107 research outputs found

    OSCURAUIT SOL: Stone Engravings and Other Contemporary Spanish Records for the a.d. 1239 and a.d. 1354 Eclipses and Their Astronomical Implications

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    The eclipse of a.d. 1239 June 3 was observed at no less than 10 sites in Europe, but the one from a.d. 1354 September 17 was observed only from two European sites. In this paper, we present several new references for the a.d. 1239 and a.d. 1354 solar eclipses, most of them from unpublished Spanish documents. In particular, we study three records engraved on stones whose existence was not known until recently. Such records are very rare in the rest of Europe. The study of ancient eclipses has proven to be useful for obtaining some astronomical data of interest to modern astronomy. In particular, the analysis of these eclipses may be useful for determining a range of T for the epochs.Part of this work was supported by a grant AICO/2015/037 from Generalitat Valenciana.Martínez Uso, MJ.; Marco Castillo, FJ.; Ibañez, L. (2016). OSCURAUIT SOL: Stone Engravings and Other Contemporary Spanish Records for the a.d. 1239 and a.d. 1354 Eclipses and Their Astronomical Implications. Journal for the History of Astronomy. 47:61-75. doi:10.1177/0021828615620985S61754

    Epigenética en técnicas de reproducción asistida: razones y evidencias para una reflexión

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    Los procesos epigenéticos producen cambios covalentes en la cadena de ADN sin alteración en la secuencia de bases nitrogenadas. Una de las modificaciones epigenéticas más relevantes es el proceso de metilación de citosina. Este proceso es de vital importancia para mantener el silenciamiento génico en el desarrollo normal, la impronta genómica y la inactivación del cromosoma X. Así, por ejemplo, cuando se producen alteraciones en la impronta, estos pueden desencadenar enfermedades, especialmente aquellas relacionadas con defectos en el desarrollo embrionario y el proceso neoplásico. En los últimos años se ha visto que mediante el uso de técnicas de reproducción asistida (TRAs), se pueden ver aumentados los desórdenes de este tipo, motivación suficiente por la que creemos que resulta de interés un mayor conocimiento de las modificaciones epigenéticas y su relación con numerosas enfermedades y disfunciones tras el uso de TRAs, con notables consecuencias sobre el manejo, tratamiento y prevención en el futuro de enfermedades en recién nacidos. En este trabajo, se describen los mecanismos de las modificaciones epigenéticas, más concretamente la metilación de citosina, las implicaciones que tiene dicha metilación de ADN sobre disfunciones y desarrollo de enfermedades en recién nacidos, los factores implicados en TRAs causantes y/o transmisión de la metilación de ADN y, finalmente, las metodologías analíticas para la determinación del grado de metilación en ADN.Epigenetic events lead to covalent modifications at the DNA chain without mutagenic alterations in the DNA sequence. One of the most relevant epigenetic modifications corresponds to the methylation process of cytosine. The above process is of outstanding importance to keep the gene silencing of normal development, genomic imprinting and inactivation of chromosome X. Thus, for instance, when the genomic imprinting suffers alterations, it can trigger the appearance of diseases, mainly those related to defects during the embrionary development or in neoplasic processes. Over the last few years, it has been observed that via the use of assisted reproductive techniques (ARTs) a number of the above disorders and dysfunctions can be proliferated, reason enough for which we strongly demand a more profound knowledge about the epigenetic modifications and their relationships with a wide number of diseases and dysfunctions after ARTs, with notable consequences in the management, treatment and prevention of diseases in newborn babies In this work, the authors describe the mechanisms involved in epigenetic modifications -more particularly cytosine methylation-, the implications of cytosine methylation at DNA upon dysfunctions and development of diseases in newborn babies, causal factors implicated in ARTs and/or transmission of DNA methylation and, finally, the analytical methodologies used for the determination of methylation grade in DNA

    Spanish Dentists’ Awareness, Knowledge, and Practice Regarding COVID-19: A Multiple Regression Analysis

