241 research outputs found
The response of Iberian rivers to the North Atlantic Oscillation
In this study we analyzed the influence of the North Atlantic Oscillation (NAO) on the streamflow in 187 sub-basins of the Iberian Peninsula. Monthly and one-month lagged correlations were conducted to assess the spatio-temporal extent of the NAO influence on Iberian river discharges. Analysis of the persistence of the winter NAO throughout the year was also undertaken, together with analysis of streamflow anomalies during positive and negative NAO phases. Moving-window correlation analyses were conducted to assess potential changes in the temporal evolution of the NAO influence on Iberian streamflows. The results show that the NAO has a large impact on surface water resources throughout the Iberian Peninsula during winter, and in the Atlantic watershed during autumn. We showed that water resources management and snowmelt are causing the persistent dependence of streamflows on the previous winter NAO. We found that strongly positive streamflow anomalies occurred during winter, especially in the Atlantic watershed, and provide evidence of non-stationarity and spatial variability in the NAO influence on Iberian water resources
Synthesis and Effect of CaTiO3 formation in CaO·Al2O3 by Solid-State Reaction from CaCO3· Al2O3 and Ti
CaO⋅Al2O3/CaTiO3 material was synthesized by a solid-state reaction. The effects of CaTiO3 formed into the CaO⋅Al2O3 during the synthesized process on the microstructure and mechanical properties were studied. CaCO3 was obtained from snail shells, Al2O3, and Ti powders were employed as a raw material. A chemical system with a 1:1 M ratio between CaCO3 and Al2O3 was formed, with an addition of 10 wt% Ti metallic particles. The microstructural analysis through optical microscopy, scanning electron microscopy, and X-ray diffraction was realized. The apparent density was determined by the Archimedes method, and the mechanical behavior (hardness, fracture
toughness, and transversal elastic modulus) were also determined. XRD analysis revealed the formation of calcium aluminate phases such as CaAl2O4, CaAl4O7, and CaAl12O19; in addition, the CaTiO3 phase was also identified. The in-situ formation of CaTiO3 in the ceramic material, improves the mechanical properties such as the transversal elastic modulus and fracture toughness (48 GPa and 1.32 MPa m1/2, respectively) in comparison to the reference material (55 GPa and 0.43 MPa m1/2, respectively). Changes in the microstructural morphology, bulk density, and hardness values were also observed with a positive effect in the compound material
Emulación del sistema músculo-esqueletal y el control de movimiento en una plataforma experimental
Muchos fisiólogos han observado que el músculo
humano o animal es una especie de tejido elástico
(como un muelle) con componentes contráctiles,
los cuales dan una longitud de umbral modificable
neuralmente para el desarrollo de fuerzas.
La determinación de las fuerzas del músculo durante
el movimiento no es solamente esencial para
el análisis de las cargas internas que actúan en
los huesos y articulaciones, si no que también
contribuyen ha entender más profundamente los
controladores neuronales. Los sistemas de control
biológicos han sido estudiados como una posible
inspiración para la construción de controladores
de sistemas robóticos. En este trabajo,
se diseño e implemento un sistema biomecánico
que tiene propiedades mécanicas casi similares a
las de un brazo humano o animal. En este sistema
se implementaron modelos matemáticos del
músculo biológico, para la generación de fuerzas
en el músculo esqueletal total. Además, se desarrollo
una red cortical para el control de movimientos
voluntarios con restricciones neurofisiológicas
y psicofísicas motoras. El controlador neuronal
es propuesto para realizar el seguimiento de trajectorias
deseadas en la articulación de un simple
eslabón controlado por un par de actuadores
agonista-antagonista con propiedades musculares.
