1,721,118 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
Advances In Disease-Resistance Breeding In Chickpea
No full textThis chapter reviews the past work on disease resistance breeding in chickpea and discusses the strategies to tackle unsolved disease problems. Methods for breeding disease-resistant chickpea cultivars are similar to those used for yield breeding, except that the segregating materials have been challenged by the pathogen and selection is made for disease resistance along with other attributes. Some of the techniques employed by breeders include hybridization and mutation. Chickpea is grown primarily by resource-poor farmers on residual moisture with little if any inputs. The short growing season at lower latitudes (0–20◦) also limits yields. The fast-rising temperatures at the reproductive phase force the crop into premature drying. Thus, yields are low (less than one t/ha). At present productivity levels, use of disease-resistant cultivars appears to be the best alternative for management of chickpea diseases
Sources of resistance to ascochyta blight in wild Cicer species
No full textAscochyta blight [Ascochyta rabiei (Pass.) Lab.] is the major foliar disease of chickpea (Cicer arietinum L.). In search of better sources of resistance to ascochyta blight, 201 accessions of 8 annual wildCicer species were evaluated in field and greenhouse for 3 years (1988 to 1991) at Tel Hadya, Syria. One accession each ofC. judaicum Boiss (ILWC 165) andC. pinnatifidum Jaub. & Spach. (ILWC 159) were consistently rated resistant in both field and greenhouse evaluations. Another three accessions ofC. judaicum (ILWC 61, ILWC 154, ILWC 199) and six accessions ofC. pinnatifidum (ILWC 78, ILWC 88, ILWC 155, ILWC 160, ILWC 162, ILWC 203) were resistant or moderately resistant. The blight-resistant accessions ofC. judaicum originated from Jordan, Lebanon, Syria, and Turkey; and those ofC. pinnatifidum from Syria and Turkey. None of the accessions ofC. bijugum, C. chorassanicum, C. cuneatum, C. echinospermum, C. reticulatum andC. yamashitae were resistant to blight
Improving chickpea yield by incorporating resistance to ascochyta blight
No full textAscochyta blight [Ascochyta rabiei (Pass.) Lab.] is the most destructive disease of chickpea (Cicer arietinum L.), but it can be managed effectively by the use of resistant cultivars. Therefore, a breeding programme was initiated during 1977-78 at ICARDA, Syria, to breed blight-resistant, high-yielding chickpeas with other desirable agronomic traits. Crosses were made in main season at Tel Hadya, Syria, and the F(1)s were grown in the off season at Terbol, Lebanon. The F-2, F-4 and F-5 generations were grown in a blight nursery in the main season where blight epidemic was artificially created. The plants and progenies were scored for blight resistance and other traits. The F-3 and F-6 generations were grown in the off season under normal day length to eliminate late-maturing plants. The pedigree method of breeding was followed initially, but was later replaced by the F-4-derived family method. The yield assessment began with F, lines, first at ICARDA sites and later internationally. A total of 1584 ascochyta blight-resistant chickpea lines were developed with a range of maturity, plant height, and seed size not previously available to growers in the blight-endemic areas in the Mediterranean region. These included 92 lines resistant to six races of the ascochyta pathogen, and 15 large-seeded and 28 early maturity lines. New cultivars produced 33% more seed yield than the original resistant sources. The yield of chickpea declined by 340 kg ha(-1), with an increase in blight severity by one class on a 1-9 scale, reaching zero yield with the 8 and 9 classes. Development of blight-resistant lines made the introduction of winter sowing possible in the Mediterranean region with the prospect of doubling chickpea production. Twenty three cultivars have been released so far in 11 countries
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