On the local existence of maximal slicings in spherically symmetric spacetimes

In this talk we show that any spherically symmetric spacetime admits locally a maximal spacelike slicing. The above condition is reduced to solve a decoupled system of first order quasi-linear partial differential equations. The solution may be accomplished analytical or numerically. We provide a general procedure to construct such maximal slicings.Comment: 4 pages. Accepted for publication in Journal of Physics: Conference Series, Proceedings of the Spanish Relativity Meeting ERE200

Optimización mediante algoritmos genéticos de la gestión del agua en el regadío

El uso de un recurso como el agua, esencial y escaso, tiene gran trascendencia ambiental, social, económica, política, etc., siendo su adecuada gestión fundamental para conseguir la sostenibilidad de sus aprovechamientos. Para alcanzar ese objetivo, la agricultura actual necesita modelos de ayuda a la toma de decisiones para la gestión y explotación agrícola. Se presenta un modelo de optimización del plan productivo en una explotación agrícola. El proceso de optimización parte de la curva que relaciona el margen bruto de los cultivos con la lámina bruta de riego descargada por el sistema y busca la alternativa de cultivos y los volúmenes estacionales brutos de riego que maximizan el margen bruto en la explotación en su conjunto. El modelo se ha aplicado en Castilla La Mancha, concretamente en el Sistema Hidrogeológico 08.29, obteniendo excelentes resultados. Las especies seleccionadas para formar parte de la alternativa de cultivos son las que ofrecen un mayor margen bruto, incluso las que presentan elevados requerimientos hídricos en los años secos. Las características de nuestro problema, con muchas variables implicadas, un amplio campo de búsqueda de las soluciones y la existencia de un gran número de máximos locales hacen que las técnicas de optimización basadas en los algoritmos evolutivos (genéticos), que guían la búsqueda estocástica de la mejor solución, resulten muy eficientes.Peer Reviewe

Los Madriles : pasatiempo cómico-lírico en dos actos y diez cuadros

En la port.: Representado en Madrid, en el Teatro del Príncipe Alfonso el 22 de junio de 1877

Alteraciones en la permeabilidad de liposomas unilamelares causadas por la presencia de sistemas mixtos de los tensioactivos dodecilbetaina y dodecilsulfato sódico.

Se investigan las alteraciones en la permeabilidad de liposomas unilamelares promovidas por la presencia de sistemas mixtos de los tensioactivos dodecilbetaina (C12-Bet)/dodecil sulfato sodico (SDS). A tal fin, se han determinado los coeficientes de partición de dichos sistemas de tensioactivos para diferentes relaciones molares del tensioactivo anfotérico al distribuirse entre la fase acuosa y la bicapa lipídica de liposomas constituídos por vesículas unilamelares de un tamaño aproximado de 100 nm. La composición lipídica de los liposomas fue fosfatidilcolina y acido fosfatídico (relación molar 9:1). Se determinó la permeabilidad del agente fluorescente 5-(6) carboxifluoresceina encapsulado en dichas bicapas a concentraciones subsolubilizantes. Puede establecerse que cuando la fracción molar de los sistemas C12-Bet/SDS es de 0.4, la concentración micelar crítica de dichos sistemas presenta un valor mínimo mientras que su coeficiente de partición es máximo. Existe una correlación directa entre la capacidad permebilizante de los sistemas estudiados y sus coeficientes de partición.The alterations due to betaine-type zwitterionic and anionic surfactant mixed systems in the permeability of unilamellar liposomes have been investigated. The partition coefficient of these systems at different molar fractions, between the aqueous phase and the lipid bilayer of liposomes has been determined. These surfactant mixed systems were formed by N-dodecyl-N,N-dimethylbetaine (C12-Bet) and sodium dodecyl sulphate (SDS) in the presence on 20 mM PIPES buffer and 110 mM Na2 SO4 at pH 7.21. Unilamellar liposomes were prepared from egg phosphatldylcholine and phosphatidic acid (9:1 molar ratio). The release of the fluorescent agent 5-(6)carboxyfluorescein induced by the systems has been studied at sub-solubilizing concentrations. When the molar fraction of C12-Bet/SDS is about 0.4, the critical micelle concentration values of these systems exhibit a minimum, whereas their partition coefficient between the aqueous phase and lipid bilayer of lipid bilayers shows a maximum. There is a consistent correlation between the partition coefficient and the ability of the different systems of surfactants to modify the permeability of liposomes.On fait des recherches sur les altérations dans la perméabilité de liposomes unilamellaires provoquées par la présence de systèmes mixtes des tensio-actifs dodécyl bétaine (C12-Bet)/dodécyl sulfate sodique (SDS). Dans cet objectif, on a déterminé les coeficients de partition molaires du tensio-actif amphotérique, se répartissant entre la phase aqueuse et la bicouche lipidique de liposomes constitués par des vesicules unilamellaires d'une grandeur aproximative de 100 nm. La composition lipidique des liposomes a été phosphatidyl choline et acide phosphatidique (relation molaire 9.7). On a déterminé la perméabilité de l'agent fluorescent 5-(6) carboxyfluorescéine encapsulé dans lesdites bicouches à des concentrations subsolubilisantes. On peut établir que, lorsque la fraction molaire des systemes C12-Bet/SDS est de 0,4, la concentration micellaire critique desdits systemes présente una valeur minimum alors que son coefficient de partition est maximum. Il existe une corrélation directe entre la capacité perméabilisante des systemes étudiés et leurs coefficients de partition.Peer Reviewe

