Optimisation of the first principle code Octopus for massive parallel architectures: application to light harvesting complexes

150 p.

Term Structure and the Estimated Monetary Policy Rule in the Eurozone

Published as an article in: Spanish Economic Review, 2008, vol. 10, issue 4, pages 251-277.

The Weekend-Dividend Effect in the Spanish Market

Revised: 2006-05

First-principles study of the electronic and magnetic properties of defective carbon nanostructures

149 p.: graf.

Astarloaren sintaxia eta hitz ordena naturala

[EN] This paper examines the syntactic ideas of Pablo Pedro Astarloa (1752-1806) as he explained in his Discursos filosóficos sobre la lengua primitiva (1805), and tries to put them in the context of the debate between rationalists and sensualists, who argued whether there is a «natural order» of words. Astarloa developed a system for accounting the word order in the primitive language of mankind (and hence in the Basque language) founded in three types of «nobleness», and in the principle that the noblest element precedes the less noble one. The first type (nobleza de origen) orders words according to their meaning. The second type (nobleza de ministerio) orders words according to the part of speech they belong to, or the semantic function they have. Finally, the third type (nobleza de mérito or de movilidad) considers the will for communication and, as a result, word order reflects the information structure. Moreover Astarloa ’s three types of nobleness are arranged in a hierarchy of superiority: movilidad > ministerio > origen. So Astarloa ’s syntax appears near to sensualists ’ conceptions on word order because it did not appeal for a fixed natural order of words; instead he proposed a variable word order based mainly on the communicative process.

Territorial Integrity and Self-Determination : The Approach of the International Court of Justice in the Advisory Opinion on Kosovo

[EN] On 17 February 2008 Kosovo approved its declaration of independence from Serbia. The declaration was raised as a unilateral secession, a category which to date is widely debated by the international community, but supported in that case by a respectable number of the United Nation member states. A great many legal issues have been raised by the International Court of Justice's Advisory Opinion on Kosovo. This opinion was eagerly awaited by legal scholars due to both its possible effects and the scope of its principles outside the context of decolonization in what it could constitute of new approach to the international scenario for the twenty-first century. The ICJ stated that the declaration of independence was in accordance with international law if it was not prohibited. The answer turned on whether or not international law prohibited the declaration of independence, without ever examining whether an entity seeking secession is entitled with a positive right to secede and if so, under which circumstances. The basic issue can be summarised as whether or not we are facing a new course in the interpretation of certain classical categories of international law: the principle of territorial integrity, statehood, sovereignty, recognition, the right to external self-determination, etc. In this study we shall analyse some of the aspects arising from the Advisory Opinion of the International Court of Justice on the Accordance with international law of the unilateral declaration of independence in respect of Kosovo focusing on the territorial issue. Firstly we shall analyse the scope of the principle of territorial integrity of States and how it operates ; secondly, we shall focus on the scope of that principle in relation to the interior of the State, and ask ourselves how international law operates in relation to declarations of independence. Lastly, we shall deal with the principle of respect for territorial integrity in the specific case of Serbia with respect to Kosovo, and then end with a series of general conclusions. This study aims, definitely, to contribute to the theoretical debate on the challenges to the traditional certainties of international law in this area.

Plasma brain-derived neurotrophic factor levels, learning capacity and cognition in patients with first episode psychosis

Background: Cognitive impairments are seen in first psychotic episode (FEP) patients. The neurobiological underpinnings that might underlie these changes remain unknown. The aim of this study is to investigate whether Brain Derived Neurotrophic Factor (BDNF) levels are associated with cognitive impairment in FEP patients compared with healthy controls. Methods: 45 FEP patients and 45 healthy controls matched by age, gender and educational level were selected from the Basque Country area of Spain. Plasma BDNF levels were assessed in healthy controls and in patients. A battery of cognitive tests was applied to both groups, with the patients being assessed at 6 months after the acute episode and only in those with a clinical response to treatment. Results: Plasma BDNF levels were altered in patients compared with the control group. In FEP patients, we observed a positive association between BDNF levels at six months and five cognitive domains (learning ability,immediate and delayed memory, abstract thinking and processing speed) which persisted after controlling for medications prescribed, drug use, intelligence quotient (IQ) and negative symptoms. In the healthy control group, BDNF levels were not associated with cognitive test scores. Conclusion: Our results suggest that BDNF is associated with the cognitive impairment seen after a FEP. Further investigations of the role of this neurotrophin in the symptoms associated with psychosis onset are warranted.

