1,721,010 research outputs found
Scent-Marking Behaviour in a Pack of Free-Ranging Domestic Dogs
No full textMost mammals scent-mark, and a variety of hypotheses have been put
forward to explain this behaviour. Most of our knowledge about scent
marking in domestic dogs comes from studies carried out on laboratory or
companion dogs, while few studies have been carried out on free-ranging
dogs. Here, we explored the functional significance of different scentmarking
behavioural patterns in a pack of free-ranging domestic dogs by
testing two non-exclusive hypotheses: the indirect territorial defence
and the dominance/threat hypotheses. Through direct observation, we
recorded the locations of dog scent marks (urination, defecation and
ground scratching) and information regarding the identity and posture of
the marking animal. We found evidence that markings are used by dogs
to form a ‘property line’ and to threaten rivals during agonistic conflicts.
Both males and females utilized scent marking to assert dominance and
probably to relocate food or maintain possession over it. Raised-leg urination
and ground scratching probably play a role in olfactory and visual
communication in both males and females. Urinations released by
females, especially through flexed-leg posture, may also convey information
about their reproductive state. Finally, our observations suggest that
defecation does not play an essential role in olfactory communication
among free-ranging dogs and that standing and squat postures are associated
with normal excretion. Our results suggest that many of the proposed
functions of marking behaviours are not mutually exclusive, and all
should be explored through detailed field and laboratory studies
L’histoire et la trame: une experience de lecture collective avec des adolescents hospitalisè.
No full textPattern of individual participation and cheating in conflicts between groups of free-ranging dogs
No full textCooperative intergroup aggression provides an example of a costly cooperative behaviour whose benefits
spill over to noncooperative animals as well. Consequently, investigating factors that promote individual
participation in intergroup contests should prove useful for understanding how cooperation may persist
in animal societies despite cheating. Here, we examined variables affecting individual participation in
naturally occurring conflicts between groups of free-ranging dogs, Canis lupus familiaris. The overall
proportion of cooperating group members decreased significantly with an increasing number of group
members present. In one pack, the individual probability of active participation decreased significantly
when this pack had a numerical advantage over opponents. Dogs belonging to the smallest pack tended
to be more cooperative than those belonging to larger groups. Social prestige (measured as the number
of submissions received during greeting) did not appear to be a consequence of cooperative behaviour.
Individual participation increased with an increasing number of affiliative partners. Young and highranking
dogs tended to cooperate more when their group was outnumbered by opponents but did
not stay at the front of the pack during conflicts. These results emphasize the greater opportunity for
cheating in larger groups and the complexity of dogs’ behaviour. Cooperation appears to be conditional
on both the ‘adversity of the environment’ (as measured by relative group size) and the identity/
behaviour of companions
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
Effect of affiliative and agonistic relationships on leadership behaviour in free-ranging dogs
No full textConsensus decisions about the nature and timing of group activities allow animals to maintain group
cohesiveness, but also entail costs because individuals often differ with respect to their optimal activity
budgets. Two mechanisms whereby animals reach a consensus include ‘consistent leadership’, in which
a single dominant individual makes the decision, and ‘variable leadership’ in which several group
members contribute to the decision outcome. Sharing of consensus decisions is expected to reduce
consensus costs to most group members. Both patterns are thought to emerge from the complexity of
social relationships of group members. We investigated the distribution of leadership during group
departures in two packs of free-ranging dogs, Canis lupus familiaris, and tested how its distribution
between individuals was affected by dominance rank-related affiliative and agonistic relationships.
Although leadership was not entirely concentrated on a single group member, both packs had a limited
number of habitual leaders. In the largest pack, the pattern of leadership changed from ‘variable’ to
nearly ‘consistent’ after its size had shrunk. Habitual leaders were usually old and high-ranking individuals.
However, high-ranking dogs that received affiliative submissions in greeting ceremonies were
more likely to lead than dominant dogs receiving submissions only in agonistic contexts. During resting
times, habitual followers associated more closely with habitual leaders than with other followers. These
results suggest that in social species collective movements may arise from the effort of subordinates to
maintain close proximity with specific valuable social partners
{1 0 4} cleavage rhombohedron of calcite: Theoretical equilibrium properties
No full textThe character of the most important crystallographic forms of calcite crystal is quantitatively reviewed according to the Hartman and Perdok theory. Specific surface and edge energies of the cleavage {1 0 4} rhombohedron are calculated in the crystal-vacuum system by means of a semi-empirical potential function and following Stranski's definition of the total surface energy of a finite crystal. A comparison is made between the calculated value and the experimental quantities entering the Dupre formula (specific crystal-solution interface energy, specific vapour-solution surface energy): the crystal-vacuum specific surface energy is proved to be quite reasonable, and for the first time, the specific crystal-solution adhesion energy for the {1 0 4} form is estimated
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