Estudio palinológico del género Rosmarinus L. (Labiatae)

Se ha llevado a cabo un estudio de l as característi cas de l os gra nos de polen del género Rosmarinus L. en microscopía ópt ica y M. E. B. . Estos s e presentan, en cuant o a su forma, como suboblados , e xacol pados , de exina sem itectada y r eticulada . Se han estud i ado 12 poblaciones de las especies R. of fici nalis L., R. eriocalyx Jordan & Four r. y R. t ome ntosus Huber-Morath & Mai re . Este género como l a mayoría de l a fam ilia Labiatae e s estenopal ino , por ello , las difer enci as que se observan , no son l o s uficien teme nte significativas como para consi derarlas como un buen carácter taxonómicoA study has been made of the poll en grai ns of the genus Rosmarinus L. •11ith light microsc.opy and S. E.M. They are with rega r d to thei r fo nn, suboblate , exacolpate, wi t h semitectate and ret i cul a t e exi ne . A t otal of 12 populations of t he speci es R. officinalis L. R. eriocalyx Jordan & Fourr . and R. tomentosus Huber-Mor ath & Maire were stud ied . This genus , l ike most of the family I..abiatae, is s t enopalynous, and consequently the d i fferences observed were not suffi ciently discrete to be cons i derated as a good taxonomic charac ter s

Estudios taxonómicos en el género Salvia L., secciones Salvia y Aethiopis Bentham: palinología

Utilizando microscopía óptica y microscopio electrónico de barrido se han estudiado los caracteres polinices de 31 poblaciones de 6 especies, 8 subespecies y 3 variedades de la Península Ibér ic ~ y Norte de Africa pertenecientes a Salvia L. sect . Salvia y sect. Aethiopis Bentham. Se ha observado que este género , como l a mayoría de la fami l ia Lamiaceae es estenopal ino, no obstante, los caracteres de la exina permiten diferenciar parcialmente ambas seccionesThe pollen characters of 6 species , 8 subspecies and 3 varieties from 31 populat ions belonging to Salvia L. sect. Sal via and sect. Aethiopis Bentharn from t he Iberian Peninsula and N Africa, were examined both wi th light and scanni ng electron micrqscopy . The resul ts show that t he genus, like the most of the family Larniaceae, is stenopalynous . However , sexine characters can be used to dis t inguish each section

Variation in the intensity of selection on codon bias over time causes contrasting patterns of base composition evolution in Drosophila

Four-fold degenerate coding sites form a major component of the genome, and are often used to make inferences about selection and demography, so that understanding their evolution is important. Despite previous efforts, many questions regarding the causes of base composition changes at these sites in Drosophila remain unanswered. To shed further light on this issue, we obtained a new whole-genome polymorphism dataset from D. simulans. We analysed samples from the putatively ancestral range of D. simulans, as well as an existing polymorphism dataset from an African population of D. melanogaster. By using D. yakuba as an outgroup, we found clear evidence for selection on 4-fold sites along both lineages over a substantial period, with the intensity of selection increasing with GC content. Based on an explicit model of base composition evolution, we suggest that the observed AT-biased substitution pattern in both lineages is probably due to an ancestral reduction in selection intensity, and is unlikely to be the result of an increase in mutational bias towards AT alone. By using two polymorphism-based methods for estimating selection coefficients over different timescales, we show that the selection intensity on codon usage has been rather stable in D. simulans in the recent past, but the long-term estimates in D. melanogaster are much higher than the short-term ones, indicating a continuing decline in selection intensity, to such an extent that the short-term estimates suggest that selection is only active in the most GC-rich parts of the genome. Finally, we provide evidence for complex evolutionary patterns in the putatively neutral short introns, which cannot be explained by the standard GC-biased gene conversion model. These results reveal a dynamic picture of base composition evolution

A new strategy to design SIW-fed arrays

In this work, a new full-wave strategy, with very low iteration times, is proposed for the optimization and design of antenna arrays fed by substrate integrated waveguides. The device is decomposed into fixed and modifiable (to be optimized) sections, whose generalized scattering matrices are precomputed. The response of the array is calculated by considering firstly only the interactions between the fixed sections, which are then coupled to the modifiable ones in each iteration of an optimization process. To validate the proposed strategy, a transversal 16-slot antenna array, placed on the top plate of a substrate integrated waveguide, has been designed. A speed-up factor of over 2000 times, compared to general purpose commercial software, has been obtained in this optimization process. The final design presents a 1.05 GHz bandwidth under - 10 dB in terms of |S11|, a maximum realized gain of 17.5 dBi at 17 GHz, and a 99.95% maximum efficiency (without dielectric and conductor losses). Index Terms—Addition theorems, cylindrical modes, spherical modes, optimization process, antenna array, substrate integrated waveguide (SIW)

