The RR Lyrae variables and Horizontal Branch of NGC6656 (M22)

The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC6656 (M22), with observations spanning a range of twenty-two years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are _{RR0}=0.66 \pm 0.02 d and _{RR1}=0.33 \pm 0.01 d, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1- to all RR-type variables is N_1/N_{RR}=0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E(B-V)=0.36 \pm 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R)=+0.97 \pm 0.1 and at least one "gap" located in an unusual part of the blue HB, in the middle of the so-called hot HB stars.Comment: accepted to A

Variabilidad en la saturación de oxigeno en relación al uso de mascarilla en el personal sanitario del Hospital General Ambato-IESS

The state of health emergency due to the SARS-CoV-2 virus has increased the demand for the use of masks, which are part of the biosafety materials and use to reduce the risk of the spread of diseases through respiratory droplets, is for For this reason, the FDA and WHO recommend the use of the mask during the COVID-19 pandemic. Objectives: The general objective of this article is to determine the variability of oxygen saturation with and without the use of a mask in the health personnel of the Ambato General Hospital-IESS. Methodology: It is a prospective descriptive observational cross-sectional cohort study. Measurement of oxygen saturation will be performed using the EDAN M3 Monitor in HGA-IESS health personnel with informed consent, in those who use a mask during the pandemic. The statistical analysis was carried out with the method of crossed tables with the objective of comparing the independent variables with the dependent one, the CI is 95% and with a p value less than 0.05 to show significance. Results: Of 129 study objects, the representative and significant age group according to p <0.05 is less than 33 years old and 24 to 32 years old; the female gender is reflected that prevails 2 to 1 over the male, the type of mask most used is the N95 in 59.7%, the variability of saturation of the study population with and without a mask is greater in men than in women, reflecting a difference of 1.2 and 0.9 respectively (p = 0.02 and p = 0.01). Conclusions: The variability of saturation with or without the use of a mask represents minimal changes in this study group, since in men and women there is the same tendency, that is, to rise, although in minimal proportionsEl estado de emergencia sanitaria por el virus SARS-CoV- 2 ha incrementado la demanda del uso de mascarillas, las que forman parte de los materiales de bioseguridad y contribuyen a disminuir el riesgo de la propagación de enfermedades través de gotitas respiratorias, es por tal motivo la Organización Mundial de la Salud recomienda el uso de la mascarilla durante la pandemia por COVID-19. Objetivos: El presente artículo tiene como objetivo general determinar la variabilidad de la saturación de oxígeno con y sin el uso de mascarilla en el personal sanitario del Hospital General Ambato-IESS. Metodología: Es un estudio observacional descriptivo prospectivo de cohorte transversal. Se realizará la medición de la saturación de oxígeno por medio del Monitor EDAN M3 en el personal sanitario del HGA-IESS bajo consentimiento informado, en quienes utilizan mascarilla durante la pandemia. El análisis estadístico se lo realizó con el método de tablas cruzadas con el objetivo de comparar las variables independientes con la dependiente, el IC es del 95% y con un valor p  menor a 0.05 para que muestre significancia. Resultados: De 129 objetos de estudio el grupo de edad representativo y significativo según p<0.05 es menor de 33 años en un rango de 24 a 32 años de edad; el género femenino prevalece 2 a 1 sobre el masculino, el tipo de mascarilla más utilizada es la N95 en 59.7%, la variabilidad de saturación de la población de estudio con y sin mascarilla es mayor en hombres que en mujeres, reflejando una diferencia de 1.2 y 0.9 respectivamente (p=0.02 y p=0.01). Conclusiones: La variabilidad de saturación con o sin el uso de mascarilla representa mínimos cambios, en este grupo de estudio, pues en hombres y mujeres existe la misma tendencia, es decir a elevar la SPO2, aunque en proporciones mínimas

Stage II B diffuse large B-cell non-Hodgkin lymphoma in a 21-year-old female patient with surgical resolution. Case Report and Review

