2,259 research outputs found

    Anomalous origin of the left coronary artery with origin in the right coronary artery from a single coronary ostium associated with multivessel coronary artery disease: case report and literature review

    Get PDF
    The anomalous origin of the coronary arteries is a group of rare congenital heart conditions in which there has been an increase in its diagnosis thanks to more accessible and less invasive imaging techniques such as coronary angiotomography, which allows visualization of the arteries in its entire path in a short exploration interval, with adequate spatial and temporal resolution. The clinical presentation is variable, up to 80% are asymptomatic and the remaining 20% may present arrhythmias, myocardial infarction, heart failure and sudden death. We present the case of a patient with unstable angina in whom an anomalous origin of the left coronary artery (LCA) with origin in the right coronary artery (RCA) from a single coronary ostium associated with multivessel coronary artery disease was diagnosed

    Análisis Comparativo del Posicionamiento Preciso Utilizando el Receptor de Bajo Costo GNSS ZED-F9P en Conjunto con la Antena BEIBT300 y Diferentes Modelos de Antena de Orden Geodésico

    Get PDF
    Con el avance de la Geodesia y la mejora de las especificaciones tĂ©cnicas de los receptores de bajo costo, los GNSS abren nuevas alternativas para investigar las capacidades tĂ©cnicas y rendimiento real que proveen este tipo de receptores para diferentes propĂłsitos geodĂ©sicos. En este contexto, la precisiĂłn alcanzable fue analizada usando el receptor de bajo costo GNSS ZED-F9P en conjunto con dos antenas de orden geodĂ©sico (ASH701975.01B y LEIAS10 NONE) y una antena de bajo costo (BEIBT300 NONE). Las observaciones GNSS fueron llevadas a cabo en un periodo de dos dĂ­as para cada modelo de antena. El análisis fue realizado en tiempos de observaciĂłn de 12, 6 y 1 h, respectivamente. Estas observaciones fueron procesadas usando el mĂ©todo relativo estático mediante la inclusiĂłn de una estaciĂłn de referencia continua del Instituto Nacional de EstadĂ­stica y GeografĂ­a, la cual está localizada a una distancia aproximada de 4 km. Los resultados demuestran que la mayor precisiĂłn es lograda en un periodo de 12 h, con diferencias mĂ­nimas de 3 cm para la componente Norte y 33 cm para la vertical. En este sentido, la soluciĂłn menos precisa es obtenida en el periodo de 1 h resultando diferencias de 70 cm, 46 cm y 2.3 m para la componente Norte, Este y vertical respectivamente.   With advancements in geodesy and enhancements in the technical specifications of low-cost receivers, GNSS opens up new avenues for investigating the capabilities and performance provided by these receivers for various geodetic purposes. In this context, the precision achievable using the low-cost GNSS receiver ZED-F9P in conjunction with two geodetic antennas (ASH701975.01B and LEIAS10 NONE) and a low-cost antenna (BEIBT300 NONE) was analyzed. GNSS observations were conducted over a 2-day period for each antenna model. The analysis involved observation durations of 12, 6, and 1 h. These observations were processed using the static relative method alongside a continuously operating GNSS station from the Active National Geodetic Network of the National Institute of Statistics and Geography, situated at ~4 km. The results demonstrate that the highest precision was achieved over a 12 h period, with minimal differences of 3 cm for the North component and 33 cm for the vertical component. Conversely, the least accurate solution was obtained within a 1 h observation period, resulting in differences of up to 70 cm, 46 cm, and 2.3 m for the North, East, and vertical components, respectively

    Diez años de estudio del comportamiento higrotérmico de la cubierta del Museo del Prado

    Get PDF
    In the current paper we present the results of the monitoring of the hygrothermal behaviour during the last ten years of the El Prado Museum roof. Sensors were installed in the south roof of the museum after it underwent mayor repair following a leak over a very important exhibition hall (the one holding Velazquez’s Las Meninas painting). The liquid water sensors reveal that water is retained at the waterproofing layer. These sensors do not show water presence in lower layers of the roof. The humidity sensors show condensation when the ambient temperature drops. The temperature sensors show the insulating capacity of the different layers of the roof, which effectively attenuate the outside temperature changes. The strain sensors placed on the liquid waterproofing layer show a constant increase of strain with time. In summary, the repaired roof can be considered to perform as intended and no more leaks have been detected.Debido a unas filtraciones detectadas al terminar la renovación de las cubiertas del Museo del Prado se decidió instalar sensores en sus diversas capas, cuyo diseño no es tradicional. Después de más de diez años de registro, los sensores de agua líquida muestran la acumulación de humedad en la capa de impermeabilización líquida. Sin embargo, no se ha detectado la presencia de agua líquida en las capas inferiores. Los sensores de humedad relativa muestran la presencia de condensaciones locales. Los sensores de temperatura muestran la capacidad aislante de las diferentes capas de la cubierta. Y los sensores de deformación muestran un incremento de deformación continuo con el tiempo, posiblemente debido a la fluencia del conjunto. Como conclusión del estudio, se puede afirmar que el comportamiento de la cubierta ha sido correcto ya que no se ha detectado la aparición de agua líquida en las capas internas de la cubierta

