Magnetic Field Effects on the Transport Properties of One-sided Rough Wires

We present a detailed numerical analysis of the effect of a magnetic field on the transport properties of a `small-$N$' one-sided surface disordered wire. When time reversal symmetry is broken due to a magnetic field $B$, we find a strong increase with $B$ not only of the localization length $\xi$ but also of the mean free path $\ell$ caused by boundary states. Despite this, the universal relationship between $\ell$ and $\xi$ does hold. We also analyze the conductance distribution at the metal-insulator crossover, finding a very good agreement with Random Matrix Theory with two fluctuating channels within the Circular Orthogonal(Unitary) Ensemble in absence(presence) of $B$Comment: 5 pages, 4 figures, to appear in Phys. Rev.

Local and average fields inside surface-disordered waveguides: Resonances in the one-dimensional Anderson localization regime

We investigate the one-dimensional propagation of waves in the Anderson localization regime, for a single-mode, surface disordered waveguide. We make use of both an analytical formulation and rigorous numerical simulation calculations. The occurrence of anomalously large transmission coefficients for given realizations and/or frequencies is studied, revealing huge field intensity concentration inside the disordered waveguide. The analytically predicted s-like dependence of the average intensity, being in good agreement with the numerical results for moderately long systems, fails to explain the intensity distribution observed deep in the localized regime. The average contribution to the field intensity from the resonances that are above a threshold transmission coefficient $T_{c}$ is a broad distribution with a large maximum at/near mid-waveguide, depending universally (for given $T_{c}$) on the ratio of the length of the disorder segment to the localization length, $L/\xi$. The same universality is observed in the spatial distribution of the intensity inside typical (non-resonant with respect to the transmission coefficient) realizations, presenting a s-like shape similar to that of the total average intensity for $T_{c}$ close to 1, which decays faster the lower is $T_{c}$. Evidence is given of the self-averaging nature of the random quantity $\log[I(x)]/x\simeq -1/\xi$. Higher-order moments of the intensity are also shown.Comment: 9 pages, 9 figure

Spinor calculus on 5-dimensional spacetimes

Penrose's spinor calculus of 4-dimensional Lorentzian geometry is extended to the case of 5-dimensional Lorentzian geometry. Such fruitful ideas in Penrose's spinor calculus as the spin covariant derivative, the curvature spinors or the definition of the spin coefficients on a spin frame can be carried over to the spinor calculus in 5-dimensional Lorentzian geometry. The algebraic and differential properties of the curvature spinors are studied in detail and as an application we extend the well-known 4-dimensional Newman-Penrose formalism to a 5-dimensional spacetime.Comment: Convention mismatch and minor typos fixed. To appear in Journal of Mathematical Physic

Técnicas SIG aplicadas al estudio del relieve de los Montes de León (NO de la Península Ibérica)

En este trabajo se presenta un método basado en el análisis de modelos digitales de elevación (MDE) a través de SIG, encaminado a realizar una cartografía preliminar de antiguas superficies de aplanamiento en los relieves que bordean la cuenca del Bierzo (oeste de la provincia de León, noroeste de la Península Ibérica). El área de estudio es un complejo sistema escalonado de niveles de aplanamiento elaborados sobre el basamento del Macizo Ibérico, constituyente de los relieves montañosos de la zona, deformado por la Orogenia Alpina durante el Cenozoico, en donde las superficies se encuentran elevadas, basculadas, fragmentadas y muy degradadas. Partiendo del MDE con paso de malla de 25 m del PNOA se realizó una caracterización general de la zona de estudio mediante la obtención de mapas derivados: pendientes, orientaciones de pendiente y sombreado, así como de la red de drenaje. Empleando la extensión EZ Profile para ArcGIS 9.3 se generaron 213 perfiles topográficos, sobre los principales cordales e interfluvios, con los que se localizaron y correlacionaron los elementos culminantes (indicios y restos de superficies de aplanamiento) presentes en toda la zona de estudio, lo que permitió reconstruir el relieve previo al desmantelamiento por parte de la red de drenaje. Una vez delimitadas las superficies de aplanamiento se procedió a su caracterización, agrupación y jerarquización, mediante el estudio de superficies de tendencia, el análisis de la red de drenaje y la relación con la actividad tectónica. Se realizó una reconstrucción teórica de cada uno de los aplanamientos a través de la interpolación de los puntos pertenecientes al antiguo relieve, generando así una superficie de tendencia de primer orden, de donde se obtuvo la orientación y pendiente de cada una de ellas. A su vez, se buscaron anomalías en los cauces de los ríos que atraviesan los aplanamientos, que pudieran indicar actividad tectónica reciente. Asimismo, se llevó a cabo un estudio de las cuencas de drenaje, sobre las que se realizaron cálculos de hipsometría y de asimetría (Factor de Asimetría). Por último, se calculó la incisión del drenaje sobre las superficies de aplanamiento cartografiadas. Como resultado se obtuvieron veinte superficies clasificadas en ocho niveles, desde los 1000m a los 2100m, en donde se observa cómo los distintos elementos de un mismo nivel se encuentran en extremos opuestos de la zona de estudio, ubicados en forma de orla perdiendo altura hacia la cuenca del Bierzo.Trabajo financiado por el proyecto de la Junta de Castilla y León LE311A12-2 y por el proyecto Consolider Ingenio 2006 CSD-2006, TopoIberia Geociencias en Iberia

