Adecuación de la granularidad de las comunicaciones en aplicaciones MPI a las características de la red de interconexión

Este estudio se centra en la granularidad de las comunicaciones en aplicaciones MPI. Nuestra hipótesis consiste en que la granularidad óptima para una red exterior al chip no es la óptima para una red interior al chip. Esto significa que las aplicaciones ejecutadas dentro del chip pueden ser aceleradas al reducir el tamaño de los mensajes.Montaner Mas, H. (2007). Adecuación de la granularidad de las comunicaciones en aplicaciones MPI a las características de la red de interconexión. http://hdl.handle.net/10251/1237

Programa de fortalecimiento de competencias del siglo XXI mediante la metodología ABP: valoración por parte de estudiantes de secundaria

In recent decades, each year are the most important countries in the development of21st century skills in the school system, but the implementation has not been free of difficulties, instead of the Program d’acompanyament i accés The Higher Education The Catholic University of Sant Concepció will design and execute a program to reinforce the competencies of the 21st century through the ABP methodology in secondary school students in vulnerable contexts. After completing the cycle, you can apply an evaluation essay, tenint in cognitive skills, intrapersonal and interpersonal skills and self-assessment of participation. The results indicate that the students will donate a high degree of appreciation to the cycle, they will publish the accent on the intrapersonal and interpersonal skills of cognition; They will also provide an appreciation of the learning methodology based on projectes com mit mità for a meaningful apprehension. They will also indicate, mitjançant an autoavaluació, an important note of participation in the project. The results show that a cycle like the one described above is a great acceptance of the students who study the learning and distressing process.En las últimas décadas son cada vez más los países que están dando una gran importancia al desarrollo de competencias del siglo XXI en sus sistemas escolares, pero la implementación de estos no han estado exenta de dificultades, antes esto que el Programa de Acompañamiento y Acceso Efectivo a la educación superior de la Universidad Católica de la Santísima Concepción diseñó y ejecutó un programa de fortalecimiento de competencias para el siglo XXI mediante la metodología de ABP en estudiantes de secundaria en contextos vulnerables.Finalizado el ciclo, se les aplicó una encuesta de valorización de éste, considerando las competencias cognitivas, intrapersonales e interpersonales y la autoevaluación de su participación. Los resultados indicaron que los estudiante otorgan un alto grado de valorización al ciclo, destacando las competencias intrapersonales e interpersonales por sobre las cognitivas, además otorgaron un alto grado de valorización a la metodología de aprendizaje basado en proyecto como vía para un aprendizaje significativo. También indicaron, mediante una autoevaluación, una nota alta de participación en el proyecto. Los resultados ponen de manifiesto que un ciclo como el descrito, tienen una alta aceptación por parte de los estudiantes respecto a su proceso de enseñanza y aprendizaje

Debilidades identificadas por docentes universitarios respecto a contenidos y habilidades de matemática en estudiantes de primer año que ingresan a la universidad por vía inclusiva / Weaknesses identified by university teachers regarding content and math skills in firstyear students who enter the university via inclusive

Esta investigación tiene como objetivo identificar las debilidades de contenidos yhabilidades de matemática en estudiantes que ingresan por vías inclusiva a launiversidad, para la identificación de estas debilidades se realizaron FocosGrupales con docentes de matemática que dictan cursos en primer año. Mediante la metodología de análisis de datos se concluyo que existen debilidades en las áreas de números, algebra, geometría, estadística y azar y en las habilidades de modelar, representar, resolución de problema y trabajo colaborativo. Ante estos resultados se hace evidente la necesidad de de diseñar programas de reforzamiento de contenidos y desarrollo de habilidades por parte de la universidad y de la escuela considerando lo que manifestaron los docentes universitarios

