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Behavioral Variation Drives Mixed-species Grouping in an Asexual-sexual Fish Species Complex
No full textPredation threat is a major driver of behavior in many prey species. Animals can recognize their relative risk of predation based on cues in the environment, including visual and/or chemical cues released by a predator or from its prey. Predator naïve fish often exhibit appropriate anti-predator responses when faced with these chemical cues. This suggests that the ability to recognize and appropriately respond to chemical cues is genetically conserved. When threat of predation is high, prey often respond by altering their behavior to reduce their probability of detection and/or capture. But not all species within a community exhibit the same type of behavioral responses. This suggests that species that form mixed-species groups may provide different types of social information when responding to risky conditions. The ability to collect and use social information produced by the actions of conspecifics and heterospecifics may be a critical driver to the formation and maintenance of mixed-species grouping. To explain why mixed-species groups are so common in nature, researchers often credit improved foraging and anti-predator behaviors as the main driver. But, I argue that improved social information produced by behavioral variation at the within- and between-species axes may mechanistically explain these improved group-level behaviors. Broadly, my dissertation evaluates whether two species of fish that naturally form mixed-species shoals in the wild exhibit similar or distinct behavioral responses to varying levels of ecological risk at the individual-level and at the shoal level using automated tracking pipelines and computer vision. Its generally assumed that small prey fish retain an innate ability to respond to chemical cues from a predator and damaged conspecifics. This is important to verify, especially in fish that have been reared in lab conditions without exposure to predation risk for multiple generations. Here, I test how a clonal fish, the Amazon molly (Poecilia formosa), behaviorally responds to predation cues. I measured aggressive and social behaviors both under ‘risk’, where chemical cues from predatory fish and injured conspecifics were present, and control contexts (no risk cues present). I predicted that mollies would exhibit reduced aggression towards a simulated intruder and increased sociability under risk contexts as aggression might increase their visibility to a predator and shoaling should decrease their chance of capture through the dilution effect. As predicted, I found that Amazon mollies spent more time with a conspecific when risk cues were present, however they did not reduce their aggression. This highlights the general result of the ‘safety in numbers’ behavioral response that many small shoaling species exhibit, including these clonal fish, which suggests that mollies may view this response as a more effective anti-predator response compared to limiting their detectability by reducing aggressive conspecific interactions. In my second chapter, I explore whether individual Amazon and Atlantic mollies (which naturally form mixed-species shoals in the wild) exhibit distinct or similar behavioral responses under varying levels of ecologically relevant risk. Animals experience varying levels of risk throughout their lives, and how individuals trade off between risk and reward has critical ecological and evolutionary consequences. However, behavioral responses to risk can differ not only between species within a community, but also among individuals of the same species. Whether species-level differences in risk sensitivity promote distinct or similar responses to variable threat can help explain why certain species coexist in a community. In this chapter, I examine the individual behavioral responses of two closely related fish species: the unisexual Amazon (Poecilia formosa) and Atlantic molly (Poecilia mexicana) which form a unique asexual-sexual species complex and naturally co-occur in the wild. I repeatedly measure individual fish in repeated trials of an open-space novel foraging task while in the presence of low, medium, and high environmental risk. For each individual, I leverage high-resolution automated tracking to measure fine-scale behavioral differences, including swimming velocity, cover use, sociability, predator inspection behaviors and overall foraging success. I find that for some behaviors, whether Amazon and Atlantic mollies exhibit distinct responses depends on the level of environmental threat. In general, Amazon mollies are more active and exploratory, can find foraging opportunities more quickly, but investigate conspecifics and predators less often than Atlantics. These species also align in behavior, expressing similar amounts of cover use and inspection of novel stimuli under different risk contexts. Overall, these results suggest that these species may have different tolerances to risk. That the Amazon and Atlantic mollies exhibit both similar and distinct responses to risk could enable the asexual and gynogenetic Amazon to persist in nature by exploiting complementary ecological niches which may facilitate their continued coexistence in the wild. In my final chapter, I assess whether the behavioral responses exhibited in asocial contexts extend to social contexts. More specifically, I evaluate whether mixed-species shoals outperform single-species shoals regarding foraging performance, and if increased behavioral variation may contribute to this pattern. Mixed-species groups exhibit behavioral variation in two different axes: within- and between species. This increased behavioral variation may enhance the availability of social information to all group members about resource abundance or potential risks in the environment. That species differ in behavior suggests that social information regarding foraging opportunities may travel faster in mixed-species groups compared to single-species groups. Here, I use the Amazon (Poecilia formosa) and Atlantic (Poecilia mexicana) mollies, who naturally co-occur and form mixed-species shoals in the wild, to investigate to what extent species-level differences in risk-taking behavior influences group foraging performance for mixed-species shoals. Do mixed-species shoals outperform single-species shoals? To test this, I assay single- and mixed-species group compositions in a novel open-space foraging task under different levels of threat. I find that single-species Amazon shoals take more risks than Atlantic shoals, while mixed-species shoals often behave differently from both, but not always. In general, mixed-species shoals show higher movement speeds, more time inspecting a threat, and increased foraging performance. However, these improved feeding rates are not experienced equally by all group members. In trials involving mixed-species shoals, Amazon mollies tend to emerge as leaders and drive improved group foraging performance, often arriving at the patch faster than Atlantic mollies. These results suggest that both species mutually benefit by forming mixed-species shoals: the gynogenetic Amazon gains reproductive benefits by parasitizing sperm, while Atlantics gain valuable social information generated via the actions of risk-prone Amazon mollies, while both continue to retain ‘safety in numbers’ and reduced predation risk. Altogether, the within- and between-species behavioral variation may give mixed-species shoals an edge over single-species compositions. 
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Data from: The making of winners (and losers): how early dominance interactions determine adult social structure in a clonal fish
Full text linkAcross a wide range of animal taxa, winners of previous fights are more likely to keep winning future contests, just as losers are more likely to keep losing. At present, such winner and loser effects are considered to be fairly transient. However, repeated experiences with winning and/or losing might increase the persistence of these effects generating long-lasting consequences for social structure. To test this, we exposed genetically identical individuals of a clonal fish, the Amazon molly (Poecilia formosa), to repeated winning and/or losing dominance interactions during the first two months of their life. We subsequently investigated whether these experiences affected the fish’s ability to achieve dominance in a hierarchy five months later during adulthood. Individuals that had only winning interactions early in life consistently ranked at the top of the hierarchy. Interestingly, individuals with only losing experience tended to achieve the middle dominance rank, whereas individuals with both winning and losing experiences generally ended up at the bottom of the hierarchy. In addition to demonstrating that early social interactions can have dramatic and long-lasting consequences for adult social behaviour and social structure, our work also shows that higher cumulative winning experience early in life can counter-intuitively give rise to lower social rank later in life
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