19,937 research outputs found

    A new species of Hormathia (Actiniaria, Hormathiidae) from the eastern Weddell Sea, Antarctica

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    A new species of sea anemone in the genus Hormathia, is described and illustrated based on fortytwo specimens collected during the Polarstern cruises ANT XV/3 and ANT XVII/3 in the Weddell Sea. The main features of the new taxon are the crown of flattened and hooked tubercles at the distal end of the scapus, the regular arrangement of pointed tubercles along the column and the cnidom. The new species shares the pointed tubercles, at least in the upper part of the scapus, with two other species of Hormathia in the southern hemisphere: Hormathia spinosa Hertwig 1882 and H. pectinata Hertwig 188

    New record of the sea anemone Kadosactis antarctica (Carlgren, 1928): re-description of an Antarctic deep-sea sea anemone, and a discussion of its generic and familial placement

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    Sagartiogeton antarcticus Carlgren, 1928 is an Antarctic deep-sea species of sea anemone only known from its holotype. The species has been assigned to the genera Sagartiogeton and Kadosactis, and is currently placed within the family Kadosactidae Riemann-Zu¨rneck, 1991. Kadosactis antarctica is re-described based on 11 specimens collected during the cruise of the R/V Polarstern ANT XIX/3 (ANDEEP-I) to the Scotia Sea and off the South Shetland Islands (Antarctica). The description includes a complete account of cnidae and photographs. Because the mesogloea is thickened on the aboral surface on the base of the tentacles, this feature becomes a generic character of Kadosactis rather than a differential specific character among the species of the genus as previously proposed. Furthermore, the known distribution of the species is enlarged to include the southern branch of the Scotia Sea

    Stephanthus antarcticus, a new genus and species of sea anemone (Actiniaria, Haloclavidae) from the South Shetland Islands, Antarctica

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    Stephanthus antarcticus gen. nov. et sp. nov. is described and illustrated from six specimens collected in the Antarctic Peninsula on the Polarstern cruises ANT XV/3 and ANT XIX/3. The new genus is characterised by the absence of sphincter and basilar musculature, the presence of a single strong siphonoglyph with a basal enlargement, distinct parietobasilar musculature, tentacles without acrospheres, two cycles of six pairs of mesenteries (only one of them perfect), and a deep fosse with parapet; another remarkable feature is the absence of microbasic p-mastigophores. The new genus shows characteristics of three families of soft-bottomdwelling sea anemones, namely Haloclavidae Verrill, 1899, Halcampoididae Appellöf, 1896, and Andresiidae Stephenson, 1922. The generic characters of Stephanthus gen. nov. are discussed and it is tentatively placed in the family Haloclavidae

    Biomechanical analysis of a cranial Patient Specific Implant on the interface with the bone using the Finite Element Method

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    - New advance technologies based on reverse engineering , design and additive manufacturing, have expanded design capabilities for biomedical applications to include Patient Specific Implants (PSI). This change in design paradigms needs advanced tools to assess the mechanical performance of the product, and simulate the impact on the patient. In this work, we perform a structural analysis on the interface of a cranial PSI under static loading conditions. Based on those simulations, we have identified the regions with high stress and strain and checked the failure criteria both in the implant and the skull. We evaluate the quality of the design of the implant and determine their response given different materials, in order to ensure optimality of the final product to be manufactured

    On the formalism of dark energy accretion onto black- and worm-holes

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    In this work a general formalism for the accretion of dark energy onto astronomical objects, black holes and wormholes, is considered. It is shown that in models with four dimensions or more, any singularity with a divergence in the Hubble parameter may be avoided by a big trip, if it is assumed that there is no coupling between the bulk and this accreting object. If this is not the case in more than four dimensions, the evolution of the cosmological object depends on the particular model.Comment: 6 page

    Adaptive Multi-Pattern Fast Block-Matching Algorithm Based on Motion Classification Techniques

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    Motion estimation is the most time-consuming subsystem in a video codec. Thus, more efficient methods of motion estimation should be investigated. Real video sequences usually exhibit a wide-range of motion content as well as different degrees of detail, which become particularly difficult to manage by typical block-matching algorithms. Recent developments in the area of motion estimation have focused on the adaptation to video contents. Adaptive thresholds and multi-pattern search algorithms have shown to achieve good performance when they success to adjust to motion characteristics. This paper proposes an adaptive algorithm, called MCS, that makes use of an especially tailored classifier that detects some motion cues and chooses the search pattern that best fits to them. Specifically, a hierarchical structure of binary linear classifiers is proposed. Our experimental results show that MCS notably reduces the computational cost with respect to an state-of-the-art method while maintaining the qualityPublicad

    La necesaria modernización del régimen presupuestario de la administración y su control

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    La disciplina presupuestaria clásica se ha venido caracterizando por una atención casi exclusiva al procedimiento de gasto, y en particular a las clasificaciones económicas y orgánicas, con niveles muy desagregados de vinculación y rigurosos controles simultáneos, atendiendo casi exclusivamente a la legalidad y regularidad del proceso de gasto. Al mismo tiempo han proliferado entes instrumentales de la más diversa naturaleza cuyo objeto, en muchos casos, no es otro que romper esas rigidices de la disciplina presupuestaria tradicional en aras de una mayor flexibilidad en la gestión. Más recientemente se han creado nuevas fórmulas que tratan de incorporar una mayor atención a los resultados y al logro de objetivos. En este nuevo contexto se incorporan propuestas tendentes a la configuración de una nueva disciplina presupuestaria para la Administracion General que permita incorporar progresivamente algunas de las soluciones más flexibles propugnadas por la nueva gestión pública evitando la creación de entes instrumentales por exclusivas razones presupuestarias
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