The Experts below are selected from a list of 1200 Experts worldwide ranked by ideXlab platform
M. Sobolewski - One of the best experts on this subject based on the ideXlab platform.
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a dual time vector clock based synchronization mechanism for key value data in the Silenus file system
International Conference on Parallel and Distributed Systems, 2007Co-Authors: M. Berger, M. SobolewskiAbstract:The Silenus federated file system was developed by the SORCER research group at Texas Tech University. The federated file system with its dynamic nature does not require any configuration by the end users and system administrators. The Silenus file system provides support for disconnected operation. To support disconnected operation a relevant synchronization mechanism is needed. This mechanism must detect and order events properly. It must detect also possible conflicts and resolve these in a consistent manner. This paper describes the new synchronization mechanism needed for providing data consistency. It introduces dual-time vector clocks to order events and detect conflicts. A conflict resolution algorithm is defined that does not require user interactions. It introduces the switchback problem and how it can be avoided. The synchronization mechanisms presented in this paper can be adapted to synchronize any key-value based data in any distributed system.
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ICPADS - A dual-time vector clock based synchronization mechanism for key-value data in the Silenus file system
2007 International Conference on Parallel and Distributed Systems, 2007Co-Authors: M. Berger, M. SobolewskiAbstract:The Silenus federated file system was developed by the SORCER research group at Texas Tech University. The federated file system with its dynamic nature does not require any configuration by the end users and system administrators. The Silenus file system provides support for disconnected operation. To support disconnected operation a relevant synchronization mechanism is needed. This mechanism must detect and order events properly. It must detect also possible conflicts and resolve these in a consistent manner. This paper describes the new synchronization mechanism needed for providing data consistency. It introduces dual-time vector clocks to order events and detect conflicts. A conflict resolution algorithm is defined that does not require user interactions. It introduces the switchback problem and how it can be avoided. The synchronization mechanisms presented in this paper can be adapted to synchronize any key-value based data in any distributed system.
M. Berger - One of the best experts on this subject based on the ideXlab platform.
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a dual time vector clock based synchronization mechanism for key value data in the Silenus file system
International Conference on Parallel and Distributed Systems, 2007Co-Authors: M. Berger, M. SobolewskiAbstract:The Silenus federated file system was developed by the SORCER research group at Texas Tech University. The federated file system with its dynamic nature does not require any configuration by the end users and system administrators. The Silenus file system provides support for disconnected operation. To support disconnected operation a relevant synchronization mechanism is needed. This mechanism must detect and order events properly. It must detect also possible conflicts and resolve these in a consistent manner. This paper describes the new synchronization mechanism needed for providing data consistency. It introduces dual-time vector clocks to order events and detect conflicts. A conflict resolution algorithm is defined that does not require user interactions. It introduces the switchback problem and how it can be avoided. The synchronization mechanisms presented in this paper can be adapted to synchronize any key-value based data in any distributed system.
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ICPADS - A dual-time vector clock based synchronization mechanism for key-value data in the Silenus file system
2007 International Conference on Parallel and Distributed Systems, 2007Co-Authors: M. Berger, M. SobolewskiAbstract:The Silenus federated file system was developed by the SORCER research group at Texas Tech University. The federated file system with its dynamic nature does not require any configuration by the end users and system administrators. The Silenus file system provides support for disconnected operation. To support disconnected operation a relevant synchronization mechanism is needed. This mechanism must detect and order events properly. It must detect also possible conflicts and resolve these in a consistent manner. This paper describes the new synchronization mechanism needed for providing data consistency. It introduces dual-time vector clocks to order events and detect conflicts. A conflict resolution algorithm is defined that does not require user interactions. It introduces the switchback problem and how it can be avoided. The synchronization mechanisms presented in this paper can be adapted to synchronize any key-value based data in any distributed system.
V. Puccini - One of the best experts on this subject based on the ideXlab platform.
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Further evidence on the internal life cycle of Przhevalskiana Silenus (Diptera, Oestridae).
Veterinary parasitology, 2000Co-Authors: D Otranto, V. PucciniAbstract:Knowledge of the internal life cycle of goat warble fly infestation is scarce despite ample data available on the aetiology, epidemiology, immunodiagnosis and treatment of such infestations. This study was carried out at the slaughterhouse of Rossano Calabro (Cosenza, southern Italy) on 154 animals from 10 months to 6 years of age from May 1997 to June 1998. 1206 Przhevalskiana Silenus larvae were collected during the trial period from the subcutaneous tissue of the slaughtered animals. The larval stage average size ranged from 4.7 mm, for first instar larvae (May), to 16.6 mm, for third instar larvae (February), in the first cycle of infestation. No larvae were found in March-April, coinciding with the pupation period. Small first instar larvae were found at the beginning of the second cycle of infestation (May-June). Necroscopic examinations were also carried out on internal organs and no larvae were found. The results pointed out that the internal life cycle of P. Silenus is exclusively subcutaneous and there is no internal migration of the larvae.
