Chaotic itinerancy in coupled dynamical recognizers

We argue that chaotic itinerancy in interaction between humans originates in the fluctuation of predictions provided by the nonconvergent nature of learning dynamics. A simple simulation model called the coupled dynamical recognizer is proposed to study this phenomenon. Daily cognitive phenomena provide many examples of chaotic itinerancy, such as turn taking in conversation. It is therefore an interesting problem to bridge two chaotic itinerant phenomena. A clue to solving this is the fluctuation of prediction, which can be translated as "hot prediction" in the context of cognitive theory. Hot prediction is simply defined as a prediction based on an unstable model. If this approach is correct, the present simulation will reveal some dynamic characteristics of cognitive interactions.     

A new ent-clerodane diterpene from the aerial parts of Baccharis gaudichaudiana

A new ent-clerodane diterpene, named bacchariol (1) was isolated from the aerial parts of Baccharis gaudichaudiana DC. (Compositae), together with known ent-clerodane diterpenes (2, 3), eight known flavonoids (4-11) and 3, 5-dicaffeoylquinic acid (12). Their structures were determined by spectroscopic analyses. Flavonoids (7, 8, 11) and 12 showed moderate scavenging activities toward 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals.     

Development of a new triphase catalyst and its application to the epoxidation of allylic alcohols

[see reaction]. A new triphase catalyst has been developed. When an aqueous solution of H3PW12O40 (1) was added to a solution of the amphiphilic chain copolymer 2, a new self-assembled and macroporous complex 3 was formed. This complex was effective as a catalyst in the epoxidation of allylic alcohols. Even in the use of 2.7 x 10(-5) mole equiv of the catalyst, the epoxidation with aqueous H2O2 proceeded without organic solvents to give the corresponding epoxy alcohols in high yields.     

Helium-4 Bose fluids formed in one-dimensional 18 A diameter pores

Bose fluids restricted in one dimension (1D) are realized by adsorbing 4He atoms on the 1D pore walls with a diameter of about 18 A. The Bose fluid appears above an adsorbed amount after the pore walls are coated with the inert 4He atoms. Heat capacity of the fluid was observed to have a temperature-linear term at low temperatures. This corresponds to the phonon heat capacity of the Bose fluid in the 1D pores. We estimate the phonon velocity and the interaction of the 1D Bose fluid.     

Strength characteristics of the self-sustained wave in grooved channels with different groove length

The self-sustained oscillations arising in a series of grooved channels are investigated experimentally. Pressure drop, time-averaged and time-various local pressure in the grooved channels with six kinds of groove length are measured with the differential transducer and the pressure sensor, respectively, and the flow structures are visualized using the aluminum dust method. The local pressure signal shows that the self-sustained wave appears in the first or second frequency, and the Strouhal number, based on the nature frequency of the self-sustained wave, is almost equivalent for the first or second frequency in the same channel. Meanwhile, the Strouhal number for each channel decreases monotonously with the groove length. Furthermore, it is found that increasing pressure will result in higher amplitude of the self-sustained wave, this behavior is significant for the efficient heat transfer in practical engineering.     

Synthesis of substituted 3-iodopyrroles by electrophilic cyclization of propargylic aziridines

The electrophilic cyclization of propargylic aziridines is described. 3-Iodopyrroles having a variety of substituents were conveniently synthesized by the reaction of propargylic aziridines with iodine. The resulting substituted 3-iodopyrrole was further functionalized to the tri-substituted pyrroles with high efficiency.     

Stereoselective synthesis of cyclic hemiacetals from 4-formylbenzoates and α,β-unsaturated aldehydes using a sulfoalkyl-substituted N-heterocyclic carbene catalyst

N-Heterocyclic carbene-catalyzed transformation of 4-formylbenzoates and α,β-unsaturated aldehydes to cyclic hemiacetals is described. The reaction proceeded smoothly when the sulfopropyl-substituted imidazolium salt was used as the catalyst. Various substrates were converted to the corresponding cyclic hemiacetals in a stereoselective manner.