How to automate a kinematic mount using a 3D printed Arduino-based system

We demonstrate a simple, flexible and cost-effective system to automatize most of the kinematic mounts available nowadays on the market. It combines 3D printed components, an Arduino board, stepper motors, and simple electronics. The system developed can control independently and simultaneously up to ten stepper motors using commands sent through the serial port, and it is suitable for applications where optical realignment using flat mirrors is required on a periodic basis.Comment: 9 pages, 8 figure

Water-Soluble Pd-Imidate Complexes as Versatile Catalysts for the Modification of Unprotected Halonucleosides

Modification of unprotected nucleosides has been attracting continuous interest, since these building blocks themselves and their phosphate-upgraded corresponding nucleotides have shown a plethora of uses in fields like biochemistry or pharmacy. Pd-catalyzed cross-coupling reactions, conducted in water or its mixtures with polar organic solvents, have frequently been the researchers' choice for the functionalization of the purine/pyrimidine base of the unprotected nucleosides. In this scenario, the availability of hydrophilic ligands and its water-soluble palladium complexes has markedly set the pace of the advances. The approach of our group to the synthesis of such complexes, Pd-imidates specifically, has faced critical stages, namely the jump to synthesize water soluble complexes from our experience working in conventional solvents, the preparation of phosphine free complexes and the overall goal of getting catalytic systems able to work close to room temperature. The continuous feedback with Kapdi's group, experienced in the chemistry of nucleosides, has produced over the last decade the interesting results in both fields presented here.This work has been partially supported by RTI2018-098233-B−C21 and PID2021-124695OB-C21 (MICINN) and 20790/PI/18 (Fundación SENECA CARM) grants. The Author wishes to thank the many students who have contributed to the chemistry described in this article, as well as the colleagues and supervisors from Universidad de Murcia, University of Sussex, Inorganic Chemistry Laboratory-University of Oxford, University of York, and Institute of Chemical Technology-Mumbai for his contribution to this work and his wise and continuous advice and support

Optical sectioning in induced coherence tomography with frequency-entangled photons

We demonstrate a different scheme to perform optical sectioning of a sample based on the concept of induced coherence [Zou et al., Phys. Rev. Lett. 67, 318 (1991)]. This can be viewed as a different type of optical coherence tomography scheme where the varying reflectivity of the sample along the direction of propagation of an optical beam translates into changes of the degree of first-order coherence between two beams. As a practical advantage the scheme allows probing the sample with one wavelength and measuring photons with another wavelength. In a bio-imaging scenario, this would result in a deeper penetration into the sample because of probing with longer wavelengths, while still using the optimum wavelength for detection. The scheme proposed here could achieve submicron axial resolution by making use of nonlinear parametric sources with broad spectral bandwidth emission.Comment: Published version. 11 pages, 9 figure

Patrones de distribución de los Carabidae ibéricos (Insecta, Coleoptera)

We have categorised the 1336 species and subspecies of the Iberian Peninsula according to the chorotype classification proposed by Vigna Taglianti et al. (1992), modified by the addition of new chorotypes. The Iberian Peninsula is noticeable among the different European and Circum-Mediterranean regions by the high proportion of endemic taxa (43.1%). The old age and stability of the northern half, the extreme position of the Peninsula within the Eurasiatic continent, alpine tectonics and abundance of caves are among the factors that have probably contributed to the origin of a distinctive fauna. Taxa with a large distribution pattern are predominant at a regional scale; the proportion of endemic taxa increases to the North and in mountain regions; Mediterranean elements are more frequent in the South whereas European elements increase in the northern half. Adaptation to a Mediterranean climatic regime and dispersal are two of the factors causing these patterns. The Peninsula is poor in Afrotropical elements, probably because of the strong isolation derived from the Sahara Desert. The Balearic Islands have high proportions of widely distributed and Mediterranean taxa, what suggests a main role of dispersal in the colonisation of the archipelago. The proportion of endemic taxa in Mallorca (7.8%) is intermediate between that of Sardinia and Sicily; in spite of a relatively long isolation, the Balearic Islands are small in size and moderately rich in caves, what explains that most endemic taxa are found in the lowlands.Se han categorizado las 1336 especies y subespecies de la fauna ibérica de Carabidae, usando los corotipos propuestos por Vigna Taglianti et al. (1992), los cuales se han completado con algunos otros adicionales. La Península Ibérica destaca entre las diversas regiones europeas y circunmediterráneas por la elevada proporción de elementos endémicos (43,1%). La antigüedad y estabilidad de la mitad norte peninsular, el aislamiento de la región, los plegamientos alpinos y la abundancia de cuevas, son factores que probablemente han contribuido a su singularidad faunística. Los elementos de amplia distribución predominan a la escala regional; las proporciones de endemismos son mayores hacia el Norte y en las zonas de montaña; la de los elementos mediterráneos se incrementa hacia el Sur, al contrario de lo que ocurre con los elementos europeos. La adaptación al régimen climático mediterráneo y la dispersión son dos de los factores que probablemente causan estos patrones. La Península es pobre en elementos afrotropicales, posiblemente debido al aislamiento causado por la barrera natural del Sahara. Las Islas Baleares tienen altas proporciones de elementos de amplia distribución y mediterráneos, lo que sugiere el papel relevante de la dispersión en la colonización de las islas. La proporción de endemismos de Mallorca (7,8%) es intermedia entre la de Cerdeña y Sicilia; a pesar de su aislamiento las Baleares son de tamaño pequeño y tienen un abundancia moderada de medios favorables para la especiación, como ocurre con las cuevas, lo que explica que la mayoría de los endemismos se encuentren en zonas abiertas de baja altitud

