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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
Estudio fitoquímico y actividad antihiperglucémica e hipolipidémica de Salvia polystachya Ort., en ratones con diabetes experimental
Get PDFINTRODUCCIÓN. La diabetes mellitus tipo 2 (DMT2) es una enfermedad endocrino metabólica caracterizada por una deficiencia o resistencia a la insulina que conduce a un estado de hiperglucemia crónica, desencadenando cambios en el metabolismo de carbohidratos, lípidos y proteínas. En la medicina tradicional mexicana, las plantas medicinales son ampliamente utilizadas como coadyuvantes en el tratamiento de la diabetes mellitus (DM). Entre estas se reportan diferentes especies del género Salvia (Lamiaceae), que en nuestro país está representado por 312 especies; de las cuales, un porcentaje importante (85-88%) es endémico; basándonos en el criterio de selección quimio taxonómico S. polystachya Ort., comparte relaciones filogenéticas con otras especies que han sido utilizadas como antidiabéticas, por lo que esta especie podría ser la fuente de nuevos metabolitos con efecto antidiabético. OBJETIVO GENERAL. Realizar un estudio biodirigido utilizando el extracto etanólico de S. polystachya en modelos in vivo, ex vivo e in silico e identificar compuestos con potencial antidiabético mediado por la inhibición de enzimas α-glucosidasas y del cotransportador SGLT1. METODOLOGIA. Las partes aéreas de S.polystachya fueron maceradas en etanol para la obtención de los extractos de tallo (SpEET), flor (SpEEF) y hoja (SpEEH), la toxicidad aguda para cada extracto fue determinada siguiendo los lineamientos de la norma OECD 423. El extracto con menor toxicidad (SpEET), se eligió para determinar su efecto sobre la glucemia de ratones macho sanos y en un modelo de diabetes mellitus experimental (DME) inducido con estreptozotocina/nicotinamida (SZT/NA), realizando pruebas agudas (0, 30, 60, 90 y 120 min). Posterior mente SpEET fue sometido a un fraccionamiento líquido/líquido obteniendo dos fracciones: acuosa residual (FrAcR) y acetato de etilo (FrAcOEt), ambas fracciones se sometieron a pruebas glucémicas agudas, en donde la FrAcOEt fue la fracción más. El extracto completo (SpEET) y la FrAcOEtse sometieron a una prueba subcrónica (45 días) en ratones con DME, registrando semanalmente el peso de los animales y los niveles de glucosa y, quincenalmente los triglicéridos (TG), lipoproteínas de alta densidad (HDL) y un examen general de orina. Para la purificación de compuestos de la FrAcOEt, se realizó una cromatografía en columna abierta de fase normal, obteniendo diez fracciones secundarias (FrSec1- FrSec10); como primer paso estas fracciones fueron comparadas con 42 compuestos estándar de diferentes polaridades utilizando técnicas cromatográficas y un análisis de HPLC para confirmar la presencia de los compuestos identificados. Los compuestos identificados se evaluaron en pruebas agudas en ratones con DME. Para determinar el efecto inhibitorio de enzimas α-glucosidasas y del cotransportador sodio-glucosa (SGLT1) se realizaron pruebas de tolerancia oral a sacarosa (PTOS), almidón (PTOA), glucosa (PTOG) y galactosa (PTOGaT), así como pruebas ex vivo, en donde se realizaron ensayos de hidrólisis intestinal de sacarosa (HIS) y de absorción intestinal de glucosa (AIG). Finalmente, en las pruebas in silico se realizaron análisis de acoplamiento molecular (docking) de ácido ursólico (AU) y ácido oleanólico (AO) contra la enzima α-glucosidasa y el cotransportador SGLT1. RESULTADOS: En la prueba de toxicidad aguda, el extracto etanólico de tallo (SpEET) fue clasificado en categoría 5 (DL50 = 2500>5000 mg/kg) de bajo riesgo toxicológico. En las pruebas glucémicas agudas, SpEET disminuyó la glucemia en ratones sanos (200 mg/kg) y diabéticos (100 mg/kg); de las fracciones obtenidas FrAcOEt mostró mayor actividad al disminuir la glucemia de ratones con DME a la dosis de 50 mg/kg. Al finalizar la prueba subrónica (45 días), SpEET y FrAcOEt disminuyeron la glucemia y TG, aumentando HDL. En la fracción secundaria 6 (FSec6) obtenida de FrAcOEt fueron aislados AO y AU, en pruebas agudas ambos compuestos disminuyeron las glucemias de ratones con DME a dosis de 50 mg/kg. Durante las pruebas de tolerancia oral a carbohidratos, todos los tratamientos (SpEET, FrAcOet, AO y AU) redujeron el pico posprandial, de forma similar a los fármacos control. En la prueba de HIS, se obtuvieron valores de IC50 de 726,3 y 739,9 µM para AO y AU, respectivamente; y en las pruebas de AIG, se obtuvieron valores de IC50 de 849,3 y 966,6 µM para AO y AU, respectivamente. Finalmente, en los estudios de acoplamiento molecular para la enzima α-glucosidasa, AO y AU mostraron valores de ∆G de -5,48 y -6,41 kcal/mol, respectivamente y en la inhibición del cotransportador SGLT1, AO y AU mostraron valores de ∆G de -9,65 y -10,55 kcal/mol. Con estos resultados se propone que AO y AU podrían ser inhibidores de las enzimas α-glucosidasas y del cotransportador SGLT1, reduciendo la absorción de carbohidratos y la hiperglucemia posprandial en la diabetes. Estos datos apoyan la hipótesis de que