1,274 research outputs found

    Mechanisms for photon sorting based on slit-groove arrays

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    Mechanisms for one-dimensional photon sorting are theoretically studied in the framework of a coupled-mode method. The considered system is a nanopatterned structure composed of two different pixels drilled on the surface of a thin gold layer. Each pixel consists of a slit-groove array designed to squeeze a large fraction of the incident light into the central slit. The Double-Pixel is optimized to resolve two different frequencies in the near infrared. This system shows high transmission efficiencies and a small crosstalk. It is found that the response of the system strongly depends on the effective area shared by overlapping pixels. According to such degree of overlap, photon sorting can be achieved within three different regimes, which are discussed in detail. Optimal photon-sorting efficiencies are obtained for a moderate number of grooves that overlap with grooves of the neighbor pixel. These results could be applied to both optical and infrared detectors.The authors gratefully acknowledge financial support by European Projects EC FP7-ICT PLAISIR Project Ref. 247991, the Spanish Ministry of Science and Innovation project MAT2011-28581-C02-02, and the CUD project Ref. 2013-13.Peer Reviewe

    Predicting global geographical distribution of "Lolium rigidum" under climate change

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    “Lolium rigidum Gaud.” (vallico) es una de las malezas más extendidas y perjudiciales en los cultivos de cereales de invierno. Un modelo bioclimático para esta especie fue desarrollado utilizando CLIMEX. El modelo fue validado con los registros de esta especie en Estados Unidos y Oceanía y utilizado para predecir la distribución potencial global de “L. rigidum” bajo el clima actual y dos escenarios de cambio climático. Las proyección en virtud de las condiciones climáticas actuales indican que “L. rigidum” no ocupa todo el área disponible para su expansión. Considerando los escenarios climáticos futuros, el área potencial de expansión aumentará 3,79% y 5,06% bajo los escenarios moderado y extremo, respectivamente. La proyección del modelo mostró un avance gradual de “L. rigidum” en Norteamérica, Europa, Sudamérica y Asia, mientras que en África y Oceanía se prevé una regresión. Estos resultados proporcionan Los conocimientos necesarios para identificar y poner de relieve las posibles zonas de riesgo de invasión.“Lolium rigidum” Gaud. (rigid ryegrass) is one of the most extended and harmful weeds in winter cereal crops. A bioclimatic model for this species was developed using CLIMEX. The model was validated with records from North America and Oceania and used to assess the global potential distribution of “L. rigidum” under the current climate and under two climate change scenarios. The projection under current climate conditions indicated that “L. rigidum” does not occupy the full extent of the climatically suitable area available to it. Under future climate scenarios, the infested potential area will increase 3.79% in the low-emission CO2 scenario and 5.06% under the most extreme scenario. The model projection showed a gradual advance of rigid ryegrass in North America, Europe, South America and Asia, whilst in Africa and Oceania it indicated regression. These results provide the necessary knowledge for identifying and highlighting the potential invasion risk areas