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    The authors thank the Spanish Society of Epidemiology and Oral Public Health (SESPO) for expert supervision of the questionnaire; the Spanish General Council of Dentists (GCD) and the Spanish societies of dental hygienists for their rapid dissemination of the survey to their members.Introduction: During the first months of the coronavirus disease 2019 (COVID-19) pandemic, Spain had the highest mortality rate and the second-highest infection rate in the world. Objective: To analyze the occupational situation of dentists, hygienists, and dental auxiliary staff during the peak of the pandemic, after the state of alarm was declared in Spain, and when the state of alarm was declared. In addition, a possible relationship between the geographical distribution of infected people and the availability of individual protection systems was investigated. Material and Methods: A cross-sectional questionnaire was answered by 6470 dentists and dental staff via WhatsApp and social media. Results: A total of 1 in 4 dental professionals ceased working completely. Of those that kept working, 25.28% of dentists and 19.61% of hygienist-auxiliary were equipped with filtering face piece (FFP) 2 masks (P < .05), and 61.8% complied with the official protection recommendations set by the General Council of Dentists of Spain. Nearly 59.4% of respondents had symptoms, but only 1.5% of dentists were tested, with 14% of dentists in isolation at the time of response. Overall, it is suggested that 10% of dental professionals may have been in direct contact with the coronavirus. Conclusions: Direct contact of Spanish dental health professionals with severe acute respiratory syndrome coronavirus disease 2 (SARS CoV-2) has been high during the most active phase of the pandemic. Dental professionals did not have personal protective equipment (PPE) necessary to care for patients, a situation that justified the reduction in scheduled dental care and only emergencies being treated. The Spanish geographical regions with the highest number of contagions had the least amount of individual protective resources (FFP2 and FFP3masks)

    Efficient generation of highly crystalline carbon quantum dots via electrooxidation of ethanol for rapid photodegradation of organic dyes

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    Achieving versatile routes to generate crystalline carbon-based nanostructures has become a fervent pursuit in photocatalysis-related fields. We demonstrate that the direct electrooxidation of ethanol, performed on Ni foam, yields ultra-small and highly crystalline graphene-like structures named carbon quantum dots (CQDs). We perform simulations of various sp2 and sp3 domains in order to understand the optical properties of CQDs by accounting their contribution as absorbance/luminescent centers in the overall optical response. Experiments and simulations reveal that absorbance bands for as-synthesized CQDs are dominated by small sp2 domains comprised of r7 aromatic-rings. After 48 h synthesis, the dispersion transition from yellow to red, exhibiting new and red shifted absorbance bands. Furthermore, fluorescence emission is governed by medium-sized sp 2 domains (with aromatic ring counts r12) and oxygen-containing groups. These oxygen-rich groups within the CQDs, confirmed by FT-IR and XPS, are responsible for the fast photodegradation of organic dyes, with B90% of methylene blue (MB) being degraded within the first 5 min of light exposure. Our work provides crucial insights about the electrochemical synthesis and overall optical properties of carbon nanostructures, while being effective and reliable toward the degradation of contaminants in water

    Periodic emission of droplets from an oscillating electrified meniscus of a low-viscosity, highly conductive liquid

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    The generation of identical droplets of controllable size in the micrometer range is a problem of much interest owing to the numerous technological applications of such droplets. This work reports an investigation of the regime of periodic emission of droplets from an electrified oscillating meniscus of a liquid of low viscosity and high electrical conductivity attached to the end of a capillary tube, which may be used to produce droplets more than ten times smaller than the diameter of the tube. To attain this periodic microdripping regime, termed axial spray mode II by Juraschek and Röllgen [R. Juraschek and F. W. Röllgen, Int. J. Mass Spectrom. 177, 1 (1998)], liquid is continuously supplied through the tube at a given constant flow rate, while a dc voltage is applied between the tube and a nearby counter electrode. The resulting electric field induces a stress at the surface of the liquid that stretches the meniscus until, in certain ranges of voltage and flow rate, it develops a ligament that eventually detaches, forming a single droplet, in a process that repeats itself periodically. While it is being stretched, the ligament develops a conical tip that emits ultrafine droplets, but the total mass emitted is practically contained in the main droplet. In the parametrical domain studied, we find that the process depends on two main dimensionless parameters, the flow rate nondimensionalized with the diameter of the tube and the capillary time, q, and the electric Bond number BE, which is a nondimensional measure of the square of the applied voltage. The meniscus oscillation frequency made nondimensional with the capillary time, f, is of order unity for very small flow rates and tends to decrease as the inverse of the square root of q for larger values of this parameter. The product of the meniscus mean volume times the oscillation frequency is nearly constant. The characteristic length and width of the liquid ligament immediately before its detachment approximately scale as powers of the flow rate and depend only weakly on the applied voltage. The diameter of the main droplets nondimensionalized with the diameter of the tube satisfies dd≈(6/π)1/3(q/f)1/3, from mass conservation, while the electric charge of these droplets is about 1/4 of the Rayleigh charge. At the minimum flow rate compatible with the periodic regimen, the dimensionless diameter of the droplets is smaller than one-tenth, which presents a way to use electrohydrodynamic atomization to generate droplets of highly conducting liquids in the micron-size range, in marked contrast with the cone-jet electrospray whose typical droplet size is in the nanometric regime for these liquids. In contrast with other microdripping regimes where the mass is emitted upon the periodic formation of a narrow capillary jet, the present regime gives one single droplet per oscillation, except for the almost massless fine aerosol emitted in the form of an electrospray

