2,905 research outputs found

    In Vitro Anticholinesterase and Inhibitory Effects of the Aqueous Extract of Combretum molle (Combretaceae) Leaf on Rabbit Breathing

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    Purpose: In previous studies, the aqueous extract of Combretum molle was shown to inhibit disturbances of breathing induced by acetylcholine. The aim of this study was to elucidate the mechanism of this inhibition. Methods: The aqueous extract of Combretum molle and an anti-asthmatic, salbutamol (reference), were tested at varying concentrations for their inhibitory effects on breathing. Acetylcholinesterase (AChE) was extracted from rabbit duodenum and its activity determined by Ellman’s assay using acethylthiocholine iodide (ACTH) as substrate. The rate of hydrolysis of acetylcholinesterase was spectrophotometrically monitored at 412 nm.Results: The results indicate that in the presence of C. molle extract, a considerable reduction in the variation of breathing amplitudes occurred. Furthermore, the extract probably contains anti-AChE substances. C. molle exerted non-competitive inhibition of acetylcholinesterase with Michaelis-Menten constant (KM) of 192 μM and velocity at maximal concentration of substrate (Vmax) of 4444 μM/min. Conclusion: These results support the use of C. molle leaf in the Pharmacopoeia of Ivory Coast as an anti-asthmatic, in view of its inhibitory effect on breathing disturbances.Keywords: Combretum molle, Acetylcholinesterase, Breathing disturbances, Salbutamol, Anti-asthmati

    Rematérialiser les études touristiques

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    Ce chapitre analyse les enjeux de l’approche matérialiste du tourisme en géographie et, plus largement, dans le champ des sciences sociales. Ces enjeux sont d\u27abord discutés à la lumière des évolutions théoriques que connaît la recherche touristique depuis une vingtaine d’années. Alors que la perspective économique a dominé ce champ de recherche jusqu’aux années 1980, les études touristiques sont particulièrement marquées par l’influence du tournant culturel depuis le début des années 1990. Si ce glissement théorique a permis une meilleure compréhension du tourisme, en particulier à travers l’étude des pratiques et des imaginaires touristiques, cette évolution a aussi contribué à éloigner la recherche touristique de l’analyse des inégalités sociales et des rapports de domination. Partant de ce constat, le texte propose une réflexion théorique permettant de ramener l’étude géographique du tourisme dans le champ des approches matérialistes. Une telle démarche s’appuie pour cela sur des recherches empiriques menées au Mexique autour de conflits locaux pour l’appropriation d’espaces touristiques, mais aussi sur un certain nombre de questionnements plus théoriques sur la dimension spatiale du tourisme. L’approche développée s’appuie notamment sur l’héritage théorique du philosophe marxiste Henri Lefebvre dont les travaux alimentent une « économie politique de l’espace ». Le retour au matérialisme historique est ainsi envisagé comme un moyen d’alimenter la lecture critique du tourisme tout en évitant les écueils des approches structuralistes et marxistes développées dans les années 1970. De cette manière, il s’agit également de montrer l’apport des études touristiques à la compréhension plus globale des sociétés capitalistes contemporaines

    A different look at the spin state of Co3+^{3+} ions in CoO5_{5} pyramidal coordination

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    Using soft-x-ray absorption spectroscopy at the Co-L2,3L_{2,3} and O-KK edges, we demonstrate that the Co3+^{3+} ions with the CoO5_{5} pyramidal coordination in the layered Sr2_2CoO3_3Cl compound are unambiguously in the high spin state. Our result questions the reliability of the spin state assignments made so far for the recently synthesized layered cobalt perovskites, and calls for a re-examination of the modeling for the complex and fascinating properties of these new materials.Comment: 5 pages 3 figure

    Conclave: ontology-driven measurement of semantic relatedness between source code elements and problem domain concepts

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    Software maintainers are often challenged with source code changes to improve software systems, or eliminate defects, in unfamiliar programs. To undertake these tasks a sufficient understanding of the system (or at least a small part of it) is required. One of the most time consuming tasks of this process is locating which parts of the code are responsible for some key functionality or feature. Feature (or concept) location techniques address this problem. This paper introduces Conclave, an environment for software analysis, and in particular the Conclave-Mapper tool that provides a feature location facility. This tool explores natural language terms used in programs (e.g. function and variable names), and using textual analysis and a collection of Natural Language Processing techniques, computes synonymous sets of terms. These sets are used to score relatedness between program elements, and search queries or problem domain concepts, producing sorted ranks of program elements that address the search criteria, or concepts. An empirical study is also discussed to evaluate the underlying feature location technique.info:eu-repo/semantics/publishedVersio

