Magnetic dipole moments for composite dark matter

We study neutral dark matter candidates with a nonzero magnetic dipole moment. We assume that they are composite states of new fermions related to the strong phase of a new gauge interaction. In particular, invoking a dark flavor symmetry, we analyze the composition structure of viable candidates depending on the assignations of hypercharge and the multiplets associated to the fundamental constituents of the extended sector. We determine the magnetic dipole moments for the neutral composite states in terms of their constituents masses.Comment: 22 pages, 3 figure

Spin excitation frequencies in magnetostatically coupled arrays of vortex state circular Permalloy dots

3 páginas, 2 figuras.-- et al.Broadband ferromagnetic resonance in square arrays of Permalloy circular dots with different interdot separations was measured in the vortex ground state. The detected spin excitations show a complicated dependence of their frequencies on the interdot coupling strength. A considerable influence of the interdot separation on the gyrotropic vortex frequency and splitting of the azimuthal spin wave frequencies was detected. The gyrotropic frequency and the first azimuthal doublet frequency splitting depend nonmonotonously on the interdot spacing, whereas the dependence of the second doublet frequency splitting on this parameter is monotonous. The observed effects are explained by the influence of both the dipolar and quadrupolar contributions to the dynamic magnetostatic interactions.The work in Madrid was supported by Spanish MICINN (Grant Nos. MAT2009-10139, MAT2006-28183-E, and CSD2007-00010) and CAM (Grant No. S-505/MAT0194). K.Y.G. and G.R.A. acknowledge support by IKERBASQUE (the Basque Science Foundation), JAE-doc grant and the SAIOTEK Grant No. S-PC09UN03. G.N.K. acknowledges support from Portuguese FCT through the “Ciencia 2007” program. The work in Kiev was supported by the STCU Grant No. 5210 and the Grant No. 220-10 from NAS of Ukraine.Peer reviewe

Constraints on Natural MNS Parameters from |U_e3|

The MNS matrix structure emerging as a result of recent neutrino measurements strongly suggests two large mixing angles (solar and atmospheric) and one small angle (|U_e3| << 1). Especially when combined with the neutrino mass hierarchy, these values turn out to impose rather stringent constraints on possible flavor models connecting the three active fermion generations. Specifically, we show that an extremely small value of |U_e3| would require fine tuning of Majorana mass matrix parameters, particularly in the context of seesaw models.Comment: 21 pages, ReVTeX, 2 .eps figure files, updated references and acknowledgment

Opportunistic linked data querying through approximate membership metadata

Between URI dereferencing and the SPARQL protocol lies a largely unexplored axis of possible interfaces to Linked Data, each with its own combination of trade-offs. One of these interfaces is Triple Pattern Fragments, which allows clients to execute SPARQL queries against low-cost servers, at the cost of higher bandwidth. Increasing a client's efficiency means lowering the number of requests, which can among others be achieved through additional metadata in responses. We noted that typical SPARQL query evaluations against Triple Pattern Fragments require a significant portion of membership subqueries, which check the presence of a specific triple, rather than a variable pattern. This paper studies the impact of providing approximate membership functions, i.e., Bloom filters and Golomb-coded sets, as extra metadata. In addition to reducing HTTP requests, such functions allow to achieve full result recall earlier when temporarily allowing lower precision. Half of the tested queries from a WatDiv benchmark test set could be executed with up to a third fewer HTTP requests with only marginally higher server cost. Query times, however, did not improve, likely due to slower metadata generation and transfer. This indicates that approximate membership functions can partly improve the client-side query process with minimal impact on the server and its interface

El ajuste osmótico como mecanismo de resistencia a la sequía en poblaciones áridas de P. pinaster y P. canariensis

Mechanisms of drought resistance were studied in two xeric populations of Pinus canariensis and Pinus pinaster. Seedlings were grown in a hydroponic culture for four months. Gradual controlled drought was imposed during two weeks by adding Polyethylene glycol (PEG-6000) to the growing medium. Two levels of water deficit (Psi = -1MPa, Psi = -2 MPa) and a control treatment (Psi = -0.03 MPa) were tested. Relative water content (RWC) was markedly low at the end of the experimenBoth populations showed a high capacity for osmotic adjustment in needles as shown by the osmotic index, 0.63 (1.33 MPa at 80% RWC) for P. canariensis and 0.54 (1.25 MPa at 80% RWC) for P. pinaster. Root growth and root:shoot (stem + needles) ratio were increased by water deficiOpposite patterns of relative biomass allocation were assessed between stressed and control plants. While stressed seedlings assigned more dry matter to roots, non-stressed plants showed a higher relative needle weighThe growing media caused additional stress to the plants, thus comparisons with other drought protocols should be made carefully.Se estudiaron mecanismos de resistencia a la sequ&iacute;a en poblaciones &aacute;ridas de P.canariensis y P. pinaster. Tras cuatro meses en cultivo hidrop&oacute;nico, se someti&oacute; a las plantas a un tratamiento de sequ&iacute;a durante dos semanas a&ntilde;adiendo polietilenglicol (PEG-6000) a la soluci&oacute;n. Se evaluaron dos niveles de d&eacute;ficit h&iacute;drico (Psi = -1MPa, Psi = -2 MPa) y un tratamiento control (Psi = -0,03 MPa). El contenido h&iacute;drico relativo (RWC) de las pl&aacute;ntulas fue muy bajo durante todo el ensayo. Las dos poblaciones mostraron una gran capacidad de ajuste osm&oacute;tico con &iacute;ndices de ajuste osm&oacute;tico de 0,63 (ajuste osm&oacute;tico de 1,33 MPa a un 80% de RWC) en P. canariensis y 0,54 (ajuste osm&oacute;tico de 1,25 MPa a un 80% de RWC) en P-. pinaster. El crecimiento radical y la relaci&oacute;n ra&iacute;z:parte a&eacute;rea fueron estimulados por la sequ&iacute;a. Se encontraron patrones de reparto de biomasa opuestos entre las plantas estresadas y las control. Mientras que las primeras destinaron m&aacute;s materia seca a las ra&iacute;ces, las no estresadas invirtieron m&aacute;s en biomasa foliar. El medio de cultivo caus&oacute; un estr&eacute;s adicional a la planta por lo que las comparaciones de ensayos de sequ&iacute;a utilizando PEG con otros protocolos deben de tenerlo en cuenta

