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Conopodium majus (Gouan) Loret (Franse aardkastanje) in de duinen bij Haarlem
No full textConopodium majus was discovered on its third locality since 1995, now in the calcareous dunes near Haarlem. Additional characters for the identification during flowering are presented: the rays are smooth (papillose in Bunium) and the upper leaves are hairy (glabrous in Bunium)
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
Ludwigia uruguayensis (Camb.) Hara (Onagraceae), verwilderd
No full textThe discovery of Ludwigia uruguayensis in a park-pond in Dalfsen (prov. of Overijssel) was the reason to do some research after the source of this record. It appeared that it is grown in some nurseries, but the trade volume did not become clear. It is likely that the species can stand Dutch winters. It must be considered as a casual escape
Ehrharta erecta Lam., weer een kosmopolitisch, warmteminnend gras op drift?
No full textEen nieuw overblijvend gras uit Zuid-Afrika, Ehrharta erecta Lam., werd in de herfst van 2004 en 2005 aangetroffen op een tweetal grachten in Amsterdam. De dwarsribbels op met name de bovenste steriele lemma zorgen voor goede herkenbaarheid. De soort heeft wereldwijd gezien een groot areaal en is mogelijk invasief van aard. Gezien de recente inburgering van warmteminnende grassen wordt aandacht gevraagd voor nieuwe vondsten.
In autumn 2004 and 2005 an unknown perennial grass was found on two different localities in the City of Amsterdam. The grass proved to belong to Ehrharta erecta Lam., a South African, but widespread and possible invasive species. The species can easily be identified by its transverse corrugations in the second sterile lemma
Hydrocotyle ranunculoides L.f. (Grote waternavel): de stand van zaken
No full textIn het voorjaarsnummer van 1996 deden wij verslag van het spectaculaire woekeren van de Grote waternavel (Hydrocotyle ranunculoides). Gedurende de zomer en herfst van 1995 veroverde deze drijvende, oorspronkelijk uit Amerika afkomstige waterplant in recordtijd grote delen van vaarten in West- en Midden-Nederland. Zo massaal, dat bijvoorbeeld in Utrecht-Rijnsweerd de watergangen tot 4 maal toe moesten worden vrijgemaakt.
Gezien de serieuze problemen die deze plant sinds enkele jaren in Australië oplevert is het van belang te weten of de Grote waternavel ook in onze streken een permanente bedreiging kan vormen. Zeker toen bleek dat de vegetatief groeiende plant onze laatste zachte winters had overleefd
Nieuwe vondsten van zeldzame planten in 2003 en 2004
No full textVanuit Europees gezichtspunt was de ontdekking van twee nieuwe vindplaatsen van Apium repens en drie van Liparis loeselii belangrijk nieuws. De ontdekking van Gagea minima was verbazend.
Na meer dan een eeuw kon de melding van Peucedanum officinale bevestigd worden door zijn herontdekking. Nieuw is de vestiging van de Wilde kool (Brassica oleracea subsp. oleracea), en de mogelijke vestiging van Verbascum virgatum. Zowel Bromus lepidus als Festuca heterophylla worden nu tot de standaardlijstsoorten gerekend. Van Utricularia intermedia en Spiranthes spiralis werd een nieuwe vestiging vastgesteld. Een flink aantal soorten breidde zijn areaal verder uit: Bidens radiata (Riviertandzaad), Bromopsis erecta (Bergdravik), Callitriche truncata (Doorschijnend sterrenkroos), Caltha palustris subsp. araneosa (Spindotter), Carex muricata (Dichte bermzegge), Carex punctata (Stippelzegge), Carex strigosa (Slanke zegge), Goodyera repens (Dennenorchis), Helianthemum nummularium (Zonneroosje), Lathyrus nissolia (Graslathyrus), Oenanthe crocata (Dodemansvingers), Oenanthe silaifolia (Weidekervel-torkruid), Ophrys apifera (Bijenorchis), Polygonum oxyspermum (Strandvarkensgras), Silene baccifera (Besanjelier), Stellaria nemorum (Bosmuur) en Vulpia membranacea (Zandlangbaardgras). In lijn met de voorgaande ontwikkelingen profiteerde een aantal soorten van een meer dynamisch natuurbeheer: Huperzia selago (Dennenwolfsklauw), Lycopodiella inundata (Moeraswolfsklauw), Lycopodium clavatum (Grote wolfsklauw), Pilularia globulifera (Pilvaren), Equisetum hyemale (Schaafstro), Equisetum telmateia (Reuzenpaardenstaart), Parnassia palustris (Parnassia), Epipactis palustris (Moeraswespenorchis), Anacamptis morio (Harlekijn), Anagallis tenella (Teer guichelheil), Apium inundatum (Ondergedoken moerasscherm), Hypericum canadense (Canadees hertshooi), Juncus tenageia (Wijdbloeiende rus), Ludwigia palustris (Waterlepeltje), Mentha pulegium (Polei), Pinguicula vulgaris (Vetblad) en Viola persicifolia (Melkviooltje).