Colección de varios monumentos antiguos y otras piezas curiosas sacadas con la mayor fidelidad de documentos originales [Manuscrito]

Contiene: "Real Panteon de San Juan de la Peña en que se conserban las venerables cenizas de los serenissimos reyes de Aragon y Navarra..." y otros documentosCopia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación bibliotecaria, 2018Manuscrito dedicado al conde de Floridablanc

Modelos animales para la investigación de priones

Spongiform encefalopathies are a group of diseases with very long incubation times, during which the pathogenic isoform PrPres accumulates slowly in the brain, till it reaches a high enough concentration as to develop clinical signs. To study these diseases, and especially to determine the etiological relationships between the PrPres from different diseases, animal models are used, mostly transgenic mice, in which their own Prnp gene is substituted by that from other species. In this way, the lesions and vacuolization pattern, as well as the Western Blot profile is like those in the original species, with the advantage that the course of the disease is faster and the convenience of infrastructures and ethical considerations of working with mice.Las encefalopatías espongiformes constituyen un grupo de enfermedades con un periodo de incubación muy largo, durante el cual la isoforma patógena PrPres se acumula lentamente en el cerebro hasta que alcanza suficiente concentración como para que se manifiesten los síntomas. Para el estudio de las mismas, y sobre todo para determinar las relaciones etiológicas entre los PrPres de distintas enfermedades se recurre al empleo de modelos animales, especialmente los ratones transgénicos, en los que se ha sustituido su propio gen Prnp por el de otra especie. De esta forma, el patrón lesional, de vacuolización y de Western Blot es igual que en la especie original, con la ventaja de que la enfermedad se produce más rápidamente y la comodidad de infraestructuras y ética de trabajar con ratones

Modelos animales para la investigación de priones

Las encefalopatías espongiformes constituyen un grupo de enfermedades con un periodo de incubación muy largo, durante el cual la isoforma patógena PrPres se acumula lentamente en el cerebro hasta que alcanza suficiente concentración como para que se manifiesten los síntomas. Para el estudio de las mismas, y sobre todo para determinar las relaciones etiológicas entre los PrPres de distintas enfermedades se recurre al empleo de modelos animales, especialmente los ratones transgénicos, en los que se ha sustituido su propio gen Prnp por el de otra especie. De esta forma, el patrón lesional, de vacuolización y de Western Blot es igual que en la especie original, con las ventajas de que la enfermedad se produce más rápidamente y la comodidad de infraestructuras y ética de trabajar con ratones.Spongiform encefalopathies are a group of diseases with very long incubation times, during which the pathogenic isoform PrPres accumulates slowly in the brain, till it reaches a high enough concentration as to develop clinical signs. To study these diseases, and especially to determine the etiological relationships between the PrPres from different diseases, animal models are used, mostly transgenic mice, in which their own Prnp gene is substituted by that from other species. In this way, the lesions and vacuolization pattern, as well as the Western Blot profile are like those in the original species, with the advantage that the course of the disease is faster and the convenience of infrastructures and ethical considerations of working with mice

Late Holocene Aleppo pine (Pinus halepensis Miller) woodlands in Mallorca (Balearic Islands, Western Mediterranean): Investigation of their distribution and the role of human management based on anthracological, dendro-anthracological and archaeopalynological data

