186,443 research outputs found
Insertional inactivation of the major autolysin gene of Streptococcus pneumoniae
No full textThe lytA gene encoding the major pneumococcal autolysin (N-acetylmuramoyl-L-alanine amidase) was inactivated by inserting the 2-kilobase MspI fragment of pE194 containing the staphylococcal ermC gene. Stable autolysis-deficient (Lyt-) mutants and their isogenic Lyt+ parents were used in experiments designed to test possible physiological functions of the amidase. No autolysis could be induced in the mutants grown at 37 degrees C by deoxycholate, by incubation in stationary phase, or by treatment with penicillin. On the other hand, the Lyt- mutants exhibited normal growth rates and yields and normal adaptive responses during shifts from one growth temperature or nutritional condition to another. There was no evidence for impeded cell separation (chain formation). Colonies of Lyt- insertional mutants produced normal hemolytic zones on blood agar; they showed normal (high) levels of competence for genetic transformation. Lyt- mutants were also able to produce type 3 and 6 capsular polysaccharides, and such strains showed the same degree of virulence in mice as did the isogenic Lyt+ parent. The physiological function(s) of the amidase remains a puzzle
Tracing the post(apartheid) novel beyond 2000 : interviews with selected contemporary South African authors /
No full textThis anthology comprises of interviews with contemporary South African authors, offering vignettes of their lives and summaries of their works. In curating this book, Danyela Demir and Olivier Moreillon step beyond pure literary theory and analysis. They welcome the authors to speak and assess the literary panorama in which they live and co-create. However, Demir and Moreillon also trace concepts and terms that describe the current South African literature, such as post-transitional literature and literature beyond 2000. By adopting a world-literary approach to (post)apartheid literature, this book contributes to debates on contemporary South African writing. In addition, Tracing the (Post)Apartheid Novel Beyond 2000 seeks to raise awareness of the imbalance in both critical and public attention between literary big names', such as Andr P. Brink, J.M. Coetzee, Nadine Gordimer and Zakes Mda, who are popular worldwide, and the younger and newer generation of South African writers, who go largely unnoticed. Print edition not for sale in Sub Saharan Africa.Includes index.This anthology comprises of interviews with contemporary South African authors, offering vignettes of their lives and summaries of their works. In curating this book, Danyela Demir and Olivier Moreillon step beyond pure literary theory and analysis. They welcome the authors to speak and assess the literary panorama in which they live and co-create. However, Demir and Moreillon also trace concepts and terms that describe the current South African literature, such as post-transitional literature and literature beyond 2000. By adopting a world-literary approach to (post)apartheid literature, this book contributes to debates on contemporary South African writing. In addition, Tracing the (Post)Apartheid Novel Beyond 2000 seeks to raise awareness of the imbalance in both critical and public attention between literary big names', such as Andr P. Brink, J.M. Coetzee, Nadine Gordimer and Zakes Mda, who are popular worldwide, and the younger and newer generation of South African writers, who go largely unnoticed. Print edition not for sale in Sub Saharan Africa.Danyela Dimakatso Demir is NRF post-doctoral fellow at the University of KwaZulu-Natal (Howard College) and the author of Reading Loss: Post-Apartheid Melancholia in Contemporary South African Novels (2019). Olivier Moreillon is research associate at the University of Johannesburg. He is the author of Reading the Post-Apartheid City: Durbanite and Capetonian Literary Topographies in Selected Texts Beyond 2000 (2019) and the co-editor of Cities in Flux: Metropolitan Spaces in South African Literary and Visual Texts (2017)
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
No full textWe 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
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
Author Rights and Scholarly Publishing
No full textOriginally posted at
http://blog.library.gsu.edu/2014/10/24/author-rights-and-scholarly-publishing/</p
Promoter and transcription analysis of penicillin-binding protein genes in Streptococcus gordonii.
No full textAn optimally cross-linked peptidoglycan requires both transglycosylation and transpeptidation, provided by class A and class B penicillin-binding proteins (PBPs). Streptococcus gordonii possesses three class A PBPs (PBPs 1A, 1B, and 2A) and two class B PBPs (PBPs 2B and 2X) that are important for penicillin resistance. High-level resistance (MIC, > or =2 microg/ml) requires mutations in class B PBPs. However, although unmutated, class A PBPs are critical to facilitate resistance development (M. Haenni and P. Moreillon, Antimicrob. Agents Chemother. 50:4053-4061, 2006). Thus, their overexpression might be important to sustain the drug. Here, we determined the promoter regions of the S. gordonii PBPs and compared them to those of other streptococci. The extended -10 box was highly conserved and complied with a sigma(A)-type promoter consensus sequence. In contrast, the -35 box was poorly conserved, leaving the possibility of differential PBP regulation. Gene expression in a penicillin-susceptible parent (MIC, 0.008 microg/ml) and a high-level-resistant mutant (MIC, 2 microg/ml) was monitored using luciferase fusions. In the absence of penicillin, all PBPs were constitutively expressed, but their expression was globally increased (1.5 to 2 times) in the resistant mutant. In the presence of penicillin, class A PBPs were specifically overexpressed both in the parent (PBP 2A) and in the resistant mutant (PBPs 1A and 2A). By increasing transglycosylation, class A PBPs could promote peptidoglycan stability when transpeptidase is inhibited by penicillin. Since penicillin-related induction of class A PBPs occurred in both susceptible and resistant cells, such a mutation-independent facilitating mechanism could be operative at each step of resistance development
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