1,720,973 research outputs found
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
Reciprocal cross-talk between Prostaglandin E2 and bone in prostate cancer: a current review.
No full textIn this review we analyzed the role of PGE2 as a possible regulator of bone metabolism and bone metastases in prostate cancer. Published studies were identified by searching computerized bibliographic systems from January 1(st), 2000 to July 1(st), 2011. PGE2 represents a key factor in the modulation of bone metabolism and bone metastatic disease in prostate cancer interacting with bone regulatory signals including the RANK/RANKL/OPG system and Wnt pathways. A high concentration of PGE2 exerts a prevalent stimulatory effect on osteoclastogenesis via OPG/RANK/RANKL axis activation and a inhibitory effect on osteoblastogenesis trough inhibition of Wnt pathway. An inversely low level of PGE2 exerts a stimulatory effect on osteoblastogenesis via activation of the Wnt pathway. Our finding suggests that PGE2 acts as a regulator in maintaining normal bone mass and indicate a mechanism whereby chemical manipulation of PGE2 levels or signaling may be therapeutically beneficial for prostate cancer treatment
Antiepileptic drugs and thyroid function.
No full textAntiepileptic drugs (AED) are a heterogeneous group of compounds widely used in both adults and children. These drugs are related to various adverse effects involving several organs and endocrinological and metabolic functions. In particular, relevant effects on thyroid function have been described. Subclinical hypothyroidism and alterations in thyroid hormone serum levels are reported in the literature; phenytoin, valproate and carbamazepine, in particular, seem to be involved in these alterations. The aim of this review is to analyse critically the principal alterations in thyroid function caused by AED therapy
Adolescents and epilepsy: hormonal aspects.
No full textEpilepsy is one of the most frequent disease in children, particularly in adolescents. Some types of epilepsy begin typically in the peripubertal period and many studies found changes in frequency or features of seizures in adolescents. This is probably related to sex hormone effects on neuronal excitability. Estrogens seem to decrease neuronal electric threshold with proconvulsant effects. On the contrary progesterone seems to have anticonvulsivant action, as well as testosterone. Changes in hormone serum levels that occur during pubertal period are probably related to modifications in seizure features and are involved in some types of epilepsy that begin typically in adolescence
Adolescents and epilepsy: hormonal aspects.
No full textEpilepsy is one of the most frequent disease in children, particularly in adolescents. Some types of epilepsy begin typically in the peripubertal period and many studies found changes in frequency or features of seizures in adolescents. This is probably related to sex hormone effects on neuronal excitability. Estrogens seem to decrease neuronal electric threshold with proconvulsant effects. On the contrary progesterone seems to have anticonvulsivant action, as well as testosterone. Changes in hormone serum levels that occur during pubertal period are probably related to modifications in seizure features and are involved in some types of epilepsy that begin typically in adolescence
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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