VNUML vs GNS3 en el desarrollo de laboratorios de redes virtuales

El aprendizaje práctico de redes de computadores es reconocido como un proceso crítico que permite a los estudiantes consolidar los conceptos introducidos en las lecciones teóricas. En este sentido, las tecnologías de virtualización están adquiriendo gran relevancia debido a que permiten desarrollar laboratorios de redes de computadores con un reducido coste de despliegue y gestión. Este artículo presenta un análisis comparativo entre GNS3 y VNUML, que son herramientas de virtualización open-source que han sido empleadas para el desarrollo de laboratorios de red virtuales para llevar a cabo el proceso de enseñanza-aprendizaje en las asignaturas Arquitectura de Redes y Arquitectura de Redes Avanzadas del Grado en Ingeniería Informática impartido en la Universidad de Murcia. El estudio presenta las principales ventajas y/o deficiencias de cada herramienta tanto para profesores como alumnos y se identifican los escenarios en los que parece más adecuada su utilización.SUMMARY -- The practical learning of computer networks is known to be a critical process in order to allow students to consolidate the concepts introduced in theoretical lessons. In this sense, virtualization technologies are becoming popular since they allow to set up a computer network laboratory with a reduced deployment and management cost. This paper presents a comparative analysis performed between GNS3 and VNUML, which are open-source tools for virtualization that have been used for developing virtual network laboratories that support the teaching-learning process in the Networks Architecture and Advanced Networks Architecture subjects of the Computer Engineering degree at the University of Murcia. The study presents the main advantages and/or deficiencies of each tool not only for professors but also for students and identifies the scenarios where the use of each tool seems to be more appropriate.Peer Reviewe

Comparing and modeling land use organization in cities

The advent of geolocated ICT technologies opens the possibility of exploring how people use space in cities, bringing an important new tool for urban scientists and planners, especially for regions where data is scarce or not available. Here we apply a functional network approach to determine land use patterns from mobile phone records. The versatility of the method allows us to run a systematic comparison between Spanish cities of various sizes. The method detects four major land use types that correspond to different temporal patterns. The proportion of these types, their spatial organization and scaling show a strong similarity between all cities that breaks down at a very local scale, where land use mixing is specific to each urban area. Finally, we introduce a model inspired by Schelling's segregation, able to explain and reproduce these results with simple interaction rules between different land uses.Comment: 9 pages, 6 figures + Supplementary informatio

Bent-core liquid crystalline cyanostilbenes : fluorescence switching and thermochromism

The authors from ICMA greatly appreciate financial support from the Spanish Government (MINECO-FEDER project MAT2012-38538-C03-01), the Aragon's Government and FSE (project E04) and the Jae PreDoc-CSIC (M. M.-A.) fellowship program.Fluorescent bent-core molecules, bearing one or two cyanostilbene units in the lateral structure and different positions of the cyano group (α- or β-isomers), are described with the aim of modulating the molecular packing and fluorescence properties. These compounds give rise to a variety of crystal polymorphs and bent-core liquid crystalline phases (SmCP, Colr and B6), offering the unique chance to study the fluorescence properties of the cyanostilbene structure in different phases. Experimental and computational studies elucidate geometrical and electronic properties of these bent-core structures but especially the fluorescence properties (spectral positions, quantum yields and decay curves), in a detailed comparison between diluted solutions, in dichloromethane (DCM) or poly(methylmethacrylate) (PMMA), and condensed phases. Quantum yields as high as 70% have been obtained in some diluted solutions (PMMA) and condensed phases. Remarkably, the quantum yield values depend on the position of the cyano group, being higher for β- than for the α-isomers due to the higher radiative rates and lower non-radiative rates of the former. The photophysical characterization in the condensed phase focuses on RT studies with solid samples and different processing, and show that, upon aggregation, interactions between the cyanostilbene groups result in changes of the emission spectra and dynamics compared to the diluted systems in DCM and PMMA, giving rise to H-aggregations of varying strength. Furthermore, the compounds exhibit thermochromism, showing a green-yellow fluorescence in the pristine crystalline phase that changes to blue on heating to the liquid crystal phase. This journal isPostprintPeer reviewe

A Light Calibration System for the ProtoDUNE-DP Detector

A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6 m3 liquid argon time-projection-chamber currently being installed at the Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes (PMTs) and will allow triggering on cosmic rays. The system serves as prototype for the PDS of the final DUNE DP far detector in which the PDS also has the function to allow the 3D event reconstruction on non-beam physics. For this purpose an equalized PMT response is desirable to allow using the same threshold definition for all PMT groups, simplifying the determination of the trigger efficiency. The light calibration system described in this paper is developed to provide this and to monitor the PMT performance in-situ.Comment: 15 pages, 5 figure

Achondroplasia with 47, xxy karyotype: a case report of the neonatal diagnosis of an extremely unusual association