    Mitogenomics of Central American weakly-electric fishes

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    Electric fishes are a diverse group of freshwater organisms with the ability to generate electric organ discharges (EODs) that are used for communication and electrolocation. This group (ca. 200 species) has originated in South America, and six species colonized the Central American Isthmus. Here, we assembled the complete mitochondrial genomes (mitogenomes) for three Central American electric fishes (i.e. Sternopygus dariensis, Brachyhypopomus occidentalis, and Apteronotus rostratus), and, based on these data, explored their phylogenetic position among Gymnotiformes. The three mitogenomes show the same gene order, as reported for other fishes, with a size ranging from 16,631 to 17,093 bp. We uncovered a novel 60 bp intergenic spacer (IGS) located between the COII and tRNALys genes, which appears to be unique to the Apteronotidae. Furthermore, phylogenetic relationships supported the traditional monophyly of Gymnotiformes, with the three species positioned within their respective family. In addition, the genus Apteronotus belongs to the early diverging lineage of the order. Finally, we found high sequence divergence (13%) between our B. occidentalis specimen and a sequence previously reported in GenBank, suggesting that the prior mitogenome of B. occidentalis represents a different South American species. Indeed, phylogenetic analyses using Cytochrome b gene across the genus placed the previously reported individual within B. bennetti. Our study provides novel mitogenome resources that will advance our understanding of the diversity and phylogenetic history of Neotropical fishesElectric fishes are a diverse group of freshwater organisms with the ability to generate electric organ discharges (EODs) that are used for communication and electrolocation. This group (ca. 200 species) has originated in South America, and six species colonized the Central American Isthmus. Here, we assembled the complete mitochondrial genomes (mitogenomes) for three Central American electric fishes (i.e. Sternopygus dariensis, Brachyhypopomus occidentalis, and Apteronotus rostratus), and, based on these data, explored their phylogenetic position among Gymnotiformes. The three mitogenomes show the same gene order, as reported for other fishes, with a size ranging from 16,631 to 17,093 bp. We uncovered a novel 60 bp intergenic spacer (IGS) located between the COII and tRNALys genes, which appears to be unique to the Apteronotidae. Furthermore, phylogenetic relationships supported the traditional monophyly of Gymnotiformes, with the three species positioned within their respective family. In addition, the genus Apteronotus belongs to the early diverging lineage of the order. Finally, we found high sequence divergence (13%) between our B. occidentalis specimen and a sequence previously reported in GenBank, suggesting that the prior mitogenome of B. occidentalis represents a different South American species. Indeed, phylogenetic analyses using Cytochrome b gene across the genus placed the previously reported individual within B. bennetti. Our study provides novel mitogenome resources that will advance our understanding of the diversity and phylogenetic history of Neotropical fishe

    tempo and mode of allopatric divergence in the weakly electric fish Sternopygus dariensis in the Isthmus of Panama

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    Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds.Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds

    Reliability and validity of the Severe Impairment Battery, short form (SIB-s), in patients with dementia in Spain

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    Las personas con demencia progresiva evolucionan hacia un estado donde los tests neuropsicológicos tradicionales dejan de ser eficaces. La batería de evaluación del deterioro grave, en su forma completa (SIB) y abreviada (SIB-s), se desarrolló para evaluar el estado cognitivo de pacientes con demencia avanzada. Objetivo. Evaluar los atributos psicométricos de la SIB-s en población española. Pacientes y métodos. Estudio transversal de 127 pacientes con demencia (86,6%, mujeres; edad media: 82,6 ± 7,5 años) evaluados con la SIB-s y las siguientes medidas: escala de deterioro global, miniexamen cognitivo (MEC), miniexamen del estado mental grave (sMMSE), índice de Barthel y escala del estado funcional. Resultados. La puntuación media total de la SIB-s fue de 19,1 ± 15,34 (rango: 0-48). Efectos suelo y techo < 20%. El análisis factorial identificó un único factor que explica el 68% de la varianza total de la escala. La consistencia interna fue alta (α de Cronbach: 0,96). La correlación ítem-total corregida osciló entre 0,27 y 0,83, y la homogeneidad de los ítems fue de 0,43. La fiabilidad test-retest e interevaluador fue satisfactoria (coeficiente de correlación intraclase: 0,96 y 0,95, respectivamente), así como la validez de constructo convergente con otras medidas cognitivas (MEC: 0,83; sMMSE: 0,9). La SIB-s mostró una correlación moderada con escalas cognitivas de dependencia funcional (índice de Barthel: 0,48; FAST: –0,74). El error estándar de la medida fue de 3,07 para el total de la escala. Conclusiones. La SIB-s es un instrumento fiable y válido, relativamente breve, para evaluar a pacientes con demencia avanzada en la población española.People with progressive dementia evolve into a state where traditional neuropsychological tests are not effective. Severe Impairment Battery (SIB) and short form (SIB-s) were developed for evaluating the cognitive status in patients with severe dementia. Aim. To evaluate the psychometric attributes of the SIB-s in patients with severe dementia. Patients and methods. 127 institutionalized patients (female: 86.6%; mean age: 82.6 ± 7.5 years-old) with dementia were assessed with the SIB-s, the Global Deterioration Scale (GDS), Mini-Mental State Examination (MMSE), Severe MiniMental State Examination (sMMSE), Barthel Index and FAST. Results. SIB-s acceptability, reliability, validity and precision were analyzed. The mean total score for scale was 19.1 ± 15.34 (range: 0-48). Floor effect was 18.1%, only marginally higher than the desirable 15%. Factor analysis identified a single factor explaining 68% of the total variance of the scale. Cronbach’s α coefficient was 0.96 and the item-total corrected correlation ranged from 0.27 to 0.83. The item homogeneity value was 0.43. Test-retest and inter-rater reliability for the total score was satisfactory (ICC: 0.96 and 0.95, respectively). The SIB-s showed moderate correlation with functional dependency scales (Barthel Index: 0.48, FAST: –0.74). Standard error of measurement was 3.07 for the total score. Conclusions. The SIB-s is a reliable and valid instrument for evaluating patients with severe dementia in the Spanish population of relatively brief instruments

