1,331 research outputs found
Genetic structure of the threatened West-Pannonian population of Great Bustard (Otis tarda).
The genetic diversity, population structure and gene flow of the Great Bustards (Otis tarda) living in Austria-Slovakia-West Hungary (West-Pannonian region), one of the few populations of this globally threatened species that survives across the Palaearctic, has been assessed for the first time in this study. Fourteen recently developed microsatellite loci identified one single population in the study area, with high values of genetic diversity and gene flow between two different genetic subunits. One of these subunits (Heideboden) was recognized as a priority for conservation, as it could be crucial to maintain connectivity with the central Hungarian population and thus contribute to keeping contemporary genetic diversity. Current conservation efforts have been successful in saving this threatened population from extinction two decades ago, and should continue to guarantee its future survival
Walls, bubbles and doom — the cosmology of HEFT
As experiment charts new territory at the electroweak scale, the enterprise to characterise all possible theories becomes all the more necessary. In the absence of new particles, this ambitious enterprise is attainable and has led to the Higgs Effective Field Theory (HEFT) as the most general characterising framework, containing the Standard Model Effective Field Theory (SMEFT) as a subspace. The characterisation of this theory space led to the dichotomy SMEFT vs. HEFT SMEFT as the two possible realisations of symmetry breaking. The criterion to distinguish these two possibilities is non-local in field space, and phenomena which explore field space beyond the neighbourhood of the vacuum manifold are in a singular position to tell them apart. Cosmology allows for such phenomena, and this work focuses on HEFT SMEFT, the less explored of the two options, to find that first order phase transitions with detectable gravitational wave remnants, domain wall formation and vacuum decay in the far, far distant future can take place and single out HEFT SMEFT. Results in cosmology are put against LHC constraints, and the potential of future ground- and space-based experiments to cover parameter space is discussed
Entrenamiento combinado de electroestimulación concéntrica y pliometría frente a entrenamiento voluntario
Se analizó si el entrenamiento con electroestimulación neuromuscular (EENM) dinámica podría mejora la velocidad, la fuerza explosiva y la fuerza máxima. Se formaron 5 grupos de entrenamiento: EENM concéntrica (Ed), EENM concéntrica más pliometría (EdP), voluntario (V), voluntario con pliometría (VP) y grupo control (GC). Los grupos experimentales entrenaron el cuádriceps durante 4 semanas (16 sesiones), valorándose el tiempo de carrera en 20 m (T-20), los saltos verticales SJ y CMJ y la fuerza máxima isométrica de los extensores de la rodilla (FMI). Los protocolos de entrenamiento realizados no modificaron los tests T-20, SJ ni CMJ, pero se observaron incrementos significativos en la FMI (+30.5% entre T1 y T2 y entre T1 y T3). La EENM dinámica parece no mejorar las acciones explosivas y de velocidad, sin embargo mejora la fuerza máxima isométrica en la misma cuantía que lo hace el entrenamiento voluntario
La concepción simple de la lectura en educación primaria: una revisión sistemática
La concepción simple de la lectura (CSL) es un modelo que trata de explicar la comprensión lectora (L) a partir de dos componentes básicos: la descodificación (D) y la comprensión del lenguaje (C). En los últimos años este modelo ha sido utilizado como base teórica para la toma de decisiones sobre el aprendizaje de la lectura en el sistema educativo de países como Reino Unido o Francia.
La CSL ha sido criticada por distintos motivos. El primero, y más importante, es que D y C dejan sin explicar una parte importante de la varianza de los resultados de L. Esta parte podría ser del 50% o más, lo que indicaría que el modelo es incompleto y existe la posibilidad de que personas con una descodificación y comprensión del lenguaje normales obtengan malos resultados en comprensión lectora. También se ha señalado que los componentes del modelo están vagamente definidos, especialmente C, y que distintos autores los evalúan de formas diferentes. Otras críticas son que la relación entre sus componentes cambia con la edad y que no ha inspirado intervenciones pedagógicas de consideración.
A pesar de estas observaciones, se considera que la CSL puede ser útil en educación ya que tiene características poco habituales en los modelos de comprensión lectora como su carácter evolutivo, el énfasis en la descodificación y su sencillez.The simple view of reading (SVR) is a model to explain reading comprehension (R) using two basic components: decoding (D) and language comprehension (C). In recent years this model has been employed as a theoretical base for decision making in the education system in countries such as United Kingdom or France.
