RCeveierwamide and ceramide 1-phosphate in health and disease

Sphingolipids are essential components of cell membranes, and many of them regulate vital cell functions. In particular, ceramide plays crucial roles in cell signaling processes. Two major actions of ceramides are the promotion of cell cycle arrest and the induction of apoptosis. Phosphorylation of ceramide produces ceramide 1-phosphate (C1P), which has opposite effects to ceramide. C1P is mitogenic and has prosurvival properties. In addition, C1P is an important mediator of inflammatory responses, an action that takes place through stimulation of cytosolic phospholipase A2, and the subsequent release of arachidonic acid and prostaglandin formation. All of the former actions are thought to be mediated by intracellularly generated C1P. However, the recent observation that C1P stimulates macrophage chemotaxis implicates specific plasma membrane receptors that are coupled to Gi proteins. Hence, it can be concluded that C1P has dual actions in cells, as it can act as an intracellular second messenger to promote cell survival, or as an extracellular receptor agonist to stimulate cell migration.

Bienestar subjetivo en el ámbito rural

El presente estudio se centra en el concepto de bienestar psicológico subjetivo, componente cualitativo de la calidad de vida y, por lo tanto, de especial relevancia en la intervención socioeducativa. El objetivo principal ha sido la valoración del bienestar subjetivo de la población en el medio rural. Se ha desarrollado en Matallana de Torio, un municipio de León de 1397 habitantes, participando en el mismo 318 personas adultas entre 18 y 86 años. Se analizó la literatura existente para valorar, por un lado, la importancia del concepto de bienestar subjetivo en relación con el de felicidad y con el de calidad de vida. Por otro lado, se exponen las concepciones sobre el medio rural para aproximarnos a una idea común acerca de este concepto tan cercano pero tan poco analizado desde este enfoque. Para llevar a cabo este análisis, se ha optado por una metodología cuantitativa, cuya naturaleza descriptiva, permite obtener resultados generalizables. Se han utilizado las escalas de Ryff, por constituir un instrumento de análisis del bienestar subjetivo contrastado y fiable. Los principales resultados derivados del análisis de datos indican niveles por debajo de la media en las dimensiones analizadas como: autoaceptación, relaciones positivas, autonomía, dominio del entorno, crecimiento personal y propósito en la vida. Este resultado puede estar relacionado con la variable cultural y las limitaciones derivadas de la escasez de servicios socioeducativos que se encuentran las personas en el ámbito rural.

Lehen Hezkuntzako ikasleen jarrerak matematikarekiko

Lan honetan Alonsotegiko ikastetxeko 6. mailako ikasleek matematikarekiko dituzten jarrerak aztertu izan dira; konkretuki antsietatea, konfiantza, motibazioa, matematikari esleitutako balioa eta gustua. Matematikarekiko jarrerak aztertu beharreko gaia direla uste dut, eremu afektiboaren osagai izanda eragin zuzena dutelako ikasleen eremu kognitiboan zein lortutako emaitzetan. Jarrerak neurtzeko ikerketa kuantitatiboa eta ikerketa kualitatiboa egin izan dira. Lehenengoa Likert motako 13 item-eko ikasleentzako galdetegiaren bidez egin da eta bigarrena irakaslearen iritzia jasotzera bideratutako galdetegi irekiaren bidez. Emaitzek matematikarekiko jarrera positiboak erakutsi dituzte. Generoaren araberako desberdintasunak daude eta mutilak dira matematikarekiko jarrera positiboagoak erakusten dituztenak.

Development of a new modelling framework to estimate the C footprint from Basque dairy farms

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Análisis de la evolución del patrimonio neto de empresas del sector energético a través del estado de cambios en el patrimonio neto.(Período 2011-2013)

Este trabajo trata de analizar el patrimonio neto de empresas del sector energético, a través del Estado de Cambios en el Patrimonio Neto. Se estructura en 4 partes, cada una corresponde a una empresa distinta. El análisis se basa fundamentalmente en dos puntos: - Estudio del Activo, Pasivo y Patrimonio Neto de la empresa a grandes rasgos con la ayuda de gráficos y ratios (ratio de inmovilización, fondo de maniobra y ratio de autonomía financiera), a fin de presentar los principales datos de cada entidad. - Análisis detallado de los cambios acontecidos en el Patrimonio Neto a través del Estado Total de Cambios en el Patrimonio Neto y del Estado de Ingresos y Gastos Reconocidos, en cada uno de los años objeto de estudio, haciendo especial énfasis en la política de aplicación de resultados. Para finalizar, he realizado las conclusiones en las cuales comparo las principales y más importantes magnitudes de cada empresa: total de Activo, Fondo de Maniobra, Autonomía Financiera, evolución del Patrimonio Neto, Resultado del ejercicio y distribución de dividendos.

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.