1,720,957 research outputs found
Design and evaluation of a series of experimental procedures to investigate cognition in fish at early developmental stages and in adulthood
No full textThis thesis had two main objectives. The first was to explore cognitive development in zebrafish larvae using reliable and rapid testing methods. The aim was to develop/adjust methodologies that are accessible and easily replicable across various scientific laboratories and disciplines, responding to the increasing demand for interdisciplinary research on zebrafish cognition. The initial part of the research examined discriminative and associative learning, along with numerical cognition, providing insights into the cognitive development of zebrafish larvae. The second part investigated working memory in guppies (Poecilia reticulata) by utilizing adaptations of the matching-to-sample (MTS) paradigm in both its simultaneous (SMTS) and delayed (DMTS) forms, with the intention of expanding experimental frameworks for studying numerical cognition in this species.
The findings revealed that the cognitive tests applied to zebrafish larvae could be effectively transferred to fields beyond comparative psychology, although some limitations were noted. Group housing during associative learning delayed the assessment of individual learning, and the rapid neural development of zebrafish larvae necessitated shorter experimental protocols. Moreover, spontaneous preferences were observed, varying significantly with the subjects’ age, highlighting a key factor influencing cognitive performance in zebrafish. In guppies, while the SMTS task revealed consistent learning, the DMTS task presented challenges due to procedural limitations.
In summary, the thesis highlights the potential of these cognitive tests for broader scientific application, offering a valuable foundation for interdisciplinary research on animal cognition. While the methodologies show promise, the need for refinement remains critical for optimizing their utility across different species and research contexts
Visual Discrimination Task in Guppies Using a Simultaneous Matching-to-Sample Procedure
Full text linkCognitive abilities in fish have been widely demonstrated using experimental protocols commonly adopted with mammals and birds. Only a few studies have tested fish in the simultaneous match-to-sample task (sMTS), and mixed evidence regarding their capacity to solve the task has been reported. Here we investigated whether guppies (Poecilia reticulata) could discriminate stimuli based on their sameness in the sMTS where fish presented with a sample stimulus had to choose which of two simultaneously presented comparison stimuli matched it. We also assessed how performance was influenced by the training set size and stimulus type. Three experiments were conducted using three different sets of stimuli: two colors (red and green), two geometric shapes (circle vs. triangle); and multiple shapes. Performance was analyzed using binomial tests, t-tests, and generalized linear mixed models. The results showed that guppies learned to select the rewarding stimulus in a relatively limited number of trials and were successful in all experiments. Although no effect of the training set size was observed, guppies were more accurate when multiple stimuli were used. These findings support previous evidence suggesting that multiple training stimuli may improve generalization abilities and set the basis for future studies that adopt a delayed version of the task
Learning and visual discrimination in newly hatched zebrafish
Full text linkWith the exception of humans, early cognitive development has been thoroughly investigated only in precocial species, well developed at birth and with a broad behavioral and cognitive repertoire. We investigated another highly altricial species, the zebrafish, Danio rerio, whose embryonic development is very rapid (< 72 h). The hatchlings’ nervous system is poorly developed, and their cognitive capacities are largely unknown. Larvae trained at 8 days post fertilization rapidly learned to associate a visual pattern with a food reward, showing significant performance at 10 days post fertilization. We exploited this ability to study hatchlings’ discrimination learning capacities. Larvae rapidly and accurately learned color and shape discriminations. They also discriminated a figure from its mirror image and from its 90°-rotated version, although with lower performance. Our study revealed impressive similarities in learning and visual discrimination capacities between newborn and adult zebrafish, despite their enormous differences in brain size and degree of development
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
- …
