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Bilbao, Spain

The University of the Basque Country ; Spanish - Universidad del País Vasco ) is the only public university in the Basque Country , in Northern Spain. It has campuses over the three provinces of the autonomous community: Biscay Campus , Gipuzkoa Campus , and Álava Campus in Vitoria-Gasteiz. It is the main research institution in the Basque Country, carrying out 90% of the basic research made in that territory and taking advantage of the good industrial environment that the region constitutes. Wikipedia.

Ruiz-Mirazo K.,University of the Basque Country | Briones C.,CSIC - National Institute of Aerospace Technology | De La Escosura A.,Autonomous University of Madrid
Chemical Reviews | Year: 2014

In order to explain how the first organisms might have appeared on Earth, or elsewhere, it is necessary to develop chemistries that enable the synthesis of information-bearing polymers, protometabolic networks, and protocellular compartments under compatible prebiotic conditions. In this direction, the first step would be the synthesis of the monomeric units that constitute peptides, nucleic acids or their analogue polymers, and vesicle membranes. Some of these building blocks could have been delivered to Earth from extraterrestrial sources, while their endogenous synthesis on our planet is another feasible option. Catalysis, in particular organocatalysis and organometallic catalysis, could have enlarged and diversified the set of compounds potentially present in different prebiotic scenarios. Vesicles composed of mixtures of simple amphiphilic molecules and surfactants, on the other hand, have shown the required stability and permeability for encapsulation of nucleic acids and peptides.

Sanchez-Beitia S.,University of the Basque Country
Experimental Mechanics | Year: 2011

The X-Ray Diffraction technique has been widely applied for decades in many industrial sectors for the quantification of residual stresses in metallic parts. The present paper describes the laboratory calibration of this technique with the aim of adapting it to the quantification of global stresses (non residual) in metallic structures, in service for civil engineering and building. A small structure specifically built for this research has been repeatedly loaded at laboratory. In each load level the global stresses in a bar of the structure have been quantified by means of X-Ray Diffraction technique. The experimental procedure allows one to discern the residual stresses and the structural (mechanical) stresses in service. The correlation between the stresses deduced experimentally and the applied stresses is excellent. As conclusion, it can be stated that the X-Ray Diffraction technique as a non-destructive technique, has been calibrated to be used for stress deduction in metallic elements in service. © 2011 Society for Experimental Mechanics.

Heras-Saizarbitoria I.,University of the Basque Country
Industrial Management and Data Systems | Year: 2011

Purpose The purpose of this paper is to develop the operational definition of the concept of internalization of ISO 9001, a theoretical construct which until recently had not received the attention it deserves in research on quality management. Design/methodology/approach Extensive exploratory fieldwork based on both in-depth interviews of general managers, middle managers and employees 65 in total as well as on intensive participant observation e.g. 139 direct field-consults and 240 documents analyzed was carried out in eight Spanish organizations that adopted the standard a long time ago. Findings A set of specific factors and subfactors aimed at operationalizing the ISO 9001 internalization construct are proposed. Moreover, it has been ascertained that the concept of internalization is a clearly relevant one, as in previous works found in the literature in other countries, the conclusion is drawn that organizations do not adopt ISO 9001 homogeneously. Practical implications The conclusions may be of interest both for academic and professional spheres of activity. For managers, the key aspects of a substantive adoption of ISO 9001 are highlighted. For academics, certain specific categorization elements are proposed for a relevant construct so that these may be used in subsequent works. Originality/value This is a new exploratory work for its field of research. On the one hand, most works to date have tended to assume the principle of homogeneous adoption of ISO 9001. On the other, they tend to be based solely on managers' opinions without giving voice to employees or using participative observation. Copyright © 2011 Emerald Group Publishing Limited. All rights reserved.

Parrondo J.,Southern University and A&M College | Mijangos F.,University of the Basque Country | Rambabu B.,Southern University and A&M College
Journal of Power Sources | Year: 2010

The performance of high temperature polymer electrolyte fuel cell (HT-PEMFC) using platinum supported over tin oxide and Vulcan carbon (Pt/SnOx/C) as cathode catalyst was evaluated at 160-200 °C and compared with Pt/C. This paper reports first time the Pt/SnOx/C preparation, fuel cell performance, and durability test up to 200 h. Pt/SnOx/C of varying SnO compositions were characterized using XRD, SEM, TEM, EDX and EIS. The face-centered cubic structure of nanosized Pt becomes evident from XRD data. TEM and EDX measurements established that the average size of the Pt nanoparticles were ∼6 nm. Low ionic resistances were derived from EIS, which ranged from 0.5 to 5 Ω-cm2 for cathode and 0.05 to 0.1 Ω-cm2 for phosphoric acid, doped PBI membrane. The addition of the SnOx to Pt/C significantly promoted the catalytic activity for the oxygen reduction reaction (ORR). The 7 wt.% SnO in Pt/SnO2/C catalyst showed the highest electro-oxidation activity for ORR. High temperature PEMFC measurements performed at 180 °C under dry gases (H2 and O2) showed 0.58 V at a current density of 200 mA cm-2, while only 0.40 V was obtained in the case of Pt/C catalyst. When the catalyst contained higher concentrations of tin oxide, the performance decreased as a result of mass transport limitations within the electrode. Durability tests showed that Pt/SnOx/C catalysts prepared in this work were stable under fuel cell working conditions, during 200 h at 180 °C demonstrate as potential cathode catalyst for HT-PEMFCs. © 2010 Elsevier B.V.

Mateo-Alonso A.,University of the Basque Country | Mateo-Alonso A.,Ikerbasque
Chemical Society Reviews | Year: 2014

Linear and ribbon-like polycyclic aromatic hydrocarbons such as acenes and graphene nanoribbons are at the forefront of current investigations, as these graphene "cut outs" possess discrete energy gaps that can be tailored with the number of rings and their arrangements. Pyrene-fused pyrazaacenes are a type of nitrogenated ribbon-like polycyclic aromatic hydrocarbons with a very high stability. As a matter of fact, ribbon-like pyrene-fused pyrazaacenes with as many as 85 linearly fused aromatic rings have been synthesised with thermal stabilities over 500 °C in air. This review covers most of the synthetic and application aspects of pyrene-fused pyrazaacenes from 1937 to our days, illustrating that pyrene-fused pyrazaacenes are a widely tuneable and a highly stable platform for developing ribbon-like nitrogenated polycyclic aromatic hydrocarbons for a broad spectrum of applications. © The Royal Society of Chemistry 2014.

Nielsen S.B.,University of Aarhus | Nielsen M.B.,Copenhagen University | Rubio A.,University of the Basque Country
Accounts of Chemical Research | Year: 2014

ConspectusIn a charge-transfer (CT) transition, electron density moves from one end of the molecule (donor) to the other end (acceptor). This type of transition is of paramount importance in nature, for example, in photosynthesis, and it governs the excitation of several protein biochromophores and luminophores such as the oxyluciferin anion that accounts for light emission from fireflies. Both transition energy and oscillator strength are linked to the coupling between the donor and acceptor groups: The weaker the coupling, the smaller the excitation energy. But a weak coupling necessarily also causes a low oscillator strength possibly preventing direct excitation (basically zero probability in the noncoupling case). The coupling is determined by the actual spacer between the two groups, and whether the spacer acts as an insulator or a conductor. However, it can be difficult or even impossible to distinguish the effect of the spacer from that of local solvent molecules that often cause large solvent shifts due to different ground-state and excited-state stabilization. This calls for gas-phase spectroscopy experiments where absorption by the isolated molecule is identified to unequivocally establish the intrinsic molecular properties with no perturbations from a microenvironment. From such insight, the effect of a protein microenvironment on the CT excited state can be deduced.In this Account, we review our results over the last 5 years from mass spectroscopy experiments using specially designed apparatus on several charged donor-acceptor ions that are based on the nitrophenolate moiety and π-extended derivatives, which are textbook examples of donor-acceptor chromophores. The phenolate oxygen is the donor, and the nitro group is the acceptor. The choice of this system is also based on the fact that phenolate is a common structural motif of biochromophores and luminophores, for example, it is a constituent of the oxyluciferin anion. A presentation of the setups used for gas-phase ion spectroscopy in Aarhus is given, and we address issues of whether double bonds or triple bonds best convey electronic coupling between the phenolate oxygen and the nitro group, the significance of separating the donor and acceptor spatially, the influence of cross-conjugation versus linear conjugation, and along this line ortho versus meta versus para configuration, and not least the effect of a single solvent molecule (water, methanol, or acetonitrile). From systematic studies, a clear picture has emerged that has been supported by high-level calculations of electronically excited states. Our work shows that CC2 coupled-cluster calculations of vertical excitation energies are within 0.2 eV of experimental band maxima, and importantly, that the theoretical method is excellent in predicting the relative order of excitation energies of a series of nitrophenolates. Finally, we discuss future challenges such as following the change in absorption as a function of the number of solvent molecules and when gradually approaching the bulk limit. © 2014 American Chemical Society.

Sanchez-Rosello M.,University of Valencia | Sanchez-Rosello M.,Research Center Principe Felipe | Acena J.L.,University of the Basque Country | Simon-Fuentes A.,University of Valencia | Del Pozo C.,University of Valencia
Chemical Society Reviews | Year: 2014

The organocatalytic intramolecular aza-Michael reaction gives access to enantiomerically enriched nitrogen-containing heterocycles in a very simple manner. Enals, enones, conjugated esters and nitro olefins have been employed as Michael acceptors, while moderate nitrogen nucleophiles such as sulphonamides, carbamates and amides have been shown to be appropriate Michael donors in this type of reaction. Additionally, the process has been performed under both covalent and non-covalent catalysis, with diaryl prolinols, imidazolidinones, thioureas and chiral binol phosphoric acids being the most frequently used catalysts. The level of efficiency reached with this protocol is demonstrated by the implementation of numerous tandem processes, as well as the total synthesis of several natural products. © 2014 the Partner Organisations.

Diaz-Emparanza I.,University of the Basque Country
Computational Statistics and Data Analysis | Year: 2014

It is often necessary to test for the presence of seasonal unit roots when working with time series data observed at intervals of less than a year. One of the most widely used methods for doing this is based on regressing the seasonal difference of the series over the transformations of the series by applying specific filters for each seasonal frequency. This provides test statistics with non-standard distributions. A generalisation of this method for any periodicity is presented and a response surface regressions approach is used to calculate the P-values of the statistics whatever the periodicity and sample size of the data. The algorithms are prepared with the Gretl open source econometrics package and two empirical examples are presented. © 2013 Elsevier B.V. All rights reserved.

Chen H.,University of the Basque Country | Chen H.,Ikerbasque
ACM Transactions on Computational Logic | Year: 2014

We systematically investigate the complexity of model checking the existential positive fragment of first-order logic. In particular, for a set of existential positive sentences, we consider model checking where the sentence is restricted to fall into the set; a natural question is then to classify which sentence sets are tractable and which are intractable. With respect to fixed-parameter tractability, we give a general theorem that reduces this classification question to the corresponding question for primitive positive logic, for a variety of representations of structures. This general theorem allows us to deduce that an existential positive sentence set having bounded arity is fixed-parameter tractable if and only if each sentence is equivalent to one in bounded-variable logic.We then use the lens of classical complexity to study these fixed-parameter tractable sentence sets. We show that such a set can be NP-complete, and consider the length needed by a translation from sentences in such a set to bounded-variable logic; we prove superpolynomial lower bounds on this length using the theory of compilability, obtaining an interesting type of formula size lower bound. Overall, the tools, concepts, and results of this article set the stage for the future consideration of the complexity of model checking on more expressive logics. © 2014 ACM.

Ilarri S.,University of Zaragoza | Mena E.,University of Zaragoza | Illarramendi A.,University of the Basque Country
ACM Computing Surveys | Year: 2010

The continuous development of wireless networks and mobile devices has motivated an intense research in mobile data services. Some of these services provide the user with context-aware information. Specifically, location-based services and location-dependent queries have attracted a lot of interest. In this article, the existing literature in the field of location-dependent query processing is reviewed. The technological context (mobile computing) and support middleware (such as moving object databases and data stream technology) are described, location-based services and location-dependent queries are defined and classified, and different query processing approaches are reviewed and compared. © 2010 ACM.

Karshenas H.,Technical University of Madrid | Santana R.,University of the Basque Country | Bielza C.,Technical University of Madrid | Larranaga P.,Technical University of Madrid
IEEE Transactions on Evolutionary Computation | Year: 2014

This paper proposes a new multiobjective estimation of distribution algorithm (EDA) based on joint probabilistic modeling of objectives and variables. This EDA uses the multidimensional Bayesian network as its probabilistic model. In this way, it can capture the dependencies between objectives, variables and objectives, as well as the dependencies learned between variables in other Bayesian network-based EDAs. This model leads to a problem decomposition that helps the proposed algorithm find better tradeoff solutions to the multiobjective problem. In addition to Pareto set approximation, the algorithm is also able to estimate the structure of the multiobjective problem. To apply the algorithm to many-objective problems, the algorithm includes four different ranking methods proposed in the literature for this purpose. The algorithm is first applied to the set of walking fish group problems, and its optimization performance is compared with a standard multiobjective evolutionary algorithm and another competitive multiobjective EDA. The experimental results show that on several of these problems, and for different objective space dimensions, the proposed algorithm performs significantly better and on some others achieves comparable results when compared with the other two algorithms. The algorithm is then tested on the set of CEC09 problems, where the results show that multiobjective optimization based on joint model estimation is able to obtain considerably better fronts for some of the problems compared with the search based on conventional genetic operators in the state-of-the-art multiobjective evolutionary algorithms. © 1997-2012 IEEE.

Senovilla J.M.M.,University of the Basque Country
Classical and Quantum Gravity | Year: 2015

I revisit a known solution of the Einstein field equations to show that it describes the formation of non-spherical black holes by the collapse of pure electromagnetic monochromatic radiation. Both positive and negative masses are feasible without ever violating the dominant energy condition. The solution can also be used to model the destruction of naked singularities and the evaporation of white holes by emission or reception of light. © 2015 IOP Publishing Ltd.

Castellano J.,University of the Basque Country | Casamichana D.,University of Malaga
Journal of Sports Science and Medicine | Year: 2010

Although beach soccer has become increasingly popular in recent years very little scientific research has been conducted into the sport. A pilot study was carried out with the aim of examining the physiological (heart rate) and physical (motion analysis) responses of beach soccer players during competitive matches. Ten players (age 25.5 ±0.5 years; height 1.80 ± 0.08 m; weight 78.2 ± 5.6 kg.) were studied over five beach soccer matches. The physiological demands were analysed by measuring heart rate (HR) using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax), with 59.3% of the time participating (TP) corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work: rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods. © Journal of Sports Science and Medicine.

Mujika I.,USP Araba Sport Clinic | Mujika I.,University of the Basque Country
Scandinavian Journal of Medicine and Science in Sports | Year: 2010

The training load is markedly reduced during the taper so that athletes recover from intense training and feel energized before major events. Load reduction can be achieved by reducing the intensity, volume and/or frequency of training, but with reduced training load there may be a risk of detraining. Training at high intensities before the taper plays a key role in inducing maximal physiological and performance adaptations in both moderately trained subjects and highly trained athletes. High-intensity training can also maintain or further enhance training-induced adaptations while athletes reduce their training before a major competition. On the other hand, training volume can be markedly reduced without a negative impact on athletes' performance. Therefore, the training load should not be reduced at the expense of intensity during the taper. Intense exercise is often a performance-determining factor during match play in team sports, and high-intensity training can also elicit major fitness gains in team sport athletes. A tapering and peaking program before the start of a league format championship or a major tournament should be characterized by high-intensity activities. © 2010 John Wiley & Sons A/S.

Osinalde N.,University of the Basque Country
Journal of proteomics | Year: 2011

Interleukin-2 (IL-2) is major cytokine involved in T cell proliferation, differentiation and apoptosis. Association between IL-2 and its receptor (IL-2R), triggers activation of complex signaling cascade governed by tyrosine phosphorylation that culminates in transcription of genes involved in modulation of the immune response. The complete characterization of the IL-2 pathway is essential to understand how aberrant IL-2 signaling results in several diseases such as cancer or autoimmunity and also how IL-2 treatments affect cancer patients. To gain insights into the downstream machinery activated by IL-2, we aimed to define the global tyrosine-phosphoproteome of IL-2 pathway in human T cell line Kit225 using high resolution mass spectrometry combined with phosphotyrosine immunoprecipitation and SILAC. The molecular snapshot at 5min of IL-2 stimulation resulted in identification of 172 proteins among which 79 were found with increased abundance in the tyrosine-phosphorylated complexes, including several previously not reported IL-2 downstream effectors. Combinatorial site-specific phosphoproteomic analysis resulted in identification of 99 phosphorylated sites mapping to the identified proteins with increased abundance in the tyrosine-phosphorylated complexes, of which 34 were not previously described. In addition, chemical inhibition of the identified IL-2-mediated JAK, PI3K and MAPK signaling pathways, resulted in distinct alteration on the IL-2 dependent proliferation. Copyright © 2011 Elsevier B.V. All rights reserved.

Quesada-Perez M.,University of Jaen | Maroto-Centeno J.A.,University of Jaen | Forcada J.,University of the Basque Country | Hidalgo-Alvarez R.,University of Granada
Soft Matter | Year: 2011

In this work, the classical theory of polymer/polyelectrolyte gel swelling is reviewed. This formalism is easy to understand and has been widely applied to gels and microgel particles. Nevertheless, its limitations and obscure aspects should be known before use. The case of temperature-sensitive gels is discussed in some detail because it deserves particular clarification. The application to experimental swelling data (of both gels and microgels) is also reviewed. In this way, strengths and weaknesses of this approach can be elucidated. Moreover, other formalisms are also outlined. Many of them are inspired by the classical one. Their improvements are briefly commented in this case. Others are based on different grounds. © 2011 The Royal Society of Chemistry.

Escobedo M.,University of the Basque Country | Velazquez J.J.L.,Complutense University of Madrid
Communications in Mathematical Physics | Year: 2010

We describe the fundamental solution of the equation that is obtained by linearization of the coagulation equation with kernel K(x, y) = (xy)λ/2, around the steady state f(x) = x-(3+λ)/2 with λ ε (1, 2). Detailed estimates on its asymptotics are obtained. Some consequences are deduced for the flux properties of the particles distributions described by such models. © 2010 Springer-Verlag.

Senovilla J.M.M.,University of the Basque Country
International Journal of Modern Physics D | Year: 2011

I review the definition and types of (closed) trapped surfaces. Surprising global properties are shown, such as their "clairvoyance" and the possibility that they enter into flat portions of the spacetime. Several results on the interplay of trapped surfaces with vector fields and with spatial hypersurfaces are presented. Applications to the quasi-local definition of Black Holes are discussed, with particular emphasis set onto marginally trapped tubes, trapping horizons and the boundary of the region with closed trapped surfaces. Finally, the core of a trapped region is introduced, and its importance discussed. © 2011 World Scientific Publishing Company.

Garcia Munoz A.,University of the Basque Country | Mills F.P.,Australian National University
Astronomy and Astrophysics | Year: 2012

Context. On 5-6 June 2012 ground-based observers have the last opportunity of the century to watch the passage of Venus across the solar disk from Earth. Venus transits have traditionally provided unique insight into the Venus atmosphere through the refraction halo that appears at the planet's outer terminator near ingress/egress. Much more recently, Venus transits have attracted renewed interest because the technique of transits is being successfully applied to the characterization of extrasolar planet atmospheres. Aims. The current work theoretically investigates the interaction of sunlight and the Venus atmosphere through the full range of transit phases, as observed from Earth and from a remote distance. Our model predictions quantify the relevant atmospheric phenomena, thereby assisting the observers of the event in the interpretation of measurements and extrapolation to the exoplanet case. Methods. Our approach relies on numerical integration of the radiative transfer equation, and includes refraction, multiple scattering, atmospheric extinction, and solar limb darkening, as well as an up-to-date description of the Venus atmosphere. Results. We produce synthetic images of the planet's terminator during ingress/egress that demonstrate the evolving shape, brightness, and chromaticity of the halo. Our simulations reveal the impact of micrometer-sized aerosols borne in the upper haze layer of the atmosphere on the halo's appearance. Guidelines are offered for the investigation of the planet's upper haze from vertically-unresolved photometric measurements. In this respect, the comparison with measurements from the 2004 transit appears encouraging. We also show integrated lightcurves of the Venus-Sun system at various phases during transit and calculate the respective Venus-Sun integrated transmission spectra. The comparison of the model predictions to those for a Venus-like planet free of haze and clouds (and therefore a closer terrestrial analog) complements the discussion and sets the conclusions into a broader perspective. © 2012 ESO.

De Almeida C.M.,University of the Basque Country
Technoetic Arts | Year: 2015

The main notion of this article is that the blurring of the limits between offline and online dimensions of knowledge and experience, in addition to the manipulation of genes, neurons, atoms and bits, is dissolving the distinction between subjectivism (i.e. idealism) and materialism (i.e. objectivism and realism). As a consequence, in the moistmedia (from Ascott) ecology in which we are increasingly immersed, a radical kind of experience of matter, time, space and self is emerging. In this form of experience, the blending of subjectivist and materialist approaches help in overcoming the classical Cartesian polarity: we feel part of an extended reality, and we feel this extended reality in ourselves by combining bodies, points of view and multiple senses with digital layers of everything. The article proposes these research questions: Which are the main factors that shape the change toward a moistmedia ecology resulting from the impact of the manipulation of genes, neurons, bits and atoms? Which transformation is being shaped in relation to the previous model of experience? What are the features of the new forms of materiality, sensitivity and action? How artists are putting themselves at risk in the moistmedia ecology? The hypothesis is that a hybrid kind of interval is opening between different layers of reality: analogue versus digital; nature versus culture; here versus there; past versus future; I versus others; and human versus non-human. In this recombination process, a third dimension of reality - that I call 'radical reality' - emerges in the moistmedia ecology. This article will analyse the radical experience (Wilson) in moistmedia environments by crossing the five dimensions (matter, space, time, identity and action) with the practices of manipulation of genes, atoms and bits using examples from art and design. This crossing shows the basic dimensions and sub-dimensions of the 'Model of Radical Experience' to reveal the nature of this third dimension between subjectivism and materialism, which is explored by artists who put themselves at risk in the turbulent zone between the physical and the digital. © 2015 Intellect Ltd.

Brizuela D.,University of the Basque Country
Classical and Quantum Gravity | Year: 2015

The evolution of polar perturbations on a spherical background spacetime is analyzed. The matter content is assumed to be a massless scalar field. This provides a nontrivial dynamics to the background and the linearized equations of motion become much more involved than in the vacuum case. The analysis is performed in a Hamiltonian framework, which makes explicit the dynamical role of each of the variables. After performing a number of canonical transformations, it is possible to completely decouple the different perturbative degrees of freedom into constrained, pure-gauge and gauge-invariant variables. In particular, two master variables are obtained: one corresponding to the polar mode of the gravitational wave, whereas the other encodes the complete physical information about the perturbative matter degree of freedom. The evolution equations for these master variables are obtained and simplified. © 2015 IOP Publishing Ltd.

Han M.H.,CICenergiGUNE | Gonzalo E.,CICenergiGUNE | Singh G.,CICenergiGUNE | Rojo T.,CICenergiGUNE | Rojo T.,University of the Basque Country
Energy and Environmental Science | Year: 2015

The room temperature Na-ion secondary battery has been under focus lately due to its feasibility to compete against the already well-established Li-ion secondary battery. Although there are many obstacles to overcome before the Na-ion battery becomes commercially available, recent research discoveries corroborate that some of the cathode materials for the Na-ion battery have indeed indisputable advantages over its Li-ion counterparts. In this publication, a comprehensive review of layered oxides (NaTMO2, TM = Ti, V, Cr, Mn, Fe, Co, Ni, and a mixture of 2 or 3 elements) as a viable Na-ion battery cathode is presented. Single TM systems are well characterized not only for their electrochemical performance but also for their structural transitions during the cycle. Binary TM systems are investigated in order to address issues regarding low reversible capacity, capacity retention, operating voltage, and structural stability. As a consequence, some materials already have reached an energy density of 520 mW h g-1, which is comparable to that of LiFePO4. Furthermore, some ternary TM systems retained more than 72% of their capacity along with over 99.7% Coulombic efficiency for 275 cycles. The goal of this review is to present the development of Na layered oxide materials in the past as well as the state of the art today in order to emphasize the compatibility and durability of layered oxides as powerful candidates for Na-ion battery cathode materials. © 2015 The Royal Society of Chemistry.

Gutierrez Garcia J.,University of the Basque Country | Romaguera S.,Polytechnic University of Valencia
Fuzzy Sets and Systems | Year: 2011

Answering a recent question posed by Gregori et al. [On a class of completable fuzzy metric spaces, Fuzzy Sets and Systems 161 (2010), 2193-2205] we present two examples of non-strong fuzzy metrics (in the sense of George and Veeramani). © 2010 Elsevier B.V. All rights reserved.

Bandos I.,University of the Basque Country | Bandos I.,Ikerbasque
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

The covariant and kappa-symmetric action for superstring in direct product of two flat D= 10 N=1 superspaces is presented. It is given by the sum of supersymmetric generalization of two copies of chiral boson actions constructed with the use of the Pasti-Sorokin-Tonin (PST) technique. The chirality of 8 'left' bosons and 8 'left' fermions and the anti-chirality of their 'right' counterparts are obtained as gauge fixed version of the equations of motion, so that the physical degrees of freedom are essentially those of the II Green-Schwarz superstring. Our action is manifestly T-duality invariant as the fields describing oscillating and winding modes enter it on equal footing. © 2015 The Author.

The Internet and virtual social networks are new technologies that have had most impact on young people and have provided many benefits to their users. However, some people become obsessed with the Internet, are unable to control their use of it, and may put their work and relation-ships in jeopardy. This paper addresses the issue of the maladaptive use of these technologies. Internet use and abuse are related to psychosocial variables, such as psychological vulnerability, life stress and family and social support. There are some specific risk factors for abuse of virtual social networks among young people. Certain alarm signs appear before a hobby becomes an addiction. The concept of "Internet addiction" has been proposed as an explanation for uncontrollable and harmful use of this technology. Symptoms of excessive Internet use can be identified with the criteria used to diagnose other chemical or non-chemical addictions. Prevention strategies in both home and school settings should be implemented on the basis of behavioral risk factors and demographic characteristics. The goal of treatment for this type of addiction, unlike the case of other addictions, cannot be total abstinence, but rather controlled use. The psychological treatment of choice appears to be stimulus control and gradual exposure to Internet, followed by a cognitive-behavioral intervention in relapse prevention. There is a need for more information about young Internet abusers and about the most appropriate programs for treating them. More research is required on the enhancement of motivation for treatment and the types of brief intervention available in relation to the problematic use of Internet among young people. The implications of the present review for clinical practice and possible future research directions in this field are discussed, as well as the problems as yet unsolved.

