THE PERFORMANCE OF SOFT CHEKPOINTING APPROACH IN MOBILE COMPUTING SYSTEMS

Mobile computing raises many new issues such as lack of stable storage, low bandwidth of wireless channel, high mobility, and limited battery life. These new issues make traditional checkpointing algorithms unsuitable. Coordinated checkpointing is an attractive approach for transparently adding fault tolerance to distributed applications since it avoids domino effects and minimizes the stable storage requirement. However, it suffers from high overhead associated with the checkpointing process in mobile computing systems. In literature mostly, two approaches have been used to reduce the overhead: First is to minimize the number of synchronization messages and the number of checkpoints; the other is to make the checkpointing process nonblocking. Since MHs are prone to failure, so they have to transfer a large amount of checkpoint data and control information to its local MSS which increases bandwidth overhead. In this paper, we introduce the concept of 201C;Soft checkpoint201D; which is neither a tentative checkpoint nor a permanent checkpoint, to design efficient checkpointing algorithms for mobile computing systems. Soft checkpoints can be saved anywhere, e.g., the main memory or local disk of MHs. Before disconnecting from the MSS, these soft checkpoints are converted to hard checkpoints and are sent to MSSs stable storage. In this way, taking a soft checkpoint avoids the overhead of transferring large amounts of data to the stable storage at MSSs over the wireless network. We have also shown that our soft checkpointing scheme also adapts its behaviour to the characteristics of network

THE PERFORMANCE OF SOFT CHEKPOINTING APPROACH IN MOBILE COMPUTING SYSTEMS

Mobile computing raises many new issues such as lack of stable storage, low bandwidth of wireless channel, high mobility, and limited battery life. These new issues make traditional checkpointing algorithms unsuitable. Coordinated checkpointing is an attractive approach for transparently adding fault tolerance to distributed applications since it avoids domino effects and minimizes the stable storage requirement. However, it suffers from high overhead associated with the checkpointing process in mobile computing systems. In literature mostly, two approaches have been used to reduce the overhead: First is to minimize the number of synchronization messages and the number of checkpoints; the other is to make the checkpointing process nonblocking. Since MHs are prone to failure, so they have to transfer a large amount of checkpoint data and control information to its local MSS which increases bandwidth overhead. In this paper, we introduce the concept of “Soft checkpoint” which is neither a tentative checkpoint nor a permanent checkpoint, to design efficient checkpointing algorithms for mobile computing systems. Soft checkpoints can be saved anywhere, e.g., the main memory or local disk of MHs. Before disconnecting from the MSS, these soft checkpoints are converted to hard checkpoints and are sent to MSSs stable storage. In this way, taking a soft checkpoint avoids the overhead of transferring large amounts of data to the stable storage at MSSs over the wireless network. We have also shown that our soft checkpointing scheme also adapts its behaviour to the characteristics of network

Synergistic Enzyme Cocktail to Enhance Hydrolysis of Steam Exploded Wheat Straw at Pilot Scale

Multiple enzymes are required for efficient hydrolysis of lignocellulosic biomass and no wild type organism is capable of producing all enzymes in desired levels. In this study, steam explosion of wheat straw was carried out at pilot scale and a synthetic enzyme mixture (EnzMix) was developed by partially replacing the cellulase with critical dosages of commercially available accessory enzymes (β-glucosidase, xylanase and laccase) through central composite design. Highest degree of synergism (DS) was observed with β-glucosidase (1.68) followed by xylanase (1.36). Finally, benchmarking of EnzMix (Celluclast, β-glucosidase and xylanase in a protein ratio of 20.40: 38.43: 41.16, respectively) and other leading commercial enzymes was carried out. Interestingly, hydrolysis improved by 75% at 6 h and 30% at 24 h, respectively in comparison of control. By this approach, 25% reduction in enzyme dosage was observed for obtaining the same hydrolysis yield with opitimized enzyme cocktail. Thus, development of enzyme cocktail is an effective and sustainable approach for high hydrolysis efficiency

Genome wide expression profiling of two accession of G. herbaceum L. in response to drought

