Madrid

University of Barcelona, Barcino, Catalonia, Spain

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Publications (24)6.35 Total impact

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    ABSTRACT: MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith observations the trigger threshold of the MAGIC telescopes is about 50GeV. The integral sensitivity for sources with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution at those energies is < 0.07 degree, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in following components: < 15% in energy scale, 11-18% in flux normalization and +/-0.15 for the energy spectrum power-law slope.
    09/2014;
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    ABSTRACT: Resumen Este artículo ofrece un análisis comparativo de los factores de liderazgo en el sector de las relaciones públicas y la gestión de la comunicación entre España y el conjunto de los 23 países que han participado en el Cross-Cultural Cultural Study of Leadership in Public Relations and Communication Management, promovido por la Universidad de Alabama y financiado por IBM y Heyman Associates. Siguiendo el modelo conceptual de Meng y Berger (2011), se abordan los desafíos que afrontan las relaciones públicas en la actualidad, así como los requisitos y características de los 'líderes excelentes'. Los resultados obtenidos suponen un avance en el conocimiento científico sobre el liderazgo en la gestión de comunicación, un tema aún de escaso desarrollo en la literatura académica internacional y especialmente poco explorado en España. Investigadores en Relaciones Públicas (AIRP) y, entre otras investigaciones, coordina en España el proyecto European Communication Monitor. Abstract This paper offers a comparative analysis of leadership dimensions in public relations and communication management between Spain and a group of 23 countries which have participated in the Cross-Cultural Study of Leadership in Public relations and Communication Management, conducted by the University of Alabama and financed by IBM and Heymann Associates. Following the conceptual model from Meng and Berger (2011), this paper investigates the challenges faced by public relations, as well as the prerequisites of excellent leaders. Achieved results make a breakthrough in scientific knowledge about leadership in communication management, a little developed subject in academic literature, especially in Spain.
    Revista Internacional de Relaciones Públicas. 05/2013; 3(5):111-132.
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    ABSTRACT: An important driver of amphibian declines is chytridiomy-cosis, a disease caused by the pathogen Batrachochytrium dendrobatidis (Bd; Berger et al. 1998; Daszak et al. 1999, 2003; Ron and Merino-Viteri 2000; Bosch et al. 2001; Collins and Stor-fer 2003, Ron et al. 2003; La Marca et al. 2005; Wake and Vre-denburg 2008; Walker et al. 2010). Bd is now known to be an emerging pathogen that is rapidly expanding its global range (Fisher et al. 2009) and now has attained a global distribution on all continents that contain amphibians (www.bd-maps.net). Research by Weldon et al. (2004) on the potential origin of Bd suggests that the panzootic originated in South Africa and has perhaps been dispersed by international trade in amphibians, becoming established around the word (Rödder et al. 2009). To date, the rapid and widespread distribution of Bd infection across hundreds of amphibian species is alarming. In Spain, outbreaks of chytridiomycosis and mass mortali-ties has been reported in many species and in different regions of the country (Bosch et al. 2001; Bosch and Martínez-Solano 2006; Walker et al. 2008, 2010). In the south of Spain, Bd is widely distributed (www.bd-maps.net); Bosch et al., unpubl. data), suggesting that its occurrence in the north of Morocco is plausible. The two regions are spatially proximate with similar Mediterranean ecologies, however are separated by the straits of Gibraltar. In addition, ecological niche modelling has shown that the environmental envelope in the north of Morocco is suitable for the establishment of Bd where susceptible amphib-ians occur (Ron 2005; Rödder et al. 2009). The legal and illegal increase in the transport of animals for pet trade (Fisher and Garner 2007), and the possibility that the fungus could be vec-tored into Morocco on the feathers of water birds, are potential modes of transmission between Spain and Morocco. However, no systematic surveillance for Bd has been undertaken across this region, where several endemic species occur with a high ecological value. The aim of the present study is to conduct the first survey for Bd in north Morocco in order to determine the presence, prevalence and intensity of infection in the amphib-ian populations that occur within region. These data will allow us to understand the distributional patterns of Bd, providing
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    ABSTRACT: The very high energy (VHE) \gamma-ray source HESS J0632+057 has recently been confirmed to be a \gamma-ray binary. The optical counterpart is the Be star MWC 148, and a compact object of unknown nature orbits it every ~321 d with a high eccentricity of ~0.8. We monitored HESS J0632+057 with the stereoscopic MAGIC telescopes from 2010 October to 2011 March and detected significant VHE \gamma-ray emission during 2011 February, when the system exhibited an X-ray outburst. We find no \gamma-ray signal in the other observation periods when the system did not show increased X-ray flux. Thus HESS J0632+057 exhibits \gamma-ray variability on timescales of the order of one to two months possibly linked to the X-ray outburst that takes place about 100 days after the periastron passage. Furthermore our measurements provide for the first time the \gamma-ray spectrum down to about 140 GeV and indicate no turnover of the spectrum at low energies. We compare the properties of HESS J0632+057 with the similar \gamma-ray binary LS I +61 303, and discuss on the possible origin of the multi-wavelength emission of the source
    The Astrophysical Journal Letters 03/2012; 754(1). · 6.35 Impact Factor
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    ABSTRACT: Resumen Desde su nacimiento, la llamada web 2.0 o web social ha puesto a disposición de las empresas un arsenal de herramientas que, por primera vez, pueden hacer realidad las promesas de diálogo, transparencia, consenso y entendimiento mutuo con los públicos, meta hacia la que deben avanzar las relaciones públicas. Carlos desde el curso 2006-2007. Además, ha trabajado en diferentes medios de comunicación escritos y en agencias de comunicación.
