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To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-937X.2009.00539.x Byline: TAKAKO FUJIWARA-GREVE (1), MASAHIRO OKUNO-FUJIWARA (2) Abstract: Ordinary repeated games do not apply to real societies where one can cheat and escape from partners. We formulate a model of endogenous relationships that a player can unilaterally end and start with a randomly assigned new partner with no information flow. Focusing on two-person, two-action Prisoner's Dilemma, we show that the endogenous duration of partnerships generates a significantly different evolutionary stability structure from ordinary random matching games. Monomorphic equilibria require initial trust building, while a polymorphic equilibrium includes earlier cooperators than any strategy in monomorphic equilibria and is thus more efficient. This is due to the non-linearity of average payoffs. Author Affiliation: (1)Keio University (2)University of Tokyo Article History: First version received August 2006; final version accepted October 2008 (Eds.)

It is well known that a silica surface cannot adsorb duplex DNA in common aqueous solution (not chaotropic solution) because of the electrostatic repulsion of the silica surface and polyanionic DNA. However, we recently found that when duplex DNA in phosphoric acid form (or in acidic solution) was used, DNA was successfully adsorbed into mesoporous silicas even in low-salt aqueous solution. The adsorption behaviors of DNA into mesoporous silicas were influenced by the pore diameter sizes. Mesoporous silicas with 2.80- or 3.82-nm peak pore diameters adsorbed DNA the best in diluted NaCl solution. Formation of the hydrogen bond between P(O)OH groups in DNA and adsorbed water, SiOH groups, or both on silica surfaces is regarded as a main factor in this adsorption. The coincidence of the pore sizes and DNA diameter realizes this unique adsorption promoted by the effect of encompassing DNA with the inner surface of mesoporous silica. Although there is no clear direct evidence for including duplex DNA in the mesopores yet, this adsorption technique is expected to provide a new tool for DNA science, because DNA in the pore size 2-5 nm in diameter has to be in unusual disentangled thread form.

Silicas were prepared by a sol-gel method from tetraethoxysilane and acetic anhydride in the presence of cholesterol in organic solution media. Some silicas had higher pore volumes than silicas obtained in the absence of cholesterol. The adsorption abilities by these silicas were compared using various compounds in benzene solution. Although no clear difference among their adsorptions of cholesterol was observed, progesterone and other analogous steroid hormones were well adsorbed by silicas prepared in the presence of cholesterol, especially, prepared with n-heptane as an additional solvent. This silica adsorbed steroid hormones more selectively than other analogous compounds such as bisphenol A and hexestrol. On the other hand, a silica prepared by the usual aqueous sol-gel method with cholesterol had no clear adsorption selectivity to steroid hormones. Furthermore, no selective adsorption of steroid hormones was observed in the case of a common silica gel for column chromatography. This unique property of adsorption observed in silicas prepared using acetic anhydride in the presence of cholesterol is likely to be induced by the imprinting effect of the steroid skeleton part of cholesterol in silica matrix.

Author(s): Nawal Kishor Mal; Masahiro Fujiwara (corresponding author); Yuko Tanaka Since the discovery [1] of MCM-41 more than ten years ago, many investigations have explored the suitability of hexagonal mesoporous [...]

Research has been conducted on Cryptosporidium parvum oocysts. The role of UV irradiation on these oocytes has been investigated vi the exposure of different oocysts' animal ineffectivities and excystation abilities to various UV doses, and the rtesults are reported.

Results demonstrate that the NO(sub)2(sup)+ nitration of an aromatic compound 1,8-dimethylnaphthalene follows an electrophilic as well as a direct charge-transfer process. The other reactions occurring during the process are ipso attack of NO(sub)2(sup)+, the 1,2-shift of the NO(sub)2 group, and an alternative charge-transfer reaction.

The Gattermann-Koch formylations of diphenyl, diphenylmethane, dibenzyl and 1,3-diphenylpropane were investigated in HF-SbF5, -TaF5, -BF3, -NbF5 and CF3SO3H-SbF5. The conformations of protonated diphenylmethane, dibenzyl and 1,3-diphenylpropane and their proton-transfer dynamics were examined by semi-empirical computations. The computation indicated that ortho monoprotonation was slightly preferable for dibenzyl and strong preference of dibenzyl over other aromatic compounds was seen in ortho-ortho intramolecular inter-ring proton transfer through a fan-shaped complex instead of a sandwich-like complex.