Aware of the fact that nowadays transmitting information is insufficient for successfully communicating, organizations are increasingly multi-channeled communicators, in addition to receiving what their public communicates, because they are aware that simply transmitting information is no longer sufficient for successful communication. In particular, political organizations and their leaders have shown a strong interest in recent years for exploring technologically advanced communication avenues, in accordance with the permanent campaign idea (Blumenthal, 1980; Ornstein; Mann, 2000). This article examines current tendencies that determine the management of political communication, outside of specific voting contexts, through a case study of five parties with parliamentary representation in the Autonomous Community of the Basque Country, Spain. Using qualitative methodology, based on website analysis and in-depth interviews with press departments, this study explains why these organizations situate themselves in a 1.5 evolutionary phase (Kalnes, 2009).

Senovilla J.M.M.,University of the Basque Country | Torres R.,Polytechnic University of Catalonia
Classical and Quantum Gravity | Year: 2015

We provide a general formalism that allows us to analyze the phenomenon of tunneling in arbitrary spacetimes. We show that a flux of particles produced by tunneling through general marginally trapped surfaces (MTSs) may be perceived by some privileged observers. We discuss how this particle perception can be related to Hawking/Unruh radiation in specific cases. Our approach naturally leads to an expression for the effective surface gravity of MTSs. The procedure is applicable to general astrophysical and cosmological dynamical situations. Some practical examples for known and new cases are provided. © 2015 IOP Publishing Ltd.

Aguirre L.,University of the Basque Country
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society | Year: 2013

Statins are a family of drugs used in hypercholesterolemia. The aim of this study was to analyze the effect of statins on body and liver fat accumulation in obese Zucker rats. Seventy Zucker (fa/fa) rats were divided into seven groups. Rats from six statin groups were treated with pravastatin, simvastatin, atorvastatin, rosuvastatin, fluvastatin and lovastatin respectively, at a dose of 0.6 mg/kg body weight/day. After 6 weeks, liver and white adipose tissue from intra-abdominal and subcutaneous locations were dissected and weighed. Subcutaneous adipose tissue from rosuvastatin, atorvastatin, fluvastatin and lovastatin treated rats was significantly increased. Fatty acid synthase (FAS) activity was increased by the administration of fluvastatin and lovastatin, as was glucose-6-P dehydrogenase (G6PDH) by the administration of atorvastatin and lovastatin. No changes were observed in malic enzyme (ME) activity. Furthermore, heparin-releasable lipoprotein lipase (HR-LPL) was increased in all groups where the subcutaneous depot was increased, and total LPL increased only in rosuvastatin and fluvastatin-treated groups. With regard to liver, there were no changes in weight but the amount of triacylglycerols was increased in rosuvastatin group, as well as its liver damage was higher. In this group FAS and G6PDH activities were increased and no changes were observed in ME, acyl CoA oxidase (ACO) and carnitine palmitoyltransferase-1a (CPT-1a) activities. All statins, with the exception of simvastatin, worsen insulin resistance. These results show that statins have different effects on body fat accumulation. Moreover, rosuvastatin also shows a prosteatotic effect. These results should be taken into account for statin choice in prescription.

Egbert M.D.,University of Sussex | Barandiaran X.E.,University of Sussex | di Paolo E.A.,University of Sussex | di Paolo E.A.,University of the Basque Country
PLoS Computational Biology | Year: 2010

Since the pioneering work by Julius Adler in the 1960's, bacterial chemotaxis has been predominantly studied as metabolism-independent. All available simulation models of bacterial chemotaxis endorse this assumption. Recent studies have shown, however, that many metabolism-dependent chemotactic patterns occur in bacteria. We hereby present the simplest artificial protocell model capable of performing metabolism-based chemotaxis. The model serves as a proof of concept to show how even the simplest metabolism can sustain chemotactic patterns of varying sophistication. It also reproduces a set of phenomena that have recently attracted attention on bacterial chemotaxis and provides insights about alternative mechanisms that could instantiate them. We conclude that relaxing the metabolism-independent assumption provides important theoretical advances, forces us to rethink some established pre-conceptions and may help us better understand unexplored and poorly understood aspects of bacterial chemotaxis. © 2010 Egbert et al.

Achucarro A.,Instituut Lorentz for Theoretical Physics | Achucarro A.,University of the Basque Country | Verbiest G.J.,Instituut Lorentz for Theoretical Physics
Physical Review Letters | Year: 2010

We report the first observation of multiple intercommutation (more than two successive reconnections) of Abelian Higgs cosmic strings at ultrahigh collision speeds, and the formation of "kink trains" with up to four closely spaced left- or right-moving kinks, in the deep type-II regime 16≤β≤64 (where β=mscalar2/mgauge2). The minimum critical speed for double reconnection goes down from ∼0.98c at β=1 to ∼0.86c for β=64. The process leading to the second intercommutation changes with β: it involves an expanding loop if β 16, but only a radiation blob if 1<β≤8. Triple reconnections are generic in the loop-mediated regime for collision parameters on the boundary between single and double reconnection. For β=16 we observe quadruple events. We comment on the effect of strongly repulsive core interactions on the small scale structure on the strings and their gravitational wave emission. © 2010 The American Physical Society.

Bandos I.A.,University of the Basque Country | Bandos I.A.,Ikerbasque
Physical Review Letters | Year: 2010

We present the equations of motion for multiple M0-brane (multiple M-wave) systems in general 11 dimensional supergravity background. These are obtained in the frame of superembedding approach, but have a rigid structure: they can be restored from SO(1,1)×SO(9) symmetry characteristic for M0. BPS (Bogomol'nyi-Prasad-Sommerfield) conditions for the 1/2 supersymmetric solution of these equations have the fuzzy 2-sphere solution modeling M2-brane. © 2010 The American Physical Society.

Peropadre B.,Institute Fisica Fundamental | Forn-Diaz P.,Technical University of Delft | Solano E.,University of the Basque Country | Solano E.,Ikerbasque | Garcia-Ripoll J.J.,Institute Fisica Fundamental
Physical Review Letters | Year: 2010

We propose different designs of switchable coupling between a superconducting flux qubit and a microwave transmission line. They are based on two or more loops of Josephson junctions which are directly connected to a closed (cavity) or open transmission line. In both cases the circuit induces a coupling that can be modulated in strength, reaching the so-called ultrastrong coupling regime in which the coupling is comparable to the qubit and photon frequencies. Furthermore, we suggest a wide set of applications for the introduced architectures. © 2010 The American Physical Society.

Larranaga P.,Computational Intelligence Group | Karshenas H.,Computational Intelligence Group | Bielza C.,Computational Intelligence Group | Santana R.,University of the Basque Country
Information Sciences | Year: 2013

Thanks to their inherent properties, probabilistic graphical models are one of the prime candidates for machine learning and decision making tasks especially in uncertain domains. Their capabilities, like representation, inference and learning, if used effectively, can greatly help to build intelligent systems that are able to act accordingly in different problem domains. Bayesian networks are one of the most widely used class of these models. Some of the inference and learning tasks in Bayesian networks involve complex optimization problems that require the use of meta-heuristic algorithms. Evolutionary algorithms, as successful problem solvers, are promising candidates for this purpose. This paper reviews the application of evolutionary algorithms for solving some NP-hard optimization tasks in Bayesian network inference and learning. © 2013 Elsevier Inc. All rights reserved.

Zhang H.,Sichuan University | Miyamoto Y.,Japan National Institute of Advanced Industrial Science and Technology | Rubio A.,University of the Basque Country
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We have used first-principles simulations based on time-dependent density functional theory to show that short laser pulses can trigger preferential hydrogen desorption from the upper or lower side of suspended graphane (H-terminated graphene). This control is achieved by using intense ultrashort p-polarized laser pulses (∼2 fs) with an asymmetric time envelope. The dynamical Stark effect induced by the pulse creates an asymmetric charge distribution and force field on the H ions, even at low laser fluence. At finite temperatures the carbon-hydrogen stretching softens, favoring H desorption from one side. This transient geometry can be modified by halogen functionalization, which results in a two-dimensional dipolar structure. © 2012 American Physical Society.

Tokatly I.V.,University of the Basque Country | Tokatly I.V.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

A rigorous formulation of time-dependent current density functional theory (TDCDFT) on a lattice is presented. The density-to-potential mapping and the V-representability problems are reduced to a solution of a certain nonlinear lattice Schrödinger equation, to which the standard existence and uniqueness results for nonlinear differential equations are applicable. For two versions of the lattice TDCDFT, we prove that any continuous-in-time current density is locally V-representable (both interacting and noninteracting), provided that in the initial state the local kinetic energy is nonzero everywhere. In most cases of physical interest, the V-representability should also hold globally in time. These results put the application of TDCDFT to any lattice model on a firm foundation, and pave the way for studying exact properties of exchange-correlation potentials. © 2011 American Physical Society.

Achurra A.,University of the Basque Country | Erseus C.,Gothenburg University
Invertebrate Systematics | Year: 2013

Individuals of the aquatic oligochaete species Stylodrilus heringianus Clapar̀de, 1862 were collected across a part of this species' distribution range in Sweden, Estonia, Great Britain and Spain to test whether they represent a single metapopulation or several separately evolving lineages. Using sequences of the barcoding gene cytochrome c oxidase subunit I (COI) and two nuclear genes (internal transcribed spacer region and histone 3), three different approaches were conducted: pairwise distance-method, Bayesian inference and network analysis. Both the COI phylogeny and network analyses were concordant in recovering six haplotype clusters, which showed a maximum genetic distance of 7.7% (K2P) among each other. Nevertheless, nuclear genes failed to confirm any lineage separation, and we conclude that the sampled specimens all belong to the same species. A phylogeographic history with allopatric divergence and secondary contact is suggested to explain this intraspecific pattern of mitochondrial divergence and nuclear non-divergence. The study shows that a mitochondrial single-locus approach can be problematic for the accurate delimitation of species, and we emphasise the need for nuclear genes as supplementary markers, when taxonomic resolution is assessed with COI barcodes. © CSIRO 2011.

Collier N.,King Abdullah University of Science and Technology | Pardo D.,University of the Basque Country | Dalcin L.,CONICET | Paszynski M.,AGH University of Science and Technology | Calo V.M.,King Abdullah University of Science and Technology
Computer Methods in Applied Mechanics and Engineering | Year: 2012

We study the performance of direct solvers on linear systems of equations resulting from isogeometric analysis. The problem of choice is the canonical Laplace equation in three dimensions. From this study we conclude that for a fixed number of unknowns and polynomial degree of approximation, a higher degree of continuity k drastically increases the CPU time and RAM needed to solve the problem when using a direct solver. This paper presents numerical results detailing the phenomenon as well as a theoretical analysis that explains the underlying cause. © 2011 Elsevier B.V.

Senovilla J.M.M.,University of the Basque Country
Journal of Physics: Conference Series | Year: 2015

Gravitational double layers, unlike their classical electromagnetic counterparts, are thought to be forbidden in gravity theories. It has been recently shown, however, that they are feasible in, for instance, gravity theories with a Lagrangian quadratic in the curvature. This is surprising with many potential consequences and the possibility of new physical behaviours. While a clear interpretation seems elusive, several lines of research are open. I present the field equations for double layers, the new physical quantities arising, and several explicit examples. © Published under licence by IOP Publishing Ltd.

Ozalp V.C.,University of the Basque Country
Analytical and Bioanalytical Chemistry | Year: 2012

An interferometry-based method was developed for detection of a small molecule, argininamide. The quantification of argininamide was demonstrated using aptamers immobilized on silicone oxynitride sensor surface via avidin-biotin binding. The aptamers formed a thin film over avidin layer corresponding to a thickness of 1.2 nm, consistent with a molecular positioning of multipoint attachment to the surface. The binding of argininamide did not cause any significant changes in the thickness of the aptamer film, suggesting that the specific binding did not affect the overall conformation of the aptamer molecules after adaptive rearrangement of aptamer molecules. However, the binding results in clearly detectable changes in mass calculated from multiple parameters determined by mass deposition and structural changes. The limit of detection of the developed sensor was determined to be 5 μM. The sensor can monitor real-time changes in argininamide concentrations with high reliability and sensitivity. The model system demonstrated that a combined measurement considering structural and mass changes through interferometry-based techniques can overcome one of the major problems associated with real-time monitoring of small mass analytes. © 2011 Springer-Verlag.

Zangi R.,University of the Basque Country | Zangi R.,Ikerbasque
Journal of Physical Chemistry B | Year: 2014

Buckyballs exhibit two seemingly opposing characters. On one hand, they are known to be insoluble in water with all potential chemical properties of being hydrophobic. On the other hand, their pairwise effective interaction in water includes a repulsive solvent-induced contribution. We perform molecular dynamics simulations of the association process of two C60 fullerenes in water at different temperatures in order to reconcile these contradicting observations. For comparison, the simulations were also performed in a nonpolar solvent, and the results were further contrasted with those obtained previously for the association of graphene sheets. Considering the association in water, we find small magnitudes for the enthalpy and entropy changes with small positive slopes as a function of temperature, implying an almost negligible change in the heat capacity at constant pressure. These findings sharply contradict the behavior of typical hydrophobic interactions. The reason for these abnormalities, as well as for the repulsive nature of the solvent-induced interactions, is the shape of the contact state that supports the existence of a distinct type of interfacial waters located between two convex surfaces of two buckyballs. These interfacial waters are characterized by smaller entropy and lower density and form a smaller number of hydrogen bonds with surrounding waters compared with those of the interfacial waters around the dissociated solutes. Thus, upon bringing the C60 fullerenes into contact, the changes associated with the liberation of the latter to bulk waters are opposed by the concomitant conversion of the latter also to the distinct waters between the two spherical solutes. We argue that although the effective pair interaction is not hydrophobic, the solvation properties are hydrophobic. In the hydration free energy of a single solute, there is no contact state. Furthermore, in the solubility at the macroscopic scale, the relative number of these distinct waters around a large aggregate is smaller, and hence, they are not predicted to influence much the solvation properties. Therefore, buckyballs can serve as an example in which hydrophobic interaction cannot be deducted from hydrophobic solvation. © 2014 American Chemical Society.

Eisler V.,Eotvos Lorand University | Zimboras Z.,University College London | Zimboras Z.,University of the Basque Country
New Journal of Physics | Year: 2014

We study the entanglement in a chain of harmonic oscillators driven out of equilibrium by preparing the two sides of the system at different temperatures, and subsequently joining them together. The steady state is constructed explicitly and the logarithmic negativity is calculated between two adjacent segments of the chain. We find that, for low temperatures, the steady-state entanglement is a sum of contributions pertaining to left- and right-moving excitations emitted from the two reservoirs. In turn, the steady-state entanglement is a simple average of the Gibbs-state values and thus its scaling can be obtained from conformal field theory. A similar averaging behaviour is observed during the entire time evolution. As a particular case, we also discuss a local quench where both sides of the chain are initialized in their respective ground states. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Manzano H.,Massachusetts Institute of Technology | Manzano H.,University of the Basque Country | Moeini S.,Massachusetts Institute of Technology | Marinelli F.,CNRS Physics Laboratory Ionic and Molecular Interactions ( PIIM ) | And 4 more authors.
Journal of the American Chemical Society | Year: 2012

Interest in microporous materials has risen in recent years, as they offer a confined environment that is optimal to enhance chemical reactions. Calcium silicate hydrate (C-S-H) gel, the main component of cement, presents a layered structure with sub-nanometer-size disordered pores filled with water and cations. The size of the pores and the hydrophilicity of the environment make C-S-H gel an excellent system to study the possibility of confined water reactions. To investigate it, we have performed molecular dynamics simulations using the ReaxFF force field. The results show that water does dissociate to form hydroxyl groups. We have analyzed the water dissociation mechanism, as well as the changes in the structure and water affinity of the C-S-H matrix and water polarization, comparing the results with the behavior of water in a defective zeolite. Finally, we establish a relationship between water dissociation in C-S-H gel and the increase of hardness due to a transformation from a two- to a three-dimensional structure. © 2011 American Chemical Society.

Tseng S.-Y.,National Cheng Kung University | Chen X.,Shanghai University | Chen X.,University of the Basque Country
Optics Letters | Year: 2012

We propose fast and robust mode conversion in multimode waveguides based on Lewis-Riesenfeld invariant theory. The design of mode converters using the multimode driving for dynamical invariant is discussed. Computergenerated planar holograms are used to mimic the shaped pulses driving the states in three-level quantum systems. We show that the invariant-based inverse engineering scheme reduces mode converter length as compared to the common adiabatic scheme. © 2012 Optical Society of America.

Heras-Saizarbitoria I.,University of the Basque Country | Molina-Azorin J.F.,University of Alicante | Dick G.P.M.,University of Kent
Journal of Cleaner Production | Year: 2011

The paper explores the bi-directional relationship between ISO 14001 certification and financial performance with the aim of shedding light on whether better performance is due to the beneficial effects of ISO 14001 or due to selection-effects where better performance precedes accreditation. The study uses a five year longitudinal analysis to compare the financial performance of firms in Spain before and after certification. The results of a multivariate panel data analysis find that firms with better than average performance have a greater propensity to pursue accreditation but there is no evidence that improvements in performance follow certification. This suggests that the inference that environmental variables cause improved financial performance may be unwise in research studies that can only measure association. © 2010 Elsevier Ltd. All rights reserved.

Cavaliere F.,University of the Basque Country
Cell death & disease | Year: 2012

We used multipotent stem cells (MSCs) derived from the young rat subventricular zone (SVZ) to study the effects of glutamate in oligodendrocyte maturation. Glutamate stimulated oligodendrocyte differentiation from SVZ-derived MSCs through the activation of specific N-methyl-D-aspartate (NMDA) receptor subunits. The effect of glutamate and NMDA on oligodendrocyte differentiation was evident in both the number of newly generated oligodendrocytes and their morphology. In addition, the levels of NMDAR1 and NMDAR2A protein increased during differentiation, whereas NMDAR2B and NMDAR3 protein levels decreased, suggesting differential expression of NMDA receptor subunits during maturation. Microfluorimetry showed that the activation of NMDA receptors during oligodendrocyte differentiation elevated cytosolic calcium levels and promoted myelination in cocultures with neurons. Moreover, we observed that stimulation of MSCs by NMDA receptors induced the generation of reactive oxygen species (ROS), which were negatively modulated by the NADPH inhibitor apocynin, and that the levels of ROS correlated with the degree of differentiation. Taken together, these findings suggest that ROS generated by NADPH oxidase by the activation of NMDA receptors promotes the maturation of oligodendrocytes and favors myelination.

Aguirre-Urizar J.M.,University of the Basque Country
World Journal of Surgical Oncology | Year: 2011

In this letter I propose the name "Proliferative Multifocal Leukoplakia" with the goal of reducing under-diagnosis of this disease, improve the early diagnosis, try to make an early therapy and control, and prevent its malignant transformation. © 2011 Aguirre-Urizar; licensee BioMed Central Ltd.

Bacigalupe A.,University of the Basque Country | Escolar-Pujolar A.,Local Health Authority
International Journal for Equity in Health | Year: 2014

Since 2008, Western countries are going through a deep economic crisis whose health impacts seem to be fundamentally counter-cyclical: when economic conditions worsen, so does health, and mortality tends to rise. While a growing number of studies have presented evidence on the effect of crises on the average population health, a largely neglected aspect of research is the impact of crises and the related political responses on social inequalities in health, even if the negative consequences of the crises are primarily borne by the most disadvantaged populations. This commentary will reflect on the results of the studies that have analyzed the effect of economic crises on social inequalities in health up to 2013. With some exceptions, the studies show an increase in health inequalities during crises, especially during the Southeast Asian and Japanese crises and the Soviet Union crisis, although it is not always evident for both sexes or all health or socioeconomic variables. In the Nordic countries during the nineties, a clear worsening of health equity did not occur. Results about the impacts of the current economic recession on health equity are still inconsistent. Some of the factors that could explain this variability in results are the role of welfare state policies, the diversity of time periods used in the analyses, the heterogeneity of socioeconomic and health variables considered, the changes in the socioeconomic profile of the groups under comparison in times of crises, and the type of measures used to analyze the magnitude of social inequalities in health. Social epidemiology should further collaborate with other disciplines to help produce more accurate and useful evidence about the relationship between crises and health equity. © 2014 Bacigalupe and Escolar-Pujolar; licensee BioMed Central Ltd.

Balleza D.,University of the Basque Country
Channels (Austin, Tex.) | Year: 2012

Material properties of lipid bilayers, including thickness, intrinsic curvature and compressibility regulate the function of mechanosensitive (MS) channels. This regulation is dependent on phospholipid composition, lateral packing and organization within the membrane. Therefore, a more complete framework to understand the functioning of MS channels requires insights into bilayer structure, thermodynamics and phospholipid structure, as well as lipid-protein interactions. Phospholipids and MS channels interact with each other mainly through electrostatic forces and hydrophobic matching, which are also crucial for antimicrobial peptides. They are excellent models for studying the formation and stabilization of membrane pores. Importantly, they perform equivalent responses as MS channels: (1) tilting in response to tension and (2) dissipation of osmotic gradients. Lessons learned from pore forming peptides could enrich our knowledge of mechanisms of action and evolution of these channels. Here, the current state of the art is presented and general principles of membrane regulation of mechanosensitive function are discussed.

Ronnestad B.R.,Lillehammer University College | Mujika I.,University of the Basque Country | Mujika I.,Finis Terrae University
Scandinavian Journal of Medicine and Science in Sports | Year: 2014

Here we report on the effect of combining endurance training with heavy or explosive strength training on endurance performance in endurance-trained runners and cyclists. Running economy is improved by performing combined endurance training with either heavy or explosive strength training. However, heavy strength training is recommended for improving cycling economy. Equivocal findings exist regarding the effects on power output or velocity at the lactate threshold. Concurrent endurance and heavy strength training can increase running speed and power output at VO2max (Vmax and Wmax, respectively) or time to exhaustion at Vmax and Wmax. Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used. It is suggested that the improved endurance performance may relate to delayed activation of less efficient type II fibers, improved neuromuscular efficiency, conversion of fast-twitch type IIX fibers into more fatigue-resistant type IIA fibers, or improved musculo-tendinous stiffness. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Perez-Garcia A.,Complutense University of Madrid | Scheyer T.M.,University of Zurich | Murelaga X.,University of the Basque Country
Cretaceous Research | Year: 2013

The faunal associations of the uppermost Jurassic and Early Cretaceous Villar del Arzobispo, El Castellar, and Camarillas formations of the Spanish town of Galve (Maestrazgo Basin of the Iberian Range) are composed of more than fifty taxa belonging to Chondrichthyes, bony fishes, lissamphibians, mammals, and reptiles. Although the presence of turtles has been recognized in these three formations, being very abundant, the published information is limited. The detailed study of these turtles allows us to recognize at least nine taxa, several of them previously not identified in the Spanish record. These taxa correspond to stem Testudines (Solemydidae), members of Paracryptodira (Pleurosternidae), several representatives of Plesiochelyidae and taxa closely related with this clade, representatives of the stem group of Cryptodira (Xinjiangchelyidae) and members of crown Cryptodira. The chelonian fauna of Galve increases the systematic, anatomical, biostratigraphic, and paleobiogeographic knowledge on several clades, represented by taxa shared with other European regions, clades also present in Early Cretaceous sites of North America or Asia, as well as taxa exclusive of the Iberian record. © 2013 Elsevier Ltd.

Barcelo-Coblijn G.,Hospital Universitari Son Espases | Fernandez J.A.,University of the Basque Country
Frontiers in Physiology | Year: 2015

These are definitively exciting times for membrane lipid researchers. Once considered just as the cell membrane building blocks, the important role these lipids play is steadily being acknowledged. The improvement occurred in mass spectrometry techniques (MS) allows the establishment of the precise lipid composition of biological extracts. However, to fully understand the biological function of each individual lipid species, we need to know its spatial distribution and dynamics. In the past 10 years, the field has experienced a profound revolution thanks to the development of MS-based techniques allowing lipid imaging (MSI). Images reveal and verify what many lipid researchers had already shown by different means, but none as convincing as an image: each cell type presents a specific lipid composition, which is highly sensitive to its physiological and pathological state. While these techniques will help to place membrane lipids in the position they deserve, they also open the black box containing all the unknown regulatory mechanisms accounting for such tailored lipid composition. Thus, these results urges to different disciplines to redefine their paradigm of study by including the complexity revealed by the MSI techniques. © 2015 Barceló-Coblijn and Fernández.

Emerich D.F.,Nsgene Inc. | Orive G.,University of the Basque Country | Orive G.,CIBER ISCIII | Thanos C.,Cytosolve Inc. | And 2 more authors.
Advanced Drug Delivery Reviews | Year: 2014

Delivering therapeutic molecules, including trophic factor proteins, across the blood brain barrier to the brain parenchyma to treat chronic neurodegenerative diseases remains one of the great challenges in biology. To be effective, delivery needs to occur in a long-term and stable manner at sufficient quantities directly to the target region in a manner that is selective but yet covers enough of the target site to be efficacious. One promising approach uses cellular implants that produce and deliver therapeutic molecules directly to the brain region of interest. Implanted cells can be precisely positioned into the desired region and can be protected from host immunological attack by encapsulating them and by surrounding them within an immunoisolatory, semipermeable capsule. In this approach, cells are enclosed within a semiporous capsule with a perm selective membrane barrier that admits oxygen and required nutrients and releases bioactive cell secretions while restricting passage of larger cytotoxic agents from the host immune defense system. Recent advances in human cell line development have increased the levels of secreted therapeutic molecules from encapsulated cells, and membrane extrusion techniques have led to the first ever clinical demonstrations of long-term survival and function of encapsulated cells in the brain parenchyma. As such, cell encapsulation is capable of providing a targeted, continuous, de novo synthesized source of very high levels of therapeutic molecules that can be distributed over significant portions of the brain. © 2013 Elsevier B.V.

Ramos J.,Grupo de Fisica de Fluidos y Biocoloides | Forcada J.,University of the Basque Country
European Polymer Journal | Year: 2010

[2-(methacryloyloxy)ethyl] trimethylammonium chloride (MATMAC), and vinylbenzyl trimethyl ammonium chloride (VBTMAC) were chosen to be used as ionic comonomers in the emulsion polymerization of styrene. The cationic nature of the two comonomers is the same (quaternary ammonium salts), however the styrene derivate (VBTMAC) is more hydrophobic than the methacrylic one (MATMAC). With the more hydrophobic cationic comonomer (VBTMAC) higher conversions were obtained due to the in situ creation of an amphiphilic copolymer with styrene and faster rates of polymerization were observed by increasing the cationic comonomer concentration. The same behavior was observed with the more hydrophilic cationic comonomer (MATMAC) at concentrations up to 0.012 M. At higher concentrations the ionic strength controls the colloidal stability of the system and coagulation occurs. © 2010 Elsevier Ltd. All rights reserved.

