The Experts below are selected from a list of 9507 Experts worldwide ranked by ideXlab platform
Dieter Braun - One of the best experts on this subject based on the ideXlab platform.
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Heat flux across an open pore enables the Continuous Replication and selection of oligonucleotides towards increasing length
Nature Chemistry, 2015Co-Authors: Moritz Kreysing, Lorenz Keil, Simon Lanzmich, Dieter BraunAbstract:The Replication of nucleic acids is central to the origin of life. On the early Earth, suitable non-equilibrium boundary conditions would have been required to surmount the effects of thermodynamic equilibrium such as the dilution and degradation of oligonucleotides. One particularly intractable experimental finding is that short genetic polymers replicate faster and outcompete longer ones, which leads to ever shorter sequences and the loss of genetic information. Here we show that a heat flux across an open pore in submerged rock concentrates replicating oligonucleotides from a constant feeding flow and selects for longer strands. Our experiments utilize the interplay of molecular thermophoresis and laminar convection, the latter driving strand separation and exponential Replication. Strands of 75 nucleotides survive whereas strands half as long die out, which inverts the above dilemma of the survival of the shortest. The combined feeding, thermal cycling and positive length selection opens the door for a stable molecular evolution in the long-term microhabitat of heated porous rock. How complex nucleic acids originally formed, despite dilution and degradation reactions, is not clear. Thermal gradients in rock pores have now been shown to be capable of trapping and thermo-cycling genetic polymers during Replication. In this system long oligonucleotide strands are seen to outcompete short strands — a prerequisite for the evolution of replicating systems towards increasing complexity.
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Heat flux across an open pore enables the Continuous Replication and selection of oligonucleotides towards increasing length
Nature Chemistry, 2015Co-Authors: Moritz Kreysing, Simon Lanzmich, Lorenz M. R. Keil, Dieter BraunAbstract:How complex nucleic acids originally formed, despite dilution and degradation reactions, is not clear. Thermal gradients in rock pores have now been shown to be capable of trapping and thermo-cycling genetic polymers during Replication. In this system long oligonucleotide strands are seen to outcompete short strands — a prerequisite for the evolution of replicating systems towards increasing complexity.
Barbara Stadlober - One of the best experts on this subject based on the ideXlab platform.
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Multilength Scale Patterning of Functional Layers by Roll-to-Roll Ultraviolet-Light-Assisted Nanoimprint Lithography
ACS Nano, 2016Co-Authors: Markus Leitgeb, Ursula Palfinger, Johannes Götz, Stephan Ruttloff, Dieter Nees, Maria R. Belegratis, Julia Götz, Robert Liska, Barbara StadloberAbstract:Top-down fabrication of nanostructures with high throughput is still a challenge. We demonstrate the fast (>10 m/min) and Continuous fabrication of multilength scale structures by roll-to-roll UV-nanoimprint lithography on a 250 mm wide web. The large-area nanopatterning is enabled by a multicomponent UV-curable resist system (JRcure) with viscous, mechanical, and surface properties that are tunable over a wide range to either allow for usage as polymer stamp material or as imprint resist. The adjustable elasticity and surface chemistry of the resist system enable multistep self-Replication of structured resist layers. Decisive for defect-free UV-nanoimprinting in roll-to-roll is the minimization of the surface energies of stamp and resist, and the stepwise reduction of the stiffness from one layer to the next is essential for optimizing the reproduction fidelity especially for nanoscale features. Accordingly, we demonstrate the Continuous Replication of 3D nanostructures and the high-throughput fabricati...
Juergen Hasslauer - One of the best experts on this subject based on the ideXlab platform.
