historically, turkish-russian relations have been cold and distant. during the cold war, the two former rivals viewed each other with hostility. after the fall of the ussr and in the early 1990s, the grounds were paved for the improvement in the bilateral ties. even though the two states have different military and security concerns, they have established closer relations in economic and trade ...

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The evolution of altruism and reciprocity has been explained mainly from ultimate perspectives. However, in order to understand from a proximate perspective how humans evolved to be such cooperative animals, comparative studies with our evolutionary relatives are essential. Here we review several recent experimental studies on chimpanzees’ altruism and reciprocity. These studies have generated ...

Selection on the level of loosely associated groups has been suggested as a route towards the evolution of cooperation between individuals and the subsequent formation of higherlevel biological entities. Such group selection explanations remain problematic, however, due to the narrow range of parameters under which they can overturn within-group selection that favours selfish behaviour. In prin...

In this work we plan to expand upon recent studies that have investigated the coevolution of network structure and strategy choice in prisoners' dilemma games played repeatedly on a network. This literature finds that assortative link formation is an important support for the evolution of cooperative behavior, and that the stability of cooperative equilibria depends on the time scale on which t...

Canada's first AIDS case was diagnosed in 1978, and a total of 2,003 cases had been recorded up to 19 September 1988. Nationwide, 82% of those afflicted have been homosexual or bisexual men, 5% have been immigrants from endemic regions, and 4.6% have been recipients of blood or blood products. Estimates of Canadians infected with HIV range from 10,000 to 50,000. A system of voluntary testing of...

From a recent re-analysis of the available data, Be and B Galactic evolution appears to show evidence for a twoslope behaviour with respect to O. The inferred Be/O abundance ratio in halo stars is constant at very low metallicity (primary behaviour) and increases proportionally to O/H at high metallicity (secondary behaviour). We show that this can be explained in the framework of one single mo...

Indirect reciprocity is a key mechanism for the evolution of human cooperation. There are normally two choices in the standard model of indirect reciprocity which works through reputation. Here we introduced the role of costly punishment into the model. The players could have the third choice besides cooperation and defection. The dynamics of cooperation in indirect reciprocity is analyzed unde...