Multicolor optical polarimetry of reddened stars in the small Magellanic cloud

First results of an on-going program to determine the wavelength dependence of the interstellar optical polarization of reddened stars in the Small Magellanic Cloud (SMC) are presented. IUE observations of reddened stars in the SMC (Bouchet et al. 1985) generally show marked differences in the extinction law as compared to both the Galaxy and the Large Megallanic Cloud. The aim here is to determine the wavelength dependence of the optical linear polarization in the direction of several such stars in the SMC in order to further constrain the dust composition and size distribution in that galaxy

Ab initio data-analytics study of carbon-dioxide activation on semiconductor oxide surfaces

The excessive emissions of carbon dioxide (CO$_2$) into the atmosphere threaten to shift the CO$_2$ cycle planet-wide and induce unpredictable climate changes. Using artificial intelligence (AI) trained on high-throughput first principles based data for a broad family of oxides, we develop a strategy for a rational design of catalytic materials for converting CO$_2$ to fuels and other useful chemicals. We demonstrate that an electron transfer to the $\pi^*$-antibonding orbital of the adsorbed molecule and the associated bending of the initially linear molecule, previously proposed as the indicator of activation, are insufficient to account for the good catalytic performance of experimentally characterized oxide surfaces. Instead, our AI model identifies the common feature of these surfaces in the binding of a molecular O atom to a surface cation, which results in a strong elongation and therefore weakening of one molecular C-O bond. This finding suggests using the C-O bond elongation as an indicator of CO$_2$ activation. Based on these findings, we propose a set of new promising oxide-based catalysts for CO$_2$ conversion, and a recipe to find more

Tethering forces of secretory granules measured with optical tweezers.

Fusion of a vesicle with its target membrane is preceded by tethering or docking. However, the physical mechanism of vesicle-tethering is unknown. To study this mechanism, we used eosinophil secretory granules, which undergo stimulated homotypic fusion events inside the cell during degranulation. Using a dual optical trap system, we observed tether formation between isolated eosinophil secretory granules. The results show that secretory granules interact stochastically with a target membrane forming physical tethers linking the vesicle and target membrane, rather than via interactions with the cytoskeleton. The necessary components are membrane-associated, and the addition of cytosolic components is not required. Tether-lifetime measurements as a function of applied mechanical force revealed at least three kinetically distinct tethered states. The tethered-state lifetimes of isolated eosinophil granules match the residence times of chromaffin granules at the plasma membrane in intact cells, suggesting that the tethering mechanisms reported here may represent the physiological mechanisms of vesicle-tethering in the cell

Profiling the publish/subscribe paradigm for automated analysis using colored Petri nets

UML sequence diagrams are used to graphically describe the message interactions between the objects participating in a certain scenario. Combined fragments extend the basic functionality of UML sequence diagrams with control structures, such as sequences, alternatives, iterations, or parallels. In this paper, we present a UML profile to annotate sequence diagrams with combined fragments to model timed Web services with distributed resources under the publish/subscribe paradigm. This profile is exploited to automatically obtain a representation of the system based on Colored Petri nets using a novel model-to-model (M2M) transformation. This M2M transformation has been specified using QVT and has been integrated in a new add-on extending a state-of-the-art UML modeling tool. Generated Petri nets can be immediately used in well-known Petri net software, such as CPN Tools, to analyze the system behavior. Hence, our model-to-model transformation tool allows for simulating the system and finding design errors in early stages of system development, which enables us to fix them at these early phases and thus potentially saving development costs

Reacción seudoséptica tras la infiltración de ácido hialurónico en el tratamiento de la artrosis de tobillo: a propósito de un caso

