An empirical study of Cloud Gaming

This work is at: 11th Annual Workshop on Network and Systems Support for Games (NetGames), took place November 22-23, 2012 in Venice (Italy)Online gaming connects players from all over the world together for fun and entertainment, and has been regarded as one of the most profitable and popular Internet services. Besides, there is a growing trend towards moving local applications to remote data centers: this is often referred to as the cloud. With the purpose of studying the impact of Cloud Gaming on the access network load, in this paper we carry out an empirical network traffic analysis of two well-known cloud gaming platforms: On-Live and Gaikai. Traffic traces have been collected and analysed from five different games of both platforms. Cloud gaming has been observed to be remarkably different from traditional online gaming in terms of network load and traffic characteristics. Moreover, the traces have revealed similarities between the two platforms regarding the packet size distribution, and differences concerning the packet inter-arrival times. However, each platform shows a similar traffic pattern for most of the games it serves. Nonetheless, the racing and shooter games considered in this work demand more bandwidth than other game-genres.This work is partly supported by the projects TRION (TEC 2009-10724), FIERRO (TEC 2010- 12250-E) and Medianet (S-2009/TIC-1468); and by the Generalitat de Catalunya through the research support program project SGR-1202 and AGAUR FI-DGR 2012 grant.Publicad

Determinantes del trabajo infantil y la escolaridad: el caso del Valle del Cauca en Colombia

Colombia, al igual que la mayoría de países latinoamericanos, consciente de las repercusiones sociales y económicas negativas del trabajo infantil, se ha comprometido en la lucha por la erradicación de este fenómeno. Prueba de ello es la ratificación por parte del gobierno colombiano en el año 2007, del Convenio 182 de la OIT sobre la Prohibición de las Peores Formas de Trabajo Infantil y la Acción Inmediata para su Eliminación. En el plano regional, como parte del Plan de Desarrollo del Departamento del Valle del Cauca 2008-2011, se está implementando actualmente una estrategia territorial de erradicación del trabajo infantil en sus 42 municipios. Considerando este panorama, este trabajo indaga cuáles son los determinantes del trabajo infantil y la escolaridad en el departamento del Valle a partir de los datos de la Encuesta Nacional de Calidad de Vida del año 2003. Para el análisis se emplea un modelo econométrico Probit Bivariado, que permite el estudio conjunto e interrelacionado de decisiones diferentes, en este caso la asistencia escolar y el trabajo.-I. Introducción. II. Aproximación a los modelos teóricos que se acercan al estudio del fenómeno del trabajo infantil. III. Algunos estudios referentes al trabajo infantil y su relación con la educación. IV. Metodología y planeamiento econométrico. V. Resultados. VI. Conclusiones. Lista de referencias

Immune-system-dependent anti-tumor activity of a plant-derived polyphenol rich fraction in a melanoma mouse model.

Recent findings suggest that part of the anti-tumor effects of several chemotherapeutic agents require an intact immune system. This is in part due to the induction of immunogenic cell death. We have identified a gallotannin-rich fraction, obtained from Caesalpinia spinosa (P2Et) as an anti-tumor agent in both breast carcinoma and melanoma. Here, we report that P2Et treatment results in activation of caspase 3 and 9, mobilization of cytochrome c and externalization of annexin V in tumor cells, thus suggesting the induction of apoptosis. This was preceded by the onset of autophagy and the expression of immunogenic cell death markers. We further demonstrate that P2Et-treated tumor cells are highly immunogenic in vaccinated mice and induce immune system activation, clearly shown by the generation of interferon gamma (IFN-γ) producing tyrosine-related protein 2 antigen-specific CD8+ T cells. Moreover, the tumor protective effects of P2Et treatment were abolished in immunodeficient mice, and partially lost after CD4 and CD8 depletion, indicating that P2Et's anti-tumor activity is highly dependent on immune system and at least in part of T cells. Altogether, these results support the hypothesis that the gallotannin-rich fraction P2Et's anti-tumor effects are mediated to a great extent by the endogenous immune response following to the exposure to immunogenic dying tumor cells

An Immunomodulatory Gallotanin-Rich Fraction From Caesalpinia spinosa Enhances the Therapeutic Effect of Anti-PD-L1 in Melanoma.

