1,720,999 research outputs found
Ligand substitution at a hexa-coordinate centre. Reaction of [Co2(Et2dtc)5]BF4 with some dithiooxamides. Part II. A kinetic study
No full textEvaluation of antioxidant capacity of antioxidant-declared beverages marketed in Italy
No full textClinical literature suggests a negative correlation between fruit juice consumption and the occurrence of various diseases. Consequently, many commercially available beverages are based on fruit juices or green tea extracts with specific additives that increase their antioxidant power. In order to fully estimate their potential antioxidant capacity, several products marketed in Italy were analyzed for total phenolics and flavonoids, DPPH scavenging activity, TEAC, FRAP and ORAC-PYR. On average, fruit-based samples had more antioxidants than green teas, but specific additives significantly improved total antioxidant power. Differences between these samples and plain fruit juices were also evaluated. Total antioxidant supply remained almost constant during the entire shelf life of the products
Psychiatric severity and treatment response in a comprehensive methadone maintenance treatment program.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Adduct formation of some tris (N, N dialkyl-di thiocarbamato) Cr(III) complexes with iodine
No full textSpectrophotometric studies of dichloromethane solutions containing iodine and some Cr(S2CNR2)3 complexes (where R2NCS-2 are: OC4H8NCS-2 = modtc; (C2H5)2NCS-2 = Et2dtc; (C6H5CH2)2NCS-2 = Bz2dtc) have shown the formation of 1:1 adducts whose spectral features were studied and which suggested that charge-transfer interaction involving iodine and a sulphur atom of a coordinated dithiocarbamato ligand occurred. A new BASIC non-linear least-squares program which performs an optimization of the absorbance data taken at several wavelengths was devised to evaluate reliable formation constants. The thermodynamic parameters have been calculated and compared with those obtained in the same conditions as above by a reinvestigation of the known 1:1 complex formation of iodine with the corresponding tetraalkylthiuram-disulphides, where the donor site is also the sulphur atom of the thiocarbonyl group. The -ΔH° values related to the Cr(dtc)3 · I2 complexes are about 2 kcal lower than those of thiuram disulphides, showing a lowering of the donor strength of the thiocarbonyl sulphur as a consequence of the coordination to the metal. © 1984
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