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Serodiagnosis of goat warble fly infestation by Przhevalskiana Silenus with a commercial ELISA kit.
The Veterinary record, 1999Co-Authors: Domenico Otranto, C??line Boulard, A. Giangaspero, M. P. Caringella, D. Rimmele, V. PucciniAbstract:Cross-reactivity between Hypoderma lineatum antigen and anti-Przhevalskiana Silenus antibodies has been demonstrated by an ELISA technique. To evaluate the applicability of a commercial ELISA kit for the immunodiagnosis of goat warble fly infestation, different dilutions of serum and conjugate were tested, the development of antibody to P Silenus in naturally infested goats was studied, and the results were compared with an ELISA technique using an antigen extracted from the first instar larvae of H lineatum. The best results were obtained with a serum dilution of 1:50; with both techniques the highest antibody concentration were recorded in October, November and December. In view of the confirmed cross-reactivity between H lineatum antigen and anti-P Silenus antibodies, and the simplicity and rapidity of the assay, the commercial ELISA kit can be considered as a useful tool for the diagnosis of goat warble fly infestation.
D Otranto - One of the best experts on this subject based on the ideXlab platform.
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Further evidence on the internal life cycle of Przhevalskiana Silenus (Diptera, Oestridae).
Veterinary parasitology, 2000Co-Authors: D Otranto, V. PucciniAbstract:Knowledge of the internal life cycle of goat warble fly infestation is scarce despite ample data available on the aetiology, epidemiology, immunodiagnosis and treatment of such infestations. This study was carried out at the slaughterhouse of Rossano Calabro (Cosenza, southern Italy) on 154 animals from 10 months to 6 years of age from May 1997 to June 1998. 1206 Przhevalskiana Silenus larvae were collected during the trial period from the subcutaneous tissue of the slaughtered animals. The larval stage average size ranged from 4.7 mm, for first instar larvae (May), to 16.6 mm, for third instar larvae (February), in the first cycle of infestation. No larvae were found in March-April, coinciding with the pupation period. Small first instar larvae were found at the beginning of the second cycle of infestation (May-June). Necroscopic examinations were also carried out on internal organs and no larvae were found. The results pointed out that the internal life cycle of P. Silenus is exclusively subcutaneous and there is no internal migration of the larvae.
Henrik Ottosson - One of the best experts on this subject based on the ideXlab platform.
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Silenes: Connectors between classical alkenes and nonclassical heavy alkenes
Coordination Chemistry Reviews, 2007Co-Authors: Henrik Ottosson, Anders M. EklöfAbstract:Forty years have passed since the first publication of the experimental evidence for formation of a SiC double bonded compound, a silene. Since then, a large number of transient as well as isolable silenes have been studied, both experimentally and theoretically. Herein, we focus on the impact of the substituents on the electronic and geometric structure, reactivity, and other properties of (formally) SiC double bonded compounds. Qualitative quantum chemical models for the bonding are reviewed, and applied to rationalize experimental observations. Silenes can have planar (classical) structures similar to alkenes, or nonplanar (nonclassical) structures similar to the heavier alkene congeners, and their substituents are pivotal in determining which of these structures is adopted. Silene properties, ranging from charge distribution and NMR chemical shifts to reactivities, are strongly connected to the electronic structure of the silene, and thus to its substitution pattern.
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Zwitterionic silenes: interesting goals for synthesis?
Chemistry - A European Journal, 2003Co-Authors: Henrik OttossonAbstract:Properties of silenes, as a function of increased reversal of the Si=C bond polarity, have been examined through quantum-chemical calculations. The aim of this study was to identify silenes that can be of general interest for organic synthesis. The calculations were carried out primarily with the B3LYP hybrid density functional method, but also with the CASSCF, MP2, MP4(SDQ), and CCSD(T) methods. The study was performed on Z(2)Si=CXY compounds which were divided into three sets that differ with regard to their Si substituents (Z), and with their C substituents (X and Y) varying from weakly to strongly pi-electron-donating groups. The charge at the Si atom (q(Si)) was used as a measure of the extent of reversed silicon-carbon bond polarity. For each of the three sets, the variation in silicon-carbon bond lengths (r(Si=C)) and extent of Si pyramidalization (SigmaSi) in relation to q(Si) follow three separate curves. Silenes with strongly pi-electron-donating X and Y groups are completely described by zwitterionic (reverse-polarized) resonance structures. Such zwitterionic silenes are singly (Si=C) rather than doubly bonded (Si=C), and have a distinctly pyramidal Si atom due to negative charge localization. These silenes also have much lower heats of dimerization than the parent silene. Finally, inversion barriers of zwitterionic silenes are increased by electron-withdrawing substituents, and this enables computational design of silenes with their Si atoms as chiral centers. It is hoped that such chiral zwitterionic silenes can find use in organic synthesis.