Hardware-Supported Cryptographic Protection of Random Access Memory

Confidential Computing is the protection of data in use from access or modification by any unauthorized agent, including privileged software. For example, in Intel SGX (Client and Scalable versions) and TDX, AMD SEV, Arm CCA, and IBM Ultravisor this protection is implemented via access control policies. Some of these architectures also include memory protection schemes relying on cryptography, to protect against physical attacks. We review and classify such schemes, from academia and industry, according to protection levels corresponding of adversaries with varying capabilities, budget, and strategy. The building blocks of all memory protection schemes are encryption and integrity primitives and modes of operation, as well as anti-replay structures. We review these building blocks, consider their possible combinations, and evaluate the performance impact of the resulting schemes. We present a framework for performance evaluation in a simulated system. To understand the best and worst case overhead, systems with varying load levels are considered. We propose new solutions to further reduce the performance and memory overheads of such technologies. Advanced counter compression techniques make it viable to store counters used for replay protection in a physically protected memory. By additionally repurposing some ECC bits to store integrity tags, we can provide the highest levels of confidentiality, integrity, and replay protection at a hitherto unattained performance penalty, namely 3.32%, even under extreme load and at costs that make them reasonable in data centers. Combinations of technologies that are suitable for client devices are also discussed

A new degree of freedom for memory allocation in clusters

Improvements in parallel computing hardware usually involve increments in the number of available resources for a given application such as the number of computing cores and the amount of memory. In the case of shared-memory computers, the increase in computing resources and available memory is usually constrained by the coherency protocol, whose overhead rises with system size, limiting the scalability of the final system. In this paper we propose an efficient and cost-effective way to increase the memory available for a given application by leveraging free memory in other computers in the cluster. Our proposal is based on the observation that many applications benefit from having more memory resources but do not require more computing cores, thus reducing the requirements for cache coherency and allowing a simpler implementation and better scalability. Simulation results show that, when additional mechanisms intended to hide remote memory latency are used, execution time of applications that use our proposal is similar to the time required to execute them in a computer populated with enough local memory, thus validating the feasibility of our proposal. We are currently building a prototype that implements our ideas. The first results from real executions in this prototype demonstrate not only that our proposal works but also that it can efficiently execute applications that make use of remote memory resources. © 2011 Springer Science+Business Media, LLC.This work has been supported by PROMETEO from Generalitat Valenciana (GVA) under Grant PROMETEO/2008/060.Montaner Mas, H.; Silla Jiménez, F.; Fröning, H.; Duato Marín, JF. (2012). A new degree of freedom for memory allocation in clusters. Cluster Computing. 15(2):101-123. https://doi.org/10.1007/s10586-010-0150-7S1011231523leaf Systems: http://www.3leafsystems.comAcharya, A., Setia, S.: Availability and utility of idle memory in workstation clusters. ACM SIGMETRICS Perform. Eval. Rev. 27(1), 35–46 (1999). doi: 10.1145/301464.301478Anderson, T., Culler, D., Patterson, D.: A case for NOW (Networks of Workstations). IEEE MICRO 15(1), 54–64 (1995). doi: 10.1109/40.342018HyperTransport Technology Consortium. HyperTransport I/O Link Specification Revision 3.10 (2008). Available at http://www.hypertransport.orgBienia, C., Kumar, S., et al.: The parsec benchmark suite: Characterization and architectural implications. In: Proceedings of the 17th PACT (2008)Chapman, M., Heiser, G.: vNUMA: A virtual shared-memory multiprocessor. In: Proceedings of the 2009 USENIX Annual Technical Conference, San Diego, USA, 2000, pp. 349–362. (2009)Charles, P., Grothoff, C., Saraswat, V., et al.: X10: an object-oriented approach to non-uniform cluster computing. ACM SIGPLAN Not. 40(10), 519–538 (2005)Consortium, H.: HyperTransport High Node Count, Slides. http://www.hypertransport.org/default.cfm?page=HighNodeCountSpecificationConway, P., Hughes, B.: The AMD opteron northbridge architecture. IEEE MICRO 27(2), 10–21 (2007). doi: 10.1109/MM.2007.43Conway, P., Kalyanasundharam, N., Donley, G., et