1,720,968 research outputs found
Parent inheritance of RB1 hypomorphic mutations and somatic mosaicism can explain low penetrance in retinoblastoma
No full textRetinoblastoma is the most common eye cancer in children. Numerous families have been described displaying reduced penetrance and expressivity. An extensive molecular characterization of seven families led us to identify the two main mechanisms underlying these phenomena: i) mosaicism of amorphic mutations; and ii) parent-of-origin-effect of hypomorphic mutations. Somatic mosaicism for RB1 splicing mutations (c.1960+5G>C and c.2106+2T>C) leading to a complete loss of function was demonstrated by high-depth NGS in two families. In both cases, the healthy carrier parent (one with retinoma) showed a mutation frequency lower than that expected for a heterozygous individual, indicating a 56-60% mosaicism level. Parent-of-origin-effect is a mechanism by which the phenotypic impact of an allele depends on the parental origin. An imprinting mechanism justifying a ~3 fold excess of the RB1 maternal canonical transcript has been previously described. As a consequence, hypomorphic mutations, if maternally inherited, may retain sufficient suppressor activity to prevent tumor onset. In five low-penetrant families we identified paternally inherited hypomorphic mutations in the affected members, namely a deletion resulting in the loss of 37 aminoacids at the N-terminus (c.608-16_608del), an exonic substitution with a “leaky” splicing effect (c.1331A>G), a partially deleterious substitution (p.Arg661Trp) and a truncating C-terminal mutation (c.2663+2T>C). The identification of these mechanisms changes the genetic/prenatal counseling and the clinical management of families, raising to a 50% the recurrence risk for unaffected carriers, offspring of RB1-mutated mothers, and imposing the need for second tumor surveillance in unaffected carriers at risk of developing adult-onset cancer such as osteosarcoma or leiomyosarcoma
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Combined ultrasound and exome sequencing approach recognizes Opitz G/BBB syndrome in two malformed fetuses
No full textOrofacial clefts are the most common congenital craniofacial anomalies and can occur as an isolated defect or be associated with other anomalies such as posterior fossa anomalies as a part of several genetic syndromes. We report two consecutive voluntary pregnancy interruptions in a nonconsanguineous couple following the fetal ultrasound finding of cleft lip and palate and posterior fossa anomalies confirmed by means of post-termination examination on the second fetus. The quantitative fluorescent PCR, the karyotype, and the comparative genomic hybridization-array analysis after amniocentesis were normal. Exome sequencing on abortive material from both fetuses detected a missense mutation in MID1, resulting in a clinical diagnosis of Opitz G/BBB syndrome. The same mutation was found in the mother and in her brother, who both revealed cerebellar anomalies at an MRI examination. Our study supports the efficacy of exome sequencing in the presence of both a family history suggestive of an inherited disorder and well-documented ultrasound findings. It reveals the importance of a synergistic effort between gynecologists and geneticists aimed at the integration of the most sophisticated ultrasound techniques with the nextgeneration sequencing tools to provide a definite diagnosis essential to orient the final decision and to estimate a proper recurrence risk
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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