2,971 research outputs found

    Interpretación crítica de gráficos estadísticos incorrectos en la sociedad de la comunicación : un desafío para futuros maestros

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    La formación de profesores para enseñar estadística en educación primaria debe estar orientada a capacitarlos para que desarrollen la cultura estadística en los alumnos de los primeros niveles educativos. La interpretación de gráficos estadísticos forma parte de la “cultura estadística” (statistical literacy) que cualquier ciudadano debe tener para poder desenvolverse plenamente en la actual sociedad de la información. El logro de este objetivo implica que los profesores de matemáticas deben tener dicha cultura y, además, estar capacitados para desarrollarla en sus alumnos. Esto requiere que los programas de formación de maestros contemplen de manera adecuada, tanto el desarrollo de los conocimientos, destrezas y disposiciones que caracterizan la cultura estadística como los conocimientos y competencias didácticas para diseñar procesos de educación estadística idóneos

    The Focal plane Detector Package on the TUNL Split-pole Spectrograph

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    A focal plane detector for the Enge Split-pole Spectrograph at Triangle Universities Nuclear Laboratory has been designed. The detector package consists of two position sensitive gas avalanche counters, a gas proportionality energy loss section, and a residual energy scintillator. This setup allows both particle identification and focal plane reconstruction. In this paper we will detail the construction of each section along with their accompanying electronics and data acquisition. Effects of energy loss throughout the detector, ray tracing procedures, and resolution as a function of fill pressure and bias voltage are also investigated. A measurement of the 27 ⁣^{27}\!Al(d,p)(d,p) reaction is used to demonstrate detector performance and to illustrate a Bayesian method of energy calibration

    Methodology for dimensioning the socio-economic impact of power-to-gas technologies in a circular economy scenario

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    Innovative and sustainable energy technologies are needed in the transition of energy toward a circular economy. Because of the use of renewable energy and carbon utilization, power-to-gas could be a cutting-edge technology that supports the circular model in future sustainable energy markets. However, this technology faces new technical and socio-economic challenges. The use of power-to-gas is limited because of barriers that limit the mobilization of investment capital. In addition, social and economic impacts on the territories in which these facilities are located are under study. In this context, the aims of this paper are: (i) To explore the determinants and barriers for power-to-gas technology to enhance the understanding of investment in innovative energy technologies; and (ii) to support effective policymaking and energy companies’ decision-making processes. This study defines and measures, from a circular economy perspective, the main impacts of the deployment of this technology on a territory in terms of volume of investment, employment generation, and CO2 capture. The study also provides a simplified methodology to contribute to the analysis of the use of power-to-gas. Finally, it improves the knowledge of the socio-economic impact of this cutting-edge technology for the transition of energy to a zero-emission scenario

    Targeted-pig trial on safety and immunogenicity of serum-derived extracellular vesicles enriched fractions obtained from Porcine Respiratory and Reproductive virus infections

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    The Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is the etiological agent of one of the most important swine diseases with a significant economic burden worldwide. Unfortunately, available vaccines are partially effective highlighting the need of novel approaches. Previously, antigenic viral proteins were described in serum-derived extracellular vesicles (EVs) from pigs previously infected with PRRSV. Here, a targeted-pig trial was designed to determine the safety and immunogenicity of such extracellular vesicles enriched fractions. Our results showed that immunizations with EV-enriched fractions from convalescence animals in combination with montanide is safe and free of virus as immunizations with up-to two milligrams of EV-enriched fractions did not induce clinical symptoms, adverse effects and detectable viral replication. In addition, this vaccine formulation was able to elicit specific humoral IgG immune response in vaccinated animals, albeit variably. Noticeably, sera from vaccinated animals was diagnosed negative when tested for PRRSV using a commercial ELISA test; thus, indicating that this new approach differentiates vaccinated from infected animals. Lastly, after priming animals with EV-enriched fractions from sera of convalescence animals and boosting them with synthetic viral peptides identified by mass spectrometry, a distinctive high and specific IFN-γ response was elicited. Altogether, our data strongly suggest the use of serum EV-enriched fractions as a novel vaccine strategy against PRRSV.Anti-CD9, Anti-CD63 and anti-CD81 antibodies were kindly donated by Francisco Sánchez-Madrid and Maria Yañez-Mo, Hospital de la Princesa, Madrid, Spain. The authors wish to particularly thank Glòria Abella for her collaboration in conducting the field study and to Marta Alcobé, Miriam Moron Font and Paula Crego Mendez for technical assistance. This study received support from Innovex Therapeutics S.L., Pinsos del Segre SA, Granja Casanyé, Grup de Sanejament Porci (GSP, Lleida, Spain) and the FEDER project (COMRDI16-1-0035-03). Sergio Montanter-Tarbes is an industrial doctorate awarded by the Government of Catalonia, Spain (No. 2014 DI 044). ISGlobal and IGTP are members of the CERCA Programme, Generalitat de Catalunya

