Resonance energy transfer and superradiance mediated by plasmonic nanowaveguides

We show how both the subwavelength confinement associated with surface plasmons and the one-dimensional character of plasmonic waveguides can be exploited to enhance the coupling between quantum emitters. Resonance energy transfer and the phenomenon of superradiance are investigated in three different waveguiding schemes (wires, wedges, and channels) by means of the Finite Element Method. We also develop a simplified model that is able to capture the main features of the numerical results. © 2010 American Chemical Societ

Diversidad ortopterológica de la Reserva Territorial Sureste de la Ciudad Universitaria (UNAM)

El crecimiento constante de la población humana hace que la mancha urbana extienda sus límites hacia las reservas ecológicasreduciendo el tamaño de éstas, generando importantes efectos deborde que acentúan la fragmentación del paisaje y que potencializan la pérdida de continuidad de la cubierta vegetal.Las reservas ecológicas, así como las áreas verdes urbanas (representadaspor parques y jardines) son hábitats relictuales para una grandiversidad de especies que sobreviven dentro de la matriz urbana. La Reserva Ecológica del Pedregal de San Ángel de Ciudad Universitaria (REPSA-CU) es la más importante en el suroeste del Distrito Federal debido a que abarca 237.3 hectáreas y en ella se conservan 377 especies de plantas vasculares, 180 especies de vertebrados nativos y por lo menos 817 especies de artrópodos, de las cuales 26 son ortópteros con una importante posición dentro de la cadena trófica y son determinantes del funcionamiento del ecosistema. Los objetivos de este trabajo fueron: 1. Conocer las especies de ortópteros presentes en la Reserva Territorial Sureste de la Ciudad Universitaria de la Universidad Nacional Autónoma de México (RTSE), mediante la elaboración de un inventario biológico; 2. Comparar los atributos de la comunidad ortopterológica (abundancia, diversidad; así como la densidad de individuos) que habitan en la RTSE en relación con los ortópteros de la Zona Núcleo Suroriente (ZNSO) de la REPSACU y finalmente, 3. Discutir sobre el valor ambiental de la RTSE como Zona de Amortiguamiento Ambiental para la REPSA-CU. La abundancia relativa por especie no varió significativamente entre la RTSE y la zona núcleo revisada. En la RTSE se encontraron cinco especies de ortópteros, la especie que registró mayor abundancia fue Sphenarium purpurascens purpurascens Charpentier, 1842 (Pyrgomorphidae) seguida en orden de importancia por Phoetaliotes nebrascensis (Thomas, 1872) (Acrididae). Destaca la presencia de Conocephalus (Xiphidion) ictus (Scudder, 1875) (Tettigoniidae) como un nuevo registro taxonómico para la zona. Se discute que la RTSE difiere en cuanto a diversidad ortopterológica con la ZNSO de la REPSA-CU y argumentamos su importancia para la conservación de vida silvestre; así como la importancia que poseen los ortópteros de acuerdo con su posición en la cadena trófica para el funcionamiento del ecosistema.

The host of the Type I SLSN 2017egm: A young, sub-solar metallicity environment in a massive spiral galaxy

Here we present an integral-field study of the massive, high-metallicity spiral NGC 3191, the host of SN 2017egm, the closest SLSN Type I to date. We use data from PMAS/CAHA and the public MaNGA survey to shed light on the properties of the SLSN site and the origin of star-formation in this non-starburst spiral galaxy. We map the physical properties different \ion{H}{II} regions throughout the galaxy and characterize their stellar populations using the STARLIGHT fitting code. Kinematical information allows to study a possible interaction with its neighbouring galaxy as the origin of recent star formation activity which could have caused the SLSN. NGC 3191 shows intense star-formation in the western part with three large SF regions of low metallicity. The central regions of the host have a higher metallicity, lower specific star-formation rate and lower ionization. Modeling the stellar populations gives a different picture: The SLSN region has two dominant stellar populations with different ages, the youngest one with an age of 2-10 Myr and lower metallicity, likely the population from which the SN progenitor originated. Emission line kinematics of NGC 3191 show indications of interaction with its neighbour MCG+08-19-017 at $\sim$45 kpc, which might be responsible for the recent starburst. In fact, this galaxy pair has in total hosted 4 SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl (SLSN-Type II) and 2017egm, underlying the enhanced SF in both galaxies due to interaction. Our study shows that one has to be careful interpreting global host and even gas properties without looking at the stellar population history of the region. SLSNe seem to still be consistent with massive stars ($>$ 20 M$_\odot$) requiring low ($< 0.6Z_{\odot}$) metallicity and those environments can also occur in massive, late-type galaxies but not necessarily starbursts.Comment: Accepted for publication in A&A, 13 pages, 11 figures, 7 tables. Abstract has been reduced to match arXiv form requirement