A personality disorder can be considered to be a generalized pattern of behaviors, cognitions, and emotions that is enduring, begins in adolescence or early adulthood, remains stable over time, and generates stress or psychological damage. The current focus on personality disorders (PDs) is found in Section II of DSM-5 and is unchanged compared to DSM-IV, except that the PDs were removed from the former Axis II of the DSM-IV and included in the central classification of disorders. However, an alternative model for further study is presented in Section III that aims to address the deficiencies in the current categorical model of PDs. The underlying idea is that PDs are an extreme version of the personality traits that everyone has. According to this approach, PDs are characterized by impaired personality functioning (areas of identity, selfdirection, empathy, and intimacy) and pathological personality factors (negative affectivity, detachment, antagonism, disinhibition, and psychoticism). The diagnostic categories derived from this model include only antisocial, avoidant, borderline, narcissistic, obsessive-compulsive, and schizotypal PDs. This hybrid approach to the diagnosis of PDs is complex and requires more empirical evidence before it can be incorporated into clinical practice. The proposals of the draft ICD-11 for PDs, which are based primarily on severity and dominant personality traits, are also included.

Guimon J.,University of the Basque Country
International Journal of Mental Health | Year: 2010

The negative attitudes toward mental illness can be based not only on ignorance and intolerance but also on such real factors as dangerousness, unpredictability, disability, and the burden the psychiatric patient represents for the community, particularly for members of the family and professionals who experience the stress that results from caring for them. A lack of access to health services can be due to discrimination or social stigma, such as in the case of chronic mental patients. However, other patients-anxious, shy, fearful, avoidant, obsessional, schizoid and other-whose behavioral difficulties also remain frequently undetected as the public can find it very difficult to overcome the barriers that society poses to obtain some services, privileges, and compensations. They are, in fact, indirectly discriminated. Questions concerning the relation between mental health and human rights are summarily addressed in some documents of international organizations, particularly, the UN Principles for the Protection of Persons with Mental Illness and the Improvement of Mental Health Care. However, many situations of inequity in relation to psychiatric care are detected in contemporary systems of managed care, but solutions are not easy to implement. If we treat disabled people as equal in dignity and right, differences in physical or mental capability among people should be accommodated without discrimination. This equal treatment requires a combination of psychological approaches such as modifications in public attitudes toward disabled people and social efforts to confront the concrete realities of disability and legal measures (including positive discrimination) when the previous steps are not sufficient. © 2010 M.E. Sharpe, Inc. All rights reserved.

Vilar J.M.G.,University of the Basque Country | Vilar J.M.G.,Ikerbasque
Biophysical Journal | Year: 2010

Gene regulation involves a hierarchy of events that extend from specific protein-DNA interactions to the combinatorial assembly of nucleoprotein complexes. The effects of DNA sequence on these processes have typically been studied based either on its quantitative connection with single-domain binding free energies or on empirical rules that combine different DNA motifs to predict gene expression trends on a genomic scale. The middle-point approach that quantitatively bridges these two extremes, however, remains largely unexplored. Here, we provide an integrated approach to accurately predict gene expression from statistical sequence information in combination with detailed biophysical modeling of transcription regulation by multidomain binding on multiple DNA sites. For the regulation of the prototypical lac operon, this approach predicts within 0.3-fold accuracy transcriptional activity over a 10,000-fold range from DNA sequence statistics for different intracellular conditions. © 2010 by the Biophysical Society.

Ozalp V.C.,University of the Basque Country
Analyst | Year: 2011

A quartz crystal microbalance with a dissipation monitoring (QCM-D) sensor was developed for highly sensitive and specific detection of adenosine-5′-triphosphate (ATP) by using an aptamer. The binding of ATP molecules on the aptamer films could be calculated as accurate mass changes using multiple frequency and dissipation measurements. The detection is achieved by calculating the mass changes from conformational rearrangements of the sensor surface upon interaction with the target. The sensor was demonstrated to respond to changes in ATP concentrations in real time suitable for continuous monitoring applications. This sensor showed excellent selectivity toward ATP compared with other chemically similar nucleotide GTP. The feasibility of the sensor was demonstrated by analyzing ATP concentrations in cell culture media with serum. The maximum frequency change was about -2 Hz after injection of 500 μM ATP. The affinity constant of the aptamer was determined to be 49 ± 7.59 μM. The proposed sensor can extend the application of the QCM-D system in medical diagnosis, and could be adopted for the detection of other small molecules with the use of specific aptamers. © 2011 The Royal Society of Chemistry.

Pedraz J.L.,University of the Basque Country
Advances in Experimental Medicine and Biology | Year: 2010

The field of cell encapsulation is advancing rapidly. This cell-based technology permits the local and long-term delivery of a desired therapeutic product reducing or even avoiding the need of immunosuppressant drugs. The choice of a suitable material preserving the viability and functionality of enclosed cells becomes fundamental if a therapeutic aim is intended. Alginate, which is by far the most frequently used biomaterial in the field of cell microencapsulation, has been demonstrated to be probably the best polymer for this purpose due to its biocompatibility, easy manipulation, gel forming capacity and in vivo performance. © 2010 Landes Bioscience and Springer Science+Business Media.

Camblong H.,University of the Basque Country
IEEE Transactions on Power Electronics | Year: 2010

In this paper, the transient operation of a four-leg inverter equipped with an innovative control strategy under unbalanced load conditions is investigated. The inverter is proposed for transformerless hybrid power system applications, in order to provide simultaneous supply of three-phase and single-phase ac loads with balanced voltage and constant frequency. The four-leg inverter is controlled to ensure balanced voltage by means of a control strategy based on the decomposition of the supply three-phase voltage and current into instantaneous positive, negative, and homopolar sequence components using phasor representation. These three sequences are controlled independently in their own reference frames as dc signals. The implementation derived for the controller design is also described. The transient operation performance of the proposed control strategy has been tested in simulations with an average model and experimentally using a laboratory prototype. © 2010 IEEE.

De La Sen M.,University of the Basque Country
Mathematical Problems in Engineering | Year: 2010

This paper investigates the stability properties of a class of dynamic linear systems possessing several linear time-invariant parameterizations (or configurations) which conform a linear time-varying polytopic dynamic system with a finite number of time-varying time-differentiable point delays. The parameterizations may be timevarying and with bounded discontinuities and they can be subject to mixed regular plus impulsive controls within a sequence of time instants of zero measure. The polytopic parameterization for the dynamics associated with each delay is specific, so that (q + 1) polytopic parameterizations are considered for a system with q delays being also subject to delay-free dynamics. The considered general dynamic system includes, as particular cases, a wide class of switched linear systems whose individual parameterizations are timeinvariant which are governed by a switching rule. However, the dynamic system under consideration is viewed as much more general since it is time-varying with timevarying delays and the bounded discontinuous changes of active parameterizations are generated by impulsive controls in the dynamics and, at the same time, there is not a prescribed set of candidate potential parameterizations. © 2010 M. de la Sen.

Bahramian A.,Hamedan University of Technology | Olazar M.,University of the Basque Country
AIChE Journal | Year: 2012

The numerical simulations and experimental data of bed hydrodynamics in a conical fluidized bed unit are compared. Experimental studies have been carried out in a bed containing TiO 2 particles belonging to A/C boundary of Geldart's classification with a wide particle-size distribution. Thus, pressure measurements and an optical fiber technique allowed determining the effect of static bed height on the fluidization characteristics of micronic particles. Numerical simulations have then been performed to evaluate the sensitivity of gas-solids drag models. The Eulerian multiphase model has been used with different drag models and three boundary conditions (BC) consisting of no-slip, partial-slip, and free-slip. The numerical predictions using the Gidaspow drag model and partial-slip BC agreed reasonably well with the experimental bed pressure drop measurements. The simulation results obtained for bed expansion ratio show that the Gidaspow model with the free-slip BC best fit with the experimental data. © 2011 American Institute of Chemical Engineers (AIChE).

Perez-Lopez U.,University of the Basque Country
Photosynthesis research | Year: 2012

The future environment may be altered by high concentrations of salt in the soil and elevated [CO(2)] in the atmosphere. These have opposite effects on photosynthesis. Generally, salt stress inhibits photosynthesis by stomatal and non-stomatal mechanisms; in contrast, elevated [CO(2)] stimulates photosynthesis by increasing CO(2) availability in the Rubisco carboxylating site and by reducing photorespiration. However, few studies have focused on the interactive effects of these factors on photosynthesis. To elucidate this knowledge gap, we grew the barley plant, Hordeum vulgare (cv. Iranis), with and without salt stress at either ambient or elevated atmospheric [CO(2)] (350 or 700 μmol mol(-1) CO(2), respectively). We measured growth, several photosynthetic and fluorescence parameters, and carbohydrate content. Under saline conditions, the photosynthetic rate decreased, mostly because of stomatal limitations. Increasing salinity progressively increased metabolic (photochemical and biochemical) limitation; this included an increase in non-photochemical quenching and a reduction in the PSII quantum yield. When salinity was combined with elevated CO(2), the rate of CO(2) diffusion to the carboxylating site increased, despite lower stomatal and internal conductance. The greater CO(2) availability increased the electron sink capacity, which alleviated the salt-induced metabolic limitations on the photosynthetic rate. Consequently, elevated CO(2) partially mitigated the saline effects on photosynthesis by maintaining favorable biochemistry and photochemistry in barley leaves. © Springer Science+Business Media B.V. 2012

Figueroa D.G.,University of Geneva | Figueroa D.G.,Helsinki Institute of Physics | Hindmarsh M.,Helsinki Institute of Physics | Hindmarsh M.,University of Sussex | And 2 more authors.
Physical Review Letters | Year: 2013

We demonstrate that any scaling source in the radiation era produces a background of gravitational waves with an exact scale-invariant power spectrum. Cosmic defects, created after a phase transition in the early universe, are such a scaling source. We emphasize that the result is independent of the topology of the cosmic defects, the order of phase transition, and the nature of the symmetry broken, global or gauged. As an example, using large-scale numerical simulations, we calculate the scale-invariant gravitational wave power spectrum generated by the dynamics of a global O(N) scalar theory. The result approaches the large N theoretical prediction as N-2, albeit with a large coefficient. The signal from global cosmic strings is O(100) times larger than the large N prediction. © 2013 American Physical Society.

Friis N.,University of Nottingham | Lee A.R.,University of Nottingham | Truong K.,University of Nottingham | Sabin C.,University of Nottingham | And 4 more authors.
Physical Review Letters | Year: 2013

We study the effects of relativistic motion on quantum teleportation and propose a realizable experiment where our results can be tested. We compute bounds on the optimal fidelity of teleportation when one of the observers undergoes nonuniform motion for a finite time. The upper bound to the optimal fidelity is degraded due to the observer's motion. However, we discuss how this degradation can be corrected. These effects are observable for experimental parameters that are within reach of cutting-edge superconducting technology. © 2013 American Physical Society.

Eltschka C.,University of Regensburg | Siewert J.,University of the Basque Country | Siewert J.,Ikerbasque
Physical Review Letters | Year: 2013

Among all entanglement measures negativity arguably is the best known and most popular tool to quantify bipartite quantum correlations. It is easily computed for arbitrary states of a composite system and can therefore be applied to discuss entanglement in an ample variety of situations. However, as opposed to logarithmic negativity, its direct physical meaning has not been pointed out yet. We show that the negativity can be viewed as an estimator of how many degrees of freedom of two subsystems are entangled. As it is possible to give lower bounds for the negativity even in a device-independent setting, it is the appropriate quantity to certify quantumness of both parties in a bipartite system and to determine the minimum number of dimensions that contribute to the quantum correlations. © 2013 American Physical Society.

Mujika I.,University of the Basque Country
International Journal of Sports Physiology and Performance | Year: 2012

Age-related fitness declines in athletes can be due to both aging and detraining. Very little is known about the physiological and performance decline of professional cyclists after retirement from competition. To gain some insight into the aging and detraining process of elite cyclists, 5-time Tour de France winner and Olympic Champion Miguel Indurain performed a progressive cycle-ergometer test to exhaustion 14 y after retirement from professional cycling (age 46 y, body mass 92.2 kg). His maximal values were oxygen uptake 5.29 L/min (57.4 mL · kg-1 · min-1), aerobic power output 450 W (4.88 W/kg), heart rate 191 beats/min, blood lactate 11.2 mM. Values at the individual lactate threshold (ILT): 4.28 L/min (46.4 mL · kg-1 · min-1), 329 W (3.57 W/kg), 159 beats/min, 2.4 mM. Values at the 4-mM onset of blood lactate accumulation (OBLA): 4.68 L/min (50.8 mL · kg-1 · min-1), 369 W (4.00 W/kg), 170 beats/min. Average cycling gross efficiency between 100 and 350 W was 20.1%, with a peak value of 22.3% at 350 W. Delta efficiency was 27.04%. Absolute maximal oxygen uptake and aerobic power output declined by 12.4% and 15.2% per decade, whereas power output at ILT and OBLA declined by 19.8% and 19.2%. Larger declines in maximal and submaximal values relative to body mass (19.4-26.1%) indicate that body composition changed more than aerobic characteristics. Nevertheless, Indurain's absolute maximal and submaximal oxygen uptake and power output still compare favorably with those exhibited by active professional cyclists. © 2012 Human Kinetics, Inc.

Barambones O.,University of the Basque Country
Energies | Year: 2012

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a sliding mode control for variable speed wind turbine that incorporates a doubly fed induction generator is described. The electrical system incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the grid. In the presented design the so-called vector control theory is applied, in order to simplify the electrical equations. The proposed control scheme uses stator flux-oriented vector control for the rotor side converter bridge control and grid voltage vector control for the grid side converter bridge control. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally simulated results show, on the one hand, that the proposed controller provides high-performance dynamic characteristics, and on the other hand, that this scheme is robust with respect to the uncertainties that usually appear in the real systems. © 2012 by the author.

Garmendia E.,Basque Center For Climate Change 3 | Garmendia E.,University of the Basque Country | Gamboa G.,Polytechnic University of Catalonia
Ecological Economics | Year: 2012

The use of multi-criteria evaluation tools in combination with participatory approaches provides a promising framework for integrating multiple interests and perspectives in the effort to provide sustainability. However, the inclusion of diverse viewpoints requires the "compression" of complex issues, a process that is controversial. Ensuring the quality of the compression process is a major challenge, especially with regards to retaining the essential elements of the various perspectives. Based on the lessons learned during a case study that assessed sustainable management options for the Urdaibai Estuary (Basque Country-Southern Europe), we propose a process in which the explicit elicitation of weights (the prioritisation of criteria) within a participatory multi-criteria evaluation serves as a quality assurance mechanism to check the robustness of the evaluation process. The results demonstrate that diverse individual priorities can be grouped in a reduced set of social preferences by means of cluster analysis reinforced with a deliberative appraisal among a wide variety of social actors. The approach presented retains relevant information regarding extreme and sometimes irreconcilable positions, allows an explicit social sensitivity analysis of the MCE process, and enables participants to learn from and reflect upon diverse social preferences without forcing their consensus. © 2012 Elsevier B.V.

Gonzalez-Eguino M.,University of the Basque Country
Renewable and Sustainable Energy Reviews | Year: 2015

Abstract In the coming decades the energy sector will have to face three major transformations concerned with climate change, security of supply and energy poverty. The first two have been extensively analysed, but less attention has been paid to the third, even though it has a great influence on the lives of millions of people. This paper presents an overview on energy poverty, different ways of measuring it and its implications. According to the WHO, indoor pollution causes an estimated 1.3 million deaths per annum in low income countries associated with the use of biomass in inadequate cookstoves. Although energy poverty cannot be delinked from the broader, more complex problem of poverty in general, access to energy infrastructures would avoid its most serious consequences and would help to encourage autonomous development. According to the IEA, the cost of providing universal access to energy by 2030 would require annual investment of $35 billion, i.e. much less than the amount provided annually in subsidies to fossil fuels. Finally, the paper argues that energy and energy poverty need to be incorporated into the design of development strategies. © 2015 Elsevier Ltd. All rights reserved.

Ruiz-Moneo P.,Hospital Universitario Of Araba | Molano-Munoz J.,Hospital Universitario Of Araba | Prieto E.,Osatek S.A. Public Society | Algorta J.,Hospital Universitario Of Araba | Algorta J.,University of the Basque Country
Arthroscopy - Journal of Arthroscopic and Related Surgery | Year: 2013

Purpose: The aim of this study was to determine whether addition of plasma rich in growth factors (PRGF) improves functional and structural outcomes after arthroscopic repair of full-thickness rotator cuff tears. Methods: The study design was independent (investigator-sponsored), randomized in parallel groups, double-blind, and controlled with a conventional surgical technique clinical trial. Sixty-nine patients with rotator cuff tears were included. Subsequently, 6 patients in whom less than 50% footprint coverage of the repair was possible were excluded. Before arthroscopic repair, patients were randomly assigned to receive PRGF at the end of arthroscopy (injected first in the repaired area and then spread over the tendon suture) or only conventional surgery. Efficacy was evaluated 1 year after surgery using functional (UCLA score) and structural (arthro-MRI) assessments. Results: The baseline UCLA scores of the PRGF (14.9; 95% confidence interval [CI]: 13.7 to 16.12) and control (13.2; 95% CI: 13.3 to 16.3) groups were similar. After surgery, both groups showed an improvement in UCLA score, without significant differences between groups (23.2; CI 95%: 20.8 to 25.7, and 23.8; 95% CI: 21.0 to 26.7, respectively). Furthermore, no significant differences were observed in satisfaction 1 year after surgery. Tendon healing evaluated with arthro-magnetic resonance imaging showed total healing in 40% of cases, partial healing in 30%, and lack of healing in 30%, again with no significant differences between groups. No adverse events were recorded. Conclusions: The present clinical trial does not support the use of plasma rich in growth factors in the arthroscopic repair of rotator cuff tears because no differences in rotator cuff healing or improvements in function were observed in the 1-year postsurgical clinical and radiological follow-up assessments. Level of Evidence: Level I, randomized, double-blind, controlled clinical trial. © 2013 by the Arthroscopy Association of North America.

Barambones O.,University of the Basque Country
Electric Power Systems Research | Year: 2015

This short communication is a discussion of the paper entitled "Adaptive sliding mode observer for induction motor using two-time-scale approach" by A. Mezouar, M.K. Fellah and S. Hadjeri published in the Electric Power Systems Research 77 (2007) pp. 604-618. In the discussed paper the authors present a current and flux sliding mode observer for the induction motor that also incorporates an adaptive law in order to estimate the inverse of the rotor time constant. However the proposed observer design uses the real value of the rotor time constant which is unknown and therefore cannot be used in the observer design. © 2014 Elsevier B.V. All rights reserved.

Skowron S.T.,University of Nottingham | Lebedeva I.V.,University of the Basque Country | Popov A.M.,Russian Academy of Sciences | Bichoutskaia E.,University of Nottingham
Chemical Society Reviews | Year: 2015

The presence of defects in graphene has an essential influence on its physical and chemical properties. The formation, behaviour and healing of defects are determined by energetic characteristics of atomic scale structure changes. In this article, we review recent studies devoted to atomic scale reactions during thermally activated and irradiation-induced processes in graphene. The formation energies of vacancies, adatoms and topological defects are discussed. Defect formation, healing and migration are quantified in terms of activation energies (barriers) for thermally activated processes and by threshold energies for processes occurring under electron irradiation. The energetics of defects in the graphene interior and at the edge is analysed. The effects of applied strain and a close proximity of the edge on the energetics of atomic scale reactions are overviewed. Particular attention is given to problems where further studies are required. This journal is © The Royal Society of Chemistry.

Mashaghi A.,Technical University of Delft | Mashaghi S.,Zernike Institute for Advanced Materials | Reviakine I.,Karlsruhe Institute of Technology | Reviakine I.,University of the Basque Country | And 3 more authors.
Chemical Society Reviews | Year: 2014

We review recent progress in the study of the structure and dynamics of phospholipid membranes and associated proteins, using novel label-free analytical tools. We describe these techniques and illustrate them with examples highlighting current capabilities and limitations. Recent advances in applying such techniques to biological and model membranes for biophysical studies and biosensing applications are presented, and future prospects are discussed. This journal is © The Royal Society of Chemistry.

Basurko O.C.,AZTI Marine Research Division | Uriondo Z.,University of the Basque Country
Applied Thermal Engineering | Year: 2015

Condition-Based Maintenance for diesel engines has contributed to reliability, energy-efficiency, and cost reduction. Both, the modelling of engine performance and fault detection require large amounts of data; usually, these are obtained on a test bench. In contrast, in operative engines, provoking faults onboard is not a viable proposition. Condition-Based Maintenance, fault detection and diagnosis need to be solved on engines installed in commercial vessels: the present contribution answers this need. A medium-speed diesel engine was monitored using thermocouples, pressure sensors, a propeller shaft torque meter and fuel oil flow-meters, during more than 10,000 running hours. Monitored data were used to train a three-layer feed-forward neural network, to generate the engine performance model; thus, determine the engine's fuel consumption and faulty conditions. The faulty conditions considered were: (1) a polluted turbine; (2) a dirty air filter/compressor; (3) a dirty air cooler; (4) and bad fuel injection, i.e. bad combustion. The sensor's precision and the experience gained by monitoring the engine served as a baseline to define the fault threshold values. The results proved the feasibility of installing a Condition-Based Maintenance, for vessels in operation, by monitoring engine performance and analysing the data with the aid of artificial neural networks. © 2015 Elsevier Ltd. All rights reserved.

Seena S.,University of Coimbra | Seena S.,University of Minho | Monroy S.,University of the Basque Country
Fungal Ecology | Year: 2016

Aquatic hyphomycetes play a key role in leaf litter decomposition and are mediators of organic matter turnover in streams. Molecular studies have shown that some aquatic fungi are also plant endophytes, however, more evidence is needed to evaluate their multiple ecological abilities. To date, little information is available on fungal lineages that might have undergone convergent evolution to adapt to multiple ecological modes. We examined the phylogenetic relationships and evolutionary divergences of aquatic hyphomycetes, endophytic aquatic hyphomycetes and other fungal endophytes of riparian/terrestrial plants by analyzing ITS1-5.8S-ITS2 sequences retrieved from the National Center for Biotechnology Information (NCBI). Sequences with close phylogenetic affinity to aquatic fungi can occur as endophytes of terrestrial plants or in soil far from streams. To fully understand the ecological impact of aquatic hyphomycetes, we need to document and interpret their niches more broadly. © 2015 Elsevier Ltd and The British Mycological Society.

Burke L.M.,Australian Institute of Sport | Mujika I.,University of the Basque Country | Mujika I.,Finis Terrae University
International Journal of Sport Nutrition and Exercise Metabolism | Year: 2014

Postexercise recovery is an important topic among aquatic athletes and involves interest in the quality, quantity, and timing of intake of food and fluids after workouts or competitive events to optimize processes such as refueling, rehydration, repair, and adaptation. Recovery processes that help to minimize the risk of illness and injury are also important but are less well documented. Recovery between workouts or competitive events may have two separate goals: (a) restoration of body losses and changes caused by the first session to restore performance for the next and (b) maximization of the adaptive responses to the stress provided by the session to gradually make the body become better at the features of exercise that are important for performance. In some cases, effective recovery occurs only when nutrients are supplied, and an early supply of nutrients may also be valuable in situations in which the period immediately after exercise provides an enhanced stimulus for recovery. This review summarizes contemporary knowledge of nutritional strategies to promote glycogen resynthesis, restoration of fluid balance, and protein synthesis after different types of exercise stimuli. It notes that some scenarios benefit from a proactive approach to recovery eating, whereas others may not need such attention. In fact, in some situations it may actually be beneficial to withhold nutritional support immediately after exercise. Each athlete should use a cost-benefit analysis of the approaches to recovery after different types of workouts or competitive events and then periodize different recovery strategies into their training or competition programs. © 2014 Human Kinetics, Inc.

Ludvigsson J.,Linkoping University | Krisky D.,Diamyd Medical | Casas R.,Linkoping University | Battelino T.,University of Ljubljana | And 8 more authors.
New England Journal of Medicine | Year: 2012

BACKGROUND: The 65-kD isoform of glutamic acid decarboxylase (GAD65) is a major autoantigen in type 1 diabetes. We hypothesized that alum-formulated GAD65 (GAD-alum) can preserve beta-cell function in patients with recent-onset type 1 diabetes. METHODS: We studied 334 patients, 10 to 20 years of age, with type 1 diabetes, fasting C-peptide levels of more than 0.3 ng per milliliter (0.1 nmol per liter), and detectable serum GAD65 autoantibodies. Within 3 months after diagnosis, patients were randomly assigned to receive one of three study treatments: four doses of GAD-alum, two doses of GAD-alum followed by two doses of placebo, or four doses of placebo. The primary outcome was the change in the stimulated serum C-peptide level (after a mixedmeal tolerance test) between the baseline visit and the 15-month visit. Secondary outcomes included the glycated hemoglobin level, mean daily insulin dose, rate of hypoglycemia, and fasting and maximum stimulated C-peptide levels. RESULTS: The stimulated C-peptide level declined to a similar degree in all study groups, and the primary outcome at 15 months did not differ significantly between the combined active-drug groups and the placebo group (P = 0.10). The use of GAD-alum as compared with placebo did not affect the insulin dose, glycated hemoglobin level, or hypoglycemia rate. Adverse events were infrequent and mild in the three groups, with no significant differences. CONCLUSIONS: Treatment with GAD-alum did not significantly reduce the loss of stimulated C peptide or improve clinical outcomes over a 15-month period. (Funded by Diamyd Medical and the Swedish Child Diabetes Foundation; ClinicalTrials.gov number, NCT00723411.) Copyright © 2012 Massachusetts Medical Society.

Martin-Luengo B.,University of the Basque Country
The Spanish journal of psychology | Year: 2013

We examined the influence of the type of radio program on the memory for radio advertisements. We also investigated the role in memory of the typicality (high or low) of the elements of the products advertised. Participants listened to three types of programs (interesting, boring, enjoyable) with two advertisements embedded in each. After completing a filler task, the participants performed a true/false recognition test. Hits and false alarm rates were higher for the interesting and enjoyable programs than for the boring one. There were also more hits and false alarms for the high-typicality elements. The response criterion for the advertisements embedded in the boring program was stricter than for the advertisements in other types of programs. We conclude that the type of program in which an advertisement is inserted and the nature of the elements of the advertisement affect both the number of hits and false alarms and the response criterion, but not the accuracy of the memory.

