1,721,331 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
A new data concentrator for the CMS muon barrel track finder
No full textThe CMS muon trigger will undergo considerable enhancements in preparation for the LHC run-2. In order to improve rate reduction and efficiency the full muon trigger chain will be completely redesigned: the plan is to move from a redundant scheme, where the three sub-detectors (CSC, DT, RPC) have a separate track finder, to three geographical track finders (barrel, endcap and overlap) that combine trigger primitives of each sub-detector. In particular, the Muon Barrel Track Finder (MBTF) will host a new algorithm, that aggregating DT and RPC trigger data, will be able to improve the fake rejection and the muon momentum measurement. This report will focus on the adaptive layer of the MBTF called Twin Mux. Its primary role will be to merge, arrange and fan-out the slow optical links from the chambers in faster links (10 Gbps). It will realize a full connectivity matrix between the on-detector electronics and the MBTF allowing for different processing schemes. The Twin Mux will be implemented in μTCA form factor compliant with all the CMS standards in terms of clock distribution, slow control and data acquisition. The Twin Mux will be centered around a powerful Virtex-7 FPGA able to exchange data on up to 96 optical lanes. The gigabit connectivity on the backplane will guarantee the connection with the central DAQ, allowing the adoption of the Twin Mux as a read out board for DT as well
Uncovering quorum sensing and quenching structural properties: a systems biology approach
No full textBacteria have the ability to coordinate their behavior in a cell density-dependent manner by using diffusible signal molecules. The mechanism, known as quorum sensing, is a cell-to-cell communication process exploited either by pathogens to regulate the expression of virulence and antimicrobial resistance-related genes and by synthetic biologists to engineer bacterial density-dependent functions. Using a systems biology approach, we developed a novel quorum sensing mathematical model and performed a comprehensive study of the equilibrium properties of this communication process. This analysis highlighted crucial structural properties as a result of bistability in the genetic circuit and underlined that bacteria exploit feedback control strategies to produce a unified and robust response. Due to increased antibiotic-resistant infections, researchers investigated enzymatic methods to interfere with quorum sensing. In this paper, we simulated two quorum quenching strategies. Using a modeling approach, we discovered core parameter values which guarantee the effectiveness of these strategies and could be exploited in rational design of synthetic biology based engineered bacteria
Modeling metabolic overload effects in bacterial growth rate in synthetic biology
No full textModeling growth in bacterial cells is a major issue in systems and synthetic biology. Despite several growth rate functions are proposed in literature, most of them focus on nutrients composition, without explicitly counting for possible perturbation provided by the expression of recombinant genes, an effect called metabolic load or burden. In this work, some already published growth functions are evaluated, highlighting possible disagreements with the biological knowledge, which allow to reject some of them. Furthermore, some alternative functions based on biological evidences are proposed and tested as well, specifically oriented on metabolic load effects. The final aim is to identify a growth rate function that can be applied to models with different levels of complexity, leading to coherent results, which also account for the addition of metabolic burden, decoupled from nutrient composition
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
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
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