Natural selection on plant resistance to herbivores in the native and introduced range

. When plants are introduced into new regions, the absence of their co-evolved natural enemies can result in lower levels of attack. As a consequence of this reduction in enemy pressure, plant performance may increase and selection for resistance to enemies may decrease. In the present study, we compared leaf damage, plant size and leaf trichome density, as well as the direction and magnitude of selection on resistance and plant size between non-native (Spain) and native (Mexico) populations of Datura stramonium. This species was introduced to Spain about five centuries ago and constitutes an ideal system to test four predictions of the enemy release hypothesis. Compared with native populations, we expected Spanish populations of D. stramonium to have (i) lower levels of foliar damage; (ii) larger plant size; (iii) lower leaf trichome density that is unrelated to foliar damage by herbivores; and (iv) weak or no selection on resistance to herbivores but strong selection on plant size. Our results showed that, on average, plants from non-native populations were significantly less damaged by herbivores, were less pubescent and were larger than those from native populations. We also detected different selection regimes on resistance and plant size between the non-native and native ranges. Positive selection on plant size was detected in both ranges (though it was higher in the non-native area), but consistent positive selection on relative resistance was detected only in the native range. Overall, we suggest that changes in selection pressure on resistance and plant size in D. stramonium in Spain are a consequence of ‘release from natural enemies’

The Kuramoto model: A simple paradigm for synchronization phenomena

Synchronization phenomena in large populations of interacting elements are the subject of intense research efforts in physical, biological, chemical, and social systems. A successful approach to the problem of synchronization consists of modeling each member of the population as a phase oscillator. In this review, synchronization is analyzed in one of the most representative models of coupled phase oscillators, the Kuramoto model. A rigorous mathematical treatment, specific numerical methods, and many variations and extensions of the original model that have appeared in the last few years are presented. Relevant applications of the model in different contexts are also included

Spatial wave intensity correlations in quasi-one-dimensional wires

Spatial intensity correlations between waves transmitted through random media are analyzed within the framework of the random matrix theory of transport. Assuming that the statistical distribution of transfer matrices is isotropic, we found that the spatial correlation function can be expressed as the sum of three terms, with distinctive spatial dependences. This result coincides with the one obtained in the diffusive regime from perturbative calculations, but holds all the way from quasi-ballistic transport to localization. While correlations are positive in the diffusive regime, we predict a transition to negative correlations as the length of the system decreases.Comment: 10 pages, 3 figures. Submitted to Physical Review Letter

Optimization of existing equations using a new genetic programming algorithm: application to the shear strength of reinforced concrete beams

[Abstract] A method based on Genetic Programming (GP) to improve previously known empirical equations is presented. From a set of experimental data, the GP may improve the adjustment of such formulas through the symbolic regression technique. Through a set of restrictions, and the indication of the terms of the expression to be improved, GP creates new individuals. The methodology allows us to study the need of including new variables in the expression. The proposed method is applied to the shear strength of concrete beams. The results show a marked improvement using this methodology in relation to the classic GP and international code procedures.Ministerio de Ciencia e Innovación; BIA2007-60197Ministerio de Ciencia e Innovación; BIA2010-21551Xunta de Galicia; 08TMT005CTXunta de Galicia; 10TMT034

Aprendizaje de imágenes histológicas utilizando un microscopio virtual: metodología y opinión de los alumnos

El concepto de tejido es un constructo teorético muy útil para aprender a conocer las estructuras microscópicas del organismo y para diagnosticar, de forma objetiva, la mayoría de las lesiones, a través de imágenes histológicas (IH). Tradicionalmente, aprender a interpretar IH se basa en su observación repetitiva y monótona. Esto y la consideración de la Histología como una disciplina meramente descriptiva, ha determinado su escasa relevancia y su alto nivel de olvido para los alumnos, como ha sido puesto de relieve en varias publicaciones. Los recursos digitales han facilitado, de forma sustancial, el aprendizaje de la Histología, aunque todavía sigue basándose en la observación iterativa y monótona de IH. Para facilitar y mejorar dicho aprendizaje hemos creando y publicado una clasificación y sistematización de las IH. En este trabajo presentamos la combinación de la sistematización de las IH con el uso de un microscopio virtual accesible a todos los alumnos en cualquier lugar y momento (tablets, smartphones, ordenadores de mesa, portátiles, etc.). La evaluación de esta metodología, mediante una encuesta, pone de manifiesto su alto grado de aceptación por los alumnos y sus enormes posibilidades para un aprendizaje, a la vez, autónomo y colaborativo

Target-language-driven agglomerative part-of-speech tag clustering for machine translation

This paper presents a method for reducing the set of different tags to be considered by a part-of-speech tagger. The method is based on a clustering algorithm performed over the states of a hidden Markov model, which is initially trained by considering information not only from the source language, but also from the target language, using a new unsupervised technique which has been recently proposed to obtain taggers involved in machine translation systems. Then, a bottom-up agglomerative clustering algorithm groups the states of the hidden Markov model according to a similarity measure based on their transition probabilities; this reduces the complexity by grouping the initial finer tags into coarser ones. The experiments show that part-of-speech taggers using the coarser tags have smaller error rates than those using the initial finest tags; moreover, considering unsupervised information from the target language results in better clusters compared to those unsupervisedly built from source language information only.Work funded by the Spanish Ministry of Science and Technology through project TIC2003-08681-C02-01, and by the Spanish Ministry of Education and Science and the European Social Found through grant BES-2004-4711

