1,170 research outputs found

    Multi-GPU maximum entropy image synthesis for radio astronomy

    Full text link
    The maximum entropy method (MEM) is a well known deconvolution technique in radio-interferometry. This method solves a non-linear optimization problem with an entropy regularization term. Other heuristics such as CLEAN are faster but highly user dependent. Nevertheless, MEM has the following advantages: it is unsupervised, it has a statistical basis, it has a better resolution and better image quality under certain conditions. This work presents a high performance GPU version of non-gridding MEM, which is tested using real and simulated data. We propose a single-GPU and a multi-GPU implementation for single and multi-spectral data, respectively. We also make use of the Peer-to-Peer and Unified Virtual Addressing features of newer GPUs which allows to exploit transparently and efficiently multiple GPUs. Several ALMA data sets are used to demonstrate the effectiveness in imaging and to evaluate GPU performance. The results show that a speedup from 1000 to 5000 times faster than a sequential version can be achieved, depending on data and image size. This allows to reconstruct the HD142527 CO(6-5) short baseline data set in 2.1 minutes, instead of 2.5 days that takes a sequential version on CPU.Comment: 11 pages, 13 figure

    Pseudoartrosis congénita de clavícula: a propósito de un caso

    Get PDF
    La pseudoartrosis congénita de clavícula es una entidad infrecuente de etiología aún controvertida. Su diagnóstico es sencillo y su abordaje terapéutico es siempre quirúrgico. Se presenta un nuevo caso de pseudoartrosis congenita de clavícula diagnosticado en un niño de 4 años de edad. El tratamiento consistió en decorticación de los fragmentos y síntesis con aguja de Kirschner. Se efectúa una revisión de la literatura abordando las teorías etiopatogénicas y el tratamiento de esta afección.Congenital pseudoarthrosis of the clavicle is an unfrequent entity with already controversial etiology. The diagnosis is easy and the therapeutic approach allways involves surgery. A new case of congenital pseudoarthrosis of the clavicle in a 4-year-old boy is reported. The treatment consisted in decortication of both fragments of the clavicle and fixation with a Kirschner wire. A review of the literature focused on etiopathogenic theories and treatment is also performed

    Transfusión autóloga diferida en cirugía primaria de prótesis total de cadera

    Get PDF
    Se analizan los resultados obtenidos mediante transfusión autóloga diferida (TAD) en 50 pacientes intervenidos de prótesis total primaria de cadera. Las extracciones de sangre se realizaron con una semana de intervalo, transcurriendo al menos 72 horas entre la última extracción y la intervención. El total de unidades extraídas para TAD ha sido 100, transfundiéndose 77, lo que supuso el 91% de la sangre transfundida a estos pacientes. 8 pacientes precisaron la transfusión de 1 unidad de sangre homóloga. No se produjeron reacciones adversas ni durante la extracción ni tras la transfusión y los pacientes recuperaron sus cifras normales de hemoglobina y hematocrito al cabo de 1 mes de la intervención. La TAD es un procedimiento sencillo y eficaz de reposición de sangre en cirugía programada de cadera.The results of deferred autologous blood transfusion in 50 patients who underwent total hip replacement are analyzed. Patients donated blood in weekly bases, last donation 72 hours before surgery. A total of 100 units were obtained by this method and 77 of them were used, wich means 91% of the blood transfused to these patients. Eight patients were transfused with homologue blood. No adverse reactions could be observed either in relation with the autodonation of blood or the autotransfusion. One month after surgery, all patients showed hemoglobin and hematocrit whitin normal limits. Autologous transfusion is a simple and efficacious procedure of blood replacement in primary hip arthroplasty

    Forest resampling for distributed sequential Monte Carlo

    Get PDF
    This paper brings explicit considerations of distributed computing architectures and data structures into the rigorous design of Sequential Monte Carlo (SMC) methods. A theoretical result established recently by the authors shows that adapting interaction between particles to suitably control the Effective Sample Size (ESS) is sufficient to guarantee stability of SMC algorithms. Our objective is to leverage this result and devise algorithms which are thus guaranteed to work well in a distributed setting. We make three main contributions to achieve this. Firstly, we study mathematical properties of the ESS as a function of matrices and graphs that parameterize the interaction amongst particles. Secondly, we show how these graphs can be induced by tree data structures which model the logical network topology of an abstract distributed computing environment. Thirdly, we present efficient distributed algorithms that achieve the desired ESS control, perform resampling and operate on forests associated with these trees

    Southern Mediterranean development through trade, Foreign Direct Investment and migration

