614 research outputs found

    IN VITRO ANTIOXIDANT ACTIVITY OF VARIOUS LEAF EXTRACTS OF CANTHIUM COROMANDELICUM(BURM.F.) ALSTON.

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    Objectives: The objective of this study was to estimate the total phenolic and flavonoid contents and to explore the antioxidant potential of various leaf extracts (chloroform, ethyl acetate, and ethanol) of Canthium coromandelicum, which is considered traditionally as an important medicinal plant.Methods: Antioxidant properties of the extracts were assessed using 1, 1- diphenyl -2- picrylhydrazyl and hydrogen peroxide radical scavenging assays for ascorbic acid equivalents. The total phenolic and flavonoid contents were also investigated to determine their correlation with the antioxidant activity of the leaf extracts and expressed in Gallic acid and quercetin equivalents, respectively.Results: The results showed that the content of total phenols and flavonoids was found to be high in ethyl acetate extract which was recorded as 61.02ƂĀ±1.30 mg Gallic acid equivalent (GAE/g) and 81.72ƂĀ±0.61 QE/g, respectively. Compared to other extracts, ethyl acetate leaf extract was found to possess high antioxidant activity at p<0.05 level, with high percentage of inhibition at 100 ƎĀ¼g/ml concentration (82.70%) toward hydrogen peroxide radical scavenging with IC50 value 62.94 ƎĀ¼g/ml. Statistically, two-tailed Pearson's correlation showed strong positive correlations between hydrogenperoxide radical scavenging activity and total phenolic contents (TPC) (r=1.000) at p<0.05 level.Conclusion: The results obtained in this study clearly signifies that the ethyl acetate leaf extract of C. coromandelicum has high content of total phenols which are correlated to its antioxidant activity and thus has the potential to use as a source of natural antioxidants and can be explored as a therapeutic agent in free radical induced diseases.Ƃ

    Translations: effects of viewpoint, feature, naming and context on identifying repeatedly copied drawings

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    We explored the tension between bottom ā€“ up and top ā€“ down contributions to object recognition in a collaboration between a visual artist and a cognitive psychologist. Initial pictorial renderings of objects and animals from various viewpoints were iteratively copied, and a series of drawings that changed from highly concrete images into highly abstract images was produced. In drawing identification in which sets were shown in reverse order, participants were more accurate, more confident, and quicker to correctly identify the evolving image when it was originally displayed from a canonical viewpoint with all salient features present. In drawing identification in which images were shown in random order, more abstract images could be resolved as a result of previously identifying a more concrete iteration of the same drawing. The results raise issues about the influence of viewpoint and feature on the preservation of pictorial images and about the role of labelling in the interpretation of ambiguous stimuli. In addition, the study highlights a procedure in which visual stimuli can degrade without necessitating a substantial loss of complexity

    Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

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    Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium

    Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

    Get PDF
    Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium

    The living and the dead; an investigation into the status of erasure within the floor of Bath Abbey

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    The floor of Bath Abbey offers a singular test of authenticity. Nineteenth century repairs and additions caused horizontal grave markers, which comprise the majority of the Abbeyā€™s floor, to become separated from the burial sites they were intended to memorialize. A century and a half of further occupation has had the effect of removing many inscriptions as surfaces are worn smooth. The result is a patchwork of unintended edits and accidental poetry. This paper explores the notions of authenticity, essence, memorial and erasure as they pertain to the Abbey floor, in particular with regard to the role the body plays in inhabiting/eroding the floorā€”from both above and below. The author argues that the stones which are most out of place or worn to a state of erasure are no less authentic than their intact equivalents, but that they can be considered to have moved to another state of authenticity rich in resonance and meaning. This paper, in short, is a defense of erasure and that erosion through occupation may be considered a form of social memory; indeed, the marks of walking become the inscription. In other words, the undesigned (erasure, the cutting and repositioning of ledger stones, the missing inscriptions) becomes considered not as a form of dirt but as the positive traces of on-going and meaningful occupation

    Adenosine Signaling through A1 Receptors Inhibits Chemosensitive Neurons in the Retrotrapezoid Nucleus.

