1,720,959 research outputs found
Severe isolated exudative vitreoretinopathy caused by biallelic FZD4 variants
Get PDFFamilial exudative vitreoretinopathy (FEVR) is linked to disruption of the Norrin/
Frizzled-4 signaling pathway, which plays an important role in retinal angiogenesis.
Severe or complete knock-down of proteins in the pathway also causes syndromic
forms of the condition. Both heterozygous and biallelic pathogenic variants in the
FZD4 gene, encoding the pathway's key protein frizzled-4, are known to cause FEVR.
However, it is not clear what effect different FZD4 variants have, and whether
extraocular features should be expected in those with biallelic pathogenic FZD4 variants. Biallelic FZD4 variants were found in a young boy with isolated, severe FEVR.
His parents were heterozygous for one variant each and reported normal vision. Invitro studies of the two variants, demonstrated that it was the combination of the
two which led to severe inhibition of the Norrin/Frizzled-4 pathway. Our observations demonstrate that biallelic FZD4-variants are associated with a severe form of
FEVR, which does not necessarily include extraocular features. In addition, variants
causing severe FEVR in combination, may have no or minimal effect in heterozygous
parents as non-penetrance is also a major feature in dominant FZD4-FEVR disease.
This underscores the importance of genetic testing of individuals and families
with FEVR
Fragile X and autism : intertwined at the molecular level leading to targeted treatments
Get PDFFragile X syndrome (FXS) is caused by an expanded CGG repeat (>200 repeats) in the 5’ un-translated portion of the fragile mental retardation 1 gene (FMR1) leading to deficiency or absence of the FMR1 protein (FMRP). FMRP is an RNA carrier protein that controls the translation of a number of other genes that regulate synaptic development and plasticity. Autism occurs in approximately 30% of FXS cases, and Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS) occurs in an additional 30% of cases. Premutation repeat expansions (55 to 200 CGG repeats) may also give rise to autism spectrum disorders (ASD), including both autism and PDD-NOS, through a different molecular mechanism that involves a direct toxic effect of the expanded-CGG-repeat FMR1 mRNA. RNA toxicity can also lead to aging effects including tremor, ataxia and cognitive decline termed the fragile X-associated tremor ataxia syndrome (FXTAS) in premutation carriers in late life. In studies of mice bearing premutation expansions, there is evidence of early post-natal neuronal cell toxicity, manifest as reduced cell longevity, decreased dendritic arborization and altered synaptic morphology. There is also evidence of mitochondrial dysfunction in premutation carriers. Many of the problems with cellular dysregulation in both premutation and full mutation neurons also parallel the cellular abnormalities that have been documented in autism without fragile X mutations. Research regarding dysregulation of neurotransmitter systems in FXS, including metabotropic glutamate receptor 1/5 (mGluR1/5) pathway and GABAA pathways, have led to new targeted treatments for FXS. Preliminary evidence suggests that these new targeted treatments will also be beneficial in non-fragile X forms of autis
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
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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