18 research outputs found

    Trigger and Aperture of the Surface Detector Array of the Pierre Auger Observatory

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    The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive air showers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidate showers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3×10183\times 10^{18} eV, for all zenith angles between 0∘^\circ and 60∘^\circ, independently of the position of the impact point and of the mass of the primary particle. In these range of energies and angles, the exposure of the surface array can be determined purely on the basis of the geometrical acceptance.Comment: 29 pages, 12 figure

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Combined measurements of Higgs boson couplings in proton- proton collisions at v s=13TeV

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    Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton-proton collision data set recorded with the CMS detector in 2016 at fb-1. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a W or Z boson, or a top quark-antiquark pair) and the following decay modes: H, ZZ, WW, , bb, and . Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be =1.17 +/- 0.10, assuming a Higgs boson mass of 125.09. Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.Peer reviewe

    Ultrahigh energy neutrinos at the Pierre Auger observatory

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    The observation of ultrahigh energy neutrinos (UHEΜs) has become a priority in experimental astroparticle physics. UHEΜs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going Μ) or in the Earth crust (Earth-skimming Μ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEΜs in the data collected with the ground array of the Pierre Auger Observatory. This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEΜs in the EeV range and above.P. Abreu ... K. B. Barber ... J. A. Bellido ... R. W. Clay ... M. J. Cooper ... B. R. Dawson ... T. A. Harrison ... A. E. Herve ... V. C. Holmes ... J. Sorokin ... P. Wahrlich ... B. J. Whelan ... et al

    Measurement of prompt D-0 and D-0 meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root S-NN=5.02 TeV

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    SCOAP

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8\ub10.7(stat)\ub16.7(syst)\u2009\u2009MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory

    Search for photons with energies above 1018eV using the hybrid detector of the Pierre Auger Observatory

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    A search for ultra-high energy photons with energies above 1EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1\u20132EeV are found, which is compatible with the expected hadron induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km 122 sr 121 yr 121 are derived at 95% C.L. for energy thresholds of 1, 2, 3, 5 and 10EeV. These limits bound the fractions of photons in the all-particle integral flux below 0.1%, 0.15%, 0.33%, 0.85% and 2.7%. For the first time the photon fraction at EeV energies is constrained at the sub-percent level. The improved limits are below the flux of diffuse photons predicted by some astrophysical scenarios for cosmogenic photon production. The new results rule-out the early top-down models 12 in which ultra-high energy cosmic rays are produced by, e.g., the decay of super-massive particles 12 and challenge the most recent super-heavy dark matter model

    Search for ultrarelativistic magnetic monopoles with the Pierre Auger Observatory

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    We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10^ 1219(cm2 sr s)^ 121 for a Lorentz factor \u3b3 = 10^9 to 2.5 7 10 1221(cm2 sr s)^ 121 for \u3b3 = 10^12. These results\u2014the first obtained with a UHECR detector\u2014improve previously published limits by up to an order of magnitude

    Impacto del proyecto PERSECC en la productividad de las MYPES de calzado de la ciudad de Trujillo, 2017