PD-1/PD-L1 pathway plays a role in inhibiting immune response. Therapeutic antibodies aimed at blocking the PD-1/PD-L1 interaction have entered clinical development and have been approved for a variety of cancers. However, the clinical benefits are reduced to a group of patients. The research in combined therapies, which allow for a greater response, is strongly encouraging. We previously characterized a polyphenol-rich extract from Caesalpinia spinosa (P2Et) with antitumor activity in both melanoma and breast carcinoma, as well as immunomodulatory activity. We hypothesize that the combined treatment with P2Et and anti-PD-L1 can improve the antitumor response through an additive antitumor effect. We investigated the antitumor and immunomodulatory activity of P2Et and anti-PD-L1 combined therapy in B16-F10 melanoma and 4T1 breast carcinoma. We analyzed tumor growth, hematologic parameters, T cell counts, cytokine expression, and T cell cytotoxicity. In the melanoma model, combined P2Et and anti-PD-L1 therapy has the following effects: decrease in tumor size; increase in the number of activated CD4 <sup>+</sup> and CD8 <sup>+</sup> T cells; decrease in the number of suppressor myeloid cells; increase in PD-L1 expression; decrease in the frequency of CD8 <sup>+</sup> T cell expressing PD-1; improvement in the cytotoxic activity of T cells; and increase in the IFN γ secretion. In the breast cancer model, P2Et and PD-L1 alone or in combination show antitumor effect with no clear additive effect. This study shows that combined therapy of P2Et and anti-PD-L1 can improve antitumor response in a melanoma model by activating the immune response and neutralizing immunosuppressive mechanisms

Metamorphic titanite–zircon pseudomorphs after igneous zirconolite

The formation of metamorphic zircon after baddeleyite is a well-known reaction that can be used to date the metamorphism of igneous silica-undersaturated rocks. By contrast, metamorphic minerals formed after igneous zirconolite have rarely been reported. In this paper, we document metamorphic titanite + zircon pseudomorphs formed from the metamorphic breakdown of igneous zirconolite in syenodiorite and syenite, in the southeastern Sveconorwegian Province, Sweden. Water-rich fluid influx during tectonometamorphism in epidote–amphibolite-facies metamorphic conditions caused the release of silica during a metamorphic reaction involving igneous feldspar and pyroxene and the simultaneous breakdown of igneous Zr-bearing phases. Typical titanite + zircon intergrowths are elongated or platy titanite crystals speckled with tiny inclusions of zircon. Most intergrowths are smaller than 15 µm; some are subrounded in shape. Locally, bead-like grains of titanite and zircon are intergrown with silicate minerals. The precursor igneous zirconolite was found preserved only in a sample of near-pristine igneous syenodiorite, as remnant grains of mainly &lt; 2 µm in size. Two somewhat larger crystals, 8 and 12 µm, allowed semiquantitative confirmation using microprobe analysis. Analogous with zircon pseudomorphs after baddeleyite, titanite + zircon pseudomorphs after zirconolite potentially offer dating of the metamorphic reaction, although the small size of the crystals makes dating with today's techniques challenging. The scarcity of reports of zirconolite and pseudomorphs reflects that they are either rare or possibly overlooked.</p

On Providing Metro Ethernet Services over Transparent WDM Optical Rings

The long list of benefits (especially cost and capacity) of Ethernet LANs has made the IEEE, the ITU-T, and the Metro Ethernet Forum define the requirements for taking Ethernet beyond the local area, toward the metropolitan region. In addition, the ever-increasing traffic demands of new applications and users can only be met by the huge bandwidth capacity provided by optical fibers. This work studies how to provide metro Ethernet services over transparent tunable-transmitter fixed-receiver WDM optical ring networks. A new adaptation layer of ME to WDM is proposed, and its benefits and drawbacks are studied. It is shown that such a transparent WDM ring network can be seen as a logical full-mesh topology by the upper ME layer, thus reducing to one the number of optical-electronic-optical conversions per unicast frame. Additionally, two different approaches are proposed in the case of broadcast/multicast traffic, since this may bring scalability difficulties in ring topologies.The work described in this article was carried out with the support of the Building the Future Optical Network in Europe (BONE) project, a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors are thankful for the support of the T2C2 (grant TIN2008-06739C04-01) and MEDIANET (grant S2009/TIC-1468) projects for the development of this work.European Community's Seventh Framework ProgramPublicad