Background: The association of achondroplasia and Klinefelter syndrome is extremely rare. To date, five cases have been previously reported, all of them diagnosed beyond the postnatal period, and only one was molecularly characterized. We describe the first case of this unusual association diagnosed in the neonatal period, the clinical findings and the molecular studies undertaken. Case presentation: The boy was born at term with clinical and radiological features indicating the diagnosis of achondroplasia or hypochondroplasia combined with the prenatal karyotype of Klinefelter syndrome (47,XXY). Neonatal FGFR3 mutation screening showed that the newborn was heterozygous for the classic achondroplasia G340R mutation. Microsatellite marker analysis showed that the sex chromosome aneuploidy had arisen from a non-disjunction error in paternal meiosis I, with a recombination event in the pseudoautosomal region 1 (PAR1). Conclusion: Specific mutation analysis is appropriate to confirm the clinical diagnosis of achondroplasia for appropriate diagnosis, prognosis, and genetic counseling, especially when the karyotype does not explain the abnormal prenatal sonographic findings. In the present case, a recombination event was observed in the PAR1 region, although recombinational events in paternally derived Klinefelter syndrome cases are much rarer than expected

Tax incentives and firm size : effects on private R&D investment in Spain

The use of fiscal policy instruments to stimulate private R&D is widespread and important in some countries like Spain. In this paper we explore the effectiveness of R&D tax incentives on knowledge capital accumulation in Spanish manufacturing firms using an unbalanced panel and compare the estimates based on claimed and claimable tax reductions. We find that while large firms use the programme more than small ones, the impact of the programme measured by the price elasticity is smaller for large firms than for SMEs. The price elasticities are higher when the ex-ante claimable tax reductions rather than the ex-post actually claimed tax eductions are used to compute the user cost of R&D

Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players

The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty‐seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7‐week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5‐m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = −0.02/0.11). Thus, in contrast to the CG (ES = −0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = −0.35/−0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players.Actividad Física y Deport

Influence of cracking on oxygen transport in UHPFRC using stainless steel sensors

