24 research outputs found

    Modeling of Current Consumption in 802.15.4/ZigBee Sensor Motes

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    Battery consumption is a key aspect in the performance of wireless sensor networks. One of the most promising technologies for this type of networks is 802.15.4/ZigBee. This paper presents an empirical characterization of battery consumption in commercial 802.15.4/ZigBee motes. This characterization is based on the measurement of the current that is drained from the power source under different 802.15.4 communication operations. The measurements permit the definition of an analytical model to predict the maximum, minimum and mean expected battery lifetime of a sensor networking application as a function of the sensor duty cycle and the size of the sensed data

    Impacto de la COVID-19 en los servicios de cirugía cardiovascular en España: Análisis de los grupos relacionados con el diagnóstico (Estudio SECCE-COVID-19 fase 2)

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    Introducción y objetivos La pandemia por COVID-19 causada por infección del virus SARS-CoV-2 ha saturado al sistema sanitario español, afectándose la atención de las enfermedades cardiovasculares. Queremos cuantificar el impacto de la pandemia en el número de las intervenciones quirúrgicas cardíacas analizando los grupos relacionados con el diagnóstico (GRD) más prevalentes de nuestra especialidad. Métodos A instancias de la Sociedad Española de Cirugía Cardiovascular y Endovascular, se solicitó a todos los centros nacionales que quisieron participar, los datos de los códigos de GRD números 162 (cirugía sobre válvulas cardíacas con infarto o diagnóstico complejo), 163 (cirugía sobre válvulas cardíacas sin infarto o diagnóstico complejo), 165 (bypass coronario con infarto o diagnóstico complejo), 166 (bypass coronario sin infarto o diagnóstico complejo) y 167 (otros procedimientos cardiotorácicos o vasculares torácicos) entre el 1 de marzo de 2020 y el 30 de septiembre de 2020 (siete meses), y como período control las mismas fechas de 2019. Resultados Se recibieron los datos de 24 hospitales, 22 públicos y dos privados. Existió un descenso global en el número de intervenciones del 30% (rango -19 a -42%, p < 0,001) de 4.648 en 2019 a 3.262 en 2020 (-1.386 de diferencia), siendo +7% para el GRD 162 (p = 0,500), -37% para el 163 (p = 0,001), -9% para el 165 (p = 0,304), -32% para el 166 (p = 0,001), y -16% para el 167 (p = 0,062). Conclusiones Existió un descenso global de cirugías estadísticamente significativo en 2020 del 30% respecto del 2019 entre el 1 de marzo y el 30 de septiembre

    The Athena X-ray Integral Field Unit (X-IFU)

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    The X-ray Integral Field Unit (X-IFU) is the high resolution X-ray spectrometer of the ESA Athena X-ray observatory. Over a field of view of 5' equivalent diameter, it will deliver X-ray spectra from 0.2 to 12 keV with a spectral resolution of 2.5 eV up to 7 keV on similar to 5 '' pixels. The X-IFU is based on a large format array of super-conducting molybdenum-gold Transition Edge Sensors cooled at similar to 90 mK, each coupled with an absorber made of gold and bismuth with a pitch of 249 mu m. A cryogenic anti-coincidence detector located underneath the prime TES array enables the non X-ray background to be reduced. A bath temperature of similar to 50 mK is obtained by a series of mechanical coolers combining 15K Pulse Tubes, 4K and 2K Joule-Thomson coolers which pre-cool a sub Kelvin cooler made of a He-3 sorption cooler coupled with an Adiabatic Demagnetization Refrigerator. Frequency domain multiplexing enables to read out 40 pixels in one single channel. A photon interacting with an absorber leads to a current pulse, amplified by the readout electronics and whose shape is reconstructed on board to recover its energy with high accuracy. The defocusing capability offered by the Athena movable mirror assembly enables the X-IFU to observe the brightest X-ray sources of the sky (up to Crab-like intensities) by spreading the telescope point spread function over hundreds of pixels. Thus the X-IFU delivers low pile-up, high throughput (> 50%), and typically 10 eV spectral resolution at 1 Crab intensities, i.e. a factor of 10 or more better than Silicon based X-ray detectors. In this paper, the current X-IFU baseline is presented, together with an assessment of its anticipated performance in terms of spectral resolution, background, and count rate capability. The X-IFU baseline configuration will be subject to a preliminary requirement review that is scheduled at the end of 2018. The X-IFU will be provided by an international consortium led by France, the Netherlands and Italy, with further ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Ireland, Poland, Spain, Switzerland and contributions from Japan and the United States.Peer reviewe

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Modelling of the Analog Electronic Stage of a Detection System for Hard X-ray Astronomy

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    Germanium detectors are used by the scientic community to study cosmic X-ray sources. In order to localize the exact 3D position of an X-ray interaction, double-sided strip detectors are used. Each strip requires a single readout electronic stage to convert induced charge into a voltage pulse. We present here the computer simulation of such an analog electronic stage. Each particular element of this stage, i.e. charge-sensitive preamplier, amplier, oset corrector, lter and analog-to-digital converter, will be simulated in detail, taking into account temperature and noise performances. Furthermore, a tool to simultaneously simulate multiple strips for several X-ray interaction points was developed. This tool will facilitate the study of all electronic chains as a whole.Validerat; 20120908 (anonymous)</p

