1,721,018 research outputs found
A Socio‐Spatial Combined Approach Confirms a Highly Compartmentalised Structure in Honeybees
No full textIntraspecific variation in invertebrate cognition: a review
No full textA well-established field of research in vertebrates focuses on the variability of cognitive abilities within species. From mammals to fish, numerous studies have revealed remarkable differences in the cognitive phenotype among individuals, particularly in terms of sex or personality. However, many aspects of the mechanisms, genetics, and selective pressures that underlie individual cognitive variation remain unclear. Surprisingly, intraspecific variability in cognition has received much less attention in invertebrates, despite the increasing evidence of remarkable cognitive abilities in this group and the insights that could be gained from examining simultaneously two distinct taxa, namely vertebrates and invertebrates. In this review, we provide evidence that certain invertebrate species exhibit all the key features of cognitive variation observed in vertebrates, including differences related to sex and personality. In many cases, invertebrate studies have provided insights into the genetic basis, evolvability and response to selection of cognitive variability. Moreover, we highlight evidence for caste differences in eusocial insects, which are linked to task specialisation within the colony. This makes insect eusociality a valuable system for understanding how selection influences cognitive variation. We propose that cognitive variation in invertebrates may be more widespread than currently thought, and that selection may operate in a similar manner on two distantly related cognitive systems (vertebrates and invertebrates). Finally, we suggest that invertebrates hold the potential to serve both as alternative and complementary models to vertebrates, contributing to a deeper understanding of cognitive evolution
Evidence for antiseptic behaviour towards sick adult bees in honey bee colonies. Journal of Insect Physiology
Full text linkSocial life is generally associated with an increased risk of disease transmission, but at the same time it allows behavioural defence at both the individual and collective level. Bees infected with deformed-wing virus were introduced into observation hives; through behavioural observations and chemical analysis of cuticular hydrocarbons from healthy and infected bees, we offer the first evidence that honeybee colonies can detect and remove infected adult bees, probably by recognising the cuticular hydrocarbon profiles of sick individuals. We also found that health-compromised colonies were less efficient at defending themselves against infected bees, thus facing an ever increasing risk of epidemics. This work reveals a new antiseptic behaviour that can only be interpreted as an adaptation at colony level and one which should be considered an element of the social immunity system of the beehive, re-enforcing the view of a colony as an integrated organism
Alterazione dell’ “acceptance threshold” in api bottinatrici sperimentalmente infettate con il virus delle ali deformi (DWV)
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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
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