Multidrug efflux pumps:structure, function and regulation

Infections arising from multidrug-resistant pathogenic bacteria are spreading rapidly throughout the world and threaten to become untreatable. The origins of resistance are numerous and complex, but one underlying factor is the capacity of bacteria to rapidly export drugs through the intrinsic activity of efflux pumps. In this Review, we describe recent advances that have increased our understanding of the structures and molecular mechanisms of multidrug efflux pumps in bacteria. Clinical and laboratory data indicate that efflux pumps function not only in the drug extrusion process but also in virulence and the adaptive responses that contribute to antimicrobial resistance during infection. The emerging picture of the structure, function and regulation of efflux pumps suggests opportunities for countering their activities

Network Resource Control for Grid Workflow Management Systems

Grid workflow management systems automate the orchestration of scientific applications with large computational and data processing needs, but lack control over network resources. Consequently, the management system cannot prevent multiple communication intensive applications to compete for network resources, which leads to unpredictable performance. Currently, the lack of control over network resources may prevent certain applications, i.e. applications that need high capacity and Quality of Service, to utilize Grids. Hence, such applications would use dedicated infrastructures. Because the costs to build dedicated infrastructures may far exceed the cost of using existing Grids, the Grid needs to support mechanisms to optimize the interworking between networks and applications. In this paper, we present the architecture and proof of concept to control network resources from Grid workflow management system and to manage network resources from workflow-enabled applications at run-time. Depending on the current network infrastructure capabilities or future advances, applications may employ existing QoS mechanisms or use application-specific ones to provide the desired network service. We believe that our approach leads to performance improvements in communication intensive applications and enables novel Grid applications, which require optimal interworking between networks and applications

Collaborative e-Science Experiments and Scientific Workflows

Recent advances in Internet and grid technologies have greatly enhanced scientific experiments' life cycle. In addition to compute- and data-intensive tasks, large-scale collaborations involving geographically distributed scientists and e-infrastructure are now possible. Scientific workflows, which encode the logic of experiments, are becoming valuable resources. Sharing these resources and letting scientists worldwide work together on one experiment is essential for promoting knowledge transfer and speeding up the development of scientific experiments. Here, the authors discuss the challenges involved in supporting collaborative e-Science experiments and propose support for different phases of the scientific experimentation life cycl