1,721,087 research outputs found
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
Employment of separation methods in the field of drug analysis II.
Get PDFEmployment of separation methods in the field of drug analysis II Diploma Thesis Markéta Ferebauerová Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control This diploma thesis summarizes findings of both drug analysis done by gas chromatography and validation of analytical method. The mixture of glycerol, 1,3-butanediol and two other substances was studied. Specifity, linearity, precision and accuracy were studied and verified. In terms of robustness, the following parameters of the method were changed: the flow rate of carier gas, spit ratio, carier gas, stability of the sample, the temperature of detector, the temperature of injection port and the temperature of column. Further, the author demonstrate that the method is mostly influenced by the flow rate of carier gas and the temperature of column of the first part. Finally,the 24-hour stability of the sample was confirmed
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
Employment of separation methods in the field of drug analysis II.
No full textEmployment of separation methods in the field of drug analysis II Diploma Thesis Markéta Ferebauerová Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control This diploma thesis summarizes findings of both drug analysis done by gas chromatography and validation of analytical method. The mixture of glycerol, 1,3-butanediol and two other substances was studied. Specifity, linearity, precision and accuracy were studied and verified. In terms of robustness, the following parameters of the method were changed: the flow rate of carier gas, spit ratio, carier gas, stability of the sample, the temperature of detector, the temperature of injection port and the temperature of column. Further, the author demonstrate that the method is mostly influenced by the flow rate of carier gas and the temperature of column of the first part. Finally,the 24-hour stability of the sample was confirmed
HPLC evaluation of tyrosine and its metabolites
No full textCharles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Panagiotis Michailellis Supervisor: PharmDr. Petr Kastner, PhD. Title of Diploma Thesis: HPLC evaluation of tyrosine and its metabolites Tyrosine is an important precursor of catecholamines, which are dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline). These are neurotransmitters and hormones, crucial for every living organism. Therefore, their identification and evaluation in biological material would aim to understand their function and behavior more accurately. This Diploma Thesis is a review on how to evaluate catecholamines and their metabolites in biological matter with analytical methods used in Pharmaceutical Analysis, especially with HPLC. First chapters present theoretical knowledge about metabolism of tyrosine and its metabolites, how a sample from an organism should be treated in order to be examined, information about HPLC, CE, GC apparatuses and the main detectors used in analysis of these compounds. In literature review, tables are presented, concerning different sample preparation methods, HPLC details and characteristics, and finally a sum of all the analytical methods studied for this Diploma Thesis. All the articles and..
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
Forced degradation study of 1-aminohydantoin hydrochloride using HPLC method
Get PDFCHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ Department of Pharmaceutical Chemistry and Drug Control Chromatography center JSC OlainFarm, Latvia Author: Kamila Benešová Supervisor: PharmDr. Pavla Pilařová, Ph.D. Specialized supervisor: Natalija Vovka Title: Forced degradation study of 1-aminohydantoin hydrochloride using HPLC method Forced degradation, also called stress testing, is a helpful practice carried out in order to explore changes to a drug substance under excessive external stress condition. This thesis focuses on content and characteristics of forced degradation studies and description of the HPLC method in theoretical part and on the study conducted in JSC OlainFarm with the substance 1-Aminohydantoine hydrochloride (AHH) in the experimental part. There is only one known impurity 2-semicarbazidoacetic acid (SAA), which is a starting material and potential product of degradation. The aim of the study is to reveal the behavior and degradation pathways of AHH under stress testing. First, the samples of AHH were prepared and exposed to stress conditions which included pH, oxidation, light, heat, combination of heat and humidity. Then, they were analyzed by previously developed HPLC method which showed the decrease of the substance and possible presence of impurities...
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