Tunable Interferometers Driven by Coherent Surface Acoustic Phonons

[EN] We demonstrate a compact tunable photonic modulator driven by surface acoustic waves (SAWs) in the low GHz frequency range. The device follows a well-known Mach-Zehnder interferometer (MZI) structure with three output channels, built upon multi-mode interference (MMI) couplers. The light continuously switches paths between the central and the side channels, avoiding losses and granting a 180¿-dephasing synchronization between them. The modulator was monolithically fabricated on (Al,Ga)As, and can be used as a building block for more complex photonic functionalities. It can also be implemented in other material platforms such as Silicon or (In,Ga)P. Light modulated at multiples of the fundamental acoustic frequency can be accomplished by adjusting the applied acoustic power. An excellent agreement between theory and experiment is achievedCrespo-Poveda, A.; Hernández-Mínguez, A.; Biermann, K.; Tahraoui, A.; Gargallo-Jaquotot, B.; Muñoz, P.; Santos, P.... (2016). Tunable Interferometers Driven by Coherent Surface Acoustic Phonons. MRS Advances. 1651-1656. doi:10.1557/adv.2016.234S16511656Beck, M., de Lima, M. M., Wiebicke, E., Seidel, W., Hey, R., & Santos, P. V. (2007). Acousto-optical multiple interference switches. Applied Physics Letters, 91(6), 061118. doi:10.1063/1.2768889Soldano, L. B., & Pennings, E. C. M. (1995). Optical multi-mode interference devices based on self-imaging: principles and applications. Journal of Lightwave Technology, 13(4), 615-627. doi:10.1109/50.372474De Lima, M. M., Beck, M., Hey, R., & Santos, P. V. (2006). Compact Mach-Zehnder acousto-optic modulator. Applied Physics Letters, 89(12), 121104. doi:10.1063/1.2354411Crespo-Poveda, A., Hey, R., Biermann, K., Tahraoui, A., Santos, P. V., Gargallo, B., … de Lima, M. M. (2013). Synchronized photonic modulators driven by surface acoustic waves. Optics Express, 21(18), 21669. doi:10.1364/oe.21.021669Crespo-Poveda, A., Hernández-Mínguez, A., Gargallo, B., Biermann, K., Tahraoui, A., Santos, P. V., … de Lima, M. M. (2015). Acoustically driven arrayed waveguide grating. Optics Express, 23(16), 21213. doi:10.1364/oe.23.021213Sun, J., Timurdogan, E., Yaacobi, A., Hosseini, E. S., & Watts, M. R. (2013). Large-scale nanophotonic phased array. Nature, 493(7431), 195-199. doi:10.1038/nature1172

Reactivity of TpMe2-containing hydride-iridafurans with alkenes, alkynes, and H2

The TpMe2-containing hydride-iridafurans 2a,b (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) cleanly reacted with ethylene to give the bicyclic derivatives 6a,b. Formation of the latter complexes is a reversible process, and it is proposed to occur by an electrocyclic ring closure that takes place between C2H4 and the 16e unsaturated intermediates A, resulting from hydride migration to the α carbon of the metallacycle. Similar reactions were observed with a variety of alkynes RC≡CR (R = H, Ph, CO2Me) and R′C≡CH (R′= CO2Me, Ph, CMe3), with the regioselectivity observed for the latter substrates depending on the nature of R′. In the case of Me3SiC≡CH the structure of an unexpected byproduct indicates that an alkyne–vinylidene rearrangement has taken place on the metal coordination sphere during the reaction, and this observation suggests that in the mechanism of all these coupling processes the corresponding π adducts are active intermediates. Finally, complexes 2a,b reacted with H2 to give products derived from the hydrogenation of their alkenyl arms.Ministerio de Ciencia e Innovación CTQ2010-17476. Consolider Ingenio 2010 CSD 2007-0006Junta de Andalucía FQM-119, P09-FQM-483

ELABORACIÓN Y VALIDACIÓN DE UNA ESCALA PARA MEDIR EL MALTRATO EN PAREJAS (EMP)

La violencia íntima de parejas ha sido un fenómeno de reciente interés científico por sus consecuencias entre los miembros que la conforman, en su descendencia y en sus demás relaciones interpersonales. Su prevención y detección temprana son una prioridad académica y profesional. El presente estudio reporta la elaboración y validación de un nuevo instrumento para medir y revelar este fenómeno: la Escala de Maltrato en Parejas – EMP. En dos estudios sucesivos, se logró demostrar su validez y confiabilidad. En la primera versión (Piloto – Estudio 1), dirigida a parejas jóvenes [EMP(J)], era unidireccional en la detección del maltrato. En la segunda versión (Validación – Estudio 2), además de incluir la bidireccional del mismo, se agregó la medición del maltrato con el uso de medios virtuales (Tecnologías de Información y Comunicación – TICs, o Comunicación Mediada por Computadores – CMC). La versión final del EMP resultó tanto válida como confiable, además de identificar dos tipos diferentes de maltrato sexual: (1) por desvaloración y (2) por coacción. Se requiere continuar con procesos de validación concurrente con otros instrumentos que midan el fenómeno de la violencia en pareja, con variables similares en definición y contenido, al igual que con otros que midan procesos opuestos como las escalas que miden satisfacción en las relaciones interpersonales

