Atmospheric monitoring and array calibration in CTA using the Cherenkov Transparency Coefficient

The Cherenkov Telescope Array (CTA) will be the next generation observatory employing different types of Cherenkov telescopes for the detection of particle showers initiated by very-high-energy gamma rays. A good knowledge of the Earth's atmosphere, which acts as a calorimeter in the detection technique, will be crucial for calibration in CTA. Variations of the atmosphere's transparency to Cherenkov light and not correctly performed calibration of individual telescopes in the array result in large systematic uncertainties on the energy scale. The Cherenkov Transparency Coefficient (CTC), developed within the H.E.S.S. experiment, quantifies the mean atmosphere transparency ascertained from data taken by Cherenkov telescopes during scientific observations. Provided that atmospheric conditions over the array are uniform, transparency values obtained per telescope can be also used for the calibration of individual telescope responses. The application of the CTC in CTA presents a challenge due to the greater complexity of the observatory and the variety of telescope cameras compared with currently operating experiments, such as H.E.S.S. We present here the first results of a feasibility study for extension of the CTC concept in CTA for purposes of the inter-calibration of the telescopes in the array and monitoring of the atmosphere.Comment: All CTA contributions at arXiv:1709.0348

Competitividad de la oferta exportable de la uva de la Región Arequipa en el mercado de Estados Unidos. periodo 2010-2019

La presente investigación se enmarca en el tema “Competitividad de la oferta exportable de la uva de la Región Arequipa en el mercado de Estados Unidos, periodo 2010 – 2019”. El propósito de la investigación es analizar la competitividad de la oferta exportable de la uva en la región Arequipa en base al cálculo de indicadores de desempeño comercial: Índice de Ventaja Comparativa Revelada (IVCR) y el Índice de Ventaja Comparativa Revelada Normalizada (IVCRN). Los resultados muestran una correlación fuerte; lo cual demuestra que el producto en estudio presenta ventajas comparativas y competitivas en el mercado de Estados Unidos, lo que contribuye en la posición del producto en las exportaciones del sector de la región Arequipa. La región Arequipa aporta con el 4% de participación a nivel nacional en los niveles de producción, y se encuentra dentro de las cinco principales regiones que aportan al total de producción; muestra la segunda mayor tasa de crecimiento en producción en el periodo con un 17%. En términos de rendimiento por hectárea, Arequipa se encuentra en el primer lugar con una tasa de crecimiento en el orden del 7%. La oferta exportable de Arequipa al 2019, es de US$18 millones del producto, lo que explica un crecimiento en el orden de 45.6$ 637 mil. Adicionalmente la uva de la región y del país ingresa a Estados Unidos cumpliendo el protocolo sanitario coordinado entre SENASA y la oficina correspondiente del United States Department of Agriculture (USDA). Por otro lado, se debe indicar sobre la presencia de la Asociación de productores de Uva de mesa del Perú (PROVID) que da soporte y representación a la producción y exportación de uva en el Perú ante instituciones públicas y privadas nacionales e internacionale

Capilares cerebelosos y su microambiente : estudio ultraestructural e inmunocitoquímico

Tesis Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, Departamento de Biología Celular (Morfología Microscópica), leída el 25-01-1993Los capilares cerebelosos constituyen la principal estructura constituyente de la barrera hematoencefalica en esta región cerebral, junto con el envoltorio glial perivascular. Las técnicas de microscopia electrónica convencional nos han permitido demostrar que la vaina glial no constituye una estructura continua, de forma que estas discontinuidades permiten el contacto entre elementos de naturaleza nerviosa y la pared de los vasos. En este sentido, todas las estirpes celulares de la corteza cerebelosa pueden entrar en contacto con la pared vascular. Las técnicas inmunohistoquimicas del pap nos han permitido demostrar la presencia de diversos neuromediadores (gaba, taurina, gilcina, serotonina, tiamina) y enzimas implicadas en su sintesis (gad, aat) en los capilares cerebelosos y su microambiente (glia perivascular y estructuras nerviosas asociadas a la pared vascular). Asi mismo, hemos puesto de manifiesto moleculas con una importante implicación funcional en los capilares y su microambiente (atpasa na+/k+, clatrina, alfa-actina). Estos hechos constituyen un importante reflejo morfológico del control glial y nervioso de la permeabilidad capilar y del flujo sanguíneo en los capilares de la corteza cerebelosa de la rataDepto. de Biología CelularFac. de Ciencias BiológicasTRUEpu

