1,720,982 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Spatial navigation in geometric mazes : a computational model of rodent behavior
Get PDFNavigation is defined as the capability of planning and performing a path from the current position towards a desired location. Different types, or strategies, of navigation are used by animals depending on the task they are trying to solve. Visible goals can be approached directly, while navigation to a hidden goal usually requires a memorized representation of relative positions of the goal and surrounding landmarks. Neurophysiological and behavioral experiments on rodents suggest that different brain areas are responsible for the expression of different navigation strategies. Specifically, dorsal striatum has been related to storage and recall of stimulus-response associations underlying simple goal-approaching behaviors, whereas hippocampus is thought to store the spatial representation of the environment. Such a representation is built during an unrewarded spatial exploration and appears to be employed in cases when simple stimulus-response strategies fail. Discovery of neurons with spatially correlated activity, i.e. place cells and grid cells, in the hippocampal formation complements behavioral and lesion data suggesting its role for spatial orientation. The overall objective of this work is to study the neurophysiological mechanisms underlying rodent spatial behavior, in particular those that are responsible for the implementation of different navigational strategies. Special attention is devoted to the question of how various types of sensory cues influence goal-oriented behavior. The model of a navigating rat described in this work is based on functional and anatomical properties of brain regions involved in encoding and storage of space representation and action generation. In particular, place and grid cells are modeled by two interconnected populations of artificial neurons. Together, they form a network for spatial learning, capable of combining different types of sensory inputs to produce a distributed representation of location. Goal-directed actions can be generated in the model via two different neural pathways: the first one drives stimulus-response behavior and associates visual input directly to motor responses; the second one associates motor actions with places and hence depends on the representation of location. The visual input is represented by responses of a large number of orientation-sensitive filters to visual images generated according to the position and orientation of the simulated rat in a virtual three-dimensional world. The model was tested in a large array of tasks designed by analogy to experimental studies on animal behavior. Results of several experimental studies, behavioral as wells as neurophysiological, were reproduced. Based on these results we formulated a hypothesis about the influence that the rat's perception of surrounding environment exerts on goal-oriented behavior. This hypothesis may provide an insight into several issues in animal behavior research that were not addressed by theoretical models until now.LC
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Emploi de l’électroencéphalographie mobile pour l’étude de la perception visuo-spatiale dans des paradigmes écologiques : application au vieillissement sain et à la restauration visuelle
No full textEn constatant l'influence de la nature tridimensionnelle et multisensorielle du monde sur le fonctionnement du cerveau, ce projet s'est axé sur l'étude de la cognition humaine par le biais d'expériences écologiques, en particulier la perception visuelle et la navigation. Les outils de neuro-imagerie actuels entravent la mobilité des participants et ne reflètent donc pas toute la complexité des activités du quotidien. Pour y remédier, ce projet a développé des méthodes d'acquisition et d'interprétation de l'activité cérébrale dans des conditions de mobilité. À cette fin, de récents progrès techniques ont été mobilisés pour garantir l’extraction robuste des signaux cérébraux issus d’enregistrements d'électro-encéphalographie (EEG) pendant le mouvement. Pour enrichir l'interprétation de la dynamique corticale en exploitant pleinement la résolution temporelle accrue de l'EEG, l'approche mobile brain/body imaging a été adoptée, préconisant le couplage des données EEG avec des mesures biométriques telles que les mouvements du corps et des yeux. L'objectif principal de cette thèse était de mieux comprendre les changements dans la cognition visuo-spatiale au cours du vieillissement sain. L’orientation dans l’espace, une aptitude essentielle au quotidien, repose sur l'intégration de multiples signaux sensoriels, parmi lesquels la vision est centrale. Une forte motivation à étudier ce sujet est que le vieillissement est associé à un déclin des capacités d’orientation, ce qui affecte l'autonomie et le bien-être des personnes âgées et peut mener à l'isolement et à des troubles neurodégénératifs. En étant plus proches des conditions écologiques de la navigation, les résultats obtenus remettent en question certains points de vue établis de la littérature. Ils apportent un nouvel éclairage sur la dynamique des mécanismes neuronaux sous-tendant les aptitudes visuo-spatiales, et en particulier dans les régions sélectives aux scènes. En rapportant un contrôle déficient de l'attention, évident au niveau cortical, associé à une tendance systématique à regarder vers le bas, ils illustrent les effets néfastes du vieillissement visuel sur la navigation. En outre, ce projet s'est intéressé au potentiel de l’EEG mobile pour évaluer des thérapies de restauration visuelle au cours de tâches visuo-spatiales