381 research outputs found

    Enhancing Network Lifetime in Wireless Sensor Networks Adopting Elephant Swarm Optimization

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    Enhancing the lifetime of wireless sensor networks had baffled researchers for quite some time now. The authors of this research manuscript draw inspiration from the behavior of large elephant swarms and incorporate their behavior into wireless sensor networks. The complex elephant swarm behavior is incorporated using a cross layer approach. The elephant optimization discussed in this paper enables optimized routing techniques, adaptive radio link optimization and balanced scheduling to achieve a cumulative enhanced network performance. The proposed elephant swarm optimization is compared with the popular protocol. The experimental study presented proves that the Elephant Swarm Optimization technique enhances the network life time by about 73%

    Critical Analysis of Solutions to Hadoop Small File Problem

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    Hadoop big data platform is designed to process large volume of data Small file problem is a performance bottleneck in Hadoop processing Small files lower than the block size of Hadoop creates huge storage overhead at Namenode s and also wastes computational resources due to spawning of many map tasks Various solutions like merging small files mapping multiple map threads to same java virtual machine instance etc have been proposed to solve the small file problems in Hadoop This survey does a critical analysis of existing works addressing small file problems in Hadoop and its variant platforms like Spark The aim is to understand their effectiveness in reducing the storage computational overhead and identify the open issues for further researc

    Revisiting Logarithmic Correction to Five Dimensional BPS Black Hole Entropy

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    We compute logarithmic correction to five dimensional BPS black hole entropy using finite temperature black hole geometry and find perfect agreement with the microscopic results and macroscopic computations based on zero temperature near horizon geometry. We also reproduce the Bekenstein-Hawking term for zero temperature black hole entropy from the corresponding term for finite temperature black hole.Comment: LaTeX, 21 pages; v2: typos corrected, references adde

    Gel-Based and Gel-Free Identification of Proteins and Phosphopeptides during Egg-to-Larva Transition in Polychaete Neanthes arenaceodentata

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    The polychaete Neanthes arenaceodentata- is cosmopolitan in distribution-, has been used as a laboratory test animal. Life history of this species has several unique features; the female dies after spawning and the male incubates the fertilized eggs through the 21-segmented stage. The larvae leave the tube and commence feeding. Changes in protein abundance and phosphorylation were examined during early development of N. arenaceodentata. A gel-based approach and gel-free enrichment of phosphopeptides coupled with mass spectrometry were used to identify proteins and phosphopeptides in fertilized ova and larval stages. Patterns of proteins and phosphoproteins changed from fertilized ova to larval stages. Twelve proteins occurred in phosphorylated form and nine as stage specific proteins. Cytoskeletal proteins have exhibited differential phosphorylation from ova to larval stages; whereas, other proteins exhibited stage-specific phosphorylation patterns. Ten phosphopeptides were identified that showed phosphorylation sites on serine or threonine residues. Sixty percent of the identified proteins were related to structural reorganization and others with protein synthesis, stress response and attachment. The abundance and distribution of two cytoskeleton proteins were examined further by 2-DE Western blot analysis. This is the first report on changes in protein expression and phosphorylation sites at Thr/Ser in early development of N. arenaceodentata. The 2-DE proteome maps and identified phosphoproteins contributes toward understanding the state of fertilized ova and early larval stages and serves as a basis for further studies on proteomics changes under different developmental conditions in this and other polychaete species

    RASCP: Providing for a Secure Group Communication Plane Using RFID

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    Predominantly large distributed networks currently provide support for group oriented protocols and applications Regardless of the type of distributed network there is a need to provide communication privacy and data integrity to the information exchange amongst the group members This paper introduces a protocol named Authentication based Secure Communication Plane adopts the commutative RSA algorithm to maintain data integrity The proposed protocol not only eliminates the overheads resulting from key distribution and key compromise attacks but also provide for information security in the presence of colluded group members Radio Frequency Identification tags is used for group member identification The RACP protocol is compared with the RFID extended Secure Lock group communication protocol and its efficiency in terms of the computational complexity involved is discussed in this pape

    Differential expression of proteins and phosphoproteins during larval metamorphosis of the polychaete Capitella sp. I