El Linfoma Difuso de Células B Grandes (LDCGB) es un tipo de linfoma no Hodgkin que se caracteriza por la proliferación de células B grandes en diferentes órganos y tejidos del cuerpo. El diagnóstico de LDCGB se basa en estudios histopatológicos, como biopsias de ganglios linfáticos, que permiten identificar las características morfológicas y la inmunofenotipificación de las células tumorales. También pueden expresar otros marcadores, como CD30, CD10, BCL-2 y BCL-6. El tratamiento de primera línea para el LDCGB es el esquema de quimioterapia CHOP-R, que combina los medicamentos ciclofosfamida, doxorubicina, vincristina y prednisona con el rituximab, un anticuerpo monoclonal dirigido contra el antígeno CD20.  Objetivo: Establecer un diagnóstico preciso y oportuno, seguido de un tratamiento efectivo que proporcione la mejor respuesta clínica y calidad de vida para los pacientes. Descripción del caso: Se presenta el caso de una paciente femenina de 21 años y se realiza una revisión literaria para poder identificar el diagnóstico de Linfoma no Hodgkin Difuso de Células B Grandes. Conclusiones: El Linfoma no Hodgkin es un cáncer que ha ido incrementado su tasa en los últimos años, llegando a ocupar el séptimo lugar en la lista de cánceres de nuestro país, que a pesar de que tenga mayor incidencia entre la sexta y séptima década de vida, se debe considerar en los adultos jóvenes, para así poder establecer un diagnóstico oportuno de la enfermedad.Diffuse Large B-Cell Lymphoma (GBCL) is a type of non-Hodgkin lymphoma that is characterized by the proliferation of large B-cells in different organs and tissues of the body. The diagnosis of GBDL is based on histopathological studies, such as lymph node biopsies, which allow the identification of morphological characteristics and immunophenotyping of tumor cells. They can also express other markers, such as CD30, CD10, BCL-2, and BCL-6. The first-line treatment for GBDL is the CHOP-R chemotherapy regimen, which combines the drugs cyclophosphamide, doxorubicin, vincristine, and prednisone with rituximab, a monoclonal antibody directed against the CD20 antigen. Objective: Establish an accurate and timely diagnosis, followed by an effective treatment that provides the best clinical response and quality of life for patients. Case description: The case of a 21-year-old female patient is presented and a literature review is carried out in order to identify the diagnosis of Diffuse Large B-Cell Non-Hodgkin Lymphoma. Conclusions: Non-Hodgkin lymphoma is a cancer that has been increasing its rate in recent years, reaching seventh place in the list of cancers in our country, which despite having a higher incidence between the sixth and seventh decade of life, it should be considered in young adults, in order to establish a timely diagnosis of the disease

A search for Very High Energy gamma-ray emission from Scorpius X-1 with the MAGIC telescopes

The acceleration of particles up to GeV or higher energies in microquasars has been the subject of considerable theoretical and observational efforts in the past few years. Sco X-1 is a microquasar from which evidence of highly energetic particles in the jet has been found when it is in the so-called Horizontal Branch (HB), a state when the radio and hard X-ray fluxes are higher and a powerful relativistic jet is present. Here we present the first very high energy gamma-ray observations of Sco X-1 obtained with the MAGIC telescopes. An analysis of the whole dataset does not yield a significant signal, with 95% CL flux upper limits above 300 GeV at the level of 2.4x10^{-12} ph/cm^2/s. Simultaneous RXTE observations were conducted to search for TeV emission during particular X-ray states of the source. A selection of the gamma-ray data obtained during the HB based on the X-ray colors did not yield a signal either, with an upper limit of 3.4x10^{-12} ph/cm^2/s. These upper limits place a constraint on the maximum TeV luminosity to non-thermal X-ray luminosity of L_{VHE}/L_{ntX}<0.02, that can be related to a maximum TeV luminosity to jet power ratio of L_{VHE}/L_{j}<10^{-3}. Our upper limits indicate that the underlying high-energy emission physics in Sco X-1 must be inherently different from that of the hitherto detected gamma-ray binaries.Comment: 5 pages, 2 figures, 2 tables. Version as published in ApJ