    Medial Orbitofrontal Cortex Regulates Instrumental Conditioned Punishment, but not Pavlovian Conditioned Fear

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    Abstract Bidirectionally aberrant medial orbitofrontal cortical (mOFC) activity has been consistently linked with compulsive disorders and related behaviors. Although rodent studies have established a causal link between mOFC excitation and compulsive-like actions, no such link has been made with mOFC inhibition. Here we use excitotoxic lesions of mOFC to investigate its role in sensitivity to punishment; a core characteristic of many compulsive disorders. In our first experiment, we demonstrated that mOFC lesions prevented rats from learning to avoid a lever that was punished with a stimulus that co-terminated with footshock. Our second experiment demonstrated that retrieval of punishment learning is also somewhat mOFC-dependent, as lesions prevented the extended retrieval of punishment contingencies relative to shams. In contrast, mOFC lesions did not prevent rats from re-acquiring the ability to avoid a punished lever when it was learned prior to lesions being administered. In both experiments, Pavlovian fear conditioning to the stimulus was intact for all animals. Together, these results reveal that the mOFC regulates punishment learning and retrieval in a manner that is separate from any role in Pavlovian fear conditioning. These results imply that aberrant mOFC activity may contribute to the punishment insensitivity that is observed across multiple compulsive disorders.</jats:p

    SCAMP:standardised, concentrated, additional macronutrients, parenteral nutrition in very preterm infants: a phase IV randomised, controlled exploratory study of macronutrient intake, growth and other aspects of neonatal care

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    <p>Abstract</p> <p>Background</p> <p>Infants born <29 weeks gestation are at high risk of neurocognitive disability. Early postnatal growth failure, particularly head growth, is an important and potentially reversible risk factor for impaired neurodevelopmental outcome. Inadequate nutrition is a major factor in this postnatal growth failure, optimal protein and calorie (macronutrient) intakes are rarely achieved, especially in the first week. Infants <29 weeks are dependent on parenteral nutrition for the bulk of their nutrient needs for the first 2-3 weeks of life to allow gut adaptation to milk digestion. The prescription, formulation and administration of neonatal parenteral nutrition is critical to achieving optimal protein and calorie intake but has received little scientific evaluation. Current neonatal parenteral nutrition regimens often rely on individualised prescription to manage the labile, unpredictable biochemical and metabolic control characteristic of the early neonatal period. Individualised prescription frequently fails to translate into optimal macronutrient delivery. We have previously shown that a standardised, concentrated neonatal parenteral nutrition regimen can optimise macronutrient intake.</p> <p>Methods</p> <p>We propose a single centre, randomised controlled exploratory trial of two standardised, concentrated neonatal parenteral nutrition regimens comparing a standard macronutrient content (maximum protein 2.8 g/kg/day; lipid 2.8 g/kg/day, dextrose 10%) with a higher macronutrient content (maximum protein 3.8 g/kg/day; lipid 3.8 g/kg/day, dextrose 12%) over the first 28 days of life. 150 infants 24-28 completed weeks gestation and birthweight <1200 g will be recruited. The primary outcome will be head growth velocity in the first 28 days of life. Secondary outcomes will include a) auxological data between birth and 36 weeks corrected gestational age b) actual macronutrient intake in first 28 days c) biomarkers of biochemical and metabolic tolerance d) infection biomarkers and other intravascular line complications e) incidence of major complications of prematurity including mortality f) neurodevelopmental outcome at 2 years corrected gestational age</p> <p>Trial registration</p> <p>Current controlled trials: <a href="http://www.controlled-trials.com/ISRCTN76597892">ISRCTN76597892</a>; EudraCT Number: 2008-008899-14</p

    A high quality Arabidopsis transcriptome for accurate transcript-level analysis of alternative splicing

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    Alternative splicing generates multiple transcript and protein isoforms from the same gene and thus is important in gene expression regulation. To date, RNA-sequencing (RNA-seq) is the standard method for quantifying changes in alternative splicing on a genome-wide scale. Understanding the current limitations of RNA-seq is crucial for reliable analysis and the lack of high quality, comprehensive transcriptomes for most species, including model organisms such as Arabidopsis, is a major constraint in accurate quantification of transcript isoforms. To address this, we designed a novel pipeline with stringent filters and assembled a comprehensive Reference Transcript Dataset for Arabidopsis (AtRTD2) containing 82,190 non-redundant transcripts from 34 212 genes. Extensive experimental validation showed that AtRTD2 and its modified version, AtRTD2-QUASI, for use in Quantification of Alternatively Spliced Isoforms, outperform other available transcriptomes in RNA-seq analysis. This strategy can be implemented in other species to build a pipeline for transcript-level expression and alternative splicing analyses
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