Wu L.-A.,University of the Basque Country | Segal D.,University of Toronto
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We study the process of heat transfer through an entangled pair of two-level systems, demonstrating the role of quantum correlations in this nonequilibrium process. While quantum correlations generally degrade with increasing the temperature bias, introducing spatial asymmetry leads to an intricate behavior: connecting the qubits unequally to the reservoirs, one finds that quantum correlations persist and increase with the temperature bias when the system is more weakly linked to the hot reservoir. In the reversed case, linking the system more strongly to the hot bath, the opposite, more natural behavior is observed, with quantum correlations being strongly suppressed upon increasing the temperature bias. © 2011 American Physical Society.

Pettini G.,University of Florence | Modugno M.,University of the Basque Country | Modugno M.,Ikerbasque
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We investigate the dynamics of a wave packet in a parity-breaking one-dimensional periodic potential slowly varied in time and perturbed by a linear potential. Parity is broken by considering an asymmetric double well per unit cell. By comparing the prediction of the semiclassical dynamics with the full Schrödinger solution, we show that Bloch oscillations are strongly affected by anomalous velocity corrections related to Berry's phase. We characterize how these effects depend on the degree of parity breaking of the potential and on the modulation parameters. We also discuss how to measure the effects of the anomalous velocity in current experiments with noninteracting Bose-Einstein condensates in bichromatic optical lattices, under the effect of gravity. © 2011 American Physical Society.

Galvez J.,University of Murcia | Guirado A.,University of the Basque Country
Journal of Computational Chemistry | Year: 2010

The different mechanisms, rotation, inversion, or intermediate mechanism, by which occur the topomerization of imine systems R2C=N-X have been studied by applying ab initio, B3LYP, and MP2 methods. The effect of a wide variety of substituents R and X on the isomerization pathway have been examined by computing fully optimized structures of the ground and transition states (136 isomers belonging to different imine families were studied and more than 300 transition structures were determined at various levels of theory). Energy barriers have been also obtained and it was found that the groups R and X have a strong influence on the type of mechanism involved and the activation energies. Thus, and depending on the type of substituents, transition state structures related to the following kinds of processes were found: pure inversion, intermediate mechanisms, rotation, and enhanced rotation (hyper-rotation). In turn, the corresponding activation energies range between very low (<10kcal/mol) and extremely high (>70kcal/mol) values. A simple index that allows us to quantify the percentage of inversion or rotation mechanism is proposed. © 2009 Wiley Periodicals, Inc.

Olano J.M.,University of Valladolid | Arzac A.,University of the Basque Country | Garcia-Cervigon A.I.,University of Valladolid | von Arx G.,Swiss Federal Institute of forest | Rozas V.,Mision Biologica de Galicia
New Phytologist | Year: 2013

Tree-ring anatomy reflects the year-by-year impact of environmental factors on tree growth. Up to now, research in this field has mainly focused on the hydraulic architecture, with ray parenchyma neglected despite the growing recognition of its relevance for xylem function. Our aim was to address this gap by exploring the potential of the annual patterns of xylem parenchyma as a climate proxy. We constructed ring-width and ray-parenchyma chronologies from 1965 to 2004 for 20 Juniperus thurifera trees growing in a Mediterranean continental climate. Chronologies were related to climate records by means of correlation, multiple regression and partial correlation analyses. Ray parenchyma responded to climatic conditions at critical stages during the xylogenetic process; namely, at the end of the previous year's xylogenesis (October) and at the onset of earlywood (May) and latewood formation (August). Ray parenchyma-based chronologies have potential to complement ring-width chronologies as a tool for climate reconstructions. Furthermore, medium- and low-frequency signals in the variation of ray parenchyma may improve our understanding of how trees respond to environmental fluctuations and to global change. © 2013 New Phytologist Trust.

Schull G.,CNRS Institute of Genetics and of Molecular and Cellular Biology | Frederiksen T.,Donostia International Physics Center | Arnau A.,Donostia International Physics Center | Arnau A.,University of the Basque Country | And 2 more authors.
Nature Nanotechnology | Year: 2011

The transport of charge through a conducting material depends on the intrinsic ability of the material to conduct current and on the charge injection efficiency at the contacts between the conductor and the electrodes carrying current to and from the material1-3. According to theoretical considerations4, this concept remains valid down to the limit of single-molecule junctions5. Exploring this limit in experiments requires atomic-scale control of the junction geometry. Here we present a method for probing the current through a single C 60 molecule while changing, one by one, the number of atoms in the electrode that are in contact with the molecule. We show quantitatively that the contact geometry has a strong influence on the conductance. We also find a crossover from a regime in which the conductance is limited by charge injection at the contact to a regime in which the conductance is limited by scattering at the molecule. Thus, the concepts of 'good' and 'bad' contacts, commonly used in macro- and mesoscopic physics, can also be applied at the molecular scale. © 2011 Macmillan Publishers Limited. All rights reserved.

Fernandez I.,Complutense University of Madrid | Cossio F.P.,University of the Basque Country
Current Organic Chemistry | Year: 2010

In this article, recent computational studies focused on double group transfer reactions and related processes are summarized. The reported results clearly indicate that these transformations can be considered as a subclass of pericyclic reactions occurring concertedly, with high activation barriers and synchronicity values, and through highly symmetric transition states. Interestingly, the aromatic nature of the latter saddle points has been also studied and discussed showing that they can be viewed as the in-plane analogues of sixmembered hetero-aromatic rings. Finally, the application of the so-called "Strain Model" on these important processes has demonstrated that the strain (the energy required to deform the reactants to the geometry they present in the corresponding transition state) is the major factor controlling the high barrier heights in spite of the stabilizing contribution of the aromaticity. © 2010 Bentham Science Publishers Ltd.

Senovilla J.M.M.,University of the Basque Country
Classical and Quantum Gravity | Year: 2010

The algebraic classification of the Weyl tensor in the arbitrary dimension n is recovered by means of the principal directions of its 'superenergy' tensor. This point of view can be helpful in order to compute the Weyl aligned null directions explicitly, and permits one to obtain the algebraic type of the Weyl tensor by computing the principal eigen value of rank-2 symmetric future tensors. The algebraic types compatible with states of intrinsic gravitational radiation can then be explored. The underlying ideas are general, so that a classification of arbitrary tensors in the general dimension can be achieved. © 2010 IOP Publishing Ltd.

Les I.,Hospital Universitario Cruces | Ruiz-Irastorza G.,Hospital Universitario Cruces | Ruiz-Irastorza G.,University of the Basque Country | Khamashta M.,Kings College London
Seminars in Thrombosis and Hemostasis | Year: 2012

Antithrombotic drugs are the therapeutic cornerstone for patients with antiphospholipid syndrome (APS) and thrombosis. Choosing the specific agent (vitamin K antagonists or antiplatelet drugs), the intensity of anticoagulation (e.g., international normalized ratio [INR] range 2.0 to 3.0 or 3.0 to 4.0), and the duration of treatment has been a recurrent matter of debate. A recent consensus document recommends warfarin to an INR range of 2.0 to 3.0 for patients with a first venous thromboembolic event. Higher anticoagulation intensity is recommended for patients presenting with arterial events. Combined therapy with warfarin and aspirin is another possibility, but some authors recommend standard intensity warfarin or aspirin, either as monotherapy. In general, a more intense regimen is warranted for high-risk patients. On the basis of an increased risk of recurrence during the first 6 months following warfarin withdrawal, long-term anticoagulation is considered the standard treatment. Nevertheless, anticoagulation regimes of shorter duration could be given in selected patients with venous thromboembolism who have transient risk factors and a low-risk profile. Copyright © 2012 by Thieme Medical Publishers, Inc.

Herrera L.,University of the Basque Country | Barreto W.,University of Los Andes, Venezuela
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We set up in detail the general formalism to model polytropic general relativistic stars with anisotropic pressure. We shall consider two different possible polytropic equations, all of which yield the same Lane-Emden equation in the Newtonian limit. A heuristic model based on an ansatz to obtain anisotropic matter solutions from known solutions for isotropic matter is adopted to illustrate the effects of the pressure anisotropy on the structure of the star. In this context, the Tolman mass, which is a measure of the active gravitational mass, is invoked to explain some features of the models. Prospective extensions of the proposed approach are pointed out. © 2013 American Physical Society.

Raducanu B.,Computer Vision Center | Dornaika F.,University of the Basque Country | Dornaika F.,Ikerbasque
Pattern Recognition | Year: 2012

In this paper we introduce a novel supervised manifold learning technique called Supervised Laplacian Eigenmaps (S-LE), which makes use of class label information to guide the procedure of non-linear dimensionality reduction by adopting the large margin concept. The graph Laplacian is split into two components: within-class graph and between-class graph to better characterize the discriminant property of the data. Our approach has two important characteristics: (i) it adaptively estimates the local neighborhood surrounding each sample based on data density and similarity and (ii) the objective function simultaneously maximizes the local margin between heterogeneous samples and pushes the homogeneous samples closer to each other. Our approach has been tested on several challenging face databases and it has been conveniently compared with other linear and non-linear techniques, demonstrating its superiority. Although we have concentrated in this paper on the face recognition problem, the proposed approach could also be applied to other category of objects characterized by large variations in their appearance (such as hand or body pose, for instance). © 2011 Elsevier Ltd. All rights reserved.

Gantz S.C.,Oregon Health And Science University | Levitt E.S.,Oregon Health And Science University | Llamosas N.,University of the Basque Country | Neve K.A.,Oregon Health And Science University | Williams J.T.,Oregon Health And Science University
Cell Reports | Year: 2015

Imbalance between the dopamine and serotonin (5-HT) neurotransmitter systems has been implicated in the comorbidity of Parkinson's disease (PD) and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPAaugmented the D2-receptor- mediated inhibitory postsynaptic current (IPSC) in dopamine neurons of the substantia nigra. This augmentation was largely due to dopamine release from 5-HT terminals. Selective optogenetic stimulation of 5-HT terminals evoked dopamine release, producing D2-receptor-mediated IPSCs following treatment with L-DOPA. In the dorsal raphe, L-DOPA produced a long-lasting depression of the 5-HT1Areceptor- mediated IPSC in 5-HT neurons. When D2 receptors were expressed in the dorsal raphe, application of L-DOPA resulted in a D2-receptor-mediated IPSC. Thus, treatment with L-DOPA caused ectopic dopamine release from 5-HT terminals and a loss of 5-HT-mediated synaptic transmission. © 2015 The Authors.

Eriksson I.,Google | Senovilla J.M.M.,University of the Basque Country
Classical and Quantum Gravity | Year: 2010

We provide a simple proof that conformally semi-symmetric spacetimes are actually semi-symmetric. We also present a complete refined classification of the semi-symmetric spacetimes. © 2010 IOP Publishing Ltd.

Stroppa A.,CNR Institute of Neuroscience | Jain P.,Florida State University | Barone P.,CNR Institute of Neuroscience | Marsman M.,University of Vienna | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2011

Forget me not: In a new multiferroic metal-organic framework (see structure, Cu green, O red, C black, N blue, H gray; arrows show spin configuration), Jahn-Teller and antiferro-distortions induce a switchable ferroelectric polarization, which is coupled to a weak ferromagnetic component. This true magnetoelectric multiferroic should be very attractive for advanced memory devices. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asua J.M.,University of the Basque Country
Progress in Polymer Science | Year: 2014

Miniemulsion polymerization facilitates the synthesis complex materials that cannot be produced otherwise. These materials have a broad range of potential applications including among others adhesives, coatings, anticounterfeiting, textile pigments, bio-based polymer dispersions, gene and drug delivery, anti-viral therapy, tissue engineering, catalyst supports, polymeric photoresists, energy storage and self-healing agents. However, 40 years after the pioneering work of Ugelstad, El-Aasser and Vanderhoff the promises have not been fulfilled and the presence of miniemulsion polymerization in commercial products is scarce. This article reviews the advances in the field, discusses the reasons for this delay and analyzes the challenges that have to be overcome in order to fully use this process in commercial practice. © 2014 Elsevier Ltd.

Abdullah S.,University of Bath | Abdullah S.,University of the Basque Country | Jeanty P.W.,Ohio State University
Renewable and Sustainable Energy Reviews | Year: 2011

A modern form of energy, in particular electricity for household use, is an important vehicle in alleviating poverty in developing countries. However, access and costs of connecting to this service for most poor in these countries is inconceivable. Policies promoting electricity connection in rural areas are known to be beneficial in improving the socio-economic and health well-being for households. This paper examines willingness to pay (WTP) for rural electrification connection in Kisumu district, Kenya, using the contingent valuation method (CVM). A nonparametric and a parametric model are employed to estimate WTP values for two electricity products: grid electricity (GE) and photovoltaic (PV) electricity. The results indicate that respondents are willing to pay more for GE services than PV and households favoured monthly connection payments over a lump sum amount. Some of the policies suggested in this paper include: subsidizing the connection costs for both sources of electricity, adjusting the payment periods, and restructuring the market ownership of providing rural electricity services. © 2011 Published by Elsevier Ltd. All rights reserved.

Herranz M.,University of the Basque Country
Journal of radiological protection : official journal of the Society for Radiological Protection | Year: 2013

Shielded metal arc welding using covered electrodes is the most common welding process. Sometimes the covering contains naturally occurring radioactive materials (NORMs). In Spain the most used electrodes are those covered with rutile mixed with other materials. Rutile contains some detectable natural radionuclides, so it can be considered a NORM. This paper mainly focuses on the use of MCNP (Monte Carlo N-Particle Transport Code) as a predictive tool to obtain doses in a factory which produces this type of electrode and assess the radiological impact in a specific facility after estimating the internal dose.To do this, in the facility, areas of highest radiation and positions of workers were identified, radioactive content of rutile and rutile covered electrodes was measured, and, considering a worst possible scenario, external dose at working points has been calculated using MCNP. This procedure has been validated comparing the results obtained with those from a pressurised ionisation chamber and TLD dosimeters. The internal dose has been calculated using DCAL (dose and risk calculation). The doses range between 8.8 and 394 μSv yr(-1), always lower than the effective dose limit for the public, 1 mSv yr(-1). The highest dose corresponds to the mixing area.

Price L.C.,University of Auckland | Peiris H.V.,University College London | Frazer J.,University of the Basque Country | Easther R.,University of Auckland
Physical Review Letters | Year: 2015

We study the tensor spectral index nt and the tensor-to-scalar ratio r in the simplest multifield extension to single-field, slow-roll inflation models. We show that multifield models with potentials V∼iλiφip have different predictions for nt/r than single-field models, even when all the couplings are equal λi=λj, due to the probabilistic nature of the fields' initial values. We analyze well-motivated prior probabilities for the λi and initial conditions to make detailed predictions for the marginalized probability distribution of nt/r. With O(100) fields and p>3/4, we find that nt/r differs from the single-field result of nt/r=-1/8 at the 5σ level. This gives a novel and testable prediction for the simplest multifield inflation models. © 2015 American Physical Society.

Heras-Saizarbitoria I.,University of the Basque Country | Dogui K.,Laval University | Boiral O.,Laval University
Journal of Cleaner Production | Year: 2013

This article analyses the extent to which the ISO 14001 certification audit can be considered as an independent and rigorous process ensuring organizational conformance with the standard and improved environmental performance. Although the ISO 14001 certification process and external recognition are based on external audits, the rigor, focus and reliability of these audits tend to be taken for granted and have been largely overlooked in the literature. Moreover, the experience of auditors and ISO 14001 professionals has rarely been taken into account in the literature. As a result, the reasons why organizations which have superficially implemented the ISO 14001 standard have succeeded in becoming certified remain unclear. This article describes a qualitative study conducted in Canada with thirty-six professionals involved in ISO 14001 certification audits, and sheds light on the rather elastic interpretation and application of this standard, with a focus on procedural rather than substantive aspects of the Environmental Management System. The findings call into question the prevailing opinion on the rather objective, rigorous and unambiguous nature of ISO 14001 certification audits. © 2013 Elsevier Ltd. All rights reserved.

Bersani D.,University of Parma | Madariaga J.M.,University of the Basque Country
Journal of Raman Spectroscopy | Year: 2012

The Sixth edition of the International Congress on the Application of Raman Spectroscopy in Art and Archeology (RAA 2011) was held in Parma (Italy) from 5 to 8 September 2011, with five Plenary Lectures, 45 Oral Presentations and 83 Poster Presentations. The number of active participants was 130 delegates from 26 countries among the 502 authors that presented at least one work to the Congress. Copyright © 2012 John Wiley & Sons, Ltd.

Rodriguez F.D.,University of Salamanca | Vecino E.,University of the Basque Country
Current Stem Cell Research and Therapy | Year: 2011

Regeneration and plasticity refer to the ability of certain progenitor cells to produce cell lineages with specific morphological and functional settings. The pathway from a less delineated or immature phenotype to a mature or specialized one follows intricate routes where a monumental array of molecular elements, basically transcription factors and epi-genetic regulators that turn off or on a specific phenotypic change, play a fundamental role. Nature itself offers procedures to healing strategies. Therapy approaches to pathologies in the realm of ophthalmology may benefit from the knowledge of the properties and mechanisms of activation of different routes controlling the pathways of cell definition and differentiation. Specification of cell identity, not only in terms of phenotypic traits, but also regarding the mechanisms of gene expression and epigenetic regulation, will provide new tools to manipulating cell fates and status, both forward and backwards. In the human eye, two main locations shelter stem cells: the limbus, which is situated in the limit of the cornea and the conjuctiva, and the ciliary body pars plana. Transplantation of limbal cells is currently used in certain pathologies where corneal epithelium is damaged. Therapeutic applications of retina progenitors are not yet fully developed due to the complexity of the cellular components of the multilayer retinal architecture. Animal models of Retinitis pigmentosa or Glaucoma offer an interesting approach to validate certain techniques, such as the direct injection of progenitors into the vitreal compartment, aimed to restoring retinal function. © 2011 Bentham Science Publishers Ltd.

Erro D.,University of the Basque Country | Moreno A.,Polytechnic University of Catalonia | Bonafonte A.,Polytechnic University of Catalonia
IEEE Transactions on Audio, Speech and Language Processing | Year: 2010

Most existing voice conversion systems, particularly those based on Gaussian mixture models, require a set of paired acoustic vectors from the source and target speakers to learn their corresponding transformation function. The alignment of phonetically equivalent source and target vectors is not problematic when the training corpus is parallel, which means that both speakers utter the same training sentences. However, in some practical situations, such as cross-lingual voice conversion, it is not possible to obtain such parallel utterances. With an aim towards increasing the versatility of current voice conversion systems, this paper proposes a new iterative alignment method that allows pairing phonetically equivalent acoustic vectors from nonparallel utterances from different speakers, even under cross-lingual conditions. This method is based on existing voice conversion techniques, and it does not require any phonetic or linguistic information. Subjective evaluation experiments show that the performance of the resulting voice conversion system is very similar to that of an equivalent system trained on a parallel corpus. © 2006 IEEE.

Erro D.,University of the Basque Country | Moreno A.,Polytechnic University of Catalonia | Bonafonte A.,Polytechnic University of Catalonia
IEEE Transactions on Audio, Speech and Language Processing | Year: 2010

Any modification applied to speech signals has an impact on their perceptual quality. In particular, voice conversion to modify a source voice so that it is perceived as a specific target voice involves prosodic and spectral transformations that produce significant quality degradation. Choosing among the current voice conversion methods represents a trade-off between the similarity of the converted voice to the target voice and the quality of the resulting converted speech, both rated by listeners. This paper presents a new voice conversion method termed Weighted Frequency Warping that has a good balance between similarity and quality. This method uses a time-varying piecewise-linear frequency warping function and an energy correction filter, and it combines typical probabilistic techniques and frequency warping transformations. Compared to standard probabilistic systems, Weighted Frequency Warping results in a significant increase in quality scores, whereas the conversion scores remain almost unaltered. This paper carefully discusses the theoretical aspects of the method and the details of its implementation, and the results of an international evaluation of the new system are also included. © 2006 IEEE.

Fontelos M.A.,Institute Ciencias Matematicas ICMAT | De La Hoz F.,University of the Basque Country
Journal of Fluid Mechanics | Year: 2010

We describe, by means of asymptotic methods and direct numerical simulation, the structure of singularities developing at the interface between two perfect, inviscid and irrotational fluids of different densities 1 and 2 and under the action of gravity. When the lighter fluid is on top of the heavier fluid, one encounters the water-wave problem for fluids of different densities. In the limit when the density of the lighter fluid is zero, one encounters the classical water-wave problem. Analogously, when the heavier fluid is on top of the lighter fluid, one encounters the Rayleigh-Taylor problem for fluids of different densities, with this being the case when one of the densities is zero for the classical Rayleigh-Taylor problem. We will show that both water-wave and Rayleigh-Taylor problems develop singularities of the Moore-type (singularities in the curvature) when both fluid densities are non-zero. For the classical water-wave problem, we propose and provide evidence of the development of a singularity in the form of a logarithmic spiral, and for the classical Rayleigh-Taylor problem no singularities were found. The regularizing effects of surface tension are also discussed, and estimates of the size and wavelength of the capillary waves, bubbles or blobs that are produced are provided. © 2010 Cambridge University Press.

Zangi R.,University of the Basque Country | Zangi R.,Ikerbasque
Journal of Physical Chemistry B | Year: 2011

We study by molecular dynamics simulations the driving force for the hydrophobic interaction between graphene sheets of different sizes down to the atomic scale. Similar to the prediction by Lum, Chandler, and Weeks for hard-sphere solvation [J. Phys. Chem. B 1999, 103, 4570 -4577], we find the driving force to be length-scale dependent, despite the fact that our model systems do not exhibit dewetting. For small hydrophobic solutes, the association is purely entropic, while enthalpy favors dissociation. The latter is demonstrated to arise from the enhancement of hydrogen bonding between the water molecules around small hydrophobes. On the other hand, the attraction between large graphene sheets is dominated by enthalpy which mainly originates from direct solute-solute interactions. The crossover length is found to be inside the range of 0.3-1.5 nm2 of the surface area of the hydrophobe that is eliminated in the association process. In the large-scale regime, different thermodynamic properties are scalable with this change of surface area. In particular, upon dimerization, a total and a water-induced stabilization of approximately 65 and 12 kJ/mol/nm2 are obtained, respectively, and on average around one hydrogen bond is gained per 1 nm2 of graphene sheet association. Furthermore, the potential of mean force between the sheets is also scalable except for interplate distances smaller than 0.64 nm which corresponds to the region around the barrier for removing the last layer of water. It turns out that, as the surface area increases, the relative height of the barrier for association decreases and the range of attraction increases. It is also shown that, around small hydrophobic solutes, the lifetime of the hydrogen bonds is longer than in the bulk, while around large hydrophobes it is the same. Nevertheless, the rearrangement of the hydrogen-bond network for both length-scale regimes is slower than in bulk water. © 2011 American Chemical Society.

Quindos G.,University of the Basque Country
Revista Iberoamericana de Micologia | Year: 2014

Invasive candidiasis is a leading cause of mortality. Candidaemia is the most common clinical presentation of invasive candidiasis but more that 30% of these infections do not yield positive blood cultures. Candida albicans remains the predominant aetiology, accounting for 50% of all cases. However, there has been an epidemiological shift in the last decades. Some species of Candida different to C. albicans have emerged as an important cause of severe candidaemia as they can exhibit resistance to fluconazole and other antifungal agents. Moreover, there is a different distribution of non C. albicans Candida species in relationship to patients' and hospital characteristics. Thus, Candida parapsilosis has been associated to candidaemia in neonates and young adults. This species usually has an exogenously origin and contaminates medical devices, causing central venous catheter-associated candidaemias. Candida glabrata, Candida tropicalis and Candida krusei are isolated in blood cultures from older patients (>65 years) with important risk factors, such as major abdominal surgery, solid tumours and haematologic malignancies, transplants, and/or prolonged treatment with corticoids. Moreover, important geographical differences in the distribution of the Candida species different to C. albicans causing invasive candidiasis have been reported: C. parapsilosis predominates in Australia, Latin America and Mediterranean countries of Africa, Asia and Europe. In contrast, C. glabrata has an important aetiological role in USA and Central and Northern Europe. Finally, an important and worrying issue is that mortality due to invasive candidiasis remains unacceptably high.This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). © 2013 Revista Iberoamericana de Micología.

Tokatly I.V.,University of the Basque Country | Tokatly I.V.,Ikerbasque
Physical Review Letters | Year: 2013

Time-dependent (current) density functional theory for many-electron systems strongly coupled to quantized electromagnetic modes of a microcavity is proposed. It is shown that the electron-photon wave function is a unique functional of the electronic (current) density and the expectation values of photonic coordinates. The Kohn-Sham system is constructed, which allows us to calculate the above basic variables by solving self-consistent equations for noninteracting particles. We suggest possible approximations for the exchange-correlation potentials and discuss implications of this approach for the theory of open quantum systems. In particular we show that it naturally leads to time-dependent density functional theory for systems coupled to the Caldeira-Leggett bath. © 2013 American Physical Society.

Bandos I.,University of the Basque Country | Bandos I.,Ikerbasque
Journal of High Energy Physics | Year: 2014

We show that, at the classical level, the recently proposed 'ambitwistor string' model is equivalent to the spinor moving frame formulation of null-supersting, which in its turn is equivalent to Siegel's formulation of closed twistor string or to its higher dimensional generalizations. Although the null-(super)string is usually considered as describing the tensionless limit of (super)string, we show that its action can be derived from the spinor moving frame formulation of superstring also in the infinite tension limit. This observation, supplemented by some indirect arguments, allows us to conjecture the absence of critical dimensions, i.e. that the (ambi)twistor string based technique(s) to calculate field theory amplitudes can be developed not only in D=10 or 26, but also in D=11 and other dimensions. The D=11 and D=10 twistor strings are described in some details. © 2014 The Author(s).

Megias E.,Autonomous University of Barcelona | Valle M.,University of the Basque Country
Journal of High Energy Physics | Year: 2014

We compute the partition function for non-interacting chiral fermions at second order in a derivative expansion of an arbitrary time-independent gravitational and gauge background. We find that Pauli-Villars regularization of the vacuum part is needed to get consistent results. We use our results to discuss some features of the non-dissipative constitutive relations of second order hydrodynamics. © 2014, The Author(s).

Bandos I.,University of the Basque Country | Bandos I.,Ikerbasque
Journal of High Energy Physics | Year: 2014

We study the Lagrangian description of chiral bosons, p-form gauge fields with (anti-)self-dual gauge field strengths, in D = 2p + 2 dimensional spacetime of non-trivial topology. We show that the manifestly Lorentz and diffeomorphism invariant Pasti-Sorokin-Tonin (PST) approach is consistent and produces the (anti-)self-duality equation also in topologically nontrivial spacetime. We discuss in what circumstances the nontrivial topology makes difference between two disconnected, da-timelike and da-spacelike branches of the PST system, the gauge fixed version of which are described by not manifestly invariant Henneaux-Teitelboim (HT) and Perry-Schwarz (PS) actions, respectively. © 2014 The Author(s).

