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Profilage chimique et valorisation pharmacologique d’Amanita amerivirosa, un champignon européen, Boscia senegalensis et Chrozophora brocchiana, deux (2) plantes antiparasitaires de la pharmacopée traditionnellle au Niger
No full textIn Niger, parasitic diseases are a real health problem for both humans and animals. This situation is aggravated by the appearance of resistance phenomena. Fortunately, medicinal plants are an inexhaustible source of antiparasitic compounds. This study aimed to contribute to ameliorate animal and human health by using natural products derived from medicinal plants against intestinal worms. Our research work focused on the chemical and pharmacological study of Boscia senegalensis(Capparaceae), Chrozophora brocchiana (Euphorbiaceae) and Amanita amerivirosa (Amanitaceae).The extracted substances were separated and identified by different chromatographic (UHPLC, HPLC, TLC) and spectroscopic (UV-visible, HRMS, 1D and 2D NMR) techniques. The dosage of phenolic compounds was carried out using standard colorimetric methods. The anthelmintic properties of B. senegalensis and C. brocchiana were evaluated at different concentrations using in vitro tests.Phytochemical screening of hexane, dichloromethane, ethyl acetate and ethanol-water (70 :30) extracts of B. senegalensis showed the presence of of alkaloids, tannins, flavonoids, quinones, saponosides, steroids and terpenoids. In C. brocchiana extracts, we notified absence of alkaloids and saponins. Total polyphenol contents of B. senegalensis extracts ranged from 3,21±0,03 mg EAG/g to 5,67±0,01 mg EAG/g. The contents of total condensed tannins ranged from 2,18 ±0,02 mg EAT/g to 5,48±0,02 mg EAT/g and total flavonoids ranged from 4,18±0,08mg EQ/g to 6,57±0,07 mg EQ/g. Concerning C. brocchiana total polyphenols contents ranged from 1,13±0,1 mg EAG/g à 3,04±0,03 mg EAG/g. The contents of total condensed tannins ranged from 1,66 ±0,03 mg EAT/g à 3,16±0,02 mg EAT/g and flavonoids contents ranged from 4,86±0,08mg EQ/g to 5,97±0,02 mg EQ/g.An LC-MS/MS analysis with molecular network approaches lead to five (5) compounds, three (3) of them are new cyclopeptide toxins. They were isolated from A. amerivirosa. They are: ameriphalloidin (1), ameriviroidin (2) and ameriviroisin (3). The other two (2) compounds are polyamine alkaloids. They were isolated from B. senegalensis. These compounds are 18-AcO-chaenorpine (4), whose structure is new and chaenorpine (5) (described for the first time in B. senegalensis to our knowledge). The evaluation of the vermicidal properties shows the anthelmintic potential of these different extracts. All extracts showed inhibitory activity on the motility of Ascaridia galli. The dichloromethane and ethyl acetate extracts of B. senegalensis were the most active (IC50 (g/L) = 1.54285 and 1.8748 respectively).Au Niger, les maladies parasitaires constituent un réel problème de santé tant au niveau humain qu’animal. Cette situation est aggravée par l’apparition des phénomènes de résistances vis-à-vis des anthelminthiques de synthèses disponibles. Fort heureusement, les plantes médicinales constituent une source inépuisable de composés antiparasitaires. C’est pourquoi, l’objectif de cette étude était de contribuer à l’amélioration de la santé animale et humaine en utilisant les produits naturels issus des plantes médicinales dans la lutte contre les vers intestinaux. Nos travaux de recherche ont porté sur l’étude chimique et pharmacologique de Boscia senegalensis (Capparaceae), Chrozophora brocchiana(Euphorbiaceae) et Amanita amerivirosa (Amanitaceae). Les substances extraites ont été séparées et identifiées par différentes techniques chromatographiques (CLUHP, CLHP, CCM) et spectroscopiques (UV-visible, HRMS, RMN 1D et 2D). Le dosage des composés phénoliques a été effectué en utilisant les méthodes classiques de colorimétrie. Les propriétés anthelminthiques de Boscia senegalensis et Chrozophora brocchiana ont été évaluées in vitro à différentes concentrations grâce aux tests d’efficacité anthelminthiques.Le criblage phytochimique des extraits à hexane, au dichlorométhane, à l’acétate d’éthyle et éthanoleau (70 :30) de B. senegalensis a montré la présence des alcaloïdes, tanins, flavonoïdes, quinones, saponosides, stéroïdes et terpenoïdes. Quant aux extraits de C. brocchiana, on a révélé l’absence des alcaloides et saponosides. En ce qui concerne la teneur en composés phenoliques totaux, B. senegalensisa donné 3,21±0,03 mg EAG/g à 5,67±0,01 mg EAG/g. La teneur en tanins condensés variait de 2,18 ±0,02 mg EAT/g à 5,48±0,02 mg EAT/g et la teneur en flavonoïdes de 4,18±0,08mg EQ/g à 6,57±0,07 mg EQ/g . Pour C. brocchiana, la teneur en composés phenoliques totaux a été de 1,13±0,1 mg EAG/g à 3,04±0,03 mg EAG/g et celle des tanins condensés variait de 1,66 ±0,03 mg EAT/g à 3,16±0,02 mg EAT/g. La teneur en flavonoides etait de 4,86±0,08mg EQ/g à 5,97±0,02 mg EQ/g.L’analyse LC-MS/MS avec des approches en réseaux moléculaires a permis d’identifier cinq (5) composés dont trois (3) d’entre eux sont des toxines cyclo peptidiques nouvellement décrites. Ils ont été identifiés d’A. amerivirosa. Il s’agit de : ameriphalloïdine (1), ameriviroïdine (2) et ameriviroïsine (3). Les deux (2) autres composés sont des alcaloïdes polyamines. Ils ont été isolés à partir de B. senegalensis. Ces composés sont la 18-AcO-chaenorpine (4), dont la structure est nouvelle et la chaenorpine (5) (décrite pour la première fois dans B. senegalensis à notre connaissance). L’évaluation des propriétés vermicides a permis de montrer le potentiel anthelminthique de ces différents extraits. Tous les extraits ont montré une activité inhibitrice de la motilité d’Ascaridia galli. Les extraits dichlorométhane et acétate d’éthyle de B. senegalensis se sont montrés plus actifs (CI 50 = 1,54 et 1,87 g/L respectivement)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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