Expansión monetaria y ciclo económico en España: 1998-2012

La grave crisis económica y financiera que atraviesa España tiene, obviamente, numerosas causas. Una de ellas ha sido el brutal impacto que ha tenido la expansión de la masa monetaria tras la entrada de España en el euro sobre los precios de los activos y la estructura económica del país. Este artículo examina precisamente el origen, mecanismo de transmisión e impacto de esta expansión monetaria sobre la economía española. La principal conclusión que alcanzamos es que el “olvido del dinero” en la teoría macroeconómica y en el diseño e implementación de las llamadas reglas monetarias óptimas por parte de los bancos centrales durante la última expansión económica está en la base de la actual crisisSpain is afflicted by a severe financial crisis caused by multiple factors. One of them has been the massive and continued expansion of money growth since Spain’s adhesion to the euro zone, and its non-negligible effects on asset prices as well as on the structure of the economy. In this article we analyse the origin, transmission mechanisms and final impact of this monetary expansion on the Spanish economy. The main claim is that the overall ‘neglect of money’ in macroeconomic theory and the adoption by most central banks of the so-called optimal monetary rules during the last economic expansion are at the core of the current crisi

Epidemiología de las fracturas de la extremidad superior del fémur: a propósito de 322 casos

Se realiza un estudio epidemiológico retrospectivo en una serie de 322 pacientes ancianos con fractura de la extremidad superior del fémur (FEPF), vistos y tratados entre los años 1985-1988, en el Servicio de Traumatología del Hospital del Insalud de Logroño, siendo comparados los resultados con los de otras series. Las caídas casuales por mínimo traumatismo fueron la principal causa de la lesión, con mayor incidencia en la mujer de 78 años y con predominio de las fracturas trocantereas sobre las cervicales. En nuestra serie el 48% de estos pacientes están afectados por más de una enfermedad previa a la fractura y a la intervención. Complicaciones locales postoperatorios (migración de los clavos, infección local, luxación de la prótesis, hematomas), los hemos encontrado en un 12% y entre los generales (Infecciones urinarias, Tromboflebitis, Embolia Pulmonar, escaras, etc.) en un 19%. En la valoración funcional, siguiendo a Nickens, hemos obtenido que un 71% caminaban después de la intervención. Los resultados obtenidos son, en esta Comunidad, análogos a los encontrados por otros autores.A retrospective epydemiologic study was undertaken in a serie of 322 aged patients with fracture of the upper extremity of the femur treated at the traumatology unit of the «Hospital del Insalud» in Logroño beetween 1985 and 1988. Accidental falls with a minimum traumatism were the main cause of the injury, with major incidence on 78 years old women, the trochanteric fractures being more frequent than femoral week fractures. In our serie, 48% of patients were affected by more than one previous disease to the fracture. Local post-operatire complications (nail migration, local infection, haematoma) were found in 12%, and general complications (urinary infection, pulmonary embolism, crust) in 19%. According to Nickens' functional evaluation we found that 71% of patients were able to walk after surgery. The results obtained in this community have been found similar to those reported by other authors

Comparison of positional accuracy between RTK and RTX GNSS gased on the autonomous agricultural vehicles under field conditions

Currently, many systems (machine vision, high resolution remote sensing, global positioning systems, and odometry techniques) have been integrated into agricultural e quipment to increase the efficiency, productivity, and safety of the individual in all field activities. This study focused upon assessing a satellite-based localization solution used in straight path guidance of an autonomou s vehicle developed for ag ricultural applica tions. The autonom ous agricultural vehicle was designed and constructed under RHEA (Robot fleets for highly effective agriculture and forestry management) project and is part of a three-unit fleet of similar vehicles. Static tests showed that 99% of all positions are placed within a circle with a 2.9 cm radius centered at the geo-position usi ng real-time satellite corrections (RTX). Dynamic tests between rows demonstrated a mean (N=610) of the standard deviation for real-time base station corrections (RTK) of 1.43 cm and for real-time satellite corrections (RTX) of 2.55 cm. These re sults demonstrate that the tractor was able to track each straight line with high degree of accuracy. The integration of a Global Navigation Satellite System (GNSS) with sensors (e.g., inertial sensor, altimeters, odomet ers, etc.) within the vehicle showed th e potential of autonomous tractors for expanding agricultural applications utilizing this technology.European Union FP7/2007-201

Stand-off Annotation of Web Content as a Legally Safer Alternative to Crawling for Distribution

Sentence-aligned web-crawled parallel text or bitext is frequently used to train statistical machine translation systems. To that end, web-crawled sentence-aligned bitext sets are sometimes made publicly available and distributed by translation technologies practitioners. Contrary to what may be commonly believed, distribution of web-crawled text is far from being free from legal implications, and may sometimes actually violate the usage restrictions. As the distribution and availability of sentence-aligned bitext is key to the development of statistical machine translation systems, this paper proposes an alternative: instead of copying and distributing copies of web content in the form of sentence-aligned bitext, one could distribute a legally safer stand-off annotation of web content, that is, files that identify where the aligned sentences are, so that end users can use this annotation to privately recrawl the bitexts. The paper describes and discusses the legal and technical aspects of this proposal, and outlines an implementation.Funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement PIAP-GA-2012-324414 (Abu-MaTran) is acknowledged