PG 1553+113: five years of observations with MAGIC

We present the results of five years (2005-2009) of MAGIC observations of the BL Lac object PG 1553+113 at very high energies (VHEs, E > 100 GeV). Power law fits of the individual years are compatible with a steady mean photon index \Gamma = 4.27 $\pm$ 0.14. In the last three years of data, the flux level above 150 GeV shows a clear variability (probability of constant flux < 0.001%). The flux variations are modest, lying in the range from 4% to 11% of the Crab Nebula flux. Simultaneous optical data also show only modest variability that seems to be correlated with VHE gamma ray variability. We also performed a temporal analysis of (all available) simultaneous Fermi/LAT data of PG 1553+113 above 1 GeV, which reveals hints of variability in the 2008-2009 sample. Finally, we present a combination of the mean spectrum measured at very high energies with archival data available for other wavelengths. The mean spectral energy distribution can be modeled with a one-zone Synchrotron Self Compton (SSC) model, which gives the main physical parameters governing the VHE emission in the blazar jet.Comment: 11 pages, 6 figures, accepted for publication in Ap

Joint Observation of the Galactic Center with MAGIC and CTA-LST-1

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs), designed to detect very-high-energy gamma rays, and is operating in stereoscopic mode since 2009 at the Observatorio del Roque de Los Muchachos in La Palma, Spain. In 2018, the prototype IACT of the Large-Sized Telescope (LST-1) for the Cherenkov Telescope Array, a next-generation ground-based gamma-ray observatory, was inaugurated at the same site, at a distance of approximately 100 meters from the MAGIC telescopes. Using joint observations between MAGIC and LST-1, we developed a dedicated analysis pipeline and established the threefold telescope system via software, achieving the highest sensitivity in the northern hemisphere. Based on this enhanced performance, MAGIC and LST-1 have been jointly and regularly observing the Galactic Center, a region of paramount importance and complexity for IACTs. In particular, the gamma-ray emission from the dynamical center of the Milky Way is under debate. Although previous measurements suggested that a supermassive black hole Sagittarius A* plays a primary role, its radiation mechanism remains unclear, mainly due to limited angular resolution and sensitivity. The enhanced sensitivity in our novel approach is thus expected to provide new insights into the question. We here present the current status of the data analysis for the Galactic Center joint MAGIC and LST-1 observations

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Measurement of the Higgs boson width and evidence of its off-shell contributions to ZZ production

Since the discovery of the Higgs boson in 2012, detailed studies of its properties have been ongoing. Besides its mass, its width—related to its lifetime—is an important parameter. One way to determine this quantity is to measure its off-shell production, where the Higgs boson mass is far away from its nominal value, and relating it to its on-shell production, where the mass is close to the nominal value. Here we report evidence for such off-shell contributions to the production cross-section of two Z bosons with data from the CMS experiment at the CERN Large Hadron Collider. We constrain the total rate of the off-shell Higgs boson contribution beyond the Z boson pair production threshold, relative to its standard model expectation, to the interval [0.0061, 2.0] at the 95% confidence level. The scenario with no off-shell contribution is excluded at a p-value of 0.0003 (3.6 standard deviations). We measure the width of the Higgs boson as $\Gamma$$_H$=3.2$^{+2.4}_{−1.7}$MeV, in agreement with the standard model expectation of 4.1 MeV. In addition, we set constraints on anomalous Higgs boson couplings to W and Z boson pairs

Search for new particles in an extended Higgs sector with four b quarks in the final state at √s = 13 TeV

A search for a massive resonance X decaying to a pair of spin-0 bosons ϕ that themselves decay to pairs of bottom quarks, is presented. The analysis is restricted to the mass ranges from 25 to 100 GeV and from 1 to 3 TeV. For these mass ranges, the decay products of each ϕ boson are expected to merge into a single large-radius jet. Jet substructure and flavor identification techniques are used to identify these jets. The search is based on CERN LHC proton-proton collision data at , collected with the CMS detector in 2016–2018, corresponding to an integrated luminosity of 138 . Model-specific limits, where the two new particles arise from an extended Higgs sector, are set on the product of the production cross section and branching fraction for as a function of the resonances' masses, where both the and branching fractions are assumed to be 100%. These limits are the first of their kind on this process, ranging between 30 and 1 fb at 95% confidence level for the considered mass ranges