522 research outputs found

    Design Aspects of a Broadband Beam-Reconfigurable Leaky-Wave Antenna

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    Design aspects of a novel beam-reconfigurable pla-nar series-fed array are addressed to achieve beam steering with frequency tunability over a relatively broad bandwidth. The design is possible thanks to the use of the complementary strip-slot, which is an innovative broadly matched microstrip radiator, and the careful selection of the phase shifter parameters.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    GPS, LiDAR and VNIR data to monitor the spatial behavior of grazing sheep

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    Traditional knowledge about the behavior of grazing livestock is about to disappear. Shepherds well know that sheep behavior follows non-random patterns. As a novel alternative to seeking behavioral patterns, this study quantified the grazing activities of two sheep flocks of Churra breed (both in the same area but separated by 10 years) based on Global Position System (GPS) monitoring and remote monitoring sensing techniques. In the first monitoring period (2009-10), geolocations were recorded every 5 min (4, 240 records), while in the second one (2018-20), records were taken every 30 min (7, 636 records). The data were clustered based on the day/night and the activity (resting, moving, or grazing). An airborne LiDAR dataset was used to study the slope, aspect, and vegetation height. Four visible-infrared orthophotographs were mosaicked and classified to obtain the land use/land cover (LU/LC) map. Then, GPS locations were overlain on the terrain features, and a Chi-square test evaluated the relationships between locations and terrain features. Three spatial statistics (directional distribution, Kernel density, and Hot Spot analysis) were also calculated. Results in both monitoring periods suggested that the spatial distribution of free-grazing ewes was non-random. The flocks showed strong preferences for grazing areas with gentle north-facing slopes, where the herbaceous layer formed by pasture predominates. The geostatistical analyses of the sheep locations corroborated those preferences. Geotechnologies have emerged as a potent tool to demonstrate the influence of environmental and terrain attributes on the non-random spatial behavior of grazing sheep. © 2022 Malque Publishing. All rights reserved

    Óxido Nitroso: Implicaciones en la morbi-mortalidad a largo plazo

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    Existe una relación fisiopatológica entre la exposición al óxido nitroso y los efectos a largo plazo en la morbilidad y mortalidad postoperatoria. Sin embargo esta relación no ha sido evaluada estadísticamente. Con los datos del estudio ENIGMA se ha demostrado que la administración de óxido nitroso está asociada con un incremento a largo plazo en el riesgo de infarto agudo de miocardio (IAM) pero no en la mortalidad ni en la incidencia de accidente cerebrovascular agudo (ACV)

    Óxido Nitroso: Implicaciones en la morbi-mortalidad a largo plazo: Leslie K, Myles P, Chan M, Forbes A, Paech M, Peyton P, et al. Nitrous oxide and long-term morbidity and mortality in the ENIGMA trial. Anesthesia-analgesia 2011;101(2):387-393.

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    Existe una relación fisiopatológica entre la exposición al óxido nitroso y los efectos a largo plazo en la morbilidad y mortalidad postoperatoria. Sin embargo esta relación no ha sido evaluada estadísticamente. Con los datos del estudio ENIGMA se ha demostrado que la administración de óxido nitroso está asociada con un incremento a largo plazo en el riesgo de infarto agudo de miocardio (IAM) pero no en la mortalidad ni en la incidencia de accidente cerebrovascular agudo (ACV)

    Canted phase in double quantum dots

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    We perform a Hartree-Fock calculation in order to describe the ground state of a vertical double quantum dot in the absence of magnetic fields parallel to the growth direction. Intra- and interdot exchange interactions determine the singlet or triplet character of the system as the tunneling is tuned. At finite Zeeman splittings due to in-plane magnetic fields, we observe the continuous quantum phase transition from ferromagnetic to symmetric phase through a canted antiferromagnetic state. The latter is obtained even at zero Zeeman energy for an odd electron number.Comment: 5 pages, 3 figure

    Enfermería : fármacos más utilizados en urgencias hospitalarias

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    El Servicio de Urgencias del C.H.G.U.V. cuenta con una plantilla de 84 Enfermeros/as. Una parte considerable de ellos es personal de nueva incorporación, de ahí que sea prioritaria la elaboración de protocolos de actuación. La administración de medicación intravenosa es sin duda una de las técnicas de mayor aplicación en los pacientes que acuden a Urgencias, que en nuestro Hospital oscila entre 550-600 atenciones diarias. Por ello nos planteamos, mediante la realización de reuniones de grupo, la elaboración del presente trabajo con el objetivo de elaborar un manual informativo sobre la medicación más habitual utilizada en nuestro Servicio de Urgencias; indicaciones, contraindicaciones, diluciones, cuidados y recomendaciones sobre la administración que nos ayude a visionar la practica en nuestro trabajo y la calidad del Servicio que prestamos a nuestros pacientes, y sirva de consulta sobre todo al personal de nueva incorporación.The First aid service of the C.H.G.U.V. Nurse is provided with a staff of 84, a considerable part of them is new staff, and therefore there is a priority of making of performance protocols. The administration of intravenous medication is undoubtedly one of the most used techniques in patients who come to the emergency room, which in our Hospital ranges between 550-600 daily attentions. For this reason, we considered that carrying out group meetings in order to elaborate the present essay. Our main objective is to prepare an informative guidebook about the most common used medicines in our first aid service: indications, contraindications, dilutions, care, and recommendations on the use. In this sense it will contribute to see the practice in our work and the service quality that we give to our patients. And what is more, it will serve as a reference particularly to the new [email protected]