Sokolovski D.,University of the Basque Country | Sokolovski D.,Ikerbasque
Physical Review Letters | Year: 2013

In classical physics, the joint probability of a number of individually rare independent events is given by the Poisson distribution. It describes, for example, the unidirectional transfer of a population between the densely and sparsely populated states of a classical two-state system. We derive a quantum version of the law for a large number of noninteracting systems (particles) obeying Bose-Einstein statistics. The classical law is significantly modified by quantum interference, which allows, among other effects, for the counterflow of particles back into the densely populated state. The suggested observation of this classically forbidden counterflow effect can be achieved with modern laser-based techniques used for manipulating and trapping cold atoms. © 2013 American Physical Society.

Santos E.,University of Cantabria | Albo J.,University of the Basque Country | Irabien A.,University of Cantabria
RSC Advances | Year: 2014

Magnetic ionic liquids are room temperature ionic liquids, which have paramagnetic properties by themselves without the need of adding magnetic particles. These paramagnetic properties are induced by the anion, the cation or both. Most common paramagnetic ionic liquids are those that contain transition metal or lanthanide complexes in their anion structure. These tuneable fluids present unique physicochemical properties, resulting in responsive materials to an external magnetic field. The reported studies on the synthesis and applications of magnetic ionic liquids have increased in the recent years. Therefore, this review attempts to highlight the achievements and current status concerning the synthesis, properties and main applications of magnetic ionic liquids, providing insights into this research frontier. This journal is © the Partner Organisations 2014.

Ran T.,Nanjing Agricultural University | Ozorowski G.,University of California at Irvine | Gao Y.,Nanjing Agricultural University | Sineshchekov O.A.,University of Houston | And 4 more authors.
Acta Crystallographica Section D: Biological Crystallography | Year: 2013

Proteorhodopsins (PRs), members of the microbial rhodopsin superfamily of seven-transmembrane-helix proteins that use retinal chromophores, comprise the largest subfamily of rhodopsins, yet very little structural information is available. PRs are ubiquitous throughout the biosphere and their genes have been sequenced in numerous species of bacteria. They have been shown to exhibit ion-pumping activity like their archaeal homolog bacteriorhodopsin (BR). Here, the first crystal structure of a proteorhodopsin, that of a blue-light-absorbing proteorhodopsin (BPR) isolated from the Mediterranean Sea at a depth of 1214;m (Med12BPR), is reported. Six molecules of Med12BPR form a doughnut-shaped C 6 hexameric ring, unlike BR, which forms a trimer. Furthermore, the structures of two mutants of a related BPR isolated from the Pacific Ocean near Hawaii at a depth of 7514;m (HOT75BPR), which show a C 5 pentameric arrangement, are reported. In all three structures the retinal polyene chain is shifted towards helix C when compared with other microbial rhodopsins, and the putative proton-release group in BPR differs significantly from those of BR and xanthorhodopsin (XR). The most striking feature of proteorhodopsin is the position of the conserved active-site histidine (His75, also found in XR), which forms a hydrogen bond to the proton acceptor from the same molecule (Asp97) and also to Trp34 of a neighboring protomer. Trp34 may function by stabilizing His75 in a conformation that favors a deprotonated Asp97 in the dark state, and suggests cooperative behavior between protomers when the protein is in an oligomeric form. Mutation-induced alterations in proton transfers in the BPR photocycle in Escherichia coli cells provide evidence for a similar cross-protomer interaction of BPR in living cells and a functional role of the inter-protomer Trp34-His75 interaction in ion transport. Finally, Wat402, a key molecule responsible for proton translocation between the Schiff base and the proton acceptor in BR, appears to be absent in PR, suggesting that the ion-transfer mechanism may differ between PR and BR. © 2013 International Union of Crystallography Printed in Singapore - all rights reserved. © 2013.

Jaegher H.D.,University of the Basque Country
Journal of Consciousness Studies | Year: 2015

What makes it possible to affect one another, to move and be moved by another person? Why do some of our encounters transform us? The experience of moving one another points to the inter-affective in intersubjectivity. Inter-affection is hard to account for under a cognitivist banner, and has not received much attention in embodied work on intersubjectivity. I propose that understanding inter-affection needs a combination of insights into self-affection, embodiment, and interaction processes. I start from Michel Henry s radically immanent idea of self-affection, and bring it into a contrastive dialogue with the enactive concepts of autonomy and (participatory) sense-making. I suggest that the latter ideas can open up Henry s idea of self-affection to inter-affection (something he aimed to do, but did not quite manage) and that, in turn, Henry's work can provide insights into under-explored elements of intersubjectivity, such as its ineffable and mysterious aspects, and erotic encounters. © Imprint Academic, 2015.

Valle M.,University of the Basque Country
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We derive a kinetic equation for chiral matter at nonzero chemical potential that governs the response of the parity-odd part of the distribution function to perturbations of the Robertson-Walker metric. The derivation is based on a recent evaluation of the gravitational polarization tensor at nonzero chemical potential. We also provide the equations for gravity waves that follow from the anisotropic stress tensor describing the lepton asymmetry. These equations can be used to assess the effects that a nonzero neutrino chemical potential would have on the evolution of cosmological perturbations. © 2013 American Physical Society.

Echeburua E.,University of the Basque Country
Terapia Psicologica | Year: 2010

Victims of natural disasters are subject to severe stress and disruption and may manifest a pattern of dissociative and anxiety/depression symptoms. The trauma may impair the person's quality of life and disrupt social and other functioning. If symptoms last beyond a month following the traumatic event, PTSD may ensue. These adverse effects do not always disappear with time. Acute stress management is focused on ensuring safety and providing support, including assessment of coping resources and support networks. An additional role of early intervention is to detect individuals who require more complex intervention. The issues addressed in therapy include the need to correct unrealistic expectations, to deal with guilt and phobic reactions as well as family and network reorganization. Cognitive-behavioral treatments, such as exposure techniques or cognitive restructuring approaches, have been shown to work. At times, work with the family members may be necessary too. Challenges for the future are discussed. Copyright 2010 by Sociedad Chilena de Psicología Clínica.

Bandos I.,University of the Basque Country | Bandos I.,Ikerbasque | Samtleben H.,Ecole Normale Superieure de Lyon | Sorokin D.,National Institute of Nuclear Physics, Italy
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We construct the duality-symmetric actions for a large class of six-dimensional models describing hierarchies of non-Abelian scalar, vector and tensor fields related to one another by first-order (self-)duality equations that follow from these actions. In particular, this construction provides a Lorentz invariant action for non-Abelian self-dual tensor fields. The class of models includes the bosonic sectors of the 6d (1,0) superconformal models of interacting non-Abelian self-dual tensor, vector, and hypermultiplets. © 2013 American Physical Society.

Gao S.,Nanjing University | Collins M.B.,University of the Basque Country | Collins M.B.,University of Southampton
Marine Geology | Year: 2014

The present knowledge of Holocene continental shelf deposits in relation to the processes for their formation, from the prospective of marine sediment dynamics, is examined. Over the last 50years, various innovative techniques have been developed to measure and calculate currents, waves and suspended sediment concentrations. Thus, sediment transport rates can be defined by in situ observations, or numerical modeling. At the same time, sediment dynamics has been applied to morphodynamics, such that deposition rate and seabed morphological change can be predicted. On the continental shelf, tide-wave action, residual circulation and sediment gravity flow are the major sediment dynamic forcing mechanisms. The tidal current is often responsible for landward transport, waves can cause landward transport of sand and gravel but seaward transport of fine-grained sediment, and shelf circulation and sediment gravity flow favor the dispersal of suspended sediment towards offshore or even across the shelf. For the various types of the shelf, wide or narrow, sediment starved or supply abundant, prediction on the basis of processes is consistent with the observed spatial distribution of Holocene sedimentary systems, e.g., river deltas, beaches, barrier islands, lagoons, tidal ridges, tidal inlets, tidal flats and shelf muds. The sedimentary records associated with these systems often consist of high-resolution slices, i.e., each record tends to have a resolution within 101years, but covers only a relatively short period of the Holocene. Nevertheless, if different records are connected, according to their chronological order, then the overall period covered by the records will be extended. In order to achieve this objective, a modeling approach to the formation of sedimentary records should be developed. Based upon an understanding of process-product relationships, simulation can be undertaken for: the formation of early Holocene reworking-induced deposits, during sea level rise; event beds due to extreme events; the preservation potential of the sedimentary sequences; the post-depositional modifications to the sedimentary records; the environmental settings during sedimentation; and the long-term effects of material budgeting processes on the sediment system behavior. © 2014 Elsevier B.V.

Herrera L.,University of the Basque Country | Barreto W.,University of Los Andes, Venezuela
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We set up the general formalism to model polytropic Newtonian stars with anisotropic pressure. We obtain the corresponding Lane-Emden equation. A heuristic model based on an ansatz to obtain anisotropic matter solutions from known solutions for isotropic matter is adopted to illustrate the effects of the pressure anisotropy on the structure of the star. In particular, we calculate the Chandrasekhar mass for a white dwarf. It is clearly displayed how the Chandrasekhar mass limit changes depending on the anisotropy. Prospective astrophysical applications of the proposed approach are discussed. © 2013 American Physical Society.

The effect of monohydration in equatorial/axial isomerism of the common motif of tropane alkaloids is investigated in a supersonic expansion by using Fourier-transform microwave spectroscopy. The rotational spectrum reveals the equatorial isomer as the dominant species in the tropinone{dot operator}{dot operator}{dot operator}H2 O complex. The monohydrated complex is stabilized primarily by a moderate O H{dot operator}{dot operator}{dot operator}N hydrogen bond. In addition, two C H{dot operator}{dot operator}{dot operator}O weak hydrogen bonds also support this structure, blocking the water molecule and avoiding any molecular dynamics in the complex. The water molecule acts as proton donor and chooses the ternary amine group over the carbonyl group as a proton acceptor. The experimental work is supported by theoretical calculations; the accuracy of the B3LYP, M06-2X, and MP2 methods is also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Perez Samartin A.L.,University of the Basque Country
Revista Internacional de Acupuntura | Year: 2011

The ancient texts of Traditional Chinese Medicine (TCM) show that the acupuncture points (APs) are located precisely and that the accuracy in their findings as well as their adequate manipulation are necessary for an achievement of a therapeutic effect. A lot of effort has been made in order to show the existence of the APs and, among them, the measurement of the electric resistance of the skin. Although some of the obtained results are contradictory, there is enough evidence that it can be found a reduction of the cutaneous resistance in the APs. These points are also located in areas where the metabolism of nitric oxide is also enhanced, something which supports the finding of the decrease of electric resistance. It would be necessary a consensus in the methodology to best use the electric detection of the AP for location and diagnosis in TCM. © 2011 Elsevier España S.L.

Senovilla J.M.M.,University of the Basque Country
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

I present the junction conditions for F(R) theories of gravity and their implications: the generalized Israel conditions and equations. These junction conditions are necessary to construct global models of stars, galaxies, etc., where a vacuum region surrounds a finite body in equilibrium, as well as to describe shells of matter and braneworlds, and they are stricter than in General Relativity in both cases. For the latter case, I obtain the field equations for the energy-momentum tensor on the shell/brane, and they turn out to be, remarkably, the same as in General Relativity. An exceptional case for quadratic F(R), previously overlooked in the literature, is shown to arise, allowing for a discontinuous R and leading to an energy-momentum content on the shell with unexpected properties, such as nonvanishing components normal to the shell and a new term resembling classical dipole distributions. For the former case, they require not only the agreement of the first and second fundamental forms on both sides of the matching hypersurface but also that the scalar curvature R and its first derivative R agree there too. I argue that, as a consequence, matched solutions in General Relativity are not solutions of F(R) models generically. Several relevant examples are analyzed. © 2013 American Physical Society.

Matute C.,University of the Basque Country
ASN neuro | Year: 2012

The phylogenetic enlargement of cerebral cortex culminating in the human brain imposed greater communication needs that have been met by the massive expansion of WM (white matter). Damage to WM alters brain function, and numerous neurological diseases feature WM involvement. In the current review, we discuss the major features of WM, the contributions of WM compromise to brain pathophysiology, and some of the mechanisms mediating WM injury. We will emphasize the newly appreciated importance of neurotransmitter signalling in WM, particularly glutamate and ATP signalling, to understanding both normal and abnormal brain functions. A deeper understanding of the mechanisms leading to WM damage will generate much-needed insights for developing therapies for acute and chronic diseases with WM involvement.

Easther R.,University of Auckland | Frazer J.,University College London | Frazer J.,University of the Basque Country | Peiris H.V.,University College London | Price L.C.,University of Auckland
Physical Review Letters | Year: 2014

We explore whether multifield inflationary models make unambiguous predictions for fundamental cosmological observables. Focusing on N-quadratic inflation, we numerically evaluate the full perturbation equations for models with 2, 3, and O(100) fields, using several distinct methods for specifying the initial values of the background fields. All scenarios are highly predictive, with the probability distribution functions of the cosmological observables becoming more sharply peaked as N increases. For N=100 fields, 95% of our Monte Carlo samples fall in the ranges ns (0.9455,0.9534), α (-9.741,-7.047)×10-4, r (0.1445,0.1449), and riso (0.02137,3.510) ×10-3 for the spectral index, running, tensor-to-scalar ratio, and isocurvature-to-adiabatic ratio, respectively. The expected amplitude of isocurvature perturbations grows with N, raising the possibility that many-field models may be sensitive to postinflationary physics and suggesting new avenues for testing these scenarios. © 2014 American Physical Society.

Bandos I.A.,University of the Basque Country
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

We study the possibility to describe multiple M0-brane system in the frame of superembedding approach. The simplest framework is provided by the maximally supersymmetric non-Abelian SU (N) Yang-Mills supermultiplet on the d = 1N = 16 superspace the embedding of which to the target D = 11 supergravity superspace is determined by the so-called superembedding equation, characteristic of the worldline superspace of a single M0-brane. We use it to obtain a covariant generalization of the Matrix model equations describing the multiple M0-system in flat target superspace. © 2010 Elsevier B.V. All rights reserved.

Hofer M.,University of Zurich | Gomez-Bengoa E.,University of the Basque Country | Nevado C.,University of Zurich
Organometallics | Year: 2014

The occurrence of direct transmetalation between gold(III) and boron species during gold-catalyzed cross-coupling reactions has recently become the subject of intense discussion. In this work, we investigate the transmetalation reaction between discrete, stable gold(III) complexes and boron reagents. Interestingly, electron-rich arylboronic acids remain unreactive under neutral conditions, whereas electron-deficient species undergo transmetalation in a highly efficient manner. © 2014 American Chemical Society.

Mujika I.,University of the Basque Country | Mujika I.,Finis Terrae University
International Journal of Sports Physiology and Performance | Year: 2014

Detailed accounts of the training programs followed by today's elite triathletes are lacking in the sport-science literature. This study reports on the training program of a world-class female triathlete preparing to compete in the London 2012 Olympic Games. Over 50 wk, she performed 796 sessions (303 swim, 194 bike, 254 run, 45 strength training), ie, 16 ± 4 sessions/wk (mean ± SD). Swim, bike, and run training volumes were, respectively, 1230 km (25 ± 8 km/wk), 427 h (9 ± 3 h/wk), and 250 h (5 ± 2 h/wk). Training tasks were categorized and prescribed based on heart-rate values and/or speeds and power outputs associated with different blood lactate concentrations. Training performed at intensities below her individual lactate threshold (ILT), between the ILT and the onset of blood lactate accumulation (OBLA), and above the OBLA for swim were 74% ± 6%, 16% ± 2%, 10% ± 2%; bike 88% ± 3%, 10% ± 1%, 2.1% ± 0.2%; and run 85% ± 2%, 8.0% ± 0.3%, 6.7% ± 0.3%. Training organization was adapted to the busy competition calendar (18 events, of which 8 were Olympic-distance triathlons) and continuously responded to emerging information. Training volumes were 35-80% higher than those previously reported for elite male and female triathletes, but training intensity and tapering strategies successfully followed recommended best practice for endurance athletes. This triathlete placed 7th in London 2012, and her world ranking improved from 14th to 8th at the end of 2012. © 2014 Human Kinetics, Inc.

Bueno G.,University of the Basque Country
Renewable and Sustainable Energy Reviews | Year: 2012

Fossil energy depletion and fight against climate change force humanity to decarbonize the economy. By year 2050 CO 2 emissions will have to reduce globally at least 85%, and probably over 95% in developed countries. The modeling of the transportation of people and commodities in the Basque Autonomous Community (Spain) in year 2008 has allowed us to draw some conclusions about the challenges ahead. The exploration of several scenarios modeled in order to reduce energy consumption in transport shows that mobility in a decarbonized world will have to be more efficient, electrified when moving people and freight on land, based on renewable generation, and organized in such a way that guarantees very high occupancies of vehicles. All these elements will be indispensable, and even not sufficient if they are still not complemented with a reduction of mobility in absolute terms, so that economic transportation intensity - the ratio between transportation and whole economic activity - recovers to levels seen in the world four decades ago, prior to the development of present hypermobility. © 2012 Elsevier Ltd. All rights reserved.

de Miguel-Beriain I.,University of the Basque Country
Advanced Drug Delivery Reviews | Year: 2015

Stem cells constitute one of the most promising tools for regenerative medicine. Thus, it seems morally compelling to explore all the sources that might provide us with them. However, some of these sources, such as somatic cell nuclear transfer, embryo destruction, or even induced pluripotency obtained by reprogramming have raised deep ethical issues. The aim of this paper is to reflect on the stem cell ethical debate at the current moment through an analysis of the academic literature. It will also provide an analysis of the ethical implications of the most relevant scientific advances that have happened in recent months or those which seem about to merge. © 2014 Elsevier B.V.

Kurth S.,University of the Basque Country | Kurth S.,Ikerbasque | Kurth S.,European Theoretical Spectroscopy Facility | Stefanucci G.,European Theoretical Spectroscopy Facility | And 2 more authors.
Physical Review Letters | Year: 2013

For molecules weakly coupled to leads the exact linear Kohn-Sham (KS) conductance can be orders of magnitude larger than the true linear conductance due to the lack of dynamical exchange-correlation (xc) corrections. In this work we show how to incorporate dynamical effects in KS transport calculations. The only quantity needed is the static xc potential in the molecular junction. Our scheme provides a comprehensive description of Coulomb blockade without breaking the spin symmetry. This is explicitly demonstrated in single-wall nanotubes where the corrected conductance is in good agreement with experimental data whereas the KS conductance fails dramatically. © 2013 American Physical Society.

Laza-Martinez A.,University of the Basque Country
Journal of Phycology | Year: 2012

The morphology, ultrastructure, phylogeny, and ecology of a new red-tide-forming cryptomonad, Urgorri complanatus Laza-Martínez gen. et sp. nov., is described. U. complanatus has been collected in southwestern European estuaries, blooming in the inner reaches of several of them. The estuarine character of the species is also supported by its in vitro salinity preferences, showing a maximum growth rate at 10 psu. U. complanatus is a distinctive species and can be easily distinguished by LM from other known brackish and marine species. Cells are dorsoventrally flattened. The plastid has two anterior lobes. One pyrenoid is located in each of the lobes, and a third one on the posterior part. Thylakoids are arranged in pairs and do not penetrate pyrenoids. The plastid is reddish due to the presence of the phycoerythrin Cr-PE545. An orange discoidal eyespot lies beneath the nucleus, in the posterior ventral face of the plastid. A long furrow runs from the vestibulum, and a gullet is lacking. The periplast is composed of an inner sheet. The nuclear 18S rDNA based molecular analysis reveals U. complanatus is not related to any of the main cryptomonad lineages. Based on ultrastructural and pigment data, the most probable relatives are those merged under the family Geminigeraceae. Its lack of derived characters, together with the presence of characters proposed in previous studies to be primitive, suggests Urgorri could be considered representative of the cryptophycean ancestral character state. © 2012 Phycological Society of America.

Herrera L.,University of the Basque Country
General Relativity and Gravitation | Year: 2014

In the context of general relativity, radiation, either gravitational or electromagnetic, is closely associated to vorticity of observers world lines. We stress in this letter that the factor that relates the two phenomena is a circular flow of energy (electromagnetic) and/or superenergy on the planes orthogonal to vorticity vector. We also stress the potential relevance of the abovementioned relationship in experiments to detect gravitational radiation. © 2013 Springer Science+Business Media New York.

De Juan F.,Lawrence Berkeley National Laboratory | De Juan F.,University of California at Berkeley | Manes J.L.,University of the Basque Country | Vozmediano M.A.H.,CSIC - Institute of Materials Science
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We revise the tight-binding approach to strained or curved graphene in the presence of external probes such as photoemission or scanning tunneling microscopy experiments. We show that extra terms arise in the continuum limit of the tight-binding Hamiltonian which cannot be accounted for by changes in the hopping parameters due to lattice deformations, encoded in the parameter β. These material-independent extra couplings are of the same order of magnitude as the standard ones and have a geometric origin. They include corrections to the position-dependent Fermi velocity and to a new vector field. We show that the new vector field does not couple to electrons like a standard gauge field and that no β-independent pseudomagnetic fields exist in strained graphene. © 2013 American Physical Society.

Pavlyukh Y.,Martin Luther University of Halle Wittenberg | Berakdar J.,Martin Luther University of Halle Wittenberg | Rubio A.,University of the Basque Country
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

Generally, the addition or removal of a single particle in a many-body system does not correspond to an exact eigenstate of the system. Thus the resulting coherent excitation evolves in time. As discussed here, the evolution at short times upon the excitation with the energy ε exhibits a quadratic decay [with the rate constant σ2(ε)]. Later on, after some time τ(ε), the exponential decay sets in. It is governed by another rate constant γ(ε). This behavior is generic for many realistic finite and extended systems. For a finite system it is possible to assess this behavior full numerically using an exact solution of the many-body problem. We present a simple model for the electron spectral function that links together all three aforementioned parameters and give a prescription for how the energy uncertainty σ2(ε) can be computed within the many-body perturbation theory. Our numerical results demonstrate that the model approach accurately reproduces the exact spectral function in a large range of energies even in the case of fragmented many-body states. We show that the central quantity of this study σ2(ε) can easily be computed exactly or from approximate theories and, hence, can be used for their validation. We also point out how the set in time can be tested by means of attosecond spectroscopy. © 2013 American Physical Society.

Leon I.,University of the Basque Country
The Journal of chemical physics | Year: 2012

Propofol (2,6-di-isopropylphenol) is probably the most widely used general anesthetic. Previous studies focused on its complexes containing 1 and 2 water molecules. In this work, propofol clusters containing three water molecules were formed using supersonic expansions and probed by means of a number of mass-resolved laser spectroscopic techniques. The 2-color REMPI spectrum of propofol[middle dot](H(2)O)(3) contains contributions from at least two conformational isomers, as demonstrated by UV/UV hole burning. Using the infrared IR/UV double resonance technique, the IR spectrum of each isomer was obtained both in ground and first excited electronic states and interpreted in the light of density functional theory (DFT) calculations at M06-2X/6-311++G(d,p) and B3LYP/6-311++G(d,p) levels. The spectral analysis reveals that in both isomers the water molecules are forming cyclic hydrogen bond networks around propofol's OH moiety. Furthermore, some evidences point to the existence of isomerization processes, due to a complicated conformational landscape and the existence of multiple paths with low energy barriers connecting the different conformers. Such processes are discussed with the aid of DFT calculations.

Pelc M.,Nicolaus Copernicus University | Chico L.,CSIC - Institute of Materials Science | Ayuela A.,University of the Basque Country | Jaskolski W.,Nicolaus Copernicus University
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We study graphene nanoribbons and carbon nanotubes containing ordered defect lines built of octagonal rings. We show that octagonal defect lines are a robust source of state localization at the Fermi energy, in some cases leading to spontaneous magnetization. We also prove that the localization at chains of octagons is a consequence of the zigzag nature of the graphene edges forming the defect lines. © 2013 American Physical Society.

D'Agosta R.,University of the Basque Country | D'Agosta R.,Ikerbasque | Di Ventra M.,University of California at San Diego
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We clarify some misunderstandings on the time-dependent current-density functional theory for open quantum systems we have recently introduced. We also show that some of the recent formulations attempting to improve on this theory suffer from some inconsistencies, especially in establishing the mapping between the external potential and the quantities of interest. We offer a general argument about this mapping, which applies to any density functional theory, showing that it must fulfill certain "dimensionality" requirements. © 2013 American Physical Society.

Echeverria-Arrondo C.,University of the Basque Country | Sherman E.Y.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We consider the relaxation of a spin qubit in a quantum dot propagating as a whole in a one-dimensional semiconductor with hyperfine coupling. We show that motion leads to qualitatively new features in this process compared to static quantum dots. For a fast straightforward motion, the initial spin density decreases to zero with the relaxation rate independent of the spatial spread of the electron wave function and inversely proportional to the electron speed. However, for the oscillatory motion, the qubit acquires memory, and the dephasing becomes Gaussian rather than exponential. After some time, one-third of the initial spin polarization is restored, as it happens for static qubits. This revival can occur either through periodic peaks or through a monotonous increase in the polarization, after a minimum, until a plateau has been reached. Our results can be useful for the understanding of the spin dynamics and decoherence in quantum wires. © 2013 American Physical Society.

Abalos B.,University of the Basque Country
International Journal of Earth Sciences | Year: 2016

A new printable 1/200.000 bedrock geological map of the onshore Basque-Cantabrian Basin is presented, aimed to contribute to future geologic developments in the central segment of the Pyrenean–Cantabrian Alpine orogenic system. It is accompanied in separate appendixes by a historic report on the precedent geological maps and by a compilation above 350 bibliographic citations of maps and academic reports (usually overlooked or ignored) that are central to this contribution. Structural scrutiny of the map permits to propose a new tectonic interpretation of the Basque Arc, implementing previously published partial reconstructions. It is presented as a printable 1/400.000 tectonic map. The Basque Arc consists of various thrust slices that can expose at the surface basement rocks (Palaeozoic to Lower Triassic) and their sedimentary cover (uppermost Triassic to Tertiary), from which they are detached by intervening (Upper Triassic) evaporites and associated rocks. The slice-bounding thrusts are in most cases reactivated normal faults active during Meso-Cenozoic sedimentation that can be readily related to basement discontinuities generated during the Hercynian orogeny. © 2016 Springer-Verlag Berlin Heidelberg

Sadreev A.F.,L.V. Kirensky Institute of Physics | Sherman E.Ya.,University of the Basque Country | Sherman E.Ya.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We consider quasiballistic electron transmission in a one-dimensional quantum wire subject to both time-independent and periodic potentials of a finger gate that results in a local time-dependent Rashba-type spin-orbit coupling. A spin-dependent conductance is calculated as a function of external constant magnetic field, the electric field frequency, and potential strength. The results demonstrate the effect of the gate-driven electric dipole spin resonance in a transport phenomenon such as spin-flip electron transmission. © 2013 American Physical Society.

