An Analysis of Performance Interference Effects on Energy-Efficiency of Virtualized Cloud Environments

Co-allocated workloads in a virtualized computing environment often have to compete for resources, thereby suffering from performance interference. While this phenomenon has a direct impact on the Quality of Service provided to customers, it also changes the patterns of resource utilization and reduces the amount of work per Watt consumed. Unfortunately, there has been only limited research into how performance interference affects energy-efficiency of servers in such environments. In reality, there is a highly dynamic and complicated correlation among resource utilization, performance interference and energy-efficiency. This paper presents a comprehensive analysis that quantifies the negative impact of performance interference on the energy-efficiency of virtualized servers. Our analysis methodology takes into account the heterogeneous workload characteristics identified from a real Cloud environment. In particular, we investigate the impact due to different workload type combinations and develop a method for approximating the levels of performance interference and energy-efficiency degradation. The proposed method is based on profiles of pair combinations of existing workload types and the patterns derived from the analysis. Our experimental results reveal a non-linear relationship between the increase in interference and the reduction in energy-efficiency as well as an average precision within +/-5% of error margin for the estimation of both parameters. These findings provide vital information for research into dynamic trade-offs between resource utilization, performance, and energy-efficiency of a data center

GABA(A) receptor phospho-dependent modulation is regulated by phospholipase C-related inactive protein type 1, a novel protein phosphatase 1 anchoring protein

GABA(A) receptors are critical in controlling neuronal activity. Here, we examined the role for phospholipase C-related inactive protein type 1 (PRIP-1), which binds and inactivates protein phosphatase 1alpha (PP1alpha) in facilitating GABA(A) receptor phospho-dependent regulation using PRIP-1(-/-) mice. In wild-type animals, robust phosphorylation and functional modulation of GABA(A) receptors containing beta3 subunits by cAMP-dependent protein kinase was evident, which was diminished in PRIP-1(-/-) mice. PRIP-1(-/-) mice exhibited enhanced PP1alpha activity compared with controls. Furthermore, PRIP-1 was able to interact directly with GABA(A) receptor beta subunits, and moreover, these proteins were found to be PP1alpha substrates. Finally, phosphorylation of PRIP-1 on threonine 94 facilitated the dissociation of PP1alpha-PRIP-1 complexes, providing a local mechanism for the activation of PP1alpha. Together, these results suggest an essential role for PRIP-1 in controlling GABA(A) receptor activity via regulating subunit phosphorylation and thereby the efficacy of neuronal inhibition mediated by these receptors

Time spent on health-related activities by senior Australians with chronic diseases: what is the role of multimorbidity and comorbidity?

This is the final version of the article. Available from the publisher via the DOI in this record.OBJECTIVE: To examine the effect of various morbidity clusters of chronic diseases on health-related time use and to explore factors associated with heavy time burden (more than 30 hours/month) of health-related activities. METHODS: Using a national survey, data were collected from 2,540 senior Australians. Natural clusters were identified using cluster analysis and clinical clusters using clinical expert opinion. We undertook a set of linear regressions to model people's time use, and logistic regressions to model heavy time burden. RESULTS: Time use increases with the number of chronic diseases. Six of the 12 diseases are significantly associated with higher time use, with the highest effect for diabetes followed by depression; 18% reported a heavy time burden, with diabetes again being the most significant disease. Clusters and dominant comorbid groupings do not contribute to predicting time use or time burden. CONCLUSIONS: Total number of diseases and specific diseases are useful determinants of time use and heavy time burden. Dominant groupings and disease clusters do not predict time use. IMPLICATIONS: In considering time demands on patients and the need for care co-ordination, care providers need to be aware of how many and what specific diseases the patient faces.The Serious and Continuing Illnesses Policy and Practice Study (SCIPPS) is an NHMRC-funded program conducted at The Australian National University and the University of Sydney and administered by the Menzies Centre for Health Policy

Multi-rendezvous Spacecraft Trajectory Optimization with Beam P-ACO

The design of spacecraft trajectories for missions visiting multiple celestial bodies is here framed as a multi-objective bilevel optimization problem. A comparative study is performed to assess the performance of different Beam Search algorithms at tackling the combinatorial problem of finding the ideal sequence of bodies. Special focus is placed on the development of a new hybridization between Beam Search and the Population-based Ant Colony Optimization algorithm. An experimental evaluation shows all algorithms achieving exceptional performance on a hard benchmark problem. It is found that a properly tuned deterministic Beam Search always outperforms the remaining variants. Beam P-ACO, however, demonstrates lower parameter sensitivity, while offering superior worst-case performance. Being an anytime algorithm, it is then found to be the preferable choice for certain practical applications.Comment: Code available at https://github.com/lfsimoes/beam_paco__gtoc

Antisickling agent in an extract of unripe pawpaw (Carica papaya): Is it real?

