1,720,963 research outputs found
Modeling Posidonia oceanica shoot density and rhizome primary production
Full text linkPosidonia oceanicameadows rank among the most important and most productive ecosystems in
the Mediterranean basin, due to their ecological role and to the goods and services they provide.
estimations of crucial ecological process such as meadows productivity could play a major role in an
environmental management perspective and in the assessment of P. oceanicaecosystem services.
In this study, a Machine Learning approach, i.e. Random Forest, was aimed at modeling P. oceanica
shoot density and rhizome primary production using as predictive variables only environmental
factors retrieved from indirect measurements, such as maps. Our predictive models showed a good
level of accuracy in modeling both shoot density and rhizome productivity (R
2
= 0.761 and R
2
= 0.736,
respectively). Furthermore, as shoot density is an essential parameter in the estimation of P. oceanica
productivity, we proposed a cascaded approach aimed at estimating the latter using predicted values
of shoot density rather than observed measurements. In spite of the complexity of the problem, the
cascaded Random forest performed quite well (R2 = 0.637). While direct measurements will always
play a fundamental role, our estimates could support large scale assessment of the expected condition
of P. oceanica meadows, providing valuable information about the way this crucial ecosystem works
A Machine Learning approach to the assessment of the vulnerability of Posidonia oceanica meadows
No full textPosidonia oceanica is an endemic Mediterranean seagrass that ranks among the most important and valuable species, with regard to both its ecological role and the services it provides. Despite this species is one of the main targets of conservation actions, the current regression trend of P. oceanica is alarming, underlying the urgent need for reliable methods capable of assessing meadows vulnerability. To address this need, we developed a Habitat Suitability Model (HSM) aimed at assessing the vulnerability of P. oceanica meadows in the Italian marine coastal waters using the Random Forest (RF) Machine Learning technique. Building on the current knowledge on both spatial distribution and condition of meadows in the Italian seas, the RF was used as a classifier aimed at modeling the habitat suitability for P. oceanica, rather than for predictive purposes. The assessment of the potentially most vulnerable P. oceanica meadows at increasing risk of regression was performed through the analysis of the RF output. The HSM showed a good level of accuracy, i.e. Cohen’s K = 0.685. The proposed approach provided valuable information regarding the vulnerability of P. oceanica meadows over the Italian marine coastal waters. In addition, an evaluation of the relative importance of the predictors was carried out using the permutation measure. The developed HSM can support conservation and monitoring programs regarding this species playing a crucial role in the marine ecosystems of the Mediterranean Sea
AÍAQUI PUBLICAÇÃO DE ARTISTA DE ISABELLE CATUCCI E TÂNIA BLOOMFIELD
No full text"aíaqui" é uma publicação de artista realizada pelas artistas Isabelle Catucci e Tânia Bloomfield, durante quinze dias de julho a agosto de 2020, no contexto da pandemia de COVID-19. A publicação apresenta um jogo de troca de imagens e palavras-chave entre as duas artistas, a partir da cidade de Curitiba, PR, e região metropolitana de Lisboa, Portugal. 40 p. Versão impressa e digital. ISBN: 978-65-84565-41-8.
OBS: a visualização do pdf deve ser feita de duas em duas páginas
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
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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