1,721,064 research outputs found
Unitary time-evolution in stochastic time-dependent Hilbert spaces
Full text linkIn this work we study the unitary time-evolutions of quantum systems defined on infinite-dimensional separable time-dependent Hilbert spaces. Two possible cases are considered: a quantum system defined on a stochas- tic interval and another one defined on a Hilbert space with stochastic integration measure (stochastic time-dependent scalar product). The formulations of the two problems and a comparison with the general theory of open quantum systems are discussed. Possible physical applications of the situations considered are analyzed
A "neglected" Source for the History of the Reformed Zoroastrian Calendar
No full textThe author analyzes the problem and the relevance of the Mandean calendar for the comprehension of the reformed Zoroastrian one
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
Muscarinic and nicotinic receptors and the function of the cholinergic synapse in the rat’s hippocampus: selective age dependent changes and therapeutic interventions.
No full textA VALIDATED HPLC METHOD WITH ELECTROCHEMICAL DETECTION FOR SIMULTANEOUS ASSAY OF 5-AMINOSALICYLIC ACID AND ITS METABOLITE IN HUMAN PLASMA
No full textA high-performance liquid chromatographic method was developed, validated and applied to the simultaneous determination
of 5-aminosalicylic acid (5-ASA) and its acetylated metabolite (acetyl-5-ASA) in human plasma. The method involves
liquid–liquid extraction with methanol followed by isocratic reversed-phase chromatography on a Kromasil KR100 C18 column
with electrochemical detection. The recovery, selectivity, linearity, precision and accuracy of the method were evaluated from
spiked human plasma samples. The effects of mobile phase composition, buffer concentration, mobile phase pH and concentration
of organic modifiers on retention of 5-ASA, acetyl 5-ASA and internal standard were investigated. Limits’ of detection were 5 ng/
mL for 5-ASA and 10 ng/mL for acetyl-5-ASA, respectively. The method can be used for supporting therapeutical drug monitoring
and pharmacokinetic studies
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
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