1,720,956 research outputs found
Intertidal and subtidal blennies: assessment of their habitat through individual and nest distribution
No full textResident and transitory intertidal fish species are expected to differ in their utilization of
space in the intertidal zone. Here we assessed fish zonation patterns on 2 rocky shores of the northwestern
Adriatic Sea (where tides can range up to 1.5 m) using blennies as study species and distribution
of both individuals and nests as methodological tools. Of the 12 species observed, 5 were
found exclusively in the intertidal zone: Aidablennius sphynx, Coryphoblennius galerita, Lipophrys
adriaticus, L. canevae and L. dalmatinus. Two species, Parablennius rouxi and P. tentacularis, were
found only in the subtidal zone, whilst P. gattorugine, P. incognitus, P. sanguinolentus, P. zvonimiri
and Salaria pavo were observed in both environments. Nest distribution mirrored individual distribution,
strongly indicating that some blenny species can be considered true intertidal residents,
spending the main part of their lives in this area. Intertidal and subtidal species showed different patterns
of space utilization. Indeed, the former nested higher in the vertical distribution than the average
depth at which individuals were recorded, and the latter, despite visiting the intertidal area at
high tide, always nested below the minimum water line. These results show that, contrary to theoretical
predictions, intertidal-resident fish may fully exploit intertidal habitats, for foraging and for
reproduction, occupying even the sectors most distal from the subtidal zone, i.e. the most variable in
terms of physical conditions. Moreover, nest distribution was found to be an effective measure of residence
and thus a useful referent to evaluate space use in intertidal fish
The influence of a new artificial structure on fish assemblages of adjacent hard substrata
No full textDeployed for diverse purposes, artificial substrata can, theoretically, act as fish attractors or as fish
producers. We tested these hypotheses by comparing fish assemblages on two artificial hard substrata,
the Ca’ Roman and Sottomarina jetties, before (1994 and 2003) and after (2005 and 2006) the deployment
of a new breakwater in the area. Our results support the fish production hypothesis. A remarkable
increase in richness and abundance of sedentary species was observed on the extant substrata with the
presence of the new barrier. More mobile species showed less definite trends. The net result has been
a total increase in abundance and richness in the area. While fish assemblage showed important
temporal variation in composition before deployment (Ca’ Roman, comparison between 1994 and 2003),
clear trends of increasing abundance were concurrent with the presence of the new barrier. This increase
in abundance, particularly of sedentary species, may be attributed to enhanced connectivity and/or an
improvement in larval retention due to the changes in water circulation connected with the new
breakwater, or to an increase in juveniles and/or adults promoted by changes in environmental conditions.
Indeed, changes in benthic cover were recorded, with an increase of uncovered rock and the
appearance of previously unrecorded algae after breakwater deployment
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
Linking male qualities to multiple display traits: An example in a fish with exclusive male care
No full textRecent theoretical models predict that the relative allocation to advertisement and parental care depends on whether paternal care is necessary for offspring survival: In species with exclusive male care, male investment in attraction is expected to reliably indicate paternal care effort and male phenotypic quality. Previous research, yielding contrasting results, has considered how one trait involved in mate attraction interacts with parental care or a specific aspect of male quality. In the blenny Salaria pavo, we perform a comprehensive analysis of the interplay between overall male attractiveness and male quality, the latter in terms of fertility, condition, and parental care. In this fish, males are larger than females, exhibit two sexually dimorphic traits (head crest and anal glands), and solely care for eggs. We generated a male attractiveness index through principal component analyses of morphological traits and quantified parental effort as the total time spent in egg care.In addition, we analyzed the relationships between specific components of attractiveness and male qualities. In agreement with theory predictions, we found that male overall attractiveness is a reliable indicator of fertility, in terms of sperm number, but is unrelated to body condition and parental care effort, with males able to perform high levels of care regardless of their level of advertisement. However, the relative expression of head crest area appears positively related to sperm number but is traded-off with parental care effort. These findings underline the need, in addressing real patterns, to consider interactions between multiple aspects of male display and quality
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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