1,721,242 research outputs found

    Seasonality and behavioural energy in Microcebus berthae and M. murinus

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    To survive and reproduce successfully in highly seasonal regions, animals must balance their energy budgets during lean seasons. We conducted a comparative study of two sympatric mouse lemur species to identify species-specific energy saving strategies for coping with seasonality and evaluated their consequences for female fitness. Since August 2002 we captured, marked and recaptured individuals of coexisting populations of Microcebus berthae and M. murinus in the Kirindy Forest and recorded activity by direct observations of radio-collared females. The species differed in their seasonal activity patterns: female M. berthae maintained high activity levels throughout the year, whereas female M. murinus all but ceased activity during the cold dry season. In M. berthae, low survival restricted female reproductive potential. Consequently, females maximized the condition in which they entered the reproductive season. In contrast, M. murinus females maximized survival but entered the reproductive season in poor condition. Thus, mouse lemur species subjected to the same environmental conditions show different species-specific energetic strategies to cope with pronounced seasonality

    Noises in the Dark: Vocal Communication in Lepilemur ruficaudatus and Other Nocturnal Pair-Living Primates

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    Although the number of pair-living species is higher in nocturnal than in diurnal primates, less is known about the communicative function of their vocalizations. One striking feature of vocal communication in diurnal pair-living primates is that partners exchange vocalizations in coordinated duets. Several functions have been attributed to duets, including mate attraction, advertizing and strengthening the pair bond, and territorial defense. To assess whether these functions can also be attributed to vocalizations of pair-living nocturnal primates, we studied the communicative function of vocalizations of red-tailed sportive lemurs (Lepilemur ruficaudatus). Social interactions between partners were equally often accompanied by vocal exchanges or not. Half of these vocal interactions included mutual but not coordinated exchanges of vocalizations between partners. In addition, playback experiments with vocalizations of the respective partner did not elicit vocal responses. Thus, exchanges of vocalizations might function to regulate spacing and interactions within pairs rather than to advertize or strengthen pair bonds. Since Lepilemur ruficaudatus interacted more often vocally with partners than with neighbors, and also vocalized when alone, we conclude that calling serves to signal an animal’s presence in its territory and to regulate spacing among conspecifics. Because vocalizations seem to serve in territorial defense in most nocturnal pair-living primates, cohesiveness between partners may have been the initial driving force behind the evolution of duets

    Seasonality and Behavioral Energy Strategies in Microcebus berthae and M. murinus

    No full text
    To survive and reproduce successfully in highly seasonal regions, ­animals must balance their energy budgets during lean seasons. We conducted a comparative study of two sympatric mouse lemur species to identify species-specific energy saving strategies for coping with seasonality and evaluated their consequences for female fitness. Since August 2002 we captured, marked and recaptured individuals of coexisting populations of Microcebus berthae and M. murinus in Kirindy Forest and recorded activity by direct observations of radio-collared females. The species differed in their seasonal activity patterns: female M. berthae maintained high activity levels throughout the year, whereas female M. murinus largely ceased activity during the cold dry season. In M. berthae, low survival restricted female reproductive potential. Consequently, females maximized the condition in which they entered the reproductive season. In contrast, M. murinus females maximized survival but entered the reproductive season in poor condition. Thus, mouse lemur species subjected to the same environmental conditions show different species-specific behavioral energy strategies to cope with pronounced seasonality

    Isochrony in titi monkeys duets: social context as a proximate cause of duets' rhythm and regularity

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    Music and rhythm are typical features of all human cultures, but their biological origins remain unclear. Recent investigations suggest that rhythmic features of human music are shared with animal vocalizations. Moreover, arousal is known to influence the structure of both human speech and animal sounds. We investigated coppery titi monkeys' (Plecturocebus cupreus) duet rhythms to assess adherence to rhythmic patterns previously observed only in Old World primates and to deepen our understanding of the proximate causes of non-human primate song rhythm. Titis' songs were remarkably isochronous, but their tempo depended on the social context: songs sung during territorial confrontations have a slower pace than during early morning singing. Songs had a faster tempo and were less regular when infants were present, suggesting a speed-accuracy trade-off. Finally, we found that pair-mates perform isochronous songs with the same precision, suggesting that isochrony plays a role in boosting pair coordination, as it does in other singing primates. Our investigation sheds light on the ultimate and proximate causes of primates' isochronous rhythm, to our knowledge confirming its presence for the first time in a New World monkey and highlighting the role of social factors in shaping its timing and regularity in the short term

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Seasonality and behavioural energy in Microcebus berthae and M. murinus

    No full text
    To survive and reproduce successfully in highly seasonal regions, animals must balance their energy budgets during lean seasons. We conducted a comparative study of two sympatric mouse lemur species to identify species-specific energy saving strategies for coping with seasonality and evaluated their consequences for female fitness. Since August 2002 we captured, marked and recaptured individuals of coexisting populations of Microcebus berthae and M. murinus in the Kirindy Forest and recorded activity by direct observations of radio-collared females. The species differed in their seasonal activity patterns: female M. berthae maintained high activity levels throughout the year, whereas female M. murinus all but ceased activity during the cold dry season. In M. berthae, low survival restricted female reproductive potential. Consequently, females maximized the condition in which they entered the reproductive season. In contrast, M. murinus females maximized survival but entered the reproductive season in poor condition. Thus, mouse lemur species subjected to the same environmental conditions show different species-specific energetic strategies to cope with pronounced seasonality

    Fiorenza Gamba, Marco Nardone, Toni Ricciardi e Sandro Cattacin (a cura di), Covid-19. La prospettiva delle scienze sociali, KrillBooks, Lecce, 2020

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    Covid-19, La prospettiva delle scienze sociali – testo edito presso la casa editrice Krill Books – è il titolo della raccolta di saggi a cura di Sandro Cattacin, Fiorenza Gamba, Marco Nardone e Toni Ricciardi, che include ventisette lavori di sociologi e ricercatori svizzeri che, durante la prima fase della pandemia 2020, hanno elaborato riflessioni, con diversa tipologia di approccio, circa i più diversificati temi. Gli spazi, i cambiamenti delle modalità di consumo, la famiglia, i giovani e l’uso delle tecnologie sono tra gli argomenti che vengono problematizzati in relazione all’impatto che il Covid-19 ha avuto, e avrà presumibilmente, sull’intera popolazione mondiale

    Variations on the Author

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    “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

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    We 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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