1,721,232 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
Q141K polymorphism of ABCG2 protein is associated with poor prognosis in adult acute myeloid leukemia treated with idarubicin-based chemotherapy.
A novel de novo NIPA1 missense mutation associated to hereditary spastic paraplegia
SPG6 accounts for 1% of autosomal dominant Hereditary Spastic Paraplegia (HSP) and is caused by pathogenic variants in NIPA1, which encodes a magnesium transporter located in plasma membrane and early endosomes, implicated in neuronal development and maintenance. Here we report a 39-year-old woman affected by progressive gait disturbance associated to absence seizures episodes within childhood. Clinical exome sequencing identified a likely pathogenic de novo heterozygous variant in NIPA1 (NM_144599.5 c.249 C > G; p.Asn83Lys). Molecular modelling was performed to evaluate putative functional consequence of the NIPA1 protein. Indeed, the Asn83Lys modification is predicted to induce a significant perturbation of the protein structure, altering signal transduction or small-molecule transport by modulating the length of the second transmembrane domain. This is the first study reporting a SPG6-affected patient harbouring the NIPA1 p.Asn83Lys mutation
Expression of fetal Hemoglobin in adult humans exposed to high altitude hypoxia
In humans, acute erythroid expansion can lead to maturation of red blood cell (RBC) precursors containing fetal hemoglobin (F red cells). This can occur in patients after recovery from bone marrow transplantation, or in individuals affected by sickle cell or thalassemic syndromes. An accelerated erythroid lineage expansion is also a hallmark of the adaptive response to high altitude hypoxia. To explore the possible effect of this environment on F red cell production, we analyzed RBCs from five subjects during and after 17 days spent at high altitude and investigated the expression of fetal hemoglobin by different methodological approaches. By flow cytometry, we found a moderate increase of circulating F red cells during and after the hypoxia exposure, with respect to control cells analyzed before the high altitude stay. The increased expression of g-globin (as the specific subunit contained in F hemoglobin together with a-globin) was further confirmed by immunoblotting of young RBC haemolysates and quantitative RT-PCR of transcripts purified from a reticulocyte-enriched RBC fraction. Thus, in healthy adults the exposure to high altitude hypoxia induces maturation of F red cells at a level higher than under normal condition. The effect appears reduced after return to normoxia
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