The SVR has been criticized for several reasons. The first, and most important, is that D and C cannot explain a substantial part of the variance of R results. This unexplained part could be 50% or even higher, which could mean that the model is not complete and that there is a possibility that people with normal decodification and language comprehension skills could perform badly in reading comprehension tasks. It has also been pointed out that the components of the model are loosely defined, particularly C, and that different researchers evaluate those components in different ways. Other criticisms are that the relation between the components of the model changes with age, and that it has not produced any relevant pedagogical interventions.
In spite of these points, the SVR can be useful in educational work. It has some characteristics that are unusual in reading comprehension models: it is evolutionary, it places emphasis on decoding, and it is an easy to understand model
Searching for extragalactic sources in the VISTA variables in the Via láctea survey
Indexación: Scopus.We search for extragalactic sources in the VISTA Variables in the Vía Láctea survey that are hidden by the Galaxy. Herein, we describe our photometric procedure to find and characterize extragalactic objects using a combination of SExtractor and PSFEx. It was applied in two tiles of the survey: d010 and d115, without previous extragalactic IR detections, in order to obtain photometric parameters of the detected sources. The adopted criteria to define extragalactic candidates include CLASS-STAR 0.002 and the colors: 0.5 0.44 mag. We detected 345 and 185 extragalactic candidates in the d010 and d115 tiles, respectively. All of them were visually inspected and confirmed to be galaxies. In general, they are small and more circular objects, due to the near-IR sensitivity to select more compact objects with higher surface brightness. The procedure will be used to identify extragalactic objects in other tiles of the VVV disk, which will allow us to study the distribution of galaxies and filaments hidden by the Milky Way.http://iopscience.iop.org/article/10.3847/1538-3881/aa9ee2/met
An exponential chemorheological model for viscosity dependence on degree-of-cure of a polyfurfuryl alcohol resin during the post-gel curing stage
Magnetic dispersive solid phase microextraction coupled with on-line chemical vapor generation method to extraction/preconcentration of mercury from environmental samples and determination by graphite furnace atomic absorption spectrometry.
Mercury (Hg) is classified as priority hazardous substances. Concentrations found in the aquatic environment are at trace levels as result of natural processes, such as erosion and volcanism, and anthropogenic discharges related mainly to industrial and mining activities. Mercury is one of the most potent neurotoxins known, showing a high number of adverse health effects in animals and humans.
For this reason, a simple and rapid method for the determination and preconcentration of mercury in environmental waters is proposed. This work is based on magnetic dispersive solid phase microextraction (MDSPME) coupled with on-line chemical vapour generation (CVG). Graphite furnace atomic absorption spectrometry (GFAAS) was employed for the quantification of Hg. In the preconcentration step, a shell structured Fe3O4@graphene oxide was suspended in the ionic liquid carrier (1-n-butyl-3-metilimidazolium tetrafluoroborate [BMIM][BF4]), obtaining a stable colloidal suspension called ferrofluid. This sorbent possesses as large contact surface area and a high density of polar groups on its surface. The nanoparticles, when finely dispersed in the sample solution, result in almost complete extraction of Hg within a few seconds. All experimental and instrumental variables were optimized and the method was adequately validated by the analysis of certified reference materials of environmental waters.
Acknowledgements
The authors would like to thank Plan Propio “Proyecto Puente” de la Universidad de Málaga for financial support of this work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Coherent artifact and time-dependent polarization in amplified ultrafast erbium-doped fibre lasers
Mode-locked erbium-doped fibre lasers are ultrashort pulsed sources widely studied due to their versatility and multiple applications in the near infrared range. Here we present the experimental study of the emission of a passive mode-locked erbium-doped fibre laser with an amplification stage outside the cavity by means of Frequency Resolved Optical Gating (FROG) and spectral interferometry. Due to shot-to-shot instabilities, the FROG traces can be understood as the combination of two different traces, corresponding to the coherent artifact and the average pulse characteristics. We have modified a Principal Components Generalized Projections Algorithm, in order to make it able to retrieve efficiently both the coherent artifact and the average pulse. In addition, we study the temporal dependence of the polarization, showing that the pulses present time-dependent polarization with a stable spectral relative phase between the horizontal and vertical projections. Up to our knowledge, this is the first experimental study that shows the FROG measurements of unstable pulse trains associated with the coherent artifact and analyses the time-dependent polarization in ultrafast fibre lasers
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