Cooperation and self-organized criticality are two main keywords in current studies of evolution. We propose a generalized Bak-Sneppen model and provide a natural mechanism which accounts for both phenomena simultaneously. We use the prisoner’s dilemma games to mimic the interactions among the members in the population. Each member is identified by its cooperation probability, and its fitness i...

Pancreatic cancer (PC) is one of the most malignant tumors. Rho GTPases can affect several types of human cancers, including PC. In this study, we investigated the role of Ras homolog family member T1 (RHOT1), a new member of Rho GTPases in PC. IHC results showed that RHOT1 was expressed significantly higher in PC tissues than paracancerous tissues (P<0.01) and SMAD family member 4 (SMAD4) was ...

The Unified Modeling Language is extensible, and so can be regarded as a family of languages. Implicitly or explicitly, any particular UML model should be accompanied by a definition of the particular UML family member used for the model. The definition should cover syntactic and semantic issues. This paper proposes a mechanism for associating models with such definitions. Any particular defini...

This paper presents an effective method to integrate the revocation mechanism into some group signature schemes that are based on the strong RSA assumption. The mechanism enables the group manager to either update a group member’s certificates, or revoke a group member. More specifically, a generic method has been proposed for the protocols of sign, verify, and revocation. We demonstrate the ef...

How do new party systems evolve over time? This article argues that system evolution requires the solution of coordination problems voters face in early elections; this happens through a learning mechanism. Elections reveal information to voters, who update their beliefs about viability and distribution voters’ preferences adjust behaviour. The institutional setting, however, strongly condition...