First-principles study of the electronic structure and dynamical electronic excitations of strong spin-orbit metal Pb: bulk, surface and nanosized films

En la presente tesis se ha realizado el estudio de primeros principios (esto es, sinhacer uso de parámetros ajustables) de la estructura electrónica y la dinámica deexcitaciones electrónicas en plomo, tanto en volumen como en superficie y en formade películas de espesor nanométrico. Al presentar el plomo un número atómico alto(82), deben tenerse en cuenta los efectos relativistas. Con este fin, el doctorando haimplementado el acoplo espín-órbita en los códigos computacionales que hanrepresentado la principal herramienta de trabajo.En volumen, se han encontrado fuertes efectos relativistas asi como de lalocalización de los electrones, tanto en la respuesta dieléctrica (excitacioneselectrónicas colectivas) como en el tiempo de vida de electrones excitados. Lacomparación de nuestros resultados con medidas experimentales ha ayudado aprofundizar en dichos efectos.En el estudio de las películas a escala nanométrica se han hallado fuertes efectoscuánticos debido al confinamiento de los estados electrónicos. Dichos efectos semanifiestan tanto en el estado fundamental (en acuerdo con estudiosexperimentales), como en la respuesta dieléctrica a través de la aparición y dinámicade plasmones de diversas características. Los efectos relativistas, a pesar de no serimportantes en la estructura electrónica de las películas, son los responsables de ladesaparación del plasmón de baja energía en nuestros resultados.

Cannabis use and involuntary admission may mediate long-term adherence in first-episode psychosis patients: a prospective longitudinal study

Background: This study aimed to examine factors associated with treatment adherence in first-episode psychosis (FEP) patients followed up over 8 years, especially involuntary first admission and stopping cannabis use. Methods: This prospective, longitudinal study of FEP patients collected data on symptoms, adherence, functioning,and substance use. Adherence to treatment was the main outcome variable and was categorized as ‘good’ or ‘bad’. Cannabis use during follow-up was stratified as continued use, stopped use, and never used. Bivariate and logistic regression models identified factors significantly associated with adherence and changes in adherence over the 8-year follow-up period. Results: Of the 98 FEP patients analyzed at baseline, 57.1% had involuntary first admission, 74.4% bad adherence,and 52% cannabis use. Good adherence at baseline was associated with Global Assessment of Functioning score (p = 0.019), Hamilton Depression Rating Scale score (p = 0.017) and voluntary admission (p < 0.001). Adherence patterns over 8 years included: 43.4% patients always bad, 26.1% always good, 25% improved from bad to good. Among the improved adherence group, 95.7% had involuntary first admission and 38.9% stopped cannabis use. In the subgroup of patients with bad adherence at baseline, involuntary first admission and quitting cannabis use during follow up were associated with improved adherence. Conclusions: The long-term association between treatment adherence and type of first admission and cannabis use in FEP patients suggest targets for intervention to improve clinical outcomes.

First occurrence of Mosasauridae (Squamata) in the Maastrichtian (latest Cretaceous) of Alicante (Valencia Community, Eastern Spain)

8 p.

The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implication

14 p.

The Equivalency Principle for Discounting the Value of Natural Assets: An Application to an Investment Project in the Basque Coast

25 p.

Ab initio study of anharmonicity in high pressure Cmca-4 metallic hydrogen

Hydrogen is the only atom for which the Schr odinger equation is solvable. Consisting only of a proton and an electron, hydrogen is the lightest element and, nevertheless, is far from being simple. Under ambient conditions, it forms diatomic molecules H2 in gas phase, but di erent temperature and pressures lead to a complex phase diagram, which is not completely known yet. Solid hydrogen was rst documented in 1899 [1] and was found to be isolating. At higher pressures, however, hydrogen can be metallized. In 1935 Wigner and Huntington predicted that the metallization pressure would be 25 GPa [2], where molecules would disociate to form a monoatomic metal, as alkali metals that lie below hydrogen in the periodic table. The prediction of the metallization pressure turned out to be wrong: metallic hydrogen has not been found yet, even under a pressure as high as 320 GPa. Nevertheless, extrapolations based on optical measurements suggest that a metallic phase may be attained at 450 GPa [3]. The interest of material scientist in metallic hydrogen can be attributed, at least to a great extent, to Ashcroft, who in 1968 suggested that such a system could be a hightemperature superconductor [4]. The temperature at which this material would exhibit a transition from a superconducting to a non-superconducting state (Tc) was estimated to be around room temperature. The implications of such a statement are very interesting in the eld of astrophysics: in planets that contain a big quantity of hydrogen and whose temperature is below Tc, superconducting hydrogen may be found, specially at the center, where the gravitational pressure is high. This might be the case of Jupiter, whose proportion of hydrogen is about 90%. There are also speculations suggesting that the high magnetic eld of Jupiter is due to persistent currents related to the superconducting phase [5]. Metallization and superconductivity of hydrogen has puzzled scientists for decades, and the community is trying to answer several questions. For instance, what is the structure of hydrogen at very high pressures? Or a more general one: what is the maximum Tc a phonon-mediated superconductor can have [6]? A great experimental e ort has been carried out pursuing metallic hydrogen and trying to answer the questions above; however, the characterization of solid phases of hydrogen is a hard task. Achieving the high pressures needed to get the sought phases requires advanced technologies. Diamond anvil cells (DAC) are commonly used devices. These devices consist of two diamonds with a tip of small area; for this reason, when a force is applied, the pressure exerted is very big. This pressure is uniaxial, but it can be turned into hydrostatic pressure using transmitting media. Nowadays, this method makes it possible to reach pressures higher than 300 GPa, but even at this pressure hydrogen does not show metallic properties. A recently developed technique that is an improvement of DAC can reach pressures as high as 600 GPa [7], so it is a promising step forward in high pressure physics. Another drawback is that the electronic density of the structures is so low that X-ray di raction patterns have low resolution. For these reasons, ab initio studies are an important source of knowledge in this eld, within their limitations. When treating hydrogen, there are many subtleties in the calculations: as the atoms are so light, the ions forming the crystalline lattice have signi cant displacements even when temperatures are very low, and even at T=0 K, due to Heisenberg's uncertainty principle. Thus, the energy corresponding to this zero-point (ZP) motion is signi cant and has to be included in an accurate determination of the most stable phase. This has been done including ZP vibrational energies within the harmonic approximation for a range of pressures and at T=0 K, giving rise to a series of structures that are stable in their respective pressure ranges [8]. Very recently, a treatment of the phases of hydrogen that includes anharmonicity in ZP energies has suggested that relative stability of the phases may change with respect to the calculations within the harmonic approximation [9]. Many of the proposed structures for solid hydrogen have been investigated. Particularly, the Cmca-4 structure, which was found to be the stable one from 385-490 GPa [8], is metallic. Calculations for this structure, within the harmonic approximation for the ionic motion, predict a Tc up to 242 K at 450 GPa [10]. Nonetheless, due to the big ionic displacements, the harmonic approximation may not su ce to describe correctly the system. The aim of this work is to apply a recently developed method to treat anharmonicity, the stochastic self-consistent harmonic approximation (SSCHA) [11], to Cmca-4 metallic hydrogen. This way, we will be able to study the e ects of anharmonicity in the phonon spectrum and to try to understand the changes it may provoque in the value of Tc. The work is structured as follows. First we present the theoretical basis of the calculations: Density Functional Theory (DFT) for the electronic calculations, phonons in the harmonic approximation and the SSCHA. Then we apply these methods to Cmca-4 hydrogen and we discuss the results obtained. In the last chapter we draw some conclusions and propose possible future work.

