520 research outputs found
Leishmaniosis: estado actual y perspectivas de futuro
Discurso de Ingreso en la Real Academia de Ciencias Veterinarias de Andalucía Oriental como Académico Correspondient
On the resonances and polarizabilities of split ring resonators
In this paper, the behavior at resonance of split ring resonators SRRs and other related topologies,
such as the nonbianisotropic SRR and the broadside-coupled SRR, are studied. It is shown that these
structures exhibit a fundamental resonant mode the quasistatic resonance and other higher-order
modes which are related to dynamic processes. The excitation of these modes by means of a
properly polarized time varying magnetic and/or electric fields is discussed on the basis of resonator
symmetries. To verify the electromagnetic properties of these resonators, simulations based on
resonance excitation by nonuniform and uniform external fields have been performed. Inspection of
the currents at resonances, inferred from particle symmetries and full-wave electromagnetic
simulations, allows us to predict the first-order dipolar moments induced at the different resonators
and to develop a classification of the resonances based on this concept. The experimental data,
obtained in SRR-loaded waveguides, are in agreement with the theory and point out the rich
phenomenology associated with these planar resonant structures.MEC (España)-TEC2004-04249-C02-01 y TEC2004-04249-C02-02Comunidad Europea (programa Eureka)-2895 TELEMACAgencia de Subvenciones de la República Checa-102/03/044
Effects of publication bias on conservation planning
Conservation planning needs reliable information on spatial patterns of
biodiversity. However, existing data sets are skewed: some habitats, taxa, and
locations are under-represented. Here, we map geographic publication density at
the sub-national scale of individual 'provinces'. We query the Web of Science
catalogues SCI and SSCI for biodiversity-related publications including country
and province names (for the period 1993-2016). We combine these data with other
provincial-scale factors hypothesised to affect research (i.e. economic
development, human presence, infrastructure and remoteness). We show that sites
that appear to be understudied, compared with the biodiversity expected from
their bioclimatic conditions, are likely to have been inaccessible to
researchers for a diversity of reasons amongst which current or recent armed
conflicts are notable. Finally, we create a priority list of provinces where
geographic publication bias is of most concern, and discuss how our
provincial-scale model can assist in adjusting for publication biases in
conservation planning.Comment: 10 pages; 3 figures; 1 table;R code on
https://github.com/raffael-hickisch; data at
https://zenodo.org/record/998889; interactive at
http://bit.ly/publication_density_ma
Effect of Bisphosphonates on Root Growth and on Chlorophyll Formation in Arabidopsis thaliana Seedlings
Capítulo 41.-- Open Access: License CC BY 3.0This work was supported by grants from the Spanish National Plan for Research, Development and Innovation (BFU 2008-00666/BMC, BFU 2009-08977 and AYA2009- 07952).Peer Reviewe
Domain wall dynamics in expanding spaces
We study the effects on the dynamics of kinks due to expansions and
contractions of the space. We show that the propagation velocity of the kink
can be adiabatically tuned through slow expansions/contractions, while its
width is given as a function of the velocity. We also analyze the case of fast
expansions/contractions, where we are no longer on the adiabatic regime. In
this case the kink moves more slowly after an expansion-contraction cycle as a
consequence of loss of energy through radiation. All these effects are
numerically studied in the nonlinear Klein-Gordon equations (both for the
sine-Gordon and for the phi^4 potential), and they are also studied within the
framework of the collective coordinate evolution equations for the width and
the center of mass of the kink. These collective coordinate evolution equations
are obtained with a procedure that allows us to consider even the case of large
expansions/contractions.Comment: LaTeX, 18 pages, 2 figures, improved version to appear in Phys Rev
Does ict resources improve the sport teaching processes in handball?
La motivación (M) y la capacidad de percepción-análisis (PA) del juego, variables del proceso de enseñanza-aprendizaje, fueron evaluadas tras utilizar diferentes recursos durante las explicaciones del entrenador. 71 jugadores(Sub-18) fueron divididos en dos grupos: G1 (n=35): recursos tradicionales; G2 (n=36): recursos multimedia. Se evaluó el nivel inicial (i) y final (f), tras 10 sesiones de entrenamiento.
Ambas variables mejoraron significativamente en ambos grupos. Fueron mayores las mejoras del G2 en ambas variables (p<.001). Se hallaron únicamente diferencias intergrupales en la evaluación final en M y PA (p<.001), mostrando el Grupo 2 mejores resultados.
Se concluye que la utilización de recursos multimedia posee un efecto positivo mayor que los recursos tradicionales sobre M y PA en jugadores de balonmano (Sub-18).Motivation (M) and game perception-analysis ability (PA), variables in the teaching-learning process, were evaluated after using different resources during the coach’s explanations. Seventy-one players (Under-18) were divided into 2 groups: G1 (n = 35) traditional resources; G2 (n = 36) multimedia resources. Initial (i) and final (f) levels of both variables were evaluated after 10 training sessions.
Both variables showed a significant improvement in both groups. The improvements shown in G2 were greater in both variables (p<0.001). Intergroup differences were only found in the final evaluation in M and PA (p<0,001), where G2 obtained better results.
It was concluded that using multimedia resources has a greater positive effect than traditional resources on M and PA in under-18 handball players
Enhanced backward wave propagation in evanescent waveguides loaded with split ring resonators
This paper reports on the design and experimental characterization of evanescent waveguides loaded
with split ring resonators SRRs supporting enhanced backward wave propagation. With respect to
previous negative refractive index devices based on metallic waveguides, the use of a direct coaxial
probe excitation inside an evanescent waveguide drastically improves transmission and reflection
characteristics of the periodic structure. Moreover, the addition of metallic windows interleaved
between consecutive resonators offers an extra degree of freedom in order to control interresonator
couplings, and hence, device parameters like overall transmission, reflection, and bandwidth of the
backward wave pass band. A numerical and experimental analysis of different structures
overcoming the high loss issue of previously published results is detailed. An experimental
validation of the proposed enhancements is done for periodic structures, where no individual tuning
of the resonator sections is performed. The proposed technology mainly offers the advantage of
miniaturization, and it could be combined in a further step with standard design techniques to
provide frequency selective devices.Ministerio de Educación y Ciencia, Gobierno de España-TEC-2004-04313-C02-01 y TEC-2004-04249.C02-02Generalitat Valenciana-ACOMP06/013 y GVA/2007/21
Near-perfect tunneling and amplification of evanescent electromagnetic waves in a waveguide filled by a metamaterial: Theory and experiments
Amplification of evanescent electromagnetic waves by a metamaterial slab is still a controversial issue. Metallic waveguides operating in cutoff provide a unique physical environment to produce and study these waves because isolated evanescent modes can be excited in such environment. In this paper, the tunneling of electromagnetic waves through a rectangular waveguide partially filled by a metamaterial is analyzed. Enhanced tunneling due to the amplification of evanescent waves in the metamaterial filled waveguide section is demonstrated. Since evanescent modes in rectangular waveguides are the superposition of two plane waves, the aforementioned results also show the amplification and tunneling of evanescent plane waves by a metamaterial slab in free spaceMinisterio de Educación y Ciencia TIC2001- 3163 y TEC2004-04249-C02-0
Obtaining the basic response pattern of physiological time series data : a comparison of methods
An understanding of the kinetics of physiological variables such as the heart rate or the rate of change of volume of oxygen uptake is fundamental not only to training methodology and competitive success in sport and exercise, but also to our knowledge of cardiovascular health. A correct and efficient means of interpreting and analyzing the data obtained is of vast importance, as exercise testing is routinely used in both of these areas
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