    Trends and area variations in Potentially Preventable Admissions for COPD in Spain (2002-2013): A significant decline and convergence between areas

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    Background: Potentially Preventable Hospitalizations (PPH) are hospital admissions for conditions which are preventable with timely and appropriate outpatient care being Chronic Obstructive Pulmonary Disease (COPD) admissions one of the most relevant PPH. We estimate the population age-sex standardized relative risk of admission for COPD-PPH by year and area of residence in the Spanish National Health System (sNHS) during the period 2002–2013. Methods: The study was conducted in the 203 Hospital Service Areas of the sNHS, using the 2002 to 2013 hospital admissions for a COPD-PPH condition of patients aged 20 and over. We use conventional small area variation statistics and a Bayesian hierarchical approach to model the different risk structures of dependence in both space and time. Results: COPD-PPH admissions declined from 24.5 to 15.5 per 10, 000 persons-year (Men: from 40.6 to 25.1; Women: from 9.1 to 6.4). The relative risk declined from 1.19 (19 % above 2002–2013 average) in 2002 to 0.77 (30 % below average) in 2013. Both the starting point and the slope were different for the different regions. Variation among admission rates between extreme areas dropped from 6.7 times higher in 2002 to 4.6 times higher in 2013. Conclusions: COPD-PPH conditions in Spain have undergone a strong decline and a reduction in geographical variation in the last 12 years, suggesting a general improvement in health policies and health care over time. Variability among areas still remains, with a substantial room for improvement

    EL ARTE RUPESTRE PALEOLÍTICO DE LA CUEVA DE AMBROSIO (VÉLEZ-BLANCO, ALMERÍA, ESPAÑA). UNA VISIÓN VEINTE AÑOS DESPUÉS

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    Durante las campañas de 1992 y 1994 se encontraron en el yacimiento solutrense de La Cueva de Ambrosio (Vélez-Blanco, Almería, España) un conjunto de representaciones artísticas parietales pintadas y grabadas del Paleolítico superior. Entre los grabados del panel I, se ha descifrado una excelente silueta de caballo, una representación de ave, unos protomos de bóvido y de caballo, así como otros trazos todavía no interpretados. En la parte inferior del panel existen pinturas, poco visibles a causa de una colada calcítica y de momento no es posible interpretar ninguna representación figurativa. En el panel II se han identificado un total de 25 figuras tanto grabadas como pintadas. La excepcionalidad del hallazgo reside en el hecho de poder interrelacionar perfectamente estas muestras de arte con los niveles arqueológicos claramente definidos desde el punto de vista cultural y cronoestratigráfico (ca. 20000 BP) Solutrense medio y Solutrense superior del mismo yacimiento.In the solutrean site of La Cueva de Ambrosio (Vélez-Blanco, Almería, Spain) several engraved and painted figures dated on the Upper Palaeolithic, have been found during the field works of 1992 and 1994. In The panel I we have identified an excellent representation of a horse, a bird, one bovidae and another protome of a horse. Below this surface there are many red ochre wall paintings covered by a calcitic speleotheme and for the time being we are unable to give any interpretation for it. In the second panel we have discovered more tone splendid red painted horse, two more enngraved horses and a little head of one other black painted horse. There are many engraved lines and pictural rests that must be studied in the future. The exceptionality of this discovery is that we can interrelate perfectly these rock art paintings with the archaeological levels clearly defined chronologically and culturally (ca. 20000 BP), Middle Solutrean and Upper Solutrean from the same site.</p