The pioneering nature of Mediterranean pines and their phytosociological role have been largely discussed in relation to different agents (e.g., edaphic, climatic or anthropogenic). In this context, Aleppo pine is one of the most widespread pine species in the Mediterranean basin, as it is especially adapted to climatic constraints, such as drought and high seasonality, and has a high tolerance for salinity and strong coastal winds. It is also well adapted to regeneration after anthropogenic landscape disturbances, highlighting its important after-fire regeneration rates. In this sense, phytosociological studies conducted in Mediterranean landscapes have found that this species'' wide distribution is mostly due to its rapid regeneration after human landscape transformation, including fire, and the abandonment of agricultural lands. Aleppo pine is considered to broadly develop after human action in sclerophyllous formation, in which it would be scarce or absent without human intervention. Parallel, paleoenvironmental and archaeobotanical studies have attempted to trace these trends back to prehistoric times to investigate this species'' role in Late Pleistocene and Holocene vegetation and evaluate the role of climate and human action in its diachronic dynamics. In this study, we present a compendium of anthracological, dendro-anthracological and archaeopalyonological data with the objective of (i) investigating the nature and distribution of Aleppo pine on the island of Mallorca and (ii) evaluating the possibility that human action could have resulted in the spread of this pine species during the first two millennia of permanent human occupation of the island (c. 2300 cal. BCE–1st-century ACE). Investigating these archaeobotanical datasets, as well as making comparisons with anthracological and paleoenvironmental studies in neighbouring Mediterranean zones (Iberia), allowed us to attest that Aleppo pine is a natural, pre-human component of the Holocene vegetation of the island, and it is especially well-adapted to coastal environments. Moreover, we describe the trends and characteristics of the human management of pine woodlands through anthracology and dendro-anthracology, suggesting that human action did not provoke widespread growth of Aleppo pine in Mallorca at the expense of other vegetation types during prehistory. Such processes, well-documented by current phytosociological studies, probably began at some unknown point after the Romanisation of the island

Historia eclesiástica elemental dividida en dos tomos o cursos escolares

Copia digital : Junta de Castilla y León. Conserjería de Cultura y Turismo, 201

Linking forest cover, soil erosion and mire hydrology to late-Holocene human activity and climate in NW Spain

This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 License (http://www.creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm).This article has been made available through the Brunel Open Access Publishing Fund.Forest clearance is one of the main drivers of soil erosion and hydrological changes in mires, although climate may also play a significant role. Because of the wide range of factors involved, understanding these complex links requires long-term multi-proxy approaches and research on the best proxies to focus. A peat core from NW Spain (Cruz do Bocelo mire), spanning the last ~3000 years, has been studied at high resolution by physical (density and loss on ignition (LOI)), geochemical (elemental composition) and palynological (pollen and non-pollen palynomorphs) analyses. Proxies related to mineral matter fluxes from the catchment (lithogenic tracers, Glomus and Entorrhiza), rainfall (Bromine), mire hydrology (HdV-18), human pressure (Cerealia-type, nitrophilous taxa and coprophilous fungi) and forest cover (mesophilous tree taxa) were the most useful to reconstruct the evolution of the mire and its catchment. Forest clearance for farming was one of the main drivers of environmental change from at least the local Iron Age (~2685 cal. yr BP) onwards. The most intense phase of deforestation occurred during Roman and Germanic times and the late Middle Ages. During these phases, the entire catchment was affected, resulting in enhanced soil erosion and severe hydrological modifications of the mire. Climate, especially rainfall, may have also accelerated these processes during wetter periods. However, it is noteworthy that the hydrology of the mire seems to have been insensitive to rainfall variations when mesophilous forest dominated. Abrupt changes were only detected once intense forest clearance commenced during the Iron Age/Roman transition (~2190 cal. yr BP) phase, which represented a tipping point in catchment's ability to buffer impacts. Overall, our findings highlight the importance of studying ecosystems' long-term trajectories and catchment-wide processes when implementing mire habitat protection measures.This work was funded by the projects CGL2010-20672 (Plan Nacional I+D+i, Spanish Ministry of Science and Innovation) and 10PXIB200182PR (General Directorate of I+D, Xunta de Galicia). N Silva-Sánchez and L López-Merino are currently supported by a FPU predoctoral scholarship (AP2010-3264) funded by the Spanish Government and a MINT postdoctoral fellowship funded by the Brunel Institute for the Environment, respectively