Towards an energy efficient 10 Gb/s optical ethernet: performance analysis and viability

The new IEEE 802.3az Energy Efficient Ethernet (EEE) standard will improve significantly the energy efficiency of 10 Gbps copper transceivers by the introduction of a sleep mode for idle transmission times. The next step towards energy saving seems to be the application of similar concepts to Optical Ethernet, both for short and long range links. To this aim, this paper starts by proposing an analytical model to estimate the energy consumption of a link that uses a sleep-mode power saving mechanism. This model can be useful to answer a number of questions that need to be carefully studied. Otherwise, the complexity of optical components could be increased for the sake of an energy saving that could turn out negligible. In the rest of the paper we analyze three key questions to try to shed some light on this design decision: (a) is the new copper EEE actually outperforming the current regular optical Ethernet in terms of energy saving in such a way that optical PHYs (transceivers) actually need a green upgrade to remain more energy efficient than their copper counterparts? (b) How much energy saving could be actually achieved by EE optical Ethernet? (c) What is the transition time required to achieve a substantial energy saving at medium traffic loads on EE 10 Gb/s optical Ethernet links? The answer to the latter question sets a concrete goal for short-term research in fast on–off laser technology.This work has been supported by a Google Research Award, by the BONE project ("Building the Future Optical Network in Europe"), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Program, by the MEDIANET project and by the Spanish MCINN grants TIN2008-06739-C04-01/TSI and PR2009- 0221. The authors would also like to acknowledge the support for this work from the UC3M-CAM Greencom research grant (under code CCG10-UC3M/TIC- 5624) and TEC2008-02552-E/TEC.Publicad

On providing mobility management in WOBANs: Integration with PMIPv6 and MIH

The Wireless-Optical Broadband Access Network (WOBAN) is a promising access architecture that combines the high performance of optical networks with the ubiquity and convenience of wireless technologies. This article proposes a network-based mobility framework that is specially tailored for WOBANs. The proposed architecture is based on Proxy Mobile IPv6 and IEEE 802.21 mobility management protocols, but it also defines a number of optimizations that enable the seamless handover of mobile nodes. In particular, the hierarchical architecture together with the broadcast-and-select nature of the optical part of the WOBAN are leveraged to: optimize the mobility of users with respect to the overall network resources, both at the wireless access and optical distribution parts, remove the overhead of IP-in-IP tunneling between the PMIPv6 entities, and perform an efficient bicasting during the handover process to minimize packet loss.The authors would like to acknowledge the support of the EU-funded MEDIEVAL (grant FP7-ICT-2009-5/258053), the CAM-funded Medianet project (under code S-2009/TIC-1468) and the MICINN research grant TIN2010-20136-C03.European Community's Seventh Framework ProgramPublicad

A CTMC-based characterisation of the propagation of errors in GMPLS Optical Rings

Abstract: This article presents a Continuous-Time Markov Chain model to characterise the propagation of failures in optical GMPLS rings. In order to characterize the behaviour of failure propagation epidemic-based models are commonly used. However, the existing epidemic models do not take into account the specific features of a multilayer network environment. A node failure in GMPLS-based networks can affect: Control Plane and Data plane reporting different failures scenarios. Consequently, an extended generic epidemic model called SID is proposed, in order to cover multiple failures and recovered states in a GMPLS Multilayer scenario. The CTMC model takes into account the SID model and provides a set of design rules to specify the values of repair rates required to achieve a given service availability, assuming a certain infection and disable rate.The work described in this paper was carried out with the support of the BONE project (''Building the Future Optical Network in Europe''), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors would like to thank the support of the T2C2 Spanish project (under code TIN2008-06739-C04-01) and the Madrid Community through the MEDIANET project (S-2009/TIC-1468) to the development of this work. This work is partially supported by Spanish Ministry of Science and Innovation project TEC 2009-10724 and by Generalitat de Catalunya research support program (SGR-1202).Publicad

