Trigonometría del cuadrado

Este escrito presenta una visión alternativa del estudio de las funciones trigonométricas, enmarcada en una manera diferente de medir ángulos que se basa en el cuadrado, y que consideramos, contribuye a enriquecer el tratamiento didáctico que se le otorga usualmente a este tipo de funciones en la enseñanza secundaria o superior. Así, se presenta un paralelo que permite evidenciar las ventajas que esta trigonometría del cuadrado tiene sobre la circular

Contribución al estudio de flavonoides en hojas y determinación de la actividad antioxidante en Chromolaena tacotana (klatt) T. M. King & H. Rob

Las Asteráceas es una de las familias más numerosas y diversas del reino de las plantas cuenta en total 24000 a 30000 especies, entre los géneros esta la Chromolaena que de acuerdo a los estudios realizados se han aislados compuestos como sesquiterpenos, cumarinas, ácidos grasos y flavonoides etc, dentro de este género se encuentra la especie Chromolaena tacotana que contiene flavonoides con actividad antineoplásica, citotóxica y antioxidante. Las hojas de C. tacotana inicialmente se sometieron a una extracción en un equipo de Soxhlet con diclorometano (CH2Cl2), después de obtener el extracto se realizó una partición por métodos cromatográficos en columna con diferentes sistemas de elución e incrementando la polaridad (Petrol:AcOEt, AcOEt:MeOH, MeOH), la pureza se monitoreaba por medio de cromatografía de capa delgada (CCD) y la elucidación estructural por RMN1H, 13C y UV-Vis. En este estudio se identificaron tres flavonoides, (Ct5) 5,3´-dihidroxi-7,4´-dimetoxiflavonol; (Ct6) 3´,4´-dihidroxi-5,7-dimetoxiflavanona; (Ct7) 4´-hidroxi-5,7-dimetoxiflavanona a los que se les evaluó la actividad antioxidante por el método de DPPH, utilizando como control positivo la quercetina que mostró una actividad equivalente a un IC50 de 8.670 μg/mL, el flavonoide Ct6 presentó la mejor respuesta de inhibición de radicales libres con un IC50 de 6,272μg/mL, Ct5 con IC50 de 53.310 μg/mL, y el Ct7 presento actividad baja.PregradoQuímico(a

Application-level differential checkpointing for HPC applications with dynamic datasets

High-performance computing (HPC) requires resilience techniques such as checkpointing in order to tolerate failures in supercomputers. As the number of nodes and memory in supercomputers keeps on increasing, the size of checkpoint data also increases dramatically, sometimes causing an I/O bottleneck. Differential checkpointing (dCP) aims to minimize the checkpointing overhead by only writing data differences. This is typically implemented at the memory page level, sometimes complemented with hashing algorithms. However, such a technique is unable to cope with dynamic-size datasets. In this work, we present a novel dCP implementation with a new file format that allows fragmentation of protected datasets in order to support dynamic sizes. We identify dirty data blocks using hash algorithms. In order to evaluate the dCP performance, we ported the HPC applications xPic, LULESH 2.0 and Heat2D and analyze them regarding their potential of reducing I/O with dCP and how this data reduction influences the checkpoint performance. In our experiments, we achieve reductions of up to 62% of the checkpoint time.This project has received funding from the European Unions Seventh Framework Programme (FP7/2007-2013) and the Horizon 2020 (H2020) funding framework under grant agreement no. H2020-FETHPC-754304 (DEEP-EST); and from the European Unions Horizon 2020 research and innovation programme under the LEGaTO Project (legato- project.eu), grant agreement No 780681.Peer ReviewedPostprint (author's final draft

