2,297 research outputs found

    Chimpanzees (Pan troglodytes) develop a successful communicative strategy to collaborate

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    Successful collaboration often relies on individuals’ capacity to communicate with each other. Despite extensive research on chimpanzee communication, there is little evidence that chimpanzees are capable, without extensive human training, of regulating collaborative activities via communication. This study investigated whether pairs of chimpanzees were capable of communicating to ensure coordination during collaborative problem-solving. The chimpanzee pairs needed two tools to extract fruits from an apparatus. The communicator in each pair could see the location of the tools (hidden in one of two boxes), whereas only the recipient could open the boxes. The subjects were first successfully tested for their capacity to understand the pointing gestures of a human who indicated the location of the tools. In a subsequent conspecifics test, the communicator increasingly communicated the tools’ location, by approaching the baited box and giving the key needed to open it to the recipients. The recipient used these signals and obtained the tools, transferring one of the tools to the communicator so that the pair could collaborate in obtaining the fruits. The study suggests that chimpanzees have the necessary socio-cognitive skills to naturally develop a simple communicative strategy to ensure coordination in a collaborative task

    How chimpanzees (Pan troglodytes) share the spoils with collaborators and bystanders

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    The study was funded by the Max Planck Society. S. Duguid wrote the manuscript supported by a grant awarded to A. P. Melis from the Templeton World Charity Foundation (TWCF0264).Chimpanzees hunt cooperatively in the wild, but the factors influencing food sharing after the hunt are not well understood. In an experimental study, groups of three captive chimpanzees obtained a monopolizable food resource, either via two individuals cooperating (with the third as bystander) or via one individual acting alone alongside two bystanders. The individual that obtained the resource first retained most of the food but the other two individuals attempted to obtain food from the "captor" by begging. We found the main predictor of the overall amount of food obtained by bystanders was proximity to the food at the moment it was obtained by the captor. Whether or not an individual had cooperated to obtain the food had no effect. Interestingly, however, cooperators begged more from captors than did bystanders, suggesting that they were more motivated or had a greater expectation to obtain food. These results suggest that while chimpanzee captors in cooperative hunting may not reward cooperative participation directly, cooperators may influence sharing behavior through increased begging.Publisher PDFPeer reviewe

    DILATION TREATMENT OF BENIGN STRICTURED OF COLOCOLONIC ANASTOMOSES

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    SCOPO DI QUESTO ARTICOLO E' DI METTERE IN LUCE LA COMPLIANCE, I BENEFICI ED IL MIGLIORAMENTO DELLA QUALITA' DELLA VITA, NEI SOGGETTI AFFETTI DA STENOSI BENIGNA POST-ANASTOMOTICA COLO-COLICA E COLO-RETTALE E TRATTATI CON DILATAZIONE ENDOSCOPICA DEL TRATTO STENOTICO. LA DILATAZION PER VIA ENDOSCOPICA RISULTA ESSERE SICURA E DI SEMPLICE ESECUZIONE E PERMETTE DI OTTENERE RISULTATI SODDISFACENTI ANCHE PER PERIODI PROLUNGATI. I CRITERI STANDARD PER UNA EFFICACE DILATAZIONE VARIANO TRA 1 10 E 13 MM

    Application of a CFD validated model to plan fan heater position within flour mills during a heat treatment for insect pest control

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    The development of environmentally-friendly methods as alternatives to chemical fumigation for controlling insect pests has attracted public attention. Among these methods, heat treatment is based on the use of fan heaters that are positioned by operators who typically establish their number and position within buildings to be treated. The aim of this research was to improve heat treatment effectiveness by applying a validated computational fluid dynamics (CFD) model for planning fan heater positions within the building environment. Based on a CFD model, which was built and validated according to experimental data acquired during heat treatment of a flour mill, simulations were carried out by changing the position and/or rotation of fan heaters with the aim of enhancing temperature distribution inside the building. The results showed that in some simulations the percentage of internal wall surfaces having a temperature value lower than that required for heat treatment efficacy was considerably reduced, by up to 56.7%. Therefore, the CFD approach proposed in this study could be used as a decision support system for improving heat treatment efficacy