Habitat association of Orthoptera in El Cimatario National Park, Querétaro, México

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Directional Coupler Calibration for Accurate Online Incident Power Measurements

© 2021 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] This letter proposes a calibration method to properly measure the incident power in a directional coupler (DC) when the measurement configuration has low directivity. The proposed method is based on measurements of short-circuits placed at different distances to calibrate the DC response. Results show that the method is clearly robust and provides accurate measurements even for directivities as low as 10 dB.This work was supported by the European Regional Development Fund (ERDF) through the Valencia Region 2014-2020 Operational Program under Project IDIFEDER/2018/027.Penaranda-Foix, FL.; Catalá Civera, JM.; Gutiérrez Cano, JD.; García-Baños, B. (2021). Directional Coupler Calibration for Accurate Online Incident Power Measurements. IEEE Microwave and Wireless Components Letters. 31(6):624-627. https://doi.org/10.1109/LMWC.2021.3070788S62462731

Dissipation-driven generation of two-qubit entanglement mediated by plasmonic waveguides

We study the generation of entanglement between two distant qubits mediated by the surface plasmons of a metallic waveguide. We show that a V-shaped channel milled in a flat metallic surface is much more efficient for this purpose than a metallic cylinder. The role of the misalignments of the dipole moments of the qubits, an aspect of great importance for experimental implementations, is also studied. A careful analysis of the quantum-dynamics of the system by means of a master equation shows that two-qubit entanglement generation is essentially due to the dissipative part of the effective qubit-qubit coupling provided by the surface plasmons. The influence of a coherent external pumping, needed to achieve a steady state entanglement, is discussed. Finally, we pay attention to the question of how to get information experimentally on the degree of entanglement achieved in the system.Comment: 13 pages, 12 figure

Enhanced Full-Wave Circuit Analysis for Modeling of a Split Cylinder Resonator

[EN] An enhanced full-wave method based on circuit analysis is presented in this paper, where the whole set of modes TEmnp and TMmnp are taken into account. The modeling of a split cylinder resonator is done with two circuit networks of one and three ports, characterized by their generalized admittance matrix, which is computed making use of the mode matching method. The improved full-wave circuit method has been applied to the accurate determination of dielectric properties of materials. The proposed method has been validated through comparisons with other published models and also with measurements.This work was supported in part by the Ministerio de Economia y Competitividad-Spanish Government and in part by the European Regional Development Funds of European Union under Project SEDMICRON - TEC2015-70272-R (MINECO/FEDER). The work of D. Marqucs-Villarroya was supported by the Universitat Politccnica de Valencia through the Programa para la formacion de personal investigador de la UPV. The work of F.L. Penarada-Foix was supported by the Conselleria de Educacion of the Generalitat Valenciana (BEST/2016/012).Marqués-Villarroya, D.; Penaranda-Foix, FL.; García-Baños, B.; Catalá Civera, JM.; Gutiérrez Cano, JD. (2017). Enhanced Full-Wave Circuit Analysis for Modeling of a Split Cylinder Resonator. IEEE Transactions on Microwave Theory and Techniques. 65(4):1191-1202. https://doi.org/10.1109/TMTT.2016.2637932S1191120265

The short and long-term effects of aerobic, strength, or mixed exercise programs on schizophrenia symptomatology

