719 research outputs found

    Antimicrobial activity of leaf extracts of Indian medicinal plants against clinical and phytopathogenic bacteria

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    The ethnobotanical efficacy of Indian medicinal plants; Achyranthes aspera, Artemisia parviflora, Azadirachta indica, Calotropis gigantean, Lawsonia inermis, Mimosa pudica, Ixora coccinea, Parthenium hysterophorus and Chromolaena odorata were examined using agar disc diffusion method against clinical bacteria (Escherichia coli and Staphylococcus aureus) and phytopathogenic bacteria (Xanthomonas vesicatoria and Ralstonia solanacearum). Leaves were extracted using different solvents such as methanol, ethanol, ethyl acetate and chloroform. Among treatments, maximum in vitro inhibition was scored in methanol extracts of C. odorata which offered inhibition zone of 10, 9, 12 and 12 mm against E. coli, S. aureus, X. vesicatoria and R. solanaccearum, respectively, followed by chloroform extract of the same plant leaf with inhibition zone of 8, 4, 4 and 4 mm, respectively. A significant inhibition of E. coli was found in aqueous and in all tested solvent extracts of A. indica. In case of S. aureus, maximum inhibition of 8 mm was obtained in aqueous extracts of A. indica and 6 mm from methanol extract of L. inermis. The minimum inhibitory concentration (MIC) value for the clinicalbacteria ranged between 0.35 to 4.0 mg/ml and 0.25 to 4.0 mg/ml for phytopathogenic bacteria when tested with all four solvents extracts of C. odorata. Whereas, extracts of A. aspera, A. parviflora, C. gigantean, L. inermis, M. pudica and I. coccinea were found to be ineffective or showed poor inhibition on tested human and phytopathogenic bacteria

    Biochemical characterization of Fusarium oxysporum f. sp. cubense isolates from India

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    The Fusarium wilt caused by Fusarium oxyspoum f. sp. cubense (Foc) is a major biotic constraint for banana production. The characteristics of F. oxyspoum f. sp. cubense isolates were investigated using electrophoretic studies of isozyme and whole-cell protein. The morphological characteristics of the isolates were very similar to each other. All the Foc isolates were pathogenic to banana cultivar ‘Nanjangud Rasabale’ but they did not induce any disease symptoms on cultivar ‘Cavendish’. F.oxyspoum (Isolate 6) did not induce wilt symptoms on either ‘Nanjangud’ or ‘Cavendish’ cultivar. Isozyme banding patterns showed 46 scoreable markers and cluster analysis with UPGMA using genetic distance showed that the isolates belonged to three main groups. Group 1 contained isolates 1, 2, 4, 5, 7 and isolate 3 and 6 were placed in group 2 and 3. Results indicated that the estimated intraspecific variation may be more pronounced with isozyme analysis than with protein markers. The levelof isozyme variability detected within F. oxysporum f.sp. cubense suggested that it is reliable, efficient and effective in determining genetic relationships among Foc isolates

    Fracturing ranked surfaces

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    Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction p=pcp=p_{c}, where pcp_{c} is the percolation threshold of random percolation. For any value of pp in the interval pc<p1p_{c}< p \leq 1, our results show that the set of bridges has a fractal dimension dBB1.22d_{BB} \approx 1.22 in two dimensions. In the limit p1p \rightarrow 1, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

    How accurately is ncRNA aligned within whole-genome multiple alignments?

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    <p>Abstract</p> <p>Background</p> <p>Multiple alignment of homologous DNA sequences is of great interest to biologists since it provides a window into evolutionary processes. At present, the accuracy of whole-genome multiple alignments, particularly in noncoding regions, has not been thoroughly evaluated.</p> <p>Results</p> <p>We evaluate the alignment accuracy of certain noncoding regions using noncoding RNA alignments from Rfam as a reference. We inspect the MULTIZ 17-vertebrate alignment from the UCSC Genome Browser for all the human sequences in the Rfam seed alignments. In particular, we find 638 instances of chimeric and partial alignments to human noncoding RNA elements, of which at least 225 can be improved by straightforward means. As a byproduct of our procedure, we predict many novel instances of known ncRNA families that are suggested by the alignment.</p> <p>Conclusion</p> <p>MULTIZ does a fairly accurate job of aligning these genomes in these difficult regions. However, our experiments indicate that better alignments exist in some regions.</p

    Combining comparative genomics with de novo motif discovery to identify human transcription factor DNA-binding motifs

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    BACKGROUND: As more and more genomes are sequenced, comparative genomics approaches provide a methodology for identifying conserved regulatory elements that may be involved in gene regulations. RESULTS: We developed a novel method to combine comparative genomics with de novo motif discovery to identify human transcription factor binding motifs that are overrepresented and conserved in the upstream regions of a set of co-regulated genes. The method is validated by analyzing a well-characterized muscle specific gene set, and the results showed that our approach performed better than the existing programs in terms of sensitivity and prediction rate. CONCLUSION: The newly developed method can be used to extract regulatory signals in co-regulated genes, which can be derived from the microarray clustering analysis

    Bio-nanotechnology application in wastewater treatment

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    The nanoparticles have received high interest in the field of medicine and water purification, however, the nanomaterials produced by chemical and physical methods are considered hazardous, expensive, and leave behind harmful substances to the environment. This chapter aimed to focus on green-synthesized nanoparticles and their medical applications. Moreover, the chapter highlighted the applicability of the metallic nanoparticles (MNPs) in the inactivation of microbial cells due to their high surface and small particle size. Modifying nanomaterials produced by green-methods is safe, inexpensive, and easy. Therefore, the control and modification of nanoparticles and their properties were also discussed

    Induction of Tachykinin Production in Airway Epithelia in Response to Viral Infection

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    The tachykinins are implicated in neurogenic inflammation and the neuropeptide substance P in particular has been shown to be a proinflammatory mediator. A role for the tachykinins in host response to lung challenge has been previously demonstrated but has been focused predominantly on the release of the tachykinins from nerves innervating the lung. We have previously demonstrated the most dramatic phenotype described for the substance P encoding gene preprotachykinin-A (PPT-A) to date in controlling the host immune response to the murine gammaherpesvirus 68, in the lung.In this study we have utilised transgenic mice engineered to co-ordinately express the beta-galactosidase marker gene along with PPT-A to facilitate the tracking of PPT-A expression. Using a combination of these mice and conventional immunohistology we now demonstrate that PPT-A gene expression and substance P peptide are induced in cells of the respiratory tract including tracheal, bronchiolar and alveolar epithelial cells and macrophages after viral infection. This induction was observed 24h post infection, prior to observable inflammation and the expression of pro-inflammatory chemokines in this model. Induced expression of the PPT-A gene and peptide persisted in the lower respiratory tract through day 7 post infection.Non-neuronal PPT-A expression early after infection may have important clinical implications for the progression or management of lung disease or infection aside from the well characterised later involvement of the tachykinins during the inflammatory response
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