Contribución al conocimiento de la flora de Andalucía: citas novedosas e interesantes de la provincia de Almería

Contribution to the knowledge about Andalusian flora: new and interesting cites of the Almería province.Palabras clave. Corología, Isla de Alborán, sureste ibérico, xenófitas.Key words. Corology, Alborán Island, South-Eastern Iberian Peninsula, xenophytes

Role of the 4Kscore test as a predictor of reclassification in prostate cancer active surveillance

Background: Management of active surveillance (AS) in low-risk prostate cancer (PCa) patients could be improved with new biomarkers, such as the 4Kscore test. We analyze its ability to predict tumor reclassification by upgrading at the confirmatory biopsy at 6 months. Methods: Observational, prospective, blinded, and non-randomized study, within the Spanish National Registry on AS (AEU/PIEM/2014/0001; NCT02865330) with 181 patients included after initial Bx and inclusion criteria: PSA =10 ng/mL, cT1c-T2a, Grade group 1, =2 cores, and =5 mm/50% length core involved. Central pathological review of initial and confirmatory Bx was performed on all biopsy specimens. Plasma was collected 6 months after initial Bx and just before confirmatory Bx to determine 4Kscore result. In order to predict reclassification defined as Grade group =2, we analyzed 4Kscore, percent free to total (%f/t) PSA ratio, prostate volume, PSA density, family history, body mass index, initial Bx, total cores, initial Bx positive cores, initial Bx % of positive cores, initial Bx maximum cancer core length and initial Bx cancer % involvement. Wilcoxon rank-sum test, non-parametric trend test or Fisher’s exact test, as appropriate established differences between groups of reclassification. Results: A total of 137 patients met inclusion criteria. Eighteen patients (13.1%) were reclassified at confirmatory Bx. The %f/t PSA ratio and 4Kscore showed differences between the groups of reclassification (Yes/No). Using 7.5% as cutoff for the 4Kscore, we found a sensitivity of 89% and a specificity of 29%, with no reclassifications to Grade group 3 for patients with 4Kscore below 7.5% and 2 (6%) missed Grade group 2 reclassified patients. Using this threshold value there is a biopsy reduction of 27%. Additionally, 4Kscore was also associated with changes in tumor volume. Conclusions: Our preliminary findings suggest that the 4Kscore may be a useful tool in the decision-making process to perform a confirmatory Bx in active surveillance management

A catalogue of young runaway Hipparcos stars within 3kpc from the Sun

Traditionally runaway stars are O and B type stars with large peculiar velocities.We want to extend this definition to young stars (up to ~50 Myr) of any spectral type and identify those present in the Hipparcos catalogue applying different selection criteria such as peculiar space velocities or peculiar one-dimensional velocities. Runaway stars are important to study the evolution of multiple star systems or star clusters as well as to identify origins of neutron stars. We compile distances, proper motions, spectral types, luminosity classes, V magnitudes and B-V colours and utilise evolutionary models from different authors to obtain star ages and study a sample of 7663 young Hipparcos stars within 3 kpc from the Sun. Radial velocities are obtained from the literature. We investigate the distributions of the peculiar spatial velocity, the peculiar radial velocity as well as the peculiar tangential velocity and its one-dimensional components and obtain runaway star probabilities for each star in the sample. In addition, we look for stars that are situated outside any OB association or OB cluster and the Galactic plane as well as stars of which the velocity vector points away from the median velocity vector of neighbouring stars or the surrounding local OB association/ cluster although the absolute velocity might be small. We find a total of 2547 runaway star candidates (with a contamination of normal Population I stars of 20 per cent at most). Thus, after subtraction of those 20 per cent, the runaway frequency among young stars is about 27 per cent. We compile a catalogue of runaway stars which will be available via VizieR.Comment: 12 pages, 8 figures, 7 tables, accepted for publication in MNRAS old version replaced due to change of the title after journal proof-readin

Frame Theory for Signal Processing in Psychoacoustics

This review chapter aims to strengthen the link between frame theory and signal processing tasks in psychoacoustics. On the one side, the basic concepts of frame theory are presented and some proofs are provided to explain those concepts in some detail. The goal is to reveal to hearing scientists how this mathematical theory could be relevant for their research. In particular, we focus on frame theory in a filter bank approach, which is probably the most relevant view-point for audio signal processing. On the other side, basic psychoacoustic concepts are presented to stimulate mathematicians to apply their knowledge in this field