Functionalized mesoporous silica nanoparticles with redox-responsive short-chain gatekeepers for agrochemical delivery.

The controlled release of salicylic acid (SA), a key phytohormone, was mediated by using a novel decanethiol gatekeeper system grafted onto mesoporous silica nanoparticles (MSNs). The decanethiol was conjugated only to the external surfaces of the MSNs through glutathione (GSH)-cleavable disulfide linkages and the introduction of a process to assemble gatekeepers only on the outer surface so that the mesopore area can be maintained for high cargo loading. Raman and nitrogen sorption isotherm analyses confirmed the successful linkage of decanethiol to the surface of MSNs. The in vitro release of SA from decanethiol gated MSNs indicated that the release rate of SA in an environment with a certain amount of GSH was significantly higher than that without GSH. More importantly, in planta experiments showed the release of SA from decanethiol gated MSNs by GSH induced sustained expression of the plant defense gene PR-1 up to 7 days after introduction, while free SA caused an early peak in PR-1 expression which steadily decreased after 3 days. This study demonstrates the redox-responsive release of a phytohormone in vitro and also indicates the potential use of MSNs in planta as a controlled agrochemical delivery system.

Equity market price interactions between China and the other markets within the Chinese states equity markets

This study examines the cointegrating and long-term causal relationships of equity market prices in equity markets of Chinese states namely, Shanghai, Shenzhen, Hong Kong, Taiwan and Singapore. I cover the period between October 5, 1992 and March 20, 2006, taking into account both the Asian financial crisis and the opening-up of China’s equity markets in recent years. First, I analysis the cointegration by utilizing Johansen’s (1988) cointegration tests. I find that a long-term equilibrium relationship measured by cointegration has been established among Shanghai, Shenzhen, Hong Kong and Taiwanese markets and, to a lesser degree, between these markets and the Singapore market since 1998. Secondly, this study examines causality by exploring the bootstrapped Toda-Yamamoto non-causality tests. I find that there is strong evidence of a bi-directional causality between Shanghai and Shenzhen markets after 1998. Furthermore, I also find that there are more causal linkages between the Chinese states equity markets: two mainland Chinese markets, Hong Kong, Taiwan, and Singapore became more dependent on each other. The robustness of the above findings is confirmed by the use of a bootstrap test employed to test the validity of my results.

State-owned enterprises, competition and product quality

We consider a general oligopoly model with consumer surplus moderated quantity competition among state-owned enterprises (SOEs), where the SOEs employ workers who are members of the state-owned worker union and produce differentiated products. We show that increasing the number of SOEs would lead to an outcome in which these enterprises choose a lower level of product quality and this, in turn, results in welfare losses for the society, depending on the degree of substitutability. Our findings are consistent with the evidence from China and uncovers important linkages that exist between worker union, product quality and competition, and that have mostly been ignored in the industrial organisation, trade and development literature.