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Kappia lobulata (Apocynaceae, Periplocoideae), a new genus from South Africa
Get PDFAbstractKappia, a new genus from the Fish River Valley in the Eastern Cape Province, South Africa is presented. At first described as Raphionacme lobulata Venter and R.L.Verh. [Venter, H.J.T., Verhoeven, R.L. 1988. Raphionacme lobulata (Periplocaceae), a new species from the eastern Cape Province, South Africa. South African Journal of Botany 54, 603–606.] based on a single specimen collected in 1936, recently discovered plants of this species proved it to be a new genus. In habit Kappia resembles Baseonema Schltr. and Rendle, Batesanthus N.E.Br., Mondia Skeels and Stomatostemma N.E.Br. However, as far as floral structure is concerned, Kappia reveals more affinity with Raphionacme Harv. DNA sequence data show Kappia to be distinct from Batesanthus, Mondia and Raphionacme Harv. and weakly supported as a sister to Stomatostemma
Nomenclature correction in Parquetina (Apocynaceae: Periplocoideae)
No full textAbstractBullock (1961) combined Periploca nigrescens Afzel. and Omphalogonus calophyllus Baill. in Parquetina nigrescens (Afzel.) Bullock. Based on their conspicuously different floral morphology, Venter and Verhoeven (1996) reversed Bullock's combination to Periploca nigrescens Afzel. and O. calophyllus Baill. However, DNA sequence analyses (Ionta and Judd, 2007) indicated that Periploca nigrescens and O. calophyllus are sister species in Parquetina. A nomenclatural correction of Parquetina and its two species, as well as a new generic protologue and species key have thus become necessary. The bitypic Parquetina is characterised by the following features: lianas that turn black when dry, relatively large and coriaceous leaves, fleshy coriaceous corolla with inside pink, maroon or deep crimson to black-violet, and pubescent or hirsute stamens with pollen in tetrads
A revision of Periploca (Periplocaceae)
No full textRevised nomenclature, a new key to the species, improved classification, diagnostic characteristics, geographic distribution and habitat of Periploca L. and its fourteen species are presented. Cyprinia Browicz is reduced to synonymy with Periploca
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
A new species of Raphionacme (Periplocaceae) from South West Africa/Namibia
No full textRaphionacme namibiana Venter & Verhoeven, a new species from South West Africa/Namibia is described. The species is recognised by the unusual fusion of the corona lobes to the corolla lobes, the stout keel-shaped follicles and the peculiar seed which has a marginal ring of hairs instead of the normal micropylar coma. Raphionacme namibiana is related to Raphionacme grandiflora N.E. Br. from Tropical East and Central Africa. In both species the corona, stamens and corolla are quite alike. The two species, however, differ distinctly with regard to their fruit and seed
Raphionacme lobulata (Periplocaceae), a new species from the eastern Cape Province, South Africa
No full textRaphionacme lobulata Venter & Verhoeven, a new species discovered in the Fish River Valley, in the eastern Cape, is described. This species is distinguished by its glabrous appearance, reddish glossy bark, glossy coriaceous leaves, hemispherical mucronate interpetiolar teeth, petiolar and blade prickles, and hemispherical corona lobules. R. lobulata mostly resembles R. abyssinica Chiov., R. flanaganii Schltr. and R. monteiroae (Oliv.) N.E. Br., especially with regard to the woody, perennial aerial stems. The habit of growth, bark and leaves also resemble Petopentia natalensis (Schltr.) Bullock, but the floral structure places this new species in Raphionacme. R. lobulata inhabits the dry euphorbiaceous scrub forest on the banks of the Fish River
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