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Chapter 6 – Exchange Server 2007 Failover Clustering
Designing Storage for Exchange 2007 SP1, 2008Co-Authors: Pierre Bijaoui, Juergen HasslauerAbstract:Publisher Summary This chapter provides an introduction to Windows Failover Clustering (WFC) in Windows Server 2003 and Windows Server 2008, followed by a discussion of Exchange Server 2007 Clustered Mailbox Servers. Clusters are multiple computers that appear to users as a single highly available system. The objective of clustering concept is a “no single point of failure” configuration. If one component fails, another component takes over the responsibility, and the service offered by the cluster should not be affected from an end-user point of view. Typically, a clustered deployment is considered if one wants to increase the availability of messaging service, or if business continuity requirements demand a geographically dispersed deployment with relatively short recovery time objectives. Exchange administrators should have at least a basic knowledge of the WFC concept to understand the various cluster architectures used by the two implementation alternatives for a Clustered Mailbox Server (CMS) in Exchange Server 2007, Cluster Continuous Replication (CCR), and Single Copy Cluster (SCC). The mailbox server role is the only role in Exchange Server 2007 that can be deployed on a cluster. In Exchange Server 2007, Outlook Web Access or transport services are provided by the Client Access Server (CAS) and Hub Transport (HT) server role. Both roles cannot be installed on a WFC. A server with the HT and another with the CAS role must be online in the same AD site; otherwise, users cannot send and receive emails or connect to their mailbox using Internet protocols. The minimal configuration is four Exchange servers: two clustered nodes for the mailbox server and two multirole servers with both the HT and CAS role installed. Additionally, two Active Directory (AD) global catalog servers are needed.
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Chapter 9 – Recovery
Designing Storage for Exchange 2007 SP1, 2008Co-Authors: Pierre Bijaoui, Juergen HasslauerAbstract:Publisher Summary This chapter describes how backup data can be used for recovery purposes. Exchange Server 2007's Continuous Replication provides the possibility of creating a second copy of Exchange databases. This replica is the first line of defense. However, activating the passive database created by Exchange Server 2007 Continuous Replication is not always successful; sometimes a failover to the passive node of Cluster Continuous Replication (CCR) deployment does not solve the problem. With Exchange Server 2007, disaster recovery tools are available in the Exchange Management Console (EMC) toolbox including the Database Recovery Manager and Database Troubleshooter. The Database Recovery Manager can be used to analyze log drive space, repair a database, show database-related event logs, verify database and transaction log files, and create and manage a Recovery Storage Group (RSG). The Exchange Server 2007 provides better support for mailbox database portability; one can mount a mailbox database to another Exchange mailbox server with a different computer name in the same Exchange organization. The portability feature is no longer limited to usage in the Recovery Storage Group (RSG); the database can be mounted to a production storage group of another Exchange server. In Microsoft Exchange Server 2007, combining mailbox database portability with the Exchange Server 2003 dial tone recovery strategy is referred to as dial tone portability. The key benefit for users is that the dial tone recovery strategy enables them to rapidly send and receive new messages.
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Data Replication Solutions for Exchange
Designing Storage for Exchange 2007 SP1, 2008Co-Authors: Pierre Bijaoui, Juergen HasslauerAbstract:This chapter discusses the methods that can be used in Exchange versions to replicate Exchange databases and the details of Exchange Server 2007 Continuous Replication (CR). Multiple Exchange servers can synchronize public folders using public folder Replication. Public folder data are then stored in multiple public folder databases. Information about mailbox users, distribution lists, and contacts are stored in the Active Directory (AD). AD Replication is utilized to increase the availability of this information. CR is a built-in Exchange function that asynchronously copies closed transaction log files to another file system path on the same server, or over a TCP/IP network to another server. Exchange uses these log files to automatically create a replica of the database in the background. This database copy is the first line of defense if AD is damaged. Local Continuous Replication is the implementation of log file shipping on a single server. This feature is available with the Standard Edition of Exchange Server 2007. Local Continuous Replication does not provide a solution for the failure of single server hardware. This is the domain of Cluster Continuous Replication (CCR) and SCC. CCR is the combination of log file shipping with Windows failover clustering. With CCR, a second server on its local disks creates passive database. CCR can be deployed on Direct Attached Storage (DAS). As a Storage Area Network (SAN) is not required, infrastructure requirement and hardware costs are reduced. With Exchange Server 2007 SP1, Microsoft introduced Standby Continuous Replication (SCR). The aim of SCR is to provide site resiliency for mailbox databases. SCR uses the same log file shipping technology as LCR and CCR. SCR ships log files from a source server to a target server. The SCR source is a mailbox server with the active database, and the SCR target is a mailbox server that hosts the target database.
