90 research outputs found
On the detection of TeV gamma-rays from GRB with km-cube neutrino telescopes --- I. Muon event rate from single GRBs
This is a preliminary study to examine the prospect of detecting TeV photons
from -ray bursts (GRB) using km-size neutrino telescopes, specifically
for the ANTARES neutrino telescope. Although optimized to detect upgoing
neutrino-induced muons, neutrino telescopes nevertheless have a potential to
detect high-energy photons by detecting downgoing muons from the
electromagnetic cascade induced by the interaction of TeV photons with the
Earth's atmosphere. The photon energy spectrum of a GRB is modeled by a simple
power law and is normalized by simple energy considerations. Taking into
account the absorption of TeV photons by cosmic infrared backgrounds, an
optical depth table calculated from a model by \cite{fin10} is used and the
arriving number of photons on top of the Earth atmosphere is determined. Muon
production in the atmosphere is determined by considering two main channels of
muon production: Pion photoproduction and direct muon pair production. The muon
energy loss during their traverse from the surface to the bottom of the sea is
determined using the standard muon energy loss formula. Assuming different
detector sizes, the number of detectable muons from single GRB events located
at different redshifts and zenith distances is determined. The background is
calculated assuming it consists primarily of cosmic ray-induced downgoing
muons. The detection significance is calculated and it can be concluded that to
obtain at least detection significance, a typical GRB has to be
located at redshift if the detector's muon effective area is
, or redshift ,
if the muon effective area is .Comment: Thirteen pages, 14 figures. Accepted for publication in MNRA
Disseny d'una planta de producció de monoetilenglicol
S'ha realitzat el disseny complert per a produir 150000 Tn/any de monoetilenglicol líquid d'alta puresa, a partir de la hidròlisi de l'òxid d'etilè a 30 at i 300ºC. La producció té lloc en continu. L'abast del projecte inclou: (i) disseny de les unitats de producció i els equips, així com les unitats d'emmagatzematge de matèries primeres i productes, (ii) disseny i especificacions de les diferents àrees de la planta, i els serveis, (iii) disseny i implementació del sistema de control i el sistema de seguretat de la planta. També s'ha fet una avaluació econòmica i la identificació dels impactes mediambientals
Experiencia de realidad virtual en el anticlinal Boixols-Sant Corneli, un ejemplo pionero de difusión y conservación del patrimonio geológico
An open natural museum using virtual and augmented reality (VR/AR) methods based on geological reconstructions of the UNESCO Global Geopark Orígens territory is envisaged. The aim is to provide an emotional experience to the public for the understanding of geological and paleoecological systems, as well as their impact on landscape and human activity. To achieve these objectives, scientific reconstructions will be combined with virtual reality production technologies to generate virtual geological, paleontological and historical scenarios of 11 selected sites. The first results on the reconstruction of the virtual reality model of the Boixols-Sant Corneli anticline, catalogued as Global Geosite, are presented here. These also include timelapse 3D models restitutions with their corresponding paleogeographic interpretations, among which those of the Upper Cretaceous inhabited by the last dinosaurs of Europe. Animation production uses technologies that allow the superimposition of virtual images over real images to display on smartphones or VR glasses. These models will help to understand the evolution of the geological landscape both at the university and divulgation level and contribute to positioning the geoheritage as a tool for the sustainable rural development
Natural and Undetermined Sudden Death: Value of Post-Mortem Genetic Investigation
Background: Sudden unexplained death may be the first manifestation of an unknown inherited cardiac disease. Current genetic technologies may enable the unraveling of an etiology and the identification of relatives at risk. The aim of our study was to define the etiology of natural deaths, younger than 50 years of age, and to investigate whether genetic defects associated with cardiac diseases could provide a potential etiology for the unexplained cases. Methods and Findings: Our cohort included a total of 789 consecutive cases (77.19% males) <50 years old (average 38.6±12.2 years old) who died suddenly from non-violent causes. A comprehensive autopsy was performed according to current forensic guidelines. During autopsy a cause of death was identified in most cases (81.1%), mainly due to cardiac alterations (56.87%). In unexplained cases, genetic analysis of the main genes associated with sudden cardiac death was performed using Next Generation Sequencing technology. Genetic analysis was performed in suspected inherited diseases (cardiomyopathy) and in unexplained death, with identification of potentially pathogenic variants in nearly 50% and 40% of samples, respectively. Conclusions: Cardiac disease is the most important cause of sudden death, especially after the age of 40. Close to 10% of cases may remain unexplained after a complete autopsy investigation. Molecular autopsy may provide an explanation for a significant part of these unexplained cases. Identification of genetic variations enables genetic counseling and undertaking of preventive measures in relatives at risk
High-energy neutrinos in the context of multimessenger physics
The field of astroparticle physics is currently developing rapidly, since new
experiments challenge our understanding of the investigated processes. Three
messengers can be used to extract information on the properties of
astrophysical sources: photons, charged Cosmic Rays and neutrinos. This review
focuses on high-energy neutrinos (E>100 GeV) with the main topics as follows.
The production mechanism of high-energy neutrinos in astrophysical shocks.
The connection between the observed photon spectra and charged Cosmic Rays is
described and the source properties as they are known from photon observations
and from charged Cosmic Rays are presented.
High-energy neutrino detection. Current detection methods are described and
the status of the next generation neutrino telescopes are reviewed. In
particular, water and ice Cherenkov detectors as well as radio measurements in
ice and with balloon experiments are presented. In addition, future
perspectives for optical, radio and acoustic detection of neutrinos are
reviewed.
Sources of neutrino emission. The main source classes are reviewed, i.e.
galactic sources, Active Galactic Nuclei, starburst galaxies and Gamma Ray
Bursts. The interaction of high energy protons with the cosmic microwave
background implies the production of neutrinos, referred to as GZK neutrinos.