    Two key steps in the evolution of human cooperation: the interdependence hypothesis

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    Modern theories of the evolution of human cooperation focus mainly on altruism. In contrast, we propose that humans’ species-unique forms of cooperation—as well as their species-unique forms of cognition, communication, and social life—all derive from mutualistic collaboration (with social selection against cheaters). In a first step, humans became obligate collaborative foragers such that individuals were interdependent with one another and so had a direct interest in the well-being of their partners. In this context, they evolved new skills and motivations for collaboration not possessed by other great apes (joint intentionality), and they helped their potential partners (and avoided cheaters). In a second step, these new collaborative skills and motivations were scaled up to group life in general, as modern humans faced competition from other groups. As part of this new group-mindedness, they created cultural conventions, norms, and institutions (all characterized by collective intentionality), with knowledge of a specific set of these marking individuals as members of a particular cultural group. Human cognition and sociality thus became ever more collaborative and altruistic as human individuals became ever more interdependent

    Phylogenomics of Southern European Taxa in the Ranunculus auricomus Species Complex: The Apple Doesn’t Fall Far from the Tree

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    The taxonomic status of many Southern European taxa of the Ranunculus auricomus complex remains uncertain despite this region’s proximity to the native ranges of the sexual progenitor species of the complex. We investigated whether additional sexual progenitor species are present in the Mediterranean region. Utilizing target enrichment of 736 single-copy nuclear gene regions and flow cytometry, we analyzed phylogenomic relationships, the ploidy level, and the reproductive mode in representatives of 16 populations in Southern Europe, with additional sequence data from herbarium collections. Additionally, phased sequence assemblies from suspected nothotaxa were mapped to previously described sexual progenitor species in order to determine hybrid ancestry. We found the majority of Mediterranean taxa to be tetraploid, with hybrid populations propagating primarily via apomixis. Phylogenomic analysis revealed that except for the progenitor species, the Mediterranean taxa are often polyphyletic. Most apomictic taxa showed evidence of mixed heritage from progenitor species, with certain progenitor genotypes having mapped more to the populations from adjacent geographical regions. Geographical trends were found in phylogenetic distance, roughly following an east-to-west longitudinal demarcation of the complex, with apomicts extending to the southern margins. Additionally, we observed post-hybridization divergence between the western and eastern populations of nothotaxa in Southern Europe. Our results support a classification of apomictic populations as nothotaxa, as previously suggested for Central Europe

    Young Children See a Single Action and Infer a Social Norm: Promiscuous Normativity in 3-Year-Olds

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    Human social life depends heavily on social norms that prescribe and proscribe specific actions. Typically, young children learn social norms from adult instruction. In the work reported here, we showed that this is not the whole story: Three-year-old children are promiscuous normativists. In other words, they spontaneously inferred the presence of social norms even when an adult had done nothing to indicate such a norm in either language or behavior. And children of this age even went so far as to enforce these self-inferred norms when third parties broke them. These results suggest that children do not just passively acquire social norms from adult behavior and instruction;rather, they have a natural and proactive tendency to go from is to ought. That is, children go from observed actions to prescribed actions and do not perceive them simply as guidelines for their own behavior but rather as objective normative rules applying to everyone equally

    Cognitive features of indirect speech acts

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    The offer of some cake can be declined by saying “I am on a diet” – an indirect reply. Here, we asked whether certain well-established psychological and conceptual features are linked to the (in)directness of speech acts – an issue unexplored so far. Subjects rated direct and indirect speech acts performed by the same critical linguistic forms in different dialogic contexts. We find that indirect replies were understood with less certainty, were less predictable by, less coherent with and less semantically similar to their context question. These effects were smaller when direct and indirect replies were matched for the type of speech acts for which they were used, compared to when they were not speech act matched. Crucially, all measured cognitive dimensions were strongly associated with each other. These findings suggest that indirectness goes hand-in-hand with a set of cognitive features, which should be taken into account when interpreting experimental findings, including neuroimaging studies of indirectness
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