Moritz Kreysing - One of the best experts on this subject based on the ideXlab platform.
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Heat flux across an open pore enables the Continuous Replication and selection of oligonucleotides towards increasing length
Nature Chemistry, 2015Co-Authors: Moritz Kreysing, Lorenz Keil, Simon Lanzmich, Dieter BraunAbstract:The Replication of nucleic acids is central to the origin of life. On the early Earth, suitable non-equilibrium boundary conditions would have been required to surmount the effects of thermodynamic equilibrium such as the dilution and degradation of oligonucleotides. One particularly intractable experimental finding is that short genetic polymers replicate faster and outcompete longer ones, which leads to ever shorter sequences and the loss of genetic information. Here we show that a heat flux across an open pore in submerged rock concentrates replicating oligonucleotides from a constant feeding flow and selects for longer strands. Our experiments utilize the interplay of molecular thermophoresis and laminar convection, the latter driving strand separation and exponential Replication. Strands of 75 nucleotides survive whereas strands half as long die out, which inverts the above dilemma of the survival of the shortest. The combined feeding, thermal cycling and positive length selection opens the door for a stable molecular evolution in the long-term microhabitat of heated porous rock. How complex nucleic acids originally formed, despite dilution and degradation reactions, is not clear. Thermal gradients in rock pores have now been shown to be capable of trapping and thermo-cycling genetic polymers during Replication. In this system long oligonucleotide strands are seen to outcompete short strands — a prerequisite for the evolution of replicating systems towards increasing complexity.
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Heat flux across an open pore enables the Continuous Replication and selection of oligonucleotides towards increasing length
Nature Chemistry, 2015Co-Authors: Moritz Kreysing, Simon Lanzmich, Lorenz M. R. Keil, Dieter BraunAbstract:How complex nucleic acids originally formed, despite dilution and degradation reactions, is not clear. Thermal gradients in rock pores have now been shown to be capable of trapping and thermo-cycling genetic polymers during Replication. In this system long oligonucleotide strands are seen to outcompete short strands — a prerequisite for the evolution of replicating systems towards increasing complexity.
Markus Leitgeb - One of the best experts on this subject based on the ideXlab platform.
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Multilength Scale Patterning of Functional Layers by Roll-to-Roll Ultraviolet-Light-Assisted Nanoimprint Lithography
ACS Nano, 2016Co-Authors: Markus Leitgeb, Ursula Palfinger, Johannes Götz, Stephan Ruttloff, Dieter Nees, Maria R. Belegratis, Julia Götz, Robert Liska, Barbara StadloberAbstract:Top-down fabrication of nanostructures with high throughput is still a challenge. We demonstrate the fast (>10 m/min) and Continuous fabrication of multilength scale structures by roll-to-roll UV-nanoimprint lithography on a 250 mm wide web. The large-area nanopatterning is enabled by a multicomponent UV-curable resist system (JRcure) with viscous, mechanical, and surface properties that are tunable over a wide range to either allow for usage as polymer stamp material or as imprint resist. The adjustable elasticity and surface chemistry of the resist system enable multistep self-Replication of structured resist layers. Decisive for defect-free UV-nanoimprinting in roll-to-roll is the minimization of the surface energies of stamp and resist, and the stepwise reduction of the stiffness from one layer to the next is essential for optimizing the reproduction fidelity especially for nanoscale features. Accordingly, we demonstrate the Continuous Replication of 3D nanostructures and the high-throughput fabricati...