    Get PDF
    Since the launch of the Barcelona Process in 1995 and later the Euro-Mediterranean Partnership, economic relationship between the European Union (EU) and Southern Mediterranean has grown tremendously. Trade volume, in terms of absolute value, between the EU and Southern Mediterranean has grown to an unprecedented height. Although the value has increased, foreign direct investment (FDI) from the EU to Southern Mediterranean remains low. South-to-North migration has also undoubtedly increased given the fact that it has become one of the priority concerns of the EU. Development has taken place through these economic exchanges. However, economic development growth rate remains considerably low compared to that of Latin America and Southeast Asia. This paper discusses about the economic development dynamic of Southern Mediterranean in comparison with that of Latin America and Southeast Asia through economic indicators, economic openness and trade, FDI and migration flows and structures. It also discusses about the challenges faced by Southern Mediterranean and how the economic crisis in the EU may affect their economic relationship.Since the launch of the Barcelona Process in 1995 and later the Euro-Mediterranean Partnership, economic relationship between the European Union (EU) and Southern Mediterranean has grown tremendously. Trade volume, in terms of absolute value, between the EU and Southern Mediterranean has grown to an unprecedented height. Although the value has increased, foreign direct investment (FDI) from the EU to Southern Mediterranean remains low. South-to-North migration has also undoubtedly increased given the fact that it has become one of the priority concerns of the EU. Development has taken place through these economic exchanges. However, economic development growth rate remains considerably low compared to that of Latin America and Southeast Asia. This paper discusses about the economic development dynamic of Southern Mediterranean in comparison with that of Latin America and Southeast Asia through economic indicators, economic openness and trade, FDI and migration flows and structures. It also discusses about the challenges faced by Southern Mediterranean and how the economic crisis in the EU may affect their economic relationship

    Utilización conjunta de técnicas de inmovilización y fitoextracción en la descontaminación de suelos

    Get PDF
    Se estudia la viabilidad de la combinación de dos técnicas (estabilización y fitoextracción) a partir del estudio de los lixiviados y de las tasas de fitoextracción. Como enmienda estabilizante se usó lodo de mármol (~ 97% de CaCO3) y como planta fitoextractora Brassica juncea L. El estudio se llevó a cabo en dos suelos (uno ácido y otro básico) contaminados por As, Pb y Zn. La adición de lodo de mármol disminuyo significativamente la concentración de contaminantes en los lixiviados, al tiempo que la fitoextracción de dichos contaminantes siguió siendo relativamente elevada. Por tanto, la utilización conjunta de ambas técnicas reduce significativamente el lavado y dispersión de contaminantes al tiempo que sigue posibilitando su fitoextracción

    2007 Symposium Announcement

    Get PDF
    The fungal genera Metarhizium and Beauveria are considered as both entomopathogens and endophytes; they are able to colonize a wide variety of plants and can cause increased plant growth and protect plants against pests. In view of the need for new biological methods for plant protection and how promising and little studied candidates entomopathogens are, the aim of this research was to evaluate the potential of two isolates of Metarhizium robertsii (ESALQ 1622) and Beauveria bassiana (ESALQ 3375) to suppress spider mite Tetranychus urticae population growth and ability to promote growth of bean plants Phaseolus vulgaris after seed treatment, in order to develop an innovative strategy by using these fungi as inoculants to improve both spider mites control and plant growth and yield. In addition, behavioral responses and predation rates of the predatory mite Phytoseiulus persimilis towards fungal treated plants and spider mites from these plants were also evaluated in leaf disc assays to assess potential conflicting effects of the fungal inoculations on overall pest control at higher trophic levels. Seed inoculations by the two isolates of M. robertsii and B. bassiana were done individually and in combinations to evaluate potential benefits of co-inoculants. The results showed a significant reduction in T. urticae populations and improved plant development when inoculated with M. robertsii and B. bassiana individually and in combination. The predatory mite P. persimilis showed no difference in the predation rate on T. urticae from treated and untreated plants even though the predators were most likely to feed on spider mites from fungal treated plants during the first half of the trial, and on spider mites from control plants during the remainder of the trial. Overall, the two fungal isolates have potential as seed inoculants to suppress spider mites in bean and the strategy appears to have no conflict with use of predatory mites. Co-inoculation of both fungal isolates showed no additional benefits compared to single isolate applications under the given test conditions

    Sarcoma de Partes Blandas como Hallazgo Casual: a Propósito de Cuatro Observaciones

    Get PDF
    Se presentan en este trabajo cuatro pacientes con sarcoma s de partes blandas que fueron diagnosticados de fibrohistiocitoma maligno, osteosarcoma extraesquelético, sarcoma sinovial y sarcoma indiferenciado. En todos ellos el tumor fué un hallazgo casual apreciado en exploraciones orientadas hacia otros procesos por los que acudieron al hospital. Se insiste en el diagnóstico precoz y en el correcto tratamiento de este tipo de sarcomas y se recomienda la punción biopsia ante la presencia de tumoraciones blandas con crecimiento progresivo, aún sin otro tipo de sintomatología.Th e author s hav e colecte d fou r patients diagnose d o f Soft tissu e Sar - comas. Th e histologica l diagnosis was, malignan t fibrou s histiocytoma , extraskele - t a l osteosarcoma , synovia l sarcom a an d no-differentiate d sarcoma . Al l o f the m th e tu m o r wa s a casua l findin g durin g th e exploratio n suspectin g othe r pathology . The y emphasiz e a t th e earl y diagnosis an d correc t managemen t o f this typ e o f sarcomas, a s wel l a s th e needl e biops y (close d biopsy ) o f soft tumor s wit h progresiv e growth , even without clinical symptoms
    corecore