369 research outputs found

    Advantage of four-electrode over two-electrode defibrillators

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    Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish the normal heart rate. We propose a new technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of such a new technique. We compare three different shock protocols, namely, a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80 % in the energy required for a defibrillation success rate of 90 %. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock

    Interacción de la radiación electromagnética. Segregación espectral y espacial de cultivos frente a malas hierbas todos ellos pertenecientes al género Brassica.

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    La interacción de la radiación electromagnética, denominada luz si abarca el rango visible por el ojo humano (400-700nm), da lugar a un espectro específico para cada objeto animado o inanimado. En el ámbito agrario, la reflectancia espectral de los productos agrícolas tanto en el rango visible como en el infrarrojo ha sido ampliamente estudiada (algunos ejemplos se encuentran recogidos en las referencias 1, 2, 3, 4, 9, 10 & II de la bibliografía)

    Desarrollo de un espectrofotómetro de campo para su aplicación en un programa de mejora genética

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    Se ha desarrollado un espectrofotómetro de campo para uso en programas de mejora del olivo en el marco de un proyecto INIA en el que trabajan conjuntamente el LPFTAG y el IFAPA de Córdoba. La robustez de los modelos en la configuración portátil es muy dependiente del número de variables latentes seleccionadas mediante modelos PLS. Se evalúa el procedimiento PDS de transferencia de calibración para mantener en uso las bases de datos acumuladas con un equipo de sobremesa a lo largo de los últimos cinco años

    Aportaciones a la flora de la provincia de Segovia (España) II

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    Se presentan en este trabajo datos de interés florístico y corológico, referentes a dieciocho especies de plantas fanerógamas, para la comunidad de Castilla y León, la mayoría alóctonas o xenófitas. Se citan por primera vez en la provincia de Segovia Polycarpon tetraphyllum, Papaver somniferum, Wisteria sinensis, Coriandrum sativum, Origanum majorana, Salpichroa origanifolia, Buddleja davidii, Orobanche rapun-genistae, Lonicera japonica, Aster novi-belgii, Galinsoga parviflora, Cosmos bipinnatus y Artemisia verlotiorum. Es novedad para la provincia de Valladolid Crataegus azarolus, y se cita por primera vez en la provincia de Soria Buddleja davidii. Consolida ajacis, Ipomoea purpurea, Solanum physalifolium var. nitidibaccatum y Gaillardia aristata requieren algún tipo de aclaración en lo que concierne a su status en las provincias de Segovia y Palencia. Para dieciséis de las especies se aportan mapas corológicos con indicación de la presencia a nivel de cuadrícula UTM de 10 x 10 km

    Independent component analysis for the identification of sources of variation on an industrial nirs application

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    A Near Infrared Spectroscopy (NIRS) industrial application was developed by the LPF-Tagralia team, and transferred to a Spanish dehydrator company (Agrotécnica Extremeña S.L.) for the classification of dehydrator onion bulbs for breeding purposes. The automated operation of the system has allowed the classification of more than one million onion bulbs during seasons 2004 to 2008 (Table 1). The performance achieved by the original model (R2=0,65; SEC=2,28ºBrix) was enough for qualitative classification thanks to the broad range of variation of the initial population (18ºBrix). Nevertheless, a reduction of the classification performance of the model has been observed with the passing of seasons. One of the reasons put forward is the reduction of the range of variation that naturally occurs during a breeding process, the other is the variations in other parameters than the variable of interest but whose effects would probably be affecting the measurements [1]. This study points to the application of Independent Component Analysis (ICA) on this highly variable dataset coming from a NIRS industrial application for the identification of the different sources of variation present through seasons

    Silicificaciones selectivas en Thalassinoides y otras estructuras biogénicas asociadas a calizas de plataforma marina y hardground (Albiense inferior, Sonabia, Cantabria)

