Browsing by Subject "COOPERATION"

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  • Seppälä, Tuija; Pirttilä-Backman, Anna-Maija; Lipsanen, Jari Olavi (2012)
    In this article, we present a trust-focused model for understanding leader’s fairness enactment. The model suggests that leaders are motivated to act fairly to gain subordinates’ trust, to show trust in their subordinates, to show that they are worth the subordinates’ trust in them, and because they are willing to be vulnerable to the actions of cooperative subordinates. The mediating role of the leader’s trust in the relationship between a subordinate’s cooperation and the leader’s fairness is also tested.
  • Kindler, Oliver; Pulkkinen, Otto; Cherstvy, Andrey G.; Metzler, Ralf (2019)
    Quorum-sensing bacteria in a growing colony of cells send out signalling molecules (so-called "autoinducers") and themselves sense the autoinducer concentration in their vicinity. Once-due to increased local cell density inside a "cluster" of the growing colony-the concentration of autoinducers exceeds a threshold value, cells in this clusters get "induced" into a communal, multi-cell biofilm-forming mode in a cluster-wide burst event. We analyse quantitatively the influence of spatial disorder, the local heterogeneity of the spatial distribution of cells in the colony, and additional physical parameters such as the autoinducer signal range on the induction dynamics of the cell colony. Spatial inhomogeneity with higher local cell concentrations in clusters leads to earlier but more localised induction events, while homogeneous distributions lead to comparatively delayed but more concerted induction of the cell colony, and, thus, a behaviour close to the mean-field dynamics. We quantify the induction dynamics with quantifiers such as the time series of induction events and burst sizes, the grouping into induction families, and the mean autoinducer concentration levels. Consequences for different scenarios of biofilm growth are discussed, providing possible cues for biofilm control in both health care and biotechnology.
  • Cairns, Johannes; Jokela, Roosa; Hultman, Jenni; Tamminen, Manu; Virta, Marko; Hiltunen, Teppo (2018)
    Experimental microbial ecology and evolution have yielded foundational insights into ecological and evolutionary processes using simple microcosm setups and phenotypic assays with one- or two-species model systems. The fields are now increasingly incorporating more complex systems and exploration of the molecular basis of observations. For this purpose, simplified, manageable and well-defined multispecies model systems are required that can be easily investigated using culturing and high-throughput sequencing approaches, bridging the gap between simpler and more complex synthetic or natural systems. Here we address this need by constructing a completely synthetic 33 bacterial strain community that can be cultured in simple laboratory conditions. We provide whole-genome data for all the strains as well as metadata about genomic features and phenotypic traits that allow resolving individual strains by amplicon sequencing and facilitate a variety of envisioned mechanistic studies. We further show that a large proportion of the strains exhibit coexistence in co-culture over serial transfer for 48 days in the absence of any experimental manipulation to maintain diversity. The constructed bacterial community can be a valuable resource in future experimental work.
  • Halko, Marja-Liisa; Lappalainen, Olli; Sääksvuori, Lauri (2021)
    We investigate the feasibility of inferring economic choices from simple biometric non-choice data. We employ a machine learning approach to assess whether biometric data acquired during sleep, naturally occurring daily chores and participation in an experi-ment can reveal preferences for competitive and team-based compensation schemes. We find that biometric data acquired using wearable devices enable equally accurate out-of-sample prediction for compensation-scheme choice as gender and performance. Our re-sults demonstrate the feasibility of inferring economic choices from simple biometric data without observing past decisions. However, we find that biometric data recorded in nat-urally occurring environments during daily chores and sleep add little value to out-of-sample predictions. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )
  • Rotkirch, Anna; Lyons, Minna; David-Barrett, Tamas; Jokela, Markus (2014)
  • Pintassilgo, Pedro; Laukkanen, Marita; Gronbaek, Lone; Lindroos, Marko (2018)
    The management of internationally shared fish stocks is a major economic, environmental and political issue. According to international law, these resources should be managed cooperatively under international fisheries agreements (IFAs). This paper studies the formation and stability of IFAs through a coalition game that accounts for both direct consumptive values (harvesting profits) and non-consumptive values of the fish stock per se. The results show that accounting for non-consumptive values helps conserve the fish stock in that equilibrium fishing efforts are smaller and fish stock larger than without non-consumptive values under all possible coalition scenarios (full, partial and no cooperation). However, considering non-consumptive values does not affect the outcome of the game in terms of the prospects for cooperation: even with substantial non-consumptive benefits, the outcome is full non-cooperation. Hence, the trap of non-cooperation in international fisheries management cannot be overcome simply by explicitly accounting for non-consumptive values within IFAs. It is suggested that strengthening the role of IFAs and limiting the ability of non-member countries to free-ride be further investigated as measures fostering cooperation.