Implications of neutrino flux limits. Recent limits given by the AMANDA
experiment and their implications regarding the physics of the sources are
presented.Comment: accepted for publication by Physics Reports, 127 pages, 29 figure
Malignancy following heart transplantation: differences in incidence and prognosis between sexes – a multicenter cohort study
[Abstract]
Male patients are at increased risk for developing malignancy postheart transplantation (HT); however, real incidence and prognosis in both genders remain unknown. The aim of this study was to assess differences in incidence and mortality related to malignancy between genders in a large cohort of HT patients. Incidence and mortality rates were calculated for all tumors, skin cancers (SCs), lymphoma, and nonskin solid cancers (NSSCs) as well as survival since first diagnosis of neoplasia. 5865 patients (81.6% male) were included. Total incidence rates for all tumors, SCs, and NSSCs were lower in females [all tumors: 25.7 vs. 44.8 per 1000 person‐years; rate ratio (RR) 0.68, (0.60–0.78), P < 0.001]. Mortality rates were also lower in females for all tumors [94.0 (77.3–114.3) vs. 129.6 (120.9–138.9) per 1000 person‐years; RR 0.76, (0.62–0.94), P = 0.01] and for NSSCs [125.0 (95.2–164.0) vs 234.7 (214.0–257.5) per 1000 person‐years; RR 0.60 (0.44–0.80), P = 0.001], albeit not for SCs or lymphoma. Female sex was associated with a better survival after diagnosis of malignancy [log‐rank p test = 0.0037; HR 0.74 (0.60–0.91), P = 0.004]. In conclusion, incidence of malignancies post‐HT is higher in males than in females, especially for SCs and NSSCs. Prognosis after cancer diagnosis is also worse in males
Genetic analyses of aplastic anemia and idiopathic pulmonary fibrosis patients with short telomeres, possible implication of DNA-repair genes
Background: Telomeres are nucleoprotein structures present at the terminal region of the chromosomes. Mutations in genes coding for proteins involved in telomere maintenance are causative of a number of disorders known as telomeropathies. The genetic origin of these diseases is heterogeneous and has not been determined for a significant proportion of patients.
Methods: This article describes the genetic characterization of a cohort of patients. Telomere length was determined by Southern blot and quantitative PCR. Nucleotide variants were analyzed either by high-resolution melting analysis and Sanger sequencing of selected exons or by massive sequencing of a panel of genes.
Results: Forty-seven patients with telomere length below the 10% of normal population, affected with three telomeropathies: dyskeratosis congenita (4), aplastic anemia (22) or pulmonary fibrosis (21) were analyzed. Eighteen of these patients presented known pathogenic or novel possibly pathogenic variants in the telomere-related genes TERT, TERC, RTEL1, CTC1 and ACD. In addition, the analyses of a panel of 188 genes related to haematological disorders indicated that a relevant proportion of the patients (up to 35%) presented rare variants in genes related to DNA repair or in genes coding for proteins involved in the resolution of complex DNA structures, that participate in telomere replication. Mutations in some of these genes are causative of several syndromes previously associated to telomere shortening
Effectiveness and safety of anti-CGRP monoclonal antibodies in patients over 65 years: a real-life multicentre analysis of 162 patients
Background Anti-CGRP monoclonal antibodies have shown notable effectiveness and tolerability in migraine patients; however, data on their use in elderly patients is still lacking, as clinical trials have implicit age restrictions and real-world evidence is scarce. In this study, we aimed to describe the safety and effectiveness of erenumab, galcanezumab and fremanezumab in migraine patients over 65 years old in real-life. Methods In this observational real-life study, a retrospective analysis of prospectively collected data from 18 different headache units in Spain was performed. Migraine patients who started treatment with any anti-CGRP monoclonal antibody after the age of 65 years were included. Primary endpoints were reduction in monthly migraine days after 6 months of treatment and the presence of adverse effects. Secondary endpoints were reductions in headache and medication intake frequencies by months 3 and 6, response rates, changes in patient-reported outcomes and reasons for discontinuation. As a subanalysis, reduction in monthly migraine days and proportion of adverse effects were also compared among the three monoclonal antibodies. Results A total of 162 patients were included, median age 68 years (range 65-87), 74.1% women. 42% had dyslipidaemia, 40.3% hypertension, 8% diabetes, and 6.2% previous cardiovascular ischaemic disease. The reduction in monthly migraine days at month 6 was 10.17.3 days. A total of 25.3% of patients presented adverse effects, all of them mild, with only two cases of blood pressure increase. Headache and medication intake frequencies were significantly reduced, and patient-reported outcomes were improved. The proportions of responders were 68%, 57%, 33% and 9% for reductions in monthly migraine days >= 30%,>= 50%,>= 75% and 100%, respectively. A total of 72.8% of patients continued with the treatment after 6 months. The reduction in migraine days was similar for the different anti-CGRP treatments, but fewer adverse effects were detected with fremanezumab (7.7%). Conclusions Anti-CGRP mAbs are safe and effective treatments in migraine patients over 65 years old in real-life clinical practice
The Pierre Auger Cosmic Ray Observatory
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world׳s largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 10¹⁷ eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km² overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km², 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km² sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.A. Aab ... K.B. Barber ... J.A. Bellido ... S.G. Blaess ... R.W. Clay ... M.J. Cooper ... B.R. Dawson ... T.D. Grubb ... G.C. Hill ... M. Malacari ... P.H.Nguyen ... S.J. Saffi ... A.G.K. Smith ... J. Sorokin ... P. van Bodegom, ... N.Wild ... et al. (Pierre Auger Collaboration
- …