El sistema es capaz de ejecutar movimientos de
alcance voluntarios, con perfiles de velocidad en
forma de campana bajo perturbaciones. Los resultados
experimentales muestran que el sistema
presenta las propiedades básicas del músculoesqueletal
las cuales son las relaciones fuerza-longitud
y fuerza-velocidad. El controlador neuronal
permite controlar los movimientos deseados
y compesar las fuerzas externas.Se agradece el apoyo recibido por los miembros
del grupo de investigación de Neurotecnología,
Control y Robótica (NEUROCOR) del departamento
de Ingeniería de Sistemas y Automática de
la Universidad Politécnica de Cartagena. Este
trabajo fue financiado en parte por la CICYTTIC99-
0446-C02-01, y por el proyecto SYNERAGH
- BRE2-CT980797 BRITE EURAM- de
Investigación Básica
Genetic association study of dyslexia and ADHD candidate genes in a Spanish cohort: Implications of comorbid samples
Published: October 31, 2018Dyslexia and attention deficit hyperactivity disorder (ADHD) are two complex neuro-behaviorally disorders that co-occur more often than expected, so that reading disability has been linked to inattention symptoms. We examined 4 SNPs located on genes previously associated to dyslexia (KIAA0319, DCDC2, DYX1C1 and FOXP2) and 3 SNPs within genes related to ADHD (COMT, MAOA and DBH) in a cohort of Spanish children (N = 2078) that met the criteria of having one, both or none of these disorders (dyslexia and ADHD). We used a case-control approach comparing different groups of samples based on each individual diagnosis. In addition, we also performed a quantitative trait analysis with psychometric measures on the general population (N = 3357). The results indicated that the significance values for some markers change depending on the phenotypic groups compared and/or when considering pair-wise marker interactions. Furthermore, our quantitative trait study showed significant genetic associations with specific cognitive processes. These outcomes advocate the importance of establishing rigorous and homogeneous criteria for the diagnosis of cognitive disorders, as well as the relevance of considering cognitive endophenotypes.The work of MSM and MC was supported by CONSOLIDER-Ingenio- 2010_COEDUCA (CSD2008-00048). AMA, LB and AG-L’s work was supported by the Basque Department of Industry, Tourism and Trade
(Etortek Program), Innovation Technology Department of Bizkaia and CIBERehd Network. MC was also supported by grants (PSI2015-67353-R), and Ayuda Centro de Excelencia Severo Ochoa SEV-2015-0490 from the MINECO, and by grant (ERC-2011-ADG-295362) from the European Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Experimental study of subwavelength grating bimodal waveguides as ultrasensitive interferometric sensors
[EN] Over the recent years, subwavelength grating (SWG) structures have increasingly attracted attention in the area of evanescent-field photonic sensors. In this Letter, for the first time
to the best of our knowledge, we demonstrate experimentally
the real-time refractive index (RI) sensing using the SWG
bimodal interferometric structures. Two different configurations are considered to compare the effect of the nonlinear
phase shift, obtained between the two first transverse electromagnetic propagating modes, in the measured bulk sensitivity. Very high experimental values up to 2270 nm/RIU are
reached, which perfectly match the numerical simulations
and significantly enhance other existing SWG and spectralbased sensors. By measuring the spectral shift, the obtained
experimental sensitivity does not depend on the sensor
length. As a result, a highly sensitive and compact singlechannel interferometer is experimentally validated for refractive index sensing, thus opening new paths in the field of
