279 research outputs found

    Artrodesis subastragalina artroscópica

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    Objetivo: evaluar la eficacia y complicaciones de la técnica artroscópica en la artrodesis subastragalina. Material y métodos: Durante los años 2007 y 2008 hemos realizado artrodesis subastragalina artroscópica por vía posterior a 12 pacientes, con una edad media de 41 años, por presentar artropatía postraumática de la articulación subastragalina, secundaria a fractura de calcáneo o astrágalo. El seguimiento medio ha sido de 9 meses. Resultados: Se ha conseguido la consolidación primaria de la artrodesis en 10 casos, evolucionando a seudoartrosis en los otros dos, que precisaron reintervención artroscópica con aporte de injerto óseo. En un caso ha existido migración proximal de un tornillo de osteosíntesis, no presentándose necrosis cutánea, infección ni afectación neurovascular en caso alguno. Conclusiones: Esta técnica se ha mostrado eficaz para la consecución de la artrodesis subastragalina, disminuyendo sensiblemente el porcentaje de complicaciones en relación con la cirugía abierta.Objective: To evaluate the effectiveness and complications of arthroscopic technique in subtalar arthrodesis. Methods: Between 2007 and 2008 we performed arthroscopic subtalar fusions with a posterior approach in 12 patients with a mean age of 41 years old, with a diagnose of posttraumatic subtalar arthropaty secondary to calcaneus or talus fractures. The mean follow-up was 9 months. Results:We obtained primary consolidation in 10 cases. Two cases developed non-union and required an arthroscopic revision with bone grafting. In one case there was proximal migration of a screw, with no skin necrosis, infection or neurovascular impairment in any case. Conclusions: This technique has been effective in order to obtain subtalar fusion, minimizing significantly the complications associated with open surgery

    Datos sobre la vegetación del centro del Perú

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    Datos sobre la vegetación del centro del Perú. El presente artículo trata de aportar algunas novedades fitosociológicas sobre los valles centrales del Departamento de Lima (Perú). Como resultado de los inventarios fitosociológicos levantados en los valles de Santa Eulalia, Rimac, Chillón y San Bartolomé, se describen 6 asociaciones (Baccharido salicifoliae-Gynerietum sagittati, Equiseto gigantei-Salicetum humboldtianae, Caricetum candicantis, Matucano haynei-Tillandsietum humilis, Aristeguietio discoloris-Baccharidetum latifoliae y Jungietum axillaris), 3 alianzas (Pityrogrammo trifoliatae-Baccharidion salicifoliae, Adiantion poiretii y Jungion axillaris) y 1 orden (Baccharidetalia salicifoliae). Además se comentan 5 nuevas subasociaciones, 5 comunidades y algunos aspectos fragmentarios de la vegetación (comunidades basales, BC y comunidades derivadas, DC). También se presenta un mapa preliminar de las series de vegetación en el centro del Perú (Departamento de Lima)

    Immature large ribosomal subunits containing the 7S pre-rRNA can engage in translation in Saccharomyces cerevisiae

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    Evolution has provided eukaryotes with mechanisms that impede immature and/or aberrant ribosomes to engage in translation. These mechanisms basically either prevent the nucleo-cytoplasmic export of these particles or, once in the cytoplasm, the release of associated assembly factors, which interfere with the binding of translation initiation factors and/or the ribosomal subunit joining. We have previously shown that aberrant yeast 40S ribosomal subunits containing the 20S pre-rRNA can engage in translation. In this study, we describe that cells harbouring the dob1–1 allele, encoding a mutated version of the exosome-assisting RNA helicase Mtr4, accumulate otherwise nuclear pre-60S ribosomal particles containing the 7S pre-rRNA in the cytoplasm. Polysome fractionation analyses revealed that these particles are competent for translation and do not induce elongation stalls. This phenomenon is rather specific since most mutations in other exosome components or co-factors, impairing the 3′ end processing of the mature 5.8S rRNA, accumulate 7S pre-rRNAs in the nucleus. In addition, we confirm that pre-60S ribosomal particles containing either 5.8S + 30 or 5.8S + 5 pre-rRNAs also engage in translation elongation. We propose that 7S pre-rRNA processing is not strictly required for pre-60S r-particle export and that, upon arrival in the cytoplasm, there is no specific mechanism to prevent translation by premature pre-60S r-particles containing 3′ extended forms of mature 5.8S rRNA

