2,384 research outputs found

    Some generalizations of the notion of Lie algebra

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    We introduce the notion of left (and right) quasi-Loday algebroids and a "universal space" for them, called a left (right) omni-Loday algebroid, in such a way that Lie algebroids, omni-Lie algebras and omni-Loday algebroids are particular substructures.Comment: Second version. 14 pages. Included some comments about previous works related to Leibniz algebras, and updated bibliography. A new example adde

    Designing optimal controls by parameter optimization for a stance-control knee-ankle-foot orthosis

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    Inverse dynamics simulation is often used in robotic and mechatronic systems to track a desired trajectory by feed-forward control. Musculoskeletal multibody systems are highly overactuated and show a switching number of closed kinematical loops. The method of inverse dynamics is also successfully applied to overactuated systems by parameter optimization for two- and three-dimensional models of the human musculoskeletal system. The presented simulation approach is fully based on optimizationPostprint (published version

    On Lie Algebroids and Poisson Algebras

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    We introduce and study a class of Lie algebroids associated to faithful modules which is motivated by the notion of cotangent Lie algebroids of Poisson manifolds. We also give a classification of transitive Lie algebroids and describe Poisson algebras by using the notions of algebroid and Lie connections

    Detection of Communities within the Multibody System Dynamics Network and Analysis of Their Relations

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    Multibody system dynamics is already a well developed branch of theoretical, computational and applied mechanics. Thousands of documents can be found in any of the well-known scientific databases. In this work it is demonstrated that multibody system dynamics is built of many thematic communities. Using the Elsevier’s abstract and citation database SCOPUS, a massive amount of data is collected and analyzed with the use of the open source visualization tool Gephi. The information is represented as a large set of nodes with connections to study their graphical distribution and explore geometry and symmetries. A randomized radial symmetry is found in the graphical representation of the collected information. Furthermore, the concept of modularity is used to demonstrate that community structures are present in the field of multibody system dynamics. In particular, twenty-four different thematic communities have been identified. The scientific production of each community is analyzed, which allows to predict its growing rate in the next years. The journals and conference proceedings mainly used by the authors belonging to the community as well as the cooperation between them by country are also analyzed

    Anestésicos locales en odontoestomatología

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    El motivo del presente trabajo es hacer una revisión bibliográfica sobre los anestésicos locales (AL) que son las drogas de más uso en Odontoestomatología y que, merced a su perfeccionamiento, en los últimos años han significado un enorme avance, tanto en los tratamientos odontológicos, para mejorar de forma determinante la operatoria dental, como el confort del paciente en estos procederes. Además al haber añadido a estos anestésicos locales un vasoconstrictor se ha conseguido que se puedan usar dosis menores de anestésico y a la vez que con menos dosis se puede actuar más tiempo y en buenas condiciones para el paciente y el dentista. Se realiza al mismo tiempo un estudio de las posibles interacciones medicamentosas, contraindicaciones, etc. de los distintos componentes de la solución anestésica, así como las posibles reacciones de alergia o de hipersensibilidad a la que puedan dar lugar y que se han de tener muy en cuenta a la hora de su utilización en la cavidad oral.The purpose of the present paper is to carry out a review of the literature on local anesthetics (LAs), which are the most commonly used drugs in dentistry. Thanks to their improvement over the last few years, they have constituted an enormous advance in both odontological treatment - improving the dental operation in a determinant manner, and the comfort of the patient during these procedures. Furthermore, the addition of a blood vessel constrictor to these local anesthetics has meant that a lower dose of anesthetic can be used, which at the same time acts for longer, providing better conditions for both the patient and dentist. In addition, a study is made of the possible drug interactions, contraindications etc. of the different components in the anesthetic solution, and likewise the possible allergic hypersensitive reactions which can take place and which must be taken closely into consideration when used in the oral cavity

    Enfoque por tareas: Un modelo de programa

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    One of the reasons to choose this topic for my final project was that I have always been taugh by teachers who mostly ignored the communicative aspect of the language. That is why I was so impressed when I first heard about task based language approach. This presentation first attempts to describe the characteristics of Task Based Learning (TBL), its stages, conditions and constraints. It then introduces briefly a possible example of a didactic programming based on TBL method. Task Based Learning approach suggests a different way of teaching languages, focussing on the learner as an individual and encouraging communication. The tasks involved in this approach are divided into three stages: Pre-task: Introductory explanation to the subject by the teacher, using photos, posters, etc. This stage can also be used as a strategy to focus their attention on and introduce them to the task, Moreover, Van Gorp and Bogaert suggest that it is the best moment to motivate learners and organize the following phase, by providing clear instructions about the performance and the goal of the task. Task Performance: Working with and using the target language. Carrying out activities in pairs or groups. During this stage, positive feedback is one of the best instruments to encourage their students Post Task: analysing the problems they have had in the process and their possible solutions. The focus here is on error-analysisFilología InglesaMáster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanzas de Idioma