optical integrated sensors.European Commission (PHC-634013 PHOCNOSIS project); Spanish Government (TEC2015-63838-C3-1-R-OPTONANOSENS project); Universitat Politecnica de Valencia (grant PAID 01-18).Torrijos-Morán, L.; Griol Barres, A.; García-Rupérez, J. (2019). Experimental study of subwavelength grating bimodal waveguides as ultrasensitive interferometric sensors. Optics Letters. 44(19):4702-4705. https://doi.org/10.1364/OL.44.004702S470247054419Cheben, P., Xu, D.-X., Janz, S., & Densmore, A. (2006). Subwavelength waveguide grating for mode conversion and light coupling in integrated optics. Optics Express, 14(11), 4695. doi:10.1364/oe.14.004695Schmid, J. H., Cheben, P., Janz, S., Lapointe, J., Post, E., & Xu, D.-X. (2007). Gradient-index antireflective subwavelength structures for planar waveguide facets. Optics Letters, 32(13), 1794. doi:10.1364/ol.32.001794Bock, P. J., Cheben, P., Schmid, J. H., Lapointe, J., Delâge, A., Janz, S., … Hall, T. J. (2010). Subwavelength grating periodic structures in silicon-on-insulator: a new type of microphotonic waveguide. Optics Express, 18(19), 20251. doi:10.1364/oe.18.020251Halir, R., Bock, P. J., Cheben, P., Ortega‐Moñux, A., Alonso‐Ramos, C., Schmid, J. H., … Janz, S. (2014). Waveguide sub‐wavelength structures: a review of principles and applications. Laser & Photonics Reviews, 9(1), 25-49. doi:10.1002/lpor.201400083Cheben, P., Halir, R., Schmid, J. H., Atwater, H. A., & Smith, D. R. (2018). Subwavelength integrated photonics. Nature, 560(7720), 565-572. doi:10.1038/s41586-018-0421-7Gonzalo Wangüemert-Pérez, J., Cheben, P., Ortega-Moñux, A., Alonso-Ramos, C., Pérez-Galacho, D., Halir, R., … Schmid, J. H. (2014). Evanescent field waveguide sensing with subwavelength grating structures in silicon-on-insulator. Optics Letters, 39(15), 4442. doi:10.1364/ol.39.004442Donzella, V., Sherwali, A., Flueckiger, J., Grist, S. M., Fard, S. T., & Chrostowski, L. (2015). Design and fabrication of SOI micro-ring resonators based on sub-wavelength grating waveguides. Optics Express, 23(4), 4791. doi:10.1364/oe.23.004791Flueckiger, J., Schmidt, S., Donzella, V., Sherwali, A., Ratner, D. M., Chrostowski, L., & Cheung, K. C. (2016). Sub-wavelength grating for enhanced ring resonator biosensor. Optics Express, 24(14), 15672. doi:10.1364/oe.24.015672Yan, H., Huang, L., Xu, X., Chakravarty, S., Tang, N., Tian, H., & Chen, R. T. (2016). Unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating waveguides. Optics Express, 24(26), 29724. doi:10.1364/oe.24.029724Huang, L., Yan, H., Xu, X., Chakravarty, S., Tang, N., Tian, H., & Chen, R. T. (2017). Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators. Optics Express, 25(9), 10527. doi:10.1364/oe.25.010527Benedikovic, D., Berciano, M., Alonso-Ramos, C., Le Roux, X., Cassan, E., Marris-Morini, D., & Vivien, L. (2017). Dispersion control of silicon nanophotonic waveguides using sub-wavelength grating metamaterials in near- and mid-IR wavelengths. Optics Express, 25(16), 19468. doi:10.1364/oe.25.019468Halir, R., Cheben, P., Luque‐González, J. M., Sarmiento‐Merenguel, J. D., Schmid, J. H., Wangüemert‐Pérez, G., … Molina‐Fernández, Í. (2016). Ultra‐broadband nanophotonic beamsplitter using an anisotropic sub‐wavelength metamaterial. Laser & Photonics Reviews, 10(6), 1039-1046. doi:10.1002/lpor.201600213Luque-González, J. M., Herrero-Bermello, A., Ortega-Moñux, A., Molina-Fernández, Í., Velasco, A. V., Cheben, P., … Halir, R. (2018). Tilted subwavelength gratings: controlling anisotropy in metamaterial nanophotonic waveguides. Optics Letters, 43(19), 4691. doi:10.1364/ol.43.004691Jahani, S., Kim, S., Atkinson, J., Wirth, J. C., Kalhor, F., Noman, A. A., … Jacob, Z. (2018). Controlling evanescent waves using silicon photonic all-dielectric metamaterials for dense integration. Nature Communications, 9(1). doi:10.1038/s41467-018-04276-8Torrijos-Morán, L., & García-Rupérez, J. (2019). Single-channel bimodal interferometric sensor using subwavelength structures. Optics Express, 27(6), 8168. doi:10.1364/oe.27.008168Levy, R., & Ruschin, S. (2009). Design of a Single-Channel Modal Interferometer Waveguide Sensor. IEEE Sensors Journal, 9(2), 146-1. doi:10.1109/jsen.2008.2011075Zinoviev, K. E., Gonzalez-Guerrero, A. B., Dominguez, C., & Lechuga, L. M. (2011). Integrated Bimodal Waveguide Interferometric Biosensor for Label-Free Analysis. Journal of Lightwave Technology, 29(13), 1926-1930. doi:10.1109/jlt.2011.2150734Kozma, P., Kehl, F., Ehrentreich-Förster, E., Stamm, C., & Bier, F. F. (2014). Integrated