1,720,973 research outputs found
Veronica peregrina (Plantaginaceae), an alien species rediscovered in Lithuania /
No full textVeronica peregrina L. (Plantaginaceae) is a native species to North and South America and an alien to Europe. This species was first found in Lithuania in 1829, and no later records were made for almost two centuries. In May 2023, Veronica peregrina was rediscovered in Vilnius, Lithuania. Groups of plants and solitary individuals were scattered over ca. 1500 m². A total of about 700 individuals were found. Observed plants belong to the type subspecies Veronica peregrina L. subsp. peregrina. It is presumed that seeds of Veronica peregrina could have been introduced with plants from nurseries. The spread of this species in anthropogenic habitats in Lithuania is quite likely. Veronica peregrina is currently considered a casual alien in Lithuania
First record of non-native woody species Amelanchier ×lamarckii (Rosaceae), in Lithuania /
No full textAmelanchier ×lamarckii F. G. Schroed., a shrub or small tree native to North America, has escaped from cultivation in Lithuania and is recorded as a new casual alien plant in Lithuanian flora. Most of the recorded young individuals have grown from seeds and spread locally through saplings. The population consists of about 50 individuals, of which approximately 10 have grown to a height of 0.5–2.5 m and are fruiting. Amelanchier ×lamarckii is recorded from the Kelmė district, between Panūdžiai and Palendriai villages, in a dry grassland habitat along the roadside. Amelanchier ×lamarckii has already been reported to have escaped to several European countries. This hybrid shares similar growth traits as its invasive congener Amelanchier spicata (Lam.) Koch. The naturalization and spread to natural habitats in Lithuania are highly probable. Amelanchier ×lamarckii has been reported from northern latitudes; therefore, the spread of this plant in Lithuania should be monitored. Planting of A. ×lamarckii close to dry grassland habitats as well as forest edges should be avoided, considering the possible spread by birds into these habitats
Lotus maritimus L. (Fabaceae), alien species new to Lithuania /
No full textInformation about the first record of alien species Lotus maritimus L. (Fabaceae) in Lithuania is provided. This species was found in disturbed grassland along the railway line in Panevėžys district (northern part of Central Lithuania), Berčiūnai village in June 2021. It is supposed that seeds of this species have been accidentally in-troduced with rock material used to maintain railway embankment. Species composition of the habitat in Lotus maritimus locality is presented. The recorded population consists of a large number of generative individuals. This species could also grow in other parts of Lithuania, as the plants produce viable seeds and might spread to new areas. Currently, Lotus maritimus is considered as a casual species in Lithuania; however, it may naturalise locally in the future
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
Pietiniuose Latvijos rajonuose aptiktos naujos svetimžemės augalų rūšys.
No full textAlien plants are one of the most dynamic and rapidly changing components of flora. Many intentionally introduced plants, which formerly were in cultivation only, now are increasingly found escaped and occur in anthropogenic or seminatural habitats. During field investigations in the southern districts of Latvia in 2014-2016, six new alien plant species were recorded: Allium nutans, Hylotelephium spectabile, Solidago ×niederederi, Symphyotrichum dumosum, S. lanceolatum and S. novae-angliae. To date, four species, Allium nutans, Hylotelephium spectabile, Symphyotrichum dumosum and S. novae-angliae, occur as casual aliens in Latvia. Solidago ×niederederi should be ascribed to the group of established species, whereas Symphyotrichum lanceolatum has naturalized and is potentially invasive. Notes on morphology and identification of species as well as characteristics of the recorded populations are discussed. A note on 20 other alien plant species recorded in wastelands, abandoned meadows and unused arable fields in the south-western part of Daugavpils city is also provided
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