Tunable entanglement distillation of spatially correlated down-converted photons

We report on a new technique for entanglement distillation of the bipartite continuous variable state of spatially correlated photons generated in the spontaneous parametric down-conversion process (SPDC), where tunable non-Gaussian operations are implemented and the post-processed entanglement is certified in real-time using a single-photon sensitive electron multiplying CCD (EMCCD) camera. The local operations are performed using non-Gaussian filters modulated into a programmable spatial light modulator and, by using the EMCCD camera for actively recording the probability distributions of the twin-photons, one has fine control of the Schmidt number of the distilled state. We show that even simple non-Gaussian filters can be finely tuned to a ~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure

Colino Quinasa como nueva diana terapéutica en Cáncer

El cáncer es la enfermedad genética más frecuente en países desarrollados, teniendo todavía un alto grado de mortalidad. Las células cancerígenas se caracterizan por la acumulación de numerosas alteraciones genéticas, las cuales terminan modificando las vías de transducción de señales que controlan la proliferación, diferenciación y apoptosis celular y, en último término, responsable de los procesos cancerígenos. Como consecuencia de ello, se han dedicado muchísimos esfuerzos a diseñar moléculas específicas que interfieran con estas cascadas de señalización envueltas en los procesos que generan tumores. Sin embargo, todavía es necesario desarrollar nuevas terapias antitumorales que permitan un tratamiento apropiado para cada paciente y para cada tumor, pudiendo tener un gran impacto en la mejora en dichas terapias. Por todo ello es necesario la identificación de los componentes moleculares envueltos en estos procesos aberrantes para el desarrollo de quimioterapeúticos que intervengan en la restauración o destrucción selectiva de las células transformadas. El desarrollo de nuevos agentes terapéuticos es probablemente una de las estrategias más seguras para mejorar nuestro éxito contra el cáncer, y el diseño de drogas inteligentes es el factor clave para lograr esta meta. Por ello, es necesaria la identificación de nuevas dianas con el fin de desarrollar nuevas drogas anticancerígenas. Esta revisión proporciona evidencias suficientes de que colino quinasa (ChoK) es una nueva diana terapeútica

Development of lntraepithelial Cells in the Porcine Small Intestine

The number, phenotype, localisation and development of intraepithelial lymphocytes (IEL) from duodenum (Du) and ileum (Il) were studied by immunohistochemistry (IHC) and light and electron microscopy in unweaned (0–7 weeks old) and six months-old pigs. Developmental changes at birth showed that 38% of the total lymphocytes in the villi were IEL, mainly of the CD2+CD4-CD8- double negative (DN) phenotype. That proportion rose to over 50% at week 5 after birth, resembling adult proportion, although still with fewer cells than in adult pigs. CD4+ cells appeared relatively early in life although they were confined to the lamina propria (LP) and CD8+ cells were found only in low numbers. In the villi of adult animals, almost half of the total number of lymphocytes were IEL (49% Du, 52% Il). Over half of these IEL (52% Du, 53% Il) showed the CD2+CD4-CD8+ phenotype and were localized at the epithelium's basement membrane. Numerous (43% Du, 42% Il) DN IEL were found grouped at the enterocyte nucleus level and relatively few (5% in Du and Il) granular IEL were found apically in the epithelium. These proportions were homogeneously maintained along the villi's tip, middle and bottom, suggesting that the IEL may have their origin in the LP. Therefore, the IEL compartment in the porcine intestine develops slowly with age and is actually composed by a heterogeneous population of cells (null, DN and CD8+). These results may explain the increased susceptibility of young animals to disease during the lactation period and should be taken into account when functional studies are carried out with IEL. The quantitative results of this paper established a model for studies on the effect of age, diet, normal flora, infection and oral immunization on the IEL of the gut

Quantum reactive scattering calculations of cross sections and rate constants for the N(2D) + O2(X3Σg-) → O(3Π) + NO(X2Π) reaction

Time-dependent quantum wavepacket calculations have been performed on the two lowest adiabatic potential energy surfaces (2 2A´ and 1 2A˝) for the N(2D) + O2(X3Σg-) → O(3Π) + NO(X2Π) reaction. The calculations have been carried out, on these recently published potential energy surfaces, using the real wavepacket method together with a new dispersion fitted finite difference technique for evaluating the action of the radial kinetic energy operator. Reaction probabilities, corresponding to the O2 reactant in its ground vibrational-rotational state, have been calculated for both surfaces and for many different values of the total angular momentum quantum number (J), within the helicity decoupling approximation. The reaction probabilities associated with all other relevant J values have been interpolated, and to a smaller extent extrapolated, using a capture model, to yield probabilities as a function of energy. The probabilities have in turn been summed to yield energy dependent cross sections and then used to compute rate constants. These rate constants are compared with ones obtained from quasiclassical trajectory (QCT) and variational transition state theory (VTST) calculations performed on the same surfaces. There is a good agreement between the wavepacket and QCT cross sections for reaction on both potential energy surfaces considered, with the exception of the near threshold region, where the reaction probability is dominated by tunnelling. Comparison of the predicted rate constants shows that for the 2 2A´ surface, above 300 K, the wavepacket, QCT and VTST results are quite similar. For the 1 2A˝ surface, however, significant differences occur between the wavepacket and the other methods. These differences become smaller with increasing temperature. It is likely that these differences arise, at least in part, from the fact that, when calculating the rate constants, the reactants are restricted to be in their lowest vibrational-rotational state in the wavepacket calculations but are selected from a thermally equilibrated population in the other methods