pertinentes pour les activités quotidiennes. Étudier les marqueurs corticaux associés à la récupération visuelle favorise une analyse objective de leur efficacité. En particulier, l'analyse EEG a mis en évidence un rythme alpha occipital, typique du traitement normal de l’information visuelle, induit par une nouvelle thérapie optogénétique chez un patient atteint de rétinite pigmentaire. Ces résultats peuvent avoir des implications socio-économiques substantielles étant donné le vieillissement de la population mondiale et l'augmentation associée de la prévalence des troubles visuels. Les fruits de cette recherche pourront se traduire en recommandations en matière d'urbanisme pour favoriser l’orientation des personnes âgées dans des environnements complexes. Ils pourront également servir à développer des thérapies de restauration visuelle plus efficaces afin d’accroître leur impact dans la vie quotidienne des patients. En conclusion, ces travaux soulignent l'importance des expériences écologiques pour comprendre la cognition et la perception humaine. En s'appuyant sur l'EEG mobile et des paradigmes innovants, ils ont contribué aux domaines de la cognition visuo-spatiale, du vieillissement sain et de la restauration visuelle. Ces résultats peuvent avoir des répercussions sur l'amélioration de l'autonomie des personnes âgées et des patients malvoyants. Cette thèse a été réalisée au sein d'un écosystème collaboratif, bénéficiant des ressources et de l'expertise de l'Institut de la Vision de Paris. La coopération avec d'autres instances de recherche a largement contribué à enrichir son approche méthodologique et à élargir le champ de ses applications.Based on the observation that the three-dimensional and multisensory nature of the world shapes the functioning of the brain, this doctoral project focused on the study of human cognition through ecological experiments, particularly in the context of visual perception and spatial navigation. Current neuroimaging tools restrict the mobility of participants and thus fail to capture the full complexity of everyday activities. In order to overcome these limitations, this project developed methods to acquire and interpret brain activity under mobile conditions. To this end, recent technological improvements were leveraged to facilitate robust extraction of brain-related signals from electro-encephalography (EEG) recordings during motion. To deepen the interpretation of cortical dynamics by fully exploiting the potential of the improved temporal resolution of EEG, the mobile brain/body imaging approach was adopted, which advocates the co-registration of neural recordings with biometric measures such as body and eye movements. The primary goal of this thesis was to better understand changes in visuo-spatial cognition during healthy aging. Spatial navigation, a ubiquitous skill in everyday life, relies on the integration of multiple sensory inputs, among which vision plays a central role. A major motivation for research on this topic is that aging is associated with a decline in navigational abilities, which affects the autonomy and well-being of older adults and may lead to isolation and neurodegenerative disorders such as Alzheimer's disease. By adopting an approach that considers more ecological aspects of spatial navigation, the results of this work challenge some established views in the literature on visuo-spatial cognition. They provide novel insights into the dynamic neural mechanisms underlying spatial behavior, and in particular into the scene-selective regions whose activity was modulated by expectations generated by natural environments. By illustrating how a downward gaze bias may interact with an impaired control of attention evident at the cortical level, they shed light on the detrimental effects of visual aging on navigation. Furthermore, this project addressed the potential of mobile neuroimaging tools in the evaluation of visual restoration therapies for retinal diseases while patients performed visuo-spatial tasks relevant to daily activities. The study of neural markers associated with visual recovery promotes an objective assessment of the effectiveness of therapeutic interventions. In particular, EEG frequency analysis helped unravel an occipital alpha rhythm typical of natural visual processing induced by a novel optogenetic therapy in a late-stage retinitis pigmentosa patient. These findings may have substantial socio-economic implications given the aging of the global population and the associated increase in the prevalence of visual disorders. The outcomes of this research may be translated into urban planning recommendations to help older adults navigate complex, unfamiliar environments. They can also contribute to the development of more effective visual restoration therapies, ultimately making a significant difference in the daily lives of low vision patients. In conclusion, this doctoral thesis emphasized the importance of ecological experiments for understanding human cognition and perception. By using mobile EEG and innovative paradigms, it contributed to the fields of visuo-spatial cognition, healthy aging, and visual restoration therapies. Its findings may have broader implications for improving the autonomy of older adults and visually impaired patients. This thesis was carried out within a collaborative ecosystem, benefiting from the resources and expertise of the Paris Vision Institute. Cooperation with other research institutions, both national and international, contributed greatly to enrich its methodological approach and broaden the scope of its applications
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
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