al.: Blade computing with the AMD Opteron processor (Magny-Cours). Hot chips 21 (2009)Duato, J., Silla, F., Yalamanchili, S., et al.: Extending HyperTransport protocol for improved scalability. First International Workshop on HyperTransport Research and Applications (2009)Feeley, M.J., Morgan, W.E., Pighin, E.P., Karlin, A.R., Levy, H.M., Thekkath, C.A.: Implementing global memory management in a workstation cluster. In: SOSP ’95: Proceedings of the Fifteenth ACM Symposium on Operating Systems Principles, pp. 201–212. ACM, New York (1995). doi: 10.1145/224056.224072Fröning, H., Litz, H.: Efficient hardware support for the partitioned global address space. In: 10th Workshop on Communication Architecture for Clusters (2010)Fröning, H., Nuessle, M., Slogsnat, D., Litz, H., Brüening, U.: The HTX-board: a rapid prototyping station. In: 3rd annual FPGAworld Conference (2006)Garcia-Molina, H., Salem, K.: Main memory database systems: an overview. IEEE Trans. Knowl. Data Eng. 4(6), 509–516 (1992). doi: 10.1109/69.180602Gaussian 03: http://www.gaussian.comGray, J., Liu, D.T., Nieto-Santisteban, M., et al.: Scientific data management in the coming decade. SIGMOD Rec. 34(4), 34–41 (2005). doi: 10.1145/1107499.1107503IBM journal of Research and Development staff: Overview of the IBM Blue Gene/P project. IBM J. Res. Dev. 52(1/2), 199–220 (2008)IBM z Series: http://www.ibm.com/systems/zIn-Memory Database Systems (IMDSs) Beyond the Terabyte Size Boudary: http://www.mcobject.com/130/EmbeddedDatabaseWhitePapers.htmKeltcher, C., McGrath, K., Ahmed, A., Conway, P.: The AMD opteron processor for multiprocessor servers. Micro IEEE 23(2), 66–76 (2003). doi: 10.1109/MM.2003.1196116Kottapalli, S., Baxter, J.: Nehalem-EX CPU architecture. Hot chips 21 (2009)Liang, S., Noronha, R., Panda, D.: Swapping to remote memory over infiniband: an approach using a high performance network block device. In: Cluster Computing, 2005. IEEE International, pp. 1–10. (2005) doi: 10.1109/CLUSTR.2005.347050Litz, H., Fröning, H., Nuessle, M., Brüening, U.: A hypertransport network interface controller for ultra-low latency message transfers. HyperTransport Consortium White Paper (2007)Litz, H., Fröning, H., Nuessle, M., Brüening, U.: VELO: A novel communication engine for ultra-low latency message transfers. In: 37th International Conference on Parallel Processing, 2008. ICPP ’08, pp. 238–245 (2008). doi: 10.1109/ICPP.2008.85Magnusson, P., Christensson, M., Eskilson, J., et al.: Simics: a full system simulation platform. Computer 35(2), 50–58 (2002). doi: 10.1109/2.982916Martin, M., Sorin, D., Beckmann, B., et al.: Multifacet’s general execution-driven multiprocessor simulator (GEMS) toolset. ACM SIGARCH Comput. Archit. News 33(4), 92–99 (2005) doi: 10.1145/1105734.1105747MBA3 NC Series Catalog: http://www.fujitsu.com/global/services/computing/storage/hdd/ehdd/mba3073nc-mba3300nc.htmlMcCalpin, J.D.: Memory bandwidth and machine balance in current high performance computers. In: IEEE Computer Society Technical Committee on Computer Architecture (TCCA) Newsletter, pp. 19–25 (1995)NUMAChip: http://www.numachip.com/Oguchi, M., Kitsuregawa, M.: Using available remote memory dynamically for parallel data mining application on ATM-connected PC cluster. In: IPDPS 2000. Proceedings, 14th International, pp. 411–420 (2000). doi: 10.1109/IPDPS.2000.846014Oleszkiewicz, J., Xiao, L., Liu, Y.: Parallel network RAM: effectively utilizing global cluster memory for large data-intensive parallel programs. In: International Conference on Parallel Processing, 2004. ICPP 2004, vol. 1, pp. 353–360 (2004). doi: 10.1109/ICPP.2004.1327942Ronstrom, M., Thalmann, L.: MySQL cluster architecture overview. Technical White Paper. MySQL (2004)ScaleMP: http://www.scalemp.comSGI: Technical advances in the SGI Altix UV architecture, White Paper. http://www.sgi.com/products/servers/altix/uv/Slogsnat, D., Giese, A., Nüssle, M., Brüning, U.: An open-source HyperTransport core. ACM Trans. Reconfigurable Technol. Syst. 1(3), 1–21 (2008). doi: 10.1007/s10586-010-0150-7Szalay, A.S., Gray, J., vandenBerg, J.: Petabyte Scale Data Mining: Dream or Reality? CoRR cs.DB/0208013 (2002)Tuck, J., Ceze, L., Torrellas, J.: Scalable cache miss handling for high memory-level parallelism. In: Microarchitecture, 2006. MICRO-39. 39th Annual IEEE/ACM International Symposium on (2006)Violin Memory: http://violin-memory.comDynamic Logical Partitioning. White Paper: http://www.ibm.com/systems/p/hardware/whitepapers/dlpar.htmlYelick, K.: Computer architecture: Opportunities and challenges for scalable applications. Sandia CSRI Workshop on Next-generation scalable applications: When MPI-only is not enough (2008)Yelick, K.: Programming models: Opportunities and challenges for scalable applications. Sandia CSRI Workshop on Next-generation scalable applications: When MPI-only is not enough (2008

