273 research outputs found

    Chemical composition, antibacterial activity of essential oil and anatomical study of Chrysanthemum morifolium

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    The aim of this study is to identify the chemical composition and to evaluate the antimicrobial activity of Chrysanthemum morifolium. The analysis and identification of essential oil which obtained by hydrodistilation method were realized by gaz chromatography and mass spectroscopy. The antibacterial activity was tested by using the agar diffusion test and the Gram positive and negative pathogenic bacteria: Staphylococcus aureus ATCC 25923. Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Citrobacter freundii ATCC 8090, Kleibseilla pneumoniae ATCC 700603 and Shigella sonnei were used to evaluate this activity. This analysis led to the identification of 26 compounds representing 88.40 % of the total essential oil mass. The major compound was Verbenone (17.33 %). Other components present in appreciable contents were: Chrysanthenone (9.71%). 4-epi-cubedol (07.25%) and Ī“-Cadinol (05.29 %). Essential oil of Chrysanthemum morifolium exhibited an antibacterial effect against pathogenic bacteria, like those observed against Staphylococcus aureus ATCC 25923 (35Ā±1.2mm) and Citrobacter freundii ATCC 8090 (21Ā±0.87mm), however Pseudomonas aeruginosa  ATCC  27853  and  Kleibseilla  pneumoniae  ATCC  700603                      were resistant. The anatomical study showed the presence of several types of trichomes including the glands secreted for essential oils and protector trichomes. Keywords: essential oil, antibacterial activity, Chrysanthemum morifolium, anatomical study, chemical compositio

    Automatic categorization and summarization of documentaries

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    In this paper, we propose automatic categorization and summarization of documentaries using subtitles of videos. We propose two methods for video categorization. The first makes unsupervised categorization by applying natural language processing techniques on video subtitles and uses the WordNet lexical database and WordNet domains. The second has the same extraction steps but uses a learning module to categorize. Experiments with documentary videos give promising results in discovering the correct categories of videos. We also propose a video summarization method using the subtitles of videos and text summarization techniques. Significant sentences in the subtitles of a video are identified using these techniques and a video summary is then composed by finding the video parts corresponding to these summary sentences. Ā© 2010 The Author(s)

    Summarization of documentaries

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    Video summarization algorithms present condensed versions of a full length video by identifying the most significant parts of the video. In this paper, we propose an automatic video summarization method using the subtitles of videos and text summarization techniques. We identify significant sentences in the subtitles of a video by using text summarization techniques and then we compose a video summary by finding the video parts corresponding to these summary sentences. Ā© 2011 Springer Science+Business Media B.V

    How transcription proceeds in a large artificial heterochromatin in human cells

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    Heterochromatin is critical for genome integrity, and recent studies have suggested the importance of transcription in heterochromatin for maintaining its silent state. We previously developed a method to generate a large homogeneously staining region (HSR) composed of tandem plasmid sequences in human cells that showed typical heterochromatin characteristics. In this study, we examined transcription in the HSR. We found that transcription of genes downstream to no-inducible SRĪ± promoter was restricted to a few specific points inside the large HSR domain. Furthermore, the HSR localized to either to the surface or to the interior of the nucleolus, where it was more actively transcribed. The perinucleolar or intranucleolar locations were biased to late or early S-phase, and the location depended on either RNA polymerase II/III or I transcription, respectively. Strong activation of the inducible TRE promoter resulted in the reversible loosening of the HSR domain and the appearance of transcripts downstream of not only the TRE promoters, but also the SRĪ± promoters. During this process, detection of HP1Ī± or H3K9Me3 suggested that transcription was activated at many specific points dispersed inside large heterochromatin. The transcriptional rules obtained from studying artificial heterochromatin should be useful for understanding natural heterochromatin
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