    Single domain antibodies targeting neuraminidase protect against an H5N1 influenza virus challenge

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    Influenza virus neuraminidase (NA) is an interesting target of small-molecule antiviral drugs. We isolated a set of H5N1 NAspecific single-domain antibodies (N1-VHHm) and evaluated their in vitro and in vivo antiviral potential. Two of them inhibited the NA activity and in vitro replication of clade 1 and 2 H5N1 viruses. We then generated bivalent derivatives of N1-VHHm by two methods. First, we made N1-VHHb by genetically joining two N1-VHHm moieties with a flexible linker. Second, bivalent N1-VHH-Fc proteins were obtained by genetic fusion of the N1-VHHm moiety with the crystallizable region of mouse IgG2a (Fc). The in vitro antiviral potency against H5N1 of both bivalent N1-VHHb formats was 30- to 240-fold higher than that of their monovalent counterparts, with 50% inhibitory concentrations in the low nanomolar range. Moreover, single-dose prophylactic treatment with bivalent N1-VHHb or N1-VHH-Fc protected BALB/c mice against a lethal challenge with H5N1 virus, including an oseltamivir-resistant H5N1 variant. Surprisingly, an N1-VHH-Fc fusion without in vitro NA-inhibitory or antiviral activity also protected mice against an H5N1 challenge. Virus escape selection experiments indicated that one amino acid residue close to the catalytic site is required for N1-VHHm binding. We conclude that single-domain antibodies directed against influenza virus NA protect against H5N1 virus infection, and when engineered with a conventional Fc domain, they can do so in the absence of detectable NA-inhibitory activity.Fil: Cardoso, Francisco Miguel. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Ibañez, Lorena Itatí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; Argentina. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Van Den Hoecke, Silvie. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: De Baets, Sarah. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Smet, Anouk. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Roose, Kenny. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Schepens, Bert. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Descamps, Francis J.. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Fiers, Walter. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; BélgicaFil: Muyldermans, Serge. Structural Biology Research Center; Bélgica. Vrije Universiteit Brussel. Laboratory of Cellular and Molecular Immunology; BélgicaFil: Depicker, Ann. VIB. Department of Plant Systems Biology; Bélgica. Department of Biotechnology and Bioinformatics; BélgicaFil: Saelens, Xavier. VIB Inflammation Research Center; Bélgica. Ghent University. Department for Biomedical Molecular Biology; Bélgic

    The thirty gigahertz instrument receiver for the Q-U-I Joint Tenerife experiment: concept and experimental results

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    This paper presents the analysis, design, and characterization of the thirty gigahertz instrument receiver developed for the Q-U-I Joint Tenerife experiment. The receiver is aimed to obtain polarization data of the cosmic microwave background radiation from the sky, obtaining the Q,U, and I Stokes parameters of the incoming signal simultaneously. A comprehensive analysis of the theory behind the proposed receiver is presented for a linearly polarized input signal, and the functionality tests have demonstrated adequate results in terms of Stokes parameters, which validate the concept of the receiver based on electronic phase switching

    Subwavelength slit acoustic metamaterial barrier

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    [EN] Reduction of noise in the transmission path is a very important environmental problem. The standard method to reduce this noise level is the use of acoustic barriers. In this paper, an acoustic metamaterial based on sound transmission through subwavelength slits, is tailored to be used as an acoustic barrier. This system consists of two rows of periodic repetition of vertical rigid pickets separated by a slit of subwavelength width, embedded in air. Here, both the experimental and the numerical analyses are presented. These analyses have facilitated the identification of the parameters that affect the insertion loss performance. The results demonstrated that the proposed barrier can be tuned to mitigate a band noise in a mechanical plant for buildings where openings for air flow are required as well as industrial noise, without excessive barrier thickness.This work was financially supported by the Spanish Ministry of Science and Innovation through project MAT2010-16879.Rubio Michavila, C.; Candelas Valiente, P.; Belmar Ibáñez, F.; Gómez Lozano, V.; Uris Martínez, A. (2015). Subwavelength slit acoustic metamaterial barrier. Journal of Physics D: Applied Physics. 48(39):1-9. https://doi.org/10.1088/0022-3727/48/39/395501S19483
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