Coexistence of calc-alkaline and ultrapotassic alkaline magmas at Mounts Cimini : evidence for transition from the Tuscan to the Roman Magmatic Provinces (central Italy)

The volcanic complex of Mts. Cimini (~0.90-1.30Ma) represents the geographical and chronological transition between the Tuscan Magmatic Province (TMP) and the Roman Magmatic Province (RMP), in central Italy. Major and trace elements, and Sr, Nd and Pb isotopes of whole-rock, as well as mineral chemistry analyses, were carried out on samples representative of the different petrographic and chronological units of Mts. Cimini. In particular, we focused on the olivine-bearing latites of Mts. Cimini that are the most mafic magmas, belong to the last phase of this volcanic activity, and are heterogeneous in highly incompatible element ratios and Sr-isotope compositions. We suggest that such heterogeneity reflects the occurrence of a heterogeneous upper mantle beneath central Italy, in which different portions, e.g., the sources of both the TMP and RMP, are characterized by distinct geochemical and petrographic features. In this scenario, about 900ka ago, the olivine-bearing latites mark the progressive decline of the TMP magma production in favour of partial melting of the RMP mantle region, thus recording the coexistence of both ultrapotassic alkaline and calc-alkaline magmas in the same volcanic region

Caracterización petrológica y geoquímica del moteado leucocrático en rocas basálticas alcalinas.

La presencia de un moteado leucocrático en basaltos alcalinos es un aspecto bastante frecuente en este tipo de lavas. A pesar de ello los estudios sobre su origen e implicaciones son hoy en día escasos y controvertidos. Es por ello que en el presente trabajo se presenta un estudio detallado del moteado en el que se incluyen relaciones de campo así como una caracterización textural, mineralógica y geoquímica de una selección de muestras. Los resultados obtenidos permiten sugerir que el moteado leucocrático se desarrolla como consecuencia del remplazamiento postmagmático de leucita primaria intersticial, dispuesta en forma de cuerpos poiquilíticos, por analcima secundaria. El aumento de volumen que supone este remplazamiento explica el mayor grado de fracturación de los minerales esenciales (olivino, clinopiroxeno y plagioclasa) así como la formación de grietas capilares que se disponen de forma radial desde los motes y que pueden llegar a comprometer la coherencia de la roca. Las observaciones realizadas indican que el desarrollo y tipología de moteado están fuertemente condicionados por la temperatura de la roca y la presencia de agua. Palabras clave: moteado leucocrático, basaltos alcalinos, analcimitización, leucita poiquilítica intersticial. /// The presence of sunburns is a common feature in alkaline basaltic rocks. Despite their frequent occurrence, works that have studied the origin and implications of sunburn presence are still scarce and controversial. In this study we present a detailed work on sunburns including field relations and a textural, mineralogical and geochemical characterization of a set of selected samples. The obtained results evidence that leucocratic discolorations are developed as a consequence of post-magmatic replacement of primary interstitial groundmass leucite arranged in poikilitic bodies by secondary analcime. The volume increase associated to this replacement explains the major degree of fracturing of the framework minerals (olivine, clinopyroxene and plagioclase) as well as the development of radial capillary cracks that radiate outwards from the sunburns. Both characteristics can compromise the coherence of the rock. Al the observations indicate that the combination of rock temperature and water supply strongly conditions de development and type of sunburns

Constraints on the steady and pulsed very high energy gamma-ray emission from observations of PSR B1951+32/CTB 80 with the MAGIC Telescope

We report on very high energy gamma-observations with the MAGIC Telescope of the pulsar PSR B1951+32 and its associated nebula, CTB 80. Our data constrain the cutoff energy of the pulsar to be less than 32 GeV, assuming the pulsed gamma-ray emission to be exponentially cut off. The upper limit on the flux of pulsed gamma-ray emission above 75 GeV is 4.3*10^-11 photons cm^-2 sec^-1, and the upper limit on the flux of steady emission above 140 GeV is 1.5*10^-11 photons cm^-2 sec^-1. We discuss our results in the framework of recent model predictions and other studies.Comment: 7 pages, 7 figures, replaced with published versio