FLUID INCLUSIONS STUDY IN THERMAL GRADIENT WELLS, NEVADO DEL RUIZ VOLCANO

El estudio de inclusiones fluidas asociadas al sistema hidrotermal-magmático del Volcán Nevado del Ruiz permitió conocer en detalle aspectos característicos de los fluidos involucrados en la evolución del sistema geotérmico. Para ello se seleccionaron muestras de la parte más profunda de tres pozos de gradiente térmico que fueron perforados en la zona de Estudio del Proyecto Geotérmico del Macizo Volcánico del Ruiz, promovido por ISAGEN S.A. ESP. Con el fin de establecer la interacción fluido-roca durante la evolución del sistema hidrotermal se analizaron principalmente inclusiones fluidas secundarias hospedadas en cuarzo, plagioclasa y carbonato; en estos minerales también se pudieron estudiar algunas inclusiones fluidas primarias. Las microestructuras permitieron identificar cuáles de los cristales analizados son minerales formadores de roca y cuales son minerales de alteración. Los carbonatos en los que se analizaron inclusiones fluidas ocurren como venas con textura coloforme que cortan una sucesión de tobas y lavas andesíticas (profundidades de 170,0 y 171,6 m). Las inclusiones en los carbonatos se interpretaron como originadas por fluidos hidrotermales de alta temperatura (superiores a 250 °C) y por fluidos de baja temperatura con salinidad variable, que posiblemente se relacionan con los fluidos del sistema geotermal actual. En estas muestras se realizaron adicionalmente análisis de catodoluminiscencia, espectrometría de dispersión de energía y se obtuvieron imágenes de electrones retrodispersados, estas técnicas permiten definir con mayor precisión la relación entre los datos de microtermometría y las variaciones texturales y composicionales asociadas al bandeamiento coloforme, en el que se desarrollan niveles de calcita y dolomita con presencia de cristales de barita relacionados con el evento hidrotermal. Las inclusiones fluidas hospedadas en cuarzo se observaron en muestras de milonitas (profundidades de 299,9 y 300,9 m), estas inclusiones se interpretan como formadas por la interacción de fluidos de metamorfismo e hidrotermales de alta temperatura, la interpretación se basa en la profundidad de las muestras y en los resultados del análisis de las inclusiones. Las inclusiones fluidas analizadas en plagioclasa corresponden a muestras de lavas andesíticas ubicadas a profundidades de 259,9 y 260,0 m, éstas inclusiones pertenecen al sistema de H2O + CO2 y se consideran como formadas de fluidos de origen magmático, se observan como dos grupos composicionales, unas inclusiones tienen fase líquida y gaseosa (CO2) y otras solamente fase gaseosa, esta característica evidencia atrapamiento heterogéneo, soportando la interpretación de origen magmático del fluido. Palabras clave: Inclusiones fluidas, Fluidos geotermales, Sistema hidrotermal, Temperatura. &nbsp;&nbsp; A fluid inclusions study in the Nevado del Ruiz volcano hydrothermal system allowed to characterize fluids involved in the evolution of the geothermal system. Fluid inclusions hosted in quartz, plagioclase and carbonate from samples of the deepest parts of three thermal gradient wells were analyzed to understand fluid-rock interaction. Fluid inclusions hosted in carbonate veins with coloform microestructure represent hydrothermal fluids with temperatures higher than 250° C. This interpretation is supported by microprobe and cathodoluminescence analysis that also indicate a hydrothermal origin for the veins. Fluid inclusions hosted in quartz (mylonites) were originated by metamorphic fluids and fluid inclusions hosted in plagioclase (andesitic lavas) are considered to be originated from magmatic fluids (H2O + CO2system). Keywords: Fluid inclusions, Geothermal fluids, Hydrothermal system, Temperature &nbsp