5,744 research outputs found

    Identification of the water stress level in olive trees during pit hardening using the trunk growth rate indicator.

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    Water scarcity is generating an increasing interest in deficit irrigation scheduling. The trunk diameter fluctuations are daily cycles that have been suggested as tools for irrigation scheduling. The trunk growth rate (TGR) was suggested as the best indicator for olive trees during pit hardening. The aim of this work is to clarify how the TGR could be used to identify water stress levels. The experiment was performed during the 2017 season, in a commercial, super-high-density orchard in Carmona (Seville, Spain). Four different irrigation treatments were performed according to midday stem water potential values and TGR. The data obtained were very variable and both indicators presented a wide range of water status throughout the season. The maximum trunk diameter data clearly showed the pattern of the trees water status but the comparison between treatments and the identification of the water stress level was not possible. The average TGR was linked to the midday stem water potential, but with a minimum amount of data. Irrigation scheduling based on the average TGR was difficult because of the great increases in some daily TGR values. For clarity, the pool of data was grouped by midday stem water potential. These water stress levels were characterized using the weekly frequency of TGR values. The increase of water stress reduced the frequency of values between -0.1 and 0.3mm day-1 from 60% to less than 25%. Moderate water stress levels increased the percentage of values lower than -0.3mm day-1 from 7% to 37%. The most severe water stress conditions increased the TGR values between -0.3 and -0.1mm day-1 from 16% up to 22%.IRNASINSTITUTO DE LA GRASACSI

    El triángulo del fraude y sus efectos sobre la integridad laboral

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    Los expertos determinaron que para que se materialice el fraude deben existir el poder, la oportunidad de cometerlo y la racionalización (D. Cressey (1961)). Estos tres puntos importantes se conocen como el triángulo del fraude. El propósito principal de este trabajo de investigación fue detectar e identificar si hay relación entre el nivel gerencial y las dimensiones del fraude. Para este trabajo de investigación se entregó un cuestionario para ser cumplimentado por gerentes que trabajan en el área de la banca hipotecaria de San Juan, Puerto Rico. Se utilizó la prueba no paramétrica Kendall Tau para correlacionar las variables de la investigación. De esta misma forma se comprobaron que las características del fraude asociadas a la dimensión de la oportunidad, están determinadas por el nivel gerencial en una organización. Con este razonamiento estadístico relacionamos las tres dimensiones del fraude: poder vs. oportunidad, poder vs. racionalización y oportunidad vs. racionalización. Sólo en esta última relación, hay evidencia para rechazar la hipótesis nula que establece que las características del fraude asociadas al ángulo de oportunidad, no están relacionadas a la racionalización del individuo que pretende o comete fraude

    Efecto de factores contextuales en la composición corporal de jugadores profesionales de fútbol. Un estudio retrospectivo

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    La exigencia de las demandas físicas en el fútbol ha evolucionado en los últimos años, poniendo de manifiesto la necesidad de investigar sobre aquellos aspectos que condicionan el rendimiento deportivo. Es por esto que el objetivo de este estudio fue describir la incidencia del entrenamiento individualizado, la compañía en las comidas, la raza y la demarcación sobre las variables antropométricas en jugadores de fútbol profesional. Para ello se desarrolló un estudio retrospectivo sobre 51 jugadores profesionales de la Segunda División B española durante las temporadas de 2015/2016, 2016/2017 y 2017/2018. La valoración antropométrica se realizó bajo las normas técnicas de medición recomendadas por el International Working Group of Kinanthropometry, adoptadas por la International Society for the Advancement of Kinanthropometry (ISAK). Los resultados revelaron que el entrenamiento individualizado y la compañía en las comidas fueron los factores que más influyeron sobre las variables antropométricas. Los valores de masa grasa y de masa muscular, y el sumatorio de pliegues son sensibles al efecto de la intervención sobre dichos factores. Los mayores niveles de interacción se producen entre la compañía en las comidas y el entrenamiento individualizado, y entre la demarcación y la compañía en las comidas. Considerando la composición corporal como un aspecto a tener en cuenta en el desarrollo del rendimiento, se concluye que la aplicación de ciertos contenidos del entrenamiento según las características individuales y el estilo de vida de los jugadores es un factor que posee una influencia significativa sobre los futbolistas profesionales

    Short-term Wholesale Funding and Systemic Risk: A Global CoVaR Approach

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    We use the CoVaR approach to identify the main factors behind systemic risk in a set of large international banks. We find that short-term wholesale funding is a key determinant in triggering systemic risk episodes. In contrast, we find weaker evidence that either size or leverage contributes to systemic risk within the class of large international banks. We also show that asymmetries based on the sign of bank returns play an important role in capturing the sensitivity of system-wide risk to individual bank returns. Since short-term wholesale funding emerges as the most relevant systemic factor, our results support the Basel Committee’s proposal to introduce a net stable funding ratio, penalizing excessive exposure to liquidity risk

    Compact set of invariants characterizing graph states of up to eight qubits

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    The set of entanglement measures proposed by Hein, Eisert, and Briegel for n-qubit graph states [Phys. Rev. A 69, 062311 (2004)] fails to distinguish between inequivalent classes under local Clifford operations if n > 6. On the other hand, the set of invariants proposed by van den Nest, Dehaene, and De Moor (VDD) [Phys. Rev. A 72, 014307 (2005)] distinguishes between inequivalent classes, but contains too many invariants (more than 2 10^{36} for n=7) to be practical. Here we solve the problem of deciding which entanglement class a graph state of n < 9 qubits belongs to by calculating some of the state's intrinsic properties. We show that four invariants related to those proposed by VDD are enough for distinguishing between all inequivalent classes with n < 9 qubits.Comment: REVTeX4, 9 pages, 1 figur

    Scattering of surface plasmon polaritons by one-dimensional inhomogeneities

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    The scattering of surface plasmons polaritons by a one-dimensional defect of the surface is theoretically studied, by means of both Rayleigh and modal expansions. The considered defects are either relief perturbations or variations in the permittivity of the metal. The dependence of transmission, reflection and out-of-plane scattering on parameters defining the defect is presented. We find that the radiated energy is forwardly directed (with respect to the surface plasmon propagation) in the case of an impedance defect. However, for relief defects, the radiated energy may be directed into backward or forward (or both) directions, depending on the defect width.Comment: 10 pages, 5 figures, corrected typos, some minor modifications in figures. Accepted in Phys. Rev.

    “Education Network” a new way to teach Chemistry

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    The complexity of chemistry has implications for the teaching of chemistry. That chemistry is a very complex subject. The majority of the students at University think that chemistry is a difficult discipline and they have difficulty in understanding the concepts. Moreover, students' interest in chemistry decreases the first year at university. The reason for this decrease might be that the contents of chemistry laboratory classes are boring, out of date and lacking of dynamism that students experience through visual media tools. For these reasons, new programs and methodologies should be developed. Those are based on making chemistry relevant through problem solving and collaborative learning hold promise for reforming chemistry education. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people. It's time to CRUSH boredom by transforming your classroom into an Escape Room adventure. School-based escape games are a great teaching tool. The students while playing, learn. The most important point is that they won’t realize they’re doing both at the same time. In this work, an educational gamification experience based on the escape room concept was developed. The first (Do It Yourself) DIY Escape Room was built the year before at Mechanical Engineer Degree started, that took more than three weeks of work. It was presented to other professors to the same subject at different degrees. That DIY Escape Room was modified and adapted to each group. Each professor changed the clues, problems and so on in order to orientate the topic as much as possible to their students.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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