487 research outputs found

    Analysis of the 40K contamination in NaI(Tl) crystals from different providers in the frame of the ANAIS project

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    NaI(Tl) large crystals are applied in the search for galactic dark matter particles through their elastic scattering off the target nuclei in the detector by measuring the scintillation signal produced. However, energies deposited in the form of nuclear recoils are small, which added to the low efficiency to convert that energy into scintillation, makes that events at or very near the energy threshold, attributed either to radioactive backgrounds or to spurious noise (non-bulk NaI(Tl) scintillation events), can compromise the sensitivity goals of such an experiment. DAMA/LIBRA experiment, using 250 kg NaI(Tl) target, reported first evidence of the presence of an annual modulation in the detection rate compatible with that expected for a dark matter signal just in the region below 6 keVee (electron equivalent energy). In the frame of the ANAIS (Annual modulation with NaI Scintillators) dark matter search project a large and long effort has been carried out in order to understand the origin of events at very low energy in large sodium iodide detectors and develop convenient filters to reject those non attributable to scintillation in the bulk NaI(Tl) crystal. 40K is probably the most relevant radioactive contaminant in the bulk for NaI(Tl) detectors because of its important contribution to the background at very low energy. ANAIS goal is to achieve levels at or below 20 ppb natural potassium. In this paper we will report on our effort to determine the 40K contamination in several NaI(Tl) crystals, by measuring in coincidence between two (or more) of them. Results obtained for the 40K content of crystals from different providers will be compared and prospects of the ANAIS dark matter search experiment will be briefly reviewed.Comment: Submitted to International Journal of Modern Physics

    Distribution of pines in Europe agrees with seedling differences in foliage frost tolerance, not with xylem embolism vulnerability

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    Drought and frosts are major determinants of plant functioning and distribution. Both stresses can cause xylem embolism and foliagedamage. The objective of this study was to analyse if the distribution of six common pine species along latitudinal and altitudinalgradients in Europe is related to their interspecific differences in frost tolerance and to the physiological mechanismsunderlying species-specific frost tolerance. We also evaluate if frost tolerance depends on plant water status. We studied survivalto a range of freezing temperatures in 2-year-old plants and assessed the percentage loss of hydraulic conductivity (PLC) duexylem embolism formation and foliage damage determined by needle electrolyte leakage (EL) after a single frost cycle to −15 °Cand over a range of predawn water potential (psipd) values.Consejo Nacional de Ciencia y Tecnología (México)Ministerio de Ciencia, Innovación y UniversidadesComunidad de Madri

    Monitorización de la presión tisular de oxígeno (ptio2) en la UVI del Hospital de la Ribera y hoja de registro de Enfermería

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    [email protected] monitorización de la presión tisular de oxigeno (PtiO2) permite el conocimiento de las repercusiones de las lesiones tisulares y el diagnóstico de lesiones secundarias en el paciente con traumatismo craneoencefálico grave (TCEG). Este método de monitorización detecta cambios fisiopatológicos que conllevan las lesiones neurotraumáticas. El objetivo de nuestro artículo es describir y analizar este tipo de monitorización, así como los cuidados de enfermería con relación a los casos que hemos atendido en nuestra unidad y según nuestra experiencia. Se ha confeccionado una hoja de “registro de enfermería” que contiene los datos del paciente, diagnóstico, tipo de catéter, constantes horarias, etc. Con estos controles, pretendemos recoger las posibles complicaciones derivadas del catéter y del propio proceso del paciente, mejorando de esta manera la calidad asistencial.Tissue pressure of oxygen (PtiO2) monitoring allows knowing the tissue injuries implications, and the diagnosis of secondary lesions in the patient with craneoencephalic traumatism. This monitoring method detects physiopathologic changes brought about by neurotraumatic injuries. The objective of our contribution is to describe and analyze this specific type of monitoring and the nurse cares with relationship to the cases taken care of in our unit, according to our experience. A Nurse’s Record Card has been developed, containing the patient's name, diagnosis, medical history number, catheter type, schedules, etc. In this way, the possible complications derived from the catheter and from the patient's own development will be avoided, and nursing quality care will be [email protected]

    Surface-Enhanced Raman Scattering Detection of Nucleic Acids Exhibiting Sterically Accessible Guanines Using Ruthenium-Polypyridyl Reagents