    Experimental results and modelling of humidity control strategies from greenhouses in continental and coastal setting in the Mediterranean regíon. I : Experimental results and model development.

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    Experimental strategies for controlling humidity were compared in a greenhouse sited in Madrid, a continental site in the Mediterranean region. Small roof window apertures significantly reduced the relative humidity with only a limited increase in associated energy consumption. A simplified climate model with four energy exchange terms (heating, insolation, losses through structure, and losses through windows) and three mass exchange terms (evapotranspiration, losses through structure, and losses through windows) was validated, allowing relative humidity to be predicted with an error of < 9%. - Se ensayaron una serie de estrategias experimentales para el control de la humedad en un invernadero de Madrid, España. Se comprobó que pequeñas aperturas de la ventana cenital reducían significativamente el nivel de humedad con limitados incrementos del consumo de energía en calefacción. Se validó un modelo climático simplificado con cuatro términos de intercambio de energía (calefacción, radiación solar, pérdidas a través de la cubierta y pérdidas a través de las ventanas) y tres términos de intercambio de humedad (evapotranspiración, pérdidas a través de la cubierta y pérdidas a través de las ventanas), modelo que permitió predecir la humedad relativa con un error inferior al 9%

    Blueprint of a Molecular Spin Quantum Processor

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    The implementation of a universal quantum processor still poses fundamental issues related to error mitigation and correction, which demand to investigate also platforms and computing schemes alternative to the main stream. A possibility is offered by employing multi-level logical units (qudits), naturally provided by molecular spins. Here we present the blueprint of a Molecular Spin Quantum Processor consisting of single Molecular Nanomagnets, acting as qudits, placed within superconducting resonators adapted to the size and interactions of these molecules to achieve a strong single spin to photon coupling. We show how to implement a universal set of gates in such a platform and to readout the final qudit state. Single-qudit unitaries (potentially embedding multiple qubits) are implemented by fast classical drives, while a novel scheme is introduced to obtain two-qubit gates via resonant photon exchange. The latter is compared to the dispersive approach, finding in general a significant improvement. The performance of the platform is assessed by realistic numerical simulations of gate sequences, such as Deutsch-Josza and quantum simulation algorithms. The very good results demonstrate the feasibility of the molecular route towards a universal quantum processor.Comment: 16 pages, 11 figures. Accepted in Physical Review Applie

