453 research outputs found

    Disociación escafo-semilunar asociada a fractura de escafoides carpiano: a propósito de un caso

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    Según el mecanismo clásico de producción de inestabilidad perilunar progresiva, la fractura de escafoides y la disociación escafo-semilunar completa no podrían producirse de forma conjunta; sin embargo, hay varios casos documentados. Debido a su baja frecuencia de diagnóstico, es escasa la literatura publicada al respecto del manejo y resultados de estas lesiones de forma conjunta. Presentamos un caso de asociación de una fractura de escafoides y disociación escafo-semilunar tratado mediante osteosíntesis percutánea, artroscopia y reanclaje abierto ligamentoso, con buenos resultados. Describimos su evolución clínica y radiológica, así como una revisión de la bibliografíaAccording to the generally accepted pathomechanisms of carpal instability, a scaphoid fracture and a scapholunate dissociation should not occur together. Several cases are published in the literature even there is no much written about this topic, its treatment and outcome. These concurrent injuries are herefore likely underdiagnosed. We present a case with scaphoid fracture and a scapholunate dissociation in association, successfully. We describe the clinical, radiological outcome as well as the important literature about this topi

    Greedy seeding procedure for GAs solving a strip packing problem

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    In this paper, the two-dimensional strip packing problem with 3-stage level patterns is tackled using genetic algorithms (GAs). We evaluate the usefulness of a greedy seeding procedure for creating the initial population, incorporating problem knowledge. This is motivated by the expectation that the seeding will speed up the GA by starting the search in promising regions of the search space. An analysis of the impact of the seeded initial population is offered, together with a complete study of the influence of these modifications on the genetic search. The results show that the use of an appropriate seeding of the initial population outperforms existing GA approaches on all the used problem instances, for all the metrics used, and in fact it represents the new state of the art for this problem.Red de Universidades con Carreras en Informática (RedUNCI

    Greedy seeding procedure for GAs solving a strip packing problem

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    In this paper, the two-dimensional strip packing problem with 3-stage level patterns is tackled using genetic algorithms (GAs). We evaluate the usefulness of a greedy seeding procedure for creating the initial population, incorporating problem knowledge. This is motivated by the expectation that the seeding will speed up the GA by starting the search in promising regions of the search space. An analysis of the impact of the seeded initial population is offered, together with a complete study of the influence of these modifications on the genetic search. The results show that the use of an appropriate seeding of the initial population outperforms existing GA approaches on all the used problem instances, for all the metrics used, and in fact it represents the new state of the art for this problem.Red de Universidades con Carreras en Informática (RedUNCI

    Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation

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    Biodegradation of lower chlorinated benzenes (tri-, di- and monochlorobenzene) was assessed at a coastal aquifer contaminated with multiple chlorinated aromatic hydro- carbons. Field-derived microcosms, established with groundwater from the source zone and amended with a mixture of lower chlorinated benzenes, evidenced biodegradation of monochlorobenzene (MCB) and 1,4-dichlorobenzene (1,4-DCB) in aerobic microcosms, whereas the addition of lactate in anaerobic microcosms did not enhance anaerobic reduc- tive dechlorination. Aerobic microcosms established with groundwater from the plume consumed several doses of MCB and concomitantly degraded the three isomers of dichloroben- zene with no observable inhibitory effect. In the light of these results, we assessed the applicability of compound stable isotope analysis to monitor a potential aerobic remediation treatment of MCB and 1,4-DCB in this site. The carbon isotopic fractionation factors ( ε) obtained from field-derived microcosms were -0.7 ¿ ± 0.1 ¿ and -1.0 ¿ ± 0.2 ¿ for MCB and 1,4-DCB, respectively. For 1,4-DCB, the carbon isotope fractionation during aerobic biodegra- dation was reported for the first time. The weak carbon isotope fractionation values for the aerobic pathway would only allow tracing of in situ degradation in aquifer parts with high extent of biodegradation. However, based on the carbon isotope effects measured in this and previous studies, relatively high carbon isotope shifts (i.e., δ13 C > 4.0 ¿ ) of MCB or 1,4- DCB in contaminated groundwater would suggest that their biodegradation is controlled by anaerobic reductive dechlorination

    Modelo en Ecosimpro® de captador solar Fresnel

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    XXXIII Jornadas de Automática. 05/09/2012. VigoSe ha desarrollado en este trabajo un conjunto de componentes de EcosimPro® para la simulación del captador tipo Fresnel de una planta solar situada en la Escuela Técnica Superior de Ingeniería de la Universidad de Sevilla. Se ha basado en un modelo de parámetros distribuidos, ajustando los parámetros del mismo con datos tomados del sistema real y comparando la respuesta del modelo con la temperatura de salida real del sistema.Ministerio de Eduación y Ciencia DPI2010-21589- C05-0

    An updated biostratigraphy for the late Aragonian and Vallesian of the Vallès-Penedès Basin (Catalonia)

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    The Vallès-Penedès Basin (Catalonia, Spain) is a classical area for the study of the Miocene land mammal faunas and includes one of the densest and most continuous records in Eurasia. Furthermore, it is the type area for the Vallesian European land mammal age. After decades of study a huge amount of bio- and magnetostratigraphic data have been collected, allowing an unprecedented dating accuracy. Here we provide an updated local biostratigraphy for the late Aragonian, Vallesian and Turolian of the Vallès-Penedès Basin. This new biostratigraphic scheme is almost exclusively based on fossil rodents, which are the most abundant and one of the best known mammal orders in the area. Our proposal represents a significant refinement compared to previous attempts and provides a formal diagnosis and description of each zone, as well as clear definition of boundaries and a reference locality and section. The chronology of zone boundaries and main bioevents is based on detailed magnetostratigraphic data. The defined biozones allow for the correlation of the sites without associated magnetostratigraphical data. Finally, the correlation of the Vallès-Penedès local zones with other detailed local biostratigraphies, such as those of the Calatayud-Montalbán and Teruel basins (east-central Spain) is discussed. The sequence and chronology of the main bioevents is roughly comparable, although the rodent succession and the structure of the assemblage show important differences between these areas

    Severe Deoxygenation Event Caused by the 2011 Eruption of the Submarine Volcano Tagoro (El Hierro, Canary Islands)

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    The shallow, near-shore submarine volcano Tagoro erupted in October 2011 at the Mar de las Calmas marine reserve, south of El Hierro island. The injection of lava into the ocean had its strongest episode during November 2011 and lasted until March 2012. During this time, in situ measurements of dissolved oxygen were carried out, using a continuous oxygen sensor constantly calibrated with water samples. A severe deoxygenation was observed in the area, particularly during October-November 2011, which was one of the main causes of the high mortality observed among the local marine ecosystem. The measured O2 concentrations were as low as 7.71 µmol kg-1, which represents a -96% decrease with respect to unaffected waters. The oxygen depletion was found in the first 250 m of the water column, with peaks between 70-120 m depth. The deoxygenated plume covered an area of at least 464 km2, distributed particularly south and south-west of the volcano, with occasional patches found north of the island. The oxygen levels were also monitored through the following years, during the degassing stage of the volcano, when oxygen depletion was no longer observed. Additionally, during the eruption, an island-generated anticyclonic eddy interacted with the volcanic plume and transported it for at least 80 km, where the O2 measurements still showed a -8% decrease after mixing and dilution. This feature draws attention to the permanence and transport of volcanic plumes far away from their source and long after the emission.En prens
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