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    <p>Abstract</p> <p>Background</p> <p>The spontaneous metamorphosis of the polychaete <it>Capitella </it>sp. I larvae into juveniles requires minor morphological changes, including segment formation, body elongation, and loss of cilia. In this study, we investigated changes in the expression patterns of both proteins and phosphoproteins during the transition from larvae to juveniles in this species. We used two-dimensional gel electrophoresis (2-DE) followed by multiplex fluorescent staining and MALDI-TOF mass spectrometry analysis to identify the differentially expressed proteins as well as the protein and phosphoprotein profiles of both competent larvae and juveniles.</p> <p>Results</p> <p>Twenty-three differentially expressed proteins were identified in the two developmental stages. Expression patterns of two of those proteins were examined at the protein level by Western blot analysis while seven were further studied at the mRNA level by real-time PCR. Results showed that proteins related to cell division, cell migration, energy storage and oxidative stress were plentifully expressed in the competent larvae; in contrast, proteins involved in oxidative metabolism and transcriptional regulation were abundantly expressed in the juveniles.</p> <p>Conclusion</p> <p>It is likely that these differentially expressed proteins are involved in regulating the larval metamorphosis process and can be used as protein markers for studying molecular mechanisms associated with larval metamorphosis in polychaetes.</p

    Attentional Networks and Biological Motion

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    Our ability to see meaningful actions when presented with pointlight traces of human movement is commonly referred to as the perception of biological motion. While traditionalexplanations have emphasized the spontaneous and automatic nature of this ability, morerecent findings suggest that attention may play a larger role than is typically assumed. Intwo studies we show that the speed and accuracy of responding to point-light stimuli is highly correlated with the ability to control selective attention. In our first experiment we measured thresholds for determining the walking direction of a masked point-light figure, and performance on a range of attention-related tasks in the same set of observers. Mask-density thresholds for the direction discrimination task varied quite considerably from observer to observer and this variation was highly correlated with performance on both Stroop and flanker interference tasks. Other components of attention, such as orienting, alerting and visual search efficiency, showed no such relationship. In a second experiment, we examined the relationship between the ability to determine the orientation of unmasked point-light actions and Stroop interference, again finding a strong correlation. Our results are consistent with previous research suggesting that biological motion processing may requite attention, and specifically implicate networks of attention related to executive control and selection

    Logarithmic Correction to BPS Black Hole Entropy from Supersymmetric Index at Finite Temperature

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    It has been argued by Iliesiu, Kologlu and Turiaci in arXiv:2107.09062 that one can compute the supersymmetric index of black holes using black hole geometry carrying finite temperature but a specific complex angular velocity. We follow their prescription to compute the logarithmic correction to the entropy of BPS states in four dimensions, defined as the log of the index of supersymmetric black holes, and find perfect agreement with the previous results for the same quantity computed using the near horizon AdS2×S2AdS_2 \times S^2 geometry of zero temperature black holes. Besides giving an independent computation of supersymmetric black hole entropy, this analysis also provides a test of the procedure used previously for computing logarithmic corrections to Schwarzschild and other non-extremal black hole entropy.Comment: 23 page

    Phosphoproteome analysis during larval development and metamorphosis in the spionid polychaete Pseudopolydora vexillosa

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    <p>Abstract</p> <p>Background</p> <p>The metamorphosis of the spionid polychaete <it>Pseudopolydora vexillosa </it>includes spontaneous settlement onto soft-bottom habitats and morphogenesis that can be completed in a very short time. A previous study on the total changes to the proteome during the various developmental stages of <it>P. vexillosa </it>suggested that little or no <it>de novo </it>protein synthesis occurs during metamorphosis. In this study, we used multicolor fluorescence detection of proteins in 2-D gels for differential analysis of proteins and phosphoproteins to reveal the dynamics of post-translational modification proteins in this species. A combination of affinity chromatography, 2D-PAGE, and mass spectrometry was used to identify the phosphoproteins in pre-competent larvae, competent larvae, and newly metamorphosed juveniles.</p> <p>Results</p> <p>We reproducibly detected 210, 492, and 172 phosphoproteins in pre-competent larvae, competent larvae, and newly metamorphosed juveniles, respectively. The highest percentage of phosphorylation was observed during the competent larval stage. About 64 stage-specific phosphoprotein spots were detected in the competent stage, and 32 phosphoproteins were found to be significantly differentially expressed in the three stages. We identified 38 phosphoproteins, 10 of which were differentially expressed during metamorphosis. These phosphoproteins belonged to six categories of biological processes: (1) development, (2) cell differentiation and integrity, (3) transcription and translation, (4) metabolism, (5) protein-protein interaction and proteolysis, and (6) receptors and enzymes.</p> <p>Conclusion</p> <p>This is the first study to report changes in phosphoprotein expression patterns during the metamorphosis of the marine polychaete <it>P. vexillosa</it>. The higher degree of phosphorylation during the process of attaining competence to settle and metamorphose may be due to fast morphological transitions regulated by various mechanisms. Our data are consistent with previous studies showing a high percentage of phosphorylation during competency in the barnacle <it>Balanus amphitrite </it>and the bryozoan <it>Bugula neritina</it>. The identified phosphoproteins may play an important role during metamorphosis, and further studies on the location and functions of important proteins during metamorphosis are warranted.</p
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