    Indicaciones Límite de las Fracturas de Húmero con Clavo Endomedular Cerrojado

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    El tratamiento de las fracturas diafisarias del húmero ha entrado en controversia en los últimos años, como lo refleja la literatura internacional. La problemática aumenta cuando se trata de fracturas diafisarias límites que alcanzan la zona metafisaria superior e inferior. En un intento de mejora terapéutica este grupo de autores ha testado un clavo cerrojado para el húmero diseñado por Seidel. El promedio de seguimiento ha sido de 12 meses con un mínimo de 6 meses. El número de casos evaluados ha sido 6. Siguiendo la cotación de Stewart, 4 de los seis pacientes obtuvieron resultados buenos o excelentes. Todos los pacientes consolidaron sus fracturas en un período de tiempo normal, entre 3 y 5 meses, con una media de 4 meses, 4 de los seis pacientes no se inmovilizaron con yeso en ningún momento. La bondad y sencillez del método hace augurar buenos resultados en otros grupos ampliando sus indicaciones.Treatment of dyaphyseal fractures of the humerus has been the source of considerable controversy in recent years. The problem increases in dimension when one is dealing with limiting diaphyseal fractures that invole the upper and lower metaphyseal zone. In an attempt to improve the therapy of this circunstance, the members of this research team have tested a locking nail for the humerus designed by Seidel. The mean follow-up time has been 12 months, with a minimum of six months. The number of cases evaluated was 6. According to the scale of Stewart, four of the cases obtained good or excellent results. All the patients consolidated their fractures within a normal period of time -between 3 and 5 months-, with a mean of 4 months. Four of the 6 patients wer e not immobilized with paster at any time. The goodness and simplicity of the method are suggestive of promising results in other groups by broadening its indications

    Stimuli Characteristics and Psychophysical Requirements for Visual Training in Amblyopia: A Narrative Review

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    Active vision therapy using perceptual learning and/or dichoptic or binocular environments has shown its potential effectiveness in amblyopia, but some doubts remain about the type of stimuli and the mode and sequence of presentation that should be used. A search was performed in PubMed, obtaining 143 articles with information related to the stimuli used in amblyopia rehabilitation, as well as to the neural mechanisms implied in such therapeutic process. Visual deficits in amblyopia and their neural mechanisms associated are revised, including visual acuity loss, contrast sensitivity reduction and stereopsis impairment. Likewise, the most appropriate stimuli according to the literature that should be used for an efficient rehabilitation of the amblyopic eye are described in detail, including optotypes, Gabor’s patches, random-dot stimuli and Vernier’s stimuli. Finally, the properties of these stimuli that can be modified during the visual training are discussed, as well as the psychophysical method of their presentation and the type of environment used (perceptual learning, dichoptic stimulation or virtual reality). Vision therapy using all these revised concepts can be an effective option for treating amblyopia or accelerating the treatment period when combining with patching. It is essential to adapt the stimuli to the patient’s individual features in both monocular and binocular training.The authors C.J.H.-R., D.P.P., A.M.-M., D.d.F., L.L.-V., M.B.C.-M. have been funded by CDTI (Centro para el Desarrollo Tecnológico Industrial, Ministry of Economy and Competitiveness of Spain) and FEDER (Fondos Europeos de Desarrollo Regional) funds by means of the program PID (“Proyectos de Investigación y Desarrollo”) in the context of the Project NEIVATECH (“Neuroplasticity through virtual reality for amblyopia”, application number 111705). The author León Morales-Quezada is supported by funding from the Spaulding Research Catalyst award. The author David P Piñero has been also supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Materiales para una «Herpetofauna Balearica 5. Las salamanquesas y tortugas del archipiélago de CabreraEcología de una población insular mediterránea del Eslizón ibérico, Chalcides bedriagai (Sauria Scincidae).Ecología alimenticia del águila imperial ibérica (Aquila adalberti) en el Coto Doñana durante la crianza de los pollosDatos sobre la dieta invernal del colirrojo tizón (Phoenicurus ochruros) en encinares de Andalucía occidentalSobre infecciones estafilocócicas en el Aguila imperial ibérica (Aquila adalberti Brehm)Breves notas sobre el Sapo partero ibérico (Alytes cisternasii Boscá)Sobre la presencia de Hyla arborea en la provincia de BadajozAlgunas presas de Elaphe scalaris.Observaciones de Tarentola maurítanica en nido de Hirundo dauricaObservación de una culebra viperina Natrix maura en agua marinaPrimera cita de la CollaIba yebélica (Oenanthe leucopyga) en la Península ibéricaObservaciones de Phoenicopterus ruber en la Ría de Vigo (PontevedraDatos sobre el Myotis emarginatus en la Península ibérica.Peer reviewe
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