638 research outputs found

    The inducers 1,3-diaminopropane and spermidine cause the reprogramming of metabolism in Penicillium chrysogenum, leading to multiple vesicles and penicillin overproduction

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    In this article we studied the differential protein abundance of Penicillium chrysogenum in response to either 1,3-diaminopropane (1,3-DAP) or spermidine, which behave as inducers of the penicillin production process. Proteins were resolved in 2-DE gels and identified by tandem MS spectrometry. Both inducers produced largely identical changes in the proteome, suggesting that they may be interconverted and act by the same mechanism. The addition of either 1,3-DAP or spermidine led to the overrepresentation of the last enzyme of the penicillin pathway, isopenicillin N acyltransferase (IAT). A modified form of the IAT protein was newly detected in the polyamine-supplemented cultures. Both inducers produced a rearrangement of the proteome resulting in an overrepresentation of enzymes involved in the biosynthesis of valine and other precursors (e.g. coenzyme A) of penicillin. Interestingly, two enzymes of the homogentisate pathway involved in the degradation of phenylacetic acid (a well-known precursor of benzylpenicillin) were reduced following the addition of either of these two inducers, allowing an increase of the phenylacetic acid availability. Both inducers produced also an increase in the intracellular content of vesicles that derived to vacuoles in late stages and promoted sporulation of P. chrysogenum in solid medium. Biological significance The analysis of global protein changes produced in response to polyamines 1,3-DAP and spermidine provides a valuable information for the understanding of the molecular mechanisms underlying the production of penicillin. This represents useful information to improve the production of this antibiotic and many other bioactive secondary metabolites not only in P. chrysogenum, but in other filamentous fungi as well

    The Servet 3.0 benchmark suite: characterization of network performance degradation

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    This is a post-peer-review, pre-copyedit version of an article published in Computers & Electrical Engineering. The final authenticated version is available online at: https://doi.org/10.1016/j.compeleceng.2013.08.012.[Abstract] Servet is a suite of benchmarks focused on extracting a set of parameters with high influence on the overall performance of multicore clusters. These parameters can be used to optimize the performance of parallel applications by adapting part of their behavior to the characteristics of the machine. Up to now the tool considered network bandwidth as constant and independent of the communication pattern. Nevertheless, the inter-node communication bandwidth decreases on modern large supercomputers depending on the number of cores per node that simultaneously access the network and on the distance between the communicating nodes. This paper describes two new benchmarks that improve Servet by characterizing the network performance degradation depending on these factors. This work also shows the experimental results of these benchmarks on a Cray XE6 supercomputer and some examples of how real parallel codes can be optimized by using the information about network degradation.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación; AP2008-01578Ministerio de Educación; AP2010-4348European Commision; HPC-Europa2 Programme; 22839

    Automatic mapping of parallel applications on multicore architectures using the Servet benchmark suite

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    This is a post-peer-review, pre-copyedit version of an article published in Computers & Electrical Engineering. The final authenticated version is available online at: https://doi.org/10.1016/j.compeleceng.2011.12.007[Abstract] Servet is a suite of benchmarks focused on detecting a set of parameters with high influence on the overall performance of multicore systems. These parameters can be used for autotuning codes to increase their performance on multicore clusters. Although Servet has been proved to detect accurately cache hierarchies, bandwidths and bottlenecks in memory accesses, as well as the communication overhead among cores, up to now the impact of the use of this information on application performance optimization has not been assessed. This paper presents a novel algorithm that automatically uses Servet for mapping parallel applications on multicore systems and analyzes its impact on three testbeds using three different parallel programming models: message-passing, shared memory and partitioned global address space (PGAS). Our results show that a suitable mapping policy based on the data provided by this tool can significantly improve the performance of parallel applications without source code modification.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación; FPU; AP2008-01578Xunta de Galicia; INCITE08PXIB105161P

