1,725,851 research outputs found
The human SUMF1 gene, required for posttranslational sulfatase modification, defines a new gene family which is conserved from pro- to eukaryotes
No full textLandgrebe J, Dierks T, Schmidt B, Figura von K. The human SUMF1 gene, required for posttranslational sulfatase modification, defines a new gene family which is conserved from pro- to eukaryotes. GENE. 2003;316:47-56.Recently, the human C-alpha-formylglycine (FGly)-generating enzyme (FGE), whose deficiency causes the autosomal-recessively transmitted lysosomal storage disease multiple sulfatase deficiency (MSD), has been identified. In sulfatases, FGE posttranslationally converts a cysteine residue to FGly, which is part of the catalytic site and is essential for sulfatase activity. FGE is encoded by the sulfatase modifying factor 1 (SUMF1) gene. which defines a new gene family comprising orthologs from prokaryotes to higher eukaryotes. The genomes of E. coli, S. cerevisiae and C. elegans lack SUMF1, indicating a phylogenetic gap and the existence of an alternative FGly-generating system. The genomes of vertebrates including mouse, man and pufferfish contain a sulfatase modifying factor 2 (SUMF2) gene encoding an FGE paralog of unknown function. SUMF2 evolved from a single exon SUMF1 gene as found in diptera prior to divergent intron acquisition. In several prokaryotic genomes, the SUMF1 gene is cotranscribed with genes encoding sulfatases which require FGly modification. The FGE protein contains a single domain that is made up of three highly conserved subdomains spaced by nonconserved sequences of variable lengths. The similarity among the eukaryotic FGE orthologs varies between 72% and 100% for the three subdomains and is highest for the C-terminal subdomain, which is a hotspot for mutations in MSD patients. (C) 2003 Elsevier B.V. All rights reserved
Identification of formylglycine in sulfatases by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
No full textPeng JH, Schmidt B, Figura von K, Dierks T. Identification of formylglycine in sulfatases by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. JOURNAL OF MASS SPECTROMETRY. 2003;38(1):80-86.C-alpha-Formylglycine, the catalytic amino acid residue in the active site of sulfatases, is generated by post-translational modification of a cysteine or serine residue. We describe a highly sensitive procedure for the detection of C-alpha-formylglycine-containing peptides in tryptic digests of sulfatase proteins, The protocol is based on the formation of hydrazone derivatives of C-alpha-formylglycine-containing peptides when using dinitrophenylhydrazine as a matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The hydrazone derivatives desorb and ionize with high efficiency and can be detected in the sub-femtomole range. The presence of C-alpha-formylglycine is indicated by a mass increment of 180.13 u, corresponding to the hydrazone moiety, and also by a unique C-terminal fragment ion, characteristic of sulfatases, that becomes prominent in MALDI post-source decay mass spectra of the hydrazone derivatives. Copyright (C) 2003 John Wiley Sons, Ltd
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Solid Mechanics. – Two-phase models for elastic membranes with soft inclusions, by Mario Santilli and Bernd Schmidt, communicated on 16 December 2022
Full text linkEffect of boron on the water speciation in (alumino)silicate melts and glasses
No full textThe investigation of hydrous boro(alumino)silicate melts and glasses with near infrared (NIR) spectroscopy revealed an important effect of boron on the water speciation. In the NIR Spectra of B-bearing glasses new hydroxy-related bands develop at the high frequency side of the 4500 cm(-1) peak. In NaAlSi3O8 + B2O3 glasses this new peak is present as a shoulder at 4650 cm(-1), and in NaAlSi3Os-NaBSi3Os (Ab-Rd) glasses it appears as a resolved peak at 4710 cm(-1). These bands increase with increasing boron concentration, suggesting that they are due to B-OH complexes. Furthermore. the variations in the. NIR spectra indicate that with increasing B-content, but constant total water concentration. the amount of structurally bonded hydroxyl groups increases at the expense of molecular H2O. For example at a total water concentration of 4 wt.%, pure Rd-glass contains similar to50% more water as hydroxyl groups than pure Ab-glass. In-situ NIR spectroscopy at high P and T using a hydrothermal diamond-anvil cell was used to gain information about the temperature dependence of the water speciation in NaBSi3OS melts. The data demonstrate the conversion of molecular H2O to hydroxyl groups with increasing temperature. However, a fully quantitative evaluation of the high T spectra was hampered by problems with defining the correct baseline in the spectra. As an alternative approach annealing experiments on a Rd-glass containing 2.8 wt.% water were performed. The results confirm the conversion of H2O to OH groups with increasing T. but also suggest that the OH groups represented by the 4710 cm(-1) peak (B-OH) participate much less in the Conversion reaction compared to X-OH, represented by the 4500 cm(-1) peak. Copyright (C) 2004 Elsevier Ltd
Introduction
No full textSpirit possession is a phenomenon that often elicits a response of fear, particular in those who are ignorant of its meaning and role within its particular religious and cultural traditions. Possession by divine beings (such as spirits or gods) is, however, a key practice in religions worldwide. It is therefore important to gain an understanding of this practice in its cultural context before trying to develop a wider theory about it. This fascinating book contains several case studies that present new interpretations of spirit possession worldwide. The authors show the diversity of possible interpretations and methodological approaches that provide a new insight into the understanding of possession and trance
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