120 research outputs found

    EPOBF: Energy Efficient Allocation of Virtual Machines in High Performance Computing Cloud

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    Cloud computing has become more popular in provision of computing resources under virtual machine (VM) abstraction for high performance computing (HPC) users to run their applications. A HPC cloud is such cloud computing environment. One of challenges of energy efficient resource allocation for VMs in HPC cloud is tradeoff between minimizing total energy consumption of physical machines (PMs) and satisfying Quality of Service (e.g. performance). On one hand, cloud providers want to maximize their profit by reducing the power cost (e.g. using the smallest number of running PMs). On the other hand, cloud customers (users) want highest performance for their applications. In this paper, we focus on the scenario that scheduler does not know global information about user jobs and user applications in the future. Users will request shortterm resources at fixed start times and non interrupted durations. We then propose a new allocation heuristic (named Energy-aware and Performance per watt oriented Bestfit (EPOBF)) that uses metric of performance per watt to choose which most energy-efficient PM for mapping each VM (e.g. maximum of MIPS per Watt). Using information from Feitelson's Parallel Workload Archive to model HPC jobs, we compare the proposed EPOBF to state of the art heuristics on heterogeneous PMs (each PM has multicore CPU). Simulations show that the EPOBF can reduce significant total energy consumption in comparison with state of the art allocation heuristics.Comment: 10 pages, in Procedings of International Conference on Advanced Computing and Applications, Journal of Science and Technology, Vietnamese Academy of Science and Technology, ISSN 0866-708X, Vol. 51, No. 4B, 201

    Qualidade da água do Córrego Chico, Ladário - MS.

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    bitstream/CPAP-2009-09/56792/1/CT77.pd

    Biological activity of antitumoural MGBG: the structural variable

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    Abstract The present study aims at determining the structure-activity relationships (SAR’s) ruling the biological function of MGBG (methylglyoxal bis(guanylhydrazone)), a competitive inhibitor of S-adenosyl-l-methionine decarboxylase displaying anticancer activity, involved in the biosynthesis of the naturally occurring polyamines spermidine and spermine. In order to properly understand its biochemical activity, MGBG’s structural preferences at physiological conditions were ascertained, by quantum mechanical (DFT) calculations

    Structural characterization of agmatine at physiological conditions

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    Abstract The present work aims at determining the structure-activity relationships (SAR's) which rule the biological function of agmatine (4-(aminobutyl)guanidinium, AGM), a biogenic amine produced by decarboxylation of arginine. Its structural preferences, both as an isolated molecule and in aqueous solution (namely at physiological conditions) were ascertained, by vibrational (Raman) spectroscopy coupled to theoretical (density functional) calculations. An evaluation of mitochondrial functions (membrane potential ( ), mitochondrial swelling, and cytochrome c release) in rat liver mitochondria (RLM) was also carried out. The results thus obtained, coupled to the conformational analysis performed for the distinct polyamine protonation states, allowed to individualize the agmatine structures which interact with the mitochondrial site responsible for its transport and for the protection against mitochondrial permeability transition (MPT) induction, a
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