Mujika F.,University of the Basque Country
Journal of Composite Materials | Year: 2012

The complementary energy of a multidirectional laminate is obtained as a function of mechanical and hygrothermal force and moment resultants. Three-point flexure is then analysed assuming that the specimen is in contact with the support rollers at four points. As this problem is statically indeterminate, the redundant force is obtained by applying Engesser's second theorem. Lift-off at supports is assumed to occur when the redundant unknown is zero. The displacement field of a multidirectional laminate in three-point flexure is then obtained by applying Engesser's first theorem, including transverse shear and hygrothermal effects. The displacements related to bending and twisting moments, hygrothermal effects and transverse shear forces are analysed separately. © 2011 The Author(s).

Eisler V.,Eotvos Lorand University | Zimboras Z.,University of the Basque Country
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We study the nonequilibrium steady state of an infinite chain of free fermions, resulting from an initial state where the two sides of the system are prepared at different temperatures. The mutual information is calculated between two adjacent segments of the chain and is found to scale logarithmically in the subsystem size. This provides an example of the violation of the area law in a quantum many-body system outside a zero-temperature regime. The prefactor of the logarithm is obtained analytically and, furthermore, the same prefactor is shown to govern the logarithmic increase of mutual information in time, before the system relaxes locally to the steady state. © 2014 American Physical Society.

Nieva J.L.,University of the Basque Country
Journal of molecular recognition : JMR | Year: 2011

The conserved membrane proximal external region (MPER), adjacent to the transmembrane domain (TMD) of human immunodeficiency virus type-1 (HIV-1) gp41 glycoprotein subunit, is accessible to the broadly neutralizing 4E10 and 2F5 monoclonal antibodies (mAbs) and, therefore, constitutes a potential target for vaccine design. This gp41 domain is postulated to be functional during the Env glycoprotein-mediated fusion reaction by destabilizing the highly rigid viral envelope. To perform this task, the aromatic-rich MPER is believed to insert into the interfacial region of the viral membrane external monolayer, thereby inducing the restructuring of the lipid bilayer required for fusion-pore opening. This model predicts that: (i) 2F5 and 4E10 mAbs are capable of binding epitopes inserted into the membrane interface; (ii) in-membrane binding will result in effective blocking of MPER membrane activity; and (iii) both processes, in-membrane recognition and blocking of membrane activity, can be modulated by altering both the lipid composition and the MPER amino acid sequence. We review here recently reported experimental data consistent with those predictions, and further speculate on their relevance for prospective anti-HIV vaccine development. Copyright © 2011 John Wiley & Sons, Ltd.

Gallego A.,Autonomous University of Madrid | Castillo O.,University of the Basque Country | Gomez-Garcia C.J.,University of Valencia | Zamora F.,Autonomous University of Madrid | Delgado S.,Autonomous University of Madrid
Inorganic Chemistry | Year: 2012

The solvothermal reactions between pyrimidinedisulfide (pym 2S 2) and CuI or CuBr 2 in CH 2Cl 2:CH 3CN lead to the formation of [Cu 11I 7(pymS) 4] n (pymSH = pyrimidine-2(1H)-thione) (1) and the dimer [Cu II(μ-Br)(Br)L] 2 (L = 2-(pyrimidin-2-ylamino)-1,3-thiazole-4-carbaldehyde) (2). In the later reaction, there is an in situ S-S, S-C(sp 2), and C(sp 2)-N multiple bond cleavage of the pyrimidinedisulfide resulting in the formation of 2-(pyrimidin-2-ylamino)-1,3-thiazole-4-carbaldehyde. Interestingly, similar reactions carried out just with a change in the solvent (H 2O:CH 3CN instead of CH 2Cl 2:CH 3CN) give rise to the formation of coordination polymers with rather different architectures. Thus, the reaction between pym 2S 2 and CuI leads to the formation of [Cu 3I(pymS) 2] n (3) and [CuI(pym 2S 3)] (pym 2S 3 = pyrimidiltrisulfide) (4), while [Cu 3Br(pymS) 2] n (5) is isolated in the reaction with CuBr 2. Finally, the solvothermal reactions between CuI and pyrimidine-2-thione (pymSH) in CH 2Cl 2:CH 3CN at different ratios, 1:1 or 2:1, give the polymers [Cu 2I 2(pymSH) 2] n (6) and [Cu 2I 2(pymSH)] n (7), respectively. The structure of the new compounds has been determined by X-ray diffraction. The studies of the physical properties of the novel coordination polymers reveal that compounds 3 and 5 present excellent electrical conductivity values at room temperature, while compounds 1, 3, and 5-7 show luminescent strong red emission at room temperature. © 2011 American Chemical Society.

Bamba K.,Nagoya University | Nojiri S.,Nagoya University | Odintsov S.D.,Nagoya University | Odintsov S.D.,Catalan Institution for Research and Advanced Studies | And 4 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We construct an F(R) gravity theory corresponding to the Weyl invariant two scalar field theory. We investigate whether such F(R) gravity can have the antigravity regions where the Weyl curvature invariant does not diverge at the Big Bang and Big Crunch singularities. It is revealed that the divergence cannot be evaded completely but can be much milder than that in the original Weyl invariant two scalar field theory. © 2014 The Authors.

Ramos J.,University of Granada | Forcada J.,University of the Basque Country
Langmuir | Year: 2011

Due to the existing interest in new hybrid particles in the colloidal range based on both magnetic and polymeric materials for applications in biotechnological fields, this work is focused on the preparation of magnetic polymer nanoparticles (MPNPs) by a single-step miniemulsion process developed to achieve better control of the morphology of the magnetic nanocomposite particles. MPNPs are prepared by surfactant-free miniemulsion polymerization using styrene (St) as a monomer, hexadecane (HD) as a hydrophobe, and potassium persulfate (KPS) as an initiator in the presence of oleic acid (OA)-modified magnetite nanoparticles. The effect of the type of cross-linker used [divinylbenzene (DVB) and bis[2-(methacryloyloxy)ethyl] phosphate (BMEP)] together with the effect of the amount of an aid stabilizer (dextran) on size, particle size distribution (PSD), and morphology of the hybrid nanoparticles synthesized is analyzed in detail. The mixture of different surface modifiers produces hybrid nanocolloids with various morphologies: from a typical core-shell composed by a magnetite core surrounded by a polymer shell to a homogeneously distributed morphology where the magnetite is uniformly distributed throughout the entire nanocomposite. © 2011 American Chemical Society.

D'Alisa G.,Autonomous University of Barcelona | Di Nola M.F.,University of the Basque Country | Di Nola M.F.,University of Rome La Sapienza | Giampietro M.,Autonomous University of Barcelona
Journal of Cleaner Production | Year: 2012

The waste crisis in Campania has inspired a vast amount of studies. Nevertheless, very little research has been done to explain the figures of waste generation and disposal in the region. The analyses carried out so far according to the indicators used by official statistics-i.e. Waste Generated, Waste Generated per capita and Separate Collection-fail to represent this hot spot case. This paper attempts to bridge this gap. Adopting the rationale of a new accounting system, the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM), two waste indicators are proposed to complement the conventional ones: the Metabolic Rate of Waste and the Density of Waste. Then a multi-scale analysis of the Density of Waste Disposed (DWD) tests its suitability to characterise Campania's waste patterns. The data cover the period from 1999 to 2007. The results show that the DWD complements available indicators and further helps to explain the biophysical pressure and ecological unsustainability of the waste management in the region. The multi-scale analysis shows that regional data hide a relevant territorial diversity, emergent in the provincial analysis and even more so in the municipal one. These results have implications for governance and for the debate about mono-scale versus multi-scale solutions to waste management problems. Finally, the analysis allows some analytical generalisations on the suitability of the DWD to detect situations of potential waste crisis in other study-contexts. © 2012 Elsevier Ltd. All rights reserved.

Vicario J.L.,University of the Basque Country
Synlett | Year: 2015

Aminocatalysis applied to cycloaddition chemistry has gained an outstanding level of efficiency and sophistication, with many examples in which the different organocatalytic activation manifolds have been applied to develop catalytic and enantioselective variants of synthetically relevant cycloaddition reactions. In this account, a selection of relevant contributions to this field carried out in our laboratories will be presented, showing that the catalytic generation of either electron-poor α,β-unsaturated iminium ions or, alternatively, electron-rich dienamines or trienamines can constitute a very useful approach for the activation of (poly)unsaturated aldehydes toward different types of reagents. Importantly, this account also shows that reactions can be designed from the beginning leading to the expected products and that proceed with excellent performance once an appropriate catalyst and conditions are selected. Alternatively, it is also shown that, in some cases, unexpected results are obtained which have led us to the discovery of interesting transformations that are unprecedented in the chemical literature. 1 Introduction 2 Formal [3+2] Cycloaddition with Azomethine Ylides 3 Attempted [3+2] Cycloaddition Using Hydrazones as Azomethine Imine Precursors 4 [5+2] Cycloaddition Between Oxidopyrylium Ylides and Enals under Dienamine Activation 5 [2+2] Cycloaddition Between Nitroalkenes and Enals under Dienamine Activation 6 Trienamine Activation. Unconjugated Dienals as Active Substrates in [4+2] Cycloaddition 7 Summary and Outlook Copyright © 2015, Georg Thieme Verlag. All rights reserved.

Branas-Garza P.,Middlesex University | Kovarik J.,University of the Basque Country | Neyse L.,University of Granada
PLoS ONE | Year: 2013

Gene-culture co-evolution emphasizes the joint role of culture and genes for the emergence of altruistic and cooperative behaviors and behavioral genetics provides estimates of their relative importance. However, these approaches cannot assess which biological traits determine altruism or how. We analyze the association between altruism in adults and the exposure to prenatal sex hormones, using the second-to-fourth digit ratio. We find an inverted U-shaped relation for left and right hands, which is very consistent for men and less systematic for women. Subjects with both high and low digit ratios give less than individuals with intermediate digit ratios. We repeat the exercise with the same subjects seven months later and find a similar association, even though subjects' behavior differs the second time they play the game. We then construct proxies of the median digit ratio in the population (using more than 1000 different subjects), show that subjects' altruism decreases with the distance of their ratio to these proxies. These results provide direct evidence that prenatal events contribute to the variation of altruistic behavior and that the exposure to fetal hormones is one of the relevant biological factors. In addition, the findings suggest that there might be an optimal level of exposure to these hormones from social perspective. © 2013 Brañas-Garza et al.

Zueco D.,University of Zaragoza | Mazo J.J.,University of Zaragoza | Solano E.,University of the Basque Country | Solano E.,Ikerbasque | Garcia-Ripoll J.J.,Institute Fisica Fundamental
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We study different architectures for a photonic crystal in the microwave regime based on superconducting transmission lines interrupted by Josephson junctions, both in one and two dimensions. A study of the scattering properties of a single junction in the line shows that the junction behaves as a perfect mirror when the photon frequency matches the Josephson plasma frequency. We generalize our calculations to periodic arrangements of junctions, demonstrating that they can be used for tunable band engineering, forming what we call a quantum circuit crystal. Two applications are discussed in detail. In a two-dimensional structure we demonstrate the phenomenon of negative refraction. We finish by studying the creation of stationary entanglement between two superconducting qubits interacting through a disordered media. © 2012 American Physical Society.

Khomitsky D.V.,Nizhny Novgorod State Technical University | Gulyaev L.V.,Nizhny Novgorod State Technical University | Sherman E.Ya.,University of the Basque Country | Sherman E.Ya.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We consider joint effects of tunneling and spin-orbit coupling on driven by electric field spin dynamics in a double quantum dot with a multilevel resonance scenario. We demonstrate that tunneling plays the crucial role in the formation of the Rabi-like spin-flip transitions. In contrast to the linear behavior for weak electric fields, the spin-flip rate becomes much smaller than expected for the two-level model and shows oscillating dependence on the driving field amplitude in stronger fields. In addition, the full spin flip is very difficult to achieve in a multilevel resonant system. These two effects have a similarity with the Zeno effect of slowing down the dynamics of an observable by its measurement. As a result, spin manipulation by electric field becomes much less efficient than expected. © 2012 American Physical Society.

Ruiz-De-Arbulo-Lopez P.,University of the Basque Country | Fortuny-Santos J.,Polytechnic University of Catalonia | Cuatrecasas-Arbos L.,Polytechnic University of Catalonia
Industrial Management and Data Systems | Year: 2013

Purpose - The purpose of this paper is to identify the shortcomings of traditional cost accounting techniques in lean companies and then it seeks to analyse the validity and convenience of value stream costing (VSC) as a tool in a company that has adopted some concepts of lean manufacturing. Design/methodology/approach - The paper reviews the relevant literature in order to discuss the deficiencies of costing methods in lean manufacturing. It evaluates the requirements of VSC and provides a concrete illustration of VSC in the continuous improvement process of a point of sales terminal assembly line. Findings - The paper evidences the possible mistakes of cost accounting. The necessity and validity of VSC in lean manufacturing are presented, followed by a case example. In order to make continuous improvement decisions, VSM, VSC and box score offer complete information on the performance of the value stream. Research limitations/implications - Although accompanied by an application on a real case study, this is not an empirical investigation on the adoption of VSC. Practical implications - VSC requirements agree with the fundamentals of lean management. Therefore, VSC is a valid tool for lean companies, although the applicability depends on the maturity of the lean implementation. Originality/value - This paper contributes to the lean accounting literature because the management accounting literature still lags behind the lean transformation. This is one of the first papers on VSC in relevant journals and the first one to combine VSC and box scores with value stream mapping. The paper will be useful to academics involved in new accounting systems but also to practitioners who are implementing lean manufacturing. © Emerald Group Publishing Limited.

Emplacement of shallow magmatic laccoliths can result in the development of domeshaped forced folds and fractures in the overburden and at the depositional surface. These folds and fractures have been described from both outcrop studies and seismic interpretation; however, the main controls on fold growth and fracture development remain unclear and, in some cases, controversial. This paper presents a new approach in the analysis of the growth of laccolith intrusions and forced folds. In this study, deep-water growth deposits at an outcrop in the Basque- Cantabrian Basin (north Iberia) record the coeval formation and evolution of a late Albianforced fold and related clastic dike system above the igneous Larragan laccolith. The vertical succession allows field mapping and characterization of the growth deposits, the underlying forced fold, and the forcible Larragan laccolith at depth. The Larragan laccolith is 600 m wide and 40 m thick and intrudes an organic-rich unit at an original (decompacted) depth of ~450 m. A multidisciplinary study (sedimentology, structure, petrology, and geochemistry) of the growth deposits reveals that the emplacement of the laccolith created a dome-shaped upwardwideningfold, which had a final relief of 18- 36 m and a width of ~850 m at the paleoseabed. Simultaneously, in the hinge zone of the fold, local tensional stress induced the formation of a fracture system, which subsequently acted as conduits for overpressured ascending fluids (methane and water) and fluidized sediments originating from the metamorphic aureole of the laccolith. This plumbing system reached the paleoseabed, where extruded sediments were deposited and methane-derived carbonates precipitated. A comprehensive model is proposed in which incremental emplacement of magma sheets induced pulsating contact metamorphism, folding and fracturing of the overburden, and episodic activity of the fluid plumbing system. © 2015 Geological Society of America.

Fernandez-Macho J.,University of the Basque Country
Physica A: Statistical Mechanics and its Applications | Year: 2012

Statistical studies that consider multiscale relationships among several variables use wavelet correlations and cross-correlations between pairs of variables. This procedure needs to calculate and compare a large number of wavelet statistics. The analysis can then be rather confusing and even frustrating since it may fail to indicate clearly the multiscale overall relationship that might exist among the variables. This paper presents two new statistical tools that help to determine the overall correlation for the whole multivariate set on a scale-by-scale basis. This is illustrated in the analysis of a multivariate set of daily Eurozone stock market returns during a recent period. Wavelet multiple correlation analysis reveals the existence of a nearly exact linear relationship for periods longer than the year, which can be interpreted as perfect integration of these Euro stock markets at the longest time scales. It also shows that small inconsistencies between Euro markets seem to be just short within-year discrepancies possibly due to the interaction of different agents with different trading horizons. © 2011 Elsevier B.V. All rights reserved.

Garcia A.,University of the Basque Country
Journal of Physics A: Mathematical and Theoretical | Year: 2012

We prove blow-up results for the solution of the initial-value problem with negative energy of the focusing mass-critical and supercritical nonlinear Schrödinger and the focusing energy-subcritical nonlinear wave equations with electromagnetic potential.

Chartier P.,Ecole Normale Superieure de Cachan | Murua A.,University of the Basque Country | Sanz-Serna J.M.,University of Valladolid
Foundations of Computational Mathematics | Year: 2010

We show how B-series may be used to derive in a systematic way the analytical expressions of the high-order stroboscopic averaged equations that approximate the slow dynamics of highly oscillatory systems. For first-order systems we give explicitly the form of the averaged systems with O(script)(εj errors, j = 1,2,3 (2πε denotes the period of the fast oscillations). For second-order systems with large O(script)(ε-1 forces, we give the explicit form of the averaged systems with O(script)(εj errors, j = 1,2. A variant of the Fermi-Pasta-Ulam model and the inverted Kapitsa pendulum are used as illustrations. For the former it is shown that our approach establishes the adiabatic invariance of the oscillatory energy. Finally we use B-series to analyze multiscale numerical integrators that implement the method of averaging. We construct integrators that are able to approximate not only the simplest, lowest-order averaged equation but also its high-order counterparts. © 2010 SFoCM.

Manes J.L.,University of the Basque Country
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We consider the existence of bulk chiral fermions around points of symmetry in the Brillouin zone of nonmagnetic three-dimensional (3D) crystals with negligible spin-orbit interactions. We use group theory to show that this is possible, but only for a reduced number of space groups and points of symmetry that we tabulate. Moreover, we show that for a handful of space groups the existence of bulk chiral fermions is not only possible but unavoidable, irrespective of the concrete crystal structure. Thus our tables can be used to look for bulk chiral fermions in a specific class of systems, namely, that of nonmagnetic 3D crystals with sufficiently weak spin-orbit coupling. We also discuss the effects of spin-orbit interactions and possible extensions of our approach to Weyl semimetals, crystals with magnetic order, and systems with Dirac points with pseudospin 1 and 3/2. A simple tight-binding model is used to illustrate some of the issues. © 2012 American Physical Society.

Shen M.,Shanghai University | Ruan L.-X.,Shanghai University | Chen X.,Shanghai University | Chen X.,University of the Basque Country
Optics Express | Year: 2010

Motivated by the realization of the Dirac point (DP) with a double-cone structure for optical field in the negative-zero-positive index metamaterial (NZPIM), we make theoretical investigations of the guided modes in the NZPIM waveguide near the DP by using the graphical method. Due to the linear Dirac dispersion, the fundamental mode is absent when the angular frequency is smaller than the DP, while the behaviors of NZPIM waveguide are similar to the conventional dielectric waveguide when the angular frequency is larger than the DP. The unique properties of the guided modes are analogous to the propagation of electron waves in graphene waveguide [Appl. Phys. Lett, 94, 212105 (2009)], corresponding to the classical motion and the Klein tunneling. These results suggest that many exotic phenomena in graphene can be simulated by the relatively simple optical NZPIM. © 2010 Optical Society of America.

Vandenbroeck K.,University of the Basque Country | Vandenbroeck K.,Ikerbasque
Journal of Interferon and Cytokine Research | Year: 2012

Cytokine (receptor) genes have traditionally attracted great interest as plausible genetic risk factors for autoimmune disease. Since 2007, the implementation of genome-wide association studies has facilitated the robust identification of allelic variants in more than 35 cytokine loci as susceptibility factors for a wide variety of over 15 autoimmune disorders. In this review, we catalog the gene loci of interleukin, chemokine, and tumor necrosis factor receptor superfamily and ligands that have emerged as autoimmune risk factors. We examine recent progress made in the clarification of the functional mechanisms by which polymorphisms in the genes coding for interleukin-2 receptor alpha (IL2RA), IL7R, and IL23R may alter risk for autoimmune disease, and discuss opposite autoimmune risk alleles found, among others, at the IL10 locus. © Copyright 2012, Mary Ann Liebert, Inc.

Xenakis I.,University of Aegean | Arnellos A.,University of the Basque Country
Design Studies | Year: 2013

Even though aesthetics and affordances are two important factors based on which designers provide effective ways of interaction through their artifacts, there is no study or theoretical model that relates these two aspects of design. We suggest a theoretical explanation that relates the underlying functionality of aesthetics, in particular, of interaction aesthetics and of affordances in the design process. Our claim is that interaction aesthetics are one among other factors that allow users to enhance the detection of action possibilities and consequently, the detection of affordances. Our aim is first to discuss the role of interaction aesthetics in the design process, and second to suggest an explanation for their role in the detection of affordances when users interact with artifacts. © 2012 Elsevier Ltd. All rights reserved.

Wozniak M.,Wroclaw University of Technology | Grana M.,University of the Basque Country | Corchado E.,University of Salamanca
Information Fusion | Year: 2014

A current focus of intense research in pattern classification is the combination of several classifier systems, which can be built following either the same or different models and/or datasets building approaches. These systems perform information fusion of classification decisions at different levels overcoming limitations of traditional approaches based on single classifiers. This paper presents an up-to-date survey on multiple classifier system (MCS) from the point of view of Hybrid Intelligent Systems. The article discusses major issues, such as diversity and decision fusion methods, providing a vision of the spectrum of applications that are currently being developed. © 2013 Elsevier B.V. All rights reserved.

Delextrat A.,London Metropolitan University | Calleja-Gonzalez J.,University of the Basque Country | Hippocrate A.,London Metropolitan University | Clarke N.D.,Coventry University
Journal of Sports Sciences | Year: 2013

The aim of this study was to compare the effects of intermittent cold-water immersion and massage on perceptual and performance markers of recovery by basketball players after competitive matches. Eight men (age 23 ± 3 years; stature 190.5 ± 8.9 cm; body mass 90.3 ± 9.6 kg; body fat 12.8 ± 4.8%) and eight women (age 22 ± 2 years; stature 179.0 ± 8.5 cm; body mass 77.6 ± 9.2 kg; body fat 22.5 ± 6.6%) basketball players participated. Massage, cold-water immersion or control were applied immediately after competitive matches, followed by assessments of perceptual measures of recovery and physical performance, countermovement jump and repeated-sprint ability 24 h after intervention. There was lower perception of fatigue overall and in the legs immediately after the massage and cold-water immersion condition (P < 0.001; = 0.91). Furthermore, women had a lower perception of fatigue in cold-water immersion than massage at any testing time (P < 0.001; = 0.37). Jump performance was greater after cold-water immersion than the control condition (P = 0.037, = 0.37). There was no effect of any of the recovery interventions on repeated-sprint measures (P at best 0.067, at best 0.68). The results suggest that both massage and cold-water immersion improve perceptual measures of recovery. Furthermore, cold-water immersion improves jump performance although neither such immersion nor massage had an effect on repeated-sprint ability. This suggests that, overall, cold-water immersion is more useful than massage in the recovery from basketball matches, especially in women. © 2013 Copyright Taylor and Francis Group, LLC.

Lu Y.-C.,University of Sheffield | Cooke M.,University of the Basque Country | Cooke M.,Ikerbasque
IEEE Transactions on Audio, Speech and Language Processing | Year: 2010

One of the principal cues believed to be used by listeners to estimate the distance to a sound source is the ratio of energies along the direct and indirect paths to the receiver. In essence, this direct-to-reverberant energy ratio reveals the absolute distance component of the direct energy by normalizing by what is assumed to be distance-independent reverberant energy. Earlier approaches to direct-to-reverberant energy ratio calculation made use of the estimated room impulse response, but these techniques are computationally expensive and inaccurate in practice. This paper proposes and evaluates an alternative approach which uses binaural signals to segregate energy arriving from the estimated direction of the direct source from that arriving from other directions, employing a novel binaural equalization-cancellation technique. The system is integrated with a probabilistic inference framework, particle filtering, to handle the nonstationarity of energy-based measurements. The algorithm is capable of using reverberation to estimate source distance in large rooms with errors of less than 1 m for static sources and 1.53.5 m for sources with varying degrees of motion complexity. Model performance can be accounted for largely in terms of a competition between auditory horizon and source energy fluctuation effects. © 2010 IEEE.

Grau-Sologestoa I.,University of the Basque Country
Environmental Archaeology | Year: 2016

This paper synthesises faunal data from medieval archaeological sites in the Iberian Peninsula, aiming to identify zooarchaeological evidence that can improve our understanding of socio-economic status and cultural identities. The main zooarchaeological indicators for social differentiation are explored: food procurement and cuisine (taking into account different types of sites – high status, urban and rural), and different socio-political systems (Islamic and Christian regions), from a diachronic perspective. © Association for Environmental Archaeology 2016

Casanova D.,Ikerbasque | Casanova D.,University of the Basque Country | Casanova D.,Donostia International Physics Center
Journal of Chemical Theory and Computation | Year: 2014

A detailed theoretical study of the singlet fission process in tetracene and two of its derivatives, that is 5,12-diphenyltetracene (DPT) and rubrene, is presented. This work aims to unravel the intricacies and the differences of their singlet fission mechanism by means of electronic structure calculations using molecular and cluster models and a variety of computational tools. Although the electronic structure at the molecular level is very similar for the three compounds, their different crystal packing has important consequences in their ability to produce two triplet states from a single exciton. The results obtained indicate that the lowest singlet is found to delocalize at least over seven molecules. Computed relative energies rule out the presence of charge transfer (CT) states as intermediates in a two-step mechanism in all cases. On the other hand, CT states do play a role as mediators, specially in tetracene. They decisively participate in the coupling between single and multiexcitonic states through second-order contributions. Finally, the present study pinpoints that the transition from the optically allowed exciton to the dark multiexciton state might be facilitated by intramolecular motion toward the lowest excited singlet geometry. © 2013 American Chemical Society.