Tools and Procedures for the CTA Array Calibration

The Cherenkov Telescope Array (CTA) is an international initiative to build the next generation ground-based very-high-energy gamma-ray observatory. Full sky coverage will be assured by two arrays, one located on each of the northern and southern hemispheres. Three different sizes of telescopes will cover a wide energy range from tens of GeV up to hundreds of TeV. These telescopes, of which prototypes are currently under construction or completion, will have different mirror sizes and fields-of-view designed to access different energy regimes. Additionally, there will be groups of telescopes with different optics system, camera and electronics design. Given this diversity of instruments, an overall coherent calibration of the full array is a challenging task. Moreover, the CTA requirements on calibration accuracy are much more stringent than those achieved with current Imaging Atmospheric Cherenkov Telescopes, like for instance: the systematic errors in the energy scale must not exceed 10%.In this contribution we present both the methods that, applied directly to the acquired observational CTA data, will ensure that the calibration is correctly performed to the stringent required precision, and the calibration equipment that, external to the telescopes, is currently under development and testing. Moreover, some notes about the operative procedure to be followed with both methods and instruments, will be described. The methods applied to the observational CTA data include the analysis of muon ring images, of carefully selected cosmic-ray air shower images, of the reconstructed electron spectrum and that of known gamma-ray sources and the possible use of stereo techniques hardware-independent. These methods will be complemented with the use of calibrated light sources located on ground or on board unmanned aerial vehicles.Comment: All CTA contributions at arXiv:1709.0348

A Newly Developed Algorithm for Cloud Shadow Detection - TIP Method

The masking of cloud shadows in optical satellite imagery is an important step in automated processing chains. A new method (the TIP method) for cloud shadow detection in multispectral satellite images is presented and compared to current methods. The TIP method is based on the evaluation of thresholds, indices and projections. Most state-of-the-art methods solemnly rely on one of these evaluation steps or on a complex working mechanism. Instead, the new method incorporates three basic evaluation steps into one algorithm for easy and accurate cloud shadow detection. Furthermore the performance of the masking algorithms provided by the software packages ATCOR (“Atmospheric Correction”) and PACO (“Python-based Atmospheric Correction”) is compared with that of the newly implemented TIP method on a set of 20 Sentinel-2 scenes distributed over the globe, covering a wide variety of environments and climates. The algorithms incorporated in each piece of masking software use the class of cloud shadows, but they employ different rules and class-specific thresholds. Classification results are compared to the assessment of an expert human interpreter. The class assignment of the human interpreter is considered as reference or “truth”. The overall accuracies for the class cloud shadows of ATCOR and PACO (including TIP) for difference areas of the selected scenes are 70.4% and 76.6% respectively. The difference area encompasses the parts of the classification image where the classification maps disagree. User and producer accuracies for the class cloud shadow are strongly scene-dependent, typically varying between 45% and 95%. The experimental results show that the proposed TIP method based on thresholds, indices and projections can obtain improved cloud shadow detection performance

Quality Model for the Evaluation of Geospatial Web Services within the Spatial Data Infrastructure of Uruguay

Quality of Service (QoS), applied in particular to Web Services, is an area of increasing interest. One approach to deal with QoS issues is the identification of quality characteristics, usually documented in quality models. Geospatial Web Services are standardized service interfaces which facilitate the processing and exchange of distributed geographic information. These services represent the technological backbone of Spatial Data Infrastructures (SDI), which are data-exchange frameworks geared towards promoting the availability and exploitation of geographic information. This paper proposes a quality model for the evaluation of Geospatial Web Services within IDEuy: the SDI of Uruguay. The development of this model was based on requirements pertaining to the Uruguayan context, leading international SDI initiatives and related work. The application of the model to evaluate services within IDEuy is also presented.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Quality Model for the Evaluation of Geospatial Web Services within the Spatial Data Infrastructure of Uruguay

Quality of Service (QoS), applied in particular to Web Services, is an area of increasing interest. One approach to deal with QoS issues is the identification of quality characteristics, usually documented in quality models. Geospatial Web Services are standardized service interfaces which facilitate the processing and exchange of distributed geographic information. These services represent the technological backbone of Spatial Data Infrastructures (SDI), which are data-exchange frameworks geared towards promoting the availability and exploitation of geographic information. This paper proposes a quality model for the evaluation of Geospatial Web Services within IDEuy: the SDI of Uruguay. The development of this model was based on requirements pertaining to the Uruguayan context, leading international SDI initiatives and related work. The application of the model to evaluate services within IDEuy is also presented.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Quality Model for the Evaluation of Geospatial Web Services within the Spatial Data Infrastructure of Uruguay

Quality of Service (QoS), applied in particular to Web Services, is an area of increasing interest. One approach to deal with QoS issues is the identification of quality characteristics, usually documented in quality models. Geospatial Web Services are standardized service interfaces which facilitate the processing and exchange of distributed geographic information. These services represent the technological backbone of Spatial Data Infrastructures (SDI), which are data-exchange frameworks geared towards promoting the availability and exploitation of geographic information. This paper proposes a quality model for the evaluation of Geospatial Web Services within IDEuy: the SDI of Uruguay. The development of this model was based on requirements pertaining to the Uruguayan context, leading international SDI initiatives and related work. The application of the model to evaluate services within IDEuy is also presented.Sociedad Argentina de Informática e Investigación Operativa (SADIO