Universal quantum computation with the Orbital Angular Momentum of a single photon

We prove that a single photon with quantum data encoded in its orbital angular momentum can be manipulated with simple optical elements to provide any desired quantum computation. We will show how to build any quantum unitary operator using beamsplitters, phase shifters, holograms and an extraction gate based on quantum interrogation. The advantages and challenges of these approach are then discussed, in particular the problem of the readout of the results.Comment: First version. Comments welcom

Banking failure prediction: a boosting classification tree approach

The recent financial crisis shows that failure of some financial institutions can cause other banks to fail and ultimately cause damage to the financial system worldwide. Eurozone banks that experienced either liquidity or solvency problems during the finan- cial markets turmoil were bailed out by their national governments with the financial support and supervision of the European Union. This paper applies the boosted classification tree methodology to predict failure in the banking sector and identifies four key scor- ecard variables that are worth tracking closely in order to anticipate and prevent bank financial distress. The data used in this study comprises 2006-2012 annual series of 25 financial ratios of 155 banks in the Eurozone. The findings indicate that the greater the size and the higher the income from non-operating items and net loans to deposits, the more likely is bank failure; conversely, the higher the Interbank ratio the lower the chances of bank financial distress. For the sake of their own financial soundness, banks should fund lending activities through clients' deposits and should avoid relying excessively on non-recurring sources of income

Delayed commutation in quantum computer networks

In the same way that classical computer networks connect and enhance the capabilities of classical computers, quantum networks can combine the advantages of quantum information and communications. We propose a non-classical network element, a delayed commutation switch, that can solve the problem of switching time in packet switching networks. With the help of some local ancillary qubits and superdense codes we can route the information after part of it has left the network node.Comment: 4 pages. 4 figures. Preliminar versio

An extreme event between the Little Ice Age and the 20th century: the snow avalanche cycle of 1888 in the Asturian Massif (Northern Spain)

Between the late Little Ice Age (LIA) cold stage and the early 20th century warmer scenario, a transitional regime characterized by an unstable climatic pattern generated a series of climate extremes affecting mid-latitude mountainous areas, as the Asturian Massif. There, the 1888 snow avalanche cycle appears as the most significant event, standing out among the rest of avalanche cycles recorded in this area during the 1800-2015 period both in terms of the number of damaging avalanches and damages caused by them. Among the factors that explain this event stands out the orographic precipitation phenomenon; the interaction of a cold and wet air mass originating from the North Atlantic with the relief of the Massif, which led to extraordinary snow thicknesses (>2 m) at very low altitudes (500 m a.s.l.), especially in the north-facing, Asturian versant of the Cantabrian Mountains. This allowed the triggering of avalanches in slopes gentler and in lower altitudes than usual, covering longer distances; consequently, avalanches reached more easily the settlements, generally placed at the bottom of the valley or in middle slope positions. The greater impact on the settlements, which suffered 84% of the damages, was the cause of this episode’s high socioeconomic impact (29 people dead, 34 injured, 123 heads of cattle dead, 124 buildings destroyed). These events occurred at a time when the mountain villages were highly populated and subjected to intense exploitation, coinciding with the development of new communication infrastructures in the upper parts of the Massif. Therefore, the 1888 episode constitutes a good example of both the impact of hydrometeorological events in mountain environments under high demographic pressure, and of climate extremes involved in a transition period from cold to warmer weather conditions.Entre la Pequeña Edad de Hielo (PEH) y las primeras décadas del siglo XX, un régimen de transición climática caracterizado por su inestabilidad generó una serie de eventos extremos que afectaron a las zonas montañosas de latitudes medias, como el Macizo Asturiano. Allí, el ciclo de aludes de 1888 fue el acontecimiento más significativo, destacando entre el resto de ciclos de avalanchas registrados en esta área entre 1800 y 2015 tanto por el número de avalanchas dañinas que se registraron como por los daños que estas causaron. Entre los factores que explican este acontecimiento destaca el fenómeno de las precipitaciones orográficas; la interacción de una masa de aire frío y húmedo (procedente del Atlántico Norte) con el relieve del Macizo, condujo a espesores de nieve extraordinarios (> 2 m) a muy bajas altitudes (500 m s.n.m.), especialmente en la vertiente asturiana (orientada al norte). Esto permitió el desencadenamiento de avalanchas en pendientes más suaves y a altitudes más bajas de lo habitual, cubriendo distancias más largas que en otros episodios. En consecuencia, estas avalanchas alcanzaron más fácilmente los asentamientos, tradicionalmente situados en el fondo del valle o en posiciones de media ladera. El mayor impacto en los asentamientos, que sufrieron el 84% de los daños, fue la causa del alto coste socioeconómico de este episodio (29 personas muertas, 34 heridas, 123 cabezas de ganado muertas, 124 edificios destruidos). Estos acontecimientos ocurrieron en un momento en que los núcleos de montaña estaban muy poblados y sometidos a una intensa explotación, coincidiendo además con el desarrollo de nuevas infraestructuras de comunicación en las partes altas del Macizo. Por lo tanto, el episodio de 1888 constituye un buen ejemplo tanto del impacto de los eventos hidrometeorológicos en ambientes montañosos bajo alta presión demográfica, como de los eventos extremos propios de un período de transición de condiciones climáticas frías a más cálidas.info:eu-repo/semantics/publishedVersio