Procesadores de bajo coste y su aplicación en la docencia de Ingeniería de Computadores

La Informática evoluciona a gran velocidad y es necesario actualizar con frecuencia los recursos de aprendizaje para mantener el interés de los estudiantes. En la actualidad, hay una gran diversidad de plataformas de cómputo de bajo coste que son utilizadas como recursos en los estudios de Informática. Raspberry Pi y algunos modelos de Arduino (como Arduino Due), ambas basadas en procesadores ARM, son ejemplos representativos de este tipo de plataformas. Las arquitecturas ARM son ejemplos de procesadores RISC que actualmente gozan de gran popularidad por su buena relación entre potencia computacional, consumo y coste. De hecho, constituyen el núcleo de muchos de los teléfonos móviles y sistemas empotrados actuales. Al estar tan cerca de los estudiantes, el uso de este tipo de recursos en el aula representa una oportunidad para: (1) motivar a los alumnos de Bachillerato y Educación Secundaria para estudiar el Grado de Informática y (2) potenciar el interés de los alumnos de Grado de Informática por la Ingeniería de Computadores. Existe una serie de eventos consolidados que tienen una gran difusión social. En ellos, se muestran vistosos ejemplos de aplicación y funcionamiento de este tipo de plataformas. En este trabajo se describen el conjunto de sistemas interactivos y basados en plataformas computacionales de bajo coste que se han desarrollado para ser utilizadas en este tipo de eventos. De acuerdo con nuestra experiencia de participación, creemos que están sirviendo para despertar el interés del alumno de secundaria por la Informática en general, y más específicamente por la Ingeniería de Computadores. Por otra parte, un porcentaje de los alumnos que cursan el Grado de Ingeniería Informática no está interesado en el análisis de los componentes hardware y de su organización para construir un computador moderno. Piensan que la asignatura de Arquitectura de Computadores del Grado en Ingeniería Informática está lejos de su futura actividad profesional. En este contexto, nos planteamos seleccionar ARM como arquitectura de referencia para desarrollar los contenidos de la asignatura de Arquitectura de Computadores. Creemos que esta decisión mejora el interés del alumno por dos motivos: (1) el objeto de estudio se usa en multitud de plataformas muy cotidianas para el alumno y (2) es posible diseñar las actividades prácticas de las asignaturas basadas en elementos reales y no únicamente virtuales. Este trabajo muestra las distintas actividades tanto a nivel teórico como práctico que se plantean al alumno en el marco de la asignatura Arquitectura de Computadores.Computer Science is advancing rapidly and it is necessary to keep the educational resources up to date in order to keep the interest of students. Nowadays, there is a wide variety of low-cost computing platforms that are used as educational resources in the Computer Science degree. Raspberry Pi and some models of Arduino (such as Arduino Due), which are both based on ARM processors, are representative examples of this kind of platforms. ARM architectures are instances of RISC processors which nowadays have reached an important popularity due to their good relation between performance, consumption and cost. In fact, they constitute the core of numerous current mobile phones and embedded systems. Considering their proximity to the students, the use of this kind of resources in the classroom is an opportunity to: (1) encourage the high schools pupils to study the Computer Science degree and (2) to increase the interest of the students for the Computer Engineering. There are several consolidated informational events of great social outreach in which different examples of application of this kind of platforms are shown. In this work, the set of interactive systems designed to be used in this kind of events is described. According to our experience, we think that they arouse the interest of high schools pupils for the Computer Science in general, and, more specifically, for the Computer Engineering. Furthermore, a percentage of the students of the Computer Science degree is not interested in the analysis of hardware components and the architecture of modern computers. They think that the subject of Computer Architecture of the Computer Science Degree is far from his/her future career. In this context, we will select ARM as a reference architecture where the contents of the subject Computer Architecture will be developed on. We think this might improve the motivation of the students mainly for two reasons: (1) the object of study is being used in a lot of modern platforms; and (2) it is possible to design the practical activities of the subjects using real platforms and not only virtual ones. This work shows the activities proposed to the students in the context of the subject Computer Architecture, considering both practical and theoretical approaches

