1,721,029 research outputs found
Taxonomy and biogeography of Sundaland Gardenia (Rubiaceae) / Low Yee Wen
Get PDFIn Southeast Asia, the genus Gardenia J.Ellis (Rubiaccae) is poorly understood and documented due to a lack of country revisions, contentious species delimitations and accumulation of poorly identified material in herbaria. This study reviewed the taxonomic history and position of the genus, and revised the taxonomy of Sundaland species (including those of Sumatra. the Malay Peninsula, Java_ Borneo, Palawan and adjacent islands). It includes a survey and cladistic study of morphological characteristics, and phylogenetic ana lyses using two chloroplast regions (atpB-rbcL and trnT-F) and the nuclear ITS region of representative species from Sundaland and adjoining regions. Twelve species are native to Sundaland and another two from mainland Asia and Wallacea commonly cultivated. Important generic characters include a woody shrub to tree habit with the growth architectural models of Leeuwen berg and Scarrone; resinous buds; tubular stipules; so litary terminal nowers; and pollen in tetracls. Calyx characters were the most use ful for species di stinction. Comparative morphological studies allowed two very closely related species, G. e/ata and G. tubijera, to be distinguished; G. tubi}era var. subcarinuta to be raised to species rank; and G. c/o/ichantha to be subsumed under the synonymy of G. griffithii. Several new species (G. beamanii Y. W.Low and G. chanii Y. W.Low) and varieties (G . . rnbcarinata var. sumatrcnia Y. W.Low and G. el at a var. kinaba/ue11sis ined.) were diagnosed. An identification key to Sundaland taxa, species descriptions, notes and identification lists are provided. The genealogies produced showed that Sundaland lineages were largely distinct from mainland Asian ones, probably renecting the biogeographic distinction of these regions. Limited introgression of the mainland lineage including G. jasminoides into the lineage with G. chanii was detected. There was evidence for reticulate evolution among Sundaland lineages indicated by discordant genealogies of chloroplast and nuclear regions. lntrogression of the widespread Sundaland species G. elata into a lineage with Lhe more locally restricted G. Beamanii (Borneo) was probably enabled by increased chances of contact during Pleistocene sealevel rn inima, when lowland forest area was contiguous between present-day Peninsular Malaysia and Borneo. Local variation in genetic characteristics implies that current for rest fragmentation in Sundaland could dimini sh the species va riab ility of G. elata. A complex of rarer species mostly occurring in pockets in peat swamps (G. chanii, G. griflthii, G. pteroca/yx, G. tubifera) and adjacent kerangas fo rests (G. cosllllata) would also be threatened by habitat disturbance and transformation
Fig. 3 in Arisaema brinchangense Y.W. Low, Scherberich & Gusman (Araceae), a new threatened species endemic to the Cameron Highlands (Peninsular Malaysia)
No full textFig. 3. – Distribution of Arisaema brinchangense Y.W. Low, Scherberich & Gusman (black circle) in Peninsular Malaysia.Published as part of Low, Yee Wen, Scherberich, David & Gusman, Guy, 2016, Arisaema brinchangense Y.W. Low, Scherberich & Gusman (Araceae), a new threatened species endemic to the Cameron Highlands (Peninsular Malaysia), pp. 83-89 in Candollea 71 (1) on page 88, DOI: 10.15553/c2016v711a10, http://zenodo.org/record/568361
Fig. 3. – Geosiris australiensis B. Gray & Y.W. Low. A in First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia: a new record and a new species from the Wet Tropics of Queensland, Australia
No full textFig. 3. – Geosiris australiensis B. Gray & Y.W. Low. A. Habit; B. Close-up of a flower bud with bracts; C. Close-up of extrorse stamens showing anthers with a longitudinal slit and forming a tight ring around the style; D. Top view of stigma showing truncate apex with short fimbriate margin.Published as part of Gray, Bruce & Low, Yee Wen, 2017, First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia: a new record and a new species from the Wet Tropics of Queensland, Australia, pp. 249-255 in Candollea 72 (2) on page 253, DOI: 10.15553/c2017v722a2, http://zenodo.org/record/718282
Fig. 2. – Geosiris australiensis B. Gray & Y.W. Low. A in First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia: a new record and a new species from the Wet Tropics of Queensland, Australia
No full textFig. 2. – Geosiris australiensis B. Gray & Y.W. Low. A. Habit showing underground rhizome; B. Close-up of stigma with a truncate apex; C. Side view of a flowering head with an unopened flower bud; D. Cross section of an open flower showing stamens in a tight ring around the style just above the corolla throat.Published as part of Gray, Bruce & Low, Yee Wen, 2017, First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia: a new record and a new species from the Wet Tropics of Queensland, Australia, pp. 249-255 in Candollea 72 (2) on page 252, DOI: 10.15553/c2017v722a2, http://zenodo.org/record/718282
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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