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    A subset of neurons in the retrotrapezoid nucleus (RTN) function as respiratory chemoreceptors by regulating depth and frequency of breathing in response to changes in tissue CO2/H+. The activity of chemosensitive RTN neurons is also subject to modulation by CO2/H+-dependent purinergic signaling. However, mechanisms contributing to purinergic regulation of RTN chemoreceptors are not entirely clear. Recent evidence suggests adenosine inhibits RTN chemoreception in vivo by activation of A1 receptors. The goal of this study was to characterize effects of adenosine on chemosensitive RTN neurons and identify intrinsic and synaptic mechanisms underlying this response. Cell-attached recordings from RTN chemoreceptors in slices from rat or wild-type mouse pups (mixed sex) show that exposure to adenosine (1 ĀµM) inhibits chemoreceptor activity by an A1 receptor-dependent mechanism. However, exposure to a selective A1 receptor antagonist (8-cyclopentyl-1,3-dipropylxanthine, DPCPX; 30 nM) alone did not potentiate CO2/H+-stimulated activity, suggesting activation of A1 receptors does not limit chemoreceptor activity under these reduced conditions. Whole-cell voltage-clamp from chemosensitive RTN neurons shows that exposure to adenosine activated an inward rectifying K+ conductance, and at the network level, adenosine preferentially decreased frequency of EPSCs but not IPSCs. These results show that adenosine activation of A1 receptors inhibits chemosensitive RTN neurons by direct activation of a G-protein-regulated inward-rectifier K+ (GIRK)-like conductance, and presynaptically, by suppression of excitatory synaptic input to chemoreceptors

    Ligand-induced sequestering of branchpoint sequence allows conditional control of splicing

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    <p>Abstract</p> <p>Background</p> <p>Despite tremendous progress in understanding the mechanisms of constitutive and alternative splicing, an important and widespread step along the gene expression pathway, our ability to deliberately regulate gene expression at this step remains rudimentary. The present study was performed to investigate whether a theophylline-dependent "splice switch" that sequesters the branchpoint sequence (BPS) within RNA-theophylline complex can regulate alternative splicing.</p> <p>Results</p> <p>We constructed a series of pre-mRNAs in which the BPS was inserted within theophylline aptamer. We show that theophylline-induced sequestering of BPS inhibits pre-mRNA splicing both in vitro and in vivo in a dose-dependent manner. Several lines of evidence suggest that theophylline-dependent inhibition of splicing is highly specific, and thermodynamic stability of RNA-theophylline complex as well as the location of BPS within this complex affects the efficiency of splicing inhibition. Finally, we have constructed an alternative splicing model pre-mRNA substrate in which theophylline caused exon skipping both in vitro and in vivo, suggesting that a small molecule-RNA interaction can modulate alternative splicing.</p> <p>Conclusion</p> <p>These findings provide the ability to control splicing pattern at will and should have important implications for basic, biotechnological, and biomedical research.</p

    Accuracy of telepsychiatric assessment of new routine outpatient referrals

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    <p>Abstract</p> <p>Background</p> <p>Studies on the feasibility of telepsychiatry tend to concentrate only on a subset of clinical parameters. In contrast, this study utilises data from a comprehensive assessment. The main objective of this study is to compare the accuracy of findings from telepsychiatry with those from face to face interviews.</p> <p>Method</p> <p>This is a primary, cross-sectional, single-cluster, balanced crossover, blind study involving new routine psychiatric referrals. Thirty-seven out of forty cases fulfilling the selection criteria went through a complete set of independent face to face and video assessments by the researchers who were blind to each other's findings.</p> <p>Results</p> <p>The accuracy ratio of the pooled results for DSM-IV diagnoses, risk assessment, non-drug and drug interventions were all above 0.76, and the combined overall accuracy ratio was 0.81. There were substantial intermethod agreements for Cohen's kappa on all the major components of evaluation except on the Risk Assessment Scale where there was only weak agreement.</p> <p>Conclusion</p> <p>Telepsychiatric assessment is a dependable method of assessment with a high degree of accuracy and substantial overall intermethod agreement when compared with standard face to face interview for new routine outpatient psychiatric referrals.</p
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