The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Catherine Blois-heulin - One of the best experts on this subject based on the ideXlab platform.
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Solitary versus Group living lifestyles, Social Group composition and cooperation in otters
Mammal Research, 2021Co-Authors: Thierry Lodé, Marie-loup Lélias, Alban Lemasson, Catherine Blois-heulinAbstract:Increased reproduction success, enhanced foraging and reduced predation risk are usually regarded as major factors favouring the evolution of Social behaviour. Here we formulate a series of hypotheses relating sexual, ecological and behavioural factors to evaluate their explanatory value for 13 extant otter species, estimating the extent to which each factor contributes to the Sociality of each species. We also compare individual behaviours within some of the species. Four otter species are obligatory Social; four are obligatory solitary; five present both types of Social organization. Social organizations of otter species are not related to their phylogenetic relationships. However, many otter species exhibit intra-species patterns of flexible Social lifestyles. Both solitary and Social otters adjust their Social patterns in response chiefly to food availability, but also to habitat features and competition. Group living is more common when intraspecific competition is reduced or trophic resources replenish rapidly. Under these circumstances, Group members often forage individually. When otters forage individually, they often switch prey type when they compete with other conspecifics. Social structures of otters fall into seven types: (1) family Groups; (2) extended family Groups, often with an alpha dominant pair; (3) highly Social Groups with helpers; (4) collective hunting Groups; (5) solitary lifestyle; (6) unstable mixed-sex Groups; and (7) single-sex bachelor Groups. When an individual of a species with variable Sociality adopts one type of Sociality, this may be only temporary. Variations in Social life are actually based on a series of events that induce individuals to make decisions taking ecological factors into account. Although ontogenetic factors can influence delayed dispersal of otters, Social factors rather than ecological factors could play an important role in the formation of Groups, and cohesiveness and kinship appear to be secondary effects of reduced dispersal more than primary causes for living in a Group. Appropriate adjustment of Group behaviour reduces the cost of Sociality because individuals avoid Social interactions when benefits are low but gather together when Group living provides real advantages. Although any one model is unlikely to explicate all facets of Sociality, evolution towards a Social Group results mainly from interactions within a family. Graphical abstract Small-clawed otters ( Aonyx cinereus) (Photo Thierry Lodé).
Thierry Lodé - One of the best experts on this subject based on the ideXlab platform.
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Solitary versus Group living lifestyles, Social Group composition and cooperation in otters
Mammal Research, 2021Co-Authors: Thierry Lodé, Marie-loup Lélias, Alban Lemasson, Catherine Blois-heulinAbstract:Increased reproduction success, enhanced foraging and reduced predation risk are usually regarded as major factors favouring the evolution of Social behaviour. Here we formulate a series of hypotheses relating sexual, ecological and behavioural factors to evaluate their explanatory value for 13 extant otter species, estimating the extent to which each factor contributes to the Sociality of each species. We also compare individual behaviours within some of the species. Four otter species are obligatory Social; four are obligatory solitary; five present both types of Social organization. Social organizations of otter species are not related to their phylogenetic relationships. However, many otter species exhibit intra-species patterns of flexible Social lifestyles. Both solitary and Social otters adjust their Social patterns in response chiefly to food availability, but also to habitat features and competition. Group living is more common when intraspecific competition is reduced or trophic resources replenish rapidly. Under these circumstances, Group members often forage individually. When otters forage individually, they often switch prey type when they compete with other conspecifics. Social structures of otters fall into seven types: (1) family Groups; (2) extended family Groups, often with an alpha dominant pair; (3) highly Social Groups with helpers; (4) collective hunting Groups; (5) solitary lifestyle; (6) unstable mixed-sex Groups; and (7) single-sex bachelor Groups. When an individual of a species with variable Sociality adopts one type of Sociality, this may be only temporary. Variations in Social life are actually based on a series of events that induce individuals to make decisions taking ecological factors into account. Although ontogenetic factors can influence delayed dispersal of otters, Social factors rather than ecological factors could play an important role in the formation of Groups, and cohesiveness and kinship appear to be secondary effects of reduced dispersal more than primary causes for living in a Group. Appropriate adjustment of Group behaviour reduces the cost of Sociality because individuals avoid Social interactions when benefits are low but gather together when Group living provides real advantages. Although any one model is unlikely to explicate all facets of Sociality, evolution towards a Social Group results mainly from interactions within a family. Graphical abstract Small-clawed otters ( Aonyx cinereus) (Photo Thierry Lodé).
Drew Nesdale - One of the best experts on this subject based on the ideXlab platform.