Aizpurua A.,University of Minnesota | Aizpurua A.,University of the Basque Country | Koutstaal W.,University of Minnesota
Psychology and Aging | Year: 2010

Aging attenuates the capacity to adaptively and flexibly use episodic memory at different levels of specificity. Older and younger adults were tested on a picture recognition task that required them to make episodic memory decisions at an item-specific (verbatim) versus category-based (gist-based) level on randomly intermixed trials. Specificity modulation was assessed using a measure of the likelihood that participants retrieved verbatim information in order to reject test items that were categorically related to studied items under item-specific recognition instructions (recollection rejection). We found that this measure positively correlated with conceptual span (an index of short-term semantic memory) and with level of fluid intelligence in older and younger adults. However, when we simultaneously considered each of four possible contributors (age, conceptual span, fluid intelligence, and frontal function), the only significant predictor of recollection rejection was the composite fluid intelligence measure (assessed by the Culture Fair Intelligence Test [Cattell & Cattell, 1960] and the Wechsler Adult Intelligence Scale-Revised Block Design subtest [Wechsler, 1981]). These findings suggest that interventions that facilitate adaptive specificity modulation in episodic memory may enhance the flexibility of thinking, and vice versa, in both older and younger adults. © 2010 American Psychological Association.

Manes J.L.,University of the Basque Country | De Juan F.,Lawrence Berkeley National Laboratory | De Juan F.,University of California at Berkeley | Sturla M.,CSIC - Institute of Materials Science | Vozmediano M.A.H.,CSIC - Institute of Materials Science
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We use a symmetry approach to construct a systematic derivative expansion of the low-energy effective Hamiltonian modifying the continuum Dirac description of graphene in the presence of nonuniform elastic deformations. We extract all experimentally relevant terms and describe their physical significance. Among them there is a new gap-opening term that describes the Zeeman coupling of the elastic pseudomagnetic field and the pseudospin. We determine the value of the couplings using a generalized tight-binding model. © 2013 American Physical Society.

Coe D.,Jet Propulsion Laboratory | Benitez N.,Institute Astrofisica Of Andalucia | Broadhurst T.,University of the Basque Country | Broadhurst T.,Ikerbasque | Moustakas L.A.,Jet Propulsion Laboratory
Astrophysical Journal | Year: 2010

We present a strong lensing (SL) mass model of A1689 which resolves substructures an estimated 25 kpc across within the central ∼400 kpc diameter. We achieve this resolution by perfectly reproducing the observed (strongly lensed) input positions of 168 multiple images of 55 knots residing within 135 images of 42 galaxies. Our model makes no assumptions about light tracing mass, yet we reproduce the brightest visible structures with some slight deviations. A1689 remains one of the strongest known lenses on the sky, with an Einstein radius of Re = 47″.0 ± 1.2 (143 +3-4 kpc) for a lensed source at zs = 2. We find that a single Navarro-Frenk-White (NFW) or Sérsic profile yields a good fit simultaneously (with only slight tension) to both our SL mass model and published weak lensing (WL) measurements at larger radius (out to the virial radius). According to this NFW fit, A1689 has a mass of Mvir = 2.0+0.5-0.3 × 1015 M ⊙h-170 (M200 = 1.8 +0.4-0.3 × 1015 M⊙h -170) within the virial radius rvir = 3.0 ± 0.2 Mpch-170 (r200 = 2.4 +0.1-0.2 Mpch-170), and a central concentration cvir = 11.5+1.5-1.4 (c 200 = 9.2 ±1.2). Our SL model prefers slightly higher concentrations than previous SL models, bringing our SL + WL constraints in line with other recent derivations. Our results support those of previous studies which find A1689 has either an anomalously large concentration or significant extra mass along the line of sight (perhaps in part due to triaxiality). If clusters are generally found to have higher concentrations than realized in simulations, this could indicate that they formed earlier, perhaps as a result of early dark energy. © 2010. The American Astronomical Society.

Echeverria-Arrondo C.,University of the Basque Country | Echeverria-Arrondo C.,Ikerbasque | Sherman E.Ya.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

One-dimensional quantum wires are considered as prospective elements for spin transport and manipulation in spintronics. We study spin dynamics in semiconductor GaAs-like nanowires with disorder and spin-orbit interaction by using a rotation in the spin subspace gauging away the spin-orbit field. If the disorder is sufficiently strong, the spin density after a relatively short relaxation time reaches a plateau. This effect is a manifestation of the Anderson localization and depends in a universal way on the disorder and the spin-orbit coupling strength. As a result, at a given disorder, semiconductor nanowires can permit a long-term spin polarization tunable with the spin-orbit interactions. © 2012 American Physical Society.

Abdullah S.,University of Bath | Abdullah S.,University of the Basque Country | Morley B.,University of Bath
Energy Economics | Year: 2014

The aim of this study is to determine the causal relationship between environmental taxes and economic growth, using different measures of environmental taxes with GDP as well as adjusted net savings. A panel of European countries and a separate panel of OECD countries are used from 1995 to 2006 and the standard Granger non-causality approach is applied. The results suggest some evidence of long-run causality running from economic growth to increased revenue from the environmental taxes, with also some evidence of short-run causality in the reverse direction. The inclusion of population and a proxy for economic subsidies had little effect on the long-run relationship, although the proxy for subsidies did have some short-run effect on growth. © 2013 Elsevier B.V.

Senovilla J.M.M.,University of the Basque Country
Classical and Quantum Gravity | Year: 2014

I analyze the properties of thin shells through which the scalar curvature R is discontinuous in gravity theories with Lagrangian F(R) = R - 2Λ + R2 on the bulk. These shells/domain walls are of a new kind because they possess, in addition to the standard energy-momentum tensor, an external energy flux vector, an external scalar pressure/tension and, most exotic of all, another energy-momentum contribution resembling classical dipole distributions on a shell: a double layer. I prove that all these contributions are necessary to make the entire energy-momentum tensor divergence-free. This is the first known occurrence of such a type of double layer in a gravity theory. I present explicit examples in constant-curvature five-dimensional bulks, with a brief study of their properties: new physical behaviors arise. © 2014 IOP Publishing Ltd.

Bro R.,Copenhagen University | Vidal M.,University of the Basque Country
Chemometrics and Intelligent Laboratory Systems | Year: 2011

For many years it has been known that PARAFAC offers a very attractive approach for modeling fluorescence excitation-emission matrices. Due to the uniqueness of the PARAFAC model and analogy between the structure of fluorescence data and the PARAFAC model, it is apparent that PARAFAC can resolve overlapping signals into pure spectra and relative concentrations under mild conditions. There are hundreds of applications exemplifying this, but still the use of PARAFAC has not spread from chemometrics to more main-stream analytical chemistry. Many reasons can be offered to explain this, but one seems to be that in practice it is difficult for chemometric novices to make use of PARAFAC. Selection of wavelengths, handling of scatter and of outliers are all issues that must be dealt with in order to build a good PARAFAC model. In this paper, a new algorithm called EEMizer is developed that aims to automate the use of PARAFAC. Through several examples it is shown how this algorithm can provide appealing PARAFAC models of data that would otherwise be hard to model. © 2010 Elsevier B.V.

Vilar J.M.,University of the Basque Country | Vilar J.M.,Ikerbasque
Physical Review X | Year: 2014

Leukemia epitomizes the class of highly complex diseases that new technologies aim to tackle by using large sets of single-cell-level information. Achieving such a goal depends critically not only on experimental techniques but also on approaches to interpret the data. A most pressing issue is to identify the salient quantitative features of the disease from the resulting massive amounts of information. Here, I show that the entropies of cell-population distributions on specific multidimensional molecular and morphological landscapes provide a set of measures for the precise characterization of normal and pathological states, such as those corresponding to healthy individuals and acute myeloid leukemia (AML) patients. I provide a systematic procedure to identify the specific landscapes and illustrate how, applied to cell samples from peripheral blood and bone marrow aspirates, this characterization accurately diagnoses AML from just flow cytometry data. The methodology can generally be applied to other types of cell populations and establishes a straightforward link between the traditional statistical thermodynamics methodology and biomedical applications.

Cembranos J.A.R.,Complutense University of Madrid | De La Cruz-Dombriz A.,University of Cape Town | Romero P.J.,University of the Basque Country
International Journal of Geometric Methods in Modern Physics | Year: 2014

In the context of f(R) modified gravity theories, we study the Kerr-Newman black hole solutions. We study nonzero constant scalar curvature solutions and discuss the metric tensor that satisfies the modified field equations. We conclude that, in the absence of a cosmological constant, the black holes (BHs) existence is determined by the sign of a parameter h dependent of the mass, the charge, the spin and the scalar curvature. Different values of this parameter lead to diverse astrophysical objects, such as extremal and marginal extremal BHs. Thermodynamics of BHs are then studied, as well as their local and global stability. We analyze these features in a large variety of f(R) models. We remark the main differences with respect to general relativity and show the rich thermodynamical phenomenology that characterizes this framework. © 2014 World Scientific Publishing Company.

Reinoso S.,University of Valencia | Reinoso S.,University of the Basque Country
Dalton Transactions | Year: 2011

Heterometallic 3d-4f polyoxometalates still remain as an almost unexplored class of polyoxoanions despite showing great potential in fields such as molecular magnetism. This Frontier reviews some of their synthetic, structural and magnetic features and gives a personal view on future research in this area. © 2011 The Royal Society of Chemistry.

Schive H.-Y.,National Taiwan University | Chiueh T.,National Taiwan University | Broadhurst T.,University of the Basque Country | Broadhurst T.,Ikerbasque
Nature Physics | Year: 2014

The conventional cold-particle interpretation of dark matter (known as 'cold dark matter', or CDM) still lacks laboratory support and struggles with the basic properties of common dwarf galaxies, which have surprisingly uniformcentralmasses and shallow density profiles1-5. In contrast, galaxies predicted by CDM extend to much lower masses, with steeper, singular profiles6-9. This tension motivates cold, wavelike dark matter ( DM) composed of a non-relativistic Bose-Einstein condensate, so the uncertainty principle counters gravity below a Jeans scale10-12. Here we achieve cosmological simulations of this quantum state at unprecedentedly high resolution capable of resolving dwarf galaxies, with only one free parameter, mB, the boson mass. We demonstrate the large-scale structure is indistinguishable from CDM, as desired, but diers radically inside galaxies where quantum interference forms solitonic cores surrounded by extended haloes of fluctuating density granules.These results allowus to determine m B=(8.0C+1.8 -2.0×10-23 eV using stellar phase-space distributions in dwarf spheroidal galaxies. Denser, more massive solitons are predicted for Milky Way sized galaxies, providing a substantial seed to help explain early spheroid formation. The onset of galaxy formation is substantially delayed relative to CDM, appearing at redshift z≲13 in our simulations. © 2014 Macmillan Publishers Limited. All rights reserved.

Eiguren A.,University of the Basque Country | Gurtubay I.G.,Donostia International Physics Center
New Journal of Physics | Year: 2014

We present a new efficient numerical approach for representing anisotropic physical quantities and/or matrix elements defined on the Fermi surface (FS) of metallic materials. The method introduces a set of numerically calculated generalized orthonormal functions which are the solutions of the Helmholtz equation defined on the FS. Noteworthy, many properties of our proposed basis set are also shared by the FS harmonics introduced by Philip B Allen (1976 Phys. Rev. B 13 1416), proposed to be constructed as polynomials of the cartesian components of the electronic velocity. The main motivation of both approaches is identical, to handle anisotropic problems efficiently. However, in our approach the basis set is defined as the eigenfunctions of a differential operator and several desirable properties are introduced by construction. The method is demonstrated to be very robust in handling problems with any crystal structure or topology of the FS, and the periodicity of the reciprocal space is treated as a boundary condition for our Helmholtz equation. We illustrate the method by analysing the free-electron-like lithium (Li), sodium (Na), copper (Cu), lead (Pb), tungsten (W) and magnesium diboride (MgB). © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Balleza D.,University of the Basque Country
Origins of Life and Evolution of Biospheres | Year: 2011

Mechanosensitive (MS) channels can prevent bacterial bursting during hypoosmotic shocks by responding to increases in lateral tension at the membrane level through an integrated and coordinated opening mechanism. Mechanical regulation in protocells could have been one of the first mechanisms to evolve in order to preserve their integrity against changing environmental conditions. How has the rich functional diversity found in present cells been created throughout evolution, and what did the primordial MS channels look like? This review has been written with the aim of identifying which factors may have been important for the appearance of the first osmotic valve in a prebiotic context, and what this valve may have been like. It highlights the mechanical properties of lipid bilayers, the association of peptides as aggregates in membranes, and the conservation of sequence motifs as central aspects to understand the evolution of proteins that gate below the tension required for spontaneous pore formation and membrane rupture. The arguments developed here apply to both MscL and MscS homologs, but could be valid to mechano-susceptible proteins in general. © 2010 Springer Science+Business Media B.V.

Basanez G.,University of the Basque Country
PLoS Biology | Year: 2012

Cell death by apoptosis is indispensable for proper development and tissue homeostasis in all multicellular organisms, and its deregulation plays a key role in cancer and many other diseases. A crucial event in apoptosis is the formation of protein-permeable pores in the outer mitochondrial membrane that release cytochrome c and other apoptosis-promoting factors into the cytosol. Research efforts over the past two decades have established that apoptotic pores require BCL-2 family proteins, with the proapoptotic BAX-type proteins being direct effectors of pore formation. Accumulating evidence indicates that other cellular components also cooperate with BCL-2 family members to regulate the apoptotic pore. Despite this knowledge, the molecular pathway leading to apoptotic pore formation at the outer mitochondrial membrane and the precise nature of this outer membrane pore remain enigmatic. In this issue of PLOS Biology, Kushnareva and colleagues describe a novel kinetic analysis of the dynamics of BAX-dependent apoptotic pore formation recapitulated in native mitochondrial outer membranes. Their study reveals the existence of a hitherto unknown outer mitochondrial membrane factor that is critical for BAX-mediated apoptotic pore formation, and challenges the currently popular view that the apoptotic pore is a purely proteinaceous multimeric assembly of BAX proteins. It also supports the notion that membrane remodeling events are implicated in the formation of a lipid-containing apoptotic pore. © 2012 Basañez et al.

Yuan J.,Max Planck Institute of Colloids and Interfaces | Mecerreyes D.,University of the Basque Country | Antonietti M.,Max Planck Institute of Colloids and Interfaces
Progress in Polymer Science | Year: 2013

This review presents a literature survey of recent work on poly(ionic liquid)s or polymerized ionic liquids (PILs), a class of polyelectrolytes that has attracted rapidly increasing interest over the past few years. The review begins with a short explanation of the interconnection as well as the intrinsic differences between PILs and ionic liquids. Recently reported PIL homopolymers with new chemical structures and synthetic trends are introduced as a complement to the overall PIL synthesis schemes reported previously. In addition, block copolymers and colloidal particles of PILs are described, followed by a discussion of the limitations of PILs due to structural instability under certain conditions and the efforts to understand PIL physics. Examples of recent applications of PILs across a multitude of fields, such as thermoresponsive materials, carbon materials, catalysis, porous polymers, separation and absorption materials, and energy harvesting/generation as well as several biological applications are described in detail. © 2013 Elsevier Ltd.

Bandos I.,University of the Basque Country | Bandos I.,Ikerbasque
Journal of High Energy Physics | Year: 2016

Abstract: We study the properties of section conditions of the E7(+7) exceptional field theory from the perspective of superparticle model in N=8 D = 4 superspace enlarged by additional bosonic coordinates related to the central charge of the maximal supersymmetry superalgebra. In particular, the superparticle model suggests that only a part of the section conditions corresponding to generators of SU(8) subgroup of E7(+7) is independent, and we show that this part indeed suffices to obtain the (classical counterpart of the) general solution of the strong section condition. © 2016, The Author(s).

Reina B.,University of the Basque Country
Monthly Notices of the Royal Astronomical Society | Year: 2016

Hartle's model for slowly rotating stars has been extensively used to compute equilibrium configurations of slowly rotating stars to second order in perturbation theory in general relativity, given a barotropic equation of state. A recent study based on the modern theory of perturbed matchings concludes that the functions in the (first and second order) perturbation tensors can always be taken as continuous at the surface of the star, except for the second-order function m0. This function presents a jump at the surface of the star proportional to the discontinuity of the energy density there. This concerns only a particular outcome of the model: the change in mass δM. In this paper, the amended change in mass is calculated for the case of constant density stars. © 2015 The Authors.

Tornos F.,CSIC - National Institute of Aerospace Technology | Velasco F.,University of the Basque Country | Hanchar J.M.,Memorial University of Newfoundland
Geology | Year: 2016

We propose an integrated model that explains the magmatic and hydrothermal features of the unique El Laco iron deposit that is located in a Pliocene-Pleistocene volcano of the Chilean Andes. (Sub)volcanic crystallization of an iron-rich melt as massive magnetite promoted the exsolution of a small volume of a hydrosaline melt and of large amounts of vapor that led to the formation of an alkali-calcic hydrothermal assemblage replacing the host andesite; this assemblage is capped and overprinted by a large zone of acid-sulfate steam-heated alteration forming as a whole a protracted shallow-level magmatic-hydrothermal system. Oxygen isotopic data for the massive magnetite (δ18O: 4.3‰-5.0‰) and the alkali-calcic altered rock (diopside δ18O: 7.2‰-8.7‰; magnetite δ18O: 4.4‰-6.7‰) suggest that these rocks are genetically related to the host andesite (δ18O: 7.4‰-9.6‰). The estimated temperature of the mineral assemblage (>~900 °C) may be the highest recorded in hydrothermal systems, is attributed to exsolution of fluids from the crystallizing iron-rich melts, and is considered unlikely to reflect the convection of surficial fluids. © 2016 Geological Society of America.

Rodrigues M.E.,Federal University of Espirito Santo | Houndjo M.J.S.,Federal University of Espirito Santo | Houndjo M.J.S.,Institute Of Mathematiques Et Of Science Physiques Imsp 01 | Saez-Gomez D.,University of the Basque Country | Rahaman F.,Jadavpur University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We investigate the cosmological reconstruction in an anisotropic universe for both the homogeneous and inhomogeneous content of the universe. Special attention is given to three interesting cases: Bianchi type I, Bianchi type III, and Kantowski-Sachs models. The de Sitter, power-law, and general exponential solutions are assumed for the scale factor in each spatial direction and the corresponding cosmological models are reconstructed. Moreover, for the general exponential solutions-from which the de Sitter and power-law solutions may be obtained-we obtain models which reproduce the early Universe (assuming inflation) and the late-time accelerated expanding Universe. The models obtained for the late-time Universe are consistent with a known result in the literature where a power-law type correction in T is added to a power-law type of f(T) for guaranteeing the avoidance of the big rip and the big freeze. © 2012 American Physical Society.

Ekstrom P.A.,Northwest Marine Technology Inc. | Zhukov A.,University of the Basque Country | Zhukov A.,TAMAG Iberica S.L.
Journal of Physics D: Applied Physics | Year: 2010

Spatial structure of a domain wall propagating in high-positive- magnetostriction glass-covered microwire was observed using a modified Sixtus-Tonks apparatus. High resolution was achieved by minimizing the size of the pickup coils using single-turn coils wound directly on the surface of glass-coated microwire. Our estimations give the equivalent width of the observed wall ranging from 2.8 to 4 mm in Fe77.5Si 7.5B15 microwire having 12 νm core diameter and 40 νm glass diameter. The shape of the induction signal was wider and more rounded for pickup loops placed near the end of the 30 mm long microwire sample, narrower and nearly triangular for a loop at the centre. © 2010 IOP Publishing Ltd.

This paper sets out to determine whether proximity constraints are more significant in new forms of production organisation in the automotive industry. An analysis is made of the extent to which new organisational technologies condition the internationalisation strategies of firms, with particular reference to whether geographical proximity requirements may condition the development of the automotive industry in the institutional and productive context of an intermediate region (such as the Basque Country) at risk from potential relocation towards central and eastern European countries (CEECs). The results derived from field work indicate that proximity constraints are not significant in the organisational configuration of the Basque automotive industry except in highly specific cases, thanks to the availability of solutions such as temporary agglomerations, new communication technologies and logistical systems. © 2010 Urban Studies Journal Limited.

Garmendia E.,Autonomous University of Barcelona | Garmendia E.,University of the Basque Country | Stagl S.,Vienna University of Economics and Business
Ecological Economics | Year: 2010

Shaping change such that it avoids losing potentially useful options for future development is a challenging task in the face of complex, coevolving socio-ecological systems. Sustainability appraisal methods, which open up dialogue and options before closing down and making suggestions, pay attention to the inclusion of various and conflicting points of view and address uncertainty, are increasingly used in the science, environment and energy policy domains. The quality of the process is seen as key to high quality appraisal outcomes. Dimensions of quality include learning opportunities which are seen as ways for addressing complexity and uncertainty. Participatory sustainability appraisal methods intend to support social learning among participants. Despite high expectations, social learning processes in sustainability appraisals are poorly conceptualized and empirically understudied. This paper (1) briefly reviews theories of social learning; (2) develops a conceptual framework for the analysis; and (3) presents an empirical application of the framework by use of data obtained from three energy and natural resource management case studies around Europe. © 2010 Elsevier B.V. All rights reserved.

Bouhmadi-Lopez M.,University of the Basque Country | Bouhmadi-Lopez M.,Ikerbasque | Kiefer C.,University of Cologne | Kramer M.,University of Cologne
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We discuss the fate of classical type IV singularities in quantum cosmology. The framework is Wheeler-DeWitt quantization applied to homogeneous and isotropic universes with a perfect fluid described by a generalized Chaplygin gas. Such a fluid can be dynamically realized by a scalar field. We treat the cases of a standard scalar field with positive kinetic energy and of a scalar field with negative energy (phantom field). We first present the classical solutions. We then discuss in detail the Wheeler-DeWitt equation for these models. We are able to give analytic solutions for a special case and to draw conclusions for the general case. Adopting the criterion that singularities are avoided if the wave function vanishes in the region of the classical singularity, we find that type IV singularities are avoided only for particular solutions of the Wheeler-DeWitt equation. We compare this result with earlier results found for other types of singularities. © 2014 American Physical Society.

Eltschka C.,University of Regensburg | Siewert J.,University of the Basque Country | Siewert J.,Ikerbasque
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

The quantitative assessment of the entanglement in multipartite quantum states is, apart from its fundamental importance, a practical problem. Recently there has been significant progress in developing new methods to determine certain entanglement measures. In particular, there is a method - in principle, analytical - to compute a certified lower bound for the three-tangle. The purpose of this work is to provide a manual for the implementation of this approach and to explicitly discuss several analytically solvable cases in order to gauge the numerical tools. Moreover, we derive a simple analytical bound for the mixed-state three-tangle. © 2014 American Physical Society.

Glazov M.M.,RAS Ioffe Physical - Technical Institute | Semina M.A.,RAS Ioffe Physical - Technical Institute | Sherman E.Y.,University of the Basque Country | Sherman E.Y.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We consider theoretically the relaxation of electron spin component parallel to the growth direction in multiple (110) GaAs quantum wells. The sources of spin relaxation are the random Rashba spin-orbit coupling due to the electric field of donors and spin-flip collisions of electrons from different quantum wells. We show that the screening of the Coulomb forces at low temperatures leads to a very strong enhancement of the spin relaxation time. In a degenerate electron gas, the Pauli blocking suppresses the electron-electron collisions, and the leading spin relaxation mechanism comes from the field of donors. If the electron gas is nondegenerate the electron-electron collisions and scattering by the ionized donors give similar contributions to the relaxation rate. © 2010 The American Physical Society.

Pedraz J.L.,University of the Basque Country
Advances in Experimental Medicine and Biology | Year: 2010

Over the last half century, the use of erythropoietin (Epo) in the management of malignancies has been extensively studied. Originally viewed as the renal hormone responsible for red blood cell production, many recent in vivo and clinical approaches demonstrate that various tissues locally produce Epo in response to physical or metabolic stress. Thus, not only its circulating erythrocyte mass regulator activity but also the recently discovered nonhematological actions are being thoroughly investigated in order to fulfill the specific Epo delivery requirements for each therapeutic approach. © 2010 Landes Bioscience and Springer Science+Business Media.

Strozecka A.,Free University of Berlin | Eiguren A.,University of the Basque Country | Eiguren A.,Donostia International Physics Center | Pascual J.I.,Free University of Berlin
Physical Review Letters | Year: 2011

On surfaces with strong spin-orbit coupling, backscattering is forbidden since it requires flipping of the spin of the electron. It has been proposed that the forbidden scattering channels in such systems can be activated if time reversal symmetry is locally broken, for example, by a magnetic scattering center. Scanning tunneling spectroscopic maps of quasiparticle interference patterns around a single magnetic MnPc molecule on a Bi(110) surface reveal only spin-conserving scattering events. Simulations based on the Green's functions approach confirm that the charge-density interference patterns are unaffected by the magnetic state of the impurity. A fingerprint of backscattering processes appears, however, in the magnetization patterns, suggesting that only spin-polarized measurements can access this information. © 2011 American Physical Society.

Fernandez I.,Complutense University of Madrid | Cossio F.P.,University of the Basque Country | Sierra M.A.,Complutense University of Madrid
Accounts of Chemical Research | Year: 2011

The seminal report by Hegedus in 1982, showing that alkoxychromium(0) carbenes reacted with imines under bright Colorado sunlight to yield β-lactams, marked the beginning of a key reaction in organometallic chemistry. Very little was known about the mechanism of this reaction. In fact, Hegedus proposed the reversible generation of a chromium-coordinated ketene, which would react with nucleophiles. This coordinated species would show all the advantages of ketenes without their shortcomings, namely, dimerization, formation of undesired adducts, and so forth. The quest for the detection of these species and the pursuit of the mechanism of the photocarbonylation (a reaction exclusive to Cr(0) and Mo(0) carbene complexes, not W(0) carbene complexes) remained unabated over the next 15 years. In fact, all attempts to experimentally determine the mechanism of this useful reaction have been fruitless. At the same time, the photocarbonylation of Cr(0) carbenes matured into a valuable synthetic reaction, allowing access to several families of organic compounds. Unfortunately, reactions other than photocarbonylation remained elusive.We used a combination of experimental and computational methodologies to study the photocarbonylation of Cr(0) carbene complexes and the subsequent reaction of the photogenerated ketenes with nucleophiles. In parallel, we discovered new photochemical processes and succeeded in making photoreactive the so-called "unreactive" W(0) carbene complexes. In this Account, we discuss the disentangling of the mechanisms of these transformations, thereby shedding some light onto the photochemistry of group 6 metal (Fischer) carbene complexes.The original designation of the electronic transitions of group 6 carbene complexes was reassigned, and the photocarbonylation step was analyzed again, resulting in the sequence S 0-T 1-S 0, which is far removed from conventional organic photochemistry. The T 1 species is a chromacyclopropanone; its unpaired electrons are primarily localized in the metal fragment and in the former carbene carbon atom. The T 1-S 0 intersystem crossing occurs with the participation of the solvent through an unusual loose-bolt radiationless mechanism. The photogenerated S 0 species reacts with imines to form the final β-lactams in a mechanism that resembles the organic Staudinger reaction, but here the metal is present during the entire reaction coordinate. The selectivity of these reactions is defined by the nucleophilic attack on the O-bonded metallaketene instead of the subsequent conrotatory ring closure, a distinct departure from the organic reaction. Appropriate modification of the substituents of the carbene ligand or in the coordination sphere of the complex results in new photoprocesses; these include 1,2-metalladyotropic rearrangements as well as α-fragmentations in which W(0) carbene complexes become photoreactive. Moreover, the inclusion of additional metal centers usually results in new reactions, such as the formation of fulvenes by η 5→ η 3 photoslippage, or in the complete inhibition of the photoreactivity. The photochemistry of group 6 metal-carbene complexes thus offers unexplored territory for pursuing new reactions and reaction mechanisms. © 2011 American Chemical Society.