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    In this work different types of chert from the Oriñón Limestone Formation (upper Aptian-lower Albian) are studied. This formation outcrops in the eastern coast of Cantabria (Liendo-Castro Urdiales area) and includes outstanding and abundant cherty nodules, lenticular layers and crusts. The host rock is mainly a biocalcarenite (wackestone/packstone) of pellets, echinoids fragments, oysters, foraminifers and calcareous or calcified siliceous sponge spicules. The Oriñón Limestone Formation was deposited in a marine open-shelf environment and preserves a hardground of regional extent with particular chert crusts. The silica source is associated to the dissolution of siliceous sponge spicules or to their calcification. Most of the chert is constituted by mosaics of micro-cryptocrystalline quartz and calcedonite, and it is generated by the selective silicification of biogenic structures, mainly dwelling trace fossils (Thalassinoides isp.) because of the higher amount of organic matter and the higher porosity and permeability of the burrow infill. In the hardground, selective silicification affects body fossils such as belemnites, oysters and echinoids, and trace fossils (feeding burrows and borings) where in addition cherts is accumulated as an indeterminate crust. The silicification of the biogenic structures firstly occurred in form of opaline phases during the early diagenesis while the oxidation of the organic matter was active. Thus, Thalassinoides trace fossils affected by silicification preserve filaments and cocoids that might have had a microbial origin. Neoformation of dolomite and calcite occur only within the Thalassinoides trace fossils which indicates that diagenetic processes taking place within these burrows differed from those affecting the host rock and other biogenic structures. Dwelling trace fossils would have supposed a close micro-environment where the oxidation conditions changed from high to low rate.El presente trabajo estudia los diferentes tipos de sílex que aparecen en la Formación Calizas de Oriñón (Aptiense superior-Albiense inferior), en un zona concreta de la costa oriental de Cantabria (Liendo-Castro Urdiales), debido a su gran abundancia y espectacularidad. Las rocas que los incluyen son principalmente biocalcarenitas (wackestones/packstones de pellets, fragmentos de equinodermos, ostreidos, foraminíferos y espículas calcáreas o silíceas calcificadas), siendo el ambiente de depósito marino de plataforma abierta, y existiendo un hardground regional, donde las silicificaciones son diferentes. La fuente de la sílice proviene de la calcitización o disolución de las espículas de esponjas silíceas. Se determina que la gran mayoría de sílex (mosaicos de cuarzo micro-microcriptalino y calcedonita principalmente), se forman por la silicificación selectiva de estructuras biogénicas, siendo las galerías de Thalassinoidespreferentemente silicificadas, debido a que en su relleno existe mayor proporción de materia orgánica y mayor porosidad y permeabilidad. En las calizas que soportan el hardground además de las silicificaciones selectivas sobre fósiles (rostros de belemnites, ostreidos y equínidos), la sílice se acumula de forma importante en huellas de alimentación y rellenos de perforaciones, dando lugar a su vez a costras sobre bioturbaciones y perforaciones que a pesar de su importancia no han podido ser clasificadas. La silicificación de todas las estructuras biogénicas, originó inicialmente fases opalinas y tuvo lugar durante la diagénesis temprana cuando la oxidación de la materia orgánica estaba todavía activa, conservándose en los Thalassinoides silicificados formas (filamentos y cocoides) que podrían ser consideradas microbianas. La transformación ópalo-cuarzo fue temprana, preservándose dichas formas. En las galerías silicificadas de Thalassinoides los procesos diagenéticos son diferentes a los de los sedimentos carbonáticos marinos que las incluyen, y al resto de estructuras biogénicas silicificadas, existiendo en estas galerías neoformación de dolomita y calcita, en un microambiente cerrado donde las condiciones cambian de oxidantes a reductoras

    Sobre la presencia de cactáceas naturalizadas en la costa meridional de Cataluña

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    The authors report on the finding of eight new alien cacti naturalised in the Baix Camp (Tarragona). Three of these are new records for Europe, two are new records for Spain and one is a first record for Tarragona province. Two further species are not new floristic records however some revision of their status in Catalonia is required. Discussed is the extensive use of alien plant species in garden design in the area and the mildness of the local climatic conditions which has resulted in the greatest accumulation of naturalised cacti in Europe.En una riera de la comarca del Baix Camp (Tarragona) hemos encontrado ocho especies de cactáceas alóctonas naturalizadas. De ellas, tres son nuevas para Europa, dos nuevas para España, una nueva para la provincia de Tarragona y, finalmente, otras dos sin ser novedad florística requieren aclaraciones en lo concerniente a su estatus en Cataluña. Este hallazgo representa la mayor biodiversidad de cactáceas citada hasta el momento para toda Cataluña, para toda la Península Ibérica e incluso para toda Europa. La introducción de especies exóticas en general y de cactáceas en particular se ve favorecida en esta comarca de la costa mediterránea por el desarrollo de una jardinería basada casi exclusivamente en elementos foráneos y en la existencia de una climatología muy favorable

    Detección óptica de harinosidad en manzana mediante una nueva técnica láser.