planar optical waveguide interferometer biosensors: A comparative review. Biosensors and Bioelectronics, 58, 287-307. doi:10.1016/j.bios.2014.02.049Levy, R., & Ruschin, S. (2008). Critical sensitivity in hetero-modal interferometric sensor using spectral interrogation. Optics Express, 16(25), 20516. doi:10.1364/oe.16.020516García-Rupérez, J., Toccafondo, V., Bañuls, M. J., Castelló, J. G., Griol, A., Peransi-Llopis, S., & Maquieira, Á. (2010). Label-free antibody detection using band edge fringes in SOI planar photonic crystal waveguides in the slow-light regime. Optics Express, 18(23), 24276. doi:10.1364/oe.18.024276Zhang, W., Serna, S., Le Roux, X., Vivien, L., & Cassan, E. (2016). Highly sensitive refractive index sensing by fast detuning the critical coupling condition of slot waveguide ring resonators. Optics Letters, 41(3), 532. doi:10.1364/ol.41.000532Di Falco, A., O’Faolain, L., & Krauss, T. F. (2009). Chemical sensing in slotted photonic crystal heterostructure cavities. Applied Physics Letters, 94(6), 063503. doi:10.1063/1.3079671Molina-Fernández, Í., Leuermann, J., Ortega-Moñux, A., Wangüemert-Pérez, J. G., & Halir, R. (2019). Fundamental limit of detection of photonic biosensors with coherent phase read-out. Optics Express, 27(9), 12616. doi:10.1364/oe.27.01261
Modernización de equipo feedback MS-150 para el aprendizaje activo en ingeniería de control
[Resumen] En este artículo se presenta el desarrollo e integración de elementos hardware para construir un sistema de adquisición de datos que permite modernizar el equipo didáctico Feedback MS-150 con el fin de ampliar su tiempo de vida y aumentar el alcance de los conceptos de control que se pueden explicar con él. El sistema de adquisición no supera los 100 €
DSL logística Arribazón 2019
Se ha procurado generar un vínculo con la comunidad nahua de la playa Ixtapilla, Michoacán, en el campamento tortuguero desde hace aproximadamente 4 años. Con el objetivo de superar la edición del año pasado, se planificó el festival arribazón del año en curso, con la finalidad de generar una mayor derrama económica en comparación con la del año pasado para poder cumplir los objetivos planteados en el campamento tortuguero punta Ixtal. En este semestre se replicaron todos los objetivos, los cuales resultaron exitosos y se replantearon nuevas estrategias para resolver aquello detalles que fallaron en la primera edición.ITESO, A.C
Constraining the dark energy equation of state with H ii galaxies
This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/mnras/stw1813We use the H II galaxies L–σ relation and the resulting Hubble expansion cosmological probe of a sample of just 25 high-z (up to z ∼ 2.33) H II galaxies, in a joint likelihood analysis with other well tested cosmological probes (cosmic microwave background, CMB, Baryon Acoustic Oscillations, BAOs) in an attempt to constrain the dark energy equation of state (EoS). The constraints, although still weak, are in excellent agreement with those of a similar joint analysis using the well established SNIa Hubble expansion probe. Interestingly, even with the current small number of available high redshift H II galaxies, the H II/BAO/CMB joint analysis gives a 13 per cent improvement of the quintessence dark energy cosmological constraints compared to the BAO/CMB joint analysis. We have further performed extensive Monte Carlo simulations, with a realistic redshift sampling, to explore the extent to which the use of the L–σ relation, observed in H II galaxies, can constrain effectively the parameter space of the dark energy EoS. The simulations predict substantial improvement in the constraints when increasing the sample of high-z H II galaxies to 500, a goal that can be achieved in reasonable observing times with existing large telescopes and state-of-the-art instrumentation.RC, RT, ET and MP are grateful to the Mexican research council (CONACYT) for supporting this research under studentship 224117 and grants 263561, CB-2005-01-49847, CB-2007-01-84746 and CB-2008-103365-F. SB acknowledges support by the Research Center for Astronomy of the Academy of Athens in the context of the programme ‘Tracing the Cosmic Acceleration’. MP acknowledges the hospitality of the KAVLI Institute for Cosmology in Cambridge, where this work was completed
