Reliable MapReduce computing on opportunistic resources

MapReduce offers an ease-of-use programming paradigm for processing large data sets, making it an attractive model for opportunistic compute resources. However, unlike dedicated resources, where MapReduce has mostly been deployed, opportunistic resources have significantly higher rates of node volatility. As a consequence, the data and task replication scheme adopted by existing MapReduce implementations is woefully inadequate on such volatile resources. In this paper, we propose MOON, short for MapReduce On Opportunistic eNvironments, which is designed to offer reliable MapReduce service for opportunistic computing. MOON adopts a hybrid resource architecture by supplementing opportunistic compute resources with a small set of dedicated resources, and it extends Hadoop, an open-source implementation of MapReduce, with adaptive task and data scheduling algorithms to take advantage of the hybrid resource architecture. Our results on an emulated opportunistic computing system running atop a 60-node cluster demonstrate that MOON can deliver significant performance improvements to Hadoop on volatile compute resources and even finish jobs that are not able to complete in Hadoop.     

Ein Beitrag zur Flora Galiziens und der Bukowina

Ohne Zusammenfassung     

Ein Beitrag zur Flora Galiziens und der Bukowina

Ohne Zusammenfassung     

Interaction of heterologous fibrinogens with human platelet receptors.

The interaction of ADP-stimulated human platelets with human 125I-fibrinogen as well as with pig and bovine fibrinogens was analysed. It was found that the fibrinogens studied were bound to the same platelet receptors but the affinity of animal preparations was about half the value observed for human fibrinogen (in a homologous system).     

Action of neurotropic substances on gamma-aminobutyric acid release from brain synaptosomes during K+ depolarization

The effects of aminazine (0.25 mM), phthoracyzine (0.5 mM), trifluperidole (0.5 mM) and imipramine (0.5 mM) on GABA release from rat brain synaptosomes depolarized with K+ (50 mM) were investigated. Incubation of synaptosomes with aminazine led to a 2-fold and that with phthoracyzine, trifluperidole and imipramine to a 1.5-fold increase in GABA release from synaptosomes as compared with its basic level. The raising of K+ in the incubation medium to 50 mM brought about a 2-fold augmentation of GABA release. Exposure of synaptosomes to drugs and a higher K+ concentration at a time did not change GABA release as compared to its basic level. Introduction into the incubation medium of the Ga-ionophore A23187 together with 50 mM K+ and trifluperidole or with K+ and imipramine led to the same increase in GABA release from synaptosomes as that produced by the psychotropic drugs as regards native synaptosomes. It is assumed that the lack of the influence of the psychotropic drugs under study of GABA release from synaptosomes depolarized with K+ is caused by blockade of synaptic membrane conductibility for Ca2+.