The application of morphodynamic indices to exposed beaches of Cadiz Bay

The aim of the present paper is to assess the validity of several energetic, morphological and morphodynamic indices, and their application to Vistahermosa and La Barrosa beaches (Cadiz Bay), as a preliminary attempt to establish the morphodynamic behaviour of these coastal zones. Earlier studies have used some of these indices, while others are completely new. All of them are involve the integration of field data, topographic restitution and granulometric analysis, as well as instrumental wave monitoring during a complete seasonal cycle. Although a good general behaviour of the indices can be concluded, the addition of high-energy data from storm events should be included in future studies.En el presente trabajo se valora la adecuación de diversos índices energéticos, morfológicos y morfodinámicos a las playas de Vistahermosa y La Barrosa como paso previo al establecimiento del comportamiento morfodinámico de las mismas. Estudios anteriores han empleado algunos de esos índices, mientras otros son totalmente nuevos. Estos índices se construyen mediante la integración de datos de campo, restitución topográfica y análisis granulométrico, y con datos instrumentales de oleaje a lo largo de un ciclo estacional completo. Aunque la valoración general del funcionamiento de los índices aplicados es buena, se concluye la necesidad de incluir situaciones energéticas de temporal en análisis ulteriores.Instituto Español de Oceanografí

Time delays, choice of energy-momentum variables, and relative locality in doubly special relativity

Doubly special relativity (DSR) theories consider (quantum-gravity motivated) deformations of the symmetries of special relativity compatible with a relativity principle. The existence of time delays for massless particles, one of their proposed phenomenological consequences, is a delicate question since, contrary to what happens with Lorentz invariance violation scenarios, they are not simply determined by the modification in the particle dispersion relation. While some studies of DSR assert the existence of photon time delays, in this paper we generalize a recently proposed model for time delay studies in DSR and show that the existence of photon time delays does not necessarily follow from a DSR scenario, determining in which cases this is so. Moreover, we clarify long-standing questions about the arbitrariness in the choice of the energy-momentum labels and the independence of the time delay on this choice, as well as on the consistency of its calculation with the relative locality paradigm of DSR theories. Finally, we show that the result for time delays is reproduced in models that consider propagation in a noncommutative spacetime

Gobernabilidad y anticorrupción: lugar de la empresa en el debate

Este artículo sostiene que la corrupción no es un problema, sino un fenómeno extremadamente complejo. Tanto las instituciones públicas como el sector privado han mostrado una capacidad muy limitada para manejar esa complejidad, produciendo estrategias escasamente eficientes. Desde esa perspectiva, pretendemos aclarar algunos aspectos del papel desempeñado por las corporaciones en el fenómeno de la corrupción, catalogadas por algunos como agentes criminales y como víctimas por otros. Este artículo sostiene que lo opuesto a la corrupción no es la transparencia y el gobierno eficiente sino la integridad, que incluye las dos anteriores pero las supera. Desde ese convencimiento, finalmente trataremos de incitar a las empresas a involucrarse en estrategias anticorrupción eficiente

Effects of new physics in neutrino propagation

In this work we consider the effects of Lorentz Invariance Violation over the observed flux of very high-energy neutrinos. For that, we study the neutrino propagation in a Modified Dispersion Relation scenario with a superluminal velocity. This makes the neutrino unstable and causes a cut-off in the flux of detected neutrinos. Using simple models, one can approximate the location of the cut-off as functions of the parameters of new physics and the closest source

Modification of the mean free path of very high-energy photons due to a relativistic deformed kinematics

Ultra-high-energy physics is about to enter a new era thanks to the impressive results of experiments such as the Large High Altitude Air Shower Observatory, detecting photons of up to 1.4×10^15 eV (PeV scale). These new results could be used to test deviations with respect to special relativity. While this has been already explored within the approach of Lorentz Invariance Violation theories, in this work we consider, for the first time, modifications due to a relativistic deformed kinematics (which appear in Doubly Special Relativity, or DSR, theories). In particular, we study the mean free path of very high-energy photons due to electron-positron pair creation when interacting with low-energy photons of the cosmic microwave background. Depending on the energy scale of the relativistic deformed kinematics, present (or near future) experiments can be sensitive enough to be able to identify deviations from special relativity

Physics of the universe transparency in a deformed kinematics

We present a first study of the possible effects of a relativistic deformation of special relativity in the recent observations of very high-energy gamma rays by the LHAASO experiment, which has opened a new phenomenological window to study deformations in the kinematics of special relativity. Our analysis of the interaction of high-energy photons with the CMB background complements theoretical studies based on Lorentz invariance violation scenarios, while making predictions that would allow one to distinguish between a violation and a deformation of the symmetries of special relativity

Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa

[EN] To investigate the effects capacitated spermatozoa may exert upon motility of the rabbit uterus, both contractility and electrical activity (frequency and intensity) were measured in 3 distinctive uterine segments of anaesthetized does: horn (UH), uterotubal junction (UTJ) and tube (UT) after 1) natural mating, 2) infusion of either seminal plasma or PBS, 3) infusion of either capacitated or non-capacitated spermatozoa. Basal values were: 17.1, 15.7, 16.4 g (contractility, P>0.05); 3.5, 3.5, 3.4 Hz (frequency, P>0.05); 0.49, 0.50, 0.57 ¿V (intensity, P>0.05) for UH, UTJ, UT, respectively. Seminal plasma caused an increase (P<0.05) in the UH contractility: 26.3 vs. 11.7 (natural mating) and 17.0 g (PBS); it also caused a decrease (P<0.05) in electrical intensity at the UTJ: 0.24 vs. 0.67 (natural mating) and 0.58 ¿V (PBS). The presence of either capacitated or non-capacitated spermatozoa caused no changes in contractility and electrical frequency in any of the uterine segments. However, there was a change in electrical intensity at UTJ (0.37 vs. 0.57 ¿V for non-capacitated and capacitated spermatozoa, respectively; P<0.05). There were also differences between segments by treatment: UTJ (0.37) vs. UT (0.59 ¿V) for non-capacitated; UH (0.46) vs. UT (0.71 ¿V) for capacitated spermatozoa (P<0.05). In conclusion, use of this experimental model showed that uterine electrical activity was slightly modified by the presence of capacitated spermatozoa.Lazcano-reyes, J.; Montiel, J.; Medrano, A. (2013). Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa. World Rabbit Science. 21(4):243-249. doi:10.4995/wrs.2013.1470.SWORD24324921

The Pseudotransannular Ring Opening of 1-Aminocyclohept-4-ene-derived Epoxides in the Synthesis of Tropane Alkaloids: Total Synthesis of (±)-Ferrugine

We have optimized a synthetic approach to (±)-Ferrugine in 8 steps starting from 5-aminocyclohept-1-ene and using the Brønsted acid-catalyzed pseudotransannular ring-opening of the epoxide derived from this cycloheptene as the key step for the construction of the 8-azabicyclo[3.2.1]octane central core. While attempting the enantioselective synthesis of this natural product from enantiopure 2-hydroxy-8-azabicyclo[3.2.1]octane we have found that this compound shows a pronounced tendency to racemize via an achiral symmetric aziridinium intermediate. This racemization side process has been studied in detail using both experimental and computational methods

Nuevos modelos de predicción del incremento en volumen para bosques mezclados del Estado de Durango, México

Thirty models were evaluated to predict the timber yield in 28 Permanent Silvicultural Research Plots (SPIS), in the Ejido Pueblo, Durango, Mexico. The most predominant plant association is the corresponding to mixed stands of Pinus and Pinus-Quercus, besides the vegetation associated to these forests. The models in their logarithmic form incorporate 10 competition indexes (IC) independent of the distance, 3 indexes of density (ID), besides the variable age and height at the average level of the stand. The new mathematical models relate in an indirect way the effect of the competition and the density in the growth of trees present in the stand. According to the variance analyses and the hypothesis tests, it was found that the best IC incorporated in a mathematical model for the prediction of the increment in volume was the competition index of area basal density (IABN), the competition index of diameter quadratic density (IDCN), the competition index of area basal total density (IABTN) and the competition index of maximum total height (IHMAX). The best models present a high level of accuracy with Prob &gt; |t| = 0.0001 and values average of 0.99 in R2. The best models presented average values of R2 = 0.99 and a highly significant level of accuracy (Pr &gt; |t| = 0.0001).Fueron evaluados 30 modelos para predecir el incremento maderable en 28 Sitios Permanentes de Investigación Silvícola (SPIS), ubicados en el Ejido Pueblo Nuevo del Estado de Durango, México. La asociación vegetal más predominante es la correspondiente a rodales mezclados de Pinus y Pinus-Quercus, además de la vegetación asociada a estos bosques. Los modelos en su forma logarítmica incorporan 10 índices de competencia (IC) independientes de la distancia, 3 índices de densidad (ID), además de las variables edad y altura a nivel promedio del rodal. Los nuevos modelos matemáticos relacionan de una manera indirecta el efecto de la competencia y la densidad en el crecimiento de los arboles presentes en el rodal. De acuerdo con los análisis de varianza y las pruebas de hipótesis realizadas, se encontró que los mejores IC incorporados en un modelo matemático para la predicción del incremento en volumen, fueron el índice de competencia de área basal densidad (IABN), índice de competencia de diámetro cuadrático densidad (IDCN), índice de competencia de área basal total densidad (IABTN) y el índice de competencia de altura total máxima (IHMAX). Los mejores modelos presentan un alto nivel de exactitud con Prob > |t| = 0,0001 y valores promedio de 0,99 en R2