25 research outputs found

    The perspectives of Brazilian homemakers concerning living with type 2 diabetes mellitus La perspectiva de ama de casa brasileña sobre la vida con diabetes mellitus tipo 2 As perspectivas de donas de casa brasileiras sobre a sua experiência com diabetes mellitus tipo 2

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    The purpose of this study is to present an understanding of the experience of Brazilian homemakers with type 2 diabetes mellitus (DM2). A descriptive exploratory design was used and semi-structured interviews were conducted with 25 Brazilian homemakers concerning their experience. The interviews were recorded, transcribed, and the resulting text was analyzed using the sequential step method. Data converged to one dominant category, "constructing one's identity in the family context", which is comprised of three categories: gender differences; day-to-day concerns; and incongruity between knowledge and behavior related to DM2. These findings suggest that participants construct their identities within the family context and that their experience of living with DM2 is integral to their self-identification as wives and mothers. This, in turn, has implications for the design and implementation of programs to assist women in managing DM2 effectively.<br>El propósito de este estudio es comprender la experiencia de las amas de casa brasileñas con la diabetes mellitus tipo 2 (DM2). Se empleo un abordaje exploratorio descriptivo, donde participaron de las entrevistas 25 amas de casa de Brasil acerca de su experiencia con el DM. Las entrevistas fueron grabadas, transcritas y el texto resultante se analizó mediante el método secuencial de cuatro etapas: aprensión, síntesis, teorización y transferencia. Los datos se reunieron en un tema dominante: "construyendo su identidad en el contexto familiar", que se compone de tres sub-temas: las diferencias de género, las preocupaciones del cotidiano y la incongruencia entre el conocimiento y el comportamiento relacionado con DM2. Estos hallazgos sugieren que los participantes construyen su propia identidad dentro del contexto familiar y que su experiencia de vivir con DM2 es parte integral de su identificación como esposas y madres. Esto, a su vez, tiene implicaciones para el planeamiento e implementación de programas para ayudar a las mujeres para administrar con eficacia la DM2.<br>O objetivo deste estudo foi compreender a experiência de donas de casa brasileiras com diabetes mellitus tipo 2 (DM2). Foi utilizada abordagem descritiva exploratória, e entrevistas semiestruturadas foram realizadas com 25 donas de casa, abordando sua experiência com o DM2. As entrevistas foram gravadas, transcritas e o texto resultante foi analisado usando-se o método de etapas sequenciais. Os dados convergiram para um tema dominante construindo sua identidade no contexto da família, composto por três subtemas: diferenças de gênero, preocupações do dia a dia e incongruência, entre conhecimento e comportamento, relacionada ao DM2. Esses achados sugerem que as participantes constroem sua identidade no contexto da família e que a experiência de viver com DM2 é parte integrante de sua identificação como esposa e mãe. Esses resultados têm implicações para o planejamento e a implementação de programas que contribuam para que as mulheres gerenciem seu DM2 de forma eficaz

    CTA – the World’s largest ground-based gamma-ray observatory

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    Monte Carlo Simulations and Validation of NectarCAM, a Medium Sized Telescope Camera for CTA

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    The upcoming Cherenkov Telescope Array (CTA) ground-based gamma-ray observatory will open up our view of the very high energy Universe, offering an improvement in sensitivity of 5-10 times that of previous experiments. NectarCAM is one of the proposed cameras for the Medium-Sized Telescopes (MST) which have been designed to cover the core energy range of CTA, from 100 GeV to 10 TeV. The final camera will be capable of GHz sampling and provide a field of view of 8 degrees with its 265 modules of 7 photomultiplier each (for a total of 1855 pixels). In order to validate the performance of NectarCAM, a partially-equipped prototype has been constructed consisting of only the inner 61-modules. It has so far undergone testing at the integration test-bench facility in CEA Paris-Saclay (France) and on a prototype of the MST structure in Adlershof (Germany). To characterize the performance of the prototype, Monte Carlo simulations were conducted using a detailed model of the 61 module camera in the CORSIKA/sim_telarray framework. This contribution provides an overview of this work including the comparison of trigger and readout performance on test-bench data and trigger and image parameterization performance during on-sky measurements

