SARS‑CoV‑2 infection. Importantly, when treated with anti‑PD‑1 and anti‑PD‑L1 antibodies, they restore their T‑cell competence and efficiently counteract the viral infection. Based on these observations, four clinical trials are currently open, to examine the efficacy of anti‑PD‑1 antibody administration to both cancer and non‑cancer individuals affected by COVID‑19. The results may prove the hypothesis that restoring exhausted T‑cells may be a winning strategy to beat SARS‑CoV‑2 infection