In-Fiber All-Optical Fractional Differentiator Using an Asymmetrical Moiré Fiber Grating

In this work, it is demonstrated numerically that an asymmetric Moiré fiber grating operated in reflection can provide the required spectral response to implement an all-optical fractional differentiator. In our case, the accumulated phase shift is not associated with a point phase shift, as when working with fiber Bragg gratings and long-period gratings with punctual defects, but is distributed all over the grating. The proposed device is supported by numerical simulations, and a dimensionless deviation factor is calculated to make quantitative analysis feasible. The performance of the proposed device is analyzed using numerical simulations by computing the fractional time derivatives of the complex field of an arbitrary transform-limited Gaussian pulse. A comparison with the performance given by theoretical differentiation is also presented

El papel del project manager en el desarrollo de proyectos universitarios multidisciplinares: Aplicación de Métrica 3 al Proyecto SIVIT

El Proyecto SIVIT tiene como objetivo el desarrollo de un sistema de información destinado a orientar a los usuarios en el territorio mediante un entorno de realidad virtual, y constituye un proyecto de innovación de gran envergadura en el ámbito de las TIC. Para su ejecución, se ha constituido un equipo multidisciplinar formado por grupos de investigación de tres Escuelas de Ingeniería de la UPM, distribuyéndose el trabajo según sus diferentes áreas de conocimiento. En este contexto, la figura del Project Manager es fundamental dada la gran amplitud del Proyecto y el hecho de que esté constituido por subproyectos de características específicas. Esto exige emplear una metodología flexible, que permita su adaptación a cada subproyecto mediante planificaciones interdependientes, por lo que se ha adoptado la metodología METRICA 3, desarrollada por el Ministerio de Administraciones Públicas. Se complementa esta metodología con el uso de herramientas comerciales de mapeado de la información (mapas mentales), así como de comunicación y colaboración (servidores de información). Igualmente, se integra en la planificación la aplicación del método de gestión del valor ganado (Earned Value Method) para una mayor eficiencia de cara a futuros proyectos en esta línea de investigació

Resonant couplings in U shaped fibers for biosensing

U-shaped tight curvatures in optical fibers lead to resonant couplings between the fundamental and higher order modes that are sensible to different parameters, such as strain or temperature, for example. The optical response of the sensor consists on the shift of the resonant wavelength of the coupling. In the case of singlemode fibers, the coupling involves a so-called 'cladding mode' and, due to its evanescent field, the curved region will be sensible to changes in the external medium, as well. In this paper, we present the fabrication and characterization of a robust, easy-to-make, U-shaped fiber sensor based on singlemode telecom fiber and its application for biosensing. The resonant nature of the sensingmechanism presents the advantage of large dynamic ranges for RI variations without the ambiguity of other techniques such as interferometry. We studied the performance of the U-shaped fiber sensor for different bending radii, to optimize its sensitivity and detection limit at 1550 nm operation wavelength, as well as the effect of temperature on its response. The shift of the resonant wavelength was measured in detail as a function of the external RI within the range [1.33-1,37]; the detection limit was established in (2.88 ± 0.03) × 10−5 RIU. Furthermore, the device was successfully tested as a proof of concept biosensor, using a system model antigen-antibody (BSA-aBSA)

Variability in the extreme helium star LSS 5121

We report a photometric and spectroscopic study of the hot extreme helium star LSS 5121. We found photometric variability, but no period was evident in its periodogram. This is consistent with the previous proposal, based on spectral line variations, that LSS 5121 is a non-radial pulsator similar to other hot extreme helium stars.Comment: 5 pages, 6 figure

Capacidad de realizar esprints repetidos en jugadores profesionales de fútbol vs. Fútbol sala

