1,721,144 research outputs found
When and how? Freshwater mussel recolonization in Lake Orta
Full text linkThanks to a video posted on a social network, live mussels of Unio elongatulus, have been recorded from Lake Orta (Italy) over one century after the last (and only) report. With its long and well documented history of pollution, Lake Orta offers the opportunity to document the post-extirpation recovery of freshwater unionid mussels. This case evidences that recovery/recolonization is possible despite a high devastation in the past, and permits to evaluate how fast recolonization may occur, in which way, and in what conditions. The answer to the \u27how fast\u27 was sought by estimating the age of the larger and seemingly older individuals of the population. To address the \u27in which way\u27 we compared the haplotypes of Lake Orta specimens of Unio elongatulus (the only species present) with those of surrounding populations. We concluded that, since Lake Orta lacks a direct connection with the putative source populations, colonizing mussels were almost certainly transported by fish carrying glochidia that were used for lake restocking after liming. Data from the long-term monitoring of water chemistry and sediments have allowed defining what conditions proved to be suitable for survival making possible the start of mussels recovery. But not only water and sediment quality matters for mussels recovery, which was delayed by nearly ten years after the reappearance of fish. This delay reflects the need of the whole trophic chain to be reestablished to allow the survival of the suitable and healthy host-fish populations necessary for mussels reproduction
Taxonomic reassessment of the freshwater mussel genus Unio (Bivalvia: Unionidae) in Russia and Ukraine based on morphological and molecular data
No full textKlishko, Olga, Lopes-Lima, Manuel, Froufe, Elsa, Bogan, Arthur, Vasiliev, Lyudmila, Yanovich, Lyudmila (2017): Taxonomic reassessment of the freshwater mussel genus Unio (Bivalvia: Unionidae) in Russia and Ukraine based on morphological and molecular data. Zootaxa 4286 (1): 93-112, DOI: https://doi.org/10.11646/zootaxa.4286.1.
Fig. 4 in Hyriopsis panhai, a new species of freshwater mussel from Thailand (Bivalvia: Unionidae)
No full textFig. 4. Bayesian inference tree based on 1,967 bp concatenated alignment dataset of COI + 16S + 28S genes. Numbers on nodes indicate bootstrap values from maximum likelihood (ML) and bipartition posterior probabilities from Bayesian inference analysis (BI), and are shown as BI/ML. Black circles on nodes indicate high support by BI (≥ 0.95) and ML (≥ 70); white circles indicate high support by BI. Shells are not to scale.Published as part of Jeratthitikul, Ekgachai, Paphatmethin, Siwanon, Zieritz, Alexandra, Lopes-Lima, Manuel & Ngor, Peng Bun, 2021, Hyriopsis panhai, a new species of freshwater mussel from Thailand (Bivalvia: Unionidae), pp. 124-136 in Raffles Bulletin of Zoology 69 on page 134, DOI: 10.26107/RBZ-2021-0011, http://zenodo.org/record/535198
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
Figure 3 in Mitogenomic phylogeny and fossil-calibrated mutation rates for all F- and M-type mtDNA genes of the largest freshwater mussel family, the Unionidae (Bivalvia)
No full textFigure 3. Phylogenetic tree of the Unionidae+Margaritiferidae estimated from 14 concatenated individual mtDNA gene sequences (12 protein-coding and 2 rRNA genes). Values for branch support above each node represent Bayesian posterior probabilities percentage/maximum likelihood bootstrap support. *Supported values ≥ 95 are represented by an asterisk.Published as part of Zieritz, Alexandra, Froufe, Elsa, Bolotov, Ivan, Gonçalves, Duarte V., Aldridge, David C., Bogan, Arthur E., Gan, Han Ming, Gomes-Dos-Santos, André, Sousa, Ronaldo, Teixeira, Amilcar, Varandas, Simone, Zanatta, David & Lopes-Lima, Manuel, 2020, Mitogenomic phylogeny and fossil-calibrated mutation rates for all F- and M-type mtDNA genes of the largest freshwater mussel family, the Unionidae (Bivalvia), pp. 1088-1107 in Zoological Journal of the Linnean Society 193 on page 1098, DOI: 10.5281/zenodo.563569
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