1,720,969 research outputs found
Letter to the editor regarding the article “Taking advantage of seagrass recovery potential to develop novel and effective meadow rehabilitation methods“ by Alagna et al., published in Marine Pollution Bulletin, 149: 2019 (110578)
No full textAlagna et al. (2019) suggest new transplantation methods for Posidonia oceanica (Linnaeus) Delile, inspired by its natural recovery process after disturbance due to dredging operations for gas-pipelines. They observe that P. oceanica vegetative fragments naturally settled only on loose calcareous stones deployed to fill the trenches of the gas-pipeline. No recovery was noted on dead matte, sand and large calcarenitic boulders. Following a new pilot restoration project currently ongoing in the same area, we demonstrate that natural recovery also occurs on dead matte. After examining other alternative transplantation methods for P. oceanica, the Authors suggest using their "habitat enhancement units" method for the restoration of seagrasses, not only on rocky bottom but also on sand and other bare substrate requiring general environmental restoration. Here we express disagreement on certain issues reported in the paper
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
Resilience of the seagrass Posidonia oceanica following pulse-type disturbance
Full text linkUnderstanding the response of species to disturbance and the ability to recover is crucial for preventing their potential collapse and ecosystem phase shifts. Explosive submarine activity, occurring in shallow volcanic vents, can be considered as a natural pulse disturbance, due to its suddenness and high intensity, potentially affecting nearby species and ecosystems. Here, we present the response of Posidonia oceanica, a long-lived seagrass, to an exceptional submarine volcanic explosion, which occurred in the Aeolian Archipelago (Italy, Mediterranean Sea) in 2002, and evaluate its resilience in terms of time required to recover after such a pulse event. The study was carried out in 2011 in the sea area off Panarea Island, in the vicinity of Bottaro Island by adopting a back-dating methodological approach, which allowed a retrospective analysis of the growth performance and stable carbon isotopes (δ13C) in sheaths and rhizomes of P. oceanica, during a 10-year period (2001-2010). After the 2002 explosion, a trajectory shift towards decreasing values for both the growth performance and δ13C of rhizomes was observed. The decreasing trend reversed in 2004 when recovery took place progressively for all the analysed variables. Full recovery of P. oceanica occurred 8 years after the explosive event with complete restoration of all the variables (rhizome growth performance and δ13C) by 2010. Given the ecological importance of this seagrass in marine coastal ecosystems and its documented large-scale decline, the understanding of its potential recovery in response to environmental changes is imperative
Ecological implications of restoring degraded marine areas using Posidonia oceanica: assessment of plant contamination and fish fauna recovery
No full textThe potential of ecological restoration to re-establish ecosystem structure and function is globally recognised. However, the ecological implications of restoring polluted sites are rarely considered in the assessment of trajectories and recovery processes. Here we present two case studies of restoration of marine coastal areas carried out by transplanting the Mediterranean seagrass Posidonia oceanica from donor meadows to polluted marine areas with the aim of assessing, within six months from transplant: (i) trace element (TE) accumulation in P. oceanica in response to environmental contamination; (ii) fish fauna recovery. We found increased Cr, Cu and Hg accumulation in roots and As in leaves of transplanted plants, confirming that P. oceanica may act as a sink, sequestering TEs and potentially decreasing their availability, but also opening questions about the potential risk of remobilising buried contaminants. At the same time, fish assemblages showed signs of rapid recovery in both areas, i.e., an increase in species richness, abundance, and diversity from the first month after transplantation, indicating a rapid improvement in habitat provision function. Although the amount of TEs potentially transferable from P. oceanica to the ecosystem seems to be low in the study areas, further investigations including cost-benefit assessments of restoring polluted sites by transplanting seagrasses would improve current knowledge in support of efficient ecosystem-based coastal biodiversity management and conservation
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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