Objetivo: Investigar los cambios producidos ante acciones de esprines repetidos (20+20 metros con cambio de dirección ), el CMJ, la respuesta metabólica (lactato) , y la relación entre estas variables y la fuerza y resistencia en jugadores profesionales de fútbol y fútbol sala. Métodos: Jugadores profesionales (n=30, doce de fútbol sala y veinte de fútbol) completaron tres sesiones de evaluación; VO2max en tapiz rodante, el salto CMJ y la RM en sentadilla completa y finalmente, se realizó el test de RSA (6 x 40 (20+20)). Resultados: Se obtuvieron valores similares de fuerza en sentadilla, en CMJ, de LAC después de la prueba RSA y de VO2max ( 95,12 kg vs 94,73 kg ; 34,5 cm vs 35,9 cm ; 13,65 mmol vs 14,33 mmol ; 62,78 ml·kg·min-1 vs . 62,95 ml·kg·min-1 fútbol vs. fútbol sala, respectivamente). Se obtuvieron diferencias significativas cuando se analizó la pérdida de rendimiento en velocidad (total y entre los tres primeros y tres últimos bloques de esprines) y en salto (2,67% vs 4,4%**; 1,28% vs 2,1%*; 2,88% vs 6,1%**; 9,71% vs 14,3%* de fútbol vs. fútbol sala, respectivamente). Conclusiones: Ambos deportes presentan diferencias significativas en las pérdidas de rendimiento en velocidad y salto a pesar de tener valores similares de fuerza, de VO2max, de lactato tras RSA y de CMJ. Podría atribuirse a los esfuerzos propios de cada deporte y puede sugerir que debería incrementarse el volumen de entrenamiento orientado a la capacidad de realizar esfuerzos repetidos frente a otro tipo de objetivo como la mejora de la capacidad aeróbica, sobre todo a nivel profesional.To investigate the changes through repeated explosive effort sequences (20+20-m sprint with change of direction), jumping, metabolic response (lactate), as well as the relationship between these variables and fitness qualities (strength and endurance) in professional futsal and soccer players. Methods: Male players (n =30, Twelve futsal and twenty soccer players) completed three testing sessions. In the first session was measured VO2max on a motorized treadmill. In the second session was measured counter movement jump (CMJ) and full squat RM in Smith Machine. Finally, in the third session six repeated-explosive effort sequences (RES) was performed. Results: Similar values of lower limbs strength, CMJ height, LAC after RSA test and VO2max (95,12 vs. 94,73; 34,5 vs. 35,9; 13,65 vs. 14,33; 62,78 vs. 62,95 soccer vs. futsal respectively) and significant differences when are analysed the loss of performance in velocity (total and between three first and three last) and vertical jump height (2,67 vs. 4,4**; 1,28 vs. 2,1*; 2,88 vs. 6,1**; 9,71 vs. 14,3* soccer vs. futsal respectively). Conclusions: Professional futsal and soccer obtain significant differences in speed and vertical jump height (CMJ) loss despite having similar values in squat, oxygen consumption, lactate after RSA test and CMJ height. Issue that could be attributed to the characteristics of the sport. This suggests that the volume should be increased oriented ability to perform repeated sprint actions over other type of training aimed at improving aerobic capacity especially at professional level.peerReviewe

Long- and short-term stability of all polarization-maintaining thulium doped passively mode-locked fiber lasers with emission wavelengths at 1.95 µm and 2.07 µm

In this work, we compare the operation of a passively modelocked polarization-maintaining emission in two thulium-doped fiber lasers pumped at 1561 nm, with emission at wavelengths of 1.951 μm in one case and 2.07 μm in the other. We obtained a sequence of light pulses at 15.6 MHz, whose temporal width was 81 ps at 1.95 μm, and a sequence of light pulses at 13.1 MHz, whose tempo- ral width was 94 ps at 2.07 μm. Finally, we also measured the long-term stability of this setup during a 24-h operation, as well as the short-term stability in a simulated harsh environment. The results confirm the superior performance of fiber laser systems with a fully polarization-maintaining design