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    Mealiness, a textural disorder that produces quality loss, combines softness and absence of juiciness. The only one (destructive) test to measure it, combines information from a mechanical test on fruit probes to classify the samples according to instrumental mealiness. Time-domain laser reflectance spectroscopy (TDRS) is able to assess simultaneously and independently the absorption of the light inside the irradiated body (µa coefficient) and the scattering of the photons across the tissues (µS, transport scattering coeff.) measured at each wavelength. Using VIS&NIR lasers as light sources, TDRS was applied to Golden Delicious and Cox apples (n=90), conforming batches of untreated samples and storage-treated (20°C&95%RH) to induce mealiness development. The collected database was clustered into different groups according to their instrumental mealiness. Optical variables were used to build discriminant functions, achieving classification scores 75-89% of correctly identified mealy apples

    Effect of Fe-olivine on the tar content during biomass gasification in a dual fluidized bed

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    8 figures, 5 tablesThe Fe/olivine catalyst effectiveness regarding tar primary reduction during biomass gasification in dual fluidized beds has been investigated. The use of Fe/olivine instead olivine leads to an important decrease in the amount of produced tar, which was reduced by up to 65% at 850. °C, naphthalene being the most stable molecule. It has been found that Fe/olivine materials have a double effect on tar destruction. On the one hand, they act as a catalyst for tar and hydrocarbon reforming. On the other hand, they can act as an oxygen carrier that transfers oxygen from the combustor to the gasifier, and part of the oxygen is used to burn volatile compounds. The catalyst was fairly stable because the result was confirmed during 48. h of continuous operation. The Fe/olivine material characterization (X-ray diffraction, Mössbauer spectroscopy, temperature programmed reduction and oxidation, etc.) revealed that the catalyst structure was maintained despite the large number of oxidizing-reducing cycles. The carbon that formed on the catalyst surface was low and easily oxidized in the combustion zone. Therefore, the inexpensive and non-toxic Fe/olivine catalyst is a material suitable for use as primary catalyst in a fluidized bed gasification of biomass.Authors would like to thank the European Commission for its financial support (EC Project UNIQUE N°211517-ENERGY FP7–2008/2011). http://www.uniqueproject.eu Authors also express our gratitude to Daniel Schwartz for his help in the improvement of English of this paper.Peer Reviewe

    Can Vitality and Mental Health Influence Upper Extremity Pain? A Prospective Cohort Study of 1185 Female Hospital Nurses

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    Musculoskeletal disorders of the upper extremity are among the most common occupational problems affecting nurses. The aim of this study was to analyze the prospective association between vitality and mental health and increased upper extremity pain intensity in female hospital nurses during a 1-year follow-up. A prospective cohort of 1185 female nurses from 19 hospitals in Denmark was conducted using baseline and 12-month follow-up questionnaires to identify potential associations between levels of vitality and mental health (SF-36 subscales) with pain intensity (0–10 scale) in the shoulder, elbow and hand/wrist regions. Associations were modeled using cumulative logistic regression. The fully adjusted model included the variables of age, baseline pain, body mass index, smoking status, years of occupation, leisure time physical activity level, number of daily patient transfers/handlings, as well as recognition and influence at work. The mean age was 48.3 (SD: 10.4) years. In the fully adjusted model, significant associations between low vitality levels and the odds of shoulder pain (OR = 1.96; 95%CI: 1.43–2.68) and hand/wrist pain (OR = 2.32; 95%CI: 1.58–3.42) were observed. Likewise, moderate levels of mental health was associated with increased odds of shoulder pain at follow-up (OR = 1.50; 95%CI: 1.16–1.93). These results provide an important incentive for nursing managers to assess vitality and mental health among hospital nurses and to consider this factor in prevention strategies to ensure good worker health and, by extension, high-quality care.Author L.L.A. obtained a grant from the Danish Working Environment Research Fund (Arbejdsmiljøforskningsfonden) for this study. Grant number 26-2015-09. Author R.N.-C. is supported by the National Research and Development Agency of Chile (ANID/2020-72210026). Author R.L.-B. is supported by the European Union—Next Generation EU
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