61 research outputs found

    FP-tree and COFI Based Approach for Mining of Multiple Level Association Rules in Large Databases

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    In recent years, discovery of association rules among itemsets in a large database has been described as an important database-mining problem. The problem of discovering association rules has received considerable research attention and several algorithms for mining frequent itemsets have been developed. Many algorithms have been proposed to discover rules at single concept level. However, mining association rules at multiple concept levels may lead to the discovery of more specific and concrete knowledge from data. The discovery of multiple level association rules is very much useful in many applications. In most of the studies for multiple level association rule mining, the database is scanned repeatedly which affects the efficiency of mining process. In this research paper, a new method for discovering multilevel association rules is proposed. It is based on FP-tree structure and uses cooccurrence frequent item tree to find frequent items in multilevel concept hierarchy.Comment: Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis


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    Objective: Insulin-like growth factor 1 receptor (IGF-1R) is over-expressed in a number of cancer cell lines and has been implicated to play a role in oncogenesis and suppression of apoptosis. Thus, the inhibition of IGF-1R activity leads to tumor regression and renders IGF-1R a plausible target for the development of anti-cancer drugs. Dietary agents are known to interfere with IGF signaling and offer a foundation for developing nontoxic agents that override any toxicity associated with synthetic IGF inhibitors. This study is designed to obtain structural motifs and active residues that preferentially interact with IGF1Rand to identify the phytochemicals from different plants and act as potential anticancer drug leadsMethods: Thus, six dietary agents known to interfere directly with circulating levels of IGF1R were undertaken for docking studies. A molecular docking simulation model of IGF1R with its bound ligand was established and validated to be used as a reference model for the study.Results: The active site residuesGLU1080, MET 1082, GLU1081, GLU1027, GLU1145 and ARG1003 were found to play a significant role in binding mechanism. The ADME properties and drug likeliness of the ligands were rigorously analyzed under four criteria of known successful drug activity in the areas of GPCR ligand activity, ion channel modulation, kinase inhibition activity, nuclear receptor ligand activity and enzyme inhibition. The dietary agents Apigenin and Luteolin demonstrated reliable interaction with IGF1R (-5.78Kcal/mol and-5.70 Kcal/mol respectively)and displayed good pharmacokinetics properties.Conclusion: It is concluded that the explored dietary agents offer profound promise to be used natural inhibitors of IGF1R and thus may be useful for the preparation of different combinations and formulations for the management of tumors.Â

    Fading AGN in Post-Starburst Galaxies

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    The role of AGN in quenching galaxies and driving the evolution from star-forming to quiescent remains a key question in galaxy evolution. We present evidence from the Mapping Nearby Galaxies at APO (MaNGA) survey for fading AGN activity in 6/93 post-starburst galaxies. These six galaxies show extended emission line regions (EELRs) consistent with ionization from past AGN activity, analogous to "Hanny's voorwerp" and other systems where the OIII5007 emission is bright enough to be visible in broadband imaging. Using the infrared luminosities from IRAS to estimate the current AGN luminosity, we find that 5/6 of the post-starburst galaxies have current AGN which have faded from the peak luminosity required to have ionized the EELRs. Given the rate at which we observe EELRs, the typical EELR visibility timescale, and an estimate of how often EELRs would be visible, we estimate the duty cycle of AGN activity during the post-starburst phase. The timescale for the galaxy to cycle between peaks in AGN luminosity is tEELR1.12.3×105t_{\rm EELR}\sim1.1-2.3\times10^5 yr. Given the rate at which we observe current AGN activity during this phase, we estimate that the AGN spends only 5.3% of this time (or tON=0.61.3×104t_{\rm ON} = 0.6-1.3\times10^4 yr) in its luminous phase, with the rest of the time spent "off" or in a low-luminosity phase. The length of this duty cycle may explain why so few luminous AGN have been observed during the post-starburst phase, despite evidence for AGN feedback at work.Comment: Re-submitted to ApJ after referee report. 20 pages, 13 figure

    Fluorescent Discrimination between Traces of Chemical Warfare Agents and Their Mimics

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    An array of fluorogenic probes is able to discriminate between nerve agents, sarin, soman, tabun, VX and their mimics, in water or organic solvent, by qualitative fluorescence patterns and quantitative multivariate analysis, thus making the system suitable for the inthe- field detection of traces of chemical warfare agents as well as to differentiate between the real nerve agents and other related compounds.Ministerio de Economía y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411) and the Swedish Ministry of Defence (no. A403913