Aspiration Dynamics of Multi-player Games in Finite Populations

Studying strategy update rules in the framework of evolutionary game theory, one can differentiate between imitation processes and aspiration-driven dynamics. In the former case, individuals imitate the strategy of a more successful peer. In the latter case, individuals adjust their strategies based on a comparison of their payoffs from the evolutionary game to a value they aspire, called the level of aspiration. Unlike imitation processes of pairwise comparison, aspiration-driven updates do not require additional information about the strategic environment and can thus be interpreted as being more spontaneous. Recent work has mainly focused on understanding how aspiration dynamics alter the evolutionary outcome in structured populations. However, the baseline case for understanding strategy selection is the well-mixed population case, which is still lacking sufficient understanding. We explore how aspiration-driven strategy-update dynamics under imperfect rationality influence the average abundance of a strategy in multi-player evolutionary games with two strategies. We analytically derive a condition under which a strategy is more abundant than the other in the weak selection limiting case. This approach has a long standing history in evolutionary game and is mostly applied for its mathematical approachability. Hence, we also explore strong selection numerically, which shows that our weak selection condition is a robust predictor of the average abundance of a strategy. The condition turns out to differ from that of a wide class of imitation dynamics, as long as the game is not dyadic. Therefore a strategy favored under imitation dynamics can be disfavored under aspiration dynamics. This does not require any population structure thus highlights the intrinsic difference between imitation and aspiration dynamics

Institutional change and regional development in China: the case of commodity trading markets

With this paper we explore how institutional changes have influenced the regional development of Yiwu City, East China. The regional development in Yiwu City can be regarded as constituting a specific model in transitional China, which revolves around the establishment, growth, and internationalization of the local commodity trading market. The success of the Yiwu model lies in the interaction between globalization, local institutions, and commodity trading markets. However, we argue that the strategic coupling perspective has its limitations in explaining the development trajectory of the Yiwu model. We develop an integrated paradigm of regional development located between new regionalism and global production networks by synthesizing Scott’s institutional framework. We identify a pronounced and long-established cultural–cognitive element in the entrepreneurial spirit of local people, which led to the establishment of a commodity trading market at the beginning of 1980s. However, the sustainable development of the Yiwu model needs to be supplemented by normative and regulative institutional pillars. We further argue that the developmental local state remains critical to the regional development in developing countries in terms of correcting market failure, encouraging entrepreneurship, and creating a competitive business environment to accommodate globalization

Tissue-specific alternative splicing and expression of ATP1B2 gene

The Na+-K+-ATPase is an essential transport enzyme expressed in all animal tissues, where it generates ion gradients to maintain membrane potential and drive the transport of other solutes. It also balances metabolism and body temperature. In this study, the characterization of three novel bovine ATP1B2 splice variants, designated as ATP1B2-AS1, ATP1B2-AS2, and ATP1B2-AS3, is discussed. All three novel splice isoforms were derived from a complete transcript (ATP1B2-complete) by alternative splicing. The pattern of splicing to produce the ATP1B2-AS1 and ATP1B2-AS2 isoforms was intron retention; these isoforms were found in liver, kidney, muscle and breast tissues. For the ATP1B2-AS3 isoform, splicing was by exon inclusion and this isoform was only found in muscle tissue. As demonstrated by real-time polymerase chain reaction, the isoforms were all expressed at significantly lower levels than the complete ATP1B2 gene transcript in all the tissues studied. After heat-stress, the expression levels of the different transcripts were lower in different tissues; however, the expression of the ATP1B2-complete transcript increased in heart and lung tissues. The results of this research provide some useful information for further studies into the function of the bovine ATP1B2 gene. Alternative splicing (AS) is recognized as the major contributor to protein diversity from limited gene pool. ATP1B2-AS2 was the splice of intron retention found from ATP1B2 in liver, kidney, muscle and breast tissues. In the study, ATP1B2-AS2 showed that many of the amino acid residues were in an unfavorable energy environment. It is interesting to speculate that this may be the perfect transcript to respond to heat-stress. So, AS may become the appropriate pathway to tackle heat-stress and reduce the economic losses in cows.Key words: ATP1B2 gene, alternative splicing, alternative splicing mechanism

The electronic structures and magnetic properties of perovskite ruthenates from constrained orbital hybridization calculations

We introduce a method to analyze the effect of hybridization by shifting corresponding atomic levels using external potentials. Based on this approach, we study perovskite ruthenates,\ and unambiguously identify that the covalency between the \textit{A}-site cation and O ion will modify the Ru-O hybridization and change the density of state at Fermi level, consequently affect the magnetic properties significantly. We also study the effect of pressure and reveal that hydrostatic pressure has a small effect on the Ru-O-Ru bond angle of SrRuO$_{3}$, while it will decrease the Ru-O length and increase the band width significantly. Therefore, the magnetic ordering temperature will decrease monotonically with pressure