1,720,957 research outputs found
Pianificazione motoria in azioni di prensione nei cebi dai cornetti (sapajus spp.)
No full textStudi sulla pianificazione motoria e sulla selezione dell’azione manuale rivelano che ciò che si sta per compiere è influenzato da ciò che s’intende fare immediatamente dopo. In particolare, molti studi hanno dimostrato che gli umani adulti adottano inizialmente delle posture scomode della mano per raggiungere una posizione più funzionale all’azione finale da compiere (end-state comfort effect). Risultati contrastanti emergono dalle ricerche condotte sulla pianificazione motoria in primati non umani. In particolare, gli scimpanzé mostrano l’end-state comfort effect in compiti di uso di strumenti ma non in azioni in cui un oggetto deve essere afferrato semplicemente per essere portato alla bocca. Nel presente studio abbiamo valutato se i cebi dai cornetti (Sapajus spp.), scimmie neotropicali famose per la loro abilità nell’utilizzo di strumenti, mostrano l’end-state comfort effect in due compiti sperimentali differenti. Nell’Esperimento 1, dieci cebi dai cornetti dovevano afferrare un bastoncino cilindrico posizionato orizzontalmente con una delle due estremità ricoperta con crema di cereali. In questo caso, una scelta dell’azione influenzata da una pianificazione dei costi motori (cioè, allo scopo di portare alla bocca in maniera comoda l’estremità ricoperta di cibo), comportava una presa radiale, con il pollice rivolto verso l’estremità con il cibo. Nell’Esperimento 2, sette cebi dai cornetti dovevano afferrare un bastoncino cilindrico allo scopo di utilizzarlo come strumento per recuperare una ricompensa al di fuori della loro portata. Il bastoncino era collocato su un supporto che poteva essere ruotato sul piano orizzontale in differenti posizioni (-60°, -30°, 0°, 30°, 60°, 90°). Anche in questo caso, una presa radiale, cioè con il pollice rivolto verso il centro del bastoncino, permetteva di eseguire il compito in maniera più confortevole. In entrambi gli esperimenti, i cebi dai cornetti hanno adottato significativamente più spesso una presa radiale rispetto ad altri tipi di presa per eseguire il compito. Tali risultati dimostrano che i cebi dai cornetti, a differenza degli scimpanzé, sono sensibili all’end-state comfort effect in contesti differenti che non implicano necessariamente l’uso di strumenti. Ulteriori studi sulla pianificazione motoria in diversi gruppi tassonomici sono auspicabili al fine di chiarire i meccanismi cognitivi e motori alla base di tale capacità nelle varie specie. I nostri protocolli di ricerca sono conformi alla Direttiva Europea 2010/63/UE e sono stati approvati dal Ministero della Salute (licenza n. 132/2014-C)
Motor planning in different grasping tasks by capuchin monkeys (Sapajus spp.)
No full textStudies on motor planning and action selection in object use reveal that what we choose to do in the present moment depends on our next planned action. In particular, many studies have shown that adult humans initially adopt uncomfortable hand postures to accommodate later task demands (i.e., the end-state comfort effect). Recent studies on action planning in different non-human primates species have provided contrasting results. Here, we tested whether capuchin monkeys (Sapajus spp.), natural tool users, would show planning abilities in two tasks with varying complexity: (i) an object-retrieval task involving self-directed actions (Experiment 1) and (ii) a tool-using task involving actions directed toward an external target (Experiment 2). In Experiment 1, six of 10 monkeys preferentially used a radial grip (i.e., with the thumb-side oriented towards the baited end) to grasp a horizontal dowel with either the left- or right-end baited and bring it to their mouth. In Experiment 2, all six tested capuchins preferentially used a radial grip (i.e., with the thumb-side oriented towards the center of the dowel) to grasp a dowel that was positioned horizontally at different orientations and to dislodge an out-of-reach food reward. Thus, we found that the capuchins showed second-order planning abilities in both tasks, but performance differences emerged in relation to hand preference and learning across sessions. Our findings support the idea that second-order motor planning occurred in an early stage of the primate lineage. Factors affecting the ability of nonhuman primates to estimate motor costs in action selection are discussed
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
- …
