1,720,966 research outputs found
β-Glucose-1,6-Bisphosphate Stabilizes Pathological Phophomannomutase2 Mutants In Vitro and Represents a Lead Compound to Develop Pharmacological Chaperones for the Most Common Disorder of Glycosylation, PMM2-CDG
Gain of function in CDKN1C
Loss-of-function mutations in the gene encoding the cyclin-dependent kinase inhibitor CDKN1C cause Beckwith-Wiedemann syndrome and cancer. A new study now identifies potentially gain-of-function missense mutations in CDKN1C that cause the undergrowth-associated IMAGe syndrome. © 2012 Nature America, Inc. All rights reserved
Accessibility of receptor-bound urokinase to type-1 plasminogen activator inhibitor.
Urokinase plasminogen activator (uPA) interacts with a surface receptor and with specific inhibitors, such as plasminogen activator inhibitor type 1 (PAI-1). These interactions are mediated by two functionally independent domains of the molecule: the catalytic domain (at the carboxyl terminus) and the growth factor domain (at the amino terminus). We have now investigated whether PAI-1 can bind and inhibit receptor-bound uPA. Binding of 125I-labeled ATF (amino-terminal fragment of uPA) to human U937 monocyte-like cells can be competed for by uPA-PAI-1 complexes, but not by PAI-1 alone. Performed 125I-labeled uPA-PAI-1 complexes can bind to uPA receptor with the same binding specificity as uPA. PAI-1 also binds to, and inhibits the activity of, receptor-bound uPA in U937 cells, as shown in U937 cells by a caseinolytic plaque assay. Plasminogen activator activity of these cells is dependent on exogenous uPA, is competed for by receptor-binding diisopropyl fluorophosphate-treated uPA, and is inhibited by the addition of PAI-1. In conclusion, in U937 cells the binding to the receptor does not shield uPA from the action of PAI-1. The possibility that in adherent cells a different localization of PAI-1 and uPA leads to protection of uPA from PAI-1 is to be considered
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
Inherited and sporadic epimutations at the IGF2-H19 locus in beckwith-wiedemann syndrome and wilms' tumor
The parent-of-origin-dependent expression of IGF2 and H19 is controlled by the imprinting center 1 (IC1) consisting of a methylation-sensitive chromatin insulator. IC1 is normally methylated on the paternal chromosome and nonmethylated on the maternal chromosome. We found that 22 cases in a large cohort of patients affected by Beckwith-Wiedemann syndrome (BWS) had IC1 methylated on both parental chromosomes, resulting in biallelic activation of IGF2 and biallelic silencing of H19. These individuals had marked macrosomia and high incidence of Wilms' tumor. A subset of these patients had 1.4- to 1.8-kb deletions with hypermethylation of the remaining IC1 region and fully penetrant BWS phenotype when transmitted maternally. Another subset of individuals with IC1 hypermethylation had a similar clinical phenotype but no mutation in the local vicinity. All these cases were sporadic and in at least two families affected and unaffected members shared the same maternal IC1 allele but not the abnormal maternal epigenotype. Similarly, no IC1 deletion was detected in 10 nonsyndromic Wilms' tumors with IC1 hypermethylation. In conclusion, methylation defects at the IGF2-H19 locus can result from inherited mutations of the imprinting center and have high recurrence risk or arise independently from the sequence context and not transmitted to the progeny. Copyright © 2009 S. Karger AG, Basel
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
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