573 research outputs found
Breakdown of tori in symplectic maps
Treballs finals del Màster en Matemàtica Avançada, Facultat de matemàtiques, Universitat de Barcelona, Any: 2014, Director: Carles SimóMost of physical phenomena can be explained in terms of Hamiltonian systems. These continuous dynamical systems can be related with symplectic maps. Under certain hypothesis one can see that these maps present some invariant tori. Then, it is really interesting to understand how these tori behave. One of the most important properties these tori present is that they persist under small perturbation of our initial systems but that for higher perturbations they are going to break down. These perturbations are usually related with equations depending on a parameter, K. For 2D symplectic maps, renormalization techniques allow to understand the
mechanisms concerning the destruction of invariant circles. Rotation numbers of these circles play a key role in the analysis of their breakdown. Throughout this work we will show some of the most important tools to deal with these invariant circles
La ayuda al desarrollo en tiempos de crisis. ¿A quíen le importa? : cooperación internacional descentralizada. La Junta de Andalucía. Estudio comparado de caso
53 páginas.Tabajo Fin de Diploma de Especialización en Estudios Contemporáneos sobre Geopolítica, Conflictos Armados y Cooperación Internacional (2019/20). Tutor: Dr. D. Alfredo Langa Herrero. Como consecuencia de la crisis económica que está padeciendo
España en los últimos años, las políticas públicas que llevan a cabo las
comunidades autónomas se han resentido. Distintos informes y expertos ponen
de manifiesto que la política de ayuda oficial al desarrollo ha sido una de las
más desfavorecidas. Este estudio profundiza en esta línea constando que
todas las administraciones, aunque con marcados matices, aplicaron severos
recortes. El trabajo trata de dar respuesta al tratamiento que ha recibido esta
política por parte de la Junta de Andalucía durante los últimos catorce años, así
como un análisis comparado con otras comunidades autónomas y el Ejecutivo
Nacional.As a result of the economic crisis that Spain is suffering in recent
years, public policies carried out by the autonomous communities have
suffered. Various reports and experts show that the policy of official
development assistance has been one of the most disadvantaged. This study
delves into this line comprising all administrations, although with marked
nuances, applied severe cuts. The work tries to respond to treatment that has
received this policy by the Government of Andalusia over the last fourteen years
as well as a comparative analysis with other autonomous communities and the
National Executive
End-to-end quality of service provisioning in multilayer and multidomain environments
Tesis doctoral inédita. Universidad Autónoma de Madrid, Escuela Politécnica Superior, marzo de 200
Admission control in Flow-Aware Networking (FAN) architectures under GridFTP traffic
This is the author’s version of a work that was accepted for publication in Optical Switching and Networking. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Optical Switching and Networking, 6, 9 (2009) DOI: 10.1016/j.osn.2008.05.003Selected papers from First International Symposium on Advanced Networks and Telecommunication Systems, ANTS 2007Computing and networking resources virtualization is the main objective of Grid services. Such a concept is already used in the context of Web-services on the Internet. In the next few years, a large number of applications belonging to various domains (biotechnology, banking, finance, car and aircraft manufacturing, nuclear energy etc.) will also benefit from Grid services. Admission control is a key functionality for Quality of Service (QoS) provision in IP networks, and more specifically for Grid services provision. Service differentiation (DS) is a widely deployed technique on the Internet. It operates at the packet level on a best-effort mode. Flow-Aware Networking (FAN) that operates at the scale of the IP flows relies on implicit flow differentiation through priority fair queuing (PFQ). It may be seen as an alternative to DS. A Grid session may be seen as a succession of parallel TCP/IP flows characterized by data transfers with much larger volume than usual TCP/IP flows. In this paper, we propose an extension of FAN for the Grid environment called Grid over FAN (GoFAN). We compare, by means of computer simulations, the efficiency of Grid over DS (GoDS) and GoFAN. Two variants of GoFAN architectures based on different fair queuing algorithms are considered. As a first step, we provide two short surveys on QoS for Grid environment and on QoS in IP networks respectively
Neuroprotective Effects of Exercise Treatments After Injury : The Dual Role of Neurotrophic Factors
Shared connections between physical activity and neuroprotection have been studied for decades, but the mechanisms underlying this effect of specific exercise were only recently brought to light. Several evidences suggest that physical activity may be a reasonable and beneficial method to improve functional recovery in both peripheral and central nerve injuries and to delay functional decay in neurodegenerative diseases. In addition to improving cardiac and immune functions, physical activity may represent a multifunctional approach not only to improve cardiocirculatory and immune functions, but potentially modulating trophic factors signaling and, in turn, neuronal function and structure at times that may be critical for neurodegeneration and regeneration. Research content related to the effects of physical activity and specific exercise programs in normal and injured nervous system have been reviewed. Sustained exercise, particularly if applied at moderate intensity and early after injury, exerts anti-inflammatory and pro-regenerative effects, and may boost cognitive and motor functions in aging and neurological disorders. However, newest studies show that exercise modalities can differently affect the production and function of brain-derived neurotrophic factor and other neurotrophins involved in the generation of neuropathic conditions. These findings suggest the possibility that new exercise strategies can be directed to nerve injuries with therapeutical benefits. Considering the growing burden of illness worldwide, understanding of how modulation of neurotrophic factors contributes to exercise-induced neuroprotection and regeneration after peripheral nerve and spinal cord injuries is a relevant topic for research, and represents the beginning of a new non-pharmacological therapeutic approach for better rehabilitation of neural disorders
Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers
Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.V. López, J. L. García-Dorado, J. A. Hernández, and J. Aracil, "Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers", in ICTON Mediterranean Winter Conference, 2007. ICTON-MW 2007, p. 1-6Recent research in optical burst switched networks has proposed solutions to support subwavelength reservation for the periodic transmission of data bursts, which can coexist with conventional asynchronous bursts, bringing the polymorphous, agile and transparent optical networks (PATON) [1]. Thus, network operators can distribute IPTV channels to their customers, whereby they can use the spare bandwidth for the transmission of best-effort traffic, making use of the free gaps in between such periodic reservations. This work proposes scheduling algorithms for the transmission of periodic channels using PATON, and studies the blocking probability observed by best-effort traffic, when such scheduling algorithms are used.This work has been partially funded by the Spanish Ministry of Science and Education under the project DIOR
(TEC2006-03246), and by the Comunidad Autónoma de Madrid under project e-Magerit (S-0505/TIC/000251).
