1,721,045 research outputs found
Characterisation of an Arabidopsis thaliana cDNA encoding a novel thylakoid lumen protein imported by the ΔpH-dependent pathway
No full textAn Arabidopsis thaliana (L.) Heynh. cDNA encoding a novel 16-kDa protein (P16) of the chloroplast thylakoid lumen has been characterised. The function of the protein is unknown but it shares some sequence similarity with alpha allophycocyanins. P16 is synthesised with a bipartite, lumen-targeting presequence, and import experiments demonstrated that this protein follows the ΔpH-dependent pathway. Analysis of the thylakoid transfer peptide revealed two unusual features. Firstly, the key targeting determinant is predicted to be a twin-arginine followed by a highly hydrophobic residue two residues later, rather than at the third position as in most transfer peptides. Secondly, the C-terminal domain of the transfer peptide contains multiple charged residues which may help to prevent mistargeting by the Sec-type protein translocase.</p
Characterisation of an Arabidopsis cDNA encoding a thylakoid lumen protein related to a novel `pentapeptide repeat' family of proteins
No full textAbstractWe have cloned an Arabidopsis cDNA encoding a novel thylakoid lumen protein, P17.4, that has been previously isolated from lumen extracts of spinach chloroplasts. The protein is synthesised with a bipartite presequence containing a Sec-type lumen-targeting signal peptide and the precursor protein is imported into the lumen of pea chloroplasts. The encoded protein is homologous to an Anabaena protein that is essential for correct glycolipid localisation, and is also related to at least 16 unassigned open reading frames in Synechocystis. This family of proteins is characterised by the presence of numerous pentapeptide repeats with the consensus structure AXLXX, and its members are predicted to be located in the cytosol, plasma membrane and periplasm/lumen. P17.4 is therefore the first higher plant member of an extended family of putative cyanobacterial proteins that may serve important roles in lipid transport or assembly
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
Precarious work - precarious health?
No full textThis thesis addresses the changes and challenges of a transforming labour market. The initial focus is on new types of employment, going beyond the standard employment relationship. Based on an international literature review a specification of precarious work is given and indicators to operationalise the concept are presented. Subsequently an overview of the current research evidence regarding the correlation between precarious work and health is given. Using the developed analytical framework of precarious work a questionnaire survey among more than 400 female cleaners addressing the consequences of job insecurity on health was carried out. The results strongly support the hypothesis of a association between insecurity and health. The thesis concludes providing an outlook that derives further requirements for research and praxis based on the presented findings
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Abstracts of the conference on recent advances in mass spectrometry at the Chemical biological centre (KBC) Umeå
No full textThis booklet contains a description, the programme, and the abstracts of the Mass Spectrometry Day at the Chemistry Biology Center (KBC) at Umeå University on 15 March 2023. At this event, leading companies in the field of modern mass spectrometry presented their latest news about analytical applications and technologies. The spectrum of topics covered metabolomics, proteomics and had a special focus on targeted applications. Both mass spectrometry in combination with separation by liquid chromatography and by gas chromatography was included. The Mass Spectrometry Day was collaboration between industry and academia, and it was organized by the Swedish Mass Spectrometry Society, the Swedish Metabolomics Center, and the Mass Spectrometry Network Umeå. The booklet of the Mass Spectrometry Day gives an overview of some recent innovations in applied mass spectrometry. It contains links to related application notes and literature and contact details to the companies that presented their innovations at this conference. Current name: Theresa KieselbachOther funders of the conference: Agilent Technologies, Bruker Nordic, Hamilton Nordic, SCIEX, Shimadzu, Thermo Fisher Scientific och Waters).</p
- …