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    RESUMEN La presente investigaciĂłn tiene como propĂłsito determinar el impacto del proyecto creado por la Oficina de Proyectos de InvestigaciĂłn, Desarrollo e InnovaciĂłn de CITEccal Trujillo, el “Proyecto de ReactivaciĂłn del Sector Cuero y Calzado” en la productividad de las MYPES del sector calzado en relaciĂłn con la incidencia que tenga este con el comportamiento de las ventas, producciĂłn y demĂĄs indicadores de las empresas que aplicaron a PERSECC durante el año 2017, con la finalidad de demostrar la labor del Estado al tomar medidas orientadas a elevar los niveles de competitividad de las empresas en estudio en relaciĂłn a la reactivaciĂłn de dicho sector. Para el desarrollo del presente trabajo de investigaciĂłn, se utilizaron fuentes de informaciĂłn primaria debido a que serĂĄn documentos directos que se obtendrĂĄn de la oficina de InvestigaciĂłn, Desarrollo e InnovaciĂłn de CITEccal Trujillo. Para esto, se tuvo en cuenta el anĂĄlisis de la documentaciĂłn de los datos recopilados del registro anual y evoluciĂłn trimestral de ventas, producciĂłn, capacidad instalada, capacidad productiva, inversiĂłn en I+D+i, recurso humano, plan de acciĂłn del programa PERSECC, los cuales fueron facilitados directamente del ĂĄrea de la oficina de proyectos I+D+i para la realizaciĂłn del proyecto. Luego, se recopilaron los datos a travĂ©s del anĂĄlisis documental para ser procesados en tablas y grĂĄficos, en seguida se determinaron las medias usando la Prueba T - Student para datos relacionados (muestras dependientes). Finalmente para medir la relaciĂłn entre las variables en estudio se calculĂł el valor de probabilidad estadĂ­stico por el cual se rechaza la hipĂłtesis nula y se acepta la hipĂłtesis alternativa. De esta manera, la investigaciĂłn llega a la conclusiĂłn que existen diferencias estadĂ­sticamente significativas entre los valores trimestrales de todos los indicadores analizados de las MYPES de calzado de la ciudad de Trujillo anteriores y posteriores de la aplicaciĂłn del proyecto PERSECC, lo que significa que el proyecto PERSECC incide de manera significativa en la evoluciĂłn de los indicadores de la productividad de cada una de las empresas del sector Calzado que aplicaron al proyecto. La principal recomendaciĂłn que se hace al ĂĄrea de Proyectos I+D+i, es que el jefe de Proyectos autorice la continuaciĂłn de la aplicaciĂłn anual del Proyecto PERSECC con la finalidad de ampliar la participaciĂłn de mĂĄs MYPES, manteniendo un continuo control del registro de la data con respecto a la evaluaciĂłn y seguimiento de indicadores en la mejora de su productividad y de esta manera, definir mejor el apoyo de la labor que viene realizando el CITEccal Trujillo para el aumento de la competitividad de las empresas del sector calzado. Palabras clave: Proyecto, Soporte Productivo, I+D, Productividad, Mypes (Micro y Pequeñas Empresas), Sector Calzado, ProducciĂłn Calzado, Comercio Calzado.ABSTRACT The purpose of this research is to determine the impact of the project created by the Research, Development and Innovation Projects Office of CITEccal Trujillo, the "PERSECC" project in the productivity of the MSEs of the footwear sector in relation to the impact that this has with the behavior of sales, production and other indicators of the companies that applied to PERSECC during the year 2017, in order to demonstrate the work of the State to take measures aimed at raising the levels of competitiveness of companies under study in relation to the reactivation of this sector. For the development of this research work, primary information sources were used because they will be direct documents that will be obtained from the Research, Development and Innovation office of CITEccal Trujillo. For this, the analysis of the documentation of the annual record and quarterly evolution of sales, production, installed capacity, productive capacity, investment in R & D & I, human resources, action plan of the PERSECC program was taken account, which were provided directly from the area of the R + D + i project office for the realization of the project. Then, the data was collected through the documentary analysis to be processed in tables and graphs, consequently sample means were determined using the T - Student test for related data (dependent samples). Finally, to measure the relationship between the variables under study, it has been estimated the statistical probability value by which the null hypothesis is rejected and the alternative hypothesis is accepted. The main recommendation made to the area of R + D + i Projects, is that the Project Manager continues to authorize the application of the PERSECC Project in the coming years in order to expand the participation of more MYPES, maintaining a continuous control of the registry of the data with respect to the evaluation and monitoring of indicators to improve their productivity and, in this way, better define the support of the work that CITEccal Trujillo has been doing to increase the competitiveness of companies in the footwear sector

    Outcomes from elective colorectal cancer surgery during the SARS‐CoV‐2 pandemic

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    Aim This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic. Method This was an international cohort study of patients undergoing elective resection of colon or rectal cancer without preoperative suspicion of SARS-CoV-2. Centres entered data from their first recorded case of COVID-19 until 19 April 2020. The primary outcome was 30-day mortality. Secondary outcomes included anastomotic leak, postoperative SARS-CoV-2 and a comparison with prepandemic European Society of Coloproctology cohort data. Results From 2073 patients in 40 countries, 1.3% (27/2073) had a defunctioning stoma and 3.0% (63/2073) had an end stoma instead of an anastomosis only. Thirty-day mortality was 1.8% (38/2073), the incidence of postoperative SARS-CoV-2 was 3.8% (78/2073) and the anastomotic leak rate was 4.9% (86/1738). Mortality was lowest in patients without a leak or SARS-CoV-2 (14/1601, 0.9%) and highest in patients with both a leak and SARS-CoV-2 (5/13, 38.5%). Mortality was independently associated with anastomotic leak (adjusted odds ratio 6.01, 95% confidence interval 2.58–14.06), postoperative SARS-CoV-2 (16.90, 7.86–36.38), male sex (2.46, 1.01–5.93), age >70 years (2.87, 1.32–6.20) and advanced cancer stage (3.43, 1.16–10.21). Compared with prepandemic data, there were fewer anastomotic leaks (4.9% versus 7.7%) and an overall shorter length of stay (6 versus 7 days) but higher mortality (1.7% versus 1.1%). Conclusion Surgeons need to further mitigate against both SARS-CoV-2 and anastomotic leak when offering surgery during current and future COVID-19 waves based on patient, operative and organizational risks
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