  • Tanskanen, Antti O.; Danielsbacka, Mirkka; Jokela, Markus; Rotkirch, Anna (2017)
    Sibling relations are by nature ambivalent with high levels of both altruistic helping and competition. Higher relatedness is often assumed to reduce the occurrence of conflicts between siblings, but evidence of this has been scarce and mixed. Siblings typically compete over resources and parental attention, and parental constellations vary with sibship types. Since full-siblings compete over the same two biological parents, while half-siblings have only one shared biological parent and often a higher number of parents overall, it is hypothesized that conflicts are more common between full- than half-siblings. This study tested this assumption using the British Millennium Cohort Study (n=7527 children at age 11). Conflicts were measured as children's reports of how much siblings picked on and hurt each other. Households with full-siblings only, maternal half-siblings only, and both full- and maternal half-siblings were compared. The results show that children who were living with only their full-siblings were more likely to experience sibling conflicts compared with children living with their maternal half-siblings only. This was the case also after controlling for several potentially confounding variables. The results suggest that differential access to parental resources of available biological and step-parents may explain the higher amount of sibling conflict between full- compared with maternal half-siblings.
  • Floyd, Simeon; Rossi, Giovanni; Baranova, Julija; Blythe, Joe; Dingemanse, Mark; Kendrick, Kobin H.; Zinken, Jörg; Enfield, N. J. (2018)
    Gratitude is argued to have evolved to motivate and maintain social reciprocity among people, and to be linked to a wide range of positive effects-social, psychological and even physical. But is socially reciprocal behaviour dependent on the expression of gratitude, for example by saying 'thank you in English? Current research has not included cross-cultural elements, and has tended to conflate gratitude as an emotion with gratitude as a linguistic practice, as might appear to be the case in English. Here, we ask to what extent people express gratitude in different societies by focusing on episodes of everyday life where someone seeks and obtains a good, service or support from another, comparing these episodes across eight languages from five continents. We find that expressions of gratitude in these episodes are remarkably rare, suggesting that social reciprocity in everyday life relies on tacit understandings of rights and duties surrounding mutual assistance and collaboration. At the same time, we also find minor cross-cultural variation, with slightly higher rates in Western European languages English and Italian, showing that universal tendencies of social reciprocity should not be equated with more culturally variable practices of expressing gratitude. Our study complements previous experimental and culture-specific research on gratitude with a systematic comparison of audiovisual corpora of naturally occurring social interaction from different cultures from around the world.
  • Mikonranta, Lauri; Mappes, Johanna; Laakso, Jouni; Ketola, Tarmo (2015)
    Background: Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequentially infect Drosophila melanogaster hosts and then compared the virulence to strains that evolved only in the outside-host environment. Results: We found that the pathogen adapted to both Drosophila melanogaster host and novel outside-host environment, leading to rapid evolutionary changes in the bacterial life-history traits including motility, in vitro growth rate, biomass yield, and secretion of extracellular proteases. Most significantly, selection within the host led to decreased virulence without decreased bacterial load while the selection lines in the outside-host environment maintained the same level of virulence with ancestral bacteria. Conclusions: This experimental evidence supports the idea that increased virulence is not an inevitable consequence of within-host adaptation even when the epidemiological restrictions are removed. Evolution of attenuated virulence could occur because of immune evasion within the host. Alternatively, rapid fluctuation between outside-host and within-host environments, which is typical for the life cycle of opportunistic bacterial pathogens, could lead to trade-offs that lower pathogen virulence.