1,720,984 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
Prey Foraging Behavior After Predator Introduction Is Driven by Resource Knowledge and Exploratory Tendency
No full textInternational audiencePredator reintroductions are often used as a means of restoring the ecosystem services that these species can provide. The ecosystem consequences of predator reintroduction depend on how prey species respond. Yet, to date, we lack a general framework for predicting these responses. To address this knowledge gap, we modeled the impacts of predator reintroduction on foragers as a function of predator characteristics (habitat domain; i.e., area threatened) and prey characteristics (knowledge of alternative habitat and exploratory tendency). Foraging prey had the capacity to both remember and return to good habitat and to remember and avoid predators. In general, we found that forager search time increased and consumption decreased after predator introduction. However, predator habitat domain played a key role in determining how much prey habitat use changed following reintroduction, and the forager's knowledge of alternative habitats and exploratory inclinations affected what types of habitat shifts occurred. Namely, habitat shifts and consumption sacrifices by prey were extreme in some cases, particularly when they were pushed far from their starting locations by broad-domain predators, whereas informed foragers spent less time searching and displayed smaller reductions to consumption than their naïve counterparts following predator exposure. More exploratory foragers exhibited larger habitat shifts, thereby sacrificing consumption but reducing encounters by relocating to refugia, whereas less exploratory foragers managed risk in place and consequently suffered increased encounters while consuming more resources. By implication, reintroductions of predators with broad habitat domains are especially likely to impose foraging and movements costs on prey, but forager spatial memory state can mitigate these effects, as informed foragers can better access alternate habitat and avoid predators with smaller reductions in consumption
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
Incorporating cognition into models of animal movement and predator--prey interaction
No full textThesis (Ph.D.)--University of Washington, 2014Incorporating cognition, i.e., learning and memory, into models of animal movement is increasingly important as models seek to answer more complex questions where individuals' prior experiences shape their choices. Two example are foraging behavior and predator avoidance. While models of predator--prey dynamics exist, the impact of cognition on movement and predator--prey interactions is largely unexplored. This dissertation presents a flexible, continuous-space, and continuous-time model incorporating an animal using memory to navigate a landscape of heterogeneous resources. The forager balances attraction to food with avoidance of predators in making movement decisions. Two streams make up the resource memory: a repulsive stream that drives the forager away from recently visited areas and an attractive stream that draws the forager back to high quality areas. The predator memory is solely repulsive. The model is used to examine questions related to the advantage of added cognitive complexity for animals in the context of foraging and balancing the food--safety trade-off with predators. First, foraging without predators is considered and several movement processes are compared: a simple correlated random walk; kinesis, a correlated random walk that switches between searching and feeding behaviors; and memory-informed movement. The model is used to examine for which landscapes the added cognitive complexity of maintaining memory is advantageous and to analyze the behavioral differences between using and not using memory. In general, a landscape where there is a larger payoff for finding a resource patch, whether in size, value, or difficulty in locating, favors memory. While memory-informed search can be difficult to differentiate from other sensory-driven search behavior, disproportionate spatial use of higher value areas, higher consumption rates, and consumption variability all point to memory influencing the movement direction. Next, predators are introduced that vary in their temporal predictability and in their correlation with the prey's resources. Memory outperforms simpler movement processes most for patchy landscapes and more predictable predators, which may be more easily avoided once learned. In these cases, memory aids foragers in managing the food--safety trade-off, as particular parameterizations of predator memory reduce predator encounters while maintaining consumption. Non-consumptive effects are highest in landscapes of concentrated, patchy resources and especially when predators are highly correlated with the forager's resources. These non-consumptive effects are also seen with the shift away from the best quality habitat compared to foraging in a predator-free environment. Finally, learning is examined in more detail with naive foragers introduced to new landscapes as well as predators introduced partway through the simulation. Most non-extreme learning rates provide the forager with sufficient information. In general, foragers that are low to moderately exploratory in new habitats are successful, though performance is habitat-dependent. In the case of introduced predators, predators vary in the area threatened and foragers vary in their memory state. While area threatened plays a key role in determining how much habitat use changes, the forager's knowledge of alternative habitats and exploratory inclinations affects what types of shifts occur
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
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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