Model for illuminance produced by LEDs as a function of distance

CIE 2015, Manchester/UK, June 28 - July 4, 2015; http://session2015.cie.co.at/The lighting industry has experienced a revolution with the arrival of novel lighting technologies in particular Light Emitting Diodes. LEDs have clear advantages in energy efficiency over conventional lighting technologies, and since 19 % of electricity worldwide is used for lighting, this can contribute significantly to saving energy problems worldwide and contributing to Europe¿s 2020 strategy. In order to validate performance claims and stimulate user confidence, as well as facilitate efficient development of this kind of products, dedicated metrology is needed. The objective of this work was to study goniometrical aspects of LEDs, and their dependence with distance to find a model to predict the illuminance at any distance. A modified inverse-square law model, considering only the offset of the LED virtual source with respect to their front tip is proposed. The applicability of the method was tested for 18 LED¿s types, with different angular and spectral distributions.This work was accomplished within the EMRP ENG05 Project “Metrology for Solid State Lighting”. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The authors are also grateful to Comunidad de Madrid for funding the project SINFOTON-CM: S2013/MIT-2790Peer Reviewe

The impact on the marine recreational fisheries of longliner operations in the Caribbean

Campos, J.L.; Muñoz-Roure, O

Antiferromagnetism in four dimensions: search for non-triviality

We present antiferromagnetism as a mechanism capable of modifying substantially the phase diagram and the critical behaviour of statistical mechanical models. This is particularly relevant in four dimensions, due to the connection between second order transition points and the continuum limit as a quantum field theory. We study three models with an antiferromagnetic interaction: the Ising and the O(4) Models with a second neighbour negative coupling, and the \RP{2} Model. Different conclusions are obtained depending on the model.Comment: 4 pages LateX. Contribution to Lat9

Performance Evaluation of Distributed Mobility Management Protocols: Limitations and Solutions for Future Mobile Networks

Mobile Internet data traffic has experienced an exponential growth over the last few years due to the rise of demanding multimedia content and the increasing number of mobile devices. Seamless mobility support at the IP level is envisioned as a key architectural requirement in order to deal with the ever-increasing demand for data and to efficiently utilize a plethora of different wireless access networks. Current efforts from both industry and academia aim to evolve the mobility management protocols towards a more distributed operation to tackle shortcomings of fully centralized approaches. However, distributed solutions face several challenges that can result in lower performance which might affect real-time and multimedia applications. In this paper, we conduct an analytical and simulated evaluation of the main centralized and proposed Distributed Mobility Management (DMM) solutions. Our results show that, in some scenarios, when users move at high speed and/or when the mobile node is running long-lasting applications, the DMM approaches incur high signaling cost and long handover latency.This work was supported by the Government of Extremadura under Grant no. GR15099 and by the European Regional Development Fund Programme (2014–2020) and the Regional Fund, through Computing and Advanced Technologies Foundation of Extremadura (COMPUTAEX)

Parámetros relevantes en el estudio de la no-linealidad de fotodiodos

OPTOEL 2015, Salamanca 13 a 15 de julio de 2015; http://optoel2015.usal.es/El comportamiento lineal en la respuesta de un fotodiodo es una condición fundamental en medidas radiométricas, espectrofotométricas y de radiación pulsada o continua. Por tanto, se requiere que la respuesta eléctrica del fotodiodo sea proporcional al flujo radiante incidente y que se mantenga estable en el tiempo y en un rango de irradiancia. Sin embargo, diversas medidas publicadas evidencian una falta de linealidad dependiente de la estructura interna del fotodiodo, de la potencia y del tamaño del haz incidente. Este trabajo, para caracterizar la no-linealidad en la respuesta de fotodiodos como función de estos mismos factores, adopta el modelo de eficiencia cuántica interna desarrollado por Ferrero et al. en el Instituto de Óptica (CSIC). Además, mediante simulaciones para distintos supuestos, evalúa la influencia de cada parámetro en la no-linealidad de respuesta comparando resultados de las simulaciones con datos experimentales seleccionados en una recopilación bibliográfica.Los autores agradecen al EMRP la subvención del proyecto NEWSTAR. El programa EMRP está financiado conjuntamente por los países de EURAMET participantes y la Unión Europea.Peer Reviewe

Effect of Solvent Choice on the Self-Assembly Properties of a Diphenylalanine Amphiphile Stabilized by an Ion Pair

A diphenylalanine (FF) amphiphile blocked at the C terminus with a benzyl ester (OBzl) and stabilized at the N terminus with a trifluoroacetate (TFA) anion was synthetized and characterized. Aggregation of peptide molecules was studied by considering a peptide solution in an organic solvent and adding pure water, a KCl solution, or another organic solvent as co-solvent. The choice of the organic solvent and co-solvent and the solvent/co-solvent ratio allowed the mixture to be tuned by modulating the polarity, the ionic strength, and the peptide concentration. Differences in the properties of the media used to dissolve the peptides resulted in the formation of different self-assembled microstructures (e.g. fibers, branched-like structures, plates, and spherulites). Furthermore, crystals of TFAFF-OBzl were obtained from the aqueous peptide solutions for X-ray diffraction analysis. The results revealed a hydrophilic core constituted by carboxylate (from TFA), ester, and amide groups, and the core was found to be surrounded by a hydrophobic crown with ten aromatic rings. This segregated organization explains the assemblies observed in the different solvent mixtures as a function of the environmental polarity, ionic strength, and peptide concentration