By numerical

simulations, it is found that the model also exhibits some other complicated dynamical behaviors. A subcritical Hopf bifurcation, a fold bifurcation of equilibria and a limit point bifurcation of limit cycles are detected, which induce five typical patterns of dynamical behaviors including the bistable phenomenon. (C) 2012 Elsevier Ltd. All rights reserved.”
“We introduce a game theory model of individual decisions to cooperate by contributing personal resources to group decisions versus by free riding on the contributions of other members. In contrast to most public-goods games that assume group returns are linear in individual contributions, the present model assumes decreasing marginal group production as a function of aggregate individual contributions. www.selleckchem.com/products/lonafarnib-sch66336.html This diminishing marginal returns assumption is more realistic and generates starkly different

predictions compared to the linear model. One important implication MLN0128 price is that, under most conditions, there exist equilibria where some, but not all, members of a group contribute, even with completely self-interested motives. An agent-based simulation confirmed the individual and group advantages of the equilibria in which behavioral asymmetry emerges from a game structure that is a priori perfectly symmetric for all agents (all agents have the same payoff function Cell Cycle inhibitor and action space but take different actions in equilibria). A behavioral experiment demonstrated that cooperators and free riders coexist in a stable

manner in groups performing with the nonlinear production function. A collateral result demonstrated that, compared to a dictatorial decision scheme guided by the best member in a group, the majority/plurality decision rules can pool information effectively and produce greater individual net welfare at equilibrium, even if free riding is not sanctioned. This is an original proof that cooperation in ad hoc decision-making groups can be understood in terms of self-interested motivations and that, despite the free-rider problem, majority/plurality decision rules can function robustly as simple, efficient social decision heuristics.”
“To the Editor: The important findings of Awad et al. (June 20 issue)(1) regarding the G2032R mutation as a cause of crizotinib resistance in lung cancer suggest an intriguing hypothesis. Despite good tumor-cell content, the allele frequencies of the mutation were very low in some tumor regions and metastases (see Fig. S2 in the Supplementary Appendix, available with the full text of the article at NEJM.org), strongly suggesting that the mutation was subclonal. This finding challenges the prevailing concept that metastases are descendants of a single founder cell. A tenable alternative is that the subclone harboring the G2032R mutation may …