Kinetic and regioselectivity studies were conducted on the intracomplex reaction in Gattermann-Koch formylation in superacids. The findings indicate the presence of intracomplex reaction via a third-order rate equation. Furthermore, high para regioselectivity results from intracomplex reaction. Regioselectivity comparison between Gattermann-Koch formylation and Friedel-Crafts formylation showed that regioselectivity trends are not reflective of the nature of the electrophile but the reaction pathway.

The synthesis and characterization of a new gold catalyst, (Au(CO)n)+ (n = 12), are described. The scheme involves the reduction of gold(III) oxide by CO to form (Au(CO)n)+ in one step in concentrated H2SO4 solution. The nonclassical gold(I) catalyst has been applied to the reaction of olefins with CO to form tert-carboxylic acids, giving good yields at room temperature and atmospheric pressure.

Catalytic coupling reaction of naphthalene derivatives and NaNO2 with CF3SO3H leads to respective 1,1'-binaphthyl derivatives in air. In the reaction, CH3CN acts as a catalyst and CF3SO3H as a Bronsted acid. The presence of a strong Bronsted acid induces the formation of binaphthyl derivatives rather than the nitro compounds. Acid promotes the formation of NO+ and restriction of nitration. The effect of steric hindrance influence the production and regioselectivity of the coupling reaction.

The formyl cation shows dual reactivity, one as an electrophile and the other as a Bronsted acid. Protonated aromatic compounds also act as Bronsted acids to form formyl cations indicating that the formylation is favoured over other substitutions under conditions, where aromatic compounds are protonated. The comparison of the formylation with acetylation and sulphonation was done using CF3SO3H-SbF5 and FSO3H-Sb5 respectively using the Gattermann-Koch formylation reaction.

Kinetic analysis of the effect of protonation on the Gatterman-Koch formylation rate of alkylbenzenes shows that the rate is accounted for by considering the protonation equilibrium of m-xylene. The reduction in the apparent formylation rate by the protonation is proportional to the ratio of protonated alkylbenzene to produce sigma-complex, so the formylation rate of alkylbenzene is inconsistent with their relative basicity under acidic conditions.

A refinement of undefeated equilibria avoids the problems posed by sequential equilibria that limit the usefulness of games of incomplete information, and an existence theorem on signalling games is provided. Difficulties in implementing the concept of forward induction are explained. The set of undefeated equilibria in continuous strategy set signalling games is shown to be non-empty, and proofs are presented.

Several conceptual points are made concerning communication in games of asymmetric information. Equilibrium refinements of Sender-Receiver cheap-talk games that are based on the concept of a putative equilibrium, and which rely on the presence of a rich language with literal meanings, are discussed. Three nested criteria are proposed: strong announcement-proofness, announcement-proofness, and weak announcement-proofness. Journal of Economic Literature Classification Number: 026.

We analyze the problem in which agents have non-public information and are to play an asymmetric information game. The agents may reveal some or all of their information to other agents prior to playing this game. Revelation is via exogenously specified certificate statements. The equilibria resulting from various revelation strategies are used to determine equilibrium revelation of information. Sufficient conditions are provided for complete revelation of all private information. A number of examples are provided illustrating when revelation will or will not occur in commonly analyzed games.

A novel external electric field-controlled release system was designed by utilizing functional dipolar molecules as nanoimpellers. The innovative method to controlled release might offer important application for tumor treatment with an advantage in terms of local release with targetability, external remote control, and the nonelectrochemical nature of the process.

The first example of the homoleptic, dinuclear, cationic metal carbonyl catalyst in concentrated sulfuric acid, with which olefins react with CO to produce tertiary carboxylic acids in high yields at atmospheric pressure and room temperature, is reported. It was observed that the cis-Pt-(CO)2 square+9solv) has a very low catalytic activity for the carbonylation of olefins in strong acids.