1,720,993 research outputs found
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
Molecular and Cellular Mechanisms for Microbial Discrimination in Sponges
Get PDFSponges (Porifera) are basal metazoans that feed on and establish symbiotic associations with microbes. How sponges discriminate between bacteria to digest as food, incorporate as symbionts, or eliminate as pathogens remains unknown. This thesis aimed to study mechanisms for microbial discrimination in sponges. Mechanisms likely to modulate sponge-microbe interactions are introduced (Chapter 1). The host transcriptomic response upon seawater and symbiont microbial consortia encounter was characterized by RNASeq in two sponges (Chapter 2). Aplysina aerophoba showed little differential gene expression and no participation of receptors, whereas Dysidea avara responded by regulating NLRs suggesting that microbial discrimination is driven by the repertoire of immune genes as well as to what degree they are induced. On the cellular level, an in-vivo phagocytosis assay was established in Halichondria panicea combining incubations with microalgae, bacteria, and latex beads with cell dissociation and fluorescence-activated cell sorting (FACS) to quantify particle incorporation into sponge cells (Chapter 3). After 30 min particles were predominantly incorporated into choanocyte-like cells and appeared to be translocated to archaeocyte-like cells after 60 min. Lastly, the established assay was combined with proteomic analysis to investigate H. panicea’s phagocytic response upon exposure to a “native” and a “foreign” Vibrio isolate (Chapter 4). Vibrio incorporation into sponge cells was indiscriminate, but the distribution of vibrios into different cell types differed between isolates. Phagocytic-related proteins were in a higher abundance in the foreign vs. the native treatment. These results indicate that bacterial discrimination in H. panicea occurs after internalization leading to differences in the processing of foreign vs native vibrio types
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
Establishing the breadcrumb sponge Halichondria panicea as an experimental model for sponge symbioses
Get PDFThe early divergent metazoan phylum Porifera (sponges) holds potentially important emerging model systems to study microbiome stability, colonization and evolutionarily early mechanisms of animal-microbe interactions. However, experimental approaches that allow the manipulation of sponge microbiomes are currently lacking. To fill this gap, the overarching aim of my PhD thesis was to establish the breadcrumb sponge Halichondria panicea and its dominant bacterial symbiont Candidatus Halichondribacter symbioticus as an experimental model. First, I approached the sponge holobiont by summarizing current knowledge on multispecies interactions within the host. Then, I focused on the host-side by exposing sponges to bacterial LPS and characterized their immune repertoire as well as induced immune response by RNAseq. We suggest that H. panicea has context-dependent strategies of immune gene expression (constitutive vs inducible; ubiquitous vs individual-specific), reflecting the diverse roles of innate immunity in sponges. Lastly, I approached the microbial-side of the sponge holobiont and developed an experimental set-up to culture sponges under sterile conditions and manipulate sponge-associated bacteria with antibiotics. Antibiotics induced repeatable shifts in bacterial community composition towards a dysbiotic state, while the total number of associated bacteria increased. We tested recolonization with the natural microbiome to recover dysbiotic microbiomes. This strategy was not successful, however single bacterial taxa were transferred by recolonization. Importantly, the combination of relative bacterial abundance data together with absolute data uncovered a high stability of Ca. H. symbioticus in spite of dysbiosis at the microbial community level. Overall, my findings contribute to an improved understanding of microbiome dynamics, host-microbe and microbe-microbe interactions in the H. panicea holobiont
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
Zur Problematik der Amphibienwanderungen im Kreis Höxter
No full textUm einen aktuellen Überblick über die Auswirkungen des Straßenverkehrs auf die Amphibien des Kreises Höxter zu erhalten, führte die Landschaftsstation Diemel-Weser-Egge in Zusammenarbeit mit dem NEW eine Erfassung der Wanderwege im Bereich der Straßen durch. Im Rahmen der Erhebungen wurden auch die bestehenden Amphibienschutzanlagen erfasst und auf ihre Tauglichkeit hin überprüft
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