820 research outputs found

    El metamorfismo de bajo y muy bajo grado de los materiales carboníferos del área hercinica de Sierra Morena.

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    Se definen las características del metamorfismo regional hercínico que afecta a los materiales carboníferos de Sierra Morena así como sus relaciones con las series Devónicas y del Paleozoico Inferior. Se analiza la influencia del metamorfismo de contacto producido por intrusiones plutónicas

    El metamorfismo de bajo grado en el Paleozoico del sector central de la Cordillera Ibérica

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    Se describe el metamorfismo de bajo grado en sus aspectos paragenéticos, intensidad y condiciones de las rocas paleozoicas del sector central de la Cordillera Ibérica

    Actividad eléctrica muscular en la marcha a distintas velocidades y en la carrera

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    En este estudio se analiza la actividad electromiográfica de los principales músculos de la extremidad inferior derecha: Glúteos Mayor y Medio, Recto Anterior y Vasto Interno del Cuádriceps, Isquiotibioperoneos, Gemelos y Tibial Anterior, al caminar en un tapiz rodante a distintas velocidades y en una carrera suave. Para dividir el ciclo de la marcha y la carrera en fases se utilizó un sistema de análisis tridimensional con dos cámaras de vídeo. La señal electromiográfica de cada una de estas fases se integró y se expresó en porcentaje de la actividad máxima isométrica de su músculo correspondiente. Los resultados obtenidos muestran que la participación muscular en la marcha lenta y normal es muy similar, sin embargo, en la marcha rápida aparecen aumentos importantes conservando el mismo patrón de actuación. En la carrera, no sólo existen actividades del triple de las halladas en la marcha a velocidad cómoda, sino que se modifica el patrón de actuación, presentando todos los músculos sus picos de actividad durante la fase de apoyo, momento en el que el centro de gravedad se lleva hacia delante sobre el miembro inferior

    Actividad eléctrica muscular en la marcha a distintas velocidades y en la carrera

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    En este estudio se analiza la actividad electromiográfica de los principales músculos de la extremidad inferior derecha: Glúteos Mayor y Medio, Recto Anterior y Vasto Interno del Cuádriceps, Isquiotibioperoneos, Gemelos y Tibial Anterior, al caminar en un tapiz rodante a distintas velocidades y en una carrera suave. Para dividir el ciclo de la marcha y la carrera en fases se utilizó un sistema de análisis tridimensional con dos cámaras de vídeo. La señal electromiográfica de cada una de estas fases se integró y se expresó en porcentaje de la actividad máxima isométrica de su músculo correspondiente. Los resultados obtenidos muestran que la participación muscular en la marcha lenta y normal es muy similar, sin embargo, en la marcha rápida aparecen aumentos importantes conservando el mismo patrón de actuación. En la carrera, no sólo existen actividades del triple de las halladas en la marcha a velocidad cómoda, sino que se modifica el patrón de actuación, presentando todos los músculos sus picos de actividad durante la fase de apoyo, momento en el que el centro de gravedad se lleva hacia delante sobre el miembro inferior

    A technique using a membrane flow cell to determine average mass transfer coefficients and tortuosity factors in biofilms

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    Average mass transfer coefficients of an inert compound (LiCl) within denitrifying biofilms were monitored during biofilm growth in a membrane flow cell under different flow conditions, until the biofilm reached (pseudo-) steady state. Average effective diffusivities were found to increase with the decrease in tortuosity factors of the biofilm matrix. The lowest tortuosity factor corresponded to the biofilm formed under the highest liquid velocity.União Europeia - BioToBio - ERBFMRXCT97-0114. Centro de Investigación Científica y Tecnológica (CICYT) - AMB 98-0288, PR404E 2000/6-

    Psychometric evaluation and validation of the Postpartum Specific Anxiety Scale for the Spanish-speaking population:PSAS-ES

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    ObjectiveThe transition to motherhood is a period of risk for the development of mood disorders. Postpartum anxiety has not been as thoroughly studied as other emotional disorders despite its impact on mothers and their babies. The absence of standardized programmes for early detection and specific tools for its diagnosis means postpartum anxiety is often underestimated or overshadowed. This study aimed to translate and validate the Postpartum Specific Anxiety Scale [PSAS] for the Spanish population and to analyse its reliability as an exploratory tool for specific anxiety in mothers.MethodFour stages were followed in this research: translation and back-translation to obtain the Spanish version [PSAS-ES]; preliminary pilot study to explore the comprehensibility and ease of responding the items (n = 53); convergent validity analyses (n = 644); and test-retest reliability (n = 234).ResultsThe PSAS-ES has shown to have good acceptability, convergent validity and high internal consistency with a Cronbach's α coefficient of 0.93 for the overall scale of PSAS. The four factors had good reliability. The results of test-retest was 0.86, indicating excellent stability over time in the first 16 weeks.ConclusionThe psychometric results show that the PSAS-ES is a valid tool to explore and detect anxiety in Spanish mothers between 0 and 16 weeks postpartum

    A comparative study between wmms and tls for the stability analysis of the San Pedro church barrel vault by means of the finite element method

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    Stability of masonry constructions is highly conditioned by the geometric disposition of its elements due to its low tensile strength and great compressive mechanical properties. Under this framework, this paper attempts to evaluate the suitability of a wearable mobile mapping solution, equipped in a backpack and based on the well-known simultaneous location and mapping paradigm, for the structural diagnosis of historical constructions. To evaluate the suitability of this device, the structural analysis obtained is compared with a high precision terrestrial laser scanner, which is considered as ground truth. The Romanesque church of San Pedro (Becerril del Carpio, Spain) was selected as a study case. This construction, initially conceived in the XIIIth century, has experimented in the past a soil settlement promoting the leaning of the north wall, several plastic hinges in its barrel vault and a visible geometrical deformation. The comparison of both techniques was carried out at different levels: i) an evaluation of the time needed to obtain the point cloud of the church; ii) an accuracy assessment based on the comparison of a terrestrial network using artificial spheres as checkpoints and; iii) an evaluation of the discrepancies, in terms of safety factor and collapse topology, found during the advance numerical evaluation of the barrel vault by means of the finite element method. This comparison places this wearable mobile mapping solution as an interesting tool for the creation of advanced numerical simulations to evaluate the structural stability of historical constructionsJunta de Castilla y León | Ref. SA075P17FEDER | Ref. SOE1/P5/P025

    Open challenges in relationship-based privacy mechanisms for social network services

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    [EN] Social networking services (SNSs) such as Facebook or Twitter have experienced an explosive growth during the few past years. Millions of users have created their profiles on these services because they experience great benefits in terms of friendship. SNSs can help people to maintain their friendships, organize their social lives, start new friendships, or meet others that share their hobbies and interests. However, all these benefits can be eclipsed by the privacy hazards that affect people in SNSs. People expose intimate information of their lives on SNSs, and this information affects the way others think about them. It is crucial that users be able to control how their information is distributed through the SNSs and decide who can access it. This paper presents a list of privacy threats that can affect SNS users, and what requirements privacy mechanisms should fulfill to prevent this threats. Then, we review current approaches and analyze to what extent they cover the requirementsThis article has been developed as a result of a mobility stay funded by the Erasmus Mundus Programme of the European Comission under the Transatlantic Partnership for Excellence in Engineering-TEE Project.López Fogués, R.; Such Aparicio, JM.; Espinosa Minguet, AR.; García-Fornes, A. (2015). Open challenges in relationship-based privacy mechanisms for social network services. International Journal of Human-Computer Interaction. 31(5):350-370. doi:10.1080/10447318.2014.1001300S35037031
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