Banuelos J.,University of the Basque Country
Chemical Record | Year: 2016

BODIPY laser dyes constitute a fascinating topic of research in modern photochemistry due to the large variety of options its chromophore offers, which is ready available for a multitude of synthetic routes. Indeed, in the literature one can find a huge battery of compounds based on the indacene core. The possibility of modulating the spectroscopic properties or inducing new photophysical processes by the substitution pattern of the BODIPY dyes has boosted the number of scientific and technological applications for these fluorophores. Along the following lines, I will overview the main results achieved in our laboratory with BODIPYs oriented to optoelectronic as well to biophotonic applications, stressing the more relevant photophysical issues to be considered in the design of a tailor-made BODIPY for a certain application and pointing out some of the remaining challenges. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sobbrio P.,Catholic University of the Sacred Heart | Jorqui M.,University of the Basque Country
Xenotransplantation | Year: 2014

Background Over time, the notion of public has evolved. While the concept of public was initially conceived of as a single undifferentiated entity, the common understanding is now that a variety of differentiated, multifaceted and multiple public(s) can be constructed for different purposes. This is equally true in xenotransplantation; the literature shows how different kind of publics can be introduced as relevant. The paper explores the notion of public and the contemporary participatory procedures as participatory rights for citizens in decisions concerning technoscience and society. Its perspective, thus, is normative; namely, it aims at understanding how the political role of citizens is changing in democratic societies where matters of innovation are concerned. It is focused on xenotransplantation whose connections with public discourse and practices are quite paradigmatic among new emerging biomedical technologies, due to its peculiar risks.Methods and results The paper reviews the historical background of risk communication and public involvement in science-based decision-making and provides an overview of the current roles and meanings of deliberative procedures in xenotransplantation. After a short discussion of the history of the social implementation of xenotransplantation, the construction of the different publics dealing with this biomedical technology is briefly analysed. Publics have been firstly conceived of as objects of research, which has looked at them to quantify people's positive and negative attitudes towards xenotransplantation. Further developments have led to the notion of the public as composed of citizens, empowered as subjects of decisions. In both Canadian and Australian consultations, citizens were engaged in a complex learning process aimed at committing them to a decision. Despite the fact both public consultations represented important forms of experimental democracy, they were still focused on seeking consensus and assessing compliance from citizens. New Zealand is the most recent example of public consultation in xenotransplantation. Likewise, several public consultations have recently been launched by the European Commission on Advanced Therapies. Unlike in the Canadian and Australian cases, the latter initiatives aimed to reach only certain parts of the population, and the overall consultations were prepared to seek approval. Conclusions Several categories of individuals may be interesting and interested publics in xenotransplantation. This is a field in which the importance of the potential risks that xenotransplants pose to society has been widely discussed. The point is that publics should not only be educated about the risk but should be given an opportunity to participate actively in the decision about whether and under what conditions they are exposed to the risk. Likewise, the boundaries between surveys, consultations and collection of advice may be blurred in actual practices. The hope remains that all different instruments either to collect or disseminate knowledge, and to explore new tools of governance may help connect science and policy to society in deeper and more complex ways. The next step points to a different meaning of public participation. It is shifting from participation as mere consensus and risk acceptance, to public engagement as a form of shared responsibility for risk control and regulatory decision-making. © 2014 John Wiley & Sons A/S Published by John Wiley & Sons Ltd.

Sendra I.,University of the Basque Country | Smith T.L.,University of California at Berkeley | Smith T.L.,University of Tokyo
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

The cosmic microwave background (CMB) is affected by the total radiation density around the time of decoupling. At that epoch, neutrinos comprised a significant fraction of the radiative energy, but there could also be a contribution from primordial gravitational waves with frequencies greater than ∼10 -15Hz. If this cosmological gravitational wave background were produced under adiabatic initial conditions, its effects on the CMB and matter power spectrum would mimic massless noninteracting neutrinos. However, with homogenous initial conditions-as one might expect from certain models of inflation, prebig bang models, phase transitions, and other scenarios-the effect on the CMB would be distinct. We present updated observational bounds for both initial conditions using the latest CMB data at small scales from the South Pole Telescope in combination with Wilkinson Microwave Anisotropy Probe, current measurements of the baryon acoustic oscillations, and the Hubble parameter. With the inclusion of the data from the South Pole Telescope, the adiabatic bound on the cosmological gravitational wave background density is improved by a factor of 1.7 to 106Ω gwh28.7 at the 95% confidence level, with weak evidence in favor of an additional radiation component consistent with previous analyses. The constraint can be converted into an upper-limit on the tension of horizon-sized cosmic strings that could generate this gravitational wave component, with Gμ2×10 -7 at 95% C. L., for string tension Gμ. The homogeneous bound improves by a factor of 3.5 to 106Ω gwh21.0 at 95% C. L., with no evidence for such a component from current data. © 2012 American Physical Society.

Ruiz-Irastorza G.,University of the Basque Country | Crowther M.,McMaster University | Branch W.,University of Utah | Khamashta M.A.,Kings College
The Lancet | Year: 2010

The antiphospholipid syndrome causes venous, arterial, and small-vessel thrombosis; pregnancy loss; and preterm delivery for patients with severe pre-eclampsia or placental insufficiency. Other clinical manifestations are cardiac valvular disease, renal thrombotic microangiopathy, thrombocytopenia, haemolytic anaemia, and cognitive impairment. Antiphospholipid antibodies promote activation of endothelial cells, monocytes, and platelets; and overproduction of tissue factor and thromboxane A2. Complement activation might have a central pathogenetic role. Of the different antiphospholipid antibodies, lupus anticoagulant is the strongest predictor of features related to antiphospholipid syndrome. Therapy of thrombosis is based on long-term oral anticoagulation and patients with arterial events should be treated aggressively. Primary thromboprophylaxis is recommended in patients with systemic lupus erythematosus and probably in purely obstetric antiphospholipid syndrome. Obstetric care is based on combined medical-obstetric high-risk management and treatment with aspirin and heparin. Hydroxychloroquine is a potential additional treatment for this syndrome. Possible future therapies for non-pregnant patients with antiphospholipid syndrome are statins, rituximab, and new anticoagulant drugs. © 2010 Elsevier Ltd.

Reyes Y.,University of the Basque Country
Fluid Phase Equilibria | Year: 2012

Using canonical Monte Carlo simulations, the vapor-liquid phase diagrams of a square-well fluid confined in hard and weakly attractive cylindrical pores are calculated. The critical temperature shows a maximum as a function of the attraction strength between the fluid particle and the pore wall. This maximum is located where the fluid-fluid equals the wall-fluid interaction strengths. With the aid of combined density profiles in the axial and radial directions the maximum of the critical temperature is correlated with the structure of the confined fluid. © 2012 Elsevier B.V.

Gomez-Lobo A.G.-P.,University of Minho | Senovilla J.M.M.,University of the Basque Country
General Relativity and Gravitation | Year: 2013

A number of scalar invariant characterizations of the Kerr solution are presented. These characterizations come in the form of quality factors defined in stationary space-times. A quality factor is a scalar quantity varying in the interval [0,1] with the value 1 being attained if and only if the space-time is locally isometric to the Kerr solution. No knowledge of the Kerr solution is required to compute these quality factors. A number of different possibilities arise depending on whether the space-time is Ricci-flat and asymptotically flat, just Ricci-flat, or Ricci non-flat. In each situation a number of quality factors are constructed and analysed. The relevance of these quality factors is clear in any situation where one seeks a rigorous formulation of the statement that a space-time is "close" to the Kerr solution, such as: its non-linear stability problem, the asymptotic settlement of a radiating isolated system undergoing gravitational collapse, or in the formulation of some uniqueness results. © 2013 Springer Science+Business Media New York.

Saez-Gomez D.,University of the Basque Country
Classical and Quantum Gravity | Year: 2013

Modified f(R) gravity is one of the most promising candidates for dark energy, and even for the unification of the whole cosmological evolution, including the inflationary phase. Within this class of theories, the so-called viable modified gravities represent realistic theories that are capable of reproducing late-time acceleration and satisfy strong constraints at local scales, where general relativity is recovered. This paper deals with the analysis of the cosmological evolution for some of these models, which indicates that the evolution may enter into a phantom phase, but the behavior may be asymptotically stable. Furthermore, the scalar-tensor equivalence of f(R) gravity is considered, which provides useful information about the possibility of the occurrence of a future singularity. The so-called Little Rip and Pseudo-Rip are also studied in the framework of this class of modified gravities. © 2013 IOP Publishing Ltd.

San-Jose Lombera J.-T.,Tecnalia | San-Jose Lombera J.-T.,University of the Basque Country | Garrucho Aprea I.,SEDICAL S.A.
Building and Environment | Year: 2010

The construction sector plays a major role in the development of society. It wields enormous influence over economic activity, employment and growth rates. However, it also has a substantial impact on the natural environment, the effects of which are evident across the world. Over recent decades, pioneering initiatives have proposed environmentally friendly buildings and sustainable construction has centred on residential and office buildings. Nevertheless, further consideration still needs to be given to sustainability in many areas of industrial construction. Accordingly, an Integrated Value Model for Sustainable Assessment (MIVES) is presented in this article that applies a set of six study scopes to define the sustainability criteria of industrial buildings. The system uses a requirements tree to quantify sustainability at various hierarchical levels, in order to assess the behaviour of industrial buildings and compliance with the criteria. Assignment of value functions to the sustainability criteria is then described in the context of a case study of a printing works, which demonstrates the effectiveness of this model at unifying both qualitative and quantitative indicators, in order to arrive at a specific "environmental sustainability index" for the industrial building. © 2009 Elsevier Ltd. All rights reserved.

Escamilla-Rivera C.,University of the Basque Country | Escamilla-Rivera C.,University of Oxford | Banados M.,University of Santiago de Chile | Ferreira P.G.,University of Oxford
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

In this paper, we consider an extension to Eddington's proposal for the gravitational action. We study tensor perturbations of a homogeneous and isotropic space-time in the Eddington regime, where modifications to Einstein gravity are strong. We find that the tensor mode is linearly unstable deep in the Eddington regime and discuss its cosmological implications. © 2012 American Physical Society.

Narros A.,University of Vienna | Moreno A.J.,University of the Basque Country | Moreno A.J.,Donostia International Physics Center | Likos C.N.,University of Vienna
Macromolecules | Year: 2013

We employ extensive computer simulations to investigate the conformations and the interactions of ring polymers under conditions of worsening solvent quality, in comparison with those for linear polymers. We determine the dependence of the Θ-temperature on knotedness by considering ring polymers of different topologies. We establish a clear decrease of the former upon changing the topology of the polymer from linear to an unknotted ring and a further decrease of the same upon introducing trefoil- or 5-fold knots but we find no difference in the Θ-point between the two knotted molecules. Our results are based on two independent methods: one considering the scaling of the gyration radius with molecular weight and one based on the dependence of the effective interaction on solvent quality. In addition, we calculate several shape-parameters of the polymers to characterize linear, unknotted, and knotted topologies in good solvents and in the proximity of the Θ-point. The shape parameters of the knotted molecules show an interesting crossover at a degree of polymerization that depends on the degree of knottedness of the molecule. © 2013 American Chemical Society.

Tokatly I.V.,University of the Basque Country | Tokatly I.V.,Ikerbasque
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

It is shown that an electric field applied to p -doped graphane generates a dissipationless orbital momentum Hall current. In the clean limit the corresponding Hall conductivity is independent of the concentration of holes. The Hall effect is related to the 2π -Berry phase accumulated when heavy and light holes are transported around the degeneracy point in the center of the Brillouin zone. This also leads to the orbital momentum edge currents in the equilibrium state and to the accumulation of the orbital momentum at the edges when the system is driven out of equilibrium. © 2010 The American Physical Society.

Mars M.,University of Salamanca | Mena F.C.,University of Minho | Vera R.,University of the Basque Country
General Relativity and Gravitation | Year: 2013

The Einstein-Straus model consists of a Schwarzschild spherical vacuole in a Friedman-Lemaître-Robertson-Walker (FLRW) dust spacetime (with or without Λ). It constitutes the most widely accepted model to answer the question of the influence of large scale (cosmological) dynamics on local systems. The conclusion drawn by the model is that there is no influence from the cosmic background, since the spherical vacuole is static. Spherical generalizations to other interior matter models are commonly used in the construction of lumpy inhomogeneous cosmological models. On the other hand, the model has proven to be reluctant to admit non-spherical generalizations. In this review, we summarize the known uniqueness results for this model. These seem to indicate that the only reasonable and realistic non-spherical deformations of the Einstein-Straus model require perturbing the FLRW background. We review results about linear perturbations of the Einstein-Straus model, where the perturbations in the vacuole are assumed to be stationary and axially symmetric so as to describe regions (voids in particular) in which the matter has reached an equilibrium regime. © 2013 Springer Science+Business Media New York.

Sokolovski D.,University of the Basque Country | Sokolovski D.,Ikerbasque | Akhmatskaya E.,Basque Center for Applied Mathematics
Annals of Physics | Year: 2013

We analyse in detail the reshaping mechanism leading to apparently 'superluminal' advancement of a wave packet traversing a classically forbidden region. In the coordinate representation, a barrier is shown to act as an effective beamsplitter, recombining envelopes of the freely propagating pulse with various spacial shifts. Causality ensures that none of the constituent envelopes are advanced with respect to free propagation, yet the resulting pulse is advanced due to a peculiar interference effect, similar to the one responsible for 'anomalous' values which occur in Aharonov's 'weak measurements'. In the momentum space, the effect is understood as a bandwidth phenomenon, where the incident pulse probes local, rather than global, analytical properties of the transmission amplitude T (p) The advancement is achieved when T (p) mimics locally an exponential behaviour, similar to the one occurring in Berry's 'superoscillations'. Seen in a broader quantum mechanical context, the 'paradox' is but a consequence of an attempt to obtain 'which way?' information without destroying the interference between the pathways of interest. This explains, to a large extent, the failure to adequately describe tunnelling in terms of a single 'tunnelling time'. © 2013 Elsevier Inc.

Zhang H.,Sichuan University | Miyamoto Y.,Nanosystem Research Institute | Rubio A.,University of the Basque Country
Physical Review Letters | Year: 2012

Helium ion microscopy (HIM), which was released in 2006 by Ward et al., provides nondestructive imaging of nanoscale objects with higher contrast than scanning electron microscopy. HIM measurement of suspended graphene under typical conditions is simulated by first-principles time-dependent density functional theory and the 30 keV He+ collision is found to induce the emission of electrons dependent on the impact point. This finding suggests the possibility of obtaining a highly accurate image of the honeycomb pattern of suspended graphene by HIM. Comparison with a simulation of He0 under the same kinetic energy shows that electron emission is governed by the impact ionization instead of Auger process initiated by neutralization of He+. © 2012 American Physical Society.

Jansen S.C.,Technical University of Delft | Teres-Zubiaga J.,University of the Basque Country | Luscuere P.G.,Technical University of Delft
Energy and Buildings | Year: 2012

In this paper the energy and exergy performance of a social dwelling of a multi-family building from the 1960s in Bilbao (Spain) is presented and various improved energy concepts based on exergy principles are proposed and investigated. The aim of this paper is to explore and demonstrate the usefulness of the exergy approach in the assessment and development of an energy system for the dwelling under consideration. The total energy supply system is analysed, including the demand (space heating, domestic hot water and electricity), the system components (for conversion, storage and distribution) and the energy input from energy resources (primary energy and renewable resources). The study includes a comparison of the primary energy input of all cases considered and an analysis of the energy and exergy losses of each system component. The study has shown that the exergy analysis reveals thermodynamic losses that are not revealed using energy analysis and secondly, that the development of an improved energy system based on exergy principles has resulted in a significantly reduced primary energy input compared to the reference situation. © 2012 Elsevier B.V. All rights reserved.

Feinstein A.,University of the Basque Country
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

I present a solution to the full Einstein-fluid equations representing a self-gravitating Bjorken flow. The motion and the geometry become inhomogeneous in the plane transversal to the flow and the energy density profile acquires, due to gravity, corrections in terms of proper time as compared to the original test hydrodynamics. The transverse distribution of energy density, for example, becomes (τ,r)/(τ,0)= cosh-4(3ar). © 2012 American Physical Society.

Herrera L.,University of the Basque Country | Barreto W.,University of Los Andes, Venezuela
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

It is shown that for a generic electrovacuum spacetime, electromagnetic radiation produces vorticity of worldlines of observers in a Bondi-Sachs frame. Such an effect (and the ensuing gyroscope precession with respect to the lattice) which is a reminiscence of generation of vorticity by gravitational radiation, may be linked to the nonvanishing of components of the Poynting and the super-Poynting vectors on the planes othogonal to the vorticity vector. The possible observational relevance of such an effect is commented upon. © 2012 American Physical Society.

Winter M.,University of Marburg | Chulkov E.V.,Donostia International Physics Center | Chulkov E.V.,University of the Basque Country | Hofer U.,University of Marburg | Hofer U.,Donostia International Physics Center
Physical Review Letters | Year: 2011

Image-potential states have been studied by two-photon photoemission for the surface of Al(100) where the whole series is energetically degenerate with free-electron-like bulk states. In contrast with expectations, the series of resonances is not smeared out to one broad structure as a result of a strong coupling to the bulk continuum. Instead, the first resonance (n=1) is found to be suppressed, and the resonances with quantum numbers n=2,3,4,5 are resolved as individual peaks in the time-resolved spectra. Both effects are suggested to be a consequence of resonance trapping. © 2011 American Physical Society.

Agirrezabala L.M.,University of the Basque Country | Dinares-Turell J.,Italian National Institute of Geophysics and Volcanology
Geological Magazine | Year: 2013

Stratigraphic, structural, palaeocurrent and palaeomagnetic analyses of Upper Albian deep-water deposits in and around the Deba block (Northern Iberia) are presented. Results indicate an anticlockwise vertical-axis rotation of this block by 35° during a maximum time span of c. 1 Ma (Late Albian intra-C. auritus ammonite Subzone). This Albian syndepositional block rotation is interpreted to be the consequence of the coeval activity of conjugate major sinistral strike-slip faults and minor (antithetic) dextral strike-slip faults, which border the Deba block. On the base of conservative estimations, a minimum block-rotation rate of 35° Ma-1 and a sinistral strike-slip rate of 1.2 km Ma-1 are calculated. As a consequence of the interaction of the rotated Deba block with adjacent non-rotated blocks, its corners experienced coeval transpressive (NW and SE corners) and transtensional deformations (SW and, possibly, NE corners). At the transtensional SW corner, two domal high-reflective seismic structures have been recorded and interpreted as high-level magmatic laccoliths. These magmatic intrusions triggered the development of a mineralizing hydrothermal system, which vented to the Late Albian seafloor warm to hot hydrocarbon-rich fluids. Vented hydrocarbon was generated from Albian organic-rich sediments by contact alteration with hydrothermal fluids. © 2013 Cambridge University Press.

Marzari N.,Theory and Simulation of Materials THEOS | Mostofi A.A.,Imperial College London | Yates J.R.,University of Oxford | Souza I.,University of the Basque Country | And 2 more authors.
Reviews of Modern Physics | Year: 2012

The electronic ground state of a periodic system is usually described in terms of extended Bloch orbitals, but an alternative representation in terms of localized "Wannier functions" was introduced by Gregory Wannier in 1937. The connection between the Bloch and Wannier representations is realized by families of transformations in a continuous space of unitary matrices, carrying a large degree of arbitrariness. Since 1997, methods have been developed that allow one to iteratively transform the extended Bloch orbitals of a first-principles calculation into a unique set of maximally localized Wannier functions, accomplishing the solid-state equivalent of constructing localized molecular orbitals, or "Boys orbitals" as previously known from the chemistry literature. These developments are reviewed here, and a survey of the applications of these methods is presented. This latter includes a description of their use in analyzing the nature of chemical bonding, or as a local probe of phenomena related to electric polarization and orbital magnetization. Wannier interpolation schemes are also reviewed, by which quantities computed on a coarse reciprocal-space mesh can be used to interpolate onto much finer meshes at low cost, and applications in which Wannier functions are used as efficient basis functions are discussed. Finally the construction and use of Wannier functions outside the context of electronic-structure theory is presented, for cases that include phonon excitations, photonic crystals, and cold-atom optical lattices. © 2012 American Physical Society.

Men'shov V.N.,RAS Research Center Kurchatov Institute | Tugushev V.V.,RAS Research Center Kurchatov Institute | Chulkov E.V.,University of the Basque Country
JETP Letters | Year: 2013

We show that, when a three-dimensional (3D) narrow-gap semiconductor with inverted band gap ("topological insulator," TI) is attached to a 3D wide-gap semiconductor with non-inverted band gap ("normal insulator," NI), two types of bound electron states having different spatial distributions and spin textures arise at the TI/NI interface. Namely, the gapless ("topological") bound state can be accompanied by the emergence of the gapped ("ordinary") bound state. We describe these states in the framework of the envelope function method using a variational approach for the energy functional; their existence hinges on the ambivalent character of the constraint for the envelope functions that correspond to the "open" or "natural" boundary conditions at the interface. The properties of the ordinary state strongly depend on the effective interface potential, while the topological state is insensitive to the interface potential variation. © 2013 Pleiades Publishing, Ltd.

Schelling X.,Basquet Manresa SAD | Calleja-Gonzalez J.,University of the Basque Country | Torres-Ronda L.,National Institute of Physical Education of Catalonia INEFC | Terrados N.,University of Oviedo
Journal of Strength and Conditioning Research | Year: 2015

The purpose of this study was to determine the responses of testosterone and cortisol, with special reference to playing positions, playing time (PT), and phase of the season. We performed a follow-up study during 4 consecutive seasons to investigate the effects of PT, positional role, and phase of the season on anabolic-catabolic biomarkers (plasma total testosterone -TT- and cortisol -C-) on 20 professional male basketball players (27.0 ± 4.2 years; 24.4 ± 1.2 kg·m-2). First blood samples were collected right after the off-season period and considered as baseline. Samples were taken periodically every 4-6 weeks, always after a 24- to 36-hour break after the last game played. Statistical procedures were nonparametric mainly. Hormonal status was playing position-dependent, power forward (PF) showed the lowest TT values (median ± interquartile range [IQR]; PF: 18.1 ± 4.9; nmol·L-1), and small forwards showed the highest ones of cortisol (0.55 ± 0.118 mmol·L-1). Players who played between 13 and 25 minutes per game showed the highest values of TT (22.8 ± 6.9 nmol·L-1) and TT/C (47.1 ± 21.2). March and April showed the most catabolic or stressed hormonal state (low TT/C values and high ones of cortisol) and that is necessary to take into account according to PT (>25-minute per game) and specific playing position. Monitoring plasma TT and cortisol is recommended to prevent excessive stress caused by professional basketball season requirements.

Lathiotakis N.N.,National Hellenic Research Foundation | Helbig N.,Julich Research Center | Rubio A.,University of the Basque Country | Gidopoulos N.I.,Durham University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We propose a scheme to bring reduced-density-matrix-functional theory into the realm of density functional theory (DFT) that preserves the accurate density functional description at equilibrium, while incorporating accurately static and left-right correlation effects in molecules and keeping the good computational performance of DFT-based schemes. The key ingredient is to relax the requirement that the local potential is the functional derivative of the energy with respect to the density. Instead, we propose to restrict the search for the approximate natural orbitals within a domain where these orbitals are eigenfunctions of a single-particle Hamiltonian with a local effective potential. In this way, fractional natural occupation numbers are accommodated into Kohn-Sham equations allowing for the description of molecular dissociation without breaking spin symmetry. Additionally, our scheme provides a natural way to connect an energy eigenvalue spectrum to the approximate natural orbitals and this spectrum is found to represent accurately the ionization potentials of atoms and small molecules. © 2014 American Physical Society.

D'Agosta R.,University of the Basque Country | D'Agosta R.,Ikerbasque
Physical Chemistry Chemical Physics | Year: 2013

Research on thermoelectrical energy conversion, the reuse of waste heat produced by some mechanical or chemical processes to generate electricity, has recently gained some momentum. The calculation of the electronic parameters entering the figure of merit of this energy conversion, and therefore the discovery of efficient materials, is usually performed starting from Landauer's approach to quantum transport coupled with Onsager's linear response theory. As it is well known, this approach suffers from certain serious drawbacks. Here, we discuss alternative dynamical methods that can go beyond the validity of Landauer's/Onsager's approach for electronic transport. They can be used to validate the predictions of Landauer's/Onsager's approach and to investigate systems for which this approach has been shown to be unsatisfactory. © 2013 The Owner Societies.

Sorochinsky A.E.,University of the Basque Country | Soloshonok V.A.,Ikerbasque
Topics in Current Chemistry | Year: 2013

This review describes self-disproportionation of enantiomers (SDE) of non-racemic mixtures, subjected to distillation, sublimation, or chromatography on achiral stationary phase using achiral eluent, which leads to the substantial enantiomeric enrichment and corresponding depletion in different fractions, as compared to the enantiomeric composition of the starting material. This phenomenon is of a very general nature as SDE has been reported for different classes of chiral organic compounds bearing various functional groups and possessing diverse elements of chirality. The literature data discussed in this review clearly suggests that SDE is typical for enantiomerically enriched chiral organic compounds and special care should always be taken in evaluation of the stereochemical outcome of enantioselective reactions as well as determination of enantiomeric ratios of non-racemic mixtures of natural products after any purification process. The role of molecular association of enantiomers on the magnitude and preparative efficiency of SDE, as a new, nonconventional method for enantiomerc purifications, is emphasized and discussed. © 2013 Springer International Publishing Switzerland.

Elosegi A.,University of the Basque Country | Sabater S.,Catalan Institute for Water Research | Sabater S.,University of Girona
Hydrobiologia | Year: 2013

Because of the serious effects of pollution on water supply much closer attention has been paid to water quality than to other aspects of river integrity. However, channel form and water flow are relevant components of river health, and recent evidences show that their impairment threatens the services derived from them. In this article, we review the literature on the effects of common hydromorphological impacts (channel modification and flow mo