1,721,035 research outputs found
Geckos differentiate self from other using both skin and faecal chemicals: evidence towards self-recognition?
Full text linkSelf-recognition is the ability to recognise stimuli originating from oneself. Humans and some non-human animals show evidence of true visual self-recognition in the mirror test. They use their reflection to inspect themselves and to remove a mark that is only visible in the mirror. Not all animals, however, rely primarily on vision. In lizards, chemical cues are crucial in social interactions, and therefore, lizards would benefit from a chemical self-other distinction. Here, we test the tokay gecko (Gekko gecko), a social species, on their ability to discriminate their own skin and faecal chemicals from those of same-sex, unfamiliar conspecifics. We predicted that individuals would show more self-directed behaviour when confronted with the chemicals from unfamiliar individuals within their home enclosure as a sign of the need for increased comparison. Geckos showed higher self-directed responses towards chemicals from unfamiliar individuals compared to self-produced chemicals and a water control. Furthermore, scat and skin chemicals (regardless of origin) elicited similar but stronger responses than peppermint oil pointing towards a possible social function of scat piles. Although further tests and controls are needed, our study provides evidence towards chemical self-recognition and for a social function of scat piling in tokay geckos
Fear of the new? Geckos hesitate to attack novel prey, feed near objects and enter a novel space.
Full text linkNeophobia, the fear of novelty, is an ecologically important response which enables animals to avoid potentially harmful situations. Neophobia is a cognitive process by which individuals distinguish novelty from familiarity. In this study, we aimed to quantify this cognitive process in captive tokay geckos (Gekko gecko) across three contexts: when encountering novel prey, foraging near novel objects and entering a novel space. We also investigated individual consistency across trials using different novel stimuli, and correlation of individual responses across the three contexts. We found that geckos hesitate to attack novel prey and prey close to objects (familiar and novel). Geckos hesitated the most when entering novel space. Repeatability of behaviour within and across contexts was low (R = 0.101-0.190) indicating that neophobia might not be expressed similarly across contexts. The strength of a neophobic response can indicate how anxious or curious an individual is. This test has great potential to help answer questions about how captivity, enrichment, rearing environment and cognition affect fear responses in different contexts in lizards. By studying reptiles, we can better understand the universality of what is known about the causes leading to difference in neophobia across individuals and species
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
Figure 4 in Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes
No full textFigure 4 Dorsal and ventral photos of glassfrogs in life. (A, B) Male of Hyalinobatrachium vireovittatum, Costa Rica. (C, D) Male of H. talamancae, Costa Rica. (E, F) Male of H. valerioi, Costa Rica. Photos by Jaime Culebras (A, C, D, E, F) and Josué Alberto Vargas (B). Full-size DOI: 10.7717/peerj.13109/fig-4Published as part of Guayasamin, Juan M., Brunner, Rebecca M., Valencia-Aguilar, Anyelet, Franco-Mena, Daniela, Ringler, Eva, Medina Armijos, Anderson, Morochz, Carlos, Bustamante, Lucas, Maynard, Ross J. & Culebras, Jaime, 2022, Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes, pp. 1-34 in PeerJ 10 on page 12, DOI: 10.7717/peerj.13109, http://zenodo.org/record/637734
Figure 11 in Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes
No full textFigure 11 Habitat of Hyalinobatrachium nouns sp. nov. (A) Tributary of the Manduriacu River, Río Manduriacu Reserve, Imbabura Province, Ecuador. (B) Tributary of the Manduriacu River, Río Manduriacu Reserve, Imbabura Province, Ecuador. (C) Río Manduriacu Reserve, Imbabura Province, Ecuador. (D) Habitat loss in the vicinity of Los Cedros Reserve, Imbabura Province, Ecuador. Photos by Jaime Culebras. Full-size DOI: 10.7717/peerj.13109/fig-11Published as part of Guayasamin, Juan M., Brunner, Rebecca M., Valencia-Aguilar, Anyelet, Franco-Mena, Daniela, Ringler, Eva, Medina Armijos, Anderson, Morochz, Carlos, Bustamante, Lucas, Maynard, Ross J. & Culebras, Jaime, 2022, Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes, pp. 1-34 in PeerJ 10 on page 24, DOI: 10.7717/peerj.13109, http://zenodo.org/record/637734
Figure 5 in Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes
No full textFigure 5 Dorsal patterns of glassfrogs in life. (A) Hyalinobatrachium mashpi sp. nov., CJ11642 (holotype). (B) H. nouns sp. nov., ZSFQ0537. (C) H. aureoguttatum, SC 435. (D) H. talamancae, Costa Rica. (E) H. vireovittatum, Costa Rica. (F) H. valerioi, Costa Rica.Photos by Jaime Culebras (A, D, E, F), Jose Vieira (B) and Luis Coloma (C). Full-size DOI: 10.7717/peerj.13109/fig-5Published as part of Guayasamin, Juan M., Brunner, Rebecca M., Valencia-Aguilar, Anyelet, Franco-Mena, Daniela, Ringler, Eva, Medina Armijos, Anderson, Morochz, Carlos, Bustamante, Lucas, Maynard, Ross J. & Culebras, Jaime, 2022, Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes, pp. 1-34 in PeerJ 10 on page 13, DOI: 10.7717/peerj.13109, http://zenodo.org/record/637734
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