1,720,991 research outputs found
Marine invasive species:Establishing pathways, their presence and potential threats in the Galapagos Marine Reserve
Full text linkWorldwide, marine biological invasions of non-native species have increased significantly in recent years due to a rapid rise in global trade, transport and tourism. Invasions occur when non-native species are transported from one region to another and establish, often resulting in competition displacing native species and changing ecosystems. Historic literature searches were conducted along with dive surveys of the main ports and in sites around the archipelago in order to produce a baseline of which non-native species are present in the Galapagos Marine Reserve at this time. Confounding processes of anthropogenic and natural activities are increasing the potential spread of marine invasive species in the Eastern Tropical Pacific and the Galapagos Marine Reserve. We discuss the potential vectors facilitating marine invasions with the suggestion that marine traffic could be the most influential vector in the transport of marine non-natives to the Galapagos Marine Reserve. The challenge for marine park authorities is to identify those species that are likely to cause negative impacts on native biodiversity and ecosystems before they establish in the Galapagos, and to develop pre-emptive strategies that would likely include prevention as well as risk-based management strategies to remove them or to mitigate their harmful effects.</p
First record of the non-native bryozoan Amathia (= Zoobotryon) verticillata (delle Chiaje, 1822) (Ctenostomata) in the Galápagos Islands
No full textThe warm water marine bryozoan Amathia (= Zoobotryon) verticillata (delle Chiaje, 1822) is reported for the first time in the Galápagos Islands based upon collections in 2015. Elsewhere, this species is a major fouling organism that can have significant negative ecological and economic effects. Comprehensive studies will be necessary to determine the extent of the distribution of A. verticillata in the Galápagos and its effects on native species. The establishment of A. verticillata emphasizes the need for regular monitoring of those vectors that could bring additional non-native species to the Archipelago
Sertularellidae Maronna, Miranda, Peña Cantero, Barbeitos and
No full textFamily SERTULARELLIDAE Maronna, Miranda, Peña Cantero, Barbeitos and Marques, 2016Published as part of Calder, Dale R., Carlton, James T., Keith, Inti, Ashton, Gail V., Larson, Kristen, Ruiz, Gregory M., Herrera, Esteban & Golfin, Geiner, 2022, Biofouling hydroids (Cnidaria: Hydrozoa) from a Tropical Eastern Pacific island, with remarks on their biogeography, pp. 565-606 in Journal of Natural History 56 (9 - 12) on page 588, DOI: 10.1080/00222933.2022.2068387, http://zenodo.org/record/701248
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
Figure 4 in Biofouling hydroids (Cnidaria: Hydrozoa) from a Tropical Eastern Pacific island, with remarks on their biogeography
No full textFigure 4. Eudendriidae. Eudendrium cf. certicaule, nematocysts. (a) microbasic eurytele, small, #240636. (b) microbasic eurytele, small, #240566. (c) microbasic eurytele, large, #240637. (d)?microbasic mastigophore, 240634. (e), haploneme, #240566. (f) haploneme, h#240566.Published as part of Calder, Dale R., Carlton, James T., Keith, Inti, Ashton, Gail V., Larson, Kristen, Ruiz, Gregory M., Herrera, Esteban & Golfin, Geiner, 2022, Biofouling hydroids (Cnidaria: Hydrozoa) from a Tropical Eastern Pacific island, with remarks on their biogeography, pp. 565-606 in Journal of Natural History 56 (9-12) on page 578, DOI: 10.1080/00222933.2022.2068387, http://zenodo.org/record/701248
Hydroids (Cnidaria, Hydrozoa) from marine fouling assemblages in the Galápagos Islands, Ecuador
No full textAn account is given of hydroids collected in 2015 and 2016 from port and harbor fouling communities in the Galápagos Islands. Also included is the hydroid of Ectopleura media, discovered on the wreck of the tanker Jessica near Isla San Cristóbal in 2001. Among 20 species reported herein were six anthoathecates and 14 leptothecates. Most common in the samples were the kirchenpaueriid Ventromma halecioides and the halopteridid Halopteris alternata. Eight species (Bougainvillia muscus, Bimeria vestita, Clytia elongata, C. obliqua, C. thornelyi, Obelia oxydentata, Eucheilota sp., and Halecium labiatum) are reported for the first time from the Galápagos archipelago. Three of them (Clytia elongata, C. thornelyi, and Halecium labiatum) are also new to the eastern Pacific. Seven species treated here are considered introduced by shipping to the islands, bringing to eight the number of introduced hydroids. In addition, we treat four species as cryptogenic, bringing to five the total number of the latter in the Galápagos. The binomena Obelia thornelyi Nutting, 1927, Clytia stolonifera Blackburn, 1938, and C. latitheca Millard and Bouillon, 1973 are regarded as synonyms, with the first of these having nomenclatural priority. Meanwhile, the senior synonym O. thornelyi is reassigned to the genus Clytia Lamouroux, 1812 as C. thornelyi. Another species in the samples, Dynamena distans Lamouroux, 1816 (also widely known as Sertularia distans and Tridentata distans), is combined for the first time with the genus Amphisbetia L. Agassiz, 1862, as A. distans
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
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