Taller de Resolución de Problemas de Matemática con material concreto: opinión de profesores

The purpose of this article is to describe a Mathematical Problem Solving workshop with specific material and to publicize the opinions of the participating teachers. Students from the Pre‐University of Bío‐Bío University participated in the workshops. A descriptive analysis of the data collected on the implementation of the workshops is carried out through a semi‐structured interview with the teachers who carry out the workshops. The results indicate that working with students with descending disciplinary content can be improved, in addition to strengthening comprehension skills, applying and evaluating the use of specific methods that lead to better preparation for university. It is important that the Mathematical Problem Solving activities are overcrowded, since there are multiple benefits that begin in the teaching‐learning process.Este articulo tiene como propósito describir un taller de Resolución de Problemas de Matemática con material concreto y dar a conocer las opiniones de los profesores participantes. En los talleres participaron estudiantes del Preuniversitario de la universidad del Bío‐Bío. Se realizó un análisis descriptivo de los datos recolectados sobre la implementación de los talleres mediante entrevistas semiestructuradas a los profesores que realizaron los talleres. Los resultados indican que el trabajo con estudiantes con contenidos disciplinares descendidos se puede ver mejorado, además se fortalecen las habilidades de comprender, aplicar y evaluar al utilizar la metodología permitiendo que lleguen con una mejor preparación a la universidad. Es importante que se masifiquen las actividades de Resolución de Problema de Matemáticas, pues son múltiples los beneficios que entregan en el proceso de enseñanza‐aprendizaje

Landscape Systems and Human Land-Use Interactions in Mediterranean Highlands and Littoral Plains during the Late Holocene: Integrated Analysis from the InterAmbAr Project (North-Eastern Catalonia).

The main goal of the InterAmbAr reseach project is to analyze the relationships between landscape systems and human land-use strategies on mountains and littoral plains from a long-term perspective. The study adopts a high resolution analysis of small-scale study areas located in the Mediterranean region of north-eastern Catalonia. The study areas are distributed along an altitudinal transect from the high mountain (above 2000m a.s.l.) to the littoral plain of Empordà (Fig. 1). High resolution interdisciplinary research has been carried out from 2010, based on the integration of palaeoenvironmental and archaeological data. The micro-scale approach is used to understand human-environmental relationships. It allows better understanding of the local-regional nature of environmental changes and the synergies between catchment-based systems, hydro-sedimentary regimes, human mobility, land-uses, human environments, demography, etc

Landscape Systems and Human Land-Use Interactions in Mediterranean Highlands and Littoral Plains during the Late Holocene: Integrated Analysis from the InterAmbAr Project (North-Eastern Catalonia).

The main goal of the InterAmbAr reseach project is to analyze the relationships between landscape systems and human land-use strategies on mountains and littoral plains from a long-term perspective. The study adopts a high resolution analysis of small-scale study areas located in the Mediterranean region of north-eastern Catalonia. The study areas are distributed along an altitudinal transect from the high mountain (above 2000m a.s.l.) to the littoral plain of Empordà (Fig. 1). High resolution interdisciplinary research has been carried out from 2010, based on the integration of palaeoenvironmental and archaeological data. The micro-scale approach is used to understand human-environmental relationships. It allows better understanding of the local-regional nature of environmental changes and the synergies between catchment-based systems, hydro-sedimentary regimes, human mobility, land-uses, human environments, demography, etc

