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Large-scale data centers leverage virtualization technology to achieve excellent resource utilization, scalability, and high availability. Ideally, the performance of an application running inside a virtual machine (VM) shall be independent of co-located applications and VMs that share the physical machine. However, adverse interference effects exist and(More)
The narX, narQ and narL genes of Escherichia coli encode a nitrate-responsive two-component regulatory system that controls the expression of many anaerobic electron-transport- and fermentation-related genes. When nitrate is present, the NarX and NarQ sensor-transmitter proteins function to activate the response-regulator protein, NarL, which in turn binds(More)
The Escherichia coli NarX, NarQ, NarL and NarP proteins comprise a two-component regulatory system that controls the expression of many anaerobic electron-transport and fermentation-related genes in response to nitrate and nitrite. Either of the two sensor-transmitter proteins, NarX and NarQ, can activate the response-regulator proteins, NarL and NarP,(More)
Expression of the Escherichia coli dmsABC operon that encodes a molybdenum-containing DMSO/TMAO reductase is increased in response to anaerobiosis and repressed by nitrate. These changes are mediated by the transcription factors Fnr and NarL respectively. Interestingly, modC strains that are defective in molybdate uptake exhibit impaired anaerobic induction(More)
Scalability challenges of DRAM technology call for advances in emerging memory technologies, among which Phase Change Memory (PCM) has received considerable attention due to its non-volatility, storage density and capacity advantages. The drawbacks of PCM include limited write endurance and high power consumption for write operations (upto 10x in comparison(More)
The success of cloud computing builds largely upon on-demand supply of virtual machines (VMs) that provide the abstraction of a physical machine on shared resources. Unfortunately, despite recent advances in virtu-alization technology, there still exists an unpredictable performance gap between the real and desired performance. The main contributing factors(More)
In response to nitrate availability, Escherichia coli regulates the synthesis of a number of enzymes involved in anaerobic respiration and fermentation. When nitrate is present, nitrate reductase (narGHJI) gene expression is induced, while expression of the DMSO/TMAO reductase (dmsABC), fumarate reductase (frdABCD) and fermentation related genes are(More)
The Escherichia coli modABCD operon, which encodes a high-affinity molybdate uptake system, is transcriptionally regulated in response to molybdate availability by ModE. Here we describe a highly effective enrichment protocol, applicable to any gene with a repressor role, and establish its application in the isolation of transposon mutations in modE. In(More)
• Modeled a complex heterogeneous computing system that uses DAGs. • Defined a robustness metric for this system. • Designed heuristics to maximize this robustness metric. • Evaluated and compared the performance of these heuristics in six scenarios. a b s t r a c t In this study, we consider an environment composed of a heterogeneous cluster of(More)
Analysis of the DNA sequence upstream of the narQ gene, which encodes the second nitrate-responsive sensor-transmitter protein in Escherichia coli, revealed an open reading frame (ORF) whose product shows a high degree of similarity to a number of iron-sulfur proteins as well as to the beta subunit of glutamate synthase (gltD) of E. coli. This ORF, located(More)