Passively Modelocked All-PM Thulium-Doped Fiber Laser at 2.07 μm

Here we present a self-started passively mode-locked thulium-doped fiber laser with in-band pumping at 1561 nm that fully retains polarization and emits beyond 2 μm. We obtained a sequence of light pulses at 13.084 MHz, where the pulse and spectral widths were 94 ps and 70 pm, respectively, at 2069.5 nm. The measured instantaneous angular frequency shows that these light pulses are chirp-free

Pharmacology and clinical drug candidates in redox medicine

SIGNIFICANCE Oxidative stress is suggested to be a disease mechanism common to a wide range of disorders affecting human health. However, so far, the pharmacotherapeutic exploitation of this, for example, based on chemical scavenging of pro-oxidant molecules, has been unsuccessful. Recent Advances: An alternative emerging approach is to target the enzymatic sources of disease-relevant oxidative stress. Several such enzymes and isoforms have been identified and linked to different pathologies. For some targets, the respective pharmacology is quite advanced, that is, up to late-stage clinical development or even on the market; for others, drugs are already in clinical use, although not for indications based on oxidative stress, and repurposing seems to be a viable option. CRITICAL ISSUES For all other targets, reliable preclinical validation and drug ability are key factors for any translation into the clinic. In this study, specific pharmacological agents with optimal pharmacokinetic profiles are still lacking. Moreover, these enzymes also serve largely unknown physiological functions and their inhibition may lead to unwanted side effects. FUTURE DIRECTIONS The current promising data based on new targets, drugs, and drug repurposing are mainly a result of academic efforts. With the availability of optimized compounds and coordinated efforts from academia and industry scientists, unambiguous validation and translation into proof-of-principle studies seem achievable in the very near future, possibly leading towards a new era of redox medicine

Identification of microbially induced sedimentary structures over a tidal flat

The influence of microbial activity in carbonatic environments leading to stromatolite build-ups is widely known. In siliciclastic environments, however, this influence has been far less studied. The present study was carried out in this type of environment and determined the importance of cyanobacterias in the preservation of sedimentary structures. Similar sedimentary structures were also recognized in the rock record by other studies. Therefore, if we know the environment of formation and conservation of such structures, then the paleoenvironment of the rock could be inferred. In the tidal flats of the Bahía Blanca Estuary, microbial mats were identified. Their interaction with sediments, lead to a stabilized flat by shielding from erosion the existing sedimentary structures. Since it is the first time these structures are mentioned in a present-day environment in Argentina, a detailed description of the bio-sedimentological interaction is presented and our results compared with others from different climatic zones, namely, temperate humid and subtropical arid. Finally the occurrence of zeolites, an authigenic mineral, indicated that the sediment would be in the early stages of diagenesis

All Polarization-maintaining Passively Mode-locked Ytterbium-doped Fiber Lasers, Behavior under Two Different Cavity Configurations

In this work, we review our recent investigations on the behavior of a polarization-maintaining passively mode-locked ytterbium-doped laser in two different cavity configurations, namely: fiber-ring (FR) and Fabry-Perot (FP). Opposed to standard configurations that rely on the use of strong filtering within the cavity by including an ad hoc component with this purpose, here the filtering action is solely performed by the spectral overlapping of the different components within the fiber lasers. We found that the lack of a specific filter within the cavity does not deteriorate the performance as compared with previous works. We also report the changes in the output light pulses when the net dispersion of the cavity was varied. Additionally, different lengths of an ad hoc anomalous polarization-maintaining (PM) photonic crystal fiber (PCF) were used as intracavity dispersion compensator, to shift the operation of the laser from net-normal to the net-anomalous regime. The shortest output light pulses [6 ps (FR) and 8 ps (FP)] were obtained when the net-cavity dispersion approached zero. Since the obtained light pulses were far to be transform-limited, we also discuss the possibility of out-of-cavity recompression by using the same PM-PCF mentioned above. After recompression, pulse widths of 3 ps were obtained, limited by the available length of PM PCF