From a European point of view, the discovery of two new localities of Apium repens and of three new localities of Liparis loeselii in the Netherlands is important news. The discovery of a large population of Gagea minima has been a big surprise. It took more than a century before the old record of Peucedanum officinale could be confirmed by the rediscovery of this species. New is the establishment of the wild Brassica oleracea subsp. oleracea, and possibly Verbascum virgatum.
Both Bromus lepidus and Festuca heterophylla are now considered to be native plants. Both Utricularia intermedia and Spiranthes spiralis extended their area to a new locality, the first new ones since ages. Quite a few species extended their area considerably: Bidens radiata, Bromopsis erecta, Callitriche truncata, Caltha palustris subsp. araneosa, Carex muricata, Carex punctata, Carex strigosa, Goodyera repens, Helianthemum nummularium, Lathyrus nissolia, Oenanthe crocata, Oenanthe silaifolia, Ophrys apifera, Polygonum oxyspermum, Silene baccifera, Stellaria nemorum and Vulpia membranacea. In conformity with the trends of the last decades, a number of species took advantage of a more dynamic nature management: Huperzia selago, Lycopodiella inundata, Lycopodium clavatum, Pilularia globulifera, Equisetum hyemale, Equisetum telmateia, Parnassia palustris, Epipactis palustris, Anacamptis morio, Anagallis tenella, Apium inundatum, Hypericum canadense, Juncus tenageia, Ludwigia palustris, Mentha pulegium, Pinguicula vulgaris and Viola persicifolia
Revisie van het NHN-herbariummateriaal van Carex lepidocarpa Tausch (Schubzegge) en Carex flava L. (Gele zegge) in Nederland
No full textDe recente studie van M.Hedrén (Lund, Zweden) van de Carex flava-groep in Scandinavië en Finland toonde aan dat op moleculair niveau vier soorten goed te onderscheiden zijn: C. flava, C. lepidocarpa, C. demissa (= C. oederi subsp. oedocarpa) en C. oederi (= C. oederi subsp. oederi).
Door de moleculaire resultaten te koppelen aan de morfologische eigenschappen van de planten kon worden aangetoond dat de vier taxa sterker bleken te overlappen in de urntjes-kenmerken dan werd aangenomen, terwijl andere kenmerken (tongetje, gesteeldheid en lengte mannelijke aar) een grotere betekenis hebben voor de identificatie van de planten. Onze herbariumstudie maakt duidelijk dat C. lepidocarpa nog voorkomt op twee van de drie vroegere vindplaatsen, dat de vindplaats in de Betuwe uitsluitend de hybride C. flava × lepidocarpa betreft, en dat deze hybride vroeger ook in het Bunderbos en bij Hoensbroek is gezien. Van C. flava komen drie vindplaatsen voor in Zuid-Limburg, en twee in het westelijke rivierengebied; de vindplaatsen in Flevoland en de Lauwersmeer zijn zeker nieuwe vestigingen.
The recent study of M. Hedrén (Lund, Sweden) of the Carex flava group in Fennoscandia proved that the 4 species C. flava, C. lepidocarpa, C. demissa (= C. oederi subsp. oedocarpa) en C. oederi (= C. oederi subsp. oederi) are well separated at molecular level. By linking the molecular characters to the morphological ones, it could be demonstrated that the traditional utrical and beak size characters show more overlap than hitherto assumed, whereas other morphological characters (ligule, pedicel length of the male spike) are more important for identification of the plants. Our herbarium study shows that C. lepidocarpa is still present on two of its former three localities and that there is one locality in the ‘Betuwe’ where only the hybrid C. flava × lepidocarpa occurs; in the nineteenth century and the early twentieth century, the hybrid was also found in two places in southern Limburg. Carex flava occurs presently at three localities in southern Limburg, at two in the western riverine area, and at two localities in the central and northern part of the country which represent certainly new and recent establishments
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