    Performance Evaluation of Sparse Matrix Products in UPC

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    This is a post-peer-review, pre-copyedit version of an article published in The Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-012-0796-4[Abstract] Unified Parallel C (UPC) is a Partitioned Global Address Space (PGAS) language whose popularity has increased during the last years owing to its high programmability and reasonable performance through an efficient exploitation of data locality, especially on hierarchical architectures like multicore clusters. However, the performance issues that arise in this language due to the irregular structure of sparse matrix operations have not yet been studied. Among them, the selection of an adequate storage format for the sparse matrices can significantly improve the efficiency of the parallel codes. This paper presents an evaluation, using UPC, of the most common sparse storage formats with different implementations of the matrix-vector and matrix-matrix products, which are key kernels in many scientific applications.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación; AP2008-01578Ministerio de Ciencia e Innovación; CAPAP-H3; TIN2010-12011-

    Servet: A Benchmark Suite for Autotuning on Multicore Clusters

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    This is a post-peer-review, pre-copyedit version of an article published in 2010 IEEE International Symposium on Parallel & Distributed Processing (IPDPS). Proceedings. The final authenticated version is available online at: http://dx.doi.org/10.1109/IPDPS.2010.5470358.[Abstract] MapReduce is a powerful tool for processing large data sets used by many applications running in distributed environments. However, despite the increasing number of computationally intensive problems that require low-latency communications, the adoption of MapReduce in High Performance Computing (HPC) is still emerging. Here languages based on the Partitioned Global Address Space (PGAS) programming model have shown to be a good choice for implementing parallel applications, in order to take advantage of the increasing number of cores per node and the programmability benefits achieved by their global memory view, such as the transparent access to remote data. This paper presents the first PGAS-based MapReduce implementation that uses the Unified Parallel C (UPC) language, which (1) obtains programmability benefits in parallel programming, (2) offers advanced configuration options to define a customized load distribution for different codes, and (3) overcomes performance penalties and bottlenecks that have traditionally prevented the deployment of MapReduce applications in HPC. The performance evaluation of representative applications on shared and distributed memory environments assesses the scalability of the presented MapReduce framework, confirming its suitability.Xunta de Galicia; INCITE08PXIB105161PRMinisterio de Ciencia e Innovación; TIN2007-67537-C03-02Ministerio de Educación; FPU; AP2008-0157

    Short-Term Branched-Chain Amino Acid Supplementation Does Not Enhance Vertical Jump in Professional Volleyball Players. A Double-Blind, Controlled, Randomized Study

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    To the best of the author's knowledge, no previous studies have described the effect of branched-chain amino acids (BCAA) on vertical performance during a week in professional volleyball players. This study assessed BCAA supplementation for a week, aiming to improve vertical jump performance in male professional volleyball players. Twelve male volleyballers were randomly assigned to a BCAA group (n = 6) or a control group (n = 6). The BCAA group ingested 21 g over a week, 7 g per day on Monday, Wednesday, and Friday, before a volleyball training session, while the control group drank a placebo drink. Participants performed 8 maximal countermovement jumps (CMJ); the 3 CMJs on Monday and Wednesday were evaluated after warm-up, after plyometric training, and at the end of the training session; and the 2 CMJs on Friday were evaluated after warm-up, and at the end of the training session. Compared with baseline, no significant differences in CMJ over the week were observed in BCAA or control group, neither between groups. The results indicated that 21 g of BCAA supplementation over a week did not improve vertical jump performance in professional volleyball players.Hasta donde los autores saben, no se han descrito estudios previos sobre el efecto de los aminoácidos ramificados (BCAA) en el rendimiento vertical durante una semana en jugadores de voleibol profesionales. Este artículo estudió la suplementación de BCAA durante una semana con el objeto de mejorar el rendimiento del salto vertical en jugadores de voleibol profesionales masculinos. Doce jugadores de voleibol masculinos se asignaron aleatoriamente a un grupo con BCAA (n = 6) o a un grupo de control (n = 6). El grupo con BCAA ingirió 21 g en una semana, 7 g por día los lunes, miércoles y viernes antes de la sesión de entrenamiento de voleibol, mientras que el grupo de control bebió una bebida placebo. Los participantes realizaron 8 saltos máximos de contramovimiento (CMJ); los 3 CMJ de lunes y miércoles se evaluaron después del calentamiento y del entrenamiento pliométrico, y al final de la sesión de entrenamiento; los 2 CMJ del viernes se evaluaron después del calentamiento y al final de la sesión de entrenamiento. En comparación con el valor inicial, no se observaron diferencias significativas en los CMJ a lo largo de la semana, ni en el grupo BCAA ni en el grupo control, tampoco hubo diferencias entre grupos. Los resultados indicaron que 21 g de BCAA administrados durante una semana no mejoraron el rendimiento del salto vertical en jugadores de voleibol profesionale