    REDMARKA UIMA-Universidad de A Coruña - CIECID. 11/2011; 7:83-109.
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    ABSTRACT: The use of techniques such as low temperature scanning electron microscopy (LTSEM) and confocal laser scanning microscopy (CLSM) allows the study of lichen thalli in different states of hydration and also near the natural state. The spatial organization of desiccated thalli, with reduced, very compact algal layers, is different from that of hydrated ones. Sometimes, the observation with transmission electron microscopy (TEM) of photobiont pyrenoids from desiccated thalli reports pyrenoids with a central part of a weak stained matrix lacking pyrenoglobuli, named “empty zones”. “Empty zones” are not distinguishable with LTSEM and do not present immunolabelling with rubisco antibody in TEM. These zones could be originated by an expansion process during rehydration produced in chemical fixation.
    International Microbiology; Vol. 2, Núm. 4 (1999); 251-257. 01/2010;
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    ABSTRACT: The role of the Classification Societies has changed today. Their task projection addresses issues of safety in navigation and protection of human life at sea and of the marine environment. The importance of their technical expertise is to be outlined in the perspective of third-party rights and general duty of care. The Classification Societies do not have an international regulation that will define their liability at present. They effectively protect themselves within the framework of the classification contract with Owners. Classification Societies, as much as Shipbuilders, have a responsibility for damage to third parties out of negligence in the performance of their work. They are exposed to Court decisions in the various jurisdictions. As international Convention is necessary and to that effect the works of the CMI should be taken into account.
    Collected Papers of Zagreb Law Faculty (zbornik@pravo.hr); Vol.58 No.1-2. 01/2008;
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    ABSTRACT: Abstract: This paper reports on a comprehensive model evaluation protocol for urban scale flow and dispersion models that has been developed within the framework of the COST action 732 on Quality Assurance and Improvement of Micro-Scale Meteorological Models. It briefly discusses the different components forming model evaluation with particular emphasis on model validation and on the implementation of the protocol for a specific test case: the MUST (Mock Urban Setting Test) experiment. The protocol was first developed with building-resolving models in mind, but more traditional integral models have also been included. Currently the Action is finalising the MUST exercise results and will suggest the best approach for further model evaluation and for the standardization of CFD modelling practise for micro-scale meteorological applications.
    Croatian meteorological journal (nikolic@cirus.dhz.hr); Vol.43 No.43/1. 01/2008;
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    ABSTRACT: Herein is described the synthesis of several analogs of the natural product IB-01211 from concatenated azoles, via a biomimetic pathway based on cyclization–oxidation of serine containing peptides combined with the Hantzsch synthesis. The macrocyclization of rigid peptide compounds 1 and 2 to give IB-01211 and its epimer 12b was explored, and the results are compared here to those previously obtained for the macrocyclization of more flexible structures in the syntheses of YM-216391, telomestatin, and IB-01211. Lastly, the preliminary results of anti-tumor activity screening of the synthesized analogs are discussed.
    Tetrahedron. 08/2007; 63(39).
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    ABSTRACT: Libre (free / open source) software is a good example of global software development. Thousands of projects, in a wide range of domains which involve hundreds of thousands of developers and contributors from all around the world. Some large (both in size and developer community) libre software projects have shown evidence of producing code with complete functionality and fast evolution (with linear or superlinear growth), while maintaining low defect den-sity. Many companies are exploring how to benefit from this situation, considering several approaches related to li-bre software development. For instance, some of them have hired full-time developers, focusing their work on some libre software projects they consider strategic. However, before joining the core development team of the project, these hired developers have to follow a process of software comprehension, and get used to the rules and com-munication mechanisms used in the project. We were inter-ested in the differences between this case and that of volun-teer developers working in the same project, Therefore, we studied the duration and basic characteristics of this joining process for the developers of GNOME (a well known, large, libre software project). In our analysis, we have found two groups with clearly different joining patterns. Moreover, we have related those patterns to the different behaviors of volunteer and hired developers: volunteers tend to follow a step-by-step joining process, while hired developers usually experience a "sudden" integration. Some reasons for this different behavior are also discussed.