The authors would also like to acknowledge the support from the European Union VI Framework Programme e-
Photon/ONe+ Network of Excellence (FP6-IST-027497)
Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures
Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. López, J. L. Añamuro, V. Moreno, J. E. L. De Vergara, J. Aracil, C. García, J. P. Fernández-Palacios, and M. Izal, "Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures", in 17th IEEE International Conference on Networks, ICON 2011, p. 89-94This paper describes an implementation of multilayer
techniques using the network infrastructure provided by
FEDERICA, PASITO and OneLab projects. FEDERICA project
provides a network infrastructure, based on virtualization capabilities
in both network and computing resources, which
creates custom-made virtual environments. PASITO is a layer-
2 network that connects universities and research centers in
Spain. OneLab measurements tools allow carrying out highaccuracy
active network measurements. Thanks to FEDERICA
and PASITO, we have a multi-layer architecture where the traffic
is routed based on the measurements of OneLab equipment.
To carry out this experiment, we have developed a Multi-layer
Traffic Engineering manager and an implementation of the Path
Computation Element Protocol to solve the lack of a control plane
in IP oriented networks. This work shows the feasibility of multilayer
techniques as a convenient solution for network operators
and it validates our Path Computation Element implementation.This work has been partially funded by the Spanish Ministry
of Education and Science under project ANFORA (TEC2009-13385), by the Spanish Ministry of Industry, Tourism and
Trade under PASITO project, and by the European Union
under project OneLab2 (FP7-224263). Authors would like
to thank Mauro Campanella (GARR, the project coordinator
of FEDERICA) and Miguel Angel Sotos (RedIris) for their
support to carry out this work
On the relationship between optical variability, visual saliency, and eye fixations: a computational approach
A hierarchical definition of optical variability is proposed that links physical magnitudes to visual saliency and yields a more reductionist interpretation than previous approaches. This definition is shown to be grounded on the classical efficient coding hypothesis. Moreover, we propose that a major goal of contextual adaptation mechanisms is to ensure the invariance of the behavior that the contribution of an image point to optical variability elicits in the visual system. This hypothesis and the necessary assumptions are tested through the comparison with human fixations and state-of-the-art approaches to saliency in three open access eye-tracking datasets, including one devoted to images with faces, as well as in a novel experiment using hyperspectral representations of surface reflectance. The results on faces yield a significant reduction of the potential strength of semantic influences compared to previous works. The results on hyperspectral images support the assumptions to estimate optical variability. As well, the proposed approach explains quantitative results related to a visual illusion observed for images of corners, which does not involve eye movementsS
Whole transcription profile of responders to anti-tnf drugs in pediatric inflammatory bowel disease
Background: Up to 30% of patients with pediatric inflammatory bowel disease (IBD) do not respond to anti-Tumor Necrosis Factor (anti-TNF) therapy. The aim of this study was to identify pharmacogenomic markers that predict early response to anti-TNF drugs in pediatric patients with IBD. Methods: An observational, longitudinal, prospective cohort study was conducted. The study population comprised 38 patients with IBD aged 0.6 or <−0.6 and p value < 0.05). After validation, FCGR1A, FCGR1B, and GBP1 were overexpressed in non-responders two weeks after initiation of anti-TNF treatment (Log2FC 1.05, 1.21, and 1.08, respectively, p value < 0.05). Conclusion: Expression of the FCGR1A, FCGR1B, and GBP1 genes is a pharmacogenomic biomarker of early response to anti-TNF agents in pediatric IBDInstituto de Salud Carlos III número de becas PI16 / 00559 y PI19 / 00792Consejería de Educación y Deporte de la Comunidad de Madrid PEJ16 / MED / AI-1260Instituto de Investigaciones Sanitarias Gregorio Marañón PRE2018-2Fondos Europeos de Desarrollo Regional (FEDER) del Comisión Europe
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