<p>Abstract</p> <p>Background</p> <p>Genome-wide gene expression profiling and detailed physiological investigation were used for understanding the molecular mechanism and physiological response of <it>Gossypium herbaceum</it>, which governs the adaptability of plants in drought conditions. Recently, microarray-based gene expression analysis is commonly used to decipher genes and genetic networks controlling the traits of interest. However, the results of such an analysis are often plagued due to a limited number of genes (probe sets) on microarrays. On the other hand, pyrosequencing of a transcriptome has the potential to detect rare as well as a large number of transcripts in the samples quantitatively. We used Affymetrix microarray as well as Roche's GS-FLX transcriptome sequencing for a comparative analysis of cotton transcriptome in leaf tissues under drought conditions.</p> <p>Results</p> <p>Fourteen accessions of <it>Gossypium herbaceum </it>were subjected to mannitol stress for preliminary screening; two accessions, namely Vagad and RAHS-14, were selected as being the most tolerant and most sensitive to osmotic stress, respectively. Affymetrix cotton arrays containing 24,045 probe sets and Roche's GS-FLX transcriptome sequencing of leaf tissue were used to analyze the gene expression profiling of Vagad and RAHS-14 under drought conditions. The analysis of physiological measurements and gene expression profiling showed that Vagad has the inherent ability to sense drought at a much earlier stage and to respond to it in a much more efficient manner than does RAHS-14. Gene Ontology (GO) studies showed that the phenyl propanoid pathway, pigment biosynthesis, polyketide biosynthesis, and other secondary metabolite pathways were enriched in Vagad under control and drought conditions as compared with RAHS-14. Similarly, GO analysis of transcriptome sequencing showed that the GO terms <it>responses to various abiotic stresses </it>were significantly higher in Vagad. Among the classes of transcription factors (TFs) uniquely expressed in both accessions, RAHS-14 showed the expression of ERF and WRKY families. The unique expression of ERFs in response to drought conditions reveals that RAHS-14 responds to drought by inducing senescence. This was further supported by transcriptome analysis which revealed that RAHS-14 responds to drought by inducing many transcripts related to senescence and cell death.</p> <p>Conclusion</p> <p>The comparative genome-wide gene expression profiling study of two accessions of <it>G.herbaceum </it>under drought stress deciphers the differential patterns of gene expression, including TFs and physiologically relevant processes. Our results indicate that drought tolerance observed in Vagad is not because of a single molecular reason but is rather due to several unique mechanisms which Vagad has developed as an adaptation strategy.</p

Measurement of nuclear modification factors of gamma(1S)), gamma(2S), and gamma(3S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at √sNN = 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S)) > RAA(ϒ(2S)) > RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at √sNN = 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.Peer reviewe

Physical and Chemical Characterization of Various Indian Agriculture Residues for Biofuels Production

Lignocellulosic material (LCM) has been considered as a potent feedstock for biofuel production either as gaseous, liquid, and/or solid fuel to meet the energy demands. Conversion of lignocellulosic materials to biofuels is possible mainly by two processes, i.e., thermochemical and biochemical. For overall efficiency of processes designed to convert the lignocellulosic materials into the desired biofuel, it is important to understand the characteristics of these lignocellulosic components. The present study aims for physicochemical characterization of common lignocellulosic agricultural residues available in India, i.e., rice straw, rice husk, cotton stalk, wheat straw, bagasse, corn stover, sorghum stalk, mustard stalk, corn cob, and jatropha pruning. Physical and chemical characterization of lignocellulosic samples is carried out by higher heating value, crystallinity index, thermal properties, CHNS/O analysis, FTIR, metal analysis, and compositional analysis. Among all of the biomass samples analyzed, corn cob has the highest content of cellulose and hemicellulose, i.e., 61.2% (w/w), making it the most potent feedstock for production of biofuels using biochemical process, whereas cotton stalk has relatively higher thermochemical potential due to its higher heating value (19.2 MJ/kg). Rice husk and rice straw have the highest ash content, i.e., 17.4 and 13.7% (w/w), respectively, indicating a significant amount of undesirable material