    Academic Resilience to Difficulties in Learning Mathematics

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    Este trabajo parte de una revisión conceptual e investigadora acerca del concepto de resiliencia académica en general, para centrarse en el estudio de la resiliencia ante las dificultades en el aprendizaje de las matemáticas mediante un análisis comparativo y sumativo de los datos extraídos de los dos principales estudios transnacionales sobre rendimiento matemático, como son TIMSS y PISA. Se utiliza información procedente de estos estudios, relacionada con los factores y mecanismos de protección y desarrollo de la resiliencia académica para postular unas líneas de investigación hacia un nuevo modelo educativo donde la educación emocional ocupe un rol modulador de los aspectos cognitivos y procedimentales que favorezca la predisposición y actitudes positivas hacia el aprendizaje de las matemáticas en la vía del desarrollo de la capacidad resiliente de perseverancia y superación de las dificultades en el aprendizaje de las matemáticas.This paper is focused on studying resilient students. It begins with a conceptual review and research on the concept of academic resilience in general, to focus on the study of resilience to the difficulties in learning mathematics and summative through a comparative analysis of the data from the two major national studies on performance mathematician, such as TIMSS and PISA. Information from these studies, related to the factors and mechanisms of protection and development of academic resilience to apply research lines towards a new educational model where the emotional education occupies a modulatory role of cognitive and procedural aspects that favors It uses the and positive disposition towards learning mathematics in the development path of the resilient capacity of perseverance and overcoming difficulties in learning mathematics attitudes

    Short communication: Application of site‐level assessment of governance and equity (sage) methodology to a candidate oecm: AndakÍ municipal natural park, caquetÁ, colombia.

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    Governance is a fundamental aspect and precondition for conservation strategies, such as protected areas or OECMs. A methodology for Site-level Assessment of Governance and Equity (SAGE) has been proposed by IUCN to explore different aspects of governance, based on ten principles. This article describes the application of SAGE to a candidate OECM for what we believe is the first time: the Andakí Municipal Natural Park in the Amazon region of Colombia. The application of SAGE generated useful insights into different aspects of governance, including the importance of good communication and recognising and respecting the rights and responsibilities of different actors. Based on this experience, we believe that the SAGE methodology could be a useful tool not only to identify priorities for improving governance, but also to assess governance and equity in order to evaluate if an area meets the criteria for an OECM that it is governed and managed to achieve sustained and effective contributions to in situ conservation of biodiversity, associated ecosystem functions and services, and cultural, spiritual, socio-economic and other locally relevant values. © 2021, IUCN - International Union for the Conservation of Nature. All rights reserved.This process was made possible with the support of: a) the Local Protected Areas Regional Project implemented by Deutsche Gesellschaft f?r Internationale Zusammenarbeit (GIZ) GmbH, ICLEI ? Local Governments for Sustainability and the International Union for Conservation of Nature (IUCN); Environment ministries in Brazil, Colombia, Ecuador and Peru; commissioned by the German Federal Ministry for the Environment, Nature Protection and Nuclear Safety; b) the project adaptation of the OECM criteria to the Colombian context supported by PPD-GEF-PNUD, and implemented by Resnatur, Instituto Humboldt, Fundaci?n Natura and the Local Protected Areas Project; and c) the EUROCLIMA+ programme supported by Expertise France, GIZ and the International Institute for the Environment and Development (IIED); and d) Thora Amend, Vice Chair, IUCN World Commission on Protected Areas (thematic area: Governance)

    Radiopurity of Micromegas readout planes

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    Micromesh Gas Amplification Structures (Micromegas) are being used in an increasing number of Particle Physics applications since their conception fourteen years ago. More recently, they are being used or considered as readout of Time Projection Chambers (TPCs) in the field of Rare Event searches (dealing with dark matter, axions or double beta decay). In these experiments, the radiopurity of the detector components and surrounding materials is measured and finely controlled in order to keep the experimental background as low as possible. In the present paper, the first measurement of the radiopurity of Micromegas planes obtained by high purity germanium spectrometry in the low background facilities of the Canfranc Underground Laboratory (LSC) is presented. The obtained results prove that Micromegas readouts of the microbulk type are currently manufactured with radiopurity levels below 30 microBq/cm2 for Th and U chains and ~60 microBq/cm2 for 40K, already comparable to the cleanest detector components of the most stringent low background experiments at present. Taking into account that the studied readouts were manufactured without any specific control of the radiopurity, it should be possible to improve these levels after dedicated development.Comment: 15 pages, 2 figure

