Efficiency of collective myosin Ⅱ motors studied with an elastic coupling power-stroke ratchet model

We proposed a modified ratchet model including power-stroke and elastic coupling to study the efficiency of collective non-processive motors such as myosin Ⅱ in muscle. Our theoretical results are in good agreement with the experimental data. Our study not only reveals that the maximum efficiency depends on elasticity and is independent of transition rates but also indicates that the parameters fitted to fast muscle are different from those fitted to a slow one. The latter may imply that the structure of the fast muscle is different from that of the slow one. The main reason that our model succeeds is that velocity in this model is an independent variable.

Trade Restrictiveness and Deadweight Loss in China＇s Imports

China is believed to have gained immensely from its admission into to the World Trade Organization （WTO） in 2001. One of the direct gains comes from the lessening of deadweight loss （DWL） due to tariff reduction. Conventional measures for DWL, however, are too aggregate to capture the trade policies, which are determined at a much higher disaggregated level, and ignore the interactions between tariff and corresponding import demand as suggested by theories. In this paper, we first systematically estimate the import demand elasticities at a highly disaggregated level and then match them with the most detailed lines of the applied tariff for the most favored nations as reported by the WTO. Using the detailed matching data, we construct Feenstra＇s （1995） simplified trade restrictiveness index （TRI）, which captures the covariance of tariff and the corresponding demand elasticity. Finally, we use the TRI to compute the DWL from1997 to 2008 and find that the DWL due to the tariff barrier was reduced to 0.73% of GNI in 2008, noticeably lower than the highest previous mark of 4.58% of GNI in 2001.

Project management maturity in construction consulting services: Case of Expo in China

For many years,project management maturity models(PMMM)derived from the software industry have brought immeasurable benefits.However,the adoption and investigation of PMMM in the construction field have been weak and insufficient,particularly in construction consulting services(CCS).Moreover,professionals have gradually realized the importance of non-process factors(e.g.,teamwork,culture,leadership)in the evaluation of PMMM.This study describes the construction of PMMM for CCS that considers non-process factors and combines them with CCS-specific process factors.To verify the effectiveness of the proposed model,we conduct a case study on the overall project management consultancy for China’s 2010 Winter Expo.The results would fill in the PMMM research gap in CCS and provide practitioners with ideas to improve their performance.