Predictors of review sites usage in hotels

The tourism industry has been strongly impacted by the consumer use of review sites. Since review travel sites such as TripAdvisor allowed accommodations to create own profiles with information, hotels began incorporating these actions into their engaging customers programming. Despite the benefits that review sites can offer to customers, hotels and accommodations, its implementation is not developed and exploited in all its possibilities, and little is known about hotels use of this review sites. This study explores the topic trough quantitative methodology, conducting multiple correlation analysis of data obtained from a sample of 301 hotel managers. Managers consider they are committed to this type of platforms and are capable of use it accurately. Also it was found evidence of correlation between use of TripAdvisor and hotel characteristics (size, ownership structure, and category). Furthermore, multiple regression analysis shows competence and commitment as the most important predictors of use intensity

Co-evolution of RDF Datasets

Linking Data initiatives have fostered the publication of large number of RDF datasets in the Linked Open Data (LOD) cloud, as well as the development of query processing infrastructures to access these data in a federated fashion. However, different experimental studies have shown that availability of LOD datasets cannot be always ensured, being RDF data replication required for envisioning reliable federated query frameworks. Albeit enhancing data availability, RDF data replication requires synchronization and conflict resolution when replicas and source datasets are allowed to change data over time, i.e., co-evolution management needs to be provided to ensure consistency. In this paper, we tackle the problem of RDF data co-evolution and devise an approach for conflict resolution during co-evolution of RDF datasets. Our proposed approach is property-oriented and allows for exploiting semantics about RDF properties during co-evolution management. The quality of our approach is empirically evaluated in different scenarios on the DBpedia-live dataset. Experimental results suggest that proposed proposed techniques have a positive impact on the quality of data in source datasets and replicas.Comment: 18 pages, 4 figures, Accepted in ICWE, 201

Towards a Soft Evaluation and Refinement of Tagging in Digital Humanities

In this paper we estimate the soundness of tagging in digital repositories within the field of Digital Humanities by studying the (semantic) conceptual structure behind the folksnonomy. The use of association rules associated to this conceptual structure (Stem and Luxenburger basis) allows to faithfully (from a semantic point of view) complete the tagging (or suggest such a completion).Ministerio de Economía y Competitividad TIN2013-41086-PJunta de Andalucía TIC-606

Influencia del consumo de sal y de analgésicos efervescentes con sodio en pacientes con hipertensión y riesgo vascular

La ingesta del sodio que contienen los alimentos y algunos medicamentos puede producir una elevación de los valores de presión arterial de los individuos. La Organización Mundial de la Salud recomienda de forma global no superar la ingesta diaria de 2 g de sodio en los adultos sanos (5 g de sal común). Para grupos de riesgo se establecen límites más estrictos (0,5-1,5 g de sodio diarios). En España se estima que cada persona consume al día 11 g de sal por término medio. Diversos estudios, realizados en distintas poblaciones, han podido objetivar una correlación directa entre la ingesta de sodio en la dieta y la prevalencia de hipertensión arterial. Otros estudios corroboran el efecto de la reducción del consumo de sal en la dieta sobre la disminución de los valores de presión arterial y de la morbilidad y mortalidad cardiovascular. Muchos medicamentos contienen una elevada cantidad de sodio por tener excipientes efervescentes (1 g de paracetamol efervescente puede llegar a aportar más de 0,5 g de sodio), de forma que, si su posología es cada 6-8 horas, pueden superar los límites diarios de sodio recomendados, incluso para un adulto sano. En este artículo se revisa la evidencia disponible sobre el efecto beneficioso de una dieta hiposódica para el control de la hipertensión, las consideraciones sobre el uso de analgésicos y AINE en los pacientes con enfermedad cardiovascular y se insiste en la advertencia de evitar, siempre que sea posible, el uso de medicamentos efervescentes, especialmente en los mayores de 50 años