Orden e integración de los meliambos cercideos

El objeto de este trabajo es el restablecimiento del orden original de los meliambos de Cércidas en el Papiro de Oxirrinco n.º 1082 y la reconstrucción de sus columnas XI-XII, primera y segunda del poema «Contra Esfero», mediante la unión entre sí de sus fragmentos principales junto con otros menores. Se intenta también integrar en la medida de lo posible los restantes escasos fragmentos en las otras columnas deterioradas.The object of this paper is the restoration of the original arrangement of Cercidas’s meliambs in the Oxyrhynchus Papyrus 1082 and the reconstitution of their coll. XI-XII, the first and second columns of the poem «Adversus Sphaerum», by fitting main fragments together with other minor ones. The author also intends to integrate as far as possible the scant number of small fragments into other deteriorated columns

Terahertz surface plasmon polariton propagation and focusing on periodically corrugated metal wires

In this letter we show how the dispersion relation of surface plasmon polaritons (SPPs) propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves. In this way, highly localized SPPs can be sustained in the terahertz region of the electromagnetic spectrum. Importantly, the propagation characteristics of these spoof SPPs can be controlled by the surface geometry, opening the way to important applications such as energy concentration on cylindrical wires and superfocusing using conical structures.Comment: accepted at PRL, submitted 29th May 200

Tracing high density gas in M 82 and NGC 4038

We present the first detection of CS in the Antennae galaxies towards the NGC 4038 nucleus, as well as the first detections of two high-J (5-4 and 7-6) CS lines in the center of M 82. The CS(7-6) line in M 82 shows a profile that is surprisingly different to those of other low-J CS transitions we observed. This implies the presence of a separate, denser and warmer molecular gas component. The derived physical properties and the likely location of the CS(7-6) emission suggests an association with the supershell in the centre of M 82.Comment: 10 pages, 3 figures, ApJ Letter - ACCEPTE

Antifungal effect and reduction of Ulmus minor symptoms to Ophiostoma novo-ulmi by carvacrol and salicylic acid

There are still no effective means to control Dutch elm disease (DED), caused by the vascular fungi Ophiostoma ulmi and O. novo-ulmi. Plant phenolics may provide a new strategy for DED control, given their known antifungal activity against pathogens and their involvement in plant defence mechanisms. The in vitro antifungal activity of salicylic acid, carvacrol, thymol, phenol, o-cresol, m-cresol, p-cresol, and 2,5-xylenol against the DED pathogens was tested. Also, the protective effect of watering Ulmus minor seedlings with these compounds was tested against O. novo-ulmi. Salicylic acid, carvacrol, and thymol showed the strongest antifungal in vitro activity, while carvacrol and salicylic acid provided the strongest in vivo protection against O. novo-ulmi (63 and 46% reduction of leaf wilting symptoms with respect to controls, respectively). The effect of the treatments on tree phenology was low, and a significant negative relation was observed between the number of days to bud burst and the leaf wilting symptoms after inoculation, probably determined by genetic differences among the elm tree progenies used. The treatments with salicylic acid, carvacrol and thymol induced the highest shift in phenolic metabolite profile with respect to control trees. The protective effect of carvacrol and salicylic acid is discussed in terms of their combined activity as antifungal compounds and as inductors of tree defence responses

Non-analyticity in the distribution of conductances in quasi one dimensional wires

We show that the distribution P(g) of conductances g of a quasi one dimensional wire has non-analytic behavior in the insulating region, leading to a discontinuous derivative in the distribution near g=1. We give analytic expressions for the full distribution and extract an approximate scaling behavior valid for different strengths of disorder close to g=1.Comment: 7 pages, 3 figures. Submitted to Europhysics Letter

Identifying past social-ecological thresholds to understand long-term temporal dynamics in Spain

A thorough understanding of long-term temporal social-ecological dynamics at the national scale helps to explain the current condition of a country’s ecosystems and to support environmental policies to tackle future sustainability challenges. We aimed to develop a methodological approach to understand past long-term (1960-2010) social-ecological dynamics in Spain. First, we developed a methodical framework that allowed us to explore complex social-ecological dynamics among biodiversity, ecosystem services, human well-being, drivers of change, and institutional responses. Second, we compiled 21 long-term, national-scale indicators and analyzed their temporal relationships through a redundancy analysis. Third, we used a Bayesian change point analysis to detect evidence of past social-ecological thresholds and historical time periods. Our results revealed that Spain has passed through four socialecological thresholds that define five different time periods of nature and society relationships. Finally, we discussed how the proposed methodological approach helps to reinterpret national-level ecosystem indicators through a new conceptual lens to develop a more systems-based way of understanding long-term social-ecological patterns and dynamicsThis work was supported by the Biodiversity Foundation (http://www.fundacion-biodiversidad.es/) of the Spanish Ministry of Agriculture, Food and Environment. Partial financial support was also provided by the Ministry of Economy and Competitiveness of Spain (project CGL2014-53782-P: ECOGRADIENTES). The Spanish National Institute for Agriculture and Food Research and Technology (INIA) funded Marina García-Llorente as part of the European Social Fund. Blanca González García-Mon participated in this article as a “la Caixa” Banking Foundation scholar. The funders had no role in the study design, data collection and analysis, preparation of the report, or the decision to submit the study for publicatio