Muchos cirujanos ortopédicos utilizan las infiltraciones de ácido hialurónico como tratamiento sintomático de la artrosis. Generalmente su uso es seguro, pero en ocasiones puede presentar alguna reacción adversa que se debe conocer, como la reacción pseudoséptica. Presentamos un caso de un varón de 48 años que acude a urgencias con fiebre y signos inflamatorios en tobillo tras la segunda infiltración de ácido hialurónico. Se realizó un artrotomía de limpieza y el cultivo de la muestra resultó negativo. Discusión: La importancia de la reacción seudoséptica radica en que es una entidad clínica superponible a una verdadera artritis séptica pero que, a diferencia de la anterior, se resuelve con reposo y antiinflamatorios, y no produce alteraciones en el cartílago.Most of the orthopedists use intraarticular supplementation of hyaluronic acid to relieve osteoarthritis ´pain. Usually this treatment is safe but, sometimes it has some adverse events that should be known, as the pseudoseptic reaction or severe acute inflammatory reaction. We present a 48 years old man that presented fever and inflammatory reaction in his ankle after the second intraarticular injection of hyaluronate. An ankle arthrotomy was performed, but the culture results were negative. Discusion: We may consider the difference between this reaction and a real septic disease, that requires antibioterapy and, in most cases, surgery. Otherwise, the pseudoseptic reaction improves with rest and anti-inflammatory drugs, and does not suppose a damage to the cartilage

Fog function virtualization: A flexible solution for IoT applications

The Internet of Things applications must carefully assess certain crucial factors such as the real-time and largely distributed nature of the “things”. Fog Computing provides an architecture to satisfy those requirements through nodes located from near the “things” till the edge. The problem comes with the integration of the Fog nodes into current infrastructures. This process requires the development of complex software solutions and prevents Fog growth. In this paper we propose three innovations to enhance Fog: (i) a new orchestration policy, (ii) the creation of constellations of nodes, and (iii) Fog Function Virtualization (FFV). All together will complement Fog to reach its true potential as a generic scalable platform, running multiple IoT applications simultaneously. Deploying a new service is reduced to the development of the application code, fact that brings the democratization of the Fog Computing paradigm through ease of deployment and cost reduction.The authors thanks Rodolfo Milito for his insightful comments and revisions. Damian Roca work was supported by a Doctoral Scholarship provided by Fundación La Caixa. Josue V. Quiroga work was supported by a Doctoral Scholarship provided by the Mexican National Council of Science and Technology (CONACyT). This work has been supported by the Spanish Government (Severo Ochoa grants SEV2015-0493) and by the Spanish Ministry of Science and Innovation (contracts TIN2015-65316-P).Peer ReviewedPostprint (author's final draft

Using a Hybrid Recommending System for Learning Videos in Flipped Classrooms and MOOCs

[EN] New challenges in education require new ways of education. Higher education has adapted to these new challenges by means of offering new types of training like massive online open courses and by updating their teaching methodology using novel approaches as flipped classrooms. These types of training have enabled universities to better adapt to the challenges posed by the pandemic. In addition, high quality learning objects are necessary for these new forms of education to be successful, with learning videos being the most common learning objects to provide theoretical concepts. This paper describes a new approach of a previously presented hybrid learning recommender system based on content-based techniques, which was capable of recommend useful videos to learners and lecturers from a learning video repository. In this new approach, the content-based techniques are also combined with a collaborative filtering module, which increases the probability of recommending relevant videos. This hybrid technique has been successfully applied to a real scenario in the central video repository of the Universitat Politècnica de València.This research was partially supported by MINECO/FEDER RTI2018-095390-B-C31 and TIN2017-89156-R projects of the Spanish government, and PROMETEO/2018/002 project of Generalitat Valenciana.Jordán, J.; Valero Cubas, S.; Turró, C.; Botti, V. (2021). Using a Hybrid Recommending System for Learning Videos in Flipped Classrooms and MOOCs. Electronics. 10(11):1-19. https://doi.org/10.3390/electronics10111226S119101

Modelado y Resolución del Problema Dinámico Inverso y Directo en Tiempo Real de Robots Industriales

ResumenEste trabajo presenta el desarrollo y la validación de una metodología que permite el modelado y la resolución del problema dinámico en tiempo real de robots manipuladores. La ecuación dinámica del robot está basada en la ecuación de movimiento de Gibbs-Appell, proporcionando un conjunto de ecuaciones bien estructuradas que pueden ser calculadas en tiempo real.El artículo aborda el cálculo e implementación del problema dinámico directo e inverso de robots, aplicándose al control en tiempo real de un robot industrial PUMA 560 equipado con una arquitectura abierta de control basada en un computador personal industrial