1,720,973 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
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
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
Development of a Hessian fly BAC-based genome map and the identification of vH13 avirulence gene candidates
No full textThe Hessian fly (Mayetiola destructor) is an important insect pest of wheat (Triticum spp.). It is also a member of one of the largest and most economically important families of the Diptera (the gall midges or Cecidomyiidae). As such, it has potential as a model insect for studies of plant-insect interactions. However, our knowledge pertaining to the molecular mechanism underlying wheat-Hessian fly interaction is limited. This is primarily due to a lack of any cloned avirulence gene in this insect. Research presented in this study was undertaken to identify putative vH13 avirulence genes. It was necessary to develop a high-resolution genomic map and estimate recombination rate near the vH13 gene. Chapter one focuses on application of Fiber-FISH in insects. Recombination rate near the vH13 locus in Hessian fly was determined and genomic rearrangement associated with Medea (Maternal Effect Dominant Embryonic Arrest) was discovered. Chapter two discusses the development of the first detailed high-resolution integrated genetic and physical map of the Hessian fly genome. The BAC based physical map has been anchored to the polytene chromosomes of Hessian fly. The map has enormous potential to aid further genomic research in this economically important pest and provide the necessary framework for the assembly of the Hessian fly genome sequence. The third chapter presents the results of an extensive chromosome walk undertaken to map the vH13 gene to a 1-cM genetic interval and 80-kb physical interval within a single BAC clone. The BAC clone containing the gene was sequenced and analyzed to identify vH13 gene candidates
Genomics of a gall midge: Avirulence and sex determination in the Hessian fly (Mayetiola destructor)
No full textThe Hessian fly, Mayetiola destructor, is economically important as one of the most destructive insect pests of wheat. This study focused on two topics related to the Hessian fly: its interaction with the host plant and its sex determination. The contents of this thesis were described in four chapters. In chapter one, I introduced some features of the Hessian fly, including the life history and damage, the avirulence, the chromosome behavior, and the sex determination pathway. In chapter two, I established the position of Avr gene vH6 in the Hessian fly genome sequence. Linkage analysis mapped 18 markers on chromosome X2. Fluorescent in situ hybridization (FISH) mapping determined that four markers are on the short arm and the other fourteen are on the long arm. vH6 was mapped in the proximal region of long arm, where recombination rate is reduced. Using a recombinant inbred line population refined the position of vH6 within three overlapping BAC clones, which correspond to a 485-505 kb DNA sequence in the Hessian fly genome. In chapter three, I determined the DNA sequence of a chromosome inversion, In(A1q1), which acts as the maternal master switch to drive the postzygotic sex determination in the Hessian fly (Benatti et al. 2010). In(A1q1) was estimated to be 2.1 Mb in length and 149 genes were predicted within the inversion. Interestingly, two predicted genes (gene 1 and gene 149) are disrupted by the breakpoints in the inverted chromosome. Transcription analysis demonstrated that gene 1 was maternal and expressed in a sex-specific mode. No differential expression was observed between females and males with regards to gene 149. In chapter four, I focused on characterization of the Hessian fly homologues of Drosophila sex determination genes, including sxl, tra-2, and dsx. Transcription analysis indicated that only dsx, not sxl and tra-2, was discriminative in females and males, supporting the hypothesis that the sex determination in insects evolves from bottom to top. In addition, the failure of identifying tra in the Hessian fly and some other nematocera species leads to a conjecture that sex determination is divergent at the level upstream of dsx between Drosophila and the Hessian fly
Identification, cloning and mapping of avirulence-linked molecular markers from the Hessian fly
No full textThe Hessian fly has an intimate genetic relationship with wheat, and the two species have co-evolved. The plant has developed genes that allow it to resist infestation by the fly. The fly has developed mutations in avirulence genes that allow it to overcome this resistance. This interaction has not been characterized at the molecular level, and much is to be learned about the interaction if durable resistance to the Hessian fly is to be developed into wheat cultivars. We are in the process of identifying and cloning the genes from the fly that are responsible for inducing a resistance response in the plant. A direct, map-based approach is being pursued because little biochemical information is available about the fly-wheat interaction. A genetic map of the Hessian fly was constructed to aid in predicting the potential success of a positional cloning approach, and to aid in the acquisition of molecular markers for Hessian fly avirulence loci. The Hessian fly has a relatively small genome (98 megabases, 545 cM) and a relatively high rate of recombination. About 180 kb represents one centimorgan of recombination. Thus, map-based cloning in the Hessian fly is feasible. Molecular markers were identified that are within walking distance of the vH13 locus—the locus that confers avirulence to the H13 wheat resistance gene. Positional cloning of this avirulence locus is underway
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