On the transmission of light through a single rectangular hole

In this Letter we show that a single rectangular hole exhibits transmission resonances that appear near the cutoff wavelength of the hole waveguide. For light polarized with the electric field pointing along the short axis, it is shown that the normalized-to-area transmittance at resonance is proportional to the ratio between the long and short sides, and to the dielectric constant inside the hole. Importantly, this resonant transmission process is accompanied by a huge enhancement of the electric field at both entrance and exit interfaces of the hole. These findings open the possibility of using rectangular holes for spectroscopic purposes or for exploring non-linear effects.Comment: Submitted to PRL on Feb. 9th, 200

Integration of a Canine Agent in a Wireless Sensor Network for Information Gathering in Search and Rescue Missions

Search and rescue operations in the context of emergency response to human or natural disasters have the major goal of finding potential victims in the shortest possible time. Multi-agent teams, which can include specialized human respondents, robots and canine units, complement the strengths and weaknesses of each agent, like all-terrain mobility or capability to locate human beings. However, efficient coordination of heterogeneous agents requires specific means to locate the agents, and to provide them with the information they require to complete their mission. The major contribution of this work is an application of Wireless Sensor Networks (WSN) to gather information from a multi-agent team and to make it available to the rest of the agents while keeping coverage. In particular, a canine agent has been equipped with a mobile node installed on a harness, providing information about the dog’s location as well as gas levels. The configuration of the mobile node allows for flexible arrangement of the system, being able to integrate static as well as mobile nodes. The gathered information is available at an external database, so that the rest of the agents and the control center can use it in real time. The proposed scheme has been tested in realistic scenarios during search and rescue exercises

Sistema móvil de información basado en una red de sensores inalámbricos aplicado a la movilidad urbana

La movilidad en las ciudades se ve comprometida por un tráfico cada vez más elevado y unas infraestructuras que no pueden ampliarse. Por tanto, la mejora de la movilidad y su sostenibilidad deben venir de la mano de una mejor gestión de los recursos, con la incorporación de estrategias de control del tráfico que se adapten en cada momento a sus condiciones. El principal obstáculo está en la obtención de esa información. Una posibilidad son las redes de sensores inalámbricos, que pueden aportar información sobre las condiciones en una zona de interés, con vistas a una planificación más eficiente y al despliegue de algoritmos de control más elaborados.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Agencia de Obra Pública de la Junta de Andalucía (proyecto GI3000/IDIZ, con apoyo financiaero de los fondos FEDER

Understanding the impact of line-of-sight in the ergodic spectral efficiency of cellular networks

In this paper we investigate the impact of lineof-sight (LoS) condition in the ergodic spectral efficiency of cellular networks. To achieve this goal, we have considered the kappa-mu shadowed model, which is a general model that provides an excellent fit to a wide set of propagation conditions. To overcome the mathematical complexity of the analysis, we have split the analysis between large and small-scale effects. Building on the proposed framework, we study a number of scenarios that range from heavily-fluctuating LoS to deterministic-LoS. Finally, we shed light on the interplay between fading severity and spectral efficiency by means of the amount of fading.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Transfer learning or design a custom CNN for tactile object recognition

International Workshop on Robotac: New Progress in Tactile Perception and Learning in RoboticsNovel tactile sensors allow treating pressure lectures as standard images due to its highresolution. Therefore, computer vision algorithms such as Convolutional Neural Networks (CNNs) can be used to identify objects in contact. In this work, a high-resolution tactile sensor has been attached to a robotic end-effector to identify objects in contact. Moreover, two CNNs-based approaches have been tested in an experiment of classification of pressure images. These methods include a transfer learning approach using a pre-trained CNN on an RGB images dataset and a custom-made CNN trained from scratch with tactile information. A comparative study of performance between them has been carried out.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Spanish project DPI2015-65186-R, the European Commission under grant agreement BES-2016-078237, the educational project PIE-118 of the University of Malag

Evolution of the silicon bottom cell photovoltaic behavior during III-V on Si multi-junction solar cells production

The evolution of the Si bulk minority carrier lifetime during the heteroepitaxial growth of III-V on Si multi-junction solar cell structures via metal-organic vapor phase epitaxy has been analyzed. Initially, the emitter formation produces important lifetime degradation. Nevertheless, a progressive recovery was observed during the growth of the metamorphic GaAsP/Si structure. A step-wise mechanism has been proposed to explain the lifetime evolution observed during this process. The initial lifetime degradation is believed to be related to the formation of thermally-induced defects within the Si bulk. These defects are subsequently passivated by fast-diffusing atomic hydrogen -coming from precursor (i.e. PH3 and AsH3) pyrolysis- during the subsequent III-V growth. These results indicate that the MOVPE environment used to create the III-V/Si solar cell structures has a dynamic impact on the minority carrier lifetime. Consequently, designing processes that promote the recovery of the lifetime is a must to support the production of high-quality III-V/Si solar cells

Genetic Diversity in Relict and Fragmented Populations of Ulmus glabra Hudson in the Central System of the Iberian Peninsula