    Searching for very-high-energy electromagnetic counterparts to gravitational-wave events with the Cherenkov Telescope Array

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    The detection of electromagnetic (EM) emission following the gravitational wave (GW) event GW170817 opened the era of multi-messenger astronomy with GWs and provided the first direct evidence that at least a fraction of binary neutron star (BNS) mergers are progenitors of short Gamma-Ray Bursts (GRBs). GRBs are also expected to emit very-high energy (VHE, > 100 GeV) photons, as proven by the recent MAGIC and H.E.S.S. observations. One of the challenges for future multi-messenger observations will be the detection of such VHE emission from GRBs in association with GWs. In the next years, the Cherenkov Telescope Array (CTA) will be a key instrument for the EM follow-up of GW events in the VHE range, owing to its unprecedented sensitivity, rapid response, and capability to monitor a large sky area via scan-mode operation. We present the CTA GW follow-up program, with a focus on the searches for short GRBs possibly associated with BNS mergers. We investigate the possible observational strategies and we outline the prospects for the detection of VHE EM counterparts to transient GW events

    Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project

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    In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory

    Reconstruction of stereoscopic CTA events using deep learning with CTLearn

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    The Cherenkov Telescope Array (CTA), conceived as an array of tens of imaging atmospheric Cherenkov telescopes (IACTs), is an international project for a next-generation ground-based gamma-ray observatory, aiming to improve on the sensitivity of current-generation instruments a factor of five to ten and provide energy coverage from 20 GeV to more than 300 TeV. Arrays of IACTs probe the very-high-energy gamma-ray sky. Their working principle consists of the simultaneous observation of air showers initiated by the interaction of very-high-energy gamma rays and cosmic rays with the atmosphere. Cherenkov photons induced by a given shower are focused onto the camera plane of the telescopes in the array, producing a multi-stereoscopic record of the event. This image contains the longitudinal development of the air shower, together with its spatial, temporal, and calorimetric information. The properties of the originating very-high-energy particle (type, energy, and incoming direction) can be inferred from those images by reconstructing the full event using machine learning techniques. In this contribution, we present a purely deep-learning driven, full-event reconstruction of simulated, stereoscopic IACT events using CTLearn. CTLearn is a package that includes modules for loading and manipulating IACT data and for running deep learning models, using pixel-wise camera data as input

    Sensitivity of CTA to gamma-ray emission from the Perseus galaxy cluster

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    In these proceedings we summarize the current status of the study of the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. Gamma-ray emission is expected in galaxy clusters both from interactions of cosmic rays (CR) with the intra-cluster medium, or as a product of annihilation or decay of dark matter (DM) particles in case they are weakly interactive massive particles (WIMPs). The observation of Perseus constitutes one of the Key Science Projects to be carried out by the CTA Consortium. In this contribution, we focus on the DM-induced component of the flux. Our DM modelling includes the substructures we expect in the main halo which will boost the annihilation signal significantly. We adopt an ON/OFF observation strategy and simulate the expected gamma-ray signals. Finally we compute the expected CTA sensitivity using a likelihood maximization analysis including the most recent CTA instrument response functions. In absence of signal, we show that CTA will allow us to provide stringent and competitive constraints on TeV DM, especially for the case of DM decay

    The Cherenkov Telescope Array: layout, design and performance

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    The Cherenkov Telescope Array (CTA) will be the next generation very-high-energy gamma-ray observatory. CTA is expected to provide substantial improvement in accuracy and sensitivity with respect to existing instruments thanks to a tenfold increase in the number of telescopes and their state-of-the-art design. Detailed Monte Carlo simulations are used to further optimise the number of telescopes and the array layout, and to estimate the observatory performance using updated models of the selected telescope designs. These studies are presented in this contribution for the two CTA stations located on the island of La Palma (Spain) and near Paranal (Chile) and for different operation and observation conditions
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