First bounds on the very high energy gamma-ray emission from Arp 220

Using the Major Atmospheric Gamma Imaging Cherenkov Telescope (MAGIC), we have observed the nearest ultra-luminous infrared galaxy Arp 220 for about 15 hours. No significant signal was detected within the dedicated amount of observation time. The first upper limits to the very high energy $\gamma$-ray flux of Arp 220 are herein reported and compared with theoretical expectations.Comment: Accepted for publication in Ap

Pre-exposure prophylaxis with hydroxychloroquine for COVID-19 : a double-blind, placebo-controlled randomized clinical trial

Background: Pre-exposure prophylaxis (PrEP) is a promising strategy to break COVID-19 transmission. Although hydroxychloroquine was evaluated for treatment and post-exposure prophylaxis, it is not evaluated for COVID-19 PrEP yet. The aim of this study was to evaluate the efficacy and safety of PrEP with hydroxychloroquine against placebo in healthcare workers at high risk of SARS-CoV-2 infection during an epidemic period. Methods: We conducted a double-blind placebo-controlled randomized clinical trial in three hospitals in Barcelona, Spain. From 350 adult healthcare workers screened, we included 269 participants with no active or past SARS-CoV-2 infection (determined by a negative nasopharyngeal SARS-CoV-2 PCR and a negative serology against SARS-CoV-2). Participants allocated in the intervention arm (PrEP) received 400 mg of hydroxychloroquine daily for the first four consecutive days and subsequently, 400 mg weekly during the study period. Participants in the control group followed the same treatment schedule with placebo tablets. Results: 52.8% (142/269) of participants were in the hydroxychloroquine arm and 47.2% (127/269) in the placebo arm. Given the national epidemic incidence decay, only one participant in each group was diagnosed with COVID-19. The trial was stopped due to futility and our study design was deemed underpowered to evaluate any benefit regarding PrEP efficacy. Both groups showed a similar proportion of participants experiencing at least one adverse event (AE) (p=0.548). No serious AEs were reported. Almost all AEs (96.4%, 106/110) were mild. Only mild gastrointestinal symptoms were significantly higher in the hydroxychloroquine arm compared to the placebo arm (27.4% (39/142) vs 15.7% (20/127), p=0.041). Conclusions: Although the efficacy of PrEP with hydroxychloroquine for preventing COVID-19 could not be evaluated, our study showed that PrEP with hydroxychloroquine at low doses is safe. Trial registration: ClinicalTrials.govNCT04331834. Registered on April 2, 2020

Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope

We report the detection of a new source of very high energy (VHE, E_gamma >= 100GeV) gamma-ray emission located close to the Galactic Plane, MAGIC J0616+225, which is spatially coincident with SNR IC443. The observations were carried out with the MAGIC telescope in the periods December 2005 - January 2006 and December 2006 - January 2007. Here we present results from this source, leading to a VHE gamma-ray signal with a statistical significance of 5.7 sigma in the 2006/7 data and a measured differential gamma-ray flux consistent with a power law, described as dN_gamma/(dA dt dE) = (1.0 +/- 0.2)*10^(-11)(E/0.4 TeV)^(-3.1 +/- 0.3) cm^(-2)s^(-1)TeV^(-1). We briefly discuss the observational technique used and the procedure implemented for the data analysis. The results are put in the perspective of the multiwavelength emission and the molecular environment found in the region of IC443.Comment: Accepted by ApJ Letter

Clustering of Alzheimer's and Parkinson's disease based on genetic burden of shared molecular mechanisms

One of the visions of precision medicine has been to re-define disease taxonomies based on molecular characteristics rather than on phenotypic evidence. However, achieving this goal is highly challenging, specifically in neurology. Our contribution is a machine-learning based joint molecular subtyping of Alzheimer’s (AD) and Parkinson’s Disease (PD), based on the genetic burden of 15 molecular mechanisms comprising 27 proteins (e.g. APOE) that have been described in both diseases. We demonstrate that our joint AD/PD clustering using a combination of sparse autoencoders and sparse non-negative matrix factorization is reproducible and can be associated with significant differences of AD and PD patient subgroups on a clinical, pathophysiological and molecular level. Hence, clusters are disease-associated. To our knowledge this work is the first demonstration of a mechanism based stratification in the field of neurodegenerative diseases. Overall, we thus see this work as an important step towards a molecular mechanism-based taxonomy of neurological disorders, which could help in developing better targeted therapies in the future by going beyond classical phenotype based disease definitions