La comarca del Cebrero

Tit. tomado de la cub.Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Tunable beam displacer

We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.Comment: 3 pages, 2 figure

Aplicación práctica del Costeo ABC para evaluar la rentabilidad de productos micro financieros con tarifas reguladas en el Ecuador: caso INSOTEC

El tener un conocimiento claro del costo de los productos que ofertan las entidades micro financieras es una herramienta fundamental para la adecuada toma de decisiones, por lo cual la correcta estructuración del mismo, de una manera técnica y basada en las mejores prácticas de la industria financiera, es muy importante, sobre todo en el Ecuador, cuyas regulaciones establecen tasas de intereses fijadas por el Banco Central y no son determinadas por un análisis de riesgo y/o de mercado, de forma que el conocimiento en el control de costos es fundamental en la gestión de las organizaciones que otorgan servicios financieros. Este documento recoge la investigación y el desarrollo de un modelo de costos ABC y un modelo de rentabilidad, para todos los productos que oferta la empresa en estudio, INSOTEC, asi como los resultados y recomendaciones de los mismos, cuyo objetivo es implementar un modelo de gestión

Gold nanoparticles modification with liquid crystalline polybenzylic dendrons via 1,3-Dipolar cycloaddition

A series of six polybenzylic dendrons with an alkynyl focal point were synthesized for their incorporation to gold nanoparticles. Five of these compounds showed columnar mesomorphism in a wide range of temperatures. These dendrons were reacted with gold nanoparticles stabilized with a combination of a dodecanethiol and 11-azidoundecane-1-thiol. The azido group of the last compound allowed the functionalization of the nanoparticles with the six polybenzylic dendrons by 1,3-dipolar cycloaddition between their alkynyl groups and the terminal azido groups of the thiols. A high efficiency of the cycloaddition process (47–69%) was confirmed by several experimental techniques and no decomposition or aggregation phenomena were detected in the dendron-coated nanoparticles. The involved mechanism and the resulting percentage composition of the final materials are discussed. The results of the ulterior growth of the nanoparticles by thermal treatment are influenced by the size and the shape of the dendron and the temperature of the process. The structures of the final nanoparticles were investigated by TEM, DSC, TGA, NMR and UV-Vis spectroscopy. These nanoparticles do not show liquid crystal properties. However, a melting process between a crystalline and a fluid phase is observed. In the solid phase, the nanomaterials prepared show a short-range interaction between nanoparticles with a 2D local hexagonal order. A near-field effect was observed in the UV-vis spectra by coupling of different surface plasmon resonance bands (SPR) probably due to the short-range interactions. The main novelty of this work lies in the scarcity of previous studies of gold nanoparticles coated with dendrons forming themselves columnar mesophases. Most of the studies reported in the literature deal with gold nanoparticles coated with calamitic mesogens. Additionally, the effect of the thermal treatment, which in a previous paper was shown to increase the mean size of the nanoparticles without increasing their size polydispersity, has been studied in these materials