Quantum Multiplexing with the Orbital Angular Momentum of light

The orbital angular momentum, OAM, of photons offers a suitable support to carry the quantum data of multiple users. We present two novel optical setups that send the information of n quantum communication parties through the same free-space optical link. Those qubits can be sent simultaneously and share path, wavelength and polarization without interference, increasing the communication capacity of the system. The first solution, a qubit combiner, merges n channels into the same link, which transmits n independent photons. The second solution, the OAM multiplexer, uses CNOT gates to transfer the information of n optical channels to a single photon. Additional applications of the multiplexer circuits, such as quantum arithmetic, as well as connections to OAM sorting are discussed

Mapa de exposición internacional de la economía española

Este estudio analiza los niveles de interdependencia y riesgo que se dan en las relaciones económicas entre España y un gran número de países. Para ello se utilizan datos bilaterales sobre vínculos comerciales y financieros de España con el resto del mundo para construir, mediante el análisis de componentes principales, un índice de interdependencia de España con cada país. Asimismo, la agregación mediante la misma técnica de diversas medidas de riesgo, como las calificaciones crediticias soberanas y otras más genéricas, permite construir un índice de riesgo para cada país. Combinando la información de ambos índices, se encuentra que las mayores interdependencias de la economía española se dan con países asociados a niveles reducidos de riesgo (esencialmente países de la OCDE), mientras que las principales interdependencias asociadas a niveles intermedios de riesgo se dan en relación a países de América Latina y países exportadores de productos energético

Improve and application of a new methodologic tool adapted to the European Higher Education Area applied in Degree in Food Science and Technology (CYTA), in Forest Engineering (GIFOR) and in Veterinary

La masificación en las aulas de las universidades plantea grandes retos en el desarrollo de la enseñanza según el modelo del Espacio Europeo de Enseñanza Superior (EEES). El presente trabajo desarrolló una herramienta metodológica (Píldoras Informativas) para potenciar la implicación del alumnado en el aprendizaje autónomo, basado en la creación y edición de videos por parte del alumnado, guiada, orientada y evaluada por el profesor mediante las Guías Director. Se ha llevado a cabo la introducción de las píldoras informativas en las sesiones expositivas de asignaturas de grados impartidos en la Universidad de Córdoba, incluyendo asignaturas inmersas en itinerario de inglés. Con los resultados obtenidos se plantea la creación de seminarios de difusión de la metodología para profesorado en formación.The overcrowding in the classrooms of the universities poses great challenges in the development of the teaching according to the model of the European Space of Higher Education (EHEA). The present work developed a methodological tool (Informative Pills) to enhance the involvement of students in autonomous learning, based on the creation and editing of videos by the students, guided and evaluated by the teacher through the Director Guides. The introduction of the informative pills has been carried out in the expositive sessions of subjects taught at the University of Córdoba, including subjects immersed in the English language. With the results obtained, it is proposed the creation of seminars to disseminate the methodology for teaching staff in training. Keywords: Information pills, short videos, active student participation

Molecular Phylogeny of the Acanthocephala (Class Palaeacanthocephala) with a Paraphyletic Assemblage of the Orders Polymorphida and Echinorhynchida

Acanthocephalans are attractive candidates as model organisms for studying the ecology and co-evolutionary history of parasitic life cycles in the marine ecosystem. Adding to earlier molecular analyses of this taxon, a total of 36 acanthocephalans belonging to the classes Archiacanthocephala (3 species), Eoacanthocephala (3 species), Palaeacanthocephala (29 species), Polyacanthocephala (1 species) and Rotifera as outgroup (3 species) were analyzed by using Bayesian Inference and Maximum Likelihood analyses of nuclear 18S rDNA sequence. This data set included three re-collected and six newly collected taxa, Bolbosoma vasculosum from Lepturacanthus savala, Filisoma rizalinum from Scatophagus argus, Rhadinorhynchus pristis from Gempylus serpens, R. lintoni from Selar crumenophthalmus, Serrasentis sagittifer from Johnius coitor, and Southwellina hispida from Epinephelus coioides, representing 5 new host and 3 new locality records. The resulting trees suggest a paraphyletic arrangement of the Echinorhynchida and Polymorphida inside the Palaeacanthocephala. This questions the placement of the genera Serrasentis and Gorgorhynchoides within the Echinorhynchida and not the Polymorphida, necessitating further insights into the systematic position of these taxa based on morphology