S. polystachya es una fuente potencial de agentes antidiabéticos. Palabras clave: Diabetes mellitus, Salvia polystachya; ácido oleanólico; ácido ursólico; actividad antihiperglucémica; inhibición de α-glucosidasa; inhibición de SGLT1.INTRODUCTION. Diabetes mellitus type 2 (DMT2) is an endocrine-metabolic disease characterized by a deficiency or resistance to insulin, that leads to state of chronic hyperglycemia, triggering changes in carbohydrate, lipid and protein metabolism. In the traditional mexican medicine, the medicinal plants are widely used as adjuvants in the treatment of diabetes mellitus (DM). Among these, are reported different species of the genus Salvia (Lamiaceae), which in our country is represented by 312 species; of them, an important percentage (85-88%) is endemic. Based on the chemotaxonomic selection criteria, S. polystachya Ort., due to its phylogenetic relationships with other species that have been used as an antidiabetic, so S. polystachya could be a new source of metabolites with antidiabetic effectso this species could be the source of new metabolites with antidiabetic effect. GENERAL OBJECTIVE. Carry out a bioguided study with the ethanolic extract of S. polystachya over in vivo, ex vivo and in silico models and identify compounds with antidiabetic potential, mediated by the inhibition of α-glucosidase enzymes and the SGLT1 cotransporter. METHODOLOGY. The aerial parts of S. polystachya were macerated in ethanol to obtain the stem (SpEET), flower (SpEEF) and leaf (SpEEH) extracts. The acute toxicity for each extract was determined following OECD 423 guidelines. The extract with less toxicity (SpEET) was chosen to determine its effect on glycemia in healthy male mice and in a model of experimental diabetes mellitus (DME) induced with streptozotocin/nicotinamide (SZT/NA), performing acute tests (0, 30, 60, 90 and 120 min). SpEET was subsequently subjected to liquid/liquid fractionation, obtaining two fractions: residual aqueous (FrAcR) and ethyl acetate (FrAcOEt), both fractions were subjected to acute glycemic tests, where FrAcOEt was the most active fraction. The complete extract (SpEET) and FrAcOEt were subjected to a subchronic test (45 days) in mice with DME, weekly recording the weight of the animals and the levels of glucose and, fortnightly the triglycerides(TG), high-density lipoproteins(HDL) and a general urine test. For the purification of compounds of the FrAcOEt, a normal phase open column chromatography was performed obtaining ten secondary fractions (FrSec1-FrSec10); As a first step, these fractions were compared with 42 standard compounds of different polarities using chromatographic techniques and a HPLC analysis was performed to confirm the presence of the identified compounds. The identified compounds were evaluated in acute testsin DME mice. To determine the inhibitory effect of α-glucosidase enzymes and the sodium-glucose cotransporter (SGLT1), oral tolerance tests to sucrose (PTOS), starch (PTOA), glucose (PTOG) and galactose (PTOGaT) were performed, as well as ex vivo tests, where performed intestinalsucrose hydrolysis(HIS) and intestinal glucose absorption (AIG) assays. Finally, in silico tests, molecular docking analyzes of oleanolic acid (AO) and ursolic acid (AU) against the α-glucosidase enzyme and the SGLT1 cotransporter were performed. RESULTS: In the acute toxicity test, the ethanolic stem extract (SpEET) was classified in category 5 (DL50 = 2500>5000 mg/kg) of low toxicological risk. In acute glycemic tests, SpEET lowered blood glucose in healthy (200 mg/kg) and diabetic mice (100 mg/kg); of the fractions obtained, FrAcOEt showed greater activity lowering the glycemia of mice with DME at a dose of 50 mg/kg. At the end of the subchronic test (45 days), SpEET and FrAcOEt decreased glycemia and TG, and increasing HDL. In the secondary fraction 6 (FrSec6) obtained from FrAcOEt, AO and AU were isolated. In acute tests, both compounds lowered glycemia in mice with DME at dose of 50 mg/kg. During oral carbohydrate tolerance tests, all treatments (SpEET, FrAcOet, AO and AU) reduced the postprandial peak, similar to the control drugs. In the HIS test, IC50 values of 726.3 and 739.9 µM were obtained for AO and AU, respectively; and in the AIG tests, IC50 values of 849.3 and 966.6 µM were obtained for AO and AU, respectively. Finally, in the molecular docking studies for the α-glucosidase enzyme, AO and AU showed ∆G values of -5.48 and -6.41 kcal/mol, respectively, and in the inhibition of the SGLT1 cotransporter, AO and AU showed ∆G values of -9.65 and - 10.55 kcal/mol. These results suggest that AO and AU could be inhibitors of α-glucosidase enzymes and the SGLT1 cotransporter, reducing carbohydrate absorption and postprandial hyperglycemia in diabetes condition. These data support the hypothesis that S. polystachya is a potential source of antidiabetic agents. Key words: Diabetes mellitus, Salvia polystachya; ursolic acid; oleanolic acid; antihyperglycemic activity; αglucosidase inhibitor; SGLT1 inhibitor
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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