1,720,966 research outputs found
Coupling an oceanographic model to a Fishery Observing System through mixed models: The importance of fronts for anchovy in the Adriatic Sea
No full textAnchovy, Engraulis encrasicolus, forms the basis of Italian small pelagic fisheries in the Adriatic Sea. The strong dependence of this stock on environmental factors and the consequent high variability makes the dynamics of this species particularly complicated to model. Weekly geo-referenced catch data of anchovy obtained by means of a Fishery Observing System (FOS) from 2005 to 2011 were referred to a 0.2 × 0.2 degree grid (about 20 km2) and associated with the environmental parameters calculated by a Regional Ocean Modelling System, AdriaROMS. Generalized Additive Mixed Models (GAMM) with and without random effects were used to identify a relationship between abundance in the catch and oceanographic conditions. The outcomes of models with no random effects, with random vessel effects and with the random vessel and random week-of-the-year effects were examined. The GAMM incorporating a random vessel and week-of-the-year effect were selected as the best model on the basis of the Akaike information criteria (AIC). This model indicated that catches (abundance) of anchovy in the Adriatic Sea correlate well with low temperatures, salinity fronts and sea surface height, and allowed the identification of areas where high concentrations of this species are most likely to occur. The results of this study demonstrate that GAMM are a useful tool to combine geo-referenced catch data with oceanographic variables and that the use of a mixed-model approach with spatial and temporal random effects is an effective way to depict the dynamics of marine species
Phytoplankton communities in the northwestern Adriatic Sea: Interdecadal variability over a 30-years period (1988–2016) and relationships with meteoclimatic drivers
Full text linkIn this study the interannual variability of phytoplankton over a ~30-years period in the coastal site of LTER-Senigallia transect (N Adriatic Sea) was investigated to document patterns potentially related to environmental/climatic drivers. Comparing physical and chemical data of the periods 1988–2002 and 2007–2016 periods, we showed that phytoplankton abundance and biomass and inorganic nutrient concentrations increased in the last decade, indicating that the tendency to oligotrophication due to the drop of the Po River outflow in the years 2002–2007 was reversed in the period 2007–2016. The typical P-limited conditions of the N Adriatic Sea seem to have been attenuated in the study area. P levels were not explained by the P concentrations in the Po River waters, suggesting the possible influence of other local P sources that could be related to the anomalous meteorological events (intense rainfalls) that took place in the 2007–2016 period. In the last decade, the community structure and seasonality of phytoplankton markedly changed, as highlighted by the different indicator species for each season: the blooms of Skeletonema marinoi shifted from winter to spring. A significant decrease of coccolithophores was observed particularly in winter months in the 2007–2016 period: some indicator species among the most relevant in the 1988–2002 period (such as Emiliania huxleyi in winter, and Syracosphaera pulchra in spring) have lost this role in 2007–2016. Dinoflagellate abundances decreased, except in spring when the occasional proliferation of large sized species caused biomass peaks. The phytoplankton annual cycle became irregular with sudden diatom blooms, reflecting the variability of meteorological events in recent years. It is noteworthy that in the last decade, an allochthonous species, i.e. the diatom Pseudo-nitzschia multistriata, became a regular inhabitant of the autumn phytoplankton communities of the NW Adriatic Sea
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
