Cheater-altruist synergy in immunopathogenic ecological public goods games

Much research has focused on the deleterious effects of free-riding in public goods games, and a variety of mechanisms that suppresses cheating behaviour. Here we argue that under certain conditions cheating behaviour can be beneficial to the population. In a public goods game, cheaters do not pay for the cost of the public goods, yet they receive the benefit. Although this free-riding harms the entire population in the long run, the success of cheaters may aid the population when there is a common enemy that antagonizes both cooperators and cheaters. Here we study models in which an immune system antagonizes a cooperating pathogen. We investigate three population dynamics models, and determine under what conditions the presence of cheaters help defeat the immune system. The mechanism of action is that a polymorphism of cheaters and altruists optimizes the average growth rate. Our results give support for a possible synergy between cooperators and cheaters in ecological public goods games

Global economic governance and economic policy: A personal perspective

The policy advice given by economists in international institutions is influenced by their prior academic work. In my case, applied general equilibrium work resulted both in a belief in the necessity of decentralized markets and in a distrust of their ability to be stable. A career in international institutions can also create a global outlook that can be a public good when trying to achieve collective action while accommodating legitimate but narrower national interests. Finally, even if an underlying economic strategy is well designed, emphasis on communications with multiple audiences is crucial for both national and international policy success

Universal Sound Absorption in Amorphous Solids: A Theory of Elastically Coupled Generic Blocks

Glasses are known to exhibit quantitative universalities at low temperatures, the most striking of which is the ultrasonic attenuation coefficient 1/Q. In this work we develop a theory of coupled generic blocks with a certain randomness property to show that universality emerges essentially due to the interactions between elastic blocks, regardless of their microscopic nature.Comment: (Revised) 16 pages, 2 figures. To appear in Journal of Non-Crystalline Solid

Efficient fast hartley transform algorithms for hypercube-connected multicomputers

Cataloged from PDF version of article.Although fast Hartley transform (FHT) provides efficient spectral analysis of real discrete signals, the literature that addresses the parallelization of FHT is extremely rare. FHT is a real transformation and does not necessitate any complex arithmetics. On the other hand, FHT algorithm has an irregular computational structure which makes efficient parallelization harder. In this paper, we propose a efficient restructuring for the sequential FHT algorithm which brings regularity and symmetry to the computational structure of the FHT. Then, we propose an efficient parallel FHT algorithm for medium-to-coarse grain hypercube multicomputers by introducing a dynamic mapping scheme for the restructured FHT. The proposed parallel algorithm achieves perfect load-balance, minimizes both the number and volume of concurrent communications, allows only nearestneighbor communications and achieves in-place computation and communication. The proposed algorithm is implemented on a 32- node iPSC12' hypercube multicomputer. High-efficiency values are obtained even for small size FHT problems