9,293 research outputs found

    Linked data in crowdsourcing purposive social network

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    Internet is an easy medium for people to collaborate and crowdsourcing is an efficient feature of social web where people with common interest and expertise come together to solve specific problems by collective thinking and create a community. It can also be used to filter out important information from large data, remove spams, and gamification techniques are used to reward the users for their contribution and keep a sustainable environment for the growth of the community. Semantic web technologies can be used to structure the community data so it can be combined, decentralized and be used across platform. Using such tools knowledge can be enhanced and easily discovered and merged together. This paper discusses the concept of a purposive social network where people with similar interest and varied expertise come together, use crowdsourcing technique to solve a common problem and build tools for common purpose. The StackOverflow website is chosen to study the purposive network, different network ties and roles of user is studied. Linked Data is used for name disambiguation of keywords and topics for easier search and discovery of experts in a field and provide useful information that is otherwise unavailable in the website

    The Dynamic Relationship between Price and Trading Volume:Evidence from Indian Stock Market

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    This study investigates the nature of relationship between price and trading volume for 50 Indian stocks. Firstly the contemporaneous and asymmetric relation between price and volume are examined. Then we examine the dynamic relation between returns and volume using VAR, Granger causality, variance decomposition (VD) and impulse response function (IRF). Mixture of Distributions Hypothesis (MDH), which tests the GARCH vs. Volume effect, is also studied between the conditional volatility and volume. The results show that there is positive and asymmetric relation between volume and price changes. Further the results of VAR and Granger causality show that there is a bi-directional relation between volume and returns. However, the results of VD imply weak dynamic relation between returns and volume which becomes more evident from the plots of IRF. On MDH, our results are mixed, neither entirely rejecting the MDH nor giving it an unconditional support.

    Price and Volatility Spillovers across North American, European and Asian Stock Markets: With Special Focus on Indian Stock Market

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    <div align=justify>This paper investigates interdependence of fifteen world indices including an Indian market index in terms of return and volatility spillover effect. Interdependence of Indian stock market with other fourteen world markets in terms of long run integration, short run dependence (return spillover) and volatility spillover are investigated. These markets are that of are Canada, China, France, Germany, Hong-Kong, Indonesia, Japan, Korea, Malaysia, Pakistan, Singapore, Taiwan, United Kingdom and United States. Long run and short run integration is examined through Johansen cointegration techniques and Granger causality test respectively. Vector autoregressive model (VAR 15) is used to estimate the conditional return spillover among these indices in which all fifteen indices are considered together. The effect of same day return in explaining the return spillover is also modeled using univariate models. Volatility spillover is estimated through AR-GARCH in which residuals from the index return is used as explanatory variable in GARCH equation. Return and volatility spillover between Indian and other markets are modeled through bivariate VAR and multivariate GARCH (BEKK) model respectively. It is found that there is greater regional influence among Asian markets in return and volatility than with European and US. Japanese market, which is first to open, is affected by US and European markets only and affects most of the Asian Markets. Also, high degree of correlation among European indices namely FTSE, CAC and DAX is observed. US market is influenced by both Asian and European markets. Specific to Indian context, it is found that Indian market is not cointegrated with rest of the world except Indonesia. This may provide diversification benefits for potential investors. However, strong short run interdependence is found between Indian markets and most of the other markets. Indian and other markets like US, Japan, Korea, and Canada positively affect each others conditional returns significantly. Indian market also has significant effect on Malaysia, Pakistan, and Singapore return. This study found that there is significant positive volatility spillover from other markets to Indian market, mainly from Hong Kong, Korea, Japan, and Singapore and US market. Indian market affects negatively the volatility of US and Pakistan. It is interesting to note that Chinese and Pakistan markets are less integrated with other Asian, European and US markets.</div>

    Stopped Flow Kinetics of MnII Catalysed Periodate Oxidation of 2, 3- dimethylaniline - Evaluation of Stability Constant of the Ternary Intermediate Complex

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    The formation of ternary intermediate unstable complex during the oxidation of aromatic amines by periodate ion catalysed by MnII has been proposed in case of some anilines. This paper is the first report on stopped-flow kinetic study and evaluation of stability constant of ternary complex forming in the MnII - catalysed periodate oxidation of 2, 3-dimethylaniline (D) in acetone-water medium. Stop-flow spectrophotometric method was used to study the ternary complex formation and to determine its stability constant. The stop-flow trace shows the reaction to occur in two steps. The first step, which is presumably the formation of ternary complex, is relatively fast while the second stage is relatively quite slow. The stability constant evaluated for D - MnII - IO4- ternary complex by determining equilibrium absorbance is (2.2 ± 1.0) × 105. Kinetics of ternary complex formation was defined by the rate law(A) under pseudo first order conditions. ln{[C2]eq / ( [C2]eq -[C2])} = kobs . t (A) where, kobs is the pseudo first order rate constant, [C2] is concentration of ternary complex at given time t, and [C2]eq is the equilibrium concentration of ternary complex. © 2015 BCREC UNDIP. All rights reserve