(b,ν)(b, \nu)-algebras and their twisted modules

We give an intrinsic characterization of the closure under shifts $\mathbb{Z}{\cal A}$ of a given strictly unital $A_\infty$-category ${\cal A}$. We study some arithmetical properties of its higher operations and special conflations in the precategory of cycles ${\cal Z}({\cal A})$ of its category of twisted modules. We exhibit a structure for ${\cal Z}({\cal A})$ similar to a special Frobenius category. We derive that the cohomology category ${\cal H}({\cal A})$ appears as the corresponding stable category and then we review how this implies that ${\cal H}({\cal A})$ is a triangulated category

Discovering the Ethereum2 P2P network

Achieving the equilibrium between scalability, sustainability, and security while keeping decentralization has prevailed as the target solution for decentralized blockchain applications over the last years. Several approaches have been proposed by multiple blockchain teams to achieve it, Ethereum being among them. Ethereum is on the path of a major protocol improvement called Ethereum 2.0 (Eth2), implementing Sharding and introducing the Proof-of-Stake (PoS). As the change of consensus mechanism is a delicate matter, this improvement will be achieved through different phases, the first of which is the implementation of the Beacon Chain. As Ethereum1, Eth2 relies on a decentralized peer-to-peer (p2p) network for the message distribution. Up to date, we estimate that there are around 5.000 nodes in the Eth2 main net geographically distributed. However, the topology of this one still prevails unknown. In this paper, we present the results obtained from the analysis we performed on the Eth2 p2p network. Describing the topology of the network, as possible hazards that this one implies.This work has been supported by the Ethereum Foundation under Grant FY20-0198.Peer ReviewedPostprint (author's final draft

Armiarma: Ethereum2 Network Monitoring Tool

Achieving the equilibrium between scalability, sustainability and security has prevailed as the ideal solution for decentralized blockchain applications over the last years. Several approaches have been proposed being Ethereum a solid proposal among them. Ethereum is on the path of a major protocol improvement called Ethereum 2.0 (Eth2), implementing Sharding and introducing the Proof-of-Stake (PoS). As the change of consensus mechanism is a delicate matter, this improvement will be achieved through different phases, the first of which is the implementation of the Beacon Chain. The implementation of the latest has been stated with the recent launch of the Eth2 main net. In this work, we introduce an Eth2 network monitor tool, called Armiarma, used to generate a complete analysis of the p2p network of the Eth2 main net. In this paper, we present some of the results of what this Eth2 network monitor can achieve

Performance Study of Non-volatile Memories on a High-End Supercomputer

The first exa-scale supercomputers are expected to be operational in China, USA, Japan and Europe within the early 2020’s. This allows scientists to execute applications at extreme scale with more than 1018 floating point operations per second (exa-FLOPS). However, the number of FLOPS is not the only parameter that determines the final performance. In order to store intermediate results or to provide fault tolerance, most applications need to perform a considerable amount of I/O operations during runtime. The performance of those operations is determined by the throughput from volatile (e.g. DRAM) to non-volatile stable storage. Regarding the slow growth in network bandwidth compared to the computing capacity on the nodes, it is highly beneficial to deploy local stable storage such as the new non-volatile memories (NVMe), in order to avoid the transfer through the network to the parallel file system. In this work, we analyse the performance of three different storage levels of the CTE-POWER9 cluster, located at the Barcelona Supercomputing Center (BSC). We compare the throughputs of SSD, NVMe on the nodes to the GPFS under various scenarios and settings. We measured a maximum performance on 16 nodes of 83 GB/s using NVMe devices, 5.6 GB/s for SSD devices and 4.4 GB/s for writes to the GPFS.This project has received funding from the European Union’sHorizon 2020 research and innovation programme under the Marie Sklodowska-Curiegrant agreement No 708566 (DURO). Part of the research presented here has receivedfunding from the European Union’s Seventh Framework Programme (FP7/2007-2013)and the Horizon 2020 (H2020) funding framework under grant agreement no. H2020-FETHPC-754304 (DEEP-EST). The present publication reflects only the authors’views. The European Commission is not liable for any use that might be made ofthe information contained therein.Peer ReviewedPostprint (author's final draft