    The impact of agricultural management on soil aggregation and carbon storage is regulated by climatic thresholds across a 3000 km European gradient

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    Organic carbon and aggregate stability are key features of soil quality and are important to consider when evaluating the potential of agricultural soils as carbon sinks. However, we lack a comprehensive understanding of how soil organic carbon (SOC) and aggregate stability respond to agricultural management across wide environmental gradients. Here, we assessed the impact of climatic factors, soil properties and agricultural management (including land use, crop cover, crop diversity, organic fertilization, and management intensity) on SOC and the mean weight diameter of soil aggregates, commonly used as an indicator for soil aggregate stability, across a 3000 km European gradient. Soil aggregate stability (−56%) and SOC stocks (−35%) in the topsoil (20 cm) were lower in croplands compared with neighboring grassland sites (uncropped sites with perennial vegetation and little or no external inputs). Land use and aridity were strong drivers of soil aggregation explaining 33% and 20% of the variation, respectively. SOC stocks were best explained by calcium content (20% of explained variation) followed by aridity (15%) and mean annual temperature (10%). We also found a threshold-like pattern for SOC stocks and aggregate stability in response to aridity, with lower values at sites with higher aridity. The impact of crop management on aggregate stability and SOC stocks appeared to be regulated by these thresholds, with more pronounced positive effects of crop diversity and more severe negative effects of crop management intensity in nondryland compared with dryland regions. We link the higher sensitivity of SOC stocks and aggregate stability in nondryland regions to a higher climatic potential for aggregate-mediated SOC stabilization. The presented findings are relevant for improving predictions of management effects on soil structure and C storage and highlight the need for site-specific agri-environmental policies to improve soil quality and C sequestration

    Water Masses and Circulation in the Tropical Pacific off Central Mexico and Surrounding Areas

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    13 páginas, 8 figuras, 2 tablasThe seasonal variations and the interactions of the water masses in the tropical Pacific off central Mexico (TPCM) and four surrounding areas were examined based on an extensive new hydrographic database. The regional water masses were redefined in terms of absolute salinity (SA) and conservative temperature (Θ) according to the Thermodynamic Equation of Seawater 2010 (TEOS-10). Hydrographic data and the evaporation minus (precipitation + runoff) balance were used to investigate the origin and seasonality of two salinity minima in the area. The shallow (50–100 m) salinity minimum originates with the California Current System and becomes saltier as it extends southeastward and mixes with tropical subsurface waters while the surface salinity minimum extends farther north in the TPCM in summer and fall because of the northward advection of tropical surface waters. The interactions between water masses allow a characterization of the seasonal pattern of circulation of the Mexican Coastal Current (MCC), the tropical branch of the California Current, and the flows through the entrance of the Gulf of California. The seasonality of the MCC inferred from the distribution of the water masses largely coincides with the geostrophic circulation forced by an annual Rossby waveThis is a product of the project CONACyT (SEP2011–168034-T), with collaboration from the following sources: CONACyT Projects 168034-T, T-9201, 4271P-T, 38797-T, 26653-T, 1076-T9201, 4271PT9601, C01–25343; 38834-T, C02-44870F,G34601-S, and 103898; Naval Postgraduate School; NOC-US; NOAA (GC04– 219); and the regular UABC budget through Projects 4009, 4015, 0324, 0333, and 0352. Funding came from CONACyT, México through the Grant 1329234 for the Ph.D. studies of Esther PortelaPeer reviewe

    ¿Con qué saboreamos?: tareas y experiencias para un taller de ciencias

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    En un grupo de primero de primaria hicimos una pregunta aparentemente simple: ¿Con qué saboreamos? La respuesta inmediata entre los niños fue “con la lengua” y, aunque ésta no fue totalmente correcta, sirvió para iniciar un proyecto en el que se ofreció a los niños la oportunidad para observar, proponer hipótesis, establecer objetivos y buscar métodos que les ayudaran a resolver la pregunta. Planteamos 4 experiencias cuya finalidad fue que los niños extendieran sus conocimientos y su comprensión sobre un proceso aparentemente sencillo como es la percepción al sabor. Primero cuestionamos la idea de que fuera la lengua el lugar primordial para la detección del sabor (experiencia 1); después incluimos al sentido del olfato como parte de la percepción del sabor (experiencia 2); tratamos de convencer a los niños de que el olor es el elemento más importante para detectar el sabor (experiencia 3); por último discutimos la posibilidad de que fuera el cerebro el que realmente saborea (experiencia 4).Palabras claves: Ciencia; métodos; percepción al sabor; creatividad; inteligencia.What do we savor with? Task and experiences for a workshop of scienceIn a primary school we asked students a seemingly simple question: What do we savor with? The immediate response was "with the tongue" and, although this answer is incomplete, it served to initiate a project that offered to the children the opportunity to observe, to propose hypotheses, to establish objectives and to develop methods that would help them resolve the question. We planned four experiences in order for the children to be conscious of their actual knowledge and to understand the perception to the flavor. First, we questioned the idea that the tongue was the basic place for the detection to the flavor (experience 1); later, we included to smell as part of the perception to the flavor (experience 2); we tried to convince the children that the smell is the most important element in the detection of flavor (experience 3); and finally, we discussed the possibility that the brain is the place where we savor (experience 4).Keywords: Science; methods; flavor perception; creativity; intelligence
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