1,721,013 research outputs found
Phosphorylation of CIITA directs its oligomerization, accumulation and increased activity on MHCII promoters
No full textThe class II transactivator (CIITA) is the master regulator
of major histocompatibility complex class II
(MHCII) transcription. Its activity is regulated at the
post-transcriptional level by phosphorylation and oligomerization.
This aggregation mapped to and depended on the phosphorylation of residues between
positions 253 and 321 in CIITA, which resulted in a
dramatic accumulation of the protein and increased
expression of MHCII genes in human promonocytic
U937 cells, which represent immature antigen-presenting
cells. Thus, the post-transcriptional modification
of CIITA plays an important role in the immune
response
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
Major histocompatibility complex class II transcriptional platform: assembly of nuclear factor Y and regulatory factor X (RFX) on DNA requires RFX5 dimers
No full textMajor histocompatibility complex class II (MHC-II) genes are regulated in a B-cell-specific and gamma
interferon-inducible manner. Conserved upstream sequences (CUS) in their compact promoters bind nuclear
factor Y (NFY) and regulatory factor X (RFX) complexes. These DNA-bound proteins form a platform that
attracts the class II transactivator, which initiates and elongates MHC-II transcription. In this report, we
analyzed the complex assembly of these DNA-bound proteins. First, we found that NFY can interact with RFX
in cells. In particular, NFYA and NFYC bound RFXANK/B in vitro. Next, RFX5 formed dimers in vivo and in
vitro. Within a leucine-rich stretch N-terminal to the DNA-binding domain in RFX5, the leucine at position 66
was found to be critical for this self-association. Mutant RFX5 proteins that could not form dimers also did
not support the formation of higher-order DNA-protein complexes on CUS in vitro or MHC-II transcription
in vivo. We conclude that the MHC-II transcriptional platform begins to assemble off CUS and then binds DNA
via multiple, spatially constrained interactions. These findings offer one explanation of why in the Bare
Lymphocyte Syndrome, which is a congenital severe combined immunodeficiency, MHC-II promoters are bare
when any subunit of RFX is mutated or missing
Rapid DNA-based prenatal diagnosis by genetic linkage in three families with Alport's Syndrome
No full textAlport's syndrome (AS) is a clinically and genetically heterogeneous progressive inherited glomerulonephritis characterized by hematuria, sensorineural hearing loss, ocular lesions, and specific alterations of the glomerular basement membrane. Typically, AS shows an X-linked dominant pattern of inheritance, with mutations affecting the collagen type IV alpha5 chain gene (COL4A5) at Xq22. Rarely, AS is caused in some families by mutations of the COL4A3/A4 genes on chromosome 2q, showing an autosomal recessive transmission. Very few families have been described with possible autosomal dominant AS, but no mutations in any of the COL4 genes have been found. We describe three unrelated families affected with a severe AS phenotype in which DNA-based prenatal diagnosis by linkage analysis was made in fetuses at risk for the disease. In two families, the pedigree structure and the clinical picture were consistent with typical X-linked dominant AS. In these families, autosomal inheritance was also ruled out molecularly. In one family, despite careful clinical and molecular evaluation, the mode of transmission could not be firmly established. We used tightly linked and intragenic COL4A5 markers, as well as COL4A3/A4-linked markers. A chromosome Y-specific marker for fetal sex determination was simultaneously used. In all the families, before the fetal analysis, the putative at-risk X haplotype was identified with high diagnostic accuracy. We diagnosed a healthy male fetus in one family, and female but carrier fetuses in the other two kindreds, who decided not to terminate their pregnancies. We used rapid nonisotopic polymerase chain reaction-based methods, and the results were available within 2 to 3 days. The genetic results significantly affected the reproductive decisions of the parents. This report illustrates the application of genetic linkage analysis as an additional tool for molecular diagnosis in AS, and also addresses the issue of the attitudes of the families toward prenatal testing. To our knowledge, prenatal diagnosis of AS using a genetic linkage approach has not been previously reported
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