    Discovery of distant RR Lyrae stars in the Milky Way using DECam

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    We report the discovery of distant RR Lyrae stars, including the most distant known in the Milky Way, using data taken in the g−g-band with the Dark Energy Camera as part of the High cadence Transient Survey (HiTS; 2014 campaign). We detect a total of 173 RR Lyrae stars over a ~120 deg^2 area, including both known RR Lyrae and new detections. The heliocentric distances d_H of the full sample range from 9 to >200 kpc, with 18 of them beyond 90 kpc. We identify three sub-groups of RR Lyrae as members of known systems: the Sextans dwarf spheroidal galaxy, for which we report 46 new discoveries, and the ultra-faint dwarf galaxies Leo IV and Leo V. Following an MCMC methodology, we fit spherical and ellipsoidal profiles of the form rho(R) ~ R^n to the radial density distribution of RR Lyrae in the Galactic halo. The best fit corresponds to the spherical case, for which we obtain a simple power-law index of n=-4.17^{+0.18}_{-0.20}, consistent with recent studies made with samples covering shorter distances. The pulsational properties of the outermost RR Lyrae in the sample (d_H>90 kpc) differ from the ones in the halo population at closer distances. The distribution of the stars in a Period-Amplitude diagram suggest they belong to Oosterhoff-intermediate or Oosterhoff II groups, similar to what is found in the ultra-faint dwarf satellites around the Milky Way. The new distant stars discovered represent an important addition to the few existing tracers of the Milky Way potential in the outer halo.Comment: Accepted for publication in The Astrophysical Journa

    Employability of University Graduates in Spain. OEEU Project

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    En los últimos años, el fomento de la empleabilidad y la adquisición de competencias se ha convertido en una de las prioridades de las universidades en el marco del Espacio Europeo de Educación Superior. Esto ha supuesto un nuevo impulso para afrontar las crecientes dificultades relacionadas con la inserción laboral de los titulados y los desajustes entre la formación recibida y los requisitos de los puestos de trabajo. En el nuevo paradigma educativo, las competencias se han convertido en la referencia a partir de la cual se organiza, planifica y evalúa el aprendizaje, y las agencias de calidad encargadas de evaluar los planes de estudio han introducido nuevos criterios ligados a la empleabilidad y la inserción laboral. Sin embargo, en España la información sobre muchos de estos temas es insuficiente, especialmente en cuanto a las competencias que se necesitan a lo largo de la vida laboral y la aportación de la universidad en su adquisición, los factores que determinan el acceso al empleo y la estabilidad laboral, la satisfacción con el trabajo y con la formación recibida, la idoneidad de las metodologías educativas utilizadas, o los desajustes entre la educación y el empleo. Con esta finalidad, en el año 2012 se creó el Observatorio de Empleabilidad y Empleo Universitarios. El objetivo de este artículo es la presentación de los resultados de esta iniciativa sistémica de política universitaria encaminada al seguimiento y a la medición de la empleabilidad y el empleo de los universitarios en España.In the last years, the promotion of employability and the achievement of competences have become a priority for universities within the European Higher Education Area. For universities, this has entailed a renovated concern for their graduates’ integration into the labour market and the mismatches between the competences achieved during academic education and the employers’ requirements. In the new educational paradigm, competences have become the reference from which the education of university students is organized, planned and evaluated, so the Quality Agencies have introduced new criteria related to employability in academic programs assessment. However, in Spain there is not enough information on these issues, especially regarding the competences that students will need in their career path and the role of higher education in its acquisition, the factors that influence to obtain a job and job stability, job and education satisfaction, the suitability of the educational methodologies, or the mismatches between education and labour market. With this aim, in 2012, the Observatory for Employability and University Employment was created. The objective of this article is to present the results of this systemic university policy initiative focused on monitoring and measuring the employability and employment of university graduates in Spain
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