Ulmus glabra Hudson, or Wych elm, occurs as fragmented and relict natural populations in the Central System, which acts as a refugium in the Iberian Peninsula. Considering the importance of the Central System populations of U. glabra, the main objective was to assess their genetic diversity using nuclear microsatellite markers. A total of 360 different genotypes were detected in the 427 U. glabra individuals analyzed. Wych elm populations showed a highly significant genetic differentiation (24%; p = 0.0001). Of the 22 populations studied, population of Rozas de Puerto Real (ROZ) showed the highest values of effective number of alleles (2.803), mean Shannon?s diversity (1.047) and expected heterozygosity (0.590). Populations of ROZ and Mombeltrán (MOM) showed the highest values of observed heterozygosity (0.838 and 0.709, respectively), and highly negative values for inbreeding coefficient (?0.412 and ?0.575, respectively). Also, most of putative hybrids (50 of 55) were observed in these two populations. Demographic analysis revealed signals for recent (four populations) and ancestral (fifteen populations) bottlenecks. Fragmented populations with diminishing number of individuals, along with anthropogenic intervention and Dutch elm disease (DED), are the main threats to U. glabra populations. From a future perspective, the information generated can be considered in the formulation of conservation strategies for U. glabra populations in the Central System

Pitfalls in spontaneous in vitro transformation of human mesenchymal stem cells

Spontaneous in vitro transformation of human primary cells was, and continues to be, a scarcely described phenomenon. Only the description of the generation of the HaCAT cell line [1] is a canonical example, worldwide accepted. More recent examples included the emergence of tumorogenic populations upon in vitro culture of fetal human mesenchymal stem cells (hMSC), induced by GM-CSF and IL-4, [2] and bone marrow hMSC [3]. Other examples have also been reported after very long-term in vitro culture of telomerized hMSCTerT [4]. In this scenario, our previous results [5-7] were only a new observation to be added to this list. Only very recently similar results have been published [8], reporting spontaneous malignant transformation in 46 % of bone marrow–derived hMSC long-term cultures (5–106 weeks). However, other authors reported opposite results.S

IGF-II promotes neuroprotection and neuroplasticity recovery in a long-lasting model of oxidative damage induced by glucocorticoids

Insulin-like growth factor-II (IGF-II) is a naturally occurring hormone that exerts neurotrophic and neuroprotective properties in a wide range of neurodegenerative diseases and ageing. Accumulating evidence suggests that the effects of IGF-II in the brain may be explained by its binding to the specific transmembrane receptor, IGFII/M6P receptor (IGF-IIR). However, relatively little is known regarding the role of IGF-II through IGF-IIR in neuroprotection. Here, using adult cortical neuronal cultures, we investigated whether IGF-II exhibits long-term antioxidant effects and neuroprotection at the synaptic level after oxidative damage induced by high and transient levels of corticosterone (CORT). Furthermore, the involvement of the IGF-IIR was also studied to elucidate its role in the neuroprotective actions of IGF-II. We found that neurons treated with IGF-II after CORT incubation showed reduced oxidative stress damage and recovered antioxidant status (normalized total antioxidant status, lipid hydroperoxides and NAD(P) H:quinone oxidoreductase activity). Similar results were obtained when mitochondria function was analysed (cytochrome c oxidase activity, mitochondrial membrane potential and subcellular mitochondrial distribution). Furthermore, neuronal impairment and degeneration were also assessed (synaptophysin and PSD-95 expression, presynaptic function and FluoroJade B® stain). IGF-II was also able to recover the long-lasting neuronal cell damage. Finally, the effects of IGF-II were not blocked by an IGF-IR antagonist, suggesting the involvement of IGF-IIR. Altogether these results suggest that, in or model, IGF-II through IGF-IIR is able to revert the oxidative damage induced by CORT. In accordance with the neuroprotective role of the IGF-II/IGF-IIR reported in our study, pharmacotherapy approaches targeting this pathway may be useful for the treatment of diseases associated with cognitive deficits (i.e., neurodegenerative disorders, depression, etc.)

Transcriptome profiling of Set5 and Set1 methyltransferases: Tools for visualization of gene expression

AbstractCells regulate transcription by coordinating the activities of multiple histone modifying complexes. We recently identified the yeast histone H4 methyltransferase Set5 and discovered functional overlap with the histone H3 methyltransferase Set1 in gene expression. Specifically, using next-generation RNA sequencing (RNA-Seq), we found that Set5 and Set1 function synergistically to regulate specific transcriptional programs at subtelomeres and transposable elements. Here we provide a comprehensive description of the methodology and analysis tools corresponding to the data deposited in NCBI's Gene Expression Omnibus (GEO) under the accession number GSE52086. This data complements the experimental methods described in Mas Martín G et al. (2014) and provides the means to explore the cooperative functions of histone H3 and H4 methyltransferases in the regulation of transcription. Furthermore, a fully annotated R code is included to enable researchers to use the following computational tools: comparison of significant differential expression (SDE) profiles; gene ontology enrichment of SDE; and enrichment of SDE relative to chromosomal features, such as centromeres, telomeres, and transposable elements. Overall, we present a bioinformatics platform that can be generally implemented for similar analyses with different datasets and in different organisms