1,721,626 research outputs found
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
Changes in community composition during dilution cultures of marine bacterioplankton as assessed by flow cytometric and molecular biological techniques
No full textDilution cultures are a common technique for measuring the growth of bacterioplankton communities. In this study, the taxonomic composition of marine bacterioplankton dilution cultures was followed in water samples from Plymouth Sound and the English Channel (UK). Bacterial abundances as well as protein and DNA content were closely monitored by flow cytometry. Denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rDNA fragments and fluorescence in situ hybridization (FISH) were applied directly to the water samples and to cells sorted from the dilution cultures based on their protein and DNA content. As expected, a rapid activation of bacteria occurred. However, molecular techniques showed that the community developed in the dilution culture within 1 day was significantly different from that in the original water samples. Whereas in the original samples, cells detectable by FISH were dominated by members of the Cytophaga/Flavobacterium (CF) cluster, in dilution cultures, gamma-proteobacteria accounted for the majority of cells detected, followed by alpha-proteobacteria. An actively growing and an apparently non-growing population with average cellular protein contents of 24 and 4.5 fg respectively, were sorted by flow cytometry. FISH indicated mostly gamma- (64%) and alpha-proteobacteria (33%) in the first active fraction and 78% members of the CF cluster in the second fraction. Sequencing of DGGE bands confirmed the FISH assignments of the latter two groups. The data presented clearly show that even relatively short-term dilution experiments do not measure in situ growth, but rather growth patterns of an enrichment. Furthermore, it was demonstrated that the combination of flow cytometric analysis and sorting combined with FISH and DGGE analysis presented a fairly rapid method of analysing the taxonomic composition of marine bacterioplankton. <br/
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
The role of a simulation tool in the creation and transformation of knowledge in a company in the automotive industry
No full textTemporal patterns of biological dimethylsulfide (DMS) consumption during laboratory-induced phytoplankton bloom cycles
No full textPhytoplankton bloom cycles were followed for 9 d in two 20 l carboy mesocosms filled with water from the offshore plume of Mobile Bay Alabama, USA, and incubated under fluorescent light. One of the blooms was enriched by addition of nitrate+phosphate (+nutrients), and both blooms were used to study how dimethylsulfide (DMS) concentrations and biological consumption varied over the bloom cycles. Peaks of algal biomass (15-22 µg chlorophyll a l-1) in the blooms were followed within 1 d by peaks of the DMS precursor, particulate dimethylsulfoniopropionate (DMSPp; 100-140 nM). DMS concentrations increased rapidly during the early bloom, rising from 1 nM on Day 1 up to 12 nM in the unamended carboy and up to 17 nM in the +nutrient carboy on Day 6. Maximum values for DMS concentrations, DMS consumption rates (as measured with 35S-DMS), and bacterial production were observed during the early decline of phytoplankton biomass. DMS consumption rates were initially 0.8 nM d-1 and increased to 3.1 nM d-1 in the unamended carboy and to 9.1 nM d-1 in the +nutrient carboy. Rate constants for DMS consumption (0.25-0.95 d-1) initially decreased as DMS concentrations increased, resulting in longer turnover times for DMS during the peak and early decline of the blooms. Assimilation of DMS-sulfur by bacterioplankton accounted for 4-22% of the total DMS consumption and higher rates of DMS assimilation occurred in the +nutrients bloom. Despite a bloom and decline of total heterotrophic bacterial abundances, bacterial community composition at the major phylogenetic group level remained relatively constant in both blooms, although the alpha proteobacteria showed a temporal increase in abundance in the +nutrient carboy. The concentration ratios of DMS:chlorophyll a and DMS:DMSP displayed non-linear, sigmoidal patterns over the bloom cycles and these ratios were not substantially affected by the nutrient amendment. Our results demonstrate that uncoupling of DMS production and biological consumption can occur early in a bloom cycle, causing DMS concentrations to rise significantly before biological consumption responds to draw down the DMS
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
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
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