[EN] Reinforced concrete elements frequently suffer small cracks that are not relevant from the mechanical point of view, but they can be an entrance point for aggressive agents, such as oxygen, which could initiate the degradation processes. Fiber-Reinforced Concrete and especially Ultra High Performance Concrete increase the multi-cracking behavior, reducing the crack width and spacing. In this work, the oxygen availability of three types of concrete was compared at similar strain levels to evaluate the benefit of multi-cracking in the transport of oxygen. The types of concrete studied include traditional, High-Performance, and Ultra-High-Performance Fiber-Reinforced Concrete with and without nanofibers. To this purpose, reinforced concrete beams sized 150 x 100 x 750 mm(3) were prepared with embedded stainless steel sensors that were located at three heights, which have also been validated through this work. These beams were pre-cracked in bending up to fixed strain levels. The results indicate that the sensors used were able to detect oxygen availability due to the presence of cracks and the detected differences between the studied concretes. Ultra High Performance Concrete in the cracked state displayed lower oxygen availability than the uncracked High Performance Concrete, demonstrating its potential higher durability, even when working in cracked state, thanks to the increased multi-cracking response.The authors would like to express their gratitude to the Spanish Ministry of Science and Innovation for the pre-doctoral scholarship granted to Ana Martinez Ibernon (FPU 16/00723), to the Universitat Politecnica de Valencia for the pre-doctoral scholarship granted to Josep Ramon Lliso Ferrando (FPI-UPV-2018), and the European Union's Horizon 2020 ReSHEALience project (Grant Agreement No. 760824).Martínez-Ibernón, A.; Roig-Flores, M.; Lliso-Ferrando, JR.; Mezquida-Alcaraz, EJ.; Valcuende Payá, MO.; Serna Ros, P. (2020). Influence of cracking on oxygen transport in UHPFRC using stainless steel sensors. Applied Sciences. 10(1):1-17. https://doi.org/10.3390/app10010239S117101Front Matter. (2013). fib Model Code for Concrete Structures 2010, I-XXXIII. doi:10.1002/9783433604090.fmatterYoo, D.-Y., & Banthia, N. (2016). Mechanical properties of ultra-high-performance fiber-reinforced concrete: A review. Cement and Concrete Composites, 73, 267-280. doi:10.1016/j.cemconcomp.2016.08.001Wittmann, F., & Van Zijl, G. (Eds.). (2011). Durability of Strain-Hardening Fibre-Reinforced Cement-Based Composites (SHCC). doi:10.1007/978-94-007-0338-4Li, V. C. (2003). On Engineered Cementitious Composites (ECC). Journal of Advanced Concrete Technology, 1(3), 215-230. doi:10.3151/jact.1.215Asgari, M. A., Mastali, M., Dalvand, A., & Abdollahnejad, Z. (2017). Development of deflection hardening cementitious composites using glass fibres for flexural repairing/strengthening concrete beams: experimental and numerical studies. European Journal of Environmental and Civil Engineering, 23(8), 916-944. doi:10.1080/19648189.2017.1327888Ravindrarajah, R. S., & Swamy, R. N. (1989). Load effects on fracture of concrete. Materials and Structures, 22(1), 15-22. doi:10.1007/bf02472690Bascoul, A. (1996). State of the art report—Part 2: Mechanical micro-cracking of concrete. Materials and Structures, 29(2), 67-78. doi:10.1007/bf02486196Damgaard Jensen, A., & Chatterji, S. (1996). State of the art report on micro-cracking and lifetime of concrete—Part 1. Materials and Structures, 29(1), 3-8. doi:10.1007/bf02486001Berrocal, C. G., Löfgren, I., Lundgren, K., Görander, N., & Halldén, C. (2016). Characterisation of bending cracks in R/FRC using image analysis. Cement and Concrete Research, 90, 104-116. doi:10.1016/j.cemconres.2016.09.016Correia, M. J., Pereira, E. V., Salta, M. M., & Fonseca, I. T. E. (2006). Sensor for oxygen evaluation in concrete. Cement and Concrete Composites, 28(3), 226-232. doi:10.1016/j.cemconcomp.2006.01.006Yoon, I.-S. (2018). Comprehensive Approach to Calculate Oxygen Diffusivity of Cementitious Materials Considering Carbonation. International Journal of Concrete Structures and Materials, 12(1). doi:10.1186/s40069-018-0242-yBanthia, N., Zanotti, C., & Sappakittipakorn, M. (2014). Sustainable fiber reinforced concrete for repair applications. Construction and Building Materials, 67, 405-412. doi:10.1016/j.conbuildmat.2013.12.073Berrocal, C. G., Löfgren, I., & Lundgren, K. (2018). The effect of fibres on steel bar corrosion and flexural behaviour of corroded RC beams. Engineering Structures, 163, 409-425. doi:10.1016/j.engstruct.2018.02.068Sisomphon, K., Copuroglu, O., & Koenders, E. A. B. (2012). Self-healing of surface cracks in mortars with expansive additive and crystalline additive. Cement and Concrete Composites, 34(4), 566-574. doi:10.1016/j.cemconcomp.2012.01.005Ferrara, L., Krelani, V., & Carsana, M. (2014). A «fracture testing» based approach to assess crack healing of concrete with and without crystalline admixtures. Construction and Building Materials, 68, 535-551. doi:10.1016/j.conbuildmat.2014.07.008Roig-Flores, M., Pirritano, F., Serna, P., & Ferrara, L. (2016). Effect of crystalline admixtures on the self-healing capability of early-age concrete studied by means of permeability and crack closing tests. Construction and Building Materials, 114, 447-457. doi:10.1016/j.conbuildmat.2016.03.196López, J. Á., Serna, P., Navarro-Gregori, J., & Camacho, E. (2014). An inverse analysis method based on deflection to curvature transformation to determine the tensile properties of UHPFRC. Materials and Structures, 48(11), 3703-3718. doi:10.1617/s11527-014-0434-0Lopez, J. A., Serna, P., Camacho, E., Coll, H., & Navarro-Gregori, J. (2014). First Ultra-High-Performance Fibre-Reinforced Concrete Footbridge in Spain: Design and Construction. Structural Engineering International, 24(1), 101-104. doi:10.2749/101686614x13830788505793Negrini, A., Roig-Flores, M., Mezquida-Alcaraz, E. J., Ferrara, L., & Serna, P. (2019). Effect of crack pattern on the self-healing capability in traditional, HPC and UHPFRC concretes measured by water and chloride permeability. MATEC Web of Conferences, 289, 01006. doi:10.1051/matecconf/20192890100

Cross-Checking Different Sources of Mobility Information

The pervasive use of new mobile devices has allowed a better characterization in space and time of human concentrations and mobility in general. Besides its theoretical interest, describing mobility is of great importance for a number of practical applications ranging from the forecast of disease spreading to the design of new spaces in urban environments. While classical data sources, such as surveys or census, have a limited level of geographical resolution (e.g., districts, municipalities, counties are typically used) or are restricted to generic workdays or weekends, the data coming from mobile devices can be precisely located both in time and space. Most previous works have used a single data source to study human mobility patterns. Here we perform instead a cross-check analysis by comparing results obtained with data collected from three different sources: Twitter, census, and cell phones. The analysis is focused on the urban areas of Barcelona and Madrid, for which data of the three types is available. We assess the correlation between the datasets on different aspects: the spatial distribution of people concentration, the temporal evolution of people density, and the mobility patterns of individuals. Our results show that the three data sources are providing comparable information. Even though the representativeness of Twitter geolocated data is lower than that of mobile phone and census data, the correlations between the population density profiles and mobility patterns detected by the three datasets are close to one in a grid with cells of 2×2 and 1×1 square kilometers. This level of correlation supports the feasibility of interchanging the three data sources at the spatio-temporal scales considered.Partial financial support has been received from the Spanish Ministry of Economy (MINECO) and FEDER (EU) under projects MODASS (FIS2011-24785) and INTENSE@COSYP (FIS2012-30634), and from the EU Commission through projects EUNOIA, LASAGNE and INSIGHT. ML acknowledges funding from the Conselleria d'Educació, Cultura i Universitats of the Government of the Balearic Islands, and JJR from the Ramón y Cajal program of MINECO.Peer Reviewe