    Spicule emission profiles observed in \ion{He}{i} 10830 \AA

    Full text link
    Off-the-limb observations with high spatial and spectral resolution will help us understand the physical properties of spicules in the solar chromosphere Spectropolarimetric observations of spicules in the \ion{He}{i} 10830 \AA\ multiplet were obtained with the Tenerife Infrared Polarimeter on the German Vacuum Tower Telescope at the Observatorio del Teide (Tenerife, Spain). The analysis shows the variation of the off-limb emission profiles as a function of the distance to the visible solar limb. The ratio between the intensities of the blue and the red components of this triplet (R=Iblue/Ired)({\cal R}=I_{\rm blue}/I_{\rm red}) is an observational signature of the optical thickness along the light path, which is related to the intensity of the coronal irradiation. We present observations of the intensity profiles of spicules above a quiet Sun region. The observable R{\cal R} as a function of the distance to the visible limb is also given. We have compared our observational results to the intensity ratio obtained from detailed radiative transfer calculations in semi-empirical models of the solar atmosphere assuming spherical geometry. The agreement is purely qualitative. We argue that future models of the solar chromosphere and transition region should account for the observational constraints presented here.Comment: letter accepted in A&A. 5 figure

    Estimation of solar prominence magnetic fields based on the reconstructed 3D trajectories of prominence knots

    Full text link
    We present an estimation of the lower limits of local magnetic fields in quiescent, activated, and active (surges) promineces, based on reconstructed 3-dimensional (3D) trajectories of individual prominence knots. The 3D trajectories, velocities, tangential and centripetal accelerations of the knots were reconstructed using observational data collected with a single ground-based telescope equipped with a Multi-channel Subtractive Double Pass imaging spectrograph. Lower limits of magnetic fields channeling observed plasma flows were estimated under assumption of the equipartition principle. Assuming approximate electron densities of the plasma n_e = 5*10^{11} cm^{-3} in surges and n_e = 5*10^{10} cm^{-3} in quiescent/activated prominences, we found that the magnetic fields channeling two observed surges range from 16 to 40 Gauss, while in quiescent and activated prominences they were less than 10 Gauss. Our results are consistent with previous detections of weak local magnetic fields in the solar prominences.Comment: 14 pages, 12 figures, 1 tabl

    A taxonomic backbone for the global synthesis of species diversity in the angiosperm order caryophyllales

    Get PDF
    The Caryophyllales constitute a major lineage of flowering plants with approximately 12?500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the “Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world. © 2015 BGBM Berlin

    Effects of external nutrient sources and extreme weather events on the nutrient budget of a Southern European coastal lagoon

    Get PDF
    The seasonal and annual nitrogen (N), phosphorus (P), and carbon (C) budgets of the mesotidal Ria Formosa lagoon, southern Portugal, were estimated to reveal the main inputs and outputs, the seasonal patterns, and how they may influence the ecological functioning of the system. The effects of extreme weather events such as long-lasting strong winds causing upwelling and strong rainfall were assessed. External nutrient inputs were quantified; ocean exchange was assessed in 24-h sampling campaigns, and final calculations were made using a hydrodynamic model of the lagoon. Rain and stream inputs were the main freshwater sources to the lagoon. However, wastewater treatment plant and groundwater discharges dominated nutrient input, together accounting for 98, 96, and 88 % of total C, N, and P input, respectively. Organic matter and nutrients were continuously exported to the ocean. This pattern was reversed following extreme events, such as strong winds in early summer that caused upwelling and after a period of heavy rainfall in late autumn. A principal component analysis (PCA) revealed that ammonium and organic N and C exchange were positively associated with temperature as opposed to pH and nitrate. These variables reflected mostly the benthic lagoon metabolism, whereas particulate P exchange was correlated to Chl a, indicating that this was more related to phytoplankton dynamics. The increase of stochastic events, as expected in climate change scenarios, may have strong effects on the ecological functioning of coastal lagoons, altering the C and nutrient budgets.Portuguese Science and Technology Foundation (FCT) [POCI/MAR/58427/2004, PPCDT/MAR/58427/2004]; Portuguese Science and Technology Foundation (FCT

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

    Get PDF
    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
    • …
    corecore