Automatic Visual Acuity Estimation by Means of Computational Vascularity Biomarkers Using Oct Angiographies

[Abstract] Optical Coherence Tomography Angiography (OCTA) constitutes a new non-invasive ophthalmic image modality that allows the precise visualization of the micro-retinal vascularity that is commonly used to analyze the foveal region. Given that there are many systemic and eye diseases that affect the eye fundus and its vascularity, the analysis of that region is crucial to diagnose and estimate the vision loss. The Visual Acuity (VA) is typically measured manually, implying an exhaustive and time-consuming procedure. In this work, we propose a method that exploits the information of the OCTA images to automatically estimate the VA with an accurate error of 0.1713.Instituto de Salud Carlos III; DTS18/00136Ministerio de Economía y Competitividad; DPI2015-69948-RXunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-047Ministerio de Ciencia, Innovación y Universidades; RTI2018-095894-B-I0

AGRONOMIC EVALUATION AND CHEMICAL COMPOSITION OF AFRICAN STAR GRASS (Cynodon plectostachyus) IN THE SOUTHERN REGION OF THE STATE OF MEXICO

African Star Grass is one of the forage resources most commonly used by farmers in regions with warm-humid climates. This study was carried out to determine the nutritional and agronomic characteristics of African Star Grass (Cynodon plectostachyus) through the following variables: crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), organic matter digestibility (OMD), net forage accumulation (NFA), stem:leaf ratio, and live:dead matter ratio in the three pastures evaluated. The work took place from April 2007 to March 2008, with evaluations carried out on a monthly basis. The data were analyzed in a randomized block design in which the blocks were the pastures, and the treatments were the months of evaluation. There were no differences between the pastures evaluated for the NDF, ADF or OMD (P>0.05). Differences were found, however, in CP, while in the monthly evaluation, differences were found between the periods evaluated (P<0.05) for these variables. Differences were also found in the agronomic evaluation of pastures (P<0.05) among height of pasture, net forage accumulation (NFA), live matter, dead matter, leaf and stem, both among pastures and in the monthly evaluations. African Star Grass can therefore be considered a good choice for milk production systems in the southern region of the state of Mexico, due to its nutritional and agronomic characteristics

Minimized natural versions of fungal ribotoxins show improved active site plasticity

Fungal ribotoxins are highly specific extracellular RNases which cleave a single phosphodiester bond at the ribosomal sarcin-ricin loop, inhibiting protein biosynthesis by interfering with elongation factors. Most ribotoxins show high degree of conservation, with similar sizes and amino acid sequence identities above 85%. Only two exceptions are known: Hirsutellin A and anisoplin, produced by the entomopathogenic fungi Hirsutella thompsonii and Metarhizium anisopliae, respectively. Both proteins are similar but smaller than the other known ribotoxins (130 vs 150 amino acids), displaying only about 25% sequence identity with them. They can be considered minimized natural versions of their larger counterparts, best represented by α-sarcin. The conserved α-sarcin active site residue Tyr48 has been replaced by the geometrically equivalent Asp, present in the minimized ribotoxins, to produce and characterize the corresponding mutant. As a control, the inverse anisoplin mutant (D43Y) has been also studied. The results show how the smaller versions of ribotoxins represent an optimum compromise among conformational freedom, stability, specificity, and active-site plasticity which allow these toxic proteins to accommodate the characteristic abilities of ribotoxins into a shorter amino acid sequence and more stable structure of intermediate size between that of other nontoxic fungal RNases and previously known larger ribotoxins

Tsunami generation potential of a strike slip fault tip in the westernmost Mediterranean

Tsunamis are triggered by sudden seafloor displacements, and usually originate from seismic activity at faults. Nevertheless, strike-slip faults are usually disregarded as major triggers, as they are thought to be capable of generating only moderate seafloor deformation; accordingly, the tsunamigenic potential of the vertical throw at the tips of strike-slip faults is not thought to be significant. We found the active dextral NW–SE Averroes Fault in the central Alboran Sea (westernmost Mediterranean) has a historical vertical throw of up to 5.4 m at its northwestern tip corresponding to an earthquake of Mw 7.0. We modelled the tsunamigenic potential of this seafloor deformation by Tsunami-HySEA software using the Coulomb 3.3 code. Waves propagating on two main branches reach highly populated sectors of the Iberian coast with maximum arrival heights of 6 m within 21 and 35 min, which is too quick for current early-warning systems to operate successfully. These findings suggest that the tsunamigenic potential of strike-slip faults is more important than previously thought, and should be taken into account for the re-evaluation of tsunami early-warning systems.Versión del edito