    Control of fouling in macroalgae culture tanks by using the gastropod Osilinus atratus (Wood, 1828)

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    We tested the use of the gastropod Osilinus atratus (Wood, 1828) to control and eliminate fouling on the walls of macroalgae culture tanks. These gastropods use such fouling as a food source, and their continuous grazing excursions prevent the attachment and development of propagules. This system of biological fouling control via the co-culture of gastropods and macroalgae, besides being an environmentally friendly, is effective in reducing production costs and in limiting the negative effects of this phenomenon. Our findings show that application of this system, which appears to be one of the most effective, reduces fouling by 95%.Se estableció un método de control y eliminación del fouling generado en las paredes de los tanques de cultivo de macroalgas mediante el uso del gasterópodo Osilinus atratus (Wood, 1828). Este gasterópodo utiliza el fouling generado como alimento y consigue, a través del pasto y de su continuo desplazamiento durante esta actividad, prevenir la fijación y el desarrollo de propágulos. Este sistema de control biológico del fouling mediante el cocultivo de gasterópodos y macroalgas permite reducir los costes de producción y mantenimiento, y constituye una alternativa a la utilización de productos químicos, en general nocivos para el medioambiente, en el tratamiento de este fenómeno. Mediante la aplicación de este método de control se alcanza una reducción de un 95 % del fouling.Instituto Español de Oceanografí

    Conventional Space-Vector Modulation Techniques versus the Single-Phase Modulator for Multilevel Converters

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    Space-vector modulation is a well-suited technique to be applied to multilevel converters and is an important research focus in the last 25 years. Recently, a single-phase multilevel modulator has been introduced showing its conceptual simplicity and its very low computational cost. In this paper, some of the most conventional multilevel space-vector modulation techniques have been chosen to compare their results with those obtained with single-phase multilevel modulators. The obtained results demonstrate that the single-phase multilevel modulators applied to each phase are equivalent with the chosen wellknown multilevel space-vector modulation techniques. In this way, single-phase multilevel modulators can be applied to a converter with any number of levels and phases avoiding the use of conceptually and mathematically complex space-vector modulation strategies. Analytical calculations and experimental results are shown validating the proposed concepts

    Environmental factors affecting lactation curve parameters in the United Kingdom’s commercial dairy herds

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    Environmental factors affecting lactation curve parameters in the United Kingdom's commercial dairy herds Factores ambientales que determinan los parámetros de la curva de lactación usando un modelo biológico en rebaños lecheros comerciales en el Reino Unido RESUMEN El objetivo del trabajo fue determinar los factores ambientales que determinan los parámetros de la curva de lactación utilizando un modelo biológico de ajuste de curva. El modelo propuesto ajusta dos curvas logísticas que simulan el incremento inicial en el número de células secretoras de leche en la lactación temprana, y la progresión de la apoptosis en la lactación tardía. Se analizaron lactaciones de 182.987 vacas Holstein-Friesian. Los factores vaca, rebaño y número de lactación explican el 74% de la suma total de cuadrados (P < 0,001). La edad promedio a primer parto fue de 28 meses, teniendo un efecto significativo sobre la mayoría de los parámetros de la curva. Incrementos en la edad a primer de parto (20-40 meses) fueron asociados con incrementos lineales en los rendimientos totales de leche. Los parámetros tasa máxima de secreción y máximo de lactación estuvieron altamente correlacionados entre sí, indicando que son virtualmente los mismos. Adicionalmente, altos valores de estos dos parámetros indican altos rendimientos totales de leche. El día del máximo de lactación se correlacionó negativamente (0,64) con persistencia de la lactación. Los factores vaca, rebaño número de lactación y edad a primer parto fueron los factores más determinantes sobre los parámetros de la curva de lactación de vacas de primera lactancia así como de lactaciones múltiples
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