    Regional variability of arsenic content in Uruguayan polished rice

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    Characterization of the country internal variability of arsenic (As) accumulation in rice grain across different rice production regions is very important in order to analyze its compliance with international and regional limits. A robust sampling study scheme (n = 150 samples) was performed to determine total arsenic (tAs) and inorganic (iAs) levels from polished rice grain covering all rice producing regions along two growing seasons. The mean and median concentration of tAs were 0.178 mg kg-1 and 0.147 mg kg-1, with a minimum and maximum value of 0.015 mg kg&minus;1 and 0.629 mg kg&minus;1, respectively and a coefficient of variation of 63.6%. The mean and median concentration of iAs were 0.062 mg kg&minus;1 and 0.055 mg kg&minus;1 respectively ranging from 0.005 mg kg&minus;1 up to a maximum of 0.195 mg kg&minus;1 and a coefficient of variation of 51.5%. A moderate correlation was revealed within iAs and tAs. Levels of iAs in all of the samples were below the international limits of 0.2 mg kg&minus;1 according to the international limits for human health by the Codex Alimentarius (FAO and WHO, 2019). Rice fields cultivated on soils originated from igneous geological material reported lower arsenic levels accumulated in rice grain in relation to sedimentary soils. Japonica cultivars presented significantly lower tAs and iAs concentrations than Indica ones (p = 0.0121 and p &lt; 0.0001; respectively). Consumption of rice by male and female adults in Uruguay is safe according to its level of annual consumption and based on the mean iAs levels determined in this study

    Irrigation management and variety effects on rice grain arsenic levels in Uruguay

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    Rice is the most important staple component of the human diet worldwide. The higher amounts of arsenic accumulation in its grain in relation to other crops, determines a potential toxicity risk to humans. This research project aimed to determine the inorganic arsenic accumulation in rice grain (iAs) in two contrasting soil sites, Paso Farias-Artigas (PF) and Paso de la Laguna-Treinta y Tres (PdL), with two different mitigation practices, in Uruguay. These being firstly irrigation management techniques and secondly the use of different varieties. Five experiments were conducted with a split plot design with four blocks over three rice growing seasons from 2014 until 2017. The experimental sites included two irrigation treatments: continuous flooded (C) and alternate wetting and drying (AWD). The split plots included different varieties: Indicas and Japonicas. Average iAs accumulated in rice grain were 0.07 mg kg-1, well below international limits, even under the C irrigation technique. It was found that iAs accumulation in rice grain can be further reduced by the implementation of AWD in certain soil types. Japonica varieties had a lower accumulation of iAs in rice grain, in comparison with Indicas at both sites

    Comparative distribution of Volatile Organic Compounds across the surface oceans

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    2018 Ocean Sciences Meeting, 11-16 February, in Portland, OregonThe oceans are a natural source of Volatile Organic Compounds (VOCs). Once emitted, VOCs play important roles in the atmosphere; they provide odour landscapes for marine animals, act as oxidant scavengers and are precursors for aerosols, which affect the Earth radiation budget by scattering solar radiation back to space and altering the properties and lifetimes of clouds. Out of all VOCs, we focus on those that typically are supersaturated in surface seawater: DMS (dimethyl sulphide), OCS, CS2, CH3I, CH2I2, CH2ClI, CHBr3, CH2Br2 and isoprene. We used gas chromatography mass spectrometry to obtain aqueous concentrations of VOCs during 5 cruises across: the Mediterranean Sea (HotMix, 2014), Atlantic Ocean (Trans-PEGASO, 2014 and ACE0, 2016) and Southern Ocean (PEGASO, 2015 and ACE, 2016-2017). We present how these compounds co-variate among them and with other oceanographic and atmospheric variables. We explore their relationship with chlorophyll a, phytoplankton taxonomy and physiology, bacterial abundances, coloured dissolved organic matter, temperature, salinity, wind speed and solar radiation as potential drivers of their production and cycling. Our results show that usually these compounds are in the lower picomolar range (nanomolar for the DMS), but there are certain hotspots with high concentrations like the Mauritanian up-welling (164.2±0.2 pM isoprene) or the South Georgia summer bloom (54.8±1.3 pM CHBr3). Although all VOCs are related directly or indirectly to plankton productivity, we found a pattern of most compounds with temperature and light in which colder and more mixed waters present lower volatile/Chl a ratiosPeer Reviewe

    The Athena X-ray Integral Field Unit (X-IFU)

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    The X-ray Integral Field Unit (X-IFU) on board the Advanced Telescope for High-ENergy Astrophysics (Athena) will provide spatially resolved high-resolution X-ray spectroscopy from 0.2 to 12 keV, with 5 arc second pixels over a field of view of 5 arc minute equivalent diameter and a spectral resolution of 2.5 eV up to 7 keV. In this paper, we first review the core scientific objectives of Athena, driving the main performance parameters of the X-IFU, namely the spectral resolution, the field of view, the effective area, the count rate capabilities, the instrumental background. We also illustrate the breakthrough potential of the X-IFU for some observatory science goals. Then we briefly describe the X-IFU design as defined at the time of the mission consolidation review concluded in May 2016, and report on its predicted performance. Finally, we discuss some options to improve the instrument performance while not increasing its complexity and resource demands (e.g. count rate capability, spectral resolution). The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with further ESA member state contributions from Belgium, Finland, Germany, Poland, Spain, Switzerland and two international partners from the United States and Japan
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