1,721,084 research outputs found
FIGURE 2. Garra longchuanensis, ihb 201306027 in Garra longchuanensis, a new cyprinid (Teleostei: Cypriniformes) from southern China
No full textFIGURE 2. Garra longchuanensis, ihb 201306027, holotype, 145.2 mm SL, China, Yunnan Province, Yiluowadi Jiang basin, Longchuan Jiang River in Tengchong; dorsal and ventral views of head.Published as part of Yu, Qian, Wang, Xuzheng, Xiong, Huan & He, Shunping, 2016, Garra longchuanensis, a new cyprinid (Teleostei: Cypriniformes) from southern China, pp. 295-300 in Zootaxa 4126 (2) on page 298, DOI: 10.11646/zootaxa.4126.2.10, http://zenodo.org/record/27173
FIGURE 2 in Systematics and molecular phylogenetics of Asian snail-eating snakes (Pareatidae)
No full textFIGURE 2. Variation in the frontal scale (top row) and the anterior pair of the chin shields (lower row) in Pareas. Both characters are shaded black. A & H: P. hamptoni (A–C, H–J all modified from Pope 1935); B & I: P. stanleyi; C & J: P. boulengeri; D & K: P. iwasakii (modified from Ota et al. 1997); E & L: P. nigriceps (modified from Guo and Deng 2009); F & M: P. carinatus (modified from Rao and Yang 1992); G & N: P. nuchalis (modified from Boulenger 1900).Published as part of Guo, Yuhong, Wu, Yunke, He, Shunping, Shi, Haitao & Zhao, Ermi, 2011, Systematics and molecular phylogenetics of Asian snail-eating snakes (Pareatidae), pp. 57-64 in Zootaxa 3001 (1) on page 62, DOI: 10.11646/zootaxa.3001.1.4, http://zenodo.org/record/528086
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
Systematics and molecular phylogenetics of Asian snail-eating snakes (Pareatidae)
No full textThe taxonomy of the Asian snail-eating snakes (Pareatidae) is an ongoing controversy, partly because morphological characters do not yield consistent results across studies. We infer phylogenetic relationships within Pareatidae using similar to 2 kilo-bases of DNA sequences including two mitochondrial (cyt b and ND4) and one nuclear gene (c-mos). Results reveal four major lineages: Aplopeltura, Asthenodipsas, a clade formed by Pareas carinatus and P. nuchalis, and a clade comprising all other species of Pareas sampled in this study. Our data do not have enough signal to either support or reject a monophyletic Pareas. However, large molecular divergence (16.5%) is observed between the two major clades of Pareas, a level that is comparable to that between Pareas and Aplopeltura. Scale characters also suggest that P. carinatus and P. nuchalis are distinct from congeners, and future morphological and/or molecular studies might assess whether a distinct genus should be recognized. The molecular phylogeny further suggests a distant relationship between P. chinensis and P. formosensis and supports the validity of the former species
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
Phylogenetic relationships of the Chinese sisorid catfishes: a nuclear intron versus mitochondrial gene approach
No full textSeveral recent molecular phylogenetic studies of the sisorid catfishes (Sisoridae) have challenged some aspects of their traditional taxonomy and cladistic hypotheses of their phylogeny. However, disagreement with respect to relationships within this family in these studies highlights the need for additional data and analyses. Here we subjected 15 taxa representing 12 sisorids genera to comprehensive phylogenetic analyses using the second intron of low-copy nuclear S7 ribosomal protein (rpS7) gene and the mitochondrial 16S rRNA gene segments both individually and in combination. The competing sisorid topologies were then tested by using the approximately unbiased (AU) test and the Shimodaira-Hasegawa (SH) test. Our results support previously suggested polyphyly of Pareuchiloglanis. The genus Pseudecheneis is likely to be nested in the glyptosternoids and Glaridoglanis might be basal to the tribe Glyptosternini. However, justified by AU and SH test, the sister-group relationship between Pseudecheneis and the monophyletic glyptosternoids cannot be rejected based on the second intron of rpS7 gene and combined data analyses. It follows that both gene segments are not suitable for resolving the phylogenetic relationships within the sisorid catfishes. Overall, the second intron of rpS7 gene yielded poor phylogenetic performance when compared to 16S rRNA gene, the evolutionary hypothesis of which virtually agreed with the combined data analyses tree. This phenomenon can be explained by the insufficient length and fast saturation of substitutions in the second intron of rpS7 gene, due to substitution patterns such as frequent indels (insertion/deletion events) of bases in the sequences during the evolution.Several recent molecular phylogenetic studies of the sisorid catfishes (Sisoridae) have challenged some aspects of their traditional taxonomy and cladistic hypotheses of their phylogeny. However, disagreement with respect to relationships within this family in these studies highlights the need for additional data and analyses. Here we subjected 15 taxa representing 12 sisorids genera to comprehensive phylogenetic analyses using the second intron of low-copy nuclear S7 ribosomal protein (rpS7) gene and the mitochondrial 16S rRNA gene segments both individually and in combination. The competing sisorid topologies were then tested by using the approximately unbiased (AU) test and the Shimodaira-Hasegawa (SH) test. Our results support previously suggested polyphyly of Pareuchiloglanis. The genus Pseudecheneis is likely to be nested in the glyptosternoids and Glaridoglanis might be basal to the tribe Glyptosternini. However, justified by AU and SH test, the sister-group relationship between Pseudecheneis and the monophyletic glyptosternoids cannot be rejected based on the second intron of rpS7 gene and combined data analyses. It follows that both gene segments are not suitable for resolving the phylogenetic relationships within the sisorid catfishes. Overall, the second intron of rpS7 gene yielded poor phylogenetic performance when compared to 16S rRNA gene, the evolutionary hypothesis of which virtually agreed with the combined data analyses tree. This phenomenon can be explained by the insufficient length and fast saturation of substitutions in the second intron of rpS7 gene, due to substitution patterns such as frequent indels (insertion/deletion events) of bases in the sequences during the evolution
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