Automatically exposing OpenLifeData via SADI semantic Web Services

Background: Two distinct trends are emerging with respect to how data is shared, collected, and analyzed within the bioinformatics community. First, Linked Data, exposed as SPARQL endpoints, promises to make data easier to collect and integrate by moving towards the harmonization of data syntax, descriptive vocabularies, and identifiers, as well as providing a standardized mechanism for data access. Second, Web Services, often linked together into workflows, normalize data access and create transparent, reproducible scientific methodologies that can, in principle, be re-used and customized to suit new scientific questions. Constructing queries that traverse semantically-rich Linked Data requires substantial expertise, yet traditional RESTful or SOAP Web Services cannot adequately describe the content of a SPARQL endpoint. We propose that content-driven Semantic Web Services can enable facile discovery of Linked Data, independent of their location. Results: We use a well-curated Linked Dataset - OpenLifeData - and utilize its descriptive metadata to automatically configure a series of more than 22,000 Semantic Web Services that expose all of its content via the SADI set of design principles. The OpenLifeData SADI services are discoverable via queries to the SHARE registry and easy to integrate into new or existing bioinformatics workflows and analytical pipelines. We demonstrate the utility of this system through comparison of Web Service-mediated data access with traditional SPARQL, and note that this approach not only simplifies data retrieval, but simultaneously provides protection against resource-intensive queries. Conclusions: We show, through a variety of different clients and examples of varying complexity, that data from the myriad OpenLifeData can be recovered without any need for prior-knowledge of the content or structure of the SPARQL endpoints. We also demonstrate that, via clients such as SHARE, the complexity of federated SPARQL queries is dramatically reduced.

Spinal circuits can accommodate interaction torques during multijoint limb movements

The dynamic interaction of limb segments during movements that involve multiple joints creates torques in one joint due to motion about another. Evidence shows that such interaction torques are taken into account during the planning or control of movement in humans. Two alternative hypotheses could explain the compensation of these dynamic torques. One involves the use of internal models to centrally compute predicted interaction torques and their explicit compensation through anticipatory adjustment of descending motor commands. The alternative, based on the equilibrium-point hypothesis, claims that descending signals can be simple and related to the desired movement kinematics only, while spinal feedback mechanisms are responsible for the appropriate creation and coordination of dynamic muscle forces. Partial supporting evidence exists in each case. However, until now no model has explicitly shown, in the case of the second hypothesis, whether peripheral feedback is really sufficient on its own for coordinating the motion of several joints while at the same time accommodating intersegmental interaction torques. Here we propose a minimal computational model to examine this question. Using a biomechanics simulation of a two-joint arm controlled by spinal neural circuitry, we show for the first time that it is indeed possible for the neuromusculoskeletal system to transform simple descending control signals into muscle activation patterns that accommodate interaction forces depending on their direction and magnitude. This is achieved without the aid of any central predictive signal. Even though the model makes various simplifications and abstractions compared to the complexities involved in the control of human arm movements, the finding lends plausibility to the hypothesis that some multijoint movements can in principle be controlled even in the absence of internal models of intersegmental dynamics or learned compensatory motor signals.