    Dungeons & Dragons as trasmedia vehicle of the 20th century literature in pop culture

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    With the new possibilities of social media and streaming services, some narratives like table-top role-playing games seem to find their way through pop culture. Their repercussion and referencing in TV shows and the Internet support the increasing awareness in pop culture at the same time that this sort of games is re-configured to meet the modern times in media, keeping their essence of pen, paper and friends around a table. This dissertation analyses the influence of the game in modern texts through its highest representative, Dungeons & Dragons. The successful show Stranger Things serves the purpose of analysing how the nostalgia created around the eighties and its aesthetic use of Dungeons & Dragons as vehicle for the main elements of plot and the focalised vision of the same. The live streaming of role-play sessions has also helped in this spread of the community, like Critical Role, allowing a higher engagement of the audience through the ease of the relaxed atmosphere of friends enjoying their hobby, yet reaching almost a professional level of production and writing. The analysis also discusses the roots of this game in the work of J. R. R. Tolkien and H. P. Lovecraft, highlighting several points of the game like the characterisation of the races, influenced by the concepts in Tolkien’s literature and the addition of a dark element from the cosmic horror genre, introducing recognisable elements of vulnerability, horror and antagonists’ new definitions

    OFAR-CM: Efficient Dragonfly networks with simple congestion management

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    Dragonfly networks are appealing topologies for large-scale Data center and HPC networks, that provide high throughput with low diameter and moderate cost. However, they are prone to congestion under certain frequent traffic patterns that saturate specific network links. Adaptive non-minimal routing can be used to avoid such congestion. That kind of routing employs longer paths to circumvent local or global congested links. However, if a distance-based deadlock avoidance mechanism is employed, more Virtual Channels (VCs) are required, what increases design complexity and cost. OFAR (On-the-Fly Adaptive Routing) is a previously proposed routing that decouples VCs from deadlock avoidance, making local and global misrouting affordable. However, the severity of congestion with OFAR is higher, as it relies on an escape sub network with low bisection bandwidth. Additionally, OFAR allows for unlimited misroutings on the escape sub network, leading to unbounded paths in the network and long latencies. In this paper we propose and evaluate OFAR-CM, a variant of OFAR combined with a simple congestion management (CM) mechanism which only relies on local information, specifically the credit count of the output ports in the local router. With simple escape sub networks such as a Hamiltonian ring or a tree, OFAR outperforms former proposals with distance-based deadlock avoidance. Additionally, although long paths are allowed in theory, in practice packets arrive at their destination in a small number of hops. Altogether, OFAR-CM constitutes the first practicable mechanism to the date that supports both local and global misrouting in Dragonfly networks.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. ERC-2012-Adg-321253- RoMoL, the Spanish Ministry of Science under contracts TIN2010-21291-C02-02, TIN2012-34557, and by the European HiPEAC Network of Excellence. M. García participated in this work while affiliated with the University of Cantabria.Peer ReviewedPostprint (author's final draft

    Antifungal effect and reduction of Ulmus minor symptoms to Ophiostoma novo-ulmi by carvacrol and salicylic acid

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    There are still no effective means to control Dutch elm disease (DED), caused by the vascular fungi Ophiostoma ulmi and O. novo-ulmi. Plant phenolics may provide a new strategy for DED control, given their known antifungal activity against pathogens and their involvement in plant defence mechanisms. The in vitro antifungal activity of salicylic acid, carvacrol, thymol, phenol, o-cresol, m-cresol, p-cresol, and 2,5-xylenol against the DED pathogens was tested. Also, the protective effect of watering Ulmus minor seedlings with these compounds was tested against O. novo-ulmi. Salicylic acid, carvacrol, and thymol showed the strongest antifungal in vitro activity, while carvacrol and salicylic acid provided the strongest in vivo protection against O. novo-ulmi (63 and 46% reduction of leaf wilting symptoms with respect to controls, respectively). The effect of the treatments on tree phenology was low, and a significant negative relation was observed between the number of days to bud burst and the leaf wilting symptoms after inoculation, probably determined by genetic differences among the elm tree progenies used. The treatments with salicylic acid, carvacrol and thymol induced the highest shift in phenolic metabolite profile with respect to control trees. The protective effect of carvacrol and salicylic acid is discussed in terms of their combined activity as antifungal compounds and as inductors of tree defence responses
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