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    This is the peer reviewed version of the following article: Martínez-Calvo, M.; Guerrini, L.; Rodríguez, J.; Álvarez Puebla, R. A.; Mascareñas, J. L. (2020), Surface-enhanced Raman Scattering Detection of Nucleic Acids exhibiting Sterically Accessible Guanines using Ruthenium-polypyridyl Reagents. J. Phys. Chem. Lett., 11: 7218–7223, which has been published in final form at https://doi.org/10.1021/acs.jpclett.0c02148. This article may be used for non-commercial purposes in accordance with ACS Terms and Conditions for Use of Self-Archived VersionsHere, we report the application of surface-enhanced Raman scattering (SERS) spectroscopy as a rapid and practical tool for assessing the formation of coordinative adducts between nucleic acid guanines and ruthenium polypyridyl reagents. The technology provides a practical approach for the wash-free and quick identification of nucleic acid structures exhibiting sterically accessible guanines. This is demonstrated for the detection of a quadruplex-forming sequence present in the promoter region of the c-myc oncogene, which exhibits a nonpaired, reactive guanine at a flanking position of the G-quartetsWe are thankful for the financial support from the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2019-2022, ED431G 2019/03) and the European Union (European Regional Development Fund – ERDF). We also acknowledge the support given by the Spanish Grant SAF2013-41943-R and SAF2016-76689-R, the Xunta de Galicia (Grants 2015-CP082, ED431C 2017/19,), the Spanish Ministry de Economia y Competitividad (CTQ2017-88648R and RYC-2016-20331), the Generalitat de Cataluña (2017SGR883), the Universitat Rovira i Virgili (2019PFR-URV-B2-02), the Universitat Rovira i Virgili and Banco Santander (2017EXIT-08), and the European Research Council (Advanced Grant No. 340055). M.M.-C. thanks the Ministerio de Economı́a y Competitividad for the Postdoctoral fellowship (IJCI-2014-19326) and the Ministerio de Ciencia e Innovación and Ministerio de Universidades for the Distinguished Researcher contract “Beatriz Galindo” (BEAGAL18/00144). J.R. thanks Xunta de Galicia for her predoctoral fellowshipS

    La salida itinerante de Geografía

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    La Salida Itinerante de Geografía es un proyecto educativo transversal y extracurricular, consistente en la realización de una salida de campo de varios días de duración. A pie y por un espacio de carácter natural y rural, profesores y alumnos de la titulación de Geografía de la Universidad de Sevilla, previamente organizados en grupos de trabajo, analizan las principales claves territoriales del ámbito recorrido. Hasta la fecha se han realizado nueve ediciones, una en cada curso académico desde 2008. El objetivo de esta comunicación es mostrar las principales aportaciones didácticas de esta actividad, detectar sus fortalezas y debilidades, y exponer perspectivas de mejora en el futuro

    Aspectos tectónicos del estudio gravimétrico de la Cuenca de Málaga

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    This work shows the results o f a gravimetric survey carried out in the Malaga Basin (sited on the Internal Zone o f the Western Betic Chain, southern Spain). Three anomalies maps are exposed and interpreted, focusing on neotectonic aspects. In order to avoid the influence of peridotitic bodies which outcrop in the studied area, and the southward thinning of the crust, a regional anomaly map has been processed and subtracted to the Bouguer anomaly. So, a residual anomaly map has been reached, where neotectonic interpretation has been done. The main tectonic feature evidenced by gravimetric data is the Albornoque Fault. It represents the southern boundary o f the Malaga Basin with a noticeable vertical component, according to its high gradient. By other hand, the fold o f Sierra de Cartama is marked by a maximum axis. This axis continues westward giving a duplicated depocenter of the basin. It is interpreted as a reverse fault, related in depth with the folding o f Sierra de Cartama, and which affects the basement o f the basin. According with the current stress field in the zone (NNW-SSE), the proposed structures imply the existence o f a compressive neotectonic activity, where the Albornoque fault is interpreted as a high angle reverse fault o f a reverse faul

    Análisis de la sinuosidad del bajo Guadalhorce y sus implicaciones en la actividad tectónica reciente en la Cuenca de Málaga

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    The sinuosity of the Cuadalhorce River in the Malaga Basin is studied in this paper. The Malaga Basin is located in the Internal Zone of the Western Betic Chain, southern Spain. The river channel is divided into 5 reaches from the mouth, according to the strike variations of the valley. The sinuosity decreases dramatically in reach 2 in comparison to the sinuosity in reaches 5, 4, and 3. We interpret this lower sinuosity in reach 2 as a decrease in the slope of the valley. This fact is also observed in the longitudinal profile of the river channel along reach 2. We conclude that the anomalies observed in reach 2 are due to a gentle syncline related to the active anticline of Sierra de Cártama

    Movimientos verticales de las fallas alpinas NE-SO del Macizo Ibérico en la región de Lugo

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    The vertical component of the movement associated to a fault system striking NE-SW has been determine using geomorphic and structural observations. These faults are located in the Iberian Massif in the Lugo region. The results of both kind o f observations have coincided in characterising these faults as hinge and pivotal faults. Moreover, considering the different periods of time recorded by these methods, we can establish that these faults are Tertiary and it is very difficult to explain a previous origin because of the structure complexity and the coincidence of the measures. In addition, and according to the results obtained from this area, we believe that the measures taken from the geomorphic markers, can be used alone as reliable indicators of the vertical component in this kind of faults, especially in areas where there are no others indicators
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