    04/2006;
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    ABSTRACT: Antirrhinum lopesianum Rothm. is a narrow endemic of the Lusitan Duriensean biogeographical sector (central western Spain and north-eastern Portugal). The species is listed as threatened in several Spanish documents, although it does not figure as such in any Portuguese document. This paper provides a detailed study of its distribution, estimates of the sizes of its populations, the threats it faces, and its current conservation status. The total number of individuals thought to exist is only 768, distributed along the valley of the River Duero on the Spanish – Portuguese border (562, 71.2%), and in the Portuguese Sabor River valley (206, 26.8%). The main threat to the species is loss of habitat: about one third of the Iberian populations can be considered threatened; one population containing 37.6% of all these plants (289) is severely threatened. To determine the Area of Occupancy and the Extent of Occurrence, an exhaustive bibliographical survey was carried out, and herbarium specimens deposited in several institutions were revised. It is, therefore, classifiable as Critically Endangered in Portugal and Endangered in Spain.
    Plant Biosystems - PLANT BIOSYST. 01/2006; 140(1).
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    ABSTRACT: Deception Island - South Shetlands, Antarctica is site of active volcanism. Since 1988 field surveys have been carried out with the aim of seismic monitoring, and in 1994 a seismic array was set up near the site of the Spanish summer base in order to better constrain the source location and spectral properties of the seismic events related to the volcanic activity. The array was maintained during the Antarctic summer of 1995 and the last field survey was carried out in 1996. Data show the existence of three different groups (or families) of seismic events: 1) long period events, with a quasi-monochromatic spectral content (1-3 Hz peak frequency) and a duration of more than 50 s, often occurring in small swarms lasting from several minutes to some day; 2) volcanic tremor, with a spectral shape similar to the long period events but with a duration of several minutes (2-10); 3) hybrid events, with a waveform characterised by the presence of a high frequency initial phase, followed by a low frequency phase with characteristics similar to those of the long period events. The high frequency phase of the hybrid events was analysed using polarisation techniques, showing the presence of P waves. This phase is presumably located at short epicentral distances and shallow source depth. All the analysed seismic events show back-azimuths between 120 and 330 degrees from north (corresponding to zones of volcanic activity) showing no seismic activity in the middle of the caldera. Particle motion, Fourier spectral and spectrogram analysis show that the low frequency part of the three groups of the seismic signals have similar patterns. Moreover careful observations show that the high frequency phase which characterises the hybrid events is present in the long period and in the tremor events, even with lower signal to noise ratios. This evidence suggests that long period events are events in which the high frequency part is simply difficult to observe, due to a very shallow source and/or hypocentral distance higher than that of hybrids, while the tremor is composed of rapidly occurring hybrid events. We propose a possible interpretation for the three groups of seismic events. These may be generated by multiple pressure-steps due to the rapid phase change from liquid to vapour in a shallow aquifer which comes in contact with hot materials. The pressure change can put a crack in resonance or excite the generation of multiple surface waves modes in the shallow layered structure.
    01/1999;
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    ABSTRACT: A pennanent geomagnetic observatory is always the ideal reference station for monitoring geomagnetic activity during airborne, marine or ground magnetic surveying, especially in Antarctica, where logistic difficulties are an important factor even for the deployment of temporary base stations. The utility of the magnetic observatory records for the correct reduction of the survey data is reinforced if both their spatial homogeneity and their particular anomaly biases are assessed. This, combined with data from the magnetic surveys themselves, can yield information on the crustal contribution to the Earth's magnetic field from a remote and poorly understood region. With these objectives in mind, we present a new geomagnetic observatory in the South Shetland Islands, where (because of the complex regional tectonic characteristics) magnetic surveys on one or another structure are conducted from time to time. An evaluation of the observatory representativeness and a look at the crustal magnetic anomaly ambience are also given.
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    ABSTRACT: The presence of class 1, 2, and 3 integrons was investigated in four pediatric isolates of Salmonella enterica ser. Typhimurium (S. Typhimurium). A class 1 integron was detected in one S. Typhimurium strain, the only one that also showed resistance to various aminoglycoside antibiotics. This integron, called InJR06, and the aminoglycoside resistance determinants were located in pS06, a large (≥55 kb) conjugative plasmid. Asingle mobile cassette (encoding the aminoglycoside adenylyltransferase ANT(3´´)-Ia) was detected in the variable region of InJR06, while the architecture of the attI1 and attC sites was conserved. [Int Microbiol 2005; 8(4):287-290]
    International Microbiology; Vol. 8, Núm. 4 (2005); 287-290.