    Probing the circumgalactic baryons through cross-correlations

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    We study the cross-correlation of distribution of galaxies, the Sunyaev-Zel'dovich (SZ) and X-ray power spectra of galaxies from current and upcoming surveys and show these to be excellent probes of the nature, i.e. extent, evolution and energetics, of the circumgalactic medium (CGM). The SZ-galaxy cross-power spectrum, especially at large multipoles, depends on the steepness of the pressure profile of the CGM. This property of the SZ signal can, thus, be used to constrain the pressure profile of the CGM. The X-ray cross power spectrum also has a similar shape. However, it is much more sensitive to the underlying density profile. We forecast the detectability of the cross-correlated galaxy distribution, SZ and X-ray signals by combining South Pole Telescope-Dark Energy Survey (SPT-DES) and eROSITA-DES/eROSITA-LSST (extended ROentgen Survey with an Imaging Telescope Array-Large Synoptic Survey Telescope) surveys, respectively. We find that, for the SPT-DES survey, the signal-to-noise ratio (SNR) peaks at high mass and redshift with SNR 9\sim 9 around Mh1013h1MM_h\sim 10^{13} h^{-1} M_{\odot} and z1.52z\sim 1.5\hbox{--} 2 for flat density and temperature profiles. The SNR peaks at 6(12)\sim 6 (12 ) for the eROSITA-DES (eROSITA-LSST) surveys. We also perform a Fisher matrix analysis to find the constraint on the gas fraction in the CGM in the presence or absence of an unknown redshift evolution of the gas fraction. Finally, we demonstrate that the cross-correlated SZ-galaxy and X-ray-galaxy power spectrum can be used as powerful probes of the CGM energetics and potentially discriminate between different feedback models recently proposed in the literature; for example, one can distinguish a `no active galactic nuclei feedback' scenario from a CGM energized by `fixed-velocity hot winds' at greater than 3σ3\sigma.Comment: 14 pages, 10 figures, 4 tables, accepted for publication in MNRA

    Gender differences in a Drosophila transcriptomic model of chronic pentylenetetrazole induced behavioral deficit

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    A male Drosophila model of locomotor deficit induced by chronic pentylenetetrazole (PTZ), a proconvulsant used to model epileptogenesis in rodents, has recently been described. Antiepileptic drugs (AEDs) ameliorate development of this behavioral abnormality. Time-series of microarray profiling of heads of male flies treated with PTZ has shown epileptogenesis-like transcriptomic perturbation in the fly model. Gender differences are known to exist in neurological and psychiatric conditions including epileptogenesis. We describe here the effects of chronic PTZ in Drosophila females, and compare the results with the male model. As in males, chronic PTZ was found found to cause a decreased climbing speed in females. In males, overrepresentation of Wnt, MAPK, TGF-beta, JAK-STAT, Cell communication, and Dorso-Ventral axis formation pathways in downregulated genes was previously described. Of these, female genes showed enrichment only for Dorso-Ventral axis formation. Most significant, ribosomal pathway was uniquely overrepresented in genes downregulated in females. Gender differences thus exist in the Drosophila model. Gender neutral, Dorso-Ventral axis formation may be considered as the candidate causal pathway in chronic pentylenetetrazole induced behavioral deficit. Prior evidence of developmental mechanisms in epileptogenesis underscores the usefulness of fly model. Gender specific pathways may provide a lead for understanding brain dimorphism in neuropsychiatric disorders

    Scurvy induced changes and ascorbate defense in albino rats, Rattus norvegicus

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    An attempt has been made to find out effectiveness of scorbutogenic diet in albino rats, Rattus norvegicus. These animals received 50 and 80 gm cakes of scorbutogenic diet for 15 and 30 days respectively. No scurvy like symptoms were observed rather boils got appeared on their hind limbs, below ear and neck region. Steroid producing glands indicated enhanced steroidogenesis as evidenced by decreased concentrations of adrenal ascorbate and cholesterol. The results suggested that scorbutogenic diet was ineffective to cause scurvy in this species
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