1,721,026 research outputs found
Generic Transfers in Malagasy Boraginales
No full textMiller, James S., Gottschling, Marc (2017): Generic Transfers in Malagasy Boraginales. Candollea 72 (2): 329-332, DOI: 10.15553/c2017v722a
Validation of the calcareous dinophyte Wallidinellum (Peridiniales), with notes on the status of fossils in the Code
No full textBauer, Wolfgang, Gottschling, Marc, Keupp, Helmut, Kusber, Wolf-Henning, Mertens, Kenneth N. (2021): Validation of the calcareous dinophyte Wallidinellum (Peridiniales), with notes on the status of fossils in the Code. Phytotaxa 520 (3): 296-300, DOI: 10.11646/phytotaxa.520.3.9, URL: http://dx.doi.org/10.11646/phytotaxa.520.3.
Taxonomic revision of the genus Cortesia (Ehretiaceae, Boraginales), a genus endemic to Argentina
Full text linkCortesia es un género halófilo y monotípico endémico de la Argentina que pertenece a Ehretiaceae (Boraginales). Se diferencia morfológicamente de los otros miembros de la familia por tener hojas con la lámina cuneiforme y el ápice 3-dentado, un involucro formado por brácteas fusionadas, lóbulos del cáliz espatulados y drupas blancas con un endocarpio 2-partido. La única especie del género, Cortesia cuneifolia, se trata e ilustra en la presente contribución con base en el estudio de numerosas colecciones de herbario. Adicionalmente, se designa un lectotipo para el nombre a fin de asegurar su aplicación. Por otro lado, se registra por primera vez la presencia de la especie en la provincia de Tucumán.Cortesia is a halophytic and monotypic genus endemic to Argentina that belongs to Ehretiaceae (Boraginales). It is morphologically distinct from the other members of the family in having cuneate leaves with a 3-dentate apex, an involucrum of fused bracts, spatulate calyx lobes, and white drupes with a two-parted endocarp. Its single species, Cortesia cuneifolia, is here treated and illustrated based on the study of numerous herbarium collections. Additionally, a lectotype is designated for the name to assure its reliable application. Furthermore, the species is recorded for the first time in Tucumán province.Fil: Mirra Gonzalez, Fabiana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Gottschling, Marc. Ludwig Maximilians Universitat; AlemaniaFil: Moroni, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin
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
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
First Miocene fossils of Vivianiaceae shed new light on phylogeny, divergence times, and historical biogeography of Geraniales
Full text linkThe origin of Geraniales (approximately 900 species in three families: Geraniaceae, Melianthaceae, and Vivianiaceae) is traced back to the Cretaceous of Gondwana, yet their geotemporal history is largely unknown because of a limited fossil record and incomplete phylogenies. In the present study, we provide the first fossil record of Vivianiaceae and a highly resolved molecular phylogeny for all extant Geraniales genera. Our results support the hypothesis that five (instead of three) families should be recognized in the order Geraniales: Francoaceae A. Juss. (Francoa, Greyia, Tetilla), Geraniaceae Juss. (Erodium, Geranium, Monsonia, Pelargonium), Hypseocharitaceae Wedd. (monogeneric), Melianthaceae Horan. (Bersama, Melianthus), and Vivianiaceae Klotzsch (Balbisia, Rhynchotheca, Viviania). The four major lineages (i.e. Geraniaceae, Francoaceae+Melianthaceae, Hypseocharitaceae, Vivianiaceae) all originated within a narrow time frame during the Eocene (36.9-49.9Mya) based on the five fossil calibration points. The divergence of most of the extant genera occurred much later, from the Miocene onwards. The South American-South African disjunction in Francoaceae apparently goes back to long distance dispersal with an estimated divergence time of the lineages in the Middle Miocene [11.2 (5.9-17.7)Mya]. Diversification in Melianthus appears to be much more recent than previously assumed [starting approximately 3.4 (1.9-5.2)Mya rather than approximately 8-20Mya]. However, divergence of the Andean Hypseocharis lineage [36.9 (31.9-42.8)Mya] significantly predates the main Andean uplift: Current distributions likely go back to northward migrations and subsequent extinctions in Patagonia. Similarly, Rhynchotheca, Balbisia, and Viviania have a current southern distribution limit >10°N of the fossil finds, indicating a massive northward displacement. The present evidence suggests that niche conservatism likely played a major role in the historical biogeography of Geraniales. © 2012 The Linnean Society of London.Fil: Palazzesi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Freie Universität Berlin; AlemaniaFil: Gottschling, Marc. Ludwig Maximilians Universitat; AlemaniaFil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Weigend, M. Freie Universität Berlin; Alemani
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