The purpose of this study was to compare the effects of three different physical exercise programs on the symptomatology, body composition, physical activity, physical fitness, and quality of life of individuals with schizophrenia. A total of 432 patients were assessed for eligibility and 86 were randomized into the aerobic (n = 28), strength (n = 29) or mixed (n = 29) groups. Positive, negative, and general symptoms of psychosis, body mass index (BMI), physical activity (IPAQ-SF), physical fitness (6-min walk test [6MWT] and hand-grip strength [HGS]), and quality of life (WHOQUOL-BREF) were assessed at baseline, post-intervention (16 weeks), and at 10-months. Our results at 16 weeks showed significant improvements in all three groups in the negative, general, and total symptoms with moderate to large effect sizes (P &lt; 0.01, ¿p2 &gt; 0.11), no change in the BMI, 6MWT or IPAQ-SF, and a significant improvement in the HGS test in the strength and mixed groups (P = 0.05, ¿p2 &gt; 0.08). Nonetheless, all the improvements had disappeared at 10 months. We concluded that 3 weekly sessions of a moderate to vigorous progressive exercise program for 16 weeks improved the symptomatology of individuals with schizophrenia in all three groups, with no differences between them. However, the effects had declined to baseline levels by the 10-month follow-up, suggesting that exercise interventions should be maintained over time. © 2021, The Author(s)

Combining SfM Photogrammetry and Terrestrial Laser Scanning to Assess Event-Scale Sediment Budgets along a Gravel-Bed Ephemeral Stream

[EN] Stream power represents the rate of energy expenditure along a stream reach and can be calculated using topographic data acquired via structure-from-motion (SfM) photogrammetry and terrestrial laser scanning (TLS). This study sought to quantitatively relate morphological adjustments in the Azohia Rambla, a gravel-bed ephemeral stream in southeastern Spain, to stream power (omega), critical power (omega(c)), and energy gradients ( partial differential omega/ partial differential s), along different reference channel reaches of 200 to 300 m in length. High-resolution digital terrain models (HRDTMs), combined with ortophotographs and point clouds from 2018, 2019, and 2020, and ground-based surveys, were used to estimate the spatial variability of morphological sediment budgets and to assess channel bed mobility during the study period at different spatial scales: reference channel reaches (RCRs), pilot bed survey areas (PBSAs), and representative geomorphic units (RGUs). The optimized complementary role of the SfM technique and terrestrial laser scanning allowed the generation of accurate and reliable HRDTMs, upon which a 1-D hydrodynamic model was calibrated and sediment budgets calculated. The resulting high-resolution maps allowed a spatially explicit analysis of stream power and transport efficiency in relation to volumes of erosion and deposition in the RCR and PBSA. In addition, net incision or downcutting and vertical sedimentary accretion were monitored for each flood event in relation to bedforms and hydraulic variables. Sediment sources and sinks and bed armoring processes showed different trends according to the critical energy and stream power gradient, which were verified from field observations. During flows exceeding bankfull discharges (between 18 and 24 m(3) s(-1) according to channel reach), significant variations in partial differential omega/ partial differential s values and omega/omega(c) ratios (e.g., -15 2 for a peak discharge of 31 m(3) s(-1)) were associated with a large amount of bedload mobilized upstream and vertical accretion along the middle reach (average rise height of 0.20 to 0.35 m for the same event). By contrast, more moderate peak flows (<= 10 m(3) s(-1)) only produced minor changes resulting in surface washing, selective transport, and local bed scouring.This research was funded by ERDF/Spanish Ministry of Science, Innovation and Universities-State Research Agency/Project CGL2017-84625-C2-1-R (CCAMICEM); State Program for Research, Development and Innovation Focused on the Challenges of Society, the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2017-85244-C2-1-P and by the University of Alicante (vigrob-157 and GRE18-05).Conesa-García, C.; Puig-Mengual, C.; Riquelme, A.; Tomás, R.; Martinez-Capel, F.; García-Lorenzo, R.; Pastor, JL.... (2020). Combining SfM Photogrammetry and Terrestrial Laser Scanning to Assess Event-Scale Sediment Budgets along a Gravel-Bed Ephemeral Stream. Remote Sensing. 12(21):1-27. https://doi.org/10.3390/rs12213624S127122