    Gaseous time projection chambers for rare event detection: Results from the T-REX project. II. Dark matter

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    As part of the T-REX project, a number of R&D and prototyping activities have been carried out during the last years to explore the applicability of Micromegas-read gaseous TPCs in rare event searches like double beta decay (DBD), axion research and low-mass WIMP searches. While in the companion paper we focus on DBD, in this paper we focus on the results regarding the search for dark matter candidates, both axions and WIMPs. Small ultra-low background Micromegas detectors are used to image the x-ray signal expected in axion helioscopes like CAST at CERN. Background levels as low as 0.8×1060.8\times 10^{-6} c keV1^{-1}cm2^{-2}s1^{-1} have already been achieved in CAST while values down to 107\sim10^{-7} c keV1^{-1}cm2^{-2}s1^{-1} have been obtained in a test bench placed underground in the Laboratorio Subterr\'aneo de Canfranc. Prospects to consolidate and further reduce these values down to 108\sim10^{-8} c keV1^{-1}cm2^{-2}s1^{-1}will be described. Such detectors, placed at the focal point of x-ray telescopes in the future IAXO experiment, would allow for 105^5 better signal-to-noise ratio than CAST, and search for solar axions with gaγg_{a\gamma} down to few 1012^{12} GeV1^{-1}, well into unexplored axion parameter space. In addition, a scaled-up version of these TPCs, properly shielded and placed underground, can be competitive in the search for low-mass WIMPs. The TREX-DM prototype, with \sim0.300 kg of Ar at 10 bar, or alternatively \sim0.160 kg of Ne at 10 bar, and energy threshold well below 1 keV, has been built to test this concept. We will describe the main technical solutions developed, as well as the results from the commissioning phase on surface. The anticipated sensitivity of this technique might reach 1044\sim10^{-44} cm2^2 for low mass (<10<10 GeV) WIMPs, well beyond current experimental limits in this mass range.Comment: Published in JCAP. New version with erratum incorporated (new figure 14

    A new triadotypomorphan insect from the Anisian (Middle Triassic), Buntsandstein facies, Spain

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    The species rubra sp. nov., a new triadotypomorphan insect from the Iberian Ranges, is described on the basis of a newly discovered specimen, found in fine grained sandstones of alluvial origin, in the lowermost part of the Eslida Formation (Buntsandstein facies), in the central part of the Iberian Ranges. The occurrence of a triadotypomorphan suggests an Anisian age of the Eslida Formation. The species represents the oldest Mesozoic insect described from Spain, and provides interesting information to better appreciate the process of ecosystems recovery after the Permian-Triassic boundary crisis.La especie rubra sp. nov., un nuevo insecto triadotipomorfo de la Cordillera Ibérica, es descrito en este trabajo en base a un nuevo espécimen hallado en un nivel de areniscas de grano fino de origen aluvial en la parte más baja de la Formación Eslida (facies Buntsandstein), en la zona central de la Cordillera Ibérica. La aparición de este triadotipomorfo confirma la edad Ansíense (Triásico Medio) de la Formación Eslida. La especie encontrada representa el insecto más antiguo hallado en el Mesozoico de España y una interesante información para comprender mejor el proceso de recuperación de los ecosistemas tras la crisis del límite Pérmico-Triásico

    CAST microbulk micromegas in the Canfranc Underground Laboratory

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    During the last taking data campaigns of the CAST experiment, the micromegas detectors have achieved background levels of 5×106\approx 5 \times 10^{-6}keV1^{-1}cm2^{-2}s1^{-1} between 2 and 9 keV. This performance has been possible thanks to the introduction of the microbulk technology, the implementation of a shielding and the development of discrimination algorithms. It has motivated new studies towards a deeper understanding of CAST detectors background. One of the working lines includes the construction of a replica of the set-up used in CAST by micromegas detectors and its installation in the Canfranc Underground Laboratory. Thanks to the comparison between the performance of the detectors underground and at surface, shielding upgrades, etc, different contributions to the detectors background have been evaluated. In particular, an upper limit <2×107< 2 \times 10^{-7}keV1^{-1}cm2^{-2}s1^{-1} for the intrinsic background of the detector has been obtained. This work means a first evaluation of the potential of the newest micromegas technology in an underground laboratory, the most suitable environment for Rare Event Searches.Comment: 6 pages, 8 figures. To appear in the proceedings of the 2nd International Conference on Technology and Instrumentation for Particle Physics (TIPP 2011
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