1,724,799 research outputs found
No homology means there can be no analyses; a comment on Jose & Harikrishnan (Letter)
No full textA recent paper (Jose & Harikrishnan 2016) considers some issues surrounding the use of mitochondrial (mt) cytochrome c oxidase subunit I (COI or COX1) sequences as DNA barcodes. They provide a particular example of how the presence of two commonly used fragments of the gene, that are largely non-homologous, could lead to confusion for taxonomy, in this case for decapod crustaceans. Jose and Harikrishnan (2016) show the divergence between two COI fragments (termed ‘Folmer’ and ‘Palumbi’) for some freshwater shrimp taxa (Family Palaemonidae, Genus Macrobrachium) through a number of analyses, including neighbor-joining phylograms, sequence distance calculations and pairwiseNo Full Tex
Dasia johnsinghi Harikrishnan, Vasudevan
No full textDasia johnsinghi Harikrishnan, Vasudevan, de Silva, Deepak, Kar, Naniwadekar, Lalremruata, Prasoona & Aggarwal, 2012 Dasia johnsinghi Harikrishnan, Vasudevan, de Silva, Deepak, Kar, Naniwadekar, Lalremruata, Prasoona & Aggarwal, 2012 Dasia haliana (non Euprepes halianus Nevill, 1887)— Vickram & Johnsingh 1985 part Dasia haliana —Joshua & Sekar 1985 part; Karthikeyan 1991 part, Somaweera & Somaweera 2009 part Dasia subcaeruleum (non Lygosoma subcaeruleum Boulenger 1891)— Wickramasinghe et al. 2011 part (6) Harikrishnan et al. (2012: 45) redescribed Dasia subcaerulea on the basis of a single specimen registered as ZSIC 25945, collected by M.S. Chaitra from Singsar game road, Kudremukh National Park, which is> 500 km north of the type locality of D. subcaerulea. However, they erroneously mention the registration number of this specimen to be BNHS 363 in their appendix of specimens examined. As the authors were unable to examine the holotype of Dasia subcaerulea, they obtained photographs and data from the Natural History Museum, London, where it is housed. They state to have assigned their new specimen from Kudremukh to D. subcaerulea based “only on external morphological characters”. The photographs of the holotype in Harikrishnan et al. (2012: 46) (and in Wickramasinghe et al., 2011: 1967) clearly depict the prefrontals being in broad contact with each other, completely preventing contact between the frontal and fronto-nasal. In the specimen of D. subcaerulea from Kudremukh (ZSIC 25945) the prefrontals areseparated from each other, enabling contact between the frontal and fronto-nasal, as stated by the authors themselves (Harikrishnan et al. 2012: 45). In addition, there are differences in the number of midbody scale rows [28 as recorded by Smith (1949) vs. 26 in Harikrishnan et al. (2012)]. This is especially ironic considering that the authors themselves have used prefrontal midline contact and midbody scale rows as diagnostic characters in their own key to distinguish species of Dasia, and have also genetically tested distributional outliers (see D. olivacea vs. D. cf. olivacea). While it is known that Dasia species are rare to encounter in south India (personal observations), the mismatch of these significant and diagnostic morphological characters coupled with the very distant and ecologically heterogeneous collection localities (Bodinayakanur: 10.02 ° N, 77.35 ° E, 353 m asl. vs. Kudremukh: 13.21 ° N, 75.18 ° E, 750 m asl.), across a significant bio-geographic barrier, the Palghat gap, raise serious doubt on the veracity of their allocation of ZSIC 25945 to D. subcaerulea sensu Smith (1949). This allocation impacts the concept of D. subcaerulea, and hence the phylogeographic implications presented by the authors. As ZSIC 25945 is currently an outlier to D. subcaerulea sensu Smith (1949), both morphologically and geographically, it would be important to seek topotypic specimens of D. subcaerulea and of populations from between the type locality and Kudremukh. Moreover, the number of congeners in the genus Dasia was repeatedly misinterpreted by Harikrishnan et al. (2012). In the first line of their introduction they mentioned “The genus is presently composed of seven valid species...”, but the map placed right below the above statement shows eight valid species (even excluding Dasia cf. olivacea and their new species D. johnsinghi which was described in that paper). Again in their discussion they misinterpreted the number of congeners in Dasia as “The description of D. johnsinghi sp. nov. from the southern Western Ghats brings the total number of Dasia species to eight...” (see Harikrishnan et al. 2012: 48)”. All of the above statements are erroneous, bringing the total species to nine including their new species, D. johnsinghi. We emphasize the importance of inferences made in taxonomic papers, which will be applied by other “end-users” such as ecologists and conservation managers. Hence, a more cautious approach towards sensitive taxonomic and nomenclatural issues is needed. Ironically, the errors that we have highlighted here recall the concerned criticism raised by Vasudevan et al. (2007) for taxonomic papers being “pernicious” by publishing “inaccurate and imprecise” descriptions that will hinder the progress in taxonomy. Such mistakes have unwittingly appeared in a number of recent research publications, and several examples in this region have been highlighted recently (Pethiyagoda, 2007). We recommend a cautious approach towards sensitive taxonomic issues and insist that taxonomic papers should undergo a thorough peer review by practicing taxonomists (Alberts et al. 2008; Bahir 2009; Bahir & Gabadage 2009), thereby minimizing the possibilities for such mistakes in future.Published as part of Chandramouli, S. R. & Thasun Amarasinghe, A. A., 2015, On some recent taxonomic advancement and the resultant problems in the arboreal skink genus Dasia Gray, 1839 (Reptilia: Scincidae), pp. 495-500 in Zootaxa 3914 (4) on pages 497-498, DOI: 10.11646/zootaxa.3914.4.9, http://zenodo.org/record/23336
Rehabilitation of Mangrove Ecosystems in India: A Review
No full textHarikrishnan, Tirunelvely A.. (1999). Rehabilitation of Mangrove Ecosystems in India: A Review. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/59290
Dataset for the study of various error measures steering adaptive model order reduction algorithms in vibroacoustic applications
No full textThe dataset is associated with the university dissertation titled "Surrogate modeling of high-dimensional vibroacoustic problems using parametric model order reduction" by Harikrishnan K. Sreekumar. To evaluate the accuracy of a reduced order model in the context of model order reduction in the frequency domain, a range of error measures are available. The error measures are extensively used in adaptive algorithms to build reduced order models of optimal dimensions with the least effort. The author performs a detailed study on some of the popular error measures using simple plate examples that are discussed in the thesis. This current dataset publication contains essential artifacts (computational notebook, model data and primary results) that enable reproducibility of the outcome presented in the dissertation
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
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