Investigations into antisickling and reversal of sickling activities of an aqueous extract of unripe pawpaw (Carica papaya) were carried out on blood from sickle cell patients (Haemoglobin SS, HbSS) using 2% sodium metabisulphite in a sickling test. The minimum concentration of the extract that achieved maximum antisickling in vitro and the fraction of the extract where the antisickling agent resides were determined. Our findings confirmed both antisickling and reversal of sickling activities ofthe extract. It was established that 1.0 g of unripe pawpaw in 1.0 ml of physiological saline was the minimum concentration that achieved maximum antisickling. Solvent partitioning of the extract withethyl acetate and butanol revealed that the antisickling agent in the extract of unripe pawpaw resides in the ethyl acetate fraction as this fraction prevented sickling of Hb SS red cells and reversed sickled HbSS red cells in 2% sodium metabisulphite whereas the butanol and aqueous fractions had none of these properties. We concluded that extract of unripe pawpaw really has antisickling agent and that thisantisickling agent lies in the ethyl acetate fraction of the extract

Is There Really a de Sitter/CFT Duality

In this paper a de Sitter Space version of Black Hole Complementarity is formulated which states that an observer in de Sitter Space describes the surrounding space as a sealed finite temperature cavity bounded by a horizon which allows no loss of information. We then discuss the implications of this for the existence of boundary correlators in the hypothesized dS/cft correspondence. We find that dS complementarity precludes the existence of the appropriate limits. We find that the limits exist only in approximations in which the entropy of the de Sitter Space is infinite. The reason that the correlators exist in quantum field theory in the de Sitter Space background is traced to the fact that horizon entropy is infinite in QFT.Comment: 12 Figures, STIAS Workshop on Quantum Gravit

Safety and practices during stress cardiac magnetic resonance in COPD: A 3-year experience from a tertiary referral centre

This is an author-submitted, peer-reviewed version of a manuscript that has been accepted for publication in the European Respiratory Journal, prior to copy-editing, formatting and typesetting. This version of the manuscript may not be duplicated or reproduced without prior permission from the copyright owner, the European Respiratory Society. The publisher is not responsible or liable for any errors or omissions in this version of the manuscript or in any version derived from it by any other parties. The final, copy-edited, published article, which is the version of record, is available without a subscription 18 months after the date of issue publication

Observational constraints on Cosmic Reionization

Recent observations have set the first constraints on the epoch of reionization (EoR), corresponding to the formation epoch of the first luminous objects. Studies of Gunn-Peterson (GP) absorption, and related phenomena, suggest a qualitative change in the state of the intergalactic medium (IGM) at $z \sim 6$, indicating a rapid increase in the neutral fraction of the IGM, from $x_{HI} 10^{-3}$, perhaps up to 0.1, at $z \ge 6$. Conversely, transmission spikes in the GP trough, and the evolution of the \lya galaxy luminosity function indicate $x_{HI} < 0.5$ at $z\sim 6.5$, while the large scale polarization of the cosmic microwave background (CMB) implies a significant ionization fraction extending to higher redshifts, $z \sim 11 \pm 3$. The results suggest that reionization is less an event than a process, with the process beginning as early as $z \sim 14$, and with the 'percolation', or 'overlap' phase ending at $z \sim 6$. The data are consistent with low luminosity star forming galaxies as being the dominant sources of reionizing photons. Low frequency radio telescopes currently under construction should be able to make the first direct measurements of HI 21cm emission from the neutral IGM during the EoR, and upcoming measurements of secondary CMB temperature anisotropy will provide fine details of the dynamics of the reionized IGM.Comment: to appear in ARAA 2006, vol 44, page 415-462; latex. 84 pages. 15 fi

Hard Thermal Loops in the n-Dimensional phi3 Theory

We derive a closed-form result for the leading thermal contributions which appear in the n-dimensional phi3 theory at high temperature. These contributions become local only in the long wavelength and in the static limits, being given by different expressions in these two limits.Comment: 3 pages, one figure. To be published in the Brazilian Journal of Physic