293 research outputs found

    Empirical Rates Characterization of Wearable Multi-Antenna Terminals for First-Responders

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    Empirical characterization of the achievable rates for a wearable multi-antenna terminal shows the potential advantages of deploying a large number of antennas at the user end. We focus on the challenges and requirements of the broadband communication in future emergency communication systems, specifically addressing the outdoor-to-indoor propagation scenario, where the first responder is within an underground area such as a garage or basement. The measurement campaign undertaken characterizes the flat fading multiple-input multiple-output (MIMO) channel matrices at 3.5 GHz for a maximum of M = 30 antennas deployed at the base station (BS), and N = 12 wearable antennas at the user. The achievable rates are obtained for two transmission strategies that account for the different levels of channel knowledge. In both cases, all the MIMO processing is carried out at the BS.This work was supported in part by the Spanish Government under Project MIMOTEX (TEC2014-61776-EXP), Project CIES (RTC-2015-4213-7), and Project TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE), and in part by the Chilean Government through projects CONICYT under Grant Proyecto Basal FB0821, Grant Fondecyt Iniciación 11171159, and Grant VRIEA-PUCV 039.462/2017.Publicad

    PRODUCCIÓN DE TOMATE EN INVERNADERO CON COMPOSTA Y VERMICOMPOSTA COMO SUSTRATO

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    The organic production of food is an alternative for consumers that prefer food free of pesticides, synthetic fertilisers, and with a high nutritional value. The purpose of this study was to evaluate substrates prepared with mixtures of compost and vermicompost with sand, at various levels, under greenhouse conditions. The tomato hybrid SUN-7705 (Lycopersicon esculentum Mill) was analized in four substrates that included compost and vermicompost mixed at three different proportions (100, 75 y 50 %). The treatments were distributed in a completely randomised design with a factorial arrangement of 4x3 and five replicates. The greatest average yield (39.811 t ha) was obtained with the compost generated by decomposing bovine manure, corn stover (Zea mays L.), elephant grass (Pennisetum purpureum Schumacher) and black earth (CEMZT) at 75% + sand, and with the vermicompost generated by manure, bahiagrass (Paspalum notatum Flügge) and black earth (VEPT) at 100 and 50% + sand. This yield was greater than that recorded for organic tomato production in the field, without affecting the quality of the fruit

    Unravelling the relevance of the polyadenylation factor EhCFIm25 in entamoeba histolytica through proteomic analysis

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    We recently reported that silencing of the polyadenylation factor EhCFIm25 in Entamoeba histolytica, the protozoan which causes human amoebiasis, affects trophozoite proliferation, death, and virulence, suggesting that EhCFIm25 may have potential as a new biochemical target. Here, we performed a shotgun proteomic analysis to identify modulated proteins that could explain this phenotype. Data are available via ProteomeXchange with identifier PXD027784. Our results revealed changes in the abundance of 75 proteins. Interestingly, STRING analysis, functional GO‐term annotations, KEGG analyses, and literature review showed that modulated proteins are mainly related to glycolysis and carbon metabolism, cytoskeleton dynamics, and parasite virulence, as well as gene expression and protein modifications. Further studies are needed to confirm the hypotheses emerging from this proteomic analysis, to thereby acquire a comprehensive view of the molecular mechanisms involved

    Observation of the hyperfine transition in lithium-like Bismuth 209Bi80+^{209}\text{Bi}^{80+}: Towards a test of QED in strong magnetic fields

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    We performed a laser spectroscopic determination of the 2s2s hyperfine splitting (HFS) of Li-like 209Bi80+^{209}\text{Bi}^{80+} and repeated the measurement of the 1s1s HFS of H-like 209Bi82+^{209}\text{Bi}^{82+}. Both ion species were subsequently stored in the Experimental Storage Ring at the GSI Helmholtzzentrum f\"ur Schwerionenforschung Darmstadt and cooled with an electron cooler at a velocity of 0.71c\approx 0.71\,c. Pulsed laser excitation of the M1M1 hyperfine-transition was performed in anticollinear and collinear geometry for Bi82+\text{Bi}^{82+} and Bi80+\text{Bi}^{80+}, respectively, and observed by fluorescence detection. We obtain ΔE(1s)=5086.3(11)meV\Delta E^{(1s)}= 5086.3(11)\,\textrm{meV} for Bi82+\text{Bi}^{82+}, different from the literature value, and ΔE(2s)=797.50(18)meV\Delta E^{(2s)}= 797.50(18)\,\textrm{meV} for Bi80+\text{Bi}^{80+}. These values provide experimental evidence that a specific difference between the two splitting energies can be used to test QED calculations in the strongest static magnetic fields available in the laboratory independent of nuclear structure effects. The experimental result is in excellent agreement with the theoretical prediction and confirms the sum of the Dirac term and the relativistic interelectronic-interaction correction at a level of 0.5% confirming the importance of accounting for the Breit interaction.Comment: 5 pages, 2 figure

    Extendiendo el modelo UTAUT para evaluar los factores que afectan la adopción del Big Data en empresas españolas

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    La implantación de técnicas de Big Data es una realidad en la toma de decisiones de marketing. Este desarrollo cuestiona qué factores afectan a las empresas en la aceptación de estas tecnologías. En respuesta, extendemos el modelo de aceptación de tecnologías UTAUT al Big Data y añadimos el riesgo percibido como inhibidor. Modelizamos mediante ecuaciones estructurales con Smart-PLS sobre una muestra de empresas que utilizan Big Data. Los resultados muestran la mayor predicción de la extensión del UTAUT planteada y el menor efecto de variables propuestas en el modelo original

    New insights into the fossil record of the turtle genus Chelus Duméril, 1806 including new specimens with information on cervicals and limb bones

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    Matamata turtles (Chelus Duméril, 1806) are composed of two extant species, Chelus fimbriata ­Schneider, 1783 and Chelus orinocensis Vargas-Ramírez, Caballero, Morales-Betancourt, Lasso, Amaya, Martínez, Silva-Viana, Vogt, Farias, Hrbek, Campbell & Fritz, 2020, inhabitants of the main freshwater drainages of northern South America. The systematics and palaeobiogeography of Chelus is still unresolved. Here, we describe several new fossil specimens from the Late Miocene of Urumaco (Venezuela) and Tatacoa (Colombia). The fossils are mostly complete, articulated shells that allow reestablishing validity of two extinct taxa, Chelus colombiana Wood, 1976 and Chelus lewisi Wood, 1976. One of the specimens of C. lewisi from Urumaco represents the first record within the genus for which autopodial bones (a left manus) and additional limb bones are preserved together with ashell, demonstrating evolutionary conservatism in limb anatomy for the genus. The specimen comes from the Socorro Formation, representing the earliest so far known record of Chelus for the Urumaco sequence. Additionally, one specimen from Tatacoa is the first fossil for which cervical and pectoral girdle elements are preserved. Phylogenetic analysis supports the existence of two separate clades inside of Chelus, one formed by the extinct species and the other by the extant ones
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