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Children's Social Groups and interGroup prejudice: Assessing the influence and inhibition of Social Group norms
British Journal of Developmental Psychology, 2011Co-Authors: Drew Nesdale, Davina DaltonAbstract:A simulation Group study examined whether the effects of Group norms on 7- and 9-year-old children's interGroup attitudes can be moderated by a contrary school norm. Children learnt that their school had an inclusion norm, were assigned to a Group with an outGroup inclusion or exclusion norm, and indicated their inGroup and outGroup attitudes under teacher surveillance or not. Results revealed reduced outGroup liking when the Group had an exclusion norm, but that the effect was moderated when the school had an inclusion norm, especially among the older children. The participants' inGroup liking was also reduced, but teacher surveillance had no effect on attitudes. The findings are discussed in relation to possible strategies to moderate Social Group norm effects.
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Social Group norms, school norms, and children's aggressive intentions
Aggressive behavior, 2010Co-Authors: Christian Nipedal, Drew Nesdale, Melanie KillenAbstract:::::::::::::: :::::::::::::::: :::::::::::: This study examined whether the effect of Social Group norms on 7- and 10-year-old children’s aggression can be moderated or extinguished by contrary school norms. Children (n 5 384) participated in a simulation in which they were assigned membership in a Social Group for a drawing competition against an outGroup. Participants learnt that their Group had a norm of inclusion, exclusion, or exclusion-plus-relational aggression, toward non-Group members, and that the school either had a norm of inclusion, or no such norm. Findings indicated that Group norms influenced the participants’ direct and indirect aggressive intentions, but that the school norm moderated the Group norm effect, with the school’s norm effect tending to be greater for indirect vs. direct aggression, males vs. females, and younger vs. older participants. Discussion focused on how school norms can be developed, endorsed, and presented so that they have their most lasting effect on children. Aggr. Behav. 36:195–204, 2010. r 2010 Wiley-Liss, Inc.
Melanie Killen - One of the best experts on this subject based on the ideXlab platform.
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Social Group norms, school norms, and children's aggressive intentions
Aggressive behavior, 2010Co-Authors: Christian Nipedal, Drew Nesdale, Melanie KillenAbstract:::::::::::::: :::::::::::::::: :::::::::::: This study examined whether the effect of Social Group norms on 7- and 10-year-old children’s aggression can be moderated or extinguished by contrary school norms. Children (n 5 384) participated in a simulation in which they were assigned membership in a Social Group for a drawing competition against an outGroup. Participants learnt that their Group had a norm of inclusion, exclusion, or exclusion-plus-relational aggression, toward non-Group members, and that the school either had a norm of inclusion, or no such norm. Findings indicated that Group norms influenced the participants’ direct and indirect aggressive intentions, but that the school norm moderated the Group norm effect, with the school’s norm effect tending to be greater for indirect vs. direct aggression, males vs. females, and younger vs. older participants. Discussion focused on how school norms can be developed, endorsed, and presented so that they have their most lasting effect on children. Aggr. Behav. 36:195–204, 2010. r 2010 Wiley-Liss, Inc.
Hamid R. Sadjadpour - One of the best experts on this subject based on the ideXlab platform.
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Effect of Social Groups on the Capacity of Wireless Networks
IEEE Transactions on Wireless Communications, 2016Co-Authors: Mohsen Karimzadeh Kiskani, Bita Azimdoost, Hamid R. SadjadpourAbstract:In this paper, we study the effects of Social interactions among nodes on the capacity of wireless networks. We consider three scenarios. In the first scenario, the size of the Social Group for all nodes is fixed while the frequency of communication within members of a Social Group follows power law distribution. In the second scenario, scale-free networks are studied where the size of the Social Group differs from node to node, and the destination in each Group is selected uniformly among the members of that Group. Further investigation in the second scenario reveals that traditional transport capacity definition provides misleading conclusions for such network models. We show that nodes with different Social status impact the capacity differently. By separating nodes with different Social status and allocating separate bandwidth to them, it is shown that majority of nodes scale in this network. In the third scenario, both the size of the Social Groups and the destination in each Group are selected according to power law distributions. Our simulation results corroborate the analytical results. Further, we observe consistently that Social interaction improves the capacity of wireless networks, which implies that the Gupta–Kumar results were pessimistic for practical networks.
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The impact of Social Groups on the capacity of wireless networks
2011 IEEE Network Science Workshop, 2011Co-Authors: Bita Azimdoost, Hamid R. Sadjadpour, J.j. Garcia-luna-acevesAbstract:The capacity of a wireless network with n nodes is studied when nodes communicate with one another in the context of Social Groups. Each node is assumed to have at least one local contact in each of the four directions of the plane in which the wireless network operates, and q(n) independent long-range Social contacts forming its Social Group, one of which it selects randomly as its destination. The distance between source and the members of its Social Group follows a power-law distribution with parameter α, and communication between any two nodes takes place only within the physical transmission range; hence, source-destination communication takes place over multi-hop paths. The order capacity of such a composite network is derived as a function of the number of nodes (n), the Social-Group concentration (α), and the size of Social Groups (q(n)). It is shown that the maximum order capacity is attained when α ≥ 3, which makes Social Groups localized geographically, and that a wireless network can be scale-free when Social Groups are localized and independent of the number of nodes in the network, i.e., q(n) is independent of n.