Exploring the key drivers of riparian woodland successional pathways across three European river reaches
"This is the peer reviewed version of the following article: Muñoz-Mas, R., V. Garófano-Gómez, I. Andrés-Doménech, D. Corenblit, G. Egger, F. Francés, M.T. Ferreira, et al. 2017. ¿Exploring the Key Drivers of Riparian Woodland Successional Pathways across Three European River Reaches.¿ Ecohydrology 10 (8). Wiley: e1888. doi:10.1002/eco.1888, which has been published in final form at https://doi.org/10.1002/eco.1888. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Climate change and river regulation are negatively impacting riparian vegetation. To evaluate these impacts, process-based models are preferred over data-driven approaches. However, they require extensive knowledge about ecohydrological processes. To facilitate the implementation of such process-based models, the key drivers of riparian woodland successional pathways across three river reaches, in Austria, Portugal, and Spain, were explored, employing two complementary approaches. The principal component analyses highlighted the importance of the physical gradients determining the placement of the succession phases within the riparian and floodplain zones. The generalized additive models revealed that the initial and pioneer succession phases, characteristic of the colonization stage, appeared in areas highly morphodynamic, close in height and distance to the water table, and with coarse substrate, whereas elder phases within the transitional and mature stages showed incremental differences, occupying less dynamic areas with finer substrate. The Austrian site fitted well the current successional theory (elder phases appearing sequentially further up and distant), but at the Portuguese site, the tolerance of the riparian species to drought and flash flood events governed their placement. Finally, at the Spanish site, the patchy distribution of the elder phases was the remnants of formative events that reshaped the river channel. These results highlight the complex relationships between flow regime, channel morphology, and riparian vegetation. The use of succession phases, which rely on the sequential evolution of riparian vegetation as a response to different drivers, may be potentially better reproducible, within numerical process-based models, and transferable to other geographical regions.This work was supported by the IWRM Era-NET Funding Initiative through the RIPFLOW project (references ERACCT-2005-026025, ERA-IWRM/0001/2008, CGL2008-03076-E/BTE), http://www.old.iwrm-net.eu/spip.php, by the Spanish Ministry of Economy and Competitiveness through the project SCARCE (Consolider¿Ingenio 2010 CSD2009-00065), and by the project ¿Natural and anthropogenic changes in Mediterranean river drainage basins: historical impacts on rivers morphology, sedimentary flows and vegetation¿ of the Spanish MINECO (CGL2013-44917-R). Virginia Garófano-Gómez received a postdoctoral grant from the Université Blaise Pascal (now: Université Clermont Auvergne). Rui Rivaes benefited from a PhD grant (SFRH/BD/52515/2014) sponsored by Fundação para a Ciência e Tecnologia (FCT) under the FCT PhD programme FLUVIO¿River Restoration and Management. Patricia María Rodríguez González was funded by FCT through an SFRH/BPD/47140/2008 postdoctoral fellowship and through an FCT Investigator Programme grant (IF/00059/2015). The authors also thank all the colleagues and master students who contributed enthusiastically to the field campaigns of this study.Muñoz Mas, R.; Garófano-Gómez, V.; Andrés Doménech, I.; Corenblit, D.; Egger, G.; Francés, F.; Ferreira, M.... (2017). Exploring the key drivers of riparian woodland successional pathways across three European river reaches. Ecohydrology. 10(8):1-19. https://doi.org/10.1002/eco.1888S11910
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