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    ABSTRACT: This paper introduces an extensive revision of the types of components of biological variation (BV), i.e. intraindividual (random fluctuation of analytes around the setting point of each individual) and interindividual (overall variation from the different person's setting point), briefly explains estimation of the magnitude of within- and between subject BV in healthy and non-healthy subjects, details the eight common applications of BV estimates and discusses the most debated points of interests. The aim is to discuss how quality specifications derived from BV determined in healthy individuals are attainable with current technology and in what cases data from non-healthy subjects should be used. Finally, the paper promotes further development of BV application, such as notifying doctors about changes in patient status.
    Biochemia Medica (biochemia-medica@hdmb.hr); Vol.19 No.3.
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    ABSTRACT: The properties of the Earth's core magnetic field and its secular variation are poorly known for the Antarctic. The increasing availability of magnetic observations from airborne and satellite surveys, as well as the existence of several magnetic observatories and repeat stations in this region, offer the promise of greatly improving our understanding of the Antarctic core field. We investigate the possible development of a Laplacian reference model of the core field from these observations using spherical cap harmonic analysis. Possible uses and advantages of this approach relative to the implementations of the standard global reference field are also considered.
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    ABSTRACT: To contribute to our understanding of the structure of the Teide volcano, a detailed aeromagnetic survey was carried out covering the area of Las Cañadas caldera and the Teide-Pico Viejo complex. Taking into account the rugged relief of the area (altitude ranges from sea level to almost 4000 m), a terrain correction has been applied. As a first approximation, the topography has been characterized by a uniform magnetization of 5 Am-1 (based on field and laboratory rock magnetic data). Several enhancement techniques have been applied to the residual map (original map minus topographic effect), such as reduction to the pole, pseudogravity integration and upward continuation. In the reduced-to-the-pole map the large positive anomaly that appears centered to the north of Pico Viejo is noteworthy and could be caused by a basaltic intrusion responsible for the last eruptions in this area. Also, a small magnetic low appears over Teide peak, which should be related to slightly-magnetized shallow phonolitic materials. The main tectonic direction of Tenerife, SW-NE, is also clearly reflected on the magnetic anomaly map. The comparison between the pseudogravity and the Bouguer anomaly maps indicates a good correlation between magnetic and gravimetric sources.
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    ABSTRACT: Middleware platforms are becoming very popular among system developers. Due to its popularity, there is an increasing demand for dependable middleware support. In the past few years several research efforts have concentrated in augmenting the dependability of middle-ware infrastructures which have led to the definition of the FT-Corba specification. Active replication is one of the main techniques that have been used to achieve some of the required dependability attributes such as high-availability. This kind of replication requires determin-istic replicas to behave as a state machine what has been traditionally achieved by restricting replicas to be single-threaded. Unfortunately, single-threading results too restrictive for mid-dleware servers, especially transactional ones, where it is not admissible to process requests sequentially. In this paper, we show how it is possible to remove this restriction. We present a deterministic scheduling algorithm for multithreaded replicas in a transactional framework. Determinism of multithreaded replicas is achieved with a combination of reliable total order multicast and a deterministic scheduler. The former guarantees that all the replicas see the external events in the same order. The latter, ensures that all threads are scheduled in the same way at all replicas. One of the novelties of the approach is that determinism is achieved without resorting to inter-replica communication. Additionally, the paper also addresses how to perform online recovery while maintaining replica determinism in order to keep a high level of availability. £ This paper consolidates results from the papers [1] and [2].
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    ABSTRACT: A local ground magnetic study of the Furnas caldera (S. Miguel Island, Azores) has provided new insight into the magnetic structure of this volcano. Analysis of the data comprised removal of the IGRF, reduction to the pole, pseudogravity integration and upward continuation. Also, a spectral method was applied to estimate the depth to the magnetic sources, as well as a 2.5D forward modelling technique. Magnetic properties obtained at the laboratory for some representative sample rocks were considered in the modelling process. The most relevant features are the existence of an important negative anomaly inside the caldera and of an intense positive anomaly to the south of the coast. The former points out a decrease in the magnetization of the caldera filling materials with respect to the surrounding rocks, which could be explained as the result of post-eruption processes such as hydrothermal alteration. This is expected as Furnas has an active hydrothermal system probably related with a magmatic reservoir at high temperature. The positive anomaly suggests the existence of a strongly-magnetized body beneath the south coast.
  • XF2006053898.