Cardioembolic Ischemic Stroke Gene Expression Fingerprint in Blood: a Systematic Review and Verification Analysis

An accurate etiological classification is key to optimize secondary prevention after ischemic stroke, but the cause remains undetermined in one third of patients. Several studies pointed out the usefulness of circulating gene expression markers to discriminate cardioembolic (CE) strokes, mainly due to atrial fibrillation (AF), while only exploring them in small cohorts. A systematic review of studies analyzing high-throughput gene expression in blood samples to discriminate CE strokes was performed. Significantly dysregulated genes were considered as candidates, and a selection of them was validated by RT-qPCR in 100 patients with defined CE or atherothrombotic (LAA) stroke etiology. Longitudinal performance was evaluated in 12 patients at three time points. Their usefulness as biomarkers for AF was tested in 120 cryptogenic strokes and 100 individuals at high-risk for stroke. Three published studies plus three unpublished datasets were considered for candidate selection. Sixty-seven genes were found dysregulated in CE strokes. CREM, PELI1, and ZAK were verified to be up-regulated in CE vs LAA (p = 0.010, p = 0.003, p < 0.001, respectively), without changes in their expression within the first 24 h after stroke onset. The combined up-regulation of these three biomarkers increased the probability of suffering from CE stroke by 23-fold. In cryptogenic strokes with subsequent AF detection, PELI1 and CREM showed overexpression (p = 0.017, p = 0.059, respectively), whereas in high-risk asymptomatic populations, all three genes showed potential to detect AF (p = 0.007, p = 0.007, p = 0.015). The proved discriminatory capacity of these gene expression markers to detect cardioembolism even in cryptogenic strokes and asymptomatic high-risk populations might bring up their use as biomarkers.Neurovascular Research Laboratory acknowledges funding for this project by PI15/00354 and PI18/804 grant from Fondo de Investigaciones Sanitarias and takes part in the Spanish stroke research network INVICTUS+ (RD16/0019/0021) of the Instituto de Salud Carlos III (co-financed by the European Regional Development Fund, FEDER). Moreover, it has been partially financed by 201528-30-31-3 grant from Fundació la Marató de TV3. A.B is supported by a Juan Rodés research contract JR16/00008 from the Instituto de Salud Carlos III

Cold stress protein RBM3 responds to hypothermia and is associated with good stroke outcome

RNA-binding motif protein 3 is a molecular marker of hypothermia that has proved neuroprotective in neurodegenerative disease models. However, its relationship to the well-recognized therapeutic effect of hypothermia in ischaemic stroke had not been studied. In this work, the expression of RNA-binding motif protein 3 was investigated in ischaemic animal models subjected to systemic and focal brain hypothermia, specifically the effects of RNA-binding motif protein 3 silencing and overexpression on ischaemic lesions. Moreover, the association of RNA-binding motif protein 3 levels with body temperature and clinical outcome was evaluated in two independent cohorts of acute ischaemic stroke patients (n = 215); these levels were also determined in a third cohort of 31 patients derived from the phase III EuroHYP-1 trial of therapeutic cooling in ischaemic stroke. The preclinical data confirmed the increase of brain RNA-binding motif protein 3 levels in ischaemic animals subjected to systemic and focal hypothermia; this increase was selectively higher in the cooled hemisphere of animals undergoing focal brain hypothermia, thus confirming the direct effect of hypothermia on RNA-binding motif protein 3 expression, while RNA-binding motif protein 3 up-regulation in ischaemic brain regions led to functional recovery. Clinically, patients with body temperature <37.5°C in the first two cohorts had higher RNA-binding motif protein 3 values at 24 h and good outcome at 3 months post-ischaemic stroke, while RNA-binding motif protein 3 levels in the cooled third cohort tended to exceed those in placebo-treated patients. These results make RNA-binding motif protein 3 a molecular marker associated with the effect of hypothermia in ischaemic stroke and suggest its potential application as a promising protective target. Hypothermia is an effective neuroprotective treatment in stroke. We have demonstrated that the expression of RBM3 is increased under hypothermia treatment in animal models of ischaemia and stroke patients. These results evidence the potential application of RBM3 as a promising protective target against ischaemi